Department of Endocrinology, Shengjing Hospital of China Medical University, Shenyang, China.
Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China.
Bioengineered. 2022 May;13(5):12421-12434. doi: 10.1080/21655979.2022.2074768.
Nicotinamide N-methyltransferase (NNMT) is a methylase, and its expression is positively correlated with obesity and insulin resistance. This study aims to detect the effects of NNMT on lipid accumulation, triglyceride content, adipocyte differentiation-related transcription factors, genes related to lipid metabolism, adipokine expression, and autophagy in adipocytes. Lentivirus vectors and eukaryotic expression plasmids were used to interfere with NNMT expression. The Oil Red O method was used to detect lipid accumulation, and colorimetry was used to detect triglyceride levels. The transcription of adipocyte differentiation-related transcription factors (PPARγ, C/EBPα, and SREBP1), lipid metabolism-related genes ( [], and ), adipokines (ADIPOQ and LEP) and autophagy-related genes (, and ) was detected by quantitative real-time polymerase chain reaction (RT-qPCR), and the protein expressions of PPARγ, ADIPOQ, LC3I, LC3II, Beclin1, and P62 were detected by western blot analysis. Compared with the control group, the knockdown of NNMT expression reduced lipid accumulation and triglyceride content in 3T3-L1 cells. The transcription of PPARγ, C/EBPα, SREBP1, , and decreased, while ADIPOQ and LEP transcription increased. The expression of PPARγ, LC3I/II, and Beclin1 proteins also decreased, while ADIPOQ and P62 protein expression increased. The over-expression NNMT group showed experimental results opposite to those described above. Interference with the expression of NNMT affects lipid accumulation, triglyceride content after cell differentiation, adipocyte differentiation-related transcription factors, genes related to lipid metabolism, the expression of adipokines, and autophagy in adipocytes.
烟酰胺 N-甲基转移酶（NNMT）是一种甲基转移酶，其表达与肥胖和胰岛素抵抗呈正相关。本研究旨在检测 NNMT 对脂肪细胞中脂质积累、甘油三酯含量、脂肪细胞分化相关转录因子、脂质代谢相关基因、脂肪因子表达和自噬的影响。使用慢病毒载体和真核表达质粒干扰 NNMT 的表达。采用油红 O 法检测脂质积累，比色法检测甘油三酯水平。采用定量实时聚合酶链反应（RT-qPCR）检测脂肪细胞分化相关转录因子（PPARγ、C/EBPα 和 SREBP1）、脂质代谢相关基因（[]、和）、脂肪因子（ADIPOQ 和 LEP）和自噬相关基因（、和）的转录水平，并通过 Western blot 分析检测 PPARγ、ADIPOQ、LC3I、LC3II、Beclin1 和 P62 的蛋白表达。与对照组相比，NNMT 表达的下调降低了 3T3-L1 细胞中的脂质积累和甘油三酯含量。PPARγ、C/EBPα、SREBP1、[]和的转录减少，而 ADIPOQ 和 LEP 的转录增加。PPARγ、LC3I/II 和 Beclin1 蛋白的表达也减少，而 ADIPOQ 和 P62 蛋白的表达增加。过表达 NNMT 组表现出与上述描述相反的实验结果。干扰 NNMT 的表达会影响脂肪细胞中的脂质积累、细胞分化后的甘油三酯含量、脂肪细胞分化相关转录因子、脂质代谢相关基因、脂肪因子表达和自噬。
