Role of Connective Tissue Growth Factor in Extracellular Matrix Degradation in Renal Tubular Epithelial Cells

In order to investigate the effects of connective tissue growth factor (CTGF) antisense oligodeoxynucleotide (ODN) on plasminogen activator inhibitor-1 (PAI-1) expression in renal tubular cells induced by transforming growth factor β1 (TGF-β1) and to explore the role of CTGF in the degradation of renal extracellular matrix (ECM), a human proximal tubular epithelial cell line (HKC) was cultured in vitro. Cationic lipid-mediated CTGF antisense ODN was transfected into HKC. After HKC were stimulated with TGF-β1 (5 μg/L), the mRNA level of PAI-1 was detected by RT-PCR. In-tracellular PAI-1 protein synthesis was assessed by flow cytometry. The secreted PAI-1 in the media was determined by Western blot. The results showed that TGF-β1 could induce tubular CTGF and PAI-1 mRNA expression. The PAI-1 mRNA expression induced by TGF-β1 was significantly inhib-ited by CTGF antisense ODN. CTGF antisense ODN also inhibited intracellular PAI-1 protein syn-thesis and lowered the levels of PAI-1 protein secreted into the media. It was concluded that CTGF might play a crucial role in the degradation of excessive ECM during tubulointerstitial fibrosis, and blocking the biological effect of CTGF may be a novel way in preventing renal fibrosis.     

Expression of transforming growth factor beta-1 in fibrosis of transplanted kidney

In order to study the role and significance of transforming growth factor beta-1 (TGF-β1)mRNA in transplanted renal fibrosis(TRF). Methods: Renal pathologic changes and expression of TGF-β1 mRNA were observed using in situ hybridization technique. The normal renal tissue as a control group. Results: Expression of TGF-β1 mRNA in the renal fibrosis increased, compared with that in the control group. The expression rate were co-related to the stage of TRF.Conclusion: TGF-β1 is related to the pathogenesis and development of TRF.     

Role of connective tissue growth factor in experimental radiation nephropathy in rats

Background Connective tissue growth factor （CTGF） is a potent fibrogenic cytokine which has been associated with progressive glomerulosclerosis and tubulointerstitial fibrosis. We investigated the role of CTGF on the progression of a rat model of radiation nephropathy. Methods The model of radiation nephropathy in rats was established as follows： control group （n=12）, underwent only laparotomy; irradiated group （n=-20）, underwent a laparotomy, then the rats were subjected to a single dose 25 Gy X-ray to the kidneys. The rats were followed up one, three, six and nine months after renal exposure to radiation. Results Renal dysfunction was noted early in irradiated rats. Histological analysis showed focal glomerular sclerotic lesions at an early stage after irradiation. Radiation-induced glomerular and tubulointerstitial injuries were particularly severe the sixth month after irradiation as compared to the control group （P 〈0.01）. By immunohistochemistry, increased expression of CTGF was noted in the irradiated kidneys, which began to increase from the first month after irradiation, and remained significantly higher at the sixth and ninth month after irradiation （P 〈0.01）. Upon Western blot analysis CTGF protein expression showed an increase in the radiation treated kidneys compared with the control rats. The expression of CTGF closely correlated with the progression of radiation nephropathy. The expression of α-smooth muscle actin, vimentin, type Ⅲ collagen and type Ⅳ collagen was also high in the irradiated kidney as compared to control rat kidneys （P 〈0.05）, and was most severe at the sixth and ninth month after irradiation （P 〈0.01）. By double immunostaining, CTGF expressing cells were found to be α-SMA-positive myofibroblasts and vimentin-positive tubular epithelial cells. Glomerular expression of CTGF closely correlated with the glomerular expression of a-SMA （r=0.628, P 〈0.01）, vimentin （r=0.462, P 〈0.05） and accumulation of type IV collagen （r=0.584,     

Upregulated DJ-1 promotes renal tubular EMT by suppressing cytoplasmic PTEN expression and Akt activation

