Insulin-Like Growth Factor-I Is an Important Antiapoptotic Factor for Rat Leydig Cells during Postnatal Development

• DOI: 10.1210/en.2006-0835
• Publication Date: 2006-10-06T00:45:27Z
• Authors: Eugenia Colón; Farasat Zaman; Magnus Axelson; Olle Larsson; Christine Carlsso...; Konstantin V. Sve...; Olle Söder
• Keywords: Flavonoids; Male; 0301 basic medicine; Cell Survival; Leydig Cells; Apoptosis; DNA; Immunohistochemistry; Rats; Receptor, IGF Type 1; Androstadienes; Rats, Sprague-Dawley; 03 medical and health sciences; Insulin-Like Growth Factor II; Testis; Animals; Insulin-Like Growth Factor I; Phosphorylation; Wortmannin; Protein Kinase Inhibitors; Cells, Cultured; Podophyllotoxin

The present investigation examines the influence of IGF-I and role receptor (IGF-IR) in apoptosis/survival Leydig cells. Immunohistochemical analysis rat testis at different ages revealed that level phosphorylated IGF-IR increases from birth to d 20 postnatal life, remaining high adult testis. Western blotting this is higher cells isolated 40-d-old than 10- or 60-d-old rats. Application terminal deoxyribonucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling assay decreases apoptosis all stages development, selective inhibitor IGF-IR, picropodophyllin, blocks antiapoptotic effect. mechanism underlying action involves phosphatidylinositol 3-kinase/Akt pathway, immature cells, growth factor enhances expression Bcl-2 cellular proteins 2, while preventing activation caspase-3 by cleavage. Furthermore, IGF-II concentrations insulin also evoke phosphorylation and, like IGF-I, enhance steroidogenic acute regulatory protein Inhibition picropodophyllin survival both presence absence demonstrating signaling via plays an important cell survival.