Open AccessThe role of signaling pathways on proliferation and self‐renewal of cultured bovine primitive germ cells
Author(s) -
Sahare Mahesh,
Otomo Ayagi,
Komatsu Kana,
Minami Naojiro,
Yamada Masayasu,
Imai Hiroshi
Publication year - 2015
Publication title -
reproductive medicine and biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.005
H-Index - 22
eISSN - 1447-0578
pISSN - 1445-5781
DOI - 10.1007/s12522-014-0189-x
Subject(s) - gonocyte , microbiology and biotechnology , glial cell line derived neurotrophic factor , biology , protein kinase b , mapk/erk pathway , stem cell , signal transduction , pi3k/akt/mtor pathway , cell growth , neurotrophic factors , germ cell , biochemistry , receptor , gene
Purpose Gonocytes are primitive male germ cells residing in the neonatal testes and are unipotent in nature, but also have pluripotent stem cell ability in mice under appropriate culture conditions. This study was performed to elucidate the molecular mechanisms of self‐renewal and survival of cultured bovine gonocytes. Methods Gonocytes were isolated from neonatal bull calves and were cultured in DMEM/F12 supplemented with 15 % knock‐out serum replacement (KSR) and glial cell‐derived neurotrophic factor (GDNF). Cells were analyzed six days after culturing for cell‐signaling molecular markers. Results Colony formation was observed 3–4 days after being cultured. Addition of GDNF enhanced mitogen‐activated protein kinase 1/2 (MAPK1/2) phosphorylation and activated the MAPK signaling pathway. Inhibition of MAPK signaling reduced cell proliferation and abolished colony formation. However, inhibition of phosphoinositide 3‐kinase‐AKT (PI3K‐AKT) signaling, a dominant pathway for self‐renewal of mouse germ cells, did not show any effects on cultured bovine gonocytes. Expression of cell cycle‐related regulators cyclin D2 and cyclin‐dependent kinase 2 (CDK2) was downregulated with inhibition of MAPK signaling. Conclusions These results indicate activation of MAPK plays a critical role in self‐renewal and survival of bovine gonocytes via cyclin D1 and CDK2.