Journal: Cardiovascular Diabetology

Article Title: Succinate–GPR91 signaling promotes cardiomyocyte metabolic reprogramming and NAD + production to alleviate HFpEF

doi: 10.1186/s12933-025-03030-x

Figure Lengend Snippet: Reduced succinate levels and downregulation of its receptor GPR91 in HFpEF. A , Succinate levels in cardiac tissue of HFpEF patients, based on targeted metabolomics data from a published study. B , Succinate levels in cardiac tissue of WT regular chow (RC) and HFpEF mice, measured using a colorimetric assay. n = 6 per group. C , The mRNA expression levels of Gpr91 in cardiac tissues of WT RC and HFpEF mice. n = 6 in WT RC, n = 9 in WT HFpEF. D , Western blot analysis and quantification for GPR91 expression in the cardiac tissues of control mice compared with db/db or HFpEF mice. n = 6 per group. E , Western blot analysis and quantification of GPR91 expression in AC16 cardiomyocytes cultured under control or HG + PA conditions for 48 h ( n = 3 per group). F , Western blot analysis and quantification of GPR91 expression in human iPSC-derived cardiac organoids exposed to control or HFpEF-like comorbidity conditions ( n = 3 per group). G , Representative images of immunofluorescence staining of GPR91 (Red) in the heart of RC and HFpEF mice, and the corresponding quantification of GPR91 fluorescence intensity. n = 7 per group. All data are presented as the mean ± SEM. P < 0.05 was considered statistically significant, and precise values are specified in corresponding figures. Data were analyzed using Kruskal-Wallis test with post hoc Dunn’s test and adjusted P values (Padj, Benjamini–Hochberg) for panel (A), or by Student’s t test for (B–H)

Article Snippet: Human cardiomyocyte cell line AC16 (ATCC, CRL-3568) was cultured in DMEM (Corning, Cat# 10013127) supplemented with 10% fetal bovine serum (Corning, Cat#35015-CV) and 1% penicillin-streptomycin (Procell, Cat# PB180120 ).

Techniques: Colorimetric Assay, Expressing, Western Blot, Control, Cell Culture, Derivative Assay, Immunofluorescence, Staining, Fluorescence

Journal: Cardiovascular Diabetology

Article Title: Succinate–GPR91 signaling promotes cardiomyocyte metabolic reprogramming and NAD + production to alleviate HFpEF

doi: 10.1186/s12933-025-03030-x

Figure Lengend Snippet: Supplementation with succinate mitigates diastolic dysfunction and metabolic remodeling. C57BL/6J male mice (8-week-old) were fed with regular chow or high-fat diet (HFD) + Nω-nitro-L-arginine methyl ester (L-NAME), and received either control or 1.5% succinate-supplemented drinking water for 12 weeks. A , Experimental design. B , Body weight. n = 6 in RC and RC + SUC; n = 13 in HFpEF and HFpEF + SUC. C , representative images of echocardiography. D , E/A ratio. E , E/E′ ratio. F , Representative image of myocardial strain analysis using VevoStrain. G , Left ventricular global longitudinal strain (GLS). H , Tei index. I , Percentage of LVEF. n = 4 in RC and RC + SUC; n = 7–10 in HFpEF and HFpEF + SUC. J , Rotarod-determined running time during the exercise exhaustion test. n = 6 in RC and RC + SUC; n = 8 in HFpEF and HFpEF + SUC. K and L , Representative heart images, heart weight (mg) and tibia length(mm) ratio (HW/TL). n = 5–6 in RC and RC + SUC; n = 7–8 in HFpEF and HFpEF + SUC. M , Representative images of H&E, Masson, WGA and Oil Red-stained sections. N , Quantification of interstitial fibrosis (%) based on Masson’s trichrome staining, and cardiomyocyte cross-sectional area based on WGA staining. n = 3 in RC and RC + SUC; n = 8 in HFpEF and HFpEF + SUC. O , mRNA levels of Nppa, Nppb, and Myh7, Col1a1, Col3a1, and Acta2 in myocardial tissue of mice from different experimental groups. n = 7 per group. Each point represents one mouse. Data are shown as mean ± SEM. Statistical significance was defined as P < 0.05. Data were analyzed using one-way ANOVA (D-O) or two-way ANOVA (B), followed by Tukey’s multiple comparisons test

Article Snippet: Human cardiomyocyte cell line AC16 (ATCC, CRL-3568) was cultured in DMEM (Corning, Cat# 10013127) supplemented with 10% fetal bovine serum (Corning, Cat#35015-CV) and 1% penicillin-streptomycin (Procell, Cat# PB180120 ).

