# The Role of Twist2 in Regulating Myogenesis

> **NIH NIH F30** · UT SOUTHWESTERN MEDICAL CENTER · 2020 · $41,918

## Abstract

Project Summary
Aging-related muscle atrophy (sarcopenia) is a process that affects nearly every person, contributing to
debilitations and reductions in quality of life. As people grow older, fast-twitch muscle fibers are selectively
atrophied resulting in weakness. Normally, muscle regenerates through a population of stem cells called
satellite cells, which differentiate and non-selectively fuse to existing myofibers in order to repair the damaged
muscle tissue. However, several recent studies have suggested that the contribution of satellite cells to muscle
during homeostasis and aging is minimal. Thus, it’s possible that loss of an alternative muscle precursor that
fuses specifically to fast-twitch fibers may be a mechanism by which aging-related muscle atrophy occurs.
Through the technique of lineage-tracing (fate-mapping) of the transcription factor Twist2, we have identified a
novel muscle progenitor that fuses specifically to type IIb/x (fast-twitch, glycolytic) muscle fibers during both
aging and homeostasis conditions. Additionally, loss of Twist2+ cells result in specific atrophy of fast-twitch
myofibers. I hypothesize that Twist2 is playing a role in regulating both the fiber type specificity as well as the
quiescence of this novel progenitor cell. To test this hypothesis, we propose to study the genes Neuropilin1
and Suv39h1 through mouse models, stripe migration assays, fusion assay, Chip-Seq, and cell culture studies.

## Key facts

- **NIH application ID:** 9878734
- **Project number:** 5F30AG056075-04
- **Recipient organization:** UT SOUTHWESTERN MEDICAL CENTER
- **Principal Investigator:** Stephen Li
- **Activity code:** F30 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $41,918
- **Award type:** 5
- **Project period:** 2017-04-01 → 2021-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9878734

## Citation

> US National Institutes of Health, RePORTER application 9878734, The Role of Twist2 in Regulating Myogenesis (5F30AG056075-04). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9878734. Licensed CC0.

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