Anti-oxidative Stress Ability Research Articles

Oral Administration of Lutein Improves Fat Graft Survival by Alleviating Oxidative Stress in Mice.

Oxidative stress induced by ischemia and hypoxia in fat transplantation is a major obstacle to graft retention. Previous studies have shown that lutein has excellent adipose tissue affinity and antioxidative stress ability, however, the effects of oral lutein on fat transplantation have not yet been studied. We aimed to investigate whether oral lutein could improve fat transplantation retention by regulating oxidative stress, apoptosis, and inflammatory cytokine levels in graft tissues. Nude mice were assigned to the control group (normal saline), low-dose lutein group (10 mg/kg/day), and high-dose lutein group (20 mg/kg/day) randomly. All mice received treatment by gavage 1 week before fat grafting and continued for 2 weeks. The grafts were collected 1, 2, and 12 weeks after treatment. By conducting histological analyses, Western blotting, quantitative polymerase chain reaction and cell metabolic function detection, the regulatory effects of lutein on apoptosis and oxidative stress in grafts were demonstrated. Additionally, RNA sequencing was conducted to further clarify the efficacy of lutein on fat grafting. Lutein induced superior graft retention, histological structures, and more viable adipocytes than the control group. It relieved tissue oxidative stress and lipid oxidative damage by decreasing reactive oxygen species and significantly reduced inflammation and apoptosis of grafts. RNA sequencing analysis confirmed that lutein could downregulate the gene expression of oxidative stress and related inflammation and apoptosis. Our study suggests that oral administration of lutein can improve fat graft survival by reducing the levels of oxidative stress, inflammation, and apoptosis in grafted fat.

Adenosine A2A Receptor Antagonist Sch58261 Improves the Cognitive Function in Alzheimer's Disease Model Mice Through Activation of Nrf2 via an Autophagy-Dependent Pathway.

Aims: Adenosine, an important endogenous neuromodulator, contributes to a broad set of several neurodegenerative diseases. The adenosine A2A receptor (A2AR) is the most involved in neuropathological effects and plays an important role in the pathogenesis of Alzheimer's disease (AD). However, the effect of A2AR antagonist and the underlying mechanism in AD model mice remains unclear. Results: The amyloid beta (Aβ)1-42-induced mice AD models were used in this study. Several behavioral experiments were performed to evaluate the improvement of AD mice treated with A2AR antagonist. For mechanism analysis, autophagy-related proteins, Kelch-like ECH-associated protein1 (Keap1)-nuclear factor erythroid-derived factor 2-related factor (Nrf2) pathway activation, and synaptic function were studied using Western blot, immunofluorescence, immunohistochemistry, transmission electron microscope, real-time quantitative PCR, and patch clamp. Pharmacological blockade of adenosine A2AR by SCH58261 (SCH) ameliorated cognitive deficits and decreased expression levels of several AD biomarkers, including Aβ and hyperphosphorylation of Tau. Moreover, SCH activated the Nrf2 pathway through autophagy mediated Keap1 degradation, resulting in the improvement of neuron autophagy dysfunction, synaptic plasticity, and synaptic transmission. Innovation: Our data clarified that the SCH (an antagonist of A2AR) could increase the level of autophagy, promote the ability of antioxidative stress by the activation of Keap1-Nrf2 pathway, and improve the synaptic function in Aβ1-42-induced AD mice or cell model, which provided a potential therapeutic strategy for AD. Conclusion: A2AR antagonism represents a promising strategy for the anti-AD agent development through autophagy-dependent pathway.

Investigating the Mechanism of Cadmium-Tolerant Bacterium Cellulosimicrobium and Ryegrass Combined Remediation of Cadmium-Contaminated Soil.

Cadmium (Cd) pollution has been rapidly increasing due to the global rise in industries. Cd not only harms the ecological environment but also endangers human health through the food chain and drinking water. Therefore, the remediation of Cd-polluted soil is an imminent issue. In this work, ryegrass and a strain of Cd-tolerant bacterium were used to investigate the impact of inoculated bacteria on the physiology and biochemistry of ryegrass and the Cd enrichment of ryegrass in soil contaminated with different concentrations of Cd (4 and 20 mg/kg). The results showed that chlorophyll content increased by 24.7% and 41.0%, while peroxidase activity decreased by 56.7% and 3.9%. In addition, ascorbic acid content increased by 16.7% and 6.3%, whereas glutathione content decreased by 54.2% and 6.9%. The total Cd concentration in ryegrass increased by 21.5% and 10.3%, and the soil's residual Cd decreased by 86.0% and 44.1%. Thus, the inoculation of Cd-tolerant bacteria can improve the antioxidant stress ability of ryegrass in Cd-contaminated soil and change the soil's Cd form. As a result, the Cd enrichment in under-ground and above-ground parts of ryegrass, as well as the biomass of ryegrass, is increased, and the ability of ryegrass to remediate Cd-contaminated soil is significantly improved.

