mRNA Levels Of Nrf2 Research Articles

Alleviating effect of quercetin on cadmium-induced oxidative damage and apoptosis by activating the Nrf2-keap1 pathway in BRL-3A cells.

Cadmium (Cd) is a toxic heavy metal extensively used in industrial and agricultural production. Among the main mechanisms of Cd-induced liver damage is oxidative stress. Quercetin (QE) is a natural antioxidant. Herein, the protective effect of QE on Cd-induced hepatocyte injury was investigated. BRL-3A cells were treated with 12.5 μmol/L CdCl2 and/or 5 μmol/L QE for 24 h. The cells and medium supernatant were collected, and the ALT, AST, and LDH contents of the medium supernatant were detected. The activities or contents of SOD, CAT, GSH, and MDA in cells were determined. Intracellular ROS levels were examined by flow cytometry. Apoptosis rate and mitochondrial-membrane potential (ΔΨm) were detected by Hoechst 33,258 and JC-1 methods, respectively. The mRNA and protein expression levels of Nrf2, NQO1, Keap1, CytC, caspase-9, caspase-3, Bax, and Bcl-2 were determined by real-time PCR (RT-PCR) and Western blot methods. Results showed that Cd exposure injured BRL-3A cells, the activity of antioxidant enzymes decreased and the cell ROS level increased, whereas the ΔΨm decreased, and the expression of apoptotic genes increased. Cd inhibited the Nrf2-Keap1 pathway, decreased Nrf2 and NQO1, or increased Keap1 mRNA and protein expression. Through the combined action of Cd and QE, QE activated the Nrf2-Keap1 pathway. Consequently, antioxidant-enzyme activity decreased, cellular ROS level decreased, ΔΨm increased, Cd-induced BRL-3A cell damage was alleviated, and cell apoptosis was inhibited. After the combined action of QE and Cd, Nrf2 and NQO1 mRNA and protein expression increased, Keap1 mRNA and protein expression decreased. Therefore, QE exerted an antioxidant effect by activating the Nrf2-Keap1 pathway in BRL-3A cells.

Influence of zinc levels and Nrf2 expression in the clinical and pathological changes in patients with diabetic nephropathy

ObjectiveWe investigated the correlation between zinc levels and Nrf2 expression and potential effects on the clinicopathology of patients with diabetic nephropathy (DN).MethodsWe selected 30 patients with DN, diagnosed via renal biopsy at our hospital from March 2018 to November 2019, and enrolled 30 healthy individuals from a medical examination center as the control group. Patients with DN were divided into normal-zinc and low-zinc groups. We detected the levels of zinc, copper, and Nrf2 mRNA in their serum, and collected the clinical and pathological data of DN patients.ResultsSerum zinc level and Nrf2 mRNA expression were significantly decreased in patients with DN compared to those of healthy people (P < 0.05). Of the 30 patients, 16 had low zinc (53.3%) and 14 had normal zinc levels (46.7%). There was no significant difference in the blood Nrf2 mRNA expression between the two groups (P > 0.05). However, the expression of Nrf2 in the kidney tissue of the low-zinc group was significantly lower compared to the normal-zinc group (P < 0.05). Diastolic blood pressure and copper levels were significantly higher in the low-zinc group (P < 0.05). In contrast, body mass index, red blood cell count, Hb level, and the ratio of zinc to copper were significantly lower in the low-zinc group (P < 0.05). The pathological classifications of the low-zinc group were more severe (P < 0.05).ConclusionPatients with DN were more likely to have zinc deficiency and lower expression of Nrf2. Additionally, DN patients with zinc deficiency were prone to have more severe clinical and pathological manifestations.

Alleviative effect of biofloc technology (BFT) on extruded soybean meal (ESBM)-induced growth inhibition and intestinal barrier dysfunction in Rhynchocypris lagowskii

