Differential Expression of Vitreous Proteins in Young and Mature New Zealand White Rabbits

Different anatomical regions have been defined in the vitreous humor including central vitreous, basal vitreous, vitreous cortex, vitreoretinal interface and zonule. In this study we sought to characterize changes in the proteome of vitreous humor (VH) related to compartments or age in New Zealand white rabbits (NZW). Vitreous humor was cryo-collected from young and mature New Zealand white rabbit eyes, and dissected into anterior and posterior compartments. All samples were divided into 4 groups: Young Anterior (YA), Young Posterior (YP), Mature Anterior (MA) and Mature Posterior (MP) vitreous. Tryptic digests of total proteins were analyzed by liquid chromatography followed by tandem mass spectrometry. Spectral count was used to determine the relative protein abundances and identify proteins with statistical differences between compartment and age groups. Western blotting was performed to validate some of the differentially expressed proteins. Our results showed that 231, 375, 273 and 353 proteins were identified in the YA, YP, MA and MP respectively. Fifteen proteins were significantly differentially expressed between YA and YP, and 11 between MA and MP. Carbonic anhydrase III, lambda crystallin, alpha crystallin A and B, beta crystallin B1 and B2 were more abundant in the anterior region, whereas vimentin was less abundant in the anterior region. For comparisons between age groups, 4 proteins were differentially expressed in both YA relative to MA and YP relative to MP. Western blotting confirmed the differential expression of carbonic anhydrase III, alpha crystallin B and beta crystallin B2. The protein profiles of the vitreous humor showed age- and compartment-related differences. This differential protein profile provides a baseline for understanding the vitreous compartmentalization in the rabbit and suggests that further studies profiling proteins in different compartments of the vitreous in other species may be warranted.     

Effects of Dietary Supplementation with Vitamin C and Vitamin E and Their Combination on Growth Performance,Some Biochemical Parameters,and Oxidative Stress Induced by Copper Toxicity in Broilers

This study investigated effects of dietary supplementation with vitamin C, vitamin E on performance, biochemical parameters, and oxidative stress induced by copper toxicity in broilers. A total of 240, 1-day-old, broilers were assigned to eight groups with three replicates of 10 chicks each. The groups were fed on the following diets: control (basal diet), vitamin C (250 mg/kg diet), vitamin E (250 mg/kg diet), vitamin C + vitamin E (250 mg/kg?+?250 mg/kg diet), and copper (300 mg/kg diet) alone or in combination with the corresponding vitamins. At the 6th week, the body weights of broilers were decreased in copper, copper + vitamin E, and copper + vitamin C + vitamin E groups compared to control. The feed conversion ratio was poor in copper group. Plasma aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase activities, iron, copper concentrations, and erythrocyte malondialdehyde were increased; plasma vitamin A and C concentrations and erythrocyte superoxide dismutase were decreased in copper group compared to control. Glutathione peroxidase, vitamin C, and iron levels were increased; aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and copper levels were decreased in copper + vitamin C group, while superoxide dismutase, glutathione peroxidase, and vitamin E concentrations were increased; aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase were decreased in copper with vitamin E group compared to copper group. The vitamin C concentrations were increased; copper, uric acid, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and malondialdehyde were decreased in copper + vitamin C + vitamin E group compared to copper group. To conclude, copper caused oxidative stress in broilers. The combination of vitamin C and vitamin E addition might alleviate the harmful effects of copper as demonstrated by decreased lipid peroxidation and hepatic enzymes.     

