What is the mechanism of genetic contributions to the development of atherosclerosis?

Subclinical atherosclerosis in Behcet's disease and its inverse relation to azathioprine use: an updated meta-analysis

To evaluate the intima media thickness of carotid arteries (IMT) and its clinical, laboratory and treatment correlates in Behcet's disease (BD). Systematic search of EMBASE and PubMed databases from January 2016 to October 2022; we employed random effect meta-analyses for continuous outcomes and Peto's odds ratio for rare events. The meta-analysis included 36 case control studies: the IMT was greater in BD (n = 1103) than in controls (n = 832) (p < 0.0001) with wide heterogeneity (I2 = 86.9%); a sensitivity analysis that included mean age of BD participants, gender, disease duration and activity, atherogenic index of plasma, blood pressure, C-reactive protein, ethnicity, smoking status, anti-inflammatory and immune suppressive agents, revealed that male gender, mean age of participants and azathioprine use (the latter two in inverse fashion) partly explained the heterogeneity variance (p = 0.02, p = 0.005, and p = 0.01). The IMT was greater in vascular (n = 114) than in non-vascular BD (n = 214) (p = 0.006). BD patients (n = 782) had a greater pooled prevalence of carotid plaques than controls (n = 537) (13.1% vs. 2.97%, p < 0.0001). Subclinical carotid artery atherosclerosis represents a vascular feature of BD, independently of the traditional cardiovascular risk factors. The inverse correlations between IMT, age and azathioprine use suggest that thicker carotid arteries at disease onset eventually regress with immune suppressive treatment: this assumption needs verification on adequately designed clinical trials.

Atherosclerosis and Inflammation: Insights from the Theory of General Pathological Processes

Recent advances have greatly improved our understanding of the molecular mechanisms behind atherosclerosis pathogenesis. However, there is still a need to systematize this data from a general pathology perspective, particularly with regard to atherogenesis patterns in the context of both canonical and non-classical inflammation types. In this review, we analyze various typical phenomena and outcomes of cellular pro-inflammatory stress in atherosclerosis, as well as the role of endothelial dysfunction in local and systemic manifestations of low-grade inflammation. We also present the features of immune mechanisms in the development of productive inflammation in stable and unstable plaques, along with their similarities and differences compared to canonical inflammation. There are numerous factors that act as inducers of the inflammatory process in atherosclerosis, including vascular endothelium aging, metabolic dysfunctions, autoimmune, and in some cases, infectious damage factors. Life-critical complications of atherosclerosis, such as cardiogenic shock and severe strokes, are associated with the development of acute systemic hyperinflammation. Additionally, critical atherosclerotic ischemia of the lower extremities induces paracoagulation and the development of chronic systemic inflammation. Conversely, sepsis, other critical conditions, and severe systemic chronic diseases contribute to atherogenesis. In summary, atherosclerosis can be characterized as an independent form of inflammation, sharing similarities but also having fundamental differences from low-grade inflammation and various variants of canonical inflammation (classic vasculitis).

Cardiovascular risk factor mediation of the effects of education and Genetic Risk Score on cardiovascular disease: a prospective observational cohort study of the Framingham Heart Study

OBJECTIVES

Level of education and genetic risk are key predictors of cardiovascular disease (CVD). While several studies have explored the causal mechanisms of education effects, it remains uncertain to what extent genetic risk is mediated by established CVD risk factors. This study sought to investigate this and explored the mediation of education and genetic effects on CVD by established cardiovascular risk factors in the Framingham Heart Study (FHS).

DESIGN

Prospective observational cohort study.

PARTICIPANTS

7017 participants from the FHS.

SETTING

Community-based cohort of adults in Framingham, Massachusetts, USA.

PRIMARY OUTCOME MEASURE

Incident CVD. The total effects of education and genetic predisposition using a 63-variant genetic risk score (GRS) on CVD, as well as those mediated by established CVD risk factors, were assessed via mediation analysis based on the counterfactual framework using Cox proportional hazards regression models.

RESULTS

Over a median follow-up time of 12.0 years, 1091 participants experienced a CVD event. Education and GRS displayed significant associations with CVD after adjustment for age and sex and the established risk factors smoking, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), body mass index, systolic blood pressure (SBP) and diabetes. For education effects, smoking, HDL-C and SBP were estimated to mediate 18.8% (95% CI 9.5% to 43%), 11.5% (95% CI 5.7% to 29.0%) and 4.5% (95% CI 1.6% to 13.3%) of the total effect of graduate degree, respectively, with the collective of all risk factors combined mediating 38.5% (95% 24.1% to 64.9%). A much smaller proportion of the effects of GRS were mediated by established risk factors combined (17.6%, 95% CI 2.4% to 35.7%), with HDL-C and TC mediating 11.5% (95% CI 6.2% to 21.5%) and 3.1% (95% CI 0.2% to 8.3%), respectively.

CONCLUSIONS

Unlike education inequalities, established risk factors mediated only a fraction of GRS effects on CVD. Further research is required to elucidate the underlying causal mechanisms of genetic contributions to CVD.

Dickkopf‑1/cysteine‑rich angiogenic inducer 61 axis mediates palmitic acid‑induced inflammation and apoptosis of vascular endothelial cells

Cardiovascular diseases (CVDs) are a major cause of mortality around the world, and the presence of atherosclerosis is the most common characteristic in patients with CVDs. Cysteine-rich angiogenic inducer 61 (CCN1) has been reported to serve an important role in the pathogenesis of atherosclerotic lesions. The aim of the present study was to investigate whether CCN1 could regulate the inflammation and apoptosis of endothelial cells induced by palmitic acid (PA). Dickkopf-1 (DKK1) is an important antagonist of the Wnt signaling pathway, which can specifically inhibit the classic Wnt signaling pathway. Firstly, the mRNA and protein expression levels of CCN1 were detected. Additionally, endothelial nitric oxide (NO) synthase (eNOS), DKK1, β-catenin, and inflammation- and apoptosis-associated proteins were measured. Detection of NO was performed using a commercial kit. The expression levels of inflammatory cytokines were assessed to explore the effect of CCN1 on PA-induced inflammation. TUNEL assay was used to detect the apoptosis of endothelial cells. The results revealed that PA upregulated the expression levels of CCN1, inflammatory cytokines and pro-apoptotic proteins in endothelial cells. PA decreased the production of NO, and the levels of phosphorylated-eNOS, whereas knockdown of CCN1 partially abrogated these effects triggered by PA. Furthermore, the Wnt/β-catenin signaling pathway was activated in PA-induced endothelial cells; however, the levels of DKK1 were downregulated. Overexpression of DKK1 could reduce CCN1 expression via inactivation of the Wnt/β-catenin signaling pathway. In conclusion, knockdown of CCN1 attenuated PA-induced inflammation and apoptosis of endothelial cells via inactivating the Wnt/β-catenin signaling pathway.