目的 基于微阵列数据鉴定膜性肾病(MN)中显著差异表达的基因,并为膜性肾病的诊断与治疗寻找新的潜在基因靶点.方法 通过基因表达数据库(GEO)下载GSE108109、GSE115857两个数据集.应用GEO2R工具筛选出正常肾组织与MN患者肾组织的差异表达基因(DEGs).应用DAVID数据库,对DEGs进行基因本体论(GO)富集和京都基因与基因组百科全书(KEGG)通路富集.然后,应用STRING工具和Cytoscape软件构建并可视化DEGs的蛋白质—蛋白质相互作用(PPI)网络,通过Degree分析识别其中的Hub基因.应用NephonSeq v5在线平台分析Hub基因表达与MN临床特征的关系.结果 共筛选出240个DEGs,其中表达上调基因149个,表达下调基因91个.DEGs涉及许多功能和表达途径,如细胞形态调节及细胞骨架的构建.在PPI网络中,共识别出13个Hub基因,包括TP53、PIK3R1、KIT、QSOX1、LAMB1、SHC1、CDK2、APOL1、NES、PTPN6、POLR2A、PRKACA、LTBP1.PRKACA、LTBP1基因表达与蛋白尿呈正相关(r分别为0.858、0.799,P分别为0.006、0.017),POLR2A的表达与蛋白尿呈负相关(r=-0.866,P=0.005).PRKACA基因表达与血肌酐呈负相关(r=-0.601,P=0.008),POLR2A的表达与血肌酐呈正相关(r=0.583,P=0.011).结论 通过生物信息学分析MN肾组织微阵列数据,发现240个DEGs和13个Hub基因,这些基因可能为MN的诊断与治疗提供潜在基因靶点.

AIM:To observed the protective effect of diminazene aceturate ( DIZE) , an angiotensin-converting enzyme 2 (ACE2) activator, on diabetic nephropathy (DN) rats.METHODS:Male Wistar rats (n=30) were randomly divided into normal control (NC) group, DN group and DIZE group (each group consisted of 10 rats).The rats in DN group and DIZE group were induced by intraperitoneal injection of streptozotocin at dose of 65 mg/kg.After 12 weeks, the rats in DIZE group and DN group received subcutaneous injection of DIZE (15 mg· kg -1 · d-1 ) or vehicle for 4 weeks. The samples of blood and urine were collected at week 16, and ratio of kidney weight to body weight (KW/BW), plasma glucose (GLU), 24 h urinary protein (24UP) and serum creatinine (SCr) were measured.The renal pathological changes in each group were observed by periodic acid-Schiff ( PAS) staining and immunohistochemistry .The levels of AngⅡ and Ang-(1-7) in the plasma, and TGF-β1 and VCAM-1 in the renal tissues were measured by ELISA .The mRNA and protein levels of collagen I and FN were determined by quantification real-time PCR and immunohistochemistry .The effects of DIZE on the expression of ACE2 in DN rats were determined by Western blot .RESULTS:DIZE remarkably increased the expression of ACE2 and Ang-(1-7) in DN rats.Compared with NC group , the GLU, KW/BW, 24UP, SCr, and the ex-pression of collagen I , FN, TGF-β1 and VCAM-1 in DN group and DIZE group were increased .However , after treatment of the DN rats with DIZE, these indicators were decreased except the KW/BW.The GLU showed no significant change . CONCLUSION:DIZE raised the activity of ACE2 and increased the expression of Ang-(1-7), thus alleviating fibrosis and inflammation in the kidney and having therapeutic potential for diabetic nephropathy .

The treatment of diabetic nephropathy (DN) currently extent to control the occurrence and development of it and delay renal failure on a certain stage.However,the effect is not satisfactory.Some traditional hypoglycemic,antihypertensive,lipid and anticoagulant drugs in DN patients with renal protective effect.And some have been in clinical use of drugs such as vitamin D,aldose reductase inhibitors,tripterygium wilfordii glycoside has proved to have the effect of the slow progress in DN,could be used more widely.For new drugs,such as renin inhibitors,phosphodiesterase inhibitors and methyl bartholomew sauron,while partialy was confirmed in a role in the treatment of DN,but before the clinical promotion,its effectiveness and safety still need further study to verify.

