PubMed Health⌕ Search

PubMed · 11037185

Muscular dystrophy.

Abstract

Muscular dystrophy is a group of genetically determined muscular disorders marked by progressive wasting and weakness of the skeletal muscle, but which often affect cardiac and smooth muscles or other tissues. The patterns of inheritance are either dominant or recessive although the gene may be defective because of a new mutation. Growing evidence revealed the marked heterogeneity of the muscle disorders, and considerable numbers of Japanese scientists and physicians have contributed to the research progress in muscular dystrophy. Among these the discovery of an increased serum creatine kinase activity in muscular dystrophy opened the way for the most reliable laboratory test for muscular dystrophy in 1959, and subsequently accelerated progress in a broad range of research areas in medicine. Progress in modern genetics and molecular pathology provided another breakthrough in muscular dystrophy research and, in 1987, dystrophin was identified, a deficiency of which causes DMD. The present review article highlights contributions of Japanese scientists to muscular dystrophy research.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

K Arahata. 2000. Muscular dystrophy.. https://doi.org/10.1046/j.1440-1789.2000.00321.x

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Calpain II colocalizes with detergent-insoluble rafts on human and Jurkat T-cells.

Calpain, a calcium-dependent cysteine protease, is known to associate with the T-cell plasma membrane and subsequently cleave a number of cytoskeletal-associated proteins. In this study, we report the novel observation that calpain II, but not calpain I, associates with membrane lipid rafts on human peripheral blood T-cells and Jurkat cells. Raft-associated calpain activity is enhanced with exogenous calcium and inhibited with calpeptin, a specific inhibitor of calpain activity. In addition, we demonstrate that calpain cleaves the cytoskeletal-associated protein, talin, during the first 30-min after cell stimulation. We propose that lipid raft associated-calpain II could function in early TCR signaling to facilitate immune synapse formation through cytoskeletal remodeling mechanisms. Hence, we demonstrate that the positioning of calpain II within T-cell lipid rafts strategically places it in close proximity to known calpain substrates that are cleaved during Ag-specific T-cell signaling and immune synapse formation.

Calpain↗

Motility is rate-limiting for invasion of bladder carcinoma cell lines.

Induced migration of tumor cells is generally considered to be one critical step in cancer progression to the invasive and metastatic stage. The implicit caveat of studies that show this is that other, unknown, signaling pathways and biophysical events are actually the operative rate-limiting steps, and not motility per se. Thus, to examine the hypothesis that motility is a single, but overall rate-limiting function required for invasion, disparate motility processes need be blocked with concordant effects on tumor invasion. Recently, we and others have described two signaling pathways that are critical to growth factor-induced motility but not mitogenesis. The key molecular switches are phospholipase C-gamma (PLCgamma) and calpain for cytoskeletal reorganization and rear detachment, respectively. We examined this hypothesis in a highly invasive tumor, bladder carcinoma. Three different human tumor cell lines, 253J-B-V, UMUC and T-24, were tested for invasiveness in vitro by transmigration of a Matrigel barrier. Inhibiting PLCgamma with the pharmacologic agent U73122 or the molecular dominant-negative PLCz construct reduced both invasiveness and motility. The same was noted when calpain was blocked using calpain inhibitor I (ALLN). These results demonstrate that one interventional target for limiting invasion is not necessarily an individual motility pathway but rather cell migration per se.

Calpain↗

Protein degradation during aging: the lysosome-, the calpain- and the proteasome-dependent cellular proteolytic systems.

Aging is a natural process determined by both genetic and environmental factors. Aging is accompanied by the imbalance of the function of several cellular homeostatic mechanisms, which results, among others, in the accumulation of abnormal (i.e. oxidized, cross-linked, unfolded) proteins. It has been proposed that the increased failure of homeostasis during aging is due to the impaired function of the major cellular proteolytic mechanisms mediated by the lysosome, the calpains and the proteasome. This article will address the issue of the function of these cellular proteolytic systems during aging.

Calpain↗