Immunophenotypical analysis of myofibroblasts and mesenchymal cells in the bleomycin-induced rat scleroderma,with particular reference to their origin

Cellular characteristics of myofibroblasts and its possible origin with mesenchymal stem cell nature in scleroderma remain to be investigated. We analyzed these cells in scleroderma induced in F344 rats by bleomycin (BLM) by immunolabeling using a panel of marker antibodies for cytoskeletons (vimentin, desmin, α-smooth muscle actin (α-SMA)) and stromal stem cells (Thy-1, A3). Skin samples were collected at 1, 2, 3, and 4 weeks after initiation of subcutaneous injections of BLM (100 μl of 1 mg/ml, daily). In double immunofluorescence, myofibroblasts reacting simultaneously to α-SMA, vimentin, and Thy-1 were seen in sclerotic lesions with a time-dependent increase. Mesenchymal cells in the perifollicular dermal sheath (PDS) displayed increased reactivity for Thy-1 and vimentin, but α-SMA expression did not increase in these cells. In double immunofluorescence, both myofibroblasts and pericytes in newly formed blood vessels in sclerotic lesions co-expressed α-SMA, vimentin and Thy-1, and the PDS cells and pericytes reacted simultaneously to A3, Thy-1 and vimentin. Desmin-positive cells were infrequently seen around the blood vessels. Based on these findings, the PDS cells and pericytes may be involved as possible progenitors of myofibroblasts in sclerotic lesions in the stromal stem cell lineage. Interestingly, increased number of TUNEL-positive apoptotic epithelial cells in the atrophied hair follicles significantly correlated with increase in immunohistochemical scoring of vimentin and Thy-1 in the PDS. Apoptosis in the hair follicle might have mediate the perifollicular fibrosis, resulting in extensive scleroderma. The present findings would provide new insights in the pathogenesis of BLM-induced scleroderma in terms of myofibroblasts and its origin.     

Characterization of glial fibrillary acidic protein (GFAP)-expressing hepatic stellate cells and myofibroblasts in thioacetamide (TAA)-induced rat liver injury

Hepatic stellate cells (HSCs), which can express glial fibrillary acidic protein (GFAP) in normal rat livers, play important roles in hepatic fibrogenesis through the conversion into myofibroblasts (MFs). Cellular properties and possible derivation of GFAP-expressing MFs were investigated in thioacetamide (TAA)-induced rat liver injury and subsequent fibrosis. Seven-week-old male F344 rats were injected with TAA (300 mg/kg BW, once, intraperitoneally), and were examined on post single injection (PSI) days 1–10 by the single and double immunolabeling with MF and stem cell marker antibodies. After hepatocyte injury in the perivenular areas on PSI days 1 and 2, the fibrotic lesion consisting of MF developed at a peak on PSI day 3, and then recovered gradually by PSI day 10. MFs expressed GFAP, and also showed co-expressions such cytoskeletons (MF markers) as vimentin, desmin and α-SMA in varying degrees. Besides MFs co-expressing vimentin/desmin, desmin/α-SMA or α-SMA/vimentin, some GFAP positive MFs co-expressed with nestin or A3 (both, stem cell markers), and there were also MFs co-expressing nestin/A3. However, there were no GFAP positive MFs co-expressing RECA-1 (endothelial marker) or Thy-1 (immature mesenchymal cell marker). GFAP positive MFs showed the proliferating activity, but they did not undergo apoptosis. However, α-SMA positive MFs underwent apoptosis. These findings indicate that HSCs can proliferate and then convert into MFs with co-expressing various cytoskeletons for MF markers, and that the converted MFs may be derived partly from the stem cell lineage. Additionally, well-differentiated MFs expressing α-SMA may disappear by apoptosis for healing. These findings shed some light on the pathogenesis of chemically induced hepatic fibrosis.     

