Research progress of traditional Chinese medicine in regulating Nrf2/HO-1 signaling pathway to interfere with myocardial ischemia-reperfusion injury / 中国药房

Myocardial ischemia-reperfusion injury （MIRI） is a serious complication of revascularization in patients with myocardial infarction. The nuclear factor erythroid 2-related factor 2 （Nrf2）/heme oxygenase-1 （HO-1） signaling pathway plays an important role in the pathological process of MIRI. Currently，research has found that traditional Chinese medicine has a good effect on myocardial injury caused by ischemia-reperfusion. Based on the Nrf2/HO-1 signaling pathway，this article summarizes the action mechanism of traditional Chinese medicine formulas and monomers in intervening with MIRI. It is found that traditional Chinese medicine formulas （Yixin formula，Wenyang tongmai formula，Dingxin formula Ⅰ），monomers such as terpenoids （ginkgolides， astragaloside Ⅳ，ginsenosides），phenols （brazilin，hematoxylin A，resveratrol） and quinones （aloe，emodin） can alleviate MIRI by activating the Nrf2/HO-1 signaling pathway，inhibiting oxidative stress and inflammatory reactions，etc.

Zarzio Ameliorates Non-alcoholic Fatty Liver Induced By a High Fat Diet in a Rat Experimental Model: A Histological and Immunohistochemical Study

SUMMARY: The therapeutic effect of a granulocyte-colony stimulating factor (G-CSF) biosimilar drug, zarzio, on non-alcoholic fatty liver disease (NAFLD) in a rat model was investigated in this study. Thirty-two rats were randomly divided into four groups. Groups I and II were fed a standard laboratory diet, whereas groups III and IV were fed a high fat diet (HFD) for 14 weeks. After 12 weeks of feeding, groups I and III were administered normal saline, and groups II and IV were intraperitoneally administered zarzio (200 mg/kg/day) for two consecutive weeks. Hematoxylin-eosin (H&E) staining was used to assess hepatic and pancreatic morphology in all groups, oil red O (ORO) staining for lipid accumulation, Masson's staining for fibrosis, and immunohistochemistry assay for hepatic protein expression of insulin receptor substrate 1 (IRS1), nuclear factor erythroid 2-related factor 2 (Nrf2), tumour necrosis factor alpha (TNF-α) and pancreatic caspase-3. The NAFLD rats (group III) developed hepatic steatosis with increased lipid accumulation, perisinusoidal fibrosis, upregulated IRS1, TNF-α (all P<0.05) without a significant increase in Nrf2 protein expression compared with normal control. In comparison, model rats treated with zarzio (group IV) showed significant rejuvenation of the hepatic architecture, reduction of fat accumulation, and fibrosis. This was accompanied by the upregulation of Nrf2, downregulation of IRS1 and TNF-α protein expression (all P<0.05). No correlation was detected between NAFLD and non-alcoholic fatty pancreas disease (NAFPD). However, the pancreatic β-cells in group III showed increased caspase-3 expression, which was decreased (P<0.05) in group IV. In conclusion, zarzio ameliorates NAFLD by improving the antioxidant capacity of liver cells, reducing hepatic IRS1, TNF-α protein expression and pancreatic β-cells apoptosis, suggesting that zarzio could be used as a potential therapy for NAFLD.

En este estudio se investigó el efecto terapéutico de un fármaco biosimilar del factor estimulante de colonias de granulocitos (G-CSF), zarzio, sobre la enfermedaddel hígado graso no alcohólico (NAFLD) en un modelo de rata. Treinta y dos ratas se dividieron aleatoriamente en cuatro grupos. Los grupos I y II fueron alimentados con una dieta estándar de laboratorio, mientras que los grupos III y IV fueron alimentados con una dieta alta en grasas (HFD) durante 14 semanas. Después de 12 semanas de alimentación, a los grupos I y III se les administró solución salina normal, y a los grupos II y IV se les administró zarzio por vía intraperitoneal (200 mg/kg/ día) durante dos semanas consecutivas. Se utilizó tinción de hematoxilina-eosina (H&E) para evaluar la morfología hepática y pancreática en todos los grupos, tinción con rojo aceite O (ORO) para la acumulación de lípidos, tinción de Masson para la fibrosis y ensayo de inmunohistoquímica para la expresión de la proteína hepática del sustrato 1 del receptor de insulina (IRS1), factor nuclear eritroide 2 relacionado con el factor 2 (Nrf2), factor de necrosis tumoral alfa (TNF-α) y caspasa-3 pancreática. Las ratas NAFLD (grupo III) desarrollaron esteatosis hepática con aumento de la acumulación de lípidos, fibrosis perisinusoidal, IRS1 y TNF-α regulados positivamente (todos P <0,05) sin un aumento significativo en la expresión de la proteína Nrf2 en comparación con el control normal. En comparación, las ratas modelo tratadas con zarzio (grupo IV) mostraron un rejuvenecimiento significativo de la arquitectura hepática, una reducción de la acumulación de grasa y fibrosis. Esto estuvo acompañado por la regulación positiva de Nrf2, la regulación negativa de la expresión de la proteína IRS1 y TNF-α (todas P <0,05). No se detectó correlación entre NAFLD y la enfermedad del páncreas graso no alcohólico (NAFPD). Sin embargo, las células β pancreáticas en el grupo III mostraron una mayor expresión de caspasa-3, que disminuyó (P <0,05) en el grupo IV. En conclusión, zarzio mejora la NAFLD al mejorar la capacidad antioxidante de las células hepáticas, reduciendo el IRS1 hepático, la expresión de la proteína TNF-α y la apoptosis de las células β pancreáticas, lo que sugiere que zarzio podría usarse como una terapia potencial para la NAFLD.

The effect of nuclear factor erythroid 2 related factor 2-induced inhibition of ferroptosis on hyperoxia lung injury / 中华实用儿科临床杂志

