[Effect of hyperoxic exposure on the expression of heme oxygenase-1 and glutamate-L-cysteine ligase catalytic subunit in lung tissue of preterm rats]

OBJECTIVE

To study the effect of hyperoxic exposure on the dynamic expression of heme oxygenase-1 (HO-1) and glutamate-L-cysteine ligase catalytic subunit (GCLC) in the lung tissue of preterm neonatal rats.

METHODS

Cesarean section was performed for rats on day 21 of gestation to obtain 80 preterm rats, which were randomly divided into air group and hyperoxia group after one day of feeding. The rats in the air group were housed in room air under atmospheric pressure, and those in the hyperoxia group were placed in an atmospheric oxygen tank (oxygen concentration 85%-95%) in the same room. Eight rats each were selected from each group on days 1, 4, 7, 10, and 14, and lung tissue samples were collected. Hematoxylin and eosin staining was used to observe the pathological changes of lung tissue at different time points after air or hyperoxic exposure. Western blot and RT-qPCR were used to measure the protein and mRNA expression of HO-1 and GCLC in the lung tissue of preterm rats at different time points after air or hyperoxic exposure.

RESULTS

Compared with the air group, the hyperoxia group had a significant reduction in the body weight (P<0.05). Compared with the air group, the hyperoxia group had structural disorder, widening of alveolar septa, a reduction in the number of alveoli, and simplification of the alveoli on the pathological section of lung tissue. Compared with the air group, the hyperoxia group had significantly lower relative mRNA expression of HO-1 in the lung tissue on day 7 and significantly higher expression on days 10 and 14 (P<0.05). Compared with the air group, the hyperoxia group had significantly lower mRNA expression of GCLC in the lung tissue on days 1, 4, and 7 and significantly higher expression on day 10 (P<0.05). Compared with the air group, the hyperoxia group had significantly higher protein expression of HO-1 in the lung tissue on all days, and the protein expression of GCLC had same results as HO-1, except on day 1 (P<0.05).

CONCLUSIONS

Hyperoxia exposure may lead to growth retardation and lung developmental retardation in preterm rats. Changes in the protein and mRNA expression of HO-1 and GCLC in the lung tissue of preterm rats may be associated with the pathogenesis of hyperoxia-induced lung injury in preterm rats.

[Expression of Cell Cycle, Oxidative Stress, and Apoptosis Related Genes Chek1, Hmox1, Casp7 in Rat Liver Exposed to Carbon Tetrachloride]

Carbon tetrachloride is a well-studied hepatotropic poison. Animal models of exposure to carbon tetrachloride resemble acute liver damage in humans. This paper presents the study of the expression of genes related to cell cycle control, apoptosis, and oxidative stress in a model of carbon tetrachloride-induced toxic hepatitis in rats. White mongrel male rats were injected with a 50% oil solution of carbon tetrachloride at a dose of 0.125-4.000 g/kg (experimental group) or olive oil (control group). The animals were decapitated 24 and 72 h after the administration of carbon tetrachloride, and the qRT-PCR expression levels of the genes encoding hemoxygenase-1 (Hmox1), cell cycle checkpoint kinase-1 (Chek1), and caspase-7 (Casp7) in the liver were analyzed. The increase in the expression levels of Hmox1 and Chek1 after exposure was detected. These genes may either play a role in promoting pathological oxidative stress in the liver or be a part of a stress response. We have concluded that the major pathway of the liver damage in carbon tetrachloride exposed animals is necrosis rather than apoptosis.

Carbon monoxide modulates melatonin synthesis in porcine pineal Cells in vitro: a preliminary study

Two main isoforms of heme oxygenase (HO-1 and HO-2), the main enzyme of heme metabolism, were identified in the pineal gland. This suggests possible interactions between the melatonin synthesis pathway and the HO system. The aim of this study was to investigate the participation of carbon monoxide (CO), an HO by-product, on the melatonin synthesis pathway. Tests were carried using primary cell cultures of porcine pineal glands. The tricarbonyldichlororuthenium (II) dimer (CORM-2) compound was used as a CO donor at concentrations of 1 and 3 μM, as low concentrations of CORM-2 affect the regulation of the melatonin synthesis pathway in pineal cells in vitro. In addition, the presence of Sn-protoporphyrin-IX, an HO inhibitor, changed the melatonin response of pineal cells. These results suggest the existence of an intermediate mechanism in the pineal gland, which is associated with HO activity, that is involved in the modulation of melatonin synthesis.

