The antioxidant effect of preischemic dexmedetomidine in a rat model: increased expression of Nrf2/HO-1 via the PKC pathway

Abstract Background The precise underlying mechanism of antioxidant effects of dexmedetomidine-induced neuroprotection against cerebral ischemia has not yet been fully elucidated. Activation of Nuclear factor erythroid 2-related factor (Nrf2) and Heme Oxygenase-1 (HO-1) represents a major antioxidant-defense mechanism. Therefore, we determined whether dexmedetomidine increases Nrf2/HO-1 expression after global transient cerebral ischemia and assessed the involvement of Protein Kinase C (PKC) in the dexmedetomidine-related antioxidant mechanism. Methods Thirty-eight rats were randomly assigned to five groups: sham (n = 6), ischemic (n = 8), chelerythrine (a PKC inhibitor; 5 mg.kg-1 IV administered 30 min before cerebral ischemia) (n = 8), dexmedetomidine (100 µg.kg-1 IP administered 30 min before cerebral ischemia (n = 8), and dexmedetomidine + chelerythrine (n = 8). Global transient cerebral ischemia (10 min) was applied in all groups, except the sham group; histopathologic changes and levels of nuclear Nrf2 and cytoplasmic HO-1 were examined 24 hours after ischemia insult. Results We found fewer necrotic and apoptotic cells in the dexmedetomidine group relative to the ischemic group (p< 0.01) and significantly higher Nrf2 and HO-1 levels in the dexmedetomidine group than in the ischemic group (p< 0.01). Additionally, chelerythrine co-administration with dexmedetomidine attenuated the dexmedetomidine-induced increases in Nrf2 and HO-1 levels (p< 0.05 and p< 0.01, respectively) and diminished its beneficial neuroprotective effects. Conclusion Preischemic dexmedetomidine administration elicited neuroprotection against global transient cerebral ischemia in rats by increasing Nrf2/HO-1 expression partly via PKC signaling, suggesting that this is the antioxidant mechanism underlying dexmedetomidine-mediated neuroprotection.

Role and mechanism of SIRT1 in regulating Nrf2/HO-1 signaling pathway in septic liver injury / 中华危重病急救医学

