Abstract:

The nemaline myopathies (NMs) are a clinically and genetically heterogeneous group of disorders characterized by nemaline rods and skeletal muscle weakness. Mutations in five sarcomeric thin filament genes have been identified. However, the molecular consequences of these mutations are unknown. Using Affymetrix oligonucleotide microarrays, we have analyzed the expression patterns of >21,000 genes and expressed sequence tags in skeletal muscles of 12 NM patients and 21 controls. Multiple complementary approaches were used for data analysis, including geometric fold analysis, two-tailed unequal variance t test, hierarchical clustering, relevance network, and nearest-neighbor analysis. We report the identification of high satellite cell populations in NM and the significant down-regulation of transcripts for key enzymes of glucose and glycogen metabolism as well as a possible regulator of fatty acid metabolism, UCP3. Interestingly, transcript level changes of multiple genes suggest possible changes in Ca(2+) homeostasis. The increased expression of multiple structural proteins was consistent with increased fibrosis. This comprehensive study of downstream molecular consequences of NM gene mutations provides insights in the cellular events leading to the NM phenotype.

Notes:

Sanoudou, DespinaHaslett, Judith NKho, Alvin TGuo, ShaoqiangGazda, Hanna TGreenberg, Steven ALidov, Hart G WKohane, Isaac SKunkel, Louis MBeggs, Alan HengP01 NS040828/NS/NINDS NIH HHS/R01 AR044345/AR/NIAMS NIH HHS/P01 NS40828/NS/NINDS NIH HHS/R01 AR44345/AR/NIAMS NIH HHS/Research Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.2003/04/05 05:00Proc Natl Acad Sci U S A. 2003 Apr 15;100(8):4666-71. doi: 10.1073/pnas.0330960100. Epub 2003 Apr 3.