Pin1 aggravates renal injury induced by ischemia and reperfusion in rats via Nrf2/HO-1 mediated endoplasmic reticulum stress

Purpose: To investigate the role of peptidyl-prolyl cis/trans isomerase 1 (Pin1) on renal ischemia-reperfusion (I/R) injury and underlying mechanism. Methods: By establishing the in vitro and in vivo models of renal I/R, the role of Pin1 was explored by using molecular assays. Results: In renal I/R, endogenous Pin1 level was up-regulated in I/R-impaired kidney. Suppression of Pin1 with juglone afforded protection against I/R-mediated kidney dysfunction, and reduced I/R-induced endoplasmic reticulum (ER) stress in vivo. Consistent with the in vivo results, repression of Pin1 with juglone or gene knockdown with si-Pin1 conferred cytoprotection and restricted hypoxia/reoxygenation (H/R)-driven ER stress in HK-2 cells. Simultaneously, further study uncovered that Nrf-2/HO-1 signals was the association between Pin1 and ER stress in response to renal I/R. In addition, Nrf-2/HO-1 signal pathway was inactivated after kidney exposed to I/R, as indicated by the down-regulation of Nrf-2/HO-1 levels. Furthermore, inhibition of Pin1 remarkably rescued the inactivation ofNrf-2/HO-1. Conclusions: Pin1 modulated I/R-mediated kidney injury in ER stress manner dependent on Nrf2-HO-1 pathway in I/R injury.

Mesenchymal stem cells have ameliorative effect on the colitis model via Nrf2/HO-1 pathway

Purpose: To evaluate the ameliorative effect of mesenchymal stem cells (MSCs) on acetic acid colitis model via Nrf2/HO-1 pathway in rats. Methods: In this study, 30 rats were divided into three groups. Acute colitis was induced by rectal administration of 4% solution of acetic acid. MSCs were injected intraperitoneally in the treatment group. Results: Increased levels of tumor necrosis factor-α (TNF-α), pentraxin-3, and malondialdehyde (MDA) in colitis group were revealed biochemically. Increased level of TNF-α and decreased levels of Nrf2 and interleukin-10 (IL-10) were observed in rectum tissues. Increased fibrous tissue proliferation, vascularization and inflammatory cell infiltration were described in the colitis group. Significant improvement was observed in MSCs treated group histopathologically. Increased immunopositivity of TNF-α, vascular endothelial growth factor (VEGF) and CD68 markers was observed in the colitis group cells, and decreased level of this positivity was observed in MSCs treated group. Conclusions: Biochemical, histopathological and immunohistochemical results strongly support the ameliorative effect of MSCs against acetic induced colitis model via Nrf2/HO-1 pathway in rats.

A Network Pharmacology-Based Study on Antidepressant Effect of Salicornia europaea L. Extract with Experimental Support in Chronic Unpredictable Mild Stress Model Mice / 中国结合医学杂志

OBJECTIVE@#To investigate the pharmacodynamic material basis, mechanism of actions and targeted diseases of Salicornia europaea L. (SE) based on the network pharmacology method, and to verify the antidepressant-like effect of the SE extract by pharmacological experiments.@*METHODS@#Retrieval tools including Chinese medicine (CM), PubMed, PharmMapper, MAS 3.0 and Cytoscape were used to search the components of SE, predict its targets and related therapeutic diseases, and construct the "Component-Target-Pathway" network of SE for central nervous system (CNS) diseases. Further, protein-protein interaction (PPI) network, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) function annotation of depression-related targets were analyzed to predict the antidepressant mechanism of SE. Chronic unpredictable mild stress (CUMS) model was used to construct a mouse model with depression-like symptoms. And the animals were randomly divided into 6 groups (n=10) including the normal group (nonstressed mice administered with distilled water), the CUMS group (CUMS mice administered with distilled water), the venlafaxine group (CUMS mice administered with venlafaxine 9.38 mg/kg), SE high-, medium-, and low-dose groups (CUMS mice administered with SE 1.8, 1.35 and 0.9 g/kg, respectively). Then some relevant indicators were determined for experimental verification by the forced swim test (FST), the tail suspension test (TST) and open-field test (OFT). Dopamine (DA) concentration in hippocampus and cerebral cortex, IL-2 and corticosterone (CORT) levels in blood, and nuclear factor E2 related factor 2 (Nrf2), kelch-like epichlorohydrin related protein 1 (Keap1), NAD(P) H dehydrogenase [quinone] 1 (NQO1) and heme oxygenase-1 (HO-1) levels in mice were measured by enzyme linked immunosorbent assay (ELISA) and Western blot respectively to explore the possible mechanisms.@*RESULTS@#The "target-disease" network diagram predicted by network pharmacology, showed that the potential target of SE involves a variety of CNS diseases, among which depression accounts for the majority. The experimental results showed that SE (1.8, 1.35 g/kg) significantly decreased the immobility period, compared with the CUMS group in FST and TST in mice after 3-week treatment, while SE exhibited no significant effect on exploratory behavior in OFT in mice. Compared with CUMS group, the SE group (0.9 g/kg) showed significant differences (P<0.05) in DA levels in the hippocampus and cerebral cortex. In addition, compared with CUMS control group, SE (1.8 g/kg) group showed a significant effect on decreasing the activities of CORT (P<0.05), and serum IL-2 level with no statistical significance. Finally, Western blot results showed that compared with the model group, Nrf2, Keap1, NQO1 and HO-1 protein expressions in SE group (1.8 g/kg) were up-regulated (all P<0.01).@*CONCLUSION@#The SE extract may have an antidepressant effect, which appeared to regulate Nrf2-ARE pathway and increased levels of DA and CORT in the hippocampus and cortex.

