Oxidative Stress and Antioxidants in Hypoxia and Human Pathophysiology Settings: Novel Pharmacological Targets

A special issue of Antioxidants (ISSN 2076-3921). This special issue belongs to the section "Health Outcomes of Antioxidants and Oxidative Stress".

Deadline for manuscript submissions: closed (30 September 2024) | Viewed by 22955

Special Issue Editor


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Guest Editor
1. Departamento de Medicina Interna Oriente, Facultad de Medicina, Universidad de Chile, Santiago 7500922, Chile
2. Unidad de Paciente Crítico, Hospital del Salvador, Santiago 7500922, Chile
Interests: cardiovascular physiology and pathophysiology; animal models of intermittent hypoxia; cardiotoxicity; internal medicine; clinical trial
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Special Issue Information

Dear Colleagues,

Hypoxic (HI) injury is defined as the worsening of organ/cellular dysfunction and cell death following reduction in blood flow due to organ targeting or increases in oxygen consumption in a related tissue. Restoration of blood flow is essential to salvage ischemic tissues. However, reperfusion itself causes further damage, contributing to reversible and irreversible changes in tissue viability and organ function, the basic pathophysiology of ischemia-reperfusion (IR) injury, especially oxidative stress, and cell death mechanism. When the blood supply is re-established, local inflammation and oxidative stress production increase, leading to secondary injury. Cell damage induced by prolonged ischemia must be distinguished from IR injury. It occurs in a wide range of organ systems, including the heart, lung, kidney, and brain. It may involve not only the ischemic organ itself but may also induce systemic damage to distant organs, potentially leading to multisystem organ failure, as different animal models have shown. Similar responses are seen in a human context, in patients exposed to acute and chronic hypoxia, from populations living in environments with low oxygen pressure, such as mountains (or high altitudes), to those suffering from conditions that induce hypoxia, such as what occurs at the cerebral and myocardial level with ischemic pathologies. Moreover, in some cancers, such as breast and colon, modulation of oxidative stress and tissue hypoxia could have a distant effect, for example, in the induction of cardiotoxicity.

This Special Issue is focused on the following topics:

-Current concepts of pathophysiology and therapies in cardiac HI and pharmacological preconditioning;

-Mechanisms of liver preconditioning in animal and clinical models of HI and IR injury;

-Current concepts of pathophysiology and therapies in cerebral HI and IR injury;

-Current concepts of anthracycline-induced cardiotoxicity in breast cancer: role of tumor microenvironment;

-Ex vivo models to reduce HI injury in organs for transplantation: role of antioxidants;

-Role of hypoxia in cardiovascular programing: mechanisms and potential therapeutic target with antioxidants;

-Role of microRNAs in the regulation of cardiac HI injury: animals and clinical settings.

Dr. Rodrigo L. Castillo
Guest Editor

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Keywords

  • tissue hypoxia
  • reperfusion injury
  • hypoxic preconditioning
  • oxidative stress
  • antioxidants
  • hypoxic programing
  • microRNA
  • clinical hypoxic settings

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Published Papers (14 papers)