OBJECTIVE@#To investigate the role and mechanism of silent information regulator 1 (SIRT1) in regulating nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway in oxidative stress and inflammatory response to sepsis-induced liver injury.@*METHODS@#A total of 24 male Sprague-Dawley (SD) rats were randomly divided into sham operation (Sham) group, cecal ligation and puncture (CLP) group, SIRT1 agonist SRT1720 pretreatment (CLP+SRT1720) group and SIRT1 inhibitor EX527 pretreatment (CLP+EX527) group, with 6 rats in each group. Two hours before operation, SRT1720 (10 mg/kg) or EX527 (10 mg/kg) were intraperitoneally injected into the CLP+SRT1720 group and CLP+EX527 group, respectively. Blood was collected from the abdominal aorta at 24 hours after modeling and the rats were sacrificed for liver tissue. The serum levels of interleukins (IL-6, IL-1β) and tumor necrosis factor-α (TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA). The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected by microplate method. Hematoxylin-eosin (HE) staining was used to observe the pathological injury of rats in each group. The levels of malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), glutathione (GSH) and superoxide dismutase (SOD) in liver tissue were detected by corresponding kits. The mRNA and protein expressions of SIRT1, Nrf2 and HO-1 in liver tissues were detected by real-time quantitative polymerase chain reaction (RT-qPCR) and Western blotting.@*RESULTS@#Compared with the Sham group, the serum levels of IL-6, IL-1β, TNF-α, ALT and AST in the CLP group were significantly increased; histopathological results showed that liver cords were disordered, hepatocytes were swollen and necrotic, and a large number of inflammatory cells infiltrated; the contents of MDA and 8-OHdG in liver tissue increased, while the contents of GSH and SOD decreased; and the mRNA and protein expressions of SIRT1, Nrf2 and HO-1 in liver tissues were significantly decreased. These results suggest that sepsis rats have liver dysfunction, and the levels of SIRT1, Nrf2, HO-1 and antioxidant protein in liver tissues were decreased, while the levels of oxidative stress and inflammation were increased. Compared with the CLP group, the levels of inflammatory factors and oxidative stress were significantly decreased in the CLP+SRT1720 group, the mRNA and protein expressions of SIRT1, Nrf2 and HO-1 were significantly increased [IL-6 (ng/L): 34.59±4.21 vs. 61.84±3.78, IL-1β (ng/L): 41.37±2.70 vs. 72.06±3.14, TNF-α (ng/L): 76.43±5.23 vs. 130.85±5.30, ALT (U/L): 30.71±3.63 vs. 64.23±4.59, AST (U/L): 94.57±6.08 vs. 145.15±6.86, MDA (μmol/g): 6.11±0.28 vs. 9.23±0.29, 8-OHdG (ng/L): 117.43±10.38 vs. 242.37±11.71, GSH (μmol/g): 11.93±0.88 vs. 7.66±0.47, SOD (kU/g): 121.58±5.05 vs. 83.57±4.84, SIRT1 mRNA (2-ΔΔCt): 1.20±0.13 vs. 0.46±0.02, Nrf2 mRNA (2-ΔΔCt): 1.21±0.12 vs. 0.58±0.03, HO-1 mRNA (2-ΔΔCt): 1.71±0.06 vs. 0.48±0.07, SIRT1 protein (SIRT1/β-actin): 0.89±0.04 vs. 0.58±0.03, Nrf2 protein (Nrf2/β-actin): 0.87±0.08 vs. 0.51±0.09, HO-1 protein (HO-1/β-actin): 0.93±0.14 vs. 0.54±0.12, all P < 0.05], these results indicated that SIRT1 agonist SRT1720 pretreatment could improve liver injury in sepsis rats. However, pretreatment with SIRT1 inhibitor EX527 showed the opposite effect [IL-6 (ng/L): 81.05±6.47 vs. 61.84±3.78, IL-1β (ng/L): 93.89±5.83 vs. 72.06±3.14, TNF-α (ng/L): 177.67±5.12 vs. 130.85±5.30, ALT (U/L): 89.33±9.52 vs. 64.23±4.59, AST (U/L): 179.59±6.44 vs. 145.15±6.86, MDA (μmol/g): 11.39±0.51 vs. 9.23±0.29, 8-OHdG (ng/L): 328.83±11.26 vs. 242.37±11.71, GSH (μmol/g): 5.07±0.34 vs. 7.66±0.47, SOD (kU/g): 59.37±4.28 vs. 83.57±4.84, SIRT1 mRNA (2-ΔΔCt): 0.34±0.03 vs. 0.46±0.02, Nrf2 mRNA (2-ΔΔCt): 0.46±0.04 vs. 0.58±0.03, HO-1 mRNA (2-ΔΔCt): 0.21±0.03 vs. 0.48±0.07, SIRT1 protein (SIRT1/β-actin): 0.47±0.04 vs. 0.58±0.03, Nrf2 protein (Nrf2/β-actin): 0.32±0.07 vs. 0.51±0.09, HO-1 protein (HO-1/β-actin): 0.19±0.09 vs. 0.54±0.12, all P < 0.05].@*CONCLUSIONS@#SIRT1 can inhibit the release of proinflammatory factors and alleviate the oxidative damage of hepatocytes by activating Nrf2/HO-1 signaling pathway, thus playing a protective role against CLP-induced liver injury.

Research Progress of HO1 on AntiOxidative Stress Injury of MSC --Review / 中国实验血液学杂志

Mesenchymal stem cell (MSC) is widely used in cell therapy because of its high proliferative and multi directional differentiation potential as well as its low immunogenicity. The transplantation of MSC can help the repair of the injured organs, however, the MSC transplanted to the local organs are affected by oxidative stress and lead to premature aging or apoptosis. Heme oxygenase 1 (HO1) is a key ratelimiting enzyme in the process of heme metabolism, which has the functions of antiinflammation, antioxidation, antiapoptosis, antiaging, reducing cell damage and promoting angiogenesis. Induced high expression of HO1 in MSC could increase the ability of MSC against oxidative stress injury, delay the senescence and apoptosis of MSC, and alleviate cell injury. In this reviews, the research progress of HO1 on antioxidative stress injury of MSC.

