bluuebunny/crossref_metadata_2025 huggingface dataset:
Thyrotropin Secretagogues Reduce Rat Pituitary Neuromedin B, a Local Thyrotropin Release Inhibitor
Authors: Ortiga-Carvalho Tânia Maria , Oliveira Karen de Jesus , Morales Marcelo Marcos , Martins Viviane Pinto , Pazos-Moura Carmen Cabanelas
Published: July 2017

Neuromedin B (NB), a bombesin-like peptide, highly concentrated in rat pituitary gland, has been shown to act as an autocrine/paracrine inhibitor of thyrotropin (TSH) release. Here it is shown that a single injection of thyrotropin-releasing hormone (TRH, 1.5 μg/animal, Ip), the most important stimulator of thyrotropin secretion, induced approximately 35%–45% decrease in pituitary NB content in rats, as well as an important decrease in NB mRNA at 15 and 30 min ( P < 0.05). Acute cold exposure, which induced higher serum TSH with a peak at 30 min, was associated with progressive decrease in pituitary NB, starting at 15 min although only reaching statistical significance after 2 hr ( P < 0.05). Although not involved in the early peak, the decrease in NB may be contributing to maintenance of higher serum TSH in cold-exposed animals compared with those at room temperature. Fed rats, 2 hr after being subcutaneously injected with mouse recombinant leptin (8 μg /100 g body wt), showed a ×2 increase in serum TSH and 38% reduction in pituitary NB ( P < 0.05). In conclusion, TRH and leptin rapidly decreased pituitary NB and it is first proposed that the reduction of the inhibitory tonus of NB on TSH release will ultimately contribute to the amplification of TSH secretion elicited by TSH secretagogues.
Multiple Sclerosis: Etiological Mechanisms and Future Directions
Authors: Lutton J. D. , Winston R. , Rodman T. C.
Published: July 2017

Multiple sclerosis (MS) is a complex human autoimmune-type disease with a predominantly unknown etiology. Immunologic destruction of myelin basic protein (MBP) throughout the nervous system is the major pathology of multiple sclerosis. This review will attempt to update new information about basic mechanisms and therapeutic management of the disease. The significance of the structure of MBP is discussed with respect to the contribution of such structures to the disease process. A number of MBP peptides that serve as the immunodominant antigens in MS patients have been identified. These peptides have been studied in animal models for their antigenic characteristics and ability to induce disease. Evidence for genetic contributions is reviewed with multigenerational twin studies providing the best evidence for susceptible haplotypes. The role of microorganisms/viruses and environmental agents are discussed as potential etiological factors but are now thought to be of minor importance to the primary causal development of the disease. Of major consideration are immunological mechanisms that contribute to the development of autoimmunity. In particular, antigen expression, cytokine and leukocyte interactions, and regulatory T-cells are discussed. Particular attention is given to regulatory T-cells (Treg), which help balance/modulate other T-cells such as Th1 and Th2 cells, and how such Treg regulate autoimmunity is addressed. The importance of the role of Tregs is exemplified by the demonstration that administration of oral antigens can induce specific Tregs that counteract experimental autoimmune encephalomyelitis in animal models. The significance of animal studies to human multiple sclerosis is discussed. A potential role for natural antibodies and innate immune mechanisms to help provide resistance to disease development is also reviewed. Finally, a variety of therapeutic agents that have been and continue to be utilized for multiple sclerosis is reviewed. Trials with oral antigens, such as glatirmer acetate (copolymer 1) especially in combination with interferon-β, have shown promise. Antibody therapy and bone marrow transplantation are also briefly discussed.
Effects of Genistein or Soy Milk During Late Gestation and Lactation on Adult Uterine Organization in the Rat
Authors: Hughes Claude L. , Liu Gentao , Beall Stephanie , Foster Warren G. , Davis Vicki
Published: July 2017

In utero and lactational exposure to estrogenic agents has been shown to influence morphological and functional development of reproductive tissues. Thus, consumption of dietary phytoestrogens, such as isoflavones, during pregnancy and lactation could influence important periods of development, when the fetus and neonate are more sensitive to estrogen exposure. In this study, reproductive outcomes after developmental exposure to isoflavones were examined in Long-Evans rats maternally exposed to isoflavones via a commercial soy beverage or as the isolated isoflavone, genistein. Most reproductive end-points examined at birth, weaning, and 2 months of age were not significantly modified in pups of either sex after lactational exposure to soy milk (provided to the dams in place of drinking water) from birth until weaning. However, soy milk exposure induced a significant increase in progesterone receptor (PR) in the uterine glandular epithelium of the 2-month-old pups. In pregnant dams treated with genistein (GEN; 15 mg/kg body weight) by gavage, from Gestational Day 14 through weaning, PR expression in the uterine glandular epithelium from 2-month-old GEN-treated females (postexposure) was also significantly increased. Diethylstilbesterol (DES) also stimulated uterine PR expression only in the glandular but not luminal epithelial cells. However, unlike DES, in utero/lactational exposure to GEN did not increase expression of the proliferation marker, proliferating cell nuclear antigen (PCNA), in the luminal epithelial cells of the 2-month-old rat uteri. These experiments demonstrate that developmental exposure to dietary isoflavones, at levels comparable to the ranges of human exposure, modify expression of the estrogen-regulated PR in the uterus of sexually mature rats weeks after exposure ended. Since the PR is essential for regulating key female reproductive processes, such as uterine proliferation, implantation, and maintenance of pregnancy, its increased expression suggests that soy phytoestrogen exposure during reproductive development may have long-term reproductive health consequences.
Urocortin Protects Coronary Endothelial Function During Ischemia-Reperfusion: A Brief Communication
Authors: García-Villalón Angel Luis , Sanz Elena , Monge Luis , Fernández Nuria , Climent Belén , Diéguez Godofredo
Published: July 2017

