Inhibition Of Reactive Oxygen Species Research Articles

Optimized Extraction of Sargahydroquinoic Acid, Major Bioactive Substance, from Sargassum yezoense Using Response Surface Methodology

Sargahydroquinoic acid (SHQA), a bioactive compound found in certain Sargassum species, exhibits significant health benefits. This study optimized the extraction of SHQA from Sargassum yezoense using response surface methodology (RSM) and evaluated its antioxidant effects through in vitro and in vivo assays. A Box–Behnken design (BBD) was effectively employed to investigate the effects of incubation temperature, time, and ethanol concentration on SHQA yield, achieving a high coefficient of determination (R2 = 0.961). Analysis of variance (ANOVA) validated the model’s reliability (F = 13.86, p = 0.005) and highlighted ethanol concentration as a highly significant factor (p < 0.001). Optimal extraction conditions were identified as 52.8 °C, 8.3 h, and 74.1% ethanol. The SHQA-maximized extract (SME) contained 67.8 ± 0.6 mg SHQA/g and 25.00 ± 1.01 mg phloroglucinol equivalent/g. SME exhibited antioxidant capacity of 26.45 ± 0.66 mg and 28.74 ± 2.30 mg vitamin C equivalent/g in ABTS and DPPH assays, respectively, and 0.29 ± 0.02 mM FeSO4 equivalent/g in the FRAP assay. Additionally, SME at 50 µg/mL and SHQA at 1 µg/mL inhibited reactive oxygen species (ROS) generation in an H2O2-induced zebrafish model. This study presents the first optimization of SHQA extraction using RSM and demonstrates SHQA’s ROS inhibition in a zebrafish model.

Dihydromyricetin Suppresses Lipopolysaccharide-Induced Intestinal Injury Through Reducing Reactive Oxygen Species Generation and NOD-Like Receptor Pyrin Domain Containing 3 Inflammasome Activation.

As an integral component of the gram-negative bacterial cellular envelope, excess production of lipopolysaccharide (LPS) regularly precipitates causing intestinal damage and barrier dysfunction in avian species. Dihydromyricetin (DHM), a naturally occurring constituent in rattan tea, exhibits protective characteristics against various tissue injuries. However, the intervention mechanism of DHM on intestinal injury induced by LPS in chickens has not been determined. Consequently, this study aimed to elucidate the mechanisms through which DHM mitigates LPS-induced intestinal damage in chickens through the reactive oxygen species (ROS)-NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome. Primary intestinal epithelial cells (IECs) were isolated and cultured from 14-day-old specific pathogen free (SPF) chicken embryos, and DHM ranging from 20 to 320 μmol/L increased cell survival rates. Additionally, DHM at 20 and 40 μmol/L demonstrated reduction in oxidative stress and ROS accumulation, mirroring the impact of ROS inhibitor (2.5 mmol/L NAC). DHM efficiently regulated ROS production, thereby augmenting ZO-1, occludin and claudin-1 expression to enhance barrier function; upregulating bcl-2 expression and downregulating bax and caspase-3 expression to regulate apoptosis and suppressing inflammation in IECs. Suppression of ROS subsequently attenuates NLRP3 inflammasome activation, leading to a remarkable downregulation of IL-1β, IL-18 and lactate dehydrogenase (LDH) secretion, consistent with direct inactivation of NLRP3 inflammasome (10 μmol/L MCC950). Notably, DHM diminished IL-1β and IL-18 levels and LDH activity via suppression of ROS-regulated NLRP3 and caspase-1 expression and activation. In summary, DHM prevents LPS-induced intestinal impairment by modulating ROS generation and NLRP3 inflammasome activation.

Electrochemical Probing of Dopamine Dynamics During Poly(I:C)-Induced Neuroinflammation.

