Epidermal growth factor-induced proliferation of chicken primordial germ cells: involvement of calcium/protein kinase C and NFKB1.
Epidermal growth factor (EGF) has been shown to stimulate survival in diverse cells in vitro. In the present study, the effects of EGF and the EGF-related signaling pathway on proliferation of chicken primordial germ cells (PGCs) were investigated. Results showed that EGF (10-100 ng/ml) increased the number and area of PGC colonies in a time- and dose-dependent manner. EGF also activated PKC, a process that was inhibited by AG1478 (an EGFR tyrosine kinase inhibitor) and ethyleneglycol-bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid (EGTA; an intracellular Ca(2+) chelator). In addition, the degradation of NFKBIA and NFKB1 (p65) translocation was observed after EGF treatment, which was significantly blocked by pretreatment with AG1478, EGTA, H(7), or SN50 (NFKB1-specific inhibitor). Furthermore, we found that EGF-induced cell proliferation was significantly attenuated by AG1478, EGTA, H(7), and SN50, respectively. On the other hand, inhibition of EGFR, Ca(2+)/PKC, or NFKB1 abolished the EGF-stimulated increase in the expression of cyclins CCND1 and CCNE1, cyclin-dependent kinase 6 (CDK6), CDK2, and BCL2, and restored the EGF-induced inhibition of BAX expression and caspase 3/9 activity, indicating that EGFR, PKC, and NFKB1 signaling cascades were involved in EGF-stimulated DNA synthesis and antiapoptosis action. In conclusion, EGF stimulated proliferation of chicken PGCs via activation of Ca(2+)/PKC involving NFKB1 signaling pathway. These observations suggest that EGF signaling is important in regulating germ cell proliferation in the chicken embryonic gonad.
Ge
Chutian
C
Key Laboratory of Animal Epidemic Etiology & Immunological Prevention of the Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou, People's Republic of China.
Yu
Minli
M
Petitte
James N
JN
Zhang
Caiqiao
C
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D002118:Calcium / Q000378:metabolism*; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D002642:Chick Embryo; D019938:Cyclin D1 / Q000378:metabolism; D051357:Cyclin-Dependent Kinase 2 / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D066246:ErbB Receptors / Q000378:metabolism; D005854:Germ Cells / Q000166:cytology* / Q000187:drug effects; D052002:NF-kappa B p50 Subunit / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D051028:bcl-2-Associated X Protein / Q000378:metabolism
D052002:NF-kappa B p50 Subunit; D051028:bcl-2-Associated X Protein; D019938:Cyclin D1; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D011493:Protein Kinase C; D051357:Cyclin-Dependent Kinase 2; D053148:Caspase 3; D053453:Caspase 9; D002118:Calcium