Tissue-specific knockouts of steroidogenic factor 1

Area of Science:

• Endocrinology
• Developmental Biology
• Genetics

Background:

• Steroidogenic factor 1 (SF-1) is an orphan nuclear receptor vital for the development and function of steroidogenic organs.
• Global knockout (KO) of SF-1 in mice results in severe developmental defects, including absence of adrenal glands and gonads.
• Understanding tissue-specific roles of SF-1 is essential for dissecting its functions within the hypothalamic-pituitary-steroidogenic axis.

Purpose of the Study:

• To investigate the tissue-specific functions of SF-1 within the hypothalamic-pituitary-steroidogenic axis.
• To generate and characterize novel mouse models with targeted inactivation of SF-1 in specific tissues.
• To define the roles of SF-1 in weight regulation, pituitary function, and reproductive development.

Main Methods:

• Generation of global SF-1 KO mice and subsequent adrenal transplantation to create a VMH-specific KO model.
• Utilizing Cre-loxP recombination strategy to achieve pituitary-specific SF-1 KO.
• Employing bacterial artificial chromosome (BAC) transgenesis for developing SF-1 expressing cell markers.

Main Results:

• Adrenal-transplanted SF-1 KO mice exhibited obesity due to decreased locomotor activity, establishing a model for hypothalamic obesity.
• Pituitary-specific SF-1 KO mice displayed hypogonadotropic hypogonadism, highlighting SF-1's essential role in pituitary function.
• Ongoing studies aim to define SF-1 roles in brain and gonadal development and function.

Conclusions:

• SF-1 plays critical, distinct roles in various tissues within the neuroendocrine system.
• Tissue-specific inactivation of SF-1 provides valuable insights into its complex functions.
• Novel mouse models are crucial for understanding SF-1's contribution to endocrine and metabolic regulation.