Differential immunoexpressions of cytoskeletons in renal epithelial and interstitial cells in rat and canine fibrotic kidneys, and in kidney-related cell lines under fibrogenic stimuli

Myofibroblasts play an important role in chronic renal interstitial fibrosis. However, the origin and developmental mechanisms remain to be elucidated. The myofibroblasts may express various cytoskeletons during the development. Immunoexpressions of vimentin, desmin and alpha-smooth muscle actin (alpha-SMA) were analyzed using experimentally (cisplatin and unilateral ureteral obstruction) induced rat and spontaneous canine fibrotic kidneys or kidney-related cell lines incubated with transforming growth factor-beta1 (TGF-beta1), platelet-derived growth factor-BB (PDGF-BB) or their combination at various concentrations. In rat fibrotic kidneys, both renal epithelia and interstitial cells showed positive reactions to alpha-SMA and vimentin, supporting epithelial-mesenchymal transition (EMT) theory; however, renal epithelia did not react to desmin, though interstitial cells were reactive. Renal epithelia in canine fibrotic kidneys did not show a positive reaction to alpha-SMA, whereas interstitial cells reacted strongly to alpha-SMA; conversely, renal epithelia reacted strongly to desmin, but interstitial cells did not; vimentin expression was infrequently seen in renal epithelia and interstitial cells of canine kidneys. Exposure of TGF-beta1 to porcine renal epithelial cells (LLC-PK1), rat renal interstitial cells (NRK-49F), and rat immature mesenchymal cells (MT-9) dose-dependently increased selectively alpha-SMA-positive cell numbers. Moreover, PDGF-BB exhibited an additive effect on TGF-beta1-induced alpha-SMA expression in these cell lines when simultaneously added. alpha-SMA was the most plastic cytoskeleton under fibrogenic stimuli. This study shows that there are interspecies differences in cytoskeletal immunoexpressions of renal epithelia or interstitial cells between rat and canine fibrotic kidneys, and that the derivation of renal myofibroblasts may be heterogeneous, such as renal epithelia, interstitial cells or immature mesenchymal cells.     

Analysis of intestinal fibrosis in chronic colitis in mice induced by dextran sulfate sodium

Fibrogenic mesenchymal cells including fibroblasts and myofibroblasts play a key role in intestinal fibrosis, however, their precise role is largely unknown. To investigate their role in intestinal fibrosis, we analyzed the lesions of chronic colitis in C57BL/6 (B6) mice induced by dextran sulfate sodium (DSS). B6 mice exposed to single cycle administration of DSS for 5 days developed acute colitis that progressed to severe chronic inflammation with dense infiltrates of mononuclear cells, irregular epithelial structure, thickening of colonic wall, and persistent deposits of collagen. Increased mRNA expressions of proinflammatory cytokines are correlated with extensive cellular infiltration, and the mRNA expressions of collagen 1, transforming growth factor (TGF)-β, and matrix metalloproteinases were also enhanced in the colon. In the colon of chronic DSS colitis, fibroblasts (vimentin(+), α-smooth muscle actin (α-SMA)(-)) were increased in both mucosal and submucosal layers, while myofibroblasts (vimentin(+), α-SMA(+)) were increased in mucosal but not in submucosal layers. Primary mouse subcutaneous fibroblast cultures experiments revealed that exogenously added TGF-β 1 substantially augmented the expressions of both vimentin and α-SMA proteins with increased production of collagen. In conclusion, profibrogenic mesenchymal cells play an important role in the development of intestinal fibrosis in this chronic DSS-induced colitis model.     

