H2O2-induced Apoptosis Research Articles

Protective effects of the Terminalia bellirica tannin-induced Nrf2/HO-1 signaling pathway in rats with high-altitude pulmonary hypertension

BackgroundOxidative stress and endothelial cell dysfunction induced by high-altitude hypoxia have important roles in the pathological process of high-altitude pulmonary hypertension (HAPH). Tannins present in Terminalia bellirica (Gaertn.) Roxb. (TTR) have pharmacological activities that produce oxidation resistance and exert anti-inflammatory effects. Whether TTR exerts a protective effect on HAPH remains unknown.MethodsA rat model of HAPH was established. The mean pulmonary arterial pressure (mPAP) of the animals was measured, the serum levels of SOD, MDA, and GSH-Px were measured using ELISA, and the expression of Bax, Bcl-2, Nrf2, and HO-1 proteins in the lung tissue of each group of rats was measured using Western blotting. Pathological changes in the lung tissue were also observed. A model of damage to H2O2-induced pulmonary artery endothelial cells (PAECs) was generated, and cell proliferation was measured using CCK-8 assays. Flow cytometry was used to measure ROS levels in PAECs. Western blotting was used to detect the expression of Bax, Bcl-2, Nrf2, and HO-1 proteins in PAECs.ResultsThe hemodynamic and pathologic findings showed that the mPAP of HAPH rats increased markedly, and the vascular wall thickness increased (P < 0.05). TTR reduced mPAP, alleviated or slowed pulmonary arterial remodeling, increased GSH-Px and SOD activity, lowered the level of MDA (P < 0.05), and downregulated the expression of Bax in the lung tissues of HAPH rats, while the expression of Bcl-2, Nrf2, and HO-1 was upregulated (P < 0.05). The results of the cell experiments showed that TTR inhibited H2O2-induced PAEC apoptosis and ROS production (P < 0.05), downregulated the expression of Bax in PAECs, and upregulated the expression of Bcl-2, Nrf2, and HO-1 (P < 0.05).ConclusionThe results suggest that TTR reduces pulmonary arterial pressure, decreases oxidative stress during HAPH, and exerts protective effects in rats with HAPH and that its mechanism of action is related to regulation of the Nrf2/HO-1 signaling pathway.

Multi-omics analysis reveals gut microbiota-ovary axis contributed to the follicular development difference between Meishan and Landrace × Yorkshire sows

BackgroundThe mechanism by which Meishan (MS) sows are superior to white crossbred sows in ovarian follicle development remains unclear. Given gut microbiota could regulate female ovarian function and reproductive capacity, this study aimed to determine the role of gut microbiota-ovary axis on follicular development in sows.MethodsWe compared the ovarian follicular development, gut microbiota, plasma metabolome, and follicular fluid metabolome between MS and Landrace × Yorkshire (L × Y) sows. A H2O2-induced cell apoptosis model was used to evaluate the effects of multi-omics identified metabolites on the apoptosis of porcine ovarian granulosa cells in vitro.ResultsCompared with L × Y sows, MS sows have greater ovary weight and improved follicular development, including the greater counts of large follicles of diameter ≥ 5 mm, secondary follicles, and antral follicles, but lesser atretic follicles. The ovarian granulosa cells in MS sows had alleviated apoptosis, which was indicated by the increased BCL-2, decreased caspases-3, and decreased cleaved caspases-3 than in L × Y sows. The ovarian follicular fluid of MS sows had higher concentrations of estradiol, progesterone, follicle-stimulating hormone, luteinizing hormone, and insulin like growth factor 1 than L × Y sows. Gut microbiota of MS sows formed a distinct cluster and had improved alpha diversity, including increased Shannon and decreased Simpson than those of L × Y sows. Corresponding to the enhanced function of carbohydrate metabolism and elevated short-chain fatty acids (SCFAs) in feces, the differential metabolites in plasma between MS and L × Y sows are also mainly enriched in pathways of fatty acid metabolism. There were significant correlations among SCFAs with follicular development, ovarian granulosa cells apoptosis, and follicular fluid hormones, respectively. Noteworthily, compared with L × Y sows, MS sows had higher follicular fluid SCFAs concentrations which could ameliorate H2O2-induced porcine granulosa cells apoptosis in vitro.ConclusionMS sows have more secondary and antral follicles, but fewer atretic follicles and apoptotic ovarian granulosa cells, as well as harbored a distinctive gut microbiota than L × Y sows. Gut microbiota may participate in regulating ovarian follicular development via SCFAs affecting granulosa cells apoptosis in sows.

