静脉注射核因子NF-E2相关因子表达质粒减轻糖尿病小鼠肾小球氧化应激损伤的实验研究

该实验旨在研究经小鼠尾静脉快速注射核因子NF-E2相关因子(nuclear factor erythroid2-related factor 2,Nrf2)表达质粒对链脲佐菌素(streptozotocin,STZ)诱导的糖尿病小鼠肾小球氧化应激损伤的保护作用。采用腹腔注射STZ诱发糖尿病小鼠模型,自成模后第3天开始,尾静脉快速注射pcDNA3/mNrf2质粒。4周后收取标本,检测动物肾小球丙二醛(malondialdehyde,MDA)含量,纤维连接蛋白(fibronectin,FN)以及Nrf2、γ-谷氨酰半胱氨酸合成酶(γ-glutamylcysteine synthethase,γ-GCS)在肾小球的表达。实验结果表明,尾静脉注射可以将Nrf2表达质粒转染入小鼠肾小球。此方法可以降低糖尿病小鼠肾小球MDA浓度,减轻FN在肾小球的表达,增加Nrf2在肾小球细胞核的积聚以及γ-GCS的转录和表达。该研究证明,应用尾静脉注射Nrf2表达质粒的方法可以减轻糖尿病小鼠肾小球氧化应激损伤,减少细胞外基质(extracellular matrix,ECM)沉积,其机制部分是通过激活Nrf2-ARE信号通路而实现的。     

Ursolic Acid Attenuates Diabetic Mesangial Cell Injury through the Up-Regulation of Autophagy via miRNA-21/PTEN/Akt/mTOR Suppression

ObjectiveTo investigate the effect of ursolic acid on autophagy mediated through the miRNA-21-targeted phosphoinositide 3 kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway in rat mesangial cells cultured under high glucose (HG) conditions.MethodsRat glomerular mesangial cells were cultured under normal glucose, HG, HG with the PI3K inhibitor {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 or HG with ursolic acid conditions. Cell proliferation and hypertrophy were assayed using an MTT assay and the ratio of total protein to cell number, respectively. The miRNA-21 expression was detected using RT-qPCR. The expression of phosphatase and tensin homolog (PTEN)/AKT/mTOR signaling signatures, autophagy-associated protein and collagen I was detected by western blotting and RT-qPCR. Autophagosomes were observed using electron microscopy.ResultsCompared with mesangial cells cultured under normal glucose conditions, the cells exposed to HG showed up-regulated miRNA-21 expression, down-regulated PTEN protein and mRNA expression, up-regulated p85PI3K, pAkt, pmTOR, p62/SQSTMI, and collagen I expression and down-regulated LC3II expression. Ursolic acid and {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 inhibited HG-induced mesangial cell hypertrophy and proliferation, down-regulated p85PI3K, pAkt, pmTOR, p62/SQSTMI, and collagen I expression and up-regulated LC3II expression. However, {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 did not affect the expression of miRNA-21 and PTEN. Ursolic acid down-regulated miRNA-21 expression and up-regulated PTEN protein and mRNA expression.ConclusionsUrsolic acid inhibits the glucose-induced up-regulation of mesangial cell miRNA-21 expression, up-regulates PTEN expression, inhibits the activation of PI3K/Akt/mTOR signaling pathway, and enhances autophagy to reduce the accumulation of the extracellular matrix and ameliorate cell hypertrophy and proliferation.     

