[The expression of SMN2 gene mRNA in neuron-like cells derived from patients with spinal muscular atrophy].
OBJECTIVE
To detect the difference of SMN2 mRNA expression between the neuron-like cells (NLCs) derived from patients with spinal muscular atrophy (SMA).


METHODS
Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed to diagnose the patients with SMA and the controls. Mesenchymal stem cells (MSCs) were induced into neuron-like cells which become the models of neurons. The transcripts of SMN2 were testified with RT-PCR combined with sequencing.


RESULTS
Two bands (266 bp and 212 bp) were found in the gel picture of RT-PCR and the band of 266 bp was the full length transcript (fl-SMN mRNA). The band of 212 bp was testified by sequencing to be deletion of the exon 7, which was the production of alternative splicing (skipping exon 7, SMNDelta7 mRNA). The expression of fl-SMN mRNA accounted for 23.2% of the total SMN mRNA in the SMA patients, being much lower than the rate in the controls (82.0%). In contrast, 76.8% of SMN gene transcripts was SMNDelta7 mRNA in the SMA patients, being much higher than the rate of 18% in the controls.


CONCLUSIONS
Alternative splicing exists in SMN2 gene transcription, that is, exon 7 is skipped during the processing of SMN2 mRNA in the NLCs of SMA patients, which is one of the reasons of the full-length SMN protein lacking.
Luo
Xin-ming
XM
Department of Neurology, Xiangya Hospital, Central South University, Changsha 410008, China.
Yang
Xiao-su
XS
Xiao
Bo
B
D000293:Adolescent; D002648:Child; D017362:Cyclic AMP Response Element-Binding Protein / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D009046:Motor Neurons / Q000378:metabolism; D009134:Muscular Atrophy, Spinal / Q000175:diagnosis* / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D016601:RNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055532:SMN Complex Proteins; D055540:Survival of Motor Neuron 2 Protein
D017362:Cyclic AMP Response Element-Binding Protein; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D055532:SMN Complex Proteins; C526477:SMN2 protein, human; D055540:Survival of Motor Neuron 2 Protein