Viruses can infiltrate the central nervous system and contribute to depression, which may include alterations in dopamine (DA) metabolism triggered by immune responses though the specific mechanisms involved remain unclear. Here, an electrochemical system to realize the real-time dynamic monitoring of DA with high sensitivity is proposed and it is demonstrated that the viral simulator polyinosinic-polycytidylic acid (poly(I:C)) can inhibit the release of DA (from 5.595 to 0.137 µm) in neurons from the perspective of single cells, cell populations and even in vivo through the combination of multiscale electrodes, including single nanowires, carbon fibers (CFs) and 2D flexible electrodes. These findings are associated with the increase in reactive oxygen species (ROS) produced by microglia. At the molecular level, poly(I:C) significantly decreases the expression of α-synuclein and increases its phosphorylation level, whereas ROS inhibitors can reverse these pathological changes and salvage DA release to half the initial level (≈2.6 µM). These results suggest that viruses may indirectly inhibit DA system function through ROS produced in inflammatory responses and that antioxidant activity may be a potential therapeutic strategy.

Cartilage Endplate‐Targeted Engineered Exosome Releasing and Acid Neutralizing Hydrogel Reverses Intervertebral Disc Degeneration

AbstractCartilage endplate cell (CEPC) and nucleus pulposus cell (NPC) inflammation are critical factors that contribute to intervertebral disc degeneration (IVDD). Recent evidence indicated that iron ion influx, reactive oxygen species (ROS), and the cGAS‐STING pathway are involved in CEPC inflammatory degeneration. Moreover, cytokines produced by degenerating CEPCs and lactic acid accumulation within the microenvironment significantly contribute to NPC inflammation. Consequently, simultaneous alleviation of CEPC inflammation and correction of the acidic microenvironment are anticipated to reverse IVDD. Herein, CEPC‐targeted engineered exosomes loaded with salvianolic acid A are incorporated into a CaCO3/chitosan hydrogel, forming a composite gel, CAP‐sEXOs@Gel. Notably, CAP‐sEXOs@Gel shows long local retention, realizes the slow release of CAP‐sEXOs and specific uptake by CEPCs. After uptake by CEPCs, CAP‐sEXOs reduce intracellular iron ion and ROS by inhibiting hypoxia‐inducible factor‐2α (HIF‐2α)/TfR1 expression. Iron ion influx and ROS inhibition contribute to the maintenance of normal mitochondrial function and reduced mtDNA leakage, suppresing the cGAS‐STING pathway. Additionally, the CaCO3 component of CAP‐sEXOs@Gel neutralizes H+, thereby alleviating NPC inflammation. Collectively, this novel composite hydrogel demonstrates the ability to concurrently inhibit CEPC and NPC inflammation, thereby presenting a promising therapeutic approach for IVDD.

Vitamin C ameliorates D-galactose-induced senescence in HEI-OC1 cells by inhibiting the ROS/NF-κB pathway.

Cochlear hair cell senescence is one of the major causes of age-related hearing loss (ARHL) and is significantly related to reactive oxygen species (ROS) accumulation. Research shows that vitamin C (VC) can inhibit ROS accumulation; however, its association with cochlear hair cell senescence remains elusive. Firstly, a cellular senescence model was established using D-galactose (D-gal) induced HEI-OC1 cells for 24 h. Senescent HEI-OC1 cells were then continued to be treated with the addition of VC or ROS inhibitor (N-acetylcysteine; NAC) for another 24 h, and explored the impact of VC on senescent cochlear hair cell and the potential regulatory mechanisms. The results indicated that D-gal-induced senescent HEI-OC1 cells, manifested as decreased cell viability, increased β-galactosidase activity and p21 protein level, and ROS and pro-inflammatory factors were upregulated, and NF-κB p65 phosphorylation was enhanced. However, the use of VC or NAC can significantly ameliorate these effects and improve HEI-OC1 cell senescence. This research indicates that VC can ameliorate D-gal-induced senescence of HEI-OC1 cochlear hair cells, and its protective effect may be related to the inhibition of the ROS/NF-κB pathway, which provides a new research direction for the prevention and treatment of ARHL.

