美满霉素抑制GFAP与β-淀粉样蛋白在糖尿病大鼠海马CA3区的表达

Minocycline inhibits expressions of GFAP and β-amyloid protein in diabetic rats'hippocampus CA3 area

目的检测美满霉素对糖尿病大鼠海马CA3区胶质纤维酸性蛋白(GFAP)、β-淀粉样蛋白(Aβ)和炎症因子IL-1β、TNF-α表达的影响,探讨糖尿病糖代谢异常在阿尔采末病中的作用。方法42只Wistar大鼠随机分为对照组(C组)、4 wk模型组(M4组)、6 wk模型组(M6组)、8 wk模型组(M8组)、治疗4 wk组(MT4组)、治疗6 wk组(MT6组)和治疗8 wk组(MT8组),每组6只。腹腔注射链佐星(STZ)诱发糖尿病大鼠动物模型。造模成功后,治疗组给予美满霉素50 mg·kg^(-1)·d^(-1)灌胃,模型组予等量生理盐水灌胃代替。分别选取造模wk 4、6、8作为观察点,行穿梭箱实验、Morris水迷宫实验检测大鼠认知行为学改变,蛋白质免疫印迹法、免疫组织化学法和酶联免疫吸附实验(ELJSA)检测GFAP、Aβ、IL-1β和TNF-α的表达。结果模型组GFAP、Aβ、IL-1β和TNF-α的表达与对照组相比明显增高(P<0.01)。美满霉素治疗后,大鼠认知功能障碍明显改善,GFAP、Aβ、IL-1β和TNF-α表达显著下调(P<0.01)。结论美满霉素可抑制糖尿病大鼠星形胶质细胞激活脑内炎症、抑制Aβ表达,具有脑保护作用。

AIM To investigate the expressions of glial fibrillary acidic protein （GFAP）, amyloid betaprotein （Aβ） , IL-1β, and TNF-α in hippocampus CA3 area of diabetes mellitus Wistar rats treated with minocycline, and to study the pathophysiological mechanism of glucose metabolic disorder in Alzheimer＇ s disease （AD）. METHODS Animal models of diabetes mellitus were established by streptozocin （STZ） with intraperitoneal injection. Forty-two Wistar rats were randomly divided into control group （group C） , 4 week diabetes model group （group M4）, 6 week diabetes model group （group M6）, 8 week diabetes model group （group M8）, minocycline treatment 4 week group （group MT4）, minocycline treatment 6 week group （group MT6） and minocycline treatment 8 week group （group MT8） with 6 rats for each group. Minocycline treatment groups were treated with minocycline 50 mg ·kg^-1 ·d^-1 intragastric infusion when models were identified to be successful; while diabetes model groups were treated with intragastrie infusion of equal volume of saline. Choosing the point of the week 4, 6 and 8 after models were made as the observing time. Cogn tested with Morris water maze and shuttle box task. Expressions of GFAP, Aβ, IL-1β itive behavior was and TNF-α were measured by Western blotting, immunohistochemistry and enzyme linked immunosorbent assay （ELISA）. The absorbance value was measured by imaging analysis. RESULTS Expressions of GFAP, Aβ, IL-1β and TNF-α in MT groups were higher than those of in C and M group （P 〈 0.01 ）. After minocycline treated, MT groups showed obvious cognitive improvement with conspicuous down regulation of GFAP, Aβ, IL-1β and TNF-α expressions （P 〈 0.01 ）. CONCLUSION Minocycline can inhibit the activated intracranial inflammation of the astroglial cells of the diabetic rats and also the Aβ expression. Minocycline can provide cerebral protection.