Irbesartan prevents myocardial remodeling in experimental thyrotoxic cardiomyopathy

Alleviation of doxorubicin-induced cardiotoxicity in rat by mesenchymal stem cells and olive leaf extract via MAPK/ TNF-α pathway: Preclinical, experimental and bioinformatics enrichment study

BACKGROUND

Toxic cardiomyopathies were a potentially fatal adverse effect of anthracycline therapy.

AIM

This study was conducted to demonstrate the pathogenetic, morphologic, and toxicologic effects of doxorubicin on the heart and to investigate how the MAPK /TNF-α pathway can be modulated to improve doxorubicin-Induced cardiac lesions using bone marrow-derived mesenchymal stem cells (BM-MSCs) and olive leaf extract (OLE).

METHODS

During the study, 40 adult male rats were used. Ten were used to donate MSCs, and the other 30 were split into 5 equal groups: Group I was the negative control, Group II obtained oral OLE, Group III obtained an intraperitoneal cumulative dose of DOX (12 mg/kg) in 6 equal doses of 2 mg/kg every 48 h for 12 days, Group IV obtained intraperitoneal DOX and oral OLE at the same time, and Group V obtained intraperitoneal DOX and BM-MSCs through the tail vein at the same time for 12 days. Four weeks after their last dose of DOX, the rats were euthanized. By checking the bioinformatic databases, a molecularly targeted path was selected. Then the histological, immunohistochemistry, and gene expression of ERK, JNK, NF-κB, IL-6, and TNF-α were done.

RESULTS

Myocardial immunohistochemistry revealed severe fibrosis, cell degeneration, increased vimentin, and decreased CD-31 expression in the DOX-treated group, along with a marked shift in morphometric measurements, a disordered ultrastructure, and overexpression of inflammatory genes (ERK, NF-κB, IL-6, and TNF-α), oxidative stress markers, and cardiac biomarkers. Both groups IV and V displayed reduced cardiac fibrosis or inflammation, restoration of the microstructure and ultrastructure of the myocardium, downregulation of inflammatory genes, markers of oxidative stress, and cardiac biomarkers, a notable decline in vimentin, and an uptick in CD-31 expression. In contrast to group IV, group V showed a considerable beneficial effect.

CONCLUSION

Both OLE and BM-MSCs showed an ameliorating effect in rat models of DOX-induced cardiotoxicity, with BM-MSCs showing a greater influence than OLE.

Sacubitril/valsartan (LCZ696) ameliorates hyperthyroid-induced cardiac hypertrophy in male rats through modulation of miR-377, let-7 b, autophagy, and fibrotic signaling pathways

Hyperthyroidism is associated with cardiac hypertrophy, fibrosis, and increased risk of cardiovascular mortality. Sacubitril/valsartan (LCZ696) is a new combined drug that has shown promise for the treatment of hyperthyroidism-associated heart failure; however, the underlying molecular mechanisms, including the contributions of epigenetic regulation, remain unclear. The present study was designed to investigate the therapeutic efficacy of LCZ696 and the potential contributions of microRNA regulation in a rat model of hyperthyroidism-induced cardiac hypertrophy. Cardiac hypertrophy was induced by intraperitoneal administration of levothyroxine. Sixty adult male Wistar rats were randomly allocated to four equal groups (15 rats each): control, cardiac hypertrophy (CH), CH + valsartan, and CH + LCZ696. Treatment with LCZ696 or valsartan significantly improved hemodynamic abnormalities, normalized serum concentrations of natriuretic peptide, fibroblast growth factor-23, and cardiac inflammatory markers compared to CH group rats. Treatment with LCZ696 or valsartan also normalized myocardial expression levels of autophagy markers, fibrotic markers, PPAR-ϒ, mir-377, and let-7b. In addition, both valsartan and LCZ696 ameliorated collagen deposition, ventricular degeneration, and various ultrastructural abnormalities induced by levothyroxine. The beneficial effects of LCZ696 were superior to those of valsartan alone. The superior efficacy of LCZ696 may be explained by the stronger modulation of miR-377 and let-7b.

Inhibition of ubiquitin protein expression and 20S proteasome activity by irbesartan prevents post-infarction ventricular remodeling and decreases TNF-α generation

Myocardial infarction (MI) may induce severe alterations of the cardiac contractile function that may, in turn, lead to heart failure (HF). The ubiquitin-proteasome system (UPS) plays a critical role in cardiac remodeling following MI. Angiotensin II type 1 receptor (AT1R) blockers effectively prevent left ventricular (LV) remodeling. However, it has not been elucidated whether the preventive effect of AT1R-blockers on LV remodeling is mediated through the UPS pathway. In the present study, with the use of cardiac morphometric parameters, haemodynamic measurements and enzyme-linked immunosorbent assay, we demonstrated that post-ischemic HF rats exhibited a significant increase in ventricular remodeling and irbesartan was effective in reversing cardiac remodeling. The expression of TNF-α, ubiquitin protein and 20S proteasome were significantly increased in the MI control group and irbesartan was shown to dose-dependently inhibit the expression of TNF-α, ubiquitin protein and 20S proteasome. In conclusion, it was hypothesized that UPS signaling is involved in ventricular remodeling following MI and the mechanism underlying the effect of irbesartan on ventricular remodeling may be associated with the downregulation of the expression of TNF-α, ubiquitin protein and 20S proteasome.