Podocin蛋白对肾小球足细胞的影响

目的：探讨肾小球足细胞裂隙膜蛋白podocin对足细胞形态及蛋白尿的影响.方法：32只体重160g～220g的雄性SD大鼠按阿霉素给药剂量随机分成小剂量组（3.0mg/Kg）、肾病剂量组（7.5mg/Kg）、超剂量组（10.0mg/Kg）、正常对照组.于给药第三周末处死大鼠,用氯化苄乙氧铵比浊法检测大鼠24h尿蛋白量,用免疫胶体金电镜检测大鼠肾小球蛋白podocin的表达和足细胞形态.结果：阿霉素组大鼠24h尿蛋白排泄量明显高于正常对照组,尤以肾病组最明显（P＜0.05）;正常对照组大鼠podocin分布在靠近肾小球基底膜（GBM）的足突基底部,主要定位于裂隙隔膜的胞质面,部分金颗粒也可发现于GBM稍远的足突细胞表面.肾病组肾小球足突广泛融合,免疫胶体金颗粒几乎见不到;超剂量组和小剂量组podocin分布在靠近肾小球基底膜（GBM）的足突基底部,免疫胶体金颗粒数明显少于正常对照组,有部分足突退缩.结论：（1）podocin表达减少或消失可能是导致肾小球足突细胞融合的关键因素（2）蛋白尿的发生与肾小球足细胞裂隙膜蛋白podocin的减少或缺失有关.     

TLR4 Activation Promotes Podocyte Injury and Interstitial Fibrosis in Diabetic Nephropathy

Toll like receptor (TLR) 4 has been reported to promote inflammation in diabetic nephropathy. However the role of TLR4 in the complicated pathophysiology of diabetic nephropathy is not understood. In this study, we report elevated expression of TLR4, its endogenous ligands and downstream cytokines, chemokines and fibrogenic genes in diabetic nephropathy in WT mice with streptozotocin (STZ) diabetes. Subsequently, we demonstrated that TLR4^−/− mice were protected against the development of diabetic nephropathy, exhibiting less albuminuria, inflammation, glomerular hypertrophy and hypercellularity, podocyte and tubular injury as compared to diabetic wild-type controls. Marked reductions in interstitial collagen deposition, myofibroblast activation (α-SMA) and expression of fibrogenic genes (TGF-β and fibronectin) were also evident in TLR4 deficient mice. Consistent with our in vivo results, high glucose directly promoted TLR4 activation in podocytes and tubular epithelial cells in vitro, resulting in NF-κB activation and consequent inflammatory and fibrogenic responses. Our data indicate that TLR4 activation may promote inflammation, podocyte and tubular epithelial cell injury and interstitial fibrosis, suggesting TLR4 is a potential therapeutic target for diabetic nephropathy.     

Toll-Like Receptor 4 Knockdown Attenuates Brain Damage and Neuroinflammation After Traumatic Brain Injury via Inhibiting Neuronal Autophagy and Astrocyte Activation

Toll-like receptor 4 (TLR4) has been linked to various pathophysiological conditions, such as traumatic brain injury (TBI). It is reported that posttraumatic neuroinflammation is an essential event in the progression of brain injury after TBI. Recent evidences indicate that TLR4 mediates glial phagocytic activity and inflammatory cytokines production. Thus, TLR4 may be an important therapeutic target for neuroinflammatory injury post-TBI. This study was designed to explore potential effects and underlying mechanisms of TLR4 in rats suffered from TBI. TBI model was induced using a controlled cortical impact in rats, and application of TLR4 shRNA silenced TLR4 expression in brain prior to TBI induction. Elevated TLR4 was specifically observed in the hippocampal astrocytes and neurons posttrauma. Interestingly, TLR4 shRNA decreased the concentrations of interleukin (IL)-1β, IL-6, and tissue necrosis factor-α; alleviated hippocampal neuronal damage; reduced brain edema formation; and improved neurological deficits after TBI. Meanwhile, to further explore underlying molecular mechanisms of this neuroprotective effects of TLR4 knockdown, our results showed that TLR4 knockdown significantly inhibited the upregulation of autophagy-associated proteins caused by TBI. More importantly, an autophagy inducer, rapamycin pretreated, could partially abolish neuroprotective effects of TLR4 knockdown on TBI rats. Furthermore, TLR4 silencing markedly suppressed GFAP upregulation and improved cell hypertrophy to attenuate TBI-induced astrocyte activation. Taken together, these findings suggested that TLR4 knockdown ameliorated neuroinflammatory response and brain injury after TBI through suppressing autophagy induction and astrocyte activation.     