Epoxyeicosatrienoic acids (EETs) are the epoxidation products of arachidonic acid catalyzed by cytochrome P450 (CYP) epoxygenases, which possess multiple biological activities. In the present study, we aimed to explore the role and effects of CYP epoxygenases/EETs in wound healing in ob/ob mice. Full-thickness skin dorsal wounds were made on ob/ob mice and C57BL/6 control mice. The mRNA and protein expression of CYP epoxygenases were determined in granulation tissues of wounds. Effects of EETs on wound healing were evaluated. Inflammation and angiogenesis in wounds were also observed. Compared with C57BL/6 mice, the mRNA and protein expression of CYP2C65 and CYP2J6 in the granulation tissues in ob/ob mice were significantly reduced. 11,12-EET treatment significantly improved wound healing in ob/ob mice, whereas 14,15-EEZE, an EET antagonist, showed the opposite effect. 11,12-EET treatment decreased neutrophil and macrophage infiltration to the wound sites, resulting in reduced production of inflammatory cytokines, decreased MMP-9 expression, and increased collagen accumulation in the granulation tissues of ob/ob mice. In addition, 11,12-EET increased angiogenesis in the granulation tissues of wounds in ob/ob mice. These findings indicate that reduced expression of CYP epoxygenases may contribute to impaired diabetic wound healing, and exogenous EETs may improve diabetic wound healing by modulating inflammation and angiogenesis.

AIM:To investigate the effect of liraglutide ( LG) on the expression of fibronectin type Ⅲdomain-containing protein 5 (FNDC5) in the C2C12 myotubes.METHODS:The C2C12 mouse myoblast cell line was induced to differentiation.Differentiated cells were stimulated with gradient concentrations (1 ~1000 nmol/L) of LG for different time (0 ~24 h).The effects of LG on the expression of FNDC5 and the activation of adenosine 5'-monophosphate ( AMP)-activated protein kinase ( AMPK) signaling pathway were determined .After pretreated with glucagon-like peptide-1 ( GLP-1 ) receptor antagonist exendin 9-39 , the inhibitor of Ca 2+/calmodulin-dependent protein kinase kinase 2 (CAMKK2), STO609, or the inhibitor of AMPK, Compound C, the LG-induced FNDC5 expression in C2C12 myotubes was examined.The expression of FNDC5 and the activation of AMPK were determined by Western blot .RESULTS: In C2C12 myotubes, LG promoted the expression of FNDC5 in a dose-and time-dependent manner .LG also activated AMPK signaling pathway .These effects of LG were partly abolished by exendin 9-39 , STO609 and Compound C .CONCLUSION:LG promotes the expression of FNDC5 via GLP-1 receptor in the C2C12 myotubes possibly through activation of the CAMKK2/AMPK signaling pathways .

目的 观察磷结合剂碳酸司维拉姆治疗尿毒症合并高磷血症的临床效果.方法 选择行维持性血液透析的尿毒症合并高磷血症患者120例,随机分为观察组和对照组各60例.在常规血液透析治疗基础上,观察组给予碳酸司维拉姆1.6 g/次,3次/d,对照组给予醋酸钙1.334 g/次、3次/d.2周后抽取静脉血,应用自动生化分析仪检测血清磷、钙、甲状旁腺素、碱性磷酸酶、总胆固醇、甘油三酯、低密度脂蛋白胆固醇、高密度脂蛋白胆固醇、尿素氮、肌酐水平.结果 治疗后两组血清磷、钙磷乘积、甲状旁腺素水平均较治疗前下降,观察组血清磷、钙磷乘积低于对照组(P均<0.05).观察组血清低密度脂蛋白胆固醇、尿素氮、肌酐水平较治疗前下降(P均<0.05),对照组上述指标与治疗前比较无统计学差异(P均>0.05).观察组血清高密度脂蛋白胆固醇水平与治疗前比较无统计学差异(P>0.05),对照组较治疗前明显下降(P<0.05).结论 碳酸司维拉姆可在短期内降低血清磷水平,在降磷的同时还可改善血脂代谢和肾功能.

