Novel methylation mark and essential hypertension

Identification of potential diagnostic biomarkers for hypertension via integrated analysis of gene expression and DNA methylation

OBJECTIVE

Hypertension refers to the elevated blood pressure (BP) in arteries, with a BP reading of 140/90 mm Hg or higher in adults. Over 40% of >25-year-old population have suffered from hypertension. Thus, this study aimed to find novel diagnostic biomarkers for hypertension.

METHODS

All hypertension-related mRNA and methylation datasets were downloaded from the GEO database. Liner model method was used to identify differentially expressed genes (DEGs) between hypertension and control groups. Gene Ontology and Kyoto Encyclopaedia of Genes and Genomes enrichment analysis was employed to obtain functional information. CpG sites and the corresponding genes associated with hypertension were screened using epigenome-wide association study (EWAS) analysis.

RESULTS

There were 37 DEGs between the hypertension group and control group, which were significantly enriched in 84 Biological Process terms, 31 Cellular Component terms, 18 Molecular Function terms and 9 signalling pathways. EWAS results indicated that 1072 CpG sites were associated with hypertension occurrence, corresponding to 1029 genes. After cross-analysis, complement factor D (CFD) and OTU deubiquitinase, ubiquitin aldehyde binding 2 (OTUB2) with methylation modification were identified as diagnostic markers for hypertension.

CONCLUSION

In conclusion, CFD and OTUB2 were potential biomarkers of hypertension occurrence. Our results will provide more information for hypertension diagnosis and would be more reliable combined with multiple biomarkers.

Epigenetics of hypertension as a risk factor for the development of coronary artery disease in type 2 diabetes mellitus

Hypertension, a multifaceted cardiovascular disorder influenced by genetic, epigenetic, and environmental factors, poses a significant risk for the development of coronary artery disease (CAD) in individuals with type 2 diabetes mellitus (T2DM). Epigenetic alterations, particularly in histone modifications, DNA methylation, and microRNAs, play a pivotal role in unraveling the complex molecular underpinnings of blood pressure regulation. This review emphasizes the crucial interplay between epigenetic attributes and hypertension, shedding light on the prominence of DNA methylation, both globally and at the gene-specific level, in essential hypertension. Additionally, histone modifications, including acetylation and methylation, emerge as essential epigenetic markers linked to hypertension. Furthermore, microRNAs exert regulatory influence on blood pressure homeostasis, targeting key genes within the aldosterone and renin-angiotensin pathways. Understanding the intricate crosstalk between genetics and epigenetics in hypertension is particularly pertinent in the context of its interaction with T2DM, where hypertension serves as a notable risk factor for the development of CAD. These findings not only contribute to the comprehensive elucidation of essential hypertension but also offer promising avenues for innovative strategies in the prevention and treatment of cardiovascular complications, especially in the context of T2DM.

N6-methyladenosine modification in ischemic stroke: Functions, regulation, and therapeutic potential

N6-methyladenosine (m6A) modification is the most frequently occurring internal modification in eukaryotic RNAs. By modulating various aspects of the RNA life cycle, it has been implicated in a wide range of pathological and physiological processes associated with human diseases. Ischemic stroke is a major cause of death and disability worldwide with few treatment options and a narrow therapeutic window, and accumulating evidence has indicated the involvement of m6A modifications in the development and progression of this type of stroke. In this review, which provides insights for the prevention and clinical treatment of stroke, we present an overview of the roles played by m6A modification in ischemic stroke from three main perspectives: (1) the association of m6A modification with established risk factors for stroke, including hypertension, diabetes mellitus, hyperlipidemia, obesity, and heart disease; (2) the roles of m6A modification regulators and their functional regulation in the pathophysiological injury mechanisms of stroke, namely oxidative stress, mitochondrial dysfunction, endothelial dysfunction, neuroinflammation, and cell death processes; and (3) the diagnostic and therapeutic potential of m6A regulators in the treatment of stroke.