Slowly progressive cholangiofibrosis induced in rats by α-naphthylisothiocyanate (ANIT), with particular references to characteristics of macrophages and myofibroblasts

A progressive cholangiofibrosis was developed as an animal model in 6-week-old male F344 rats by repeated intraperitoneal injections of α-naphthylisothiocyanate (ANIT) for 19 weeks; liver samples were examined at post-first injection (PFI) weeks 3, 7, 10, 13, 16 and 19, focusing on characteristics of macrophages and myofibroblasts by immunohistochemical analyses. In the affected Glisson's sheath consisting of inflammatory cell infiltrates, bile duct proliferation and advancing fibrosis, the number of macrophages reacting to OX6 (recognizing MHC class II) increased consistently (PFI weeks 3–19), suggesting a central role of antigen presenting cells in the biliary fibrosis; macrophages reacting to ED1 (CD68, reflecting phagocytic activity) and ED2 (CD163, relating to proinflammatory factor production) showed a significantly increased number at PFI weeks 7–19 and PFI weeks 13–19, respectively. Interestingly, macrophages positive for SRA-E5 (CD204, reflecting lipid metabolism) increased at PFI weeks 7–19, and the appearance was limited in the sinusoids around the affected Glisson's sheath. Myofibroblasts appearing in the affected Glisson's sheath reacted to vimentin and desmin at early (PFI weeks 3–7) and mid (PFI weeks 10–13) stages, and then they came to strongly express α-smooth muscle actin at late stage (PFI weeks 16–19). This study shows that macrophages exhibit heterogeneous properties depending on stages and locations; in association with such macrophage populations, myofibroblasts expressing various cytoskeletons participate in cholangiofibrosis. These characteristics would be useful in evaluating the pathogenesis of possible cholangio-toxicants.     

IL-17在肾间质纤维化中的作用初探

探讨白细胞介素17(IL-17)在肾间质纤维化发生发展中的作用。采用的体内实验为,以单侧输尿管梗阻(unilateral ureteric obstruction,UUO)启动纤维化病理过程。将C57BL/6小鼠分为假手术组(Sham)和单侧输尿管梗阻(unilateral ureteric obstruction,UUO)组,分别于术后第1、3、7天处死,留取手术侧肾组织。采用HE、PAS、PASM、Masson染色评价肾间质组织病理变化。以免疫组化、实时荧光定量PCR(qRT-PCR)法检测α平滑肌肌动蛋白(α-SMA)表达水平;酶联免疫吸附试验(ELISA)检测IL-17在肾组织中的表达情况。体外实验为,分离培养C57BL/6小鼠肾成纤维细胞,转化生长因子β1(TGF-β1)刺激使其转化为肌成纤维细胞,继而用蛋白免疫印迹法(western blotting)检测IL-17的刺激下α-SMA表达水平。结果显示,组织病理学检查显示随着梗阻时间延长,炎性细胞浸润明显,肾小管萎缩,间质面积增大,Ⅰ型胶原和α-SMA增多。PCR检测显示α-SMA mRNA表达增多。但ELISA结果显示肾组织中IL-17含量呈下降趋势。Western blot结果表明肌成纤维细胞在IL-17的刺激下,α-SMA蛋白水平显著下降。实验说明,单侧输尿管梗阻手术可导致相应侧肾组织发生纤维化病变,但肾组织中IL-17含量与纤维化病变并不一致,在体外实验中IL-17可下调肌成纤维细胞表达的α-SMA。     

α-SCA、α-SMA和结蛋白与小鼠胚胎心肌发育成熟的关系

目的观察α-横纹肌肌节肌动蛋白（α-SCA）、α-平滑肌肌动蛋白（ct-SMA）和中间丝结蛋白在小鼠心脏发育过程中的时空表达特征,以探讨这些蛋白质表达与胚胎及生后小鼠心脏成熟的关系。方法用抗α-SCA、抗α-SMA及抗结蛋白单克隆抗体对胚胎及生后小鼠心脏连续切片进行染色。结果胎龄9d,心室和流出道α-SCA、α-SMA表达较强,而结蛋白表达较弱。在心房α-SCA、α-SMA的表达限于背侧壁和腹侧壁,静脉窦仅见少许α-SCA弱阳性细胞。心房和静脉窦则无结蛋白表达。α-SCA、α-SMA和结蛋白的表达于胎龄12d达高峰。较高水平的α-SCA表达将持续到生后。心脏各部α-SMA和结蛋白表达于胎龄12d后逐渐下降,但在右心室表达持续时间较长。出生后,结蛋白表达主要集中于明带Z线和闰盘。结论α-SMA和结蛋白在小鼠胚胎心脏表达的时空差异性表明小鼠胚胎心脏不同部位发育成熟的时问有差异,右心室成熟较慢。α-SMA表达可能与早期胚胎心脏的缓慢蠕动收缩有关。肌节的发育成熟需要较高的结蛋白表达。     