This study evaluated the alleviative effect of bioflocs technology (BFT) on intestinal morphology, permeability, digestive function, immune function, antioxidant capacity and microbiota of Rhynchocypris lagowskii sensitized by extruded soybean meal (ESBM). In a 2 × 2 factorial design, R. lagowskii (6.40 ± 0.01 g) was randomly divided into 4 groups, which contains two culture modes (traditional mode and biofloc mode) and two levels of dietary ESBM (0% and 68%). At the end of the experiment (8 weeks), the results showed that the growth performance of R. lagowskii was significantly increased by BFT, but significantly decreased by feeding diets with 68% ESBM (P < 0.05). Culture mode significantly affected intestinal growth indexes, morphology, the levels of tight junction protein mRNA, the activities of digestive enzymes, immune function, inflammation response and antioxidant capacity in proximal intestines (PI), mid intestines (MI) and distal intestines (DI) (P < 0.05). These indexes (except fold height, lamina propria width, the levels of tight junction protein mRNA, the activities of protease, AKP and LZM, the levels of inflammation related mRNA, the levels of T-SOD and PC, the levels of Nrf2, Keap1, HO-1 and Maf mRNA in PI, the activities of CAT in MI, the activities of lipase and amylase in intestines) were also significantly affected the levels of dietary ESBM (P < 0.05). Intestinal permeability (DAO, 5-HT, ET-1 and D-LA) were only significantly affected by the levels of dietary ESBM (P < 0.05). In addition, the interaction between culture mode and the levels of dietary ESBM was observed for muscular layer thickness and T-AOC in PI, fold height, ZO-1, NF-κB and Nrf2 in MI, Claudin-2, IL-1β, TGF-β, T-AOC, Nrf2, HO-1 and Maf in DI (P < 0.05). Results of intestinal microbiota showed that relative abundance of Amaricoccus, Aquitalea, Chelatococcus and Nakamurella were significantly affected by culture mode, the levels of ESBM in diets and their interaction (P < 0.05). Therefore, this study indicated that intestinal morphology, permeability, digestive function, immune function, antioxidant capacity and microbiota in R. lagowskii could be affected by ESBM and alleviated by BFT.

Resveratrol Attenuates Heat Stress-Induced Impairment of Meat Quality in Broilers by Regulating the Nrf2 Signaling Pathway.

Simple SummaryBroilers easily experience heat stress (HS), especially in summer, due to a lack of sweat glands. HS has unfavorable effects on the production efficiency, meat quality, antioxidant capacity, and welfare of broilers, which can be mitigated with nutritional strategies. Resveratrol (RES) has been found to mitigate the HS-induced decrease of antioxidant capacity in muscle and, therefore, improve the meat quality of broilers under HS. Nevertheless, there are few reports on the mechanism of action of RES on meat quality and antioxidant status in the muscle of broilers subjected to HS. Our study demonstrated that RES could improve the antioxidant ability of muscle in broilers under HS by activating the Nrf2 signaling pathway and ultimately relieving the HS-induced deterioration of meat quality.Studies have indicated that dietary resveratrol (RES) improves the meat quality of broilers subjected to heat stress (HS), but the mechanism of action remains unclear. Therefore, the main purpose of this study was to investigate the effect of RES on meat quality, muscle antioxidant status, and its mechanism of action in broilers under HS. A total of 162 male AA broilers at 21 days old with similar weight were randomly assigned to 3 treatment groups with 6 replicates each. The control group (ambient temperature: 22 ± 1 °C) and HS group (ambient temperature: 33 ± 1 °C for 10 h a day from 8:00 to 18:00 and 22 ± 1 °C for the remaining time) were fed a basal diet and the HS + RES group was fed a basal diet with 400 mg/kg RES. The feeding was conducted for 21 continuous days. The results indicated that HS decreased final body weight (BW), average daily gain (ADG), average daily feed intake (ADFI), breast and leg muscle yield, a*24h, pH24h, the activities of catalase (CAT), glutathione S-transferase (GST) and glutathione peroxidase (GSH-Px), and mRNA levels of nuclear factor erythroid 2–related factor 2 (Nrf2), heme oxygenase-1 (HO-1), NADPH quinone oxidoreductase 1 (NQO1), and GSH-Px (p < 0.05). HS also increased b*45min, L*24h, drip loss, malondialdehyde (MDA) content, and kelch-like epichlorohydrin-associated protein 1 (Keap1) mRNA level (p < 0.05). Compared with the HS group, the HS + RES group exhibited a higher ADG, breast and leg muscle yield, a*24h, pH24h, activities of GST and GSH-Px, and mRNA levels of Nrf2, HO-1, and NQO1 but had lower drip loss and Keap1 mRNA level (p < 0.05). RES can improve meat quality and the muscle antioxidant ability of heat-stressed broilers by activating the Nrf2 signaling pathway.