Angiotensin II Receptor Blocker Attenuates Intrarenal Renin-Angiotensin-System and Podocyte Injury in Rats with Myocardial Infarction

The mechanisms and mediators underlying common renal impairment after myocardial infarction (MI) are still poorly understood. The present study aimed to test the hypothesis that angiotensin II type 1 receptor blockers (ARBs) provides renoprotective effects after MI by preventing augmented intrarenal renin-angiotensin-system (RAS)-induced podocyte injury. Sprague–Dawley rats that underwent ligation of their coronary arteries were treated with losartan (20 mg/kg/d) or vehicle for 3 or 9 weeks. Renal function, histology and molecular changes were assessed. The current study revealed that MI-induced glomerular podocyte injury was identified by increased immunostaining for desmin and p16^ink4a, decreased immunostaining for Wilms’ tumor-1 and podocin mRNA expression, and an induced increase of blood cystatin C at both 3 and 9 weeks. These changes were associated with increased intrarenal angiotensin II levels and enhanced expressions of angiotensinogen mRNA and angiotensin II receptor mRNA and protein. These changes were also associated with decreased levels of insulin-like growth factor (IGF-1) and decreased expressions of IGF-1 receptor (IGF-1R) protein and mRNA and phosphorylated(p)-Akt protein at 9 weeks, as well as increased expressions of 8-hydroxy-2’-deoxyguanosine at both time points. Treatment with losartan significantly attenuated desmin- and p16^ink4a-positive podocytes, restored podocin mRNA expression, and decreased blood cystatin C levels. Losartan also prevented RAS activation and oxidative stress and restored the IGF-1/IGF-1R/Akt pathway. In conclusion, ARBs prevent the progression of renal impairment after MI via podocyte protection, partially by inhibiting the activation of the local RAS with subsequent enhanced oxidative stress and an inhibited IGF-1/IGF-1R/Akt pathway.     

Regulation of Podocyte Injury by CircHIPK3/FUS Complex in Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a major microvascular complication of diabetes mellitus and is one of the leading causes of end-stage kidney disease. Circular RNAs (circRNAs) are a class of endogenous non-coding RNAs that play important roles in various diseases, yet their roles in DKD are poorly understood. CircRNA HIPK3 (circHIPK3), a highly conserved circRNA, is closely related to various cellular functions, including cell proliferation and apoptosis. The association between circHIPK3 and diabetic complications has been well demonstrated in multiple previous studies. However, the role of circHIPK3 in podocyte injury in DKD remains unclear. Herein, we discovered that circHIPK3 expression is markedly elevated in cultured podocytes under high-glucose (HG) conditions and glomeruli of diabetic mice, which is closely associated with podocyte injury in DKD. Functionally, lentivirus-mediated knockdown of circHIPK3 dramatically suppresses HG-induced podocyte apoptosis in vitro. Therapeutically, silencing circHIPK3 by adeno-associated virus-mediated RNA interference ameliorates podocyte injury and albuminuria in STZ-induced diabetic mice. Mechanistically, circHIPK3 facilitates the enrichment of fused in sarcoma (FUS) on the ectodysplasin A2 receptor (EDA2R) promoter, resulting in the upregulation of EDA2R expression and activation of apoptotic signaling. Taken together, these results indicate circHIPK3/FUS/EDA2R axis as a therapeutic target for podocyte injury and DKD progression.     

Trehalose,an mTOR Independent Autophagy Inducer,Alleviates Human Podocyte Injury after Puromycin Aminonucleoside Treatment

Glomerular diseases are commonly characterized by podocyte injury including apoptosis, actin cytoskeleton rearrangement and detachment. However, the strategies for preventing podocyte damage remain insufficient. Recently autophagy has been regarded as a vital cytoprotective mechanism for keeping podocyte homeostasis. Thus, it is reasonable to utilize this mechanism to attenuate podocyte injury. Trehalose, a natural disaccharide, is an mTOR independent autophagy inducer. It is unclear whether trehalose alleviates podocyte injury. Therefore, we investigated the efficacy of trehalose in puromycin aminonucleoside (PAN)-treated podocytes which mimic cell damage in minimal change nephrotic syndrome in vitro. Human conditional immortalized podocytes were treated with trehalose with or without PAN. Autophagy was investigated by immunofluorescence staining for LC3 puncta and Western blotting for LC3, Atg5, p-AMPK, p-mTOR and its substrates. Podocyte apoptosis and necrosis were evaluated by flow cytometry and by measuring lactate dehydrogenase activity respectively. We also performed migration assay to examine podocyte recovery. It was shown that trehalose induced podocyte autophagy in an mTOR independent manner and without reactive oxygen species involvement. Podocyte apoptosis significantly decreased after trehalose treatment, while the inhibition of trehalose-induced autophagy abolished its protective effect. Additionally, the disrupted actin cytoskeleton of podocytes was partially reversed by trehalose, accompanying with less lamellipodias and diminished motility. These results suggested that trehalose induced autophagy in human podocytes and showed cytoprotective effects in PAN-treated podocytes.     

