骨形成蛋白-7对晚期糖基化终产物诱导大鼠腹膜间皮细胞上皮-间叶转化的影响

目的探讨骨形成蛋白-7(BMP-7)对晚期糖基化终产物诱导大鼠腹膜间皮细胞上皮-间叶转化(EMT)的影响。方法晚期糖基化终产物诱导发生上皮-间叶转化的体外培养大鼠腹膜间皮细胞,分别经含5 ng/mL及80 mmol/L晚期糖基化终产物的M199培养基和含10 ng/mL BMP-7及80 mmol/L晚期糖基化终产物的M199培养基培养48 h,以含80 mmol/L晚期糖基化终产物的M199培养基为对照,应用实时定量PCR法检测间皮细胞E-cadherin、α平滑肌肌动蛋白(α-SMA)、Ⅰ型胶原(Collagen I)、转化生长因子β1(TGF-β1)、血管内皮生长因子(VEGF)mRNA的表达;应用Western印迹法检测E-cadherin、α-SMA蛋白的表达;应用ELISA法检测间皮细胞TGF-β1、VEGF蛋白表达水平。结果 BMP-7作用后,上皮-间叶转化的大鼠腹膜间皮细胞E-cadherin mRNA和E-cadherin蛋白表达水平显著增加(P<0.05)。BMP-7作用后,上皮-间叶转化的大鼠腹膜间皮α-SMA、Collagen I、TGF-β1、VEGFmRNA和α-SMA、TGF-β、VEGF蛋白表达水平显著下降(P<0.05)。结论 BMP-7能上调上皮-间叶转化的大鼠腹膜间皮细胞E-cadherin表达和下调α-SMA、Collagen I、TGF-β、VEGF表达,BMP-7能逆转晚期糖基化终产物诱导大鼠腹膜间皮细胞EMT。     

高浓度葡萄糖诱导大鼠腹膜间皮细胞上皮-间叶转化

目的探讨高浓度葡萄糖对大鼠腹膜间皮细胞上皮-间叶转化(EMT)的影响,建立大鼠腹膜间皮细胞EMT模型。方法体外培养的大鼠腹膜间皮细胞经含60、120 mmol/L葡萄糖的M199培养基分别培养48、72 h;以正常M199培养基和含120 mmol/L甘露醇的M199培养基为对照。采用相差显微镜观察细胞形态学改变,应用实时定量PCR法检测间皮细胞E-cad-herin、α-SMA、Collagen I mRNA的表达;应用Western印迹法检测E-cadherin、α-SMA蛋白的表达。结果高浓度葡萄糖(60、120 mmol/L)刺激后,大鼠腹膜间皮细胞由典型的上皮细胞形态逐渐变为梭形及不规则形,类似肌成纤维细胞;大鼠腹膜间皮细胞α-SMA、Collagen I mRNA和α-SMA蛋白表达水平显著增加(P0.05);大鼠腹膜间皮细胞E-cadherin mRNA和E-cad-herin蛋白表达水平显著下降(P0.05)。结论高浓度葡萄糖能上调α-SMA、Collagen I表达和下调E-cadherin表达,高浓度葡萄糖诱导大鼠腹膜间皮细胞EMT。     

高浓度葡萄糖诱导大鼠腹膜间皮细胞上皮-间叶转化

目的探讨高浓度葡萄糖对大鼠腹膜间皮细胞上皮-间叶转化（EMT）的影响,建立大鼠腹膜间皮细胞EMT模型。方法体外培养的大鼠腹膜间皮细胞经含60、120 mmol/L葡萄糖的M199培养基分别培养48、72 h;以正常M199培养基和含120 mmol/L甘露醇的M199培养基为对照。采用相差显微镜观察细胞形态学改变,应用实时定量PCR法检测间皮细胞E-cad-herin、α-SMA、Collagen I mRNA的表达;应用Western印迹法检测E-cadherin、α-SMA蛋白的表达。结果高浓度葡萄糖（60、120 mmol/L）刺激后,大鼠腹膜间皮细胞由典型的上皮细胞形态逐渐变为梭形及不规则形,类似肌成纤维细胞;大鼠腹膜间皮细胞α-SMA、Collagen I mRNA和α-SMA蛋白表达水平显著增加（P〈0.05）;大鼠腹膜间皮细胞E-cadherin mRNA和E-cad-herin蛋白表达水平显著下降（P〈0.05）。结论高浓度葡萄糖能上调α-SMA、Collagen I表达和下调E-cadherin表达,高浓度葡萄糖诱导大鼠腹膜间皮细胞EMT。     

