Dietary Taurine Supplementation Ameliorates Diabetic Retinopathy via Anti-excitotoxicity of Glutamate in Streptozotocin-induced Sprague-Dawley Rats

The purpose of this study was to investigate whether taurine ameliorate the diabetic retinopathy, and to further explore the underlying mechanisms. The Sprague-Dawley rats were injected with streptozotocin to establish experimental diabetic model, then fed without or with 1.2% taurine for additional 4–12 weeks. After that, the protective effects of dietary taurine supplementation on diabetic retinopathy were estimated. Our results showed that chronic taurine supplement effectively improved diabetic retinopathy as changes of histopathology and ultrastructure. The supplementation could not lower plasma glucose concentration (P > 0.05), but caused an elevation in taurine content and a decline in levels of glutamate and γ-aminobutyric acid (GABA) in diabetic retina (P < 0.05). Moreover, chronic taurine supplementation increased glutamate transporter (GLAST) expression (P < 0.05), decreased intermediate filament glial fibrillary acidic protein (GFAP) and N-methyl-d-aspartate receptor subunit 1 (NR1) expression in diabetic retina (P < 0.05). These results demonstrated that chronic taurine supplementation ameliorates diabetic retinopathy via anti-excitotoxicity of glutamate in rats.     

Staurosporine Induces Astrocytic Phenotypes and Differential Expression of Specific PKC Isoforms in C6 Glial Cells

Abstract: In this study we examined the effects of staurosporine, a potent inhibitor of protein kinase C (PKC), on the differentiation of C6 glial cells and on the expression and cellular distribution of specific PKC isoforms. Staurosporine reduced cell proliferation and induced distinctive changes in the morphological appearance of the cells to that characteristic of cells exhibiting astrocytic phenotypes. The differentiative effect of staurosporine was further indicated by the increased expression of two proteins related to astrocytic phenotypes, glial fibrillary acidic protein (GFAP) and glutamine synthetase. Thus, staurosporine induced a dose-dependent increase both in GFAP immunoreactivity and in the activity and protein levels of glutamine synthetase. Staurosporine also induced a decrease in the expression of PKC-β₂ and an increase in that of PKC-γ. In addition, it induced translocation of PKC-ε from the membrane to the cytosol, whereas no differences were observed in the distribution of the other PKC isoforms. The results of our study indicate that staurosporine induced astrocytic phenotypes in glial cells and that changes in the expression and cellular distribution of these PKC isoforms may be related to astrocytic differentiation.     

牛磺酸对高糖培养下视网膜Mü ller细胞GFAP和TAUT表达的影响

目的：通过检测高糖培养条件下视网膜Mü ller细胞神经纤维酸性蛋白（glial fibrillary acid protein,GFAP）和牛磺酸转运蛋白（taurine transporter,TAUT）的表达变化,观察葡萄糖对Mü ller细胞牛磺酸（taurine）转运功能的影响,探讨牛磺酸对早期糖尿病视网膜病（DR）可能的保护作用.方法：高糖培养大鼠视网膜Mü ller细胞,用免疫细胞荧光化学双染色、Western blotting技术检测不同浓度牛磺酸干预下Mü ller细胞GFAP及TAUT的蛋白表达.结果：高糖可引起Mü ller细胞GFAP表达增强,TAUT表达减弱;牛磺酸可减弱高糖引起的Mü ller细胞GFAP表达增强,TAUT在0.1mmol/L～10 mmo1/L的牛磺酸干预后表达增强.结论：牛磺酸可以抑制高糖导致的Müller细胞功能改变.     

Systemic Neurochemical Alterations in Schizophrenic Brain: Glutamate Metabolism in Focus

We have used a systemic approach to establish a relationship between enzyme measures of glial glutamate and energy metabolism (glutamine synthetase and glutamine synthetase-like protein, glutamate dehydrogenase isoenzymes, brain isoform creatine phosphokinase) and two major glial proteins (glial fibrillary acidic protein and myelin basic protein) in autopsied brain samples taken from patients with schizophrenia (SCH) and mentally healthy subjects (23 and 22 cases, respectively). These biochemical parameters were measured in tissue extracts in three brain areas (prefrontal cortex, caudate nucleus, and cerebellum). Significant differences in the level of at least one of the glutamate metabolizing enzymes were observed between two studied groups in all studied brain areas. Different patterns of correlative links between the biochemical parameters were found in healthy and schizophrenic brains. These findings give a new perspective to our understanding of the impaired regulation of enzyme levels in the brain in SCH.     