Dietary L-theanine supplementation improves lipid metabolism and antioxidant capacity in weaning piglets

The aim of this study was to explore the effects of dietary L-theanine (LT) supplementation on lipid metabolism and antioxidant capacity in weaned piglets. Twenty-one castrated DLY weaning piglets were randomly divided into three groups: a basal diet, a basal diet supplemented with 0.05% and 0.1% LT, respectively. Our data showed that dietary LT supplementation decreased T-CHO, TG, LDL-C and apoB levels and increased apoA and HDL-C levels in serum, but decreased the hepatic TG and T-CHO contents. Dietary LT supplementation increased the antioxidant capacity in serum and liver, and significantly increased the Nrf2 mRNA level and the nucleus Nrf2 protein level, but decreased the mRNA level of keap1 in the liver. In addition, dietary LT supplementation significantly increased HSL enzyme activity and the levels of CPT1 and TBA, while decreasing the enzyme activities of LPL and FAS in the liver. Furthermore, the mRNA levels HMG-CoAR, CPT-1a and PPARα and the protein levels of phosphorylated-AMPK and PGC-1α were increased by LT. Together, our data provide the first evidence that dietary supplementation of LT could improve lipid metabolism and antioxidant capacity in the liver of weaned piglets, and the effect might be mediated by activation of AMPK and Nrf2 signaling, respectively.

Study on the Correlation Between Regulatory Proteins of N6-methyladenosine and Oxidative Damage in Cadmium-induced Renal Injury.

As a common environmental heavy metal pollutant, cadmium has been well evidenced to cause kidney damage; yet, the underlying mechanisms are still not fully clarified. In this study, cell viability of human renal tubular epithelial cell (HK-2) was determined by CCK-8 assay after treatment with CdSO4. Then, apoptotic morphology of cells was observed by Hoechst staining and level of reactive oxygen species (ROS) was detected by fluorescent probes. Subsequently, mRNA levels of Nrf2, HO-1, m6A methyltransferases (METTL3, METTL14, METTL16, WATP), m6A demethylases (FTO, ALKBH5), m6A methyl-binding proteins (YTHDF1, YTHDF2, YTHDF3, YTHDC1, YTHDC2) were detected by real-time polymerase chain reaction (RT-PCR), closely followed by correlation analysis between Nrf2 mRNA levels and m6A methyltransferases and demethylases. Lastly, protein expressions of Nrf2, METTL3, and FTO were tested by western blotting assay. The detection results demonstrated that the treatment of CdSO4 decreased viability while increased apoptosis rate. The Nrf2 mRNA level in CdSO4-treated cells was significantly increased when compared with that in the control cells, and the HO-1 mRNA level elevated with the increasing of CdSO4 concentrations. In addition, mRNA levels of METTL3, METTL14, METTL16, WTAP, FTO, and methyl-binding proteins in CdSO4-treated cells were all higher than those in corresponding control cells. Further determination showed that protein expressions of Nrf2, METTL3, and FTO were also upregulation under the treatment of CdSO4. Lastly, correlation analysis indicated that mRNA level of Nrf2 was positively correlated with mRNA levels of m6A methyltransferases and demethylases. In a word, our results demonstrated that the molecular changes of Nrf2 signaling pathway are correlated with the levels of m6A regulatory proteins, suggesting that there may be a regulatory relationship between Nrf2 signaling pathway and m6A regulatory proteins in the process of cadmium-induced renal cell cytotoxicity.

Novel Chalcone BDD-39 Mitigated Diabetic Nephropathy through the Activation of Nrf2/ARE Signaling.

In this study, we investigated the Nrf2/ARE signaling pathway activating capacity of Biphenyl Diester Derivative-39 (BDD-39) in diabetic nephropathy in order to elucidate the mechanism surrounding its antidiabetic potential. Protein expressions of Nrf2, HO-1, NQO-1 and biomarkers of kidney fibrosis were executed after which mRNA levels of Nrf2, HO-1 and NQO-1 were estimated after creating the models following BBD-39 treatment. Type 2 diabetes model was established in mice with high-fat diet feeding combined with streptozocin intraperitoneal administration. The diabetic mice were then treated with BDD-39 (15, 45mg· kg-1· d-1, ig) or a positive control drug resveratrol (45mg· kg-1·d-1, ig) for 8 weeks. Staining techniques were used to investigate collagen deposition in the glomerulus of the renal cortex and also to investigate the expression and localization of Nrf2 and extracellular matrix (ECM) proteins (collagen IV and laminin) in vitro and in vivo. Furthermore, we studied the mechanism of action of BDD-39 using RNA-mediated Nrf2 silencing technique in mouse SV40 glomerular mesangial cells (SV40 GM cells). We found that BDD-39 activates Nrf2/ARE signaling pathway, promotes Nrf2 nuclear translocation (Nrf2nuc/Nrf2cyt) and modulate prominent biomarkers of kidney fibrosis at the protein level. However, BDD-39 could not activate Nrf2/ARE signaling in RNA-mediated Nrf2-silenced HG-cultured SV40 GM cells. Taken together, this study demonstrates for the first time that BDD-39 ameliorates experimental DN through attenuation of renal fibrosis progression and modulation of Nrf2/ARE signaling pathway.

