Inhibition of HDACs (Histone Deacetylases) Ameliorates High-Fat Diet-Induced Hypertension Through Restoration of the MsrA (Methionine Sulfoxide Reductase A)/Hydrogen Sulfide Axis

Histone Modifications and Their Contributions to Hypertension

Essential hypertension, a multifaceted disorder, is a worldwide health problem. A complex network of genetic, epigenetic, physiological, and environmental components regulates blood pressure (BP), and any dysregulation of this network may result in hypertension. Growing evidence suggests a role for epigenetic factors in BP regulation. Any alterations in the expression or functions of these epigenetic regulators may dysregulate various determinants of BP, thereby promoting the development of hypertension. Histone posttranslational modifications are critical epigenetic regulators that have been implicated in hypertension. Several studies have demonstrated a clear association between the increased expression of some histone-modifying enzymes, especially HDACs (histone deacetylases), and hypertension. In addition, treatment with HDAC inhibitors lowers BP in hypertensive animal models, providing an excellent opportunity to design new drugs to treat hypertension. In this review, we discuss the potential contribution of different histone modifications to the regulation of BP.

Traditional Therapeutics and Potential Epidrugs for CVD: Why Not Both?

Cardiovascular disease (CVD) is the leading cause of death worldwide. In addition to the high mortality rate, people suffering from CVD often endure difficulties with physical activities and productivity that significantly affect their quality of life. The high prevalence of debilitating risk factors such as obesity, type 2 diabetes mellitus, smoking, hypertension, and hyperlipidemia only predicts a bleak future. Current traditional CVD interventions offer temporary respite; however, they compound the severe economic strain of health-related expenditures. Furthermore, these therapeutics can be prescribed indefinitely. Recent advances in the field of epigenetics have generated new treatment options by confronting CVD at an epigenetic level. This involves modulating gene expression by altering the organization of our genome rather than altering the DNA sequence itself. Epigenetic changes are heritable, reversible, and influenced by environmental factors such as medications. As CVD is physiologically and pathologically diverse in nature, epigenetic interventions can offer a ray of hope to replace or be combined with traditional therapeutics to provide the prospect of addressing more than just the symptoms of CVD. This review discusses various risk factors contributing to CVD, perspectives of current traditional medications in practice, and a focus on potential epigenetic therapeutics to be used as alternatives.

Hypertension Related to Obesity: Pathogenesis, Characteristics and Factors for Control

The World Health Organization (WHO) refers to obesity as abnormal or excessive fat accumulation that presents a health risk. Obesity was first designated as a disease in 2012 and since then the cost and the burden of the disease have witnessed a worrisome increase. Obesity and hypertension are closely interrelated as abdominal obesity interferes with the endocrine and immune systems and carries a greater risk for insulin resistance, diabetes, hypertension, and cardiovascular disease. Many factors are at the interplay between obesity and hypertension. They include hemodynamic alterations, oxidative stress, renal injury, hyperinsulinemia, and insulin resistance, sleep apnea syndrome and the leptin-melanocortin pathway. Genetics, epigenetics, and mitochondrial factors also play a major role. The measurement of blood pressure in obese patients requires an adapted cuff and the search for other secondary causes is necessary at higher thresholds than the general population. Lifestyle modifications such as diet and exercise are often not enough to control obesity, and so far, bariatric surgery constitutes the most reliable method to achieve weight loss. Nonetheless, the emergence of new agents such as Semaglutide and Tirzepatide offers promising alternatives. Finally, several molecular pathways are actively being explored, and they should significantly extend the treatment options available.

Increasing angiotensin-converting enzyme 1 regulated by histone 3 lysine 27 hyperacetylation in high-fat diet-induced hypertensive rat kidney

BACKGROUND

Obesity is a key risk factor of hypertension. Angiotensin-converting enzyme 1 (ACE1) is a key enzyme involved in the renin-angiotensin-aldosterone system (RAAS), which contributes to obesity-related hypertension (OrHTN). Emerging evidence has shown that histone acetylation is also involved in OrHTN. As kidney is an effector organ that activates the RAAS by secreting renin after hypertension occurs, this study aimed to explore the regulatory role of histone acetylation on renal RAAS expression.

METHODS

Nineteen male Wistar rats were randomly divided into a control group ( n  = 9, fed normal chow) and a high-fat diet (HFD) group ( n  = 10, fed HFD for 16 weeks). The renal transcriptome and histone acetylation spectrum was analyzed by RNA sequencing and tandem mass spectrometry and was further confirmed by RT-qPCR, western blot, and immunohistochemistry. Then, chromatin immunoprecipitation (ChIP)-qPCR analysis was performed for the detection of DNA-protein interaction.

RESULTS

After 16-week HFD, the rats became obese with increased plasma triglyceride and high blood pressure. Increased ACE1 and histone 3 lysine 27 acetylation (H3K27ac) expression levels were found in OrHTN rat kidneys. The following ChIP-qPCR analysis illustrated that the upregulation of ACE1 transcription was mediated by increased H3K27ac.

CONCLUSION

H3K27ac could be an important histone acetylation site that activates renal ACE1 in HFD-induced hypertensive rats.