bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth hormone upregulates intestinal trefoil factor expression in the ileum of rats after γ-radiation
Authors: Posadas Sinforiano J , Largo Carlota , Merino Jose J , Elvira Marcos , Gonzalez Gonzalo , Caz Victor , Caballero Isabel , De Miguel Enrique
Published: April 2011

Growth hormone (GH) and intestinal trefoil factor (ITF) have been involved in intestinal protection and repair. This study investigates the effects of GH administration on ITF expression and histological changes associated with tissue injury in an intestinal rat model of radiation. Adult male rats were divided into four groups: control, GH, radiation and radiation + GH (GHyRAD). Ileum samples were obtained at 2 or 72 h after radiation and processed to determine ITF levels (mRNA and protein) by quantitative polymerase chain reaction, Western blot and immunohistochemistry. In addition, goblet ITF-positive cells were identified by immunohistochemistry at 72 h. Our results showed an upregulation of mRNA and protein production of ITF in ileum samples after GH and radiation + GH compared with control and irradiated samples. Irradiation alone affected ITF protein expression. However, irradiation after GH pretreatment produced the highest ITF mRNA and protein levels at both the tested time points. ITF-producing goblet cells were identified in intestinal villi (apical location). GH treatment increased the number of ITF-producing goblet cells, and radiation after GH treatment displayed further increase in the number of ITF-positive goblet cells. GH upregulates ITF in normal intestinal tissue. This upregulation is higher when radiation is given after GH treatment. Nevertheless, the mechanism by which GH regulates ITF expression remains unclear and is still under investigation. These results could open up new avenues in the therapeutic reparative and protective effects of GH during radiotherapy and chemotherapy.
The tissue and plasma concentration of polyols and sugars in sheep intrauterine growth retardation
Authors: Regnault Timothy R H , Teng Cecilia , de Vrijer Barbra , Galan Henry L , Wilkening Randall B , Battaglia Frederick C
Published: April 2011

In an ovine model of placental insufficiency-induced intrauterine growth retardation (PI-IUGR), characterized by hypoxia, hypoglycemia and a significant reduction in fetal weight, we assessed alterations in fetal and placental polyols. Arterial maternal–fetal concentration differences of glucose and mannose were greater in the PI-IUGR fetus; glucose: C ( n = 7), 2.68 ± 0.14 mmol/L versus PI-IUGR ( n = 9), 3.18 ± 0.16 mmol/L ( P < 0.02) and mannose: C, 42.9 ± 8.1 μmol/L versus PI-IUGR, 68.5 ± 19.1 μmol/L ( P < 0.001). For PI-IUGR fetuses, fetal arterial plasma myo-inositol concentrations were significantly increased ( P < 0.001). The concentrations of sorbitol, glucose and fructose were significantly reduced ( P < 0.03, 0.01, 0.02, respectively). The cotyledons of IUGR placentas had a significantly increased concentration of myo-inositol ( P < 0.003) and decreased concentrations of sorbitol, fructose and glycerol ( P < 0.01, 0.02, 0.01, respectively). Fetal hepatic concentrations of sorbitol ( P < 0.001) and fructose ( P < 0.03) were also significantly reduced. These profound changes in both placental and fetal concentrations of polyols and sugars in sheep PI-IUGR pregnancies support the conclusion that within the PI-IUGR placenta there is an increased flux through the glucose 6-P:inositol 1-P cyclase system and decreased flux through the polyol dehydrogenase system, leading to increased placental myo-inositol production and decreased sorbitol production. The decreased placental supply of sorbitol to the fetal liver may lead to decreased fetal hepatic fructose production. These observations highlight that, in association with hypoxic and hypoglycemic PI-IUGR fetuses, there are major placental and fetal alterations in polyol production. The manner in which these alterations in fetoplacental carbohydrate metabolism contribute to the pathophysiology of PI-IUGR is currently unknown.
2-Aminoethoxydiphenyl borate, a inositol 1,4,5-triphosphate receptor inhibitor, prevents atrial fibrillation
Authors: Xiao Junjie , Liang Dandan , Zhao Hong , Liu Ying , Zhang Hong , Lu Xiaowei , Liu Yi , Li Jun , Peng Luying , Chen Yi-Han
Published: April 2011

The expression of the inositol 1,4,5-triphosphate receptor (IP3R) is upregulated and the function of IP3R also increases during atrial fibrillation (AF). 2-Aminoethoxydiphenyl borate (2-APB) is a membrane-permeable inhibitor of IP3R. However, the effect of 2-APB on AF is unknown. The aim of the present study is to explore the effects of 2-APB on AF. In vitro rabbit heart models of ischemia-, stretch- and cholinergic agitation-induced AF were developed. Fura-2-acetoxymethyl (Fura-2-AM) and Mg2+-Fura-2-AM were used to monitor alterations of intracellular Ca2+ and ATP, respectively, in HL-1 cells, an atrial muscle cell line, under chemical ischemia or cholinergic agitation. The results showed that inhibition of IP3R significantly reduced the incidence and its probability of being sustained in all three types of AF. IP3R inhibition ameliorated the cytoplasmic Ca2+ overload and energy compromise resulting from chemical ischemia or cholinergic agitation. Thus, IP3R inhibition may be a novel target for AF treatment, and IP3R may be an important molecule in the context of different kinds of AF.
Effect of noble gases on oxygen and glucose deprived injury in human tubular kidney cells
Authors: Rizvi Maleeha , Jawad Noorulhuda , Li Yuantao , Vizcaychipi Marcela P , Maze Mervyn , Ma Daqing
Published: April 2011