Inhibition of VDAC1 oligomerization blocks cysteine deprivation-induced ferroptosis via mitochondrial ROS suppression

Ferroptosis, a regulated form of cell death dependent on reactive oxygen species (ROS), is characterized by iron accumulation and lethal lipid peroxidation. Mitochondria serve as the primary source of ROS and thus play a crucial role in ferroptosis initiation and execution. This study highlights the role of mitochondrial ROS and the significance of voltage-dependent anion channel 1 (VDAC1) oligomerization in ferroptosis induced by cysteine deprivation or ferroptosis-inducer RSL3. Our results demonstrate that the mitochondria-targeted antioxidants MitoQ and MitoT effectively block ferroptosis induction and that dysfunction of complex III of the mitochondrial electron transport chain contributes to ferroptosis induction. Pharmacological inhibitors that target VDAC1 oligomerization have emerged as potent suppressors of ferroptosis that reduce mitochondrial ROS production. These findings underscore the critical involvement of mitochondrial ROS production via complex III of the electron transport chain and the essential role of VDAC1 oligomerization in ferroptosis induced by cysteine deprivation or RSL3. This study deepens our understanding of the intricate molecular networks governing ferroptosis and provides insights into the development of novel therapeutic strategies targeting dysregulated cell death pathways.

Uric acid mediates kidney tubular inflammation through the LDHA/ROS/NLRP3 pathway

ABSTRACT Purpose Hyperuricemia (HUA) is an important factor leading to chronic kidney disease (CKD). The kidney tubular inflammatory response is activated in HUA. This study aimed to investigate whether lactate dehydrogenase A (LDHA) is involved in mediating uric acid-induced kidney tubular inflammatory response. Methods In vivo, an HUA mouse model was established by continuous intraperitoneal injection of potassium oxonate (PO) for one week. A total of 18 C57BL/6J male adult mice were divided into three groups: control group, HUA group, and HUA+oxamate group, with six mice in each group. Oxamate was intraperitoneally injected into the mice one hour after PO injection. In vitro, an HUA model was simulated by stimulating HK-2 cells with uric acid. Oxamate and tempol inhibited LDHA and reactive oxygen species (ROS) in HK-2 cells. Results In HUA mice, blood uric acid levels were significantly elevated. LDHA in kidney tubular cells was significantly increased in both in vivo and in vitro HUA models, accompanied by an increase in kidney tubular inflammation and ROS. Mechanistically, LDHA mediates uric acid-induced inflammation to kidney tubular cells through the ROS/NLRP3 pathway. Pharmacologic inhibition of LDHA or ROS in kidney tubular cells can significantly ameliorate inflammation response caused by uric acid. Conclusions LDHA in kidney tubular cells significantly was increased in HUA models. LDHA mediates kidney inflammation response induced by uric acid through the ROS/NLRP3 pathway. This study may provide a new intervention target for preventing kidney tubular inflammation caused by uric acid.

Oxidized Low-Density Lipoprotein Induces Reactive Oxygen Species-Dependent Proliferation of Intestinal Epithelial Cells.

Background/Objectives: Oxidized low-density lipoprotein (ox-LDL) is a proinflammatory particle associated with various diseases and affects cell proliferation and viability in multiple cell types. However, its impact on intestinal epithelial cells remains underexplored. This study investigates the effect of ox-LDL on colonic epithelial cell proliferation and viability, as well as the underlying mechanisms involved. Methods: The expression levels of ox-LDL receptors in human colonoids were analyzed at baseline and in response to proinflammatory signals by qRT-PCR. The effect of ox-LDL on organoid proliferation was analyzed using morphometric measurements, viability assays, and the incorporation of a thymidine analog into DNA. The generation of reactive oxygen species (ROS) was determined by Amplex Red assays. Additionally, ox-LDL-induced ROS-dependent organoid proliferation was studied by exposing colonoids to an antioxidant or ROS inhibitors. Results: Colonic epithelial cells express ox-LDL receptors. Ox-LDL significantly induces the proliferation of colonic epithelial cells, which are dependent on ROS generation. Notably, ROS scavengers and NADPH inhibitors reduced ox-LDL-induced proliferation, highlighting the crucial role of oxidative stress in this process. Conclusions: This study demonstrates for the first time that ox-LDL stimulates CEC proliferation mediated by ROS production and validates that the colonic organoid model enables the analysis of potential pharmacological strategies for intestinal diseases characterized by oxidative stress and inflammation.

