Functional analysis of mesangial cell syncytium and elucidation of mechanisms involving progressive glomerulosclerosis

1.我们已经明确了连接蛋白43在与内皮细胞、离体肾小球共培养系统和体内系膜细胞间的细胞间通讯中起重要作用。此外，我们发现肾小球内颗粒细胞分泌肾素的协调是通过atp嘌呤能受体的信号转导诱导的。我们从实验结果中得出一个假设，内皮细胞和系膜细胞之间的生理病理相互作用的丧失可能导致系膜细胞合胞功能的紊乱，导致肾小球硬化的不可逆进展。在高浓度葡萄糖的情况下，培养的肾小球内皮细胞中内皮NOS的可用性急剧下降，可能是由于超氧化物的过量产生。我们用SV40病毒转染人肾小球内皮细胞，建立了永久系。该细胞系对抗内皮细胞抗体的标准化和大规模建立肾小球内皮细胞培养体系具有重要意义。我们用gst融合蛋白法确定了抗Thy-1.1抗体1-22-3单克隆抗体识别的大鼠Thy-1.1分子的功能表位。在体内，与系膜细胞表面表达的1-22-3结合可导致严重的肾小球肾炎。比较注射1-22-3诱导的单肾组和双肾组，可以判断肾脏疾病分为可逆和不可逆病程的转折期。利用egfp转基因大鼠，我们可以确定骨髓源性内皮前体细胞在肾小球内皮细胞再生中的作用。综上所述，募集骨髓源性内皮前体细胞在严重系膜细胞损伤后的肾小球损伤修复中发挥重要作用。

1.We have clarified that connexin 43 play an important role of intercellular communication among mesangial cells in co-culture system with endothelial cells, isolated glomeruli, and in vivo. In addition, we found out that co-ordination of renin secretion from granular cells in the paraglomerular apparatus was induced by signal transduction via ATP-purinergic receptor.2.We drew a running hypothesis from our experimental results that loss of physiopathological interaction between endothelial and mesangial cells may cause disturbance of mesagial cell syncytial function, leading to irreversible progression of glomerulosclerosis.3.In high concentration of glucose, the availability of endothelial NOS in cultured glomerular endothelial cells was decreased dramatically, perhaps, by overproduction of superoxide.4.We established a permanent line of cultured human glomerular endothelial cells by transformation with SV40 virus. This cell line is very useful for the standardization of anti-endothelial cell antibody and for establishing culture system of glomerular endothelial cells at large scale.5.We determined the functional epitope of rat Thy-1.1 molecule recognized by monoclonal antibody, named by 1-22-3, one kind of anti-Thy-1.1 antibodies, by the GST-fusion protein method. In vivo binding of 1-22-3 expressed on the surface of mesangial cells results in severe glomerulonephritis.6.Comparing one-kidney and two-kidney groups induced by 1-22-3 injection, we could determine the turning period when the renal disease will divide into reversible or irreversible course.7.Using EGFP-transgenic rats, we could determine the involvement of bone marrow-derived endothelial precursor cells in the regeneration of glomerular endothelial cells. In conclusion, bone marrow-derived endothelial precursor cells recruited play an important role in repairing glomerular injury after severe mesangial cell damage.