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Research

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15 pages, 2602 KiB  
Article
Oxidative Stress in Polycystic Ovary Syndrome: Impact of Combined Oral Contraceptives
by Nicolás Santander, Esteban G. Figueroa, Alejandro González-Candia, Manuel Maliqueo, Bárbara Echiburú, Nicolás Crisosto and Francisca Salas-Pérez
Antioxidants 2024, 13(10), 1168; https://doi.org/10.3390/antiox13101168 - 26 Sep 2024
Viewed by 1452
Abstract
Polycystic Ovary Syndrome (PCOS) is a complex hormonal disorder that is associated with heightened metabolic risks. While oxidative stress (OS) is known to play a role in PCOS, the precise nature of the relationship between PCOS and increased OS remains not entirely understood. [...] Read more.
Polycystic Ovary Syndrome (PCOS) is a complex hormonal disorder that is associated with heightened metabolic risks. While oxidative stress (OS) is known to play a role in PCOS, the precise nature of the relationship between PCOS and increased OS remains not entirely understood. Combined oral contraceptives (COCs) are the first-line treatment to regulate menstrual cycles and androgen levels, but their impact on oxidative stress requires further study. We conducted a transcriptomic analysis using RNAseq and assessed the levels of various oxidative stress (OS) markers in serum samples from women with PCOS and controls and whether they were using combined oral contraceptives (COCs), including enzymatic activities, FRAP, and 8-isoprostane (8-iso). A total of 359 genes were differentially expressed in women with PCOS compared to control women. Genes differentially expressed were enriched in functions related to inflammation and, interestingly, oxidative stress response. In controls, 8-iso levels were increased in women using COCs, whereas in women with PCOS, 8-iso levels were reduced in those using oral contraceptives (191.1 ± 97 vs. 26.4 ± 21 pg/mL, p: <0.0001). Correlation analyses showed a trend for a negative correlation between 8-iso and Ferriman score in women with PCOS consuming COCs (r = −0.86, p = 0.06) and a negative correlation between GSH and hyperandrogenism in women with PCOS (r = −0.89, p = 0.01). These results reveal the presence of lipid peroxidation in women with PCOS, which was modified by the use of COCs, providing new insights into the pathophysiology of PCOS in the Chilean population. Full article
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15 pages, 5732 KiB  
Article
Dimethyl Fumarate Strongly Ameliorates Gray and White Matter Brain Injury and Modulates Glial Activation after Severe Hypoxia–Ischemia in Neonatal Rats
by Jon Ander Alart, Antonia Álvarez, Ana Catalan, Borja Herrero de la Parte and Daniel Alonso-Alconada
Antioxidants 2024, 13(9), 1122; https://doi.org/10.3390/antiox13091122 - 16 Sep 2024
Viewed by 920
Abstract
Neonatal hypoxia–ischemia is a major cause of infant death and disability. The only clinically accepted treatment is therapeutic hypothermia; however, cooling is less effective in the most severely encephalopathic infants. Here, we wanted to test the neuroprotective effect of the antioxidant dimethyl fumarate [...] Read more.
Neonatal hypoxia–ischemia is a major cause of infant death and disability. The only clinically accepted treatment is therapeutic hypothermia; however, cooling is less effective in the most severely encephalopathic infants. Here, we wanted to test the neuroprotective effect of the antioxidant dimethyl fumarate after severe hypoxia–ischemia in neonatal rats. We used a modified Rice–Vannucci model to generate severe hypoxic–ischemic brain damage in day 7 postnatal rats, which were randomized into four experimental groups: Sham, Sham + DMF, non-treated HI, and HI + DMF. We analyzed brain tissue loss, global and regional (cortex and hippocampus) neuropathological scores, white matter injury, and microglial and astroglial reactivity. Compared to non-treated HI animals, HI + DMF pups showed a reduced brain area loss (p = 0.0031), an improved neuropathological score (p = 0.0016), reduced white matter injuries by preserving myelin tracts (p < 0.001), and diminished astroglial (p < 0.001) and microglial (p < 0.01) activation. After severe hypoxia–ischemia in neonatal rats, DMF induced a strong neuroprotective response, reducing cerebral infarction, gray and white matter damage, and astroglial and microglial activation. Although further molecular studies are needed and its translation to human babies would need to evaluate the molecule in piglets or lambs, DMF may be a potential treatment against neonatal encephalopathy. Full article
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12 pages, 1694 KiB  
Article
Impact of Hypoxia on Neutrophil Degranulation and Inflammatory Response in Alpha-1 Antitrypsin Deficiency Patients
by María Magallón, Silvia Castillo-Corullón, Lucía Bañuls, Teresa Romero, Daniel Pellicer, Alberto Herrejón, María Mercedes Navarro-García, Cruz González and Francisco Dasí
Antioxidants 2024, 13(9), 1071; https://doi.org/10.3390/antiox13091071 - 2 Sep 2024
Viewed by 765
Abstract
Background: Alpha-1 antitrypsin deficiency (AATD) is an inflammatory disorder where neutrophils play a key role. Excessive neutrophil activation leads to local hypoxia and tissue damage. Most research on neutrophil function has been conducted under atmospheric conditions (21% O2), which may not [...] Read more.