Cucumber Green Mottle Mosaic Virus Coat Protein Hijacks Mitochondrial ATPδ to Promote Viral Infection.

The production and scavenging of reactive oxygen species (ROS) are critical for plants to adapt to biotic and abiotic stresses. In this study, we investigated the interaction between the coat protein (CP) of cucumber green mottle mosaic virus (CGMMV) and ATP synthase subunit δ (ATPδ) in mitochondria. Silencing of ATPδ by tobacco rattle virus-based virus-induced gene silencing impeded CGMMV accumulation in Nicotiana benthamiana leaves. Both the overexpression of ATPδ in transgenic plants and transient expression promoted CGMMV infection. Nitro blue tetrazolium (NBT) and 3,3'-diaminobenzidine (DAB) staining revealed that ATPδ inhibited O2 - production but not H2O2 production. The treatment of CGMMV-infected leaves with the ROS inhibitor diphenylene iodonium (DPI) induced a ROS burst that inhibited CGMMV infection. Reverse transcription-quantitative PCR and superoxide dismutase (SOD) activity assays showed that ATPδ, CGMMV infection, and CP expression specifically induced NbFeSOD3/4 expression and SOD activity, and silencing NbFeSOD3/4 inhibited CGMMV infection. We speculate that CGMMV CP interacts with ATPδ and hijacks it, thereby enhancing O2 - quenching by upregulating NbFeSOD expression and, in turn, SOD activity.

Cytotoxic effect of polystyrene nanoplastics in human umbilical vein endothelial cells (HUVECs) and normal rat kidney cells (NRK52E)

Plastics play a crucial role in nearly each aspect of societal production and everyday life, therefore making them one of the most widespread pollutants on a global scale. Because synthetic plastics are not entirely biodegradable, they often remain in the environment and fragment into micro- and nanoplastic particles. The detrimental impacts of nanoplastics on the environment and human health have received substantial worldwide interest in recent years. However, the effects of nanoplastics on human health have not yet been fully explored. Our study aimed to investigate the cytotoxic effects of polystyrene nanoplastics on two distinct mammalian cell lines: normal rat kidney cells (NRK52E) and human umbilical vein endothelial cells (HUVECs). Results showed that polystyrene nanoplastics generate cytotoxicity in both NRK52E and HUVECs in a concentration- and time-dependent manner. Additionally, polystyrene nanoplastics induced pro-oxidant levels (e.g., reactive oxygen species and hydrogen peroxide) and reduced antioxidants (glutathione content and glutathione peroxidase enzyme activity) in both types of cells. We also found that polystyrene nanoplastics cause apoptosis in both NRK52E and HUVECs, as shown by the activation of the caspase-3 enzyme and the loss of mitochondrial membrane potential. Interestingly, it was noticed that the vulnerability of HUVECs cells against polystyrene nanoplastics was a little higher than that of NRK52E cells. Also, the cell toxicity caused by polystyrene nanoplastics in NRK52E and HUVECs was effectively alleviated by co-exposure to a reactive oxygen species inhibitor, N-acetyl-cysteine. This suggests that oxidative stress could be one of the possible pathways by which polystyrene nanoplastics cause cell toxicity. The present work warrants future study to explore the toxicity mechanisms of polystyrene nanoplastics in appropriate in vivo models.

Isoxazole based nucleosides induce autophagy through the production of ROS and the suppression of the β-catenin pathway in human colorectal carcinoma cells

β-catenin is frequently implicated in signaling pathways that regulate autophagy, and the production of reactive oxygen species (ROS) has been linked to autophagy activation. Isoxazole-based nucleoside compounds have demonstrated anti-cancer properties. In this study, we report the identification of novel isoxazole-nucleosides as anti-tumor agents and their impact on autophagy in human colorectal carcinoma (CRC) cells. Among the ITP series, ITP-7 and ITP-9 (ITP-7/9) exhibited significant cytotoxicity compared to other compounds. Treatment with ITP-7/9 upregulated the expression of key autophagy-related proteins, including LC3 II, Atg7, and phosphorylated Beclin-1. Additionally, ITP-7/9 promoted the formation of LC3 II puncta and increased the number of AO-stained and MDC-stained cells, indicating enhanced autophagy. ROS levels were elevated following ITP-7/9 exposure, and treatment with N-acetyl l-cysteine (NAC), a ROS inhibitor, reduced the ITP-7/9-induced expression of LC3 II. Furthermore, ITP-7/9 inhibited β-catenin's role as a transcription factor, as observed in ICC assays. Moreover, cells with β-catenin gene deletion exhibited stronger autophagy when treated with ITP-7/9 compared to those treated with ITP-7/9 alone. These findings suggest that ITP-7/9 induces autophagy and promotes CRC cell death by downregulating β-catenin.

