Objective To investigate the effect of peptidyl arginine deiminase 4(PAD4)on the differentiation of mesenchymal stem cells isolated from oral bones(OMSC)and craniomaxillofacial development.Methods Immunofluorescence was used to detect the ex-pression of PAD4 in the mandibular of mice E13.5 embryo.A peptidyl arginine deiminase 4 knockout(PAD4-KO)mouse model was constructed.Craniomaxillofacial development was investigated by micro-CT.CCK-8 assay and Transwell assay were used to detect the OMSC proliferation ability and migration ability of PAD4-KO and wild type(WT)mouse.ALP staining was used to detect the changes in OMSC osteogenic differentiation ability.The expression of osteogenesis-related genes was detected by immunofluorescence and PCR assay.Results PAD4 was highly expressed in the mandibular tissue of mouse embryos at E13.5.On the cellular level,PAD4 was ex-pressed in the nucleus and mitochondria of OMSC.Compared to the WT mice,micro-CT showed that PAD4-KO mice had retrusive jaw and decreased mineralization.The proliferation and migration ability of OMSC in PAD4-KO mice were decreased.OMSCs lacking PAD4 had significantly decreased ALP staining level,and the expression levels of osteogenesis-related genes were decreased.In addition,it was found that PAD4 might affect OMSC mineralization by regulating Runx2 transcription.Conclusion PAD4 is expressed in the jaw during embryonic development.It might affect the embryonic development by regulating the proliferation and differentiation of OMSC,leading to craniomaxillofacial abnormalities

Objective To investigate the effect of peptidyl arginine deiminase 4(PAD4)on the differentiation of mesenchymal stem cells isolated from oral bones(OMSC)and craniomaxillofacial development.Methods Immunofluorescence was used to detect the ex-pression of PAD4 in the mandibular of mice E13.5 embryo.A peptidyl arginine deiminase 4 knockout(PAD4-KO)mouse model was constructed.Craniomaxillofacial development was investigated by micro-CT.CCK-8 assay and Transwell assay were used to detect the OMSC proliferation ability and migration ability of PAD4-KO and wild type(WT)mouse.ALP staining was used to detect the changes in OMSC osteogenic differentiation ability.The expression of osteogenesis-related genes was detected by immunofluorescence and PCR assay.Results PAD4 was highly expressed in the mandibular tissue of mouse embryos at E13.5.On the cellular level,PAD4 was ex-pressed in the nucleus and mitochondria of OMSC.Compared to the WT mice,micro-CT showed that PAD4-KO mice had retrusive jaw and decreased mineralization.The proliferation and migration ability of OMSC in PAD4-KO mice were decreased.OMSCs lacking PAD4 had significantly decreased ALP staining level,and the expression levels of osteogenesis-related genes were decreased.In addition,it was found that PAD4 might affect OMSC mineralization by regulating Runx2 transcription.Conclusion PAD4 is expressed in the jaw during embryonic development.It might affect the embryonic development by regulating the proliferation and differentiation of OMSC,leading to craniomaxillofacial abnormalities

Objective:To investigate the phenotype, genotype and clinical course of centronuclear myopathy(CNM) in children.Methods:Clinical data of patients with CNM in the Department of Pediatrics, Peking University First Hospital from October 2008 to December 2018 were collected.The clinical, pathological and genetic data of 9 children with CNM were retrospectively analyzed.The patients were followed up from 8 months to 8.6 years [(4.4±3.1) years].Results:(1)Clinical phenotype: there were 6 males and 3 females with onset age ranging from 1 d to 10 years.Generalized muscle weakness or motor retardation was the main complaint in 8 cases, while elevated muscle enzymes presented in 1 case.Varying degrees of skeletal muscle weakness were noted on examination in all patients, with facial muscle involvement in 4 cases.Six patients were followed up.No deterioration in motor function was noted, while 2 patients had improvement.There was no significant cardiac involvement in all 6 patients.Scoliosis occurred in 4 patients.Restrictive ventilator disorder developed in 2 out of the 5 patients who underwent pulmonary function tests.(2)Genotype: 8 out of 9 patients underwent gene test, confirmed gene diagnosis in 4 patients including: DNM2 gene (c.1856C>T, c.1893+ 1G>A was novel) de novo heterozygous mutation in 2 cases, RYR1 gene (c.2044C>G, c.6823G>A, both were novel) compound heterozygous mutation in 1 case, and TTN gene (c.107377+ 1G>A, c.2106_2107 insAAGCTGTA was novel) compound heterozygous mutation in 1 case. Conclusions:The course of centronuclear myopathy is relatively static, with more frequent involvement of facial muscles than myocardium.This study enriched the gene mutation spectrum of centronuclear myopathy (4 novel mutations).