Background: Alpha-1 antitrypsin deficiency (AATD) is an inflammatory disorder where neutrophils play a key role. Excessive neutrophil activation leads to local hypoxia and tissue damage. Most research on neutrophil function has been conducted under atmospheric conditions (21% O2), which may not represent physiological or pathological conditions. This study aimed to determine the effects of hypoxia on neutrophil degranulation and cytokine production in AATD patients. Methods: Neutrophils isolated from 54 AATD patients (31 MZ; 8 SZ; 15 ZZ) and 7 controls (MM) were exposed to hypoxia (1% O2) for 4 h. Neutrophil degranulation was assessed by measuring elastase (NE), myeloperoxidase (MPO), lactoferrin, and matrix metalloproteinase-9 (MMP-9) levels using immunoassay-based methods. Pro-inflammatory (IL-8, IL-1 beta, IL-6, and TNF-alpha) and anti-inflammatory (IL-4 and IL-10) cytokine levels were assessed by a Luminex-based method. Results: Our results indicate a significantly increased release of NE (p = 0.015), MPO (p = 0.042), lactoferrin (p = 0.015), and MMP-9 (p = 0.001) compared to controls. Pro-inflammatory cytokines show a significant rise in IL-8 (p = 0.019), a trend towards increased IL-1 beta (p = 0.3196), no change in IL-6 (p = 0.7329), and reduced TNF-alpha (p = 0.006). Anti-inflammatory cytokines show increased IL-4 (p = 0.057) and decreased IL-10 (p = 0.05703). Conclusions: Increased neutrophil degranulation and inflammatory phenotype are observed in AATD neutrophils under physiological hypoxia. Full article
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16 pages, 19441 KiB  
Article
Ocular Inflammation and Oxidative Stress as a Result of Chronic Intermittent Hypoxia: A Rat Model of Sleep Apnea
by Nina Donkor, Jennifer J. Gardner, Jessica L. Bradshaw, Rebecca L. Cunningham and Denise M. Inman
Antioxidants 2024, 13(7), 878; https://doi.org/10.3390/antiox13070878 - 22 Jul 2024
Cited by 1 | Viewed by 1264
Abstract
Obstructive sleep apnea (OSA) is a sleep disorder characterized by intermittent complete or partial occlusion of the airway. Despite a recognized association between OSA and glaucoma, the nature of the underlying link remains unclear. In this study, we investigated whether mild OSA induces [...] Read more.
Obstructive sleep apnea (OSA) is a sleep disorder characterized by intermittent complete or partial occlusion of the airway. Despite a recognized association between OSA and glaucoma, the nature of the underlying link remains unclear. In this study, we investigated whether mild OSA induces morphological, inflammatory, and metabolic changes in the retina resembling those seen in glaucoma using a rat model of OSA known as chronic intermittent hypoxia (CIH). Rats were randomly assigned to either normoxic or CIH groups. The CIH group was exposed to periodic hypoxia during its sleep phase with oxygen reduction from 21% to 10% and reoxygenation in 6 min cycles over 8 h/day. The eyes were subsequently enucleated, and then the retinas were evaluated for retinal ganglion cell number, oxidative stress, inflammatory markers, metabolic changes, and hypoxic response modulation using immunohistochemistry, multiplex assays, and capillary electrophoresis. Statistically significant differences were observed between normoxic and CIH groups for oxidative stress and inflammation, with CIH resulting in increased HIF-1α protein levels, higher oxidative stress marker 8-OHdG, and increased TNF-α. Pyruvate dehydrogenase kinase-1 protein was significantly reduced with CIH. No significant differences were found in retinal ganglion cell number. Our findings suggest that CIH induces oxidative stress, inflammation, and upregulation of HIF-1α in the retina, akin to early-stage glaucoma. Full article
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17 pages, 2960 KiB  
Article
Isobolographic Analysis of the Cytoprotective Effect of Dapsone and Cannabidiol Alone or Combination upon Oxygen–Glucose Deprivation/Reoxygenation Model in SH-SY5Y Cells
by Marcela Islas-Cortez, Camilo Ríos, Jorge Manzanares, Araceli Díaz-Ruiz and Ricardo Pérez-Pastén-Borja
Antioxidants 2024, 13(6), 705; https://doi.org/10.3390/antiox13060705 - 8 Jun 2024
Viewed by 1230
Abstract
Oxidative stress and apoptosis cell death are critical secondary damage mechanisms that lead to losing neighboring healthy tissue after cerebral ischemia. This study aims to characterize the type of interaction between dapsone (DDS) and cannabidiol (CBD) and its cytoprotective effect in an in [...] Read more.