microRNA-192在晚期糖基化终产物诱导人腹膜间皮细胞上皮-间叶转化中的作用

目的探讨microRNA-192(miR-192)对晚期糖基化终产物(AGEs)诱导人腹膜间皮细胞上皮-间叶转化(EMT)的调控作用。方法人腹膜间皮细胞、转染miR-192抑制物后人腹膜间皮细胞和转染miR-192抑制物阴性对照的人腹膜间皮细胞在含AGEs的培养基培养72 h,以M199培养基和含80 m M BSA的M199培养基为对照,然后运用实时荧光定量PCR法检测miR-192和mRNA的表达情况,运用蛋白质印迹法检测蛋白的表达情况。结果在AGEs刺激后,人腹膜间皮细胞miR-192、胶原蛋白I(Collagen I)mRNA、α-平滑肌肌动蛋白(α-SMA)mRNA和蛋白表达水平显著上升(P0.05),而E-钙黏蛋白(E-cadherin)mRNA和蛋白表达水平显著下降(P0.05)。与转染miR-192抑制物阴性对照的人腹膜间皮细胞相比,转染miR-192抑制物的人腹膜间皮细胞miR-192、Collagen I mRNA、α-SMAmRNA和蛋白表达水平显著下降(P0.05),而E-cadherin mRNA和蛋白表达水平显著上升(P0.05)。结论 AGEs可能通过上调miR-192表达诱导人腹膜间皮细胞EMT。miR-192抑物可能通过下调miR-192表达阻止AGEs诱导人腹膜间皮细胞EMT。miR-192在AGEs诱导人腹膜间皮细胞EMT中起重要调控作用。     

MicroRNA-302c通过结缔组织生长因子调控腹膜透析相关腹膜纤维化

目的通过观察microRNA-302c(miR-302c)对腹膜间皮细胞结缔组织生长因子(connect tissue growth factor,CTGF)表达及上皮细胞-间充质细胞转分化(epithelial-to-mesenchymal transition,EMT)的影响,探讨miR-302c对腹膜透析(peritoneal dialysis,PD)相关腹膜纤维化的作用及机制。方法收集PD患者腹膜透析流出液中腹膜间皮细胞,检测miR-302c、CTGF、EMT及纤维化相关指标的表达,并分析其相关性;体外培养人腹膜间皮细胞株,通过转染慢病毒过表达miR-302c,检测腹膜间皮细胞CTGF、EMT及纤维化相关指标的变化。结果 PD患者腹膜透析流出液中miR-302c水平降低(F=443.165,P0.001),与波形蛋白(Vimentin)(r=-0.887,P=0.001)和CTGF(r=-0.840,P=0.002)水平呈负相关,与紧密连接蛋白-1(Zo-1)水平呈正相关(r=0.873,P=0.001)。过表达miR-302c抑制转化生长因子β1(transforming growth factor-β1,TGF-β1)诱导的人腹膜间皮细胞株E-钙黏蛋白(E-cadherin)(F=13.910,P=0.043)表达下调,α-平滑肌肌动蛋白(α-SMA)(F=11.833,P=0.026)及Ⅰ型胶原蛋白(Collagen Ⅰ)(F=10.673,P=0.031)表达上调,同时也抑制了TGF-β1诱导的CTGF表达上调(F=8.340,P=0.044)。结论 miR-302c可能通过CTGF调控PD过程中腹膜间皮细胞EMT及纤维化。     

