| 1. |
|
|
| 2. |
|
|
| 3. |
- Renlund, N, et al.
(author)
-
Induction of steroidogenesis in immature rat Leydig cells by interleukin-1alpha is dependent on extracellular signal-regulated kinases
- 2006
-
In: Journal of molecular endocrinology. - : Bioscientifica. - 0952-5041 .- 1479-6813. ; 36:2, s. 327-336
-
Journal article (peer-reviewed)abstract
- Interleukin-1α (IL-1α) plays an important role in the regulation of immune responses as well as in non-inflammatory events in different types of cells. Here we have investigated the involvement of the extracellular signal-regulated kinase (ERK) cascade in IL-1α-induced steroidogenesis by primary cultures of immature rat Leydig cells. Our findings indicate that protein kinase C functions as an upstream component of signal transduction from the IL-1 receptor type I (IL-1RI) to the ERK cascade. It was observed that IL-1α upregulated both steroidogenic acute regulatory (StAR) protein expression and its phosphorylation when compared with controls. Selective inhibition of these mitogen-activated protein kinases (MAPKs) by UO126 enhanced both the expression and phosphorylation of the StAR protein, but suppressed androgen production by the immature Leydig cells as well as dissipating the mitochondrial electrochemical potential (Ψm) in these cells. The evidence that water-soluble cholesterol but not 22R-hydroxycholesterol-stimulated steroidogenesis was inhibited by UO126 suggested that an intact Ψm across the inner mitochondrial membrane is required for cholesterol translocation and is positively regulated by the ERK cascade. We propose that activation of ERKs by IL-1α plays a dual role in the regulation of steroidogenesis in immature Leydig cells: these MAPKs downregulate StAR expression and phosphorylation, while at the same time they support an intact Ψm across the inner mitochondrial membrane, thereby promoting translocation of cholesterol into the mitochondria of the Leydig cell.
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- Svechnikov, K, et al.
(author)
-
Origin, development and regulation of human Leydig cells
- 2010
-
In: Hormone research in paediatrics. - : S. Karger AG. - 1663-2826 .- 1663-2818. ; 73:2, s. 93-101
-
Journal article (peer-reviewed)abstract
- Sex steroids are crucial regulators of sexual differentiation and the proper development of secondary sex characteristics and patterns of sexual behavior. Since Leydig cells are the primary major producers of these steroid hormones, maintenance of the normal functions of these cells determines the reproductive capacity and fertility of males. The present minireview discusses recent findings concerning endocrine and paracrine regulation of the proliferation, differentiation and involution of human Leydig cells. The physiology and function of the two distinct fetal and adult populations of human Leydig cells are described, with particular focus on the paracrine environment that triggers their differentiation and functional maturation. The roles of established and more recently discovered paracrine regulators of this maturation, including insulin-like factor 3, platelet-derived growth factor-α, desert hedgehog, ghrelin and leptin are considered. A brief description of the origin, ontogenesis and functional markers of human fetal and adult Leydig cells is presented.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