Techniques: Control, Staining

Journal: Cardiovascular Diabetology

Article Title: Succinate–GPR91 signaling promotes cardiomyocyte metabolic reprogramming and NAD + production to alleviate HFpEF

doi: 10.1186/s12933-025-03030-x

Figure Lengend Snippet: Succinate Fails to Confer Cardiometabolic Protection in Gpr91 Knockout HFpEF Mice. Global Gpr91 knockout (Gpr91 -/- ) and wild-type (WT) C57BL/6J male mice (8 weeks old) were fed with either regular chow or HFD + L-NAME, and received either control or 1.5% succinate-supplemented drinking water for 12 weeks. A , Experimental design. B , Body weight. n = 7–10. C , Representative echocardiographic images. D , E/A ratio. E , E/E′ ratio. F , Representative myocardial strain analysis using VevoStrain. G , Tei index. H , Left ventricular global longitudinal strain (GLS). I , Left ventricular ejection fraction (LVEF, %). n = 6–12 per group. J , Rotarod-determined running time during the exercise exhaustion test. n = 7–8 per group. K , L , Representative images of hearts and heart weight-tibia length ratio (HW/TL). n = 9–10 per group. M , Representative histological sections stained with H&E, Masson’s trichrome, wheat germ agglutinin (WGA), and Oil Red O. N , Quantification of interstitial fibrosis (%) based on Masson’s staining, and cardiomyocyte cross-sectional area based on WGA staining. n = 6 per group. O , Relative mRNA expression levels of Nppa, Nppb, and Myh7, Col1a1, Col3a1, and Acta2 in cardiac tissue from each group. n = 6 per group. Each data point represents one mouse. Data are presented as mean ± SEM. P < 0.05 was considered statistically significant, and exact P-values are indicated in the respective figure panels. Data were analyzed using one-way ANOVA (D–O) or two-way ANOVA (B), followed by Tukey’s multiple comparisons test

Article Snippet: Human cardiomyocyte cell line AC16 (ATCC, CRL-3568) was cultured in DMEM (Corning, Cat# 10013127) supplemented with 10% fetal bovine serum (Corning, Cat#35015-CV) and 1% penicillin-streptomycin (Procell, Cat# PB180120 ).

Techniques: Knock-Out, Control, Staining, Expressing

Journal: Cardiovascular Diabetology

Article Title: Succinate–GPR91 signaling promotes cardiomyocyte metabolic reprogramming and NAD + production to alleviate HFpEF

doi: 10.1186/s12933-025-03030-x

Figure Lengend Snippet: Succinate-Mediated Improvement of Diastolic Dysfunction in HFpEF Depends on Cardiomyocyte GPR91. Cardiomyocyte-specific GPR91 knockout mice and their littermate controls C57BL/6J male mice (8 weeks old) were fed with either regular chow or HFD + L-NAME, and received either control or 1.5% succinate-supplemented drinking water for 12 weeks. A , Experimental design. B , E/A and C , E/E′ ratio. D ,Representative echocardiographic images. E , Left ventricular global longitudinal strain (GLS). F , Tei index. G , Representative myocardial strain analysis using VevoStrain. H , Left ventricular ejection fraction (LVEF, %). n = 6–12 in each group. I , Rotarod-determined running time during the exercise exhaustion test. n = 6–9 in each group. J , Representative images of hearts and heart weight/tibia length ratio (HW/TL). n = 8–10 in each group. K , L , Quantification of interstitial fibrosis (%) based on Masson’s staining, and cardiomyocyte cross-sectional area based on WGA staining. n = 7 in each group. M , Representative histological sections stained with H&E, Masson’s trichrome, wheat germ agglutinin (WGA), and Oil Red O. N , Representative electron microscopy image shows the lipid droplets (yellow) in cardiomyocytes and mitochondria (red arrow). Data are expressed as mean ± SEM. P < 0.05 was considered statistically significant, and exact P-values are indicated in the respective figure panels. Data were analyzed using one-way ANOVA (B-L), followed by Tukey’s multiple comparisons test

Article Snippet: Human cardiomyocyte cell line AC16 (ATCC, CRL-3568) was cultured in DMEM (Corning, Cat# 10013127) supplemented with 10% fetal bovine serum (Corning, Cat#35015-CV) and 1% penicillin-streptomycin (Procell, Cat# PB180120 ).