The aim of this study was to assess the effects of hydrogen sulfide on high glucose-induced mouse podocyte (MPC) injury and the underlying mechanisms. Mouse podocytes were randomly divided into 4 groups, including high glucose (HG), normal glucose (NG), normal glucose + DL-propargylglycine (PPG), and high glucose + NaHS (HG + NaHS) groups for treatment. Then, ZO-2, nephrin, β-catenin, and cystathionine γ-lyase (CSE) protein expression levels were determined by western blot. We found that high glucose significantly reduced nephrin, ZO-2, and CSE expression levels (P<0.05), and overtly elevated β-catenin amounts (P<0.05), in a time-dependent manner. Likewise, PPG at different concentrations in normal glucose resulted in significantly lower CSE, ZO-2, and nephrin levels (P<0.05), and increased β-catenin amounts (P<0.05). Interestingly, significantly increased ZO-2 and nephrin levels, and overtly reduced β-catenin amounts were observed in the HG + NaHS group compared with HG treated cells (P<0.01). Compared with NG treated cells, decreased ZO-2 and nephrin levels and higher β-catenin amounts were obtained in the HG + NaHS group. In conclusion,CSE downregulation contributes to hyperglycemia induced podocyte injury, which is alleviated by exogenous H2S possibly through ZO-2 upregulation and the subsequent suppression of Wnt/β-catenin pathway.

Accumulation of extracellular matrix (ECM) in glomerular mesangium correlates with loss of renal function in diabetic nephropathy. However, the mechanisms underlying are still incompletely known. In the present study, we explored the role of caveolae in ECM production in rat mesangial cells (MCs) stimulated by high glucose or transforming growth factor-β1 (TGF-β1), and investigated the possible mechanisms. High glucose (HG) or TGF-β1 significantly increased collagen-1 and fibronectin expression at both mRNA and protein levels in time- course dependent manners, and simultaneously induced caveolin-1 tyrosine phosphorylation. Disruption of caveolae with Methyl-β-cyclodextrin (β-MCD) prevented HG and TGF-β1 induced caveolin-1 tyrosine phosphorylation, and attenuated fibronectin but not collagen-1 production. This effect of β-MCD on fibronectin production could be abolished by cholesterol, which restored HG and TGF-β1 induced caveolin-1 tyrosine phosphorylation. In addition, HG and TGF-β1 induced fibronectin production was attenuated by a caveolin-1 scaffold domain peptide. These findings indicate that mesangial cell caveolae regulate fibronectin production at least partly through caveolin-1 phosphorylation.

AIM:To investigate the effect of hydrogen sulfide ( H2 S) on high glucose ( HG)-induced injury of the mouse podocyte cell line MPC5.METHODS: The cultured MPC5 cells were randomly divided into 4 groups: HG group, normal glucose (NG) group, NG+DL-propargylglycine (PPG) group, and HG+NaHS group.After treated for a certain time, the cells were collected for further detection .The expression of zonula occludens-2 (ZO-2), nephrin,β-cate-nin and cystathionine γ-lyase ( CSE) was determined by Western blotting .RESULTS:High glucose significantly reduced the expression of nephrin, ZO-2 and CSE (P<0.05), while the level of β-catenin was elevated obviously (P<0.05), all in a time-dependent manner.NG+PPG inhibited the levels of ZO-2 and nephrin significantly (P<0.05), and increased the level of β-catenin (P<0.05), all in a PPG concentration-dependent manner.HG+NaHS induced a more significant increase in the levels of ZO-2 and nephrin as compared with HG group (P<0.01), whereas a severe reduction of β-cate-nin in HG+NaHS group was observed as compared with HG group .Compared with NG group , the expression of ZO-2 and nephrin was decreased obviously , and the level of β-catenin was increased in HG +NaHS group.CONCLUSION:Down-regulation of CSE contributes to hyperglycemia-induced podocyte injury .Exogenous H 2 S protects against hyperglycemia-in-duced podocyte injury , possibly through up-regulation of ZO-2 and subsequent suppression of Wnt/β-catenin pathway .

