组蛋白H3K36me3与缺血再灌注诱导小鼠急性肾损伤的相关性研究

目的:研究组蛋白H3K36三甲基化(H3K36me3)在缺血再灌注(IR)诱导的急性肾损伤(AKI)小鼠肾组织中的表达,分析其与肾组织中N-赖氨酸甲基转移酶SMYD2及肾损伤程度的相关性,为临床治疗IR-AKI提供新的靶点。方法:30只ICR小鼠随机分为IR组(n=15)和假手术组(sham组,n=15),应用微动脉夹夹闭双侧肾蒂45 min构建IR模型,于造模后24 h收取小鼠血清和肾组织标本。生化法检测血尿素氮(BUN)和血清肌酐(SCr);HE染色检测肾组织病理学改变;免疫组织化学(IHC)染色检测肾组织中NGAL和cleaved caspase-3的表达;Western blot检测肾组织NGAL、SMYD2、H3K36me3、p-P53、P53、cleaved caspase-3、Bax、Bcl-2、STAT3、p-STAT3、JNK和p-JNK1/2/3蛋白的水平。应用Pearson相关法分析H3K36me3与肾组织SMYD2及NGAL的相关性。结果:与sham组相比,IR组BUN和SCr水平显著升高(P<0.05);HE染色显示,IR组肾小管上皮细胞水肿、脱落、坏死...

Relationship between histone H3K36 trimethylation and acute renal injury induced by ischemia/reperfusion

AIM: To observe the expression change of H3 K36 trimethylation(H3 K36 me3) in acute kidney injury(AKI) induced by ischemia/reperfusion(IR) and analyze its correlation with SMYD2 and renal injury, and to provide a new target for clinical treatment of IR-AKI. METHODS: The ICR mice(n=30) were randomly divided into IR group(n=15) and sham operation group(sham group, n=15). The AKI model was established by clamping bilateral renal pedicles for 45 min. The serum and renal tissues of the mice were collected after the model was established for 24 h. The levels of blood urea nitrogen(BUN) and serum creatinine(SCr) were detected by biochemical method. The pathological changes of the kidney were observed by HE staining. The changes of NGAL and cleaved caspase-3 were observed by immunohistochemical(IHC) staining. The protein levels of NGAL, SMYD2, H3 K36 me3, p-P53,P53, cleaved caspase-3, Bax, Bcl-2, STAT3, p-STAT3, JNK and p-JNK1/2/3 in the renal tissues were determined by Western blot. The relationship between H3 K36 me3 and SMYD2/NGAL was analyzed by Pearson correlation method. RESULTS: Compared with sham group, BUN and SCr levels of the mice in IR group were significantly increased(P<0.05). HE staining showed significant edema, abscission and necrosis in renal tubular epithelial cells of the micc in IR group, and abscission of brush border and large amount of cell debris in the lumen were also observed. The IHC staining results showed that the protein levels of NGAL and cleaved caspase-3 in IR group were significantly increased. The results of Western blot showed that the protein levels of NGAL,SMYD2, H3 K36 me3, p-P53, cleaved caspase-3, Bax, STAT3, p-STAT3, JNK and p-JNK1/2/3 in IR group were significantly up-regulated(P<0.05), while the Bcl-2 levels were significantly down-regulated(P<0.05). The correlation analysis showed that H3 K36 me3 was positively correlated with the levels of SMYD2 and NGAL. CONCLUSION: H3 K36 me3 is closely related to SMYD2 and renal injury in IR-AKI mice, and the up-regulated expression of H3 K36 me3 may be involved in the regulation of IR-AKI occurrence and development together with the activation of STAT3 and JNK signaling pathways.