DNA, protein and lipid oxidative damage in tissues of spontaneously hypertensive versus normotensive rats

Quantification of oxidative stress markers in the blood sera following subacute administration of different oximes in rats

Oxidative stress status, as a disruption of redox homeostasis, in the blood sera of Wistar rats caused by repeated application of selected acetylcholinesterase reactivators - asoxime, obidoxime, K027, K048, K074, and K075 were evaluated. Throughout this study, each oxime in a dose of 0.1 of LD50/kg im was given 2x/week for 4 weeks. Then, seven days after the last oximes' application, markers of lipid peroxidation (malondialdehyde, MDA), and protein oxidation (advanced oxidation protein products, AOPP), as well as the activity of antioxidant enzymes (catalase, CAT, superoxide dismutase, SOD, reduced glutathione, GSH, and oxidized glutathione, GSSG), were determined. Oxidative stress parameters, MDA and AOPP were significantly highest in the K048-, K074- and K075-treated groups (p < 0.001). The activity of CAT was significantly elevated in the obidoxime-treated group (p < 0.05), while treatment with K027, K048, and K074 induced high elevation in SOD levels (p < 0.01, p < 0.001). Interestingly, the activity of GSH in each oxime-treated group was significantly elevated. Unlike, treatment with obidoxime caused elevation in GSSG levels (p < 0.01). As a continuation of our previously published data, these results assure that applied oximes following subacute treatment ameliorated the oxidative status and further adverse systemic toxic effects in rats.

Treatment of spontaneously hypertensive rats during pregnancy and lactation with the antioxidant tempol lowers blood pressure and reduces oxidative stress

Genetic and environmental factors interact in a complex manner in the pathogenesis of essential hypertension in humans. Oxidative stress is considered one of the more important environmental factors. We used the spontaneously hypertensive rat (SHR) model to test whether continuous feeding with the antioxidant tempol reduces maternal oxidative stress during pregnancy and potentially contributes to the prevention of cardiovascular disease onset. Pregnant female rats were divided into control and tempol-treated groups. Tempol was continuously administered in drinking water. The administration period lasted approximately 40 days, from the confirmation of a vaginal plug until birth of the pups and their subsequent weaning. The blood pressure (BP) of each adult female was measured three times during pregnancy and post parturition. Milk was collected three times from nursing mother rats in the immediate postpartum period. Markers of oxidative stress were measured: 8-hydroxyl-2'-deoxyguanosine (8-OHdG) levels in milk during the experimental period and 8-OHdG and corticosterone levels in urine of adult and neonatal rats. The urinary level of 8-OHdG in the tempol-treated group was significantly lower than that in the control group. Corticosterone levels were significantly lower in urine of neonatal rats from the tempol-treated group compared with the levels of the control group. The levels of total antioxidant in milk were significantly greater in the tempol-treated group than in the control group. This study demonstrated that continuous administration of tempol to pregnant SHRs reduced maternal oxidative stress and contributed to reduced oxidative stress in neonatal rats.

A novel angiotensin I-converting enzyme inhibitory peptide from walnut (Juglans sigillata) protein hydrolysates and its evaluation in Ang II-induced HUVECs and hypertensive rats

This study aims to seek angiotensin-I-converting enzyme inhibitory (ACEi) peptides from walnut using different enzymatic hydrolysis, and further to validate the potent ACEi peptides identified and screened via peptidomics and in silico analysis against hypertension in spontaneously hypertensive rats (SHRs). Results showed that walnut protein hydrolysate (WPH) prepared by combination of alcalase and simulated gastrointestinal digestion exhibited high ACEi activity. WPH was separated via Sephadex-G25, and four peptides were identified, screened and verified based on their PeptideRanker score, structural characteristic and ACE inhibition. Interestingly, FDWLR showed the highest ACEi activity with IC50 value of 8.02 μg/mL, which might be related to its close affinity with ACE observed in molecular docking. Subsequently, high absorption and non-toxicity of FDWLR was predicted via in silico absorption, distribution, metabolism, excretion and toxicity. Furthermore, FDWLR exhibited positively vasoregulation in Ang II-induced human umbilical vein endothelial cells, and great blood pressure lowering effect in SHRs.