Objective To stu-dy the effects of Cordyceps sinensis on expression of fibronectin(FN),Dickkopf-1(DKK1) and β-catenin in the kidney of diabetic rats,and to investigate the mechanisms underlying.Methods Diabetes was induced in Wistar rats by intraperitoneal injection of Streptozotocin(60 mg/Kg).Diabetic rats were randomly divided into the none-treatment group(n=12) and the Cordyceps treatment group(n=12).None diabetic Wistar rats were used as controls(n=12).After 12 weeks,the rats were sacrificed.The level of blood glucose,urinary albumin to creatinine ratio(UACR) and creatinine clearance rate(Ccr) were determined.The protein and mRNA levels of DKK1,β-catenin and FN were evaluated by immunohistochemistry and real-time PCR.DKK1 protein expression was further examined by western blot.Results Compared with control group,the levels of UACR and Ccr in no treatment group and Cordyceps treatment group were significantly increased(P0.05),the mRNA and protein levels of FN and DKK1 were significantly elevated(P0.05).Compared to no treatment group,the levels of UACR and Ccr in Cordyceps treatment group were decreased,the mRNA and protein levels of FN and DKK1 were reduced(P0.05).Compared with control group,β-catenin expression was significantly reduced in none-treatment group as demonstrated by immunostaining(P0.05);while β-catenin expression was significantly higher in Cordyceps-treatment group compared with no treatment group(P0.05).Conclusion Cordyceps sinensis may reduce the excessive accumulation of FN in the kidney of diabetic rats through suppressing DKK1 expression and stabilizing β-catenin protein.

目的 观察冬虫夏草 (CS) 对糖尿病肾病 (DN)大鼠纤溶系统功能的影响.方法 44只大鼠随机分为正常对照组、模型组 (给予链脲佐菌素55 mg/kg体重腹腔注射),CS早期干预组及冬虫夏草晚期干预组,12 w后测体重、肾重、血糖、血肌酐 (Scr)、24 h尿蛋白等指标,光镜观察肾脏病理变化,免疫组化法分别检测组织型纤溶酶原激活物 (t-PA)/纤溶酶原激活物抑制剂表达 (PAI).结果 模型组肾重、血糖、Scr、24 h尿蛋白均明显高于正常对照组(P＜0.01),PAI表达明显高于正常对照组,体重、t-PA表达明显低于正常对照组;两干预组肾重、Scr、血尿素氮 (BUN)、24 h尿蛋白、t-PA表达均高于模型组(P＜0.05),低于正常对照组(P＜0.01),体重、PAI表达低于模型组,高于正常组,血糖较模型组无明显变化;冬虫夏草早期干预组效果优于晚期干预组(P＜0.05).结论 DN时存在t-PA/PAI失衡,冬虫夏草治疗DN的机制之一为矫正t-PA/PAI失衡.

Objective To study the effects of cordyceps sinensis on renal expressions of cathepsin B(CB)and cystatin C(CC)in diabetic nephropathy(DN)rats,and investigate its mechanisms.Methods100 healthy male Wistar rats were divided into normal and diabetic groups.The diabetic rat models were established by intraperitoneal injection of STZ(55 mg/kg),then the diabetic model rats were divided into model and treatment groups.At the end of 4,8 and 16 weeks,the urine of each group rats was collected,then 10 rats of each group were sacrificed and the kidneys and blood of them were collected.The expressions of CB,CC,ColⅣ and fibronectin(FN)in renal tissue were measured by real time PCR and immunohistochemical technique.ResultsCompared with normal group,the levels of Ccr and urine protein excretion of model group and treatment group were increased at 4 weeks(P<0.01),the expressions of CB,CC,ColⅣ and FN were significantly increased at 8 weeks(P<0.01,P<0.05),but the expression of CB in model group at 16 weeks was significantly decreased(P<0.01).Compared with model group,the expressions of CC,ColⅣ and FN in treatment group were significantly decreased at 16 weeks(P<0.01,P<0.05),but the expression of CB was significantly increased(P<0.01).ConclusionsCordyceps sinensis can reduce the excessive accumulation of ECM in the kidney of DN rats through balancing the expressions of CB and CC.

