Mutations in the microrchidia CW-type zinc finger protein 2(MORC2)gene are the causative agent of Charcot-Marie-Tooth disease type 2Z(CMT2Z),and the hotspot mutation p.S87L is associated with a more seve re spinal mus...Mutations in the microrchidia CW-type zinc finger protein 2(MORC2)gene are the causative agent of Charcot-Marie-Tooth disease type 2Z(CMT2Z),and the hotspot mutation p.S87L is associated with a more seve re spinal muscular atrophy-like clinical phenotype.The aims of this study were to determine the mechanism of the severe phenotype caused by the MORC2 p.S87L mutation and to explore potential treatment strategies.Epithelial cells were isolated from urine samples from a spinal muscular atrophy(SMA)-like patient[MORC2 p.S87L),a CMT2Z patient[MORC2 p.Q400R),and a healthy control and induced to generate pluripotent stem cells,which were then differentiated into motor neuron precursor cells.Next-generation RNA sequencing followed by KEGG pathway enrichment analysis revealed that differentially expressed genes involved in the PI3K/Akt and MAP K/ERK signaling pathways were enriched in the p.S87L SMA-like patient group and were significantly downregulated in induced pluripotent stem cells.Reduced proliferation was observed in the induced pluripotent stem cells and motor neuron precursor cells derived from the p.S87L SMA-like patient group compared with the CMT2Z patient group and the healthy control.G0/G1 phase cell cycle arrest was observed in induced pluripotent stem cells derived from the p.S87L SMA-like patient.MORC2 p.S87Lspecific antisense oligonucleotides(p.S87L-ASO-targeting)showed significant efficacy in improving cell prolife ration and activating the PI3K/Akt and MAP K/ERK pathways in induced pluripotent stem cells.Howeve r,p.S87L-ASO-ta rgeting did not rescue prolife ration of motor neuron precursor cells.These findings suggest that downregulation of the PI3K/Akt and MAP K/ERK signaling pathways leading to reduced cell proliferation and G0/G1 phase cell cycle arrest in induced pluripotent stem cells might be the underlying mechanism of the severe p.S87L SMA-like phenotype.p.S87L-ASO-targeting treatment can alleviate disordered cell proliferation in the early stage of pluripotent stem cell induction.展开更多
To the Editor:Charcot–Marie–Tooth disease type 2A(CMT2A),caused by mutations in Mitofusin-2(MFN2),is the most common form of axonal CMT,accounting for 20–30%of CMT2.[1,2]CMT2A exhibits clinical and genetic heteroge...To the Editor:Charcot–Marie–Tooth disease type 2A(CMT2A),caused by mutations in Mitofusin-2(MFN2),is the most common form of axonal CMT,accounting for 20–30%of CMT2.[1,2]CMT2A exhibits clinical and genetic heterogeneity,with most disease-causing mutations located within the conserved guanosine triphosphatase(GTPase)domains.[3]Intra-familial variability within the family has been observed.Consequently,comprehensive genotype–phenotype studies of CMT2A,particularly in large cohorts,are essential for advancing the understanding of CMT.展开更多
基金supported by the National Natural Science Foundation of China,Nos.82171172(to RZ)and 81771366(to RZ)Fundamental Research Funds for the Central Universities of Central South University,Nos.2021zzts1095(to SZ)and 2022zzts0832(to HY)。
文摘Mutations in the microrchidia CW-type zinc finger protein 2(MORC2)gene are the causative agent of Charcot-Marie-Tooth disease type 2Z(CMT2Z),and the hotspot mutation p.S87L is associated with a more seve re spinal muscular atrophy-like clinical phenotype.The aims of this study were to determine the mechanism of the severe phenotype caused by the MORC2 p.S87L mutation and to explore potential treatment strategies.Epithelial cells were isolated from urine samples from a spinal muscular atrophy(SMA)-like patient[MORC2 p.S87L),a CMT2Z patient[MORC2 p.Q400R),and a healthy control and induced to generate pluripotent stem cells,which were then differentiated into motor neuron precursor cells.Next-generation RNA sequencing followed by KEGG pathway enrichment analysis revealed that differentially expressed genes involved in the PI3K/Akt and MAP K/ERK signaling pathways were enriched in the p.S87L SMA-like patient group and were significantly downregulated in induced pluripotent stem cells.Reduced proliferation was observed in the induced pluripotent stem cells and motor neuron precursor cells derived from the p.S87L SMA-like patient group compared with the CMT2Z patient group and the healthy control.G0/G1 phase cell cycle arrest was observed in induced pluripotent stem cells derived from the p.S87L SMA-like patient.MORC2 p.S87Lspecific antisense oligonucleotides(p.S87L-ASO-targeting)showed significant efficacy in improving cell prolife ration and activating the PI3K/Akt and MAP K/ERK pathways in induced pluripotent stem cells.Howeve r,p.S87L-ASO-ta rgeting did not rescue prolife ration of motor neuron precursor cells.These findings suggest that downregulation of the PI3K/Akt and MAP K/ERK signaling pathways leading to reduced cell proliferation and G0/G1 phase cell cycle arrest in induced pluripotent stem cells might be the underlying mechanism of the severe p.S87L SMA-like phenotype.p.S87L-ASO-targeting treatment can alleviate disordered cell proliferation in the early stage of pluripotent stem cell induction.
基金supported by the National Natural Science Foundation of China(Nos.81771366 and 82171172)the Hunan Provincial Natural Science Foundation(Nos.2022JJ30910 and 2025JJ60567).
文摘To the Editor:Charcot–Marie–Tooth disease type 2A(CMT2A),caused by mutations in Mitofusin-2(MFN2),is the most common form of axonal CMT,accounting for 20–30%of CMT2.[1,2]CMT2A exhibits clinical and genetic heterogeneity,with most disease-causing mutations located within the conserved guanosine triphosphatase(GTPase)domains.[3]Intra-familial variability within the family has been observed.Consequently,comprehensive genotype–phenotype studies of CMT2A,particularly in large cohorts,are essential for advancing the understanding of CMT.