Decolorized Aloe vera polysaccharide enriched preparations and their effects on human gastrointestinal cell lines

Introduction: Aloe vera (A. vera) has been used as a folk remedy to treat different gastrointestinal and metabolic symptoms as well as for traditional therapeutic and topical cosmetic uses.It has been proposed that its benefits are based on aloe´s unique composition of phytochemicals, in particular the complex polysaccharides that are present in the gel. Commercial A. vera juice is purified to remove latex constituents (such as anthraquinones) via activated charcoal filtration (decolorization). Limited information is available regarding A. vera’s biological effects after decolorization on the gastrointestinal tract. Objective: To evaluate the effect of different polysaccharide-enriched decolorized preparations of A. vera (whole leaf -WL- or inner leaf -InL-) on two human cells lines: stomach gastric adenocarcinoma (AGS) and Intestinal Myofibroblast (InMyoFib) cells. We hypothesize that these enriched preparations will have beneficial effects in these gut cell models. M&amp;M: Proliferation: Cell Proliferation Kit I (MTS, Cat. No: 11465007001-Roche-SIGMA-ALDRICH).Scratch studies: Quantification was carried out using ImageJ software (NIH, Bethesda, MD).Apoptosis: H2O2 and Cytokine mix-induced apoptosis was analyzed using cell death detection ELISA plus (Sigma Cat. No 11 774 425 001; Roche Cat. No 11 544 675 001).Statistics: ANOVA, repeated measured design. 5 independent experiments. Results: 6 different preparations were tested at 3 concentrations: 10, 50 and 100 ug/ml in all the experiments. Proliferation: None of the preparations induced cell proliferation in AGS and Inmyofib cells.; 2 InL and 1 WL preparation inhibited AGS and Inmyofib cell proliferation in comparation to the negative control. Wound healing: A significant improvement was induced by all fractions tested in both cell types. Preparations improved the percentage of wound healing in comparation with the negative control, one WL improved this parameter to levels similar to the positive control. Apoptosis: Four out of the six extracts protected cells from H2O2-induced apoptosis in both cell lines. In the case of the cytokine stimulation, AGS cells evoked a 55% increase over the negative control. None of the herbal extracts could revert/prevent apoptosis in this cell line. Conversely, cytokines evoked an 80% increase in apoptosis in Inmyofyb cells and Aloe preparations were largely effective in inhibiting this process. Conclusion: It has been proposed that A. vera gel has the ability to treat or protect gastric ulcers and to alleviate intestinal discomfort in both in animals and humans. These activities have been attributed to several possible mechanisms, including its anti-inflammatory properties, healing effects, mucus-stimulatory effects and regulation of gastric secretions. Here we show that decolorized A. vera polysaccharide-enriched preparations can modulate gastrointestinal cell lines. Conflict of Interest Disclosure: This work was funded by Herbalife Nutrition International of America, Inc. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Curcumin protects against the age-related hearing loss by attenuating apoptosis and senescence via activating Nrf2 signaling in cochlear hair cells

Age-related hearing loss (ARHL) is a most widespread neurodegenerative disease affecting the elderly population, but effective pharmacological treatments remain limited. Curcumin is a bioactive compound of Curcuma longa with antioxidant properties. Herein, we looked into the effects of curcumin on the H2O2-induced oxidative stress in cochlear hair cells and hearing function in an ARHL animal model (C57BL/6J mice). We found that pretreatment of curcumin could attenuate H2O2-induced apoptosis and cell senescence in auditory hair cells and prevent mitochondrial function dysfunction. More specifically, Western blot and luciferase activity assay showed that curcumin activated the nuclear translocation of Nrf2, which in turn triggered the activation of its downstream target gene Heme Oxygenase1 (HO-1). The enhanced Nrf2 and HO-1 activity by curcumin was blocked by the AKT inhibitor LY294002, indicating the protective effect of curcumin was mainly achieved by activating Nrf2/HO-1 through the AKT pathway. Furthermore, the knockdown of Nrf2 with siRNA diminished the protective effects of Nrf2 against apoptosis and senescence, consolidating the pivotal role of Nrf2 in the protective effect of curcumin on auditory hair cells. More importantly, curcumin (10 mg/kg/d) could attenuate progressive hearing loss in C57BL/6J mice, as evident from the reduced threshold of auditory nerve brainstem response. Administration of curcumin also elevated the expression of Nrf2 and reduced the expression of cleaved-caspase-3, p21, and γ-H2AX in cochlear. This study is the first to demonstrate that curcumin can prevent oxidative stress-induced auditory hair cell degeneration through Nrf2 activation, highlighting its potential therapeutic value in preventing ARHL.