Objective:To observe the expression changes of nuclear factor erythroid 2 related factor 2 (Nrf2) and glutathione peroxidase (GPX4) in human pulmonary microvascular endothelial cells (HPMEC) under different experimental conditions, and to explore the role of Nrf2 in inhibiting ferroptosis in the process of alleviating hyperoxic lung injury(HLI).Methods:Hyperoxic model was established by hyperoxia exposure.HPMEC were treated with blank control (control group), oxygen exposure at the concentration of 950 mL/L (hyperoxia group), oxygen exposure at the concentration of 950 mL/L+ 10 μmol/L Ferrostatin (ferroptosis inhibitor group) and oxygen exposure at the concentration of 950 mL/L + 10 μmol/L ML385 (Nrf2 inhibitor group). Cell viability at 24 h and 48 h was tested by the Cell Counting Kit-8 assay, and reactive oxygen species (ROS) levels were detected by a commercial ROS kit.The mRNA and protein levels of Nrf2 and GPX4 were detected by real-time quantitative polymerase chain reaction and Western blot, respectively.Differences were analyzed using the Student′s t-test for a two-group comparison or one-way ANOVA test among groups. Results:(1)Compared with the control group, significantly decreased viability and increased ROS levels were detected in hyperoxia group.Meanwhile, the mRNA (24 h: 0.750±0.010 vs.1.010±0.160, 48 h: 0.690±0.050 vs.1.000±0.070) and protein levels of GPX4 (24 h: 0.160±0.010 vs.0.290±0.010, 48 h: 0.190±0.010 vs.0.250±0.010) at 24 h and 48 h were significantly downregulated, while the mRNA (24 h: 1.740±0.050 vs.1.000±0.050, 48 h: 2.130±0.020 vs.1.000±0.030) and protein levels of Nrf2 (24 h: 0.840±0.010 vs.0.480±0.010, 48 h: 0.840±0.010 vs.0.550±0.030) at 24 h and 48 h were significantly upregulated in hyperoxia group than those of control group (all P<0.05). (2)Compared with the hyperoxia group, significantly increased viability and decreased ROS levels were detected in ferroptosis inhibitor group.Meanwhile, the mRNA (24 h: 1.520±0.110, 48 h: 1.880±0.050) and protein levels of GPX4 (24 h: 0.290±0.010, 48 h: 0.250±0.004) at 24 h and 48 h were significantly upregulated, while the mRNA (24 h: 0.780±0.040, 48 h: 0.760±0.030) and protein levels of Nrf2 (24 h: 0.480±0.010, 48 h: 0.540±0.020) at 24 h and 48 h were significantly downregulated in ferroptosis inhibitor group than those of hyperoxia group (all P<0.05). (3)Compared with the hyperoxia group, significantly decreased viability and increased ROS levels were detected in Nrf2 inhibitor group.Meanwhile, the mRNA (24 h: 0.600±0.030, 48 h: 0.590±0.003) and protein levels of GPX4 (24 h: 0.150±0.001, 48 h: 0.180±0.001) at 24 h and 48 h were significantly downregulated, while the mRNA level of Nrf2 was significantly upregulated at 24 h (3.360±0.130), but downregulated at 48 h (1.430±0.130) (all P<0.05). No significant difference was detected in the protein level of Nrf2 at 24 h and 48 h between hyperoxia group and Nrf2 inhibitor group ( P>0.05). Conclusions:Ferroptosis is involved in the development of HLI, and Nrf2 is able to alleviate hyperoxic lung injury by inhibiting ferroptosis.Therefore, inhibition of ferroptosis by Nrf2 may provide a new therapeutic target for HLI.

Red light-emitting diode light mediated by the KEAP1-NRF2/HO-1 pathway induces osteogenic differentiation and attenuates the oxidative stress damage of human periodontal ligament stem cells induced by high glucose / 口腔疾病防治

Objective@# To explore the effects of red LED light mediated by the Kelch-like ECH-associated protein 1-nuclear factor erythroid 2-related factor 2/heme oxygenase-1 (KEAP1-NRF2/HO-1) pathway on osteogenic differentiation and oxidative stress damage of human periodontal ligament stem cells (hPDLSCs) induced by high glucose, which provides a basis for the application of red light-emitting diode (LED) light in cell antioxidative damage.@*Methods@#hPDLSCs were identified by flow cytometric analysis, alkaline phosphatase (ALP) staining and Alizarin red-S staining; hPDLSCs were pretreated in a high glucose environment for 48 hours and irradiated with 1, 3, or 5 J/cm2 red LED light. A CCK-8 assay was performed to choose the radiant exposure that had the strongest effect on promoting the cell proliferation rate for subsequent experiments. hPDLSCs were divided into a control group, a high glucose group and a high glucose+light exposure group. ALP staining, ALP activity, Alizarin red-S staining and quantitative calcified nodules were used to detect the osteogenic differentiation of hPDLSCs; qRT-PCR and Western blot were used to detect the gene and protein expression levels of ALP, runt-related transcription factor 2 (RUNX2) and osterix (OSX); the relative mRNA expression levels of antioxidant enzyme-related genes superoxide dismutase 2 (SOD2) and catalase (CAT) in hPDLSCs were detected by qRT-PCR; reactive oxygen species (ROS) levels were detected by fluorescence microscopy and flow cytometry; the tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) levels in cell supernatants were detected by ELISA; the NRF2-specific inhibitor ML385 was used to inhibit the NRF2 pathway; ALP staining and ALP activity were used to detect the markers of early osteogenic differentiation; qRT-PCR was used to detect the gene expression of ALP, RUNX2 and OSX; and the protein expression levels of KEAP1, NRF2 and HO-1 were detected by Western blot.@*Results @# Identified, and irradiant exposure of 5 J/cm2 was chosen for subsequent experiments. Red LED light irradiation (5 J/cm2) improved the osteogenic differentiation of hPDLSCs induced by high glucose (P<0.05), increased the mRNA and protein levels of ALP, RUNX2 and OSX (P<0.05), upregulated the mRNA expression levels of SOD2 and CAT (P<0.05), reduced the levels of ROS (P<0.05), and reduced TNF-α and IL-1β levels in the cell supernatants (P<0.05). When ML385 was added to inhibit the NRF2 pathway, the ALP activity of cells was decreased (P<0.05); the gene expression levels of ALP, RUNX2 and OSX were downregulated (P<0.05); the protein level of KEAP1 was upregulated (P<0.05); and the protein levels of NRF2 and HO-1 were downregulated (P<0.05)@*Conclusion@#Red LED light may promote the proliferation and osteoblastic differentiation of hPDLSCs induced by high glucose through the KEAP1-NRF2/HO-1 pathway and reduce the oxidative stress damage to hPDLSCs induced by high glucose.