AIM:To observe the expressions of cathepsin B (CB) and cystatin C (CC) in different stage of diabetic rats and to investigates their potential roles.METHODS:Sixty rats were divided into diabetes mellitus group induced by intravenous injection of streptozotocin (55 mg/kg) and normal group injected with citrate buffer. Ten rats were sacrificed respectively at the end of fourth week,eighth week and sixteenth week in both groups. 24 h urine excretion was collected in rats before sacrifice. The blood and the kidney were also collected. The mRNA and protein expressions of CB and CC in kidney were detected by real time PCR and immunohistochemical staining,respectively.RESULTS:At the end of eighth week,the expression of Ccr,24 h urinary protein excretion,CB,CC in diabetic rats increased significantly,compared to the results at the fourth week (P0.01 or P0.05). With the aggravation of diabetic nephropathy,the expressions of CC,colⅣ,FN and 24 h urinary protein excretion were up-regulated significantly (P0.01 or P0.05). The expression of CB in diabetic rats was up-regulated at eighth week significantly (P0.01),whereas,at the end of sixteenth week it was down-regulated significantly (P0.01). The 24 h urinary protein excretion,the expressions of colⅣ at protein and mRNA levels and FN were negatively correlated with CB (P0.01).CONCLUSION:The unbalance of CB and CC exists in diabetic nephropathy renal tissue,which is likely to lead to the accumulation of extracellular matrix.

Objective To observe the effects of cordycepic hypha(cordyceps sinensis,CS)on the pathological changes,the expression of matrix metalloproteinase(MMP)-2 and tissue inhibitor of metalloproteinase(TIMP)-2 in nephridial tissue of diabetic nephropathy(DN)rats and to explore the protective effects of CS and its mechanisms on the kidney.Methods Diabetic rat models were induced by injection of streptozotocin(STZ).These rats were randomly divided into diabetes model,CS 1(5.0 g·kg-1·d-1,given at the onset of DM model)and CS2(5.0 g·kg-1·d-1,given after 4 w)groups.At the same time,negative control group was set up.Plasma glucose,serum creatinine(SCr),blood urea nitrogen(BUN),and 24 h urinary protein(Upro)were observed after 8 weeks.The pathological changes of kidney were observed by light microscopy.The expressions of MMP-2,TIMP-2 and Col Ⅳ were detected in nephridial tissue by immunohistochemical technique.Results Compared with negative control group,the other three groups had significantly higher plasma glucose,Scr,BUN and Upro levels(all P<0.01);MMP-2 expression was decreased significantly in nephridial tissues(P<0.01),but Col Ⅳ as well as TIMP-2 expressions increased(P<0.01).After interfered,compared with DM model group,the above-mentioned abnormal indexes were improved significantly(P<0.05 or P<0.01),except for plasma glucose.CS1 group had better effect than CS2(P<0.05 or P<0.01),except for plasma glucose and BUN.Conclusions CS has some protective effect on the kidney of diabetic rats,which may be related with the inhibition of excessive deposition of glomeruli extracellular matrix by up-regulating MMP-2 and downregulating TIMP-2 expressions.And the earlier treatment,the better effect.

