Antioxidants & redox signaling最新文献

Aims: Intracranial aneurysm (IA) is a critical cerebrovascular disorder strongly linked to phenotypic switching and apoptosis of vascular smooth muscle cells (VSMCs). This study aimed to investigate the role of circGNAQ in IA development and elucidate its underlying molecular mechanisms. Results: Reverse transcription-quantitative polymerase chain reaction and fluorescence in situ hybridization revealed significant upregulation of circGNAQ in IA tissues, predominantly localized within VSMCs. In vitro, circGNAQ knockdown attenuated hydrogen peroxide-induced VSMC phenotypic switching and apoptosis, whereas circGNAQ overexpression aggravated these pathological processes. RNA pull-down and mass spectrometry demonstrated that circGNAQ specifically binds to serine/arginine-rich splicing factor 1 (SRSF1), promoting its ubiquitination and degradation, thereby destabilizing SRSF1. Cotransfection assays confirmed that SRSF1 functions as a downstream mediator of circGNAQ in regulating VSMC phenotypic switching and apoptosis. In vivo, circGNAQ knockdown significantly suppressed IA formation in a murine model by inhibiting VSMC phenotypic switching and apoptosis. Innovation and Conclusion: This study identifies circGNAQ as a novel regulator of VSMC phenotypic switching and apoptosis through targeting SRSF1. The findings highlight circGNAQ as a potential therapeutic target for preventing and treating IA. Antioxid. Redox Signal. 00, 000-000.

Aim: Metabolic dysfunction-associated steatotic liver disease (MASLD) is a major cause of chronic liver disease, yet its pathogenesis remains incompletely understood. Oxidative stress is thought to play a key role in MASLD progression. This study aimed to investigate the role of cystathionine γ-lyase (CSE), an enzyme essential for cysteine and glutathione (GSH) biosynthesis, in MASLD development. Results: Choline-deficient high-fat diet (CDHFD) feeding led to elevated aspartate aminotransferase, alanine aminotransferase, hepatic triglyceride accumulation, vacuolization, macrophage infiltration, and cell death in both genotypes, with significantly greater changes observed in Cse^-/- mice. CDHFD also reduced hepatic CSE expression in Cse^+/+ mice and decreased cysteine/GSH levels in both genotypes, with more pronounced reductions in Cse^-/- mice. Furthermore, Cse deletion was associated with increased oxidized glutathione/total GSH ratios and elevated levels of 4-hydroxynonenal and malondialdehyde. Expression of glutathione synthetase and γ-glutamyl transpeptidase was increased by CDHFD in Cse^+/+ mice but blunted in Cse^-/- mice. Furthermore, CSE deficiency exacerbated CDHFD-induced hepatic iron accumulation. Innovation: Our findings suggest that the CSE-cysteine-GSH axis may serve as a potential therapeutic target for MASLD, providing new intervention strategies beyond traditional approaches. This study provides new insights into the molecular mechanisms of MASLD and supports the development of antioxidant-based therapies. Conclusions: CSE deficiency exacerbates CDHFD-induced impairments of cysteine-GSH antioxidant axis, leading to hepatic oxidative stress and cell death. This indicates that CSE plays a protective role against MASLD development and progression. Antioxid. Redox Signal. 00, 000-000.

Significance: Oxidative stress is a key factor in inducing cellular senescence and age-related diseases. When the redox balance within the body is disrupted, sustained oxidative stress can lead to cellular senescence. The accumulation of senescent cells, in turn, triggers a variety of age-related diseases. Peroxiredoxin 6 (Prdx6) is a critical target in the intracellular regulation of redox homeostasis. Recent Advances: Prdx6 is a widely expressed antioxidant enzyme and the sole member of the peroxiredoxin family endowed with multiple enzymatic functions, including peroxidase activity along with acidic calcium-independent phospholipase A2 (aiPLA2) and lysophosphatidylcholine acyltransferase (LPCAT) activities. Its fundamental physiological functions involve protecting against oxidative stress and maintaining phospholipid homeostasis. Recent studies have shown that Prdx6 is widely involved in the regulation of cellular senescence and influences the development and progression of various age-related diseases. Critical Issues: Cellular senescence and age-related diseases, due to their complex mechanisms, lack effective treatments. Therefore, there is an urgent need to identify new therapeutic targets. This review discusses the biological characteristics of Prdx6 and its pathophysiological roles in cellular senescence and age-related diseases. Prdx6 may serve as a potential target for modulating cellular senescence and age-related diseases. Future Directions: The regulatory mechanisms of Prdx6 in age-related diseases warrant further investigation. Additionally, conducting drug screening to identify more molecules that can specifically target Prdx6 will provide new strategies for the treatment of age-related diseases. Antioxid. Redox Signal. 43, 400-426.