Vinpocetine Attenuates Neointimal Hyperplasia in Diabetic Rat Carotid Arteries after Balloon Injury

Background

Diabetes exacerbates abnormal vascular smooth muscle cell (VSMC) accumulation in response to arterial wall injury. Vinpocetine has been shown to improve vascular remolding; however, little is known about the direct effects of vinpocetine on vascular complications mediated by diabetes. The objective of this study was to determine the effects of vinpocetine on hyperglycemia-facilitated neointimal hyperplasia and explore its possible mechanism.

Materials and Methods

Nondiabetic and diabetic rats were subjected to balloon injury of the carotid artery followed by 3-week treatment with either vinpocetine (10 mg/kg/day) or saline. Morphological analysis and proliferating cell nuclear antigen (PCNA) immunostaining were performed on day 21. Rat VSMCs proliferation was determined with 5-ethynyl-20-deoxyuridine cell proliferation assays. Chemokinesis was monitored with scratch assays, and production of reactive oxygen species (ROS) was assessed using a 2′,7′-dichlorodihydrofluorescein diacetate (H2DCFDA) flow cytometric assay. Apoptosis was detected by annexin V-FITC/PI flow cytometric assay. Cell signaling was assessed by immunblotting.

Results

Vinpocetine prevented intimal hyperplasia in carotid arteries in both normal (I/M ratio: 93.83 ± 26.45% versus 143.2 ± 38.18%, P<0.05) and diabetic animals (I/M ratio: 120.5 ± 42.55% versus 233.46 ± 33.98%, P<0.05) when compared to saline. The in vitro study demonstrated that vinpocetine significantly inhibited VSMCs proliferation and chemokinesis as well as ROS generation and apoptotic resistance, which was induced by high glucose (HG) treatment. Vinpocetine significantly abolished HG-induced phosphorylation of Akt and JNK1/2 without affecting their total levels. For downstream targets, HG-induced phosphorylation of IκBα was significantly inhibited by vinpocetine. Vinpocetine also attenuated HG-enhanced expression of PCNA, cyclin D1 and Bcl-2.

Conclusions

Vinpocetine attenuated neointimal formation in diabetic rats and inhibited HG-induced VSMCs proliferation, chemokinesis and apoptotic resistance by preventing ROS activation and affecting MAPK, PI3K/Akt, and NF-κB signaling.     

Podocyte Developmental Defects Caused by Adriamycin in Zebrafish Embryos and Larvae: A Novel Model of Glomerular Damage

The zebrafish pronephros is gaining popularity in the nephrology community, because embryos are easy to cultivate in multiwell plates, allowing large number of experiments to be conducted in an in vivo model. In a few days, glomeruli reach complete development, with a structure that is similar to that of the mammalian counterpart, showing a fenestrated endothelium and a basement membrane covered by the multiple ramifications of mature podocytes. As a further advantage, zebrafish embryos are permeable to low molecular compounds, and this explains their extensive use in drug efficacy and toxicity experiments. Here we show that low concentrations of adriamycin (i.e. 10 and 20 µM), when dissolved in the medium of zebrafish embryos at 9 hours post-fertilization and removed after 48 hours (57 hpf), alter the development of podocytes with subsequent functional impairment, demonstrated by onset of pericardial edema and reduction of expression of the podocyte proteins nephrin and wt1. Podocyte damage is morphologically confirmed by electron microscopy and functionally supported by increased clearance of microinjected 70 kDa fluorescent dextran. Importantly, besides pericardial edema and glomerular damage, which persist and worsen after adriamycin removal from the medium, larvae exposed to adriamycin 10 and 20 µM do not show any myocardiocyte alterations nor vascular changes. The only extra-renal effect is a transient delay of cartilage formation that rapidly recovers once adriamycin is removed. In summary, this low dose adriamycin model can be applied to analyze podocyte developmental defects, such as those observed in congenital nephrotic syndrome, and can be taken in consideration for pharmacological studies of severe early podocyte injury.     