The Effect of Fasting on Oxidative Stress in the Vital Organs of New Zealand White Rabbit

Background:Oxidative stress is defined as the condition in which balance between the synthesis and detoxification of reactive oxygen species in cells is disrupted. This research explored the effects of intermittent and prolonged fasting on malondialdehyde (MDA), carbonyl, reduced glutathione (GSH), and specific activity of catalase as biomarkers for oxidative stress in hearts, brains, and kidneys of New Zealand White (NZW) rabbits.Methods:Fifteen NZW rabbits were divided into control, intermittent fasting (IF), and prolonged fasting (PF) groups. The controls were fed ad lib. IF and PF groups were fasted for 16 and 40 hours, respectively, followed by eight hours of non-fasting, for six days and were sacrificed on the 7^th day. One hundred mg of heart, brain, and kidney tissues were homogenized in 1 ml of phosphate-buffered saline. MDA, carbonyl, GSH, and catalase were analyzed by spectrophotometry. Data were analyzed using One-way ANOVA and post hoc test.Results:In heart, MDA was significantly greater in the control than in the IF and PF groups. In brain, GSH was greater in the IF than in the PF and control groups. Also, in brain, catalase specific activity was significantly greater in the control than in the IF and PF groups. In kidney, catalase specific activity was significantly less in the PF than in the control group.Conclusion:The effect of fasting on oxidative stress in various organs showed various responses, however fasting reduced oxidative stress based on MDA and GSH levels in the heart and brain, respectively.Key Words: Fasting, Oxidative stress, Vital organs, Rabbit     

Effects of Dietary Supplementation with Glutamate and Aspartate on Diquat-Induced Oxidative Stress in Piglets

This study aimed to investigate the protective effects of dietary glutamate and aspartate supplementations on diquat-induced oxidative stress in piglets. Diquat injection significantly reduced growth performance, including body weight, average daily weight gain, and feed intake (P<0.05). Meanwhile, diquat administration induced oxidative stress evidenced by the decreased serum nitric oxide (NO) and elevated malondialdeyhde (MDA) concentration (P<0.05). Furthermore, diquat-induced oxidative stress disrupted intestinal absorption system and decreased serum threonine, serine, and glycine levels. Dietary supplementation with glutamate improved final body weight, antioxidant system, and expressions of amino acids transporters and enhanced serum glutamate concentration compared with diquat group (P<0.05). While aspartate failed to alleviate diquat-induced oxidative stress, growth depression, and dysfunction of nutrients absorption except for liver relative weight. In conclusion, dietary supplementation with glutamate confers beneficial effects on diquat-induced oxidative stress in piglets, while aspartate exhibits little effects.     

A Diet High in Saturated Fat and Sucrose Alters Glucoregulation and Induces Aortic Fatty Streaks in New Zealand White Rabbits

A new and convenient animal model for studying peripheral vascular and coronary artery disease in diabetes was established in this study. Male New Zealand White rabbits weighing approximately 2 kg were divided into 2 groups: a normal control group fed standard laboratory chow and a diabetogenic diet–fed group received a high-fat/high-sucrose diet. The high-fat/high-sucrose diet (contained 10% lard and 37% sucrose) feeding was maintained for 6 months. Plasma total cholesterol, high-density lipoprotein (HDL) cholesterol, triglyceride, superoxide dismutase, nitric oxide, nitric oxide synthase, insulin, and glucose were quantitated at monthly or bimonthly intervals. The aortic fatty streak lesions were quantified following lipid staining with Sudan IV. The aortic samples were observed by electron microscopy. High plasma triglyceride and glucose concentrations were induced. At the end of 6 months, the aortic fatty streak lesions were present in the animals'' vascular specimens. As far as we know, this is the first report that demonstrates that New Zealand White rabbits can develop obvious aortic fatty streaks by feeding a high-fat/high-sucrose diet. Our results suggest that NewZealand White rabbits fed a high-fat/high-sucrose diet would provide a convenient model for studying peripheral vascular and coronary artery disease in diabetes.     