Astragaloside IV improved antioxidative stress capacity and related gene expression of the Keap1-Nrf2 pathway in grass carp (Ctenopharyngodon idella) hepatocytes under heat stress.

This study aims to investigate the protective effects of astragaloside IV (AS-IV) on the hepatocytes of grass carp (Ctenopharyngodon idella) on heat stress. Cultured cells were treated with AS-IV (0, 50, 100 and 200 μg/ml) at 28°C for 24 h and then exposed to heat stress by increasing the culturing temperature (32 ± 0.5°C) for 6h. The increased temperatures significantly reduced cell viability and superoxide dismutase (SOD) activity, and increased malondialdehyde (MDA) levels in the 0μg/ml AS-IV treatment group at 32°C, but the grass carp hepatocytes treated with 100 and 200 μg/ml AS-IV had significantly increased cell viability and SOD activity and decreased MDA levels. The mRNA levels of keap1a, keap1b, nrf2, gsh-px, cat, cu-zn sod, mgst1 and il-6 were significantly lower in the 0μg/ml AS-IV treatment group at 32°C, while those of keap1a, nrf2, gsh-px, cat, cu-zn sod, gstp1, ho-1 and il-6 were significantly higher in cells treated with 100 or 200 μg/ml AS-IV. Our findings indicate that AS-IV could enhance the antioxidative stress capacity of grass carp hepatocytes under heat stress, and its mechanism may be associated with the activation of the Keap1-Nrf2 pathway. Thus, these results provide new insights into how to alleviate heat stress in grass carp.

Nestin Regulates Keap1-Nrf2-HO-1-Mediated Antioxidant Responses during Stress and Malignant Hematopoiesis.

Objective To investigate the role of nestin in regulating Keap1-nuclear factor erythroid-2-related factor 2 (Nrf2)-heme oxygenase-1-(HO-1-) mediated antioxidant responses in stress and malignant hematopoiesis. Methods The mRNA of peripheral blood mononuclear cells was extracted from 20 leukemia patients and 20 healthy people who were hospitalized in the Hematology Department of our hospital from September 2020 to December 2021, and the mRNA levels of nestin, Keap1, Nrf2, and HO-1 were detected by real-time- (RT-) PCR. Results Compared with healthy controls, the mRNA of nestin, Keap1, Nrf2, and HO-1 in peripheral blood mononuclear cells of leukemia patients was significantly upregulated. Conclusion The occurrence and development of leukemia are closely related to nestin regulating Keap1-Nrf2-Ho-1 signal pathway. Research Significance. This study determined the effect of nestin on the biological behavior of leukemia cells and its possible mechanism and confirmed that nestin may be a marker of tumor and tumor blood vessels.

Effect of a Plateau Environment on the Oxidation State of the Heart and Liver through AMPK/p38 MAPK/Nrf2-ARE Signaling Pathways in Tibetan and DLY Pigs.

Simple SummaryPlateau stress is a main factor limiting pig production. There are great differences in oxidation state and antioxidant defense between Tibetan pigs (TPs) and DLY pigs exposed to a plateau environment. However, there are limited reports on the mechanism of adaptation of TPs and DLY pigs to the plateau environment involving a signal pathway related to oxidation state. In the present study, we found that TPs exhibit a stronger heart and liver antioxidant stress capacity than DLY pigs through AMPK/p38 MAPK/Nrf2-ARE signaling pathways under a plateau hypoxic environment.This study evaluated the effect of a plateau environment on the heart and liver oxidation state of Tibetan pigs (TPs) and DLY pigs through analyzing AMPK, p38 MAPK, and Nrf2 signaling pathways. Twelve 120-day-old TPs and twelve 120-day-old DLY pigs were randomly divided into two groups in a plateau environment for three weeks. Exposed to a plateau environment, TPs exhibited a lower (p < 0.05) malondialdehyde level but higher (p < 0.05) glutathione, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC) activities in the liver and heart than those observed in DLY pigs. TPs also showed higher (p < 0.05) mRNA levels of SOD and GSH-Px in the liver and heart compared with those of DLY pigs. The TPs showed higher (p < 0.05) mRNA and protein levels of AMPK and Nrf2 in the liver and heart compared with those of DLY pigs. Furthermore, TPs showed higher (p < 0.05) mRNA and protein levels of p38 MAPK in the heart and higher mRNA levels of p38 MAPK in the liver compared with those of DLY pigs under a plateau environment. In summary, TPs possess a stronger antioxidant capacity in the heart and liver than that of DLY pigs in a plateau environment through AMPK/p38 MAPK/Nrf2-ARE signaling pathways.

