scholarly journals Proanthocyanidins Antagonize Arsenic-Induced Oxidative Damage and Promote Arsenic Methylation through Activation of the Nrf2 Signaling Pathway

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Mengchuan Xu ◽  
Qiang Niu ◽  
Yunhua Hu ◽  
Gangling Feng ◽  
Haixia Wang ◽  
...  

Purpose. To investigate the effects of grape seed proanthocyanidin extract (GSPE) on oxidative damage and arsenic (As) methylation and to clarify the role of Nrf2 in the process. Methods. L-02 cells were treated with arsenic (25 μM) and GSPE (10, 25, and 50 mg/L) for 24 h. Cell viability was analyzed by MTT assay. Cell apoptosis and ROS fluorescence were detected by flow cytometry. Oxidative stress marker levels were measured using commercial kits. mRNA and protein expression were detected by qRT-PCR and western blotting. The cellular concentrations of methylation products were measured by HPLC-HGAFS. Arsenic methylation ability of cells was determined. Results. Cell survival rate was significantly lower in the As group than in the control group (P<0.05), while cell apoptosis increased and the number of apoptotic cells decreased gradually after GSPE intervention. Superoxide dismutase, glutathione, and sulfhydryl levels in the intervention group were significantly higher (P<0.05), while MDA and ROS levels were significantly lower (P<0.05) than those in the As group. The mRNA and protein expression of Nrf2, HO-1, NQO1, and glutathione-S-transferase increased in the As + GSPE group compared with that in the As group (P<0.05). GSPE significantly increased methylated As level, primary methylation index, secondary methylation index, average growth rate of methylation, and average methylation speed compared with the GSPE untreated group (P<0.05). After Nrf2 inhibition, the effect of GSPE decreased significantly. Conclusion. GSPE activates the Nrf2 signaling pathway to antagonize As-induced oxidative damage and to promote As methylation metabolism. Therefore, GSPE may be a potential agent for relieving As-induced hepatotoxicity.

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 400 ◽  
Author(s):  
Xi Cheng ◽  
Shuhua Yang ◽  
Chuang Xu ◽  
Lanzhi Li ◽  
Yi Zhang ◽  
...  

Metabolic diseases, such as ketosis, are closely associated with decreased reproductive performance (such as delayed estrus and decreased pregnancy rate) in dairy cows. The change of β-hydroxybutyrate (BHBA) concentration in dairy cattle is an important mechanism leading to ketosis, and its blood concentration in ketotic cows is always significantly higher than in nonketotic cows. Many studies indicated that BHBA can induce oxidative damage in liver and other organs. Proanthocyanidins (PCs) have gained substantial attention in the last decade as strong antioxidative substances. This study aimed to demonstrate a protective effect of PCs against BHBA-induced oxidative stress damage in bovine endometrial (BEND) cells by activating the nuclear erythroid2-related factor2 (Nrf2) signaling pathway. Our research show that PCs could significantly increase activities of catalase (CAT) and glutathione peroxidase (GSH-PX), glutathione (GSH) content, and antioxidant capacity (T-AOC), while significantly decreasing malondialdehyde (MDA) content in BEND cells. Both mRNA and protein expression levels of Nrf2 were significantly increased in BEND cells, and glutamate–cysteine ligase catalytic subunit (GCLC), heme oxygenase 1 (HO-1), manganese superoxide dismutase (Mn-SOD), and NAD(P)H quinone dehydrogenase 1 (NQO-1) were also significantly increased. These results indicate that PCs can antagonize BHBA-induced oxidative damage by activating the Nrf2 signaling pathway to exert an antioxidant effect.


2017 ◽  
Vol 41 (6) ◽  
pp. 2461-2474 ◽  
Author(s):  
Qing Ling ◽  
Xiao Yu ◽  
Tao Wang ◽  
Shao-Gang Wang ◽  
Zhang-Qun Ye ◽  
...  

