Protein tyrosine phosphatase 1B (PTP1B) is one of the major negative regulators of leptin and insulin signaling, and has been strongly implicated in insulin resistance development in the course of obesity and metabolic syndrome conditions; however, its exact role in controlling adipose tissue biogenesis is still poorly understood. This investigation aimed to elucidate whether selective inhibition of PTP1B using MSI-1436 compound may improve and restore the defective adipogenicity of ASCs isolated from EMS-affected horses. Equine ASC EMS cells were cultured under adipogenic conditions in the presence of PTP1B inhibitor and were subsequently tested for expression of the main adipogenic-related genes using RT-qPCR, changes in free fatty acid profiles by means of GC-MS technique, and for mitochondrial dynamics improvement through the analysis of mitochondrial transmembrane potential and oxidative stress. Selective inhibition of PTP1B in equine ASC EMS cells improved substantially adipogenic differentiation by promoting cellular proliferation and normalizing expression of C/EBPalpha, PPARγ, and Adipoq markers that are critical for proper adipogenesis. Levels of secreted adiponectin and PPARγ were also shown to be increased in MSI-1436-conditioned cells, while total leptin levels markedly dropped under the same conditions. Moreover, MSI-1436 treatment enabled the regulation of metabolic-related transcripts that are crosslink to adipogenesis, namely Akt1, Akt2, and SHBG. The obtained results demonstrated also an obvious reduction in intracellular accumulated ROS and NO, as well as mitigated ER stress through the downregulation of Chop, Perk, Atf6, Ire1, and Xbp1 transcripts upon PTP1B inhibition. Furthermore, general fluctuations in FFA composition of all differentiated groups have been highlighted, where palmitic acid, palmitoleic acid, stearic acid, and linolelaidic acid that are known to be associated with the development of metabolic disorders were found to be normalized upon PTP1B inhibition during adipogenic differentiation. The presented data provides the evidence that the use of PTP1B inhibitor may be successful in controlling and enhancing adipogenic differentiation of impaired equine ASCs affected by metabolic syndrome, and thus offers new insights for the management of obesity through the regulation of adipose tissue dynamics.

中文翻译：

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MSI-1436 通过调节 ER 应激、细胞凋亡和氧化应激改善脂肪分化过程中的 EMS 脂肪源性祖干细胞

蛋白酪氨酸磷酸酶 1B (PTP1B) 是瘦素和胰岛素信号传导的主要负调节因子之一，与肥胖和代谢综合征过程中胰岛素抵抗的发展密切相关；然而，它在控制脂肪组织生物发生中的确切作用仍然知之甚少。本研究旨在阐明使用 MSI-1436 化合物选择性抑制 PTP1B 是否可以改善和恢复从受 EMS 影响的马中分离出的 ASCs 的成脂能力缺陷。马 ASC EMS 细胞在存在 PTP1B 抑制剂的脂肪形成条件下培养，随后使用 RT-qPCR 测试主要脂肪形成相关基因的表达，通过 GC-MS 技术测试游离脂肪酸谱的变化，并检测线粒体通过分析线粒体跨膜电位和氧化应激来改善动力学。马 ASC EMS 细胞中 PTP1B 的选择性抑制通过促进细胞增殖和使 C/EBPα、PPARγ 和 Adipoq 标记物的表达正常化来显着改善脂肪形成分化，这些标记物对于正确的脂肪形成至关重要。在 MSI-1436 条件下的细胞中，分泌的脂联素和 PPARγ 水平也有所增加，而总瘦素水平在相同条件下显着下降。此外，MSI-1436 治疗能够调节与脂肪生成交联的代谢相关转录本，即 Akt1、Akt2 和 SHBG。获得的结果还表明，PTP1B 抑制后，细胞内累积的 ROS 和 NO 明显减少，并通过下调 Chop、Perk、Atf6、Ire1 和 Xbp1 转录本减轻 ER 应激。此外，所有分化组的 FFA 组成的一般波动都得到了强调，其中已知与代谢紊乱的发展相关的棕榈酸、棕榈油酸、硬脂酸和亚油酸被发现在脂肪生成过程中 PTP1B 抑制后正常化。差异化。所提供的数据提供了证据，表明使用 PTP1B 抑制剂可以成功控制和增强受代谢综合征影响的受损马 ASC 的脂肪形成分化，从而为通过调节脂肪组织动力学来管理肥胖提供新的见解。