You are seeing this message because your Web browser does not support basic Web standards. Find out more about why this message is appearing and what you can do to make your experience on this site better.


ABOUT ARCHIVES
Advanced Search

Welcome   | My Account | E-mail Alerts | Access Rights | Sign In


  Vol. 54 No. 12, December 1997 TABLE OF CONTENTS
  Archives
  •  Online Features
  ORIGINAL CONTRIBUTIONS
 This Article
 •References
 •Full text PDF
 • Reply to article
 •Send to a friend
 • Save in My Folder
 •Save to citation manager
 •Permissions
 Citing Articles
 •Citation map
 •Citing articles on HighWire
 •Contact me when this article is cited
 Related Content
 •Similar articles in this journal
 Social Bookmarking
  Add to CiteULike Add to Connotea Add to Del.icio.us Add to Digg Add to Reddit Add to Technorati Add to Twitter What's this?

Abnormal Expression of Laminin β1 Chain in Skeletal Muscle of Adult-Onset Limb-Girdle Muscular Dystrophy

Mian Li, MD, PhD; Dennis W. Dickson, MD; Alfred J. Spiro, MD

Arch Neurol. 1997;54(12):1457-1461.


Abstract

Background
Laminin 2 is a major component of the basal lamina of skeletal muscle cells. It is a heterotrimer composed of 3 chains: merosin (laminin {alpha}2 chain), β1, and {gamma}1. Deficiency of merosin, with or without laminin β1 chain reduction, is associated with some forms of congenital muscular dystrophy. Deficient expression of laminin β1 chain is also associated with some cases of merosin-positive congenital muscular dystrophy. The expression of laminin 2 subunits has not been well studied in the skeletal muscle of limb-girdle muscular dystrophy (LGMD), nor has much attention been given to the significance of reduction of individual laminin 2 subunits, such as β1.

Objectives
To examine the expression of laminin 2 subunits in skeletal muscle in patients with LGMD and to define the clinical features of patients with LGMD who have abnormal expression of laminin 2 subunits.

Methods
We studied muscle biopsy specimens from 18 patients with LGMD using immunofluorescence with antibodies against dystrophin C-terminus, β-dystroglycan, {alpha}-sarcoglycan, {gamma}-sarcoglycan, and the laminin subunits merosin, β1, and {gamma}1. Of the 18 biopsy specimens, 9 were available for electron microscopic examination of the muscle basement membrane. The clinical features associated with abnormal laminin β1 chain immunoreactivity were further described.

Results
Laminin β1 chain was either barely detectable or severely reduced in 3 cases of patients with LGMD in which the biopsy specimens showed normal staining with the other antibodies. Patients in all 3 cases had common clinical features consistent with a slowly progressive, adultonset LGMD. Specimens from 2 of the 3 cases that were available for ultrastructural examination showed significant abnormalities of the muscle fiber basement membrane.

Conclusions
Abnormal expression of laminin β1 chain without concomitant deficiency of {alpha}-sarcoglycan in skeletal muscle has not been previously described in LGMD. Reduced laminin β1 chain immunoreactivity may potentially serve as a marker for defining subsets of individuals with LGMD, in particular those with slowly progressive, adult-onset pelvifemoral presentation. The abnormality of muscle fiber basement membranes in specimens from cases that were available for ultrastructural study suggests that defects in the extracellular matrix may play a role in the pathogenesis of this subset of LGMD.



Author Affiliations

From the Departments of Neurology and Pathology, Albert Einstein College of Medicine, Bronx, NY.



Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter     What's this?

THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES

Novel mutations in collagen VI genes: Expansion of the Bethlem myopathy phenotype
Scacheri et al.
Neurology 2002;58:593-602.
ABSTRACT | FULL TEXT  

NEW PERSPECTIVES IN PEDIATRIC NEUROMUSCULAR DISORDERS Hotel Intercontinental Sydney, Sydney, Australia, August 28, 1998
North
J Child Neurol 1999;14:26-57.
 

Characterization of Monoclonal Antibodies to Calpain 3 and Protein Expression in Muscle from Patients with Limb-Girdle Muscular Dystrophy Type 2A
Anderson et al.
Am. J. Pathol. 1998;153:1169-1179.
ABSTRACT | FULL TEXT  





HOME | CURRENT ISSUE | PAST ISSUES | TOPIC COLLECTIONS | CME | SUBMIT | SUBSCRIBE | HELP
CONDITIONS OF USE | PRIVACY POLICY | CONTACT US | SITE MAP
 
© 1997 American Medical Association. All Rights Reserved.