整合素连接激酶在肾小管上皮细胞转分化中的作用

目的探讨整合素连接激酶（ILK）在转化生长因子β1（TGF-β1）介导的肾小管上皮细胞转分化（EMT）中的表达及作用。方法采用不同浓度的TGF-β1刺激体外培养的人肾小管上皮细胞（HKC）,观察HKC形态学改变,并应用Western blotting方法检测其ILK、α-平滑肌肌动蛋白（α-SMA）的表达,实时RT-PCR法测定ILK、α-SMA、纤维连接蛋白（FN）、E钙黏蛋白（E-cadherin）mRNA的表达。结果（1）细胞形态学改变：在TGF-β1刺激下HKC细胞由正常状态下的圆形或卵圆形变为梭形,且随着孵育时间的延长,梭形细胞比例增大。（2）Western blotting和实时RT-PCR检测结果：在TGF-β1刺激下,ILK和α-SMA的蛋白表达量显著增加;ILK、α-SMA和FN的mRNA表达量也明显升高,而E-cadherin mRNA表达量明显减少。TGF-β1呈时间和剂量依赖性刺激HKC表达ILK蛋白和mRNA。（3）相关分析：ILK蛋白表达量与α-SMA蛋白表达量呈正相关（r=0.940,P〈0.01）;ILK mRNA表达量与α-SMA mRNA、FN mRNA表达量呈正相关（r=0.926,r=0.915,P〈0.01）,与E-cadherin mRNA表达量呈负相关（r=-0.820,P〈0.01）。结论ILK参与TGF-β1诱导的肾小管EMT,并在其中发挥关键作用。     

氟伐他汀抑制高糖腹透液诱导人腹膜细胞TGF-β合成及细胞外基质产生的机制研究

目的 观察不同浓度氟伐他汀对高糖腹膜透析液诱导的人腹膜间皮细胞（HPMC）转化生长因子β（TGF-β）合成及细胞外基质产生的抑制作用.方法 体外培养HPMC,同步化24 h后分组,正常对照组、高糖腹透液组、高糖腹透液＋氟伐他汀（108～106 mol/L）组.RT-PCR方法检测过氧化物酶增殖物激活受体γ（PPAR-γ）、TGF-β1、I型胶原（Collagen I）、纤维连接蛋白（Fibronectin）mRNA的表达.ELISA法检测上清液FN蛋白表达的变化.结果 高糖上调HPMC刺激后PPAR-γ、TGF-β1、Collagen I、Fibronectin mRNA的表达,12 h达到最高峰.与高糖组比较,氟伐他汀10-7M、10-6M可以降低高糖诱导的PPAR-γ、TGF-β1、Collagen I、Fibronectin mRNA的升高,差异有统计学意义（P〈0.01）.氟伐他汀10-7M、10-6M可以降低高糖诱导的Fibronectin蛋白表达的升高（P〈0.01）.结论 氟伐他汀可以降低高糖腹透液诱导的人腹膜间皮细胞PPAR-、TGF-β1、Collagen I的表达进而达到减少纤维连接蛋白表达.     

基于TGF-β1/AKT信号通路的西格列汀对人肾小管上皮细胞转化的干预及机制

目的:观察西格列汀(sitagliptin,SIT)对高糖诱导的肾小管上皮-间充质转化(epithelial-mesenchymal transition,EMT)的干预效应及对AKT信号通路的影响,探讨西格列汀防治早期糖尿病肾病(diabetic nephropathy,DN)的作用机制。方法:将体外培养的人肾小管上皮细胞(HK-2)分为正常组(NG,5.56 mmol/L葡萄糖)、高糖组(HG,60 mmol/L葡萄糖)、西格列汀组(SIT组,60 mmol/L葡萄糖+1,5,10μmol/L西格列汀)、TGF-β1抑制剂组(60 mmol/L葡萄糖+5μmol/L SB-431542)。MTT法检测细胞活力;ELISA法检测细胞中TGF-β1蛋白分泌;蛋白质印迹法检测细胞中Akt蛋白磷酸化水平及EMT指标蛋白质变化。结果:高糖提高了肾小管上皮细胞的活力,促进TGF-β1蛋白分泌,激活AKT蛋白磷酸化,降低细胞中上皮表型蛋白质E-cadherin的表达,并增加间质表型蛋白质α-SMA的表达。西格列汀显著降低HK-2细胞的活力,降低高糖环境下TGF-β1蛋白分泌,降低AKT蛋白磷酸化水平,改善E-cadherin表达的减少及α-SMA表达的增加。结论:西格列汀可以改善高糖诱导的HK-2细胞上皮-间充质转分化,此效应可能与抑制TGF-β1/AKT信号通路有关。     

