荜茇酰胺通过抗炎作用缓解糖尿病心肌病小鼠的心肌病变

目的:探究荜茇酰胺(PL)对糖尿病心肌病模型中心肌损伤和纤维化的作用。方法:高糖刺激心肌H9C2细胞模拟高糖环境建立细胞模型,随后分为对照组、高糖组、低剂量(2.5μmol/L)PL组及高剂量(5μmol/L)PL组,qPCR检测炎症因子肿瘤坏死因子α(TNF-α)和白细胞介素6(IL-6)的mRNA表达水平,Western blot检测纤维化指标转化生长因子β(TGF-β)和Ⅳ型胶原蛋白(collagen IV)的蛋白表达水平。将C57BL/6小鼠随机分为对照组、1型糖尿病模型组、低剂量(2.5 mg/kg)PL组及高剂量(5 mg/kg)PL组,每组6只。除对照组外,其余各组每日腹腔注射链脲佐菌素(STZ) 50 mg/kg,连续5日,1周后检测空腹血糖≥12 mmol/L认为造模成功。造模成功后,按不同分组给予不同剂量PL,腹腔注射给药13周,每隔2周尾静脉取血检测空腹血糖,第13周检测超声心动图,第13周末麻醉后处死小鼠,取血清检测肌酸激酶同工酶MB(CK-MB)和乳酸脱氢酶(LDH)水平;取心脏固定包埋切片,HE染色和天狼星红染色观察病理变化。结果:(1)高糖诱导下的H9C2细胞TNF-α和IL-6的mRNA表达水平以及TGF-β和collagen IV的蛋白表达水平较对照组明显升高,PL处理后上述指标均有所下降(P<0.05);(2) STZ造模成功后,腹腔注射PL可逆转糖尿病心肌病小鼠心肌组织结构排列紊乱及纤维化等病理改变,并降低心肌损伤血清学指标CK-MB及LDH水平(P<0.05)。结论:PL可以减轻糖尿病心肌病模型的炎症反应和心肌组织损伤,延缓纤维化进程。

Piperlongumine protects mice against diabetic cardiomyopathy by alleviating inflammation

AIM: To investigate the effect of piperlongumine(PL) on myocardial injury and fibrosis in diabe-tic cardiomyopathy(DCM) models. METHODS: To imitate cardiomyocytes in a high glucose environment, H9 C2 cells were stimulated by high glucose(33 mmol/L), and then the cells were divided into control group, high glucose group, low dose(2.5 μmol/L) of PL group and high dose(5 μmol/L) of PL group. The mRNA levels of inflammatory cytokines tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6), and the protein levels of pro-fibrotic markers including transforming growth factor-β(TGF-β) and collagen IV were determined. C57 BL/6 mice were randomly divided into control group, type 1 diabetes mellitus group, low dose(2.5 mg/kg) of PL group and high dose(5 mg/kg) of PL group. The mice were intraperitoneally injected with streptozotocin at dose of 50 mg/kg for 5 consecutive days. The fasting glucose le-vels higher than or equal to 12 mmol/L meant the establishment of type 1 diabetes mellitus. The treatment with PL was initiated. The fasting blood glucose was detected every 2 weeks. After echocardiography at the 13 th week, the mice were killed after anesthesia at the 13 th weekend. The blood was collected to measure the serum levels of creatine kinase isoenzyme MB(CK-MB) and lactate dehydrogenase(LDH). The heart tissues were prepared with formaldehyde for 24 h, and was embedded in paraffin for pathological sectioning. HE staining and Sirius red staining were conducted. The morphological changes were observed under microscope. RESULTS: In the H9 C2 cell model induced by high glucose, the mRNA expression levels of TNF-α and IL-6, as well as the protein expression levels of TGF-β and collagen IV were significantly higher than those in control group. The above indexes were decreased after PL treatment(P<0.05). PL alleviated the disorder of basic structure, and cardiac fibrosis in the DCM mice. After the administration of PL, the serum levels of CK-MB and LDH were decreased significantly(P<0.05). CONCLUSION: PL is a potential cardioprotective agent in treatment of DCM as it can inhibit inflammation and mitigate the diabetic myocardial injury.