Journal: Basic Research in Cardiology
Article Title: Single-cell transcriptomics reveal distinctive patterns of fibroblast activation in heart failure with preserved ejection fraction
doi: 10.1007/s00395-024-01074-w
Figure Lengend Snippet: Angptl4 improves diastolic dysfunction by reducing collagen IV deposition in vivo and in vitro. A In vivo study design comparing recombinant murine Angptl4 peptide (rANGPTL4, 200 ng in 50 µl NaCl) vs. NaCl control (0.9%, 50 µl) administration every second day i.p. for 5 weeks starting after 5 weeks of dietary induction. Murine HFpEF induction by 0.5 g/L L-NAME and 60% high-fat diet for 10 weeks in total. Echocardiography (echo) captured cardiac systolic and diastolic function at baseline, after 5 (prior to i.p. injection start) and 10 weeks. Created with BioRender. B Time course of diastolic function determined by E/E’ (PW Doppler velocity across the mitral valve (E) and peak tissue Doppler at the mitral valve annulus (E’) during early diastole). n = 10/10/9/9. C Comparison of the experimental groups after 10 weeks. n = 10/10/9/9. One-way ANOVA with Tukey correction for multiple comparison or Kruskal–Wallis test according to normality determined by Shapiro–Wilk test. p values < 0.09 shown above bars, p < 0.05 defined as statistically significant. HW/TL heart weight/ tibia length, LA left atrium, LVEF left ventricular ejection fraction, LWDd left ventricular lateral wall diameter in end-diastole from short axis views D Comparison of E/E’ after 10 weeks in HFpEF mice either treated with control or rANGPTL4. n = 9/9, unpaired t test, p value shown above bar. E Experimental design (left panel) of stimulating human ventricular cardiac fibroblasts (cFBs) in vitro with 2 µg/ml human recombinant ANGPTL4 or PBS for 24 h. Resulting mRNA levels (right panel) were determined by qPCR and values indicate fold change relative to control mean. n = 12/12, unpaired t test or Mann–Whitney test according to normality determined by Shapiro–Wilk test, p values shown above bars. Created with BioRender. F Representative immunofluorescence stainings of collagen IV 1:200 (pink) and DAPI (blue). Whole heart long-axis cryo-sections depicted in the top row with white boxes indicating magnifications shown in bottom row and respective scale bars. G Quantification of F by scanning whole heart sections using a slide scanner and semi-automated analysis of the whole left ventricular (LV) tissue by normalizing the collagen IV positive LV area to total LV area using QuPath. One-way ANOVA, p values < 0.05 shown above bars
Article Snippet: Human primary cardiac ventricular fibroblasts (Lonza, #CC-2904) at passage 6 were cultured according to the manufacturers recommendations and respective basal and growth media.
Techniques: In Vivo, In Vitro, Recombinant, Control, Injection, Comparison, MANN-WHITNEY, Immunofluorescence