a-SMA与Vimentin在慢性硬膜下血肿外膜中的表达及意义

目的 采用a-平滑肌肌动蛋白（a-SMA）与波形蛋白 （VIM）鉴定和分类慢性硬膜下血肿（CSDH）外膜中的肌成纤维细胞 （MFB）,并探讨两者表达的意义.方法 选取CSDH 9例患者的硬脑膜和其下的血肿膜,采用免疫组化法检测a-SMA和VIM在CSDH外膜中的表达,采用透射电镜观察细胞形态结构.结果 CSDH血肿膜中细胞数量较多,可见许多新生毛细血管;共同表达a-SMA和VIM的细胞有两种,其中一类细胞呈梭形（为肌成纤维细胞）,另一类是血管管壁的细胞（为血管内皮细胞）;阳性表达的棕黄色颗粒状均位于胞质内.电镜观察可见MFB细胞特征性形态,胞核有很多切迹,沿细胞长轴的边缘有束状肌动蛋白细丝排列.结论 a-SMA与VIM的广泛表达和持续分布可能在CSDH的发生发展中有重要作用.     

Pro-fibrogenic potential of PDGF-D in liver fibrosis

BACKGROUND/AIMS: We analyzed the expression of platelet-derived growth factor D (PDGF-D) in an experimental bile duct-ligated (BDL) rat model and assessed its biological function in cultured hepatic stellate cells (HSC) and myofibroblasts (MFB). METHODS: The mRNA for PDGF-A, -B, -C, -D and for PDGF receptor-alpha and -beta chains (PDGFRalpha and PDGFRbeta) in normal and fibrotic rat livers was assessed quantitatively. Protein levels of PDGF-D were quantified by immunoblotting and immunohistochemistry. RESULTS: The relative mRNA expression of all PDGF isoforms and receptors upregulated upon BDL and PDGF-A, -B and -D expression was significantly higher than that of PDGF-C. PDGF-D and PDGFRbeta protein also increased markedly. Immunostaining revealed that PDGF-D is localized along the fibrotic septa of the periportal- and perisinusoidal areas. Besides PDGF-B, PDGF-D is the second most potent PDGF isoform in PDGFRbeta signaling within HSC/MFB, evidenced by PDGFRbeta autophosphorylation and activation of the downstream signaling molecules ERK1/2-, JNK-, p38 MAPK, and PKB/Akt while PDGF-C effects were minimal. PDGF-D exerted mitogenic and fibrogenic effects in both cultured HSC and MFB comparable to PDGF-B but PDGF-A and -C showed only marginal fibrogenic effects. CONCLUSIONS: PDGF-D possesses potential pathogenetic properties for HSC activation and matrix remodeling in liver fibrosis.     

Two forms of diffuse alveolar damage in the lungs of patients with acute respiratory distress syndrome

Acute respiratory distress syndrome is a severe disease, the treatment and pathophysiology of which are not completely established. The pathology of acute respiratory distress syndrome involves diffuse alveolar damage, which comprises severe alveolar epithelial cell damage, hyaline membrane formation, and festinate myofibroblast proliferation and fibrosis in the intra-alveolar spaces. We performed a clinicopathologic investigation of 26 autopsy cases of diffuse alveolar damage. Three cases of them were diagnosed as acute interstitial pneumonia that is idiopathic illness and resembles pathologically organizing diffuse alveolar damage. Immunohistochemical staining for types I and IV collagen, α-smooth muscle actin, and Ki-67 was carried out, and the sites of myofibroblast proliferation and type I collagen production were examined. All diffuse alveolar damage cases in the proliferative phase showed intra-alveolar myofibroblast proliferation. When diffuse alveolar damage was diagnosed pathologically as being due to severe infection, all 7 patients showed multiple organ dysfunction syndrome, whereas only 2 of 7 patients showed interstitial myofibroblast proliferation. When diffuse alveolar damage was attributed to tumor treatment with chemotherapy or to drug toxicity, 3 of 16 patients showed multiple organ dysfunction syndrome; 15 of 16 showed interstitial myofibroblast proliferation, 3 of 3 acute interstitial pneumonia patients did not show multiple organ dysfunction syndrome; and 3 of 3 acute interstitial pneumonia showed marked interstitial myofibroblast proliferation. These results suggest that the pathophysiologic mechanism of diffuse alveolar damage caused by severe infection is one of systemic circulation disturbance, although the mechanism underlying diffuse alveolar damage due to tumor with chemotherapy or drug toxicity appears to involve interstitial pneumonia-like lesions that are similar to acute interstitial pneumonia.     