Epigallocatechin-3-gallate attenuates microcystin-LR-induced apoptosis in human umbilical vein endothelial cells through activation of the NRF2/HO-1 pathway

Our previous study showed that the tea extract, epigallocatechin-3-gallate (EGCG), protects against microcystin-LR (MC-LR) -mediated apoptosis of human umbilical vein endothelial cells (HUVECs); however, the mechanism underlying MC-LR-induced HUVEC apoptosis remains incompletely understood. In this study, we investigated whether the nuclear factor erythroid-like 2 (NRF2)/heme oxygenase-1 (HO-1) pathway, which regulates antioxidant transcriptional regulation of oxidative stress and apoptosis, is involved in this process. Mitochondrial membrane potential (MMP) and caspase-3/-9 activities were evaluated in HUVECs by JC-1 staining and colorimetric activity assay, and a DCFH-DA fluorescent probe assay was used to quantitate reactive oxygen species (ROS) generation. The effects of MC-LR, EGCG, NF2, and HO-1 on HUVEC apoptosis were explored by western blotting and small interfering RNA (siRNA) analyses. MC-LR treatment downregulated HUVEC mitochondrial membrane potential, and decreased levels of cytochrome c release and activated caspase-3/-9, ROS generation, consequently inducing HUVEC apoptosis. EGCG treatment attenuated MC-LR-mediated HUVEC oxidative stress and mitochondria-related apoptosis. EGCG induced NRF2/HO-1 expression and activation in MC-LR treated HUVECs, while downregulation of NRF2/HO-1 by specific siRNAs revealed that NRF2/HO-1 signaling was involved in EGCG attenuation of MC-LR-induced HUVEC apoptosis. Our findings indicate that EGCG treatment protects against MC-LR-mediated HUVEC apoptosis via activation of NRF2/HO-1 signaling.

[HO-1Cδ23 reduces the permeability of the blood-spinal barrier by upregulating miR-125a-5p after hypoxic injury]

Objective To detect the effects of microRNA 125a-5p (miR-125a-5p) in heme oxygenase 1 (HO-1) truncation (HO-1Cδ23) regulating the blood-spinal barrier (BSCB) after hypoxic injury. Methods HCMEC/D3 and astrocytes were co-cultured in Transwell^TM chamber to establish BSCB model in vitro, and then prepared with cobalt chloride to establish BSCB hypoxic injury model. The experiment was divided into blank group, non-virus loading group, HO-1Cδ23 group (Lv-HO-1Cδ23), miRNA negative control group (Lv-HO-1Cδ23 combined with miR-NC treatment), miRNA mimic group (Lv-HO-1Cδ23 combined with miR-125a-5p mimics treatment) and miRNA inhibitor group (Lv-HO-1Cδ23 combined with miR-125a-5p inhibitor treatment). The expression levels of miR-125a-5p and zonula occludens-1 (ZO-1), occludin and vascular endothelial adhesion protein (VE-cadherin) were detected by reverse transcription PCR and real-time quantitative PCR. Western blot was used to detect the expressions of HO-1, ZO-1, occludin and VE-cadherin proteins. The permeability of BSCB in vitro was evaluated by the spillage rate of horseradish peroxidase (HRP). Results The success rate of HO-1Cδ23 transfection was about 70%. After transfection, the content of HO-1Cδ23 was significantly increased, and the expression of miR-125a-5p up-regulated compared with the blank group. Compared with the blank group, the mRNA and protein levels of ZO-1, occludin, and VE-cadherin in the HO-1Cδ23 group, the miRNA negative control group, and miRNA mimic group increased, but the HRP spillover rate decreased; on the contrary, the mRNA and protein levels of ZO-1 occludin and VE-cadherin in the miRNA inhibitor group decreased, while the HRP spillover rate increased significantly. Compared with the HO-1Cδ23 group, the mRNA and protein levels of ZO-1, occludin and VE-cadherin increased significantly in the miRNA mimic group, and the HRP spillover rate decreased significantly, while the mRNA and protein levels of ZO-1, occludin, and VE-cadherin as well as the HRP spillover rate in the miRNA inhibitor group showed the opposite trend. Conclusion Under hypoxic injury, HO-1Cδ23 may promote the transcription and translation of the genes involved in junction and adhesion and reduce the permeability of BSCB by up-regulating the expression of miR-125a-5p.