超声微泡介导hVEGF165 基因靶向转染糖尿病鼠缺血骨骼肌

目的：探讨超声介导微泡破裂法促进血管内皮生长因子（VEGF）基因在糖尿病鼠缺血骨骼肌内转染的作用,评估其转染效 率和安全性。方法：建立糖尿病鼠缺血骨骼肌动物模型,以绿色荧光蛋白基因为报告基因, 观察接受超声及微泡治疗组hVEGF165 基因在糖尿病鼠缺血骨骼肌内表达,并与对照组相比。同时取糖尿病鼠缺血骨骼肌进行HE染色行组织学检查。结果：在超声介导 微泡破裂组内,hVEGF165 基因表达明显增强(42.87± 5.12),与单纯接受质粒治疗组(5.02± 1.21)和接受质粒和超声治疗组（8.16± 2.43）相比,差异具有统计学意义（P<0.001）,HE 切片未发现肌组织结构的改变。结论：超声介导微泡破裂法能有效促进外源基因 在糖尿病鼠缺血骨骼肌中表达, 为糖尿病周围血管疾病的基因治疗提供了实验依据。     

康柏西普在糖尿病大鼠早期视网膜病变中的作用及对VEGF、ICAM-1及CRP的影响

摘要 目的：探讨康柏西普在糖尿病大鼠早期视网膜病变中的作用及对血管内皮生长因子 (vascular endothelial growth factor,VEGF)和细胞间粘附分子-1(Intercellular adhesion molecule-1,ICAM-1)及C-反应蛋白(C-reactive protein,CRP)的影响。方法：糖尿病大鼠早期视网膜病变模型(n=27)随机平分为三组-模型组、替米沙坦组与康柏西普组,造模成功后当天三组分别给予注射生理盐水、替米沙坦、康柏西普治疗,1次/w,持续4 w,检测VEGF、ICAM-1及CRP表达情况。结果：大鼠造模成功后均出现食欲增多、饮水、尿量、体重减轻的现象。替米沙坦组与康柏西普组治疗第1 w与第4 w的体重高于模型组(P<0.05),康柏西普组高于替米沙坦组(P<0.05)。替米沙坦组与康柏西普组治疗第1 w与第4 w的空腹血糖低于模型组(P<0.05),康柏西普组低于替米沙坦组(P<0.05)。替米沙坦组与康柏西普组治疗第4 w的视网膜VEGF、ICAM-1、CRP蛋白相对表达水平低于模型组(P<0.05),康柏西普组低于替米沙坦组(P<0.05)。康柏西普组视网膜厚度变薄不明显,内、外核层细胞排列整齐,神经纤维层未见明显空泡样变性。结论：康柏西普在糖尿病大鼠早期视网膜病变中的应用能抑制VEGF、ICAM-1及CRP的表达,能促进降低血糖,增加大鼠体重。     

Tumor Necrosis Factor-α and Basic Fibroblast Growth Factor Decrease Glial Fibrillary Acidic Protein and Its Encoding mRNA in Astrocyte Cultures and Glioblastoma Cells

Abstract: Tumor necrosis factor-α is a pluripotent cytokine that is reportedly mitogenic to astrocytes. We examined expression of the astrocyte intermediate filament component glial fibrillary acidic protein in astrocyte cultures and the U373 glioblastoma cell line after treatment with tumor necrosis factor-α. Treatment with tumor necrosis factor-α for 72 h resulted in a decrease in content of glial fibrillary acidic protein and its encoding mRNA. At the same time, tumor necrosis factor-α treatment increased the expression of the cytokine interleukin-6 by astrocytes. The decrease in glial fibrillary acidic protein expression was greater when cells were subconfluent than when they were confluent. Thymidine uptake studies demonstrated that U373 cells proliferated in response to tumor necrosis factor-α, but primary neonatal astrocytes did not. However, in both U373 cells and primary astrocytes tumor necrosis factor-α induced an increase in total cellular protein content. Treatment of astrocytes and U373 cells for 72 h with the mitogenic cytokine basic fibroblast growth factor also induced a decrease in glial fibrillary acidic protein content and an increase in total protein level, demonstrating that this effect is not specific for tumor necrosis factor-α. The decrease in content of glial fibrillary acidic protein detected after tumor necrosis factor-α treatment is most likely due to dilution by other proteins that are synthesized rapidly in response to cytokine stimulation.     

