Patent Publication Number: US-2007099867-A1

Title: Pharmaceutical agent containing hyaluronan as an active ingredient

Description:
FIELD OF THE INVENTION  
      The present invention relates to a pharmaceutical agent containing hyaluronan as an active ingredient. More specifically, the invention relates to an autoimmune disease-treating agent, inflammatory disease-treating agent and neural disease-treating agent, autoimmune disease-preventing agent, inflammatory disease-preventing agent and neural disease-preventing agent, a cell viability enhancer, a cytokine-associated gene and chemokine-associated gene expression inhibitor, a synaptic transmission promoter and a synaptic protector containing hyaluronan as an active ingredient. The invention also relates to a pharmaceutical for the treatment of a spinal cord injury, asthma and allergy.  
     BACKGROUND OF THE INVENTION  
      Hyaluronan is a long chain polysaccharide constructed from disaccharide repeating units each consisting of a D-glucuronic acid and an N-acetyl-D-glucosamine, and its oligosaccharide form is also known. Hyaluronan is an extract from a biological tissue, such as a rooster comb, umbilical cord, skin, and articular fluid, or is produced by a fermentative method using a Streptococcal bacterium. Since toxicological and immunological effects are not present, hyaluronan is utilized in a pharmaceutical or cosmetic component, such as in a well-known treatment of an arthritis employing an intraarticular injection of hyaluronan. In the following description, tetrasaccharide hyaluronan is designated as HA4.  
      HA4 was reported to have a therapeutic and inhibitory effect in an organ preservation, hepatic disorder and gastric ulcer (see, WO2002/004471). HA4 is also known to have a stress protein expression enhancing effect and a cell death inhibiting effect (see, Xu H, Ito T, Tawada A, Maeda H, Yamanokuchi H, Isahara K, Yoshida K, Uchiyama Y, Asari A. Effect of hyaluronan oligosaccharides on the expression of heat shock protein 72, J. Biol. Chem. 2002, 10; 277(19): 17308-14). In addition, hyaluronan oligosaccharide was reported to have a variety of physiological activities (see, Asari A, Novel Functions of Hyaluronan Oligosaccharides. In Science of Hyaluronan Today, Editors: Vincent C. Hascall. Masaki Yanagishita Glycoforum, (http://www.glycoforum.gr.jp/science/hyaluroRan/HA.12/HA12J.html). 2005). In addition, HA4 is known to be effective therapeutically in a spinal cord injured model (see, WO2004/084912).  
      A multiple sclerosis is developed frequently during a period from adolescence to forties and accompanied with symptoms such as an unsteady walking, dim vision, double vision, difficulty in urination, and pain and numbness. When developed in pediatric or juvenile cases, it is sometimes accompanied with epilepsy. One or more pathologic foci responsible for the symptoms are developed diffusively in a cerebrum or spinal cord. Moreover, the pathologic foci are diffusive not only in terms of spatial diffusiveness but also in terms of temporal diffusiveness with occasional occurrence and disappearance. The pathologic condition of the multiple sclerosis involves an immune system, and is considered to be an autoimmune disease or inflammation. Also since the spinal cord nerve is injured, it is also considered to be one of a neural disease.  
      Cell viability means an active condition of a cell. Since some diseases involve reduced cell viability or cellular denaturation, an improvement in the cell viability is expected to provide a therapeutic effect in such a disease. The cell viability can be determined based on a Rhodamine 123 staining performance as an index. While a mitochondria acts pivotally in an energy metabolism, the fluorescent intensity of the Rhodamine 123 increases in a mitochondrial membrane potential-dependent manner. Accordingly, the Rhodamine 123 staining performance serves as an index of the mitochondrial activity, thus, an index of the cellular activity degree (see, Kim, M, Cooper D D, Hayes S F, Spangrude G J, Rhodamine-123 staining in hematopoietic stem cells of young mice indicates mitochondrial action on rather than dye efflux. Blood, 1998 Jun 191(11): 4106-17).  
      A cytokine is a generic name covering proteinous factors (mostly glycoproteins), which are released from a cell and then mediate intercellular interactions such as immune or inflammatory reaction controlling effects, anti-viral effects, anti-tumor effects, and cellular growth/differentiation regulating effects. Those known as such cytokines include interleukins, interferons, tumor necrosis factors (TNF) and the like. On the other hand, chemokines are defined as a group of chemtactic cytokines having leukocyte chemotactic ability. As used herein, the chemokines are defined as a concept excluded from the cytokines.  
      A cytokine-associated gene refers generally to a gene which encodes the cytokine and a gene which regulates the expression of said gene. A variety of cytokine-associated genes are known, and a relationship between the promotion of a cytokine-associated gene expression and a disease is suggested. An effective inhibition of a cytokine-associated gene expression contributes greatly to the treatment of a variety of diseases.  
     SUMMARY OF THE INVENTION  
      An object of the present invention is to provide an autoimmune disease-treating agent, inflammatory disease-treating agent and neural disease-treating agent. Another object of the invention is to provide an autoimmune disease-preventing agent, inflammatory disease-preventing agent and neural disease-preventing agent.  
      Another object of the invention is to provide a novel cell viability enhancer.  
      Accordingly, an object of the invention is to provide a novel cytokine-associated genes and chemokine-associated genes expression inhibitor.  
      Accordingly, an object of the invention is to provide a novel synaptic transmission promoter and a synaptic protector.  
      An autoimmune disease-treating agent, inflammatory disease-treating agent and neural disease-treating agent according to the invent in which accomplished the objects described above contain hyaluronan as an active ingredient. Similarly, an autoimmune disease-preventing agent, inflammatory disease-preventing agent and neural disease-preventing agent according to the invention which accomplished the objects described above contain hyaluronan as an active ingredient.  
      A cell viability enhancer according to the invention which accomplished the objects described above contains hyaluronan as an active ingredient.  
      A cytokine-associated gene and chemokine-associated gene expression inhibitor according to the invention which accomplished the objects described above contains hyaluronan as an active ingredient. Thus, the invention has been established based on the discovery that hyaluronan has a novel function to inhibit the expression of cytokine-associated genes and chemokine-associated genes.  
      Thus, a cytokine-associated gene and chemokine-associated gene expression inhibitor according to the invention contains hyaluronan as an active ingredient. Hyaluronan employed herein preferably is a tetrasaccharide containing 2 units, with a single unit being -D-glucuronic acid-β-1,3-D-N-acetylglucosamine-β-1,4-. Especially, it can inhibit the expression of pro-inflammatory cytokine-associated genes as cytokine-associated genes described above.  
      A synaptic transmission promoter and a synaptic protector according to the invention which accomplished the objects described above contain a tetrasaccharide hyaluronan as an active ingredient.  
      Since each of a pharmaceutical agent, cell viability enhancer, cytokine-associated gene and chemokine-associated gene expression inhibitor, synaptic transmission promoter and a synaptic protector according to the invention contains hyaluronan as an active ingredient, it can advantageously be produced readily at a large scale at a relatively low cost. Also since hyaluronan has almost no toxicity or antigenicity and enhances a therapeutic and prophylactic ability against disease which is possessed naturally by a living body of to prevent, it is expected to provide a therapeutic, prophylactic and inhibitory agent having an extremely reduced side effect. Thus, according to the invention, a novel pharmaceutical agent which is effective against an autoimmune disease, inflammation and neural disease can be provided. In addition, a novel pharmaceutical agent which is effective in the treatment of a disease attributable to a reduced cellular activity can be provided. A novel pharmaceutical agent which is effective in the treatment of a disease attributable to a promotion of the expression of cytokine-associated genes and chemokine-associated genes. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  shows a schematic view of a function of Hsp72 in a synapse, with the left showing a synapse having a disorder and the right showing a synapse protected by Hsp72.  
       FIG. 2  shows a graph obtained by plotting the average of scores of EAE neural symptoms observed in multiple sclerosis model animals receiving a treatment with HA4 right after an inoculation on the ordinate and the days after the Day 0 inoculation on the abscissa.  
       FIG. 3  shows a graph obtained by plotting the average of scores of EAE neural symptoms observed in multiple sclerosis model animals treated with HA4 for 11 days after the onset of a disease on the ordinate and the days after the Day 0 inoculation on the abscissa.  