MicroRNA Profiling of Transgenic Mice with Myocardial Overexpression of Nucleolin

BACKGROUND

Nucleolin (NCL) is the most abundant RNA-binding protein in the cell nucleolus and plays an important role in chromatin stability, ribosome assembly, ribosomal RNA maturation, ribosomal DNA transcription, nucleocytoplasmic transport, and regulation of RNA stability and translation efficiency. In addition to its anti-apoptotic properties, the underlying mechanisms associated with NCL-related roles in different cellular processes remain unclear. In this study, the effect of NCL on microRNA (miRNA) expression was evaluated by generating transgenic mice with myocardial overexpression of NCL and by analyzing microarrays of mature and precursor miRNAs from mice.

METHODS

Using microinjection of alpha-MyHc clone 26-NCL plasmids, we generated transgenic mice with myocardial overexpression of NCL firstly, and then mature and precursor miRNAs expression profiles were analyzed in NCL transgenic mice (n = 3) and wild-type (WT) mice (n = 3) by miRNA microarrays. Statistical Package for the Social Sciences version 16.0 software (SPSS, Inc., Chicago, IL, USA) was used to perform Student's t-test, and statistical significance was determined at P < 0.05.

RESULTS

Several miRNAs were found to be differentially expressed, of which 11 were upregulated and 4 were downregulated in transgenic mice with myocardial overexpression of NCL compared to those in WT mice. Several differentially expressed miRNAs were subsequently confirmed and quantified by real-time quantitative reverse transcription-polymerase chain reaction. Bioinformatics analysis was used for the prediction of miRNA targets. Furthermore, in vitro experiments showed that NCL regulated miR-21 expression following hydrogen peroxide preconditioning.

CONCLUSIONS

Myocardial-protection mechanisms exerted by NCL might be mediated by the miRNAs identified in this study.

Effects of bioactive constituents in the Traditional Chinese Medicinal formula Si-Wu-Tang on Nrf2 signaling and neoplastic cellular transformation

BACKGROUND

The nuclear factor erythroid 2-related factor 2 (Nrf2) is a potential molecular target for cancer chemoprevention. Si-Wu-Tang (SWT), a popular traditional Chinese medicine for women's health, was reported with a novel activity of cancer prevention.

PURPOSE

The present study was aimed to identify the bioactive constituents in SWT responsible for the Nrf2 activating and cancer preventive activity and explore the pharmacological mechanisms.

METHODS

Nine compounds detectable from various batches of SWT were ranked using in silico molecular docking based on their ability to interfere the forming of Nrf2-Keap1 complex. The predicted Nrf2 activating effect was validated using the antioxidant response element (ARE) luciferase reporter assay and quantitative RT-PCR analysis for select Nrf2 regulated genes Hmox1, Nqo1 and Slc7a11. The antimutagenic activity of the compounds were determined by the Ames test. The chemopreventive activity of these compounds were assessed on EGF-induced neoplastic transformation of JB6 P+ cells, an established non-cancerous murine epidermal model for studying tumor promotion and identifying cancer preventive agents. These compounds were further characterized using luciferase reporter assay on EGF-induced activation of AP-1, a known transcription factor mediating carcinogenesis.

RESULTS

Three of the nine compounds predicted as Nrf2 activators by molecular docking, gallic acid (GA), Z-liguistilide (LIG), and senkyunolide A (SA), were confirmed with highest potency of increasing the Nrf2/ARE promoter activity and upregulating the expression of Hmox1, Nqo1 and Slc7a11. In addition, GA, LIG and SA exhibited an antimutagenic activity against the direct mutagen 2-nitrofluorene while no mutagenic effects were observed at the same time in Ames test. At nontoxic concentrations, GA, LIG, and SA inhibited EGF-induced neoplastic transformation of JB6 P+ cells. Combined treatment of GA, LIG and SA, in the same ratio as detected in SWT, showed enhanced effect against JB6 transformation compared with that of the single compound alone. GA, LIG and SA, alone or in combination, suppressed EGF-induced activation of AP-1.

CONCLUSION

We identified three bioactive constituents in SWT responsible for the Nrf2 activating and cancer preventive activity. This study provides evidence supporting novel molecular basis of SWT in cancer prevention.