间充质干细胞在肝纤维化形成中的作用

目的:肌成纤维细胞在肝纤维化形成中起着关键作用。有报道骨髓间充质干细胞可分化为肌成纤维细胞,并迁徙至损伤器官参与其纤维化形成过程。因此,本研究拟探讨骨髓间充质干细胞在肝纤维化形成中的可能作用及机制。方法:(1)以携带增强型绿色荧光蛋白(eGFP)的重组逆转录病毒感染大鼠间充质干细胞株(MSCs)Ap8c3进行标记(Ap8c3-eGFP)。(2)制作胆总管结扎(BDL)及猪血清腹腔注射(IPS)诱导的大鼠肝纤维化动物模型。(3)经大鼠尾静脉将Ap8c3-eGFP注入前述动物体内。(4)检测大鼠肝脏、骨髓中eGFP阳性(eGFP+)细胞分布及表达α平滑肌肌动蛋白(α-SMA)情况。结果:(1)静脉注射的Ap8c3-eGFP干细胞最终可出现于发生肝纤维化的大鼠肝脏及骨髓中。(2)大鼠肝脏中的eGFP+细胞同时表达α-SMA,主要分布于肝脏增生纤维束内。(3)迁徙至骨髓的Ap8c3-eGFP细胞可分化为肌成纤维细胞,表达α-SMA。结论:间充质干细胞可分化为肌成纤维细胞,在肝纤维化形成中起重要作用。     

不同预缺血时间对肾小管间质纤维化的影响

目的：在建立缺血所诱发的肾小管间质纤维化大鼠模型基础上，探讨不同预缺血时间对肾脏纤维化的影响。方法:双侧肾蒂夹闭40 min后恢复灌注，制作缺血再灌注损伤模型，8 d前用同样方法分别造成肾脏预缺血10 min、20 min和30 min。预缺血后1 d、4 d、8 d和第2次缺血后5 周收集血样和肾脏标本。Masson特殊染色法观察小管间质纤维化程度；Western blotting法测定α-平滑肌肌动蛋白(α-SMA)、TGF-β1和磷酸化Smad2蛋白表达；免疫组织化学法观察肾脏α-SMA 和TGF-β1的分布。结果:术后5周单纯缺血再灌注组（I/R）和10 min 缺血预处理组（I-10/I）出现了相似程度的小管间质纤维化病变；30 min缺血预处理组（I-30/I）的肾脏纤维化明显加重，并伴有肾脏重量的增加、肾功能的减退和α-SMA、TGF-β1、phospho-Smad2蛋白表达进一步上调；相反，20 min缺血预处理组（I-20/I）的肾脏纤维化显著减轻甚至消失，与假手术对照组（sham）相比上述蛋白的表达无显著差异。结论:长时间的肾脏缺血可以引起小管间质纤维化，提前进行缺血预处理影响此病理改变，其作用结果与预缺血的时间长短密切相关，时间适中的预缺血能保护肾脏免于纤维化结局，其保护机制有待进一步研究。另外，肌成纤维细胞增多（α-SMA阳性）和TGF-β1/Smad信号通路激活可能参与缺血性小管间质纤维化病变过程。     

Mesenchymal hamartoma of the liver: A proliferative lesion of possible hepatic stellate cell (Ito cell) origin

