Adrenomedullin ameliorates podocyte injury induced by puromycin aminonucleoside in vitro and in vivo through modulation of Rho GTPases

International Urology and Nephrology - Podocyte injury is a key event in proteinuric kidney disease and eventually glomerular scarring. While adrenomedullin (AM), a potent vasodilatory peptide, has...     

Rho/Rock 信号通路在大鼠呼吸机相关性肺损伤中的作用

目的评价Rho/Rock信号通路在大鼠呼吸机相关性肺损伤(ventilator-induced lung injury,VILI)中的作用。方法选择健康雄性SD大鼠96只,12~15周龄,体重300~350g,采用随机数字表法将大鼠随机分为四组:空白对照组(C组)、Rho激酶抑制药法舒地尔组(F组)、高潮气量组(H组)和高潮气量+Rho激酶抑制药法舒地尔组(HF组),每组24只。C组和F组不行机械通气,H组和HF组行高潮气量40ml/kg机械通气4h。F组和HF组在机械通气前1h给予腹腔注射法舒地尔10mg/kg。分别于通气前(T0)、通气后4h(T1)、8h(T2)和24h(T3)每组随机取6只大鼠,采集血样,测定血清TNF-α、IL-6及IL-10浓度;采血结束后处死大鼠,收集支气管肺泡灌洗液(BALF),采用考马斯亮兰法检测BALF总蛋白;测定肺组织湿/干重比(W/D);光镜下行肺组织病理学损伤评分;采用分光光度法检测肺组织髓过氧化物酶(MPO)活性;采用Western blot和RT-PCR法分别检测肺组织RhoA、Rock2蛋白含量和mRNA表达水平。结果与C组比较,T1~T3时H组和HF组大鼠血清TNF-α、IL-6及IL-10浓度、BALF总蛋白含量、肺组织W/D、病理学损伤评分、MPO活性、RhoA、Rock2蛋白含量和mRNA表达水平明显升高(P0.05);与H组比较,T1~T3时HF组大鼠血清TNF-α、IL-6浓度、BALF总蛋白含量、肺组织W/D、病理学损伤评分、MPO活性、RhoA、Rock2蛋白含量和mRNA表达水平明显下降,血清IL-10浓度明显升高(P0.05)。结论Rho激酶抑制药法舒地尔可减轻大鼠呼吸机相关性肺损伤,其机制可能与其抑制Rho/Rock信号通路,降低肺组织内炎性反应有关。     

Microencapsulated islet transplantation alleviates podocyte injury in diabetic nephropathy via inhibiting Notch-1 signaling

ObjectivePodocyte injury has a critical role in the pathogenesis of diabetic nephropathy (DN). Microencapsulated islet transplantation (MIT) is identified as an effective method for improving the clinical condition of DN. This study aimed to explore the role and mechanism of MIT in alleviating podocyte injury in DN.MethodsA mouse model of DN was constructed using streptozotocin (STZ). Mice were divided into 3 groups: the untreated diabetic nephropathy group (DN group), the microencapsulated islet transplantation-treated group (MIT group) and the control group. The mice were raised for 6 weeks posterior to islet transplantation to identify the role of MIT. Renal function and structure of glomerular filtration barrier were assessed by urine analysis, histopathological examination, and transmission electron microscopy. The expression levels of several proteins including Caspase-3, Bcl2/Bax, β-galactosidase, Ki-67, synaptopodin, WT-1, Jagged-1, Notch-1, and Hes-1 in renal tissues were identified via immunohistochemistry (IHC), immunofluorescence (IF), and western blotting techniques.ResultsCompared with the DN group, the MIT group presented decreased levels of blood glucose, urinary albumin/creatinine, urea nitrogen, and serum creatinine while their body weight gradually increased. Glomerular injury in the MIT group was significantly better than that in the DN group. The MIT group indicated significantly decreased expression of Caspase-3, β-galactosidase, Bax/Bcl-2, and Ki-67 when compared with DN group, while the proportion of synaptopodin- and WT-1-positive cells was significantly increased (P < 0.05). The protein expression of Jagged-1, Notch-1, and Hes-1 in the glomerulus of the MIT group was significantly lower than that in the DN group (P < 0.05).ConclusionMIT alleviates podocyte injury induced by DN by inhibiting Notch-1 signaling. The identification of signaling pathways influencing podocyte restoration can help evaluate personalized medicine efficacy for patients treated with islet transplantation.     

