Huanji Zhang

Epigenetics is closely related to cardiovascular diseases. Genome-wide linkage and association analyses and candidate gene approaches illustrate the multigenic complexity of cardiovascular disease. Several epigenetic mechanisms, such as DNA methylation, histone modification, and noncoding RNA, which are of importance for cardiovascular disease development and regression. Targeting epigenetic key enzymes, especially the DNA methyltransferases, histone methyltransferases, histone acetylases, histone deacetylases and their regulated target genes, could represent an attractive new route for the diagnosis and treatment of cardiovascular diseases. Herein, we summarize the knowledge on epigenetic history and essential regulatory mechanisms in cardiovascular diseases. Furthermore, we discuss the preclinical studies and drugs that are targeted these epigenetic key enzymes for cardiovascular diseases therapy. Finally, we conclude the clinical trials that are going to target some of these processes.

<h2>Abstract</h2><h3>Background</h3> Cardiorenal syndrome (CRS) is a complex condition characterized by the interplay of immune imbalance and inflammation. The C-reactive protein-Albumin-lymphocyte (CALLY) CALLY index serves as a new immune-nutritional scoring system, but its predictive value for CRS remains to be established. <h3>Methods</h3> In this study, we analyzed data from 27,978 participants in National Health and Nutrition Examination Survey (NHANES) from 1999 to 2010. The CALLY index was calculated as the ratio of albumin to lymphocyte, divided by C-reactive protein (CRP) multiplied by 10⁴. CRS was defined by the coexistence of cardiovascular disease and chronic kidney disease (eGFR <60 mL/min/1.73 m²). Multivariate weighted logistic regression models were employed to determine the odds ratio and 95 % confidence interval for the association between the CALLY index and CRS. Receiver operating characteristic (ROC) curves and restricted cubic spline (RCS) curves were used to assess the predictive efficacy and nonlinear relationship, respectively. <h3>Results</h3> The prevalence of CRS in the study population was 1.22 %. Our findings revealed a significant inverse relationship between the CALLY index and CRS risk, with lower CALLY index values being associated with a higher likelihood of CRS (OR = 0.95, 95 % CI = 0.94–0.96, P < 0.001). Participants in higher quartiles of the CALLY index showed a progressively reduced risk of CRS (P for trend <0.001). Moreover, the CALLY index demonstrated superior predictive performance compared to other inflammatory indicators, such as systemic immune-inflammation index (SII), neutrophil/high-density lipoprotein ratio (NHR), lymphocyte/high-density lipoprotein ratio (LHR), monocyte/high-density lipoprotein ratio (MHR), and platelet/high-density lipoprotein ratio (PHR) (AUC = 0.672, 95 % CI = 0.643–0.701). <h3>Conclusions</h3> This study underscores the significant negative correlation between the CALLY index and the risk of cardiorenal syndrome. The CALLY index emerges as a robust and independent predictor of CRS, outperforming traditional inflammatory markers. This finding highlights the potential utility of the CALLY index as a clinical tool for identifying individuals at risk for CRS.

BACKGROUND: Cardiovascular-kidney-metabolic (CKM) syndrome is characterized as a systemic disease resulting from the pathophysiological interplay among metabolic risk factors, chronic kidney disease (CKD), and cardiovascular disease (CVD). The Klotho protein may serve as a novel biomarker. However, the utility of serum Klotho levels as an indicator of severity and mortality risk in CKM syndrome remains uncertain. METHODS: This study involved 9,871 participants from the National Health and Nutrition Examination Survey (NHANES) conducted between 2007 and 2016. Serum Klotho levels were measured using an enzyme-linked immunosorbent assay kit. The optimal cutoff value was established through the maximum Youden's index. Multivariable weighted regression models were employed to calculate the odds ratio and hazard ratio, along with the 95% confidence interval, to evaluate the association between serum Klotho levels and the severity of CKM syndrome, as well as all-cause and cardiovascular mortality. Additionally, the receiver operating characteristic curve and restricted cubic spline curves were utilized to assess predictive efficacy and to explore nonlinear relationships. RESULTS: After adjusting for potential confounding factors, a non-linear relationship was seen between the Klotho protein, and CKM syndrome. In the multivariable, piecewise logistic regression, when the Serum klotho was less than 801, the risk of CKM syndrome decreased with the increase in Serum klotho (OR = 0.82, 95%CI 0.70, 0.96; p < 0.001). Furthermore, we observed the association when the Serum klotho was greater than 801 (OR = 0.94, 95%CI 0.89, 0.99; p = 0.035). The relationship between serum Klotho levels and all-cause mortality was U-shaped, while the relationship with cardiovascular mortality was L-shaped. Specifically, low serum Klotho levels were associated with an increase in all-cause mortality by 21% and cardiovascular mortality by 76% among patients with CKM syndrome. Furthermore, serum Klotho levels demonstrated excellent predictive efficacy for both the severity and mortality associated with CKM syndrome. CONCLUSIONS: This study indicates that low serum Klotho levels serve as reliable indicators of both the severity of CKM syndrome and the associated risk of mortality.

The coronary reperfusion following acute myocardial infarction can paradoxically trigger myocardial ischemia-reperfusion (IR) injury. This complex phenomenon involves the intricate interplay of different subsets of macrophages. These macrophages are crucial players in the post-infarction inflammatory response and subsequent myocardial anti-inflammatory repair. However, their diverse functions can lead to both beneficial and detrimental effects. On one hand, these macrophages play a crucial role in orchestrating the inflammatory response, aiding in the clearance of cellular debris and initiating tissue repair mechanisms. On the other hand, their excessive infiltration and activation can contribute to the perpetuation of the inflammatory cascade, leading to additional myocardial injury and adverse cardiac remodeling. Multiple mechanisms contribute to the IR injury mediated by macrophages, including oxidative stress, apoptosis, and autophagy. These processes further exacerbate the damage to the already vulnerable myocardial tissue. To address this delicate balance, therapeutic strategies aiming to target and modulate macrophage polarization and function are being explored. By fine-tuning the immune inflammatory response, such interventions hold promise in mitigating post-infarction myocardial injury and fostering a more favorable environment for myocardial healing and recovery. Through advancements in this area of research, potential anti-inflammatory interventions may pave the way for improved clinical outcomes and better management of patients after acute myocardial infarction.