In the present study, we were to screen the specific microRNA (miRNA) of exercise-induced muscle damage (EIMD) and assess the EIMD-specific miRNAs-regulated target of sarcolemmal damage in rats. Twenty-four male Sprague-Dawley (SD) rats were randomly divided into 3 groups, which included sedentary (C), 24 h post-exercise (E24) and 48 h post-exercise (E48) groups. Rat EIMD model was established by an acute eccentric exercise, i.e., a downhill running treatment at -16º gradient. EIMD characteristics were verified by Evans blue dye staining, differentially expressed miRNAs were detected by microarray assay, EIMD-specific miRNAs expressions were further validated by real-time quantitative RT-PCR (RT-qPCR), and targets of the miRNAs were predicted based on mRNA expressions of associated proteins and related pathway core molecules of sarcolemmal damage. Two EIMD-specific expressed miRNAs, including miR-206-3p and miR-139-3p, were found in the study. There was a significantly negative correlation (P < 0.05) between miR-206-3p expression and dystrophin (r = -0.68), utrophin (r = -0.64), JNK (r = -0.62) or ERK1 (r = -0.68) respectively, but no correlation was found between miR-139-3p and these biomolecules. The results suggest that: i) the expression profile of miRNAs in rat is significantly affected by EIMD, ii) miR-206-3p and miR-139-3p are the EIMD-specific miRNAs, and iii) miR-206-3p may control sarcolemmal damage by regulating dystrophin, utrophin, JNK and ERK1.
Animals ; Dystrophin ; genetics ; MAP Kinase Kinase 4 ; genetics ; MAP Kinase Signaling System ; Male ; MicroRNAs ; genetics ; Physical Conditioning, Animal ; adverse effects ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Running ; Sarcolemma ; pathology ; Utrophin ; genetics

Cap myopathy is pathologically characterized by cap structures comprising well-demarcated areas under the sarcolemma and containing deranged myofibrils and scattered Z-disks. Clinically it presents with slowly progressive muscle weakness, myopathic face, and frequent respiratory insufficiency. Four genes have been reported to be associated with the disease: TPM2, TPM3, ACTA1, and NEB. Here we describe that a patient presenting with mild limb weakness with facial affection showed cap structures on muscle pathology and carried a heterozygous TPM3 mutation.
Extremities ; Humans ; Muscle Weakness ; Muscular Diseases* ; Mutation, Missense* ; Myofibrils ; Pathology ; Respiratory Insufficiency ; Sarcolemma ; Tropomyosin

OBJECTIVEOver the last few decades, diabetic cardiomyopathy has been identified as a significant contributor in cardiac morbidity. However, the mechanisms of diabetic cardiomyopathy have not been clarified.

METHODSIn the present study, a diabetic rat model was induced by the intraperitoneal injection of streptozotocin. The myocardial CD147 expression and extent of glycosylation, as well as thematrixmetalloproteinases(MMPs) expression and activity, were observed in the diabetic and synchronous rats.

RESULTSThe results showed that CD147 located on sarcolemma of cardiomyocytes. The myocardial CD147 expression and glycosylation were significantly increased in the diabetic rats as compared with the control. Expression of MMP-2 protein, MMP-2 and MMP-9 activity were also increased in left ventricular myocardium in the diabetic rats. Tamoxifen only inhibited the enhanced expression of myocardial CD147 in the diabetic rats, but not in synchronous control rats. Tamoxifen inhibited glycosylation of myocardial CD147 in both diabetic and control rats. The inhibition of tamoxifen on CD147 glycosylation was stronger than on the expression in the myocardium. The extent of myocardial CD147glycosylation was positively related toMMP-2 and MMP-9 activity. Tamoxifen induced an inhibition of myocardial MMP-2 and MMP-9 activity in the control and diabetic rats.

CONCLUSIONThese results indicate that myocardial CD147 expression, especially the extent of glycosylation, regulates MMP-2 and MMP-9 activity, then accelerates cardiac pathological remodeling inducing diabetic cardiomyopathy. Tamoxifen inhibits myocardial CD147 glycosylation and further depress the activity of MMPs. Therefore, tamoxifen may protect the diabetic rats against diabetic myocardium.