Objective: This study aims to explore the effects of the exogenous hydrogen sulfide (H2S)-mediated scavenger receptor A (SR-A) signaling pathway on renal ischemia/reperfusion injury (IRI) by regulating endoplasmic reticulum (ER) stress-induced autophagy in rats. Methods: A total of 48 normal Sprague-Dawley (SD) rats and SR-A knockout rats were selected and divided into six groups (n = 8): wild-type (WT) + sham, WT + ischemia-reperfusion (I/R), WT + I/R + NaHS, SR-A-/- + sham, SR-A-/- + I/R and SR-A-/- + I/R + NaHS. The concentrations of urinary protein, blood urea nitrogen (BUN), serum creatinine (SCR), malondialdehyde (MDA) and H2S in renal tissue were detected. qRT-PCR and Western blotting were used to detect the mRNA and protein levels of IL-6, TGF-β, SR-A, LC3I, LC3II, P62, PERK, ATF6 and IRE1 pathway-related genes. A TUNEL assay was used to detect cell apoptosis. Electron microscopy was applied to observe the structure of renal autophagosomes. Results: Compared with the WT + sham group, in the rates of the WT + I/R group, the urine volume, urinary protein, BUN, SCR and MDA concentrations, the mRNA and protein expression of IL-6, TGF-β, LC3II/I, and ER stress pathway-related genes, the cell apoptosis index, and the number of autophagosomes were significantly increased 24 h after I/R, while P62 and SR-A protein expression and SOD and H2S concentrations were significantly decreased (all P < 0.05). The levels of renal injury, autophagy and ER stress pathway-related genes were decreased in the WT + I/R + NaHS group but were increased in the SR-A-/- + I/R group relative to the WT + I/R group. No significant differences were observed in the urine volume; the concentrations of urinary protein, BUN, SCR and MDA; the SOD activity; the mRNA and protein expression of IL-6, TGF-β, SR-A, GRP78, SR-A, GPR94, ATF4, IRE1, XBP1, ATF6, and eIF2α; the cell apoptosis index; or the number of autophagosomes in rats of the SR-A-/- + I/R and SR-A-/- + I/R + NaHS groups (all P > 0.05). Conclusion: These results demonstrate that the exogenous H2S-mediated SR-A signaling pathway reduces renal IRI injury by up-regulating ER stress-induced autophagy in rats.


Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 158
Author(s):  
Li Kong ◽  
Lijuan Zhu ◽  
Xianglian Yi ◽  
You Huang ◽  
Haoqiang Zhao ◽  
...  

T-2 toxin, which is mainly produced by specific strains of Fusarium in nature, can induce immunotoxicity and oxidative stress, resulting in immune organ dysfunction and apoptosis. Betulinic acid (BA), a pentacyclic triterpenoids from nature plants, has been demonstrated to possess immunomodulating and antioxidative bioactivities. The purpose of the study was to explore the effect of BA on T-2 toxin-challenged spleen oxidative damage and further elucidate the underlying mechanism. We found that BA not only ameliorated the contents of serum total cholesterol (TC) and triglyceride (TG) but also restored the number of lymphocytes in T-2 toxin-induced mice. BA dose-dependently reduced the accumulation of reactive oxygen species (ROS), enhanced superoxide dismutase (SOD) activity, and decreased malondialdehyde (MDA) content, as well as increased the total antioxidant capacity (T-AOC) in the spleen of T-2-toxin-exposed mice. Moreover, BA reduced inflammatory cell infiltration in the spleen, improved the morphology of mitochondria and enriched the number of organelles in splenocytes, and dramatically attenuated T-2 toxin-triggered splenocyte apoptosis. Furthermore, administration of BA alleviated the protein phosphorylation of p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinases (ERK); decreased the protein expression of kelch-like erythroid cell-derived protein with CNC homology [ECH]-associated protein1 (Keap1); and increased the protein expression of nuclear factor erythroid 2 [NF-E2]-related factor (Nrf2) and heme oxygenase-1 (HO-1) in the spleen. These findings demonstrate that BA defends against spleen oxidative damage associated with T-2 toxin injection by decreasing ROS accumulation and activating the Nrf2 signaling pathway, as well as inhibiting the mitogen-activated protein kinase (MAPK) signaling pathway.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yueqin Qiu ◽  
Jun Yang ◽  
Li Wang ◽  
Xuefen Yang ◽  
Kaiguo Gao ◽  
...  