Oxidative stress and apoptosis cell death are critical secondary damage mechanisms that lead to losing neighboring healthy tissue after cerebral ischemia. This study aims to characterize the type of interaction between dapsone (DDS) and cannabidiol (CBD) and its cytoprotective effect in an in vitro model of oxygen and glucose deprivation for 6 h followed by 24 h of reoxygenation (OGD/R), using the SH-SY5Y cell line. For the combined concentrations, an isobolographic study was designed to determine the optimal concentration–response combinations. Cell viability was evaluated by measuring the lactate dehydrogenase (LDH) release and 3-[4, 5-dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assays. Also, the reactive oxygen species (ROS) and reduced glutathione (GSH) levels were analyzed as oxidative stress markers. Finally, caspase-3 activity was evaluated as a marker cell death by apoptosis. The results showed a decrease in cell viability, an increase in oxidant stress, and the activity of caspase-3 by the effect of OGD/R. Meanwhile, both DDS and CBD demonstrated antioxidant, antiapoptotic, and cytoprotective effects in a concentration–response manner. The isobolographic study indicated that the concentration of 2.5 µM of DDS plus 0.05 µM of CBD presented a synergistic effect so that in treatment, cell death due to OGD/R decreased. The findings indicate that DDS–CBD combined treatment may be a helpful therapy in cerebral ischemia with reperfusion. Full article
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24 pages, 9238 KiB  
Article
The Reducing Agent Dithiothreitol Modulates the Ventilatory Responses That Occur in Freely Moving Rats during and following a Hypoxic–Hypercapnic Challenge
by Paulina M. Getsy, Gregory A. Coffee, Walter J. May, Santhosh M. Baby, James N. Bates and Stephen J. Lewis
Antioxidants 2024, 13(4), 498; https://doi.org/10.3390/antiox13040498 - 22 Apr 2024
Viewed by 1129
Abstract
The present study examined the hypothesis that changes in the oxidation–reduction state of thiol residues in functional proteins play a major role in the expression of the ventilatory responses in conscious rats that occur during a hypoxic–hypercapnic (HH) gas challenge and upon return [...] Read more.
The present study examined the hypothesis that changes in the oxidation–reduction state of thiol residues in functional proteins play a major role in the expression of the ventilatory responses in conscious rats that occur during a hypoxic–hypercapnic (HH) gas challenge and upon return to room air. A HH gas challenge in vehicle-treated rats elicited robust and sustained increases in minute volume (via increases in frequency of breathing and tidal volume), peak inspiratory and expiratory flows, and inspiratory and expiratory drives while minimally affecting the non-eupneic breathing index (NEBI). The HH-induced increases in these parameters, except for frequency of breathing, were substantially diminished in rats pre-treated with the potent and lipophilic disulfide-reducing agent, L,D-dithiothreitol (100 µmol/kg, IV). The ventilatory responses that occurred upon return to room air were also substantially different in dithiothreitol-treated rats. In contrast, pre-treatment with a substantially higher dose (500 µmol/kg, IV) of the lipophilic congener of the monosulfide, N-acetyl-L-cysteine methyl ester (L-NACme), only minimally affected the expression of the above-mentioned ventilatory responses that occurred during the HH gas challenge or upon return to room air. The effectiveness of dithiothreitol suggests that the oxidation of thiol residues occurs during exposure to a HH gas challenge and that this process plays an essential role in allowing for the expression of the post-HH excitatory phase in breathing. However, this interpretation is contradicted by the lack of effects of L-NACme. This apparent conundrum may be explained by the disulfide structure affording unique functional properties to dithiothreitol in comparison to monosulfides. More specifically, the disulfide structure may give dithiothreitol the ability to alter the conformational state of functional proteins while transferring electrons. It is also possible that dithiothreitol is simply a more efficient reducing agent following systemic injection, although one interpretation of the data is that the effects of dithiothreitol are not due to its reducing ability. Full article
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17 pages, 12726 KiB  
Article
Protective and Regenerative Effects of Reconstituted HDL on Human Rotator Cuff Fibroblasts under Hypoxia: An In Vitro Study
by Ra Jeong Kim and Hyung Bin Park
Antioxidants 2024, 13(4), 497; https://doi.org/10.3390/antiox13040497 - 22 Apr 2024
Viewed by 1229
Abstract
Hypoxia and hypo-high-density lipoproteinemia (hypo-HDLemia) are proposed risk factors for rotator cuff tear. HDL is recognized for its potential benefits in ischemia-driven angiogenesis and wound healing. Nevertheless, research on the potential benefits of reconstituted HDL (rHDL) on human rotator cuff fibroblasts (RCFs) under [...] Read more.
Hypoxia and hypo-high-density lipoproteinemia (hypo-HDLemia) are proposed risk factors for rotator cuff tear. HDL is recognized for its potential benefits in ischemia-driven angiogenesis and wound healing. Nevertheless, research on the potential benefits of reconstituted HDL (rHDL) on human rotator cuff fibroblasts (RCFs) under hypoxia is limited. This study investigates the cytoprotective and regenerative effects of rHDL, as well as N-acetylcysteine (NAC), vitamin C (Vit C), and HDL on human RCFs under hypoxic conditions. Sixth-passage human RCFs were divided into normoxia, hypoxia, and hypoxia groups pretreated with antioxidants (NAC, Vit C, rHDL, HDL). Hypoxia was induced by 1000 µM CoCl2. In the hypoxia group compared to the normoxia group, there were significant increases in hypoxia-inducible factor-1α (HIF-1α), heme oxygenase-1 (HO-1), and Bcl-2/E1B-19kDa interacting protein 3 (BNIP3) expressions, along with reduced cell viability, elevated reactive oxygen species (ROS) production, apoptosis rate, expressions of cleaved caspase-3, cleaved poly ADP-ribose polymerase-1 (PARP-1), vascular endothelial growth factors (VEGF), and matrix metalloproteinase-2 (MMP-2), as well as decreased collagen I and III production, and markedly lower cell proliferative activity (p ≤ 0.039). These responses were significantly mitigated by pretreatment with rHDL (p ≤ 0.046). This study suggests that rHDL can enhance cell proliferation and collagen I and III production while reducing apoptosis in human RCFs under hypoxic conditions. Full article