雷帕霉素通过调节mTOR-ULK1信号通路减轻高糖诱导的足细胞损伤

目的探讨雷帕霉素对高糖环境下足细胞自噬和损伤作用的机制。 方法体外培养永生化小鼠肾小球足细胞(mouse podocyte cell 5,MPC5)并进行分组：甘露醇等渗组(mannitol isotonic group,MG组)、高糖组( high glucose group,HG组)、雷帕霉素组(rapamycin group,RG组)以及自噬相关蛋白5-siRNA组(SiG组)。PCR和Western印迹检测足细胞标志Synaptopodin、自噬相关的ULK1以及mTOR通路相关蛋白p70S6K的表达。 结果与MG组相比,HG组的Synaptopodin表达降低,自噬活性降低,p-ULK1以及p70S6K表达明显升高。与HG组相比,RG组的Synaptopodin表达升高,自噬活性较高,p-ULK1以及p70S6K表达较低。SiG组表现出与HG组相似的变化趋势。 结论雷帕霉素可能通过mTOR-ULK1信号通路调节足细胞内自噬反应、减轻高糖环境引起的足细胞损伤。     

Tolvaptan, a selective oral vasopressin V2 receptor antagonist, ameliorates podocyte injury in puromycin aminonucleoside nephrotic rats

Background  

Proteinuria caused by glomerular disease is characterized by podocyte injury. Vasopressin V2 receptor antagonists are effective in reducing albuminuria, although their actions on glomerular podocytes have not been explored. The objective of this study was to evaluate the effects of tolvaptan, a selective oral V2 receptor antagonist, on podocytes in a puromycin aminonucleoside (PAN)-induced nephrosis rat model.     

Ca antagonist ameliorates glomerular injury via suppression of glomerular hypertrophy in spontaneously hypertensive rats

Summary: A study was conducted to determine whether calcium blockers (CCB) have renoprotective effects, and if so to elucidate the mechanisms of such effects.
A total of 30 uninephrectomized (UNX) spontaneously hypertensive rats (SHR), 5 weeks of age, were divided into three groups. Group 1 was fed a diet containing 0.01% manidipine and 8% NaCl, while groups 2 and 3 were fed diets containing only 8 and 0.5% NaCl, respectively. Feeding of these diets began 7 days after UNX (experimental day 0). Bodyweight, urinary protein /24 h, urinary sodium excretion/24 h, and food intake were measured at certain time intervals.
At time of death (day 9 or 21), estimations of inulin clearance (Cin) and morphological evaluations, determination of glomerular sclerosis index (GSI), tubulointerstitial index (TII) and glomerular volume were performed.
Urinary protein was significantly higher in groups 1 and 2 than in group 3 from day 7 onward, but did not differ between the former two groups. Cin in group 2 was higher than in groups 1 and 3 on day 9, but declined to lower levels than in groups 1 and 3 by day 21. There was no difference in Cin between group 1 and group 3 on day 21. Morphometry (GSI and TII) revealed that renal lesions were more progressive in group 2 than in group 1. Glomeruli in group 2 were markedly larger than those in group 1, but no difference in glomerular volume was noted between groups 1 and 3.
Our findings suggest that CCB prevent progression of renal injury induced by accelerated hypertension in UNX SHR. the mechanisms of prevention may, at least in part, be related to suppression of glomerular hypertrophy. Inhibition of renal injury can be achieved without significant reduction of proteinuria.     

Simvastatin ameliorates gentamicin-induced renal injury in rats

Gentamicin nephrotoxicity is one of the most common causes of acute renal failure. Simvastatin is one of the antioxidative drugs, which has anti-inflammatory and anabolic effects and modulates the immune system. The present study was conducted to assess the effect of simvastatin on ameliorating the gentamicin-induced renal injury in 87 Sprague-Dawley rats, which were allocated randomly to 11 study groups: (A) and (B) groups with only gentamicin in 2 dosages; (C), (D), and (E) gentamicin 50 mg/kg/day and simvastatin with different dosage; (F), (G), and (H) gentamicin 80 mg/kg/day and simvastatin with different dosage; (I) only simvastatin; (J) Injected normal saline; (K) control (no gentamicin and no simvastatin) group. Our study intervention period for injection of drugs was 12 days. Serum creatinine level and clearance were measured in all groups. At the end of the study, the rats were killed and both kidneys were removed and processed for histopathologic examination using the standard methods. The 50 mg/kg/day dose was utilized because it induces a mild form of renal toxicity, whereas the 80 mg/kg/day dose cause a more severe degree of renal injury. Morphologic examination of specimens from all rats was qualitatively assessed with blindness to treatment groups and proximal tubular profiles that were presented in each file were counted. The results demonstrated amelioration of gentamicin-induced renal toxicity in rats by simvastatin due to its antioxidant drug dose-related effect.     

