Redox Report最新文献

Background: Inflammatory pain is the most common type of chronic pain, and it is rapidly becoming a global health problem. Ginkgo biloba (EGb761) is a natural plant that contains several bioactive components with antioxidant and free radical scavenging properties. However, its underlying mechanism in inflammatory pain remains unclear. The aim of this study was to assess the effects and mechanisms of EGb761 on a complete Freund's adjuvant (CFA)-induced inflammatory pain model in rats.Methods: A single dose of CFA was subcutaneously injected into the right hind paws of the rats, after which EGb761 (100 mg/kg/day) was orally administered for 14 days.Results: Oral EGb761 markedly decreased hind paw edema in CFA-treated rats. In addition, EGb761 significantly reduced thermal hyperalgesia by increasing the hot plate latency and improved motor coordination. Notably, EGb761 significantly reduced nitric oxide levels and catalase enzyme activity in the lumbar spinal cord (LSPC) of CFA-treated rats. Furthermore, EGb761 inhibited the mRNA expression of NF-ĸB, CXCL1, and CXCR2. At the histological level, EGb761 prevented CFA-induced tissue and neuronal damage in the LSPC dorsal horn. The immunohistochemical analysis revealed that caspase-3 levels were significantly reduced, whereas Bcl-2 expression was insignificantly increased with EGb761 treatment in rats with CFA-induced inflammation.Conclusion: EGb761 alleviated CFA-induced chronic inflammatory pain by attenuating oxidant-antioxidant dysregulation, blocking the NF-κB-CXCL1/CXCR2 inflammatory axis, and counteracting neural cell apoptosis in the LSPC. Our results suggest that EGb761 can be used as an analgesic for the treatment of pain associated with inflammation and tissue injury.

Periodontitis, a common dental illness, causes periodontal tissue inflammation and irreversible bone loss, inevitably resulting in tooth loss. Hyperhomocysteinaemia (HHcy), defined as blood total homocysteine (Hcy) levels greater than 15 µmol/L, is linked to increased cardiovascular disease risk. Mounting evidence indicates a connection between HHcy and periodontitis; however, the underlying processes remain unknown. Herein, we explored the mechanisms by which HHcy exacerbates periodontal tissue inflammation and osteoclast formation. In an animal model of periodontitis treated with HHcy, periodontal attachment loss was aggravated, and both systemic and gingival tissue inflammation levels tended to increase; additionally, antioxidant-related proteins were suppressed and expressed at low levels, whereas oxidative damage-related protein expression increased. In RAW264.7 cells treated with LPS or LPS + Hcy, the LPS + Hcy group presented increased reactive oxygen species (ROS) fluorescence intensity, and Nrf2/HO-1 signalling pathway suppression was associated with inflammatory cytokine (TNF-α) expression. In monocyte osteoclasts treated with Rankl or Rankl + Hcy, the Rankl + Hcy group presented Nrf2/HO-1 signalling pathway suppression, an increase in osteoclast-related proteins (NFATc-1 and CTSK), and a more pronounced osteoclastic phenotype. Therefore, HHcy may exacerbate inflammation severity and osteoclast generation in periodontitis by promoting ROS production and inhibiting the Nrf2/HO-1 signalling pathway.

Background: Oxidative stress plays a critical role in the degeneration of midbrain dopaminergic (DA) neurons in Parkinson's disease (PD). However, therapies targeting redox mechanisms are hindered by a lack of scalable and inexpensive redox-focused preclinical models.

Methods: We stably expressed the glutathione-specific redox-sensitive fluorescent protein Grx-roGFP2 in SH-SY5Y and BE(2)-M17 neuroblastoma cell lines. We developed an improved differentiation protocol using staurosporine and dbcAMP to enhance dopaminergic-like characteristics, assessed by DA marker expression, and characterized responses to PD-relevant toxins.

Results: BE(2)-M17 cells expressed higher DA markers than SH-SY5Y cells, and the improved protocol further increased DA markers. Differentiated neuroblastoma cells with dopaminergic-like features showed greater sensitivity to MPP+ and paraquat, with reduced viability, increased oxidative stress, glutathione oxidation, decreased TH expression, and altered neuronal morphology, paralleling patterns observed in PD-related oxidative injury. roGFP2 enabled robust, real-time redox monitoring, correlating oxidative stress with phenotype. Sublethal toxin exposure caused mitochondrial alterations and redox shifts. Pretreatment with N-acetyl-L-cysteine (NAC) mitigated oxidative stress, improved viability, and partially restored TH expression and morphology.

Conclusion: This neuroblastoma-based model with dopaminergic-like features enables scalable, real-time redox monitoring and detailed phenotypic analyses. It expands access to redox biology platforms for investigating neurodegeneration and evaluating antioxidant therapeutic strategies relevant to neurodegeneration.