The noble gas xenon has been shown to be protective in preconditioning settings against renal ischemic injury. The aims of this study were to determine the protective effects of the other noble gases, helium, neon, argon, krypton and xenon, on human tubular kidney HK2 cells in vitro. Cultured human renal tubular cells (HK2) were exposed to noble gas preconditioning (75% noble gas; 20% O2; 5% CO2) for three hours or mock preconditioning. Twenty-four hours after gas exposure, cell injury was provoked with oxygen–glucose deprived (OGD) culture medium for three hours. Cell viability was assessed 24 h post-OGD by a 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay. Other cohorts of cultured cells were incubated in the absence of OGD in 75% noble gas, 20% O2and 5% CO2and cellular signals phospho-Akt (p-Akt), hypoxia-inducible factor-1 α (HIF-1 α) and Bcl-2 were assessed by Western blotting. OGD caused a reduction in cell viability to 0.382 ± 0.1 from 1.0 ± 0.15 at control ( P < 0.01). Neon, argon and krypton showed no protection from injury (0.404 ± 0.03; 0.428 ± 0.02; 0.452 ± 0.02; P > 0.05). Helium by comparison significantly enhanced cell injury (0.191 ± 0.05; P < 0.01). Xenon alone exerted a protective effect (0.678 ± 0.07; P < 0.001). In the absence of OGD, helium was also detrimental (0.909 ± 0.07; P < 0.01). Xenon caused an increased expression of p-Akt, HIF-1 α and Bcl-2, while the other noble gases did not modify protein expression. These results suggest that unlike other noble gases, preconditioning with the anesthetic noble gas xenon may have a role in protection against renal ischemic injury.
Impact of far-infrared ray exposure on the mechanical properties of unwounded skin of rats
Authors: Yang Cheng-San , Yeh Cheng-Hsin , Tung Chun-Liang , Chen Meng-Yi , Jiang Cheng-Hsiang , Yeh Ming-Long
Published: April 2011

Far-infrared ray (FIR) has been applied to promote growth, modulate sleep, speed up the healing of wounds and accelerate microcirculation. The action of FIR on wounds has been well established in previous studies. However, whether the same action also works on normal skin is unclear. Therefore, the aim of this study was to evaluate the impact of FIR exposure on the tensile strength (TS) and composition of unwounded skin. In this study, 84 Sprague–Dawley (SD) rats were randomly divided into control and FIR groups. The dorsum samples were harvested for mechanical testing and histological observation at one, two, four and six weeks. The TS in the control group had no significant difference for all durations. However, a steep increase in the TS occurred between one and two weeks ( P = 0.033) in the FIR group. The TS in the FIR group was found to be significantly higher than the TS in the control group at two weeks ( P = 0.049). From histological observation, capillary dilation and increased inflammatory cells around the capillaries were observed at one week in FIR-treated groups. However, the mild inflammatory changes vanished after two weeks. In conclusion, our results showed that FIR may induce inflammatory changes and enhance skin TS in the short term, but the effect diminished with time.
Lactobacillus plantarum strain No. 14 reduces adipocyte size in mice fed high-fat diet
Authors: Takemura Naoki , Okubo Takuma , Sonoyama Kei
Published: April 2011

Because gut microbiota has recently attracted much attention as an environmental factor involved in the development of obesity, probiotics may be useful in preventing and/or improving obesity and its related disorders. The present study aimed to investigate the effects of Lactobacillus plantarum strain No. 14 (LP14), a bacterial strain reported to decrease body fat percentage in healthy volunteers, on adipocyte size in mice. Female C57BL/6 mice were fed either normal- or high-fat diet and administered intragastrically with LP14 (1 × 108 colony-forming units/mouse) or vehicle daily for 11 weeks. High dietary fat intake increased body weight gain, white adipose tissue weight, mean adipocyte size and serum total cholesterol and leptin concentrations, and decreased serum adiponectin concentration. In mice fed the high-fat diet, LP14 administration significantly reduced the mean adipocyte size and tended to reduce the white adipose tissue weight and serum total cholesterol and leptin concentrations as compared with the vehicle-administered mice. All mice had undetectable serum levels of conjugated linoleic acids that reportedly exert antiobesity action. In a separate experiment, LP14 ingestion had no influence on serum triacylglycerol accumulation following olive oil administration in Triton WR1339-treated mice, suggesting that dietary fat absorption is unaffected by LP14. In conclusion, we propose that LP14 may exert a beneficial effect on the onset of diet-induced obesity by reducing the cell size of white adipose tissues, and it seems unlikely that previously reported mechanisms for other bacterial strains are involved in the action of LP14.
Smurf1 ubiquitin ligase causes downregulation of BMP receptors and is induced in monocrotaline and hypoxia models of pulmonary arterial hypertension
Authors: Murakami Koko , Mathew Rajamma , Huang Jing , Farahani Reza , Peng Hong , Olson Susan C , Etlinger Joseph D
Published: April 2011