The modified 6-chromanol SUL-238 protects against accelerated vascular aging in vascular smooth muscle Ercc1-deficient mice

Introduction: Vascular aging is marked by increased mitochondrial reactive oxygen species (ROS) production, which leads to decreased nitric oxide (NO)-mediated vasodilation. Loss of NO can be partially compensated by endothelium-derived hyperpolarization (EDH), which partly relies on increased mitochondrial Ca2+ release to maintain vascular dilation. Thus, intervention in mitochondria may target both NO and EDH signaling to alleviate aging-related vascular dysfunction. DNA damage by mitochondrial ROS is an important cause of organismal aging. Previous work showed that local vascular Ercc1 knockout dramatically accelerates vascular aging. The aim of the study was to investigate the effect of chronic treatment with the modified 6-chromanol, SUL-238, an inhibitor of mitochondrial reverse electron flux and ROS, in a mouse model of accelerated vascular smooth muscle aging induced by DNA repair endonuclease Ercc1 knockout (SMC-KO). Aim: The aim of the study was to investigate the effect of chronic treatment with the modified 6-chromanol, SUL-238, an inhibitor of mitochondrial reverse electron flux and ROS, in a mouse model of accelerated vascular smooth muscle aging induced by DNA repair endonuclease Ercc1 knockout (SMC-KO). Methods: SMC-KO mice and healthy wild-type littermates received SUL-238 (90 mg/kg/day) in drinking water from 12 to 22 weeks of age. At the age of 21 weeks, arterial stiffness was measured in vivo with echography and they were euthanized at the age of 22 weeks. Ex vivo vascular function was assessed in wire myography setups and mitochondrial function of the thoracic aorta was assessed using a seahorse assay. Results: SMC-KO mice showed reduced EDH-mediated vasodilation, elevated arterial stiffness, and increased elastin breaks at 22 weeks of age compared to their wild-type littermates. SUL-238 improved EDH, thus restoring aortic and mesenteric relaxation in SMC-KO mice. Furthermore, the number of elastin breaks was reduced and arterial stiffness normalized after treating SMC-KO mice with SUL-238. Mitochondrial respiration measured in the aorta was not different between the groups. Conclusion: Chronic treatment with SUL-238 alleviates features of vascular aging, including decreased vasodilation and increased arterial stiffness. SUL-238 seems to have a more general effect on aging rather than involving a direct coupling between mitochondrial function and vascular signaling. SUL-238 is the first small-molecule drug reported to increase EDH after chronic treatment.

A natural polyphenolic nanoparticle--knotted hydrogel scavenger for osteoarthritis therapy

Exploring highly efficient and cost-effective biomaterials for osteoarthritis (OA) treatment remains challenging, as current therapeutic strategies are difficult to eradicate the excessive reactive oxygen species (ROS) and nitric oxide (NO) at damaged sites. Tea polyphenol (TP) nanoparticles (NPs), a nature-inspired antioxidant in combination with 2-(4-Carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO), a NO scavenger, could provide maximized positive therapeutic effects on OA by eradicating both ROS and NO. Notably, this combination not only improves the half-life of the TP monomer and the drug loading efficiency of carboxy-PTIO but also prevents nitrite from being harmful to tissue. Moreover, the protonation ability of carboxy-PTIO allows smart acid-responsive release in response to environmental pH, which provides conditioned treatment strategies for OA. In in vitro experiments, TP/PTIO NPs downregulated proinflammatory cytokine release via synergistic removal of ROS and NO and suppression of ROS/NF-κB and iNOS/NO/Caspase-3 signaling. For in vivo experiments, NPs were cross-linked with 4-arm-PEG-SH to form an injectable hydrogel system. The release of TP and carboxy-PTIO from the system efficiently prevents cartilage inflammation and damage via similar signaling pathways. Overall, the proposed system provides an efficient approach for OA therapy.