Genetic association and epistatic interaction of the interleukin-10 signaling pathway in pediatric inflammatory bowel disease

AIM

To study the genetic association and epistatic interaction of the interleukin (IL)-10 and IL-10/STAT3 pathways in pediatric inflammatory bowel disease (IBD).

METHODS

A total of 159 pediatric inflammatory IBD patients (Crohn’s disease, n = 136; ulcerative colitis, n = 23) and 129 matched controls were studied for genetic association of selected single nucleotide polymorphisms (SNPs) of the IL-10 gene and the genes IL10RA, IL10RB, STAT3, and HO1, from the IL-10/STAT3 signaling pathway. As interactions between SNPs from different loci may significantly affect the associated risk for disease, additive (a) and dominant (d) modeling of SNP interactions was also performed to examine high-order epistasis between combinations of the individual SNPs.

RESULTS

The results showed that IL-10 rs304496 was associated with pediatric IBD (P = 0.022), but no association was found for two other IL-10 SNPs, rs1800872 and rs2034498, or for SNPs in genes IL10RA, IL10RB, STAT3, and HO1. However, analysis of epistatic interaction among these genes showed significant interactions: (1) between two IL-10 SNPs rs1800872 and rs3024496 (additive-additive P = 0.00015, Bonferroni P value (Bp) = 0.003); (2) between IL-10RB rs2834167 and HO1 rs2071746 (dominant-additive, P = 0.0018, Bp = 0.039); and (3) among IL-10 rs1800872, IL10RB rs2834167, and HO1 rs2071746 (additive-dominant-additive, P = 0.00015, Bp = 0.005), as well as weak interactions among IL-10 rs1800872, IL-10 rs3024496, and IL-10RA (additive-additive-additive, P = 0.003; Bp = 0.099), and among IL10RA, IL10RB, and HO1 genes (additive-dominant-additive, P = 0.008, Bp = 0.287).

CONCLUSION

These results indicate that both the IL-10 gene itself, and through epistatic interaction with genes within the IL-10/STAT3 signaling pathway, contribute to the risk of pediatric IBD.

A novel antioxidant peptide, purified from Bacillus amyloliquefaciens, showed strong antioxidant potential via Nrf-2 mediated heme oxygenase-1 expression

A novel antioxidant peptide YD1 (∼1.0kDa), purified from the strain Bacillus amyloliquefaciens CBSYD1, displayed activity in several in vitro assays and was also efficient against Gram-positive, Gram-negative as well as multidrug-resistant (MDR) bacteria. Strain growth was adapted to bile-salt conditions where a clear halos-zone was observed in a bile-salt plate assay and was viable in different digestive track conditions. YD1 treatment on RAW 264.7 cells increased the transcriptional and translational activities of NF-E2-related factor-2 (Nrf-2) through the enhanced levels of heme oxygenase-1 (HO-1). Furthermore, the YD1-treated group showed higher levels of antioxidant enzymes compared to the oxidative stress group. YD1 demonstrated a strong antioxidant activity by decreasing nitric oxide (NO) and reactive oxygen species (ROS) in RAW 264.7 cells. This study suggests that YD1 and the strain could be a natural antioxidant and a probiotic candidate respectively.

Moringa oleifera Lam. improves lipid metabolism during adipogenic differentiation of human stem cells

OBJECTIVE

Moringa oleifera Lam., a multipurpose tree, is used traditionally for its nutritional and medicinal properties. It has been used for the treatment of a variety of conditions, including inflammation, cancer and metabolic disorders.

MATERIALS AND METHODS

We investigated the effect of Moringa oleifera Lam. on adipogenic differentiation of human adipose-derived mesenchymal stem cells and its impact on lipid metabolism and cellular antioxidant systems.

RESULTS

We showed that Moringa oleifera Lam. treatment during adipogenic differentiation reduces inflammation, lipid accumulation and induces thermogenesis by activation of uncoupling protein 1 (UCP1), sirtuin 1 (SIRT1), peroxisome proliferator-activated receptor alpha (PPARα), and coactivator 1 alpha (PGC1α). In addition, Moringa oleifera Lam. induces heme oxygenase-1 (HO-1), a well established protective and antioxidant enzyme. Finally Moringa oleifera Lam. significantly decreases the expression of molecules involved in adipogenesis and upregulates the expression of mediators involved in thermogenesis and lipid metabolism.

CONCLUSIONS

Our results suggest that Moringa oleifera Lam. may promote the brown remodeling of white adipose tissue inducing thermogenesis and improving metabolic homeostasis.

