The accumulation of lipid droplets (LDs) in the cytoplasm plays an important role in energy balance, membrane synthesis and cell signal transduction. The aim of this study was to investigate the profile of phospholipids after SCAP-induced LD formation in bovine mammary epithelial cells (BMECs). A shRNA-SCAP vector and a SCAP/SREBP vector were used to knock down and overexpress the SCAP gene in BMECs prior to evaluating the effects on LDs using Western blotting, real-time PCR, LD staining and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The average LD diameter was determined following oil red O staining. The overexpression of SCAP increased the abundance of SCD, ACACA and FASN genes and nuclear SREBP1a. In contrast, knocking down SCAP decreased the abundance of the nuclear SREBP1a protein and downregulated the abundance of target genes. Lipid droplet staining revealed that knocking down SCAP reduced LD formation and average LD diameter. In contrast, overexpression of SCAP increased the formation and size of the LDs. The results from an analysis of cellular lipids revealed that phospholipids are the predominant species in the profile of cell lipids. phosphatidylethanolamine (PE) and phosphatidylcholine (PC) are important for determining the size of LDs. The LD formation induced by SCAP gene overexpression and knockdown underscored the role of phospholipids involved in lipid droplet formation and fusion.

中文翻译：

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SCAP诱导牛乳腺上皮细胞中脂质滴形成中磷脂分子的脂质谱分析。

脂质滴（LDs）在细胞质中的积累在能量平衡，膜合成和细胞信号转导中起重要作用。这项研究的目的是调查牛乳腺上皮细胞（BMECs）中SCAP诱导的LD形成后磷脂的概况。在使用Western印迹，实时荧光定量PCR，LD染色和液相色谱-串联质谱（LC）评估对LD的影响之前，先使用shRNA-SCAP载体和SCAP / SREBP载体敲除并过表达BMEC中的SCAP基因。 -MS / MS）。油红O染色后确定平均LD直径。SCAP的过表达增加了SCD，ACACA和FASN基因以及核SREBP1a的丰度。相反，敲低SCAP减少了核SREBP1a蛋白的丰度，并下调了靶基因的丰度。脂质液滴染色显示，降低SCAP可以减少LD的形成和平均LD直径。相反，SCAP的过表达增加了LD的形成和大小。细胞脂质分析的结果表明，磷脂是细胞脂质谱中的主要物质。磷脂酰乙醇胺（PE）和磷脂酰胆碱（PC）对于确定LD的大小很重要。SCAP基因过表达和敲低诱导的LD形成强调了磷脂参与脂质液滴形成和融合的作用。SCAP的过表达增加了LD的形成和大小。细胞脂质分析的结果表明，磷脂是细胞脂质谱中的主要物质。磷脂酰乙醇胺（PE）和磷脂酰胆碱（PC）对于确定LD的大小很重要。SCAP基因过表达和敲低诱导的LD形成强调了磷脂参与脂质液滴形成和融合的作用。SCAP的过表达增加了LD的形成和大小。细胞脂质分析的结果表明，磷脂是细胞脂质谱中的主要物质。磷脂酰乙醇胺（PE）和磷脂酰胆碱（PC）对于确定LD的大小很重要。SCAP基因过表达和敲低诱导的LD形成强调了磷脂参与脂质液滴形成和融合的作用。