Figure 2

Transplantation of MSC-ERBB4 reduced fibrosis and improved heart function. Heart function was measured using a pressure-volume conductance catheter system 4 weeks after injection of NRG1, MSCe or MSC-ERBB4. (a) Representative single PV-loop recording images are shown. MI resulted in a rightward shift in the loop, which increased the volume and depression of the ESPVR slope (aii versus ai, red line). MSC-ERBB4 but not MSCe (av versus aiv) or NRG1(av versus aiii) reduced the volume and restored the original slope of the ESPVR. (b) Enhanced peak velocities of pressure change (dp/dt) occurred during isovolumic contraction (+dp/dt) and isovolumic relaxation (−dp/dt) in mice injected with MSC-ERBB4. (c) ERBB4 overexpression reduced scar formation following MI. Masson’s trichrome staining indicated the thinning and expansion of the infarct scar (blue color) in the MI group (cii versus ci) and was attenuated in the MSC and NRG1 treated groups at 4 weeks post-MI (ciii, civ and cv). Representative photomicrographs for each group are shown. (d) Quantification of fibrotic area presented as the percentage of LV area positively stained with Masson trichrome. (e) Quantification of LV wall thickness. MSC-ERBB4 transplantation resulted in smaller infarct zone within the total LV area compared with that in the MI, MI+NRG1 and MI+MSCe groups and increased infarct wall thickness. LV, left ventricular; ESPVR, end-systolic pressure-volume relationship. n=12 for each group