Reduced bone morphogenetic protein (BMP) receptor (BMPR) expression and BMP signaling have been implicated in vascular cell proliferation and remodeling associated with pulmonary arterial hypertension (PAH). The low penetrance of the BMPR II disease gene in familial PAH suggests that additional genetic or environmental factors are involved in clinical manifestation of PAH. Smurf1 ubiquitin ligase, together with inhibitory SMAD 6/7, forms a negative feedback loop for the attenuation of BMP signals by downregulating BMPR and signaling molecules and, in addition, functions in the integration of MAPK/Ras mitogenic pathways. The present study found that Smurf1 was significantly elevated in pulmonary arteries of monocrotaline and hypoxia-induced PAH rats. In the pulmonary artery of hypoxia-exposed mice, elevation of Smurf1 and SMAD7 was correlated with reduced expression of BMPR II protein. Over-expression of Smurf1 in cultured cells induced ubiquitination and degradation of BMPR I and II whereas ligase-inactive Smurf1 reduced ubiquitination and elevated their protein levels, thus serving a dominant-negative function. Smurf1-induced receptor degradation was inhibited by both proteasomal and lysosomal inhibitors. Thus, Smurf1 reduces steady-state levels of BMPRs by ubiquitination and subsequent degradation involving proteasomes and lysosomes. Therefore, these results show that Smurf1 induction could be a key event for triggering downregulation of BMP signaling and causing vascular cell proliferation and remodeling in PAH and that abrogating Smurf1 function could be a strategy for PAH therapeutics.
Soluble uric acid increases intracellular calcium through an angiotensin II-dependent mechanism in immortalized human mesangial cells
Authors: Albertoni Guilherme , Maquigussa Edgar , Pessoa Edson , Barreto Jose Augusto , Borges Fernanda , Schor Nestor
Published: April 2011

Hyperuricemia is associated with increases in cardiovascular risk and renal disease. Mesangial cells regulate glomerular filtration rates through the release of hormones and vasoactive substances. This study evaluates the signaling pathway of uric acid (UA) in immortalized human mesangial cells (ihMCs). To evaluate cell proliferation, ihMCs were exposed to UA (6–10 mg/dL) for 24–144 h. In further experiments, ihMCs were treated with UA (6–10 mg/dL) for 12 and 24 h simultaneously with losartan (10−7 mmol/L). Angiotensin II (AII) and endothelin-1 (ET-1) were assessed using the enzyme-linked immunosorbent assay (ELISA) technique. Pre-pro-ET mRNA was evaluated by the real-time PCR technique. It was observed that soluble UA (8 and 10 mg/dL) stimulated cellular proliferation. UA (10 mg/dL) for 12 h significantly increased AII protein synthesis and ET-1 expression and protein production was increased after 24 h. Furthermore, UA increased [Ca2+]i, and this effect was significantly blocked when ihMCs were preincubated with losartan. Our results suggested that UA triggers reactions including AII and ET-1 production in mesangial cells. In addition, UA can potentially affect glomerular function due to UA-induced proliferation and contraction of mesangial cells. The latter mechanism could be related to the long-term effects of UA on renal function and chronic kidney disease.
Beneficial effects of olmesartan, an angiotensin II receptor type 1 antagonist, in rats with dilated cardiomyopathy
Authors: Sukumaran Vijayakumar , Watanabe Kenichi , Veeraveedu Punniyakoti T , Thandavarayan Rajarajan A , Gurusamy Narasimman , Ma Meilei , Yamaguchi Ken'ichi , Suzuki Kenji , Kodama Makoto , Aizawa Yoshifusa
Published: April 2011

Favorable effects of angiotensin II type 1 receptor blockers on patients with ischemic or idiopathic dilated cardiomyopathy (DCM) have already been suggested by several human trials, but their effects on DCM remain unknown. Hence, we investigated the effect of olmesartan on myocardial remodeling in a rat model in which myosin-induced experimental autoimmune myocarditis (EAM) might develop into DCM. EAM was elicited in Lewis rats by immunization with cardiac myosin, and 28 d after immunization, the surviving Lewis rats were divided into two groups and treated with either olmesartan (10 mg/kg/d) or vehicle. Age-matched normal rats without immunizations were also used. After four weeks of treatment, we investigated the effects of olmesartan on cardiac function, inflammatory cytokines and cardiac remodeling in EAM rats. Myocardial functional parameters measured by hemodynamic and echocardiographic analyses were significantly improved by the treatment with olmesartan compared with those of vehicle-treated rats. Olmesartan significantly reduced cardiac fibrosis as well as hypertrophy and its molecular markers (left ventricular [LV] mRNA expressions of transforming growth factor beta1, collagen-I and -III, and atrial natriuretic peptide) compared with those of vehicle-treated rats. Increased myocardial mRNA expressions of proinflammatory cytokines (interleukin [IL]-6, IL-1β), monocyte chemoattractant protein-1 and matrix metalloproteinases (MMP-2 and -9) were also suppressed by the treatment with olmesartan in rats with DCM. Further, the plasma level of angiotensin II was significantly increased in olmesartan-treated rats. These findings demonstrate that olmesartan treatment significantly improved LV function and ameliorated the progression of cardiac remodeling in rats with DCM after EAM.
Immunoglobulin M antiplatelet autoantibodies from mice immunized with rat platelets induce thrombocytopenia and platelet function impairment
Authors: Detalle Laurent , Su Dan , van Rooijen Nico , Coutelier Jean-Paul
Published: April 2011

Antiplatelet monoclonal autoantibodies (mAbs) were derived from CBA mice immunized with rat platelets. Two IgM antiplatelet mAbs were further analyzed. L1C43 mAb bound a 150–160 kDa antigen, recognized activated platelets better than resting ones and impaired platelet adhesion, but not clot retraction. L1H31 mAb recognized a ±95 kDa molecule, bound similarly activated and resting platelets and did not modify platelet adhesion, but inhibited clot retraction. Both mAbs induced in vivo thrombocytopenia most likely through phagocytosis of opsonized platelets. These autoreactive antibodies can thus induce both platelet destruction and impairment of their function. They are reflective of autoantibodies found in human patients and may serve for further analysis of antiplatelet autoantibody pathogenicity and mechanisms of autoimmune disease.
Nanoparticle-induced pulmonary toxicity
Authors: Li Jasmine Jia'en , Muralikrishnan Sindu , Ng Cheng-Teng , Yung Lin-Yue Lanry , Bay Boon-Huat
Published: April 2011

