Undifferentiated spermatogonia regulate expression through NOTCH signaling and drive germ cell differentiation.

Cytochrome P450 family 26 subfamily B member 1 (CYP26B1) regulates the concentration of all-trans retinoic acid (RA) and plays a key role in germ cell differentiation by controlling local distribution of RA. The mechanisms regulating expression in postnatal Sertoli cells, the main components of the stem cell niche, are so far unknown. During gonad development, expression of is maintained by Steroidogenic Factor 1 (SF-1) and Sex-Determining Region Y Box-9 (SOX9), which ensure that RA is degraded and germ cell differentiation is blocked.

Regulation of GDNF expression in Sertoli cells.

Sertoli cells regulate male germ cell proliferation and differentiation and are a critical component of the spermatogonial stem cell (SSC) niche, where homeostasis is maintained by the interplay of several signaling pathways and growth factors. These factors are secreted by Sertoli cells located within the seminiferous epithelium, and by interstitial cells residing between the seminiferous tubules. Sertoli cells and peritubular myoid cells produce glial cell line-derived neurotrophic factor (GDNF), which binds to the RET/GFRA1 receptor complex at the surface of undifferentiated spermatogonia.

Biomarkers in cancer therapy related cardiac dysfunction (CTRCD).

Biomarkers are at the cornerstone of preventive measures and contribute to the screening process. More recently, biomarkers have been used to gauge the biological response to the employed therapies. Since it is ubiquitously used to detect subclinical disease process, biomarkers also have found its place in cancer therapy related cardiac dysfunction (CTRCD).