trans-Chalcone inhibits transforming growth factor-β1 and connective tissue growth factor-dependent collagen expression in the heart of high-fat diet-fed rats

The emerging role of leptin in obesity-associated cardiac fibrosis: evidence and mechanism

Cardiac fibrosis is a hallmark of various cardiovascular diseases, which is quite commonly found in obesity, and may contribute to the increased incidence of heart failure arrhythmias, and sudden cardiac death in obese populations. As an endogenous regulator of adiposity metabolism, body mass, and energy balance, obesity, characterized by increased circulating levels of the adipocyte-derived hormone leptin, is a critical contributor to the pathogenesis of cardiac fibrosis. Although there are some gaps in our knowledge linking leptin and cardiac fibrosis, this review will focus on the interplay between leptin and major effectors involved in the pathogenesis underlying cardiac fibrosis at both cellular and molecular levels based on the current reports. The profibrotic effect of leptin is predominantly mediated by activated cardiac fibroblasts but may also involve cardiomyocytes, endothelial cells, and immune cells. Moreover, a series of molecular signals with a known profibrotic property is closely involved in leptin-induced fibrotic events. A more comprehensive understanding of the underlying mechanisms through which leptin contributes to the pathogenesis of cardiac fibrosis may open up a new avenue for the rapid emergence of a novel therapy for preventing or even reversing obesity-associated cardiac fibrosis.

Remodeling and Fibrosis of the Cardiac Muscle in the Course of Obesity-Pathogenesis and Involvement of the Extracellular Matrix

Obesity is a growing epidemiological problem, as two-thirds of the adult population are carrying excess weight. It is a risk factor for the development of cardiovascular diseases (hypertension, ischemic heart disease, myocardial infarct, and atrial fibrillation). It has also been shown that chronic obesity in people may be a cause for the development of heart failure with preserved ejection fraction (HFpEF), whose components include cellular hypertrophy, left ventricular diastolic dysfunction, and increased extracellular collagen deposition. Several animal models with induced obesity, via the administration of a high-fat diet, also developed increased heart fibrosis as a result of extracellular collagen accumulation. Excessive collagen deposition in the extracellular matrix (ECM) in the course of obesity may increase the stiffness of the myocardium and thereby deteriorate the heart diastolic function and facilitate the occurrence of HFpEF. In this review, we include a rationale for that process, including a discussion about possible putative factors (such as increased renin–angiotensin–aldosterone activity, sympathetic overdrive, hemodynamic alterations, hypoadiponectinemia, hyperleptinemia, and concomitant heart diseases). To address the topic clearly, we include a description of the fundamentals of ECM turnover, as well as a summary of studies assessing collagen deposition in obese individuals.

Atheroprotective and hepatoprotective effects of trans-chalcone through modification of eNOS/AMPK/KLF-2 pathway and regulation of COX-2, Ang-II, and PDGF mRNA expression in NMRI mice fed HCD

BACKGROUND

The effects of trans-chalcone on atherosclerosis and NAFLD have been investigated. However, the underlying molecular mechanisms of these effects are not completely understood. This study aimed to deduce the impacts of trans-chalcone on the eNOS/AMPK/KLF-2 pathway in the heart tissues and the expression of Ang-II, PDFG, and COX-2 genes in liver sections of NMRI mice fed HCD.

METHODS AND RESULTS

Thirty-two male mice were divided into four groups (n = 8): control group; fed normal diet. HCD group; fed HCD (consisted of 2% cholesterol) (12 weeks). TCh groups; received HCD (12 weeks) besides co-treated with trans-chalcone (20 mg/kg and 40 mg/kg b.w. dosages respectively) for 4 weeks. Finally, the blood samples were collected to evaluate the biochemical parameters. Histopathological observations of aorta and liver sections were performed by H&E staining. The real-time PCR method was used for assessing the expression of the aforementioned genes. Histopathological examination demonstrated atheroma plaque formation and fatty liver in mice fed HCD which were accomplished with alteration in biochemical factors and Real-time PCR outcomes. Administration of trans-chalcone significantly modulated the serum of biochemical parameters. These effects were accompanied by significant increasing the expression of eNOS, AMPK, KLF-2 genes in heart sections and significant decrease in COX-2, Ang-II, and PDGF mRNA expression in liver sections.

CONCLUSION

Our findings propose that the atheroprotective and hepatoprotective effects of trans-chalcone may be attributed to the activation of the eNOS/AMPK/KLF-2 pathway and down-regulation of Ang-II, PDFG, and COX-2 genes, respectively.