Lipidomics and transcriptomics analysis revealed the role of the spleen of Nile tilapia (Oreochromis niloticus) in lipid metabolism

In fish, the development of the spleen is not as perfect as that of higher vertebrates, but it has the same functions that the spleen should have. Up to date, research on fish spleen is mostly focused on its immune function, and the roles and mechanisms of spleen in the regulation of fish metabolism are still unclear. For this purpose, we established a spleen-deficient model of Nile tilapia (Oreochromis niloticus) by splenectomy and integrated lipidomics and transcriptomics to study the changes and mechanisms of lipid metabolism in splenectomy tilapia so as to understand the effect of spleen on lipid metabolism in tilapia. We found that splenectomy can lead to lipid deposition in the liver of tilapia, significant changes in liver and serum lipid mass spectrometry, abnormal lipid metabolism, decreased anti-oxidative stress ability, and being more prone to lipid toxicity and fatty liver. Combined with the results of transcriptomics, we found that splenectomy resulted in down-regulation of differentially expressed genes in “cellular iron ion homeostasis,” “extracellular region,” “small molecule binding,” and “TGF-beta signaling pathway,” and iron metabolism-related genes such as tfa, bmp2b, bmp6, hamp, and slc40a1, etc. were closely related to differential lipid changes. Therefore, it is speculated that the abnormal lipid metabolism in tilapia after splenectomy is closely related to iron metabolism, and its molecular mechanism may be related to the hepcidin regulatory pathway—BMP-SMAD signaling pathway. This study can provide a new understanding of the relationship and mechanism between immune and nutritional metabolism in fish and also provide new ideas for the study of fish hepatic diseases.

Superoxide dismutase 1-modified dental pulp stem cells alleviate high-altitude pulmonary edema by inhibiting oxidative stress through the Nrf2/HO-1 pathway.

High-altitude pulmonary edema (HAPE) is a deadly form of altitude sickness, and there is no effective treatment for HAPE. Dental pulp stem cells (DPSCs) are a type of mesenchymal stem cell isolated from dental pulp tissues and possess various functions, such as anti-inflammatory and anti-oxidative stress. DPSCs have been used to treat a variety of diseases, but there are no studies on treating HAPE. In this study, Sprague-Dawley rats were exposed to acute low-pressure hypoxia to establish theHAPE model, and SOD1-modified DPSCs (DPSCsHiSOD1) were administered through thetail vein. Pulmonary arterial pressure, lung water content (LWC), total lung protein content of bronchoalveolar lavage fluid (BALF) and lung homogenates, oxidative stress, and inflammatory indicators were detected to evaluate the effects of DPSCsHiSOD1 on HAPE. Rat type II alveolar epithelial cells (RLE-6TN) were used to investigate the effects and mechanism of DPSCsHiSOD1 on hypoxia injury. We found that DPSCs could treat HAPE, and the effect was better than that of dexamethasone treatment. SOD1 modification could enhance the function of DPSCs in improving the structure of lung tissue, decreasing pulmonary arterial pressure and LWC, and reducing the total lung protein content of BALF and lung homogenates, through anti-oxidative stress and anti-inflammatory effects. Furthermore, we found that DPSCsHiSOD1 could protect RLE-6TN from hypoxic injury by reducing the accumulation of reactive oxygen species (ROS) and activating the Nrf2/HO-1 pathway. Our findings confirm that SOD1 modification could enhance the anti-oxidative stress ability of DPSCs through the Nrf2/HO-1 signalling pathway. DPSCs, especially DPSCsHiSOD1, could be a potential treatment for HAPE. Schematic diagram of the antioxidant stress mechanism of DPSCs in the treatment of high-altitude pulmonary edema. DPSCs can alleviate oxidative stress by releasing superoxide dismutase 1, thereby reducing ROS production and activating the Nrf2/HO-1 signalling pathway to ameliorate lung cell injury in HAPE.

Bufei Huoxue capsule attenuates COPD-related inflammation and regulates intestinal microflora, metabolites.

Background: Bufei Huoxue capsule (BFHX) is widely used for the clinical treatment of chronic obstructive pulmonary disease (COPD) in China. Objectives: The aim of this study is to explore the effects on COPD and the underlying mechanism of BFHX. The process and methods: In this study, we established a COPD mouse model through cigarette smoke (CS) exposure in combination with lipopolysaccharide (LPS) intratracheal instillation. Subsequently, BFHX was orally administrated to COPD mice, and their pulmonary function, lung pathology, and lung inflammation, including bronchoalveolar lavage fluid (BALF) cell count and classification and cytokines, were analyzed. In addition, the anti-oxidative stress ability of BFHX was detected by Western blotting, and the bacterial diversity, abundance, and fecal microbiome were examined using 16S rRNA sequencing technology. Outcome: BFHX was shown to improve pulmonary function, suppress lung inflammation, decrease emphysema, and increase anti-oxidative stress, whereas 16S rRNA sequencing indicated that BFHX can dynamically regulate the diversity, composition, and distribution of the intestinal flora microbiome and regulate the lysine degradation and phenylalanine metabolism of COPD mice. These results highlight another treatment option for COPD and provide insights into the mechanism of BFHX.