Protective Effects of a Jellyfish-Derived Thioredoxin Fused with Cell-Penetrating Peptide TAT-PTD on H2O2-Induced Oxidative Damage.

Thioredoxin (Trx) plays a critical role in maintaining redox balance in various cells and exhibits anti-oxidative, anti-apoptotic, and anti-inflammatory effects. However, whether exogenous Trx can inhibit intracellular oxidative damage has not been investigated. In previous study, we have identified a novel Trx from the jellyfish Cyanea capillata, named CcTrx1, and confirmed its antioxidant activities in vitro. Here, we obtained a recombinant protein, PTD-CcTrx1, which is a fusion of CcTrx1 and protein transduction domain (PTD) of HIV TAT protein. The transmembrane ability and antioxidant activities of PTD-CcTrx1, and its protective effects against H2O2-induced oxidative damage in HaCaT cells were also detected. Our results revealed that PTD-CcTrx1 exhibited specific transmembrane ability and antioxidant activities, and it could significantly attenuate the intracellular oxidative stress, inhibit H2O2-induced apoptosis, and protect HaCaT cells from oxidative damage. The present study provides critical evidence for application of PTD-CcTrx1 as a novel antioxidant to treat skin oxidative damage in the future.

Effects of adipose derived stem cells pretreated with resveratrol on sciatic nerve regeneration in rats

Adipose derived stem cells (ADSCs) are popular in regenerative medicine due to their easy availability, low immunogenicity and lack of controversy regarding their ethical debate use. Although ADSCs can repair nerve damage, the oxidative microenvironment of damaged tissue can induce apoptosis of transplanted stem cells, which weakens the therapeutic efficacy of ADSCs. Resveratrol (Res) is a type of natural polyphenol compound that regulates the proliferation, senescence and differentiation of stem cells. Therefore, we investigated whether incubation of ADSCs with Res improves their to promote peripheral nerve regeneration. ADSCs were cultured in vitro and treated with H2O2 to establish an apoptosis model. The control, H2O2 and Res groups were set up. The cell survival rate was detected by the CCK-8 method. The TUNEL assay was used to detect the apoptosis of the cells. qRT‒PCR was used to analyze the expression of apoptosis-related mRNA, and the effect of Res on the proliferation of ADSCs was investigated. In vivo, 40 SD rats were randomly divided into the control, model, ADSCs and ADSC + Res groups, with 13 rats in each group. The sciatic nerve injury rat model was established by the clamp method. Gait was observed on Days 7, 14, 21, and 28. Sciatic nerve regeneration was detected on Day 28. Res had no effect on the proliferation of ADSCs, and the TUNEL assay confirmed that Res pretreatment could significantly improve H2O2-induced apoptosis in ADSCs. Compared with the control group, caspase-3, Bax and Bcl-2 expression levels were significantly increased in the H2O2 group. Compared with the H2O2 group caspase-3 and Bax expression levels were significantly decreased, and Bcl-2 expression levels were significantly increased in ADSCs + Res group. At 4 weeks after surgery, the functional index of the sciatic nerve in the ADSCs + Res group was significantly higher than that in the model group. On Day 28, the average density of the sciatic nerve myelin sheath in the ADSCs + Res group was significantly increased compared with that in the model group, and Nissl staining showed that the number of motor neurons in the spinal cord was significant compared with that in the model group. Compared with the control group, the wet weight ratio of gastrocnemius muscle and muscle fiber area in ADSCs + Res group were significantly increased. Res enhanced the ability of ADSCs to promote sciatic nerve regeneration in rats.

Roflumilast enhances the melanogenesis and attenuates oxidative stress-triggered damage in melanocytes