       FIG. 4  shows a graph obtained by plotting the average of a score of EAE neural symptoms observed in multiple sclerosis model animals treated once with HA4 immediately after inoculation on the ordinate and the days after inoculation on the abscissa.  
       FIG. 5  is a photograph of cells in each group prepared in Example 2.  
       FIG. 6  shows a performance representing results of a measurement of a fluorescent intensity in cells in each group prepared in Example 2.  
       FIG. 7  shows the results of an immunostaining with Hsp72 at a primary injury site, with (a) being a photograph of a section in each group after staining and (b) being a performance representing results of a measurement of a light intensity in the immunostaining with Hsp72.  
       FIG. 8  shows the results of an immunostaining with Hsp72 at secondary injury sites, with (a) being a photograph of a section in each group after staining and (b) being a performance representing results of a measurement of a light intensity in the immunostaining with Hsp72.  
       FIG. 9  shows the results of an immunostaining with a synaptophysin at a primary injury site, with (a) being a photograph of a section in each group after the staining and (b) being a performance representing the results of a measurement of a light intensity in the immunostaining with the synaptophysin.  
       FIG. 10  shows the results of an immunostaining with a synaptophysin at a secondary injury site, with (a) being a photograph of a section in each group after staining and (b) being a performance representing the results of a measurement of a light intensity in the immunostaining with the synaptophysin.  
       FIG. 11  ( a ) is a photograph of grey and white matters after double staining with Hsp72 and the synaptophysin and  FIG. 11  ( b ) is a photograph of grey matters after double staining with Hsp72 and the synaptophysin, with the right being a photograph showing Hsp72 appearing red, the left being a photograph showing the synaptophysin appearing green and the center being a photograph of the right overlapped by the left.  
       FIG. 12  is a graph showing the results of a measurement of a production of an IL-1α and an IL-1β using a cytokine array.  
       FIG. 13  is a graph showing the results of a measurement of a production of an IL-6 and a TGF-β1 using a cytokine array.  
       FIG. 14  is a graph showing the results of a measurement of a production of a TNF-α and a TNF-β using a cytokine array.  
       FIG. 15  is a graph showing the results of a measurement of a production of an IL-6 using an ELISA.  
       FIG. 16  shows a schematic view representing an assumed action mechanism of HA4 in a treatment of a multiple sclerosis.  
       FIG. 17  shows a schematic view representing an assumed action mechanism of HA4 in a treatment of spinal cord injury.  
       FIG. 18  shows a schematic view representing an assumed action mechanism of HA4 against asthma and allergic disease. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      The invention is further detailed below. A cell viability enhancer according to the invention is a pharmaceutical agent having a function of improving cellular viability. The term “improving cell viability” means that the cellular physiological viability is facilitated or that the reduction in the cell physiological viability is inhibited. An improvement in the cell viability results in a treatment or amelioration of a disease which reduces the cellular activity or a disease which causes a denaturation of the cell.  
      Cytokine-associated genes and chemokine-associated genes expression inhibitor according to the invention is an agent having a function of inhibiting the expression of a variety of cytokine-associated genes and chemokine-associated genes. The phrase “inhibiting the expression of cytokine-associated genes and chemokine-associated genes” means that when comparing the expression level of relevant genes in an untreated animal cell with the expression level of relevant genes in an animal cell which has been treated with an inventive agent, the latter is lower significantly. The expression level can be measured using a DNA chip formed by immobilizing a large number of probe DNAs on a substrate.  
      A synaptic transmission promoter according to the invention exhibits an effect to promote synaptic functions. A synaptic protector according to the invention exhibits an effect to restore synaptic functions. A synaptic transmission promoter and synaptic protector according to the invention can enhance the level of the transmission of a neurotransmitter between pre- and post-synapses. In the pre-synapse, a synaptic vesicle consisting of heat shock protein 72 (Hsp72) and a neurotransmitter is present. In the post-synapse, Hsp72 and neurotransmitter receptors are present. A synaptic transmission promoter and a synaptic protector according to the invention acts in such a manner that the condition shown on the left in  FIG. 1  is transferred to the condition shown on the right, thus in such a manner that the neurotransmitter level is increased.  
      The invention is detailed below. In the following description, therapeutic and prophylactic agents, cell viability enhancer, cytokine-associated gene and chemokine-associated gene expression inhibitors, synaptic transmission promoters and a synaptic protectors according to the invention are referred collectively to as pharmaceutical agents.  
      Hyaluronan contained in a pharmaceutical agent according to the invention may be any disaccharide or higher saccharide which includes at least one disaccharide unit in which the position 1 of a β-D-glucuronic acid is bound to the position 3 of a β-D-N-acetylglucosamine and which is constructed basically from a β-D-glucuronic acid and a β-D-N-acetylglucosamine, even if such elements are bound to one or more such disaccharide units bound together, and its derivatives, such as those having hydrolytic protective groups such as an acyl group may also be employed. Such a saccharide may be unsaturated, and such an unsaturated saccharide may for example be a non-reduced terminal saccharide, generally, a glucuronic acid having an unsaturation between the carbon atoms in the 4 and 5 positions. Hyaluronan employed in the invention may typically be one extracted from a naturally-occurring material such as an animal, one obtained by a microorganism fermentation, one synthesized chemically or enzymatically. For example, hyaluronan can be obtained from a biological tissue, such as a crest, umbilical cord, skin, and articular fluid by an extraction method and a purification method known in the art. In addition, it can be produced also by a fermentative method using a Streptococcal bacterium.  
      In the invention, hyaluronan oligosaccharide is also included in hyaluronan, and ones from a low molecular weight hyaluronan such as the disaccharide consisting of a single disaccharide unit described above and a derivative thereof to a high molecular weight hyaluronan whose weight-average molecular weight is as high as about 4,000,000 can be employed. Preferably, hyaluronan whose weight-average molecular weight is about 380 to about 900,000 which provides an excellent permeability in a tissue may be contemplated, with hyaluronan of 2 to 20 saccharides being more preferred.  
      It is preferred to produce hyaluronan having a low molecular weight specifically by reducing the molecular weight of the hyaluronan using a known method such as an enzymatic degradation, an alkaline degradation, a heat treatment, and an ultrasonication (Biochem.33 (1994) p 6503-6507), or by synthesizing chemically or enzymatically (Glycoconjugate J., (1993) p 435-439, WO93/20827). For example, such an enzymatic degradation may be a method in which an enzyme capable of degrading the hyaluronan such as hyaluronan degradation enzyme (hyaluronidase (derived from testes), hyaluronidase (derived from  Streptomyces ), hyaluronidase SD and the like), chondroitinase AC, chondroitinase ACII, chondroitinase ACIII, and chondroitinase ABC is allowed to act on the hyaluronan to yield hyaluronan oligosaccharide (see, Shin-Seikagaku Jikkenkoza, “Saccharides II-Proteoglycans and glycosaminoglycans”, p 244-248, Published in 1991, Tokyo Kagaku Dozin Co., LTD).  
      An alkaline degradation method may for example be a process in which a base such as an about 1N sodium hydroxide is added to an aqueous solution of hyaluronan which is then warmed for a several hours to reduce the molecular weight, and then an acid such as hydrochloric acid is added for neutralization whereby obtaining low molecular weight hyaluronan. hyaluronan employed in the invention includes its salt form, and a pharmaceutically acceptable salt can be employed as desired in view of the drug formulation. For example, it may be an alkaline metal salt, such as a sodium salt and potassium salt, an alkaline earth metal salt, such as a calcium salt and magnesium salt, an amine salt such as a tri (n-butyl) amine salt, triethylamine salt, pyridine salt, and amino acid salt.  