Effect of Shenling Baizhusan on Alcoholic Liver Injury in Rats by Regulating Ferroptosis Based on Nrf2 Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo observe the effect of Shenling Baizhusan on the intervention of the nuclear factor erythroid 2-related factor 2 （Nrf2） signaling pathway by regulating ferroptosis in rats with alcoholic liver injury. MethodForty SD rats were randomly divided into model group， polyene phosphatidylcholine group， and high， medium， and low-dose Shenling Baizhusan groups， with 8 rats in each group. Another 8 SD rats were taken as blank group. The model group， polyene phosphatidylcholine group， high， medium， and low-dose Shenling Baizhusan groups were given 10 mL·kg-1 liquor by gavage for modeling， and the blank group was given equal volume of distilled water by gavage. After 4 h of daily alcoholic administration， 143.64 mg·kg-1 of polyene phosphatidylcholine group was given to the polyene phosphatidylcholine group， 15， 7.5， 3.75 mg·kg-1 of Shenling Baizhusan were given to Shenling Baizhusan high， medium， and low-dose groups， respectively， and the blank group and the model group were given equal volume of distilled water. The gavage lasted for 6 weeks. The levels of alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， glutamyl transpeptidase （GGT）， total cholesterol （TC）， and triglyceride （TG） were detected by automatic biochemical analyzer. The levels of tumor necrosis factor-α （TNF-α） and interleukin-β （IL-β） were detected by the enzyme-linked immunosorbent assay （ELISA）. The levels of lipopolysaccharide （LPS）， malondialdehyde （MDA）， superoxide dismutase （SOD）， glutathione （GSH）， and Fe+ were detected by biochemical assay. The pathological changes in the liver were observed by hematoxylin-eosin （HE） staining and oil red O staining. The mRNA expression levels of Nrf2， heme oxygenase-1 （HO-1）， glutathione peroxidase 4 （GPX4）， ferritin heavy polypeptide 1 （FTH1）， and nuclear factor-κB （NF-κB） were detected by Real-time polymerase chain reaction （Real-time PCR）. The protein expression levels of Nrf2， HO-1， GPX4， FTH1， p65， and phosphorylation （p）-p65 were detected by Western blot. ResultAs compared with the blank group， the levels of liver function （ALT， AST， and GGT） and blood lipids （TC and TG） in the model group were significantly increased （P<0.05）. The liver showed obvious steatosis， with a large number of fat deposition， the oxidative stress and inflammatory factors were significantly increased （P<0.05）， and the level of Fe+ was significantly increased in model group （P<0.05）. The protein expression levels of Nrf2， HO-1， GPX4， and FTH1 was significantly down-regulated （P<0.05）， and those of p65 and p-p65 was significantly up-regulated in the model group （P<0.05）. The mRNA expression levels of Nrf2， HO-1， GPX4， and FTH1 were significantly down-regulated （P<0.05）， and the mRNA expression level of NF-κB was significantly up-regulated （P<0.05）. As compared with the model group， the levels of liver function （ALT， AST， and GGT） and blood lipids （TC and TG） in the high-dose and medium-dose Shenling Baizhusan groups were significantly decreased （P<0.05）， liver steatosis was significantly improved， fat deposition was significantly reduced， oxidative stress and inflammatory factors were significantly decreased （P<0.05 ）， and Fe+ level was significantly decreased （P<0.05）. In the high-dose and medium-dose Shenling Baizhusan， the protein expression levels of Nrf2， HO-1， GPX4， and FTH1 were significantly up-regulated （P<0.05）， and those of p65， p-p65 were significantly down-regulated （P<0.05）. The mRNA expression levels of Nrf2， HO-1， GPX4， and FTH1 were significantly up-regulated （P<0.05）， and the mRNA expression level of NF-κB was significantly down-regulated （P<0.05）. ConclusionShenling Baizhusan can effectively reduce liver injury in rats with ALD， regulate steatosis and fat deposition， and play an antioxidant and anti-inflammatory role in the liver. Its mechanism may be related to the inhibition of ferroptosis in hepatocytes by up-regulating the Nrf2 signaling pathway to improve oxidative stress

Leonurine inhibits ferroptosis in renal tubular epithelial cells by activating p62/Nrf2/HO-1 signaling pathway / 中国中药杂志

To investigate the protective effect and the potential mechanism of leonurine(Leo) against erastin-induced ferroptosis in human renal tubular epithelial cells(HK-2 cells), an in vitro erastin-induced ferroptosis model was constructed to detect the cell viability as well as the expressions of ferroptosis-related indexes and signaling pathway-related proteins. HK-2 cells were cultured in vitro, and the effects of Leo on the viability of HK-2 cells at 10, 20, 40, 60, 80 and 100 μmol·L~(-1) were examined by CCK-8 assay to determine the safe dose range of Leo administration. A ferroptosis cell model was induced by erastin, a common ferroptosis inducer, and the appropriate concentrations were screened. CCK-8 assay was used to detect the effects of Leo(20, 40, 80 μmol·L~(-1)) and positive drug ferrostatin-1(Fer-1, 1, 2 μmol·L~(-1)) on the viability of ferroptosis model cells, and the changes of cell morphology were observed by phase contrast microscopy. Then, the optimal concentration of Leo was obtained by Western blot for nuclear factor erythroid 2-related factor 2(Nrf2) activation, and transmission electron microscope was further used to detect the characteristic microscopic morphological changes during ferroptosis. Flow cytometry was performed to detect reactive oxygen species(ROS), and the level of glutathione(GSH) was measured using a GSH assay kit. The expressions of glutathione peroxidase 4(GPX4), p62, and heme oxygenase 1(HO-1) in each group were quantified by Western blot. RESULTS:: showed that Leo had no side effects on the viability of normal HK-2 cells in the concentration range of 10-100 μmol·L~(-1). The viability of HK-2 cells decreased as the concentration of erastin increased, and 5 μmol·L~(-1) erastin significantly induced ferroptosis in the cells. Compared with the model group, Leo dose-dependently increased cell via-bility and improved cell morphology, and 80 μmol·L~(-1) Leo promoted the translocation of Nrf2 from the cytoplasm to the nucleus. Further studies revealed that Leo remarkably alleviated the characteristic microstructural damage of ferroptosis cells caused by erastin, inhibited the release of intracellular ROS, elevated GSH and GPX4, promoted the nuclear translocation of Nrf2, and significantly upregulated the expression of p62 and HO-1 proteins. In conclusion, Leo exerted a protective effect on erastin-induced ferroptosis in HK-2 cells, which might be associated with its anti-oxidative stress by activating p62/Nrf2/HO-1 signaling pathway.

Protective effect of breviscapine against brain injury induced by intrauterine inflammation in preterm rats and its mechanism / 中国当代儿科杂志

OBJECTIVES@#To study the protective effect of breviscapine against brain injury induced by intrauterine inflammation in preterm rats and its mechanism.@*METHODS@#A preterm rat model of brain injury caused by intrauterine inflammation was prepared by intraperitoneal injections of lipopolysaccharide in pregnant rats. The pregnant rats and preterm rats were respectively randomly divided into 5 groups: control, model, low-dose breviscapine (45 mg/kg), high-dose breviscapine (90 mg/kg), and high-dose breviscapine (90 mg/kg)+ML385 [a nuclear factor erythroid 2-related factor 2 (Nrf2) inhibitor, 30 mg/kg] (n=10 each). The number and body weight of the live offspring rats were measured for each group. Hematoxylin-eosin staining was used to observe the pathological morphology of the uterus and placenta of pregnant rats and the pathological morphology of the brain tissue of offspring rats. Immunofluorescent staining was used to measure the co-expression of ionized calcium binding adaptor molecule-1 (IBA-1) and nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) in the cerebral cortex of offspring rats. ELISA was used to measure the levels of interleukin-6 (IL-6), interleukin-8 (IL-8), and interleukin-1β (IL-1β) in the brain tissue of offspring rats. Western blotting was used to measure the expression of Nrf2 pathway-related proteins in the brain tissue of offspring rats.@*RESULTS@#Pathological injury was found in the uterus, and placenta tissue of the pregnant rats and the brain tissue of the offspring rats, and severe microglia pyroptosis occurred in the cerebral cortex of the offspring rats in the model group. Compared with the control group, the model group had significant reductions in the number and body weight of the live offspring rats and the protein expression levels of Nrf2 and heme oxygenase-1 (HO-1) in the brain tissue of the offspring rats (P<0.05), but significant increases in the relative fluorescence intensity of the co-expression of IBA-1 and NLRP3, the levels of the inflammatory factors IL-6, IL-8, and IL-1β, and the protein expression levels of NLRP3 and caspase-1 in the brain tissue of the offspring rats (P<0.05). Compared with the model group, the breviscapine administration groups showed alleviated pathological injury of the uterus and placenta tissue of the pregnant rats and the brain tissue of the offspring rats, significant increases in the number and body weight of the live offspring rats and the protein expression levels of Nrf2 and HO-1 in the brain tissue of the offspring rats (P<0.05), and significant reductions in the relative fluorescence intensity of the co-expression of IBA-1 and NLRP3, the levels of the inflammatory factors IL-6, IL-8, and IL-1β, and the protein expression levels of NLRP3 and caspase-1 in the brain tissue of the offspring rats (P<0.05). The high-dose breviscapine group had a significantly better effect than the low-dose breviscapine (P<0.05). ML385 significantly inhibited the intervention effect of high-dose breviscapine (P<0.05).@*CONCLUSIONS@#Breviscapine can inhibit inflammatory response in brain tissue of preterm rats caused by intrauterine inflammation by activating the Nrf2 pathway, and it can also inhibit microglial pyroptosis and alleviate brain injury.