1,25(OH)2D3 ameliorates high glucose-induced podocyte injury via PI3K/p-Akt signalling pathway

Objective To investigate the effect of 1,25(OH)2D3 on high glucose induced podocyte injury and its signal transduction mechanism. Methods Differentiated mouse podocytes were exposed to normal glucose, high glucose, and different concentrations of 1,25(OH)2D3 or LY294002 (a selective PI3K inhibitor) for 24 h. PCR and immunofluorescent staining were used to detect nephrin, podocin, and desmin. Western blotting was used to detect protein expression of nephrin, podocin, desmin, PI3K, Akt and p-Akt. Results Compared with high glucose group, 1,25(OH)2D3 (100 nmol/L and 1000 nmol/L) significantly up-regulated the expression of podocin and nephrin in podocytes induced by high glucose (P＜0.05). Meanwhile, 1,25(OH)2D3 (100 nmol/L) significantly reduced the expression of desmin (P＜0.05). PI3K and p-Akt were obviously reduced in high glucose group. In the presence of 1,25(OH)2D3, the trends were reversed. However the above effects of 1,25(OH)2D3 were abolished when p-Akt was blocked by the PI3K inhibitor LY294002. Conclusions 1,25 (OH)2D3 can inhibit high glucose-induced podocyte injury through PI3K/p-Akt signaling pathway.     

糖尿病肾损伤患者的尿足细胞排泄特点

我们以往的研究发现糖尿病(DM)和非DM患者在肾功能正常的情况下亦可检测到足细胞尿[1-2],据此我们认为足细胞尿的检测亦可作为DM伴肾损伤的早期诊断和动态检测指标.为此,我们观察了DM伴不同程度肾损伤患者的尿足细胞排泄特点.     

L-carnitine ameliorates gentamicin-induced renal injury in rats.

BACKGROUND: This study examined whether administration of L-carnitine ameliorates gentamicin-induced renal injury in rats. METHODS: Male Sprague-Dawley rats were assigned to one of seven treatment groups: group A (control) rats were given normal saline injections daily for 8 consecutive days; group B, C and D rats were given gentamicin injections, 50 mg/kg body weight/day daily for 8 consecutive days; and group E, F and G rats were given gentamicin injections, 80 mg/kg/day daily for 8 consecutive days. Starting 4 days before these injections, all groups were given additional injections, for 12 consecutive days, of normal saline (groups A, B and E) or L-carnitine at 40 mg/kg (groups C and F) or 200 mg/kg (groups D and G). Histological scoring of renal cortical pathology was performed after day 12. RESULTS: Among rats injected with gentamicin 50 mg/kg/day, those given either 40 or 200 mg/kg/day of L-carnitine had higher creatinine clearances at day 12 than the rats not given carnitine. In the rats given 80 mg/kg gentamicin and no carnitine, renal function tended to be lower than in controls. At day 12, the rats given gentamicin 80 mg/kg and L-carnitine 200 mg/kg/day, compared with rats given gentamicin 80 mg/kg and no carnitine, displayed lower serum urea and probably creatinine concentrations, and higher creatinine clearances, and their serum urea was not different from control (group A) rats. Both doses of gentamicin induced renal cortical histopathology. Changes were milder with gentamicin 50 mg/kg/day, and L-carnitine, particularly at 200 mg/kg/day, ameliorated the severity of renal pathology induced by both gentamicin doses. In rats given gentamicin 80 mg/kg/day, the animals treated with carnitine 200 mg/kg/day had significantly less severe proximal tubular necrosis and significantly greater mild proximal tubular necrosis compared with rats receiving L-carnitine 40 mg/kg/day or no carnitine. CONCLUSIONS: In rats receiving gentamicin, daily L-carnitine injections, particularly at 200 mg/kg/day, ameliorate the severity of renal cortical proximal tubular necrosis and maintain greater renal function.     