Recently,phosphatase and tensin homolog deleted on chromosome 10(PTEN) is suggested as a new agent in the fighting against fibrogenesis.In tumor,DJ-1 is identified as a negative regulator of PTEN.But the expression of DJ-1 and the regulation of PTEN in fibrosis are unclear.Renal fibrosis was induced in 5/6 subtotal nephrectomy rat model.Human proximal tubular epithelial cells(HKC) were treated with transforming growth factor-beta 1(TGF-β1),or transfected with DJ-1 or PTEN.Confocal microscope was used to investigate the localization of DJ-1 and PTEN.The selective phosphoinositide-3 kinase(PI3K) inhibitor,LY294002,was administered to inhibit PI3K pathway.The DJ-1 and PTEN expression,markers of epithelial-mesenchymal transition(EMT) and Akt phosphorylation were measured by RT-PCR,Western blotting or immunocytochemistry.In vitro,after HKC cells were stimulated with 10 ng/mL TGF-β1 for 72 h,the expression of DJ-1 was increased,and that of PTEN was decreased.In vivo,the same results were identified in 5/6-nephrectomized rats.In normal HKC cells,most of DJ-1 protein localized in cytoplasm,and little in nucleus.TGF-β1 upregulated DJ-1 expression in both cytoplasma and nuclei.In contrary,TGF-β1 emptied cytoplasmic PTEN protein into nucleus.Overexpression of DJ-1 decreased the expression of PTEN,promoted the activation of Akt and the expression of vimentin,and also led to the loss of cytoplasmic PTEN.Contrarily,overexpression of PTEN protected HKC cells from TGF-β1-induced EMT.In conclusion,DJ-1 is upregulated in renal fibrosis and DJ-1 mediates EMT by suppressing cytoplasmic PTEN expression and Akt activation.     

Rhein inhibits transforming growth factor β1 induced plasminogen activator inhibitor-1 in endothelial cells

Objectives To investigate the effect of rhein on endothelial plasminogen activator inhibitor-1 (PAI-1) mRNA expression and protein production induced by transforming growth factor β1 (TGFβ1), and to explore the mechanism of the protective action of rhein on endothelial cells. Methods A human umbilical endothelium derived cell line (ECV-304) from ATCC was used in this study. The PAI-1 mRNA expression and protein synthesis in the endothelial cells were detected by Northern blot and flow cytometry analysis, respectively. The activity of phospho-p44/p42 MAP kinase induced by TGFβ1 was determined by immunoprecipitation analysis and western blot. Results TGFβ1 rapidly increased PAI-1 mRNA expression in the endothelial cells, and this effect lasted at least 24 hours. The upregulation of PAI-1 mRNA expression induced by TGFβ1 in endothelial cells was inhibited by rhein in a dose-dependent manner. In addition, rhein inhibited endothelial PAI-1 protein production. Further study revealed that rhein had a significant inhibitory effect on the activity of phospho-p44/p42 MAP kinase induced by TGFβ1 in human endothelial cells. Conclusions Our results showed that rhein may have a protective effect on the endothelial dysfunction by inhibiting overexpression of PAI-1, indicating a way for the treatment of vascular diseases.     

Parathyroid hormone-mitogen-activated protein kinase axis exerts fibrogenic effect of connective tissue growth factor on human renal proximal tubular cells