Techniques: Knock-Out, Control, Staining, Electron Microscopy

Journal: Cardiovascular Diabetology

Article Title: Succinate–GPR91 signaling promotes cardiomyocyte metabolic reprogramming and NAD + production to alleviate HFpEF

doi: 10.1186/s12933-025-03030-x

Figure Lengend Snippet: Gq-Dependent AMPK Activation Mediates Succinate–GPR91 Metabolic Effects. AC16 were treated with high glucose (33mM) plus palmitate (200µM) for 48 h in a sustained medium to mimic HFpEF-like conditions in vitro. A , Representative immunoblot images and densitometry analysis of GPR91 in AC16 cells treated with succinate (400µM) 24 h, under normal or HG + PA conditions 48h. n = 3 in each group. B , Representative immunoblot images and densitometry analysis of p-AMPK/AMPK in primary neonatal ventricular cardiomyocytes isolated from WT and Gpr91 −/− mice. n = 3 in each group. C , AC16 cells were treated with high glucose (33mM) plus palmitate (200µM) for 48 h, then 1µM Gqi pretreat 1 h, succinate treat 5 min, Representative blot images of p-AMPK and AMPK. n = 3 in each group. D , qPCR analysis of AMPK downstream target genes in AC16 cells under indicated treatments. n = 4 in each group. E , Intracellular NAD + levels in AC16 cells treated with succinate and/or Gqi (1µM) in normal and HG + PA environments. n = 5–6 in each group. F , NAD + levels following treatment with succinate and/or AMPK inhibitor (Compound C 10µM) in normal and HG + PA environments. n = 3 in each group. Data are expressed as mean ± SEM. P < 0.05 was considered statistically significant, and exact P-values are indicated in the respective figure panels. Data were analyzed using one-way ANOVA(A-B) and two-way ANOVA (C-F), followed by Tukey’s multiple comparisons test

Article Snippet: Human cardiomyocyte cell line AC16 (ATCC, CRL-3568) was cultured in DMEM (Corning, Cat# 10013127) supplemented with 10% fetal bovine serum (Corning, Cat#35015-CV) and 1% penicillin-streptomycin (Procell, Cat# PB180120 ).

Techniques: Activation Assay, In Vitro, Western Blot, Isolation

Journal: Cardiovascular Diabetology

Article Title: Succinate–GPR91 signaling promotes cardiomyocyte metabolic reprogramming and NAD + production to alleviate HFpEF

doi: 10.1186/s12933-025-03030-x

Figure Lengend Snippet: NAM supplementation partially restores cardiac function and NAD + levels in Gpr91 −/− HFpEF mice. WT mice were fed with RC diet. Gpr91 −/− mice receiving HFD + L-NAME were treated with or without 40 mM nicotinamide in drinking water for 12 weeks. A , Experimental design. B , Body weight. n = 6–10. C , Representative echocardiographic images. D , E/A ratio. E , E/E′ ratio. F , Tei index. G , Left ventricular global longitudinal strain (GLS). H , Representative myocardial strain analysis using VevoStrain. I , Left ventricular ejection fraction (LVEF, %). n = 6–10 in each group. J , Rotarod-determined running time during the exercise exhaustion test. n = 6–10 in each group. K , L , Representative images of hearts and heart weight/tibia length ratio (HW/TL). n = 7–8 in each group. M , Representative histological sections stained with H&E, Masson’s trichrome, wheat germ agglutinin (WGA), and Oil Red O. N , Quantification of interstitial fibrosis (%) based on Masson’s staining, and cardiomyocyte cross-sectional area based on WGA staining. n = 6 in each group. O , Relative mRNA expression levels of Nppa, Nppb, and Myh7, Col1a1, Col3a1, and Acta2 in cardiac tissue from each group. n = 6 per group. P , Heart NAD + levels and NAD + /NADH ratio in WT RC, Gpr91 −/− HFpEF or HFpEF + NAM groups. n = 6 in each group. Each data point represents an indicidual mouse. Data are expressed as mean ± SEM. P < 0.05 was considered statistically significant, and exact P-values are indicated in the respective figure panels. Data were analyzed using one-way ANOVA (D–P) or two-way ANOVA (B), followed by Tukey’s multiple comparisons test

Article Snippet: Human cardiomyocyte cell line AC16 (ATCC, CRL-3568) was cultured in DMEM (Corning, Cat# 10013127) supplemented with 10% fetal bovine serum (Corning, Cat#35015-CV) and 1% penicillin-streptomycin (Procell, Cat# PB180120 ).

Techniques: Staining, Expressing