BACKGROUND: Recent genetic analyses have shown that Miyoshi myopathy (MM) is caused by a mutation in the DYSF, which induces the dysfunction of dysferlin. We identified the deficiency of dysferlin by immunohistochemistry and Western blot in four patients with clinically diagnosed MM, and investigated the clinical and pathological characteristics of MM. METHODS: A muscle biopsy was performed in four patients who were diagnosed with MM by clinical and electrophysiological study. Immunostaining of muscle specimens for dyferlin, dystrophin, alpha, beta, gamma, sigma-sarcoglycan, beta-dystroglycan, and caveolin-3 were performed in all four patients. We analyzed the quantitative analysis for dysferlin by Western blot in three of four patients. RESULTS: All four patients showed clinical onset during adolescence or early adulthood (15-26 year old), a slowly progressive course, and a relatively high serum creatine kinase level (2240-6400 IU/L). Routine pathological studies showed non-specific myopathic changes. On immunocytochemistry, there was negative immunoreacticity for dysferlin on muscle specimens in all patients. The immunoreactivities for dystrophin, alpha, beta, gamma, sigma-sarcoglycan, beta-dystroglycan, and caveolin-3 were normal. On Western blotting, complete loss of dysferlin was noted in all three patients with MM CONCLUSIONS: Identification of isolated deficiency of dysferlin on immunocytochemistry or Western blot is important for the confirmative diagnosis of MM.
Adolescent ; Biopsy ; Blotting, Western* ; Caveolin 3 ; Creatine Kinase ; Diagnosis ; Dystroglycans ; Dystrophin ; Humans ; Immunohistochemistry ; Muscular Diseases*

OBJECTIVETo analyze clinical features and genetic mutations in a Chinese family affected with autosomal dominant caveolinopathies.

METHODSClinical data of the proband and her family members were collected. Genomic DNA was extracted from peripheral blood samples with a standard procedure. Next generation sequencing was carried out for the proband, and direct sequencing was employed to detect potential mutation of the CAV gene.

RESULTSThe proband presented with slowly progressing distal muscle weakness and atrophy, especially distal upper limbs and muscular soreness during early childhood, with her CK level moderately elevated and EMG showing myogenic and neurogenic injuries. Her sisters presented mild symptoms with hand muscle atrophy and fasciculation after exercise. A heterozygous missense mutation c.80G>A (p.Arg27Gln), which was reported as being pathogenic, was identified in the CAV3 gene in the proband and her sisters.

CONCLUSIONA heterozygous c.80G>A (p.Arg27Gln) mutation in the CAV3 gene probably underlies the autosomal dominant caveolinopathies in this Chinese family.

Caveolin 3 ; genetics ; Female ; High-Throughput Nucleotide Sequencing ; Humans ; Middle Aged ; Muscular Dystrophies ; genetics ; Mutation

Caveolin 3 ; genetics ; Diagnosis, Differential ; Humans ; Muscular Diseases ; diagnosis ; genetics ; therapy ; Prognosis

OBJECTIVE: To exhibit the caveolin-3 immunoreactivities (IRs) in the peripheral nerve, which was previously known to be present only within the muscle and to be a causative agent of myopathy METHOD: The sciatic nerves of the rat were removed after the perfusion and frozen after cryoprotection by sucrose. The tissue specimens were cut on cryostat and immunostained with anti-caveolin-3 and growth associated protein-43 (GAP-43) antibodies. The sections were observed with a fluorescence microscope. RESULTS: We detected caveolin-3 IRs in myelin sheath of the peripheral nerves, while GAP IRs were detected in the axon. Caveolin-3 IRs were active in the rat of postnatal 1 week, but they were reduced in the rat of postnatal 3 week and disappeared in that of 5 week. CONCLUSION: We detected caveolin-3 IRs in the myelin sheath of peripheral nerve. Caveolin-3 might play roles in the early myelination of peripheral nerve.
Animals ; Antibodies ; Axons ; Caveolin 3* ; Fluorescence ; Immunohistochemistry ; Muscular Diseases ; Myelin Sheath* ; Perfusion ; Peripheral Nerves* ; Rats ; Regeneration ; Sciatic Nerve ; Sucrose