Investigating the Potential Mechanism of Huazhi Rougan Granules Against Alcoholic Liver Disease by Network Pharmacology and Experiment

Abstract Objective: Huazhi Rougan granules (HRGs) are a promising drug to improve alcoholic liver disease (ALD), but its mechanism remains unclear. Materials and Methods: Network pharmacology, molecular docking, and animal experiments were used to reveal the potential mechanism of HRG against ALD. Results: A total of 245 potential targets of HRG against ALD were obtained. Functional enrichment analysis suggests that HRG could synergistically regulate various biological pathways to exert therapeutic effects on ALD. Molecular docking showed that the key targets exhibited the good binding ability with the key compounds. The in vivo experiments showed that HRG can effectively alleviate pathological changes in liver tissue, improve blood lipid levels, antioxidant stress ability, and liver function, and reduce the release of inflammatory cytokines in the liver. Conclusions: This study reflects that HRG is an effective strategy for treating ALD, providing a basis for revealing the prevention and treatment mechanisms of ALD.

M2 Microglia-Derived Exosomes Protect Against Glutamate-Induced HT22 Cell Injury via Exosomal miR-124-3p

As one of the most serious complications of sepsis, sepsis-associated encephalopathy has not been effectively treated or prevented. Exosomes, as a new therapeutic method, play a protective role in neurodegenerative diseases, stroke and traumatic brain injury in recent years. The purpose of this study was to investigate the role of exosomes in glutamate (Glu)-induced neuronal injury, and to explore its mechanism, providing new ideas for the treatment of sepsis-associated encephalopathy. The neuron damage model induced by Glu was established, and its metabolomics was analyzed and identified. BV2 cells were induced to differentiate into M1 and M2 subtypes. After the exosomes from both M1-BV2 cells and M2-BV2 cells were collected, exosome morphological identification was performed by transmission electron microscopy and exosome-specific markers were also detected. These exosomes were then cocultured with HT22 cells. CCK-8 method and LDH kit were used to detect cell viability and toxicity. Cell apoptosis, mitochondrial membrane potential and ROS content were respectively detected by flow cytometry, JC-1 assay and DCFH-DA assay. MiR-124-3p expression level was detected by qRT-PCR and Western blot. Bioinformatics analysis and luciferase reporter assay predicted and verified the relationship between miR-124-3p and ROCK1 or ROCK2. Through metabolomics, 81 different metabolites were found, including fructose, GABA, 2, 4-diaminobutyric acid, etc. The enrichment analysis of differential metabolites showed that they were mainly enriched in glutathione metabolism, glycine and serine metabolism, and urea cycle. M2 microglia-derived exosomes could reduce the apoptosis, decrease the accumulation of ROS, restore the mitochondrial membrane potential and the anti-oxidative stress ability in HT22 cells induced by Glu. It was also found that the protective effect of miR-124-3p mimic on neurons was comparable to that of M2-EXOs. Additionally, M2-EXOs might carry miR-124-3p to target ROCK1 and ROCK2 in neurons, affecting ROCK/PTEN/AKT/mTOR signaling pathway, and then reducing Glu-induced neuronal apoptosis. M2 microglia-derived exosomes may protect HT22 cells against Glu-induced injury by transferring miR-124-3p into HT22 cells, with ROCK being a target gene for miR-124-3p.

Repair effect of neurotrophic factor III (NT-3) on rats with spinal injury model and its mechanism.

The present study aimed to study the repair effect of neurotrophic factor III (NT-3) on spinal injury model rats and its mechanism. Wistar rats with spinal injury were established by accelerated compression stroke after the operation and divided into control group, model group, and NT-3 intervention group. The motor function of rats in each group was evaluated at different postoperative time points (3, 7, 14 d). HE staining was used to detect the changes in tissue structure and morphology of the injured spinal column in each group. The changes of SOD, MDA and GSH in serum of rats were detected. The concentrations of inflammatory cytokines IL-1β, IL-6, IL-17 and TNF-α in serum were detected by enzyme-linked immunosorbent assay (ELISA). Western blot was used to detect the expression changes of anti-apoptotic protein (Bcl-2) and pro-apoptotic protein (Bax) in injured spinal tissue of rats in each group. Compared with model group, motor function score of NT-3 intervention group increased gradually, and had statistical significance at 7 and 14 days (5.29±1.62 vs 9.33±2.16, 5.92±1.44 vs 14.56±2.45, T =7.386, 9.294, P =0.004, 0.000). The levels of SOD and GSH in serum of NT-3 intervention group were significantly increased (t=9.117, 12.207, P=0.000, 0.000), while the level of MDA was significantly decreased (t=5.089, P=0.011). Serum levels of inflammatory cytokines IL-1β, IL-6, IL-17 and TNF-α in NT-3 intervention group were significantly decreased (T =6.157, 7.958, 6.339, 6.288, P=0.008, 0.005, 0.005, 0.007). In the NT-3 treatment group, Bax protein was significantly decreased (0.24±0.05 vs 0.89±0.12, T =8.579, P=0.001), and the relative expression of Bcl-2 protein was significantly increased (0.75±0.06 vs 0.13±0.05, T =9.367, P=0.001). Neurotrophic factor III can promote spinal injury repair in spinal injury model rats, and play a role by enhancing antioxidant stress ability, inhibiting inflammatory factors, promoting Bcl-2 and decreasing Bax expression.

