Macrophage colony stimulating factor (M-CSF), commonly known as CSF1, is a cytokine produced by osteoblast cells, and is well known for its important role in differentiation of osteoclasts and white adipocyte hyperplasia. However, the role of M-CSF in lipid metabolic activity is lacking insight. In the current study, we explore unidentified actions of M-CSF in adipocytes. Levels of M-CSF were determined for white and brown adipose tissues and cells, and the expression levels of the important protein markers in lipid metabolism were evaluated through immunoblot analysis, subsequent to blocking M-CSF in fat cells by silencing its receptor Csf1r. Interestingly, we observed presence of M-CSF in brown fat cells. In addition, the lack of M-CSF in HIB1B cells attenuated the expressions of protein markers responsible for lipid metabolism in the brown adipocytes. Further, deficiency of M-CSF resulted in decreased adipogenesis along with reduced expression of lipogenic markers for both white and brown adipocytes. Moreover, lipid metabolism was balanced by M-CSF via the PPARγ-mediated LPL activity in white adipocytes. Taken together, the results from this study indicate that MCSF is an important regulatory protein in both white and brown adipocytes.

巨噬细胞集落刺激因子（M-CSF），通常称为CSF1，是由成骨细胞产生的细胞因子，以其在破骨细胞和白色脂肪细胞增生的分化中的重要作用而闻名。但是，M-CSF在脂质代谢活动中的作用尚缺乏见解。在当前的研究中，我们探索脂肪细胞中M-CSF的未知作用。测定白色和棕色脂肪组织和细胞的M-CSF水平，通过免疫印迹分析评估脂质代谢中重要蛋白质标志物的表达水平，然后通过沉默其受体Csf1r阻断脂肪细胞中的M-CSF。有趣的是，我们观察到棕色脂肪细胞中存在M-CSF。此外，HIB1B细胞中缺乏M-CSF减弱了褐色脂肪细胞中负责脂质代谢的蛋白质标志物的表达。此外，M-CSF的缺乏导致脂肪形成减少，以及白色和棕色脂肪细胞的脂肪生成标记的表达降低。此外，M-CSF通过白色脂肪细胞中PPARγ介导的LPL活性来平衡脂质代谢。两者合计，这项研究的结果表明MCSF是白色和棕色脂肪细胞中的重要调节蛋白。