Protection Against Oxidative Stress Caused by Intermittent Cold Exposure by Combined Supplementation with Vitamin E and C in the Aging Rat Hypothalamus

This study investigated the effects of combined supplementation with vitamin E and C against oxidative stress (OS) caused by intermittent cold exposure (ICE) in the hypothalamus (HY) of aging male Wistar rats [adult (3-months), middle-aged (18-months) and old (24-months)]. Each age was divided into sub-groups: control (CON), cold-exposed at 10 °C (C10), cold-exposed at 5 °C (C5), supplemented control (CON+S) and supplemented cold-exposed at either 5 °C (C5+S) or 10 °C (C10+S). The supplement was a daily dose of 400 mg vitamin C and 50 IU of vitamin E/kg body weight. Cold exposure lasted 2 h/day for 4 weeks. All age groups exposed to cold showed increase in body mass and feeding efficiency. Feeding efficiency in the supplemented old group showed a statistically significant increase in the cold (p < 0.001). Age-related increases in levels of hydrogen peroxide (H₂O₂), protein carbonyl (PrC), advanced oxidation protein products and thiobarbituric acid reactive substances (TBARS) were further increased by cold in the HY. Cold reduced thiol(P-SH) levels and increased superoxide dismutase (SOD) and, catalase (CAT) activities as well as Hsp72 levels. However, supplementation lowered H₂O₂, PrC and TBARS with decreases in Hsp72 levels and in SOD and CAT activities. These changes were concomitant with elevations in P-SH, vitamin E and C levels. The results show that the OS caused by ICE in the HY and its subsequent protection following supplementation is related to the intensity of ICE as well as age of the animal. Immunohistochemical studies are underway to examine the findings on ICE-induced oxidative injury in the HY, and the prospects for vitamin E and C supplementation in the senescent.     

Escherichia coli O157:H7 Infection in Dutch Belted and New Zealand White Rabbits

Enterohemorrhagic Escherichia coli (EHEC) produce one or more types of Shiga toxins and are foodborne causes of bloody diarrhea. The prototype EHEC strain, Escherichia coli O157:H7, is responsible for both sporadic cases and serious outbreaks worldwide. Infection with E. coli that produce Shiga toxins may lead to diarrhea, hemorrhagic colitis, or (less frequently) hemolytic uremic syndrome, which can cause acute kidney failure. The exact mechanism by which EHEC evokes intestinal and renal disease has not yet been determined. The development of a readily reproducible animal oral-infection model with which to evaluate the full pathogenic potential of E. coli O157:H7 and assess the efficacy of therapeutics and vaccines remains a research priority. Dutch belted (DB) rabbits are reported to be susceptible to both natural and experimental EHEC-induced disease, and New Zealand white (NZW) rabbits are a model for the intestinal manifestations of EHEC infection. In the current study, we compared the pathology caused by E. coli O157:H7 infection in DB and NZW rabbits. Both breeds of rabbits developed clinical signs of disease and intestinal lesions after experimental infection. In addition, one of the infected DB rabbits developed renal lesions. Our findings provide evidence that both breeds are susceptible to E. coli O157:H7 infection and that both may be useful models for investigating EHEC infections of humans.Abbreviations: EHEC, enterohemorrhagic E. coli; HUS, hemolytic uremic syndrome; DB, Dutch belted; STEC, Shiga-toxin– producing E. coli; NZW, New Zealand whiteEscherichia coli O157:H7 is the prototype enterohemorrhagic strain of Shiga-toxin–producing E. coli (STEC), which cause food and waterborne outbreaks and sporadic cases of serious intestinal disease that manifest as diarrhea or hemorrhagic colitis (or both).^12,13,31 Enterohemorrhagic E. coli (EHEC) are a subset of STEC that, in addition to elaborating Shiga toxins, encode the locus of enterocyte effacement, whose products allow intimate attachment of the bacteria to the epithelium.^16,19 Children infected with STEC are more susceptible than adults and may subsequently develop hemolytic uremic syndrome (HUS) that is characterized by hemolytic anemia, thrombocytopenia, and kidney dysfunction or failure.²⁹ Shiga toxins are considered to be major determinants involved in the pathogenesis of these E. coli-induced infections. Indeed, the capacity of STEC to cause bloody diarrhea and HUS derives from the activity of the Stx.^8,25,30,40 The 2 types of Shiga toxins, Stx1 and Stx2, are quite similar in sequence and structure, although their polyclonal antisera do not crossreact.^7,38,39,42A vaccine is currently not available to protect humans from infection or disease caused by STEC. There is a need to define the pathogenic mechanisms by which STEC cause disease and to develop strategies for the prevention and treatment of STEC-mediated HUS. Achieving this goal would benefit from a small animal model that displays gastroenteritis or signs of HUS similar to those occurring in humans. Naturally infected DB rabbits mimic the clinical and pathologic signs (including diarrhea, hemorrhagic colitis, and HUS) produced by STEC in humans.¹¹ In addition, infant NZW rabbits become infected with EHEC and subsequently exhibit diarrhea and hemorrhagic colitis.^20,28,34,36 The current study compared DB and NZW rabbits for breed-specific differences in response to E. coli O157:H7 infection.     