Sodium selenite inhibits cervical cancer progression via ROS-mediated suppression of glucose metabolic reprogramming

AimsThis study aims to explore the inhibitory effect of selenium on cervical cancer through suppression of glucose metabolic reprogramming and its underlying mechanisms. MethodsSodium selenite (SS) treated HeLa and SiHa cells were assessed for proliferation using the CCK-8 assay and immunofluorescence. DNA synthesis was measured with the EdU assay. A nude mouse xenograft model evaluated SS's anti-cervical cancer effects. Reactive oxygen species (ROS) and mitochondrial membrane potential were measured using flow cytometry, DCFH-DA, and JC-1 probes, respectively. Apoptosis was detected via Annexin V/PI staining and Western blot. Glucose uptake, lactate production, and ATP generation were determined using 2-NBDG probes and assay kits. The mRNA and protein levels of glycolysis-related genes HK2, GLUT1, and PDK1 were measured using RT-qPCR and Western blot. Key findingsSS inhibited HeLa and SiHa cells viability in a dose- and time-dependent manner. Intraperitoneal injection of SS in nude mice significantly inhibited HeLa cell xenograft growth without evident hepatotoxicity or nephrotoxicity. SS inhibited glucose metabolic reprogramming in cancer cells primarily via ROS-mediated AKT/mTOR/HIF-1α pathway inhibition. Pretreatment with N-acetylcysteine (NAC) or MHY1485 (an mTOR activator) partially reversed the inhibitory effects of SS on glucose metabolic reprogramming, cell proliferation, and migration, as well as its pro-apoptotic effects. SignificanceSS exhibited anti-cervical cancer effects, likely through the induction of ROS generation and inhibition of glucose metabolic reprogramming in cervical cancer cells, thereby inhibiting cell proliferation and promoting apoptosis. These findings provide new insights into understanding the molecular mechanisms underlying SS for potential new drug development for cervical cancer.

The MADS-box gene XAANTAL1 participates in Arabidopsis thaliana primary root growth and columella stem cell patterns in response to ROS, via direct regulation of PEROXIDASE 28 and RETINOBLASTOMA RELATED.

The balance between cell growth, proliferation and differentiation emerges from gene regulatory networks coupled to various signal transduction pathways, including reactive oxygen species (ROS) and transcription factors (TFs), enabling developmental responses to environmental cues. The Arabidopsis thaliana's primary root has become a valuable system for unraveling such networks. Recently, the role of TFs that mediate the ROS's inhibition of primary root growth has begun to be characterized. This study demonstrates that the MADS-box transcription factor XAANTAL1 (XAL1) is an essential regulator of hydrogen peroxide (H2O2) in primary root growth and root stem cell niche identity. Interestingly, our findings suggest that XAL1 acts as a positive regulator of H2O2 concentration in the root meristem by directly regulating genes involved in oxidative stress response, such as PEROXIDASE 28 (PER28). Moreover, we found that XAL1 is necessary for the H2O2-induced inhibition of primary root growth through the negative regulation of peroxidase and catalase activities. Furthermore, XAL1, in conjunction with RETINOBLASTOMA-RELATED (RBR), is essential for positively regulating the differentiation of columella stem cells and for participating in primary root growth inhibition in response to oxidative stress induced by H2O2 treatment.