      A pharmaceutical agent of the present invention may be any hyaluronan having a certain molecular weight alone or a combination of hyaluronan preparations having various molecular weights, without any limitation. The pharmaceutical agent contains hyaluronan as an active ingredient, and can ameliorate at least one disease selected from the group consisting of an autoimmune disease, inflammation and neural disease without affecting a living body adversely when administered in an effective amount to a mammal including a human. The autoimmune disease, inflammation and neural disease may for example be a multiple sclerosis. However, the autoimmune disease and inflammation are not limited to the multiple sclerosis, and those also exemplified are a rheumatism, systemic lupus erythematosus, inflammatory colitis, uveitis, nephritis, nephropathy, type I diabetes, atopic dermatitis, Sjogren&#39;s syndrome, insulin receptor abnormality, angitis, myasthenia gravis, polymyositis, asthma and Hasimoto&#39;s disease. The neural disease is not limited to the multiple sclerosis and may for example be neuritis, neuralgia, neuroparalysis, stroke, cerebral palsy, depression, geriatric dementia, Parkinson&#39;s disease, Alzheimer disease, Recklinghausen&#39;s disease, Willis circle occlusion, Krabbe disease, acute diffuse encephalomyelitis, myeloradiculopathy, acute disseminated encephalomyelitis, neuromyelitis optica, adrenal leukodystrophy, metachromatic leukodystrophy, amyotrophic lateral sclerosis, peripheral neuropathy (peripheral nerve injury, Guillain-Barre syndrome, entrapment neuropathy, brachial plexus paralysis, diabetic neuropathy and the like). Thus, a pharmaceutical agent containing hyaluronan as an active ingredient has a therapeutic effect and a prophylactic effect against various autoimmune diseases, inflammatory diseases and neural diseases described above.  
      Also, the pharmaceutical agent contains hyaluronan as an active ingredient, and can inhibit reduction in cell viability and/or can activate a cell without affecting a living body adversely when administered in an effective amount to a mammal including a human.  
      The pharmaceutical agent contains hyaluronan as an active ingredient, and can inhibit the expression of certain activated cytokine- and chemokine-associated genes without affecting a living body adversely when administered in an effective amount to a mammal including a human.  
      The pharmaceutical agent contains hyaluronan as an active ingredient, and can promote a synaptic transmission and protect a synapse without affecting a living body adversely when administered in an effective amount to a mammal including a human.  
      The pharmaceutical agent can be formulated into a desired dosage form as it is or in combination with a carrier, excipient and other additives as desired for forming a pharmaceutical product for oral or parenteral administration (administration into a tissue (injection) such as intraarticular, intravenous, intramuscular, subcutaneous tissues, or enteral administration, and percutaneous administration), and may be given to a patient by any administration mode. Especially when using as a cell viability enhancer, an oral formulation is preferable. Also when using especially as an inhibitor of the expression of cytokine-associated genes and chemokine-associated genes, an injection formulation and an oral formulation are desirable. When using especially as a synaptic transmission promoter and a synaptic protector, an intradural formulation is preferred.  
      An oral formulation may for example be a solid formulation such as a powder, granule, capsule, and tablet; a liquid formulation such as a syrup, elixir, and emulsion. A powder formulation can be obtained as a mixture with an excipient such as lactose, starch, crystalline cellulose, calcium lactate, calcium hydrogen phosphate, magnesium aluminate metasilicate, and silicic anhydride. A granule formulation can be obtained by means of a wet or dry granulation process with adding, in addition to the excipients listed above, a binder such as a sugar, hydroxypropyl cellulose, polyvinyl pyrrolidone and the like, a binder such as a carboxymethyl cellulose, and calcium carboxymethyl cellulose, and a disintegrant such as a carboxymethyl cellulose, and calcium carboxymethyl cellulose, as desired. A tablet formulation can be obtained by compacting the powder or the granule described above as it is or together with a lubricant such as magnesium stearate, and talc. The powder or the granule described above can be coated with an enteric coating base such as hydroxypropyl methyl cellulose phthalate, methyl methacrylate copolymer and the like, or may be coated with ethyl cellulose, carnauba wax, and hydrogenated oil, whereby formulating into an enteric or sustained-release formulation. A hard capsule formulation can be obtained by filling the powder or the granule described above as in a hard capsule. A soft capsule formulation can be obtained by mixing hyaluronan or its salt with a glycerin, polyethylene glycol, sesame oil, olive oil and the like followed by coating with a gelatin membrane. A syrup formulation can be obtained by dissolving a sweetener such as a sugar, sorbitol, and glycerin together with hyaluronan or its salt in water. In addition to a sweetener and water, an essential oil or ethanol may be added to form an elixir, or a gum arabic, tragacanth, polysorbate 80 or sodium carboxymethyl cellulose may be added to form an emulsion or suspension. Such a liquid formulation may be supplemented also with a flavor, colorant, preservative and the like, if desired.  
      A parenteral formulation may for example be an injection formulation, rectal formulation, pessary, dermal application formulation, inhalant, aerosol, instillation formulation and the like. An injection formulation can be obtained by adding to hyaluronan or its salt a pH modifier such as hydrochloric acid, sodium hydroxide, lactic acid, sodium lactate, sodium monohydrogen phosphate, and sodium dihydrogen phosphate; an osmotic agent such as sodium chloride, and glucose; and a distilled water for injection, followed by a sterile filtration, and then filling into an ampoule. In addition, it may be supplemented also with mannitol, dextrin, cyclodextrin, gelatin and the like, and lyophilized under vacuum to form an injection formulation for reconstitution before use. It can also be formulated into an emulsion for injection by adding to hyaluronan or its salt an emulsifier such as lecithin, polysorbate 80, and polyoxyethylene hydrogenated castor oil followed by emulsifying in water.  
      A rectal formulation can be obtained by adding to hyaluronan or its salt a suppository base such as a mono-, di- or triglyceride of a cocoa butter fatty acid, and polyethylene glycol, followed by warming to melt, and then casting into a mold and cooling, or by mixing hyaluronan or its salt with a polyethyleneglycol, soybean oil and the like followed by coating with a gelatin membrane. A dermal application formulation can be obtained by adding to hyaluronan or its salt a white petrolatum, beeswax, liquid paraffin, polyethylene glycol and the like if necessary with warming and then kneading. A tape formulation can be obtained by kneading hyaluronan or its salt together with an adhesive such as rosin, and alkyl acrylate polymer, followed by spreading over an unwoven fabric and the like. An inhalant can be obtained by dissolving or dispersing hyaluronan or its salt in a propellant such as a pharmaceutically acceptable inert gas followed by filling into a pressure-resistant container.  
      (Administration Mode)  
      While the administration mode of a pharmaceutical agent of the present invention containing hyaluronan as an active ingredient is not limited particularly, it may be intraspinal, intravenous, intraarticular, intradural, oral or internasal administration.  
      (Dosage)  
      While the dosage may appropriately be selected depending on the disease to be subjected, age, general condition and body weight of the patient and the like, it is generally 0.05 to 50 mg/kg which is given once a day or in divided doses.  
      (Toxicity)  
      Hyaluronan employed in the invention exhibited almost or completely no cytotoxicity at a dose exhibiting a biological activity of a pharmaceutical.  
      A pharmaceutical agent according to the invention is further detailed below with reference to Examples, which are not intended to restrict the technological scope of the invention.  
     EXAMPLE 1  
      In this example, HA4 was administered to an experimental autoimmune encephalomyelitis (EAE) which is a multiple sclerosis model to examine its efficacy.  
      Four-week old Lewis rats for multiple sclerosis models were purchased and used when they became five-week old. In accordance with the method by Shibaki et al (Shibaki K, Nomura K, Ono R, Shimazu K, Inhibition of experimental autoimmune encephalomyelitis by NINJINEIYOTO, SHINKEICHIRYO 19(2): 159-166, 2002), 300 μg/animal of a guinea pig myelin basic protein (GPMBP, Sigma) was dissolved in 50 μl of PBS, which was then supplemented with an equivalent amount of Freund Complete Adjuvant (FCA, Difco) and sterilized  Mycobacterium tuberculosis  (MT, Difco) at the concentration of 0.75 mg/ml, each 50 μl of which was inoculated to each paw of both rear extremities of the animal.  
      In this example, the multiple sclerosis model animals were received HA4 immediately after the inoculation or upon the onset of neural symptoms.  