The role of Nrf2 in the alteration of tight junction protein expression in choroid plexus epithelial cells created by lanthanum-activated MMP9 / 中华劳动卫生职业病杂志

Objective: To investigate the effect of nuclear factor erythroid 2-related factor 2 (Nrf2) in the alteration of tight junction protein expression in choroid plexus epithelial cells created by lanthanum-activated matrix metalloproteinase 9 (MMP9) . Methods: In October 2020, immortalized rat choroid plexus epithelial cell line (Z310) cells were used as the blood-cerebrospinal fluid barrier in vitro, and were divided into control group and 0.125, 0.25, 0.5 mmol/L lanthanum chloride (LaCl(3)) treatment group. After treating Z310 cells with different concentrations of LaCl(3) for 24 hours, the morphological changes of Z310 cells were observed under inverted microscope, the protein expression levels of MMP9, occludin and zonula occludens-1 (ZO-1) were observed by cellular immunofluorescence method, and the protein expression levels of MMP9, tissue inhibitors of metalloproteinase1 (TIMP1) , occludin, ZO-1 and Nrf2 were detected by Western blotting. The level of reactive oxygen species (ROS) in cells was detected by flow cytometry. Results: Compared with the control group, Z310 cells in the LaCl(3) treatment group were smaller in size, with fewer intercellular junctions, and more dead cells and cell fragments. The expression level of MMP9 protein in cells treated with 0.25 and 0.5 mmol/L LaCl(3) was significantly higher than that in the control group (P<0.05) , and the expression level of TIMP1 and tight junction proteins occudin and ZO-1 was significantly lower than that in the control group (P<0.05) . Compared with the control group, the ROS production level in the 0.25, 0.5 mmol/L LaCl(3) treatment group was significantly increased (P<0.05) , and the Nrf2 protein expression level in the 0.125, 0.25, 0.5 mmol/L LaCl(3) treatment group was significantly decreased (P<0.05) . Conclusion: Lanthanum may increase the level of ROS in cells by down regulating the expression of Nrf2, thus activating MMP9 to reduce the expression level of intercellular tight junction proteins occludin and ZO-1.

Mechanism of Alisma plantago-aquatica Linn. improving chronic glomerulonephritis based on network pharmacology and experimental verification / 药学学报

This study aims to explore the improvement and the mechanism of the Alisma plantago-aquatica Linn. (ApL) on chronic glomerulonephritis (CGN). All animal experiments were followed the regulation of the Experimental Animal Ethical Committee of Shanghai University of Traditional Chinese Medicine. CGN mouse model was established by a single tail-vein injection of doxorubicin (Dox) (20 mg·kg-1). One week after Dox administration, the mice received water extract of ApL (85 and 255 mg·kg-1) by gavage once a day for 14 days. At the end of experiment, the urine albumin-to-creatinine ratio (ACR), serum albumin (ALB), blood urea nitrogen (BUN) and serum creatinine (SCr) were detected, kidney histopathological H&E staining was analyzed. Active ingredients and action targets of ApL were collected from TCMSP database, and CGN-related targets were obtained from Genecards database. STRING platform was employed to perform protein-protein interaction (PPI), and Metascape platform was used for KEGG pathway and GO enrichment analysis. The results of experiments demonstrated that ApL (85 and 255 mg·kg-1) could reduce the ACR and the content of SCr and BUN, and increase the content of ALB in mice. Network pharmacology results predicted that nuclear factor kappa-B (NF-κB)-related pathway and biological process of oxidoreductase activity regulation may be involved in the ApL-provided amelioration on CGN. The verification results showed that ApL could inhibit the activation of NF-κB and the expression of inflammatory factors in mice, and reduce the activity of renal myeloperoxidase (MPO). Meanwhile, ApL promoted the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) and increased the expression of its downstream gene mRNA, and reduced the level of renal malondialdehyde (MDA) and reactive oxygen species (ROS), and further elevated renal glutathione (GSH) level. Based on network pharmacology combined experiments, this study found that ApL may improve CGN in mice through multiple targets and multiple pathways, in which the inhibition of NF-κB signaling and the activation of Nrf2 signaling may be important mechanisms involved.

Effect of Glycyrrhizae Radix et Rhizoma-containing Serum on LPS-induced Inflammation in Caco2 Cells Based on Inhibition of Ferroptosis by Nrf2/HO-1 Pathway / 中国实验方剂学杂志

ObjectiveTo investigate the effect of Glycyrrhizae Radix et Rhizoma （GR）-containing serum on lipopolysaccharide （LPS）-induced inflammation in human colon epithelial adenocarcinoma cells （Caco2） based on inhibition of ferroptosis by the nuclear factor erythroid 2-related factor 2 （Nrf2）/heme oxygenase-1 （HO-1） pathway. MethodCaco2 cells were divided into a normal group， a model group （LPS， 200 μg·L-1）， low-， medium-， and high-dose GR-containing serum groups （5%， 10%， 20%）， and a ferroptosis inhibitor group （3-amino-4-cyclohexylamino-benzoic acid ethyl ester， Fer-1， 10 μmol·L-1）. The cells in the normal group were cultured normally， while those in other groups underwent the induction of an inflammation model. The cells in the low-， medium-， and high-dose GR-containing serum groups were treated with 5%， 10%， and 20% GR-containing serum for 24 hours， respectively， and the cells in the ferroptosis inhibitor group were treated with Fer-1 for 24 hours. Transmission electron microscopy was used to observe mitochondrial morphology in each group. Flow cytometry was used to detect intracellular Fe2+ levels. Microplate assays were performed to measure superoxide dismutase （SOD） activity， malondialdehyde （MDA） and glutathione peroxidase （GSH-Px） levels. Enzyme-linked immunosorbent assay （ELISA） was used to measure interleukin-1β （IL-1β）， IL-6， IL-10， and tumor necrosis factor-α （TNF-α） levels. Western blot was used to measure the expression levels of Nrf2， HO-1， ferritin heavy chain 1 （FTH1）， and glutathione peroxidase 4 （GSH-Px4） proteins. Small interfering RNA （siRNA） was used to investigate the role of Nrf2 in ferroptosis regulation. The cells after interference were divided into a negative control （NC） group， a Si-Nrf2 group， a GR-containing serum （20%） + Si-Nrf2 group， and a GR-containing serum （20%） + NC group. Microplate assays were performed to measure MDA， SOD， and GSH-Px levels， and Western blot was used to measure the expression levels of Nrf2， HO-1， FTH1， and GSH-Px4 proteins. ResultCompared with the normal group， the model group showed mitochondrial contraction， increased mitochondrial membrane thickness， and smaller mitochondrial morphology， increased Fe2+ content （P<0.01）， blunted SOD activity （P<0.01）， decreased GSH-Px expression （P<0.01）， increased MDA content （P<0.01）， reduced expression levels of Nrf2 and HO-1 （P<0.05）， reduced FTH1 expression （P<0.01）， and down-regulated GSH-Px4 expression （P<0.01）. In the GR-containing serum groups， the medium- and high-dose groups showed a significant decrease in Fe2+ content （P<0.01）， potentiated SOD and GSH-Px activities （P<0.01）， and decreased MDA levels （P<0.01）. The high-dose group showed a significant increase in Nrf2 expression （P<0.05）， and the medium-dose group showed increased expression of HO-1 and GSH-Px4 proteins （P<0.05）. The expression levels of FTH1 significantly increased in the low-， medium-， and high-dose groups （P<0.01）. The study on mechanism revealed that compared with the NC group， the cells transfected with Nrf2 siRNA showed increased MDA content （P<0.01）， blunted SOD activity （P<0.01）， decreased GSH-Px activity （P<0.01）， decreased expression of Nrf2 and HO-1 （P<0.01）， and reduced levels of FTH1 and GSH-Px4 proteins （P<0.01）. Compared with the Si-Nrf2 group， the cells treated with GR-containing serum showed a decrease in MDA content （P<0.01）， an increase in SOD activity （P<0.01）， an increase in GSH-Px activity （P<0.01）， increased expression of Nrf2 and FTH1 proteins （P<0.05）， and higher expression levels of HO-1 and GSH-Px4 proteins （P<0.01）. ConclusionGR-containing serum can reduce the inflammatory cytokines and oxidative stress levels in LPS-induced Caco2 cells. Its mechanism is related to the promotion of Nrf2/HO-1 signaling pathway expression， alleviating intracellular lipid peroxidation and inhibiting ferroptosis.