Objectives: The study aimed to investigate the signalling mechanism for TRPM2 channel activation by non-cytolytic oxidative stress in microglia.

Methods: Microglia from wild-type (WT) and TRPM2-knockout (KO) mice were exposed to 10-30 mM H₂O₂ for up to 24 hours. Morphological changes characteristic of microglial activation, [Ca²⁺]_c, ROS generation and the effects of inhibiting particular signalling pathways were examined.

Results: Exposure of WT microglia to H₂O₂ for 24 hours caused no cell death but induced salient morphological changes, which was prevented by TRPM2-KO. Exposure of WT microglia to H₂O₂ to 2 hours failed, and extension to 8 hours was required, to induce an increase in [Ca²⁺]_c, which was abolished by TRPM2-KO. Exposure of microglia to H₂O₂ for 8 hours induced ROS generation, which was suppressed by inhibition of PKC and NADPH oxidases (NOX). H₂O₂-induced PARP activation in TRPM2-KO cells was lower than that in WT cells. Furthermore, H₂O₂-induced activation of PARP and TRPM2 and morphological changes were attenuated by inhibition of PCK and NOX as well as PYK2 and MEK/ERK.

Conclusion: Our results support that PKC/NOX-mediated ROS generation and TRPM2-mediated Ca²⁺-induced activation of the PYK2/MEK/ERK pathway form a positive feedback mechanism to drive TRPM2 channel activation by non-cytolytic oxidative stress.

Friedreich's Ataxia (FRDA) is a rare neurological disorder caused by an abnormal expansion of Guanine-Adenine-Adenine (GAA) repeat in intron 1 of the FXN gene, which encodes frataxin, leading to reduced expression of frataxin, a mitochondrial protein essential for cellular homeostasis. Frataxin deficiency results in oxidative stress and mitochondrial dysfunction and impaired redox balance. Currently, there is no cure for FRDA. This study aimed to evaluate the therapeutic potential of antioxidants dimethyl fumarate (DMF), N-acetylcysteine (NAC), and L-ascorbic acid (LAA) in restoring mitochondrial redox homeostasis and frataxin levels in FRDA patient-derived fibroblasts and 2D sensory neurons. We assessed cell viability, mitochondrial and cellular reactive oxygen species (ROS) levels, mitochondrial DNA copy number, mitochondrial membrane potential, and frataxin and NRF2 expression at both mRNA and protein levels following antioxidant treatment, either individually or in combination. Treatment with LAA, NAC, and DMF resulted in significant reductions in mitochondrial and cellular ROS, along with increased FXN and NRF2 expression, and enhanced NRF2 nuclear translocation. Furthermore, these compounds improved aconitase/citrate synthase activity, GSH/GSSG ratios, and mitochondrial membrane potential. Notably, the combination of LAA and NAC consistently alleviated multiple disease-associated defects in FRDA cells, suggesting its potential as a promising therapeutic approach.

Objectives: Cerebral ischemic stroke is a leading cause of death worldwide. Though timely reperfusion reduces the infarction size, it exacerbates neuronal apoptosis due to oxidative stress. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor regulating the expression of antioxidant enzymes. Activating Nrf2 gives a therapeutic approach to ischemic stroke.

Methods: Herein we explored flavonoids identified from Polypodium hastatum as Nrf2 activators and their protective effects on PC12 cells injured by oxygen and glucose deprivation/restoration (OGD/R) as well as middle cerebral artery occlusion (MCAO) mice.

Results: The results showed among these flavonoids, AAKR significantly improved the survival of PC12 cells induced by OGD/R and activated Nrf2 in a Keap1-dependent manner. Further investigations have disclosed AAKR attenuated oxidative stress, mitochondrial dysfunction and following apoptosis resulting from OGD/R. Meanwhile, activation of Nrf2 by AAKR was involved in the protective effects. Finally, it was found that AAKR could protect MCAO mice brains against ischemia/reperfusion injury via activating Nrf2.

Discussion: This investigation could provide lead compounds for the discovery of novel Nrf2 activators targeting ischemia/reperfusion injury.

Background: Sympathetic overactivity is closely associated with vascular remodeling. Sympathetic fibers dominantly innervate the adventitia of arteries rather than tunica media. Vascular adventitial fibroblasts (VAFs) play crucial roles in vascular remodeling. However, the link between sympathetic overactivity and VAF proliferation and migration is unknown.

Methods: Primary VAFs were isolated from the thoracic aorta of spontaneously hypertensive rats and Wistar-Kyoto rats. Norepinephrine (NE) bitartrate monohydrate was applied to VAFs to simulate the sympathetic overactivity.

