Suppression of the development of diabetic nephropathy by expression of non-smooth muscle calponin

碱性钙调蛋白（calponin-h1）是平滑肌分化特异性基因，可改善肾小球对损伤的反应。相反，没有证据表明钙调素-h2亚型对肾脏疾病的影响。中性钙调蛋白（Calponin-h2，CN 2）是一种非平滑肌亚型，在细胞骨架组织中可能发挥生理作用。CN2还有力地抑制平滑肌细胞迁移。我们假设CN2参与了糖尿病间质损伤的过程。本研究采用CRE-loxP位点特异性重组系统建立了CN2转基因小鼠（CN2-Tg），其中CN2的表达仅在硫酸镉（0.5mg/kg BW/d）处理期间被诱导。用链脲佐菌素（STZ，100 mg/kg BW × 2次/3天）对CN 2-Tg小鼠和野生型小鼠（WT）诱导糖尿病。在第一次STZ注射前5天开始硫酸镉腹膜内治疗。分别于发病后第8、30天及发病后第0天行肾切除术（n=6）。 ...更多信息 n个）。增殖细胞（ki-67）、巨噬细胞（F4/80）和间质细胞表型变化的免疫染色使用细胞因子（α-平滑肌肌动蛋白，aSMA）对所有小鼠的间质炎症进行评估，并且通过计算机分析系统评估所有数据。（ki-67^+细胞/高倍视野，hpf）在第8天在CN 2-Tg中被显著抑制（CN 2-Tg中3.7±0.5（m±SE），相对于WT中5.7±0.4，p<0.05），但在第30天没有（1.1±0.4相对于1.2±0.2）。CN2-Tg在第8天（3.7±0.1 vs 6.9±1.3，p<0.02）和第30天（2.2±0.7 vs 5.4±0.5，p<0.01）诱导了巨噬细胞在胰岛中募集的减少（F4/80^+细胞/hpf）。两组间aSMA表达和血压（收缩压和舒张压）均无显著性差异。因此，CN2过表达抑制了糖尿病早期肾间质细胞增殖和巨噬细胞浸润，提示CN2的抗炎作用可能是糖尿病肾间质损伤发生发展的关键。少

Basic calponin (calponin-h1), smooth muscle differentiation-specific gene, may improve the glomerular response to injury. To the contrary, there was no evidence about calponion-h2 isoform, on the effect of kidney disease. Neutral calponin (Calponin-h2, CN2) is a non-smooth muscle isoform, and a may play a physiological role in cytoskeletal organization. CN2 also powerfully suppresses smooth muscle cell migration. We hypothesized that CN2 is involved in the course of diabetic interstitial injury. We established CN2 transgenic (CN2-Tg) mouse with the CRE-loxP site-specific recombination system, in that CN2 expression is induced only during the treatment of cadmium sulfate (0.5mg/kg BW/day). Diabetes was induced by streptozocin (STZ, 100mg/kg BW x 2 times/3days) on both of CN2-Tg mouse and wild type ones (WT). Cadmium sulfate intraperitoneal treatment was started 5 days before the first STZ injection. Nephrectomy was done on 8 and 30 days after disease induction as well as on day 0 (n=6 i … More n each). Immunostaining for proliferating cells (ki-67), macrophages (F4/80) and phenotypic change of interstitial cells (a-smooth muscle actin, aSMA) for evaluation of interstitial inflammation on all mice and all data were evaluated by computer-analysis system.The interstitial cell proliferation (ki-67^+ cells/high power field, hpf) was significantly suppressed in CN2-Tg at day 8 (3.7±0.5 (m±SE) in CN2-Tg, vs 5.7±0.4 in WT, p<0.05), but not at day 30 (1.1±0.4 vs 1.2±0.2). Reduction of macrophages recruitment in the interstitium (F4/80^+ cells/hpf) was induced in CN2-Tg at day 8 (3.7±0.1 vs 6.9±1.3, p<0.02), and day 30 (2.2±0.7 vs 5.4±0.5, p<0.01). There was no significant difference in both of aSMA expression and blood pressure (both systolic and diastolic) between two groups. Thus, CN2 overexpression suppressed both of interstitial cell proliferation and macrophages infiltration from early phase in diabetes mellitus.In conclusion, precedent anti-inflammatory property of CN2 may be critical for subsequebt development of interstitial renal injuriy in diabetes mellitus. Less