Background Enhanced and prolonged expression of connective tissue growth factor （CTGF） is associated with kidney fibrosis. Parathyroid hormone （PTH） is involved in the genesis of disturbed calcium/phosphate metabolism and ostitis fibrosa in renal failure. PTH activated mitogen-activated protein kinase （MAPK） signaling pathway is present in renal tubular cells. The aim of this study was to identify the mechanism how the signal is transduced to result in extracellular signal-regulated protein kinase （ERK） activation, leading to upregulation of CTGF.Methods The levels of CTGF mRNA and protein in human kidney proximal tubular cells （HK-2） treated with PTH in the presence or absence of the MAPK inhibitor PD98059 were analyzed by quantitative real-time polymerase chain reaction （RT-PCR） and immunoblotting assay. The activation of the CTGF promoter in HK-2 cells was determined by the dual-luciferase assay. The effects of the protein kinase A （PKA） activator 8-Br-cAMP and protein kinase C （PKC） activator phorbol 12-myristate 13-acetate （PMA） on MAPK phosphorylation, and the effects of the PKA inhibitor H89 and PKC inhibitor calphostin C on MAPK phosphorylation and CTGF expression were detected by immunoblotting assay.Results PD98059 inhibited the PTH stimulated expression of CTGF, which strongly suggested that the MAPK signaling pathway plays an important role in the PTH-induced CTGF upregulation in renal tubular cells. A PKA activator as well as PKC activators induced MAPK phosphorylation, and both PKA and PKC inhibitors antagonized PTH-induced MAPK phosphorylation and CTGF expression.Conclusion CTGF expression is upregulated by PTH through a PKC/PKA-ERK-dependent pathway.     

Expression of Serum and Glucocorticoid-inducible Kinase1 in Diabetic Rats and Its Modulation by Fluvastatin

The expression of serum and glucocorticoid-induced protein kinase in the renal cortex of diabetic rats was examined, and the function of signal transduction mediated by SGK1 in diabetic nephropathy and its modulation by fluvastatin were also investigated. 24 male Wistar rats were randomly divided into normal control group （n = 8）, diabetic nephropathy group （n = 8） and fluvastatin-treated diabetic nephropathy group （15 mg/kg/d, n=8）. The metabolic parameters were measured at the 8th week. The expression of transforming growth factor β1 （TGF-β1） and fibronectin （FN） was immunohistochemically examined. The expression of SGK1 was detected by RT-PCR and Western blot, and CTGF mRNA was assessed by RT-PCR. As compared to DN, blood glucose, 24-h urinary protein, Cer and kidney weight index were all decreased and the weight was increased obviously in group F. At the same time, mesangial cells and extracellular matrix proliferation were relieved significantly. The levels of cortex SGK1 mRNA and protein were up-regulated, and both TGF-β1 and FN were down-regulated by fluvastatin. The mRNA of SGK1 was positively correlated with the CTGF, TGF-β1 and FN. SGK1 expression is markedly up-regulated in the renal cortex of DN group and plays an important role in the development and progress of diabetic nephropathy by means of signal transduction. Fluvastatin suppressed the increased SGKlmRNA expression in renal cortex and postponed the development of diabetic nephropathy.     

Role of Protease Activated Receptor-2 Expression in Renal Interstitial Fibrosis Model in Mice

Summary： The role of protease activated receptor-2 （PAR-2） in the renal tubulointerstitial lesion induced by unilateral ureteral obstruction （UUO） was explored. Mice were sacrificed on the day 1, 3, 5, 7, 10, 14 and 21 after UUO. The expression of PAR-2 mRNA and protein and a-smooth muscle actin （α-SMA） protein in tubuloin,terstitium was detected by RT-PCR and immunohistochemistry at each time point, respedtively. The results showed that the PAR-2 expression in renal tubulointerstitium was increased progressively starting from 24 h to the day 14 post-ligation, and it was significantly associated with the relative volume of interstitium and the positive area of α-SMA. PAR-2 was mainly expressed in renal tubule epithelial cells, especially in proximal tubular cells. It also located in renal capillary ansa, interstitial infiltrate cells and fibroblasts. It was concluded that PAR-2 was active in interstitial and tubular cells in the early phase of fibrotic process and played an important role in mediating the tubulointerstitial lesion after UUO.     