Berberine alleviates programmed necrosis of metabolic-associated fatty liver disease via activating Nrf2 pathway in mice / 中华肝脏病杂志

Objective: To investigate the effect of berberine on programmed necrosis of hepatocytes induced by metabolic-associated fatty liver disease (MAFLD) in mice and its related molecular mechanism. Methods: Twenty male C57BL/6N mice were randomly divided into four groups (n=5 in each group): control group (S), fatty liver group (H), berberine group(B), nuclear factor erythroid 2-related factor 2 inhibitor group (Nrf2), and all-trans-retinoic acid (ATRA) group (A). Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), triglycerides (TG), total cholesterol (TC), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) concentrations were detected at the end of week 12 to calculate fatty liver index (liver mass/body mass ratio). Liver tissue was stained with HE, Masson and Oil Red O, and SAF score was used to evaluate the degree of liver injury. The expression levels of hepatic programmed necrosis-related proteins, namely receptor-interacting protein kinase 3 (RIPK3), phosphorylated mixed series protease-like domain (p-MLKL) and Nrf2 were detected by Western blot method. One-way ANOVA was used for intragroup comparisons and LSD-t tests were used for intergroup comparisons. Results: Compared with S group, H group serum ALT, AST, LDH, TG, TC, TNF-α, IL-1β levels and fatty liver index were significantly increased. The liver tissue was filled with vacuolar-like changes and inflammatory cell infiltration. Numerous red lipid droplets were observed with oil red O staining. Collagen fiber hyperplasia was evident with Masson staining. SAF scores (6.60 ± 0.55 and 0.80 ± 0.45) were significantly increased. The expressions of RIPK3 and p-MLKL were up-regulated. Nrf2 level was relatively increased, and the differences were statistically significant (P < 0.05). Compared with H group, berberine intervention group liver biochemical indexes, lipid levels, pro-inflammatory mediator expression, fatty liver index, and SAF score were significantly reduced, and the expression of RIPK3 and p-MLKL were down-regulated, while Nrf2 levels were further increased, and the differences were statistically significant (P<0.05). Compared with B group, treatment with Nrf2 inhibitor had antagonized the protective effect of berberine on fatty liver. Serum ALT, AST, LDH, TG, TC and TNF-α, IL-1β levels, fatty liver index, and SAF scores were significantly increased and the expressions of RIPK3 and p-MLKL were relatively increased, and the differences were statistically significant (P < 0.05). Conclusion: Berberine can significantly improve the metabolic-associated fatty liver disease injury in mice, and its mechanism is related to activation of Nrf2 and inhibition of programmed necrosis of hepatocytes.

Four-Octyl itaconate ameliorates periodontal destruction via Nrf2-dependent antioxidant system / 国际口腔科学杂志·英文版

Periodontitis is a widespread oral disease characterized by continuous inflammation of the periodontal tissue and an irreversible alveolar bone loss, which eventually leads to tooth loss. Four-octyl itaconate (4-OI) is a cell-permeable itaconate derivative and has been recognized as a promising therapeutic target for the treatment of inflammatory diseases. Here, we explored, for the first time, the protective effect of 4-OI on inhibiting periodontal destruction, ameliorating local inflammation, and the underlying mechanism in periodontitis. Here we showed that 4-OI treatment ameliorates inflammation induced by lipopolysaccharide in the periodontal microenvironment. 4-OI can also significantly alleviate inflammation and alveolar bone loss via Nrf2 activation as observed on samples from experimental periodontitis in the C57BL/6 mice. This was further confirmed as silencing Nrf2 blocked the antioxidant effect of 4-OI by downregulating the expression of downstream antioxidant enzymes. Additionally, molecular docking simulation indicated the possible mechanism under Nrf2 activation. Also, in Nrf2-/- mice, 4-OI treatment did not protect against alveolar bone dysfunction due to induced periodontitis, which underlined the importance of the Nrf2 in 4-OI mediated periodontitis treatment. Our results indicated that 4-OI attenuates inflammation and oxidative stress via disassociation of KEAP1-Nrf2 and activation of Nrf2 signaling cascade. Taken together, local administration of 4-OI offers clinical potential to inhibit periodontal destruction, ameliorate local inflammation for more predictable periodontitis.

Anti-oxidative and anti-apoptotic effects and molecular mechanisms of catalpol against H_2O_2-induced oxidative damage in pancreatic β cells (INS-1 cells) / 中国中药杂志

The present study investigated the anti-oxidative and anti-apoptotic effects and molecular mechanisms of catalpol on the H_2O_2-induced pancreatic β-cells(INS-1 cells).The oxidative damage model of INS-1 cells was induced and optimized by the stimulation of H_2O_2 of different concentrations for different time.CCK-8 assay was used to detect cell viability after catalpol intervention(1, 5, 10, 20, 40, 80, and 160 μmol·L~(-1)) for 24 h.Intracellular reactive oxygen species(ROS), superoxide dismutase(SOD), and lipid peroxide malondialdehyde(MDA) were measured by DCFH-DA fluorescent probe, WST-1, and TBA respectively.Moreover, the apo-ptotic effect was detected by AO-EB and Annexin V-FITC/PI staining.In addition, the protein expression levels were detected by Wes-tern blot, and intracellular insulin concentration was measured by ELISA.The results showed that the oxidative damage model of INS-1 cells was stably induced by 50 μmol·L~(-1) H_2O_2 treatment for 2 h, and catalpol at 1-80 μmol·L~(-1) did not affect cell viability of INS-1 cells.Compared with the conditions in the model group, 1, 5, and 10 μmol·L~(-1) catalpol intervention for 2 h could protect INS-1 cells from oxidative damage(P<0.001), reduce ROS and MDA, increase SOD, and inhibit excessive cell apoptosis.Moreover, 1, 5, and 10 μmol·L~(-1) catalpol could also up-regulate the phosphorylation of nuclear transcription factor NF-E2 related factors, negatively regulate Kelch-like ECH-associated protein 1(Keap1), phosphorylation of extracellular signal-regulated kinase(ERK), and heme oxyge-nase 1(HO-1), and promote the protein expression of pancreatic-duodenal homeobox factor-1(PDX-1) and glucose transporter 2(GLUT2).In addition, 1, 5, and 10 μmol·L~(-1) catalpol increased insulin secretion of INS-1 cells under oxidative damage in the high-glucose culture medium, indicating function recovery of pancreatic β cells.PDX-1 is a key nuclear transcription factor of pancreatic β cell function that directly regulates GLUT2 and insulin synthesis, and affects glucose homeostasis.In conclusion, catalpol can reduce the oxidative damage and apoptosis of INS-1 cells, activate antioxidant pathway, protect the function of pancreatic β cells, and improve insulin synthesis and secretion.