      Administration of Test Substances  
      In this example, HA4 was prepared at 1 mg/ml and 10 mg/ml. Specifically, HA4 was prepared by the method of Tawada et al. (Tawada A, Masa T, Oonuki Y, Watanabe A, Matsuzaki Y, Asari A. Large-scale preparation, purification, and characterization of hyaluronan oligosaccharides from 4-mers to 52-mers. Glycobiology, 2002; 12(7): 421-6). As a control, physiological saline was used.  
      At the two time points, that is, immediately after the inoculation and upon the onset of the disease as confirmed by the observation of neural symptoms, a catheter was placed in a medullary space of the multiple sclerosis model animal, where an intradural administration was effected during a predetermined period. For a continuous administration, an osmotic pump (model 2004, Alzet) was employed. The animals were assigned to the treatment groups shown in Table 1.  
                                       TABLE 1                                   Dosing                           Dose   concentration   Start of   Treatment   Number of       Group   Test substance   (μg/day)   (μg/ml)   dosing   period   animals                  1   Physiological   —   —   Immediately   22 Days   6           saline           after                       inoculation                       of antigen       2   HA4   6   1   Immediately   22 Days   6                       after                       inoculation                       of antigen       3   HA4   6   1   Time upon   11 Days   4                       onset*       4   HA4   60    10    Time upon   Single dose   4                       onset*                 *Time point of observation of EAE grade 1 (reduced tonus of tail)             
 
 EAE Neural Symptom Evaluation 
 
      Everyday after the antigen inoculation, the neural symptoms were assessed by two observation personnel with one of the scores of the following 5 grades.  
      EAE grade:  
      0: No symptoms  
      1: Loss of tail tone  
      2: Hind limb weakness  
      3: Hind limb paralysis sometimes accompanied with incontinence of urine and feces  
      4: Hind limb and fore limb paralysis  
      Results  
      1) Effect (Prophylactic) of Intraspinal Continuous Administration of HA4 Immediately after Inoculation (Challenge) and Thereafter  
      After the inoculation of the antigen, HA4 intraspinal continuous administration made the neural symptoms milder clearly comparing with the physiological saline ( FIG. 2 ).  FIG. 2  shows a graph obtained by plotting the average of a score of the EAE neural symptom described above and the days after the inoculation on the ordinate. When comparing the neural symptoms at the EAE climax, the clinical score in the physiological saline group on Day 13 after the antigen inoculation was 2.2±0.41, while that in the HA4 continuous administration group on Day 13 was 0.2±0.41 which was significantly lower (p&lt;0.001), with only ⅙ of the cases developing the disease in the HA4 continuous administration group. Based on the results shown in  FIG. 2 , it was proven that the pharmaceutical agent containing the hyaluronan as an active ingredient is effective for the prophylaxis of the multiple sclerosis.  
      2) Effect (Therapeutic) of Intraspinal Continuous Administration Of HA4 Immediately after Onset of Disease  
      After the onset of the disease, the HA4 intraspinal continuous administration caused the neural symptoms which became milder clearly when comparing with the physiological saline group ( FIG. 3 ).  FIG. 3  shows a graph obtained by plotting the average of a score of the EAE neural symptom described above and the days after the inoculation on the ordinate. When comparing the neural symptoms at the EAE climax, the clinical score in the physiological saline group on Day 13 after the antigen inoculation was 2.2±0.41, while that in the HA4 continuous administration group on Day 13 was 1.5±1.0 which was significantly lower. When comparing the diseased period, 6.5±0.55 days in the physiological saline group and 4.3±1.5 days in the (glucNac-GlcA) 2  continuous treatment group revealed a significant reduction (p&lt;0.01) in the latter. Based on the results shown in  FIG. 3 , it was proven that the pharmaceutical agent containing HA4 as an active ingredient is effective for the prophylaxis of the multiple sclerosis.  
      3) Effect (Therapeutic) of Intraspinal Single Administration of HA4 Immediately after Onset of Disease.  
      After the onset of the disease, the HA4 intraspinal single administration made the neural symptoms milder clearly comparing with the physiological saline group ( FIG. 4 ).  FIG. 4  shows a graph obtained by plotting an average of a score of the EAE neural symptom described above and the days after the inoculation on the ordinate. When comparing the neural symptoms at the EAE climax, the clinical score in the physiological saline group on Day 13 after the antigen inoculation was 2.2±0.41, while that in the HA4 continuous administration group on Day 13 was 1.8±0.5 which was significantly lower. When comparing the diseased period, 6.5±0.55 days in the physiological saline group and 5.0±1.5 days in the HA4 continuous treatment group revealed a significant reduction (p&lt;0.001) in the latter. Based on the results shown in  FIG. 4 , it was proven that the pharmaceutical agent containing HA4 as an active ingredient is effective for the prophylaxis of the multiple sclerosis.  
     EXAMPLE 2  
      In this example, effect of the inventive pharmaceutical agent on cell viability was measured using Rhodamine 123. Rhodamine 123 exhibits a fluorescence whose intensity is increased in a manner dependent on the membrane potential of a mitochondria which acts pivotally in an energy metabolism. Accordingly, the degree of the staining with Rhodamine 123 serves as an index of the mitochondrial activity, thus the index of the cellular activity (see, non-patent reference 2).  
      Cell to be Activated  
      In this example, a K562 (referred to as human erythroleukemia cell or human erythroblastoid leukemia cell) was used. The K562 was purchased from RIKEN, Japan.  
      In this example relating to preparation of test substance, HA4 was prepared at 100 ng/ml. Specifically, HA4 was prepared by the method of Tawada et al. (Tawada A, Masa T, Oonuki Y, Watanabe A, Matsuzaki Y, Asari A. Large-scale preparation, purification and characterization of hyaluronan oligosaccharides from 4-mers to 52-mers. Glycobiology, 2002; 12(7): 421-6) and the concentration was adjusted using a physiological saline.  
      Experimental Method  
      First, the K562 was incubated under the condition described below. The culture medium for the K562 was an RPMI-1640 medium. In this example, the K562 was incubated in Groups 1 to 3 shown below. Each group was cultured under the condition described below. The culture medium in Group  3  was supplemented with HA4 (100 ng/ml).  
      Group  1 : 80 minutes at 37° C.  
      Group  2 : 20 minutes at 43° C. (heat treatment) followed by 60 minutes at 37° C.  
      Group  3 : 20 minutes at 43° C. (heat treatment) followed by 60 minutes at 37° C.  
      After the incubation, a Rhodamine 123 dissolved in an MI medium was added to each group. The final concentration of the Rhodamine 123 was 1 μg/ml. After adding the Rhodamine 123 followed by incubation at 37° C. for 10 minutes, the K562 was washed with the RPMI medium.  
      The K562 after washing was inoculated at 1×10 4  cells/ml in a 96-well plate and a photograph was taken using a fluorescent microscope (Nikon). The image was sent to an Adobe Photoshop (Adobe Systems) where the fluorescent intensity of a cell was measured.  
      The image of each group is shown in  FIG. 5 , and the measured fluorescent intensity is shown in  FIG. 6 . Based on the results shown in  FIGS. 5 and 6 , the heat treatment at 43° C. for 20 minutes caused a reduction in the Rhodamine 123 staining performance (Group 2), while the presence of HA4 inhibited such a reduction (Group 3). The difference in the fluorescent intensity between Groups 2 and 3 was significant.  
      Discussion  
      Apparent from the results described above, HA4 inhibited the reduction in the mitochondrial membrane potential, that is, the reduction in the mitochondrial activity. These findings suggest that HA4 has an effect to suppress the reduction in the mitochondrial activity which is inevitable under hazardous condition (heat treatment), or has an effect to recover the mitochondrial activity which has once been reduced, thus has a mitochondria activating effect. Since the mitochondria is an organelle which produces a cellular energy (ATP), HA4 has a cell viability enhancing effect.  
      References  
     
         
          1. Martin W, Hoffineisterher M, Rotte C, Henze K. An overview of endosymbiotic models for the origins of eukaryotes, their ATP-producing organelles (mitochondria and hydrogenosomes), and their heterotrophic lifestyle. Biol. Chem. 2001 November; 382(11): 1521-39.  
