Permanent myopathy caused by mutation of SCN4A Metl592Val: Observation on myogenesis in vitro and on effect of basic fibroblast growth factor on the muscle.
OBJECTIVE
The present study is to observe in vitro the proliferation ability of the muscle cells from permanent myopathy (PM) patients of nomokalaemic periodic paralysis (normKPP), which is caused by mutations of Met1592Val in the skeletal muscle voltage gated sodium channel (SCN4A) gene on chromosome 17q23.1. We also evaluate the possible effect of the foreign basic fibroblast growth factor (bFGF) in preventing and curing PM.


METHODS
The gastrocnemius muscle cells were taken from two male patients with PM of the same Chinese family with Met1592Val mutation of SCN4A, determined by gene screening. Four male patients suffering from the skeletal injury without PM were taken as control. All preparations were protogenerationally cultured in vitro. Proliferation of the cultured preparations was measured by MTT. Activities of the lactic dehydrogenase (LDH), creatine kinase (CK), and protein content in these cells were also detected. The effects of bFGF with different doses (10 ng/mL, 20 ng/mL, 40 ng/mL, 80 ng/mL, 120 ng/mL and 160 ng/mL) on the above mentioned parameters were also evaluated.


RESULTS
Cells from both PM and control subjects were successfully cultured in vitro. The cultivation of the muscle cells from PM patients in vitro was not yet seen. Results indicated the obvious stimulation of bFGF on cell proliferation, activities of LDH and CK, protein synthesis, in a dose dependent manner. The optimal dose of bFGF was 120 ng/mL (P<0.05), beyond which greater dose caused a less effect. The effect of bFGF on 160 ng /mL was stronger than that on 80 ng/mL, but there was no significant difference (P>0.05).


CONCLUSIONS
Myoblastic cells from patients with PM had a weaker ability of developing into the myotubules, thus they were unable to perform effective regeneration, which resulted in a progressive necrosis. The exogenous bFGF could promote the division and proliferation of the muscle cells in vitro. These results shield a light on bFGFos potential role in preventing and treating PM.
Feng
Yu
Y
Department of Neurology, First Affiliated Hospital of China Medical University, Shenyang 110001, China.
Wang
Hong
H
Luo
Xiao-Guang
XG
Ren
Yan
Y
D000328:Adult; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D003402:Creatine Kinase / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D008715:Methionine / Q000235:genetics; D008875:Middle Aged; D024510:Muscle Development / Q000235:genetics / Q000502:physiology*; D009135:Muscular Diseases / Q000235:genetics* / Q000473:pathology*; D009154:Mutation / Q000235:genetics; D032446:Myoblasts / Q000187:drug effects*; D062553:NAV1.4 Voltage-Gated Sodium Channel; D015222:Sodium Channels / Q000235:genetics*; D014633:Valine / Q000235:genetics
D062553:NAV1.4 Voltage-Gated Sodium Channel; C106251:SCN4A protein, human; D015222:Sodium Channels; D016222:Fibroblast Growth Factor 2; D008715:Methionine; D007770:L-Lactate Dehydrogenase; D003402:Creatine Kinase; D014633:Valine