Urocortin is a vasodilator peptide related to corticotrophin-releasing factor, which may protect myocardium during coronary ischemia-reperfusion. To study whether urocortin also protects coronary endothelial function during ischemia-reperfusion, hearts from Sprague-Dawley rats were perfused at constant flow and then exposed to 15 mins ischemia followed by 15 mins reperfusion. In one series of experiments, we found that the coronary relaxation to urocortin (10–11 to 10–8 M) was reduced by ischemia-reperfusion (51 ± 4% vs. 79 ± 4% of the active tone, for the 10–10 Mdose). In other series of experiments, we observed that ischemia-reperfusion reduced the coronary relaxation to a test dose of acetylcholine (10–6 M) (25 ± 2% vs. 54 ± 9% of active tone), without modifying the relaxation to sodium nitroprusside (10–6 M). Treatment with a low threshold concentration of urocortin (10–11 M), administered before ischemia and during reperfusion, partly improved the coronary relaxation to acetylcholine (36 ± 3% of active tone). These results suggest that ischemia-reperfusion impairs the coronary vasodilation to urocortin and produces endothelial dysfunction and that this endothelial dysfunction may be improved by urocortin.
Peroxynitrite Induces Apoptosis in Rat Aortic Smooth Muscle Cells: Possible Relation to Vascular Diseases
Authors: Li Jianfeng , Li Wenyan , Su Jialin , Liu Weimin , Altura Bella T. , Altura Burton M.
Published: July 2017

An emerging body of evidence is accumulating to suggest that in vivo formation of free radicals in the vasculature, such as peroxynitrite (ONOO–), and programmed cell death (i.e., apoptosis) play important roles in vascular diseases such as atherosclerosis, hypertension, and restenosis. The present study was designed to determine whether primary rat aortic smooth muscle cells (SMCs) undergo apoptosis following treatment with ONOO–. Direct exposure of primary rat aortic SMCs to ONOO– induced apoptosis in a concentration-dependent manner, as confirmed by means of quantitative fluorescence staining and TUNEL assays. ONOO–-induced apoptosis in rat aortic SMCs appears to involve activation of Ca2+-dependent endonucleases. Although the precise mechanisms by which peroxynitrite induces apoptosis in rat aortic SMCs need to be further investigated, the present, preliminary findings could be used to suggest that ONOO– formation in the vasculature may play roles in the processes of vascular diseases, such as atherosclerosis, hypertension, and restenosis, via adverse actions on blood vessels.
Injury-Associated Differential Regulation of Histone Expression and Modification in the Thymus of Mice
Authors: Jeong Jayoung , Adamson Lee K. , Greenhalgh David G. , Cho Kiho
Published: July 2017

One of the key events in the regulation of gene expression is chromatin remodeling involving histone regulation. We investigated the effects of burns on the expression of histone that might be associated with altered molecular and pathological profiles in the thymus. A markedly decreased expression of histone variant H2A.1 mRNA was identified in the thymus after burn during a differential display experiment. Subsequently, we examined the histone expression (mRNA and protein) and posttranslational modification in the thymus after burn. Also, changes in proliferating cell nuclear antigen (PCNA), a central molecule in chromatin assembly, was examined. Reverse-transcription polymerase chain reaction analysis revealed a transient decrease in the expression of several histone variants (H2A.1, H1(r1), H3-B, H3-1, and H4-D) mRNAs in the thymus at 1 day after burn. A decrease in histone subtypes H2A, H2B, H3, and H4, but not H1, was demonstrated 1 and 3 days after burn according to the results of Western blot. Furthermore, there were different levels of decreases in acetylated and dimethylated forms of histone H3 1 and 3 days after burn. In addition, decreased levels of PCNA were evident in the thymus 1 day after burn. Changes in the expression of histones and PCNA may reflect mere decrease in proliferating cells and/or a reorganization of the chromatin structure associated with altered transcriptional activities, eventually contributing to the phenotypic changes in the thymus after burn.
Growth Repression in Diethylstilbestrol/Dimethylbenz[a]anthracene–Induced Rat Mammary Gland Tumor Using Hecate-CGβ Conjugate
Authors: Zaleska Monika , Waclawik Agnieszka , Bodek Gabriel , Zezula-Szpyra Anna , Li Xiangdong , Janowski Tomasz , Hansel Wiliam H. , Rahman Nafis A. , Ziecik Adam J.
Published: July 2017

