title: TRPV3 Channel Negatively Regulates Cell Cycle Progression and Safeguards the Pluripotency of Embryonic Stem Cells.
abstract: Embryonic stem cells (ESCs) have tremendous potential for research and future therapeutic purposes. However, the calcium handling mechanism in ESCs is not fully elucidated. Aims of this study are (1) to investigate if transient receptor potential vanilloid-3 (TRPV3) channels are present in mouse ESCs (mESCs) and their subcellular localization; (2) to investigate the role of TRPV3 in maintaining the characteristics of mESCs. Western blot and immunocytochemistry showed that TRPV3 was present at the endoplasmic reticulum (ER) of mESCs. Calcium imaging showed that, in the absence of extracellular calcium, TRPV3 activators camphor and 6-tert-butyl-m-cresol increased the cytosolic calcium. However, depleting the ER store in advance of activator addition abolished the calcium increase, suggesting that TRPV3 released calcium from the ER. To dissect the functional role of TRPV3, TRPV3 was activated and mESC proliferation was measured by trypan blue exclusion and MTT assays. The results showed that TRPV3 activation led to a decrease in mESC proliferation. Cell cycle analysis revealed that TRPV3 activation increased the percentage of cells in G2 /M phase; consistently, Western blot also revealed a concomitant increase in the expression of inactive form of cyclin-dependent kinase 1, suggesting that TRPV3 activation arrested mESCs at G2 /M phase. TRPV3 activation did not alter the expression of pluripotency markers Oct-4, Klf4 and c-Myc, suggesting that the pluripotency was preserved. Our study is the first study to show the presence of TRPV3 at ER. Our study also reveals the novel role of TRPV3 in controlling the cell cycle and preserving the pluripotency of ESCs.
authors.affiliation: School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR.
authors.forename: Iek Chi
authors.initials: IC
authors.lastname: Lo
authors.affiliation: School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR.
authors.forename: Hing Chung
authors.initials: HC
authors.lastname: Chan
authors.affiliation: School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR.
authors.forename: Zenghua
authors.initials: Z
authors.lastname: Qi
authors.affiliation: School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR.
authors.forename: Kwun Lam
authors.initials: KL
authors.lastname: Ng
authors.affiliation: School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR.
authors.forename: Chun
authors.initials: C
authors.lastname: So
authors.affiliation: School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR.|Key Laboratory for Regenerative Medicine, Ministry of Education, The Chinese University of Hong Kong, Hong Kong SAR.|State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong SAR.|Centre of Novel Biomaterials, The Chinese University of Hong Kong, Hong Kong SAR.
authors.forename: Suk Ying
authors.initials: SY
authors.lastname: Tsang
mesh_terms: D000818:Animals; D017209:Apoptosis; D020013:Calcium Signaling / Q000187:drug effects; D002164:Camphor / Q000494:pharmacology; D059447:Cell Cycle Checkpoints / Q000187:drug effects / Q000502:physiology*; D002454:Cell Differentiation; D002460:Cell Line; D049109:Cell Proliferation; D003408:Cresols / Q000494:pharmacology; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D059565:G2 Phase Cell Cycle Checkpoints / Q000502:physiology; D000090062:Kruppel-Like Factor 4; D051379:Mice; D039904:Pluripotent Stem Cells / Q000166:cytology* / Q000378:metabolism*; D050916:TRPV Cation Channels / Q000819:agonists / Q000235:genetics / Q000378:metabolism*
chemical_list: D003408:Cresols; C000715468:Klf4 protein, mouse; D000090062:Kruppel-Like Factor 4; D050916:TRPV Cation Channels; C486760:Trpv3 protein, mouse; D002164:Camphor