Epigenetic Signatures in Hypertension

Clear epigenetic signatures were found in hypertensive and pre-hypertensive patients using DNA methylation data and neural networks in a classification algorithm. It is shown how by selecting an appropriate subset of CpGs it is possible to achieve a mean accuracy classification of 86% for distinguishing control and hypertensive (and pre-hypertensive) patients using only 2239 CpGs. Furthermore, it is also possible to obtain a statistically comparable model achieving an 83% mean accuracy using only 22 CpGs. Both of these approaches represent a substantial improvement over using the entire amount of available CpGs, which resulted in the neural network not generating accurate classifications. An optimization approach is followed to select the CpGs to be used as the base for a model distinguishing between hypertensive and pre-hypertensive individuals. It is shown that it is possible to find methylation signatures using machine learning techniques, which can be applied to distinguish between control (healthy) individuals, pre-hypertensive individuals and hypertensive individuals, illustrating an associated epigenetic impact. Identifying epigenetic signatures might lead to more targeted treatments for patients in the future.

Biotechnological and endophytic-mediated production of centellosides in Centella asiatica

In vitro culture of a plant cell, tissue and organ is a marvellous, eco-friendly biotechnological strategy for the production of phytochemicals. With the emergence of recent biotechnological tools, genetic engineering is now widely practiced enhancing the quality and quantity of plant metabolites. Triterpenoid saponins especially asiaticoside and madecassoside of Centella asiatica (L.) Urb. are popularly known for their neuroprotective activity. It has become necessary to increase the production of asiaticoside and madecassoside because of their high pharmaceutical and industrial demand. Thus, the review aims to provide efficient biotechnological tools along with proper strategies. This review also included a comparative analysis of various carbon sources and biotic and abiotic elicitors. The vital roles of a variety of plant growth regulators and their combinations have also been evaluated at different in vitro growth stages of Centella asiatica. Selection of explants, direct and callus-mediated organogenesis, root organogenesis, somatic embryogenesis, synthetic seed production etc. are also highlighted in this study. In a nutshell, this review will present the research outcomes of different biotechnological interventions used to increase the yield of triterpenoid saponins in C. asiatica. KEY POINTS: • Critical and updated assessment on in vitro biotechnology in C. asiatica. • In vitro propagation of C. asiatica and elicitation of triterpenoid saponins production. • Methods for mass producing C. asiatica.

Genetic Modifications to Alter Blood Pressure Level

Genetic manipulation is one of the indispensable techniques to examine gene functions both in vitro and in vivo. In particular, cardiovascular phenotypes such as blood pressure cannot be evaluated in vitro system, necessitating the creation of transgenic or gene-targeted knock-out and knock-in experimental animals to understand the pathophysiological roles of specific genes on the disease conditions. Although genome-wide association studies (GWAS) in various human populations have identified multiple genetic variations associated with increased risk for hypertension and/or its complications, the causal links remain unresolved. Genome-editing technologies can be applied to many different types of cells and organisms for creation of knock-out/knock-in models. In the post-GWAS era, it may be more worthwhile to validate pathophysiological implications of the risk variants and/or candidate genes by creating genome-edited organisms.

DNA N6-Methyladenine Modification in Eukaryotic Genome

DNA methylation is treated as an important epigenetic mark in various biological activities. In the past, a large number of articles focused on 5 mC while lacking attention to N6-methyladenine (6 mA). The presence of 6 mA modification was previously discovered only in prokaryotes. Recently, with the development of detection technologies, 6 mA has been found in several eukaryotes, including protozoans, metazoans, plants, and fungi. The importance of 6 mA in prokaryotes and single-celled eukaryotes has been widely accepted. However, due to the incredibly low density of 6 mA and restrictions on detection technologies, the prevalence of 6 mA and its role in biological processes in eukaryotic organisms are highly debated. In this review, we first summarize the advantages and disadvantages of 6 mA detection methods. Then, we conclude existing reports on the prevalence of 6 mA in eukaryotic organisms. Next, we highlight possible methyltransferases, demethylases, and the recognition proteins of 6 mA. In addition, we summarize the functions of 6 mA in eukaryotes. Last but not least, we summarize our point of view and put forward the problems that need further research.