%0 Journal Article %T Unraveling Estrogen and PCSK9's Roles in Lipid Metabolism Disorders among Ovariectomized Mice. %A Yang J %A Xu M %A Wang Z %A He M %A Zhang G %A Jin L %A Zhao R %A Pan Y %A Tong J %A Nie L %J Reprod Sci %V 0 %N 0 %D 2024 Jun 13 %M 38871967 %F 2.924 %R 10.1007/s43032-024-01614-8 %X We explore the interaction between estrogen and PCSK9 and their collective impact on lipid metabolism, especially concerning the regulation of low-density lipoprotein receptor levels. Utilizing both animal and cellular models, including ovariectomized mice and HepG2 cell lines, we demonstrate that estrogen deficiency leads to a disruption in lipid metabolism, characterized by elevated levels of total cholesterol and LDL-C. The study commences with mice undergoing ovariectomy, followed by a diet regimen comprising either high-fat diet or normal feed for a four-week duration. Key assessments include analyzing lipid metabolism, measuring PCSK9 levels in the bloodstream, and evaluating hepatic low-density lipoprotein receptor expression. We will also conduct correlation analyses to understand the relationship between PCSK9 and various lipid profiles. Further, a subset of ovariectomized mice on high-fat diet will undergo treatment with either estrogen or PCSK9 inhibitor for two weeks, with a subsequent re-evaluation of the earlier mentioned parameters. Our findings reveal that estrogen inhibits PCSK9-mediated degradation of low-density lipoprotein receptor, a process crucial for maintaining lipid homeostasis. Through a series of experiments, including immunohistochemistry and western blot analysis, we establish that PCSK9 is involved in lipid metabolism disorders caused by estrogen deficiency and that estrogen regulates PCSK9 and low-density lipoprotein receptor at post-transcriptional level. The study provides a mechanism for the involvement of PCSK9 in elucidating the disorders of lipid metabolism caused by estrogen deficiency due to perimenopause and ovarian decline.