结缔组织生长因子对肾小管上皮细胞转分化的调节机制

目的 观察结缔组织生长因子（CTGF）对体外培养的人肾小管上皮细胞转分化的直接影响,并探讨阻断内源性CTGF表达对转化生长因子- β1（TGF-β）诱导人肾小管上皮细胞转分化的干预效果,以阐明CTGF在肾小管上皮细胞转分化中的作用。方法 体外培养人近曲小管上皮细胞（HKC）。在观察CTGF对HKC的直接作用时,将HKC细胞分为三组：（1）对照组;（2）小剂量CTGF组：培养液中加入重组人CTGF（rhCTGF）,终浓度为2．5μg／L;（3）大剂量CTGF组：rhCTGF终浓度为5．0μg／L。在探讨CTGF在TGF-β诱导HKC转分化中的作用时,将细胞分为4组：（1）正常对照组;（2）TGF-β刺激组（培养液加入重组人TGF-β1蛋白,浓度为10．0μg／L）;（3）TGF-β1＋CTGF正义寡核苷酸（ODN）组（先以CTGF正义ODN转染HKC,再加TGF-β1刺激）;（4）TGF-β1＋CTGF反义ODN组（先以CTGF反义ODN转染HKC,再加TGF-β1刺激）。用逆转录-聚合酶链反应（RT-PCR）方法测定HKC α-平滑肌肌动蛋白（α—SMA）和Ⅳ型胶原（col Ⅳ）mRNA水平的变化;间接免疫荧光方法检测HKC胞浆内α—SMA的表达;流式细胞仪检测α—SMA阳性细胞百分率;ELISA方法测定培养液上清中col Ⅳ的浓度。结果 不同浓度rhCTGF作用于HKC24h后,α-SMAmRNA水平显著升高（P〈0．01）,而colⅣmRNA表达水平明显下降（均P〈0．01）;刺激48h后,胞浆α—SMA表达明显增强,流式细胞仪测得三组细胞α-SMA阳性百分率依次为：2．4％、38．9％、65．5％（P〈0．01）;ELISA结果表明,rhCTGF抑制了colⅣ的分泌（P〈0．01）。TGF-β1可诱导HKC高表达CTGF和α-SMA。转染后6h,CTGF反义ODN可显著抑制HKC表达CTGF和α-SMA mRNA（P〈0．01）。转染后48h,CTGF反义ODN可明显抑制胞内α-SMA蛋白合成。结论 CTGF在体外能刺激肾小管上皮细胞向肌成纤维细胞（MyoF）转分化,而CTGF反义ODN的导人可有效抑制TGF-β1诱导的转分化过程。因此,CTGF可能是调节肾小管上皮细胞转分化的重要因子。     

Effects of hepatocyte growth factor on TGF-beta1 triggered tubular epithelial-myofibroblast transdifferentiation by CTGF in vitro]

OBJECTIVE: To observe the effects of hepatocyte growth factor (HGF) on TGF-beta1 triggered tubular epithelial-myofibroblast transdifferentiation (TEMT) and on the expression of connective tissue growth factor (CTGF). METHODS: The morphology of transdifferentiate tubular cells was observed using phase-contrast microscopy and scanning electron microscopy. alpha-SMA was assessed by immunohistochemistry and semiquantified by mean intergrated opitical density (IOD). The level of fibronectin (FN) in the culture supernatant was measured by ELISA. CTGF mRNA expression was examined by RT-PCR. RESULTS: The TGF-beta1-induced TEMT characterized by expression of alpha-SMA was shown by immunohistochemistry. TGF-beta1 was also shown to stimulate the secretion of FN in cultured supernatant and the CTGF mRNA expression of NRK52E cells. There was no statistically significant difference between HGF-treated groups and control group in the result of alpha-SMA immunostaining and the level of FN, except that CTGF mRNA expression was slightly increased in the HGF-treated groups. The addition of HGF inhibited the TGF-beta1-induced TEMT, the secretion of FN, and the CTGF expression of NRK52E cells, there was a significant correlation between the expression of CTGF and the expression of alpha-SMA. CONCLUSION: HGF could block TEMT and FN secretion triggered by TGF-beta1, which implies that HGF could participate in renal interstitial fibrosis as a negative regulator. The negative regulation of transdifferentiation of HGF may be partially achieved by attenuation of CTGF expression.     

