Ca2+ signaling driving pacemaker activity in submucosal interstitial cells of Cajal in the murine colon

  1. Salah A Baker  Is a corresponding author
  2. Wesley A Leigh
  3. Guillermo Del Valle
  4. Inigo F De Yturriaga
  5. Sean M Ward
  6. Caroline A Cobine
  7. Bernard T Drumm
  8. Kenton M Sanders
  1. University of Nevada, Reno, United States
  2. Institute of Technology, Dundalk, Ireland
  3. University of Nevada, United States

Abstract

Interstitial cells of Cajal (ICC) generate pacemaker activity responsible for phasic contractions in colonic segmentation and peristalsis. ICC along the submucosal border (ICC-SM) contribute to mixing and more complex patterns of colonic motility. We show the complex patterns of Ca2+ signaling in ICC-SM and the relationship between ICC-SM Ca2+ transients and activation of SMCs using optogenetic tools. ICC-SM displayed rhythmic firing of Ca2+ transients ~15 cpm and paced adjacent SMCs. The majority of spontaneous activity occurred in regular Ca2+ transients clusters (CTCs) that propagated through the network. CTCs were organized and dependent upon Ca2+ entry through voltage-dependent Ca2+ conductances, L- and T-type Ca2+ channels. Removal of Ca2+ from the external solution abolished CTCs. Ca2+ release mechanisms reduced the duration and amplitude of Ca2+ transients but did not block CTCs. These data reveal how colonic pacemaker ICC-SM exhibit complex Ca2+ firing patterns and drive smooth muscle activity and overall colonic contractions.

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. Salah A Baker

    Physiology and Cell Biology, University of Nevada, Reno, Reno, United States
    For correspondence
    sabubaker@med.unr.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-1514-6876
  2. Wesley A Leigh

    Physiology and Cell Biology, University of Nevada, Reno, Reno, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Guillermo Del Valle

    Physiology and Cell Biology, University of Nevada, Reno, Reno, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Inigo F De Yturriaga

    Physiology and Cell Biology, University of Nevada, Reno, Reno, United States
    Competing interests
    The authors declare that no competing interests exist.
  5. Sean M Ward

    Physiology and Cell Biology, University of Nevada, Reno, Reno, United States
    Competing interests
    The authors declare that no competing interests exist.
  6. Caroline A Cobine

    Physiology and Cell Biology, University of Nevada, Reno, Reno, United States
    Competing interests
    The authors declare that no competing interests exist.
  7. Bernard T Drumm

    Department of Life & Health Science,, Institute of Technology, Dundalk, Dundalk, Ireland
    Competing interests
    The authors declare that no competing interests exist.
  8. Kenton M Sanders

    Physiology and Cell Biology, University of Nevada, Reno, United States
    Competing interests
    The authors declare that no competing interests exist.

Funding

National Institute of Diabetes and Digestive and Kidney Diseases (R01 DK-120759)

  • Salah A Baker

National Institute of Diabetes and Digestive and Kidney Diseases (R01 DK-120759)

  • Kenton M Sanders

National Institute of Diabetes and Digestive and Kidney Diseases (R01 DK-078736)

  • Caroline A Cobine

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

Ethics

Animal experimentation: The animals used, protocols performed and procedures in this study were in accordance with the National Institutes of Health Guide for the Care and Use of Laboratory Animals and approved by the Institutional Animal Use and Care Committee at the University of Nevada, Reno (IACUC; Protocol# 00053).

Reviewing Editor

  1. Mark T Nelson, University of Vermont, United States

Publication history

  1. Received: October 16, 2020
  2. Accepted: January 4, 2021
  3. Accepted Manuscript published: January 5, 2021 (version 1)
  4. Version of Record published: January 13, 2021 (version 2)

Copyright

© 2021, Baker 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

  • 1,212
    Page views
  • 146
    Downloads
  • 6
    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. Salah A Baker
  2. Wesley A Leigh
  3. Guillermo Del Valle
  4. Inigo F De Yturriaga
  5. Sean M Ward
  6. Caroline A Cobine
  7. Bernard T Drumm
  8. Kenton M Sanders
(2021)
Ca2+ signaling driving pacemaker activity in submucosal interstitial cells of Cajal in the murine colon
eLife 10:e64099.
https://doi.org/10.7554/eLife.64099

Further reading

    1. Cell Biology
    Yang Zhang et al.
    Research Article Updated

    TMEM16F, a Ca2+-activated phospholipid scramblase (CaPLSase), is critical for placental trophoblast syncytialization, HIV infection, and SARS-CoV2-mediated syncytialization, however, how TMEM16F is activated during cell fusion is unclear. Here, using trophoblasts as a model for cell fusion, we demonstrate that Ca2+ influx through the Ca2+ permeable transient receptor potential vanilloid channel TRPV4 is critical for TMEM16F activation and plays a role in subsequent human trophoblast fusion. GSK1016790A, a TRPV4 specific agonist, robustly activates TMEM16F in trophoblasts. We also show that TRPV4 and TMEM16F are functionally coupled within Ca2+ microdomains in a human trophoblast cell line using patch-clamp electrophysiology. Pharmacological inhibition or gene silencing of TRPV4 hinders TMEM16F activation and subsequent trophoblast syncytialization. Our study uncovers the functional expression of TRPV4 and one of the physiological activation mechanisms of TMEM16F in human trophoblasts, thus providing us with novel strategies to regulate CaPLSase activity as a critical checkpoint of physiologically and disease-relevant cell fusion events.

    1. Cancer Biology
    2. Cell Biology
    Johnny M Tkach et al.
    Research Article

    Centrosomes act as the main microtubule organizing center (MTOC) in metazoans. Centrosome number is tightly regulated by limiting centriole duplication to a single round per cell cycle. This control is achieved by multiple mechanisms, including the regulation of the protein kinase PLK4, the most upstream facilitator of centriole duplication. Altered centrosome numbers in mouse and human cells cause p53-dependent growth arrest through poorly defined mechanisms. Recent work has shown that the E3 ligase TRIM37 is required for cell cycle arrest in acentrosomal cells. To gain additional insights into this process, we undertook a series of genome-wide CRISPR/Cas9 screens to identify factors important for growth arrest triggered by treatment with centrinone B, a selective PLK4 inhibitor. We found that TRIM37 is a key mediator of growth arrest after partial or full PLK4 inhibition. Interestingly, PLK4 cellular mobility decreased in a dose-dependent manner after centrinone B treatment. In contrast to recent work, we found that growth arrest after PLK4 inhibition correlated better with PLK4 activity than with mitotic length or centrosome number. These data provide insights into the global response to changes in centrosome number and PLK4 activity and extend the role for TRIM37 in regulating the abundance, localization, and function of centrosome proteins.