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12 pages, 4708 KiB  
Article
Serelaxin Protects H9c2 Cardiac Myoblasts against Hypoxia and Reoxygenation-Induced Damage through Activation of AMP Kinase/Sirtuin1: Further Insight into the Molecular Mechanisms of the Cardioprotection of This Hormone
by Virginia Zizi, Matteo Becatti, Daniele Bani and Silvia Nistri
Antioxidants 2024, 13(2), 163; https://doi.org/10.3390/antiox13020163 - 27 Jan 2024
Cited by 1 | Viewed by 1691
Abstract
Serelaxin (RLX), namely the human recombinant Relaxin-2 hormone, protects the heart from ischemia/reperfusion (I/R)-induced damage due to its anti-inflammatory, anti-apoptotic and antioxidant properties. RLX acts by binding to its specific RXFP1 receptor whereby it regulates multiple transduction pathways. In this in vitro study, [...] Read more.
Serelaxin (RLX), namely the human recombinant Relaxin-2 hormone, protects the heart from ischemia/reperfusion (I/R)-induced damage due to its anti-inflammatory, anti-apoptotic and antioxidant properties. RLX acts by binding to its specific RXFP1 receptor whereby it regulates multiple transduction pathways. In this in vitro study, we offer the first evidence for the involvement of the AMP kinase/Sirtuin1 (AMPK/SIRT1) pathway in the protection by RLX against hypoxia/reoxygenation (H/R)-induced damage in H9c2 cells. The treatment of the H/R-exposed cells with RLX (17 nmol L−1) enhanced SIRT1 expression and activity. The inhibition of SIRT1 signaling with EX527 (10 µmol L−1) reduced the beneficial effect of the hormone on mitochondrial efficiency and cell apoptosis. Moreover, RLX upregulated the AMPK pathway, as shown by the increase in the expression of phospho-AMPK-activated protein. Finally, AMPK pathway inhibition by Compound C (10 and 20 μmol L−1) abrogated the increase in SIRT1 expression induced by RLX, thus suggesting the involvement of the AMPK pathway in this effect of RLX. These results strengthen the concept that RLX exerts its cardioprotective effects against H/R-induced injury through multiple pathways which also include AMPK/SIRT1. These new findings support the use of RLX or RLX-derived molecules as a promising therapeutic for those diseases in which I/R and oxidative stress play a pathogenic role. Full article
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16 pages, 3348 KiB  
Article
Nitroxide—HMP—Protects Human Trophoblast HTR-8/SVneo Cells from H2O2-Induced Oxidative Stress by Reducing the HIF1A Signaling Pathway
by Diana Pintye, Réka Eszter Sziva, Maxim Mastyugin, Marianna Török, Sonako Jacas, Agnes Lo, Saira Salahuddin and Zsuzsanna K. Zsengellér
Antioxidants 2023, 12(8), 1578; https://doi.org/10.3390/antiox12081578 - 8 Aug 2023
Cited by 3 | Viewed by 2402
Abstract
Preeclampsia (PE) is a pregnancy-specific syndrome affecting 5–7% of patients. There is no effective treatment available. Early abnormal placental development is associated with oxidative stress (OS) and a release of reactive oxygen species (ROS) in the placenta. This phenomenon leads to downstream signaling, [...] Read more.
Preeclampsia (PE) is a pregnancy-specific syndrome affecting 5–7% of patients. There is no effective treatment available. Early abnormal placental development is associated with oxidative stress (OS) and a release of reactive oxygen species (ROS) in the placenta. This phenomenon leads to downstream signaling, Hypoxia Inducible Factor 1A (HIF1A) stabilization and transcription of the anti-angiogenic factors soluble fms-like tyrosine kinase 1 (sFLT1) and soluble endoglin (sEng), which are known to cause endothelial and trophoblast dysfunction and cardinal features of PE: hypertension, proteinuria and, in severe cases, eclampsia. We tested whether 3-(Hydroxymethyl)-1-oxy-2,2,5,5-tetramethylpyrrolidine (HMP)—a nitroxide-type antioxidant molecule—can reduce placental OS and mitigate PE symptoms in vitro. We induced OS in human trophoblast (HTR-8/SVneo) cells with hydrogen peroxide (H2O2) and assessed whether modulating cell redox function with HMP reduces cell injury, mitochondrial stress and HIF1A and sFLT1 production. Pre-treatment with HMP reduced mitochondrial-derived ROS production, restored LC3B expression and reduced HIF1A and sFLT1 expression in H2O2-exposed HTR-8/SVneo trophoblast cells. HMP improved the mitochondrial electron chain enzyme activity, indicating that a reduction in OS alleviates mitochondrial stress and also reduces anti-angiogenic responses. In reducing placental trophoblast OS, HMP presents a potential novel therapeutic approach for the treatment of PE. Future investigation is warranted regarding the in vivo use of HMP. Full article
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Review