Effects of dietary potassium diformate on growth performance, fillet quality, plasma indices, intestinal morphology and liver health of juvenile golden pompano (Trachinotus ovatus)

This study was conducted to investigate the impacts of potassium diformate (KDF) on growth performance, fillet quality, plasma indices, immune response and intestinal morphology of juvenile Trachinotus ovatus. Six diets with 0 (KDF1), 3.00 (KDF2), 6.00 (KDF3), 9.00 (KDF4), 12.00 (KDF5) and 15.00 (KDF6) g/kg KDF were formulated to feed T. ovatus (average fish weight: 5.87 ± 0.03 g) for 8 weeks. The results indicated that 3.00 g/kg and 6.00 g/kg KDF significantly increased the growth parameters of juvenile T. ovatus (P < 0.05), whereas 6.00 g/kg and 9.00 g/kg KDF significantly reduced feed conversion ratio (P < 0.05). KDF level presented a significant improvement on fillet quality of juvenile T. ovatus (P < 0.05). With the increasing levels of KDF, triglyceride and glucose of plasma significantly declined (P < 0.05), whereas high density lipoprotein cholesterol significantly increased (P < 0.05). 6.00 g/kg dietary KDF significantly up-regulated mRNA levels of Nrf2, CAT, CuZn-SOD, MnSOD (P < 0.05) and increased antioxidative enzyme activities in liver (P < 0.05). Furthermore, 6.00 g/kg KDF supplementation significantly enhanced immune function of juvenile golden pompano by regulating the expression levels of hepatic NF-κB, TGF-β, ZO-1, Occludin and Claudin-3a (P < 0.05). 6.00 g/kg KDF significantly improved intestinal morphology compared with KDF1 diets (the control) (P < 0.05). In conclusion, the supplement of dietary KDF was beneficial for T. ovatus by promoting growth performance, improving fillet quality and intestinal morphology and enhancing immune response. The optimum supplement level of KDF in T. ovatus diet was 6.58 g/kg based on WGR.

Low-Dose Gamma Radiation Modulates Liver and Testis Tissues Response to Acute Whole Body Irradiation.

AimThis work aims to investigate whether the pre-exposure to low dose/low dose rate (40 mGy, 2.2 mGy/hour) γ-radiation as a priming dose can produce a protective effect against the subsequent high one (4 Gy, .425 Gy/minute).MethodsRats were divided into Group I (control), Group II (L); exposed to 40 mGy, Group III (H); exposed to 4 Gy, and Group IV (L+H); exposed to 40 mGy 24 hours before the exposure to 4Gy. The molecular and biochemical changes related to oxidative stress, DNA damage, apoptosis, and mitochondrial activity in the liver and testis were studied 4 hours after irradiation.ResultsExposure to 40 mGy before 4 Gy induced a significant increase in the levels of Nrf2, Nrf2 mRNA, TAC, and mitochondrial complexes I & II accompanied by a significant decrease in the levels of LPO, 8-OHdG, DNA fragmentation, TNF-α, caspase-3, and caspase-3 mRNA compared with H group.ConclusionExposure to low-dose γ-radiation before a high dose provides protective mechanisms that allow the body to survive better after exposure to a subsequent high one via reducing the oxidative stress, DNA damage, and apoptosis-induced early after irradiation. However, further studies are required to identify the long-term effects of this low dose.

Rumex nervosus could alleviate streptozotocin-induced diabetic nephropathy in rats by activating Nrf2 signaling.