BackgroundThe management of vitiligo is challenging due to limited treatment options, and therapeutic strategy varies according to the active or stable stage of vitiligo. PDE4 inhibitor has been used to treat various skin diseases, but the efficacy in vitiligo treatment is mixed. ObjectiveIn this study, we aimed to investigate whether roflumilast, a PDE4 inhibitor, induces melanogenesis and attenuates oxidative stress-triggered damage in melanocytes, and if so, what is the mechanism. MethodsMelanin content assay, qRT-PCR, western blotting, ELISA, immunofluorescence assays, immunohistochemistry, small interfering RNA, flow cytometry, and transmission electron microscopy were employed. ResultsOur results demonstrated that roflumilast alone only slightly increased melanogenesis, however, the combination of roflumilast and forskolin could boost cAMP levels, hence promoting melanogenesis more significantly. Moreover, roflumilast attenuated H2O2-induced apoptosis and mitochondrial morphological changes in melanocytes by reducing ROS levels. Furthermore, roflumilast activated AhR/Nrf2 pathway via cAMP whereas AhR silencing blocked roflumilast-induced Nrf2 nuclear translocation and reversed the inhibitory effect of roflumilast on H2O2-induced ROS production. Finally, we observed that the lesional skin of active vitiligo patients exhibited higher PDE4 expression levels. Conclusionroflumilast enhances the melanogenesis effect of forskolin and protects melanocytes from H2O2-induced apoptosis by cAMP/AhR/Nrf2-activated ROS inhibition, highlighting its therapeutic potential in vitiligo treatment.

Resveratrol Attenuates Hydrogen Peroxide-induced Injury of Rat Ovarian Granulosa-lutein Cells by Resisting Oxidative Stress via the SIRT1/Nrf2/ARE Signaling Pathway.

This paper aims to reveal the molecular mechanism of resveratrol against oxidative stress and cell injury. The ovarian granulosa-lutein cell injury and apoptosis induced by oxidative stress may be responsible for female luteal phase deficiency. The antioxidant function of resveratrol has been confirmed; however, its effect on the expression of antioxidant enzymes and regulatory mechanisms in ovarian granulosa-lutein cells remains unclear. This study aimed to investigate the role of the SIRT1/Nrf2/ARE signaling pathway in the effect of resveratrol on the hydrogen peroxide-induced injury of rat ovarian granulosa-lutein cells. In this study, ovarian granulosa-lutein cells extracted from 3-week female SD rats were treated with 200 μM H2O2 in the presence or absence of 20 μM resveratrol. siRNA-SIRT1 and siRNA-Nrf2 were used to inhibit the expression of SIRT1 and Nrf2, respectively. Cell counting kit 8 (CCK-8), cellular morphology, progesterone secretion, and estradiol were used to evaluate cell injury. Hoechst 33258 staining was used to measure cell apoptosis. DHE staining, DCFH-DA staining, malondialdehyde content, protein carbonyl content, total antioxidant capacity and SOD viability were used to estimate the levels of oxidative stress. Western blot analysis was used to detect the levels of apoptosis-related proteins, and SIRT1/Nrf2/ARE signaling pathway-related proteins. The H2O2 treatment-induced rat ovarian granulosa-lutein cells injury was shown as decreased cell viability, impaired cellular morphology, and decreased levels of progesterone and estradiol. The H2O2 treatment also exacerbated cell apoptosis demonstrated as more apoptotic cells stained by Hoechst staining, decreased level of anti-apoptosis protein Bcl-2 and increased level of pro-apoptosis protein Bax. These effects of cell injury and apoptosis induced by H2O2 can be ameliorated by resveratrol. Resveratrol also alleviated oxidative stress induced by H2O2, supported by decreased superoxide anion and cellular total ROS, decreased malondialdehyde and protein carbonyl levels, and increased total antioxidant capacity and SOD viability. Western blot results demonstrated resveratrol reversed the H2O2-induced decrease in levels of antioxidant enzymes containing ARE sequences and activated SIRT1/Nrf2 pathway. Further treatment by siRNA-Nrf2 suggested resveratrol could not activate the expression of antioxidant enzymes under a condition of inhibition of Nrf2. This study demonstrates that resveratrol attenuated oxidative stress to protect H2O2-induced rat ovarian granulosa-lutein cell injury and apoptosis via SIRT1/Nrf2/ARE signaling pathway.

Mammalian Ste20-like kinase 1 inhibition as a cellular mediator of anoikis in mouse bone marrow mesenchymal stem cells

