Angiotensin II Increases HMGB1 Expression in the Myocardium Through AT1 and AT2 Receptors When Under Pressure Overload

HMGB family proteins: Potential biomarkers and mechanistic factors in cardiovascular diseases

Cardiovascular disease (CVD) is the most fatal disease that causes sudden death, and inflammation contributes substantially to its occurrence and progression. The prevalence of CVD increases as the population ages, and the pathophysiology is complex. Anti-inflammatory and immunological modulation are the potential methods for CVD prevention and treatment. High-Mobility Group (HMG) chromosomal proteins are one of the most abundant nuclear nonhistone proteins which act as inflammatory mediators in DNA replication, transcription, and repair by producing cytokines and serving as damage-associated molecular patterns in inflammatory responses. The most common and well-studied HMG proteins are those with an HMGB domain, which participate in a variety of biological processes. HMGB1 and HMGB2 were the first members of the HMGB family to be identified and are present in all investigated eukaryotes. Our review is primarily concerned with the involvement of HMGB1 and HMGB2 in CVD. The purpose of this review is to provide a theoretical framework for diagnosing and treating CVD by discussing the structure and function of HMGB1 and HMGB2.

Inhibition of GSDMD activation by Z-LLSD-FMK or Z-YVAD-FMK reduces vascular inflammation and atherosclerotic lesion development in ApoE-/- mice

Pyroptosis is a form of pro-inflammatory cell death that can be mediated by gasdermin D (GSDMD) activation induced by inflammatory caspases such as caspase-1. Emerging evidence suggests that targeting GSDMD activation or pyroptosis may facilitate the reduction of vascular inflammation and atherosclerotic lesion development. The current study investigated the therapeutic effects of inhibition of GSDMD activation by the novel GSDMD inhibitor N-Benzyloxycarbonyl-Leu-Leu-Ser-Asp(OMe)-fluoromethylketone (Z-LLSD-FMK), the specific caspase-1 inhibitor N-Benzyloxycarbonyl-Tyr-Val-Ala-Asp(OMe)-fluoromethylketone (Z-YVAD-FMK), and a combination of both on atherosclerosis in ApoE-/- mice fed a western diet at 5 weeks of age, and further determined the efficacy of these polypeptide inhibitors in bone marrow-derived macrophages (BMDMs). In vivo studies there was plaque formation, GSDMD activation, and caspase-1 activation in aortas, which increased gradually from 6 to 18 weeks of age, and increased markedly at 14 and 18 weeks of age. ApoE-/- mice were administered Z-LLSD-FMK (200 µg/day), Z-YVAD-FMK (200 µg/day), a combination of both, or vehicle control intraperitoneally from 14 to 18 weeks of age. Treatment significantly reduced lesion formation, macrophage infiltration in lesions, protein levels of vascular cell adhesion molecule-1 and monocyte chemoattractant protein-1, and pyroptosis-related proteins such as activated caspase-1, activated GSDMD, cleaved interleukin(IL)-1β, and high mobility group box 1 in aortas. No overt differences in plasma lipid contents were detected. In vitro treatment with these polypeptide inhibitors dramatically decreased the percentage of propidium iodide-positive BMDMs, the release of lactate dehydrogenase and IL-1β, and protein levels of pyroptosis-related proteins both in supernatants and cell lysates elevated by lipopolysaccharide + nigericin. Notably however, there were no significant differences in the above-mentioned results between the Z-LLSD-FMK group and the Z-YVAD-FMK group, and the combination of both did not yield enhanced effects. These findings indicate that suppression of GSDMD activation by Z-LLSD-FMK or Z-YVAD-FMK reduces vascular inflammation and lesion development in ApoE-/- mice.

Sodium Ferulate Inhibits Rat Cardiomyocyte Hypertrophy Induced by Angiotensin II Through Enhancement of Endothelial Nitric Oxide Synthase/Nitric Oxide/Cyclic Guanosine Monophosphate Signaling Pathway