Ozone therapy mitigates parthanatos after ischemic stroke

BackgroundStroke is a leading cause of death worldwide, with oxidative stress and calcium overload playing significant roles in the pathophysiology of the disease. Ozone, renowned for its potent antioxidant properties, is commonly employed as an adjuvant therapy in clinical settings. Nevertheless, it remains unclear whether ozone therapy on parthanatos in cerebral ischemia–reperfusion injury (CIRI). This study aims to investigate the impact of ozone therapy on reducing parthanatos during CIRI and to elucidate the underlying mechanism.MethodsHydrogen peroxide (H2O2) was utilized to mimic the generation of reactive oxygen species (ROS) in SH-SY5Y cell reperfusion injury in vitro, and an in vivo ischemic stroke model was established. Ozone saline was introduced for co-culture or intravenously administered to mice. Apoptosis and oxidative stress were assessed using flow cytometry and immunofluorescence. Western blotting was utilized to examine the expression of parthanatos signature proteins. The mechanism by which ozone inhibits parthanatos was elucidated through inhibiting PPARg or Nrf2 activity. ResultsThe findings demonstrated that ozone mitigated H2O2-induced parthanatos by either upregulating nuclear factor erythroid 2-related factor 2 (Nrf2) or activating peroxisome proliferator-activated receptorg (PPARg). Furthermore, through the use of calcium chelators and ROS inhibitors, it was discovered that ROS directly induced parthanatos and facilitated intracellular calcium elevation. Notably, a malignant feedback loop between ROS and calcium was identified, further amplifying the induction of parthanatos. Ozone therapy exhibited its efficacy by increasing PPARg activity or enhancing the Nrf2 translation, thereby inhibiting ROS production induced by H2O2. Concurrently, our study demonstrated that ozone treatment markedly inhibited parthanatos in stroke-afflicted mice. Additionally, ozone therapy demonstrated significant neuroprotective effects on cortical neurons, effectively suppressing parthanatos.ConclusionsThese findings contribute valuable insights into the potential of ozone therapy as a therapeutic strategy for reducing parthanatos during CIRI, highlighting its impact on key molecular pathways associated with oxidative stress and calcium regulation.

Mitochondrial-Derived Signaling Mediates Differentiation of Parietal Epithelial Cells into Podocytes.

Aims: Parietal epithelial cells (PECs) are potential stem cells within the glomerulus, migrating into site of podocyte loss to differentiate into podocytes. Little is known about the mechanism mediating differentiation of PECs into podocytes. Results: In vitro differentiation of PECs into podocytes led to upregulation of podocyte markers such as Wilms' tumor gene 1 (WT-1), Forkhead box C1 (FOXC1), synaptopodin and podocin, accompanied by increased mitochondrial abundance. Preincubation with a mitochondrial reactive oxygen species (ROS) inhibitor prevented all these events in PECs. In vivo, adriamycin (ADR)-treated mice exhibited albuminuria, decreased WT1 positive cells, and claudin-1 expressed in glomerular capillary tuft, as well as peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α) overproduction in PECs. Expression of the ROS-related molecule nuclear factor erythroid 2-related factor 2 (Nrf2) and its target protein Brahma-related gene 1 (Brg1) increased during differentiation of PECs into podocytes. Suppressing Nrf2 or Brg1 reduced the differentiation of PECs, whereas overexpression had the opposite effect. Brg1 directly regulated WT-1 transcription in PECs. Activation of Nrf2 with bardoxolone-methyl (CDDO-Me) resulted in less proteinuria and more WT1 positive cells in ADR mice. PECs conditional human Nrf2 knock-in mice showed increased WT1 cell numbers. Conclusion: It concluded that mitochondria-derived ROS mediated differentiation of PECs into podocytes via Nrf2 and Brg1 signaling.

