HDAC抑制剂CG200745促进STZ诱导糖尿病大鼠胰岛β细胞损伤后的再生修复

HDAC inhibitor CG200745 promotes regeneration and repair of isletβ-cells in STZ-induced diabetic rats

目的探讨组蛋白去乙酰化酶(HDAC)抑制剂CG200745对链脲佐菌素(STZ)诱导糖尿病幼鼠胰岛β细胞的作用及其可能的机制。方法40只Sprauge-Dawley(SD)幼鼠随机分为空白对照组、糖尿病组、CG低剂量组和CG高剂量组,每组各10只。除空白对照组外,其余组幼鼠腹腔注射STZ50 mg/kg建立糖尿病模型。CG低、高剂量组分别腹腔注射CG2007451.25 mg/(kg·d)和5.0 mg/(kg·d),空白对照组和糖尿病组腹腔注射等量生理盐水。持续给药3周后,测定幼鼠体重、胰腺重量、血糖和血浆胰岛素水平;苏木精-伊红(HE)染色法检测胰腺病理组织学变化;免疫组织化学染色检测胰岛素和增殖细胞核抗原(PCNA)表达;原位末端转移酶标记(TUNEL)染色检测胰岛β细胞凋亡率;应用蛋白免疫印迹法(Western-blot)检测胰腺组织的组蛋白3(H3)、组蛋白乙酰化H3(Ac-H3)和磷脂酰肌醇3激酶(PI3K)/蛋白激酶B(PKB或Akt)通路蛋白表达水平。结果与空白对照组相比,糖尿病组幼鼠胰腺组织中胰岛β细胞数量明显减少,且分布不均匀,排列紊乱,体重、胰腺重量和血浆胰岛素水平降低(P均<0.05),胰腺胰岛素、PCNA和Ac-H3/H3表达降低(P均<0.05),血糖水平、胰岛β细胞凋亡率升高(P均<0.05),胰腺磷酸化磷脂酰肌醇3激酶(p-PI3K)/PI3K和磷酸化蛋白激酶B(p-Akt)/Akt蛋白比值降低;与糖尿病组相比,CG低、高剂量组幼鼠胰岛β细胞数量增多,且分布和排列趋于规整,体重、胰腺重量和血浆胰岛素水平明显升高(P均<0.05),胰腺胰岛素、PCNA和Ac-H3/H3表达升高(P均<0.05),血糖水平、胰岛β细胞凋亡率降低(P均<0.05),胰腺p-PI3K/PI3K和p-Akt/Akt蛋白比值升高。结论HDAC抑制剂CG200745对糖尿病幼鼠胰岛β细胞具有保护作用。

Objective To investigate the effect of histone deacetylase(HDAC)inhibitor CG200745 on isletβcells in streptozocin(STZ)induced diabetic rats and its possible mechanism.Methods Forty Sprauge-Dawley(SD)juvenile rats were randomly divided into blank control group,diabetes group,CG low-dose group and CG high-dose group,with 10 rats in each group.Except for the blank control group,juvenile rats were intraperitoneally injected with STZ 50 mg/kg to establish the diabetes model.The CG low-and high-dose groups were intraperitoneally injected with CG2007451.25 mg/(kg·d)and 5.0 mg/(kg·d)respectively,and the blank control group and diabetes group were intraperitoneally injected with the same amount of normal saline.After continuous administration for 3 weeks,the body weight,pancreas weight,blood glucose and plasma insulin levels of young mice were measured;HE staining was used to detect the pathological changes of pancreas;immunohistochemical staining was used to detect the expression of insulin and proliferating cell nuclear antigen(PCNA);TUNEL staining was used to detect isletsβ-cell apoptosis rate;Western-blot was used to detect the protein expression of histone acetylation(Ac-H3),histone(H3)and phosphoinositide 3-kinase(PI3K)/protein kinase B(Akt)pathway.Results Compared with the blank control group,the number of isletβcells was significantly reduced,the distribution was uneven,the arrangement was disordered,the body mass,pancreas weight and plasma insulin levels were reduced(all P<0.05),the expression of PCNA and Ac-H3/H3 were decreased(all P<0.05),the blood glucose level and the apoptosis rate of isletβcell were increased(all P<0.05),and the protein expression levels of p-PI3K/PI3K and p-Akt/Akt in the pancreas were decreased in the pancreas tissue of the diabetic rats;Compared with diabetes group,the number of isletβcells increased in the juvenile rats of CG low and high dose group,and the distribution and arrangement tended to be regular.The body mass,pancreas weight and plasma insulin level of juvenile rats in CG low-and high-dose groups were significantly increased(all P<0.05),and the expression of pancreatic insulin,PCNA and Ac-H3/H3 increased(all P<0.05),the blood glucose level and the apoptosis rate of isletβcell decreased(all P<0.05),and the protein expression levels of p-PI3K/PI3K and p-Akt/Akt in the pancreas were increased.Conclusion HDAC inhibitor CG200745 may play a protective effect on isletβcells in diabetic young rats.