Recently, we have shown that Hecate-CGβ conjugate, which is a fusion of the lytic peptide Hecate and a 15–amino acid fragment of the β-chain of chorionic gonadotropin (CGβ), selectively destroys mammary gland carcinoma cells that possess luteinizing hormone receptors (LHR) in vitro. We induced mammary gland tumors using combined prenatal exposure to synthetic diethylstilbestrol (DES) and additional postnatal exposure to dimethylbenz[a]anthracene (DMBA). Rats with tumors were equally randomized (10/group) and treated with either sham (control) or 12 mg/kg body wt of either Hecate or Hecate-CGβ once a week for 3 weeks by tail vein injections. One week after the last injection, rats were kilted. Reverse-transcription–nested polymerase chain reaction/Southern blotting revealed alternatively spliced mRNA for LHR in tumor tissues of 5 of 30 females, which was further confirmed by Western blot analysis. The percentage of tumor volume increase was lowest in the group treated with Hecate-CGβ (45.3 ± 27.6), compared with Hecate- and shamtreated, control group (324.8 ± 78.1 and 309.9 ± 51.2, respectively; P < 0.001). Hecate-CGβ induced a significant decrease in tumor burden compared with controls (9.5 ± 2.1 mg/g body wt vs. 21.6 ± 2.9; P < 0.01). A smaller reduction in tumor burden was also observed in Hecate-treated females (17.6 ± 1.6 mg/g body wt vs. 21.6 ± 2.9; P < 0.05). Our results prove the principle that Hecate-CGβ conjugate is able to repress mammary gland tumor growth, even in tumor tissues that lack or have very low levels of LHR. The mechanism of Hecate-CGβ conjugate action in repression of DES/DMBA-induced tumor growth needs to be further analyzed to clarify the molecular mechanisms of Hecate-CGβ conjugate action in vivo.
Increased Sensitivity to Dietary Cholesterol in Diabetic and Hypothyroid Rats Associated with Low Levels of Hepatic HMG-CoA Reductase Expression
Authors: Ness Gene C. , Gertz Karen R.
Published: July 2017

We recently postulated that hepatic 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase functions as a cholesterol buffer to protect against the serum and tissue cholesterol raising action of dietary cholesterol. This postulate predicts that diminished basal expression of hepatic HMG-CoA reductase results in increased sensitivity to dietary cholesterol. Because diabetic and hypothyroid animals are known to have markedly reduced hepatic HMG-CoA reductase, these animals were selected as models to test our postulate. When rats were rendered diabetic with streptozotocin, their hepatic HMG-CoA reductase activity decreased from 314 to 22 pmol • min-1 • mg-1, and their serum cholesterol levels increased slightly. When the diabetic animals were challenged with a diet containing 1% cholesterol, their serum cholesterol levels doubled, and their hepatic reductase activity decreased further to 0.9 pmol • min-1 • mg-1. Hepatic low-density lipoprotein (LDL) receptor immunoreactive protein levels were unaffected in the diabetic rats whether fed cholesterol-supplemented diets or not. In rats rendered hypothyroid by thyroparathyroidectomy, serum cholesterol levels rose from 100 to 386 mg/dl in response to the 1% cholesterol challenge, whereas HMG-CoA reductase activity dropped from 33.8 to 3.4 pmol • min-1 • mg-1. Hepatic LDL receptor immunoreactive protein levels decreased only slightly in the hypothyroid rats fed cholesterol-supplemented diets. Taken together, these results show that rats deficient in either insulin or thyroid hormone are extremely sensitive to dietary cholesterol largely due to low basal expression of hepatic HMG-CoA reductase.
Nutrition and Infectious Diseases in Developing Countries and Problems of Acquired Immunodeficiency Syndrome
Authors: Ambrus Julian L. , Ambrus Julian L.
Published: July 2017

Infectious diseases are the major causes of death and morbidity in underdeveloped countries, particularly in children. Increasing evidence suggests that malnutrition—both Protein-Energy type Malnutrition (PEM) and essential micronutrient (vitamins, trace minerals, essential amino acids, polyunsaturated fatty acids) type—is the underlying reason for increased susceptibility to infections. On the other hand, certain infectious diseases also cause malnutrition, which results in a vicious cycle. Before its viral origin was known, acquired immunodeficiency syndrome (AIDS) had been termed the thin disease because cachexia was AIDS' main clinical manifestation.

The relationship between infection and malnutrition is well documented in the literature. Our experience supports this. Preventive and therapeutic measures are suggested.
Role of Fatty Acid Composition in the Development of Metabolic Disorders in Sucrose-Induced Obese Rats
Authors: Fukuchi Satoshi , Hamaguchi Kazuyuki , Seike Masataka , Himeno Katsuro , Sakata Toshiie , Yoshimatsu Hironobu
Published: July 2017

Fatty acids have been shown to be involved in the development of insulin resistance associated with obesity. We used sucrose loading in rats to analyze changes in fatty acid composition in the progression of obesity and the related metabolic disorder. Although rats fed a sucrose diet for 4 weeks had body weights similar to those of control animals, their visceral fat pads were significantly larger, and serum triglyceride levels were higher; however, neither plasma glucose nor insulin levels were significantly higher. After 20 weeks of sucrose loading, body weight and visceral and subcutaneous fat pads had increased significantly compared with those in control rats. Moreover, plasma glucose, Insulin, and triglyceride levels were significantly higher. An analysis of individual fatty acid components in the blood and peripheral tissues demonstrated phase- and tissue-dependent changes. After 20 weeks of sucrose loading, palmitoleic acid (16:1 n-7) and oleic acid (18:1 n-9), the major components of monounsaturated fatty acid, showed a ubiquitous increase in plasma and all tissues analyzed. In contrast, linoleic acid (18:2 n-6) and arachidonic acid (20:4 n-6), the major components of polyunsaturated fatty acid in the n-6 family, decreased in plasma and all tissues analyzed. After 4 weeks of sucrose loading, these changes in fatty acid composition were observed only in the liver and plasma and not in fat and muscle. This led us to conclude that elevation of plasma glucose and insulin develop at the late phase of sucrose-induced obesity, when changes in fatty acid composition appear in fat and muscle. Furthermore, changes in fatty acid composition in liver seen after 4 weeks of sucrose loading, when increases in neither plasma glucose nor insulin were detected, suggest that liver may be the initial site of fatty acid imbalance and that aberrations in hepatic fatty acid composition may lead to fatty acid imbalances in other tissues.
Dietary Copper Restriction-Induced Changes in Myocardial Gene Expression and the Effect of Copper Repletion
Authors: Elsherif Laila , Jiang Youchun , Saari Jack T. , Kang Y. James
Published: July 2017

