Molecular regulation of muscle-resident mesenchymal stem cells

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Abstract/Contents

Abstract
The platelet-derived growth factor receptor alpha (PDGFR [alpha]) exhibits divergent effects in skeletal muscle. At physiological levels, signaling through this receptor promotes muscle development in growing embryos and proper angiogenesis in regenerating adult muscle. However, increased PDGF ligands and enhanced PDGFR [alpha] pathway cause pathological fibrosis. This excessive collagen deposition, which is seen in aged and diseased muscle, interferes with proper muscle contraction and limits the effectiveness of gene- and cell- based therapies for muscle disorders. Although compelling evidence exists for the role of PDGFR [alpha] in fibrosis, little is known about the cells through which this pathway acts. Here we show that PDGFR [alpha] signaling regulates a population of muscle-resident mesenchymal stem cells (MSCs) that play a supportive role in muscle regeneration but may also cause fibrotic buildup when aberrantly regulated. Unexpectedly, our investigation revealed that changes in alternative polyadenylation of PDGFR [alpha] control MSC activation and consequently tissue regenerative potential. MSCs produce multiple transcriptional variants of PDGFR alpha] with different polyadenylation sites including an intronic variant of PDGFR [alpha] that codes for a protein isoform containing a truncated kinase domain. This variant, upregulated during regeneration, inhibits PDGF signaling and prevents MSC over-activation. Increasing expression of this isoform through administration of specified morpholinos limits fibrosis in vivo. Furthermore, in our global analysis of polyadenylation patterns in MSCs, we show that intronic polyadenylation is not limited to PDGFR [alpha]. Rather, it is a widespread phenomenon, and the levels of intronic polyadenylation variants compared to their full-length counterparts increases with cell activation on a global level. Overall, our findings suggest both biological relevance and therapeutic potential of modulating polyadenylation patterns in stem cell populations.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Publication date 2014
Issuance monographic
Language English

Creators/Contributors

Associated with Mueller, Alisa Anne
Associated with Stanford University, Cancer Biology Program.
Primary advisor Rando, Thomas A
Thesis advisor Rando, Thomas A
Thesis advisor Brunet, Anne, 1972-
Thesis advisor Chang, Howard Y. (Howard Yuan-Hao), 1972-
Thesis advisor Fire, Andrew Zachary
Advisor Brunet, Anne, 1972-
Advisor Chang, Howard Y. (Howard Yuan-Hao), 1972-
Advisor Fire, Andrew Zachary

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Alisa Anne Mueller.
Note Submitted to the Program in Cancer Biology.
Thesis Thesis (Ph.D.)--Stanford University, 2014.
Location electronic resource

Access conditions

Copyright
© 2014 by Alisa Anne Mueller
License
This work is licensed under a Creative Commons Attribution Non Commercial No Derivatives 3.0 Unported license (CC BY-NC-ND).

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