Project description:BackgroundNonsense or loss-of-function mutations in the non-lysosomal cysteine protease calpain-3 result in limb-girdle muscular dystrophy type 2A (LGMD2A). While calpain-3 is implicated in muscle cell differentiation, sarcomere formation, and muscle cytoskeletal remodeling, the physiological basis for LGMD2A has remained elusive.MethodsCell growth, gene expression profiling, and mitochondrial content and function were analyzed using muscle and muscle cell cultures established from healthy and calpain-3-deficient mice. Calpain-3-deficient mice were also treated with PPAR-delta agonist (GW501516) to assess mitochondrial function and membrane repair. The unpaired t test was used to assess the significance of the differences observed between the two groups or treatments. ANOVAs were used to assess significance over time.ResultsWe find that calpain-3 deficiency causes mitochondrial dysfunction in the muscles and myoblasts. Calpain-3-deficient myoblasts showed increased proliferation, and their gene expression profile showed aberrant mitochondrial biogenesis. Myotube gene expression analysis further revealed altered lipid metabolism in calpain-3-deficient muscle. Mitochondrial defects were validated in vitro and in vivo. We used GW501516 to improve mitochondrial biogenesis in vivo in 7-month-old calpain-3-deficient mice. This treatment improved satellite cell activity as indicated by increased MyoD and Pax7 mRNA expression. It also decreased muscle fatigability and reduced serum creatine kinase levels. The decreased mitochondrial function also impaired sarcolemmal repair in the calpain-3-deficient skeletal muscle. Improving mitochondrial activity by acute pyruvate treatment improved sarcolemmal repair.ConclusionOur results provide evidence that calpain-3 deficiency in the skeletal muscle is associated with poor mitochondrial biogenesis and function resulting in poor sarcolemmal repair. Addressing this deficit by drugs that improve mitochondrial activity offers new therapeutic avenues for LGMD2A.
Project description:Transcriptional profiling of calpain-6-deficient murine bone marrow-derived macrophages comparing with calpain-6 wild-type macrophages. Total RNA was extracted from the pooled cells. Two-condition experiment, wild-type macrophages vs. calpain-6-deficiennt macrophages. The cells were derived from four mice, and were pooled for analysis.
Project description:Transcriptional profiling of calpain-6-deficient murine bone marrow-derived macrophages comparing with calpain-6 wild-type macrophages. Total RNA was extracted from the pooled cells.
Project description:Aim: To understand the role of DEK1 in Arabidopsis development. Background: DEK1 has an essential role during embryogenesis and is involved in the maintenance of the epidermis. Tissues: Comparison of wild-type and ADEK1 calpain-overexpressing line. 9 samples were used in this experiment.
Project description:Aim: To understand the role of DEK1 in Arabidopsis development. Background: DEK1 has an essential role during embryogenesis and is involved in the maintenance of the epidermis. Tissues: Comparison of wild-type and ADEK1 calpain-overexpressing line.