ABSTRACT

Sodium ferulate (SF) is the sodium salt of ferulic acid, which is one of the effective components of Angelica sinensis and Lignsticum chuanxiong , and plays an important role in protecting the cardiovascular system. In this study, myocardial hypertrophy was induced by angiotensin II 0.1 μmol/L in neonatal Sprague-Dawley rat ventricular myocytes. Nine groups were designed, that is, normal, normal administration, model, L-arginine (L-arg 1000 μmol/L), SF (50, 100, 200 μmol/L) group, and N G -nitro-L-arg-methyl ester 1500 μmol/L combined with SF 200 μmol/L or L-arg 1000 μmol/L group, respectively. Cardiomyocyte hypertrophy was confirmed by observing histological changes and measurements of cell diameter, protein content and atrial natriuretic factor, and β-myosin heavy chain levels of the cells. Notably, SF could inhibit significantly myocardial hypertrophy of neonatal rat cardiomyocytes in a concentration-dependent manner without producing cytotoxicity, and the levels of nitric oxide, NO synthase (NOS), endothelial NOS, and cyclic guanosine monophosphate were increased, but the level of cyclic adenosine monophosphate was decreased in cardiomyocytes. Simultaneously, levels of protein kinase C beta, Raf-1, and extracellular regulated protein kinase 1/2 (ERK1/2) were downregulated, whereas levels of mitogen-activated protein kinase phosphatase-1 were significantly upregulated. All the beneficial effects of SF were blunted by N G -nitro-L-arg-methyl ester. Overall, these findings reveal that SF can inhibit angiotensin II-induced myocardial hypertrophy of neonatal rat cardiomyocytes, which is closely related to activation of endothelial NOS/NO/cyclic guanosine monophosphate, and inhibition of protein kinase C and mitogen-activated protein kinase signaling pathways.

Sodium tanshinone IIA sulfonate improves adverse ventricular remodeling post MI by reducing myocardial necrosis, modulating inflammation and promoting angiogenesis

BACKGROUND AND OBJECTIVE

Myocardial infarction (MI) leads to pathological cardiac remodeling and heart failure. Sodium tanshinone IIA sulfonate (STS) shows therapeutic values. The present study aimed to explore the potential role of STS in ventricular remodeling post-MI.

METHODS

Mice were randomly divided into sham, MI + normal saline (NS) and MI + STS (20.8 mg/kg/day intraperitoneally) groups. MI was established following left anterior descending artery ligation. Cardiac function was evaluated using echocardiography. Scar size and myocardial fibrosis-associated markers were detected using Masson's trichrome staining and western blot analysis (WB). Necrosis and inflammation were assessed using H&E staining, lactate dehydrogenase (LDH) detection, ELISA, immunohistochemical staining, and WB. Furthermore, angiogenesis markers and associated proteins were detected using immunohistochemical staining and WB.

RESULTS

Mice treated with STS exhibited significant improvements in cardiac function, smaller scar size, and low expression levels of α-smooth muscle actin and collagen I and III at 28 days following surgery, compared with the NS-treated group. Moreover, treatment with STS reduced eosinophil necrosis, the infiltration of inflammatory cells, plasma levels of LDH, high mobility group protein B1, interleukin-1β and tumor necrosis factor-α, and protein expression of these cytokines at 3 days. Macrophage infiltration was also decreased in the STS group in the early phase. Additionally, CD31+ vascular density, protein levels of hypoxia-inducible factor-1α, and vascular endothelial growth factor were elevated in the STS-treated mice at 28 days.

CONCLUSION

STS improved pathological remodeling post-MI, and the associated therapeutic effects may result from a decrease in myocardial necrosis, modulation of inflammation, and an increase in angiogenesis.

Sunlight Exposure and Phototherapy: Perspectives for Healthy Aging in an Era of COVID-19

Most humans depend on sunlight exposure to satisfy their requirements for vitamin D₃. However, the destruction of the ozone layer in the past few decades has increased the risk of skin aging and wrinkling caused by excessive exposure to ultraviolet (UV) radiation, which may also promote the risk of skin cancer development. The promotion of public health recommendations to avoid sunlight exposure would reduce the risk of skin cancer, but it would also enhance the risk of vitamin D₃ insufficiency/deficiency, which may cause disease development and progression. In addition, the ongoing global COVID-19 pandemic may further reduce sunlight exposure due to stay-at-home policies, resulting in difficulty in active and healthy aging. In this review article, we performed a literature search in PubMed and provided an overview of basic and clinical data regarding the impact of sunlight exposure and vitamin D₃ on public health. We also discuss the potential mechanisms and clinical value of phototherapy with a full-spectrum light (notably blue, red, and near-infrared light) as an alternative to sunlight exposure, which may contribute to combating COVID-19 and promoting active and healthy aging in current aged/superaged societies.