Spironolactone alleviates myocardial fibrosis via inhibition of Ets‑1 in mice with experimental autoimmune myocarditis

Pirfenidone improves early cardiac function following myocardial infarction by enhancing the elastin/collagen ratio

BACKGROUND

Acute myocardial infarction (AMI) is a leading cause of mortality worldwide, with reduced elastin/collagen ratios exacerbating cardiac dysfunction due to collagen-rich scar tissue replacing necrotic myocardial cells. This study aims to evaluate pirfenidone's therapeutic effect on early cardiac function post-AMI and elucidate its impact on the elastin/collagen ratio.

METHODS

Sprague-Dawley rats were divided into four groups: Sham, AMI, AMI treated with PBS (AMI-PBS), and AMI treated with pirfenidone (AMI-PFD) (n=12 each). AMI was induced via coronary artery ligation. The AMI-PFD and AMI-PBS groups received pirfenidone and PBS for 14 days, respectively. Cardiac function, fibrosis, serum cytokines, collagen and elastin content, and their ratios were assessed. Cardiac fibroblasts (CFs) from neonatal rats were categorized into control, hypoxia-induced (LO), LO+PBS, and LO+PFD groups. ELISA measured inflammatory factors, and RT-PCR analyzed collagen and elastin gene expression.

RESULTS

The AMI-PFD group showed improved cardiac function and reduced serum interleukin-1β (IL-1β), IL-6, and transforming growth factor-β (TGF-β). Type I and III collagen decreased by 22.6 % (P=0.0441) and 34.4 % (P=0.0427), respectively, while elastin content increased by 79.4 % (P=0.0126). E/COLI and E/COLIII ratios rose by 81.1 % (P=0.0026) and 88.1 % (P=0.0006). CFs in the LO+PFD group exhibited decreased IL-1β, IL-6, TGF-β, type I and III collagen, with increased elastin mRNA, enhancing the elastin/collagen ratio.

CONCLUSION

Pirfenidone enhances cardiac function by augmenting the early elastin/collagen ratio post-AMI.

Gene expression analysis to identify mechanisms underlying improvement of myocardial fibrosis by finerenone in SHR

Both spironolactone and finerenone treatments significantly reduced SBP and there was no statistical difference in their antihypertensive effects. The differences in body weight (at the end of 1/2/3/4 week) to pre-dose body weight ratio and heart rate (at the end of 1/2/3/4 week) to pre-dose heart rate ratio were not statistically significant in the vehicle, spironolactone, finerenone, and control groups.There was no statistically significant difference in mortality among the vehicle, spironolactone, and finerenone groups. The relative heart mass, ANP, BNP, CVF, Col I, TGF-β, and Casp-3 were gradually decreased in vehicle group, spironolactone group, and finerenone group. Among them, BNP, CVF, TGF-β, and Casp-3 were significantly decreased in the finerenone group compared with the vehicle group. HE and Masson staining showed that the cardiomyocytes of rats in the vehicle group and spironolactone group were disorganized, with cell hypertrophy, significantly enlarged cell gaps and a large amount of collagen deposition, whereas the cardiomyocytes of rats in the finerenone group and the control group were more neatly arranged, with smaller cell gaps and a small amount of collagen tissue deposition. RNA sequencing (RNA-seq) showed that there was a total of 119 differentially expressed genes (DEGs) between finerenone treatment and vehicle treatment. Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis showed that the signaling pathways involved were mainly in drug metabolism-cytochrome P450, chemical carcinogenesis, IL-17 signaling pathway, axon guidance, and hematopoietic cell lineage. Protein-protein interaction (PPI) analysis showed that the core genes were Oaslf, Nos2, LOC687780, Rhobtb1, Ephb3, and Rps27a.

Co-expression of fibrotic genes in inflammatory bowel disease; A localized event?

Introduction

Extracellular matrix turnover, a ubiquitous dynamic biological process, can be diverted to fibrosis. The latter can affect the intestine as a serious complication of Inflammatory Bowel Diseases (IBD) and is resistant to current pharmacological interventions. It embosses the need for out-of-the-box approaches to identify and target molecular mechanisms of fibrosis.

Methods and results

In this study, a novel mRNA sequencing dataset of 22 pairs of intestinal biopsies from the terminal ileum (TI) and the sigmoid of 7 patients with Crohn's disease, 6 with ulcerative colitis and 9 control individuals (CI) served as a validation cohort of a core fibrotic transcriptomic signature (FIBSig), This signature, which was identified in publicly available data (839 samples from patients and healthy individuals) of 5 fibrotic disorders affecting different organs (GI tract, lung, skin, liver, kidney), encompasses 241 genes and the functional pathways which derive from their interactome. These genes were used in further bioinformatics co-expression analyses to elucidate the site-specific molecular background of intestinal fibrosis highlighting their involvement, particularly in the terminal ileum. We also confirmed different transcriptomic profiles of the sigmoid and terminal ileum in our validation cohort. Combining the results of these analyses we highlight 21 core hub genes within a larger single co-expression module, highly enriched in the terminal ileum of CD patients. Further pathway analysis revealed known and novel inflammation-regulated, fibrogenic pathways operating in the TI, such as IL-13 signaling and pyroptosis, respectively.

Discussion

These findings provide a rationale for the increased incidence of fibrosis at the terminal ileum of CD patients and highlight operating pathways in intestinal fibrosis for future evaluation with mechanistic and translational studies.

Effect of spironolactone therapy on the activity of the matrix metalloproteinase system in patients with heart failure after COVID-19

Aim. To assess the change in the activity of the matrix metalloproteinase (MMP) system after 6-month spironolactone therapy in patients with heart failure (HF) with preserved (HFpEF) and mildly reduced ejection fraction (HFmrEF) after coronavirus disease 2019 (COVID-19).

Material and methods. The study included 90 patients treated at the University Clinical Hospital № 4 of the I.M. Sechenov First Moscow State Medical University with a laboratory-confirmed COVID-19. There were following inclusion criteria: age of 18-85 years; the presence of HFpEF and HFmrEF. The patients were randomized into two groups: group I (n=60) — patients with 6-month spironolactone therapy (25 mg/day) in addition to the standard therapy for HF, spironolactone was taken at a dose of 25 mg/day; Group II (comparison group, n=30) — patients who received standard therapy without spironolactone. All patients were determined plasma MMP concentrations.

Results. There were no significant differences in the levels of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) between the groups when included in the study. A repeated investigation revealed a significant decrease in the concentrations of MMP-9 and TIMP-1 only in group I. In patients of group II, there were no significant changes in the plasma concentrations of MMP-9 and TIMP-1. The MMP-9/TIMP-1 ratio during the initial examination of patients did not have significant differences. After 6-months therapy, a significant decrease in the ratio of MMP-9/TIMP-1 was observed only in patients taking spironolactone.

Conclusion. The results obtained confirm a significant decrease in MMP system activity after 6-month spironolactone therapy in patients with HFpEF and HFmrEF after COVID-19. The described antifibrotic effects of spironolactone make it possible to recommend the use of this drug in this category of patients to reduce the negative effect of MMPs on cardiovascular system.