Aims: Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder among the elderly. Uric acid (UA), the end product of purine metabolism, functions as a potent free radical scavenger and helps mitigate oxidative stress. Several epidemiological studies revealed that serum UA levels are negatively correlated with the risk of AD; however, the molecular mechanisms remain unclear. Notably, β-amyloid (Aβ) deposition is implicated in the disruption of mitophagy, leading to neuronal apoptosis. In this study, we aim to elucidate the link between UA and AD and explore the underlying mechanisms. Results: We demonstrated that UA improved cognitive impairment in 5×FAD mice and reduced neuronal apoptosis both in vivo and in vitro. UA reversed the expression of phosphatase and tensin homolog (PTEN)-induced kinase 1 (PINK1), p-Parkin^S65, parkin, microtubule-associated protein 1 light chain 3 II/I, and p62 proteins inhibited by Aβ treatment, alleviated Aβ induced mitochondrial dysfunction, and disturbed dynamics. We found that UA activated nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1(HO-1) signaling both in vivo and in vitro. Furthermore, ML385, a Nrf2-specific inhibitor, reversed the increase in mitochondrial membrane potential and mitophagy promoted by UA and increased neuronal apoptosis in HT22 cells. The antiapoptotic effects of UA in HT22 cells were prevented by treatment with small interfering RNAs targeting PINK1. Conclusions and Innovation: These data suggest that UA stimulates PINK1/parkin-mediated mitophagy reducing Aβ-induced neuronal apoptosis through the Nrf2/HO-1 pathway, which plays a neuroprotective role in AD. Our findings confirmed that UA effectively reduces neuronal damage and cognitive impairment, highlighting its potential clinical applications in the treatment of AD. Antioxid. Redox Signal. 43, 381-399. [Figure: see text].

Aims: We previously demonstrated that aryl hydrocarbon receptor (AhR) activation attenuates the cytoprotective effect of hydrogen sulfide (H₂S), leading to indoxyl sulfate (IS)-mediated renal tubular damage. However, it is unclear whether this pathway would be present in an in vivo uremic model. Results: In a rat chronic kidney disease (CKD) model with 5/6 nephrectomized (Nx), we found that poor renal filtration is associated with accumulation of IS and homocysteine (Hcy), an H₂S precursor. Compared with controls, the protein and mRNA levels of H₂S-producing enzymes, including cystathionine β-synthase, cystathionine γ-lyase, and 3-mercaptopyruvate sulfurtransferase, were attenuated in Nx kidneys. Since the transcription factor, specificity protein 1 (Sp1), acts as an upstream regulator of these enzyme expressions, we found that the protein level and activity of Sp1 were significantly decreased in Nx kidneys. Interestingly, employing the blocker of the AhR CH-223191 not only reverses the decrease in H₂S-producing enzymes and Sp1, but it also reverses H₂S reduction in Nx rats. These are associated with the mitigation of plasma Hcy accumulation, renal excretion, perfusion insufficiency, and tubular damage. Moreover, the oxidative stress in Nx kidneys due to increased superoxide formation and decreased glutathione contents was also attenuated by AhR inhibition. Innovation: Our findings highlight the deleterious effect of AhR activation on renal H₂S formation may be due to IS accumulation and underline AhR blockade as a novel therapy for CKD. Conclusion: AhR is detrimental to Sp1 function in vivo, leading to impeding renal H₂S generation and exacerbating oxidative stress during CKD progression. Antioxid. Redox Signal. 43, 448-464.