螺内酯对糖尿病大鼠肾小球保护作用的机制探讨

目的 观察螺内酯对糖尿病大鼠肾小球的保护作用并探讨其机制。 方法 将SD大鼠随机分为健康对照组、病理组、螺内酯治疗组。治疗30 d后处死，观察肾小球病理形态变化；RT-PCR法观察肾脏皮质纤溶酶原激活剂抑制物1(PAI-1) 和转化生长因子β1(TGF-β1)mRNA的变化； Western印迹法观察肾脏皮质PAI-1的表达；免疫组化方法观察肾脏皮质TGF-β1、纤连蛋白(FN)变化及检测肾皮质丙二醛(MDA) 含量、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px) 、总抗氧化能力(T-AOC)活性。 结果 与病理组比，螺内酯治疗后可下调肾皮质TGF-β1、PAI-1 mRNA与蛋白表达（P均< 0.05）；降低肾皮质MDA水平[（0.95±0.20）比（1.23±0.31） nmol/mg，P < 0.05]；增强SOD、GSH-Px、T-AOC活性[分别为（550.19±20.06）比（509.53±33.25） U/mg，（21.67±2.70）比（18.91±2.30） U/mg，（1.15±0.21）比（0.86±0.26） U/mg，P均< 0.05]；减少FN在肾小球的沉积(P < 0.01)；改善肾小球的病理状况。 结论 螺内酯可能通过下调糖尿病大鼠肾皮质TGF-β1、PAI-1表达，降低肾皮质氧化应激水平，起到保护糖尿病大鼠肾脏，延缓肾小球硬化的作用。     

Involvement of endoplasmic reticulum (ER) stress in podocyte injury induced by excessive protein accumulation

BACKGROUND: An imbalance between protein load and folding capacity is referred to as endoplasmic reticulum (ER) stress. As a defense mechanism, cells express ER stress inducible chaperons, such as oxygen-regulated proteins 150 (ORP150) and glucose-regulated proteins (GRPs). While ER stress is important in various diseases, a pathophysiologic role for ER stress in kidney disease remains elusive. Here we investigate expression of ER stress proteins in cultured rat podocytes as well as in our recently developed animal model of abnormal protein retention within the ER of podocytes (i.e., megsin transgenic rat). METHODS: The expression of ER stress inducible proteins (ORP150, GRP78, or GRP94) in cultured podocytes treated with tunicamycin, A23187, SNAP, hypoxia, or hyperglycemia, and the renal tissues or isolated glomeruli from megsin transgenic rats was analyzed by Western blotting analysis, immunohistochemistry, or confocal microscopy. RESULTS: Cultured podocytes demonstrated that treatment with tunicamycin, A23187, and SNAP, but not hypoxia or hyperglycemia, up-regulate expression of ER stress proteins. Extracts of isolated glomeruli from megsin transgenic rats reveal marked up-regulation of ER stress chaperones in podocytes, which was supported by immunohistochemical analysis. Confocal microscopy revealed that ER stress in podocytes was associated with cellular injury. Podocytes of transgenic rats overexpressing a mutant megsin, without the capacity for polymerization within the ER, do not exhibit ER stress or podocyte damage, suggesting a pathogenic role of ER retention of polymerized megsin. CONCLUSION: This paper implicates a crucial role for the accumulation of excessive proteins in the podocyte ER in the induction of ER stress and associated podocyte injury.     

Hemolysate pretreatment ameliorates ischemic acute renal injury in rats

Heme oxygenase-1 (HO-1) is an antioxidant enzyme and is believed to protect against oxidative stress-induced tissue injury. Renal ischemia-reperfusion (IR) injury seems at least in part to be caused by the oxidative stress. The aim of this study was to improve the renal IR injury by clinically available means. When littermate hemolysate was intravenously administered into rats, HO-1 was markedly induced in the kidneys. To investigate whether prior induction of HO-1 by the hemolysate injection ameliorates the subsequent renal IR injury, we assessed the levels of blood urea nitrogen (BUN) and serum creatinine (SCr), markers for renal injury, in rats with 45 min of ischemia followed by 18 h of reperfusion. To avoid the nephrotoxicity induced by hemolysate, small but effective amounts of hemolysate was injected into rats at 48 h prior to the ischemia. The levels of BUN and SCr values were significantly improved as compared to the rats with renal IR injury alone. Administration of HO inhibitor abolished the efficacy of hemolysate pretreatment. Our findings indicated that the prior induction of HO-1 by treatment of littermate hemolysate ameliorated the subsequent renal IR injury. Prior injection of self-hemolysate would be clinically useful for the protection against the renal IR injury induced by kidney transplantation and kidney surgery without immunological and infectious problems.     