Danggui Shaoyao San protects cyclophosphamide-induced premature ovarian failure by inhibiting apoptosis and oxidative stress through the regulation of the SIRT1/p53 signaling pathway

Ethnopharmacological relevanceIt has been reported that apoptosis and oxidative stress are related to cyclophosphamide (CYC)-induced premature ovarian failure (POF). Therefore, anti-apoptotic and anti-oxidative stress treatments exhibit therapeutic efficacy in CYC-induced POF. Danggui Shaoyao San (DSS), which has been extensively used to treat gynecologic diseases, is found to inhibit apoptosis and reduce oxidative stress. However, the roles of DSS in regulating apoptosis and oxidative stress during CYC-induced POF, and its associated mechanisms are still unknown. Aim of the studyThis work aimed to investigate the roles and mechanisms of DSS in inhibiting apoptosis and oxidative stress in CYC-induced POF. Materials and methodsCYC (75 mg/kg) was intraperitoneally injected in mice to construct the POF mouse model for in vivo study. Thereafter, alterations of body weight, ovary morphology and estrous cycle were monitored to assess the ovarian protective properties of DSS. Serum LH and E2 levels were analyzed by enzyme-linked immunosorbent assay (ELISA). Hematoxylin-eosin (HE) staining was employed for examining ovarian pathological morphology and quantifying follicles in various stages. Meanwhile, TUNEL staining and apoptosis-related proteins were adopted for evaluating apoptosis. Oxidative stress was measured by the levels of ROS, MDA, and 4-HNE. Western blot (WB) assay was performed to detect proteins related to the SIRT1/p53 pathway. KGN cells were used for in vitro experiment. TBHP stimulation was carried out for establishing the oxidative stress-induced apoptosis cell model. Furthermore, MTT assay was employed for evaluating the protection of DSS from TBHP-induced oxidative stress. The anti-apoptotic ability of DSS was evaluated by hoechst/PI staining, JC-1 staining, and apoptosis-related proteins. Additionally, the anti-oxidative stress ability of DSS was measured by detecting the levels of ROS, MDA, and 4-HNE. Proteins related to SIRT1/p53 signaling pathway were also measured using WB and immunofluorescence (IF) staining. Besides, SIRT1 expression was suppressed by EX527 to further investigate the role of SIRT1 in the effects of DSS against apoptosis and oxidative stress. ResultsIn the in vivo experiment, DSS dose-dependently exerted its anti-apoptotic, anti-oxidative stress, and ovarian protective effects. In addition, apoptosis, apoptosis-related protein and oxidative stress levels were inhibited by DSS treatment. DSS treatment up-regulated SIRT1 and down-regulated p53 expression. From in vitro experiment, it was found that DSS treatment protected KGN cells from TBHP-induced oxidative stress injury. Besides, DSS administration suppressed the apoptosis ratio, apoptosis-related protein levels, mitochondrial membrane potential damage, and oxidative stress. SIRT1 suppression by EX527 abolished the anti-apoptotic, anti-oxidative stress, and ovarian protective effects, as discovered from in vivo and in vitro experiments. ConclusionsDSS exerts the anti-apoptotic, anti-oxidative stress, and ovarian protective effects in POF mice, and suppresses the apoptosis and oxidative stress of KGN cells through activating SIRT1 and suppressing p53 pathway.

The protective effect of PL 1-3 on D-galactose-induced aging mice.

