目的  探讨卵泡抑素样蛋白1（FSTL1）在小鼠棕色脂肪组织（BAT）退化中的作用。 方法  选取6~8周野生型雄性小鼠，分为3组，分别在22 ℃、30 ℃和4 ℃环境下喂养3 d，取材BAT组织，HE染色观察形态变化；Real-time PCR、Western blotting和免疫组织化学（IHC）染色检测小鼠BAT产热功能和线粒体相关基因以及FSTL1的表达。选取Fstl1Pdgfrα^+/-小鼠及其同窝Fstl1Pdgfrα^+/+对照小鼠，检测BAT产热基因和线粒体相关基因的表达。 结果  相比于22 ℃和4 ℃组，30 ℃组小鼠BAT脂肪细胞直径明显增大，单腔样形态细胞占比增多，FSTL1的表达与解耦联蛋白1（UCP1）的表达均显著减少并呈现显著的正向线性相关性，产热和线粒体相关基因表达降低，BAT表现为形态和功能退化。同时我们发现Fstl1Pdgfrα^+/-小鼠BAT的适应性产热功能和线粒体相关基因表达受到抑制。 结论  FSTL1的表达下降与BAT退化密切相关，FSTL1能够抑制BAT的退化。

Objective  To investigate the role of follistatin-like 1 (FSTL1) in the degeneration of brown adipose tissue (BAT) in mice.  Methods  Wild-type male mice aged 6-8 weeks were divided into three groups and housed at 4 ℃，22 ℃ and 30 ℃ for three days，respectively. The mice BAT was weighed，and HE staining was then performed to observe its morphological changes. Real-time PCR，Western blotting，and immunohistochemistry（IHC）were used to detect the expression of thermogenic function-related genes，mitochondrial function-related genes and FSTL1 in mouse BAT. Additionally，Fstl1Pdgfrα^+/- mice and their littermate Fstl1Pdgfrα^+/+ control mice were selected to detect the expression of BAT thermogenic genes and mitochondrial-related genes.  Results  Compared with the mice in the 22 ℃ and 4 ℃ groups，those in the 30 ℃ group exhibited significantly increased diameter of BAT，a higher proportion of unilocular-like adipocytes，and markedly reduced expression levels of both FSTL1 and uncoupling protein 1 (UCP1) with a significant positive linear correlation observed between their expressions. Additionally，the expression of thermogenesis-related and mitochondria-associated genes was downregulated，indicating that BAT underwent morphological and functional deterioration. Meanwhile，we found that the adaptive thermogenic capacity and the expression of mitochondria-related genes in BAT were impaired in Fstl1Pdgfrα^+/-mice.   Conclusion  The decreased expression of FSTL1 is closely associated with BAT degeneration，and FSTL1 can inhibit the degeneration of BAT.