Update on Endovascular Treatment of Cerebrovascular Diseases

Several developments in endovascular technology have greatly expanded the application of these techniques to treat extra- and intracranial cerebrovascular diseases. This review explores the indications, techniques, and clinical results for endovascular treatment of ischemic stroke and intracranial stenoses, aneurysms, and arteriovenous malformations.

Heme Oxygenase-1 Mediates Up-Regulation of Adhesion Molecule Expression Induced by Peroxynitrite in Endothelial Cells

OBJECTIVE

Endothelial cell (EC) activation with up-regulation of cellular adhesion molecule (CAM) expression is a pathophysiologic feature in preeclampsia (PE). Enhanced peroxynitrite formation in the vasculature of women with PE was also reported. This study was to test whether EC oxidative stress induced by peroxynitrite could up-regulate EC CAM expression, and whether heme oxygenase-1 (HO-1) has protective effects on this peroxynitrite-induced cellular response.

METHODS

Confluent ECs were stimulated with 3-morpholinosydnonimine-HCl (SIN-1, a peroxynitrite generator) alone or combined with Mn(III) tetrakis (1-methyl-4-pyridyl) porphyrin pentachloride (MnTMPyP, a peroxynitrite scavenger) up to 4 hours. EC surface protein expressions for ICAM, VCAM, P-selectin, and E-selectin were measured by colorimetric assay. ECs were also treated with Sn(IV) mesophorphyrin IX dichloride (SnMP, a HO-1 inhibitor) to determine if HO-1 was involved in the increased CAM expression in stressed cells. Protein and mRNA expressions for HO-1 were determined by Western blot analysis and reverse-transcriptase polymerase chain reaction (RT-PCR). Data are presented as the mean +/- SE and analyzed by analysis of variance (ANOVA).

RESULTS

Endothelial CAM expressions for VCAM, P-selectin, and E-selectin, but not ICAM, were significantly increased in SIN-1-treated ECs. Protein and mRNA expressions for HO-1 were also up-regulated in cells treated with SIN-1. MnTMPyP blocked both mRNA and protein expressions for HO-1, whereas SnMP only blocked HO-1 protein expression. Both MnTMPyP and SnMP abolished SIN-1-induced up-regulation of VCAM, P-selectin, and E-selectin expression in ECs.

CONCLUSIONS

Peroxynitrite-induced EC oxidative stress produces differential effects on CAM expression, which may be mediated by HO-1 regulation. Our results suggest that increased peroxynitrite formation in the maternal vasculature may contribute to the increased CAM expression and enhanced neutrophil-endothelial interaction associated with PE.

Differential Cellular and Subcellular Localization of Heme-Binding Protein 23/Peroxiredoxin I and Heme Oxygenase-1 in Rat Liver

Heme-binding protein 23 (HBP23), also termed peroxiredoxin (Prx) I, and heme oxygenase-1 (HO-1) are distinct antioxidant stress proteins that are co-ordinately induced by oxidative stress. HBP23/Prx I has thioredoxin-dependent peroxidase activity with high binding affinity for the pro-oxidant heme, while HO-1 is the inducible isoform of the rate-limiting enzyme of heme degradation. We investigated the cellular and subcellular localization of both proteins in rat liver. Whereas by immunohistochemistry (IHC) a uniformly high level of HBP23/Prx I expression was observed in liver parenchymal and different sinusoidal cells, HO-1 expression was restricted to Kupffer cells. By immunoelectron microscopy using the protein A-gold technique, HBP23/Prx I immunoreactivity was detected in cytoplasm, nuclear matrix, mitochondria, and peroxisomes of parenchymal and non-parenchymal liver cell populations. In contrast, the secretory pathway, i.e., the endoplasmic reticulum and Golgi complex, was free of label. As determined by immunocytochemical (ICC) studies in liver cell cultures and by Western and Northern blotting analysis, HBP23/Prx I was highly expressed in cultures of isolated hepatocytes and Kupffer cells. In contrast, HO-1 was constitutively expressed only in Kupffer cell cultures but was also inducible in hepatocytes. These data suggest that HBP23/Prx I and HO-1 may have complementary antioxidant functions in different cell populations in rat liver.