烟酰胺核糖抑制小鼠糖尿病心肌病损伤的作用研究

目的:探讨烟酰胺核糖(Nicotinamide riboside,NR)在糖尿病小鼠心肌病中的保护作用及其可能机制。方法:80只20~25 g雄性昆明小鼠随机分为对照组(n=20)、对照+NR组(n=20)、DCM组(n=20)、DCM+NR组(n=20)。链脲佐菌素(STZ)对小鼠腹腔注射诱导1型糖尿病,最后1次STZ注射完成后第5日,血糖仪检测小鼠尾静脉血葡萄糖水平,三次测量随机血糖均≥16.7 mmol/L的视为糖尿病小鼠。糖尿病小鼠继续喂养12w,小动物超声检测提示心功能减退的为DCM小鼠。从中随机选出20只,腹腔注射NR(1000 mg/kg),2次/日,连续2w,为DCM+NR组。采用小动物超声分别检测各组小鼠心功能,天狼星红染色观察各组小鼠的心肌纤维化程度,Western blot检测心肌组织Atg7、Beclin-1、P62、Sirt3的表达。结果:与DCM组相比,DCM+NR组左室射血分数[LVEF(%)]增加(P0.01),为DCM组的2.12倍;左室短轴缩短率[LVFS(%)]增加(P0.01),为DCM组的2.79倍;左心室收缩末期容积(LV Vol;s)降低(P0.01),为DCM组的0.25;左心室舒张末期容积(LV Vol;d)降低(P0.01)、为DCM组的0.66;心肌纤维化程度减少(P0.01)、为DCM组的0.63;Atg7、Beclin-1、Sirt3表达增加(P0.05),P62表达降低(P0.01)。结论:NR能够减轻小鼠DCM心肌间质纤维化、改善心功能,Sirt3通路的激活可能参与了NR减轻小鼠DCM损伤的保护作用。     

达格列净通过增强营养剥夺信号促进糖尿病肾病大鼠足细胞自噬的研究

摘要 目的：探究达格列净是否通过增强营养剥夺信号促进糖尿病大鼠肾脏足细胞自噬,延缓糖尿病肾病进展。方法：采用高脂饮食和低剂量链脲佐菌素（STZ）腹腔注射诱导糖尿病模型。将成模大鼠随机分为糖尿病组（n=6）,达格列净组（n=7）,另设正常对照组（n=7）。达格列净组和糖尿病组分别给予达格列净和生理盐水灌胃4周。灌胃结束后收集大鼠24 h尿液以及血液、肾脏。记录体重、肾重、肾周脂肪重并测定空腹血糖、空腹血清胰岛素、血肌酐、尿素氮、甘油三酯以及尿白蛋白、尿总蛋白、尿白蛋白/肌酐比值;ELISA法检测血清酮体水平;HE染色、PAS染色以及电镜观察肾脏组织病理学改变;免疫组化和免疫荧光检测各组自噬相关蛋白7（ATG7）和足细胞标记蛋白NPHS1的表达情况; Western blot检测各组肾皮质中ATG7、沉默信息调节因子同源蛋白1（SIRT1）、过氧化物酶体增殖物激活受体γ共激活物-1α（PGC-1α）、成纤维细胞生长因子21（FGF21）、磷酸烯醇丙酮酸羧激酶（PEPCK）、过氧化物酶体增殖物激活受体α（PPARα）的蛋白水平。结果：与糖尿病组相比,达格列净组空腹血糖、24 h尿白蛋白、24 h尿总蛋白、尿白蛋白/肌酐比值降低,肾重/体重比、肾周脂肪重/体重比减小（P<0.05）;HE和PAS染色和电镜观察到糖尿病组较达格列净组肾小球基底膜增厚,足细胞足突增宽、融合（P<0.05）;达格列净组甘油三酯、空腹血清胰岛素以及胰岛素抵抗指数低于糖尿病组,血清酮体高于糖尿病组（P<0.05）;电镜下观察到达格列净组足细胞内自噬溶酶体数密度高于糖尿病组（P<0.05）;免疫组化和免疫荧光显示达格列净组足细胞NPHS1和ATG7的表达高于糖尿病组（P<0.05）; Western blot显示达格列净组肾皮质ATG7、SIRT1/PGC-1α/FGF21信号通路以及PEPCK、PPARα的表达较糖尿病组明显升高（P<0.05）。结论：达格列净增强营养剥夺信号的同时,观察到糖尿病大鼠肾脏足细胞自噬增强,这种自噬的增强可能是通过营养剥夺信号诱导的,其中的机制可能与达格列净上调SIRT1/PGC-1α /FGF21信号通路有关。     