          2. Hatefi Y. ATP synthesis in mitochondria. Eur J. Biochem. 1993 Dec. 15; 218(3): 759-67.  
       
    
     EXAMPLE 3  
      In this example, the cell viability enhancement of a pharmaceutical agent according to the invention was assessed using a DNA chip capable of monitoring a gene expression promotion/inhibition.  
      Experimental Method  
      First, the K562 was incubated in Groups 1 and 2 in the RP plate medium described above. The both groups were incubated at 42° C. for 20 minutes followed by 37° C. for 30 minutes. The medium of Group  2  was supplemented with HA4 (10 ng/ml).  
      After the incubation, the medium was removed by centrifugation at 1000 rpm. The obtained cells were stored in a deep freezer at −60° C. From the cells thus stored, RNA was extracted according to a standard method. The extracted RNA was subjected to the DNA chip to analyze gene expressions. The DNA chip gene expression analysis was subtracted to DNA CHIP Research Inc. Specifically, the trade name: AceGene Human Oligo Chip 30K 1 Chip Version manufactured by DNA CHIP Research Inc. was employed.  
      Results  
      The results of the DNA chip expression analysis revealed that the cells incubated in the medium containing HA4 exhibited a significant change in the expression profile of many genes involved in the cell viability listed in Table 2.  
               TABLE 2                          HA4 cell viability enhancing effect                             HAA+/−               ratio   Functions                                     &lt;Apoptosis-related&gt;               STK17b (DARK2)   0.09   Signal inducing apoptosis       pawr (Par-4)   0.45   Increased expression in neuron               being ready for apoptosis       Caspase 2   0.27   TNF-induced apoptosis               executing factor       Granzyme H   0.38   Serine protease               Apoptosis inducing       &lt;Transcription       control-related&gt;       DNAJ2   0.34   Heat-inducible transcriptional               repressor (Transcription               inhibition)       TAF9L   0.43   Transcription factor               (Transcription inhibition)       &lt;Heat shock       protein-related&gt;       dnaj (hsp40) homolog   2.62   Heat shock protein                  
 
      As shown in Table 2, HA4 served (1) to inhibit the apoptosis-related gene expressions, (2) to inhibit the transcription inhibition-related gene expression and (3) to promote the heat shock protein-related gene expression. Specifically, HA4 inhibited the gene expression of STK17b (DDRAK2), pawr (Par-4), Caspase 2 and Granzyme H, which are factors relating to the apoptosis induction or execution. In addition, HA4 inhibited the gene expression of DNAJ2 and TAF9L which are factors causing a transcription inhibition. Moreover, HA4 promoted the gene expression of dnaj (hsp40) homolog which is a heat shock protein.  
      Discussion  
      Since STK17b (Dmm) and pawr (Par4) among the apoptosis-related genes in the results shown above are the factors serving to induce or promote the apoptosis, the inhibition of the expression of these genes leads to the inhibition of the apoptosis. For STK17b (DRAK2), see Sanjo H, Kawai T, Akira S. DRAKs, novel serine/threonine kinases related to death-associated protein kinase that trigger apoptosis. J Biol Chem. 1998273(44): 29066-71. For pawr (Par-4), see Johnstone R W, See R E, Sells S F, Wang J, Muthukkumar S, Englert C, Haber D A, Licht J D, Sugrue S P, Roberis T. Rangnekar V M, Shi Y. A novel repressor, par-4, modulates transcription and growth suppression functions of the Wilms&#39; tumor suppressor WT1. Mol Cell Biol. 1996 16(12): 6945-56 and Mattson M P, Duan W, Chan S L, Camandola S. Par-4: emarerg pivotal player in neuronal apoptosis and neurodegenerative disorders. J Mol Neurosci. 1999 Aug-Oct; 13(1-2): 17-30.  
      Also since Caspase 2 is an apoptosis executing factor, the relevant gene expression inhibition leads to an inhibition of apoptosis. For Caspase 2, see Zhivotovsky B, Orrenius S. Caspase-2 function in response to DNA damage. Biochem Biophys Res Commun. 2005 331(3): 859-67.  
      Since Granzyme H is a factor by which a lymphocyte induces the apoptosis in other cells, the relevant gene expression inhibition leads to an inhibition of apoptosis. For Granzyme H, see Sedelies K A, Sayers T J, Edwards K M, Chen W, Pellicci D G, Godfrey D I, Trapani J A Discordant regulation of granzyme H and granzyme B expression in human lymphocytes. J Biol Chem, 2004 279(25): 26581-7. Epub 2004 Apr 6.  
      The results described above indicated that the inhibition of the gene expression of DNAJ2 and TAFgL leads to the recovery of the transcription activity once having been inhibited. For DNAJ2, see Terada K, Mori H. Human DnaJ homologs dj2 and dj3, and bag-1 are positive cochaperones of hsc70. J Biol Chem, 2000275(32): 24728-34. For TAFgL, see Chen Z, Manley Jl, In vivo function a analysis of the histone 3-like TAF9L and a TAF9-related factor, TAF9L. J Biol. Chem. 2003 278(37): 35172-83.  
      We have already reported that HA4 has a heat shock protein 72 (Hsp72) expression promoting effect (Xu H, Ito T, Tawada A, Maeda H, H, Yamanokuchi H, Isahara K, Yoshida K, Uchiyama Y, Asari A. Effect of hyaluronan oligosaccharides on the expression of heat shock protein 72. J Biol Chem, 2002 10; 277(19): 17308-14). In this example, an analysis using a DNA chip revealed that HA4 promotes the gene expression of dnaj (hsp40) homolog which is a heat shock protein. The dnaj (hsp40) homolog has a intracellular protein denaturation inhibiting effect and a cell death inhibiting effect, similarly to Hsp72.  
      Based on the results of this example discussed above, HA4 was revealed to have novel functions such as the apoptosis inhibition, transcription activity recovery and protein denaturation inhibition. Since these functions are all related to the cell viability, it can be concluded that HA4 has a cell viability enhancing effect.  
     EXAMPLE 4  
      In this example, the cytokine-associated gene and chemokine-associated gene expression inhibition of a pharmaceutical agent according to the invention was assessed using a DNA chip capable of monitoring a gene expression promotion/inhibition.  
      Experimental method: First, the K562 was incubated in Groups 1 and 2 in the RPMI medium described above. The both groups were incubated at 42° C. for 20 minutes followed by 37° C. for 30 minutes. The medium of Group  2  was supplemented with HA4 (10 ng/ml).  
      After the incubation, the medium was removed by centrifugation at 1000 rpm. The obtained cells were stored in a deep freezer at −60° C. From the cells thus stored, RNA was extracted according to a standard method. The extracted RNA was subjected to the DNA chip to analyze the gene expression. The DNA chip gene expression analysis was subtracted to DNA CHIP Research Inc. Specifically, the trade name: AceGene Human Oligo Chip 30K 1 Chip Version manufactured by DNA CHIP Research Inc. was employed.  
      Results  
      The results of the DNA chip expression analysis revealed that the cells incubated in the medium containing HA4 exhibited a significant change in the expression profile of many genes involved in the cell viability listed in Table 3.  
