The results of the present study indicated that MSCs may be differentiated in vitro and in vivo into cells with characteristics commonly attributed to cardiomyocytes. Nesprin protein was detected in the nuclear membrane via immunofluorescence, and following MSC differentiation into cardiomyocyte‑like cells, the expression of nesprin protein was significantly higher (*P=0.03<0.05).
Cardiomyocyte‑like cells were positive for desmin, α‑sarcomeric actin and cTnI. Following differentiation, the MSCs appeared spindle‑shaped with irregular processes and were positive for CD90 and CD29, but negative for CD45. The expression of nesprin‑1 protein in MSCs was identified by immunofluorescence and western blot analysis, prior to and following MSC differentiation. The messenger RNA expression levels of cardiac‑myogenic specific genes desmin, α‑actinin and cardiac troponin I (cTnI) were detected by reverse transcription quantitative polymerase chain reaction. Characteristics of the putative cardiac‑myogenic cells were evaluated using immunohistochemical and immunofluorescent analysis.
Two weeks following myocardial infarction, DAPI‑marked MSCs were injected into the infarcted region in the experimental group, while DMEM was injected into the infarcted region of the control group. Sprague‑Dawley rats were anesthetized prior to thoracotomy and subsequent ligation of the left anterior descending coronary artery to establish a model of myocardial infarction. MSC differentiation was induced by treatment with 10 µmol/l 5‑azacytidine. Surface‑associated antigens of MSCs were detected by flow cytometry. The aim of the present study was to investigate the expression of nesprin‑1 protein in MSCs and its effects on the differentiation of rat bone‑marrow mesenchymal stem cells (MSCs).