The aging population has become an issue that cannot be ignored, and research on aging is receiving increasing attention. PL 1-3 possesses diverse pharmacological properties including anti-oxidative stress, inhibits inflammatory responses and anti-apoptosis. This study showed that PL 1-3 could protect mice, especially the brain, against the aging caused by D-galactose (D-gal). D-gal could cause oxidative stress, inflammation, apoptosis and tissue pathological injury and so on in aging mice. The treatment of PL 1-3 could increase the anti-oxidative stress ability in the serum, liver, kidney and brain of aging mice, via increasing the total antioxidant capacity and the levels of anti-oxidative defense enzymes (superoxide dismutase, glutathione peroxidase, and catalase), and reducing the end product of lipid peroxidation (malondialdehyde). In the brain, in addition to the enhanced anti-oxidative stress via upregulating the level of the nuclear factor erythroid 2-related factor 2 and heme oxygenase 1, PL 1-3 could improve the dysfunction of the cholinergic system via reducing the active of acetylcholinesterase so as to increase the level of acetylcholine, increase the anti-inflammatory and anti-apoptosis activities via downregulating the expressions of pro-inflammatory cytokines (interleukin-6 and tumor necrosis factor-α) and pro-apoptosis proteins (Bcl-2 associated X protein and Caspase-3) in the D-gal-induced aging mice, to enhance the anti-aging ability via upregulating the expression of sirtuin 1 and downregulating the expressions of p53, p21, and p16. Besides, PL 1-3 could reverse the liver, kidney and spleen damages induced by D-gal in aging mice. These results suggested that PL 1-3 may be developed as an anti-aging drug for the prevention and intervention of age-related diseases.

Photothermal synergistic nitric oxide controlled release injectable self-healing adhesive hydrogel for biofilm eradication and wound healing.

The development of injectable self-healing adhesive hydrogel dressings with excellent bactericidal activity and wound healing ability is urgently in demand for combating biofilm infections. Herein, a multifunctional hydrogel (QP/QT-MB) with near-infrared (NIR) light-activated mild photothermal/gaseous antimicrobial activity was developed based on the dynamic reversible borate bonds and hydrogen bonds crosslinking between quaternization chitosan (QCS) derivatives alternatively containing phenylboronic acid and catechol-like moieties in conjunction with the in situ encapsulation of BNN6-loaded mesoporous polydopamine (MPDA@BNN6 NPs). Given the dynamic reversible cross-linking feature, the versatile hybrid hydrogel exhibited injectability, flexibility, and rapid self-healing ability. The numerous phenylboronic acid and catechol-like moieties on the QCS backbone confer the hydrogel with specific bacterial affinity, desirable tissue adhesion, and antioxidant stress ability that enhance bactericidal activity and facilitate the regeneration of infection wounds. Under NIR irradiation, the QP/QT-MB hydrogels exhibited a desirable mild photothermal effect and NIR-activity controllable NO delivery, combined with the endogenous contact antimicrobial activity of hydrogel, contributing jointly to induce dispersal of biofilms and disruption of the bacterial plasma membranes, ultimately leading to bacteria inactivation and biofilm elimination. In vivo experiments demonstrated that the fabricated QP/QT-MB hydrogel platform was capable of inducing efficient eradication of the S. aureus biofilm in a severely infected wound model and accelerating infected wound repair by promoting collagen deposition, angiogenesis, and suppressing inflammatory responses. Additionally, the QP/QT-MB hydrogel demonstrated excellent biocompatibility in vitro and in vivo. Collectively, the hydrogel (QP/QT-MB) reveals great potential application prospects as a promising alternative in the field of biofilm-associated infection treatment.

Nrf2 enhances the therapeutic efficiency of adipose-derived stem cells in the treatment of neurogenic erectile dysfunction in a rat model

BackgroundErectile dysfunction (ED) caused by intraoperative nerve injury is a major complication of pelvic surgery. Adipose-derived stem cells (ADSCs) have presented therapeutic potential in a rat model of bilateral cavernous nerve injury (BCNI), while inadequate in vivo viability has largely limited their application. Nuclear factor-E2-related Factor (Nrf2) is a key transcription factor that regulates cellular anti-oxidative stress. In this work, we investigated the effect of Nrf2 expression regulation on the viability of ADSCs, and explore its repair potential in a BCNI rat model.ResultsThe survival time of tert-Butylhydroquinone (tBHQ)-ADSCs in BCNI model increased obviously. In addition, the tBHQ-ADSCs group presented better restoration of major pelvic ganglion (MPG) nerve contents and fibers, better improvement of erectile function, and less penile fibrosis than the other groups. Moreover, the expression of Nrf2 and superoxide dismutase 1 (SOD1) were higher than those of other groups.ConclusionNrf2 could enhance the anti-oxidative stress ability of ADSCs, so as to improve the therapeutic effect of ADSCs on BCNI rat model.