结缔组织生长因子协同转化生长因子β1的促肾纤维化效应

目的　探讨结缔组织生长因子 (CTGF)和转化生长因子 β1(TGF β1)对肾脏成纤维细胞合成和分泌基质金属蛋白酶 2 (MMP 2 )和细胞表型转化的影响。方法　将大鼠肾成纤维细胞分为对照组、CTGF刺激组、TGF β1刺激组、CTGF加TGF β1联合刺激组 ,以明胶酶谱法和Western印迹方法分别检测细胞上清中MMP 2活性和蛋白的变化 ,实时定量 聚合酶链反应 (PCR)方法检测细胞中MMP 2mRNA的水平。Western印迹方法检测成肌纤维细胞标志蛋白α 平滑肌肌动蛋白 (α SMA)的表达水平和细胞上清中细胞外基质成分纤黏连蛋白 (FN)的水平。结果　MMP 2的活性和蛋白水平在刺激 2 4h时 ,各组之间无明显差异 ;刺激 4 8h ,10 0ng/mlCTGF组和 5ng/mlTGF β1组明显属于对照组 (P <0 0 5 ) ;而不同浓度的CTGF加TGF β1联合刺激组分别低于CTGF刺激组、TGF β1刺激组 ,其中 10 0ng/mlCTGF加 5ng/mlTGF β1、5 0ng/mlCTGF加 5ng/mlTGF β1均分别明显低于CTGF刺激组、TGF β1刺激组 (P <0 0 5 )。上述各组细胞刺激 12h ,MMP 2mRNA水平在 10 0ng/mlCTGF组和 5ng/mlTGF β1组均明显高于对照组 (1 72 ,1 6 8vs 1 2 9,P <0 0 1) ,而 10 0ng/mlCTGF加 5ng/mlTGF β1联合组明显低于CTGF刺激组、TGF β1刺激组 (0 6 7v     

虫草菌粉对慢性马兜铃酸肾病大鼠模型肾间质纤维化的保护作用

目的研究虫草菌粉对慢性马兜铃酸肾病（CAAN）模型大鼠肾间质纤维化的拮抗作用。方法雄性sD大鼠随机分为对照组、模型组和虫草组;每组6只。于0、1、4,8及12周末分别检测大鼠体重、尿糖、尿蛋白定量和血清肌酐（SCr）;并于第12周末处死大鼠留取肾组织,行Masson染色观察肾间质纤维化程度,逆转录实时聚合酶链反应和免疫组织化学方法检测肾组织中转化生长因子-β1（TGF-β1）、结缔组织生长因子（CTGF）、纤溶酶原激活物抑制物-1（PAI-1）、金属蛋白酶组织抑制物-1（TIMP-1）和Ⅰ型胶原（ColⅠ）mRNA及蛋白质表达。结果模型组大鼠尿蛋白定量及SCr显著高于对照组（P〈0．01及P〈0．05）;12周时肾间质纤维化面积显著增加（P〈0．01）;肾组织内上述指标的mRNA及蛋白质表达显著上调（P〈0．01）。与对照组相比,模型组大鼠肾组织TGF-β1、CTGF、PAI-1、TIMP-1和ColⅠ的mRNA表达分别上调4．19、2．66、6．12、3．09和7．03倍;蛋白质表达分别上调2．31、3．53、3．17、3．18和6．87倍。虫草组大鼠第12周时尿蛋白定量、SCr及肾间质纤维化面积均显著低于模型组（P〈0．05）,上述高表达的mRNA及蛋白质指标均被显著抑制（P〈0．05）,与模型组相比,虫草组大鼠肾组织TGF-β1、CTGF、PAI-1、TIMP-1和ColⅠ的mRNA表达分别下调45％、41％、47％、48％和67％;蛋白质表达分别下调38％、39％、49％、46％和61％。结论虫草菌粉可通过抑制肾组织促细胞外基质（ECM）合成因子（TGF-β1、CTGF）及抗ECM降解因子（TIMP-1、PAI-1）生成,而改善CAAN的肾间质纤维化及肾功能。     

