ABSTRACT
Bone marrow mesenchymal stem cells (BMSCs) have been shown to be multipotent cells that possess high self-replicating capacity.The purpose of our study was to investigate the feasibility of using enteric neuron-like cells obtained by in vitro induction and differentiated from rat BMSCs for the treatment of Hirschsprung's disease (HD).Glial cell-derived neurotrophic factor (GDNF) and neurotrophin-3 (NT-3) are neurotrophic factors that play important roles in neuronal development,differentiation,survival and function.Meanwhile,GDNF mutations are a major cause of HD.In this study,BMSCs were transfected with eukaryotic expression plasmids co-expressing GDNF and NT-3,and the transfected cells displayed neuron-like changes after differentiation induced by fetal gut culture medium (FGCM).Immunofluorescence assay showed positive expression of the neuronal marker NSE and the enteric neuronal markers PGP9.5,VIP and nNOS.Reverse transcription-polymerase chain reaction (RT-PCR) revealed the expression of GDNF and NT-3 in transfected BMSCs.The present study indicates that genetically modified BMSCs co-expressing GDNF and NT-3 are able to differentiate into enteric neuronal cells and express enteric nerve markers when induced by FGCM.This study provides an experimental basis for gene therapy to treat enteric nervous system-related disorders,such as HD.
ABSTRACT
This study examined the expression pattern of programmed cell death 5 (PDCD5) in cochlear hair cells and spiral ganglion neurons (SGNs) and its association with age-related hearing loss in mice.Sixty C57BL/6J (C57) mice at different ages were divided into four groups (3,6,9 or 12 months).PDCD5 expression was detected by using immunohistochemistry,real-time PCR and Western blot.Morphological change of the cochleae was also evaluated by using immunoassay.The results showed that the expression of PDCD5 had a gradual increase with ageing in both protein and RNA levels in C57 mice,as well as gradually increased apoptosis of cochlear hair cells and SGNs.In addition,we also found that caspase-3 activity was enhanced and its expression was enhanced with ageing.It is implied that overexpression of PDCD5 causes the increase in caspase-3 activity and the subsequent increase of apoptosis in cochlear hair cells and SGNs,and thereby plays a role in the pathogenesis of presbycusis.Thus,PDCD5 may be a new target site for the treatment and prevention of age-related hearing loss.