Protective effects of Polygonatum odoratum polysaccharides on alcohol-induced injury of HepG2 cells and its mechanisms / 中国应用生理学杂志

Objective: To investigate the protective effects of Polygonatum odoratum polysaccharides (POP) on alcohol-induced injury of HepG2 cells and its potential molecular mechanisms. Methods: After screening the appropriate concentration of alcohol-treated HepG2 cells and the intervention concentration of POP by MTT method, HepG2 cells were divided into three groups according to different intervention concentrations (200 μg/L, 400 μg/L and 600 μg/L) of POP, and the blank group without POP. After pretreated for 1 h, HepG2 cells were treated with 4% alcohol for 24 h. The activities of intracellular alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured, and the levels of intracellular reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH), interleukin-1β (IL-1β) and tumor necrosis factor α (TNF- α) were measured. The protein expressions of Kelch-like epichlorohydrin-associated protein-1 (Keap1), phosphorylated nuclear factor E2-related factor 2 (p-Nrf2), phosphoamide adenine dinucleotide quinone oxidoreductase -1 (NQO1), B lymphocyte tumor-2 (Bcl-2), Bcl-2-associated X protein (Bax) and caspase 3 were detected. Results: Compared with the HepG2 cells treated with 4% alcohol, POP at the various concentrations could effectively down-regulate the activities of ALT and AST in HepG2 cells induced by alcohol (P＜0.05). The levels of IL-1β and TNF-α in the 200 μg/L POP treated group were decreased significantly (P＜0.05), while the level of GSH was increased significantly (P＜0.01). The levels of ROS, MDA, IL-1β and TNF-α in the 400 μg/L and 600 μg/L POP treated groups were decreased significantly (P＜0.05 or P＜0.01), while the GSH level was increased significantly (P＜0.01). POP effectively up-regulated the expressions of p-Nrf2 and NQO1 protein in HepG2 cells induced by alcohol, and also down-regulated the Bax/Bcl-2 index (P＜0.05), and inhibited the protein expressions of Keap1 and cleaved-caspase-3 (P＜0.05). Conclusion: POP can improve alcohol-induced oxidative stress injury in HepG2 cells by regulating the Nrf2/Keap1 pathway, thereby reducing the inflammatory index and apoptosis level of HepG2 cells. Among them, 400 μg/L and 600 μg/L POP have better intervention effects.

Honokiol reduces doxorubicin-induced cardiotoxicity in vitro by inhibiting pyroptosis via activating AMPK/Nrf2 signaling / 南方医科大学学报

OBJECTIVE@#To investigate the effect of honokiol (HKL) for reducing doxorubicin (DOX)-induced cardiotoxicity in H9c2 cells and the underlying mechanisms.@*METHODS@#H9c2 cells were divided into control group, DOX group, HKL + DOX group, and HKL+compound C+DOX group. After 24 h of corresponding treatment, the cells were examined for morphological changes and cell viability using CCK-8 assay. The mRNA expressions of the inflammatory factors including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) were detected by RT-PCR, and the protein levels of cleaved caspase-3, cytochrome c, NOD-like receptor pyrin domain containing 3 (NLRP3), caspase-1, apoptosis-associated speck-like protein containing a CARD (ASC), p-AMPK and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) were detected with Western blotting; the expressions of NLRP3 and p-AMPK also detected with immunofluorescence staining.@*RESULTS@#DOX treatment caused swelling and significantly lowered the viability of H9c2 cells (P < 0.05), resulting also in increased mRNA expressions of TNF-α, IL-6 and IL-1β (P < 0.05) and protein expressions of cleaved caspase-3, cytochrome c, NLRP3, caspase-1 and ASC (P < 0.05) but reduced protein levels of p-AMPK and Nrf2 (P < 0.05); fluorescence staining showed significantly increased NLRP3 expression and decreased expression of p-AMPK in DOX-treated cells (P < 0.05). All these changes in COX-treated cells were significantly alleviated by HKL treatment (P < 0.05). The application of compound C obviously mitigated the protective effects of HKL against DOX-induced cardiotoxicity in H9c2 cells.@*CONCLUSIONS@#HKL can alleviate DOX-induced cardiotoxicity by inhibiting pyroptosis in H9c2 cells, and this effect is mediated by activation of AMPK to regulate Nrf2 signaling.