A feedback loop of PPP and PI3K/AKT signal pathway drives regorafenib-resistance in HCC

BackgroundHepatocellular carcinoma (HCC) is a principal type of liver cancer with high incidence and mortality rates. Regorafenib is a novel oral multikinase inhibitor for second-line therapy for advanced HCC. However, resistance to regorafenib is gradually becoming a dilemma for HCC and the mechanism remains unclear. In this study, we aimed to reveal the metabolic profiles of regorafenib-resistant cells and the key role and mechanism of the most relevant metabolic pathway in regorafenib resistance.MethodsMetabolomics was performed to detect the metabolic alteration between drug-sensitive and regorafenib-resistant cells. Colony formation assay, CCK-8 assay and flow cytometry were applied to observe cell colony formation, cell proliferation and apoptosis, respectively. The protein and mRNA levels were detected by western blot and RT-qPCR. Cell lines of Glucose-6-phosphate dehydrogenase(G6PD) knockdown in regorafenib-resistant cells or G6PD overexpression in HCC cell lines were stably established by lentivirus infection technique. G6PD activity, NADPH level, NADPH/NADP+ ratio, the ratio of ROS positive cells, GSH level, and GSH/GSSG ratio were detected to evaluate the anti-oxidative stress ability of cells. Phosphorylation levels of NADK were evaluated by immunoprecipitation.ResultsMetabonomics analysis revealed that pentose phosphate pathway (PPP) was the most relevant metabolic pathway in regorafenib resistance in HCC. Compared with drug-sensitive cells, G6PD enzyme activity, NADPH level and NADPH/NADP+ ratio were increased in regorafenib-resistant cells, but the ratio of ROS positive cells and the apoptosis rate under the conditions of oxidative stress were decreased. Furthermore, G6PD suppression using shRNA or an inhibitor, sensitized regorafenib-resistant cells to regorafenib. In contrast, G6PD overexpression blunted the effects of regorafenib to drug-sensitive cells. Mechanistically, G6PD, the rate-limiting enzyme of PPP, regulated the PI3K/AKT activation. Furthermore, PI3K/AKT inhibition decreased G6PD protein expression, G6PD enzymatic activity and the capacity of PPP to anti-oxidative stress possibly by inhibited the expression and phosphorylation of NADK.ConclusionTaken together, a feedback loop of PPP and PI3K/AKT signal pathway drives regorafenib-resistance in HCC and targeting the feedback loop could be a promising approach to overcome drug resistance.

Characterization of a DsbA family protein reveals its crucial role in oxidative stress tolerance of Listeria monocytogenes.

Listeria monocytogenes is a facultative, intracellular foodborne pathogen widely distributed in nature and is responsible for severe invasive infection in humans and animals with a mortality rate as high as 30%. L. monocytogenes can adapt to various oxidative stresses since it has evolved oxidative modification and regulation mechanisms. The disulfide bond formation protein (Dsb) is required to catalyze the formation of disulfide bonds to promote oxidative folding or modification of proteins involved in bacterial virulence and survival. However, the functions of Lmo1059, a DsbA family protein of L. monocytogenes, remain unknown. In this study, we found that Lmo1059 could efficiently catalyze oxidized glutathione (GSSG) reduction, with the residues Cys36 and Cys39 as the key amino acids for its catalytic activity. Moreover, Lmo1059 plays a critical role in oxidative stress tolerance for L. monocytogenes, and Cys36 is the crucial amino acid to participate in this process. When Lmo1059 was deleted, the adhesion and invasion of L. monocytogenes were reduced while the cell-to-cell spread was increased, suggesting an intricate role of Lmo1059 during bacterial infection. Altogether, these data indicate that the DsbA family protein Lmo1059 is an important participant in the antioxidant stress system and works in concert with other proteins to help protect L. monocytogenes from oxidative stress and establish intracellular infection. IMPORTANCE The adaption and tolerance to various environmental stresses are the fundamental factors for the widespread existence of Listeria monocytogenes. Anti-oxidative stress is the critical mechanism for the survival and pathogenesis of L. monocytogenes. The thioredoxin (Trx) and glutaredoxin (Grx) systems are known to contribute to the anti-oxidative stress of L. monocytogenes, but whether the Dsb system has similar roles remains unknown. This study demonstrated that the DsbA family protein Lmo1059 of L. monocytogenes participates in bacterial oxidative stress tolerance, with Cys36 as the key amino acid of its catalytic activity and anti-oxidative stress ability. It is worth noting that Lmo1059 was involved in the invading and cell-to-cell spread of L. monocytogenes. This study lays a foundation for further understanding the specific mechanisms of oxidative cysteine repair and antioxidant stress regulation of L. monocytogenes, which contributes to an in-depth understanding of the environmental adaptation mechanisms for foodborne bacterial pathogens.

