中性调宁蛋白对糖尿病早期肾间质炎症的抑制作用

Neutrul calponin (calponin h2) suppresses active interstitial inflammation in the kidney from early phase of experimental diabetes mellitus

目的:探讨中性调宁蛋白(calponin h2,CN2)在糖尿病肾损害过程中的作用。方法:分别给予中性调宁蛋白转基因(CN2-Tg)小鼠与野生性(WT)C57BL/6J小鼠腹腔注射链脲佐菌素(STZ)制备糖尿病模型,观察两组糖尿病小鼠在注射STZ前及后第8、30天的体重、血糖、血压、尿白蛋白、尿肌酐(Cr)、尿8羟基脱氧鸟苷(8-OHdG)变化及肾组织α-SMA、Ki-67、F4/80免疫组化染色评价肾间质炎症改善情况。结果:CN2-Tg组尿8-OHdG/Cr(ng/mg)明显低于WT组(P<0.05);在第8天CN2-Tg组肾间质细胞纤维化(Ki-67染色)受到明显抑制(P<0.05),第30天不明显(P>0.05);CN2-Tg组肾间质巨噬细胞浸润表现(F4/80染色)在第8(P<0.05)、30天(P<0.01)均受到明显抑制;两组间肾组织α-SMA表达和血压变化无区别。结论:CN2过表达能抑制糖尿病早期肾间质细胞增殖和巨噬细胞浸润,表明CN2可能在糖尿病肾病间质损害的过程中扮演着重要的角色,推断其可能成为治疗糖尿病肾病的新靶点。

Objective ： To study the role of neutral ealponin （ ealponin-h2, CN2 ） in the course of diabetic interstitial injury. Methodology：Diabetes was induced by streptozocin （100 mg/kg BW） on both CN2-Tg C57BL/6J mice and wild type ones （WT）. The body weight, blood pressure, blood glucose, levels of 24 hour urinary 8-hydroxy- 2＇deoxyguanosine （8-OHdG） , ereatinine（Cr） and albumin, and nephreetomy were done on 8 and 30 days after disease induction as well as on day 0. The immunohistochemieal stains for proliferating cells （ki-67）, macrophages （F4/80） and phenotypie change of interstitial cells （a-smooth muscle acfin, α-SMA ） for evaluation of interstitial inflammation on all mice and all data were evaluated by computer-analysis system. Results：CN2-Tg diabetic mice showed significantly lower excretion of 24 hour urinary 8-OHdG/Cr（ng/mg） than WT diabetic mice at day 8（ 1.03 ±0. 07 in CN2-Tg vs. 1.56 ±0. 15 in WT,P 〈 0.05）. The interstitial cell proliferation （ki-67^ ＋ cells/high power field, hpf） was significantly suppressed in CN2-Tg at day 8 （ 3.75 ± 0. 51 vs. 5.70 ± 0. 42, P 〈 0. 05 ）, but not at day 30 （ 1.14± 0. 44 vs. 1.23± 0. 24, P 〈 0. 05 ）. Reduction of macrophages recruitment in the interstitium （ F4/80 ＋ eells/bpf） was induced in CN2-Tg at clay 8 （ 3. 69± 0. 14 vs. 6. 87 ± 1.33 ,P 〈0. 05） , and day 30 （2. 19 ±0. 70 vs. 5.37 ±0. 48 ,P 〈0. 01 ）. There were no significant differences in both α-SMA expression and blood pressure （both systolic and diastolic） between two groups. Conclusion：CN2 overexpression suppressed both of interstitial cell proliferation and maerophages infiltration from early phase in diabetes mellitus. Precedent anti-inflammatory property of CN2 may be critical for subsequent development of interstitial renal injuriy in diabetes mellitus and a novel target in treatment of diabetes nephropathy.