Jump to: Research

24 pages, 1093 KiB  
Review
Role of NLRP3 Inflammasome in Heart Failure Patients Undergoing Cardiac Surgery as a Potential Determinant of Postoperative Atrial Fibrillation and Remodeling: Is SGLT2 Cotransporter Inhibition an Alternative for Cardioprotection?
by Rodrigo L. Castillo, Jorge Farías, Cristian Sandoval, Alejandro González-Candia, Esteban Figueroa, Mauricio Quezada, Gonzalo Cruz, Paola Llanos, Gonzalo Jorquera, Sawa Kostin and Rodrigo Carrasco
Antioxidants 2024, 13(11), 1388; https://doi.org/10.3390/antiox13111388 - 14 Nov 2024
Viewed by 708
Abstract
In heart failure (HF) patients undergoing cardiac surgery, an increased activity of mechanisms related to cardiac remodeling may determine a higher risk of postoperative atrial fibrillation (POAF). Given that atrial fibrillation (AF) has a negative impact on the course and management of HF, [...] Read more.
In heart failure (HF) patients undergoing cardiac surgery, an increased activity of mechanisms related to cardiac remodeling may determine a higher risk of postoperative atrial fibrillation (POAF). Given that atrial fibrillation (AF) has a negative impact on the course and management of HF, including the need for anticoagulation therapy, identifying the factors associated with AF occurrence after cardiac surgery is crucial for the prognosis of these patients. POAF is thought to occur when various clinical and biochemical triggers act on susceptible cardiac tissue (first hit), with oxidative stress and inflammation during cardiopulmonary bypass (CPB) surgery being potential contributing factors (second hit). However, the molecular mechanisms involved in these processes remain poorly characterized. Recent research has shown that patients who later develop POAF often have pre-existing abnormalities in calcium handling and activation of NLRP3-inflammasome signaling in their atrial cardiomyocytes. These molecular changes may make cardiomyocytes more susceptible to spontaneous Ca2+-releases and subsequent arrhythmias, particularly when exposed to inflammatory mediators. Additionally, some clinical studies have linked POAF with elevated preoperative inflammatory markers, but there is a need for further research in order to better understand the impact of CPB surgery on local and systemic inflammation. This knowledge would make it possible to determine whether patients susceptible to POAF have pre-existing inflammatory conditions or cellular electrophysiological factors that make them more prone to developing AF and cardiac remodeling. In this context, the NLRP3 inflammasome, expressed in cardiomyocytes and cardiac fibroblasts, has been identified as playing a key role in the development of HF and AF, making patients with pre-existing HF with reduced ejection fraction (HFrEF) the focus of several clinical studies with interventions that act at this level. On the other hand, HFpEF has been linked to metabolic and non-ischemic risk factors, but more research is needed to better characterize the myocardial remodeling events associated with HFpEF. Therefore, since ventricular remodeling may differ between HFrEF and HFpEF, it is necessary to perform studies in both groups of patients due to their pathophysiological variations. Clinical evidence has shown that pharmacological therapies that are effective for HFrEF may not provide the same anti-remodeling benefits in HFpEF patients, particularly compared to traditional adrenergic and renin–angiotensin–aldosterone system inhibitors. On the other hand, there is growing interest in medications with pleiotropic or antioxidant/anti-inflammatory effects, such as sodium–glucose cotransporter 2 inhibitors (SGLT-2is). These drugs may offer anti-remodeling effects in both HFrEF and HFpEF by inhibiting pro-inflammatory, pro-oxidant, and NLRP3 signaling pathways and their mediators. The anti-inflammatory, antioxidant, and anti-remodeling effects of SGLT-2 i have progressively expanded from HFrEF and HFpEF to other forms of cardiac remodeling. However, these advances in research have not yet encompassed POAF despite its associations with inflammation, oxidative stress, and remodeling. Currently, the direct or indirect effects of NLRP3-dependent pathway inhibition on the occurrence of POAF have not been clinically assessed. However, given that NLRP3 pathway inhibition may also indirectly affect other pathways, such as inhibition of NF-kappaB or inhibition of matrix synthesis, which are strongly linked to POAF and cardiac remodeling, it is reasonable to hypothesize that this type of intervention could play a role in preventing these events. Full article