Sagittaria sagittifolia polysaccharides regulates Nrf2/HO-1 to relieve liver injury caused by multiple heavy metals in vivo and in vitro / 中国中药杂志

This study explored whether Sagittaria sagittifolia polysaccharides(SSP) activates the nuclear factor erythroid-2-related factor2(Nrf2)/heme oxygenase-1(HO-1) signaling pathway to protect against liver damage jointly induced by multiple heavy metals. First, based on the proportion of dietary intake of six heavy metals in rice available in Beijing market, a heavy metal mixture was prepared for inducing mouse liver injury and HepG2 cell injury. Forty male Kunming mice were divided into five groups: control group, model group, glutathione positive control group, and low-and high-dose SSP groups, with eight mice in each group. After 30 days of intragastric administration, the liver injury in mice was observed by HE staining. In the in vitro experiment, MTT assay was conducted to detect the effects of SSP at 0.25, 0.5, 1, and 2 mg·mL~(-1) on HepG2 cell survival at different time points. The content of alanine transaminase(ALT) and aspartate aminotransferase(AST) in the 48-h cell culture fluid was measured using micro-plate cultivation method, followed by the detection of the change in reactive oxygen species(ROS) content by flow cytometry. The mRNA expression levels of Nrf2 and HO-1 in cells were determined by RT-PCR, and their protein expression by Western blot. HE staining results showed that compared with the model group, the SSP administration groups exhibited significantly alleviated inflammatory cell infiltration and fatty infiltration in the liver, with better outcomes observed in the high-dose SSP group. In the in vitro MTT assay, compared with the model group, SSP at four concentrations all significantly increased the cell survival rate, decreased the ALT, AST, and ROS content(P<0.05), and down-regulated Nrf2 and HO-1 mRNA and protein expression(P<0.05). SSP significantly improves inflammatory infiltration in the liver tissue of mice exposed to a variety of heavy metals and corrects the liver fat degeneration, which may be related to its regulation of the Nrf2/HO-1 signaling pathway, reduction of ROS, and alleviation of oxidative damage.

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.

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.

Bone marrow-derived mesenchymal stem cells modulate autophagy in RAW264.7 macrophages via the phosphoinositide 3-kinase/protein kinase B/heme oxygenase-1 signaling pathway under oxygen-glucose deprivation/restoration conditions / 中华医学杂志(英文版)

BACKGROUND@#Autophagy of alveolar macrophages is a crucial process in ischemia/reperfusion injury-induced acute lung injury (ALI). Bone marrow-derived mesenchymal stem cells (BM-MSCs) are multipotent cells with the potential for repairing injured sites and regulating autophagy. This study was to investigate the influence of BM-MSCs on autophagy of macrophages in the oxygen-glucose deprivation/restoration (OGD/R) microenvironment and to explore the potential mechanism.@*METHODS@#We established a co-culture system of macrophages (RAW264.7) with BM-MSCs under OGD/R conditions in vitro. RAW264.7 cells were transfected with recombinant adenovirus (Ad-mCherry-GFP-LC3B) and autophagic status of RAW264.7 cells was observed under a fluorescence microscope. Autophagy-related proteins light chain 3 (LC3)-I, LC3-II, and p62 in RAW264.7 cells were detected by Western blotting. We used microarray expression analysis to identify the differently expressed genes between OGD/R treated macrophages and macrophages co-culture with BM-MSCs. We investigated the gene heme oxygenase-1 (HO-1), which is downstream of the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signaling pathway.@*RESULTS@#The ratio of LC3-II/LC3-I of OGD/R treated RAW264.7 cells was increased (1.27 ± 0.20 vs. 0.44 ± 0.08, t = 6.67, P  < 0.05), while the expression of p62 was decreased (0.77 ± 0.04 vs. 0.95 ± 0.10, t = 2.90, P  < 0.05), and PI3K (0.40 ± 0.06 vs. 0.63 ± 0.10, t = 3.42, P  < 0.05) and p-Akt/Akt ratio was also decreased (0.39 ± 0.02 vs. 0.58 ± 0.03, t = 9.13, P  < 0.05). BM-MSCs reduced the LC3-II/LC3-I ratio of OGD/R treated RAW264.7 cells (0.68 ± 0.14 vs. 1.27 ± 0.20, t = 4.12, P  < 0.05), up-regulated p62 expression (1.10 ± 0.20 vs. 0.77 ± 0.04, t = 2.80, P  < 0.05), and up-regulated PI3K (0.54 ± 0.05 vs. 0.40 ± 0.06, t = 3.11, P  < 0.05) and p-Akt/Akt ratios (0.52 ± 0.05 vs. 0.39 ± 0.02, t = 9.13, P  < 0.05). A whole-genome microarray assay screened the differentially expressed gene HO-1, which is downstream of the PI3K/Akt signaling pathway, and the alteration of HO-1 mRNA and protein expression was consistent with the data on PI3K/Akt pathway.@*CONCLUSIONS@#Our results suggest the existence of the PI3K/Akt/HO-1 signaling pathway in RAW264.7 cells under OGD/R circumstances in vitro, revealing the mechanism underlying BM-MSC-mediated regulation of autophagy and enriching the understanding of potential therapeutic targets for the treatment of ALI.

