Jack Babalwa Unice, Dias Stephanie, Pheiffer Carmen
Biomedical Research and Innovation Platform, South African Medical Research Council, Tygerberg, Cape Town, 7505, South Africa.
Centre for Cardiometabolic Research in Africa, Division of Medical Physiology, Stellenbosch University, Tygerberg, Cape Town, 7505, South Africa.
Cell Biochem Biophys. 2025 Mar;83(1):905-918. doi: 10.1007/s12013-024-01522-3. Epub 2024 Sep 13.
We have previously reported that dysregulated lipid metabolism and inflammation in 3T3-L1 adipocytes is attributed to tumor necrosis factor alpha (TNFα) rather than lipopolysaccharide (LPS) and palmitate (PA). In this study, we further compared the modulative effects of TNFα, LPS, and PA on mitochondrial function by treating 3T3-L1 adipocytes with TNFα (10 ng/mL), LPS (100 ng/mL), and PA (0.75 mM) individually or in combination for 24 h. Results showed a significant reduction in intracellular adenosine triphosphate (ATP) content, mitochondrial bioenergetics, total antioxidant capacity, and the mRNA expression of citrate synthase (Cs), sirtuin 3 (Sirt3), protein kinase AMP-activated catalytic subunit alpha 2 (Prkaa2), peroxisome proliferator-activated receptor gamma coactivator 1 alpha (Ppargc1α), nuclear respiratory factor 1 (Nrf1), and superoxide dismutase 1 (Sod1) in cells treated with TNFα individually or in combination with LPS and PA. Additionally, TNFα treatments decreased insulin receptor substrate 1 (Irs1), insulin receptor substrate 2 (Irs2), solute carrier family 2, facilitated glucose transporter member 4 (Slc2a4), and phosphoinositide 3 kinase regulatory subunit 1 (Pik3r1) mRNA expression. Treatment with LPS and PA alone, or in combination, did not affect the assessed metabolic parameters, while the combination of LPS and PA increased lipid peroxidation. These results show that TNFα but not LPS and PA dysregulate mitochondrial function, thus inducing oxidative stress and impaired insulin signaling in 3T3-L1 adipocytes. This suggests that TNFα treatment can be used as a basic in vitro model for studying the pathophysiology of mitochondrial dysfunction and related metabolic complications and screening potential anti-obesity therapeutics in 3T3-L1 adipocytes.
我们之前曾报道，3T3-L1脂肪细胞中脂质代谢和炎症的失调归因于肿瘤坏死因子α（TNFα），而非脂多糖（LPS）和棕榈酸（PA）。在本研究中，我们通过用TNFα（10 ng/mL）、LPS（100 ng/mL）和PA（0.75 mM）单独或联合处理3T3-L1脂肪细胞24小时，进一步比较了TNFα、LPS和PA对线粒体功能的调节作用。结果显示，单独用TNFα或与LPS和PA联合处理的细胞中，细胞内三磷酸腺苷（ATP）含量、线粒体生物能量学、总抗氧化能力以及柠檬酸合酶（Cs）、沉默调节蛋白3（Sirt3）、蛋白激酶AMP激活的催化亚基α2（Prkaa2）、过氧化物酶体增殖物激活受体γ共激活因子1α（Ppargc1α）、核呼吸因子1（Nrf1）和超氧化物歧化酶1（Sod1）的mRNA表达均显著降低。此外，TNFα处理降低了胰岛素受体底物1（Irs1）、胰岛素受体底物2（Irs2）、溶质载体家族2促进葡萄糖转运蛋白成员4（Slc2a4）和磷脂酰肌醇3激酶调节亚基1（Pik3r1）的mRNA表达。单独或联合使用LPS和PA处理对所评估的代谢参数没有影响，而LPS和PA的联合增加了脂质过氧化。这些结果表明，TNFα而非LPS和PA会失调线粒体功能，从而在3T3-L1脂肪细胞中诱导氧化应激和胰岛素信号受损。这表明TNFα处理可作为研究线粒体功能障碍和相关代谢并发症病理生理学以及筛选3T3-L1脂肪细胞中潜在抗肥胖治疗药物的基础体外模型。