Animals ; Basigin ; metabolism ; Diabetes Mellitus, Experimental ; complications ; Diabetic Cardiomyopathies ; drug therapy ; Glycosylation ; Heart ; drug effects ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Myocardium ; metabolism ; Myocytes, Cardiac ; cytology ; Rats ; Sarcolemma ; metabolism ; Tamoxifen ; pharmacology

Previously, we reviewed biological evidence that mercury could induce autoimmunity and coronary arterial wall relaxation as observed in Kawasaki syndrome (KS) through its effects on calcium signaling, and that inositol 1,4,5-triphosphate 3-kinase C (ITPKC) susceptibility in KS would predispose patients to mercury by increasing Ca2+ release. Hg2+ sensitizes inositol 1,4,5-triphosphate (IP3) receptors at low doses, which release Ca2+ from intracellular stores in the sarcoplasmic reticulum, resulting in delayed, repetitive calcium influx. ITPKC prevents IP3 from triggering IP3 receptors to release calcium by converting IP3 to inositol 1,3,4,5-tetrakisphosphate. Defective IP3 phosphorylation resulting from reduced genetic expressions of ITPKC in KS would promote IP3, which increases Ca2+ release. Hg2+ increases catecholamine levels through the inhibition of S-adenosylmethionine and subsequently catechol-O-methyltransferase (COMT), while a single nucleotide polymorphism of the COMT gene (rs769224) was recently found to be significantly associated with the development of coronary artery lesions in KS. Accumulation of norepinephrine or epinephrine would potentiate Hg2+-induced calcium influx by increasing IP3 production and increasing the permeability of cardiac sarcolemma to Ca2+. Norepinephrine and epinephrine also promote the secretion of atrial natriuretic peptide, a potent vasodilator that suppresses the release of vasoconstrictors. Elevated catecholamine levels can induce hypertension and tachycardia, while increased arterial pressure and a rapid heart rate would promote arterial vasodilation and subsequent fatal thromboses, particularly in tandem. Genetic risk factors may explain why only a susceptible subset of children develops KS although mercury exposure from methylmercury in fish or thimerosal in pediatric vaccines is nearly ubiquitous. During the infantile acrodynia epidemic, only 1 in 500 children developed acrodynia whereas mercury exposure was very common due to the use of teething powders. This hypothesis mirrors the leading theory for KS in which a widespread infection only induces KS in susceptible children. Acrodynia can mimic the clinical picture of KS, leading to its inclusion in the differential diagnosis for KS. Catecholamine levels are often elevated in acrodynia and may also play a role in KS. We conclude that KS may be the acute febrile form of acrodynia.
Acrodynia ; Arterial Pressure ; Autoimmunity ; Calcium ; Calcium Signaling ; Catechol O-Methyltransferase ; Catecholamines ; Child ; Coronary Vessels ; Diagnosis, Differential ; Epinephrine ; Heart Rate ; Humans ; Hydrazines ; Hypertension ; Inositol ; Inositol 1,4,5-Trisphosphate ; Inositol 1,4,5-Trisphosphate Receptors ; Inositol Phosphates ; Mucocutaneous Lymph Node Syndrome ; Norepinephrine ; Permeability ; Phosphorylation ; Polymorphism, Single Nucleotide ; Powders ; Relaxation ; Risk Factors ; S-Adenosylmethionine ; Sarcolemma ; Sarcoplasmic Reticulum ; Tachycardia ; Thimerosal ; Thrombosis ; Tooth ; Tooth Eruption ; Vaccines ; Vasoconstrictor Agents ; Vasodilation

OBJECTIVETo evaluate the histopathological characteristics and clinical implication of sarcolemma tissue in prepubertal concealed penis.

METHODSAfter measurement of the penile length, 10 prepubertal children with congenital concealed penis underwent modified Devine's operation (treatment group), and another 10 normal prepubertal children received circumcision (control group). The anatomic features of the penile sarcolemma tissue was observed intraoperatively, and its fibrosis was evaluated by Masson trichrome staining.

RESULTSThe penile length of the treatment group was significantly shorter than that of the control group preoperatively ([1.49 +/- 0.17 ] cm vs [4.26 +/- 0.23 ] cm, P < 0.01). The degree of penile concealment was correlated with the distal point of the attachment of its sarcolemma fibrous tissue: the closer the distal attachment point was to the coronary ditch, the more serious was penile concealment. The proportion of the area of collagen fibers in the penile sarcolemma tissue was significantly higher in the treatment group than in the control ([65.6 +/- 6.9]% vs [37.1 +/- 4.7]%, P < 0.01).

CONCLUSIONSarcolemma fibrosis was obvious in congenital concealed penis, and the key to its management is drastic removal of all the fibrous sarcolemma tissue.