Effects and mechanism of human umbilical vein endothelial cells-derived exosomes on wound healing in diabetic rabbits / 中华烧伤杂志

Objective: The investigate the effects and mechanism of exosomes derived from human umbilical vein endothelial cells (HUVECs) on wound healing in diabetes rabbits. Methods: The experimental research methods were used. The primary vascular endothelial cells (VECs) and human skin fibroblasts (HSFs) were extracted from skin tissue around ulcer by surgical excision of two patients with diabetic ulcer (the male aged 49 years and the female aged 58 years) admitted to Xiangya Third Hospital of Central South University in June 2019. The cells were successfully identified through morphological observation and flow cytometry. The HUVEC exosomes were extracted by ultracentrifugation and identified successfully by morphological observation, particle size detection, and Western blotting detection. Twenty female 3-month-old New Zealand rabbits were taken to create one type 2 diabetic full-thickness skin defect wound respectively on both sides of the back. The wounds were divided into exosomes group and phosphate buffer solution (PBS) group and treated accordingly, with 20 wounds in each group, the time of complete tissue coverage of wound was recorded. On PID 14, hematoxylin-eosin staining or Masson staining was performed to observe angiogenesis or collagen fiber hyperplasia (n=20). The VECs and HSFs were co-cultured with HUVEC exosomes for 24 h to observe the uptake of HUVEC exosomes by the two kinds of cells. The VECs and HSFs were divided to exosome group treated with HUVEC exosomes and PBS group treated with PBS to detect the cell proliferation on 4 d of culture with cell count kit 8, to detect and calculate the cell migration rate at 24 and 48 h after scratch by scratch test, to detect the cell migration number at 24 h of culture with Transwell test, and to detect the mRNA expressions of nuclear factor-erythroid 2-related factor 2 (NRF2) and transcription activating factor 3 (ATF3) by real time fluorescence quantitative reverse transcription polymerase chain reaction. Besides, the number of vascular branches and vascular length were observed in the tube forming experiment after 12 h of culture of VECs (n=3). The VECs and HSFs were taken and divided into PBS group and exosome group treated as before, and NRF2 interference group, ATF3 interference group, and no-load interference group with corresponding gene interference. The proliferation and migration of the two kinds of cells, and angiogenesis of VECs were detected as before (n=3). Data were statistically analyzed with analysis of variance for repeated measurement, one-way analysis of variance, independent sample t test, and least significant difference test. Results: The time of complete tissue coverage of wound in exosome group was (17.9±1.9) d, which was significantly shorter than (25.2±2.3) d in PBS group (t=4.54, P<0.05). On PID14, the vascular density of wound in PBS group was significantly lower than that in exosome group (t=10.12, P<0.01), and the collagen fiber hyperplasia was less than that in exosome group. After 24 h of culture, HUVEC exosomes were successfully absorbed by VECs and HSFs. The proliferative activity of HSFs and VECs in exosome group was significantly higher than that in PBS group after 4 d of culture (with t values of 54.73 and 7.05, respectively, P<0.01). At 24 and 48 h after scratch, the migration rates of HSFs (with t values of 3.42 and 11.87, respectively, P<0.05 or P<0.01) and VECs (with t values of 21.42 and 5.49, respectively, P<0.05 or P<0.01) in exosome group were significantly higher than those in PBS group. After 24 h of culture, the migration numbers of VECs and HSFs in exosome group were significantly higher than those in PBS group (with t values of 12.31 and 16.78, respectively, P<0.01). After 12 h of culture, the mRNA expressions of NRF2 in HSFs and VECs in exosome group were significantly higher than those in PBS group (with t values of 7.52 and 5.78, respectively, P<0.05 or P<0.01), and the mRNA expressions of ATF3 were significantly lower than those in PBS group (with t values of 13.44 and 8.99, respectively, P<0.01). After 12 h of culture, the number of vascular branches of VECs in exosome group was significantly more than that in PBS group (t=17.60, P<0.01), and the vascular length was significantly longer than that in PBS group (t=77.30, P<0.01). After 4 d of culture, the proliferation activity of HSFs and VECs in NRF2 interference group was significantly lower than that in PBS group and exosome group (P<0.05 or P<0.01); the proliferation activity of HSFs and VECs in ATF3 interference group was significantly higher than that in PBS group (P<0.05 or P<0.01) and significantly lower than that in exosome group (P<0.05 or P<0.01). At 24 and 48 h after scratch, the migration rates of HSFs and VECs in ATF3 interference group were significantly higher than those in PBS group (P<0.05 or P<0.01) and significantly lower than those in exosome group (P<0.05 or P<0.01). At 24 and 48 h after scratch, the migration rates of HSFs and VECs in NRF2 interference group were significantly lower than those in PBS group and exosome group (P<0.05 or P<0.01). After 24 h of culture, the migration numbers of VECs and HSFs in ATF3 interference group were significantly more than those in PBS group (P<0.05) and significantly less than those in exosome group (P<0.05 or P<0.01); the migration numbers of VECs and HSFs in NRF2 interference group were significantly less than those in PBS group and exosome group (P<0.01). After 12 h of culture, the vascular length and number of branches of VECs in NRF2 interference group were significantly decreased compared with those in PBS group and exosome group (P<0.01); the vascular length and number of branches of VECs in ATF3 interference group were significantly increased compared with those in PBS group (P<0.01) and were significantly decreased compared with those in exosome group (P<0.01). Conclusions: HUVEC exosomes can promote the wound healing of diabetic rabbits by promoting the proliferation and migration of VECs and HSFs, and NRF2 and ATF3 are obviously affected by exosomes in this process, which are the possible targets of exosome action.

