title: Retinoic acid promotes proliferation of chicken primordial germ cells via activation of PI3K/Akt-mediated NF-κB signalling cascade.
abstract: As embryonic progenitors for the gametes, PGCs (primordial germ cells) proliferate and develop under strict regulation of numerous intrinsic and external factors. As the most active natural metabolite of vitamin A, all-trans RA (retinoic acid) plays pivotal roles in regulating development of various cells. The proliferating action of RA on PGCs was investigated along with the intracellular PI3K (phosphoinositide 3-kinase)/Akt (protein kinase B; also known as Akt)-mediated NF-κB (nuclear factor κB) signalling cascade. The results show that RA significantly promoted PGC proliferation in a dose- and time-dependent manner, confirmed by BrdU (bromodeoxyuridine) incorporation and cell cycle analysis. However, this promoting effect was attenuated by sequential inhibitors of LY294002 for PI3K, KP372-1 for Akt and SN50 for NF-κB respectively. Western blot analysis showed increased Akt phosphorylation (Ser473) of PGCs after stimulation with RA, but this was abolished by LY294002 or KP372-1. Treatment with RA increased expression of NF-κB and decreased IκBα (inhibitory κBα) expression, which were inhibited by SN50. Blockade of PI3K or Akt activity inhibited NF-κB translocation from the cytoplasm to the nucleus. Finally, mRNA expression of cell cycle regulating genes [cyclin D1 and E, CDK6 (cyclin-dependent kinase 6) and CDK2] was up-regulated in the RA-treated cells. This stimulation was also markedly retarded by combined treatment with LY294002, KP372-1 and SN50. These results suggest that RA activates the PI3K/Akt and NF-κB signalling cascade to promote proliferation of the cultured chicken PGCs.
authors.affiliation: Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou 310058, Peoples Republic of China.
authors.forename: Minli
authors.initials: M
authors.lastname: Yu
authors.forename: Chutian
authors.initials: C
authors.lastname: Ge
authors.forename: Weidong
authors.initials: W
authors.lastname: Zeng
authors.forename: Yuling
authors.initials: Y
authors.lastname: Mi
authors.forename: Caiqiao
authors.initials: C
authors.lastname: Zhang
mesh_terms: D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D002645:Chickens / Q000378:metabolism; D002867:Chromones / Q000494:pharmacology; D005854:Germ Cells / Q000166:cytology / Q000378:metabolism*; D006576:Heterocyclic Compounds, 4 or More Rings / Q000494:pharmacology; D020672:I-kappa B Proteins / Q000378:metabolism; D009025:Morpholines / Q000494:pharmacology; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010455:Peptides / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation / Q000187:drug effects; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D013777:Tetrazoles / Q000494:pharmacology; D014212:Tretinoin / Q000494:pharmacology*; D015854:Up-Regulation
chemical_list: D018797:Cell Cycle Proteins; D002867:Chromones; D006576:Heterocyclic Compounds, 4 or More Rings; D020672:I-kappa B Proteins; D009025:Morpholines; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B; D010455:Peptides; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D047428:Protein Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt; D013777:Tetrazoles; D014212:Tretinoin; C501199:KP372-1; C118258:SN50 peptide; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one