波生坦及缬沙坦对马兜铃酸肾病大鼠肾间质纤维化的影响

目的研究非选择性内皮素受体拮抗剂(波生坦)及血管紧张素Ⅱ1型受体拮抗剂(缬沙坦)能否抑制慢性马兜铃酸肾病(CAAN)大鼠模型肾间质纤维化的进程。方法雄性SD大鼠予关木通浸膏水溶液灌胃致成CAAN模型,并分为模型组,波生坦组(100mg·kg-1·d-1灌胃)和缬沙坦组(30mg·kg-1·d-1灌胃)。对照组予自来水灌胃。每组动物6只。检测大鼠体重、24h尿蛋白定量、β2微球蛋白(β2mG)、血清肌酐(SCr);于第16周处死大鼠,取肾组织切片做Masson染色;用RTPCR及免疫组化方法检测肾组织中转化生长因子β1(TGFβ1)、结缔组织生长因子(CTGF)、纤溶酶原激活物抑制物1(PAI1)、金属蛋白酶组织抑制物1(TIMP1)和Ⅰ型胶原(ColⅠ)mRNA及蛋白质的表达。结果与对照组相比,CAAN模型组大鼠24h尿蛋白定量、尿β2mG、SCr到实验后期均显著上升(P<0.05或0.01);肾间质纤维化面积显著性扩大(P<0.01);肾组织内TGFβ1、CTGF、PAI1、TIMP1及ColⅠ各指标的mRNA及蛋白质表达均显著上调(P<0.01)。在波生坦及缬沙坦干预组上述上调指标均被显著抑制(P<0.05或0.01),而两干预组间无明显差异(P>0.05)。结论波生坦及缬沙坦能抑制CAAN大鼠肾间质纤维化进程,延缓肾损害进展,此作用可能是通过抑制促细胞外基质合成因子(TGFβ1、CTGF)及抑制抗细胞外基质降解因子(PAI1、TIMP1)而获得。     

Inhibition effect of small interfering RNA of connective tissue growth factor on the expression of vascular endothelial growth factor and connective tissue growth factor in cultured human peritoneal mesothelial cells

Background The peritoneum response to peritoneal dialysis can lead to fibrosis. The transforming growth factor β1 （TGF-β1 ） plays a key role in regulating tissue repair and remodelling after injury. Connective tissue growth factor （CTGF）, a downstream mediator of TGF-β1 inducing fibrosis, has been implicated in peritoneal fibrosis. Vascular endothelial growth factor （VEGF） plays a key role in angiogenesis that can hasten peritoneal fibrosis. In this study, we investigated the effect of small interfering RNA （siRNA） of CTGF by pRETRO-SUPER （PRS） retrovirus vector on the expression of CTGF and VEGF in human peritoneal mesothelial cells. Methods Retrovirus producing CTGF siRNA were constructed from the inverted oligonucleotides and transferred into packaging cell line PT67 with lipofectamine, and the virus supernatant was used to infect human peritoneal mesothelial cell （HPMC）. The cells were divided into seven groups： low glucose DMEM, low glucose DMEM ＋ TGF-β1 5 ng/ml, low glucose DMEM ＋ TGF-β1 5 ng/ml ＋ PRS-CTGF-siRNA1-4 and low glucose DMEM ＋ TGF-β1 5 ng/ml ＋ PRS. The expression of CTGF and VEGF were measured by semiquantitative RT-PCR and Western blot. Results Low levels of CTGF and VEGF were detected in confluent HPMCs. Following stimulation with TGF-β1 , the levels of CTGF and VEGF were significantly upregulated （P〈0.01）. Introduction of PRS-CTGF-siRNA1-4 resulted in the significant reduction of CTGF mRNA and protein, and VEGF mRNA （P〈0.01）, especially in groups PRS-CTGF-siRNA, and PRS-CTGF-siRNA4. The introduction of PRS void vector did not have these effects （P〉0.05）. Conclusions The expression of CTGF siRNA mediated by PRS retrovirus vector can effectively reduce the level of CTGF and VEGF induced by TGF-β1 in cultured HPMCs. This study may provide potential therapeutic strategies to prevent the peritoneal fibrosis.     

