The Role Of FABP3 In The Inhibition Of Diastolic Calcium Removal

Objective: We have reported that FABP3 inhibits calcium re-uptake during diastolic relaxation in mouse ventricular myocytes.However,the detailed mechanism is still incompletely understood at the current stage.SR calcium pump SERCA is the major protein responsible for diastolic calcium re-uptake,the activity of SERCA could be regulated through multiple approaches.Protein binding could be a major mechanism.Addit ionally,it is already well known that PLB binds to SERCA,and PKA mediated phosphorylation of PLB is the major mechanism to dissociate PLB from SERCA and to cause the activation of SERCA.Therefore,th is project is designed to further explore how FABP3 regulates the activity of SERCA in cardiomyocytes.Methods: 1.Male C57BL/6 mice 12-14 weeks of age provided by Hebei Exp erimental Animal Center were used in this study? 2.Co-immunoprecipitation to study whether FABP3 binds to PLB? 3.Calcium imaging was used to study the dynamic changes of cal cium transients in mouse left ventricular cardiomyocytes? 4.Observe the measurement of myocardial cellular calcium transients under FABP3 dosing condition? 5.Immunofluorescence analysis of colocalization of FABP3 with SERCA? 6.Co-immunoprecipitation to detect the interaction of FABP3 with Drd1 in myocardial tissue? 7.Statistical analysis and related analysis,The data was represented by MEAN ± SE.SPSS 13.0software was used for statistical analysis.The test was significant at P < 0.05?Results: 1.FABP3 inhibits calcium re-uptake rate in mouse ventric ular myocytes;2.FABP3 promotes binding between PLB and SERCA;3.FABP3 has little effect on PKA phosphorylation of PLB,but signifi cantly alters PKA mediated phosphorylation of Ry R2;4.FABP3 has noeffect on PKA phosphorylation of PLB,but significantly alters PKA mediated phosphorylation of Ry R2;5.FABP3 can be immunoprecipitated with PLB;6.FABP3 interacts with Drd1?Conclusions: 1.FABP3 has no significant effect on PKA phosphorylation of PLB? 2.FABP3 can be immunoprecipitated with PLB,suggesting that bin ding of fabp3 to PLB may facilitate the binding between SERCA and PLB?...