Background and Aims: Ischemic stroke (IS) remains the third leading cause of death, and the treatment of acute ischemic stroke (AIS) is still a formidable challenge to clinicians. This study tested the hypothesis that combined silencing Mnf2 gene in adipose-derived mesenchymal stem cells (ADMSCs^sil-Mnf2) and melatonin (Mel) therapy was superior to monotherapy on attenuating the brain infarct volume (BIV) and improving neurological function in AIS rats. Results: In vitro and in vivo studies were conducted. In vitro results showed that as compared with the controls (i.e., ADMSCs/N2a cells), the cellular/protein levels of oxidative stress/reactive oxygen species (ROS)/mitochondrial and DNA damaged/apoptotic/cell stress signaling (tumor necrosis factor [TNF] receptor associated factor 6/ apoptosis signal regulating kinase/MKK^4/7/JUN/ERK^1/2/c-Jun) biomarkers were significantly increased in these cells treated by H₂O₂ that were significantly reversed by ADMSCs^sil-Mnf2 or Mel and further significantly reversed by combined therapy (all p < 0.0001). Animals were categorized into groups 1 (sham-operated control)/2 (AIS)/3 (AIS + Mel)/4 (AIS + ADMSCs^sil-Mnf2)/5 (AIS + Mel-ADMSCs^sil-Mnf2) and euthanized by day 28 after AIS. By day 28, the BIV and the brain infarct area (BIA) were lowest in group 1/highest in group 2/significantly lower in group 5 than in groups 3 and 4/significantly increased in group 4 than in group 3, whereas the neurological function displayed an opposite manner of BIV (all p < 0.0001). The protein expressions of oxidative stress/mitochondrial damaged/apoptotic/inflammatory/cell stress signaling biomarkers displayed an identical pattern, whereas the protein expressions of mitochondrial biogenesis/antioxidants and cellular level of neuronal cells exhibited an opposite manner of BIV among the groups (all p < 0.0001). Innovation and Conclusion: ADMSCs^sil-Mnf2 and Mel combined therapy offered synergic effects on attenuating the BIV/BIA and preserving neurological function in rodents after AIS mainly through suppressing oxidative stress/ROS/inflammatory signalings and upregulating antioxidants. Combined ADMSCs^sil-Mnf2 and Mel therapy offered additional benefits on protecting the brain against AIS in rodents. Antioxid. Redox Signal. 43, 427-447.

Aims: Total flavones of Rhododendron (TFR) extracted from the flowers of Rhododendron contains bioactive components. We investigated the main components of TFR and explored the role of TFR in microglial polarization in poststroke mice with depression-like behavior. Results: Using ultraperformance liquid chromatography-tandem mass spectrometry, we identified the main and potential active compounds in TFR as kaempferol, astragalin, epicatechin, myricetin, rutin, isoquercitrin, quercetin, and quercitrin. In addition, we demonstrated that TFR (60 and 120 mg/kg) efficiently ameliorated depression-like behavior in mice and promoted microglial polarization to the M2 subtype in the mouse hippocampal tissues. We also revealed that TFR (160 mg/L) facilitated microglial polarization to the M2 subtype following oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro. RNA sequencing revealed the upregulation of NADPH oxidase 2 (NOX2) in the mouse brain tissues after cerebral ischemia/reperfusion (I/R) injury. TFR (120 mg/kg) inhibited NOX2 expression in the hippocampal tissues of cerebral I/R mice. In addition, TFR (160 mg/L) downregulated NOX2 expression in OGD/R-treated microglial cells and decreased reactive oxygen species (ROS) production. Notably, NOX2 inhibition promoted microglial polarization to the M2 subtype. Conclusion and Innovation: TFR promotes microglial polarization to the M2 subtype by inhibiting the NOX2/ROS pathway. Antioxid. Redox Signal. 43, 465-481.