Bartter/Gitelman syndromes as a model to study systemic oxidative stress in humans

Reactive oxygen species (ROS) are intermediates in reduction-oxidation reactions that begin with the addition of one electron to molecular oxygen, generating the primary ROS superoxide, which in turn interacts with other molecules to produce secondary ROS, such as hydrogen peroxide, hydroxyl radical, and peroxynitrite. ROS are continuously produced during metabolic processes and are deemed to play an important role in cardiovascular diseases, namely, myocardial hypertrophy and fibrosis and atherosclerosis, via oxidative damage of lipids, proteins, and deoxyribonucleic acid. Angiotensin II (Ang II) is a potent vasoactive agent that also exerts mitogenic, proinflammatory, and profibrotic effects through several signaling pathways, in part involving ROS, particularly superoxide and hydrogen peroxide. Moreover, Ang II stimulates NADPH oxidases, leading to higher ROS generation and oxidative stress. Bartter/Gitelman syndrome patients, despite elevated plasma renin activity, Ang II, and aldosterone levels, exhibit reduced peripheral resistance, normal/low blood pressure, and blunted pressor effect of vasoconstrictors. In addition, notwithstanding the activation of the renin-angiotensin system and the increased plasma levels of Ang II, these patients display decreased production of ROS, reduced oxidative stress, and increased antioxidant defenses. In fact, Bartter/Gitelman syndrome patients are characterized by reduced levels of p22(phox) gene expression and undetectable plasma peroxynitrite levels, while showing increased plasma antioxidant power and expression of antioxidant enzymes, such as heme oxygenase-1. In conclusion, multifarious data suggest that Bartter and Gitelman syndrome patients are a model of low oxidative stress and high antioxidant defenses. The contribution offered by the study of these syndromes in elucidating the molecular mechanisms underlying this favorable status could offer chances for new therapeutic targets in disease characterized by high levels of reactive oxygen species.

[Effect of PON1 overexpression on mouse diaphragmatic muscle cells injury caused by acute dichlorvos poisoning]

OBJECTIVE

To investigate the effect of paraoxonase1 (PON1) overexpression on mouse diaphragmatic muscle cells injury caused by acute dichlorvos poisoning.

METHODS

Mouse diaphragmatic muscle cells were cultured routinely and infected with overexpression lentivirus. Cells were divided into normal control group, DDVP group, LV-GFP + DDVP group, LV-PON1 + DDVP group. Cell viability was determined by CCK-8 assay. Flow cytometry was used to detect cell apoptosis. The mRNA and protein expression of PON1 and Nrf2 in mouse diaphragmatic muscle cells was measured by RT-PCR and Western blot. Enzyme-linked immunosorbent assay was used to determine levels of acetyl cholinesterase (AchE), heme oxygenase 1 (HO-1) and quinone oxidoreductase-1 (NQO-1) in mouse diaphragmatic muscle cells. The activity of superoxide dismutase (SOD) and catalase (CAT) as well as malondialdehyde (MDA) content in cells was measured by chemical colorimetry.

RESULTS

After induced by 0, 80, 160, 320, 640 µmol/L DDVP for 24 hours, the viability of mouse diaphragmatic muscle cells was (100 ± 3.82)%, (82.13 ± 2.60)%, (53.57 ± 5.05)%, (30.77 ± 3.30)%, (14.20 ± 2.19)% respectively, changing in a concentration-dependent manner (P < 0.05). After induced by 160 µmol/L DDVP for 0, 6, 12, 24 hours, the viability of mouse diaphragmatic muscle cells was (100.17 ± 2.74)%, (76.13 ± 6.01)%, (66.53 ± 3.55)%, (53.57 ± 5.05)%, changing in a time-dependent manner (P < 0.05). The PON1 protein level in LV-PON1 group was higher than that of blank control group (0.370 ± 0.015 vs 0.232 ± 0.004, 0.197 ± 0.015 vs 0.037 ± 0.003, P < 0.05). The cell viability of LV-PON1 group is higher than that of DDVP group at different time point after induction of DDVP (P < 0.05). After induced by DDVP for 24 hours, the cell apoptosis rate and MDA content in LV-PON1 group were lower than those of DDVP group (P < 0.05). While levels of AchE, PON1 and Nrf2 protein expression, SOD and CAT, HO-1 and NQO-1 were higher than those of DDVP group (P < 0.05).

CONCLUSIONS

The overexpression of PON1 could effectively alleviate AchE inhibition by DDVP and induce Nrf2 expression to exert antioxidant effect, thus protected the mouse diaphragmatic muscle cells.

