The human myocardium harbours resident multi-potent cardiac progenitor cells (CPCs). We investigated the distribution, properties, differentiation potential and effect of LV function on CPCs in all chambers of the human heart.
Biopsies from all chambers of the heart from the same patient with good (EF>45; n=5) and impaired LV function (EF<45; n=5) was analysed for c-kitpos and MDR-1pos CPCs. CPCs were isolated using MACS from ten patients (Good and Impaired LV, n=5/group) and was characterised.
CPCs were identified in all chambers of the heart in both groups. The RA from good LV group had significantly (p<0.05) less c-kitpos (6± 0CPCs/mm2) and MDR-1pos CPCs (5± 1 CPCs/mm2). In the impaired LV group, the LV (38± 2 CPCs /mm2) had significantly more c-kitpos CPCs. Overall, the impaired LV group had significantly (p<0.05) more c-kitpos (32± 1CPCs /mm2) and MDR-1pos (47± 1 CPCs /mm2). Irrespective of LV function both c-kitpos and MDR-1pos CPCs were significantly higher (p<0.05) in ventricle than atria.
CPCs from the LV (80±2%) are significantly (p<0.05) more proliferative than RV (64±4%) and RA (64±6%) in good and impaired LV group, respectively. Regardless of LV function the atria and ventricle showed no difference in proliferation. Cardiosphereogenesis was significantly (p<0.05) higher in the good LV group. Irrespective of the LV function, cardiosphereogenesis, α-sarcomeric actin and calponin expression were significantly increased (p<0.05) in the LV chamber. In impaired LV group, the LV showed significant (p<0.05) expression for Nkx2.5. Overall, the cardiomyogenic and calponin expression were significantly (p<0.05) increased in impaired LV patients. The vWF expression was significantly (p<0.05) increased in LA and the atria of the good LV group.
In conclusion, there is a variation in the distribution, stem cell properties and differentiation potential of CPCs across all 4 chambers of the human heart. These variations are also affected by the LV function.