Effect of Nrf2/HO-1 signaling pathway in intestinal protection by Sishen Pills against ulcerative colitis in mice / 中国中药杂志

The present study aimed to explore the effect of nuclear factor erythroid 2 related factor 2(Nrf2)/heme oxygenase-1(HO-1) signaling pathway in intestinal protection by Sishen Pills against ulcerative colitis(UC). After the UC model was induced by 3% dextran sodium sulfate(DSS), experimental animals were randomly divided into control group, model group, salazosulfapyridine(SASP) group, and low-and high-dose Sishen Pills groups. Drug intervention(ig) was performed for seven consecutive days during modeling. On the 7 th day, the mice were euthanized. The body weight and colon length were recorded, and the histopathological changes of the colon were observed by HE staining. Serum interleukin-6(IL-6), tumor necrosis factor-α(TNF-α), total antioxidant capacity(T-AOC), malondialdehyde(MDA), and reactive oxygen species(ROS) were detected by ELISA. The protein and mRNA expression of Nrf2, HO-1, and NADPH quinine oxidoreductase-1(NQO-1) was determined by Western blot and reverse transcription-polymerase chain reaction(RT-PCR). Compared with the normal group, the model group exhibited reduced body weight, colon length, and T-AOC, increased IL-6, TNF-α, MDA, and ROS, and diminished protein and mRNA expression of Nrf2, HO-1, and NQO-1 in the colon tissues. Compared with the model group, the SASP group and high-dose Sishen Pills group showed elevated body weight, colon length, and T-AOC, lowered IL-6, TNF-α, MDA, and ROS levels, and increased protein and mRNA expression of Nrf2, HO-1, and NQO-1 in the colon tissues. As assessed by HE staining, Sishen Pills could improve the pathological changes of the colon. The findings suggested that Sishen Pills could protect the colon against UC induced by 3% DSS. The specific mechanism of action may be related to the anti-inflammatory and anti-oxidative stress effects by the activation of the Nrf2/HO-1 signaling pathway.

Arsenic Trioxide Combining Leflunomide Activates Nrf2-ARE-HO-1 Signaling Pathway and Protects Heart Xenografts / 中国结合医学杂志

OBJECTIVE@#To investigate the molecular mechanisms underlying the effects of arsenic trioxide (As@*METHODS@#Transplantation of LVG hamster hearts to Lewis rats was performed by anastomosis of vessels in the neck using end-to-end anastomosis with a non-suture cuff technique. Four groups of recipient rats (n=6 in each) were treated with normal saline (control), As@*RESULTS@#Expression of Nrf2-ARE-HO-1 signaling pathway was upregulated in heart xenografts in rats treated with As@*CONCLUSION@#Combination treatment with As

Effect of methyl eugenol on hypoxia/reoxygenation injury of human renal tubular epithelial cells and its mechanism / 中国中药杂志

