Evaluation of the transverse aortic constriction model in ICR and C57BL/6J mice

Procyanidin B2 Attenuates Pathologic Cardiac Fibrosis and Inflammation: Role of PPARγ

ABSTRACT

Procyanidin B2 (PB2) is a prominent procyanidin isomer. Its effects and mechanisms in cardiac remodeling are not fully understood. Peroxisome proliferator-activated receptor gamma (PPAR-γ) plays a crucial role in regulating cardiac hypertrophy, fibrosis, and inflammation. This study aims to investigate the effect of PB2 on pathologic cardiac fibrosis and inflammation, focusing on the underlying mechanisms involving PPAR-γ. In vitro, cardiac fibrosis was induced in cardiac fibroblasts using angiotensin II. In vivo, a mouse model of pathologic cardiac fibrosis was generated through transverse aortic constriction to induce pressure overload. We found that PB2 inhibited proliferation, differentiation, collagen accumulation, and the NF-κB inflammation pathway in cardiac fibroblasts triggered by angiotensin II. These inhibitory effects were negated by the PPAR-γ antagonist GW9662 and RNA interference. In addition, PB2 directly elevated PPAR-γ expression in cardiac fibroblasts. Similarly, PB2 alleviated transverse aortic constriction-induced cardiac dysfunction, myocardial fibrosis, and inflammation in mice. These cardioprotective effects of PB2 in vivo were counteracted by coadministration with GW9662. Correspondingly, the upregulation of PPAR-γ protein expression by PB2 in pressure-overloaded hearts was also counteracted by GW9662 coadministration. In conclusion, this study demonstrates that PB2 exerts protective effects against pathologic cardiac fibrosis and inflammation through a PPAR-γ-dependent mechanism.

Targeting inflammatory signaling pathways with SGLT2 inhibitors: Insights into cardiovascular health and cardiac cell improvement

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have attracted significant attention for their broader therapeutic impact beyond simply controlling blood sugar levels, particularly in their ability to influence inflammatory pathways. This review delves into the anti-inflammatory properties of SGLT2 inhibitors, with a specific focus on canagliflozin, empagliflozin, and dapagliflozin. One of the key mechanisms through which SGLT2 inhibitors exert their anti-inflammatory effects is by activating AMP-activated protein kinase (AMPK), a crucial regulator of both cellular energy balance and inflammation. Activation of AMPK by these inhibitors leads to the suppression of pro-inflammatory pathways and a decrease in inflammatory mediators. Notably, SGLT2 inhibitors have demonstrated the ability to inhibit the release of cytokines in an AMPK-dependent manner, underscoring their direct influence on inflammatory signaling. Beyond AMPK activation, SGLT2 inhibitors also modulate several other inflammatory pathways, including the NLRP3 inflammasome, expression of Toll-like receptor 4 (TLR-4), and activation of NF-κB (Nuclear factor kappa B). This multifaceted approach contributes to their efficacy in reducing inflammation and managing associated complications in conditions such as diabetes and cardiovascular disorders. Several human and animal studies provide support for the anti-inflammatory effects of SGLT2 inhibitors, demonstrating protective effects on various cardiac cells. Additionally, these inhibitors exhibit direct anti-inflammatory effects by modulating immune cells. Overall, SGLT2 inhibitors emerge as promising therapeutic agents for targeting inflammation in a range of pathological conditions. Further research, particularly focusing on the molecular-level pathways of inflammation, is necessary to fully understand their mechanisms of action and optimize their therapeutic potential in inflammatory diseases.

Pharmacodynamics and Mechanism of Astragali Radix and Anemarrhenae Rhizoma in Treating Chronic Heart Failure by Inhibiting Complement Activation

Astragali radix (AR) and anemarrhenae rhizoma (AAR) are used clinically in Chinese medicine for the treatment of chronic heart failure (CHF), but the exact therapeutic mechanism is unclear. In this study, a total of 60 male C57BL/6 mice were divided into 5 groups, namely sham, model, AR, AAR, and AR-AAR. In the sham group, the chest was opened without ligation. In the other groups, the chest was opened and the transverse aorta was ligated to construct the transverse aortic constriction model. After 8 weeks of feeding, mice were given medicines by gavage for 4 weeks. Left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) were detected by echocardiography. Heart weight index (HWI) and wheat germ agglutinin staining were used to evaluate cardiac hypertrophy. Hematoxylin-eosin staining was used to observe the pathological morphology of myocardial tissue. Masson staining was used to evaluate myocardial fibrosis. The content of serum brain natriuretic peptide (BNP) was detected by enzyme-linked immunosorbent assay kit. The content of serum immunoglobulin G (IgG) was detected by immunoturbidimetry. The mechanism of AR-AAR in the treatment of CHF was explored by proteomics. Western blot was used to detect the protein expressions of complement component 1s (C1s), complement component 9 (C9), and terminal complement complex 5b-9 (C5b-9). The results show that AR-AAR inhibits the expression of complement proteins C1s, C9, and C5b-9 by inhibiting the production of IgG antibodies from B cell activation, which further inhibits the complement activation, attenuates myocardial fibrosis, reduces HWI and cardiomyocyte cross-sectional area, improves cardiomyocyte injury, reduces serum BNP release, elevates LVEF and LVFS, improves cardiac function, and exerts myocardial protection.