This study tested the protective effect of Rumex nervous (R. nervosus) methanol extract against streptozotocin (STZ)-mediated type 1 diabetes mellitus (T1DM)-induced nephropathy in rats and examined if this protection involves activating the nuclear factor erythroid 2 related factor-2 (Nrf2). Rats were divided into control, R. nervous (300 mg), STZ (T1DM), STZ + R. nervosus (100, 200, or 300 mg/kg), and STZ + R. nervosus (300 mg/kg) + brusatol (an Nrf2 inhibitor). With no effect on fasting glucose and insulin levels, R. nervosus methanol extract preserved kidney histological structure and alterations kidney function markers (e.g. albumin, creatinine, and urine volume) in the STZ-diabetic rats. R. nervosus also reduced levels of reactive oxygen species (ROS), malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), and interleukine-6 (IL-6), nuclear levels of the nuclear factor kappa beta (NF-κB), and mRNA of caspase-3 and Bax in the kidneys of these diabetic rats. Concomitantly, it stimulated renal mRNA levels of Bcl2 and Nrf2, cytoplasmic and nuclear levels of Nrf2, and levels of glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD). All these effects were dose-dependent, with the maximum effect seen with the 300 mg/kg dose, all prevented by brusatol. Also, these effects occurred without any alteration in the transcription of the Kelch-like ECH-associated protein 1 (keap-1). Similar effects on levels of GSH, SOD, CAT, and NF-κB, as well as expression of Nrf2, were also observed in the kidney of control + R. nervous-treated rats. In conclusion, R. nervosus prevents diabetic nephropathy in rats by upregulating and activating Nrf2.

Phytoconstituents of Sansevieria suffruticosa N.E.Br. Leaves and Its Hepatoprotective Effect via Activation of the NRF2/ARE Signaling Pathway in an Experimentally Induced Liver Fibrosis Rat Model.

Sansevieria species possess antioxidant and hepatoprotective activities. However, the therapeutic potential of Sansevieria suffruticosa N.E.Br. in liver fibrosis was not evaluated yet. Twenty-seven phytoconstituents were tentatively identified in the phytoconstituents profile of Sansevieria suffruticosa N.E.Br. leaves extract (SSLE) using high-performance liquid chromatography coupled with mass spectrometry (HPLC-ESI/MS-MS). Using column chromatography, hesperetin, 4-hydroxybenzoic acid, ginsenoside Rg2, and quinic acid were isolated from SSLE. The hepatoprotective effect of SSLE via the activation of the NRF2 signaling pathway was evaluated using a rat model of thioacetamide-induced liver fibrosis. Five groups of 6 male adult Wistar rats were used. All animals except the normal control were injected with 200 mg/kg of TAA intraperitoneally twice weekly for 6 weeks. SSLE-treated groups were orally administered 200 and 100 mg/kg/day of the extract, two weeks before the liver fibrosis induction and were continued concomitantly with TAA injection. A reference group received 100 mg/kg b.wt of silymarin orally. SSLE treated groups exhibited a marked reduction in serum alanine transaminase (ALT), aspartate transaminase (AST) and malondialdehyde (MDA) levels compared with the TAA group. The levels of reduced glutathione (GSH) content and hepatic mRNA levels of Nrf2 and HO-1 were significantly increased. Histological findings further confirmed the protective role of SSLE against TAA. In conclusion, the aforementioned results indicated that the hepatoprotective mechanism of SSLE was exerted via activating the Nrf2 pathway to counteract oxidative stress.

Increased expression of Nrf2 and elevated glucose uptake in pheochromocytoma and paraganglioma with SDHB gene mutation

BackgroundPheochromocytomas (PCC) and paragangliomas (PGL) are catecholamine-producing neuroendocrine tumors. According to the World Health Organization Classification 2017, all PCC/PGL are considered to have malignant potential. There is growing evidence that PCC/PGL represent a metabolic disease that leads to aerobic glycolysis. Cellular energy metabolism involves both transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) and succinate dehydrogenase (SDH) subtypes, but the association of these substances with PCC/PGL is largely unknown.MethodsWe investigated SDHB gene mutation and protein expressions for SDHB and Nrf2 in surgical specimens from 29 PCC/PGL. We also assessed preoperative maximum standard glucose uptake (SUVmax) on [18F]fluorodeoxy-glucose positron emission tomography and mRNA levels for Nrf2.ResultsAmong 5 PCC/PGL with a PASS Score ≥ 4 or with a moderately to poorly differentiated type in the GAPP Score, 4 were metastatic and found to be SDHB mutants with homogeneous deletion of SDHB protein. SDHB mutants showed a higher expression of Nrf2 protein and a higher preoperative SUVmax than non-SDHB mutants with a PASS < 4 or a well-differentiated GAPP type. Furthermore, protein expression of Nrf2 was positively associated with preoperative SUVmax. The Nrf2 mRNA level positively correlated with malignant phenotype, higher expression for Nrf2 protein and SDHB gene mutant, but negatively correlated with expression for SDHB protein. There was also a positive correlation between Nrf2 mRNA level and SUVmax.ConclusionThese results suggest that activation of Nrf2 and elevated metabolism play roles in PCC/PGL with malignant potential that have SDHB gene mutation and SDHB deficiency.