Polyenylphosphatidylcholine pretreatment ameliorates ischemic acute renal injury in rats

AIM: Polyenylphosphatidycholine has been demonstrated to have antioxidant, cytoprotective and anti-inflammatory effects. Whether polyenylphosphatidycholine pretreatment affects ischemia/reperfusion-induced renal damage in vivo is not known and was investigated here in rats. METHODS: Forty female Sprague-Dawley rats were divided into three groups. Group 1 (n = 10) was given saline (control, sham operated). Group 2 (n = 15) were given saline, and Group 3 (n = 15) were given polyenylphosphatidycholine (100 mg/day for 10 days prior to experiment). Groups 2 and 3 were subjected to bilateral renal ischemia (60 min) followed by reperfusion (6 h). After the reperfusion period, the rats were sacrificed and kidney tissue superoxide dismutase, glutathione, total nitrite and nitrate, malondialdehyde and myeloperoxidase levels, plasma aspartate aminotransferase, blood urea nitrogen and creatinine concentrations, and nuclear factor kappa beta expression were determined. RESULTS: Serum levels of aspartate aminotransferase, blood urea nitrogen and creatinine were significantly decreased (P < 0.05) in the treatment group compared to those in the ischemic group. There were significant differences between treatment and ischemic groups regarding the tissue superoxide dismutase, glutathione, total nitrite and nitrate, malondialdehyde, and myeloperoxidase levels (P < 0.05). In addition, polyenylphosphatidycholine pretreatment reduced nuclear factor kappa beta expression in ischemic kidney tissue. Kidneys obtained from rats pretreated with polyenylphosphatidycholine demonstrated marked reduction of the histological features of renal injury compared to kidneys obtained from Group 2 rats, including a little vacuolization, pyknosis and necrosis. CONCLUSIONS: Polyenylphosphatidycholine pretreatment provided significant protection against ischemia/reperfusion injury to the kidney. This treatment could be therapeutic in kidney transplantation and other conditions associated with ischemia/reperfusion injury to the kidney.     

活性维生素D通过调节糖尿病肾病大鼠巨噬细胞M1及M2表型活化防治足细胞损伤

目的 探讨活性维生素D（VD）能否通过调节肾组织巨噬细胞M1 及M2 表型活化从而防治糖尿病肾病（DN）大鼠足细胞损伤。 方法 利用腹腔注射链脲菌素（STZ）建立糖尿病大鼠模型。将SD 雄性大鼠按随机数字表法分为4 组：对照组1（NC-1 组,n=8）、对照组2（NC-2 组,n=8,对照+骨化三醇0.1 μg·kg^-1·d^-1 灌胃）、DN 组（n=24）、DN+VD 干预组（VD 组,n=24,DN+骨化三醇0.1 μg·kg^-1·d^-1 灌胃）,定期检测血糖、体质量,收集尿标本,分别于干预后8周、14周、18周末处死动物,检测Scr、BUN和尿蛋白变化;PAS染色观察肾脏病理改变;免疫组化法检测肾组织CD68+巨噬细胞浸润数量;Western 印迹法检测nephrin、podocin、CD68 以及M1巨噬细胞特异性标志物诱导型氮氧化物合酶（iNOS）、肿瘤坏死因子α（TNF-α）和M2巨噬细胞特异性标志物CD163、精氨酸酶1（Arg-1）、甘露糖受体（MR）表达。 结果 （1）与两对照组相比,DN 组Scr、BUN、24 h 尿蛋白量及肾小球系膜基质增生程度显著增加（P＜0.05）,podocin、nephrin蛋白表达下降（P＜0.05）。VD干预后能明显改善上述病理现象（均P＜0.05）。（2）与两对照组相比,DN组肾组织CD68⁺巨噬细胞浸润数量明显增加,呈时间依赖性。VD干预后能显著减少CD68⁺巨噬细胞浸润数量（P＜0.05）。（3）进一步确定肾组织巨噬细胞M1、M2活化表型发现,8周、14周、18周末DN组iNOS、TNF-α蛋白表达较对照组显著升高（均P＜0.05）,VD干预后能明显抑制同期DN肾组织iNOS、TNF-α表达（均P＜0.05）;8周、14周末VD组CD163、Arg-1、MR蛋白表达与DN组相比差异无统计学意义（均P＞0.05）,而18周末VD组CD163、Arg-1、MR蛋白表达较DN 组显著升高（均P＜0.05）,CD163/CD68 蛋白表达比例亦显著增加（P＜0.05）。（4）相关分析显示,M1 标志物iNOS 与nephrin、podocin 蛋白表达均呈负相关（r＝-0.707,P＜0.01;r＝-0.712,P＜0.01）;M2标志物CD163与nephrin、podocin蛋白表达均呈正相关（r＝0.627,P＜0.01;r＝0.613,P＜0.01）。 结论 活性维生素D具有调节巨噬细胞表型活化的能力,通过抑制巨噬细胞M1型活化并增强M2型活化,进而发挥足细胞保护作用。     