Research progress of Kelch-like ECH-associated protein 1-nuclear factor erythroid 2-related factor 2 signaling pathway regulated retinal oxidative stress / 国际眼科杂志(Guoji Yanke Zazhi)

Oxidative stress(OS)is a major reason for body damage. Studies have shown that a variety of factors, such as ischemia and hypoxia, excessive light and hyperglycemia can cause the increase of reactive oxygen species and free radicals in the retina, thus inducing OS, damaging retina and affecting the normal visual function. Kelch-like ECH-associated protein 1(KEAP1)and nuclear factor erythroid 2 related factor 2(NRF2), which together constitute the main antioxidant stress signaling pathway in the body, play an antioxidant role by regulating retinal energy metabolism and cell proliferation, apoptosis and autophagy through various ways, so as to reduce retinal damage caused by OS. In this paper, the role and mechanism of the KEAP1-NRF2 signaling pathway regulation of OS in the retinal are briefly reviewed, aiming to provide ideas for subsequent research.

Caffeic acid phenethyl ester improves peritoneal dialysis-associated peritoneal fibrosis by alleviating oxidative stress injury through activating nuclear factor erythroid-2-related factor 2/heme oxygenase-1 pathway / 中华肾脏病杂志

Objective:To investigate whether caffeic acid phenethyl ester (CAPE) would improve peritoneal dialysis (PD)-associated peritoneal fibrosis by alleviating oxidative stress through activating nuclear factor erythroid-2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway.Methods:Thirty-two male Sprague-Dawley rats were randomly divided into four groups by the random number table: control (CON) group (0.9% normal saline 20 ml/d intraperitoneal injection), CAPE group (0.9% normal saline 20 ml/d+CAPE 10 mg·kg -1·d -1 intraperitoneal injection), PD group [4.25% glucose peritoneal dialysis fluid (PDF) 20 ml/d intraperitoneal injection with lipopolysaccharide 0.6 mg/kg intraperitoneal injection at day 1, 3, 5 and 7], and PD+CAPE group (CAPE 10 mg·kg -1·d -1 intraperitoneal injection in addition to PD group), with 8 rats per group. On day 28, rats were euthanized after peritoneal equilibration test, and then the parietal peritoneum and omentum were collected for follow-up tests. To further investigate the mechanism, primary peritoneal mesothelial cells (PMCs) of rats were isolated and cultured. The PMCs were stimulated with 2.5% glucose PDF and added with 5 μmol/L CAPE intervention. The Nrf2 inhibitor (ML385) was used to identify whether CAPE protected PMCs from PDF by activating the Nrf2/HO-1 pathway. Histopathological staining was used to detect structural changes of the peritoneum, and immunohistochemical analysis was performed on cleaved caspase-3, Bax, α-smooth muscle actin (α-SMA), fibronectin (FN), and typeⅠ collagen (Col-Ⅰ) protein. Western blotting was used to detect the protein expression of α-SMA, FN, transforming growth factor-β1 (TGF-β1), HO-1 and nuclear Nrf2 (N-Nrf2). The apoptosis detection kit was used to detect apoptosis and flow cytometry was used to detect reactive oxygen species (ROS) in PMCs. The malondialdehyde (MDA) and superoxide dismutase (SOD) activity detection kit were used to detect MDA content and SOD activity. Cell immunofluorescence was used to analyze the protein expression of Nrf2 in PMCs. Results:Compared with the CON group, the PD group had thicker peritoneum, and the expression levels of cleaved caspase-3, Bax, α-SMA, FN, Col-Ⅰand MDA in peritoneum were significantly higher, while HO-1, N-Nrf2 protein expression and SOD activity were lower (all P<0.05). Compared with the PD group, the parietal peritoneum morphology of CAPE+PD group was improved, accompanied by reduced cleaved caspase-3, Bax, α-SMA, FN, Col-Ⅰ protein expression, and MDA content, while N-Nrf2, HO-1 protein expression, and SOD activity were higher (all P<0.05). Compared with the CON group, the PD group had significantly lower ultrafiltration volume and higher peritoneal permeability (both P<0.05). After CAPE intervention, the peritoneal transport function of the rats was significantly improved ( P<0.05). In cultured PMCs, PDF inhibited nuclear translocation of Nrf2 and protein expression of HO-1, and upregulated intracellular ROS level. In addition, PDF increased cell apoptosis and the protein expression levels of α-SMA, TGF-β1 and FN (all P<0.05). CAPE activated nuclear translocation of Nrf2, increased HO-1 protein expression, downregulated intracellular ROS level, and partially reversed PDF-induced cell apoptosis and epithelial- mesenchymal transition (all P<0.05). The protective effects of CAPE on PMCs were partially abolished by ML385 (all P<0.05). Conclusions:CAPE can reduce PD-induced PMCs apoptosis and epithelial-mesenchymal transition by attenuating oxidative stress, and significantly improve peritoneal fibrosis and ultrafiltration function. The beneficial effects of CAPE on peritoneum are related to activation of Nrf2/HO-1 pathway.