PCI-neo-肝细胞生长因子对脂多糖刺激的大鼠肾小球系膜细胞α-平滑肌肌动蛋白表达的影响

目的探讨PCI-neo-肝细胞生长因子(PCI-neo-HGF)对脂多糖(LPS)刺激的大鼠肾小球系膜细胞(GMCs)的α-平滑肌肌动蛋白(α-SMA)的表达是否有抑制作用,以及这种抑制作用是否与对转化生长因子-β1(TGF-β1)表达的抑制有关。方法体外培养GMCs并分为5组,(1)Ctrl:对照;(2)C+L:GMCs+LPS(10μg/ml);(3)C+L+P-n:GMCs+LPS(10μg/ml)+PCI-neo(2μg);(4)C+L+P-n-H2:GMCs+LPS(10μg/ml)+PCI-neo-HGF(2μg);(5)C+L+P-n-H8:GMCs+LPS(10μg/ml)+PCI-neo-HGF(8μg);用RT-PCR的方法测定α-SMA及β-actin mRNA的表达,用Western方法检测及α-SMA,TGF-β1及β-actin的蛋白表达。结果与Ctrl组相比,C+L及C+L+P-n组α-SMA mRNA及蛋白表达增多(P0.05),TGF-β1蛋白表达增多(P0.05);与C+L相比,C+L+P-n-H2及C+L+P-n-H8组α-SMA mRNA及蛋白的表达均减少(P0.05),TGF-β1蛋白的表达减少(P0.05)。与C+L组比较,加入TGF-β1抑制剂组α-SMA蛋白表达水平下降(P0.05)。结论PCI-neo-HGF可抑制LPS刺激的GMCs的α-SMA的mRNA及蛋白表达,且这种抑制作用可能与其对TGF-β1表达的抑制有关。     

肝细胞生长因子对肾小管上皮细胞转分化及整合素连接激酶表达的影响

目的探讨肝细胞生长因子（HGF）在转化生长因子β1（TGF-β1）介导的肾小管上皮细胞转分化中的作用及对整合素连接激酶（ILK）表达的影响。方法将体外培养人肾小管上皮细胞（HKC）分为正常对照组、TGF-β1刺激组和HGF干预组。应用Western blotting方法检测ILK、α-平滑肌肌动蛋白（α-SMA）的蛋白表达,实时RT-PCR法测定ILK、α-SMA、纤维连接蛋白（Fn）、E钙黏蛋白（E-cadherin）的mRNA表达。结果在TGF-β1刺激组,ILK和α-SMA的蛋白表达量显著增加,ILK、α-SMA和Fn的mRNA表达量也明显升高,E-cad-herin mRNA表达量则明显降低（与正常对照组比较,P〈0.001）。而在HGF干预组,ILK、α-SMA的蛋白表达量以及ILK、α-SMA、Fn的mRNA表达量均较TGF-β1刺激组显著降低,E-cadherin mRNA表达量则明显升高（与TGF-β1刺激组比较,P〈0.01）。结论HGF能抑制TGF-β1介导的肾小管上皮细胞转分化,并可降低ILK蛋白和mRNA表达水平。     