Differential Affinity and Catalytic Activity of CheZ in E. coli Chemotaxis

Push–pull networks, in which two antagonistic enzymes control the activity of a messenger protein, are ubiquitous in signal transduction pathways. A classical example is the chemotaxis system of the bacterium Escherichia coli, in which the kinase CheA and the phosphatase CheZ regulate the phosphorylation level of the messenger protein CheY. Recent experiments suggest that both the kinase and the phosphatase are localized at the receptor cluster, and Vaknin and Berg recently demonstrated that the spatial distribution of the phosphatase can markedly affect the dose–response curves. We argue, using mathematical modeling, that the canonical model of the chemotaxis network cannot explain the experimental observations of Vaknin and Berg. We present a new model, in which a small fraction of the phosphatase is localized at the receptor cluster, while the remainder freely diffuses in the cytoplasm; moreover, the phosphatase at the cluster has a higher binding affinity for the messenger protein and a higher catalytic activity than the phosphatase in the cytoplasm. This model is consistent with a large body of experimental data and can explain many of the experimental observations of Vaknin and Berg. More generally, the combination of differential affinity and catalytic activity provides a generic mechanism for amplifying signals that could be exploited in other two-component signaling systems. If this model is correct, then a number of recent modeling studies, which aim to explain the chemotactic gain in terms of the activity of the receptor cluster, should be reconsidered.     

Histomorphology of Seminal Vesicles Subsequent to Exogenous Neurokinin B Administration in New Zealand White Rabbits

International Journal of Peptide Research and Therapeutics - Neurokinin B exists as a member of tachykinin family, which is encoded by Tac3 gene and binds to Tac3R. Several studies have shown that...     

高糖高脂饮食对兔肾小管间质纤维化的影响

为研究高糖高脂饮食对新西兰兔(Oryctolagus cuniculus)肾小管间质纤维化的影响,将20只雄兔随机均分2组,分别喂正常饲料(对照组)和高糖高脂饲料(模型组),每月测空腹血糖和甘油三酯(TG),5个月后取尿液测尿糖、微量白蛋白(mAlb)和N-乙酰β-氨基葡萄糖苷酶(NAG),H.E、VG染色观察肾髓质病理改变,计算肾小管间质纤维化指数(TIFI)和胶原纤维面积,免疫组化测Ⅳ型胶原、纤维连接蛋白(FN)和转化生长因子β1(TGF-β1)的蛋白表达。结果显示,与对照组相比,模型组血糖、TG、尿糖、mAlb和NAG上升(P0.05或P0.01);肾小管间质肿胀,炎症细胞浸润,胶原纤维面积增加(22.47%±5.66%vs.9.43%±3.03%,P0.01),TIFI升高(2.369±0.6734vs.0.6810±0.2248,P0.01);Ⅳ型胶原、FN和TGF-β1的表达显著增加(P0.01)。上述结果说明,高糖高脂喂养兔5个月可导致肾小管、间质的结构和功能发生改变,细胞外基质表达增加,促进纤维化形成。     

Selenium and Vitamin E Modulates Cigarette Smoke Exposure-Induced Oxidative Stress in Blood of Rats

