STAT3 expression is reduced in cardiac pericytes in HFpEF and its loss reduces cellular adhesion and induces pericyte senescence

Fig. 1. STAT3 expression is reduced in HFpEF pericytes. (A, B) Immunofluorescence staining of control (Ctrl) and HFpEF patient biopsy. (A) Measurement of capillary perimeter. (B) Quantification of pericyte coverage normalised to the vasculature. N = 4 for control and N = 7 for HFpEF. Every data point represents one independent patient. Data are shown as mean ± SEM. P values were calculated using unpaired, two‐tailed Student's t‐test. (C) Immunofluorescence staining of control and HFpEF mice. Quantification of pericyte coverage normalised to the vasculature. Pericytes were labelled with NG2. N = 4 for control and N = 4 for HFpEF. Every data point represents one independent mouse. Data are shown as mean ± SEM. P value was calculated using unpaired, two‐tailed Student's t‐test. (D) Uniform Manifold Approximation and Projection (UMAP) plot showing cell‐type specific clustering of all data points from cardiac single‐nuclei sequencing. we identified 13 individual cell types: Cardiomyocytes (CM), Artery (ArtEC), Vein (VeinEC), Capillary (CapEC) and Lymphatic (LymphEC) Endothelial Cells, B Cells, Macrophages (MP), Adipocytes (Adip), Fibroblasts (FB), Pericytes (PC), Smooth Muscle Cells (SMC),…

Fig. 2. STAT3 deficiency compromises pericytes adhesion. (A) Scheme of the experimental design and RT‐qPCR gene expression analysis of STAT3 showing efficient STAT3 silencing in pericytes. Every data point (n = 6) represents an independent transfection. Data are shown as mean ± SEM. P values were calculated using unpaired, two‐tailed Student's t‐test. (B) RT‐qPCR gene expression analysis of PDGFRB and CSPG4. Every data point (n = 6) represents an independent transfection. Data are shown as mean ± SEM. P values were calculated using unpaired, two‐tailed Student's t‐test. (C) Immunofluorescence staining of control and STAT3‐deficient pericytes. Every data point (n = 6) represents an independent transfection. Data are shown as mean ± SEM. P values were calculated using unpaired, two‐tailed Student's t‐test. (D) RT‐qPCR gene expression analysis of COL1A1 and COL3A1. Every data point (n = 6) represents an independent transfection. Data are shown as mean ± SEM. P values were calculated using unpaired, two‐tailed Student's t‐test. (E) Immunofluorescence staining of control and STAT3‐deficient pericytes. Violin plots representing every analysed cell in a total of N = 6 independent transfections.…

Fig. 3. STAT3 deficiency induces cellular senescence in pericytes. (A) Representative FACS plots showing the gating strategy for BrdU proliferation assay. Cell cycle phases distribution differences in control and STAT3‐deficient pericytes. (B) RT‐qPCR gene expression analysis of CDKN1A and TP53. (C) Measurement of dehydrogenase activity in pericytes using CCK‐8. (D) RT‐qPCR analysis of relative telomere length in control and STAT3‐deficient pericytes. (E) β‐Galactosidase staining of control and STAT3‐deprived pericytes and quantification of β‐galactosidase+ area (%). (A–E) Every data point (n = 6) represents an independent transfection. Data are shown as mean ± SEM. P values were calculated using unpaired, two‐tailed Student's t‐test.

Fig. 4. STAT3 knockdown induces a transcriptional signature similar to HFpEF. (A) Gene Ontology (GO) enrichment analysis of significant differentially expressed genes in STAT3‐deficient pericytes. Represented are the top 6 dysregulated pathways. (B) Scatter plot showing CDKN1A, CDKN1B and CDKN2B normalised gene expression values (fragments per kilobase of transcript per million mapped reads, FPKM) in control and STAT3‐deficient pericytes hearts. Every data point (n = 3) represents an independent transfection. Data are shown as mean ± SEM. P values were calculated using cuffdiff test. (C) Gene Ontology (GO) enrichment analysis of significant differentially expressed genes in STAT3‐deficient pericytes. Represented are the top six dysregulated cellular components. (D) Scatter plot showing ARPC5L, RAB21 and GJA1 normalised gene expression values (fragments per kilobase of transcript per million mapped reads, FPKM) in control and STAT3‐deficient pericytes hearts. Every data point (n = 3) represents an independent transfection. Data are shown as mean ± SEM. P values were calculated using the Wald test for significance of the negative binomial model coefficients, as implemented in DESeq2. (E)…