This study aimed to investigate the effect of methyl eugenol(ME) on hypoxia/reoxygenation(H/R)-induced injury of human renal tubular epithelial HK-2 cells and its mechanism. The viability of HK-2 cells cultured with different concentrations of ME and exposed to H/R was detected by cell counting kit-8(CCK-8) assay. The effect of ME on the morphology of HK-2 cells was observed under an inverted microscope. The content of intracellular reactive oxygen species in different groups was detected after 2',7'-dichlorodihydrofluorescein diacetate(DCFH-DA) fluorescence staining. Cell apoptosis was determined by flow cytometry. Changes in mitochondrial membrane potential were monitored by JC-1 dye. The concentrations of nuclear factor erythroid 2 related factor 2(Nrf2), heme oxygenase-1(HO-1), and nicotinamide adenine dinucleotide phosphatase oxidase 4(Nox4) were measured by Western blot, followed by the assay of Nrf2 concentration changes in cytoplasm and nucleus by confocal fluorescence staining. The results showed that when the concentration of ME was 0-40 μmol·L~(-1), the activity of HK-2 cells was not affected. Compared with the model group, ME enhanced the activity of HK-2 cells and the cell morphology was normal. As revealed by further experiments, ME inhibited the release of reactive oxygen species and the decline in mitochondrial membrane potential of HK-2 cells after H/R injury, promoted Nrf2/HO-1 expression and Nrf2 translocation to the nucleus, and down-regulated the expression of Nox4, thereby significantly reducing apoptosis. This protective effect of ME could be reversed by the specific Nrf2 inhibitor ML385. These findings have preliminarily proved that ME effectively protected HK-2 cells against H/R injury, which might be related to its promotion of Nrf2/HO-1 signaling pathway and inhibition of Nox4. Such exploration on the possible mechanism of ME in the treatment of renal ischemia-reperfusion injury(IRI) and protection of organ function from the perspective of antioxidant stress has provided reference for related research on the treatment of acute kidney injury with traditional Chinese medicine.

The renoprotective effects of Heme Oxygenase-1 during contrast-induced acute kidney injury in preclinical diabetic models

OBJECTIVES: Contrast-induced acute kidney injury (CI-AKI) is an important clinical problem that can be aggravated by diabetes mellitus, a major risk factor. However, heme oxygenase-1 (HO-1), a promising therapeutic target, can exert antioxidant effects against CI-AKI. Thus, we investigated the role of HO-1 in CI-AKI in the presence of diabetes mellitus. METHODS: Twenty-eight male Wistar rats weighing 250-300g were subjected to left uninephrectomy, and concomitantly, diabetes induced by streptozotocin (65 mg/kg). After 12 weeks, iodinated contrast (meglumine ioxithalamate, 6 mL/kg) and hemin (HO-1 inducer-10 mg/k) were administered 60 min before iodinated contrast treatment. The rats were randomly divided into four groups: control, diabetes mellitus (DM), DM iodinated contrast (DMIC), and DMIC hemin (DMICH). Kidney function, albuminuria, oxidative profile, and histology were assessed. All experimental data were subjected to statistical analyses. RESULTS: CI-AKI in preclinical diabetic models decreased creatinine clearance and increased urinary neutrophil gelatinase-associated lipocalin (NGAL) levels and the degree of albuminuria. Additionally, the levels of oxidative and nitrosative stress metabolites (urinary peroxides, thiobarbituric acid-reactive substances, and NO) were elevated, while thiol levels in kidney tissue were reduced. Kidney histology showed tubular cell vacuolization and edema. HO-1 inducer treatment improved kidney function and reduced urinary the NGAL levels. The oxidative profile showed an increase in the endogenous thiol-based antioxidant levels. Additionally, the tubular injury score was reduced following HO-1 treatment. CONCLUSIONS: Our findings highlight the renoprotective effects of HO-1 in CI-AKI and preclinical diabetic models. Therefore, HO-1 ameliorates kidney dysfunction, reduces oxidative stress, and prevents cell necrosis.

