Involvement of calmodulin-dependent protein kinase I in the regulation of the expression of connexin 43 in MA-10 tumor Leydig cells.

Connexin 43 (Cx43, also known as Gja1) is the most abundant testicular gap junction protein. It has a crucial role in the support of spermatogenesis by Sertoli cells in the seminiferous tubules as well as in androgen synthesis by Leydig cells. The multifunctional family of Ca/calmodulin-dependent protein kinases (CaMK) is composed of CaMK I, II, and IV and each can serve as a mediator of nuclear Ca signals.

The AP-1 family of transcription factors are important regulators of gene expression within Leydig cells.

Purpose: Members of the AP-1 family of transcription factors are immediate early genes being modulated by different extracellular signals. The aim of this review is to highlight the important roles of AP-1 members in transcriptional regulation of genes important for testicular Leydig cell function and male testosterone production.

Methods: A search of the relevant literature was performed in Google Scholar and NCBI Pubmed for AP-1 members and Leydig cells.

Luteolin modulates gene expression related to steroidogenesis, apoptosis, and stress response in rat LC540 tumor Leydig cells.

In males, androgens are mainly produced by Leydig cells from the testis. A critical and highly regulated step of steroidogenesis involves the importation of cholesterol within the mitochondria by the steroidogenic acute regulatory (STAR) protein. During aging, STAR protein levels in Leydig cells gradually decrease, leading to a reduced entry of cholesterol into mitochondria and lower testosterone production.