抗增殖蛋白抑制转化生长因子-β1诱导的肾脏成纤维细胞增殖和表型改变

目的 研究抗增殖蛋白（prohibitin,PHB）在肾间质纤维化发生中的作用。方法（1）检测48例原发性肾小球肾炎患儿肾组织中PHB蛋白表达,并比较其与肾小管间质损伤程度的相关性。（2）观察PHB在大鼠肾脏成纤维细胞（NRK-49F）中亚细胞定位,以Western印迹和RT-PCR测定NRK-49F受到转化生长因子B1（TGF-β1）刺激后PHB表达的变化。（3）构建PHB表达质粒并转染,观察PHB对NRK-49F细胞周期以及表达α-平滑肌肌动蛋白（α-SMA）蛋白质和mRNA的影响。结果 （1）PHB蛋白主要表达于肾间质细胞和肾小管上皮细胞的胞质,随肾小管间质损伤程度加重而逐渐减弱（组间比较,均P〈0．01）,PHB表达量与肾小管间质损伤程度显著负相关（r=-0．802,P〈0．01）。（2）激光共焦显微镜下见PHB主要分布于NRK49F的细胞质,细胞核亦有较弱表达。TGF-β1刺激后PHB蛋白和mRNA表达均下调,呈现时间和剂量依赖关系（组间比较,P〈0．01）。（3）成功构建PHB真核表达质粒,转染48h细胞中PHB蛋白量升高约2．54倍（与未转染组比较,P〈0．01）。（4）转染PHB基因明显抑制TGF—β1所诱导的细胞增殖,使更多的细胞处于G0／G1期（与TGF-β1组比较,P〈0．01）,而对未受刺激的细胞无影响（P〉0．05）。（5）转染PHB基因明显抑制TGF—β1所诱导的α-SMA蛋白质和mRNA表达（与TGF-β1组比较,P〈0．01）,而对α-SMA基础表达无影响（与TGF-β1组比较,P〉0．05）。结论 PHB在肾组织中的表达水平可以反映肾小管间质损伤程度．外源性PHB显著抑制TGF-β1诱导的成纤维细胞增殖和表型改变。     

肾间质纤维化组织中组织型转谷氨酰胺酶和结缔组织生长因子共表达

目的:探讨组织型转谷氨酰胺酶(tTG)和结缔组织生长因子(CTGF)在肾间质纤维化组织中的表达及二者的关系.方法: 采用单侧输尿管结扎(UUO)致肾间质纤维化大鼠模型.将大鼠随机分为假手术组(5只)、模型组(6只)、依那普利治疗组(6只).术后9天处死各组大鼠,肾组织标本用过碘酸-席夫染色(PAS)确证肾间质纤维化病变.以免疫组织化学染色方法观察肾组织内tTG 和CTGF的表达部位,以及细胞外基质成份纤维连接蛋白(FN)的表达变化.用Western蛋白印迹方法分析肾组织内tTG 和CTGF蛋白表达水平.结果: 假手术组大鼠tTG,CTGF和FN分别在肾小管、肾间质区仅有微量表达,肾小球内无阳性表达;模型组大鼠tTG、CTGF和FN在肾小管、肾间质区的表达信号比假手术组强;依那普利治疗后三者表达减少.双重染色结果显示,在模型组肾间质tTG阳性表达部位同时表达CTGF,并且强度相似.Western blot结果显示,模型组tTG和CTGF蛋白水平明显高于假手术组;依那普利治疗组tTG和CTGF蛋白水平明显低于模型组.各组大鼠肾内tTG蛋白水平与CTGF蛋白水平之间(r=0.683,P<0.05)以及tTG蛋白水平与肾间质内FN半定量水平之间(r=0.737,P<0.05)均有显著相关关系.结论: tTG和CTGF可能共同参与肾间质纤维化,依那普利减轻肾间质纤维化的作用可能通过下调两者的表达而实现.