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17 pages, 1222 KiB  
Review
Ischemic Brain Injury: Involvement of Lipids in the Pathophysiology of Stroke and Therapeutic Strategies
by Nathalie Bernoud-Hubac, Amanda Lo Van, Adina-Nicoleta Lazar and Michel Lagarde
Antioxidants 2024, 13(6), 634; https://doi.org/10.3390/antiox13060634 - 23 May 2024
Cited by 2 | Viewed by 1557
Abstract
Stroke is a devastating neurological disorder that is characterized by the sudden disruption of blood flow to the brain. Lipids are essential components of brain structure and function and play pivotal roles in stroke pathophysiology. Dysregulation of lipid signaling pathways modulates key cellular [...] Read more.
Stroke is a devastating neurological disorder that is characterized by the sudden disruption of blood flow to the brain. Lipids are essential components of brain structure and function and play pivotal roles in stroke pathophysiology. Dysregulation of lipid signaling pathways modulates key cellular processes such as apoptosis, inflammation, and oxidative stress, exacerbating ischemic brain injury. In the present review, we summarize the roles of lipids in stroke pathology in different models (cell cultures, animal, and human studies). Additionally, the potential of lipids, especially polyunsaturated fatty acids, to promote neuroprotection and their use as biomarkers in stroke are discussed. Full article
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33 pages, 2109 KiB  
Review
Modulating Nitric Oxide: Implications for Cytotoxicity and Cytoprotection
by Igor Belenichev, Olena Popazova, Nina Bukhtiyarova, Dmytro Savchenko, Valentyn Oksenych and Oleksandr Kamyshnyi
Antioxidants 2024, 13(5), 504; https://doi.org/10.3390/antiox13050504 - 23 Apr 2024
Cited by 10 | Viewed by 1762
Abstract
Despite the significant progress in the fields of biology, physiology, molecular medicine, and pharmacology; the designation of the properties of nitrogen monoxide in the regulation of life-supporting functions of the organism; and numerous works devoted to this molecule, there are still many open [...] Read more.
Despite the significant progress in the fields of biology, physiology, molecular medicine, and pharmacology; the designation of the properties of nitrogen monoxide in the regulation of life-supporting functions of the organism; and numerous works devoted to this molecule, there are still many open questions in this field. It is widely accepted that nitric oxide (NO) is a unique molecule that, despite its extremely simple structure, has a wide range of functions in the body, including the cardiovascular system, the central nervous system (CNS), reproduction, the endocrine system, respiration, digestion, etc. Here, we systematize the properties of NO, contributing in conditions of physiological norms, as well as in various pathological processes, to the mechanisms of cytoprotection and cytodestruction. Current experimental and clinical studies are contradictory in describing the role of NO in the pathogenesis of many diseases of the cardiovascular system and CNS. We describe the mechanisms of cytoprotective action of NO associated with the regulation of the expression of antiapoptotic and chaperone proteins and the regulation of mitochondrial function. The most prominent mechanisms of cytodestruction—the initiation of nitrosative and oxidative stresses, the production of reactive oxygen and nitrogen species, and participation in apoptosis and mitosis. The role of NO in the formation of endothelial and mitochondrial dysfunction is also considered. Moreover, we focus on the various ways of pharmacological modulation in the nitroxidergic system that allow for a decrease in the cytodestructive mechanisms of NO and increase cytoprotective ones. Full article
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28 pages, 2359 KiB  
Review
Oxidative Stress Induced by Lipotoxicity and Renal Hypoxia in Diabetic Kidney Disease and Possible Therapeutic Interventions: Targeting the Lipid Metabolism and Hypoxia
by Seung Yun Chae, Yaeni Kim and Cheol Whee Park
Antioxidants 2023, 12(12), 2083; https://doi.org/10.3390/antiox12122083 - 6 Dec 2023
Cited by 8 | Viewed by 2920
Abstract