Effect of diosmetin on ferroptosis of hippocampal cells in rats with bacterial meningitis and the mechanism of SIRT1-Nrf2 signaling pathway / 中华行为医学与脑科学杂志

Objective:To explore the effect and mechanism of diosmetin (Dio) on neuronal ferroptosis in rats with bacterial meningitis (BM).Methods:Male SD rats aged 6-7 weeks of SPF grade were selected for the experiment. The BM model was established by injecting group B hemolytic streptococcus into the cisterna magna of cerebellum. Sixty BM model rats were successfully modeled and divided into model group, low-dose Dio group, medium-dose Dio group, high-dose Dio group and inhibitor group according to the random number table method, with 12 rats in each group. Another 12 weight-matched rats were taken as the control group.The rats in the low-dose Dio group, medium-dose Dio group, high-dose Dio group and the inhibitor group were intragastrically administered with Dio at 50 mg/kg, 100 mg/kg, 200 mg/kg and 200 mg/kg, respectively. The rats in the control group were intragastrically administered with an equal volume of 0.9 % sodium chloride solution. On the day of intragastric administration, the rats in the inhibitor group were intraperitoneally injected with SIRT1 pathway inhibitor EX527 (10 mg/kg), and the rats in the other groups were injected with an equal volume of 0.9% sodium chloride solution. The above interventions were performed once a day for 28 consecutive days. Loeffler neurological score was used to evaluate the neurological impairment in rats. Interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in cerebrospinal fluid of rats were detected by ELISA. The number of white blood cells in cerebrospinal fluid was detected by a blood cell analyzer. Glutathione (GSH) was detected by micro-enzyme labeling method, malondialdehyde (MDA) was detected by thiobarbituric acid colorimetric method, reactive oxygen species(ROS) was detected by colorimetry, and Fe 2+ level was detected by ferrozine method. Hematoxylin-eosin staining, Prussian blue staining and TUNEL staining were used to observe the pathological damage, iron accumulation and apoptosis in the hippocampus, respectively.Western blot was applied to measure the expression of transferrin (Tf), proliferating cell nuclear antigen (PCNA), Bcl-2-associated X protein (Bax), caspase-3 and SIRT1/Nrf2/HO-1/Gpx4 signaling pathway proteins. Graphpad Prism 9.0 was used for data analysis. One-way ANOVA was used for statistical analysis, and SNK- q test was used for further pairwise comparisons. Results:(1) There was a statistically significant difference in neurological function scores among the 6 groups of rats ( F=125.451, P<0.001). The neurological function score of the model group was lower than that of control group, while the neurological function scores of the low-dose Dio group, medium-dose Dio group, and high-dose Dio group were higher than those of the model group (all P<0.05). The neurological function score of the inhibitor group ((2.57±0.26)) was lower than that of high-dose Dio group ((4.34±0.48)) ( P<0.05). (2) There were statistically significant differences in the levels of IL-6, TNF-α and the number of white blood cells in the cerebrospinal fluid of rats among the 6 groups ( F=127.817, 102.413, 180.967, all P<0.001). The levels of IL-6, TNF-α and the number of white blood cells in model group were higher than those of control group(all P<0.05). The levels of IL-6, TNF-α and the number of white blood cells in low-dose Dio group, medium-dose Dio group and high-dose Dio group were lower than those of model group (all P<0.001), and those in inhibitor group were all higher than those in high-dose Dio group(all P<0.001). (3) There were statistically significant differences in iron deposition rate and neuronal apoptosis rate among the 6 groups of rats ( F=90.857, 88.835, both P<0.001). The iron deposition rate ((18.37±3.14)%) and neuronal apoptosis rate ((27.58±2.63)%) in the inhibitor group were higher than those in the high-dose Dio group ((6.35±1.08)%, (14.02±1.87)%) (both P<0.05). (4) The levels of GSH, ROS, MDA, and Fe 2+ in the hippocampus of the 6 groups of rats showed statistically significant differences ( F=54.465, 106.453, 55.969, 105.457, all P<0.001). The GSH content in the inhibitor group ((103.48±8.76) mmol/g) was lower than that in the high-dose Dio group ((133.97±10.54) mmol/g), while the contents of ROS, MDA, Fe 2+ ((225.17±16.32) μmol/mg, (10.73±1.58) μmol/mg, (62.71±5.43) μg/g) were higher than those of the high-dose Dio group ((131.87±11.67) μmol/mg, (4.35±0.87) μmol/mg, (34.86±2.95) μg/g) (all P<0.05). (5)There were statistically significant differences in the protein levels of Tf, PCNA, Bax, caspase-3, SIRT1, Nrf2, HO-1 and Gpx4 in the hippocampus of the 6 groups of rats ( F=120.179, 107.568, 157.265, 98.031, 90.932, 52.283, 59.424, 114.539, all P<0.001). The protein levels of Tf, Bax and caspase-3 in the hippocampus of inhibitor group were higher than those of the high-dose Dio group, while the protein levels of PCNA, SIRT1, Nrf2, HO-1, Gpx4 were lower than those of the high-dose Dio group (all P<0.05). Conclusion:Diosmetin can activate SIRT1/Nrf2/HO-1/Gpx4 signaling pathway, thereby inhibiting neuronal ferroptosis in BM rats.

Protective effect of proanthocyanidins on neurotoxicity of benzoapyrene / 环境与职业医学

Background Benzo[a]pyrene (BaP) is neurotoxic and can cause neuronal damage by oxidative stress. Proanthocyanidin (PC) has antioxidant activity, and its mechanism may related to nuclear factor-erythroid 2-related factor 2 (Nrf2)-heme oxygenase-1 (HO-1) signaling pathway. Objective To explore potential protective effect of PC on hippocampal neuron injury induced by BaP oxidative stress. Methods Hippocampal neurons of neonatal SD rats delivered within 24 h were isolated and cultured, and cell activity was detected by cell counting kit-8 (CCK-8) method. According to the pre-experimental results, a control group and three BaP groups of 10, 20 and 40 µmol·L−1 were set up for Stage I experiment. The length of neurites and number of branches of hippocampal neurons in each group were observed by immunofluorescence method. Reactive oxygen species (ROS) fluorescence probe method was used to measure ROS levels in cells. Real-time quantitative fluorescent polymerase chain reaction (qRT-PCR) and Western blotting were used to detect the mRNA and protein expression of Nrf2, Kelch-like epichlorohydrin associated protein-1 (Keap1), HO-1, B-cell lymphoma-2 (Bcl-2), and Bcl-2-associated X (Bax) in hippocampal neurons of each group, respectively. According to the results of Stage I experiment, three group were set up, including control group, BaP alone treatment group (BaP 20 µmol·L−1), and PC intervention group (BaP 20 µmol·L−1 + PC 2.5 µg·mL−1) for Stage II experiment, with the same protocol as Stage I. Results For Stage I experiment, compared with the control group, the 10, 20, and 40 µmol·L−1 BaP groups showed gradually shortened length of neurites [(177.60±3.49), (142.40±6.52), and (100.50±19.40) µm] (P<0.05) and decreased number of branches (8.00±1.00, 6.33±1.53, 4.33± 0.58) of hippocampal neurons (P<0.05); increased ROS production (2.38±0.33, 8.08±0.26, 9.86±0.19) (P<0.05); the qRT-PCR results showed that the mRNA expression levels of Nrf2 (0.35±0.03, 0.25±0.01, 0.13±0.03), Keap1 (0.70±0.01, 0.47±0.03, 0.15±0.02), HO-1 (0.77±0.02, 0.60±0.02, 0.32±0.01), and Bcl-2 (0.65±0.03, 0.47±0.02, 0.18±0.02) gradually decreased, and the mRNA expression level of Bax gradually increased (1.24±0.01, 2.25±0.15, 4.98±0.30) (P<0.05); the Western blotting results showed that the protein expression trends of Nrf2, Keap1, HO-1, Bcl-2, and Bax were consistent with the mRNA results. For Stage II experiment, compared with the BaP alone treatment group, the length of neurites in the PC intervention group became longer, (149.90±3.01) μm vs (202.00±4.45) μm (P<0.05), the number of branches increased, (4.67±0.58) vs (8.33±0.58) (P<0.05); the ROS production reduced, (10.81±0.63) vs (7.31±0.70) (P<0.05); the mRNA expression levels of Nrf2, Keap1, HO-1, and Bcl-2 increased (P<0.05), and the mRNA expression levels of Bax decreased (P<0.05); the Nrf2, Keap1, HO-1, and Bcl-2 protein expression levels increased (P<0.05), and Bax protein expression level decreased (P<0.05). Conclusion PC may exert neuroprotective effects by activating the Nrf2-HO-1 signaling pathway, inhibiting BaP-induced oxidative stress in neuronal cells, and reducing cytotoxicity.

