Figure 2

Conditioned medium of ADSC promotes proliferation rate of cardiomyocytes. Serum-free culturing reduced the proliferation rate of rat neonatal cardiomyocytes (A) and HL-1 murine cardiomyocytes (B) both under normoxic (21% oxygen) and hypoxic (2% oxygen) conditions compared to the serum control (10% FBS). This proliferation rate was not significantly influenced by treatment with TNF-α or IL-1β. Incubation of rnCM and HL-1 cardiomyocytes for 24h with serum-free conditioned media of human ADSC (n = 3 donors) pre-stimulated with TNF-α, IL-1β or none, restored the proliferation of HL-1 cardiomyocytes (p < 0.05). The stimulatory capacity of hypoxically preconditioned ADSC medium on the proliferation rate of rnCM and HL-1 cardiomyocytes under hypoxia was significantly larger than under normoxic conditions (p < 0.05). Proliferation was assessed by immunofluorescence detection of 6h incorporated BrdUrd and quantification with Tissue Gnostics Tissue FAXS equipment. C) Representative micrographs of immunofluorescence staining for BrdUrd of HL-1 cardiomyocytes in normal serum (10% FBS), serum-free or with serum-free ADSC conditioned medium after stimulation with IL-1β. Proliferation, i.e. BrdUrd incorporation – green, nuclei (DAPI) – blue. Graphs represent triplicates (with SEM) data from n = 3 independent experiments from 3 donors.