Relations of neuropeptide Y and heme oxygenase-1 expressions with fetal brain injury in rats with intrahepatic cholestasis of pregnancy

Abstract Purpose: To investigate the relations of neuropeptide Y (NPY) and heme oxygenase-1 (HO-1) expressions with fetal brain injury in rats with intrahepatic cholestasis of pregnancy (ICP). Methods: Sixty rats pregnant for 15 days were randomly divided into experimental and control groups. The ICP model was established in experimental group. On the 21st day, the blood biochemical test, histopathological examination of pregnant rat liver and fetal brain tissues and immunohistochemical analysis of fetal rat brain tissues were performed. Results: On the 21st day, the alanineaminotransferase, aspartate aminotransferase and total bile acid levels in experimental group were significantly higher than control group (P<0.01). Compared with control group, there was obvious vacuolar degeneration in pregnant rat liver tissue and fetal brain tissue in experimental group. NPY expression in fetal brain tissue was negative in control group and positive in experimental group. HO-1 expression in fetal brain tissue was strongly positive in control group and positive in experimental group. There was significant difference of immunohistochemical staining optical density between two groups (P<0.01). Conclusion: In fetal brain of ICP rats, the NPY expression is increased, and the HO-1 expression is decreased, which may be related to the fetal brain injury.

Effects of propofol pretreatment on lung morphology and heme oxygenase-1 expression in oleic acid-induced acute lung injury in rats

Abstract Purpose: To investigate the effects of propofol pretreatment on lung morphology and heme oxygenase-1 expression in oleic acid -induced acute lung injury in rats. Methods: A total of 32 male Sprague-Dawley rats (250-300g) were randomly divided into the following four groups (n=8/group): group C, group OA, group OA+PR, and group OA+IX to compare related parameter changes. Results: PaO2, PCO2, and PaO2/FiO2 were significantly different among the four treatment groups (P<0.05 or P<0.01). Lung wet/dry weight ratio and HO-1 protein expression also significantly differed among the groups (P<0.01). Immunohistochemistry showed that the expression of HO-1 in group OA+PR was stronger than those in groups OA, OA+IX, and C. Light microscopy revealed that pathological changes in lung tissues in group OA+PR were milder than those in group OA and group OA+IX. Electron microscopy showed that alveolar type II epithelial cell ultrastructure in group OA was relatively irregular with cell degeneration and disintegration and cytoplasmic lamellar bodies were vacuolized. Changes in group OA+PR were milder than those in group OA; however, they were more severe in group OA+IX than in group OA. Conclusion: Propofol significantly increases the expression of HO-1 in the lung tissueand prevents changes in lung morphology due to ALI in rats.

Gastrodin induced HO-1 and Nrf2 up-regulation to alleviate H2O2-induced oxidative stress in mouse liver sinusoidal endothelial cells through p38 MAPK phosphorylation

Nuclear factor erythroid-related factor 2 (Nrf2) has been implicated in several detoxifying and antioxidant defense processes. Nrf2-mediated heme oxygenase-1 (HO-1) expression was demonstrated to play a key role against oxidative stress. Gastrodin (GSTD) is a well-known active compound isolated from the roots of Rhizoma gastrodiae, a plant used in ancient Chinese traditional medicine. The aim of this work was to investigate whether GSTD could alleviate H2O2-induced oxidative stress in mouse liver sinusoidal endothelial cells (LSECs). In LSECs exposed to 1 mM H2O2, treatment with GSTD (1, 10, or 50 µM) resulted in higher cell viability than the untreated control. Treated cells maintained a higher Bcl2/Bax ratio and suppressed caspase-9 expression compared with untreated cells, reducing cell apoptosis. GSTD was protective for H2O2-induced oxidative injury by reducing the generation of intracellular reactive oxygen species and malondialdehyde. HO-1 and Nrf2 expressions were synergistically upregulated by GSTD. Inhibition of HO-1 by 10 µM zinc protoporphyrin resulted in less protective effects on cell viability and malondialdehyde reduction by GSTD treatment in H2O2-exposed LSECs. Additionally, phosphorylated p38 in LSECs exposed to H2O2 was elevated by GSTD. Inhibition of p38 phosphorylation by SB203580 did not induce Nrf2 and HO-1 expression after 1 or 10 µM GSTD treatment and the protective effect on cell viability and malondialdehyde reduction in H2O2-exposed LSECs was reduced. The data conclusively demonstrated that GSTD-induced HO-1 and Nrf2 expression is involved in protection of LSECs from H2O2-induced oxidative injury, which may be regulated by p38 phosphorylation.