Glomerular Endothelial Cell Injury and Damage Precedes That of Podocytes in Adriamycin-Induced Nephropathy

The role of podocytes in the development and progression of glomerular disease has been extensively investigated in the past decade. However, the importance of glomerular endothelial cells in the pathogenesis of proteinuria and glomerulosclerosis has been largely ignored. Recent studies have demonstrated that endothelial nitric oxide synthatase (eNOS) deficiency exacerbates renal injury in anti-GBM and remnant kidney models and accelerates diabetic kidney damage. Increasing evidence also demonstrates the importance of the glomerular endothelium in preventing proteinuria. We hypothesize that endothelial dysfunction can initiate and promote the development and progression of glomerulopathy. Administration of adriamycin (ADR) to C57BL/6 mice, normally an ADR resistant strain, with an eNOS deficiency induced overt proteinuria, severe glomerulosclerosis, interstitial fibrosis and inflammation. We also examined glomerular endothelial cell and podocyte injury in ADR-induced nephropathy in Balb/c mice, an ADR susceptible strain, by immunostaining, TUNEL and Western blotting. Interestingly, down-regulation of eNOS and the appearance of apoptotic glomerular endothelial cells occurred as early as 24 hours after ADR injection, whilst synaptopodin, a functional podocyte marker, was reduced 7 days after ADR injection and coincided with a significant increase in the number of apoptotic podocytes. Furthermore, conditioned media from mouse microvascular endothelial cells over-expressing GFP-eNOS protected podocytes from TNF-α-induced loss of synaptopodin. In conclusion, our study demonstrated that endothelial dysfunction and damage precedes podocyte injury in ADR-induced nephropathy. Glomerular endothelial cells may protect podocytes from inflammatory insult. Understanding the role of glomerular endothelial dysfunction in the development of kidney disease will facilitate in the design of novel strategies to treat kidney disease.     

Maraviroc Attenuates Trauma-Hemorrhage-Induced Hepatic Injury through PPAR Gamma-Dependent Pathway in Rats

