Abstract
The milieu of testicular germline stem cells (mGSCs) is characterized as low oxygen (O2) environment, whereas, there in-vitro expansion is typically performed under normoxia (20-21% O2). Here, we evaluated and compared the culture and multilineage differentiation characteristics of enriched (through differential platting and percoll density centrifugation) caprine mGSCs (cmGSCs) under hypoxic (5% O2) and normoxic (21% O2) culture conditions. For this, in addition to growth characteristics and population-doubling time (PDT); viability, proliferation, senescence, and expression of key-markers of adhesion (β-integrin and E-Cadherin) and stemness (OCT-4, THY-1 and UCHL-1) were evaluated and compared under normoxia and hypoxia. Moreover, the extent of multilineage differentiation (neurogenic, adipogenic, and chondrogenic differentiation) was assessed. The survival, viability and proliferation were significantly promoted and PDT was reduced (p < 0.05), thus yielding a higher number of viable cells with larger colonies under hypoxia. Furthermore, expression of stemness and adhesion markers was distinctly increased under lowered O2 condition. Conversely, the presence of differentiated regions and expression of differentiation specific key genes [C/EBPα (adipogenic), nestin and β-tubulin (neurogenic), and COL2A1 (chondrogenic)] were significantly (p < 0.05) reduced under hypoxic conditions. These data demonstrate that culturing cmGSCs under hypoxia augments the growth characteristics, and stemness but not the multilineage differentiation potential of cmGSCs as compared with normoxia. These data are important for the development of robust methodologies for ex-vivo expansion and lineage-committed differentiation of cmGSCs for clinical applications.
Correction to: Multilineage differentiation of muscle-derived stem cells from GFP transgenic mice