Cigarette smoke contains about 5,000 chemicals that include organic and metallic compounds. The current study was undertaken to investigate the effects of selenium and vitamin E on oxidative stress-induced damage in rats exposed to cigarette smoke. Forty male rats were equally divided into four groups. The first and second groups were used as control and cigarette smoke groups, respectively. Selenium was administered to rats constituting the third group for 27 days. The Se and vitamin E combination was given to animals in fourth group for 27 days. All groups except the control, were exposed to cigarette smoke starting at the third day of the experiment and continuing for 27 days. The blood samples from all groups were taken at the end of 27 days. Plasma lipid peroxidation, triacylglycerol, and total cholesterol levels were higher in the cigarette smoke group than in the control, although erythrocytic superoxide dismutase and glutathione peroxidase activities were lower in the cigarette smoke group than in the control. The plasma lipid peroxidation, triacylglycerol, and total cholesterol levels were lower in cigarette smoke+Se+VE group than in the cigarette smoke group, although erythrocytic superoxide dismutase activity and glutathione peroxidase activity in selenium and vitamin E-administered groups were higher than in the exposed to cigarette smoke group. High-density lipoprotein-cholesterol level was not affect by selenium and vitamin E administrations. In conclusion, selenium and vitamin E seem to have protective effects on the cigarette smoke-induced blood toxicity by supporting the enzymatic antioxidant redox systems.     

Saccharomyces cerevisiae: Population Divergence and Resistance to Oxidative Stress in Clinical,Domesticated and Wild Isolates

Background

Saccharomyces cerevisiae has been associated with human life for millennia in the brewery and bakery. Recently it has been recognized as an emerging opportunistic pathogen. To study the evolutionary history of S. cerevisiae, the origin of clinical isolates and the importance of a virulence-associated trait, population genetics and phenotypic assays have been applied to an ecologically diverse set of 103 strains isolated from clinics, breweries, vineyards, fruits, soil, commercial supplements and insect guts.

Methodology/Principal Findings

DNA sequence data from five nuclear DNA loci were analyzed for population structure and haplotype distribution. Additionally, all strains were tested for survival of oxidative stress, a trait associated with microbial pathogenicity. DNA sequence analyses identified three genetic subgroups within the recombining S. cerevisiae strains that are associated with ecology, geography and virulence. Shared alleles suggest that the clinical isolates contain genetic contribution from the fruit isolates. Clinical and fruit isolates exhibit high levels of recombination, unlike the genetically homogenous soil isolates in which no recombination was detected. However, clinical and soil isolates were more resistant to oxidative stress than any other population, suggesting a correlation between survival in oxidative stress and yeast pathogenicity.

Conclusions/Significance

Population genetic analyses of S. cerevisiae delineated three distinct groups, comprising primarily the (i) human-associated brewery and vineyard strains, (ii) clinical and fruit isolates (iii) and wild soil isolates from eastern U.S. The interactions between S. cerevisiae and humans potentiate yeast evolution and the development of genetically, ecologically and geographically divergent groups.     

Genetic Characterization and Role in Virulence of the Ribonucleotide Reductases of Streptococcus sanguinis

Streptococcus sanguinis is a cause of infective endocarditis and has been shown to require a manganese transporter called SsaB for virulence and O₂ tolerance. Like certain other pathogens, S. sanguinis possesses aerobic class Ib (NrdEF) and anaerobic class III (NrdDG) ribonucleotide reductases (RNRs) that perform the essential function of reducing ribonucleotides to deoxyribonucleotides. The accompanying paper (Makhlynets, O., Boal, A. K., Rhodes, D. V., Kitten, T., Rosenzweig, A. C., and Stubbe, J. (2014) J. Biol. Chem. 289, 6259–6272) indicates that in the presence of O₂, the S. sanguinis class Ib RNR self-assembles an essential diferric-tyrosyl radical (Fe^III₂-Y^•) in vitro, whereas assembly of a dimanganese-tyrosyl radical (Mn^III₂-Y^•) cofactor requires NrdI, and Mn^III₂-Y^• is more active than Fe^III₂-Y^• with the endogenous reducing system of NrdH and thioredoxin reductase (TrxR1). In this study, we have shown that deletion of either nrdHEKF or nrdI completely abolishes virulence in an animal model of endocarditis, whereas nrdD mutation has no effect. The nrdHEKF, nrdI, and trxR1 mutants fail to grow aerobically, whereas anaerobic growth requires nrdD. The nrdJ gene encoding an O₂-independent adenosylcobalamin-cofactored RNR was introduced into the nrdHEKF, nrdI, and trxR1 mutants. Growth of the nrdHEKF and nrdI mutants in the presence of O₂ was partially restored. The combined results suggest that Mn^III₂-Y^•-cofactored NrdF is required for growth under aerobic conditions and in animals. This could explain in part why manganese is necessary for virulence and O₂ tolerance in many bacterial pathogens possessing a class Ib RNR and suggests NrdF and NrdI may serve as promising new antimicrobial targets.     

