The impact of protein oxidation on sustained and white coat hypertension

DNA damage and arterial hypertension. A systematic review and meta-analysis

Oxidative DNA damage markers (8OHdG, comet assay, gammaH2AX) are becoming widely used in clinical cardiology research. To conduct this review of DNA damage in relation to hypertension in humans, we used databases (e.g. PubMed, Web of Science) to search for English-language publications up to June 30, 2022 and the terms: DNA damage, comet assay, gammaH2AX, 8OHdG, strand breaks, and arterial hypertension. Exclusion criteria were: children, absence of relevant controls, extra-arterial hypertensive issues, animal, cell lines. From a total of 79526, 15 human studies were selected. A total of 902 hypertensive patients (pts): (comet: N=418 pts; 8OHdG: N=484 pts) and 587 controls (comet: N=203; 8OHdG: N=384) were included. DNA damage was significantly higher in hypertensive pts than healthy controls (comet 26.6±11.0 vs 11.7±4.07 arbitrary units /A.U./; P<0.05 and="" 8ohdg="" 13="" 1="" 4="" 12="" vs="" 6="" 97="" 2="" 67="" ng="" mg="" creatinine="" i=""> P<0.05) confirmed with meta-analysis for both. Greater DNA damage was observed in more adverse cases (concentric cardiac hypertrophy 43.4±15.4 vs 15.6±5.5; sustained/untreated hypertension 31.4±12.1 vs 14.2±5/35.0±5.0 vs 25.0 ±5.0; non-dippers 39.2±15.5 vs 29.4±11.1 A.U.; elderly 14.9±4.5 vs 9.3±4.1 ng/mg creatinine; without carvedilol 9.1±4.2 vs 5.7±3.9; with coronary heart disease 0.5±0.1 vs 0.2±0.1 ng/mL) (P<0.05) confirmed with meta-analysis. DNA damage correlated strongly positively with serum glycosylated haemoglobin (r=0.670; P<0.05) and negatively with total antioxidant status (r=-0.670 to -0.933; P<0.05). This is the first systematic review with meta-analysis showing that oxidative DNA damage was increased in humans with arterial hypertension compared to controls.

Oxidative Stress and Hypertension

A link between oxidative stress and hypertension has been firmly established in multiple animal models of hypertension but remains elusive in humans. While initial studies focused on inactivation of nitric oxide by superoxide, our understanding of relevant reactive oxygen species (superoxide, hydrogen peroxide, and peroxynitrite) and how they modify complex signaling pathways to promote hypertension has expanded significantly. In this review, we summarize recent advances in delineating the primary and secondary sources of reactive oxygen species (nicotinamide adenine dinucleotide phosphate oxidases, uncoupled endothelial nitric oxide synthase, endoplasmic reticulum, and mitochondria), the posttranslational oxidative modifications they induce on protein targets important for redox signaling, their interplay with endogenous antioxidant systems, and the role of inflammasome activation and endoplasmic reticular stress in the development of hypertension. We highlight how oxidative stress in different organ systems contributes to hypertension, describe new animal models that have clarified the importance of specific proteins, and discuss clinical studies that shed light on how these processes and pathways are altered in human hypertension. Finally, we focus on the promise of redox proteomics and systems biology to help us fully understand the relationship between ROS and hypertension and their potential for designing and evaluating novel antihypertensive therapies.

Apelin, Omentin-1, and Vaspin in patients with essential hypertension: association of adipokines with trace elements, inflammatory cytokines, and oxidative damage markers

BACKGROUND

Hypertension (HT) is a disease associated with endothelial dysfunction which is related to some adipokines and pro- and anti-inflammatory cytokines.

AIMS

Our aim was to investigate roles of apelin, omentin-1, and vaspin in essential HT and to evaluate their relationships with other pro- and anti-inflammatory cytokines, trace elements, and oxidative stress. We also investigated these parameters to determine asymptomatic target organ damage period and grading essential hypertension.

METHODS

One hundred fifty-three patients diagnosed with essential hypertension and 45 healthy controls were included in the study. Hypertension was defined as a systolic blood pressure > 140 mmHg and/or a diastolic blood pressure > 90 mm Hg or current use of an antihypertensive medication. The patients who had secondary HT, other chronic metabolic, cardiovascular, cerebrovascular diseases were excluded. History and physical exam including detailed cardiovascular examination were performed in all participants. Adipokines, cytokines, trace elements, lipid peroxidation, and ischemia-modified albumin levels were measured in blood samples by biochemical methods.

RESULTS

Vaspin, IL-4, IL-8, IL-10, selenium, and zinc levels were significantly lower in the HT group compared to healthy controls while omentin-1, TNF-α, copper, iron, MDA, SOD, and IMA-C levels were significantly higher in HT patients compared to controls. Multiple ordinal regression revealed that TNF-α, IL-10, and body mass index of patients were statistically significant independent predictors (P = 0.024, P = 0.019, and P = 0.032, respectively) for grading of HT. IL-4 and IL-10 were significantly higher in patients with asymptomatic target organ damage, compared to patients without asymptomatic target organ damage (P = 0.032 and P = 0.015, respectively). Our findings suggest that adipokines apelin, omentin, and vaspin may be involved in hypertension by a complex interaction with the anti- and pro-inflammatory cytokines, trace elements, and oxidative stress pathways.

Association of Higher Advanced Oxidation Protein Products (AOPPs) Levels in Patients with Diabetic and Hypertensive Nephropathy

Background and Objectives: Diabetes mellitus (DM) and hypertension (HT) are characterized by cell damage caused by inflammatory and metabolic mechanisms induced by alteration in reduction-oxidative status. Serum advanced oxidation protein products (AOPP) are new markers of protein damage induced by oxidative stress. We evaluated serum levels of AOPP in a cohort of patients with DM and HT, with or without renal complications, compared with a control healthy population. Materials and Methods: The study group comprised of 62 patients with type 2 DM and 56 with HT. The 62 patients affected by DM were further distinguished in 24 subjects without renal impairment, 18 with diabetic nephropathy (DN), 20 with chronic kidney disease (CKD) stage 2–3 secondary to DN. The subgroup of 56 patients with primary HT comprised 26 subjects without renal complications and 30 with CKD (stage 2–3) secondary to HT. Thirty healthy controls, matched for age and sex, were recruited among blood donors. Results: Increased AOPP levels were found in DM patients compared with healthy subjects, although not significantly. This index was higher and more significant in patients with DN and CKD secondary to DN than in DM patients without nephropathy (p < 0.05) or controls (p < 0.0001). Patients with HT and with kidney impairment secondary to HT also had significantly higher AOPP serum levels than controls (p < 0.01 and p < 0.0001, respectively). There were no significant differences in mean AOPP levels among DM and HT patients. Conclusion: Our study showed that oxidative stress was higher in diabetic or hypertensive subjects than in healthy controls and, in particular, it appeared to be more severe in patients with renal complications. We suggest that the assessment of AOPP in diabetic and hypertensive patients may be important to predict the onset of renal failure and to open a new perspective on the adoption of antioxidant molecules to prevent CKD in those settings.