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Updated: May 13, 2026

Fiber Type Identification of Human Skeletal Muscle
07:04

Fiber Type Identification of Human Skeletal Muscle

Published on: September 22, 2023

Mechanisms for fiber-type specificity of skeletal muscle atrophy

Yichen Wang1, Jeffrey E Pessin

  • 1Department of Molecular Pharmacology, Albert Einstein College of Medicine, Diabetes Research and Training Center, Bronx, New York 10461, USA.

Current Opinion in Clinical Nutrition and Metabolic Care
|March 16, 2013
PubMed
Abstract

Insights

Skeletal muscle atrophy affects different fiber types uniquely. Fast-twitch fibers are more vulnerable to atrophy, while slow-twitch fibers show resistance due to specific protective mechanisms like PPARGC1A.

Area of Science:

  • Muscle physiology
  • Molecular biology
  • Cellular signaling

Background:

  • Skeletal muscle atrophy results from diverse pathophysiologic conditions.
  • Distinct molecular pathways mediate muscle wasting with varying fiber-type sensitivity.

Purpose of the Study:

  • To review molecular mechanisms of fiber-specific muscle mass regulation.
  • To elucidate differential sensitivities of skeletal muscle fiber subtypes to atrophy.

Main Methods:

  • Literature review of molecular mechanisms.
  • Analysis of signaling pathways involved in muscle atrophy.

Main Results:

  • Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A) protects slow-twitch oxidative fibers from disuse atrophy.
  • Nutrient-related atrophies (cachexia, sepsis, heart failure, diabetes) primarily affect fast-twitch glycolytic fibers via protein degradation pathways.
  • Nuclear factor-kappaB (NF-κB) activation contributes to both fast-twitch and slow-twitch fiber atrophy.

Conclusions:

  • Fast-twitch glycolytic fibers are more susceptible to atrophy induced by FOXO, autophagy inhibition, TGF-β, and NF-κB signaling.
  • Slow-twitch oxidative fibers exhibit resistance, potentially due to PPARGC1A-mediated protection.

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