Dietary copper (Cu) restriction leads to cardiac hypertrophy and failure in mice, and Cu repletion (CuR) reverses the hypertrophy and prevents the transition to heart failure. The present study was undertaken to determine changes in myocardial gene expression involved in Cu deficient (CuD) cardiomyopathy and its reversal by CuR. Analysis was performed on three groups of mice: 4-week-old CuD mice that exhibited signs of cardiac failure, their age-matched copper-adequate (CuA) controls, and the CuD mice that were re-fed adequate Cu for 2 weeks. Total RNA was isolated from hearts and subjected to cDNA microarray and real-time reverse transcription-polymerase chain reaction analysis. Dietary CuD caused a decrease in cardiac mRNA of β-MHC, L-type Ca2+ channel, K-dependent NCX, MMP-2, -8, and -13, NF-κB, and VEGF. The mRNA levels of ET-1, TGF-β, TNF-α, and procollagen-l-α1 and III-α1 were increased in the CuD cardiac tissue. Copper repletion resulted in cardiac mRNA levels of most of the genes examined returning to control levels, although the K-dependent NCX and MMP-2 values did not reach those of the CuA control. In addition, CuR caused an increase in β-MHC, L-type Ca2+channel, MMP-13 to levels surpassing those of CuA control, and a decrease in ET-1, and TNF-at mRNA levels. In summary, changes in gene expression of elements involved in contractility, Ca2+ cycling, and inflammation and fibrosis may account for the altered cardiac function found in CuD mice. The return to normal cardiac function by CuR may be a result of the favorable regression in gene expression of these critical components in myocardial tissue.
Structures of Integrin Domains and Concerted Conformational Changes in the Bidirectional Signaling Mechanism of αIIbβ3
Authors: Calvete Juan J.
Published: July 2017

Integrins are heterodimeric type I transmembrane cell-adhesive receptors whose affinity for ligands is regulated by tertiary and quaternary conformational changes that are transmitted from the cytoplasmic tails to the extracellular ectodomains during the transition from the inactive to the active state. Receptor occupancy initiates further structural alterations that transduce signals across the plasma membrane and result in receptor clustering and recruitment of signaling molecules and cytoskeletal rearrangements at the integrin's cytoplasmic domains. The large distance between the intracellular cytoplasmic domains and the ligand-binding site, which in an extended conformation spans more that 200 Å, imposes a complex mechanism of interdomain communication for the bidirectional information flow across the plasma membrane. Significant progress has recently been made in elucidating the crystal and electron microscopy structures of integrin ectodomains in its unliganded and liganded states, and the nuclear magnetic resonance solution structures of stalk domains and the cytoplasmic tails. These structures revealed the location of sites that are functionally important and provided the basis for defining new models of integrin activation and signaling through bidirectional conformational changes, and for understanding the structural basis of the cation-dependent ligand-binding specificity of integrins. Platelet integrin αIIbβ3 has served as a paradigm for many aspects of the structure and function of integrins The aim of this minireview is to combine recent structural and biochemical studies on integrin receptors that converge into a model of the tertiary and quaternary conformational changes in αIIbβ3 and other homologous integrins that propagate inside-out and outside-in signals.
Cu, Zn-Superoxide Dismutase is Lower and Copper Chaperone CCS is Higher in Erythrocytes of Copper-Deficient Rats and Mice
Authors: West Elizabeth C. , Prohaska Joseph R.
Published: July 2017

Discovery of a sensitive blood biochemical marker of copper status would be valuable for assessing marginal copper intakes. Rodent models were used to investigate whether erythrocyte concentrations of copper, zinc–superoxide dismutase (SOD), and the copper metallochaperone for SOD (CCS) were sensitive to dietary copper changes. Several models of copper deficiency were studied in postweanling male Holtzman rats, male Swiss Webster mice offspring, and both rat and mouse dams. Treatment resulted in variable but significantly altered copper status as evaluated by the presence of anemia, and lower liver copper and higher liver iron concentrations in copper-deficient compared with copper-adequate animals. Associated with this copper deficiency were consistent reductions in immunoreactive SOD and robust enhancements in CCS. In most cases, the ratio of CCS:SOD was several-fold higher in red blood cell extracts from copper-deficient compared with copper-adequate rodents. Determination of red cell CCS:SOD may be useful for assessing copper status of humans.
Differential Translational Effects of Myristic Acid and Eicosapentaenoic Acid on 3-Hydroxy-3-Methylglutaryl-CoA Reductase From Reuber H35 Hepatoma Cells
Authors: García-Pelayo M. Carmen , García-Peregrín Eduardo , Martínez-Cayuela Marina
Published: July 2017

