Related Experiment Video

Updated: Jun 26, 2026

Dissection of Single Skeletal Muscle Fibers for Immunofluorescent and Morphometric Analyses of Whole-Mount Neuromuscular Junctions
08:41

Dissection of Single Skeletal Muscle Fibers for Immunofluorescent and Morphometric Analyses of Whole-Mount Neuromuscular Junctions

Published on: August 14, 2021

Differential involvement of sarcomeric proteins in myofibrillar myopathies: a morphological and immunohistochemical

Kristl G Claeys1, Peter F M van der Ven, Anthony Behin

  • 1Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, Paris, France. k.claeys@institut-myologie.org

Acta Neuropathologica
|January 20, 2009
PubMed

Insights

Myofibrillar myopathies (MFMs) primarily affect specific Z-disc proteins, not the entire myofibril. Distinct fiber changes like "rubbed-out" fibers suggest desmin or alphaB-crystallin involvement in these rare neuromuscular disorders.

Area of Science:

  • Neuromuscular Disorders
  • Muscle Biology
  • Genetic Diseases

Background:

  • Myofibrillar myopathies (MFMs) are a heterogeneous group of progressive neuromuscular disorders.
  • Understanding the specific protein defects in MFMs is crucial for diagnosis and treatment.
  • Genetic and histopathological variability complicates MFM classification.

Purpose of the Study:

  • To analyze histopathological and immunohistochemical features in genetically identified MFM patients.
  • To differentiate MFM subgroups based on morphological and protein localization data.
  • To identify specific protein alterations underlying different MFM types.

Main Methods:

  • Morphological and morphometrical analysis of muscle biopsies from 24 MFM patients.
  • Immunohistochemical study using antibodies against Z-disc and M-band proteins.
  • Genetic identification of patients with desmin, alphaB-crystallin, ZASP, and myotilin mutations.

Main Results:

  • 'Rubbed-out' fibers were characteristic of desminopathies and alphaB-crystallinopathies.
  • Vacuoles were frequent in ZASPopathies and myotilinopathies; necrosis seen in myotilinopathy.
  • Altered localization of specific Z-disc proteins (filamin C, myotilin, Xin) observed, while M-band proteins remained normal.

Conclusions:

  • 'Rubbed-out' fibers are a potential diagnostic marker for desminopathy or alphaB-crystallinopathy.
  • MFM pathogenesis involves specific stress-responsive Z-disc proteins, not a general myofibrillar defect.
  • Histopathological findings correlate with genetic subtypes, aiding in MFM characterization.

More Related Videos

Semi-automated Analysis of Mouse Skeletal Muscle Morphology and Fiber-type Composition08:36

Semi-automated Analysis of Mouse Skeletal Muscle Morphology and Fiber-type Composition

Published on: August 31, 2017

Related Concept Videos

The Sarcomere01:08

The Sarcomere

A sarcomere is a microscopic segment repeating in a myofibril. The sarcomere fundamentally consists of two main myofilaments: thick filaments called myosin and thin filaments called actin. These filaments interact by sliding past each other in response to stimulus. In addition to myosin and actin, several other proteins, such as tropomyosin, troponin, titin, nebulin, myomesin, α-actinin, and dystrophin, play crucial roles in regulating, structuring, and functioning of the sarcomere.
Each myosin...
Classification of Skeletal Muscle Fibers01:48

Classification of Skeletal Muscle Fibers

Skeletal muscles continuously produce ATP to provide the energy that enables muscle contractions. Skeletal muscle fibers can be categorized into three types based on differences in their contraction speed and how they produce ATP, as well as physical differences related to these factors. Most human muscles contain all three muscle fiber types, albeit in varying proportions.
Slow-Twitch Muscle Fibers
Slow oxidative, muscle fibers appear red due to large numbers of capillaries and high levels of...
Microscopic Anatomy of Skeletal Muscles01:13

Microscopic Anatomy of Skeletal Muscles

Skeletal muscle cells, also called muscle fibers, are distinctly elongated, multi-nucleated, slender biological units. They are packed with specialized structures designed to facilitate their primary function, which is contraction.
The muscle sarcolemma is a plasma membrane enclosing each muscle cell that conducts electrical signals called action potentials. The sarcolemma extends into the cell to form T-tubules, ensuring the neural impulses are uniformly distributed across the entire muscle...