采用RT-PCR技术检测细胞内p53及bcl-2基因的改变,以观察六价铬[Cr(Ⅵ)]对人胚肺细胞(HEL)内癌基因和抑癌基因的影响及绿茶对其的拮抗作用.结果 显示,不同浓度的Cr(Ⅵ)溶液和绿茶浸泡液处理HEL细胞24 h后,5 μmol/L及10 μmol/L Cr(Ⅵ)单独处理组细胞内p53 mRNA和bcl-2 mRNA含量显著高于阴性对照组(P＜0.05).绿茶浸泡液处理组与Cr(Ⅵ)单独处理组相比,细胞内p53 mRNA和bcl-2mRNA含量降低(P＜0.05).提示六价铬可引起p53及bcl-2mRNA水平升高,绿茶浸泡液可以降低其表达水平.

Objective:To investigate the efficacy and safety of leflunomide(LEF) in the treatment of refractory primary nephrotic syndrome.Methods: Fifty-one patients with refractory nephrotic syndrome,26 with minor lesions(8 with minimal lesion nephropathy and 16 with mesangial proliferative glomerulonephritis),16 with membranous nephropathy(MN),6 with focal segmental glomerulosclerosis(FSGS),and 3 with mesangioproliferative glomerulonephritis(MPGN),were treated by LEF combined with prednisone.The initial dosage of LEF was 50?mg/d,3 days later,30?mg/d, for three months and then the dosage was gradually tapered off.The duration of LEF treatment was 6 to 12 months.Prednisone at a dosage of 20-60?mg/d was used at the beginning of the combined treatment and then the dosage was gradually tapered off.Follow up interviews were regularly conducted.Results: The urine protein was decreased by the combined treatment of LEF/prednisone and the serum albumin significantly elevated among patients with minor lesion and MN(P0.001).All patients with minor lesions achieved clinical remission.Fifteen of the twenty-six cases responded within four weeks and seventeen of them obtained complete clinical remission.The dosage of prednisone could be smoothly tapered off among the steroid dependent patients.Eleven of the sixteen patients with MN achieved remission,however,only five responded within four weeks and only three of them achieved complete clinical remission.During the treatment,six patients experienced a transient increase of the urine protein due to infection and spontaneously recovered without an alteration of treatment.Side effects were tolerable.Renal function remained stable during the treatment.Conclusion: LEF is an effective and safe immunosuppressive agent for refractory nephrotic syndrome.

为探索改善糖尿病肾病(DN)病理改变的新方法,我们观察了缬沙坦联合丹参干预前后实验性DM大鼠血、尿及肾组织中内皮素(ET-1)、转化生长因子β1(TGF-β1)水平的变化,结合肾功能指标探讨其肾保护作用,为临床改善DN预后提供理论依据.

目的 应用缬沙坦联合丹参对糖尿病肾病(DN)大鼠模型进行干预,观察其对肾小球平均体积、肾毛细血管基底膜平均厚度及肾组织中转化生长因子β1(TGF-β1)表达的影响,探讨两药联用的肾保护作用及可能的机制.方法 应用链脲佐菌素(STZ)建立糖尿病(DM)大鼠模型,随机分为4组:正常对照组、模型组、缬沙坦组、缬沙坦与丹参联合治疗组(联合组).8 w后观察各组血糖、糖化血红蛋白(HbAlc)、内生肌酐清除率(Ccr)、尿白蛋白排泄率(UAE)、尿β2微球蛋白排泄率(β2-MG)等变化.光镜观察肾组织病理变化并测定肾小球的平均体积、电镜观察并测定肾小球毛细血管基底膜平均厚度.免疫组化法检测肾组织TGF-β1蛋白的表达.结果 与对照组相比,模型组及各给药组大鼠血糖、HbAlc、Ccr、UAE、β2-MG均显著上升(P＜0.01);肾小球平均体积、毛细血管基底膜平均厚度均显著扩大(P＜0.01);肾组织中TGF-β1的蛋白质表达显著上调(P＜0.01).缬沙坦和(或)丹参干预后,上述上调指标除血糖、HbAlc外均被显著抑制(P＜0.05或0.01),联合组优于缬沙坦组(P＜0.05).结论 缬沙坦联合丹参对DM大鼠具有改善肾脏病理结构的肾保护作用.其机制可能与其下调肾组织中TGF-β1的表达有关.

