肝癌细胞外泌体诱导单核细胞代谢重编程的机制研究

Mechanism of exosome-induced metabolic reprogramming of monocytes in liver cancer cells

目的探讨缺氧环境下肝癌细胞外泌体诱导单核细胞代谢重编程的潜在机制。方法缺氧环境下,正常肝细胞LO2外泌体或肝癌细胞HepG2外泌体处理,检测单核细胞代谢关键指标葡萄糖摄取和乳酸产生水平。miRNA-seq检测miRNA表达水平并筛选以鉴定诱导单核细胞代谢重编程的关键miRNA。通过HumanTargetScan在线分析预测以及遗传学筛选鉴定miRNA的靶标。结果缺氧环境下,肝癌细胞外泌体单核细胞葡萄糖摄取和乳酸产生(分别为34856±2944、174±16)高于正常肝细胞外泌体(分别为23454±2194、135±12)(P<0.05)。过表达miR-34b-3p、OMA1及敲低PHB2能够促进单核细胞葡萄糖摄取和乳酸产生(分别为22287±2207与36399±3123;121±10与158±17;22972±2330与32099±2017;121±11与161±16;24020±2156与37901±3084;110±10与151±16,均P<0.05);敲低miR-34b-3p、OMA1及过表达PHB2能够抑制单核细胞葡萄糖摄取和乳酸产生(分别为22287±2207与17541±1716;121±10与92±9;23827±2184与18891±1623;113±10与84±8;22469±2361与18801±1595;132±11与88±8,均P<0.05)。过表达miR-34b-3p能够降低PHB2的mRNA和蛋白表达水平(分别为0.22±0.03与0.05±0.01,P<0.05);敲低miR-34b-3p能够提升PHB2的mRNA和蛋白表达水平(分别为0.22±0.03与0.49±0.05,P<0.05)。敲低PHB2及过表达miR-34b-3p后,发现OMA1的表达水平上升(P<0.05);过表达PHB2及敲低miR-34b-3p后,发现OMA1的表达水平下降(P<0.05)。结论肝癌细胞外泌体中miR-34b-3p通过PHB2/OMA1轴促进单核细胞葡萄糖摄取和乳酸产生,诱导了单核细胞代谢重编程。

Objective To investigate the potential mechanism of exosome-induced metabolic reprogramming of monocytes in hepatocellular carcinoma cells under hypoxic environment.Methods In the hypoxic environment,LO2 exosomes from normal hepatocytes or HepG2 exosomes from liver cancer cells were treated to detect glucose uptake and lactate production levels,key indicators of monocyte metabolism.miRNA-seq was used to detect miRNA expression levels and screen to identify key mirnas that induce metabolic reprogramming in monocytes.miRNA targets were identified by HumanTargetScan online analysis,prediction and genetic screening.Results Under hypoxia,glucose uptake and lactate production of hepatocellular exosome monocytes were significantly higher than those of normal hepatocellular exosomes(23454±2194 vs 34856±2944;135±12 vs 174±16,respectively,all P<0.05).Overexpression of miR-34b-3p,OMA1 and knockdown of PHB2 promoted glucose uptake and lactate production in monocytes(22287±2207 vs 36399±3123;121+10 vs 158+17;22972+2330 vs 32099+2017.11 vs 161+121+16;24020+2156 vs 37901+3084.110±10 vs 151±16,respectively,all P<0.05);Knockdown of miR-34b-3p,OMA1 and overexpression of PHB2 inhibited glucose uptake and lactate production in monocytes(22287±2207 vs 17541±1716;121+10 vs 92+9;23827+2184 vs 18891+1623.113+10 vs 84+8;22469+2361 vs 18801+1595.132±11 vs 88±8,respectively,P<0.05).Overexpression of miR-34b-3p decreased the mRNA and protein expression levels of PHB2(0.22±0.03 vs 0.05±0.01,P<0.05).Knockdown of miR-34b-3p increased the m RNA and protein expression levels of PHB2(0.22±0.03 vs 0.49±0.05,P<0.05).After knockdown of PHB2 and overexpression of miR-34b-3p,the expression level of OMA1 increased(P<0.05).After overexpression of PHB2 and knockdown of miR-34b-3p,the expression level of OMA1 was decreased(P<0.05).Conclusion miR-34b-3p in exosomes of liver cancer cells promotes glucose uptake and lactate production in monocytes via the PHB2/OMA1 axis,induced metabolic reprogramming of monocytes.