In recent decades, advances in nanotechnology engineering have given rise to the rapid development of many novel applications in the biomedical field. However, studies into the health and safety of these nanomaterials are still lacking. The main concerns are the adverse effects to health caused by acute or chronic exposure to nanoparticles (NPs), especially in the workplace environment. The lung is one of the main routes of entry for NPs into the body and, hence, a likely site for accumulation of NPs. Once NPs enter the interstitial air spaces and are quickly taken up by alveolar cells, they are likely to induce toxic effects. In this review, we highlight the different aspects of lung toxicity resulting from NP exposure, such as generation of oxidative stress, DNA damage and inflammation leading to fibrosis and pneumoconiosis, and the underlying mechanisms causing pulmonary toxicity.
Rice protein isolate improves lipid and glucose homeostasis in rats fed high fat/high cholesterol diets
Authors: Ronis Martin J , Badeaux Jamie , Chen Ying , Badger Thomas M
Published: April 2011

In order to understand the molecular mechanisms underlying effects of feeding rice protein on lipid and glucose homeostasis, weanling rats were fed AIN-93G diets made with casein or rice protein isolate (RPI) for 14 d. Peroxisome proliferator-activated receptor (PPAR) α genes and proteins involved in fatty acid degradation were upregulated by feeding RPI ( P < 0.05), accompanied by increased promoter binding and nuclear expression of PPAR α and its heterodimerization partner retinoid X receptor ( P < 0.05). Effects of RPI feeding on hepatic PPAR γ signaling were significant but less robust. Feeding RPI also increased hepatic genes involved in cholesterol metabolism and transport. However, feeding RPI had no effect on binding of liver X-receptor (LXR) α to the cytochrome P450 (CYP)7A1 promoter. The effect of RPI feeding on PPAR α signaling appeared to be direct and was reversed when RPI diets were switched to casein. In another experiment, male Sprague–Dawley rats were fed casein diets from postnatal day (PND) 24 to PND64 or were fed high fat ‘Western’ diets containing 0.5% cholesterol made with either casein or RPI. Increased liver triglyceride content, hypercholesterolemia and insulin resistance in the ‘Western’ diet-fed rats were partially prevented by feeding RPI ( P < 0.05). mRNA and protein expression of hepatic enzymes involved in fatty acid synthesis were suppressed by feeding ‘Western diets’ containing RPI ( P < 0.05), despite a lack of effects on nuclear concentrations of sterol regulatory element binding protein-1c. These data suggest that attenuation of metabolic syndrome observed in RPI-fed rats after consumption of diets high in fat and cholesterol occur as a result of improved lipid and glucose homeostasis partly as a result of activation of PPARs.
RD114 envelope proteins provide an effective and versatile approach to pseudotype lentiviral vectors
Authors: Bell Anthony J , Fegen David , Ward Maureen , Bank Arthur
Published: April 2011

Lentiviral vectors derived from the HIV-1 genome offer great promise for gene therapy due to their ability to transduce non-dividing cells and sustain long-term expression of transgenes. The majority of current lentiviral vectors are pseudotyped with the vesicular stomatitis viral envelope (VSV-G). VSV-G equips lentiviral vectors with a broad host cell tropism and increased stability. Increased particle stability enables viral supernatants to be concentrated by high-speed centrifugation to enhance their infectivity. Despite its efficacy, VSV-G is cytotoxic – a feature that prohibits the development of stable cell lines that constitutively express this envelope. Therefore, non-toxic envelope proteins are being investigated. RD114 is an attractive alternative because it also provides increased particle stability and its receptor is widely expressed on hematopoietic stem cells (HSCs). In this study, the packaging efficiency of three envelope proteins, RD114, RDpro and VSV-G, were evaluated with two lentiviral vectors (TRIP GFP and HPV-402). RDpro is an RD114-HIV chimera designed to pseudotype lentiviral vectors more efficiently. In transient systems, VSV-G generated titers of 108 and 107 viral particles/mL for TRIP GFP and HPV-402. RDpro possessed titers of 107 and 106, while RD114 titers were one log lower for each vector. Despite having relatively lower titers, RD114 proteins are less toxic; this was demonstrated in the extension of transient transfection reactions from 48 to 96 h. VSV-G transfections are generally limited to 48 h. In regard to gene therapy applications, we show that RDpro supernatants efficiently transduce peripheral blood HSCs. The versatility of RD114 envelopes was again demonstrated by using a ‘mixed’ expression system; composed of stably expressed RD114 envelope proteins to pseudotype lentiviral vectors generated in trans (titer range 103–105). Our data show that RD114 envelope proteins are effective and versatile constructs that could prove to be essential components of therapeutic lentiviral gene transfer systems.
Comparative analyses of differentially induced T-cell receptor-mediated phosphorylation pathways in T lymphoma cells
Authors: Ortiz Serina , Lee Wenhui , Smith David , Forman Stephen J , Lee Terry D , Liu Chih-Pin
Published: April 2011