Regulation of Reactive Oxygen Species on Platelet Activation and Apoptosis

To investigate how reactive oxygen species (ROS) regulates the signal transduction of platelet activation and apoptosis, and to explore the relationship between platelet activation and apoptosis. Platelets were directly stimulated with thrombin or pretreated with ROS inhibitor N-acetylcysteine (NAC) before being stimulated with thrombin, and then flow cytometry was used to detect the effects of thrombin and NAC on P-selectin expression, αⅡbβ3 activation, mitochondrial membrane potential depolarization, phosphatidylserine (PS) externalization, ROS expression and platelet aggregation. Thrombin could induce the production of ROS in platelets in a concentration- and time-dependent manner. 0.01 U thrombin induced ROS-dependent high degree of integrin αⅡbβ3 activation, P-selectin expression, and platelet aggregation. The platelets induced by different concentration gradients of thrombin exhibited ROS-dependent mitochondrial membrane potential depolarization and PS externalization in platelets. After induction with thrombin for 30 min, the activation of integrin αⅡbβ3 in platelets reached its maximum level, and after 60 minutes, the depolarization of mitochondrial membrane potential in platelets reached its maximum level. However, the expression of P-selectin, depolarization of mitochondrial membrane potential, and platelet aggregation function were all inhibited to a certain extent when the platelets were pretreated with ROS inhibitor NAC and then induced with thrombin. When platelets are induced by thrombin, ROS first regulates the activation of platelets, and then regulates the apoptosis of platelets. Both platelet activation and apoptosis depend on the production of ROS in platelets, and the signals of activation and apoptosis occur orderly. Inhibiting the ROS signal in platelets can effectively inhibit the activation and apoptosis of platelets.

Lens capsule advanced glycation end products induce senescence in epithelial cells: Implications for secondary cataracts.

Posterior capsule opacification (PCO) is a common complication after cataract surgery. Residual lens epithelial cells (LECs) on the anterior lens capsule, after cataract surgery, migrate to the posterior lens capsule and undergo transdifferentiation into myofibroblast-like cells. Those cells synthesize excessive amounts of extracellular matrix and contribute to fibrosis during PCO. Cellular senescence, a phenomenon that increases with aging, has been implicated in several fibrotic diseases. Here, we have investigated the prevalence of senescent LECs within the lens posterior capsule and the ability of advanced glycation end products (AGEs) in lens capsules to induce senescence, contributing to PCO. Aged lens capsules from pseudophakic human cadaver eyes showed the presence of senescent LECs. In human capsular bags, LECs showed an age-dependent increase in senescence after 28 days of culture. Human LECs cultured on aged lens capsules for 3 days underwent senescence; this effect was not seen in LECs cultured on young lens capsules. Human LECs cultured on an AGE-modified extracellular matrix (ECM-AGEs) showed an AGE-concentration-dependent increase in the expression of senescence markers and reactive oxygen species (ROS) levels. Treatment with a RAGE antagonist and ROS inhibitor reduced the expression of senescence and fibrotic markers. Additionally, conditioned media from ECM-AGEs-treated cells induced the expression of fibrotic markers in naïve LECs. Together, these suggest that AGEs in the capsule induce senescence of LECs, which triggers the mesenchymal transition of neighboring non-senescent LECs and contributes to PCO.

Drug-Loaded Mesoporous Polydopamine Nanoparticles in Chitosan Hydrogels Enable Myocardial Infarction Repair through ROS Scavenging and Inhibition of Apoptosis.

In this study, we synthesized mesoporous polydopamine nanoparticles (MPDA NPs) using an emulsion-induced interface assembly strategy and loaded epigallocatechin gallate (EGCG) into MPDA NPs via electrostatic attraction to form EGCG@MPDA NPs. In the post myocardial infarction (MI) environment, these interventions specifically aimed to eliminate reactive oxygen species (ROS) and facilitate the repair of MI. We further combined them with a thermosensitive chitosan (CS) hydrogel to construct an injectable composite hydrogel (EGCG@MPDA/CS hydrogel). Utilizing in vitro experiments, the EGCG@MPDA/CS hydrogel exhibited excellent ROS-scavenging ability of H9C2 cells under the oxidative stress environment and also could inhibit their apoptosis. The EGCG@MPDA/CS hydrogel significantly promoted left ventricular ejection fraction (LVEF) in infarcted rat models post injection for 28 days compared to the PBS group (51.25 ± 1.73% vs 29.31 ± 0.78%, P < 0.05). In comparison to the PBS group, histological analysis revealed a substantial increase in left ventricular (LV) wall thickness in the EGCG@MPDA/CS hydrogel group (from 0.58 ± 0.03 to 1.39 ± 1.11 mm, P < 0.05). This work presents a novel approach to enhance MI repair by employing the EGCG@MPDA/CS hydrogel. This hydrogel effectively reduces local oxidative stress by ROS and stimulates the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway.