Hydrogen inhalation enhances autophagy via the AMPK/mTOR pathway, thereby attenuating doxorubicin-induced cardiac injury

Roles of HSP70 in autophagic protection of cardiomyocytes induced by heat acclimation: A review

In conditions of extreme high temperature, the heart is susceptible to injury induced by heat stress, which can manifest as myocardial ischemia and hypoxia, cardiomyocyte apoptosis, oxidative damage, and inflammatory responses. The normal function of cardiomyocytes is contingent upon the maintenance of protein homeostasis, and dysregulation of protein homeostasis is the underlying cause of myocardial structural damage. Autophagy and Heat Shock Protein 70 (Hsp70) play pivotal roles in regulating cellular protein quality and mitigating stress injury. Heat acclimation has been shown to induce Hsp70 expression and provide cardiomyocyte protection. However, the mechanism by which Hsp70 mediates cardiomyocyte autophagy to exert protective effects has not been fully elucidated. The objective of this review is to synthesize the existing literature on the effects of Hsp70 on autophagy during heat exposure, to explore the potential mechanisms by which Hsp70 regulates myocardial autophagy and the molecular pathways it involves, and to provide a theoretical basis for future therapeutic strategies for cardiac diseases.

The Role of mTOR in the Doxorubicin-Induced Cardiotoxicity: A Systematic Review

Doxorubicin (DOX) is a chemotherapy drug known to induce metabolic changes in the heart, leading to potential heart toxicity. These changes impact various cellular functions and pathways such as disrupting the mechanistic target of rapamycin (mTOR) signaling pathway. The study aimed to investigate the effect of DOX on the mTOR pathway through an in vivo systematic review. Databases were searched on September 11, 2023. We finally included 30 in vivo studies that examined the mTOR expression in cardiac tissue samples. The present study has shown that the PI3K/AKT/mTOR, the AMPK/mTOR, the p53/mTOR signaling, the mTOR/TFEB pathway, the p38 MAPK/mTOR, the sestrins/mTOR, and the KLF15/eNOS/mTORC1 signaling pathways play a crucial role in the development of DOX-induced cardiotoxicity. Inhibition or dysregulation of these pathways can lead to increased oxidative stress, apoptosis, and other adverse effects on the heart. Strategies that target and modulate the mTOR pathways, such as the use of mTOR inhibitors like rapamycin, have the potential to enhance the anticancer effects of DOX while also mitigating its cardiotoxic side effects.

New possibilities of the prevention and treatment of cardiovascular pathologies. the potential of molecular hydrogen in the reduction of oxidative stress and its consequences

Disproportion between reactive oxygen species (ROS) production and the body's antioxidant system can cause oxidative stress, which is considered a common denominator in various pathological conditions, including cardiovascular diseases, aging, and cognitive disorders. The generation of free radicals, which occurs through partial reduction of oxygen, can quickly overwhelm the endogenous antioxidant system capacity of the cell. This causes lipid, protein, DNA and RNA damage, inflammation, and overall cell degeneration, which can be mitigated by various antioxidants. However, their use in human medicine did not bring the expected effect. Molecular hydrogen (H2), due to its unique physical and chemical properties, provides a number of benefits for alleviating oxidative stress. H2 is superior to conventional antioxidants as it can selectively reduce (.)OH radicals while preserving important ROS that are otherwise used for normal cell signaling. Key words Oxidative stress, Cardiovascular diseases, Molecular hydrogen, ROS, Inflammation.

Mechanisms underlying dose-limiting toxicities of conventional chemotherapeutic agents

Dose-limiting toxicities (DLTs) are severe adverse effects that define the maximum tolerated dose of a cancer drug. In addition to the specific mechanisms of each drug, common contributing factors include inflammation, apoptosis, ion imbalances, and tissue-specific enzyme deficiencies. Among various DLTs are bleomycin-induced pulmonary fibrosis, doxorubicin-induced cardiomyopathy, cisplatin-induced nephrotoxicity, methotrexate-induced hepatotoxicity, vincristine-induced neurotoxicity, paclitaxel-induced peripheral neuropathy, and irinotecan, which elicits severe diarrhea. Currently, specific treatments beyond dose reduction are lacking for most toxicities. Further research on cellular and molecular pathways is imperative to improve their management. This review synthesizes preclinical and clinical data on the pharmacological mechanisms underlying DLTs and explores possible treatment approaches. A comprehensive perspective reveals knowledge gaps and emphasizes the need for future studies to develop more targeted strategies for mitigating these dose-dependent adverse effects. This could allow the safer administration of fully efficacious doses to maximize patient survival.

Hydrogen-Rich Water to Enhance Exercise Performance: A Review of Effects and Mechanisms

Background: Hydrogen-rich water (HRW) has garnered significant interest within the sports and exercise science community due to its selective antioxidant properties. Despite its potential benefits, comprehensive reviews specifically addressing its effects on athletic performance are limited. This review aims to assess the impact of HRW on sports performance and explore the underlying molecular biological mechanisms, with the goal of elucidating how HRW might enhance athletic performance. Methods: This review synthesizes research on HRW by examining articles published between 1980 and April 2024 in databases such as PubMed, the Cochrane Library, Embase, Scopus, and Web of Science. Results: It highlights HRW's effects on various aspects of athletic performance, including endurance, strength, sprint times, lunge movements, countermovement jump height, and time to exhaustion. While the precise mechanisms by which HRW affects athletic performance remain unclear, this review investigates its general molecular biological mechanisms beyond the specific context of sports. This provides a theoretical foundation for future research aimed at understanding how HRW can enhance athletic performance. HRW targets the harmful reactive oxygen and nitrogen species produced during intense exercise, thereby reducing oxidative stress-a critical factor in muscle fatigue, inflammation, and diminished athletic performance. HRW helps to scavenge hydroxyl radicals and peroxynitrite, regulate antioxidant enzymes, mitigate lipid peroxidation, reduce inflammation, protect against mitochondrial dysfunction, and modulate cellular signaling pathways. Conclusions: In summary, while a few studies have indicated that HRW may not produce significant beneficial effects, the majority of research supports the conclusion that HRW may enhance athletic performance across various sports. The potential mechanisms underlying these benefits are thought to involve HRW's role as a selective antioxidant, its impact on oxidative stress, and its regulation of redox homeostasis. However, the specific molecular biological mechanisms through which HRW improves athletic performance remain to be fully elucidated.

Anthracycline-induced cardiotoxicity: An overview from cellular structural perspective

Anthracyclines are broad-spectrum anticancer drugs, but their clinical use is limited due to their severe cardiotoxicity. Anthracycline-induced cardiotoxicity (AIC) remains a significant cause of heart disease-related mortality in many cancer survivors. The underlying mechanisms of AIC have been explored over the past few decades. Reactive oxygen species and drug-induced inhibition of topoisomerase II beta are well-studied mechanisms, with mitochondria being a prominently investigated organelle. Emerging mechanisms such as ferroptosis, Ca2+ overload, autophagy and inflammation mediators have been implicated in recent years. In this review, our goal is to summarize and update the roles of various mechanisms in AIC, focusing on different cellular levels and further explore promising therapeutic approaches targeting these organelles or pathways.

Anti-inflammatory and antioxidant activity of high concentrations of hydrogen in the lung diseases: a systematic review and meta-analysis

As a small molecule, hydrogen is colorless, odorless and lightest. Many studies conducted that hydrogen can protect almost every organ, including the brain, heart muscle, liver, small intestine, and lungs. To verify whether high concentrations of hydrogen (HCH) has anti-inflammatory and antioxidant activities on respiratory system, we product a systematic review and meta-analysis. We investigated MEDLINE-PubMed, Cochrane Library, ScienceDirect, Wiley and SpringerLink database and selected in vivo studies related to the anti-inflammatory or antioxidant effects of HCH in the lung diseases which were published until September 2023. We firstly identified 437 studies and only 12 met the inclusion criteria. They all conducted in rodents. The results showed that HCH had a positive effect on the reduction of tumor necrosis factor alpha (TNF-α), interleukin (IL)-1β, IL-4, IL-8, malondialdehyde (MDA), superoxide dismutase (SOD) and reactive oxygen species (ROS); but there is no effect on IL-6, we speculated that may contribute to the test results for different body fluids and at different points in time. This meta-analysis discovered the protective effects on inflammation and oxidative stress, but whether there exists more effects on reduction of inflammatory and oxidant mediators needs to be further elucidated.

Molecular Hydrogen Protects against Various Tissue Injuries from Side Effects of Anticancer Drugs by Reducing Oxidative Stress and Inflammation

While drug therapy plays a crucial role in cancer treatment, many anticancer drugs, particularly cytotoxic and molecular-targeted drugs, cause severe side effects, which often limit the dosage of these drugs. Efforts have been made to alleviate these side effects by developing derivatives, analogues, and liposome formulations of existing anticancer drugs and by combining anticancer drugs with substances that reduce side effects. However, these approaches have not been sufficiently effective in reducing side effects. Molecular hydrogen (H2) has shown promise in this regard. It directly reduces reactive oxygen species, which have very strong oxidative capacity, and indirectly exerts antioxidant, anti-inflammatory, and anti-apoptotic effects by regulating gene expression. Its clinical application in various diseases has been expanded worldwide. Although H2 has been reported to reduce the side effects of anticancer drugs in animal studies and clinical trials, the underlying molecular mechanisms remain unclear. Our comprehensive literature review revealed that H2 protects against tissue injuries induced by cisplatin, oxaliplatin, doxorubicin, bleomycin, and gefitinib. The underlying mechanisms involve reductions in oxidative stress and inflammation. H2 itself exhibits anticancer activity. Therefore, the combination of H2 and anticancer drugs has the potential to reduce the side effects of anticancer drugs and enhance their anticancer activities. This is an exciting prospect for future cancer treatments.