Retroprosthetic membrane: A complication of keratoprosthesis with broad consequences

Keratoprosthesis (KPro) devices have the remarkable ability to restore vision in patients suffering from corneal blindness who are poor candidates for traditional penetrating keratoplasty. However, eyes with KPro can experience various complications, including the development of retroprosthetic membrane (RPM). RPMs reduce visual acuity in patients due to physical obstruction of the visual axis, but studies have shown that RPM can also lead to a variety of other consequences, from melting of the corneal carrier graft to precipitating retinal detachments. Histopathologic studies have shown that RPMs are composed of elements from both the recipient and donor. The presence of myofibroblasts in RPMs imparts them with contractile properties, which can contribute to their downstream complications, including angle closure, hypotony, and retinal detachment. At present, there are limited treatments to combat the growth of RPM. Future therapies could include anti-metabolites and targeted anti-inflammatory treatments, as well as device coatings or textured device surfaces that can hinder RPM proliferation. The long-term success of KPro depends on devising an effective solution for preventing RPM growth.     

In vivo responses of macrophages and myofibroblasts in the healing following isoproterenol-induced myocardial injury in rats

To clarify the relation between macrophage and myofibroblast involvement in various myocardial diseases, the authors investigated the kinetics of these cells in the healing (scar tissue formation) following isoproterenol-induced myocardial injury in rats. Alphasmooth muscle actin (-SMA) expressing myofibroblasts were seen at the border of the affected area and appeared in the greatest numbers on days 3–7 post-injection, followed by a gradual decrease by day 35. The peak on day 3 was consistent with the timing of the highest proliferative activity of myofibroblasts. The number of ED1-positive macrophages began to increase as early as day 1, reaching a peak on day 3 within the injured myocardium. The expansion of EDI-positive macrophages preceded an increased number of -SMA-positive myofibroblasts suggesting that myofibroblast proliferation and activation may be mediated by factors released by ED1-positive mcrophages in response to myocardial injury. The number of ED2-positive tissue-fixed, resident macrophages gradually increased from day 3 post-injection, and peaked on day 14, but the number of ED2-positive macrophages was consistently fewer than that of ED1-positive macrophages during the 35 day-observation period after the injection. The labelling index of the ED2-positive cells was maximal on day 14, indicative of local proliferation of resident macrophages. In the healing process after myocardial injury, EDI-positive macrophages increase markedly in the early stages; ED2-positive macrophages appear later.     

Muscular hamartoma of the breast

Summary A rare case of muscular hamartoma of the breast was presented. An electron microscopic study confirmed that the proliferating spindle cells were of smooth muscle cell origin.     