Activation of T lymphoma cells expressing Syk, but not ZAP-70 tyrosine kinase, has been shown to negatively regulate cell activation and activation-induced cell death (AICD), perhaps due to differential induction of tyrosine phosphorylation modified proteins. To better understand the role of these proteins and their associated molecules/pathways, we studied a previously described model of T lymphoma cells expressing either a kinase-activated chimeric Syk or ZAP-70 genetically linked to T-cell receptor (TCR) ζ chain (Z/Syk or Z/ZAP cells, respectively). To help identify molecules and pathways linked to cell activation or AICD, a comparative semi-quantitative proteomics-based approach was utilized to analyze tyrosine-phosphorylated protein immunoprecipitates from two-minute short-term activated Z/Syk or Z/ZAP cells. Using the resulting bioinformatics data-sets, we identified several differentially immunoprecipitated proteins that could be validated biochemically. More tyrosine-phosphorylated and phosphotyrosine-associated proteins were found in Z/Syk than in Z/ZAP cells. Proteins involved in different unique functional pathways were induced in these cells and showed altered intermolecular interactions in varied pathways. Remarkably, 41% of differentially identified proteins in Z/Syk cells belonged to cell cycle or vesicle/trafficking pathways. In contrast, 21% of such proteins in Z/ZAP cells belonged to metabolism pathways. Therefore, molecular pathways involved in post-translational modifications linked to distinct cellular/physiological functions are differentially activated, which may contribute to varied activation and AICD responses of these cells. In summary, we identified proteins belonging to novel differentially activated pathways involved in TCR-mediated signaling, which may be targets for regulating activation and AICD of T lymphoma cells and for potential cancer therapy.
Dietary soy protein benefit in experimental kidney disease is preserved after isoflavone depletion of diet
Authors: Ogborn Malcolm R , Nitschmann Evan , Bankovic-Calic Neda , Weiler Hope A , Aukema Harold M
Published: April 2011

Soy diet ameliorates renal injury in the Han:SPRD- cy rat. The relative roles of protein, isoflavones and changes in polyunsaturated fatty acid (PUFA) status are not determined. We fed male Han:SPRD- cy heterozygotes casein (C), high isoflavone soy protein (HIS), alcohol-extracted low isoflavone soy protein (LIS) or mixed soy protein diet (MIS). LIS and MIS were associated with a small decrease in animal weight compared with HIS or C. Soy diets preserved normal renal function and reduced relative renal weight (10.9–14.6 g/kg, cf. 23.6, P < 0.001), scores for cystic change (0.168–0.239, cf. 0.386, P < 0.05), fibrosis (0.013–0.015, cf. 0.032, P < 0.05), tissue oxidized LDL content (0.012–0.021, cf. 0.048, P < 0.05), inflammation (8.5–12.9, cf. 31.2, P < 0.05) and epithelial cell proliferation (6.5–13.8, cf. 26.3, P < 0.05). In post hoc testing, LIS produced a greater reduction in relative renal weight, cystic change and epithelial proliferation, whereas HIS produced a significantly greater reduction in oxidized-LDL. Soy diets were associated with increased hepatic content of 18C PUFA ( P < 0.001). LIS and HIS diets were associated with a small increase in body fat content ( P < 0.001). Alcohol-extracted soy protein retains its major protective effects in this model with subtle differences attributable to isoflavones.
Vitamin D and host resistance to infection? Putting the cart in front of the horse
Authors: Bruce Danny , Ooi Jot Hui , Yu Sanhong , Cantorna Margherita T
Published: April 2011

Vitamin D is being touted as an anti-infective agent and it has even been suggested that vitamin D supplementation could be effective against the H1N1 influenza virus. The claims are largely based on the ability of vitamin D to induce antibacterial peptides and evidence that the immune system produces active vitamin D (1,25(OH)2D3) in situ. While there are many examples of immune production of 1,25(OH)2D3 in vitro, there is little in vivo evidence. In addition, it is not clear what role immune production of 1,25(OH)2D3 has on the course of disease. Vitamin D and 1,25(OH)2D3 inhibit T helper type 1 (Th1)/Th17-mediated immune responses and autoimmune diseases by acting on the innate and acquired immune system to inhibit the function of Th1 and Th17 cells. Th1 and Th17 cells are important in host resistance to many infections including tuberculosis (TB) caused by Mycobacterium tuberculosis. Paradoxically the innate immune system is induced to produce antibacterial peptides that are effective against TB in vitro. Data from several models of infection have so far not supported a role for vitamin D in affecting the course of disease. There is also very little evidence that vitamin D affects the course of human TB infection. Experiments have not been done in cells, mice or humans to evaluate the effect of vitamin D on influenza virus. At this time it would be premature to claim that vitamin D has an effect on TB, influenza or any other infection.
D225G mutation in hemagglutinin of pandemic influenza H1N1 (2009) virus enhances virulence in mice
Authors: Zheng Bojian , Chan Kwok-Hung , Zhang Anna J X , Zhou Jie , Chan Chris C S , Poon Vincent K M , Zhang Ke , Leung Virtual H C , Jin Dong-Yan , Woo Patrick C Y , Chan Jasper F W , To Kelvin K W , Chen Honglin , Yuen Kwok-Yung
Published: April 2011

Although the majority of infections by the pandemic influenza H1N1 (2009) virus is mild, a higher mortality occurs in young adults with no risk factors for complications. Some of these severe cases were infected by the virus with an aspartate to glycine substitution at 225 position (D225G, H3 numbering) in the hemagglutinin (HA). Previous studies with the highly virulent 1918 pandemic H1N1 virus suggested that such substitution was associated with a dual binding specificity of the virus for both α2,3- and α2,6-linked sialic acid receptors on host cells. Thus, the D225G mutant may cause more severe disease with its increased predilection for the lower respiratory tract, where the α2,3 sialic acid receptor is more prevalent, but this hypothesis has not been investigated. We obtained a mutant virus after four sequential passages in lungs of BALB/c mice with a wild-type pandemic influenza A H1N1 (2009) virus. One plaque purified mutant virus had a single non-synonymous D225G mutation in the HA gene. This mutant was more lethal to chick embryo and produced a viral load of about two log higher than that of the wild-type parental virus during the first 24 h. A pathogenicity test showed that the 50% lethal dose in mice (LD50) was reduced from over 2 × 106 plaque-forming units (PFU) with the parental virus to just 150 PFU with the mutant virus. The survival of mice challenged with the mutant virus was significantly decreased when compared with the parental virus ( P < 0.0001). Significantly higher viral titers and elevated proinflammatory cytokines in lung homogenates of mice infected with the mutant virus were found, which were compatible with severe histopathological changes of pneumonitis. The only consistent mutation in the genomes of viral clones obtained from dying mice was D225G substitution.
Exon-skipping brain natriuretic peptide variant is overexpressed in failing myocardium and attenuates brain natriuretic peptide production in vitro
Authors: Torrado Mario , Iglesias Raquel , Centeno Alberto , López Eduardo , Mikhailov Alexander T
Published: April 2011