An asymptomatic 17-month-old male infant was incidentally found to have a hepatic mass measuring 12 cm in maximum dimension. The histopathologic appearance of the resected mass was that of a typical mesenchymal hamartoma. Spindle cells that comprised a predominant cellular constituent of the lesion were studied immunohistochemically and ultrastructurally. These cells were immunoreactive for vimentin, α-smooth muscle actin (α-SMA), desmin, tenascin, and α B-crystallin, and displayed fibroblastic or myofibroblastic ultrastructural features. These immunohistochemical and ultrastructural findings of the spindle cells were similar to those of “activated” hepatic stellate cells (Ito cells), and they confirmed and reinforced the hypothesis proposed by von Schweinitz et al. that spindle cells forming the predominant cellular constituent of mesenchymal hamartoma are derived from hepatic stellate cells, although another possibility that the spindle cells are derived from myofibroblasts in the portal tracts cannot be ruled out.     

Ac-SDKP suppresses epithelial–mesenchymal transition in A549 cells via HSP27 signaling

The synthetic tetrapeptide N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) has been shown to be a modulator of molecular aspects of the fibrosis pathway. This study reveals that Ac-SDKP exerts an anti-fibrotic effect on human type II alveolar epithelial cells (A549), which are a source of myofibroblasts once exposed to TGF-β1, by decreasing the expression of heat shock protein 27 (HSP27). We used A549 cells in vitro to detect morphological evidence of epithelial–mesenchymal transition (EMT) by phase-contrast microscopy. Immunocytochemical and western blot analysis determined the distributions of cytokeratin 8 (CK8), α-smooth muscle actin (α-SMA), and SNAI1. Confocal laser scanning microscopy revealed a colocalization of HSP27 and SNAI1 on TGF-β1-induced A549 cells. These results also demonstrated that A549 cells became spindle-like when exposed to TGF-β1. Coincident with these morphological changes, expression levels of CK8 and E-cad decreased, while those of vimentin and α-SMA increased. This process was accompanied by increases in levels of HSP27, SNAI1, and type I and type III collagen. In vitro transfection experiments demonstrated that the inhibition of HSP27 in cultured A549 cells could decrease the expression of SNAI1 and α-SMA while increasing the expression of E-cad. A noticeable reduction in collagen types I and III was also evident. Our results found that Ac-SDKP inhibited the transition of cultured A549 cells to myofibroblasts and attenuated collagen synthesis through modulating the expression of HSP27.     

Dynamic Regulation of Platelet-Derived Growth Factor Receptor α Expression in Alveolar Fibroblasts during Realveolarization

Although the importance of platelet-derived growth factor receptor (PDGFR)-α signaling during normal alveogenesis is known, it is unclear whether this signaling pathway can regulate realveolarization in the adult lung. During alveolar development, PDGFR-α-expressing cells induce α smooth muscle actin (α-SMA) and differentiate to interstitial myofibroblasts. Fibroblast growth factor (FGF) signaling regulates myofibroblast differentiation during alveolarization, whereas peroxisome proliferator-activated receptor (PPAR)-γ activation antagonizes myofibroblast differentiation in lung fibrosis. Using left lung pneumonectomy, the roles of FGF and PPAR-γ signaling in differentiation of myofibroblasts from PDGFR-α-positive precursors during compensatory lung growth were assessed. FGF receptor (FGFR) signaling was inhibited by conditionally activating a soluble dominant-negative FGFR2 transgene. PPAR-γ signaling was activated by administration of rosiglitazone. Changes in α-SMA and PDGFR-α protein expression were assessed in PDGFR-α-green fluorescent protein (GFP) reporter mice using immunohistochemistry, flow cytometry, and real-time PCR. Immunohistochemistry and flow cytometry demonstrated that the cell ratio and expression levels of PDGFR-α-GFP changed dynamically during alveolar regeneration and that α-SMA expression was induced in a subset of PDGFR-α-GFP cells. Expression of a dominant-negative FGFR2 and administration of rosiglitazone inhibited induction of α-SMA in PDGFR-α-positive fibroblasts and formation of new septae. Changes in gene expression of epithelial and mesenchymal signaling molecules were assessed after left lobe pneumonectomy, and results demonstrated that inhibition of FGFR2 signaling and increase in PPAR-γ signaling altered the expression of Shh, FGF, Wnt, and Bmp4, genes that are also important for epithelial-mesenchymal crosstalk during early lung development. Our data demonstrate for the first time that a comparable epithelial-mesenchymal crosstalk regulates fibroblast phenotypes during alveolar septation.     