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 status assessment of rats' brains injury following subacute exposure to K-oximes

Oxidative stress status and morphological injuries in the brain of Wistar rats induced by repeated application of selected acetylcholinesterase reactivators - asoxime, obidoxime, K027, K048, K074, and K075 were evaluated. Each oxime in a dose of 0.1 of LD50/kg im was given 2x/week for 4 weeks. Markers of lipid peroxidation (malondialdehyde, MDA), and protein oxidation (advanced oxidation protein products, AOPP), as well as the activity of antioxidant enzymes (catalase, CAT, superoxide dismutase, SOD, glutathione reductase, GR, and glutathione peroxidase, GPx), were estimated in the brain tissue homogenates on day 35 of the study. Brain alterations were carefully quantified by semiquantitative grading scales - brain damage score (BDS). Oxidative stress parameters, MDA and AOPP were significantly highest in the asoxime-, obidoxime- and K075-treated groups (p < 0.001). The activity of SOD and CAT was significantly elevated in the obidoxime-, K048-, and K075-treated groups (p < 0.001). Besides, GR was markedly decreased in the obidoxime- and K074-treated groups (p < 0.01), while treatment with K048, K074 and K075 induced extremely high elevation in GPx levels (p < 0.001). In the same groups of rats, brain alterations associated with polymorphonuclear cell infiltrate were significantly more severe than those observed in animals receiving only asoxime or K027 (p < 0.001). The presented results confirmed that treatment with different oximes significantly improved the oxidative status and attenuated signs of inflammation in rats' brains. Presented results, together with our previously published data can help to predict likely adverse systemic toxic effects, and target organ systems, which are crucial for establishing risk categories, as well as in dose selection of K-oximes as drug candidates.

The role of oxidative stress in ovarian aging: a review

Ovarian aging refers to the process by which ovarian function declines until eventual failure. The pathogenesis of ovarian aging is complex and diverse; oxidative stress (OS) is considered to be a key factor. This review focuses on the fact that OS status accelerates the ovarian aging process by promoting apoptosis, inflammation, mitochondrial damage, telomere shortening and biomacromolecular damage. Current evidence suggests that aging, smoking, high-sugar diets, pressure, superovulation, chemotherapeutic agents and industrial pollutants can be factors that accelerate ovarian aging by exacerbating OS status. In addition, we review the role of nuclear factor E2-related factor 2 (Nrf2), Sirtuin (Sirt), mitogen-activated protein kinase (MAPK), protein kinase B (AKT), Forkhead box O (FoxO) and Klotho signaling pathways during the process of ovarian aging. We also explore the role of antioxidant therapies such as melatonin, vitamins, stem cell therapies, antioxidant monomers and Traditional Chinese Medicine (TCM), and investigate the roles of these supplements with respect to the reduction of OS and the improvement of ovarian function. This review provides a rationale for antioxidant therapy to improve ovarian aging.

A nanoreactor boosts chemodynamic therapy and ferroptosis for synergistic cancer therapy using molecular amplifier dihydroartemisinin

Background

Chemodynamic therapy (CDT) relying on intracellular iron ions and H₂O₂ is a promising therapeutic strategy due to its tumor selectivity, which is limited by the not enough metal ions or H₂O₂ supply of tumor microenvironment. Herein, we presented an efficient CDT strategy based on Chinese herbal monomer-dihydroartemisinin (DHA) as a substitute for the H₂O₂ and recruiter of iron ions to amplify greatly the reactive oxygen species (ROS) generation for synergetic CDT-ferroptosis therapy.

Results

The DHA@MIL-101 nanoreactor was prepared and characterized firstly. This nanoreactor degraded under the acid tumor microenvironment, thereby releasing DHA and iron ions. Subsequent experiments demonstrated DHA@MIL-101 significantly increased intracellular iron ions through collapsed nanoreactor and recruitment effect of DHA, further generating ROS thereupon. Meanwhile, ROS production introduced ferroptosis by depleting glutathione (GSH), inactivating glutathione peroxidase 4 (GPX4), leading to lipid peroxide (LPO) accumulation. Furthermore, DHA also acted as an efficient ferroptosis molecular amplifier by direct inhibiting GPX4. The resulting ROS and LPO caused DNA and mitochondria damage to induce apoptosis of malignant cells. Finally, in vivo outcomes evidenced that DHA@MIL-101 nanoreactor exhibited prominent anti-cancer efficacy with minimal systemic toxicity.

Conclusion

In summary, DHA@MIL-101 nanoreactor boosts CDT and ferroptosis for synergistic cancer therapy by molecular amplifier DHA. This work provides a novel and effective approach for synergistic CDT-ferroptosis with Chinese herbal monomer-DHA and Nanomedicine.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01455-0.

The pathological role of damaged organelles in renal tubular epithelial cells in the progression of acute kidney injury

Acute kidney injury (AKI) is a common clinical condition associated with high morbidity and mortality. The pathogenesis of AKI has not been fully elucidated, with a lack of effective treatment. Renal tubular epithelial cells (TECs) play an important role in AKI, and their damage and repair largely determine the progression and prognosis of AKI. In recent decades, it has been found that the mitochondria, endoplasmic reticulum (ER), lysosomes, and other organelles in TECs are damaged to varying degrees in AKI, and that they can influence each other through various signaling mechanisms that affect the recovery of TECs. However, the association between these multifaceted signaling platforms, particularly between mitochondria and lysosomes during AKI remains unclear. This review summarizes the specific pathophysiological mechanisms of the main TECs organelles in the context of AKI, particularly the potential interactions among them, in order to provide insights into possible novel treatment strategies.