Cell-autonomous regulation of epithelial cell quiescence by calcium channel Trpv6

  1. Yi Xin
  2. Allison Malick
  3. Meiqin Hu
  4. Chengdong Liu
  5. Heya Batah
  6. Haoxing Xu
  7. Cunming Duan  Is a corresponding author
  1. University of Michigan, United States

Abstract

Epithelial homeostasis and regeneration require a pool of quiescent cells. How the quiescent cells are established and maintained is poorly understood. Here we report that Trpv6, a cation channel responsible for epithelial Ca2+ absorption, functions as a key regulator of cellular quiescence. Genetic deletion and pharmacological blockade of Trpv6 promoted zebrafish epithelial cells to exit from quiescence and re-enter the cell cycle. Reintroducing Trpv6, but not its channel dead mutant, restored the quiescent state. Ca2+ imaging showed that Trpv6 is constitutively open in vivo. Mechanistically, Trpv6-mediated Ca2+ influx maintained the quiescent state by suppressing insulin-like growth factor (IGF)-mediated Akt-Tor and Erk signaling. In zebrafish epithelia and human colon carcinoma cells, Trpv6/TRPV6 elevated intracellular Ca2+ levels and activated PP2A, which down-regulated IGF signaling and promoted the quiescent state. Our findings suggest that Trpv6 mediates constitutive Ca2+ influx into epithelial cells to continuously suppress growth factor signaling and maintain the quiescent state.

Data availability

All data generated or analysed during this study are included in the manuscript and supporting files.

Article and author information

Author details

  1. Yi Xin

    Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Allison Malick

    Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Meiqin Hu

    Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Chengdong Liu

    Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, United States
    Competing interests
    The authors declare that no competing interests exist.
  5. Heya Batah

    Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, United States
    Competing interests
    The authors declare that no competing interests exist.
  6. Haoxing Xu

    Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-3561-4654
  7. Cunming Duan

    Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, United States
    For correspondence
    cduan@umich.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-6794-2762

Funding

National Science Foundation (IOS-1557850)

  • Cunming Duan

National Science Foundation (IOS-1755262)

  • Cunming Duan

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Ethics

Animal experimentation: This study was performed in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. All experiments were conducted in accordance with the protocol approved by the University of Michigan Institutional Committee on the Use and Care of Animals (Protocol # PRO00008801).

Reviewing Editor

  1. Rosemary O’Connor

Publication history

  1. Received: April 26, 2019
  2. Accepted: September 13, 2019
  3. Accepted Manuscript published: September 17, 2019 (version 1)
  4. Version of Record published: September 27, 2019 (version 2)
  5. Version of Record updated: June 25, 2020 (version 3)

Copyright

© 2019, Xin et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 1,853
    Page views
  • 264
    Downloads
  • 8
    Citations

Article citation count generated by polling the highest count across the following sources: Crossref, PubMed Central, Scopus.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Yi Xin
  2. Allison Malick
  3. Meiqin Hu
  4. Chengdong Liu
  5. Heya Batah
  6. Haoxing Xu
  7. Cunming Duan
(2019)
Cell-autonomous regulation of epithelial cell quiescence by calcium channel Trpv6
eLife 8:e48003.
https://doi.org/10.7554/eLife.48003

Further reading

    1. Developmental Biology
    Yulong Liu et al.
    Research Article

    Zebrafish are an established research organism that has made many contributions to our understanding of vertebrate tissue and organ development, yet there are still significant gaps in our understanding of the genes that regulate gonad development, sex, and reproduction. Unlike the development of many organs, such as the brain and heart that form during the first few days of development, zebrafish gonads do not begin to form until the larval stage (≥5 dpf). Thus, forward genetic screens have identified very few genes required for gonad development. In addition, bulk RNA sequencing studies which identify genes expressed in the gonads do not have the resolution necessary to define minor cell populations that may play significant roles in development and function of these organs. To overcome these limitations, we have used single-cell RNA sequencing to determine the transcriptomes of cells isolated from juvenile zebrafish ovaries. This resulted in the profiles of 10,658 germ cells and 14,431 somatic cells. Our germ cell data represents all developmental stages from germline stem cells to early meiotic oocytes. Our somatic cell data represents all known somatic cell types, including follicle cells, theca cells and ovarian stromal cells. Further analysis revealed an unexpected number of cell subpopulations within these broadly defined cell types. To further define their functional significance, we determined the location of these cell subpopulations within the ovary. Finally, we used gene knockout experiments to determine the roles of foxl2l and wnt9b for oocyte development and sex determination and/or differentiation, respectively. Our results reveal novel insights into zebrafish ovarian development and function and the transcriptome profiles will provide a valuable resource for future studies.

    1. Developmental Biology
    2. Stem Cells and Regenerative Medicine
    Giacomo Leon Glotzer et al.
    Research Article

    The expression of Fibroblast growth factors (Fgf) ligands in a specialized epithelial compartment, the Apical Ectodermal Ridge (AER), is a conserved feature of limb development across vertebrate species. In vertebrates, Fgf 4, 8, 9, and 17 are all expressed in the AER. An exception to this paradigm is the salamander (axolotl) developing and regenerating limb, where key Fgf ligands are expressed in the mesenchyme. The mesenchymal expression of Amex.Fgf8 in axolotl has been suggested to be critical for regeneration. To date, there is little knowledge regarding what controls Amex.Fgf8 expression in the axolotl limb mesenchyme. A large body of mouse and chick studies have defined a set of transcription factors and canonical Wnt signaling as the main regulators of epidermal Fgf8 expression in these organisms. In this study, we address the hypothesis that alterations to one or more of these components during evolution has resulted in mesenchymal Amex.Fgf8 expression in the axolotl. To sensitively quantify gene expression with spatial precision, we combined optical clearing of whole-mount axolotl limb tissue with single molecule fluorescen in situ hybridization and a semi-automated quantification pipeline. Several candidate upstream components were found expressed in the axolotl ectoderm, indicating that they are not direct regulators of Amex.Fgf8 expression. We found that Amex.Wnt3a is expressed in axolotl limb epidermis, similarly to chicken and mouse. However, unlike in amniotes, Wnt target genes are activated preferentially in limb mesenchyme rather than in epidermis. Inhibition and activation of Wnt signaling results in downregulation and upregulation of mesenchymal Amex.Fgf8 expression respectively. These results implicate a shift in tissue responsiveness to canonical Wnt signaling from epidermis to mesenchyme as one step contributing to the unique mesenchymal Amex.Fgf8 expression seen in the axolotl.