高氧暴露对新生大鼠肺成纤维细胞α-平滑肌肌动蛋白与Ⅰ型胶原蛋白表达的影响

目的 探讨持续吸入高氧后新生大鼠肺成纤维细胞中α平滑肌肌动蛋白(α-smoothmuscle actin,α-SMA)及Ⅰ型胶原蛋白表达的影响.方法 30只足月新生Wistar大鼠,于生后12h内分别持续吸入90％的高浓度氧(高氧组,15只)和空气(空气组,15只).各组于3d,7d和14 d随机处死大鼠后,进行肺成纤维细胞的原代培养,应用免疫组织化学法检测大鼠α-SMA表达,ELISA法检测细胞培养液上清中Ⅰ型胶原蛋白的含量.结果 持续吸入高氧3d,高氧组与空气组大鼠α-SMA表达与Ⅰ型胶原蛋白含量比较,差异均无统计学意义(P＞0.05).持续吸入高氧7d和14 d,高氧组大鼠肺成纤维细胞α-SMA表达的吸光度与空气组比较显著增加(112.60±4.61 vs 94.69±2.38,200.30±3.97 vs 103.04±1.91,P＜0.01).同时,细胞培养液上清中Ⅰ型胶原蛋白含量高氧组7d、14 d时也较空气组明显增加[(28.66±1.15) μg/L vs (24.62±3.15) μg/L,(30.60 ±0.65) μg/L vs (27.46±1.68) μg/L,P ＜0.05].高氧组大鼠α-SMA表达与Ⅰ型胶原蛋白含量呈正相关(r=0.72,P＜0.01).结论 高氧可促进新生大鼠肺成纤维细胞向肌成纤维细胞转化,Ⅰ型胶原合成增加,最终导致肺纤维化的发生.     

α-平滑肌肌动蛋白在高氧肺损伤中的表达变化及意义

目的 探讨高氧暴露下大鼠肺损伤中肌成纤维细胞表面标志α-平滑肌肌动蛋白(α -SMA)的表达变化及意义.方法 将64只3周龄SD大鼠按随机数字表法分为正常对照组(置于空气中,吸入氧浓度0.21)和高氧暴露组(置于玻璃氧舱中,95％氧),每组于高氧暴露1、7、14、21d随机处死8只大鼠.苏木素-伊红(HE)染色观察肺组织病理改变,免疫组化法观察α -SMA在肺组织中的表达与分布,蛋白质免疫印迹法( Western blotting)检测肺组织α-SMA表达.结果 HE染色发现,早期高氧肺损伤时肺组织以炎症水肿表现为主,后期则以间质纤维增生为主.免疫组化结果显示,正常对照组α -SMA在细支气管上皮、肺泡表面及肺泡间隔上表达极为微弱;高氧暴露后随时间的延长α-SMA在肺泡表面及肺泡间隔上表达逐渐增强,以21d时最为明显.Western blotting检测发现,与正常对照组相比,高氧暴露1d、7d时肺组织α-SMA表达无明显差异(1.02±0.12比1.00±0.13,1.05±0.14比0.99±0.12,均P＞0.05),高氧暴露14d、21d时α-SMA表达明显增强(1.27±0.21比1.05±0.15,2.26±0.28比1.05±0.14,P＜0.05和P＜0.01).结论 大鼠高氧暴露后随时间延长,α-SMA在肺组织中的表达逐渐升高,肺纤维化逐渐加重,说明肌成纤维细胞在肺组织纤维化重构过程中起重要作用.     

肌成纤维细胞在创面收缩中的作用

目的：研究肌成纤维细胞在创面收缩过程中的作用，探讨创面收缩机理。方法：对兔耳及背部创面进行创面收缩观察并用电镜、免疫组化等方法对比研究肌成纤维细胞出现及变化规律。结果：肌成纤维细胞出现的时间晚于创面收缩时间，出现的量与创面收缩的程度关系密切。结论；肌成纤维细胞不是创面收缩的始动因素，但参与了创面收缩过程。     

平滑肌肌动蛋白(SMA)在胆道愈合过程中的表达及意义

目的：观察ＳＭＡ及肌成纤维细胞在胆道愈合过程中的表达，探讨其在医源性胆管狭窄形成过程中的作用及意义。方法通过制作犬肝外胆管损伤修复模型，分别于术后１周、３周、３月、６月取材行ＳＭＡ免疫组化ＳＰ染色观察。结果ＳＭＡ表达于肌成纤维细胞浆，术后１周至６月表达均较强。肌成纤维细胞功能活跃，细胞外基质过度沉积，结果导致瘢痕性挛缩，管腔狭窄，结论ＳＭＡ及肌成纤维细胞是导致胆道瘢痕性挛缩的主要原因。