[The role of heme oxygenase-1 in the protection of chronic intermittent hypoxia-induced lung injury in vivo]

OBJECTIVE

To investigate the effect of chronic intermittent hypoxia (CIH) on inflammatory and pathological changes of the lung in an animal model as well as the protective effect of heme oxygenase-1 in this process.

METHODS

Twenty-four Male Sprague-Dawley rats were randomly divided into 4 groups: intermittent normoxia (IN) group, CIH group, IN+hemin injection (hemin) group and CIH+hemin injection (CIH+hemin) group. The CIH profiling was repetitive 4 min 10% O₂and 2 min 21% O₂for 8 hours per day for 6 weeks. Animals exposed to IN were kept in an identical chamber receiving intermittent air at the same flow rate. Hemin was intraperitoneally injected (4 mg/kg) to induced HO-1 expression, and other 2 groups only received an injection of same amount of saline. Western blot was utilized to detect the pulmonary HO-1 expression levels and ELISA was used to examine the pulmonary cytokine levels. H&E staining was used to investigate pathological changes of the lung.

RESULTS

CIH significantly induced HO-1 expression in the lung and hemin induced a synergistic increase of HO-1 expression. CIH exposure significantly increased pulmonary inflammatory cytokines levels, TNF-α [(2.20 ± 0.10) vs (1.80 ± 0.08) ng/ml], IL-6 [(0.87 ± 0.05) vs (0.52 ± 0.05) ng/ml], CINC-1 [(66 ± 6) vs (39 ± 5) pg/ml] and MCP-1 [(2.20 ± 0.09) vs (1.40 ± 0.10) ng/ml], accelerated cell apoptosis and induced pathological changes of the lung, while hemin could inhibit the elevation of cytokines [(TNF-α:(1.60 ± 0.20) ng/ml, IL-6: (0.60 ± 0.07) ng/ml, CINC-1: (45 ± 6) pg/ml, MCP-1: (1.80 ± 0.10) ng/ml, all P<0.05] and cell apoptosis, as well as reversing the structural injury of the lung under CIH condition.

CONCLUSIONS

CIH leads to inflammatory stress, cell apoptosis and pathological changes within the lung, while HO-1 could inhibit inflammation and apoptosis, thereby reversing the pulmonary injury.

[Regulation of α-tocopherol on NFκB and Nrf2 signaling pathway at early stage of N-nitrosomethylbenzylamine⁃induced human esophageal cell carcinogenesis]

OBJECTIVE

To investigate the regulation of α-Tocopherol on NFκB and Nrf2 signaling pathway at early stage of N-nitrosomethylbenzylamine (NMBzA)-induced human esophageal carcinogenesis.

METHODS

Human normal esophageal HET-1A cells were treated with NMBzA at 50 µmol/L, 100 µmol/L for 24 h to intimate the initiation of esophageal carcinogenesis. For intervention groups, HET-1A cells were pre-treated with α-T at 25, 50, 100 µmol/L for 3 h and then co-treated with NMBzA (100 µmol/L) for 24 h. In comparison with HET-1A cells, human esophageal cancer EC109 cells were treated with α-T at corresponding concentrations. Cells treated with 0.1% DMSO were used as negative control. Immunofluorence staining was used for the determination of distribution and activation of NFκB p65 and Nrf2 in the cell. Real time PCR and Western blot were used to determine the expression levels of target genes including cyclinD1, KI67, proliferating cell nuclear antigen (PCNA), cyclo-oxygen-ase 2 (COX2), 5LOX, HO-1, NQO1 and GCLC. Flow cytometry was utilized to analyze the reactive oxygen species contents in the cells.