Heat-tonifying acupuncture relieves pain and synovial inflammatory injury by regulating Keap1-Nrf2/ARE/ HO-1 signaling pathway in rabbits with cold syndrome type rheumatoid arthritis

To observe the effect of heat-tonifying needling on Keap1-Nrf2/ARE/HO-1 signal transduction pathway in knee synovium in rabbits with cold syndrome type rheumatoid arthritis (RA), so as to explore its mechanisms underl-ying improvement of RA. New Zealand rabbits were randomly divided into normal control, RA model, uniform reinforcing-reducing acupuncture, twisting reinforcing acupuncture and heat-tonifying acupuncture groups, with 6 rabbits in each group. The cold syndrome type RA model was established by subcutaneous injection of mixture fluid of ovalbumin and Freund's complete adjuvant at the shoulder-back as well as injection of mixture of ovalbumin and normal saline into knee-joint cavity combined with ice-compress freezing. Acupuncture stimulation (uniform reinforcing-reducing, or twisting reinforcing or heat-tonifying) was applied to bilateral "Zusanli"(ST36) for 1 min with the needle retained for 30 min, once a day for 7 consecutive days. The general conditions of rabbits in each group were recorded, the thermal pain threshold (TPT) and perimeter of knee joints was measured. Conditions of the synovium in the knee cavity, hydrops, blood flow signal, articular surface, and related muscles were observed by using a color Doppler ultrasonic diagnostic apparatus, and the blood flow signals inside the synovium (image scores) were divided into 0 (no signals), I (1 or 2 dot-like signal), II (less than half) ad III (more than half). After H.E. staining, the pathological changes (0-3 points) were assessed according to the state of inflammatory cell infiltration, and hyperplasia of synovial matrix and coating cells. The expression levels of Keap1, Nrf2, HO-1 and GSH-PX1 mRNAs in the knee synovium were detected by quantitative real-time PCR, and the expression of knee synovial HO-1 protein was measured by Western blot. In comparison with the normal control group, the model group had a significant increase in the perimeter, pathological score, expression of Nrf2, HO-1 mRNAs and HO-1 protein (P<0.05), and an obvious decrease in the TPT, expression levels of Keap1 and GSH-PX1 mRNAs (P<0.05). Relevant to the model group, all the three acupuncture maneuvers reversed modeling-induced increase of perimeter and pathological score (P<0.05), decrease of TPT and expression of GSH-PX1 mRNA(P<0.05), further down-regulated expression of Keap1 mRNA (P<0.05), further up-regulated the expression of Nrf2, HO-1 mRNAs and HO-1 protein (P<0.05). The heat-reinforcing manipulation was significantly superior to uniform reinforcing-reducing and twirling reinforcing manipulations in up-regulating TPT, and expression of Nrf2 mRNA, GSH-PX1 mRNA, HO-1 mRNA and protein (P<0.05), and in down-regulating pathological score and Keap1 mRNA expression (P<0.05). Heat-tonifying, uniform reinforcing-reducing and twirling reinforcing needling manipulations may relieve pain and improve pathological state in RA rabbits, which may be associated with their functions in raising the ability of anti-oxidative stress by regulating Keap1-Nrf2/ARE/ HO-1 signaling pathway, the therapeutic effect of heat-tonifying needling is superior to that of uniform reinforcing-reducing and twirling reinforcing needling.

Electroacupuncture promotes expression of glutathione related regulatory enzymes in ovary tissue of rats with diminished ovarian reserve

To observe the effect of electroacupuncture (EA) on ovarian function and expression of glutathione (GSH) related regulatory enzymes γ-glutamylcysteine synthetase (γ-GCS), glutathione reductase (GR) protein and gene in rats with diminished ovarian reserve (DOR), so as to explore its mechanisms underlying up-regulation of antioxidant stress ability. A total of 30 female SD rats with normal estrous cycle were randomly divided into blank control, model and EA groups, with 10 rats in each group. The DOR model was established by gavage of tripterygium wilfordii polyglycoside suspension (50 mg·kg-1·d-1) for 14 consecutive days, while the rats in the blank group were given equal volume of 0.9% sodium chloride solution. One hour after daily gavage, EA (1.0 mA, 100 Hz) was applied alternately to bilateral "Shenshu"(BL23), and "Zhongwan"(CV12)+"Guanyuan"(CV4) for 10 min, for 14 consecutive days. Estrous cycles of rats in each group were observed and recorded daily during intervention.After the intervention, H.E.staining was used to observe histopathological changes of the ovarian tissue. The contents of serum sex hormones ［follicle stimulating hormone (FSH), anti-mullerian hormone (AMH), estradiol (E2)］ and oxidative damage markers ［8-hydroxydeoxyguanosine (8-OHDG) and nitrotyrosine (NTY)］ were determined by ELISA. The contents of GSH and oxidized glutathione (GSSG) in the liver tissue were determined by colorimetry, and their ratios were calculated. Immunohistochemistry and real-time fluorescence quantitative PCR were used to detect the immunoactivity and gene expression levels of γ-GCS and GR in the ovarian tissues, respectively. Compared with the blank group, the model group had a marked increase in the disorder rate of estrous cycle, serum FSH, 8-OHDG and NTY contents (P<0.01) and a considerable decrease in the levels of serum AMH and E2, liver GSH and GSSG contents and GSH/GSSG ratio, ovarian optical density and cell number as well as the expression of γ-GCS and GR mRNAs (P<0.05, P<0.01). After EA intervention, the increase of the disorder rate of estrous cycle, serum FSH, 8-OHDG and NTY contents and the decrease of serum AMH and E2, liver GSH and GSSG contents and GSH/GSSG ratio, ovarian optical density and cell number of γ-GCS and GR as well as the expression of γ-GCS genes were all reversed (P<0.01, P<0.05). H.E. staining showed degenerative changes of the ovarian tissue, fewer follicles at every level and increase of atretic follicles, disarrangement and layer number decrease of granulosa cells, and atrophy of corpus luteum in the model group, which were relatively milder in the EA group. EA can improve ovarian function, and reduce oxidative stress damage in DOR rats, which may be associated with its functions in up-regulating the expression of γ-GCS and GR protein and gene in the ovarian tissue.

