Evidence map›Paper›PMID 42387635›Full record

ArticleSkeletal muscle2026

Regenerative Index: a method to assess muscle regeneration in patients with Duchenne muscular dystrophy.

Johnathan K Smid, Charis A McPherson, Jacob G Monast, Shanti S S Rayagiri, Steven A Moore, Michael A Rudnicki

Abstract read
In one paragraph

Article in Skeletal muscle, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

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No citing paper in PubMed yet.

4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

6 authors.

Johnathan K SmidSprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Canada.
Charis A McPhersonSprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Canada.
Jacob G MonastSprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Canada.
Shanti S S RayagiriSprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Canada.
Steven A MooreDepartment of Pathology, Carver College of Medicine, University of Iowa, Iowa City, USA.
Michael A RudnickiSprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Canada. mrudnicki@ohri.ca.ORCID https://orcid.org/0000-0002-3866-5249

Funding

Muscular Dystrophy Specialized Research Center: Project 2P50NS053672 · NINDS · UNIVERSITY OF IOWA · PI KEVIN P. CAMPBELL · 2020 to 2026
$11.9M
NINDS NIH HHS P50 NS053672NINDS NIH HHS P50NS053672
6 · The paper itself

Abstract

backgroundDuchenne muscular dystrophy (DMD) is a devastating disease manifested in skeletal muscle by repetitious myonecrosis and regeneration. Because the regenerative process is closely linked to the cumulative severity of muscle damage, which is variably distributed within and between muscle groups, accurately quantifying muscle regeneration has remained a significant challenge.

methodsMyofibers are delineated by immunostaining for laminin, and subsequent image analysis employed to generate a masked outline precisely within each myofiber boundary. Morphometric parameters including minimal Feret's diameter, cross-sectional area, and circularity were measured for each myofiber. In addition, the number of Pax7-expressing satellite cells were quantified. To evaluate regenerative activity, newly formed myofibers were identified by immunostaining for expression of embryonic myosin heavy chain (eMHC). Necrotic myofibers were enumerated by immunofluorescent detection of immunoglobulin G (IgG) infiltration. The Regenerative Index (RI) was calculated as the number of regenerating (eMHC

resultsA trend toward an increasing minimal Feret's diameter, cross-sectional area and circularity was observed with increasing age in DMD boys, with circularity showing the strongest trend. Furthermore, compared to DMD boys 7- to 8-years old, the boys 9- to 11-years old had increased myofiber circularity. Pax7-expressing cells per myofiber were elevated in DMD boys compared to control boys of similar ages, without any observation of age-related changes. The Regenerative Index in DMD boys exhibited a decline between 7 and 11 years of age, with an inverse correlation between RI and age.

conclusionsThe use of eMHC and IgG immunostaining to calculate RI appears to provide a way to assess regeneration across biopsies that differ in histopathologic severity. Using this approach, RI showed a negative correlation with age in DMD boys aged 7 to 11 years which requires further investigation.

Indexed as

Muscle Fibers, SkeletalMuscle, SkeletalMuscular Dystrophy, DuchenneRegenerationAdolescentBiopsyChildHumansMaleMyosin Heavy ChainsNecrosisPAX7 Transcription FactorSatellite Cells, Skeletal MuscleMyosin Heavy ChainsPAX7 protein, humanPAX7 Transcription FactorDuchenne muscular dystrophy (DMD)DystrophinEmbryonic myosin heavy chain (eMHC)Muscle regenerationNecrotic myofibersRegenerating myofibersRegenerative Index (RI)

Identifiers

PMID42387635
PMCPMC13584490

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.