结缔组织生长因子在单侧输尿管梗阻大鼠肾组织中的表达

目的：检测大鼠单侧输尿管梗阻（UUO）模型不同时期，肾组织中结缔组织生长因子（CTGF）、转化生长因子β1（TGF-β1）和α-平滑肌肌动蛋白（α-SMA）的表达，观察比较在间质纤维化不同阶段，3者的动态变化及关系。 方法： 采用雄性SD大鼠36只，分为假手术组和模型组，模型组行左侧输尿管结扎术，再分3、7、14、21和28 d共6组，每组6只，于各时点处死大鼠，取肾组织，常规HE、Masson染色，按小管间质损害的特征进行半定量评分。免疫组化检测CTGF、TGF-β1和α-SMA表达。 结果： 随梗阻时间的延长，小管间质纤维化加重，28 d间质已基本被纤维化组织所代替。随间质纤维化程度的加重，CTGF和α-SMA表达逐渐增加，两者与小管间质损害积分呈正相关，CTGF与α-SMA的表达之间也呈正相关。TGF-β1表达在7-14 d达高峰后，逐渐减少，但仍高于对照组。 结论： UUO致CTGF表达增加可能与TGF-β升高有关，CTGF可能通过促进间质中肌成纤维细胞的形成而参与肾间质纤维化。     

低氧诱导肌成纤维细胞生成并通过ERK1/2途径促进Ⅰ型胶原的表达

目的：探讨低氧能否激活成纤维细胞转化为肌成纤维细胞,以及低氧环境对肾皮质肌成纤维细胞表达Ⅰ型胶原（Col-Ⅰ）的影响及其可能的信号通路。方法：（1）采用正常大鼠肾成纤维细胞系（NRK-49F），应用Western blotting方法检测低氧诱导因子-1α(HIF-1α)的表达;比较低氧和正常氧条件下α-平滑肌肌动蛋白(α-SMA)的蛋白水平。（2）原代培养正常大鼠肾皮质肌成纤维细胞，Western blotting方法检测低氧和正常氧条件下，HIF-1α和Ⅰ型胶原蛋白水平以及ERK1/2的活化及其特异阻断剂 PD98059的阻断效应；RT-PCR方法检测Ⅰ型胶原mRNA表达水平；细胞免疫化学法检测HIF-1α胞内表达部位的变化；明胶酶谱法检测细胞上清中基质金属蛋白酶-2（MMP-2）和基质金属蛋白酶-9（MMP -9）的活性。结果：（1）低氧刺激6 h，NRK-49F细胞和肌成纤维细胞胞内和核内均有HIF-1α蛋白表达，核内更明显。（2）低氧培养12 h,NRK-49F细胞表达α-SMA蛋白明显增高，是正常氧组的187%±32%（P<0.05），验证了低氧可引起成纤维细胞表型转化。（3）低氧刺激原代培养的正常大鼠肾皮质肌成纤维细胞6 h、12 h上清中Ⅰ型胶原蛋白水平增加，分别为正常氧组的171%±27%（P<0.05）和256%±61% （P<0.05）；低氧刺激4 h、6 h，Ⅰ型胶原mRNA表达增加，为正常氧组的189%±28%（P<0.05）和221%±44%（P<0.05）。（4）低氧刺激肌成纤维细胞6 h、12 h、24 h，培养上清液中MMP-9、MMP-2活性无明显变化。（5）低氧刺激肌成纤维细胞15 min 即可使ERK1/2活化，阻断实验显示，PD98059可以使低氧12 h引起Ⅰ型胶原增加（低氧刺激组为正常氧对照组的273%±51%，P<0.05)显著减少（PD98059 +低氧组为正常氧组的108%±19%，P>0.05)。结论： 低氧促肾纤维化可能与其诱导肾成纤维细胞转化为肌成纤维细胞并经ERK1/2途径增加Ⅰ型胶原蛋白的表达有关。     