Abstract Background Deoxynivalenol (DON) is a widespread mycotoxin that induces intestinal inflammation and oxidative stress in humans and animals. Resveratrol (RES) effectively exerts anti-inflammatory and antioxidant effects. However, the protective effects of RES on alleviating DON toxicity in piglets and the underlying mechanism remain unclear. Therefore, this study aimed to investigate the effect of RES on growth performance, gut health and the gut microbiota in DON-challenged piglets. A total of 64 weaned piglets [Duroc × (Landrace × Yorkshire), 21-d-old, 6.97 ± 0.10 kg body weight (BW)] were randomly allocated to 4 treatment groups (8 replicate pens per treatment, each pen containing 2 males; n = 16 per treatment) for 28 d. The piglets were fed a control diet (CON) or the CON diet supplemented with 300 mg RES/kg diet (RES group), 3.8 mg DON/kg diet (DON) or both (DON+RES) in a 2 × 2 factorial design. Results DON-challenged piglets fed the RES-supplemented diet had significantly decreased D-lactate concentrations and tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β) mRNA and protein expression, and increased zonula occludens-1 (ZO-1) mRNA and protein expression compared with those of DON-challenged piglets fed the unsupplemented diet (P < 0.05). Compared with unsupplemented DON-challenged piglets, infected piglets fed a diet with RES showed significantly decreased malondialdehyde (MDA) levelsand increased mRNA expression of antioxidant enzymes and antioxidant genes (i.e., GCLC, GCLM, HO-1, SOD1 and NQO-1) and glutamate-cysteine-ligase modulatory subunit (GCLM) protein expression (P < 0.05). Moreover, RES supplementation significantly abrogated the increase in the proportion of TUNEL-positive cells and the protein expression of caspase3 in DON-challenged piglets (P < 0.05). Finally, RES supplementation significantly increased the abundance of Roseburia and butyrate concentrations, while decreasing the abundances of Bacteroides and unidentified-Enterobacteriaceae in DON-challenged piglets compared with DON-challenged piglets alone (P < 0.05). Conclusions RES supplementation improved gut health in DON-challenged piglets by strengthening intestinal barrier function, alleviating intestinal inflammation and oxidative damage, and positively modulating the gut microbiota. The protective effects of RES on gut health may be linked to increased Roseburia and butyrate concentrations, and decreased levels of Bacteroides and unidentified-Enterobacteriaceae.


2018 ◽  
Vol 1 (3) ◽  
Author(s):  
Shiqiang Wang

Objective To investigate the effects of exercise on the myocardial oxidative stress injury of diabetic rats, and discussed the role of Keap1/Nrf2 signaling pathway in this process Methods  Tyep 2 diabetic rat model was established by streptozotocin injection through abdominal cavity and high fat diet. The all the diabetic rats were divided into three groups: control group (NC), diabetes group(T2DM) and diabetes exercise group, NC and T2DM group were kept quiet for 8 weeks, T2DME group was trained for 8 weeks. After the exercise, weight, heart weight and blood were measured. MDA, T-SOD and GSH-PX enzyme were measured by biochemical method. Ho-1, Keap1, Nrf2 gene and protein expression were detected by RT-PCR and WesternBlotting. Results Compared with NC group, the weight of rats in the T2DM group significantly decreased [(528+/-71g vs 362+/-33g), P<0.05], HWI  significantly increased [(2.845+/-0.22 vs 3.841+/-0.21, P <0.05], blood glucose was significantly increased [(6.4±3.8 vs 26±7.5mmol/L), P <0.01],T-SOD and GSH-PX activity decreased significantly (P<0.05), Ho-1 protein expression increased (P<0.01), Keap1 and Nrf2 showed no significant changes, and Nrf2 nuclear transposition decreased (P<0.05). Compared with the T2DM group, no significant change in body weight and heart weight in the T2DME group, with significant decrease in HWI[(3.841±0.21 vs 3.235±0.23),P<0.05], with significant decrease in blood glucose [(26.0±7.5 vs 21.0±6.8),P<0.05]. Ho-1 gene and protein expression increased significantly(P<0.05and P<0.01), with no significant change of Keap1, while Nrf2 expression increased significantly (P < 0.05), and Nrf2 nuclear transposition increased significantly (P < 0.01). Conclusions Exercise activates the myocardial Keap1/Nrf2 signaling pathway in rats, promotes the expression of downstream antioxidant enzymes, increases cardiac antioxidant capacity, and resists diabetic myocardial oxidative stress injury.


2020 ◽  
Author(s):  
yutao guan ◽  
Fu-bin Zhang ◽  
Yan-qing Huang ◽  
Ling-ling Zhou ◽  
Wei-feng Li ◽  
...  