The mechanisms by which saturated and polyunsaturated fatty acids may exert their effects on levels of blood cholesterol and human atherosclerosis have not been fully established. In this work, we studied the translational effects of myristic (14:0) and eicosapentaenoic (20:5) acids on 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase from Reuber H35 hepatoma cells. This enzyme is an intrinsic membrane, 96-kDa protein whose proteolysis releases an enzymatically active, 52- to 56-kDa, soluble fragment. We optimized an immunoblot procedure for quantifying small amounts of both the native and the soluble forms of HMG-CoA reductase from Reuber H35 hepatoma cells. We demonstrated that the upregulation of HMG-CoA reductase by myristic acid is due to an increase of the HMG-CoA reductase protein; therefore, protein synthesis would be required for the increase of HMG-CoA reductase activity caused by this fatty acid. In contrast, the downregulation of HMG-CoA reductase caused by eicosapentaenoic acid is not due to decreased protein synthesis, since similar levels of protein were found in the presence and absence of this fatty acid. Results obtained with cycloheximide as a protein-synthesis inhibitor confirm these findings.
Nutrition- and Virus-Induced Stress Represses the Expression of Manganese Superoxide Dismutase in Vitro
Authors: Berger Martina M. , Jia Xi Yu , Legay Vincent , Aymard Michelle , Tilles Jeremiah G. , Lina Bruno
Published: July 2017

The relationship between oxidative stress and neuronal cell death has been suggested for many years. To understand the influence of oxidative stress on neuronal cell death, we investigated the influence of oxidative stress on DEV cells, a human glial cell line. Using enterovirus infection and/or malnutrition to induce oxidative stress, our results demonstrate that those stressors severely influence the antioxidant defense system in DEV cells. Although the expression of mitochondrial manganese superoxide dismutase (MnSOD) in DEV cells was significantly increased in acute infection with viral and nutritional stress, in persistent infection and nutritional stress, the expression of the MnSOD was drastically downregulated. We believe that this downregulation of MnSOD expression in the chronic stress model is due to repression of antioxidant defense. The downregulation of the MnSOD expression may lead to an increase of free-radical production and thus explain why the cells in the chronic stress model were more vulnerable to other oxidative stress influences. The vulnerability of DEV cells to additional stress factors resulted in progressive cell death, which may be analogous to the cell death in neurodegenerative diseases.
Genomics and Clinical Medicine: Rationale for Creating and Effectively Evaluating Animal Models
Authors: Swanson Kelly S. , Mazur Meredith J. , Vashisht Kapil , Rund Laurie A. , Beever Jonathan E. , Counter Christopher M. , Schook Lawrence B.
Published: July 2017

Because resolving human complex diseases is difficult, appropriate biomedical models must be developed and validated. In the past, researchers have studied diseases either by characterizing a human clinical disease and choosing the most appropriate animal model, or by characterizing a naturally occurring or induced mutant animal and identifying which human disease it best resembled. Although there has been a great deal of progress through the use of these methods, such models have intrinsic faults that limit their relevance to clinical medicine. The recent advent of techniques in molecular biology, genomics, transgenesis, and cloning furnishes investigators with the ability to study vertebrates (e.g., pigs, cows, chickens, dogs) with greater precision and utilize them as model organisms. Comparative and functional genomics and proteomics provide effective approaches for Identifying the genetic and environmental factors responsible for complex diseases and in the development of prevention and treatment strategies and therapeutics. By identifying and studying homologous genes across species, researchers are able to accurately translate and apply experimental data from animal experiments to humans. This review supports the hypothesis that associated enabling technologies can be used to create, de novo, appropriate animal models that recapitulate the human clinical manifestation. Comparative and functional genomic and proteomic techniques can then be used to identify gene and protein functions and the Interactions responsible for disease phenotypes, which aids in the development of prevention and treatment strategies.
Fermentable Dietary Fiber Potentiates the Localization of Immune Cells in the Rat Large Intestinal Crypts
Authors: Ishizuka Satoshi , Tanaka Seiji , Xu Hong , Hara Hiroshi
Published: July 2017

Intestinal crypts are composed of a well-defined hierarchy of epithelial cells, and proliferating epithelial cells reside close to the bottom of the crypts—even in the large intestine. We investigated whether CD8+ and CD4+ intraepithelial lymphocytes (IELs) and CD161+ natural killer (NK) cells localized in proliferating or differentiated epithelial region of cecum and colon. Both proliferating epithelial layer cells and the immune cells along the longitudinal crypt axis of the large intestine were measured histochemically. Dietary intervention revealed that the physiological localization of the immune cells in the longitudinal crypt axis depended on the immune cell type. CD8+ IELs were preferentially located among differentiated epithelial cells. In contrast, CD161+ NK cells were located adjacent to the epithelial cells at the bottom of crypt. Cecal crypts contained significantly larger numbers of CDS+ IELs than did colonic crypts. However, there was only a minor population of CD4+ IEL in the cecal and colonic epithelia. Some dietary fibers increased the densities of CD8+ IELs and CD161+ NK cells in the cecum, with the magnitude of response varying among the types of fiber. There was a significant relationship between SCFA and the localization of Immune cells, especially CD8+ IEL and CD161+ NK celts, which are considered to be involved in the maintenance of epithelial homeostasis.
Induction of a Phosphate Appetite in Adult Male and Female Rats
Authors: Czarnogorski Maggie , Woda Craig B. , Schulkin Jay , Mulroney Susan E.
Published: July 2017