Polygonati Rhizoma Polysaccharide Prolongs Lifespan and Healthspan in Caenorhabditis elegans.

Polygonati Rhizoma is the dried rhizome of Polygonatum kingianum coll.et hemsl., Polygonatum sibiricum Red. or Polygonatum cyrtonema Hua, and has a long history of medication. Raw Polygonati Rhizoma (RPR) numbs the tongue and stings the throat, while prepared Polygonati Rhizoma (PPR) can remove the numbness of the tongue, and at the same time enhance its functions of invigorating the spleen, moistening the lungs and tonifying the kidneys. There are many active ingredients in Polygonati Rhizoma (PR), among which polysaccharide is one of the most important active ingredients. Therefore, we studied the effect of Polygonati Rhizoma polysaccharide (PRP) on the lifespan of Caenorhabditis elegans (C. elegans) and found that polysaccharide in PPR (PPRP) was more effective than Polysaccharide in RPR (RPRP) in prolonging the lifespan of C. elegans, reducing the accumulation of lipofuscin, and increasing the frequency of pharyngeal pumping and movement. The further mechanism study found that PRP can improve the anti-oxidative stress ability of C. elegans, reduce the accumulation of reactive oxygen species (ROS) in C. elegans, and improve the activity of antioxidant enzymes. The results of quantitative real-time PCR(q-PCR) experiments suggested that PRP may prolong the lifespan of C. elegans by down-regulating daf-2 and activating daf-16 and sod-3, and the transgenic nematode experiments were consistent with its results, so it was hypothesized that the mechanism of age delaying effect of PRP was related to daf-2, daf-16 and sod-3 of the insulin signaling pathway. In short, our research results provide a new idea for the application and development of PRP.

Mechanical Regulation of Redox Balance via the Induction of the PIN1/NRF2/ARE Axis in Pancreatic Cancer.

Pancreatic cancer is one of the most lethal malignancies. Desmoplastic stroma and metabolic reprogramming are two hallmarks of pancreatic cancer that support its malignant biological behaviors. However, the underlying mechanism by which the stroma maintain the redox balance remains unclear in pancreatic ductal adenocarcinoma (PDAC). Here, we demonstrated that the physical properties of the stroma could regulate the expression of PIN1 in pancreatic cancer cells. Moreover, we found that hard matrix-cultured pancreatic cancer cells induced the upregulation of PIN1 expression. Since PIN1 maintained redox balance via synergistic activation of NRF2 transcription, PIN1 promoted the expression of NRF2 to induce the expression of intracellular antioxidant response element (ARE)-driven genes. Consequently, the antioxidant stress ability of PDAC was increased, and the intracellular level of reactive oxygen species (ROS) was decreased. Thus, PIN1 is expected to be an important target for the treatment of PDAC, especially PDAC with an exuberant desmoplastic stroma.

Bifidobacterium animalis A12 and Lactobacillus salivarius M18-6 Alleviate Alcohol Injury by keap1-Nrf2 Pathway and Thioredoxin System.

Excessive drinking can significantly damage people's health and well-being. Although some lactic acid bacterial strains have been previously shown to alleviate the symptoms of alcohol injury, the mechanism underlying these effects remains unclear. The aim of this study was to establish an alcohol injury model and examine the protective effect and mechanism of B. animalis A12 and L. salivarius M18-6. The results showed that A12 freeze-dried powder could maintain the survival rate of mice with alcohol injury at 100%. Compared with Alco group, L. salivarius M18-6 dead cell improved the survival rate of mice, attenuated liver steatosis, and significantly down-regulated serum Alanine transaminase (ALT) level; at the same time, it activated keap1-Nrf2 signaling pathway and up-regulated Superoxide dismutase (SOD), it protects mouse liver cells from oxidative stress induced by alcohol injury. In addition, B. animalis A12 can reduce the stress response to short-term alcohol intake and improve the ability of anti-oxidative stress by upregulating the level of isobutyric acid, reducing the level of keap1 protein in the liver of mice and upregulating the expression of thioredoxin genes (Txnrd1, Txnrd3, Txn1). Taken together, the results showed that B. animalis A12 and L. salivarius M18-6 alleviate alcohol injury in mice through keap1-Nrf2 signaling pathway and thioredoxin system.