                           TABLE 3                                   HA4(+)/               HA4(−) ratio   Functions                                                IFN-γ   0.11   Th1-type cytokine       Mig(CXCL9)   0.11   Th1-type C—X—C chemokine       IL-5   0.28   Th2-type cytokine       IL-17b   0.31   Th1-type cytokine       IL-18RAP   0.32   Bound to IL-li8 to aid for receptor               binding       CCL28   0.32   Chemokine (epithelium, produced by KC)       IL-1β   0.36   Inflammatory cytokine       IFN-ω1   0.5   NK cell activating cytokine                  
 
      As shown in Table 3, the HA4 treatment resulted in a plurality of inhibitions of the cytokine-associated gene and chemokine-associated gene expression. Among the cytokine-associated genes and chemokine-associated genes shown in Table 3, for IFN-γ gene, see Schroder K, Hertzog P J, Ravasi T, Home D A. Interferon-gamma: an overview of signals, mechanisms and functions. J Leukoc Biol. 2004 75(2): 163-89. For Mig (CXCL9) gene, see Farber J M. Mig and IP-10: CXC chemokines that target lymphocytes. J Leukoc Biol. 1997 61(3): 246-57. For IL-S gene, see Adachi T, Alam R. The mechanism of IL-5 signal transduction Am J. Physiol. 1998 275(3 Pt 1): C623-33. For IL-17b, see Li H, Chen J, Huang A, Stinson J, Heldens S, Foster J, Dowd P, Gurney A L, Wood W I. Cloning and characterization of IL-17B and IL-17C, two new members of the IL-17 cytokine family. Proc Nat1 Acad Sci USA. 2000 18 97(2): 773-8. For IL-18RAP, see Cheung H, Chen N J, Cao Z, Ono N, Ohashi P S, Yeh W C. Accessory protein-like is essential for IL-18-mediated signaling. J Immunol. 2005 174(9): 5351-7. For CCL28, see Wang W, Soto H, Oldham E R, Buchanan M E, Homey B, Catron D, Jenkins N, Copeland N G, Gilbert D J, Nguyen N, Abrams J, Kershenovich D, Smith K, McClanahan T, Vicari A P, Zlotnik A. Identification of a novel chemokine (CCL28), which binds CCR10 (GPR2). J Biol. Chem. 2000 275 (29): 22313-23. For IL-1β, see Okamura H. IL-1 family (IL-lipha/beta, IL-iRa, IL-18), IL-16, IL-17. Nippon Rinsho. 2005 63 Supp-1 4: 226-33. For IFN-ω1, see Bekisz J, Schmeisser H, Hernandez J, Goldman N D, Zoon K C. Human interferons alpha, beta and omega. Growth Factors. 2004 22(4): 243-51. And Adolf G K Maurer-Fogy I, Kalsner I, Cantell K. Purification and characterization of natural human interferon omega 1. Two alternative cleavage sites for the signal peptidase. J Biol. Chem. 1990 265(16): 9290-5.  
      Discussion  
      In this example, the HA4 treatment resulted in the inhibition of the cytokine-associated gene and chemokine-associated gene expression. Since the K562 cells employed here were leukocyte-derived cells, it naturally undergoes the expression of the cytokine-associated gene and chemokine-associated gene. Since HA4 promotes Hsp72 expression (see, Xu H, Ito T, Tawada A, Maeda H, Yamanokuchi H, Isahara K, Yoshida K, Uchiyama Y, Asari A. Effect of hyaluronan oligosaccharides on the expression of heat shock protein 72, J. Biol. Chem, 2002 10; 277(19): 17308-14), it is possible that Hsp72 is recognized in vivo by γδT cells to produce an IL-10 and then the IL-10 inhibits the production of various inflammatory cytokines and chemokines. However, since the γδT cells are not included in this example, the expression of the cytokine-associated genes and chemokine-associated genes involved in an inflammation or autoimmune disease is inhibited directly by the HA4 treatment.  
     EXAMPLE 5  
      In this example, a rat spinal injury model was treated continuously with a physiological saline (saline group) or a physiological saline containing HA4 (HA4 group) followed by sampling the spinal tissue, which was then immunostained with an anti-Hsp72 antibody and/or an anti-synaptophysin antibody. Also in this example, a rat which had been subjected to a Sham-operation was handled as an intact control (Sham-operation group).  
      The rat spinal injury model was prepared by subjecting a Wistar rat (11-week old when receiving, 12-week old when using) to the procedure described below. First, a cervical to lumbar region of a test rat was clipped using an electric clipper under an anesthesia with pentobarbital and then the clipped region was cleaned with a 70% alcohol and ISOGIN. Then, the dorsal skin was excised to expose the 5th to 10th thoracic vertebrae and then the 6th thoracic vertebra was subjected to a semi-laminectomy. Then a dura was incised slightly and then under an anesthesia with xylocaine, the tip (fabricated to be 0.3 mm) of a microforceps was introduced over the width of the spinal posterior funiculus (about 1.5 mm) until the tip of the microforceps was brought into contact with the abdominal side vertebral body, and the microforceps were moved for 10 seconds to effect a debridement of the spinal cord (hereinafter referred to as a primary injury site). In the rat spinal injury model, a secondary injury site, which is defined as an injury site formed as a result of transmission of the axon denaturation and the cell death from the primary injury site, is formed. The secondary injury site is considered to involve the effects of an inflammatory cell infiltrated into the primary injury site.  
      Immediately after the debridement of the spinal cord, the tip of a tube (OD:0.3 mm) was placed cranially in the injury site and then connected to an osmotic pump (Alzet pump, Model 2004 (Alza Corporation)), via which an intrathecal continuous administration was effected over a predetermined period. For the purpose of a separation between the injury site and the surrounding tissues, a gelatin sponge (Gelform, Pharmacia) was placed and then the wound was sutured and the animal was returned to its cage.  
      A rat in the Sham-operation group was prepared by a dural incision followed by suturing.  
      The rats in the Sham-operation group thus prepared were assigned to Group  1 . Among the rats of the rat spinal injury model, those receiving the continuous intrathecal administration of the physiological saline was assigned to Group  2 . Among the rats of the rat spinal injury model, those receiving the continuous intraspinal administration of the physiological saline containing HA4 was assigned to Group  3 . The grouping is shown in Table 4.  
                                   TABLE 4                                   Dosing       Number           Test   Dose   concentration   Treatment   of       Group   substance   (μg/day)   (mg/ml)   period   animals                  1   —   —   —   —   6       2   Physiological   —   —   7 Days   6           saline       3   HA4   6   1   7 Days   6                  
 
      The physiological saline containing HA4 given to Group  3  was prepared by the method of Tawada et. al. (Tawada A, Masa T, Oonuki Y, Watanabe A, Matsuzaki Y, Asari A. Large-scale preparation, purification and characterization of hyaluronan oligosaccharides from 4-mers to 52-mers. Glycobiology. 2002 12(7): 421-6). Using these rats in each group, the tissue sections of the primary and secondary injury sites were prepared, fixed in a formalin, and then immunostained by a standard method. For Hsp72, an anti-Hsp72 antibody (Amersham) was employed as a primary antibody, and in the case of double staining a peroxidase-labeled anti-rabbit IgG antibody, or Texas Red-labeled anti-rabbit IgG antibody was employed as a secondary antibody. For the synaptophysin, an anti-synaptophysin antibody (Funakoshi) was employed as a primary antibody, and in the case of double staining a peroxidase-labeled anti-mouse IgG antibody or FITC-labeled anti-mouse IgG antibody was employed as a secondary antibody.  
      Results  
      The results of the immunostaining test of Hsp72 at the primary and secondary injury sites are shown in  FIG. 7  and  FIG. 8 , respectively. In  FIG. 7  and  FIG. 8 , the upper shows photographs of the tissue sections in the respective groups, while the lower shows of the light intensities of the respective groups measured by an NIH image. As shown in  FIGS. 7 and 8 , while few Hsp72 was observed in Group  1 , a slight staining was observed in Group  2  and a further intense staining was observed in Group  3 . Such a staining performance exhibited no difference between the primary and secondary injury sites.  
      The results of the immunostaining test of the synaptophysin at the primary and secondary injury sites are shown in  FIG. 9  and  FIG. 10 , respectively. In  FIG. 9  and  FIG. 10 , the upper shows photographs of the tissue sections in the respective groups, while the lower shows of the light intensities of the respective groups measured by an NIH image. As shown in  FIGS. 9 and 10 , the synaptophysin exhibited a high expression in the grey matter and a moderate expression of in the white matter in Group  1 , but exhibited very little expression in Group  2 . On the contrary, in Group  3 , the synaptophysin exhibited an expression close to that observed in Group  1 . Such a staining performance exhibited no difference between the primary and secondary injury sites.  
      The results of the double staining with Hsp72 and the synaptophysin in the rats of Group  3  are shown in  FIG. 11 .  FIG. 11  ( a ) is a photograph of grey and white matters. The right in  FIG. 11  ( b ) is a photograph (grey matter) with Hsp72 appearing red, and the left is a photograph (grey matter) with the synaptophysin appearing green, and the center being a photograph (grey matter) of the right overlapped by the left. In the photograph in the center of  FIG. 11  ( b ), the co-localization of Hsp72 with the synaptophysin appears yellow. As shown in  FIG. 11  ( a ), a ubiquitous staining with Hsp72 was observed in Group 3. On the other hand,  FIG. 11  ( b ) revealed that a consistent localization between Hsp72 and the synaptophysin.  
