ABSTRACT
BACKGROUND:Bone mesenchymal stem cells(BMSCs) can accelerate vascularization of myocardial cell,relieve myocardial remodeling,and improve heart function.However,whether its paracrine action can facilitate the differentiation of CD117+ cardiac stem cells(CSCs) by effecting transforming growth factor-? Ⅲ(TGF-? Ⅲ) receptor expression is still unknown.OBJECTIVE:To study the influence of BMSCs on the expression of TGF-? Ⅲ receptor in the process of differentiation of CD117+ CSCs.DESIGN,TIME AND SETTING:In vitro cytology contract observation.The experiment was performed at the Xinhua Hospital from February 2008 to February 2009.MATERIALS:Neonatal rats,weighing 5-8 g,were used to prepare CSCs.Sprague Dawley rats,4 weeks old,weighing 200-250 g,were prepared for BMSCs.METHODS:CD117+CSCs were obtained from neonatal rats by explant cultures and magnetic bead cell sorting.Immunohistochemical experiment was performed to identify specificity of CSCs.CD117+CSCs suspension were synchronization without serum for 24 hours,washed by PBS for 3 times,and then cultured with DMEM/F12,followed by inoculation into 6-well plate.The cells were divided into the control and co-culture groups.In the control group,CSCs were induced differentiation by cardiac spheres,and Transwell chamber were used in the co-culture group.MAIN OUTCOME MEASURES:The growth of CSCs was observed by inverted microscope.The changes of cardiac Troponin T(cTnT),connexin43,TGF-? Ⅲ receptor,smad2 and phospho-smad2 expressions were detected by western blot at days 1,3,5 and 7 after culture.RESULTS:①CSCs isolated by explants cultures and MACS expressed CD117,which grew in disperse with smaller body.② The expression of cTnT and connexin43 were significantly higher in the co-culture group than that of the control group at days 5 and 7(P