Research progress on the role of nuclear factor erythroid 2-related factor 2 in ferroptosis of sepsis / 中华危重病急救医学

Sepsis is a life-threatening organ dysfunction caused by the disorder of the body's response to infection, and is one of the main causes of death in critically ill patients. Ferroptosis is a kind of iron dependent cell death, characterized by intracellular reactive oxygen species (ROS) accumulation. Sepsis can cause a substantial accumulation of ROS in cells. The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) is a key regulator of antioxidant and plays a critical protective role in sepsis induced ferroptosis by regulating the expression of proteins related to the ferroptosis pathway. Current studies have found that activation of Nrf2 has a protective effect on ferroptosis induced by sepsis. In this paper, we summarized the regulation mechanism of Nrf2 in ferroptosis, in order to provide references for the treatment of sepsis.

The mechanism of itaconic acid alleviating acute lung injury induced by lipopolysaccharide / 中华急诊医学杂志

Objective:To investigate the role and mechanism of exogenous derivative 4-octyl itaconate (4-OI) in lipopolysaccharide (LPS)-induced acute lung injury (ALI).Methods:C57BL/6 male mice were randomly divided into the control group, 4-OI group, LPS group, 4-OI+LPS group and deferiprone (DFP)+LPS group, with 6 mice in each group. LPS-induced ALI model was established by intraperitoneal injection of LPS. For the 4-OI+LPS group, mice were pretreated with 4-OI for 2 h before stimulation with LPS. The mice were sacrificed 12 h later and lung tissues were collected for pathological and molecular biological examination. Hematoxylin-eosin and Masson staining were used to detect the level of lung injury and collagen deposition. The expression levels of inflammatory cytokines and ferroptosis associated genes were detected by real-time quantitative PCR, and ferroptosis associated proteins were detected by Western blotting. The chi-square test was performed before the measurement data were counted. One-way analysis of variance was used to compare differences between multiple groups.Results:Compared with the control group, the histopathological damage was aggravated, and collagen deposition and lung injury score and lung wet-dry ratio were significantly increased in the LPS group (all P<0.05), and 4-OI pre-treatment significantly alleviated LPS-induced ALI. 4-OI treatment also significantly reduced the mRNA level of inflammatory cytokines, including IL-1β [(4.38±0.47) vs. (32.65±4.49)], IL-6 [(3.97±0.64) vs. (12.22±0.91)] and TNF-α [(15.06±2.26) vs. (38.53±2.31)]. At the same time, compared with the control group, the levels of lipid peroxidation metabolite 4-hydroxynonenal and malondialdehyde, iron level of lung tissue were significantly increased in the LPS group, and the mRNA level of ferroptosis marker prostaglandin-endoperoxide synthase 2 was also significantly increased (all P<0.05), but these indicators were significantly lower in the 4-OI+LPS group than in the LPS group. The results of immunofluorescence, Western blotting and PCR showed that the protein levels of nuclear factor erythroid 2-related factor 2 (Nrf2), glutathione peroxidase 4 (GPX4) and ferritin heavy chain (FTH1) significantly decreased in the LPS group, while 4-OI treatment significantly increased the Nrf2, GPX4 and FTH1 levels, and showed similar inhibition of ferroptosis with DFP (all P<0.05). Conclusions:4-OI attenuates LPS-induced ALI by increasing Nrf2 and upregulating FTH1 and GPX4, providing a potential drug and its theoretical mechanism for the prevention and treatment of ALI.

Xinhui citrus fermentation liquor ameliorates acute ulcerative colitis in mice via regulating intestinal bacteria homeostasis and Nrf2/NLRP3 pathway to repair intestinal mucosa / 药学学报

This study investigated the protective effect and related mechanisms of Xinhui citrus fermentation liquor on mice with ulcerative colitis. Animal experiments follow the rules of Animal Ethics Committee of Southern Medical University. C57BL/6 mice were given 3% dextran sodium sulfate (DSS) for 6 days to induce acute ulcerative colitis. During this period, Xinhui citrus fermentation liquor, decoction of Citrus reticulata blanco (both orally administrated with 300 mg·kg-1·d-1 crude polysaccharide) or positive drug 5-aminosalicylic acid (100 mg·kg-1·d-1) were gavaged continuously for 9 days. Cecal contents were collected for 16S rRNA sequencing analysis. The levels of inflammatory factors, tight junction proteins and nuclear factor erythroid 2 related factor 2 / Nod-like receptor protein 3 (Nrf2/NLRP3) pathway related proteins in the colon were detected by real-time PCR (RT-PCR), immunofluorescence and Western blot. Our results showed that Xinhui citrus fermentation liquor and Citrus reticulata blanco protected against UC-induced weight loss, diarrhea, bloody stool, and colon shortening. The mRNA and protein levels of pro-inflammatory factors, such as interleukin 6 (Il-6) and CXC chemokine ligand 10 (Cxcl10) and NLRP3 inflammasome were significantly decreased; the mRNA levels of colon anti-inflammatory factor (Il-10), tight junction protein [zonula occludens-1 (Zo-1), occludin, claudin-1], mucin 2 (Muc2), Nrf2, as well as the mRNA and protein levels of NAD(P)H quinine oxidoreductase 1 (NQO1) and heme oxygenase 1 (HO-1) were significantly increased. In addition, Xinhui citrus fermentation liquor increased the abundance of Akkermansia and reduced the abundance of harmful bacteria Enterococcus and Streptococcus. The correlation analysis showed that the abundance of Akkermansia was positively correlated with anti-inflammatory factors, tight junction protein and the related genes levels of Nrf2 signaling pathway. In summary, Xinhui citrus fermentation liquor ameliorates acute ulcerative colitis in mice via regulating intestinal bacteria homeostasis and Nrf2/NLRP3 pathway to repair intestinal mucosa.