Heat shock proteins and other components of cellular machinery for protein synthesis are up-regulated in vascular endothelial cell growth factor-activated human endothelial cells

Proteome analysis of human umbilical endothelial cells was performed to identify proteins that are modified during vascular endothelial cell growth factor (VEGF)-induced transition from the quiescent into the proliferating-migrative phenotype. Subtractive analysis of two-dimensional gel patterns of human endothelial cells, before and after stimulation with VEGF(165), revealed differences in 85 protein spots. All proteins were identified by peptide sequencing and peptide mass fingerprinting using an electrospray spectrometer. The proteins identified were members of specific families including Ca(2+)-binding proteins, fatty-acid binding proteins, structural proteins, and chaperones. Remarkably, there was a massive activation of cellular machinery for both protein synthesis and protein degradation. Thus, among up-regulated proteins there were members of all groups of heat shock proteins (HSPs; HSP 27, HSP 60, HSP 70p5, HSP 70p8, HSP 90, and HSP 96) and some other proteins showing either chaperone activity or which participate in assembly of multimolecular structures (TCP-1, desmoplakins, junction plakoglobin, GRP 94, thioredoxin related protein, and peptidylprolyl isomerase). The increased expression of HSPs was confirmed at the mRNA level at different stages of treatment with VEGF. Similarly, components of the proteolytic machinery for the degradation of misfolded proteins (ER-60, cathepsin D, proteasome subunits, and protease inhibitor 6) were also up-regulated. On the other hand, changes in the expression of structural proteins (T-plastin, vimentin, alpha tubulin, actin, and myosin) could account, at least in part, for the different morphologies displayed by migrating endothelial cells. In summary, our data show that VEGF levels similar to those during physiological stresses induce a number of genes and multiple endogenous pathways seem to be engaged in restoring cellular homeostasis. To ensure cell survival, the molecular chaperones (the heat shock family of stress proteins) are highly up-regulated providing protein-folding machinery to repair or degrade misfolded proteins.     

Role of Thyroid Hormone and Nerve Growth Factor in the Development of Choline Acetyltransferase and Other Cell-Specific Marker Enzymes in the Basal Forebrain of the Rat

The effects of treatment with L-thyroxine (subcutaneously 0.3 microgram/g body weight daily from birth, i.e., day 1) and 2.5S nerve growth factor (NGF; intraventricularly 2 micrograms on 1, 3, 5, 7, and 9 postnatal days), separately and together, were studied on the biochemical development of different cell types in the basal forebrain of 10-day-old rats. The development of cholinergic, gamma-aminobutyric acid-ergic (GABAergic), and glutamatergic neurons was monitored respectively in terms of choline acetyltransferase (ChAT), glutamate decarboxylase (GAD), and glutaminase activities, whereas glutamine synthetase (GS) and 2',3'-cyclic nucleotide-3'-phosphohydrolase (CNPase) activities were used to judge the maturation of astroglial and oligodendroglial cells. Treatment with either thyroid hormone or NGF from birth significantly increased the expression of ChAT activity in the basal forebrain of neonatal rats. When both agents were administered to the same animal, in agreement with our earlier in vitro findings, the stimulation in ChAT activity was much greater than the sum of the individual effects. In hypothyroid rats, significant effects of NGF at the low doses used were not detectable, although the increase of ChAT activity induced by thyroxine was potentiated by NGF in these animals. Under the present experimental conditions neither thyroxine nor NGF treatment had an appreciable effect on the activities of glutaminase, GS, and lactate dehydrogenase. However, the administration of thyroxine markedly increased CNPase activity in normal rats, whereas in hypothyroid rats the effect on both CNPase and GAD was also significant. Similar elevations in CNPase and GAD activities were not observed after NGF treatment, suggesting that the effect of NGF was specific to the cholinergic cells.(ABSTRACT TRUNCATED AT 250 WORDS)     

