OBJECTIVE: Restless legs syndrome (RLS) is a highly heritable and common neurological sensorimotor disease disturbing sleep. The objective of study was to investigate significant gene for RLS by performing GWA and replication study in a Korean population. METHODS: We performed a GWA study for RLS symptom group (n=325) and non-RLS group (n=2,603) from the Korea Genome Epidemiology Study. We subsequently performed a replication study in RLS and normal controls (227 RLS and 229 controls) to confirm the present GWA study findings as well as previous GWA study results. RESULTS: In the initial GWA study of RLS, we observed an association of rs11645604 (OR=1.531, p=1.18×10−6) in MPHOSPH6 on chromosome 16q23.3, rs1918752 (OR=0.6582, p=1.93×10−6) and rs9390170 (OR=0.6778, p=7.67×10−6) in UTRN on chromosome 6q24. From the replication samples, we found rs9390170 in UTRN (p=0.036) and rs3923809 and rs9296249 in BTBD9 (p=0.045, p=0.046, respectively) were significantly associated with RLS. Moreover, we found the haplotype polymorphisms of rs9357271, rs3923809, and rs9296249 (overall p=5.69×10−18) in BTBD9 was associated with RLS. CONCLUSION: From our sequential GWA and replication study, we could hypothesize rs9390170 polymorphism in UTRN is a novel genetic marker for susceptibility to RLS. Regarding with utrophin, which is encoded by UTRN, is preferentially expressed in the neuromuscular synapse and myotendinous junctions, we speculate that utrophin is involved in RLS, particularly related to the neuromuscular aspects.
Epidemiology ; Genetic Markers ; Genome ; Genome-Wide Association Study* ; Haplotypes ; Korea ; Restless Legs Syndrome* ; Synapses ; Utrophin

OBJECTIVETo review the recent research progress in dystrophin-related muscular dystrophy includes X-linked hereditary Duchenne and Becker muscular dystrophies (DMD and BMD).

DATA SOURCESInformation included in this article was identified by searches of PUBMED and other online resources using the key terms DMD, dystrophin, mutations, animal models, pathophysiology, gene expression, stem cells, gene therapy, cell therapy, and pharmacological. Study selection Mainly original milestone articles and timely reviews written by major pioneer investigators of the field were selected.

RESULTSThe key issues related to the genetic basis and pathophysiological factors of the diseases were critically addressed. The availabilities and advantages of various animal models for the diseases were described. Major molecular and cellular therapeutic approaches were also discussed, many of which have indeed exhibited some success in pre-clinical studies but at the same time encountered a number of technical hurdles, including the efficient and systemic delivery of a functional gene and myogenic precursor/stem cells to repair genetic defects.

CONCLUSIONSFurther understanding of pathophysiological mechanisms at molecular levels and regenerative properties of myogenic precursor/stem cells will promote the development of multiple therapeutic strategies. The combined use of multiple strategies may represent the major challenge as well as the greatest hope for the therapy of these diseases in coming years.

Animals ; Disease Models, Animal ; Dystrophin ; genetics ; physiology ; Genetic Therapy ; methods ; Humans ; Models, Biological ; Muscular Dystrophies ; genetics ; physiopathology ; therapy ; Mutation ; genetics ; Utrophin ; therapeutic use

OBJECTIVETo investigate the differentiation of rat bone marrow mesenchymal stem cells (MSCs) into myocytes and their expression of dystrophin/utrophin after transplantation in mdx mice.

METHODSBrdU-labeled fifth-passage rat MSCs were transplanted in mdx mice with previous total body gamma irradiation (7 Gy). At 4, 8, 12 and 16 weeks after the transplantation, the mice were sacrificed to detect dystrophin/BrdU and utrophin expressions in the gastrocnemius muscle using immunofluorescence assay, RT-PCR and Western blotting. Five normal C57 BL/6 mice and 5 mdx mice served as the positive and negative controls, respectively.

RESULTSFour weeks after MSC transplantation, less than 1% of the muscle fibers of the mdx mice expressed dystrophin, which increased to 15% at 16 weeks. Donor-derived nuclei were detected in both single and clusters of dystrophin-positive fibers. Some BrdU-positive nuclei were centrally located, and some peripherally within myofibers. Utrophin expression decreased over time after transplantation.