Hydrogen-rich solution alleviates acute radiation pneumonitis by regulating oxidative stress and macrophages polarization

This study was aimed to investigate the effect of hydrogen-rich solution (HRS) on acute radiation pneumonitis (ARP) in rats. The ARP model was induced by X-ray irradiation. Histopathological changes were assessed using HE and Masson stains. Inflammatory cytokines were detected by ELISA. Immunohistochemistry and flow cytometry were performed to quantify macrophage (CD68) levels and the M2/M1 ratio. Western blot analysis, RT-qPCR, ELISA and flow cytometry were used to evaluate mitochondrial oxidative stress injury indicators. Immunofluorescence double staining was performed to colocalize CD68/LC3B and p-AMPK-α/CD68. The relative expression of proteins associated with autophagy activation and the adenosine 5'-monophosphate-activated protein kinase/mammalian target of rapamycin/Unc-51-like kinase 1 (AMPK/mTOR/ULK1) signaling pathway were detected by western blotting. ARP decreased body weight, increased the lung coefficient, collagen deposition and macrophage infiltration and promoted M1 polarization in rats. After HRS treatment, pathological damage was alleviated, and M1 polarization was inhibited. Furthermore, HRS treatment reversed the ARP-induced high levels of mitochondrial oxidative stress injury and autophagy inhibition. Importantly, the phosphorylation of AMPK-α was inhibited, the phosphorylation of mTOR and ULK1 was activated in ARP rats and this effect was reversed by HRS treatment. HRS inhibited M1 polarization and alleviated oxidative stress to activate autophagy in ARP rats by regulating the AMPK/mTOR/ULK1 signaling pathway.

Low-intensity pulsed ultrasound alleviates doxorubicin-induced cardiotoxicity via inhibition of S100a8/a9-mediated cardiac recruitment of neutrophils

Doxorubicin (DOX)-induced cardiotoxicity limits its broad use as a chemotherapy agent. The development of effective and non-invasive strategies to prevent DOX-associated adverse cardiac events is urgently needed. We aimed to examine whether and how low-intensity pulsed ultrasound (LIPUS) plays a protective role in DOX-induced cardiotoxicity. Male C57BL/6J mice were used to establish models of both acute and chronic DOX-induced cardiomyopathy. Non-invasive LIPUS therapy was conducted for four consecutive days after DOX administration. Cardiac contractile function was evaluated by echocardiography. Myocardial apoptosis, oxidative stress, and fibrosis were analyzed using terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) staining, dihydroethidium (DHE) staining, and picrosirius red staining assays. RNA-seq analysis was performed to unbiasedly explore the possible downstream regulatory mechanisms. Neutrophil recruitment and infiltration in the heart were analyzed by flow cytometry. The S100a8/a9 inhibitor ABR-238901 was utilized to identify the effect of S100a8/a9 signaling. We found that LIPUS therapy elicited a great benefit on DOX-induced heart contractile dysfunction in both acute and chronic DOX models. Chronic DOX administration increased serum creatine kinase and lactate dehydrogenase levels, as well as myocardial apoptosis, all of which were significantly mitigated by LIPUS. In addition, LIPUS treatment prevented chronic DOX-induced cardiac oxidative stress and fibrosis. RNA-seq analysis revealed that LIPUS treatment partially reversed alterations of gene expression induced by DOX. Gene ontology (GO) analysis of the downregulated genes between DOX-LIPUS and DOX-Sham groups indicated that inhibition of neutrophil chemotaxis might be involved in the protective effects of LIPUS therapy. Flow cytometry analysis illustrated the inhibitory effects of LIPUS on DOX-induced neutrophil recruitment and infiltration in the heart. Moreover, S100 calcium binding protein A8/A9 (S100a8/a9) was identified as a potential key target of LIPUS therapy. S100a8/a9 inhibition by ABR-238901 showed a similar heart protective effect against DOX-induced cardiomyopathy to LIPUS treatment. LIPUS therapy prevents DOX-induced cardiotoxicity through inhibition of S100a8/a9-mediated neutrophil recruitment to the heart, suggesting its potential application in cancer patients undergoing chemotherapy with DOX.