Ketone Analog of Caffeic Acid Phenethyl Ester Exhibits Antioxidant Activity via Activation of ERK-Dependent Nrf2 Pathway

Due to their robust antioxidant properties, phenolic acids and their analogs are extensively studied for their ability to activate cellular antioxidant pathways, including nuclear factor (erythroid-derived-2)-like 2 (Nrf2)-antioxidant response element (ARE) pathway. Caffeic, ferulic, and gallic acid are well-studied members of phenolic acids. Constant efforts are made to improve the pharmacological effects and bioavailability of phenolic acids by synthesizing their chemical derivatives. This study determines how modifications of the chemical structure of these phenolic acids affect their antioxidant and cytoprotective activities. We have selected six superior antioxidant compounds (12, 16, 26, 35, 42, and 44) of the 48 caffeic acid phenethyl ester (CAPE) analogs based on their ability to scavenge free radicals in vitro using standard antioxidant assays. These compounds exhibited minimal toxicity as indicated by cell cycle and cytochrome C release assays. Among these compounds, 44, the ketone analog of CAPE, exhibited the ability to increase p-Nrf2 (Ser40) levels in 293T cells (p &lt; 0.05). Further, 44, exhibited its antioxidant effect in Drosophila Melanogaster as indicated by an increase in mRNA levels of Nrf2 and GPx (p &lt; 0.05). Finally, the ability of 44 to activate the antioxidant pathway was abolished in the presence of extracellular signal-regulated kinase (ERK) inhibitor in 293T cells. Thus, we identify 44, the ketone analog of CAPE, as a unique antioxidant molecule with the function of ERK-mediated Nrf2 activation.

Postconditioning with Irisin Attenuates Lung Ischemia/Reperfusion Injury by Suppressing Ferroptosis via Induction of the Nrf2/HO-1 Signal Axis.

Iron-dependent lipid peroxidation causes ferroptosis. This study was aimed at verifying that irisin postconditioning can inhibit ferroptosis and minimize lung ischemia/reperfusion (I/R) damage via activating the Nrf2/HO-1 signal axis. We constructed a murine model of I/R lung damage. At the onset of reperfusion, irisin, ferroptosis inhibitor ferrostatin-1, and ferroptosis inducer Fe-citrate were all administered. We discovered that irisin could reduce lung I/R injury, consistent with ferrostatin-1's action. Furthermore, irisin suppressed ferroptosis in lung I/R damage, as evidenced by lower ROS, MDA, and Fe2+, as well as alterations in critical protein expression (GPX4 and ACSL4). However, Fe-citrate abolished the protective effects of irisin. Transcriptome research found that irisin increased the mRNA levels of Nrf2 and HO-1. Thus, we used siRNA to investigate the role of the Nrf2/HO-1 axis in irisin-mediated protection against hypoxia/reoxygenation (H/R) damage in MLE-12 cells. Irisin consistently reduced ferroptosis and improved mitochondrial dysfunction caused by H/R. Irisin's cytoprotective function was eliminated when Nrf2 was silenced. As a result, irisin postconditioning may protect against lung I/R damage by suppressing ferroptosis via the Nrf2/HO-1 signaling axis.

Aerobic exercise training combined with probiotic supplement improves antioxidant defence of cardiomyocytes by regulating Nrf2 and caspase3 gene expression in type 2 diabetic rats

This study aimed to evaluate the effect of four weeks of aerobic exercise training combined with probiotic supplementation on mRNA levels of Nrf-2 and caspase-3 genes, superoxide dismutase (SOD), and serum total antioxidant capacity (TAC) in rats with type 2 diabetes. 40 male Wistar diabetic rats were divided into five groups: healthy placebo control group (NC), diabetic control group without supplement (DC), diabetic control group with supplement (SDC), diabetic aerobic training group without supplement (DT), and diabetic aerobic training group with probiotic supplement (SDT). Each training group performed training five days per week for four weeks and each session of training consisted of 30 min running on a treadmill with an intensity of 65-60% of maximum speed. Simultaneously, rats were fed probiotic supplements. Serum glucose, SOD, and TAC were analysed. The real-time PCR technique was used to determine the gene expression of Nrf-2 and caspase-3. Both aerobic exercise training and probiotic supplementation interactively reduced caspase 3 gene expression, increased Nrf-2 gene expression and enhanced TAC in the left ventricle of diabetic rats. Also, the reduction of caspase-3 mRNA in the left ventricle was more effective in the SDT group than in other diabetic groups. There was no interaction effect on SOD. However, a simultaneous effect of training and supplementation was observed on increasing TAC levels when compared to the DC group. Pearson’s correlation showed that the heart weight gain in the SDT group occurred only by decreasing the expression of the caspase-3 gene. Based on these results, probiotics combined with exercise training can be a strategy for improving the antioxidant defence system and preventing risk factors of diabetic cardiomyocytes, especially cell death and myocardial ischemia.

