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Updated: Sep 1, 2025
11:35
Isolation of Quiescent Stem Cell Populations from Individual Skeletal Muscles
Published on: December 9, 2022
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HYPOTHESIS: Do LRIG Proteins Regulate Stem Cell Quiescence by Promoting BMP Signaling?
Carl Herdenberg1, Håkan Hedman2
1Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden.
Stem Cell Reviews and Reports
|August 15, 2022
Summary
Leucine-rich repeats and immunoglobulin-like domains 1 (LRIG1) protein regulates stem cell quiescence. This study hypothesizes LRIG1 promotes quiescent stem cells by enhancing bone morphogenetic protein (BMP) signaling.
Area of Science:
- Stem cell biology
- Molecular and cellular biology
Background:
- Leucine-rich repeats and immunoglobulin-like domains (LRIG) proteins are integral membrane proteins.
- LRIG1 is known to regulate stem cell quiescence across various mammalian tissues and in planarian neoblasts.
- The precise mechanism of LRIG1 in stem cell regulation is unclear, with previous assumptions focusing on receptor tyrosine kinases.
Purpose of the Study:
- To investigate the mechanism by which LRIG1 regulates stem cell quiescence.
- To test the hypothesis that LRIG1 promotes stem cell quiescence through bone morphogenetic protein (BMP) signaling.
Main Methods:
- Analysis of Lrig-null mouse embryonic fibroblasts (MEFs) to assess receptor tyrosine kinase function.
- Examination of the relationship between LRIG1/LRIG3 expression and BMP signaling pathways.
- Comparative study of LRIG1 function in mammalian stem cells and planarian neoblasts.
Main Results:
- Lrig-null MEFs showed normal receptor tyrosine kinase activity, challenging prior assumptions.
- Bone morphogenetic protein (BMP) signaling was found to be dependent on LRIG1 and LRIG3 expression.
- BMPs are established regulators of stem cell quiescence.
Conclusions:
- LRIG1 may regulate stem cell quiescence by promoting BMP signaling, rather than through direct regulation of receptor tyrosine kinases.
- This finding offers a new mechanistic insight into stem cell regulation by LRIG proteins.
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