Aims: Doxorubicin (Dox) is a potent chemotherapy agent, yet its clinical use is hampered by cardiotoxicity. Although extensive research has focused on Dox-induced cardiotoxicity (DIC), its mechanism remains elusive. Recent evidence implicates ferroptosis as a key contributor to DIC. The 15-lipoxygenase-1 (ALOX15), involved in lipid peroxidation, is known to play an essential role in ischemia-induced myocardial damage and heart failure; however, its function in DIC is undefined. This study seeks to elucidate the role of ALOX15 in DIC and unravel its underlying mechanism. Results: Both ALOX15 mRNA and protein levels were elevated in DIC models in vivo and in vitro. Inhibition or silencing of ALOX15 ameliorated lipid peroxidation, ferroptosis, and cardiac dysfunction in Dox-treated mice. Consistently, ALOX15 loss of function protected H9C2 cells against Dox and RSL3-induced toxicity. In addition, we found that linoleic acid increased the susceptibility of H9C2 cells toward Dox-induced damage, which was abolished by ALOX15 inhibition. Furthermore, Alox15 overexpression aggravated Dox-induced cell damage by aggravating reactive oxygen species (ROS)-mediated ferroptosis. Mechanistically, we discovered that the amelioration of Dox-induced ferroptosis by ALOX15 loss of function occurred through inhibiting the ROS-mediated mitogen-activated protein kinase (MAPK) signaling pathway activation. Innovation and Conclusion: These results reveal that ALOX15 regulates ferroptosis through ROS-mediated MAPK signaling pathway in DIC, suggesting a potential therapeutic target for DIC intervention. Antioxid. Redox Signal. 43, 363-380.

Aims: Periprosthetic osteolysis (PPO), a leading cause of aseptic loosening in joint replacement, arose from complex interactions among osteoblasts, osteoclasts, and osteocytes. Given the pivotal role of connexin 43 (Cx43) in osteocyte communication and bone remodeling, investigating its function was essential for understanding the mechanisms of osteolysis. Our previous studies showed that titanium (Ti) particles increased Cx43 expression in osteocytes. However, the role of Cx43 in osteolysis remained unclear. This study investigated the role of Cx43-mediated regulation of osteocytes on osteoclastogenesis in wear debris-induced osteolysis. Results: Using Dmp1-cre conditional Cx43 knockout mice and the MLO-Y4 osteocyte cell line, we demonstrated that Cx43 deficiency reduced bone resorption and osteoclastogenesis, thereby improving bone remodeling in a Ti particle-induced osteolysis model. Sequencing analysis revealed that Cx43 gene expression changes might be linked to oxidative stress and the Janus Kinase (JAK)-STAT pathway. Elevated Cx43 expression in osteocytes stimulated by Ti particles increased STAT1 protein phosphorylation, induced oxidative stress, elevated the Receptor Activator of Nuclear Factor Kappa-Β Ligand (RANKL)/Osteoprotegerin (OPG) ratio, and promoted osteoclast activation and bone resorption. Conversely, Cx43 gene knockout decreased STAT1 protein phosphorylation and enhanced Nuclear Factor Erythroid 2-Related Factor 2 (NrF2) protein expression. Blocking the JAK-STAT signaling pathway activated by Cx43 increased NrF2 expression, reduced reactive oxygen species levels, and subsequently decreased the RANKL/OPG ratio. Innovation and Conclusions: This study identified a novel mechanism where Cx43 in osteocytes promoted osteoclastogenesis through JAK-STAT pathway activation and oxidative stress in wear debris-induced osteolysis. These findings highlighted the critical role of Cx43 in bone resorption and suggested targeting Cx43 or the JAK-STAT pathway as potential therapeutic strategies to mitigate osteolysis and improve implant longevity. Antioxid. Redox Signal. 43, 215-238.

Aims: Radiation-induced pneumonia (RP) is a common complication after radiotherapy for clinical thoracic tumors, and increasing evidence suggests that miRNAs have potential value in regulating radiation-induced lung injury. However, the potential mechanism is still obscure. Here, we evaluated the miRNAs-dependent mechanism involved in the progression of RP. Results: Our data showed that mmu-miR-208a-3p was consistently highly expressed in the lung tissue of irradiated mice. In vitro studies demonstrated that the expression of miR-208a-3p in cells was significantly increased after X-ray irradiation. Further mechanism studies indicated that radiation-induced upregulation of miR-208a-3p promoted inflammatory responses by suppressing the expression of protein phosphatase 6C (PPP6C) and activating the cyclic GMP-AMP synthase/stimulator of interferon genes protein pathway. Overexpression of PPP6C can alleviate radiation-induced DNA damage and excessive accumulation of ROS. It was also observed that PPP6C inhibited ionizing RP in vivo. Innovation and Conclusion: miR-208a-3p/PPP6C represents a potential therapeutic target for RP which needs to be verified by future clinical studies. Antioxid. Redox Signal. 43, 239-253.