Elements in Sera of Elite Taekwondo Athletes: Effects of Vitamin E Supplementation

Many researchers have emphasized the relation between nutrition and development and sustaining performance. Two methods are commonly employed to identify the interaction between physical activity and nutrition. The first consists of administering food with a variety of contents to people engaged in physical activity and observing their performance responses, and the other is concerned with determining the effects of physical activity on nutrition. Therefore, it can be said that there has been a growing interest in the explorations into the relation between exercise and vitamins, minerals, and elements. The present study reports the effects of 6 weeks administration of 300 mg/day vitamin E on the distribution of serum elements in elite taekwondo athletes. Seven male athletes, mean ages 22.1 ± 0.5 years weighing on average 66.4 ± 2.4 kg were included in the study. The athletes had been practicing taekwondo for 10–12 years. Resting blood samples were collected in duplicate before and after supplementation for determination of serum levels of cobalt, boron, cadmium, chromium, nickel, manganese, sulfur, copper, iron, zinc, phosphorus, sodium, potassium, and calcium. Supplementation resulted in significant increases of all elements relative to values before supplementation (p < 0.001), with the exception of boron and sulfur, which remained without change. The results of the present study demonstrate that vitamin E supplementation crucially influences the element and mineral metabolism in elite athletes.     

In Vitro Susceptibilities of Wild and Drug Resistant Leishmania donovani Amastigote Stages to Andrographolide Nanoparticle: Role of Vitamin E Derivative TPGS for Nanoparticle Efficacy

Visceral leishmaniasis (VL) is a chronic protozoan infection in humans associated with significant global morbidity and mortality. There is an urgent need to develop drugs and strategy that will improve therapeutic response for effective clinical treatment of drug resistant VL. To address this need, andrographolide (AG) nanoparticles were designed with P-gp efflux inhibitor vitamin E TPGS (D-α-tocopheryl polyethyleneglycol 1000 succinate) for sensitivity against drug resistant Leishmania strains. AG loaded PLGA (50∶50) nanoparticles (AGnps) stabilized by vitamin E TPGS were prepared for delivery into macrophage cells infested with sensitive and drug resistant amastigotes of Leishmania parasites. Physico-chemical characterization of AGnps by photon correlation spectroscopy exhibited an average particle size of 179.6 nm, polydispersity index of 0.245 and zeta potential of −37.6 mV. Atomic force microscopy and transmission electron microscopy visualization revealed spherical nanoparticles with smooth surfaces. AGnps displayed sustained AG release up to 288 hours as well as minimal particle aggregation and drug loss even after three months study period. Antileishmanial activity as revealed from selectivity index in wild-type strain was found to be significant for AGnp with TPGS in about one-tenth of the dosage of the free AG and one-third of the dosage of the AGnp without TPGS. Similar observations were also found in case of in vitro generated drug resistant and field isolated resistant strains of Leishmania. Cytotoxicity of AGnp with and without TPGS was significantly less than standard antileishmanial chemotherapeutics like amphotericin B, paromomycin or sodium stibogluconate. Macrophage uptake of AGnps was almost complete within one hour as evident from fluorescent microscopy studies. Thus, based on these observations, it can be concluded that the low-selectivity of AG in in vitro generated drug resistant and field isolated resistant strains was improved in case of AG nanomedicines designed with vitamin E TPGS.