Effects from the induction of heat shock proteins in a murine model due to progression of aortic atherosclerosis

Lack of alpha CGRP exacerbates the development of atherosclerosis in ApoE-knockout mice

The effects of calcitonin gene-related peptide (CGRP) on atherosclerosis remain unclear. We used apolipoprotein E-deficient (ApoE-/-) mice to generate double-knockout ApoE-/-:CGRP-/- mice lacking alpha CGRP. ApoE-/-:CGRP-/- mice exhibited larger atherosclerotic plaque areas, peritoneal macrophages with enhanced migration functions, and elevated levels of the inflammatory cytokine tumor necrosis factor (TNF)-⍺. Thus, we also explored whether inhibiting TNF-⍺ could improve atherosclerosis in ApoE-/-:CGRP-/- mice by administering etanercept intraperitoneally once a week (5 mg/kg) alongside a high-fat diet for 2 weeks. This treatment led to significant reductions in aortic root lesion size, atherosclerotic plaque area and macrophage migration in ApoE-/-:CGRP-/- mice compared with mice treated with human IgG (5 mg/kg). We further examined whether results observed in ApoE-/-:CGRP-/- mice could similarly be obtained by administering a humanized monoclonal CGRP antibody, galcanezumab, to ApoE-/- mice. ApoE-/- mice were subcutaneously administered galcanezumab at an initial dose of 50 mg/kg, followed by a dose of 30 mg/kg in the second week. Galcanezumab administration did not affect systolic blood pressure, serum lipid levels, or macrophage migration but led to a significant increase in lipid deposition at the aortic root. These findings suggest that alpha CGRP plays a critical role in inhibiting the progression of atherosclerosis.

The role of heat shock proteins in the pathogenesis of heart failure (Review)

The influence of heat shock proteins (HSPs) on protein quality control systems in cardiomyocytes is currently under investigation. The effect of HSPs on the regulated cell death of cardiomyocytes (CMCs) is of great importance, since they play a major role in the implementation of compensatory and adaptive mechanisms in the event of cardiac damage. HSPs mediate a number of mechanisms that activate the apoptotic cascade, playing both pro‑ and anti‑apoptotic roles depending on their location in the cell. Another type of cell death, autophagy, can in some cases lead to cell death, while in other situations it acts as a cell survival mechanism. The present review considered the characteristics of the expression of HSPs of different molecular weights in CMCs in myocardial damage caused by heart failure, as well as their role in the realization of certain types of regulated cell death.

T Cells in Atherosclerosis: Key Players in the Pathogenesis of Vascular Disease

Atherosclerosis is a chronic inflammatory disease characterized by the accumulation of lipid-rich plaques within arterial walls. T cells play a pivotal role in the pathogenesis of atherosclerosis in which they help orchestrate immune responses and contribute to plaque development and instability. Here, we discuss the recognition of atherosclerosis-related antigens that may trigger T cell activation together with additional signaling from co-stimulatory molecules and lesional cytokines. Although few studies have indicated candidates for the antigen specificity of T cells in atherosclerosis, further research is needed. Furthermore, we describe the pro-atherogenic and atheroprotective roles of diverse subsets of T cells such as CD4+ helper, CD8+ cytotoxic, invariant natural killer, and γδ T cells. To classify and quantify T cell subsets in atherosclerosis, we summarize current methods to analyze cellular heterogeneity including single cell RNA sequencing and T cell receptor (TCR) sequencing. Further insights into T cell biology will help shed light on the immunopathology of atherosclerosis, inform potential therapeutic interventions, and pave the way for precision medicine approaches in combating cardiovascular disease.

Smooth muscle α-actin missense variant promotes atherosclerosis through modulation of intracellular cholesterol in smooth muscle cells

AIMS

The variant p.Arg149Cys in ACTA2, which encodes smooth muscle cell (SMC)-specific α-actin, predisposes to thoracic aortic disease and early onset coronary artery disease in individuals without cardiovascular risk factors. This study investigated how this variant drives increased atherosclerosis.

METHODS AND RESULTS

Apoe-/- mice with and without the variant were fed a high-fat diet for 12 weeks, followed by evaluation of atherosclerotic plaque formation and single-cell transcriptomics analysis. SMCs explanted from Acta2R149C/+ and wildtype (WT) ascending aortas were used to investigate atherosclerosis-associated SMC phenotypic modulation. Hyperlipidemic Acta2R149C/+Apoe-/- mice have a 2.5-fold increase in atherosclerotic plaque burden compared to Apoe-/- mice with no differences in serum lipid levels. At the cellular level, misfolding of the R149C α-actin activates heat shock factor 1, which increases endogenous cholesterol biosynthesis and intracellular cholesterol levels through increased HMG-CoA reductase (HMG-CoAR) expression and activity. The increased cellular cholesterol in Acta2R149C/+ SMCs induces endoplasmic reticulum stress and activates PERK-ATF4-KLF4 signaling to drive atherosclerosis-associated phenotypic modulation in the absence of exogenous cholesterol, while WT cells require higher levels of exogenous cholesterol to drive phenotypic modulation. Treatment with the HMG-CoAR inhibitor pravastatin successfully reverses the increased atherosclerotic plaque burden in Acta2R149C/+Apoe-/- mice.