Child ; Circumcision, Male ; Fibrosis ; Humans ; Male ; Penis ; abnormalities ; pathology ; surgery ; Phimosis ; pathology ; surgery ; Sarcolemma ; pathology

To explore the changes and regulation mechanism of dystropin and desmin under muscle injury without mechanic stress, 40 male Sprague-Dawley rats were randomly divided into 5 groups, which included normoxia control and hypoxia groups for 1, 2, 4 and 7 d with 10% O2. Two rats from each group were examined for sarcolemma integrity using Evans blue dye (EBD) and EBD-positive fiber typing by metachromatic dye-ATPase method. The rest six rats from each group were analyzed for the changes of protein content and gene expression using Western blot, RT-PCR and fluorescence assays. The results showed that the EBD-positive muscle fibers, mainly type IIA and type IIB, appeared at 1 d after hypoxia exposure. Both the ratio of EBD-positive cell and the mean fluorescence density were significantly higher in hypoxia groups than those in control group (P<0.05). The contents of dystrophin and desmin fluctuated after hypoxia exposure, increased at 1 d, decreased at 2 d, increased dramatically again at 4 d, and returned to a normal level at 7 d. Consistently, the gene expression began to increase significantly after 2 d. The total activity of calpain was significantly higher in hypoxia groups at 1, 4 and 7 d. Significantly higher levels of HSP70 and HSP90 were also observed at 4 and 7 d, respectively (P<0.05). These results suggest that the mechanical stress is not the only cause of damage of sarcolemma membrane integrity. In contrast to eccentric contraction, hypoxia-induced muscle damage is not accompanied by the loss of dystrophin and desmin. The types of muscle fibers recruited by motor units and the activities of calpain may be important in hypoxia-induced damage of sarcolemma membrane integrity.
Animals ; Calpain ; metabolism ; Desmin ; metabolism ; Dystrophin ; metabolism ; Hypoxia ; metabolism ; physiopathology ; Male ; Muscle, Skeletal ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley ; Sarcolemma ; pathology

Effect of strophanthidin (Str) on intracellular calcium concentration ([Ca2+]i) was investigated on isolated ventricular myocytes of guinea pig. Single ventricular myocytes were obtained by enzymatic dissociation technique. Fluorescent signal of [Ca2+]i was detected with confocal microscopy after incubation of cardiomycytes in Tyrode' s solution with Fluo3-AM. The result showed that Str increased [Ca2+]i in a concentration-dependent manner. The ventricular myocytes began to round-up into a contracture state once the peak level of [Ca2+]i was achieved in the presence of Str (10 micromol L(- 1)), but remained no change in the presence of Str (1 and 100 nmol L(-1)). Tetrodotoxin (TTX), nisodipine, and high concentration of extracellular Ca2+ changed the response of cardiomycytes to Str (1 and 100 nmol L(-1)) , but had no obvious effects on the action of Str (10 micromol L(-1)). The elevation of [Ca2+]i caused by Str at all of the detected concentrations was partially antagonized by rynodine (10 micromol L(-1)) or the removal of Ca2+ from Tyrode's solution. In Na+, K+ -free Tyrode' s solution, the response of cardiomycytes in [Ca2+]i elevation to Str (10 micromol L(-1)) was attenuated, while remained no change to Str (1 and 100 nmol L(-1)). TTX, nisodipine, and high concentration of extracellular Ca2+ changed the response of cardiomycytes to Str at all of the detected concentrations in Na+, K+ -free Tyrode's solution. The study suggests that the elevation of [Ca2+]i by Str at the low (nomomolar) concentrations is partially mediated by the extracellular calcium influx through Ca2+ channel or a "slip mode conductance" of TTX sensitive Na+ channel. While the effect of Str at high (micromolar) concentrations was mainly due to the inhibition of Na+, K+ -ATPase. Directly triggering the release of intracellular Ca2+ from sarcoplasmic reticulum (SR) by Str may be also involved in the mechanism of [Ca2+]i elevation.
3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester ; pharmacology ; Aequorin ; pharmacology ; Animals ; Calcium ; metabolism ; Calcium Channel Blockers ; pharmacology ; Calcium Channels ; metabolism ; Fura-2 ; pharmacology ; supply & distribution ; Guinea Pigs ; Myocardium ; pathology ; Nifedipine ; pharmacology ; Ryanodine ; pharmacology ; Sarcolemma ; metabolism ; pathology ; Sarcoplasmic Reticulum ; drug effects ; metabolism ; Sodium-Calcium Exchanger ; Sodium-Potassium-Exchanging ATPase ; antagonists & inhibitors ; Strophanthidin ; pharmacology ; Tetrodotoxin ; pharmacology ; Thapsigargin ; pharmacology