Study on the Protective effect and mechanism of Nicotinamide Riboside on lung injury in paraquat intoxicated mice / 中华劳动卫生职业病杂志

Objective: To investigate the protective effect and mechanism of Nicotinamide Riboside (NR) on lung injury caused by Paraquat intoxicated mice. Methods: Eighty clean male BALB/C mice were selected and averagely divided forty mice into 4 groups with 10 mice in each group, PQ group was given 25% PQ solution (60 mg/kg) by one-time gavage. PQ+NR group were intraperitoneally injected with NR solution (300 mg/kg) 1 hour before given the same amount of PQ solution (60 mg/kg) by one-time gavage, The Control group were given the same amount of saline by one-time gavage, The same amount of NR was intraperitoneally injected before NR group were given saline by one-time gavage. Observed and recorded general condition of PQ intoxicated mice. Observed and recorded the death of mice every half an hour and counted the mortality and drew survival curve of each group after 72 hours exposure. another forty mice were averagely divided and treated by the same way. After 24 hours of modelling, mice were anaesthetized and killed. Then blood was extracted after eyeball was removed. The changes of TNF-a、IL-6 and MPO in serum of mice were detected by ELISA.Two lung tissues were removed from the chest and used to measure the D/W ratio of the lung. The pathological changes of lung were observed and scored under light microscope.The levels of SOD, MDA and Caspase-3 in lung tissues were determined by chemical colorimetry. The expression of Sirt1 and Nrf2 in lung tissues was detected by Western-blot. Results: Compared with the Control group and the NR group, the mice in the PQ group had a poor general condition, such as depression, crouching, skin disorder and reduced activity, food, urine and feces. The symptoms in the PQ+NR group were reduced compared with the PQ group. The survival rate at 72 hours after exposure: 80% in the PQ+NR group and 40% higher than that in the PQ group (P=0.029) . Compared with Control group and NR group, the D/W ratio (0.09±0.07) , lung pathology score under light microscope (11.80±0.37) , TNF-a (39.89±1.48) pg/ml、IL-6 (77.29±2.38) pg/ml、MPO (0.31±0.01) μg/ml、SOD (6.62±0.30) U/mgprot、MDA level (1.21±0.14) mmol/mgprot, Caspase-3 activity (356.00± 27.16) %, Sirt1 and Nrf2 protein expression (1.02±0.14、0.82±0.06) were significantly decreased in PQ group (P=0.004、0.023) ; Compared with PQ group, PQ+NR group significantly increased the D/W ratio (0.10±0.10) , decreased the pulmonary pathology score under light microscope (7.400.51) , decreased TNF-a (33.00± 0.65) pg/ml、IL-6 (52.23±4.23) pg/ml、MPO leve (0.23±0.01) μg/mll, increased SOD leve (9.28±0.45) U/mgprotl, decreased MDA level (0.78±0.02) mmol/mgprot, decreased Caspase-3 activity (222.80±7.59) %, and increased the protein expressions of Sirt1 and Nrf2 (1.62±0.16、1.06±0.04) (P=0.048、0.035) . Conclusion: NR can prolong the survival time of PQ poisoned mice; NR intervention can effectively inhibit the inflammatory response, peroxidation injury and apoptosis of PQ poisoned mice; NR intervention can upregulate the expression of Sirt1 and Nrf2 protein and effectively reduce the lung injury of PQ poisoning.

Apigenin alleviates neomycin-induced oxidative damage via the Nrf2 signaling pathway in cochlear hair cells / 医学前沿

Oxidative stress plays an important role in the pathogenesis of aminoglycoside-induced hearing loss and represents a promising target for treatment. We tested the potential effect of apigenin, a natural flavonoid with anticancer, anti-inflammatory, and antioxidant activities, on neomycin-induced ototoxicity in cochlear hair cells in vitro. Results showed that apigenin significantly ameliorated the loss of hair cells and the accumulation of reactive oxygen species upon neomycin injury. Further evidence suggested that the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway was activated by apigenin treatment. Disruption of the Nrf2 axis abolished the effects of apigenin on the alleviation of oxidative stress and subsequent apoptosis of hair cells. This study provided evidence of the protective effect of apigenin on cochlear hair cells and its underlying mechanism.

Shenmai Injection Attenuates Myocardial Ischemia/Reperfusion Injury by Targeting Nrf2/GPX4 Signalling-Mediated Ferroptosis / 中国结合医学杂志

OBJECTIVE@#To examine the effect of Shenmai Injection (SMJ) on ferroptosis during myocardial ischemia reperfusion (I/R) injury in rats and the underlying mechanism.@*METHODS@#A total of 120 SPF-grade adult male SD rats, weighing 220-250 g were randomly divided into different groups according to a random number table. Myocardial I/R model was established by occluding the left anterior descending artery for 30 min followed by 120 min of reperfusion. SMJ was injected intraperitoneally at the onset of 120 min of reperfusion, and erastin (an agonist of ferroptosis), ferrostatin-1 (Fer-1, an inhibitor of ferroptosis) and ML385 (an inhibitor of nuclear factor erythroid-2 related factor 2 (Nrf2)) were administered intraperitoneally separately 30 min before myocardial ischemia as different pretreatments. Cardiac function before ischemia, after ischemia and after reperfusion was analysed. Pathological changes in the myocardium and the ultrastructure of cardiomyocytes were observed, and the myocardial infarction area was measured. Additionally, the concentration of Fe2+ in heart tissues and the levels of creatine kinase-MB (CK-MB), troponin I (cTnl), malondialdehyde (MDA) and superoxide dismutase (SOD) in serum were measured using assay kits, and the expressions of Nrf2, glutathione peroxidase 4 (GPX4) and acyl-CoA synthetase long-chain family member 4 (ACSL4) were examined by Western blot.@*RESULTS@#Compared with the sham group, I/R significantly injured heart tissues, as evidenced by the disordered, ruptured and oedematous myocardial fibres; the increases in infarct size, serum CK-MB, cTnI and MDA levels, and myocardial Fe2+ concentrations; and the decreases in SOD activity (P<0.05). These results were accompanied by ultrastructural alterations to the mitochondria, increased expression of ACSL4 and inhibited the activation of Nrf2/GPX4 signalling (P<0.05). Compared with I/R group, pretreatment with 9 mL/kg SMJ and 2 mg/kg Fer-1 significantly reduced myocardial I/R injury, Fe2+ concentrations and ACSL4 expression and attenuated mitochondrial impairment, while 14 mg/kg erastin exacerbated myocardial I/R injury (P<0.05). In addition, cardioprotection provided by 9 mL/kg SMJ was completely reversed by ML385, as evidenced by the increased myocardial infarct size, CK-MB, cTnI, MDA and Fe2+ concentrations, and the decreased SOD activity (P<0.05).@*CONCLUSIONS@#Ferroptosis is involved in myocardial I/R injury. Pretreatment with SMJ alleviated myocardial I/R injury by activating Nrf2/GPX4 signalling-mediated ferroptosis, thereby providing a strategy for the prevention and treatment of ischemic heart diseases.