CONCLUSION

These data establish a novel mechanism by which a pathogenic missense variant in a smooth muscle-specific contractile protein predisposes to atherosclerosis in individuals without hypercholesterolemia or other risk factors. The results emphasize the role of increased intracellular cholesterol levels in driving SMC phenotypic modulation and atherosclerotic plaque burden.

Mechanistic insights into heat shock protein 27, a potential therapeutic target for cardiovascular diseases

Heat shock protein 27 (HSP27) is a small chaperone protein that is overexpressed in a variety of cellular stress states. It is involved in regulating proteostasis and protecting cells from multiple sources of stress injury by stabilizing protein conformation and promoting the refolding of misfolded proteins. Previous studies have confirmed that HSP27 is involved in the development of cardiovascular diseases and plays an important regulatory role in this process. Herein, we comprehensively and systematically summarize the involvement of HSP27 and its phosphorylated form in pathophysiological processes, including oxidative stress, inflammatory responses, and apoptosis, and further explore the potential mechanisms and possible roles of HSP27 in the diagnosis and treatment of cardiovascular diseases. Targeting HSP27 is a promising future strategy for the treatment of cardiovascular diseases.

Proteotoxic stress response in atherosclerotic cardiovascular disease: Emerging role of heat shock factor 1

Atherosclerosis is a major risk factor for cardiovascular diseases. Hypercholesterolemia has been both clinically and experimentally linked to cardiovascular disease and is involved in the initiation of atherosclerosis. Heat shock factor 1 (HSF1) is involved in the control of atherosclerosis. HSF1 is a critical transcriptional factor of the proteotoxic stress response that regulates the production of heat shock proteins (HSPs) and other important activities such as lipid metabolism. Recently, HSF1 is reported to directly interact with and inhibit AMP-activated protein kinase (AMPK) to promote lipogenesis and cholesterol synthesis. This review highlights roles of HSF1 and HSPs in critical metabolic pathways of atherosclerosis, including lipogenesis and proteome homeostasis.

Gene and Protein Accumulation Changes Evoked in Porcine Aorta in Response to Feeding with Two Various Fructan Sources

In this study, two different ITFs sources were incorporated into a cereal-based diet to evaluate possible aortic protein and gene changes in nursery pigs. The animals were fed two different experimental diets from the 10th day of life, supplemented with either 4% of dried chicory root (CR) or with 2% of native inulin (IN). After a 40-day dietary intervention trial, pigs were sacrificed at day 50 and the aortas were harvested. Our data indicate that dietary ITFs have the potential to influence several structural and physiological changes that are reflected both in the mRNA and protein levels in porcine aorta. In contrast to our hypothesis, we could not show any beneficial effects of a CR diet on vascular functions. The direction of changes of several proteins and genes may indicate disrupted ECM turnover (COL6A1 and COL6A2, MMP2, TIMP3, EFEMP1), increased inflammation and lipid accumulation (FFAR2), as well as decreased activity of endothelial nitric oxide synthase (TXNDC5, ORM1). On the other hand, the IN diet may counteract a highly pro-oxidant environment through the endothelin-NO axis (CALR, TCP1, HSP8, PDIA3, RCN2), fibrinolytic activity (ANXA2), anti-atherogenic (CAVIN-1) and anti-calcification (LMNA) properties, thus contributing to the maintenance of vascular homeostasis.

Immunological mechanisms of exercise therapy in dyslipidemia

Numerous studies demonstrated the strong link between dyslipidemia and the cardiovascular risk. Physical activity and exercise represent effective prevention and therapy strategies for dyslipidemia and at the same time counteract numerous comorbidities that often accompany the disease. The physiological mechanisms are manifold, and primary mechanisms might be an increased energy consumption and associated adaptations of the substrate metabolism. Recent studies showed that there are bidirectional interactions between dyslipidemia and the immune system. Thus, abnormal blood lipids may favor pro-inflammatory processes, and at the same time inflammatory processes may also promote dyslipidemia. Physical activity has been shown to affect numerous immunological processes and has primarily anti-inflammatory effects. These are manifested by altered leukocyte subtypes, cytokine patterns, stress protein expression, and by reducing hallmarks of immunosenescence. The aim of this review is to describe the effects of exercise on the treatment dyslipidemia and to discuss possible immunological mechanisms against the background of the current literature.

With or without You: Co-Chaperones Mediate Health and Disease by Modifying Chaperone Function and Protein Triage

Heat shock proteins (HSPs) are a family of molecular chaperones that regulate essential protein refolding and triage decisions to maintain protein homeostasis. Numerous co-chaperone proteins directly interact and modify the function of HSPs, and these interactions impact the outcome of protein triage, impacting everything from structural proteins to cell signaling mediators. The chaperone/co-chaperone machinery protects against various stressors to ensure cellular function in the face of stress. However, coding mutations, expression changes, and post-translational modifications of the chaperone/co-chaperone machinery can alter the cellular stress response. Importantly, these dysfunctions appear to contribute to numerous human diseases. Therapeutic targeting of chaperones is an attractive but challenging approach due to the vast functions of HSPs, likely contributing to the off-target effects of these therapies. Current efforts focus on targeting co-chaperones to develop precise treatments for numerous diseases caused by defects in protein quality control. This review focuses on the recent developments regarding selected HSP70/HSP90 co-chaperones, with a concentration on cardioprotection, neuroprotection, cancer, and autoimmune diseases. We also discuss therapeutic approaches that highlight both the utility and challenges of targeting co-chaperones.