Fig. 3.

HIF-1α-EVs exhibited an anti-apoptosis effect in cardiomyocytes and a pro-angiogenesis effect in HUVECs in vitro. (A) Hoechest33342/PI double staining was used to observe the survival of cardiomyocytes treated with PBS, MSCs-EVs or HIF-1α-EVs under H/SD condition. Scale bar ​= ​100 ​μm. (B) Caspase3/caspase7 activity of cardiomyocytes treated with PBS, MSCs-EVs or HIF-1α-EVs under H/SD condition. Scale bar ​= ​100 ​μm. (C) HIF-1α EVs improved cell viability of cardiomyocytes under H/SD condition. (D) Quantitative analysis of viable cells treated with PBS or EVs. (E) Quantitative analysis of caspase3/caspase7 positive cells between the three groups. (F) Quantitative analysis of TUNEL-positive cells between the three groups. (G) Representative photographs showing the TUNEL-positive cells in cardiomyocytes among the different groups. Green, TUNEL-positive nuclei; red, α-actin; blue, DAPI-stained nuclei. Scale bar ​= ​100 ​μm. (H) Representative images showing tube formation in HUVECs treated with PBS, MSCs-EVs or HIF-1α-EVs. Scale bar ​= ​100 ​μm. (I) Quantification of tube length in each group. Continuous variables were described by means ​± ​SEM. ∗P< 0.05, ∗∗P< 0.01, ∗∗∗∗P< 0.0001 vs. PBS group; #P< 0.05, ##P< 0.01 vs. NC-EVs group; NS, not significant. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)