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Calcium State-Dependent Regulation of Epithelial Cell Quiescence by Stanniocalcin 1a
The molecular mechanisms regulating cell quiescence-proliferation balance are not well defined. Using a zebrafish model, we report that Stc1a, a secreted glycoprotein, plays a key role in regulating the quiescence-proliferation balance of Ca(2+) transporting epithelial cells (ionocytes). Zebrafish s...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Frontiers Media S.A.
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8063699/ https://www.ncbi.nlm.nih.gov/pubmed/33898465 http://dx.doi.org/10.3389/fcell.2021.662915 |
Sumario: | The molecular mechanisms regulating cell quiescence-proliferation balance are not well defined. Using a zebrafish model, we report that Stc1a, a secreted glycoprotein, plays a key role in regulating the quiescence-proliferation balance of Ca(2+) transporting epithelial cells (ionocytes). Zebrafish stc1a, but not the other stc genes, is expressed in a Ca(2+) state-dependent manner. Genetic deletion of stc1a, but not stc2b, increased ionocyte proliferation, leading to elevated body Ca(2+) levels, cardiac edema, body swelling, and premature death. The increased ionocyte proliferation was accompanied by an increase in the IGF1 receptor-mediated PI3 kinase-Akt-Tor signaling activity in ionocytes. Inhibition of the IGF1 receptor, PI3 kinase, Akt, and Tor signaling reduced ionocyte proliferation and rescued the edema and premature death in stc1a(–/–) fish, suggesting that Stc1a promotes ionocyte quiescence by suppressing local IGF signaling activity. Mechanistically, Stc1 acts by inhibiting Papp-aa, a zinc metalloproteinase degrading Igfbp5a. Inhibition of Papp-aa proteinase activity restored ionocyte quiescence-proliferation balance. Genetic deletion of papp-aa or its substrate igfbp5a in the stc1a(–/–) background reduced ionocyte proliferation and rescued the edema and premature death. These findings uncover a novel and Ca(2+) state-dependent pathway regulating cell quiescence. Our findings also provide new insights into the importance of ionocyte quiescent-proliferation balance in organismal Ca(2+) homeostasis and survival. |
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