We investigated the effect of phenylephrine (PE)- and isoproterenol (ISO)-induced cardiac hypertrophy on subcellular localization and expression of caveolin-3 and STAT3 in H9c2 cardiomyoblast cells. Caveolin-3 localization to plasma membrane was attenuated and localization of caveolin-3 to caveolae in the plasma membrane was 24.3% reduced by the catecholamine-induced hypertrophy. STAT3 and phospho-STAT3 were up-regulated but verapamil and cyclosporin A synergistically decreased the STAT3 and phospho-STAT3 levels in PE- and ISO-induced hypertrophic cells. Both expression and activation of STAT3 were increased in the nucleus by the hypertrophy. Immunofluorescence analysis revealed that the catecholamine-induced hypertrophy promoted nuclear localization of pY705-STAT3. Of interest, phosphorylation of pS727-STAT3 in mitochondria was significantly reduced by catecholamine-induced hypertrophy. In addition, mitochondrial complexes II and III were greatly down-regulated in the hypertrophic cells. Our data suggest that the alterations in nuclear and mitochondrial activation of STAT3 and caveolae localization of caveolin-3 are related to the development of the catecholamine-induced cardiac hypertrophy.
Animals ; Catecholamines/*pharmacology ; Caveolae/*metabolism ; Caveolin 3/*metabolism ; Cell Line ; Hypertrophy/metabolism ; Mitochondria/*metabolism ; Myocardium/cytology/*pathology ; Myocytes, Cardiac/cytology/*drug effects/metabolism ; Rats ; STAT3 Transcription Factor/*metabolism

Exercise training can improve strength and lead to adaptations in the skeletal muscle and nervous systems. Skeletal muscles can develop into two types: fast and slow, depending on the expression pattern of myosin heavy chain (MHC) isoforms. Previous studies reported that exercise altered the distribution of muscle fiber types. It is not currently known what changes in the expression of caveolins and types of muscle fiber occur in response to the intensity of exercise. This study determined the changes in expression of caveolins and MHC type after forced exercise in muscular and non-muscular tissues in rats. A control (Con) group to which forced exercise was not applied and an exercise (Ex) group to which forced exercise was applied. Forced exercise, using a treadmill, was introduced at a speed of 25 m/min for 30 min, 3 times/day (07:00, 15:00, 23:00). Homogenized tissues were applied to extract of total RNA for further gene analysis. The expression of caveolin-3 and MHC2a in the gastrocnemius muscle of female rats significantly increased in the Ex group compared with the Con group (P<0.05). Furthermore, in the gastrocnemius muscle of male rats, the expression of MHC2x was significantly different between the two groups (P<0.05). There was an increased expression in caveolin-3 and a slightly decreased expression in TGFbeta-1 in muscular tissues implicating caveolin-3 influences the expression of MHC isoforms and TGFbeta-1 expression. Eventually, it implicates that caveolin-3 has positive regulatory function in muscle atrophy induced by neural dysfunction with spinal cord injury or stroke.
Animals ; Caveolin 3 ; Caveolins ; Female ; Humans ; Male ; Muscle, Skeletal ; Muscles ; Muscular Atrophy ; Myosin Heavy Chains ; Myosins ; Nervous System ; Protein Isoforms ; Rats ; RNA ; Spinal Cord Injuries ; Stroke

OBJECTIVE: Caveolae are the microdomain of the plasma membrane that have been implicated in signal transduction and caveolin is a principal component of the caveolae. Caveolin-3, a family of caveolin related protein, is expressed only in muscle tissue. Here we examined the expression of caveolin-3 in the course of myobalst differentiation and within the muscle tissue. METHOD: L6 cell, rat skeletal myoblast, was cultured in the low mitogen medium and caveolin-3 expression was observed both by immunocytochemistry and western blot analysis. Localization of caveolin-3 within the muscle tissue was investigated and compared to that of dystrophin. RESULTS: While caveolin-3 was not expressed in the proliferating myolast, caveolin-3 was expressed in the differentiated myoblast. Caveolin-3 and dystrophin were co-expressed in the membrane of muscle tissue and integrated density of caveolin-3 was elevated in the area of muscle injury. In the Duchenne muscular dystrophy, caveolin-3 was expressed in the membrane of muscle tissue, but dystrophin was not. CONCLUSION: Caveolin-3 was induced during the myobalst differentiation and its expression was increased during the muscle regeneration. Caveolin-3 was physically associated with dystrophin as a complex, but not absolutely required for the biogenesis of dystrophin complex.
Animals ; Organelle Biogenesis ; Blotting, Western ; Caveolae ; Caveolin 3* ; Cell Membrane ; Dystrophin ; Humans ; Immunohistochemistry ; Membranes ; Muscle Cells* ; Muscle, Skeletal ; Muscular Dystrophy, Duchenne ; Myoblasts ; Myoblasts, Skeletal ; Rats ; Regeneration ; Signal Transduction