We have reported that dietary inorganic phosphate (Pi) deprivation induces a Pi-seeking behavior in juvenile male rats. The purpose of the present study was to determine whether the Pi appetite is present in adult animals, and if so, whether it is altered during times of increased demand for Pi, such as pregnancy and lactation. Both male and female animals fed a low-phosphate diet (LPD) ingested significantly greater amounts of PiH20 daily than their normal phosphate diet (NPD) controls, and per 100 g of body weight (BW), the female animals fed LPD tended to ingest greater amounts of PiH20 than male rats fed LPD. Pregnant and lactating rats fed LPD ingested significantly more PiH20 than those fed NPD, however, neither group displayed a Pi appetite different than virgin females. However, lactation further reduced Pi levels in plasma and cerebral spinal fluid compared with control values. Despite the additional Pi from the PiH20 in the mothers fed LPD, pup birth weight was significantly lower than in NPD litters, and this was exacerbated 9 days after birth. This attenuated BW gain was associated with lower plasma Pi levels in the pups. In conclusion, a mild but consistent Pi-seeking behavior is induced in adult male and female rats after only 2 days of dietary Pi restriction. On a relative basis, the amount of PiH20 ingested is greater in female than in male animals, but does not increase further during pregnancy and lactation.
Effect of the Knockdown of Podocin mRNA on Nephrin and α-Actinin in Mouse Podocyte
Authors: Fan Qingfeng , Ding Jie , Zhang Jingjing , Guan Na , Deng Jianghong
Published: July 2017

Recently, the novel podocyte proteins podocin, nephrin, and α-actinin-4 have been identified in three congenital/family nephrotic syndromes, respectively. Further studies showed that these podocyte proteins were involved in some acquired nephrotic syndromes and various experimental models of proteinuria. However, the molecular interactions among these podocyte proteins remain unclear. In this study, to investigate the molecular interactions among podocin, nephrin, and α-actinin-4, we reconstructed the RNA interference (RNAI) expression vector, pSilencer 2.1-U6, specifically targeting podocin mRNA, and it was transfected into the mouse podocyte clone (MPC5). Immunofluorescence staining, double-immunolabeling, confocal microscopy, semiquantitative reverse transcription polymerase chain reaction (RT-PCR), and Western blotting were used to detect the distribution and expression of podocin, nephrin, α-actinin-4, and glyseraldehyde-3-phosphate dehydrogenase (GAPDH)/β-actin. The fluorescence intensity of podocin and nephrin decreased obviously, along with the evident distribution change from the cell membrane surface to the nucleus circumference in podocyte. In relation to GAPDH, the mRNA reductions of podocin and nephrin were observed by about 65% and 70%, respectively. The expression of podocin protein was too low to be detected in the interference group. In relation to β-actin, the protein level of nephrin decreased by about 78%. The distribution and the mRNA and protein level of α-actinin showed no appreciable change. Alpha-actinin localized mainly in the cytoplasm and also extended to the processes. Thus, the significant decreased expression of nephrin along with the redistribution were detected with the knockdown of podocin mRNA, whereas the expression and distribution of α-actinin-4 showed no change. These results suggest that podocin may interact directly with nephrin, but not with α-actinin.
Fibrin(ogen)-αMβ2Interactions Regulate Leukocyte Function and Innate Immunity In Vivo
Authors: Flick Matthew J. , Du Xinli , Degen Jay L.
Published: July 2017

In addition to its well-characterized role in hemostasis, fibrin(ogen) has been proposed to be a central regulator of the inflammatory response. Multiple in vitro studies have demonstrated that this hemostatic factor can alter leukocyte function, including cell adhesion, migration, cytokine and chemokine expression, degranulation, and other specialized processes. One important link between fibrin(ogen) and leukocyte biology appears to be the integrin receptor αMβ2/Mac-1, which binds to immobilized fibrin(ogen) and regulates leukocyte activities. Although it is well established that fibrin(ogen) is a ligand for αMβ2, the precise molecular determinants that govern this interaction are only now becoming clear. A novel line of mice expressing a mutant form of fibrinogen (Fibγ390_396A) has revealed that γ chain residues 390–396 are important for the high-affinity engagement of fibrinogen by αMβ2and leukocyte unction in vivo. Fibrinogen γ390–396Afailed to support αMβ2-mediated adhesion of primary neutrophils, monocytes, and macrophages, and mice expressing this fibrinogen variant were found to exhibit a major defect in the host inflammatory response following acute challenges. Most notably, Fibγ390–396Amice display a profound impediment in Staphylococcus aureus elimination by leukocytes following intraperitoneal inoculation. These findings have positively established the physiological importance of fibrin(ogen) as a ligand for αMβ2and illustrate that the fibrin(ogen) γ chain residues 390–396 constitute a critical feature of the αMβ2binding motif. Finally, the Fibγ390–396Amice represent a valuable system for better defining the contribution of fibrin(ogen) to the inflammatory response in the absence of any confounding alteration in clotting function.
Mammalian Septin Function in Hemostasis and Beyond
Authors: Martinez Constantino , Ware Jerry
Published: July 2017