普罗布考对脂多糖刺激下大鼠腹膜间皮细胞白细胞介素18的表达和对氧化应激的影响

目的 研究普罗布考对脂多糖(lipopolysaccharide,LPS)刺激下大鼠腹膜间皮细胞(rat peritoneal mesothelial cells,RPMC)白细胞介素18(interleukin-18,IL-18)和氧化应激产物丙二醛(malondialdehyde,MDA)表达的影响.方法原代培养RPMC,第3代腹膜间皮细胞达80%融合时进入试验.用无血清培养液培养24 h使细胞同步化.随机分组:①正常对照组:只加无血清DMEM/F12培养液;②LPS组:不同浓度LPS(1,10,100 mg/L)培养6 h;10 mg/L LPS分别作用于RPMC 0,3,6,12,24 h;③普罗布考组:20,40,80 μmol/L普罗布考预孵育1 h,加入10 mg/L LPS再作用11 h.用实时聚合酶链反应法检测IL-18 mRNA的表达,酶联免疫吸附法检测细胞上清液中IL-18的蛋白水平,硫代巴比妥酸法检测细胞中MDA的含量.结果与正常对照组比较,LPS刺激下RPMC IL-18和MDA的表达明显增加(P＜0.05),且呈浓度依赖性;随着刺激时间的延长,上述指标呈递增趋势,IL-18于12h达高峰(P＜0.01).与10 mg/L LPS组比较,普罗布考可抑制IL-18及MDA的表达(P＜0.05),随普罗布考浓度增加,抑制作用越强.结论 LPS作用下RPMC促炎症因子IL-18及氧化应激产物MDA表达增加,普罗布考能抑制上述指标的表达,修复间皮细胞的损伤,改善腹膜炎症状态.     

Changes in volume of peritoneal mesothelial cells exposed to osmotic stress.

OBJECTIVE: To evaluate changes in volume of mesothelial cells exposed to hypertonic medium and the role of volume regulatory mechanisms in adaptation to hyperosmolality. DESIGN: Experiments were performed on primary cultures of human peritoneal mesothelial cells. Cell volume was estimated by measuring equilibrated (intracellular/extracellular space) 14C-urea in cellular water. Cells in monolayers were exposed to hyperosmotic media and changes in cellular water or intracellular uptake of 3H-proline were measured. RESULTS: Exposure of mesothelial cell monolayers to hyperosmotic media reduced the cell volume; the effect was proportional to the osmolality of the medium. Volume of cells exposed to medium supplemented with glucose (180 mmol/L) decreased by 26%, p < 0.001, after 30 minutes' incubation. Prolonged exposure of mesothelial cells to hyperosmotic medium resulted in gradual recovery, after initial decline, of their volume. Intracellular uptake of amino acid 3H-proline increased after 240 minutes' exposure of the mesothelial cells to medium supplemented with glucose (90 mmol/L) (+40%, p < 0.05). When cells cultured for 7 days in medium supplemented with glucose (45 mmol/L) were exposed to medium with low glucose content (5 mmol/L) their volume increased by 17%, p < 0.05. CONCLUSION: Mesothelial cells shrink after exposure to hypertonic medium. Increased intracellular uptake of amino acids may be one of the regulatory mechanisms that ensure subsequent volume increase in these cells. Mesothelial cells chronically exposed to hypertonic medium swell after transfer to a medium with physiologic osmolality.     

单宁酸对高糖及AGEs引起肾小球系膜细胞增殖和Ⅳ型胶原生成的影响

目的观察单宁酸(tannic acid,TA)对高糖及糖化终产物(AGEs)引起的肾小球系膜细胞(GMC)增殖和Ⅳ型胶原生成的影响。方法体外培养肾小球系膜细胞,分别用高浓度葡萄糖(30 mmol/L)、不同浓度AGEs(25、50、100、200及400 mg/L)处理,同时用不同浓度单宁酸(10、20、40及80μmol/L)进行干预,设立相应对照组,于不同时间段(24、48 h)用MTT法检测肾小球系膜细胞的增殖情况,ELISA法检测培养48 h后条件培养基中Ⅳ型胶原的含量。结果葡萄糖及AGEs均能明显促进系膜细胞增殖和Ⅳ型胶原的生成,与对照组比较具有显著差别。单宁酸可明显抑制高糖或AGEs引起的系膜细胞增殖,能减少Ⅳ型胶原的生成,并呈一定浓度依赖关系。结论单宁酸能抑制高糖或AGEs引起的GMC增殖,并能减少Ⅳ型胶原生成。     

Expression of aquaporin-1 in the peritoneal tissues: localization and regulation by hyperosmolality.

