Pharmaceutics & Pharmacokinetics Division, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
Pharmaceutics & Pharmacokinetics Division, CSIR-Central Drug Research Institute, Lucknow 226031, India.
Life Sci. 2023 Mar 1;316:121415. doi: 10.1016/j.lfs.2023.121415. Epub 2023 Jan 21.
Pancreastatin (PST), an anti-insulin peptide derived from chromogranin A. Its levels increase in cases of obesity, which contributes to adipose tissue inflammation and insulin resistance. This study aims to investigate the immunometabolic effect of PST inhibitor (PSTi8) against PST by using in vitro and in vivo finding.
3T3-L1 cells were differentiated with or without PSTi8, and Oil Red O staining was performed. J774A.1 cells were used for macrophage polarization study. The diet-induced obesity and T2DM model was developed in C57BL/6 mice through high-fat diet for 8 weeks. Alzet osmotic pumps were filled with PSTi8 (release rate: 2 mg/kg/day) and implanted in mice for eight weeks. Further, insulin and glucose tolerance tests were performed. Liver and eWAT sections were stained with hematoxylin and eosin. FACS was used to measure mitochondrial ROS and membrane potential, while Oroboros O2k was used to measure oxygen consumption rate. Immunocytochemistry and qRT-PCR were done for protein and gene expression, respectively.
PSTi8 inhibited the expression of lipolytic genes and proteins in 3T3-L1 adipocytes. PSTi8 improved the inulin sensitivity, lipid profile, MMP, and OCR levels in the 3T3-L1 adipocyte and eWAT. It also increased the M1 to M2 macrophage polarization in J77A.1 cells and eWAT. Further, PSTi8 attenuated inflammatory CD4 T, CD8 T cells and increased the anti-inflammatory T-reg and eosinophil populations in the eWAT. It also reduced the expression of pro-inflammatory genes like Mcp1, Tnfα, and Il-6.
Collectively, PSTi8 exerted its beneficial effect on adipose tissue inflammation and restored energy expenditure against diet-induced obesity.
胰抑素（PST）是一种源自嗜铬粒蛋白 A 的抗胰岛素肽。在肥胖症患者中，其水平升高，导致脂肪组织炎症和胰岛素抵抗。本研究旨在通过体外和体内研究来探讨 PST 抑制剂（PSTi8）对 PST 的免疫代谢作用。
用或不用 PSTi8 分化 3T3-L1 细胞，并进行油红 O 染色。使用 J774A.1 细胞进行巨噬细胞极化研究。通过高脂饮食 8 周，在 C57BL/6 小鼠中建立饮食诱导肥胖和 2 型糖尿病模型。将 Alzet 渗透泵充满 PSTi8（释放率：2mg/kg/天）并植入小鼠 8 周。进一步进行胰岛素和葡萄糖耐量试验。对肝和附睾白色脂肪组织（eWAT）切片进行苏木精和伊红染色。使用 FACSTM 测量线粒体 ROS 和膜电位，使用 Oroboros O2k 测量耗氧量。进行免疫细胞化学和 qRT-PCR 分别用于蛋白质和基因表达。
PSTi8 抑制了 3T3-L1 脂肪细胞中脂肪分解基因和蛋白质的表达。PSTi8 改善了 3T3-L1 脂肪细胞和 eWAT 中的胰岛素敏感性、脂质谱、MMP 和 OCR 水平。它还增加了 J77A.1 细胞和 eWAT 中的 M1 到 M2 巨噬细胞极化。此外，PSTi8 减轻了 eWAT 中促炎 CD4 T、CD8 T 细胞的表达，并增加了抗炎 T 调节细胞和嗜酸性粒细胞的数量。它还降低了促炎基因如 Mcp1、Tnfα 和 Il-6 的表达。
总之，PSTi8 对脂肪组织炎症发挥了有益作用，并恢复了对抗饮食诱导肥胖的能量消耗。