Role of PDGFs/PDGFRs signaling pathway in myocardial fibrosis of DOCA/salt hypertensive rats

This study aimed to investigate the role of PDGF/PDGFR signaling pathway in myocardial fibrosis of desoxycorticosterone (DOCA) induced salt-sensitive hypertensive rats and explore the influence of PDGF/PDGFR signaling pathway on fibroblasts and myofibroblasts in the heart. 60 male SD rats underwent right nephrectomy and bred with 1% sodium chloride and 0.1% potassium chloride for 4 weeks, and then randomly divided into 3 groups (CON group, DOCA group and DOCA+IMA group). Results showed that: 1) 14 and 28 days after intervention, the SBP in DOCA and DOCA+IMA group was significantly higher than that in CON group. At days 28, the severity of myocardial fibrosis and PVCA/VA ratio in DOCA group were significantly increased when compared with CON group. The severity of myocardial fibrosis and PVCA/VA ratio in DOCA+IMA group were markedly lower than those in DOCA group although they were higher than those in CON group. 2) At days 14, the mRNA expressions of PDGFRα and PDGFRβ in DOCA group were significantly higher than CON and DOCA+IMA group. At days 28, the mRNA expressions of PDGFRβ, FSP-1, α-SMA, procollagen I and procollagen III in DOCA group were significantly higher than those in CON group. In addition, in a specific group, the PDGFRβ mRNA expression was higher than the PDGFRα mRNA expression. In DOCA+IMA group, the mRNA expressions of PDGFRβ, FSP-1, α-SMA, procollagen I and procollagen III were markedly reduced when compared with DOCA group. 3) At 14 days, the protein expressions of PDGFRα and PDGFRβ in DOCA group were significantly higher than those in CON group. The PDGFRα protein expression in DOCA+IMA group was markedly lower than that in DOCA group. At days 28, the protein expressions of PDGFRα and PDGFRβ in DOCA group were significantly increased when compared with CON group. The protein expressions of PDGFRα and PDGFRβ in DOCA+IMA group were significantly lower than those in DOCA group. At day 28, the cardiac interstitium mainly contained vimentin positive fibroblasts, and α-SMA positive cells were less identified in CON group. In DOCA group, α-SMA positive fibroblasts (spindle-shaped) increased significantly, but the myofibroblasts reduced significantly in DOCA+IMA group when compared with DOCA group. 4) PDGFRα protein expression was observed in fibroblasts and myofibroblasts, but not in VSMCs. PDGFRβ protein expression was noted in not only fibroblasts and myofibroblasts but also VSMCs. Thus, During myocardial fibrosis of DOCA induced salt-sensitive hypertensive rats, PDGFRα acts at early stage, but PDGFRβ functions in the whole process. PDGFRα and PDGFRβ expressions increase in fibroblasts and myofibroblasts, suggesting that PDGF/PDGFR signaling pathway is involved in the myocardial fibrosis via stimulating fibroblasts to proliferate and transform into myofibroblasts.     

