Inhibition of cell proliferation in glomeruli using overexpression of anti-oxidative enzyme

慢性肾小球肾炎的肾小球细胞增殖与晚期糖基化终产物和其他氧化产物的积累以及炎症细胞的侵袭密切相关。在与细胞外基质分化的条件下，人系膜细胞表达EC-SOD。细胞外超氧化物歧化酶（EC-SOD）在间质来源的细胞中合成，可防止氧自由基引起的损伤。我们研究了肾系膜细胞（MCs）是否产生EC-SOD及其产生与趋化因子分泌的关系。在非刺激条件下，MCs产生EC-SOD，其产生与环磷酸腺苷（cAMP）呈正相关，与白细胞介素(IL)-6或IL-8的产生负相关。强的松龙或肉豆蔻酸佛波酯处理后，EC-SOD水平与IL-6、IL-8水平呈负相关。腺苷酸环化酶抑制剂2',3'-二脱氧腺苷的存在失去了强的松龙的作用。强的松龙通过cAMP途径刺激EC-SOD的产生可能是强的松龙对MCs的重要作用之一。为了研究系膜区对氧自由基的保护功能，我们在体外评估了系膜细胞（MCs）的细胞外超氧化物歧化酶（EC-SOD）的产生。这些细胞对细胞外空间的氧自由基具有重要的保护作用。在含有胎牛血清的“生长培养基”和含有减少生长因子的“分化培养基”和四种细胞外基质两种不同的培养条件下；MC培养中加入I型胶原、IV型胶原、层粘连蛋白和纤维连接蛋白。随着培养基的不同，分化培养基诱导EC-SOD过量产生，同时抑制细胞增殖，抑制IL-6和IL-8的产生。与细胞外基质不同，VI型胶原和层粘连蛋白的存在比纤维连接蛋白和I型胶原的存在促进了EC-SOD的产生。IV型胶原和层粘连蛋白与肾小球生理状态相关，而I型胶原和纤维连接蛋白主要位于病理状态，与之相比，IV型胶原和层粘连蛋白促进EC-SOD的产生。与分化培养基相比，生长培养基中EC-SOD的抑制以及MC增殖和趋化因子的过量产生可能模拟肾小球肾炎系膜增殖过程中抗氧自由基毒性保护能力的降低。I型胶原和纤维连接蛋白的MC增殖可能通过抑制EC-SOD的产生，增强肾小球氧自由基毒性，加速肾小球硬化。少

Glomerular cell plorifrration in hronic glomerular nephritis was closely associated with the accumulation of the advanced glycation end products and other oxidative products with inflammatory cell invasion. Under the differentiated condition with extra-cellular matrix, human mesangial cel express the EC-SOD. Extracellular superoxide dismutase (EC-SOD) is synthesized in mesenchymally derived cells and prevents the oxygen radical-induced injury. We studied whether kidney mesangial cells (MCs) produce EC-SOD and how its production is associated with chemokine secretion. Under unstimulated condition, MCs produced EC-SOD, and its production was correlated positively with cyclic adenosine monophosphate (cAMP), but negatively with interleukin (IL)-6 or IL-8 production. By prednisolone or phorbol myristate acetate treatment, EC-SOD levels were correlated negatively with levels of IL-6 and IL-8. The presence of adenylate cyclase inhibitor 2',3'-dideoxyadenosine lost the prednisolone effect. The … More stimulation of EC-SOD production might be one of the important effects of prednisolone via cAMP pathway in MCs.To study the protective function against oxygen radicals in the mesangial area, we assessed extracellular superoxide dismutase (EC-SOD) production in mesangial cells (MCs) in vitro. These cells have a major protective function against oxygen radicals in the extracellular space. In two different kinds of culture conditions : "growth medium" with fetal cow serum, and "differentiation medium" with reduced growth factor, and four extracellular matrixes ; type I collagen, type IV collagen, laminin and fibronectin, were added to the MC culture. With the difference in the culture media, differentiation medium induced EC-SOD hyper-production associated with the both of the slowing down of cell proliferation and the suppression of IL-6 and IL-8 production. With difference in the extracellular matrix, the presence of type VI collagen and laminin promoted higher production of EC-SOD than fibronectin and type I collagen. Type IV collagen and laminin associated with the physiological condition of the glomeruli promoted EC-SOD production compared with the presence of type I collagen and fibronectin dominantly located in pathological condition. Suppression of EC-SOD production in growth medium along with MC proliferation and chemokine hyper-production compared with production in differentiation medium might mimic reduction of the protective capacity against oxygen radical toxity during mesangial proliferation in the glomerular nephritis. MC proliferation with type I collagen and fibronectin might enhance oxygen radical toxity in the glomeruli, and accelerate glomerular sclerosis through the suppression of EC-SOD production. Less