Changes of m6A modification in arsenic-induced oxidative stress of human embryonic lung fibroblasts / 环境与职业医学

Background Arsenic can be toxic to human by triggering oxidative stress, which is companied by epigenetic modifications. Objective To investigate the modification of N6-methyladenosine (m6A) in human embryonic lung fibroblasts (HELF) during oxidative stress induced by sodium arsenite (NaAsO2). Methods HELF cells were treated by designed concentrations of NaAsO2 (0, 2.5, 5, 10, and 20 μmol·L−1) for 48 h. Cell viability was detected by 3-(4,5-dimethylthia zol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfopheny)-2H-tetrazolium (MTS) method; the activities of total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) as well as the content of malondialdehyde (MDA) were detected with corresponding kits; the level of m6A methylation in total RNA was detected by enzyme-linked immunosorbent assay; the mRNA expressions of m6A modified enzymes were detected by real-time fluorescence quantitative PCR, including methyltransferase-like 3 (METTL3), methyltransferase-like 14 (METTL14), Wilms' tumor 1-associated protein (WTAP), fat mass and obesity-associated protein (FTO), alkB family of Fe(II)/α-ketoglutarate-dependent dioxygenases 5 (ALKBH5), YTH domain containing protein 2 (YTHDC2), YTH domain family protein 2 (YTHDF2), and YTH domain family protein 3 (YTHDF3); the protein expressions of METTL3, FTO, YTHDC2, YTHDF3, and nuclear factor erythroid 2-related factor 2 (NRF2) were detected by Western blotting. The enrichment of m6A in NRF2 mRNA was detected by RNA methylated immunoprecipitation combined with real-time fluorescence quantitative PCR (MeRIP-qPCR). Results After the 0, 2.5, 5, 10, and 20 μmol·L−1 NaAsO2 treatment, the MTS results showed that compared with the control group, the cell viability of the 20 μmol·L−1 group decreased to 84% (P<0.05). The colorimetry results showed that compared with the control group, the activities of T-SOD in the 10 and 20 μmol·L−1 groups decreased (P<0.05); the activities of GSH-Px in the 2.5 and 10 μmol·L−1 groups decreased (P<0.05); the contents of MDA in the 10 and 20 μmol·L−1 groups increased. The results of enzyme-linked immunosorbent assay showed that the overall m6A methylation levels in the 0, 2.5, 5, 10, and 20 μmol·L−1 groups were (0.193 ± 0.023)%, (0.247 ± 0.021)%, (0.253 ± 0.006)%, (0.233 ± 0.006)%, and (0.262 ± 0.010)%, respectively, and compared with the control group, the m6A methylation levels in all the NaAsO2 treated groups increased (P<0.05). The real-time fluorescence quantitative PCR results showed that compared with the control group, the mRNA relative expression level of METTL3 decreased in the 2.5, 10, and 20 μmol·L−1 groups (P<0.05); the mRNA relative expression level of FTO decreased in the 20 μmol·L−1 group; the mRNA relative expression level of YTHDC2 increased in the 10 and 20 μmol·L−1 groups (P<0.05); the mRNA relative expression level of YTHDF3 increased in the 2.5, 10, and 20 μmol·L−1 groups (P<0.05). The Western blotting results showed that compared with the control group, the relative protein expression of METTL3 decreased in the 10 and 20 μmol·L−1 groups; the relative protein expression of FTO decreased in the 5 and 20 μmol·L−1 groups; the relative protein expression of YTHDC2 decreased in the 20 μmol·L−1 group (P<0.05); the relative nuclear protein expression of NRF2 decreased in the 10 and 20 μmol·L−1 groups (P<0.05). The MeRIP-qPCR results showed that m6A enrichment was significantly increased in the 20 μmol·L−1 NaAsO2 exposure group compared with the control group (P<0.05). After over-expression of FTO, the mRNA and protein relative expression levels of FTO and the relative expression level of nuclear protein of NRF2 in the FTO group were higher than those in the control group (P<0.05); the mRNA and protein relative expression levels of FTO in the NaAsO2 + FTO group and the nuclear protein expression level of NRF2 were higher than those in the NaAsO2 group (P<0.05). Conclusion In the process of oxidative stress induced by NaAsO2, m6A methylation level, m6A modified enzymes, m6A modification of NRF2 mRNA, and NRF2 expression could change in HELF cells.

Role of NRF2 signaling pathway in trichloromethane-induced oxidative stress in L02 cells / 中国职业医学

@#Objective - （ ） To investigate the effects of nuclear factor erythroid 2 related factor 2 NRF2 on the oxidative stress （ ） Methods ） ，， induced by trichloromethane TCM in human normal hepatocyte L02 cells. i L02 cells were stimulated with 1 2 ， ， ， （ ）， 4 8 12 16 and 20 mmol/L TCM solution dissolved in dimethyl sulfoxide and the control group and blank group were set ， - ， up. After culturing for 24 hours the cell viability was detected by CCK 8 colorimetric method and the concentration of TCM ） -， - stimulation was screened. ii L02 cells in logarithmic growth phase were randomly divided into control group and low medium - ， ， ， and high dose groups. After 24 hours of exposure to 0 4 8 and 12 mmol/L TCM the cells were collected. The activity of （ ）， （ ）， （ - ） （ ） superoxide dismutase SOD catalase CAT glutathione peroxidase GSH Px and the level of malondialdehyde MDA NRF2， - （HO-1）， were detected by colorimetric analysis. The mRNA expression levels of heme oxygenase 1 glutamate cysteine （GCLC） （） （NQO1） - ligase catalytic subunit and NAD P H quinone dehydrogenase 1 were detected by real time fluorescence ， - ， polymerase chain reaction. The protein levels of NRF2 HO 1 GCLC and NQO1 were detected by Western blotting.Results ） ， ， ， ， i When the concentration of TCM was 4 8 12 16 and 20 mmol/L the survival rate of L02 cells decreased （ P ） ， ， significantly compared with the control group all <0.05 . The concentration of 0 4 8 and 12 mmol/L were selected as the ） ， - stimulation doses for subsequent experiments. ii Compared with the control group the activities of SOD and GSH Px in L02 （ P ） （ P ）， - cells in the three doses groups decreased all <0.05 and the levels of MAD increased all <0.05 with a dose effect - （P ）， relationship. The CAT activity of L02 cells in the medium dose group was lower than that in the control group <0.05 and the - （ P ） CAT activity of L02 cells in the high dose group was lower than that in the others three groups all <0.05 . Compared with the ， NRF2 - （P ），NRF2 control group the relative expression levels of mRNA in L02 cells in the low dose group decreased <0.05 - （P ）， NRF2 mRNA in L02 cells in the medium dose group increased <0.05 mRNA and NRF2 protein expression in L02 cells in （ P ） HO-1，GCLC， NQO1 ， the highdose group increased both <0.05 . The relative expression level of mRNA and GCLC NQO1 （ P ） protein expression in L02 cells in the three doses groups increased compared with the control group all <0.05 . The relative NRF2 - - - expression level of mRNA in L02 cells in the high dose group was higher than that in the low and medium dose groups （ P ）， - （P ）， both <0.05 and the relative expression of NRF2 protein was higher than that in the low dose group <0.05 but the HO-1 GCLC - - （ relative expression levels of and mRNA and HO 1 protein level were lower than those in the medium dose group all P ）Conclusion - <0.05 . TCM exposure can inhibit the proliferation of L02 cells by inducing oxidative stress with a dose effect ， relationship. In this process the antioxidant mechanism mediated by NRF2 was activated. The expression of antioxidant defense ， - ， and detoxification related target genes downstream of NRF2 signaling pathway was activated and the expression of HO 1 - GCLC and NQO1 was up regulated to alleviate the oxidative damage caused by TCM.

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.