IgA肾病PTEN表达及其对肾间质纤维化的影响

目的： 探讨IgA肾病（IgAN）肾组织中染色体10上缺失的磷酸酶与张力蛋白同源物基因（PTEN）表达及其对肾间质纤维化的影响。方法: 选择IgAN患者47例,并详细收集资料;10例肾脏肿瘤切除后正常远端肾组织作对照。肾小管间质病变程度用Katafuchi等标准分为4组。应用免疫组化SP法检测PTEN、转化生长因子-β1（TGF-β1）、α-平滑肌肌动蛋白（α-SMA）、Ⅲ型胶原（Col Ⅲ）以及原位杂交法检测PTEN mRNA表达。结果: ①IgAN和对照肾组织中PTEN及PTEN mRNA表达部位主要在肾小管上皮细胞胞浆中,肾小球内无或仅有极少量表达。IgAN随肾小管间质病变程度加重,PTEN与PTEN mRNA表达逐渐减少,无病变组明显高于其它3组（均P<0.05）。②IgAN肾组织PTEN与PTEN mRNA表达正相关（P<0.05）;两者分别与eGFR、尿渗透压正相关（P<0.01）,与TGF-β1、α-SMA、ColⅢ、24 h尿蛋白排泄量、硬化肾小球数以及血管积分负相关（均P<0.01）。结论: IgAN中TGF-β1可能在基因转录水平下调PTEN表达,诱导肾小管上皮转分化以及细胞外基质的沉积,从而在肾小管间质纤维化过程中起到重要作用。     

ROCK抑制剂对青光眼术后瘢痕形成的作用机制

目的：探讨Rho 相关卷曲螺旋形成蛋白激酶（ROCK）抑制剂对青光眼手术后瘢痕形成的影响,分析 ROCK抑制剂对瘢痕修复的作用机制。方法：健康大鼠分为模型组和ROCK抑制剂组（RR组）,采用MTT法测 定瘢痕组织中成纤维细胞增殖情况,RT-PCR 检测滤过道瘢痕组织转化生长因子-β1（TGF-β1）、α 平滑肌肌动蛋 白（α-SMA）、ROCK mRNA表达,免疫组织化学检测白细胞介素（IL）-1β（IL-1β）、α-SMA 蛋白阳性表达,免 疫印迹检测IL-1β、IL-6、血管内皮生长因子（VEGF）、α-SMA 蛋白表达。结果：模型组成纤维细胞的抑制率低 于RR组的抑制率,差异有统计学意义。RT-PCR 检测结果显示模型组TGF-β1、ROCK、α-SMA mRNA 的表达高 于RR组。免疫组织化学检测结果显示RR组IL-1β、α-SMA 的阳性表达显著低于模型组。免疫印迹检测结果显示 模型组IL-1β、IL-6、VEGF、α-SMA 的表达水平高于RR组,差异均有统计学意义。结论：ROCK抑制剂可通过 降低TGF-β1 mRNA、ROCK mRNA、IL-1β、IL-6、VEGF、α-SMA 蛋白的表达进而抑制成纤维细胞的增殖,阻 碍青光眼术后瘢痕的形成。     

5-氟尿嘧啶抑制TGF-β1诱导人肝内胆管上皮细胞间质化

目的探讨5-氟尿嘧啶对TGF-β1诱导人肝内胆管上皮细胞间质化的抑制作用,并探讨其作用机制。方法原代培养人肝内胆管上皮细胞,角蛋白19荧光染色鉴定;细胞分为:对照(normal)组,TGF-β1(TGF-β1)组,5-氟尿嘧啶(TGF-β1+5-FU)组;免疫荧光染色观察CK-19、E-cadherin、vimentin和α-SMA标记蛋白;Western blot检测细胞标记蛋白及TGF-β1表达量;Real-time PCR检测细胞Ⅰ、Ⅲ型胶原及TGF-β1 mRNA含量。结果原代培养的人肝内胆管上皮细胞呈多边形或者锥形,CK-19荧光染色为胞质着色;TGF-β1诱导72 h后,胆管上皮出现间质化表现,与正常组比较,vimentin、α-SMA和TGF-β1表达明显增强(P0.05),CK-19和E-cadherin表达显著减弱(P0.05),Ⅰ、Ⅲ型胶原及TGF-β1 mRNA含量显著升高(P0.05);5-FU抑制胆管上皮间质化,与TGF-β1组比较,CK-19和E-cadherin表达增强(P0.05),vimentin、α-SMA和TGF-β1表达明显减弱(P0.05),TGF-β1 mRNA和Ⅲ型胶原mRNA含量明显降低(P0.05)。结论 5-FU通过下调TGF-β1的表达抑制胆管上皮细胞间质化。