The low survival rate of mesenchymal stem cells (MSCs) caused by anoikis, a form of apoptosis, limits the therapeutic efficacy of MSCs. As a proapoptotic molecule, mammalian Ste20-like kinase 1 (Mst1) can increase the production of reactive oxygen species (ROS), thereby promoting anoikis. Recently, we found that Mst1 inhibition could protect mouse bone marrow MSCs (mBMSCs) from H2O2-induced cell apoptosis by inducing autophagy and reducing ROS production. However, the influence of Mst1 inhibition on anoikis in mBMSCs remains unclear. To investigate the mechanisms by which Mst1 inhibition acts on anoikis in isolated mBMSCs. Poly-2-hydroxyethyl methacrylate-induced anoikis was used following the silencing of Mst1 expression by short hairpin RNA (shRNA) adenovirus transfection. Integrin (ITGs) were tested by flow cytometry. Autophagy and ITGα5β1 were inhibited using 3-methyladenine and small interfering RNA, respectively. The alterations in anoikis were measured by Terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling and anoikis assays. The levels of the anoikis-related proteins ITGα5, ITGβ1, and phospho-focal adhesion kinase and the activation of caspase 3 and the autophagy-related proteins microtubules associated protein 1 light chain 3 II/I, Beclin1 and p62 were detected by Western blotting. In isolated mBMSCs, Mst1 expression was upregulated, and Mst1 inhibition significantly reduced cell apoptosis, induced autophagy and decreased ROS levels. Mechanistically, we found that Mst1 inhibition could upregulate ITGα5 and ITGβ1 expression but not ITGα4, ITGαv, or ITGβ3 expression. Moreover, autophagy induced by upregulated ITGα5β1 expression following Mst1 inhibition played an essential role in the protective efficacy of Mst1 inhibition in averting anoikis. Mst1 inhibition ameliorated autophagy formation, increased ITGα5β1 expression, and decreased the excessive production of ROS, thereby reducing cell apoptosis in isolated mBMSCs. Based on these results, Mst1 inhibition may provide a promising strategy to overcome anoikis of implanted MSCs.

Age-related cataract: GSTP1 ubiquitination and degradation by Parkin inhibits its anti-apoptosis in lens epithelial cells

PurposeOxidative stress-induced apoptosis of lens epithelial cells (LECs) contributes to the pathogenesis of age-related cataract (ARC). The purpose of this research is to underlie the potential mechanism of E3 ligase Parkin and its oxidative stress-associated substrate in cataractogenesis. MethodsThe central anterior capsules were obtained from patients with ARC, Emory mice, and corresponding controls. SRA01/04 cells were exposed to H2O2 combined with cycloheximide (a translational inhibitor), MG-132 (a proteasome inhibitor), chloroquine (an autophagy inhibitor), Mdivi-1 (a mitochondrial division inhibitor), respectively. Co-immunoprecipitation was employed to detect protein-protein interactions and ubiquitin-tagged protein products. Levels of proteins and mRNA were evaluated by western blotting and quantitative RT-PCR assays. ResultsGlutathione-S-transferase P1 (GSTP1) was identified as a novel Parkin substrate. Compared with corresponding controls, GSTP1 was significantly decreased in the anterior lens capsules obtained from human cataracts and Emory mice. Similarly, GSTP1 was declined in H2O2-stimulated SRA01/04 cells. Ectopic expression of GSTP1 mitigated H2O2-induced apoptosis, whereas silencing GSTP1 aggregated apoptosis. In addition, H2O2 stimulation and Parkin overexpression could promote the degradation of GSTP1 through the ubiquitin-proteasome system, autophagy-lysosome pathway, and mitophagy. After co-transfection with Parkin, the non-ubiquitinatable GSTP1 mutant maintained its anti-apoptotic function, while wildtype GSTP1 failed. Mechanistically, GSTP1 might promote mitochondrial fusion through upregulating Mitofusins 1/2 (MFN1/2). ConclusionOxidative stress induces LECs apoptosis via Parkin-regulated degradation of GSTP1, which may provide potential targets for ARC therapy.

HSPA1A ameliorated spinal cord injury in rats by inhibiting apoptosis to exert neuroprotective effects.

Traumatic spinal cord injury (TSCI) is a serious nervous system insult, and apoptosis in secondary injury is an important barrier to recovery from TSCI. Heat shock protein family A member 1A (HSPA1A) is a protective protein whose expression is elevated after stress. However, whether HSPA1A can inhibit apoptosis after spinal cord injury, and the potential mechanism of this inhibition, remain unclear. In this study, we established in vivo and in vitro models of TSCI and induced HSPA1A overexpression and silencing. HSPA1A upregulation promoted the recovery of neurological function and pathological morphology at the injury site, enhanced neurological cell survival, and inhibited apoptosis in rats following TSCI. In the in vitro model, HSPA1A overexpression inhibited H2O2-induced apoptosis, indicating that HSPA1A suppressed the expression of Bax, caspase-9, and cleaved-caspase-3, promoted the expression of Bcl-2. Furthermore, inhibition of HSPA1A expression can aggravate H2O2-induced apoptosis. We also found that HSPA1A overexpression activated the Wnt/β-catenin signaling pathway, and that inhibition of this pathway attenuated the inhibitory effect of HSPA1A overexpression on apoptosis. Together, these results indicate that HSPA1A has neuroprotective effects against TSCI that may be exerted through activation of the Wnt/β-catenin signaling pathway to inhibit apoptosis.