The mechanism of electroacupuncture for treating spinal cord injury rats by mediating Rho/Rho-associated kinase signaling pathway

Objective: To determine the changes of gene and protein expression through Rho/ROCK signaling pathway in EA treated spinal cord injury (SCI) rats and to unveil the possible underlying mechanism.Design: Animal study.Setting: Affiliated Hospital of Jiangxi University of Traditional Chinese Medicine.Participants: Eighty Male Sprague Dawley rats.Interventions: Electroacupuncture at Yaoyangguan (GV3), Dazhui (GV14), Zusanli (ST36) and Ciliao (BL32) and/or blocking agent Y27632 treatment.Outcome Measures: Protein expression was detected by ELISA and Western blotting, mRNA expression was detected by quantitative PCR and in situ hybridization. Morphological changes in spinal cord were evaluated by HE-staining and Nissl staining. Hindlimb motor function in the rats was evaluated by Basso–Beattie–Bresnahan (BBB) assessment methods.Results: Compared with injured rats in SCI group, EA, blocking agent Y27632 and EA + blocking agent Y27632 treatment had significantly reduced mRNA and protein expression levels of RhoA and ROCKII, decreased p-MLC protein expression and p-MLC/MLC ratio, suppressed cPLA2 activity and PGE₂ level, improved spinal cord tissue morphology and BBB score of lower limb movement function at 7 days and at 14 days (P < 0.01 or <0.05).Conclusion: Similar to the blocking agent Y27632, EA may have a notable inhibitory effect on the Rho/ROCK signaling pathway after SCI, therefore reducing the inhibition of axonal growth and inflammatory reaction may be a key mechanism of EA treatment for SCI.     

Inhibition of cyclooxygenase-2 expression contributes to podocyte injury in streptozotocin-induced diabetic rats

Objective To investigate the role of cyclooxygenase-2 (COX-2) in podocyte injury in diabetic rats mediated by the disruption of low-density lipoprotein receptor (LDLr) pathway. Methods Eight-week old male Sprague-Dawley (SD) rats were treated for 12 weeks by dividing into three groups: control rats, streptozotocin (STZ) induced diabetic rats (DM), and diabetic rats treated with aspirin (DM+Aspirin). The plasma lipid profile was checked by clinical biochemistry assay. The ratio of urinary microalbumin to creatinine (ACR) was detected by enzyme-linked immunosorbent assay. Intracellular lipid accumulation was evaluated by Oil Red O staining and a free cholesterol quantitative assay. The glomerular podocyte injury and the expression of molecules related with LDLr pathway were evaluated by electron microscope, immunohistochemical staining, immunofluorescent staining, and Western blotting. Results There were increased levels of urinary ACR (P＜0.01) and podocyte injury(P＜0.01) in DM rats compared with the controls. Additionally, lipid accumulation in kidneys of DM rats were significantly increased (P＜0.01), due to increased protein expressions of COX-2, LDLr, sterol regulatory element–binding protein (SREBP) cleavage activating protein (SCAP), and SREBP-2 (P＜0.01). However, these changes were significantly inhibited by an inhibitor of COX-2, Aspirin (P＜0.05). It's worth noting that, COX-2 protein expression was closely correlated with LDLr protein expression (r=0.85, P＜0.01). Conclusion Dysregulation of LDLr pathway contributes to podocyte injury in diabetic nephropathy, which may be mediated through the increased COX-2 expression.