ABSTRACT Leptin is an important adipokine and plays a vital role in animals. However, the role of leptin in the autophagic response of pig fibroblast cells (PFCs) has not been fully elucidated. In this study, we investigated the relationship between leptin and autophagy as well as underlying molecular basis. We found that PFCs treated with EBSS could secrete leptin, and the leptin concentration in the supernatant of leptin transgenic PFCs was higher than that of WT PFCs. We found an increase in LC3-II protein level and a decrease in p62 protein level in treated leptin transgenic PFCs compared with treated WT PFCs. Meanwhile, we observed an increase of autophagosomes by transmission electron microscopy and an enhancement of the accumulation of LC3 puncta in the cytoplasm of treated leptin transgenic PFCs, and these effects were further augmented by Baf A1 treatment. Furthermore, we detected the expression levels of 7 autophagy signaling pathway genes and 17 autophagy-related (ATG) genes by q-PCR. We found that between the two types of EBSS-treated cells 3 genes expression pattern were significantly different among the 7 autophagy signaling pathway genes and 8 genes expression pattern were significantly differernt among the ATG genes. These results indicated that leptin may promote autophagy and involving the downregulation of FOXO1 and LMNA genes via an unknown pathway which causes the upregulation of the 4 genes and the downregulation of 4 genes.

中文翻译：

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内源性瘦素促进 EBSS 诱导的 PFC 中的自噬

摘要 瘦素是一种重要的脂肪因子，在动物体内发挥着至关重要的作用。然而，瘦素在猪成纤维细胞（PFC）自噬反应中的作用尚未完全阐明。在这项研究中，我们研究了瘦素和自噬之间的关系以及潜在的分子基础。我们发现经EBSS处理的PFCs可以分泌瘦素，并且瘦素转基因PFCs上清液中的瘦素浓度高于WT PFCs。我们发现，与处理的野生型 PFC 相比，经处理的瘦素转基因 PFC 中 LC3-II 蛋白水平增加，p62 蛋白水平降低。同时，我们通过透射电子显微镜观察到经过处理的瘦素转基因PFCs细胞质中自噬体的增加和LC3斑点的积累增加，并且这些效果通过Baf A1处理进一步增强。此外，我们通过q-PCR检测了7个自噬信号通路基因和17个自噬相关（ATG）基因的表达水平。我们发现，在两种类型的EBSS处理的细胞之间，7个自噬信号通路基因中有3个基因表达模式存在显着差异，ATG基因中有8个基因表达模式存在显着差异。这些结果表明瘦素可能促进自噬并通过未知途径下调FOXO1和LMNA基因，导致4个基因上调和4个基因下调。