Progress of NRF2 Signaling Pathway in Promoting Proliferation of Non-small Cell Lung Cancer / 中国肺癌杂志

The morbidity and mortality of lung cancer ranks among the top cancers in the world. Non-small cell lung cancer (NSCLC) is the main pathological type of lung cancer, with limited treatment options and poor prognosis. The nuclear factor E2-related factor 2 (NRF2) signaling pathway is highly mutated and activated in NSCLC, and promotes the malignant progression of lung cancer through various mechanisms. NRF2-targeted therapy will provide new treatment strategies for patients with NSCLC. This article will review the basic structure and response pathways of the NRF2 pathway, the mechanism of NRF2 regulating lung cancer cell proliferation, and the research and development progress of NRF2 inhibitors.
.

Berberine inhibits erastin-induced ferroptosis of mouse hippocampal neuronal cells possibly by activating the Nrf2-HO-1/GPX4 pathway / 南方医科大学学报

OBJECTIVE@#To explore the mechanism by which berberine inhibits ferroptosis of mouse hippocampal neuronal cells (HT22).@*METHODS@#Cultured HT22 cells were pretreated with 30 or 60 μmol/L berberine for 2 h before exposure to 0.5 μmol/L erastin for 8 h, and the cell proliferation, intracellular ferric iron level, changes in intracellular reactive oxygen species (ROS) and cell apoptosis were detected using CCK-8, Fe2+ fluorescent probe, fluorescent dye (DAPI) and fluorescent probe (H2DCFH-DA). RT-qPCR and Western blotting were used to detect the mRNA and protein expressions of Nrf2, HO-1 and GPX4 in the cells. We further tested the effects of treatments with 2 μmol/L ML385 (a Nrf2 inhibitor), 60 μmol/L berberine and erastin in the cells to explore the protective mechanism of berberine against erastin-induced ferroptosis in the neuronal cells.@*RESULTS@#Treatment with 0.5 μmol/L erastin significantly lowered the viability of HT22 cells (P < 0.05) and increased the production of ROS, cell apoptosis rate and ferric iron level (P < 0.05). Pretreatment with 30 and 60 μmol/L berberine both significantly increased the vitality of erastin-exposed cells (P < 0.05) and lowered the levels of intracellular ROS and ferric iron content (P < 0.05). RT-qPCR and Western blotting showed that berberine obviously promoted the expressions of Nrf2, HO-1 and GPX4 in the cells (P < 0.05), and treatment with ML385 significantly inhibited the Nrf2-HO-1/GPX4 pathway, increased intracellular ROS and ferric iron contents and mitigated the protective effect of berberine against erastin-induced ferroptosis (P < 0.05).@*CONCLUSION@#Berberine can inhibit erastin-induced ferroptosis in HT22 cells possibly by activating the Nrf2-HO-1/ GPX4 pathway.

Effects of butyphthalide on microglia polarization after intracerebral hemorrhage and the underlying mechanisms / 中南大学学报(医学版)

OBJECTIVES@#Because intracerebral hemorrhage (ICH) has high morbidity, disability and mortality, it is significant to find new and effective treatments for ICH. This study aims to explore the effect of butyphthalide (NBP) on neuroinflammation secondary to ICH and microglia polarization.@*METHODS@#A total of 48 healthy male SD rats were randomly divided into 6 groups: a sham 24 h group, a sham 72 h group, an ICH 24 h group, an ICH 72 h group, an ICH+NBP 24 h group, and an ICH+NBP 72 h group (8 rats per group). After operation, the neurological deficiencies were assessed based on improved Garcia scores and corner test. The expressions of Toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB), nuclear factor erythroid 2-related factor 2 (Nrf2), aquaporin-4 (AQP4), zonula occludens-1 (ZO-1), occludin, CD68, CD86, and CD206 were observed by Western blotting. Inflammatory cytokines were detected by ELISA. The immunofluorescence was to detect the polarization of microglia.@*RESULTS@#1) Compared with the sham groups, the expression of TLR4 (24 h: P<0.05; 72 h: P<0.01), NF-κB (both P<0.01) and Nrf2 (both P<0.01) in the perihematoma of the ICH group was increased, leading to microglia activation (P<0.01). The expressions of IL-6 (24 h: P<0.05; 72 h: P<0.01) and TNF-α (both P<0.01), the pro-inflammatory cytokines were up-regulated, and the expression of anti-inflammatory cytokine IL-4 was down-regulated (both P<0.01). Besides, the expression of AQP4 was enhanced (both P<0.01). The protein level of tightly connected proteins (including ZO-1, occludin) was decreased (all P<0.01). The neurological function of the rats in the ICH group was impaired in the 2 time points (both P<0.01). 2) Compared with the sham group at 24 h and 72 h after the intervention of NBP, the expressions of TLR4 (both P<0.05) and NF-κB (both P<0.01) were significantly declined, and the expression of Nrf2 was further enhanced (both P<0.05) in the perihematoma of the ICH+NBP group. Furthermore, the expression of M1 microglia marker was inhibited (P<0.05), and the polarization of microglia to the M2 phenotype was promoted (P<0.01). 3) In terms of inflammation after ICH, the IL-4 expression in the ICH+NBP group was increased compared with the ICH group (24 h: P<0.05; 72 h: P<0.01); the expression of IL-6 was decreased significantly in the ICH+NBP 72 h group (P<0.01); the level of AQP4 was declined significantly in the ICH+NBP 24 h group (P<0.05), there was a downward trend in the 72-hour intervention group but without significant statistical difference. 4) Compared with the ICH group, the ZO-1 protein levels were increased (24 h: P<0.05; 72 h: P<0.01), and the symptoms of nerve defect were improved eventually (both P<0.05) in the ICH+NBP groups.@*CONCLUSIONS@#After ICH, the TLR4/NF-κB pathway is activated. The M1 microglia is up-regulated along with the release of detrimental cytokines, while the anti-inflammatory cytokines are down-regulated. The expression of AQP4 is increased, the tight junction proteins from the blood-brain barrier (BBB) is damaged, and the neurological function of rats is impaired. On the contrary, NBP may regulate microglia polarization to M2 phenotype and play a role in the neuroprotective effect mediated via inhibiting TLR4/NF-κB and enhancing Nrf2 pathways, which relieves the neuroinflammation, inhibits the expression of AQP4, repairs BBB, and improves neurological functional defects.