      Discussion  
      The treatment with HA4 resulted in an increase in the expression of Hsp72 at the spinal cord injury site. In this case, while Hsp72 exhibited a ubiquitous presence, it is noteworthy that the localization was similar to that of the synaptophysin. The synaptophysin is present in a synaptic vesicle and involved in a synaptic transmission. Accordingly, HA4 is considered to protect the synaptic vesicle and the synaptophysin via a promotion of the Hsp72 expression in the synaptic vesicle (left in  FIG. 1 ). While a long term promotion of the transmission efficiency in a hippocampal synapse is subjected to an inhibition by a scopolamine, a previous heat treatment of the hippocampus to induce Hsp70 is known to prevent such an inhibition (Lin, Y W, Yang H W, Min M Y, Chiu T H. Heat-shock pretreatment prevents suppression of long-term potentiation induced by scopolamine in rat hippocampal CA1 synapses. Brain Res. 2004; 5; 999(2): 222-6). Hsp72 (a member of Hsp70 family) whose expression was promoted by HA4 also serves as a chaperone to aid in a protein function related to a synaptic transmission, and is considered to facilitate or recover such a function. On the other hand, no pharmaceutical agent which promotes the Hsp72 expression in the synaptic vesicle has been reported so far. This example identifies HA4 as a novel pharmaceutical agent which promotes the Hsp72 expression in the synaptic vesicle.  
      Based on the results and the discussion shown above, HA4 was revealed to have a novel function as a synaptic transmission promoter and a synaptic protector.  
     EXAMPLE 6  
      By a DNA array analysis using a K562 cell, HA4 was proven to inhibit the production of various cytokines such as IL-1β and IFNγ in the presence of a heat shock. In this example, an U937 cell known to produce various cytokines via a LPS stimulation was used to examine HA4 for its effect on the cytokine production.  
      Materials  
      1. Test substance: HA4, prepared in accordance with the method of Tawada et al. (1).  
      2. Cell: U937 cell (human monocyte line), purchased from Dainipon Sumitomo Seiyaku.  
      3. Culture medium: RPMI medium (containing 10% FBS).  
      4. LPS  E. coli,  0111B4, Chemicon.  
      Methods  
      An U937 cell was disseminated in a 2 ml aliquot in a 6-well microplate at 5×10 5  cell/ml, supplemented with an LPS at a final concentration of 100 or 1000 ng/ml, and then incubated for 24 hours with 5% CO 2  at 37° C. in the presence or absence of HA4 (100 ng/ml). The culture supernatant was centrifuged at 3000 rpm for 5 minutes to obtain a test substance. A 1 ml aliquot of the recovered supernatant was subjected to Human Cytokine Antibody array (Raybio) using an ELISA (ENDOGEN) to detect the production of various cytokines.  
      More specifically, the following procedure was employed to measure the production of the cytokines by the cytokine array and the ELISA.  
      Cytokine Antibody Array  
      A 2 ml aliquot of a blocking buffer was added to a membrane blotted with an antibody, which was then shaken for 30 minutes. The blocking buffer was removed, and a 1 ml aliquot of the culture supernatant was added and shaken at room temperature for 2 hours, washed 5 times, and then admixed with a primary antibody solution. After agitating at room temperature for 1.5 hours followed by washing 5 times, a secondary antibody solution was added and agitated overnight at 4° C. After washing 5 times, a chemiluminescence was allowed to develop and photographed by a Polaroid. The photograph was scanned to obtain its digital data which were subjected to an Image J to measure the luminescent intensity. The ratio based on the luminescent intensity of an internal standard placed in 6 positions in the membrane was calculated. In addition, a relative level (%) based on the expression level in a non-treatment group (NT) being 100 was calculated.  
      ELISA (IL-6)  
      To a microplate, 50 μl of a biotinylated antibody solution and 50 μl of the culture supernatant were added, and allowed to stand at room temperature for 2 hours. After washing with a washing buffer three times, 100 μl of a streptoavidin-HRP solution was added, allowed to stand at room temperature for 30 minutes, and washed with the washing buffer three times. A TMB was added, allowed to stand for at room temperature 30 minutes, and then a quencher was added to stop the reaction and the absorbance at 450 nm was measured (reference: 562 nm). The IL-6 concentration (pg/ml) was calculated based on the standard solutions measured in parallel.  
      Results  
      In the presence of a stimulation with 100 ng/ml of the LPS, the addition of HA4 at 100 ng/ml resulted in a reduction in the production of inflammatory cytokines IL-1α, β, IL-6, TGF-β, TNF-α and β (FIGS.  12  to  14  (cytokine array),  FIG. 15  (ELISA)). In the graphs shown in FIGS.  12  to  14 , the ordinate represents a relative value (%) based on the expression level in the non-treatment group (NT) being 100. Only the IL-6 was represented as a relative concentration.  
      These results revealed that HA4 has a pharmacological effect as an inflammatory cytokine production inhibitor.  
      References  
      1. Tawada A, Masa T, Oonuki Y, Watanabe A, Matsuzaki Y, Asari A. Large-scale preparation, purification, and characterization of hyaluronan oligosaccharides from 4-mers to 52-mers. Glycobiology. 2002 12(7): 421-6.  
     EXAMPLE 7  
      HA4 administered intrathecally after an antigen inoculation (challenge) to an experimental autoimmune encephalomyelitis (EAE) which is a multiple sclerosis model leads to a significant inhibition of the development of a neural symptom such as a paralysis. When a DNA array was employed to analyze overall mRNA expression in a cerebrospinal tissue, it was revealed that the HA4 administration resulted in an increased IL-6 expression and a reduced transthyretin expression. Since an administration of the IL-6 to a multiple sclerosis model was reported to induce an amelioration, the increase in the IL-6 expression by the HA4 administration is considered to lead to an inhibition of the development of the neural symptoms in EAE. On the other hand, a reduced expression of the transthyretin is known to result in an increased noradrenaline expression. The noradrenaline has an inflammatory cytokine expression inhibiting effect and an activity promoting effect. Based on such an understanding, the inhibition of the expression of the neural symptom such as the paralysis by HA4 is considered to involve the reduction in the expression of the transthyretin. In the Example 1, the effect of HA4 on the autoimmune disease/inflammation and the multiple sclerosis which is a neural disease was described. Accordingly, in this example, the experimental autoimmune encephalomyelitis (EAE) model which is a multiple sclerosis model was treated with HA4 or a physiological saline (negative control), and on Day 14 after the treatment when the symptom became severest, the brain and spinal cord tissues were collected and subjected to a DNA array to examine the action mechanisms.  
      &lt;Materials and Methods&gt; 
      Lewis rats which were four-week old when purchased and five-week old when used were employed as experimental animals. As a test substance, HA4 (1 mg/ml, 10 mg/ml) was employed. HA4 was prepared by the method of Tawada et al. (Tawada A, Masa T, Oonuki Y, Watanabe A, Matsuzaki Y, Asari A. Large-scale preparation, purification and characterization of hyaluronan oligosaccharides from 4-mers to 52-mers. Glycobiology, 2002; 12(7): 421-6).  
      Preparation of Multiple Sclerosis Model (EAE)  
      (1) Test Substances  
      Guinea pig myelin basic protein (GPMBP), Sigma  
      Sterilized  Mycobacterium tuberculosis  (MT, Difco)  
      Freund&#39;s adjuvant Complete (FCA, Difco)  
      Physiological saline (PS)  
      (2) Model Preparation  
      In accordance with the method by Shibaki et al (Shibaki K, Nomura K, Ono R, Shimazu K, Inhibition of experimental autoimmune encephalomyelitis by NINJIN-EIYOTO, SHINKEI-CHIRYO 19(2): 159-166, 2002), 300 μg/animal of the GPMBP was dissolved in 50 μl of PBS, which was then supplemented with an equivalent amount of FCA and sterilized  Mycobacterium tuberculosis  adjusted at the concentration of 0.75 mg/ml, each 50 μl of which was inoculated to each paw of both rear extremities of the animal.  
