肥胖儿童脂肪组织细胞死亡激活剂-DNA断裂因子相似蛋白C表达及与胰岛素抵抗的相关性研究

目的研究脂肪组织中细胞死亡激活剂-DNA断裂因子相似蛋白C(CIDEC)表达与脂解、胰岛素抵抗的关系。方法选取2014年7月-2016年9月在在西安交通大学第二附属医院和西安市儿童医院因疝气、隐睾等非炎症性疾病手术患儿共42例分为肥胖组和对照组,测量体重指数(BMI)、腰围、血压、血脂、空腹血糖、血清血游离脂肪酸(NEFA)及胰岛素抵抗指数(HOMA-IR);取脂肪组织,用Western blot和RT-PCR检测CIDEC、肿瘤坏死因子α(TNF-α)、过氧化物酶体增殖剂激活受体(PPARγ)的表达;脂肪组织中CIDEC与TNF-α表达、NEFA及HOMA-IR水平相关性分析。结果1)肥胖组BMI、腰围、收缩压、舒张压、HOMA-IR、血游离脂肪酸均相比正常对照组显著升高(P<0.01),HDL-C较对照组显著降低(P<0.05);2)肥胖组脂肪组织中CIDEC mRNA和蛋白表达均减低(P<0.01),TNF-α mRNA表达增高(P<0.01);3)相关性分析结果显示,脂肪组织CIDEC mRNA表达水平与TNF-α mRNA表达水平、HOMA-IR以及NEFA均呈显著负相关(r=-0.583,-0.560,-0.606,P<0.05)。结论TNF-α可能通过下调CIDEC的表达,致使脂肪细胞脂解增加,进而引起胰岛素抵抗。

Study on the correlation between cell death-inducing DNA fragmentation factor 45-like effector C expression in adipose tissue and insulin resistance in obese children

Objective To evaluate the expression level of cell death-inducingDNA fragmentation factor45-like effector C(CIDEC) in adipose tissue of obese children and its correlation with lipolysis and insulin resistance. Methods A total of 42 children who underwent surgery for non-inflammatory diseases such as hernia and cryptomchidism in the Second Affiliated Hospital of Xi′an Jiaotong University and Xi ′an Children′s Hospital were selected in this study from July 2014 to September 2016,and were divided into obesity group and control group.The body mass index (BMI),waist circumference,blood pressure,blood lipids,fasting blood glucose,serum free fatty acid (NEFA) and insulin resistance index (HOMA-IR) of children were measured.Meanwhile,western blot and RT-PCR were applied to detect the expression level of CIDEC,tumor necrosis factor-α(TNF-α),peroxisome proliferators-activated receptors (PPARγ).And the associations among TNF-α,NEFA,HOMA-IR and CIDEC were studied by Pearson correlation analysis. Results 1) Indexes in obese children,including BMI,waist circumference,systolic blood pressure (SBP),diastolic blood pressure (DBP),HOMA-IR and NEFA,were significantly higher than those in normal controls(P＜0.05),while HDL-C was relatively lower in obese group.2) The expression level of CIDEC mRNA and protein in adipose tissue of obese group decreased (P<0.01),while the expression of TNF-α mRNA increased (P<0.01).3) Correlation analysis showed that the expression level of CIDEC mRNA in adipose tissue was negatively correlated with the levels of TNF-α mRNA,HOMA-IR,NEFA (r=-0.583,-0.560,-0.606,P＜0.05). Conclusions TNF-α causes adipocyte lipolysis,thereby leading to insulin resistance,possibly resulting from down-regulating the expression of CIDEC.