Brain natriuretic peptide/natriuretic peptide precursor B (NPPB) is one of the most studied genes in relation to heart failure (HF) conditions. However, it is still unclear as to whether alternative splicing could create NPPB mRNA variants, which may be expressed in normal and diseased myocardium. We aimed to identify and characterize a novel alternatively spliced variant of porcine and human NPPB resulting from exon 2 skipping (designated as ΔE2-NPPB). A variety of conventional molecular, biochemical and immunochemical methods were used to examine the expression and functional consequences of ΔE2-NPPB in vitro and in vivo. The pig ΔE2-NPPB mRNA is effectively translated into stable protein in cell-based assays but, in contrast to normally spliced NPPB, the ΔE2-NPPB protein is not secreted into the media. Co-transfection assays demonstrate that ΔE2-NPPB attenuates production and secretion of normally spliced NPPB, suggesting a negative feedback loop of NPPB signaling through generation of ΔE2-NPPB. The inhibitory effects of ΔE2-NPPB on the expression of NPPB are associated with sequence elements residing in exon 3 of ΔE2-NPPB. In piglets, ΔE2-NPPB gene expression is downregulated in both ventricles after birth, but it is markedly re-activated in the postnatal myocardium in experimental diastolic heart failure. In addition, we demonstrate that the exon-skipped NPPB variants are expressed in the postnatal and adult human myocardium and upregulated at end-stage HF due to dilated cardiomyopathy. Our work uncovers an important role of alternative exon skipping in the regulation of NPPB gene expression, thereby pinpointing a putative new mechanism for post-transcriptional regulation of NPPB production and secretion.
Prognostic significance of cytoplasmic SOX9 in invasive ductal carcinoma and metastatic breast cancer
Authors: Chakravarty Geetika , Moroz Krzysztof , Makridakis Nick M , Lloyd Shelby Alaine , Galvez Sarah E , Canavello Peter R , Lacey Michelle R , Agrawal Krishna , Mondal Debasis
Published: April 2011

SOX9, a high mobility group (HMG) box transcription factor, is required for development, differentiation and lineage commitment. It is known to exert its effects through nuclear translocation, such as cell cycle changes in response to retinoic acid treatment in breast cancer cells. However, it is not known whether SOX9 has prognostic significance in human breast cancer. Over-expression and cytoplasmic sequestration of nuclear proteins are implicated in tumor progression. To determine whether SOX9 has any prognostic significance in human breast cancer, its expression and subcellular localization were analyzed in more than 200 human breast carcinomas (BCs). SOX9 mRNA expression data for human BCs were computed from microarray studies available in public databases and correlated with known poor prognostic parameters of BCs. SOX9 protein expression and its correlation with Ki-67 staining in human BCs were assessed using immunohistochemistry. Higher SOX9 mRNA levels were significantly associated with estrogen receptor negative ( P ≤ 0.001) and higher grade ( P ≤ 0.01) human breast tumors. Patients with higher SOX9 mRNA level had significantly shorter overall survival ( P ≤ 0.0001). SOX9 protein, which is normally nuclear, was instead localized in the cytoplasm of 25–30% invasive ductal carcinomas (IDCs) and lymph node metastases. Its cytoplasmic accumulation significantly correlated with enhanced proliferation in breast tumors (Kendall's tau = 0.337 with a P value < 0.0001). Cytoplasmic SOX9 can serve as a valuable prognostic marker for IDCs and metastatic breast cancer. Its significant correlation with breast tumor cell proliferation implies that SOX9 directly contributes to the poor clinical outcomes associated with invasive breast cancer.
Poly(ADP-ribose) polymerase inhibition modulates experimental acute necrotizing pancreatitis-induced oxidative stress, bacterial translocation and neopterin concentrations in rats
Authors: Yasar Mehmet , Uysal Bulent , Kaldirim Umit , Oztas Yesim , Sadir Serdar , Ozler Mehmet , Topal Turgut , Coskun Omer , Kilic Abdullah , Cayci Tuncer , Poyrazoglu Yavuz , Oter Sukru , Korkmaz Ahmet , Guven Ahmet
Published: April 2011

Various studies have been performed to find out novel treatment strategies for acute necrotizing pancreatitis (ANP). Inhibition of poly(ADP-ribose) polymerase (PARP) is shown to reduce inflammation in several pathological conditions. We aimed to evaluate the efficacy of benzamide, a PARP inhibitor, in an experimental model of ANP. Thirty Sprague–Dawley rats were divided into three groups: sham-operated, ANP and ANP + benzamide groups. All groups except the sham-operated group were subjected to the ANP procedure, induced by infusing of 1 mL/kg of 3% sodium taurocholate into the common biliopancreatic duct. The ANP + benzamide group received 100 mg/kg/day benzamide intraperitoneally for a total of three days after induction of pancreatitis. The surviving animals were killed at the fourth day and the pancreas was harvested for biochemical, microbiological and histological analysis. Blood samples were also obtained from the animals. In the ANP group, a significant increase was observed in concentrations of serum amylase and neopterin and tissue oxidative stress indices (malondialdehyde, superoxide dismutase and glutathione peroxidase). Almost all of these changes were found to be reversed to near their normal values in the ANP + benzamide group. Histological injury scores were significantly higher in the ANP group than in the sham group ( P < 0.05, ANP versus sham), and were significantly lower in the ANP + benzamide group than in the ANP group ( P < 0.05, ANP + benzamide versus ANP). Evaluation of bacterial translocation identified significantly fewer infected sites in the ANP + benzamide group than in the ANP animals ( P < 0.01). We observed that inhibition of PARP with benzamide reduced the severity, the mortality, the bacterial translocation rates and the neopterin concentrations in an experimental ANP model in rats. These findings suggest that it may be possible to improve the outcome of ANP by using PARP inhibitors.
In vivo angiogenesis imaging of solid tumors by αvβ3-targeted, dual-modality micellar nanoprobes
Authors: Kessinger Chase W , Khemtong Chalermchai , Togao Osamu , Takahashi Masaya , Sumer Baran D , Gao Jinming
Published: April 2011