Design, synthesis, and evaluation of N-methyl-propargylamine derivates as isoform-selective monoamine oxidases inhibitors for the treatment of nervous system diseases

A novel series of N-methyl-propargylamine derivates were designed, synthesized, and evaluated as isoform-selective monoamine oxidases (MAO) inhibitors for the treatment of nervous system diseases. The in vitro studies showed some of the compounds exhibited considerable MAO-A selective inhibitory activity (IC50 of 14.86–17.16 nM), while some of the others exhibited great MAO-B selective inhibitory activity (IC50 of 4.37–17.00 nM). Further studies revealed that compounds A2 （IC50 against MAO-A: 17.16 ± 1.17 nM） and A5 (IC50 against MAO-B: 17.00 ± 1.10 nM) had significant abilities to protect PC12 cells from H2O2-induced apoptosis and reactive oxygen species (ROS) production. The parallel artificial membrane permeability assay showed A2 and A5 would be potent to cross the blood–brain barrier. The results indicated that A2 showed potential use in the therapy of MAO-A related diseases, such as depression and anxiety; while A5 exhibited promising ability in the treatment of MAO-B related diseases, such as Alzheimer’s disease and Parkinson’s disease.

New perspective for an old drug: Can naloxone be considered an antioxidant agent?

BackgroundExperimental evidence indicates that Naloxone (NLX) holds antioxidant properties. The present study aims at verifying the hypothesis that NLX could prevent oxidative stress induced by hydrogen peroxide (H2O2) in PC12 cells. MethodsTo investigate the antioxidant effect of NLX, initially, we performed electrochemical experiments by means of platinum-based sensors in a cell-free system. Subsequently, NLX was tested in PC12 cells on H2O2-induced overproduction of intracellular levels of reactive-oxygen-species (ROS), apoptosis, modification of cells' cycle distribution and damage of cells’ plasma membrane. ResultsThis study reveals that NLX counteracts intracellular ROS production, reduces H2O2-induced apoptosis levels, and prevents the oxidative damage-dependent increases of the percentage of cells in G2/M phase. Likewise, NLX protects PC12 cells from H2O2- induced oxidative damage, by preventing the lactate dehydrogenase (LDH) release. Moreover, electrochemical experiments confirmed the antioxidant properties of NLX. ConclusionOverall, these findings provide a starting point for studying further the protective effects of NLX on oxidative stress.

The involvement of EGR1 in neuron apoptosis in the in vitro model of spinal cord injury via BTG2 up-regulation

ABSTRACT Objective EGR1 has been implicated in the progression of spinal cord injury (SCI). Nevertheless, its specific mechanism in SCI remains to be investigated. Hence, this study explored the potential mechanism of EGR1 in SCI by focusing on neuron apoptosis. Methods H2O2 was utilized to treat rat neurons-dorsal spinal cord (RN-dsc) for the construction of an in vitro model of SCI. Afterwards, cell survival, apoptosis, and LDH leakage were detected to evaluate the injury degree of H2O2-treated RN-dsc. The expression of apoptosis-related proteins was also measured. Additionally, EGR1 was silenced and/or BTG2 was overexpressed in RN-dsc before H2O2 treatment to assess the impacts of EGR1 and BTG2 on H2O2-induced RN-dsc. Jasper online website was utilized to predict binding sites of EGR1 on BTG2, and dual-luciferase reporter gene and chromatin immunoprecipitation (ChIP) assays were utilized to verify the binding between EGR1 and BTG2. Results H2O2 treatment suppressed survival and promoted apoptosis in RN-dsc, accompanied by upregulated LDH, Bax, and cleaved-caspase-3 and down-regulated Bcl-2. Moreover, EGR1 and BTG2 were up-regulated in H2O2-induced RN-dsc. Mechanistically, EGR1 was bound to the promoter of BTG2 to transcriptionally activate BTG2. EGR1 knockdown diminished apoptosis and LDH, Bax, and cleaved-caspase-3 levels while elevating survival and Bcl-2 levels in H2O2-induced RN-dsc. These effects of EGR1 knockdown were abrogated by further BTG2 overexpression. Discussion Conclusively, EGR1 promotes H2O2-induced apoptosis in RN-dsc by activating BTG2 transcription.