Oxymatrine ameliorates renal ischemia-reperfusion injury from oxidative stress through Nrf2/HO-1 pathway

PURPOSE: To investigate if oxymatrine pretreatment could ameliorate renal I/R injury induced in rats and explore the possible role of oxymatrine in Nrf2/HO-1 pathway. METHODS: Unilaterally nephrectomized rats were insulted by I/R in their left kidney. Twenty four rats were randomly divided into three groups: sham group, I/R + saline-treated group, I/R + OMT-treated group. Oxymatrine or vehicle solution was administered intraperitoneally injected 60 min before renal ischemia, respectively. Renal function, histology, makers of oxidative stress, cell apoptosis and Nrf2/HO-1 expressions were assessed. RESULTS: Oxymatrine pretreatment exhibited an improved renal functional recovery, alleviated histological injury and oxidative stress, inhibiting tubular apoptosis, and accompanied by upregulated the expression of Nrf2/HO-1 proteins. CONCLUSION: Oxymatrine may attenuate renal ischemia/reperfusion injury, and this renoprotective effect may be through activating the Nrf2/HO-1 pathway. .

Maternidade atrás das grades: em busca da cidadania e da saúde. Um estudo sobre a legislação brasileira / Motherhood behind bars: the struggle for citizens' rights and health for women inmates and their children in Brazil / La maternidad entre rejas: en búsqueda de la ciudadanía y de la salud. Un estudio sobre la legislación brasileña

Este estudo analisa as conexões entre saúde, direitos, legislação e políticas públicas a partir da pesquisa documental realizada no âmbito federal e nos estados do Rio Grande do Sul, Mato Grosso, Paraná e São Paulo, acerca das garantias legais das mulheres e seus filhos que vivem no cárcere. Busca instrumentalizar uma atuação garantista dos agentes públicos e dar visibilidade à problemática, diante das extremas vulnerabilidades e invisibilidade jurídica e administrativa da questão. Foram identificadas 33 normas legais, com pontos de tensão, como a possibilidade de prisão domiciliar e as disparidades quanto a prazos e condições de permanência das crianças no sistema penitenciário. A garantia legal constitucional do direito à amamentação é refletida nas regulamentações identificadas. Mas constatam-se ausências de outros aspectos relativos à maternidade na prisão, que se traduzem em dupla penalidade às mulheres, arbitrariamente estendida aos seus filhos. É necessária a ampliação e efetivação da regulamentação existente para prevenir e coibir as violações de direitos apontadas.

This study analyzes the links between health, rights, legislation, and public policies based on document research on legal safeguards for women and their children residing in prison. The research was conducted at the Federal level and in four States of Brazil: Rio Grande do Sul, Mato Grosso, Paraná, and São Paulo. The study aims to back measures by public agencies to guarantee such rights and to raise awareness of the problem, given the extreme vulnerability of women inmates and their children and the issue's legal and administrative invisibility. The authors identified 33 different legal provisions as points of tension, such as the possibility of house arrest and disparities in the terms and conditions for children to remain inside the prison system. Various provisions cite the Constitutional guarantee of women inmates' right to breastfeed in prison. Meanwhile, the study found gaps in other issues pertaining to motherhood in prison, expressed as dual incarceration (imprisonment arbitrarily extended to their children). It is necessary to expand and enforce the existing legislation to prevent such violations of rights.

Este estudio analiza las conexiones entre la salud, derechos humanos, legislación y políticas públicas, partiendo de una investigación documental, realizada a nivel federal y en los estados de Río Grande do Sul, Mato Grosso, Paraná y São Paulo, sobre las garantías jurídicas de las mujeres presas y sus hijos. El estudio pretende instrumentalizar una actuación garantista de los agentes públicos y dar visibilidad a esta problemática, frente a la extrema vulnerabilidad e invisibilidad jurídica y administrativa existente. Se identificaron 33 normas legales, con puntos de tensión, como la posibilidad de arresto domiciliario y disparidades en cuanto a los términos y condiciones de la estancia de los niños en el sistema penitenciario. La garantía constitucional del derecho a la lactancia materna se refleja en las regulaciones identificadas. No obstante, hay ausencias de otros aspectos de la maternidad en la cárcel, que se traduce en una doble pena para las mujeres, extendida arbitrariamente a sus hijos. Es necesaria la ampliación y ejecución efectiva de las regulación existente para prevenir y frenar las violaciones de los derechos.