      Immediately after the antigen inoculation, a catheter was placed in a medullary space, where an intrathecal administration was effected during a predetermined period. For a continuous administration, an osmotic pump (model 2004, Alzet) was employed. The animals were assigned to two groups shown below and one group was treated with HA and the other with the physiological saline as a control.  
                                       TABLE 5                                   Dosing           Number           Test   Dose   concentration   Start of   Treatment   of       Group   substance   (μg/day)   (mg/ml)   dosing   period   animals                  1   Physiological   —   —   Immediately   14 Days   6           saline           after                       inoculation                       of                       antigen       2   HA   6   1   Immediately   14 Days   6                       after                       inoculation                       of                       antigen                  
 
 DNA Array Analysis 
 
      On Day 14 after administration, a cerebrospinal tissue was taken and pooled for each group, and then subjected to the RNA extraction. The RNA sample thus extracted was subjected to a DNA array analysis by TAKARABIO. The results are shown in the following table.  
                       TABLE 6                                   Expression level           ratio           (HA/physiological           saline)                                                    Transthyretin   0.38           Fibroblast growth factor receptor   2.3           substrate 2           Decoy TRAIL receptor without death   2.0           domain                      
 
 &lt;Discussion&gt;
 
      A reduced transthyretin expression is known to lead to an increased noradrenaline expression (Caggiula M, Batocchi A P, Frisullo G, Angelucci F, Patanella A K, Sancricca C, Nociti V, Tonali P A, Mirabella M. Neurotrophic factors and clinical recovery in relapsing-remitting multiple sclerosis. Scand J Immunol. 2005 August; 62(2): 176-82). The noradrenaline has an inflammatory cytokine expression inhibiting effect (Sousa J C, Grandela C, Fernandez-Ruiz J, de Miguel R, de Sousa L, Magalhaes A I, Saraiva M J, Sousa N, Palha J A. Transthyretin is involved in depression-like behaviour and exploratory activity. J. Neurochem. 2004; 88(5): 1052-8) and a searching behavior/activity increasing effect (Feinstein D L, Heneka M T, Gavrilyuk V, Dello Russo C, Weinberg G, Galea E. Noradrenergic regulation of inflammatory gene expression in brain. Neurochem Int. 2002; 41(5): 357-65. Review). From the understanding described above, the inhibitory effect of HA4 on the ultromotivity reduction/paralysis is considered to involve the transthyretin expression reduction described above.  
      A fibroblast growth factor receptor substrate 2 is a receptor substrate for a fibroblast growth factor (GFG) and for a neural growth factor such as a nerve growth factor. Accordingly, an increase in the fibroblast growth factor receptor substrate 2 means an increase in the sensitivity to the neural growth factor expressed in the multiple sclerosis (Caggiula M, Batocchi A P, Frisullo G, Angelucci F, Patanella A K, Sancricca C, Nociti V, Tonali P A, Mirabella M. Neurotrophic factors and clinical recovery in relapsing-remitting multiple sclerosis. Scand J Immunol. 2005 Aug; 62(2): 176-82; Triaca V, Tirassa P, Aloe L. Presence of nerve growth factor and TrkA expression in the SVZ of EAE rats: evidence for a possible functional significance. Exp Neurol. 2005; 191(1): 53-64.; Laudiero L B, Aloe L, Levi-Montalcini R, Buttinelli C, Schilter D, Gillessen S, Otten U. Multiple sclerosis patients express increased levels of beta-nerve growth factor in cerebrospinal fluid. Neurosci Lett. 1992 Nov. 23; 147 (1): 9-12). Accordingly, it can be assumed that the HA4 treatment provides the effects of the neural growth factors, such as neuron death inhibition, neuron differentiation and axonal growth by which the symptoms of the multiple sclerosis were suppressed (Villoslada P, Genain C P. Role of nerve growth factor and other trophic factors in brain inflammation. Prog Brain Res. 2004; 146: 403-14. Review.; Gielen A, Khademi M, Muhallab S, Olsson T, Piehl F. Increased brain-derived neurotrophic factor expression in white blood cells of relapsing-remitting multiple sclerosis patients. Scand J. Immunol. 2003; 57(5): 493-7.; Villoslada P, Hauser S L, Bartke I, Unger J, Heald N, Rosenberg D, Cheung S W, Mobley W C, Fisher S, Genain C P. Human nerve growth factor protects common marmosets against autoimmune encephalomyelitis by switching the balance of T helper cell type 1 and 2 cytokines within the central nervous system. J Exp Med. 2000 15; 191(10): 1799-806.; Boutros T, Croze E, Yong V W. Interferon-beta is a potent promoter of nerve growth factor production by astrocytes. J. Neurochem. 1997; 69(3): 939-46.; Massaro A R, Soranzo C, Bigon E, Battiston S, Morandi A, Carnevale A, Callegaro L. Nerve growth factor (NGF) in cerebrospinal fluid (CSF) from patients with various neurological disorders. Ital J Neurol Sci. 1994; 15(2): 105-8.; Althaus H H, Kloppner S, Schmidt-Schultz T, Schwartz P. Nerve growth factor induces proliferation and enhances fiber regeneration in oligodendrocytes isolated from adult pig brain. Neurosci Lett. 1992 3; 135(2): 219-23).  
      A decoy TRAIL receptor without death domain exhibits a competitive inhibition of the binding of the TRAIL to its receptor (Pan G, Ni J, Wei Y F, Yu G, Gentz R, Dixit V M. An antagonist decoy receptor and a death domain-containing receptor for TRAIL. Science. 1997 8; 277 (5327): 815-8). Accordingly, HA4 is considered to inhibit the cell death of neurons and an oligodendrocyte (myelin) by the TRAIL via an increase in the decoy TRAIL receptor without death domain (urewicz A, Matysiak M, Andrzejak S, Selmaj K. TRAIL-induced death of human adult oligodendrocytes is mediated by JNK pathway. Glia. 2006 15; 53(2): 158-66).  
      Review  
      &lt;Effects of HA4 on Multiple Sclerosis, Spinal Cord Injury and Asthma/Allergic Disease&gt; 
      As described above, when HA4 was given to the rat EAE (experimental allergic encephalomyelitis) model which is the multiple sclerosis model, the inhibition of the neural symptoms was observed.  
      Also based on the DNA array analysis using the rat cerebrospinal tissue, the mitochondrial potential activity and DNA array analysis using the K562 cells and the synaptophysin/Hsp72 immunostaining in the spinal cord injury model, HA4 was revealed to have (1) an inflammation inhibiting effect, and (2) a neural function improving effect (inhibition of a reduction in a neurotransmission) via a synapse protecting effect, oligodendrocyte (myelin) cell death inhibiting effect and neuron death inhibition/neuron differentiation/axon extension ( FIG. 16 ).  
      In the DNA array analysis using the K562 cells, the inhibition of the IL-1β expression was observed. The IL-1β is known to be a factor which exacerbates a spinal cord injury (Yang L, Jones N R, Blumbergs P C, Van Den Heuvel C, Moore E J, Manavis J, Sarvestani G T, Ghabriel M N. Severity-dependent expression of pro-inflammatory cytokines in traumatic spinal cord injury in the rat. J Clin Neurosci. 2005 April; 12(3):276-84). The abovementioned HA4 effects (1) and (2) also contributes to the inhibition of the exacerbation/treatment in the spinal cord injury. The fact discussed above indicates a therapeutic effect of HA4 also on the spinal cord injury.  
      The DNA array analysis using the K562 cells showed the inhibition of the IL-5 expression. The IL-5 is known to be a factor which exacerbates an allergic disease such as an asthma (Hamelmann E, Gelf and EW). IL-5-induced airway eosinophilia—the key to asthma? Immunol Rev. 2001 February; 179: 182-91). In addition, the transthyretin reducing effect of HA4 contributes to the inhibition of the exacerbation/treatment in the cases of asthma or allergic diseases, since it leads to an increased noradrenaline production and a bronchial dilation. The fact discussed above indicates a therapeutic effect of HA4 also on the asthma and allergic diseases ( FIG. 18 ).