Protective Mechanism of Electroacupuncture on Peripheral Neurotoxicity Induced by Oxaliplatin in Rats / 中国结合医学杂志

OBJECTIVE@#To study the effect of electroacupuncture (EA) on oxaliplatin-induced peripheral neuropathy (OIPN) in rats.@*METHODS@#Male Sprague-Dawley rats were equally divided into 3 groups using a random number table: the control group, the OIPN group, and the EA (OIPN + EA) group, with 10 rats in each. The time courses of mechanical, cold sensitivity, and microcirculation blood flow intensity were determined. The morphology of the dorsal root ganglion (DRG) was observed by electron microscopic examination. The protein levels of nuclear factor E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and the transient receptor potential (TRP) protein family in DRGs were assayed by Western blot.@*RESULTS@#EA treatment significantly reduced mechanical allodynia and cold allodynia in OIPN rats (P<0.01). Notably, oxaliplatin treatment resulted in impaired microcirculatory blood flow and pathomorphological defects in DRGs (P<0.01). EA treatment increased the microcirculation blood flow and attenuated the pathological changes induced by oxaliplatin (P<0.01). In addition, the expression levels of Nrf2 and HO-1 were down-regulated, and the TRP protein family was over-expressed in the DRGs of OIPN rats (P<0.01). EA increased the expression levels of Nrf2 and HO-1 and decreased the level of TRP protein family in DRG (P<0.05 or P<0.01).@*CONCLUSION@#EA may be a potential alternative therapy for OIPN, and its mechanism may be mainly mediated by restoring the Nrf2/HO-1 signaling pathway.

Protective Effects of Anthocyanins Extracted from Vaccinium Uliginosum on 661W Cells Against Microwave-Induced Retinal Damage / 中国结合医学杂志

OBJECTIVE@#To study the protective effect of anthocyanins extracted from Vaccinium Uliginosum (VU) on retinal 661W cells against microwave radiation induced retinal injury.@*METHODS@#661W cells were divided into 6 groups, including control, model [661W cells radiated by microwave (30 mW/cm2, 1 h)] and VU groups [661W cells pretreated with anthocyanins extracted from VU (25, 50, 100 and 200 µg/mL, respectively) for 48 h, and radiated by microwave 30 mW/cm2, 1 h]. After treatment with different interventions, the cell apoptosis index (AI) was determined using Heochst staining; contents of malonaldehyde (MDA), glutataione (GSH), and activity of superoxide dismutase (SOD) were measured. mRNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1(HO-1) were detected by real time quantitative polymerase chain reaction, and the expression of HO-1 protein was examined by Western blot analysis. Nucleus and cytoplasm were separated and Nrf2 protein expression was further verified by Western blot analysis.@*RESULTS@#There was significant difference in AI among the groups (F=322.83, P<;0.05). Compared with the control group, AI was significantly higher in the model group and was lower in 4 VU-pretreated groups (P<;0.05). Linear regression analysis showed the decline of AI was in a dose-dependent manner with VU treatment (r=0.8419, P<;0.05). The MDA and GSH contents of 661W cells in VU-treated groups were significantly lower than the model group (P<;0.05). Compared with the model group, the SOD activity in the VU-treated groups (50, 100 and 200 µg/mL) was significantly higher (all P<;0.05). The Nrf2 and HO-1 mRNA expressions were slightly increased after irradiation, and obviously increased in 100 µg/mL VU-treated group. After irradiation, the relative expressions of HO-1 and Nrf2 proteins in nucleus were slightly increased (P<;0.05), and the changes in cytoplasm were not obvious, whereas it was significantly increased in both nucleus and cytoplasm in the VU treatment groups.@*CONCLUSIONS@#Anthocyanins extracted from VU could reduce apoptosis, stabilize cell membrane, and alleviate oxidant injury of mouse retinal photoreceptor 661W cells. The mechanism might be through activating Nrf2/HO-1 signal pathway and inducing HO-1 transcription and translation.