Interest in the biology of mammalian septin proteins has undergone a birth in recent years. Originally identified as critical for yeast budding throughout the 1970s, the septin family is now recognized to extend from yeast to humans and is associated with a variety of events ranging from cytokinesis to vesicle trafficking. An emerging theme for septins is their presence at sites where active membrane or cytoplasmic partitioning is occurring. Here, we briefly review the mammalian septin protein family and focus on a prototypic human and mouse septin, termed SEPT5, that is expressed in the brain, heart, and megakaryocytes. Work from neurobiology laboratories has linked SEPT5 to the exocytic complex of neurons, with implications that SEPT5 regulates neurotransmitter release. Striking similarities exist between neurotransmitter release and the platelet-release reaction, which is a critical step in platelet response to vascular injury. Work from our laboratory has characterized the platelet phenotype from mice containing a targeted deletion of SEPT5. Most strikingly, platelets from SEPT5null animals aggregate and release granular contents in response to subthreshold levels of agonists. Thus, the characterization of a SEPT5-deficient mouse has linked SEPT5 to the Platelet exocytic process and, as such, illustrates it as an important protein for regulating platelet function. Recent data suggest that platelets contain a wide repertoire of different septin proteins and assemble to form macromolecular septin complexes. The mouse platelet provides an experimental framework to define septin function in hemostasis, with implications for neurobiology and beyond.
Mounting Evidence for Vitamin D as an Environmental Factor Affecting Autoimmune Disease Prevalence
Authors: Cantorna Margherita T. , Mahon Brett D.
Published: July 2017

Low vitamin D status has been implicated in the etiology of autoimmune diseases such as multiple sclerosis, rheumatoid arthritis, insulin-dependent diabetes mellitus, and inflammatory bowel disease. The optimal level of vitamin D intake required to support optimal immune function is not known but is likely to be at least that required for healthy bones. Experimentally, vitamin D deficiency results in the increased incidence of autoimmune disease. Mechanistically, the data point to a role for vitamin D in the development of self-tolerance. The vitamin D hormone (1,25-dihydroxy vitamin D3) regulates T helper cell (Th1) and dendritic cell function while inducing regulatory T-cell function. The net result is a decrease in the Th1-driven autoimmune response and decreased severity of symptoms. This review discusses the accumulating evidence pointing to a link between vitamin D and autoimmunity. Increased vitamin D intakes might decrease the incidence and severity of autoimmune diseases and the rate of bone fracture.
The Effect of Purified Compared with Nonpurified Diet on Bone Changes Induced by Hindlimb Suspension of Female Rats
Authors: Tou Janet C. L. , Arnaud Sara B. , Grindeland Richard , Wade Charles
Published: July 2017

The purpose of this study was to compare the bone changes induced by unloading in rats fed different diets, because space flight studies use a semipurified diet, whereas space flight simulation studies typically use nonpurified diets. Female Sprague-Dawley rats were fed a purified American Institute of Nutrition (AIN) 93G diet or a standard nonpurified diet and kept ambulatory or subjected to unloading by hindlimb suspension (HLS) for 38 days. Bone mineral content (BMC), mechanical strength, and factors related to the diet that affect bone (i.e., urinary calcium excretion, estradiol, and corticosterone) were measured. Average food intakes (grams per day) differed for diets, but caloric intake (kilocalories per day) and the final body masses of treatment groups were similar. The HLS-induced decrease in femoral BMC was not statistically different for rats fed a nonpurified diet (–8.6%) compared with a purified AIN-93G diet (–11.4%). The HLS-induced decrease in femoral mechanical strength was not statistically different for rats fed a nonpurified diet (–24%) compared with a purified AIN-93G diet (–31%). However, bone lengths were decreased (P < 0.05) in rats fed a nonpurified diet compared with a purified diet. Plasma estradiol levels were lower (P < 0.05) in the HLS/AIN-93G group but similar in the HLS and ambulatory rats fed a nonpurified diet. Plasma estradiol was related to femoral BMC (r = 0.85, P < 0.01). Urinary calcium excretion was higher (P < 0.05) in rats fed a nonpurified diet than those fed a purified AIN-93G diet, which is consistent with the higher level of calcium in the nonpurified diet. Urinary corticosterone levels were higher (P < 0.05) in rats fed a nonpurified diet than rats fed the AIN-93G diet. Although the osteopenia induced by unloading was similar in both diet groups, there were differences in longitudinal bone growth, calcium excretion, plasma estradiol levels, and urinary corticosterone levels. Results indicate that the type of standard diet used is an important factor to consider when measuring bone end points.
Introduction
Authors: Ikehara Susumu
Published: July 2017

In the last decade, remarkable advances have been made in bone marrow transplantation (BMT), which is now becoming a powerful strategy in the treatment of various intractable diseases, such as leukemia, aplastic anemia, congenital immunodeficiency, and autoimmune diseases.

This is a collection of the abstracts presented at the Symposium. The Symposium focused on the development of new strategies (including gene therapy) for the treatment of intractable diseases, such as autoimmune diseases and cancer, using bone marrow cells and ES cells.

The Organizing Committee believes that this collection of abstracts will provide new insights into hematopoietic stem cells, mesenchymal stem cells, ES cells, virus infection, gene regulation and gene therapy, and BMT.
Modulation of p-Glycoprotein Transport Function at the Blood-Brain Barrier
Authors: Bauer Björn , Hartz Anika M. S. , Fricker Gert , Miller David S.
Published: July 2017

The central nervous system (CNS) effects of many therapeutic drugs are blunted because of restricted entry into the brain. The basis for this poor permeability is the brain capillary endothelium, which comprises the blood-brain barrier. This tissue exhibits very low paracellular (tight-junctional) permeability and expresses potent, multispecific, drug export pumps. Together, these combine to limit use of pharmacotherapy to treat CNS disorders such as brain cancer and bacterial or viral infections. Of all the xenobiotic efflux pumps highly expressed in brain capillary endothelial cells, p-glycoprotein handles the largest fraction of commonly prescribed drugs and thus is an obvious target for manipulation. Here we review recent studies focused on understanding the mechanisms by which p-glycoprotein activity in the blood-brain barrier can be modulated. These include (i) direct inhibition by specific competitors, (ii) functional modulation, and (iii) transcriptional modulation. Each has the potential to specifically reduce p-glycoprotein function and thus selectively increase brain permeability of p-glycoprotein substrates.
γ-Tocotrienol Inhibits Neoplastic Mammary Epithelial Cell Proliferation by Decreasing Akt and Nuclear Factor κB Activity
Authors: Shah Sumit J. , Sylvester Paul W.
Published: July 2017