Maraviroc is a CC-chemokine receptor 5 (CCR5) antagonist with potent antiviral and cancer preventive effects. Recent evidence suggests that the co-existence of CCR5 in various cell types is involved in inflammation. However, the effects that CCR5 antagonists produce in trauma-hemorrhage remain unknown. The peroxisome proliferator-activated receptor gamma (PPAR_γ) pathway exerts anti-inflammatory effects in injury. In this study, we hypothesized that maraviroc administration in male rats, after trauma-hemorrhage, decreases cytokine production and protects against hepatic injury through a PPAR_γ-dependent pathway. Male Sprague-Dawley rats underwent trauma-hemorrhage (mean blood pressure maintained at approximately 35-40 mmHg for 90 minutes), followed by fluid resuscitation. During resuscitation, a single dose of maraviroc (3 mg/kg, intravenously) with and without a PPAR_γ antagonist GW9662 (1 mg/kg, intravenously), GW9662 or vehicle was administered. Plasma alanine aminotransferase (ALT) with aspartate aminotransferase (AST) concentrations and various hepatic parameters were measured (n=8 rats/group) at 24 hours after resuscitation. The results showed that trauma-hemorrhage increased hepatic myeloperoxidase activity, intercellular adhesion molecule-1 and interleukin-6 levels, and plasma ALT and AST concentrations. These parameters were significantly improved in the maraviroc-treated rats subjected to trauma-hemorrhage. Maraviroc treatment also increased hepatic PPAR_γ expression compared with vehicle-treated trauma-hemorrhaged rats. Co-administration of GW9662 with maraviroc abolished the maraviroc-induced beneficial effects on the above parameters and hepatic injury. These results suggest that the protective effect of maraviroc administration on alleviation of hepatic injury after trauma-hemorrhage, which is, at least in part, through PPAR_γ-dependent pathway.     

The Accumulation of VEGFA in the Glomerular Basement Membrane and Its Relationship with Podocyte Injury and Proteinuria in Alport Syndrome

The pathogenesis of proteinuria in Alport syndrome (AS) remains unclear. Vascular endothelial growth factor A (VEGFA) is a key regulator of the glomerular filtration barrier (GFB). This study explored the expression of VEGFA in the glomeruli and its accumulation in the glomerular basement membrane (GBM) and their relationship with podocyte injury and proteinuria in Alport syndrome (AS). Clinical data and renal tissues of control patients (11 cases) and AS patients (25 cases) were included. AS patients were further divided into 2 groups according to the quantities of their urinary protein: mild to moderate proteinuria group (proteinuria <50 mg/kg/d, 15 cases) and heavy proteinuria group (proteinuria ≥50 mg/kg/d, 10 cases). The expression and distribution of VEGFA and VEGF receptor 2 (VEGFR2) in the GFB, the phosphorylation of VEGFR2 (p-VEGFR2) and nephrin (p-nephrin), and the expression of synaptopodin and nephrin in the glomeruli were detected by immune electron microscopy and/or immunofluorescence, and their relationships to proteinuria in AS patients were analyzed. The accumulation of VEGFA in the GBM was increased in AS patients. The expression of VEGFA and the levels of p-VEGFR2 and p-nephrin in glomeruli were increased and were positively correlated with the degree of proteinuria in AS patients. The expression of synaptopodin and nephrin were decreased and were negatively correlated with the degree of proteinuria in AS patients. The over expressed VEGFA in the glomeruli and its accumulation in the GBM may activate the VEGFA-VEGFR2 and nephrin signaling pathways and lead to podocyte injury and occurrence of proteinuria in AS.     

DHA通过抑制氧化应激反应减轻七氟烷所致神经元损伤

目的:观察二十二碳六烯酸(DHA)是否通过抑制氧化应激反应减轻七氟烷所致神经元损伤。方法:HT22小鼠海马神经元分为Con组、DHA组和Sevo组和DHA+Sevo组,药物处理各组细胞24 h后,在倒置相差显微镜下拍照记录各组细胞形态改变,采用MTT法检测神经元存活情况,检测各组培养基中LDH, NO, SOD及MDA的含量。结果:CON组和DHA组细胞形态正常,Sevo组细胞皱缩,胞体破裂,正常形态消失,而DHA+Sevo组细胞形态基本正常,皱缩破裂的细胞较少;与CON组和DHA组相比,Sevo组HT22细胞存活率下降至CON组的25.79%,培养液中LDH的漏出量显著增加至CON组的400.15%,SOD活力下降至CON组的30.96%,培养液中NO及MDA的含量分别增加至CON组的507.62%和342.15%(P0.05);而与Sevo组相比,DHA+Sevo组HT22细胞存活率增加至CON组的75.68%,培养液中LDH的漏出量下降至CON组的175.68%,SOD活力增加至CON组的70.48%,培养液中NO及MDA的含量分别下降至CON组的355.80%和192.27%(P0.05)。结论:DHA通过抗氧化应激反应减轻七氟烷对HT22细胞的损伤。