Figure 4.

7G-modRNA delivery resulted in a subpopulation of CM-like cells expressing mesenchymal stromal cell markers and pro-angiogenic pathways

(A) Experimental plan for lineage tracing using tamoxifen injection, LAD ligation, and modRNA delivery followed by isolation of hearts from transgenic mice. (B) Representative immunostaining images of in vivo CM-like cells (in magenta) collected from Luc and 7G-modRNA-injected mice, showing positive staining for cardiomyocyte marker cTnI (blue) and Tdtomato-cre (red). (C) Quantification of CM-like cells depicted by immunostaining in (B) (Luc, n = 3; 7G, n = 3). (D and E) Single-cell RNA analysis to identify single cells without (D) or with (E) 21 days of 7G treatment (repeat transfection every 3 days), visualized in different colors using uniform manifold approximation and projection (UMAP) plots of 42,747 cells. (F and G) List of upregulated biological processes with GO and enriched GO functions (using Enricher) in cells treated with 7G for 21 days. (H–K) Top differentially expressed genes in cell cluster 9. Feature plots and violin plots show the relative gene expression strength of Sca-1/Ly6a (H and I) and Ccl2 (J and K), respectively. Unpaired two-tailed t test for (C). ∗∗p < 0.01. Scale bar = 50 μm and 5 μm (B).