翼状胬肉纤维组织起源于间充质干细胞的证据(英文)

Evidence of pterygial fibrous tissues derived from mesenchymal stem cells

背景:翼状胬肉与阳光、风尘等各种外界因素的慢性刺激和局部慢性炎症反应有关。目前关于翼状胬肉发病机制有多种理论和学说,但均未得到公认。目的:观察翼状胬肉组织病理学特征,探讨多能干细胞在翼状胬肉发生过程中的作用。设计:开放性实验。单位:中山大学中山眼科中心。材料:实验于2006-09/2007-01在中山大学眼科学国家重点实验室完成。218例经临床及病理诊断为翼状胬肉的石蜡标本均来自中山大学中山眼科中心病理室。方法:对手术切除的翼状胬肉标本进行形态学、免疫组织化学和免疫荧光共聚焦显微镜观察。主要观察指标:翼状胬肉形态学变化及CD34、波形纤维蛋白、平滑肌肌动蛋白、S-100在翼状胬肉中的表达。结果:①形态学变化:纤维组织增生及新生血管形成为翼状胬肉的主要病理改变。增生的纤维组织不同区域变化不一,主要呈现两类变化:一为排列致密,类似巩膜纤维组织;另外就是疏松区:仅见一些梭形、多角形、星状具有一些突起的纤维母细胞样的细胞,疏松排列,之间无明显的胶原纤维存在。②CD34免疫组织化学染色显示一些增生活跃的纤维母细胞明显表达CD34,成熟的纤维组织内的纤维细胞CD34则为阴性。波形纤维蛋白免疫组织化学染色在大部分纤维细胞、血管内皮细胞、血管壁及周细胞呈阳性反应。平滑肌肌动蛋白染色显示嗜碱性的小团状、梭形或不规则形的细胞束呈阳性反应,证明为平滑肌,218例中56例显示了平滑肌的存在。S-100染色神经纤维丝及脂肪细胞均呈阳性反应,218例中44例有脂肪组织。免疫荧光染色共聚焦显微镜进一步证明增生活跃的细胞为阳性反应,呈现为苹果绿色。结论:翼状胬肉组织中的纤维组织源自于间充质干细胞,并可向平滑肌及脂肪组织分化。

BACKGROUND： Pterygium is associated with local chronic inflammatory responses and chronic stimulation from external factors such as, sunlight and wind dust. Presently, there are various theories concerning the onset mechanism of pterygium, but these theories are not generally accepted. OBJECTIVE： To investigate histopathological characteristics of pterygium and analyze the multipotent stem cell effects on the onset of pterygium. DESIGN： An open experiment. SETTING： Zhongshan Ophthalmic Center of Sun Yat-sen University. MATERIALS： Experiments were performed at the State Key Laboratory of Ophthalmology, Sun Yat-sen University from September 2006 to January 2007. 218 pterygial parafffm specimens following clinical and pathological diagnosis were obtained from Pathology Lab of Zhongshan Ophthalmic Center, Sun Yat-sen University. METHODS： Pterygial specimens harvested from clinical operations received morphology, immunohistochemistry and immunofluorescence under a confocal microscope. MAIN OUTCOME MEASURES： Morphology of pterygium and expressions of CD34, vimentin （VIM）, smooth muscle actin （SMA）, S-100 in pterygium. RESULTS： Changes in morphology： Fibroplasia and neovascularizadon were the main changes in pteryginm. Fibroplasia was diverse in different regions, and two main phenomena were observed. First, the tissues arranged tightly like the scleral fiber. Secondly, in some loose region, some of spindle-shape, polygonal, asteroid fibroblast-like cells, arranging loosely, could be seen only. No apparent collagen fibers were identified between them. Immunohistochemistry were positive for CD34 in some region where the fibroblast actively proliferated, whereas fibrocytes in mature fibrous tissue were negatively stained. Immunohistochemistry was positive for VIM in a large fraction of fibrocytes, vascular endothelial cells, vessel wall and perithelial cells. SMA staining was positive in basophilous small blocks, spindle or irregular cell cluster. Of the 218 cases, 56 cases had smooth muscle. S-100 staining demonstrated that neurofilament protein and adipocytes were positive. Of the 218 cases, 44 cases had adipose tissue. Immunofluorescence showed that proliferative active cells were positive and stained green under a confocal microscope. CONCLUSION： The fibrous tissues in pterygium originate from mesenchymal stem cells, and can differentiate into smooth muscle and adipose tissue.