目的 观察糖尿病大鼠肾组织中内皮素-1(ET-1)、转化生长因子β1(TGF-β1)水平的变化及缬沙坦与丹参联合治疗对它们的影响.方法 建立链脲佐菌素(STZ)诱导的单侧肾切除糖尿病大鼠模型,随机分为5组:单肾对照组(A组)、模型组(B组)、丹参组(C组)、缬沙坦组(D组)及缬沙坦与丹参联合给药组(E组),8周后观察血糖、糖化血红蛋白(HbAlc)、肌酐清除率(Ccr)、尿白蛋白排泄率(UAE)、尿β2微球蛋白排泄率(β2-MG)等变化.放射免疫法检测血浆、尿液及肾组织中ET-1的水平;ELISA法检测血清、尿液中TGF-β1水平.结果 ①模型组及各给药组大鼠血糖、HbAlc、Ccr、UAE、β2-MG,血、尿中ET-1、TGF-β1及肾组织中ET-1水平均明显高于对照组(P＜0.01).②B组血、尿中ET-1、TGF-β1及肾组织中ET-1水平明显高于各给药组(P＜0.05).③各给药组均可降低血、尿中ET-1、TGF-β1和肾组织中ET-1水平及Ccr、UAE、β2-MG(P＜0.01),联合组优于单给药组(P＜0.05).结论 缬沙坦联合丹参对糖尿病肾脏的保护作用优于单药治疗.并可抑制糖尿病大鼠肾脏ET-1、TGF-β1等的水平.

Objective: To estimate the effect of losartan on diabetic nephropathy before or after microalbuminuria.Methods:Forty uninephrectomized male Wistar rats were divided into 4 groups at random: normal control(NC),diabetic nephropathy control(DN),early treatment with losartan(DL1) and late treatment with losartan(DL2),and they were made diabetes by single intraperitoneal injection of streptozotocin(STZ,60?mg/kg).DL1 group was treated with losartan(20?mg·kg~(-1)·d~(-1)) for 8 weeks immediately,while DL2 group from the 9~(th) week.At the end of the 16~(th) week,all rats were sacrificed,and their left kidneys were removed and weighed.The mean glomerular volume(MGV) and the fractional mesangial area(FMA) were calculated by medical image analysis system.The mRNA expression of TGF-β1, CTGF,PAI-1 and FN were detected by quantitative real time RT-PCR.Urinary albumin excretion rate(UAER),as well as serum creatinine(sCr) and creatinine clearance rate(Ccr) was detected.Results: ①Compared with group NC,UAER increased by 1268% at the end of the 8~(th) week and 2192% at the end of the 16~(th) week in group DN;At the same time,Scr in DN group elevated significantly(136%),and KW/BW,MGV and FMA in DN too(129%,98% and 183% separately).The mRNA expression of TGF-β1,CTGF,PAI-1 and FN in group DN increased by 2292%,1342%,2861% and 596% separately.Whereas all these indexs decreased in group DL1 and DL2(P0.05),and there was no significant difference between group DL1 and DL2(P0.05);②However,Ccr in group DN began to decline at the end of the 16~(th) week(14.8%,P0.05),but it in group DL1 and DL2 was still higher than that in group NC(P0.05);③FMA was negatively correlated with Ccr in group DN at the 16~(th) week.And the mRNA expression level of TGF-β1,CTGF,PAI-1 and FN was positively correlated with UAER,KW/BW,MGV and FMA.Conclusion:①The mRNA expression level of TGF-β1,CTGF,PAI-1 and FN is higher in diabetic rats,which is responsible for renal hypertrophy,excess ECM deposition and UAER increase;②Losartan down-regulates the mRNA expression of such renal cytokines,and therefore prevents the progress of DN;③Whether the treatment is performed before microalbuminuria or not,the therapeutic effect is similar,suggesting that microalbuminuria is the appropriate time for beginning clinical treatment of DN.