Atherosclerotic Calcification: Wnt Is the Hint

Glycemic variability is associated with vascular calcification by the markers of endoplasmic reticulum stress-related apoptosis, Wnt1, galectin-3 and BMP-2

BACKGROUND

The present study identified whether glycemic variability (GV) was associated with vascular calcification and explored the underlying mechanisms.

METHODS

Eighty-four consecutive type 2 diabetic patients with unstable angina (UA) were included from January 2018 to June 2018 to calculate calcification scores using computerized tomographic angiography (CTA), and the patients were divided into 2 groups: high calcification score group (HCS group) and low calcification score group (LCS group). Intergroup differences in GV were determined via comparisons of the standard deviation (SD) of blood glucose. Calcification staining, content measurement, apoptosis evaluation and Western blot analysis of endoplasmic reticulum (ER) stress-related apoptosis, Wnt1, galectin-3 and bone morphogenetic protein-2 (BMP-2) were compared in cell cultures from rat vascular smooth muscle cells in the different degrees of GV.

RESULTS

The SD increased significantly with the increases in calcification scores from human studies (HCS group 2.37 ± 0.82 vs. LCS group 1.87 ± 0.78, p = 0.007). Multivariate logistic regression analysis suggested that increased SD and serum creatinine were independent predictors of calcification. The high GV group had a higher apoptotic rate, higher calcification content and higher expressions of glucose-regulated protein, caspase-3, Wnt1, galectin-3 and BMP-2 markers compared to the low GV group in the in vitro studies (p < 0.001).

CONCLUSION

We report the novel finding that GV is associated with vascular calcification, and ER stress-related apoptosis, Wnt1, galectin-3 and BMP-2 may be involved in this regulation.

The Interplay of SIRT1 and Wnt Signaling in Vascular Calcification

Vascular calcification is a major health risk and is highly correlated with atherosclerosis, diabetes, and chronic kidney disease. The development of vascular calcification is an active and complex process linked with a multitude of signaling pathways, which regulate promoters and inhibitors of osteogenesis, the balance of which become deregulated in disease conditions. SIRT1, a protein deacetylase, known to be protective in inhibiting oxidative stress and inflammation within the vessel wall, has been shown as a possible key player in modulating the cell-fate determining canonical Wnt signaling pathways. Suppression of SIRT1 has been reported in patients suffering with cardiovascular pathologies, suggesting that the sustained acetylation of osteogenic factors could contribute to their activation and in turn, lead to the progression of calcification. There is clear evidence of the synergy between β-Catenin and elevated Runx2, and with Wnt signaling being β-Catenin dependent, further understanding is needed as to how these molecular pathways converge and interact, in order to provide novel insight into the mechanism by which smooth muscle cells switch to an osteogenic differentiation programme. Therefore, this review will describe the current concepts of pathological soft tissue mineralization, with a focus on the contribution of SIRT1 as a regulator of Wnt signaling and its targets, discussing SIRT1 as a potential target for manipulation and therapy.

Senescent Microvesicles: A Novel Advance in Molecular Mechanisms of Atherosclerotic Calcification

Atherosclerosis, a chronic inflammatory disease that causes the most heart attacks and strokes in humans, is the leading cause of death in the developing world; its principal clinical manifestation is coronary artery disease. The development of atherosclerosis is attributed to the aging process itself (biological aging) and is also associated with the development of chronic diseases (premature aging). Both aging processes produce an increase in risk factors such as oxidative stress, endothelial dysfunction and proinflammatory cytokines (oxi-inflamm-aging) that might generate endothelial senescence associated with damage in the vascular system. Cellular senescence increases microvesicle release as carriers of molecular information, which contributes to the development and calcification of atherosclerotic plaque, as a final step in advanced atherosclerotic plaque formation. Consequently, this review aims to summarize the information gleaned to date from studies investigating how the senescent extracellular vesicles, by delivering biological signalling, contribute to atherosclerotic calcification.

Nutriepigenetics and cardiovascular disease

PURPOSE OF REVIEW

We present a current perspective of epigenetic alterations that can lead to cardiovascular disease (CVD) and the potential of dietary factors to counteract their actions. In addition, we discuss the challenges and opportunities of dietary treatments as epigenetic modifiers for disease prevention and therapy.

RECENT FINDINGS

Recent epigenome-wide association studies along with candidate gene approaches and functional studies in cell culture and animal models have delineated mechanisms through which nutrients, food compounds and dietary patterns may affect the epigenome. Several risk factors for CVD, including adiposity, inflammation and oxidative stress, have been associated with changes in histone acetylation, lower global DNA methylation levels and shorter telomere length. A surplus of macronutrients such as in a high-fat diet or deficiencies of specific nutrients such as folate and other B-vitamins can affect the activity of DNA methyltransferases and histone-modifying enzymes, affecting foetal growth, glucose/lipid metabolism, oxidative stress, inflammation and atherosclerosis. Bioactive compounds such as polyphenols (resveratrol, curcumin) or epigallocatechin may activate deacetylases Sirtuins (SIRTs), histone deacetylases or acetyltransferases and in turn the response of inflammatory mediators. Adherence to cardioprotective dietary patterns, such as the Mediterranean diet (MedDiet), has been associated with altered methylation and expression of genes related to inflammation and immuno-competence.

SUMMARY

The mechanisms through which nutrients and dietary patterns may alter the cardiovascular epigenome remain elusive. The research challenge is to determine which of these nutriepigenetic effects are reversible, so that novel findings translate into effective dietary interventions to prevent CVD or its progression.