It is well known that exercise can have beneficial effects on insulin resistance by activation of glucose transporter. Following up our previous report that caveolin-1 plays an important role in glucose uptake in L6 skeletal muscle cells, we examined whether exercise alters the expression of caveolin-1, and whether exercise-caused changes are muscle fiber and exercise type specific. Fifity week-old Sprague Dawley (SD) rats were trained to climb a ladder and treadmill for 8 weeks and their soleus muscles (SOL) and extensor digitorum longus muscles (EDL) were removed after the last bout of exercise and compared with those from non-exercised animals. We found that the expression of insulin related proteins and caveolins did not change in SOL muscles after exercise. However, in EDL muscles, the expression of insulin receptor beta (IRbeta) and glucose transporter-4 (GLUT-4) as well as phosphorylation of AKT and AMPK increased with resistance exercise but not with aerobic exercise. Also, caveolin-1 and caveolin-3 increased along with insulin related proteins only in EDL muscles by resistance exercise. These results suggest that upregulation of caveolin-1 in the skeletal muscle is fiber specific and exercise type specific, implicating the requirement of the specific mode of exercise to improve insulin sensitivity.
AMP-Activated Protein Kinases ; Animals ; Caveolin 1/*biosynthesis ; Caveolin 3/metabolism ; Female ; Glucose Transporter Type 4/biosynthesis ; Insulin/*physiology ; Multienzyme Complexes/metabolism ; Muscle Fibers, Skeletal/*metabolism ; Muscle, Skeletal/metabolism/*physiology ; Phosphorylation ; *Physical Conditioning, Animal ; Protein-Serine-Threonine Kinases/metabolism ; Proto-Oncogene Proteins c-akt/metabolism ; Rats ; Rats, Sprague-Dawley ; Receptor, Insulin/biosynthesis ; Up-Regulation

Porphyromonas gingivalis is one of the most important periodontal pathogens and has been to known to invade various types of cells, including endothelial cells. The present study investigated the mechanisms involved in the internalization of P. gingivalis in human umbilical vein endothelial cells (HUVEC). P. gingivalis internalization was reduced by clathrin and lipid raft inhibitors, as well as a siRNA knockdown of caveolin-1, a principal molecule of lipid raft-related caveolae. The internalization was also reduced by perturbation of actin rearrangement, while microtubule polymerization was not required. Furthermore, we found that Src kinases are critical for the internalization of P. gingivalis into HUVEC, while neither Rho family GTPases nor phosphatidylinositol 3-kinase are required. Taken together, this study indicated that P. gingivalis internalization into endothelial cells involves clathrin and lipid rafts and requires actin rearrangement associated with Src kinase activation.
Actins ; Caveolae ; Caveolin 1 ; Clathrin* ; Endothelial Cells* ; GTP Phosphohydrolases ; Human Umbilical Vein Endothelial Cells ; Humans ; Microtubules ; Phosphatidylinositol 3-Kinase ; Phosphotransferases ; Polymerization ; Polymers ; Porphyromonas gingivalis* ; RNA, Small Interfering ; src-Family Kinases

OBJECTIVETo investigate the role of caveolin-1 down-regulation in human hepatocyte proliferation in vitro.

METHODSThe expression vector psiRNA-CAV1 was constructed and transfected into Chang liver cells (CHL). The caveolin-1 down-regulated cell clones were selected by the antibiotic zeocin. The proliferation of the cell strain CAV7 was examined by MTT, in which untransfected CHL and HepG2 cells were set as controls. Expression of caveolin-1, Akt, Erk1/2, p-Akt and p-Erk1/2 in the transfected and control cells was detected by Western blot.

RESULTSAfter caveolin-1 expression was down-regulated by RNAi, CHL increased faster at first (24 h and 72 h, P<0.05; 96 h, P<0.01), but slower later. P-Akt and p-Erk1/2 expressions were down-regulated, indicating that the growth and proliferation related Akt and Erk1/2 pathways were inhibited after caveolin-1 down-regulation.

CONCLUSIONCaveolin-1 may play an important role in hepatocyte proliferation.

Caveolin 1 ; genetics ; metabolism ; Cell Line ; Cell Proliferation ; Down-Regulation ; Hepatocytes ; cytology ; Humans ; Phosphatidylinositol 3-Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; RNA Interference ; RNA, Small Interfering ; Signal Transduction ; Transfection