Nitro-fatty acids: novel anti-inflammatory lipid mediators

Nitro-fatty acids are formed and detected in human plasma, cell membranes, and tissue, modulating metabolic as well as inflammatory signaling pathways. Here we discuss the mechanisms of nitro-fatty acid formation as well as their key chemical and biochemical properties. The electrophilic properties of nitro-fatty acids to activate anti-inflammatory signaling pathways are discussed in detail. A critical issue is the influence of nitroarachidonic acid on prostaglandin endoperoxide H synthases, redirecting arachidonic acid metabolism and signaling. We also analyze in vivo data supporting nitro-fatty acids as promising pharmacological tools to prevent inflammatory diseases.

Cyclooxygenase-2 and hypoxia-regulated proteins are modulated by basic fibroblast growth factor in acute renal failure

Acute renal failure (ARF) can be caused by injuries that induce tissue hypoxia, which in turn can trigger adaptive or inflammatory responses. We previously showed the participation of basic fibroblast growth factor (FGF-2) in renal repair. Based on this, the aim of this study was to analyze the effect of FGF-2 signaling pathway manipulation at hypoxia-induced protein levels, as well as in key proteins from the vasoactive systems of the kidney. We injected rat kidneys with FGF-2 recombinant protein (r-FGF) or FGF-2 receptor antisense oligonucleotide (FGFR2-ASO) after bilateral ischemia, and evaluated the presence of iNOS, EPO and HO-1, in representation of hypoxia-induced proteins, as well as COX-2, renin, kallikrein, and B2KR, in representation of the vasoactive systems of the kidney. A reduction in iNOS, HO-1, EPO, renin, kallikrein, B2KR, and in renal damage was observed in animals treated with r-FGF. The opposite effect was found with FGF-2 receptor down-regulation. In contrast, COX-2 protein levels were higher in kidneys treated with r-FGF and lower in those that received FGFR2-ASO, as compared to saline treated kidneys. These results suggest that the protective role of FGF-2 in the pathogenesis of ARF induced by I/R is a complex process, through which a differential regulation of metabolic pathways takes place.

Biliverdin reductase A in the prevention of cellular senescence against oxidative stress

Biliverdin reductase A (BLVRA), an enzyme that converts biliverdin to bilirubin, has recently emerged as a key regulator of the cellular redox cycle. However, the role of BLVRA in the aging process remains unclear. To study the role of BLVRA in the aging process, we compared the stress responses of young and senescent human diploid fibroblasts (HDFs) to the reactive oxygen species (ROS) inducer, hydrogen peroxide (H2O2). H2O2 markedly induced BLVRA activity in young HDFs, but not in senescent HDFs. Additionally, depletion of BLVRA reduced the H2O2-dependent induction of heme oxygenase-1 (HO-1) in young HDFs, but not in senescent cells, suggesting an aging-dependent differential modulation of responses to oxidative stress. The role of BLVRA in the regulation of cellular senescence was confirmed when lentiviral RNAitransfected stable primary HDFs with reduced BLVRA expression showed upregulation of the CDK inhibitor family members p16, p53, and p21, followed by cell cycle arrest in G0-G1 phase with high expression of senescence-associated beta-galactosidase. Taken together, these data support the notion that BLVRA contributes significantly to modulation of the aging process by adjusting the cellular oxidative status.

Immunohistochemical expression of HO-1 in traumatic human brain tissue / 法医学杂志

OBJECTIVE@#To investigate the expression of heme oxygenase-1 (HO-1) at different intervals and to provide evidence for estimation on injury intervals after brain contusion in human.@*METHODS@#Twenty-four patients died of serious brain injury were assigned as injury group and 4 patients died of non-brain injury were served as control group. HO-1 expression was analyzed in brain tissue at different time intervals (3 h, 6-9 h, 12-24 h, 36 h-3d, 5-8d, 17-20d) by immunohistochemistry and auto-image analysis system.@*RESULTS@#The level of HO-1 expression started to increase in 3 h after brain contusion compared to the control group (P < 0.05). The level of HO-1 expression highest level in 12-24 h group, and maintained high level in 36 h-3 d, then decreased gradually.@*CONCLUSION@#The expression of HO-1 might be a strong evidence for human brain contusion time estimation.