联合应用NGF 和胰岛素对糖尿病大鼠烫伤创面表皮干细胞的影响

目的:通过局部联合应用神经生长因子和胰岛素对糖尿病大鼠深II度烫伤创面表皮干细胞标记物β1整合素和角蛋白19(K19)表达的影响,探讨神经生长因子和胰岛素联合应用于糖尿病烫伤创面治疗后对创面愈合的影响。方法:雄性wistar大鼠腹腔注射链脲佐菌素(STZ)建立糖尿病模型60只,1月后在大鼠背部造成深II度烫伤。将大鼠随机分为糖尿病对照组(B)、胰岛素治疗组(C)、神经生长因子治疗组(D)、神经生长因子联合胰岛素治疗组(E),每组15只。另取15只正常雄性wistar大鼠作为正常对照组(A)。观察伤后3、7、11、15、21 d各组创面愈合情况,检测创面β1整合素和角蛋白19(K19)的表达并计算创面愈合率。结果:E组创面愈合率自第7天起较A、B、C、D组增加,为[(25.33±2.32)%,(P<0.05)];A、C、D组创面愈合率较B组增加分别为[(22.51±1.78)%,(16.68±1.95)%,(18.29±1.70)%,(P<0.05)]。E组整合素β1和角蛋白19(K19)表达自伤后第7至21天各时相点显著增加,(P<0.05)。结论:糖尿病大鼠深II度烫伤创面局部联合应用神经生长因子和胰岛素可促进表皮干细胞的增殖与分化从而加速创面的愈合。     

shASPP2 H22稳转肝癌细胞系的构建及ASPP2敲低对H22移植瘤小鼠血管生成的影响

摘要 目的：构建小鼠shASPP2 H22稳转肝癌细胞系,观察ASPP2敲低对血管生成的影响。方法：针对小鼠ASPP2基因设计了3个不同的shRNA干扰序列（Y18421,Y18422,Y18423）及1个对照序列（GL427NC2）,采用双酶切（Age Ⅰ和EcoR Ⅰ）及质粒连接构建重组质粒,使用菌落PCR和测序比对进行鉴定;使用293T细胞将各重组质粒包装慢病毒并测定滴度;将 shASPP2和对照慢病毒质粒转染H22细胞,采用流式细胞术测定转染效率;采用qRT-PCR、Western Blot法观察shASPP2慢病毒对H22细胞ASPP2的干扰效果;采用CCK8法观察ASPP2敲低对H22细胞增殖的影响;采用Western Blot法观察ASPP2敲低对H22细胞及上清VEGF表达和分泌的影响;采用细胞注射法建立小鼠ASPP2敲低H22细胞皮下移植瘤模型,游标卡尺法观察肿瘤体积大小,采用活体激光共聚焦观察肿瘤血管生成情况,采用Western Blot法观察肿瘤组织VEGF的表达。结果：双酶切、菌落PCR和测序鉴定结果表示各重组质粒构建成功;各重组质粒经慢病毒包装后,测定显示Y18421、Y18422、Y18423和GL427NC2慢病毒质粒的滴度分别为3.40×10⁸ TU/mL、4.08×10⁸ TU/mL、5.49×10⁸ TU/mL和1.7×10⁹ TU/mL;Y18421、Y18422、Y18423及GL427NC2慢病毒质粒转染效率分别为：86.2 %、69.6 %、60.8 %和76.9 %。与GL427NC2 H22细胞相比,Y18421 H22细胞的ASPP2 mRNA及蛋白的表达明显降低（P<0.01,P<0.05）;Y18421细胞在培养24,48,72 h后增殖速率显著增加（P<0.0001,P<0.001,P<0.01）;Y18421细胞及上清的VEGF表达显著升高（P<0.001,P<0.01,P<0.05）。与GL427NC2 细胞移植瘤相比,Y18421细胞移植瘤体积明显增大（P<0.05）,总血管长度显著增加（P<0.05）,VEGF蛋白的表达明显上调（P<0.05）。结论：小鼠shASPP2 H22稳转肝癌细胞系构建成功,ASPP2敲低可能通过上调VEGF的表达促进小鼠H22细胞移植瘤血管生成。     

活血化瘀方对糖尿病模型大鼠糖脂代谢、血管内皮生长因子和血管紧张素II1型受体表达的影响

目的:探讨活血化瘀方对糖尿病模型大鼠糖脂代谢、血管内皮生长因子(VEGF)和血管紧张素Ⅱ1型受体(AT1R)表达的影响。方法:选取健康雄性SD大鼠50只,适应性喂养7 d后以随机数字表法分成对照组10只、模型组13只、中药组14只、西药组13只。其中模型组与对照组予以纯净水灌胃,中药组予以活血化瘀通络中药配方颗粒灌胃,西药组则予以厄贝沙坦灌胃,1次/d,连续灌胃16周。分别比较各组大鼠的糖脂代谢指标水平及24 h尿蛋白定量、糖化血红蛋白、血清肌酐水平,并检测肾组织VEGF和AT1R表达情况。结果:模型组、中药组、西药组大鼠空腹血糖(FBG)、总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)水平均高于对照组,中药组、西药组大鼠LDL-C水平低于模型组,中药组大鼠FBG水平低于模型组与西药组(P0.05)。模型组、中药组、西药组大鼠24 h尿蛋白定量与糖化血红蛋白均高于对照组,中药组、西药组大鼠24 h尿蛋白定量低于模型组(P0.05)。模型组、中药组、西药组大鼠VEGF、AT1R水平均高于对照组,中药组、西药组大鼠VEGF、AT1R水平低于模型组,中药组大鼠AT1R水平低于西药组(P0.05)。结论:活血化瘀方可有效改善糖尿病大鼠糖脂代谢状态,通过抑制VEGF与AT1R的表达水平,延缓糖尿病的发生与发展。     