A Multifunctional (-)-Meptazinol-Serotonin Hybrid Ameliorates Oxidative Stress-Associated Apoptotic Neuronal Death and Memory Deficits via Activating the Nrf2/Antioxidant Enzyme Pathway.

The pathogenesis of Alzheimer's disease (AD) involves multiple pathophysiological processes. Oxidative stress is a major cause of AD-associated neuronal injury. The current research was designed to examine whether a novel (-)-meptazinol-serotonin hybrid (Mep-S) with potent antioxidant activity and additional inhibitory properties for acetylcholinesterase (AChE) activity could attenuate oxidative neuronal damage and cognitive deficits. In human SH-SY5Y cells, Mep-S suppressed H2O2-induced apoptosis by restoring mitochondrial membrane potential and inhibiting caspase-3 activation. Meanwhile, it attenuated oxidative stress elicited by H2O2 through lessening generation of reactive oxygen species as well as enhancing production of glutathione (GSH) and activity of superoxide dismutase (SOD). Mechanistically, Mep-S promoted nuclear translocation of a transcription factor nuclear factor E2-related factor-2 (Nrf2) in H2O2-challenged cells. This effect was accompanied by reduction in Kelch-like ECH-associated protein-1 (Keap1) levels as well as augmentation of Akt phosphorylation and expression of heme oxygenase-1 (HO-1) and NAD(P)H quinine oxidoreductase-1 (NQO-1). Molecular docking analysis revealed that Mep-S may disrupt the protein-protein interactions between Keap1 and Nrf2. In an in vivo mouse model, Mep-S attenuated scopolamine-caused cognitive deficits with inhibition of apoptotic neuronal death and brain AChE activity. Furthermore, the scopolamine-induced impairment of total antioxidant capacity and reduction in SOD1, SOD2, and γ-glutamate-cysteine ligase expression in the brain were counteracted by Mep-S, accompanied by decreased Keap1 levels, increased Akt catalytic subunit and Nrf2 phosphorylation, and decreased Nrf2, HO-1, and NQO-1 expression. Collectively, our results suggest that Mep-S ameliorates apoptotic neuronal death and memory dysfunction associated with oxidative stress by regulating the Nrf2/antioxidant enzyme pathway through inactivating Keap1 and phosphorylating Nrf2 via Akt activation. Therefore, Mep-S may be a potential lead for multitarget neuroprotective agents to treat AD-like symptoms.

Circ_0005280 Protects Human Lens Epithelial Cells against H2O2-induced Apoptosis and Oxidative Stress though miR-326/PLCD3 Axis

Circ_0005280 Protects Human Lens Epithelial Cells against H2O2-induced Apoptosis and Oxidative Stress though miR-326/PLCD3 Axis

Recombinant Adenovirus siRNA Knocking Down the Ndufs4 Gene Alleviates Myocardial Apoptosis Induced by Oxidative Stress Injury.

Oxidative stress results in myocardial cell apoptosis and even life-threatening heart failure in myocardial ischemia-reperfusion injury. Specific blocking of the complex I could reduce cell apoptosis. Ndufs4 is a nuclear-encoded subunit of the mitochondrial complex I and participates in the electron transport chain. In this study, we designed and synthesized siRNA sequences knocking down the rat Ndufs4 gene, constructed recombinant adenovirus Ndufs4 siRNA (Ad-Ndufs4 siRNA), and primarily verified the role of Ndufs4 in oxidative stress injury. The results showed that the adenovirus infection rate was about 90%, and Ndufs4 mRNA and protein were decreased by 76.7% and 64.9%, respectively. Furthermore, the flow cytometry assay indicated that the cell apoptosis rate of the Ndufs4 siRNA group was significantly decreased as compared with the H2O2-treated group. In conclusion, we successfully constructed Ndufs4 siRNA recombinant adenovirus; furthermore, the downexpression of the Ndufs4 gene may alleviate H2O2-induced H9c2 cell apoptosis.

