Division of Clinical Nephrology and Rheumatology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
Nephrology (Carlton). 2011 Feb;16(2):211-8. doi: 10.1111/j.1440-1797.2010.01322.x.
SM22α (transgelin) has been focused upon as a player in the process of phenotypic changes of types of cells. The SM22α expression in the rat anti-glomerular basement membrane (GBM) nephritis model and differences from an established phenotypic marker for the myofibroblast, α-smooth muscle actin (αSMA), were investigated.
The rat kidney tissues were processed for histological studies, immunohistochemical and immunoelectronmicroscopy analyses on days 0, 7, 28, 42 and 56 after injection of rabbit anti-GBM serum for the disease induction.
Immunohistochemistry with anti-SM22α antibodies (Ab) revealed that kidneys of the nephritic rats on day 7 expressed SM22α in podocytes, crescentic cells and epithelial cells of Bowman's capsule. After 28 days, SM22α was also expressed in peritubular interstitial cells. Double immunofluorescence with anti-SM22α Ab and anti-αSMA Ab showed that SM22α was preferentially expressed in podocytes, whereas αSMA was positive in mesangial cells on day 7. After day 28, both molecules became positive in peritubular interstitial cells.
SM22α was expressed in epithelial cells of inflamed glomeruli in the early phase, and then also in peritubular interstitial cells in the later phase of anti-GBM nephritis model. SM22α presented unique kinetics of expression distinct from αSMA.
SM22α（转谷氨酰胺酶）一直被认为是细胞表型变化过程中的一个参与者。本研究旨在研究大鼠抗肾小球基底膜（GBM）肾炎模型中 SM22α的表达情况，并与肌成纤维细胞的一个既定表型标志物α-平滑肌肌动蛋白（αSMA）进行比较。
在注射兔抗 GBM 血清诱导疾病后第 0、7、28、42 和 56 天，对大鼠肾脏组织进行组织学研究、免疫组织化学和免疫电镜分析。
用抗 SM22α 抗体（Ab）进行免疫组织化学染色显示，肾炎大鼠在第 7 天的肾小球足细胞、新月形细胞和鲍曼囊上皮细胞中表达 SM22α。28 天后，SM22α也在肾小管间质细胞中表达。用抗 SM22α Ab 和抗 αSMA Ab 进行双重免疫荧光染色显示，SM22α 优先在足细胞中表达，而 αSMA 在第 7 天的系膜细胞中呈阳性。28 天后，这两种分子在肾小管间质细胞中均呈阳性。
SM22α 在抗 GBM 肾炎模型的早期阶段在炎症性肾小球的上皮细胞中表达，随后在后期阶段也在肾小管间质细胞中表达。SM22α 的表达动力学与 αSMA 不同，具有独特的特征。
