Melatonin (MLT) protects cells by reducing reactive oxygen species (ROS) levels, which are key for inducing cellular autophagy. The aim of this study was to investigate the molecular mechanisms underlying MLT regulation of autophagy in granulosa cells (GCs) with BMPR-1B homozygous (Fec^B BB) and wild type (Fec^B ++) mutations. GCs collected from small-tailed Han sheep with different Fec^B genotypes were typed using a TaqMan probe assay, and autophagy levels were found to be significantly higher in GCs with Fec^B BB than the levels in those with Fec^B ++. Autophagy-related 2 homolog B (ATG2B) was associated with cell autophagy and was highly expressed in GCs with the Fec^B BB genotype in small-tailed Han sheep. Overexpression of ATG2B in the GCs of sheep with both Fec^B genotypes promoted GC autophagy, and the contrary was observed after the inhibition of ATG2B expression. Subsequently, treatment of GCs with different genotypes of Fec^B and MLT revealed a significant decrease in cellular autophagy and an increase in ATG2B expression. Addition of MLT to GCs with inhibited ATG2B expression revealed that MLT could protect GCs by decreasing ROS levels, especially in GCs with Fec^B ++ genotype. In conclusion, this study determined that autophagy levels were significantly higher in sheep GCs with Fec^B BB genotype than the levels in those with Fec^B ++ genotype, which may have contributed to the difference in lambing numbers between the two Fec^B genotypes. Autophagy was regulated by ATG2B and was able to protect GCs by reducing the high levels of ROS produced following inhibition of ATG2B through the addition of MLT in vitro.

中文翻译：

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褪黑素对ATG2B介导的不同FecB基因型绵羊颗粒细胞自噬调节的影响

褪黑素 (MLT) 通过降低活性氧 (ROS) 水平来保护细胞，而活性氧是诱导细胞自噬的关键。本研究的目的是探讨 MLT 调节BMPR-1B纯合子 ( Fec ^B BB) 和野生型 ( Fec ^B ++) 突变的颗粒细胞 (GC) 自噬的分子机制。采用 TaqMan 探针检测对小尾寒羊不同Fec ^B基因型的 GC 进行分型，发现Fec ^B BB 的 GC 的自噬水平显着高于Fec ^B ++ 的 GC。自噬相关 2 同源物 B ( ATG2B) 与细胞自噬相关，在小尾寒羊具有Fec ^{B BB 基因型的 GC 中高表达。}在两种Fec ^B基因型的绵羊GC中过表达ATG2B均促进GC自噬，而抑制ATG2B表达后则相反。随后，用不同基因型的Fec ^B和 MLT处理 GC，发现细胞自噬显着减少， ATG2B表达增加。将 MLT 添加到抑制ATG2B表达的 GC 中表明，MLT 可以通过降低 ROS 水平来保护 GC，特别是在含有Fec ^{B的 GC 中}++ 基因型。总之，本研究确定，Fec ^B BB 基因型绵羊 GC 的自噬水平显着高于Fec ^B ++ 基因型绵羊 GC，这可能是造成两种Fec ^B基因型产羔数差异的原因。自噬受ATG2B调节，并且能够通过体外添加 MLT抑制ATG2B后产生的高水平 ROS 来保护 GC。