Abstract Background: Endometriosis is a progressive and benign disease characterized by the presence of endometrial glands and stroma tissue outside of the uterine cavity. Though endometriosis is a benign disease, it has the characteristics of malignant tumour growth. Abnormal expression of T-cadherin is involved in the occurrence and progression of many tumours. We aimed to investigate whether T-cadherin promotes the migration and invasion of endometriosis cells through the PI3K/AKT/mTOR signaling pathway. Methods: Ectopic and eutopic endometrial samples from 62 female patients with endometriosis and endometrial samples from 51 female patients without endometriosis were collected. The immortalized endometrial stromal cell line hEM15A was cultured. Real-time RT-PCR, immunohistochemistry and Western blot were used to detect the expression of T-cadherin, phospho-PI3K/Akt/mTOR and matrix metalloproteinase 2 (MMP-2). Transfection technology was employed to upregulate T-cadherin expression. The migration and invasion abilities of hEM15A cells were measured by the transwell assay with uncoated or Matrigel-coated membranes. Results: The mRNA and protein expression of T-cadherin was significantly decresed in the ectopic tissues of the patients with endometriosis, while the mRNA and protein expression in the eutopic endometrial tissues of the same patients did not significantly differ from that in the patients without endometriosis. The migration and invasion ability and phospho-PI3K/Akt/mTOR and MMP-2 expression levels were decreased in hEM15A cells with high T-cadherin expression compared with the corresponding parameters in the normal control group. However, everolimus and BEZ235 inhibited cell migration and invasion in cells with low T-cadherin expression, and weakened overexpression of T‑cadherin significantly attenuated MMP-2 protein expression. Conclusion: Loss of T-cadherin promotes cell migration and invasion in endometriosis via the PI3K/AKT/mTOR signalling pathway.


2018 ◽  
Vol 143 ◽  
pp. 9-18 ◽  
Author(s):  
Bei Li ◽  
Xiu Jing Feng ◽  
Xue Yuan Hu ◽  
Yong Ping Chen ◽  
Ji Chen Sha ◽  
...  

2018 ◽  
Vol 46 (6) ◽  
pp. 2250-2260 ◽  
Author(s):  
Chunming Jiang ◽  
Shenglin Ma ◽  
Runlei Hu ◽  
Xuepeng Wang ◽  
Maoqiang Li ◽  
...  

Background/Aims: Osteosarcoma, the most common primary bone malignancy, arises from primitive transformed cells of mesenchymal origin with the worldwide increasing morbidity and mortality. Previous studies found apoptosis of osteosarcoma cells was essential for an effective manner to improve the progress of osteosarcoma, and CXCR4 has been demonstrated to be relevant with various tumor progress and metastasis. Methods: The proliferation of cells transfected with CXCR4 shRNA and control shRNA were measured by BrdU assay. Apoptosis was detected by flow cytometry. Apoptotic protein expression levels were detected by Western blot. Caspase activity was detected by Colorimetric Assay Kits using microplate reader. Activation of NF-κβ signaling after CXCR4 down-regulation in osteosarcoma cells was examined by constructing NF-κβ promoter luciferase reporter plasmid. The expression and activation of NF-κβ Signaling relevant protein were analyzed to investigate the relationship between Akt and NF-κβ signaling after the down-regulation of CXCR4 in osteosarcoma cells. Results: Down-regulation of CXCR4 significantly reduced the cell proliferation, while remarkably increased the cell apoptosis and apoptotic protein expression levels in osteosarcoma cells. Furthermore, down-regulation of CXCR4 induced cell apoptosis was caspase dependent in osteosarcoma cells. This study also showed CXCR4 down-regulation induced apoptosis through inhibiting PI3K/Akt/NF-κβ signaling pathway. In addition, endoplasmic reticulum stress (ERS) activation was involved in cell apoptosis induced down-regulation of CXCR4. Knockdown of partial ERS relevant proteins followed down-regulation of CXCR4 significantly inhibited cell apoptosis and the apoptotic protein expression levels. Conclusions: Taken together, the results demonstrated that down-regulation of CXCR4 could induce apoptosis of human osteosarcoma cells through inhibiting PI3K/Akt/NF-κβ signaling pathway, indicating that CXCR4 could be vital for the clinical therapy of osteosarcoma.


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