OBJECTIVE: The purpose of this study was to determine the localization of the aquaporin-1 (AQP1) water channel in peritoneal tissues and the effect of hyperosmolality on the peritoneal expression and function of AQP1. METHODS: Immunohistochemical localization of AQP1 was identified in rat peritoneal tissues. Cultured rat peritoneal mesothelial cells (RPMCs) were exposed to hyperosmolality by adding 4% glucose to the culture medium. After 1 hour, 4 hours, 24 hours, and 48 hours, AQP1 was identified by semiquantitative immunoblot and immunocytochemistry. Osmotic water permeability was measured using a light-scattering method. RESULTS: Immunohistochemistry of rat peritoneal tissues showed the presence of AQP1 in mesothelial cells, venular endothelial cells, and capillary endothelial cells, but not in arteriole and interstitial cells. Semiquantitative immunoblot revealed that exposure to hyperosmolality significantly increased AQP1 expression after 24 hours in whole RPMC lysates (3.3-fold at 24 hours and 3.9-fold at 48 hours). Consistent with the immunoblot, osmotic water permeability of RPMC was augmented 1.7-fold and 2.7-fold after 1 hour and 24 hours, respectively, in a hyperosmotic environment. In RPMC membrane fractions, AQP1 expression was significantly increased after 1 hour of exposure to hyperosmolality (3.9-fold at 1 hour, 7.1-fold at 4 hours, and 8.7-fold at 24 hours). Immunocytochemistry of RPMCs showed that AQP1 was gradually redistributed from the perinuclear area to the peripheral cytoplasm, and then to the plasma membrane after a 1-hour hyperosmotic challenge, suggesting hyperosmolality-induced translocation of AQP1. Upregulation of AQP1 was also observed in the omentum of rats loaded intraperitoneally with hyperosmotic dialysate every day for 10 weeks. CONCLUSION: AQP1 is widely distributed in the peritoneal cavity and may provide the major aqueous pathway across the peritoneal barrier. In addition, our findings suggested that hyperosmolality increases AQP1-dependent water permeability in peritoneal tissues by regulatIng the translocation and synthesis of AQP1 protein.     

The John F. Maher Recipient Lecture 2004: Rage in the peritoneum.

Several conditions in the peritoneal membrane of peritoneal dialysis (PD) patients promote the accumulation of advanced glycation end-products (AGEs), that is, the uremic state, exposure to high glucose concentrations, and exposure to glucose degradation products (GDPs). AGEs exert some of their biologic actions through binding with a cell surface receptor, termed RAGE. Interaction of AGEs with RAGE induces sustained cellular activation, including the production of the fibrogenic growth factor, transforming growth factor-beta (TGF-beta). TGF-beta is pivotal in the process of epithelial-to-mesenchymal transition, through which cells of epithelial origin acquire myofibroblastic characteristics. Myofibroblasts are involved in virtually all conditions of pathological fibrosis. Submesothelial fibrosis is an important feature in peritoneal biopsies of PD patients, especially of those with clinical problems. We therefore examined the role of RAGE in peritoneal fibrosis, in an animal model of uremia, of high glucose exposure, and of peritoneal dialysate exposure. All three models were characterized by accumulation of AGEs, upregulation of RAGE, and fibrosis. Antagonism of RAGE prevented the upregulation of TGF-beta and fibrosis in the peritoneal membrane. We further examined the underlying mechanism of peritoneal fibrosis in the uremic model. Prominent myofibroblast transdifferentiation of mesothelial cells was identified by co-localization of cytokeratin and alpha-smooth muscle actin in submesothelial and interstitial fibrotic tissue. Antagonism of RAGE prevented conversion of mesothelial cells to myofibroblasts in uremia. In conclusion, we hypothesize that accumulation of AGEs in the peritoneal membrane, as a consequence of the uremic environment, chronic exposure to high glucose, and exposure to GDPs, results in an increased expression of RAGE. The interaction of AGEs with RAGE induces peritoneal fibrosis by virtue of upregulation of TGF-beta and subsequent conversion of mesothelial cells into myofibroblasts.