Fucoxanthin regulates Nrf2/Keap1 signaling to alleviate myocardial hypertrophy in diabetic rats / 南方医科大学学报

OBJECTIVE@#To investigate the protective effect of fucoxanthin (FX) against diabetic cardiomyopathy and explore the underlying mechanism.@*METHODS@#Rat models of diabetes mellitus (DM) induced by intraperitoneal injection of streptozotocin (60 mg/kg) were randomized into DM model group, fucoxanthin treatment (DM+FX) group and metformin treatment (DM+ Met) group, and normal rats with normal feeding served as the control group. In the two treatment groups, fucoxanthin and metformin were administered after modeling by gavage at the daily dose of 200 mg/kg and 230 mg/kg, respectively for 12 weeks, and the rats in the DM model group were given saline only. HE staining was used to examine the area of cardiac myocyte hypertrophy in each group. The expression levels of fibrotic proteins TGF-β1 and FN proteins in rat hearts were detected with Western blotting. In the cell experiment, the effect of 1 μmol/L FX on H9C2 cell hypertrophy induced by exposure to high glucose (HG, 45 mmol/L) was evaluated using FITC-labeled phalloidin. The mRNA expression levels of the hypertrophic factors ANP, BNP and β-MHC in H9C2 cells were detected using qRT-PCR. The protein expressions of Nrf2, Keap1, HO-1 and SOD1 proteins in rat heart tissues and H9C2 cells were determined using Western blotting. The DCFH-DA probe was used to detect the intracellular production of reactive oxygen species (ROS).@*RESULTS@#In the diabetic rats, fucoxanthin treatment obviously alleviated cardiomyocyte hypertrophy and myocardial fibrosis, increased the protein expressions of Nrf2 and HO-1, and decreased the protein expressions of Keap1 in the heart tissue (P < 0.05). In H9C2 cells with HG exposure, fucoxanthin significantly inhibited the enlargement of cell surface area, lowered the mRNA expression levels of ANP, BNP and β-MHC (P < 0.05), promoted Nrf2 translocation from the cytoplasm to the nucleus, and up-regulated the protein expressions its downstream targets SOD1 and HO-1 (P < 0.05) to enhance cellular antioxidant capacity and reduce intracellular ROS production.@*CONCLUSION@#Fucoxanthin possesses strong inhibitory activities against diabetic cardiomyocyte hypertrophy and myocardial fibrosis and is capable of up-regulating Nrf2 signaling to promote the expression of its downstream antioxidant proteins SOD1 and HO-1 to reduce the level of ROS.

Hyperoside protects mouse spermatocytes GC-2 cells from oxidative damage by activating the Keap1/Nrf2/HO-1 pathway / 南方医科大学学报

OBJECTIVE@#To study the protective effect of hyperoside (Hyp) against ydrogen peroxide (H2O2)- induced oxidative damage in mouse spermatocytes GC-2 cells and explore the role of the Keap1/Nrf2/HO-1 pathway in this protective mechanism.@*METHODS@#GC-2 cells were treated with 2.5 mmol/L azaacetylcysteine (NAC), 50, 100, and 200 μmol/L hyperoside, or the culture medium for 48 h before exposure to H2O2 (150 μmol/L) for 2 h. CCK-8 assay was used to detect the changes in cell viability, and cell apoptosis was analyzed using flow cytometry. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), catalase (CAT) activity and malondialdehyde (MDA) in the culture medium. Western blotting and RT-qPCR were used to detect the protein and mRNA expression levels of nuclear factor erythroid 2-related factor2 (Nrf2), Kelch-like ECH-associated protein 1 (Keap1), and heme oxygenase-1 (HO-1); the nuclear translocation of Nrf2 was detected using immunofluorescence assay.@*RESULTS@#Exposure to H2O2 significantly lowered the proliferation rate, reduced the activities of SOD, GSH and CAT, and obviously increased MDA content, cell apoptosis rate, and the expressions of Keap1 and Nrf2 mRNA and Keap1 protein in GC-2 cells (P < 0.05 or 0.01). Treatment of the cells prior to H2O2 exposure with either NAC or 200 μmol/L hyperoside significantly increased the cell proliferation rate, enhanced the activities of SOD, GSH-PX and CAT, and lowered MDA content and cell apoptosis rate (P < 0.05). Treatment with 200 μmol/L hyperoside significantly decreased the mRNA and protein expressions of Keap1 and increased the expressions of HO-1 mRNA and the protein expressions of Nrf2 and HO-1 (P < 0.05 or 0.01). Hyperoside also caused obvious nuclear translocation of Nrf2 in the cells (P < 0.05).@*CONCLUSION@#Hyperoside protects GC-2 cells against H2O2- induced oxidative damage possibly by activation of the Keap1/Nrf2/HO-1 signaling pathway.

Abdominal puncture drainage alleviates severe acute pancreatitis in rats by activating Nrf-2/HO-1 pathway and promoting autophagy / 南方医科大学学报

OBJECTIVE@#To assess the effect of early abdominal puncture drainage (APD) on autophagy and Nrf-2/HO-1 pathway in rats with severe acute pancreatitis (SAP) and explore the possibile mechanism.@*METHODS@#Thirty-two male SD rats were randomly divided into sham-operated (SO) group, SAP group with retrograde injection of 4% sodium taurocholate, APD group with insertion of a drainage tube into the lower right abdomen after SAP induction, and APD + ZnPP group with intraperitoneal injection of 30 mg/kg ZnPP 12 h before APD modeling. Blood samples were collected from the rats 12 h after modeling for analysis of amylase and lipase levels and serum inflammatory factors. The pathological changes of the pancreatic tissue were observed with HE staining. Oxidative stress in the pancreatic tissue was detected with colorimetry, and sub-organelle structure and autophagy in pancreatic acinar cells were observed by transmission electron microscopy. The expressions of autophagy-related proteins and Nrf-2/HO-1 pathway were detected using RT-PCR and Western blotting.@*RESULTS@#Compared with those in SAP group, the rats with APD treatment showed significantly alleviated pathologies in the pancreas, reduced serum levels of lipase, amylase and inflammatory factors, lowered levels of oxidative stress, and activated expressions of Nrf-2/HO-1 pathway in the pancreas. The ameliorating effect of ADP was significantly inhibited by ZnPP treatment before modeling. APD obviously reversed mitochondrial and endoplasmic reticulum damages and p62 accumulation induced by SAP.@*CONCLUSION@#APD treatment can suppress oxidative stress and repair impaired autophagy in rats with SAP by activating the Nrf-2/HO-1 pathway, thereby reducing the severity of SAP.