Activation of Mas and pGCA receptor pathways protects renal epithelial cell damage against oxidative-stress-induced injury

Over-activation of the renin-angiotensin-aldosterone system (RAAS) is a leading cause of cardio-renal complications. Oxidative stress is one of the major contributing factors in the over-activation of RAAS. Angiotensin-converting enzyme2/Angiotensin1–7/MasR and natriuretic peptide/particulate guanylyl cyclase receptor-A pathways play a key role in cardiorenal disease protection. Even though individual activation of these pathways possesses cardiorenal protective effects. However, the dual activation of these pathways under stress conditions and the underlying mechanism has not been explored. The study aimed to investigate whether activation of these pathways by dual-acting peptide (DAP) shows a protective effect in-vitro in oxidative stress-induced renal epithelial cells. Oxidative stress was induced in renal epithelial NRK-52E cells with H2O2. Co-treatment with Ang 1–7, BNP, and DAP was given for 30 min. AT1, MasR, and pGCA expression were measured by RT-PCR. The markers of oxidative stress and apoptosis were measured by confocal microscopy and FACS analysis. A significant increase in AT1, renin, α-SMA, and NFk-β expression and a significant decrease in MasR and pGCA expression was observed in H2O2-induced cells. DAP improved H2O2-induced pathological changes in NRK-52E cells. The effect of DAP was superior to that of Ang1–7 and BNP alone. Interestingly, MasR and pGCA inhibitors could block the effect of DAP in H2O2-induced cells. DAP shows superior anti-RAAS activity, and it is effective against H2O2-induced oxidative stress, apoptosis, fibrosis, and inflammation compared to Ang1–7 and BNP alone. The protective effect is mediated by the dual activation of MasR and pGCA.

Resveratrol protects osteocytes against oxidative stress in ovariectomized rats through AMPK/JNK1-dependent pathway leading to promotion of autophagy and inhibition of apoptosis

A large number of studies in recent years indicate that osteocytes are the orchestrators of bone remodeling by regulating both osteoblast and osteoclast activities. Oxidative stress-induced osteocyte apoptosis plays critical roles in the pathological processes of postmenopausal osteoporosis. Resveratrol is a natural polyphenolic compound that ameliorates postmenopausal osteoporosis. However, whether resveratrol regulates osteocyte apoptosis via autophagy remains largely unknown. The effects of resveratrol on regulating osteocyte apoptosis and autophagy were analyzed both in vivo and in vitro. In vitro, cultured MLO-Y4 cells were exposed to H2O2 with or without resveratrol. In vivo, an ovariectomy-induced osteoporosis model was constructed in rats with or without daily intraperitoneal injection of 10 mg/kg body weight resveratrol. It was found that resveratrol attenuated H2O2-induced apoptosis through activating autophagy in cultured MLO-Y4 cells, which was mediated by the dissociation of Beclin-1/Bcl-2 complex in AMPK/JNK1-dependent pathway, ultimately regulating osteocytes function. Furthermore, it was shown that resveratrol treatment reduced osteocytes oxidative stress, inhibited osteocytes apoptosis and promoted autophagy in ovariectomized rats. Our study suggests that resveratrol protects against oxidative stress by restoring osteocytes autophagy and alleviating apoptosis via AMPK/JNK1 activation, therefore dissociating Bcl-2 from Beclin-1.

PH-Responsive Hydrogel as a Potential Oral Delivery System of Baicalin for Prolonging Gastroprotective Activity

Gastric ulcer is one of the most common gastrointestinal diseases, and natural products have obvious advantages in the treatment of gastrointestinal diseases. Baicalin (Bai) extracted from scutellaria baicalensis exhibits anti-inflammatory, antioxidant, and anti-apoptotic activities. Herein, a pH-responsive sodium alginate/polyaspartate/CaCO3 (SA/PASP@CaCO3) in situ hydrogel was established for the oral delivery of Bai. In this study, we detected the gelling properties, mechanical strength, in vitro erosion, and in vitro release behavior of the hydrogels. Meanwhile, the efficiency of Bai/SA/PASP@CaCO3 hydrogel on ethanol-induced acute gastric ulcers, acetic acid-induced chronic gastric ulcers, and H2O2-stimulated human gastric epithelial GES-1 cells was explored. The pathological examination revealed that Bai-loaded hydrogel alleviated acute and chronic gastric ulcers. In vivo and in vitro results further confirmed that Bai/SA/PASP@CaCO3 in situ hydrogels significantly relieved oxidative stress injury. Moreover, through Western blot assay, Bai/SA/PASP@CaCO3 hydrogel was also found to dramatically increase the proteins levels of NRF2, HO-1, and Bcl2, and reduce levels of p-JNK, cleaved-caspase-3 and Bax; through flow cytometry, it was observed to significantly inhibit the H2O2-induced apoptosis of GES-1 cells. Importantly, the Bai/SA/PASP@CaCO3 in situ hydrogel system showed better anti-gastric ulcer efficiency than free drug, and could serve as a potential drug delivery system for the clinical treatment of gastric ulcers.