Resveratrol exhibits neuroprotection against paraquat-induced PC12 cells via heme oxygenase 1 upregulation by decreasing MiR-136-5p expression

ABSTRACT Resveratrol (Res) is a flavonoid with an antioxidant effect and has been utilized to treat oxidative stress-related illnesses; however, its mechanism remains ambiguous. This research aims to explore whether Res inhibits miR-136-5p expression, increases heme oxygenase 1 (HMOX1) expression, and mitigates oxidative stress and PC12 cell apoptosis triggered by paraquat (PQ). Results showed that PQ dose-dependently increased the expression of miR-136-5p, the apoptosis of PC12 cells, the activities of reactive oxygen species (ROS), and the levels of lactate dehydrogenase (LDH), malondialdehyde (MDA), caspase-3, and pro-apoptotic protein Bax. In addition, PQ reduced the expression of anti-apoptotic protein Bcl-2, HMOX1 mRNA and protein, and nuclear factor-erythroid factor 2-related factor 2 (Nrf2) protein and the activity of superoxide dismutase 1 (SOD1) and PC12 cells. After the PQ-treated PC12 cells were administered with different Res concentrations for 24 h, the miR-136-5p expression was dose-dependently decreased. An increase was observed in the activity and survival rate of PC12 cells, the protein and mRNA levels of HMOX1 and Nrf2, and the content of anti-apoptotic protein B-cell lymphoma/leukemia gene-2 (Bcl-2). By contrast, the activities of ROS, LDH, and MDA and the apoptosis of PC12 cells decreased. These findings illustrated that Res could reduce the oxidative stress and apoptosis triggered by PQ and enhance the activity and survival rate of PC12 cells. The underlying mechanism might be correlated with the reduced miR-136-5p expression and the elevated activity of the HMOX1/Nrf2 pathway.

Fisetin Attenuates Doxorubicin-Induced Cardiomyopathy In Vivo and In Vitro by Inhibiting Ferroptosis Through SIRT1/Nrf2 Signaling Pathway Activation

Doxorubicin (DOX) is an anthracycline antibiotic that is used extensively for the management of carcinoma; however, its clinical application is limited due to its serious cardiotoxic side effects. Ferroptosis represents iron-dependent and reactive oxygen species (ROS)-related cell death and has been proven to contribute to the progression of DOX-induced cardiomyopathy. Fisetin is a natural flavonoid that is abundantly present in fruits and vegetables. It has been reported to exert cardioprotective effects against DOX-induced cardiotoxicity in experimental rats. However, the underlying mechanisms remain unknown. The present study investigated the cardioprotective role of fisetin and the underlying molecular mechanism through experiments in the DOX-induced cardiomyopathy rat and H9c2 cell models. The results revealed that fisetin treatment could markedly abate DOX-induced cardiotoxicity by alleviating cardiac dysfunction, ameliorating myocardial fibrosis, mitigating cardiac hypertrophy in rats, and attenuating ferroptosis of cardiomyocytes by reversing the decline in the GPX4 level. Mechanistically, fisetin exerted its antioxidant effect by reducing the MDA and lipid ROS levels and increasing the glutathione (GSH) level. Moreover, fisetin exerted its protective effect by increasing the SIRT1 expression and the Nrf2 mRNA and protein levels and its nuclear translocation, which resulted in the activation of its downstream genes such as HO-1 and FTH1. Selective inhibition of SIRT1 attenuated the protective effects of fisetin in the H9c2 cells, which in turn decreased the GSH and GPX4 levels, as well as Nrf2, HO-1, and FTH1 expressions. In conclusion, fisetin exerts its therapeutic effects against DOX-induced cardiomyopathy by inhibiting ferroptosis via SIRT1/Nrf2 signaling pathway activation.