CONCLUSIONThe myofibers of mdx mice with MSC transplantation express dystrophin, which is derived partially from the transplanted MSCs. Dystrophin expression from the transplanted MSCs partially inhibits the upregulation of utrophin in mdx mouse muscle, showing a complementary relation between them.

Animals ; Bone Marrow Cells ; cytology ; Cell Differentiation ; physiology ; Dystrophin ; genetics ; metabolism ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells ; cytology ; Mice ; Mice, Inbred C57BL ; Mice, Inbred mdx ; metabolism ; Muscle Fibers, Skeletal ; cytology ; metabolism ; Muscular Dystrophy, Animal ; metabolism ; therapy ; Rats ; Utrophin ; metabolism

OBJECTIVETo observe dystrophin and utrophin expression in muscle tissues of Duchenne muscular dystrophy (DMD) mouse model (dko mouse) after having been treated with bone marrow mesenchymal stem cells (MSC) transplantation.

METHODSThe fifth generation of MSCs, cultured in vitro, was transplanted into dko mice by tail vein. The fluorescent expression of dystrophin and utrophin in gastrocnemius muscle tissue of dko mouse was detected and the average optical density of positive fibers was calculated.

RESULTSMSCs that had been cultured for three generations had good homogeneousness and the immunological reaction after vein transplantation was low. There was an increasing tendency of dystrophin and utrophin fluorescent expression in sarcolemma of dko mouse within 5-20 weeks. Significant difference existed in fluorescent average optical density of positive fibers fifteen weeks before and after cell transplantation.

CONCLUSIONSMSC has strong plasticity both in vitro and in vivo. MSC has a trend to reach the injured muscle tissues and turn into muscle fibers, which express dystrophin and utrophin. There is some plerosis function for myatrophy of dko mouse by MSC transplantation.

Animals ; Bone Marrow Cells ; cytology ; Cytoskeletal Proteins ; biosynthesis ; Dystrophin ; biosynthesis ; Female ; Male ; Membrane Proteins ; biosynthesis ; Mesenchymal Stem Cell Transplantation ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Muscle, Skeletal ; metabolism ; Muscular Dystrophy, Duchenne ; metabolism ; surgery ; Rats ; Rats, Sprague-Dawley ; Utrophin

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

OBJECTIVEStudy the improvement of locomotive faculty of dystrophin/utropin gene double knock-out mice (dko mice) by transplanting bone marrow stem cells.

METHODSThe bone marrow stem cells of C57BL/6 mice (4- to 5-weeks age) were cultured in vitro for three days, before transplanted intravenously (1.0 x 10(7) for each) into 11 dko mice (7- to 8-weeks age). The dko mice were irridiated with 7Gy gamma-ray before transplantation. 8-9 weeks after transplantation, the locomotroy function, electromyography items and expression of dystrophin in transplanted mice and controls were observed.

RESULTS8-9 weeks after transplantation, the dropping times of hauling wire were 3.09 +/- 2.47, compared with that of the control dko mice(16.78 +/- 3.60), there are distinct differences. About electromyography items, the duration of active potential and amplitude of maxim contractions were (4.99 +/- 1.62) ms and(2872 +/- 1474.33) microV, compare with those of control dko mice(3.69 +/- 0.40) ms and(1210.0 +/- 551.0) microV, respectively, about 7% fibers of the muscle tissue of transplanted dko mice expressed dystrophin protein.

CONCLUSIONS8-9 weeks after transplanted with homology bone marrow stem cells, the locomotive function and electromyography items of transplanted dko mice were obviously improved, and about 7% muscle tissue fibers of the mice expressing dystrophin protein were observed. It suggested that there is an ideal prospect for DMD therapy with bone marrow stem cells transplantation.

Animals ; Cytoskeletal Proteins ; biosynthesis ; deficiency ; genetics ; Dystrophin ; deficiency ; genetics ; Hematopoietic Stem Cell Transplantation ; Membrane Proteins ; biosynthesis ; genetics ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Motor Activity ; Muscular Dystrophy, Duchenne ; physiopathology ; surgery ; Utrophin