Epigenetic Mechanisms Involved in Inflammaging-Associated Hypertension

Vascular Inflammation and Smooth Muscle Contractility: The Role of Nox1-Derived Superoxide and LRRC8 Anion Channels

Vascular inflammation underlies the development of hypertension, and the mechanisms by which it increases blood pressure remain the topic of intense investigation. Proinflammatory factors including glucose, salt, vasoconstrictors, cytokines, wall stress, and growth factors enhance contractility and impair relaxation of vascular smooth muscle cells. These pathways share a dependence upon redox signaling, and excessive activation promotes oxidative stress that promotes vascular aging. Vascular smooth muscle cell phenotypic switching and migration into the intima contribute to atherosclerosis, while hypercontractility increases systemic vascular resistance and vasospasm that can trigger ischemia. Here, we review factors that drive the initiation and progression of this vasculopathy in vascular smooth muscle cells. Emphasis is placed on the contribution of reactive oxygen species generated by the Nox1 NADPH oxidase which produces extracellular superoxide (O2•-). The mechanisms of O2•- signaling remain poorly defined, but recent evidence demonstrates physical association of Nox1 with leucine-rich repeat containing 8 family volume-sensitive anion channels. These may provide a pathway for influx of O2•- to the cytoplasm, creating an oxidized cytoplasmic nanodomain where redox-based signals can affect both cytoskeletal structure and vasomotor function. Understanding the mechanistic links between inflammation, O2•- and vascular smooth muscle cell contractility may facilitate targeting of anti-inflammatory therapy in hypertension.

Mitochondrial DNA leakage triggers inflammation in age-related cardiovascular diseases

Mitochondrial dysfunction is one of the hallmarks of cardiovascular aging. The leakage of mitochondrial DNA (mtDNA) is increased in senescent cells, which are resistant to programmed cell death such as apoptosis. Due to its similarity to prokaryotic DNA, mtDNA could be recognized by cellular DNA sensors and trigger innate immune responses, resulting in chronic inflammatory conditions during aging. The mechanisms include cGAS-STING signaling, TLR-9 and inflammasomes activation. Mitochondrial quality controls such as mitophagy could prevent mitochondria from triggering harmful inflammatory responses, but when this homeostasis is out of balance, mtDNA-induced inflammation could become pathogenic and contribute to age-related cardiovascular diseases. Here, we summarize recent studies on mechanisms by which mtDNA promotes inflammation and aging-related cardiovascular diseases, and discuss the potential value of mtDNA in early screening and as therapeutic targets.

Genomic Instability Evolutionary Footprints on Human Health: Driving Forces or Side Effects?

In this work, we propose a comprehensive perspective on genomic instability comprising not only the accumulation of mutations but also telomeric shortening, epigenetic alterations and other mechanisms that could contribute to genomic information conservation or corruption. First, we present mechanisms playing a role in genomic instability across the kingdoms of life. Then, we explore the impact of genomic instability on the human being across its evolutionary history and on present-day human health, with a particular focus on aging and complex disorders. Finally, we discuss the role of non-coding RNAs, highlighting future approaches for a better living and an expanded healthy lifespan.

Hypertension and cellular senescence

Essential or primary hypertension is a wordwide health problem. Elevated blood pressure (BP) is closely associated not only with increased chronological aging but also with biological aging. There are various common pathways that play a role in cellular aging and BP regulation. These include but not limited to inflammation, oxidative stress, mitochondrial dysfunction, air pollution, decreased klotho activity increased renin angiotensin system activation, gut dysbiosis etc. It has already been shown that some anti-hypertensive drugs have anti-senescent actions and some senolytic drugs have BP lowering effects. In this review, we have summarized the common mechanisms underlying cellular senescence and HT and their relationships. We further reviewed the effect of various antihypertensive medications on cellular senescence and suggest further issues to be studied.

Epigenetic modifications and fetal programming: Molecular mechanisms to control hypertension inheritance

Cardiovascular diseases (CVD) are the number 1 cause of death in the United States and hypertension is a highly prevalent risk factor for CVD. It is estimated that up to 50 % of the hypertensive trait is genetically inherited while the other 50 % is determined by modifiable factors involving lifestyle, behaviors, and the environment. Interestingly, the hypertensive trait is induced or inhibited by epigenetic modifications modulated by modifiable factors. This review focused on the underlying mechanisms of stress, sleep deprivation, obesity and sedentarism as key players for epigenetic modifications contributing to the development of the hypertensive trait and, on the other hand, how epigenetic modifications induced by physical exercise and healthier habits may contribute to overturn and prevent the inheritance of hypertension trait. Furthermore, adversities during gestation and perinatal life also increase the risk for hypertension and CVD later in life, which can perpetuate the inheritance of the hypertensive trait whereas healthier habits during gestation and lactation may counteract fetal programming to improve the cardiovascular health of the progeny. Therefore, it is promising that a healthier lifestyle causes long-lasting epigenetic modifications and is transmitted to the next generation, strengthening the fight against the inheritance of hypertension.

Hypertension, type 2 diabetes, obesity, and p53 mutations negatively correlate with metastatic colorectal cancer patients' survival

Introduction

We studied the predictive and prognostic influences of hypertension (HT), type 2 diabetes (T2D), weight, and p53 mutations in metastatic colorectal cancer (CRC) patients.

Patients and methods

T2D was diagnosed according to the ADA criteria. HT was classified according to the ACC/AHA guidelines. BMI (body-mass index) was calculated and classified according to the WHO criteria. TruSigt™Oncology 500 kit was applied to construct the genomic libraries for Next Generation Sequencing (NGS) analysis. The Illumina NovaSeq 6000 technological platform and the Illumina TruSight Oncology 500 bioinformatics pipeline were applied to analyze results. Overall survival (OS) was calculated through Kaplan-Meier curves. Univariate and multivariate analyses were performed to assess the relationships between clinical and/or molecular covariates. Associations between HT, T2D, BMI, p53, and clinical variables were evaluated by the χ2 test. P < 0.05 were considered statistically significant.

Results

Two-hundred-forty-four patients were enrolled. One-hundred-twenty (49.2%), 110 (45.1%), and 50 (20.5%) patients were affected by overweight, HT, and T2D, respectively. DC (disease control) was achieved more frequently in patients without T2D (83.1%) compared to the diabetic ones (16.9%) (P = 0.0246). DC, KRAS mutational status, T2D, BMI, and concomitant presence of T2D, BMI, and HT associated with survival (P < 0.05). At multivariate analysis, age (≥65 vs. <65 years), response to first-line chemotherapy (DC vs. no DC), and concomitant presence of T2D, BMI, and HT (HR: 4.56; 95% CI: 2.40-8.67; P = 0.0217) emerged as independent prognostic variables. P53 was mutated in 31/53 analyzed cases (60.4%). The most frequent gene variants were p.Arg175His and p.Cys135Tyr. High BMI (>25 kg/m²) associated with occurrence of p53 mutations (P < 0.0001). P53 mutated patients presented a worse prognosis compared to the wild-type ones (HR: 3.21; 95% CI: 1.43-7.23; P = 0.0047).

Conclusion

Diabetic, hypertensive and overweight metastatic CRC patients are a negative prognostic subgroup deserving specific therapeutic strategies. P53 mutations associate with prognosis and BMI unrevealing complex and unexplored connections between metabolism and cancer occurrence.