IGF-1对缺血性脑损伤大鼠脑内神经发生的影响

目的:建立大鼠单侧局灶脑缺血模型,观察胰岛素样生长因子-1(IGF-1)对局灶脑缺血后的鼠脑神经发生及增殖后细胞生存的影响.方法:用健康雄性SD大鼠建立大脑中动脉阻塞(MCAO)模型,随机分成假手术组,缺血对照组和IGF-1治疗组.各组再按不同的治疗时间分为7d、14d、28d、42d组.免疫组化法观察BrdU、PSA-NCAM的变化,免疫双标法观察BrdU/PSA-NCAM、BrdU/MAP2和BrdU/GFAP的共同表达变化.结果:BrdU标记细胞和PSA-NCAM标记细胞计数均在缺血后第7d最多,分别是缺血对照组的4.0倍和1.8倍,是假手术组的9.9倍和5.4倍.BrdU和PSA-NCAM双标细胞在缺血发生后双侧SVZ和DG区可以检测到,于第7d计数最多,之后逐渐降低;而BrdU和MAP2以及BrdU和GFAP双标细胞却从第14d开始逐渐增多,直到第42d.随着BrdU/PSA-NCAM双标阳性表达的逐渐降低,BrdU/MAP2双标阳性表达逐渐增高,呈现此消彼涨的变化.结论:IGF-1侧脑室注射后,在早期(7d内)诱导了缺血性脑损伤后神经细胞的增殖;在中期(7d-14d)诱导了新生细胞的迁移;在后期(14d后)伴随着迁移的进行新生细胞逐渐发生了分化.     

超声对早期糖尿病肾病的诊断价值及肾动脉血流阻力指数与血清hs-CRP、VEGF的关系分析

目的:研究彩色多普勒超声对早期糖尿病肾病的诊断价值及肾动脉血流阻力指数与血清超敏C反应蛋白(hs-CRP)、血管内皮生长因子(VEGF)的关系。方法:选取从2017年2月～2018年2月兰州大学第二医院收治的早期糖尿病肾病患者50例记为病变组,另取同期于该院进行体检的健康人员50例记为对照组。分别对两组人员进行彩色多普勒超声检查,比较肾血流参数。采用酶联免疫吸附法检测两组人员血清hs-CRP、VEGF水平,并作指标间的相关性分析。结果:病变组肾主动脉、肾锥体两侧叶间动脉、肾段动脉的收缩期峰值速度、舒张期最低速度较对照组降低,病变组肾主动脉、肾锥体两侧叶间动脉、肾段动脉的阻力指数较对照组升高(均P0.05)。病变组血清hs-CRP、VEGF水平较对照组升高(均P0.05)。经Pearson相关性分析显示:早期糖尿病肾病患者肾主动脉、肾锥体两侧叶间动脉、肾段动脉的血流阻力指数与血清hs-CRP、VEGF均呈正相关关系(均P0.05)。结论:彩色多普勒超声应用于早期糖尿病肾病的诊断价值较高,且肾动脉血流阻力指数与血清hs-CRP、VEGF密切相关,临床工作中通过联合检测血清hs-CRP、VEGF,从而有助于早期糖尿病肾病的诊断。     

Retinoic acid decreases nitric oxide production in endothelial cells: a role of phosphorylation of endothelial nitric oxide synthase at Ser(1179)