Objective: To investigate the expression of toll-like receptor (TLR)-2, 4 and 9 in idiopathic inflammatory myopathies (IIMs). Methods: The expression of TLR-2, 4 and 9 was measured by real-time RT-PCR and immunohistochemical stain (IHS) from muscle tissues in patients with IIMs and controls. Results: The expression levels of TLR-2, 4 and 9 in IIMs were significantly higher than controls. TLR-2, 4 and 9 were mainly expressed on sarcolemma of muscle fibers, perimysial vascular endothelium and infiltrating inflammatory cells in dermatomyositis, whereas, they were mainly expressed on sarcolemma of muscle fibers, destructed muscle fibers, and enodmysial infiltrating inflammatory cells in polymyositis. Conclusion: TLR-2, 4 and 9 were highly expressed in muscle tissue of IIMs. These results suggest that TLR-2, 4 and 9 play a role in pathogenesis of IIMs.
Dermatomyositis ; Endothelium, Vascular ; Humans ; Myositis* ; Polymyositis ; Sarcolemma ; Toll-Like Receptors*

BACKGROUND: Dysferlin is a 230 kDa protein of the sarcolemma. This encoding gene is mutated in patients with dysferlinopathy (limb-girdle muscular dystrophy 2B and Miyoshi myopathy), which is characterized byan active muscle degeneration and regeneration process. Dysferlin is known to play an essential role in muscle signaling and muscle fiber repair. We studied the gene to define its functional role in muscle repair and differentiation in human skeletal muscle of the patients with myopathies and cultured human myoblast. METHODS: An immunohistochemical analysis of dysferlin and N-CAM in biopsied muscle tissue obtained from eleven patients with myopathies [six patients with Duchenne muscular dystrophy (DMD), two patients with dermatomyositis (DM), two patients with polymyositis (PM), and one patient with dysferlinopathy (MM)] and eight normal controls. Cultured human myoblast obtained from normal muscle tissue was also analyzed by the expression of dysferlin through immunocytochemical staining and western blot. RESULTS: The immunoreactivity of dysferlin was strongly expressed in regenerative muscle fibers of myopathies except dysferlinpathy, which was co-localization with N-CAM by double immunohistochemistry. By western blot analysis, the expression level of dysferlin was variable in myopathies compared to normal controls, but no expression in dyferlinopathy. The expression of dysferlin in myotubes was significantly increased compared to that in myoblast by immunostaining and western blot analysis. CONCLUSIONS: These results indicated that the expression of dysferlin increased in regenerative and degenerative muscle fibers and also increased in myoblast differentiation. Our study supports that dysferlin not only has a role in skeletal muscle development but also in regeneration/repair process.
Blotting, Western ; Dermatomyositis ; Humans ; Humans* ; Immunohistochemistry ; Muscle Fibers, Skeletal ; Muscle, Skeletal* ; Muscular Diseases* ; Muscular Dystrophies ; Muscular Dystrophy, Duchenne ; Myoblasts ; Polymyositis ; Regeneration ; Sarcolemma

To assess the changes of sarcolemma Na+/K+ ATPase (CMNKA) and sarcoplasmic reticulum membrane Ca2+ ATPase (SERCA) activities after stem cells transplantation in heart failure. Rabbit was used as heart failure model by intravenously injecting adriamycin. Autologous bone marrow mononuclear cells (BMCs), bone marrow mesenchymal stem cells (MSCs) or skeletal myoblasts (SMs) were introduced into coronary arteies through the root of aorta when two balloons occluding just above sinus of Valsalva. After 4 weeks, left ventricular ejection fraction (LVEF)was evaluated by echocardiography, and the activities of CMNKA and SERCA were measured by colorimeter. In BMCs (n=8)and MSCs (n=8) group, LVEF were significantly improved (P < 0.05). No significant improvement were seen in SMs group (n=6) compared to sham group (n=8). The CMNKA activity in all stem cells groups was significantly increased compared to sham group (P < 0.05). Meanwhile, in comparison with sham group, the incremental tendencies of SERCA activity were seen in stem cells groups. In conclusion, stem cells transplantation could increase the activities of CMNKA and SERCA in heart failure, a possible mechanism to improve heart function.
Animals ; Doxorubicin ; Female ; Heart Failure ; chemically induced ; enzymology ; therapy ; Male ; Myocardium ; enzymology ; Rabbits ; Random Allocation ; Sarcolemma ; enzymology ; Sarcoplasmic Reticulum Calcium-Transporting ATPases ; metabolism ; Sodium-Potassium-Exchanging ATPase ; metabolism ; Stem Cell Transplantation