Results: NE increased NADPH oxidase (NOX) 2 expression and superoxide level, which were almost abolished by NOX2 inhibitor GSK2795039 or α-adrenoceptor antagonist prazosin, but not significantly affected by NOX1 inhibitor ML171, NOX4 inhibitor GLX351322 or β-adrenoceptor antagonist propranolol. Superoxide scavenger tempol or NOX2 inhibitor GSK2795039 attenuated NE-induced VAF proliferation and migration. NE promoted protein kinase C (PKC) phosphorylation and NFκB-p65 nuclear translocation. Either PKC inhibitor Go6983 or NFκB inhibitor BAY11-7082 attenuated NE-induced NOX activation, NOX2 upregulation, superoxide production, proliferation and migration.

Conclusion: NE promotes oxidative stress by α-receptor/PKC/NFκB-mediated NOX2 upregulation, which contributes to proliferation and migration of VAFs.

Background: Alopecia is a global dermatological challenge. Adipose-derived stem cells (ADSC) show therapeutic potential, but their mechanisms in promoting hair regrowth, particularly under oxidative stress conditions, remain unclear..

Objective: To investigate ADSC's role in promoting hair regrowth by mitigating oxidative stress.

Methods: Using H₂O₂-stressed HaCaT cells, ADSC's protective effects were evaluated via conditioned medium (CM) and co-culture. Assessments included cell viability, colony formation, ROS, MDA, antioxidant enzymes, and 8-OHdG. Nrf2 activation was analyzed by immunofluorescence and Western blot. A mouse radiation injury model validated findings.

Results: Non-pretreated ADSC offered limited oxidative protection to HaCaT cells. Conversely, H₂O₂-pretreated ADSC significantly enhanced HaCaT viability and proliferation in both CM and co-culture systems. This involved paracrine activation of the Nrf2 pathway in HaCaT cells, boosting antioxidant enzymes, accelerating ROS clearance, and reducing lipid peroxidation. These effects were reversible with Nrf2 inhibition. In vivo, CM from H₂O₂-stimulated ADSC promoted hair regrowth in irradiated mice, outperforming CM from non-pretreated ADSC by activating Nrf2 and reducing tissue oxidative damage.

Conclusions: Oxidative stress potentiates the protective capacity of ADSC against oxidative via Nrf2-dependent paracrine mechanisms, offering a promising strategy for alopecia treatment.

Heatstroke (HS)-induced acute lung injury (ALI) has high morbidity and mortality with no specific therapies. Ferroptosis, a form of programmed cell death driven by lipid peroxidation due to reduced Glutathione Peroxidase 4 (GPX4) activity, is closely linked to HS-induced ALI. This study investigated the effect of alpha-linolenic acid (ALA), a plant-derived ω-3 fatty acid, on ferroptosis in a mouse model of HS-induced ALI. Histopathology analysis found that ALA can attenuate lung injury and improve the 7-day survival rate in mice with HS-induced ALI. In addition, ALA significantly reduced the levels of reactive oxygen species (ROS) and malondialdehyde (MDA), while increasing the level of antioxidant glutathione (GSH). Further analysis showed that ALA upregulated the levels of SLC7A11 and GPX4 by promoting the nuclear translocation of Nrf2. This led to increased GSH synthesis but reduced ROS accumulation, which in turn suppressed ferroptosis and protected the mice against HS-induced ALI. Additionally, the protective effect of ALA was found to be diminished in Nrf2-deficient mice. In summary, ALA inhibits ferroptosis in macrophages by activating the Nrf2/SLC7A11/GPX4 pathway and attenuates HS-induced ALI.

Spermidine (SPD) is an organic compound known for its powerful antioxidant stress and anti-aging properties, and whether SPD has the ability to reduce bone mass in elderly iron overload rats is unknown. The study aimed to assess SPD's impact on iron overload-induced bone loss in elderly rats. In our aged rat model, we found that iron overload negatively influences bone metabolism and remodeling, resulting in decreased bone mineral density and increased bone loss. However, SPD treatment effectively alleviated these harmful effects, as shown by reduced serum levels of MDA and increased SOD and GSH levels. Additionally, SPD-treated rats exhibited enhanced bone mass and higher expression of OC, BMP2, SIRT1, and SOD2 in their bones. Moreover, SPD restored the imbalance in bone metabolism by counteracting the inhibition of osteogenic differentiation and promoting osteoclast differentiation induced by iron overload in MC3T3-E1 and RAW264.7 cells affected by EX527. In summary, our findings suggest that SPD's antioxidant properties may exert anti-osteoporosis effects through activation of the SIRT1/SOD2 signaling pathway.