The objective of this study was to develop and evaluate an αv β3-specific nanoprobe consisting of fluorescent superparamagnetic polymeric micelles (FSPPM) for in vivo imaging of tumor angiogenesis. Spherical micelles were produced using poly(ethylene glycol)- b-poly(d,l-lactide) co-polymers conjugated with tetramethylrhodamine, a fluorescent dye, and loaded with superparamagnetic iron oxide nanoparticles. The resulting micelle diameter was 50–70 nm by dynamic light scattering and transmission electron microscopy measurements. Micelles were encoded with an αv β3-specific peptide, cyclic RGDfK, and optimized for maximum fluorescence and targeting in αv β3-overexpressing cells in vitro. In mice, cRGD-FSPPM-treated animals showed αv β3-specific FSPPM accumulation in human lung cancer subcutaneous tumor xenografts. Together with the histological validation, the three-dimensional gradient echo magnetic resonance imaging (MRI) data provide high spatial resolution mapping and quantification of angiogenic vasculature in an animal tumor model using targeted, ultrasensitive MRI nanoprobes.
Vagal modulation of heart rate variability during atrial fibrillation in pigs
Authors: Kneip Christina F , Mallet Robert T , Williams Arthur G , Hamdan Mohamed H , Smith Michael L
Published: April 2011

Atrial fibrillation (AF) is the most common sustained cardiac dysrhythmia and is associated with an increased risk for sudden cardiac death. The ventricular rhythm is irregular and displays both non-linear and linear patterns; however, it has not been determined whether vagally derived patterns are manifest within the irregular rhythm. Moreover, indices of increased vagal control are associated with reduced risk of sudden cardiac death. In this study, we sought to determine whether the ventricular rhythm pattern during AF is, in part, modulated by vagal activity. Vagal oscillations were forced at 0.15 Hz by neck suction in 12 pigs with sustained AF with and without glycopyrrolate (0.15 μg/kg, intravenously) vagal blockade. Vagal activity was evaluated using time- and frequency-domain heart rate variability measures. The standard deviation of RR intervals (SDRRI) was significantly increased during vagal activation compared with baseline ( P = 0.006). Moreover, SDRRI correlated significantly with spectral power at 0.15 Hz during baseline ( r = 0.90, P < .001) and vagal activation ( r = 0.86, P < 0.05). Glycopyrrolate blocked the increase in SDRRI ( P < 0.001) and blunted spectral power at 0.15 Hz ( P < 0.05). These results indicate that: (1) power spectral analysis may be used to assess parasympathetic regulation during AF, and (2) vagal oscillations produce an entrainment of the ventricular rhythm during AF in pigs.
Vascular rhexis: loss of integrity of coronary vasculature in mice subjected to myocardial infarction
Authors: French Christopher J , Zaman A K M T , Kelm Robert J , Spees Jeffrey L , Sobel Burton E
Published: April 2011

We previously observed gross hemorrhage in plasminogen activator inhibitor type-1 (PAI-1) knockout (PKO) mice with induced myocardial infarction (MI). We hypothesized that it reflected degradation of vessels – a phenomenon we termed vascular rhexis. Accordingly, in the present study we characterized vascular rhexis in C57BL6 mice. MI was induced in 10- to 12-week-old mice by coronary artery ligation for 24, 48, 72 or 96 h. Hemorrhage was quantified by non-cross-reacting enzyme-linked immunosorbent assay of left ventricular (LV) hemoglobin corrected for myoglobin. Degradation of vasculature was quantified by the appearance of alpha smooth muscle actin ( αSMA) in low salt soluble fractions of LV homogenates (Western blotting) and by immunohistochemistry (residual αSMA). Co-staining for CD31 (endothelial cells) and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) (a marker of cell death) was used to identify capillary rhexis. PKO mice ( n = 9) had marked hemorrhage in infarct zones (432 ± 27 standard error of mean µL blood/g). Hemorrhage was evident in C57BL6 mice as well ( n = 6): 51 ± 8 μL/g LV 96 h after coronary occlusion compared with 10 ± 5 μL /g, n = 13 in normal LVs. Residual intact vasculature was reduced 48 h after infarction. Thus, an average of 16 ± 1.6 small- and medium-sized vessels ( n = 5 hearts) were seen compared with 84 ± 4.8 in normal LVs ( n = 3, P ≤ 0.05). An approximately three-fold increase in soluble αSMA 48 h after MI (2.68 ± 0.28, n = 6) was seen relative to that in normal LVs defined as 1.0 ± 0.04, n = 10, P ≤ 0.05. Capillary degradation was evident as well, as judged from CD31 and TUNEL co-localization. Vascular rhexis occurs within 48 h after the onset of MI. It may contribute to the early no-reflow phenomenon and to late negative LV remodeling.
In the nose of the beholder: are olfactory influences on human mate choice driven by variation in immune system genes or sex hormone levels?
Authors: Roberts Thomas , Roiser Jonathan P
Published: April 2011