Oxidative stress, a hallmark pathophysiological feature in diabetic kidney disease (DKD), arises from the intricate interplay between pro-oxidants and anti-oxidants. While hyperglycemia has been well established as a key contributor, lipotoxicity emerges as a significant instigator of oxidative stress. Lipotoxicity encompasses the accumulation [...] Read more.
Oxidative stress, a hallmark pathophysiological feature in diabetic kidney disease (DKD), arises from the intricate interplay between pro-oxidants and anti-oxidants. While hyperglycemia has been well established as a key contributor, lipotoxicity emerges as a significant instigator of oxidative stress. Lipotoxicity encompasses the accumulation of lipid intermediates, culminating in cellular dysfunction and cell death. However, the mechanisms underlying lipotoxic kidney injury in DKD still require further investigation. The key role of cell metabolism in the maintenance of cell viability and integrity in the kidney is of paramount importance to maintain proper renal function. Recently, dysfunction in energy metabolism, resulting from an imbalance in oxygen levels in the diabetic condition, may be the primary pathophysiologic pathway driving DKD. Therefore, we aim to shed light on the pivotal role of oxidative stress related to lipotoxicity and renal hypoxia in the initiation and progression of DKD. Multifaceted mechanisms underlying lipotoxicity, including oxidative stress with mitochondrial dysfunction, endoplasmic reticulum stress activated by the unfolded protein response pathway, pro-inflammation, and impaired autophagy, are delineated here. Also, we explore potential therapeutic interventions for DKD, targeting lipotoxicity- and hypoxia-induced oxidative stress. These interventions focus on ameliorating the molecular pathways of lipid accumulation within the kidney and enhancing renal metabolism in the face of lipid overload or ameliorating subsequent oxidative stress. This review highlights the significance of lipotoxicity, renal hypoxia-induced oxidative stress, and its potential for therapeutic intervention in DKD. Full article
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Review
Protein Carbonylation as a Biomarker of Oxidative Stress and a Therapeutic Target in Neonatal Brain Damage
by José Martínez-Orgado, María Martínez-Vega, Laura Silva, Angela Romero, María de Hoz-Rivera, María Villa and Aarón del Pozo
Antioxidants 2023, 12(10), 1839; https://doi.org/10.3390/antiox12101839 - 10 Oct 2023
Cited by 3 | Viewed by 2088
Abstract
Oxidative stress (OS) constitutes a pivotal factor within the mechanisms underlying brain damage, for which the immature brain is particularly vulnerable. This vulnerability is caused by the abundance of immature oligodendrocytes in the immature brain, which are highly susceptible to OS-induced harm. Consequently, [...] Read more.
Oxidative stress (OS) constitutes a pivotal factor within the mechanisms underlying brain damage, for which the immature brain is particularly vulnerable. This vulnerability is caused by the abundance of immature oligodendrocytes in the immature brain, which are highly susceptible to OS-induced harm. Consequently, any injurious process involving OS within the immature brain can lead to long-term myelination impairment. Among the detrimental repercussions of OS, protein carbonylation stands out as a prominently deleterious consequence. Noteworthy elevation of protein carbonylation is observable across diverse models of neonatal brain injury, following both diffuse and focal hypoxic–ischemic insults, as well as intraventricular hemorrhage, in diverse animal species encompassing rodents and larger mammals, and at varying stages of brain development. In the immature brain, protein carbonylation manifests as a byproduct of reactive nitrogen species, bearing profound implications for cell injury, particularly in terms of inflammation amplification. Moreover, protein carbonylation appears as a therapeutic target for mitigating neonatal brain damage. The administration of a potent antioxidant, such as cannabidiol, yields substantial neuroprotective effects. These encompass the reduction in cerebral damage, restoration of neurobehavioral performance, and preservation of physiological myelination. Such effects are linked to the modulation of protein carbonylation. The assessment of protein carbonylation emerges as a reliable method for comprehending the intricate mechanisms underpinning damage and neuroprotection within neonatal brain injury. Full article
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