The effects of retinoic acid (RA) on nitric oxide (NO) production are controversial. Furthermore, it has never been studied whether these effects are mediated by direct modulation of phosphorylation of endothelial nitric oxide synthase (eNOS). Using bovine aortic endothelial cells, we found that all-trans RA (atRA) dose- and time-dependently decreased NO production without alteration in eNOS expression. This decrease was accompanied by reduction in eNOS-Ser(1179) phosphorylation. However, atRA did not alter the phosphorylation of eNOS-Ser(116) or eNOS-Thr(497). Concurrently, atRA also decreased the expressions of vascular endothelial growth factor (VEGF) and its receptor KDR/Flk-1, and Akt phosphorylation. Co-treatment with troglitazone, an activator of VEGF expression, reversed the atRA-induced reductions in eNOS-Ser(1179) phosphorylation and NO production, with concomitant restoration in VEGF expression. Direct treatment with VEGF also reversed these inhibitory effects, suggesting an important role for VEGF. Nonetheless, the RARalpha antagonist Ro 41-5253 did not block all the inhibitory effects of atRA, indicating that these inhibitory effects are not mediated by the RA response element (RARE). Thus, atRA decreases eNOS-Ser(1179) phosphorylation through a mechanism that depends on VEGF-KDR/Flk-1-mediated Akt phosphorylation but is independent of RARE, leading to reduction in NO production.     

cis-9,trans-11 conjugated linoleic acid stimulates expression of angiopoietin like-4 in the placental extravillous trophoblast cells

A number of studies have been carried out to examine the biological function of conjugated linoleic acid (CLA) and its potential health benefits. However, not much is known about how CLA isomers mediate their effect on angiogenesis and vascularization during early placentation. In this paper we demonstrate that cis-9,trans-11(c9,t11)-CLA stimulated the expression of angiopoietin like-4 (ANGPTL4) mRNA and protein accompanied by tube formation in first trimester placental trophoblast cells, HTR8/SVneo whereas the other CLA isomer, trans-10,cis-12 (t10,c12)-CLA had no such effects. c9,t11-CLA however did not stimulate expression of the most potent angiogenic factor, vascular endothelial growth factor (VEGF) in these cells. Silencing ANGPTL4 in these cells significantly reduced the stimulatory effect of c9,t11-CLA on tube formation, indicating the involvement of ANGPTL4. In addition, c9,t11-CLA increased the mRNA expression of several pro-angiogenic factors such as fatty acid binding protein-4 (FABP4), cyclooxygenase-2 (COX-2) and adipose differentiation-related protein (ADRP) in HTR8/SVneo cells. c9,t11-CLA also induced the uptake of docosahexaenoic acid, 22:6n − 3 (DHA), a stimulator of tube formation in these cells. Triacsin C, an acylCoA synthetase inhibitor, attenuated c9,t11-CLA induced DHA uptake, tube formation and cellular proliferation in HTR8/SVneo cells.     

The role of amino acid transporters in GSH synthesis in the blood-brain barrier and central nervous system

Glutathione (GSH) plays a critical role in protecting cells from oxidative stress and xenobiotics, as well as maintaining the thiol redox state, most notably in the central nervous system (CNS). GSH concentration and synthesis are highly regulated within the CNS and are limited by availability of the sulfhydryl amino acid (AA) l-cys, which is mainly transported from the blood, through the blood-brain barrier (BBB), and into neurons. Several antiporter transport systems (e.g., x(c)(-), x(-)(AG), and L) with clearly different luminal and abluminal distribution, Na(+), and pH dependency have been described in brain endothelial cells (BEC) of the BBB, as well as in neurons, astrocytes, microglia and oligodendrocytes from different brain structures. The purpose of this review is to summarize information regarding the different AA transport systems for l-cys and its oxidized form l-cys(2) in the CNS, such as expression and activity in blood-brain barrier endothelial cells, astrocytes and neurons and environmental factors that modulate transport kinetics.     

Hypoxia-inducible factor 1 signalling,metabolism and its therapeutic potential in cardiovascular disease

Cardiovascular disease (CVD) accounts for the largest number of deaths worldwide, necessitating the development of novel treatments and prevention strategies. Given the huge energy demands placed on the heart, it is not surprising that changes in energy metabolism play a key role in the development of cardiac dysfunction in CVD. A reduction in oxygen delivery to the heart, hypoxia, is sensed and responded to by the hypoxia-inducible factor (HIF) and its family of proteins, by regulating the oxygen-dependent signalling cascade and subsequent response. Hypoxia is one of the main drivers of metabolic change in ischaemic disease and myocardial infarction, and we therefore suggest that HIF may be an attractive therapeutic target. In this review, we assess cardiac energy metabolism in health and disease, and how these can be regulated by HIF-1α activation. We then present an overview of research in the field of hypoxia-mimetic drugs recently developed in other treatment fields, which provide insight into the potential of systemic HIF-1α activation therapy for treating the heart.