Tocotrienols, a subgroup within the vitamin E family of compounds, have been shown to display potent anticancer activity and inhibit preneoplastic and neoplastic mammary epithelial cell proliferation at treatment doses that have little or no effect on normal cell growth and function. However, the specific intracellular mechanisms mediating the antiproliferative effects of tocotrienols are presently unknown. Because Akt and nuclear factor κB (NFκB) are intimately involved in mammary tumor cell proliferation and survival, studies were conducted to determine the effects of γ-tocotrienol on Akt and NFκB activity in neoplastic +SA mammary epithelial cells in vitro. Treatment with 0–8 μM γ-tocotrienol for 0–3 days caused a dose-responsive inhibition in +SA cell growth and mitotic activity, as determined by MTT colorimetric assay and proliferating cell nuclear antigen immunocytochemical staining, respectively. Studies also showed that treatment with 4 μM γ-tocotrienol, a dose that inhibited +SA cell growth by more than 50% compared with that of untreated control cells, decreased intracellular levels of activated phosphotidylinositol 3-kinase-dependent kinase (PI3K)-dependent kinase 1 (phospho-PDK-1) and Akt, and reduced phospho-Akt kinase activity. Furthermore, these effects were not found to be associated with an increase in either phosphatase and tensin homologue deleted from chromosome 10 (PTEN) or protein phosphatase type 2A phosphatase activity. In addition, γ-tocotrienol treatment was shown to decrease NFκB transcriptional activity, apparently by suppressing the activation of IκB-kinase-α/β, an enzyme associated with inducing NFκB activation, in summary, these findings demonstrate that the antiproliferative effects of γ-tocotrienol result, at least in part, from a reduction in Akt and NFκB activity in neoplastic +SA mammary epithelial cells.
Serum Leptin in Nonpregnant and Pregnant Women and in Old and New World Nonhuman Primates
Authors: Castracane V. Daniel , Hendrickx Andrew G. , Henson Michael C.
Published: July 2017

Leptin is a hormone that is produced during mammalian pregnancy in the placental trophoblast and other tissues, including! fetal and maternal adipocytes. Synthesis of the polypeptide and the presence of its specific receptors throughout the human maternal fetoplacental unit suggest direct effects on conceptus growth and development. However, both the physiologic roles of leptin and the mechanisms regulating leptin synthesis in human pregnancy differ from those in laboratory and domestic species, necessitating the development of nonhuman primate research models. Therefore, we compared serum leptin concentrations in nonpregnant and pregnant women with those in both old world nonhuman primates (i.e., baboon, rhesus monkey, cynomolgus monkey) and new world nonhuman primates (i.e., squirrel monkey, titi monkey). As expected, maternal leptin levels were elevated in human and baboon pregnancies (P < 0.05 and P < 0.001, respectively). Levels in both species of old world monkeys were also greatly enhanced (P < 0.001). Although maternal serum concentrations were slightly elevated compared to nonpregnant levels in both species of new world monkeys, overall concentrations were dramatically lower than for either old world primates or humans. Results provide comparisons of serum leptin concentrations in pregnant and nonpregnant humans and baboons with those in both old and new world monkeys and further characterize these nonhuman primates as models for the investigation of leptin dynamics in pregnancy.
Differential Response to DNA Damage May Explain Different Cancer Susceptibility Between Small and Large Intestine
Authors: Hong Mee Young , Turner Nancy D. , Carroll Raymond J. , Chapkin Robert S. , Lupton Joanne R.
Published: July 2017

Although large intestine (LI) cancer is the second-leading cause of cancer-related deaths in the United States, small intestine (SI) cancer is relatively rare. Because oxidative DNA damage is one possible initiator of tumorigenesis, we investigated if the SI is protected against cancer because of a more appropriate response to oxidative DNA damage compared with the LI. Sixty rats were allocated to three treatment groups: 3% dextran sodium sulfate (DSS, a DNA-oxidizing agent) for 48 hrs, withdrawal (DSS for 48 hrs + DSS withdrawal for 48 hrs), or control (no DSS). The SI, compared with the LI, showed greater oxidative DNA damage (P < 0.001) as determined using a quantitative immunohistochemical analysis of 8-oxodeoxyguanosine (8-oxodG). The response to the DNA adducts in the SI was greater than in the LI. The increase of TdT–mediated dUTP-biotin nick end labeling (TUNEL)-positive apoptosis after DSS treatment was greater in the SI compared with the LI (P < 0.001), and there was a positive correlation (P = 0.031) between DNA damage and apoptosis in the SI. Morphologically, DSS caused an extensive loss of crypt structure shown in lower crypt height (P = 0.006) and the number of intact crypts (P = 0.0001) in the LI, but not in the SI. These data suggest that the SI may be more protected against cancer by having a more dynamic response to oxidative damage that maintains crypt morphology, whereas the response of the LI makes it more susceptible to loss of crypt architecture. These differential responses to oxidative DNA damage may contribute to the difference in cancer susceptibility between these two anatomic sites of the intestine.