The human leukocyte antigen (HLA) is the most polymorphic region of the genome, coding for proteins that mediate human immune response. This polymorphism may be maintained by balancing selection and certain populations show deviations from expected gene frequencies. Supporting this hypothesis, studies into olfactory preferences have suggested that females prefer the scent of males with dissimilar HLA to their own. However, it has also been proposed that androstenones play a role in female mate choice, and as these molecules inhibit the immune system, this has implications for the theory of HLA-driven mate preference. This review will critically analyze the findings of studies investigating olfactory preference in humans, and their implications for these two contrasting theories of mate choice.
Commonly consumed and specialty dietary mushrooms reduce cellular proliferation in MCF-7 human breast cancer cells
Authors: Martin Keith R , Brophy Sara K
Published: April 2011

Worldwide, over one million women will be newly diagnosed with breast cancer in the next year. Moreover, breast cancer is the second leading cause of cancer death in the USA. An accumulating body of evidence suggests that consumption of dietary mushrooms can protect against breast cancer. In this study, we tested and compared the ability of five commonly consumed or specialty mushrooms to modulate cell number balance in the cancer process using MCF-7 human breast cancer cells. Hot water extracts (80°C for 2 h) of maitake (MT, Grifola frondosa), crimini (CRIM, Agaricus bisporus), portabella (PORT, Agaricus bisporus), oyster (OYS, Pleurotus ostreatus) and white button (WB, Agaricus bisporus) mushrooms or water alone (5% v/v) were incubated for 24 h with MCF-7 cells. Cellular proliferation determined by bromodeoxyuridine incorporation was significantly ( P < 0.05) reduced up to 33% by all mushrooms, with MT and OYS being the most effective. MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) reduction, an often used mitochondrion-dependent marker of proliferation, was unchanged although decreased ( P > 0.05) by 15% with OYS extract. Lactate dehydrogenase release, as a marker of necrosis, was significantly increased after incubation with MT but not with other test mushrooms. Furthermore, MT extract significantly increased apoptosis, or programmed cell death, as determined by terminal deoxynucleotidyl end labeling method, whereas other test mushrooms displayed trends of ∼15%. The total numbers of cells per flask, determined by hemacytometry, were not different from control cultures. Overall, all test mushrooms significantly suppressed cellular proliferation, with MT further significantly inducing apoptosis and cytotoxicity in human breast cancer cells. This suggests that both common and specialty mushrooms may be chemoprotective against breast cancer.
Diamide decreases deformability of rabbit erythrocytes and attenuates low oxygen tension-induced ATP release
Authors: Sridharan Meera , Sprague Randy S , Adderley Shaquria P , Bowles Elizabeth A , Ellsworth Mary L , Stephenson Alan H
Published: April 2011

Exposure of erythrocytes to reduced oxygen (O2) tension activates the heterotrimeric G-protein Gi, resulting in the accumulation of cyclic AMP (cAMP) and release of ATP. The mechanism by which exposure of erythrocytes to reduced O2 tension activates Gi is not known. Here we investigate the hypothesis that, in rabbit erythrocytes, ATP release in response to exposure to reduced O2 tension is linked to erythrocyte membrane deformability. If this hypothesis is correct, then decreasing the deformability of the erythrocyte membrane should decrease the release of ATP in response to reduced O2 tension. We report that treating erythrocytes with diamide, a compound that decreases erythrocyte deformability, inhibits low O2 tension-induced ATP release. Treating erythrocytes with diamide does not, however, interfere with cAMP accumulation or ATP release in response to a direct activator of Gi (mastoparan 7) or in response to receptor-mediated activation of Gs (the prostacyclin analog, iloprost). These results demonstrate that diamide (100 μmol/L) does not directly inhibit the signaling pathways for ATP release from rabbit erythrocytes and support the hypothesis that low O2 tension-induced ATP release from these cells is linked to membrane deformability.
Molecular signaling of pruritus induced by endothelin-1 in mice
Authors: Liang Jiexian , Kawamata Tomoyuki , Ji Wenjin
Published: April 2011

Endothelin-1 (ET-1) has recently been identified to evoke pruritus/itching sensation in both humans and animals. It is most likely that the signaling is through the specific G-protein-coupled ETA and ETB receptors, but the downstream signaling mediators for ET-1 remain elusive. In the present study, we examined the potential involvement of several distinct signaling molecules in ET-1-induced pruritus in a murine model. We applied an in vivo pruritus model in C57BL/6J mice by injecting ET-1 intradermally into the scruff, and recording the number of scratching bouts within 30 min after injection. Then specific antagonists/inhibitors for distinct signaling molecules, including cell-surface ETA and ETB receptors, histamine receptor type 1 (H1 receptor), protein kinases A (PKA) and C (PKC), phospholipase C (PLC) or adenylyl cyclase (AC), were co-injected with ET-1. The results showed that ET-1 induced a vigorous scratching response in mice in a dose-dependent manner. This response was further enhanced by a specific antagonist for ETB receptor, BQ-788, reduced by a specific antagonist for ETA receptor, BQ-123, and not affected by mepyramine, the specific inhibitor for H1 receptor. In addition, the scratching response was significantly reduced by inhibitors for PKC and AC, but was significantly enhanced by PLC inhibitor, while PKA inhibitors showed no effects in the ET-1-induced scratching response. Our data suggested that ET-1 may signal through the ETA receptor, AC and PKC pathway to induce pruritus sensation, while ETB receptor and PLC may antagonize the pruritus evoked by ET-1. These results may provide a basis for the future development of antipruritic therapy.