RESULTS

As compared to the control group (1.00 ± 0.08), the expression of CyclinD1 (2.99 ± 0.15), KI67 (2.35 ± 0.38) and PCNA (2.46 ± 0.25) in HET-1A were all markedly increased by NMBzA treatment (F values were 97.23, 65.28, 34.62, P < 0.001). Also, the proportion of cells with nucleus translocation of NFκB p65 (71.0%, 98/138) or Nrf2 (36.3%, 49/135) were significantly increased (χ² values were 194.71, 133.72, P < 0.001), and the expression of COX2 (3.22 ± 0.17), 5LOX (2.87 ± 0.12) as well as HO-1 (1.87 ± 0.22), NQO1 (2.14 ± 0.08), GCLC (2.63 ± 0.41) at protein levels were elevated (F values were 72.35, 43.87, 69.23, 71.34, 85.79, P values were 0.013, 0.015, 0.010, 0.011, 0.002). Under the treatment with 50 µmol/L α-T, comparing with the control group(59.1%,65/110),the nuclear translocation of NFκB p65 (77.7%, 8/104) was clearly inhibited (χ² = 148.1, P < 0.001), and protein expression levels of COX2 (0.74 ± 0.19) and 5LOX (0.42 ± 0.13) were decreased (F values were 56.31, 73.25, P values were 0.003, 0.001). However, no changes on Nrf2 signaling pathway were observed; α-T showed little impact on NFκB or Nrf2 pathway in EC109 cells.

CONCLUSIONS

At the early stage of NMBz-induced esophageal cancer, α-T could block the initiation of carcinogenesis through suppressing the activation of NFκB signaling pathway. It might be the major mechanism by which α-T is potentially chemopreventive to esophageal cancer. During the progression of esophageal cancer, the cells may acquire the adaptive functions to accommodate oxidative stress via activating Nrf2 pathway.

[Overexpression of heme oxygenase 1 in spinal cord alleviates bone cancer pain in mice]

OBJECTIVE

To explore the anti-nociceptive effects of heme oxygenase 1 (HO-1) on bone cancer pain in mice.

METHODS

The model of bone cancer pain was established by an inoculation of prostate tumor cell line RM-1 cells into intramedullary space of murine femur. Bone destruction and tumor formation in femur were checked by hematoxylin and eosin staining. The mechanical allodynia and heat hyperalgesia were examined by behavioral testing. After intraperitoneal injections of HO-1 inducer (CoPP) and HO-1 inhibitor (SnPP), the protein content of HO-1 in spinal cord was examined by Western blot.

RESULTS

The invasion of tumor cells into bone and bone destruction were induced by an injection of RM-1 into right femur. The paw withdrawal threshold (PWL) and paw withdrawal latency (PWL) decreased significantly at 7 days after inoculation and maintained for over 21 days. HO-1 inducer CoPP increased PWT and PWL dramatically in mice with bone cancer pain after consecutive intraperitoneal dosing of CoPP for 5 days. However, SnPP unaltered pain behaviors. Western blot showed the expression of HO-1 in spinal cord was up-regulated after an intraperitoneal injection of CoPP and unchanged after an intraperitoneal injection of SnPP.

CONCLUSION

Intramedullary inoculation of prostate tumor cell line RM-1 cells produces bone cancer and induces bone cancer pain. An up-regulation of HO-1 in spinal cord may alleviate bone cancer pain.

[The anti-inflammatory effects of heme oxygenase-1 on emphysema model]

OBJECTIVES

The effects of HO-1 on smoke-induced emphysema were tested and the mechanisms were explored in a smoking rat model.

METHODS

In this study, rats were either exposed or sham-exposed to cigarette smoke for emphysema modeling. Hemin were injected during this period to induce HO-1. Subsequently, emphysema development, inflammatory cells and cytokine levels were analyzed.

RESULTS

Smoke exposure induced emphysema [MLI: (34.0 ± 2.2) µm, MAN: 2.3 ± 0.5, MAA: (0.5 ± 0.1) µm²], increased the inflammatory cells count [total number: (41.0 ± 13.9) × 10⁴/ml, Neutrophil: (25.0 ± 9.8) × 10⁴/ml, Macrophage: (7.2 ± 2.8) × 10⁴/ml] and inflammatory cytokine levels especially IL-17 [serum: (33 ± 8.4) pg/ml, lung tissue homogenate: (79 ± 7) pg/ml, BALF: (39 ± 8) pg/ml], IL-8 [serum: (181 ± 51) pg/ml, BALF: (162 ± 79) pg/ml] and TNF-α [serum: (607 ± 85) pg/ml, BALF: (504 ± 223) pg/ml]. HO-1 reduced the severity of emphysema [MLI: (28.6 ± 1.1) µm, MAN: (2.7 ± 0.7), MAA: (0.4 ± 0.1) µm²]; total number: (17.6 ± 5.6) × 10²/ml, Neutrophil: (10.2 ± 3.6) × 10²/ml, Macrophage: (2.6 ± 1.1) × 10²/ml, suppressed the secretion of IL-17 [serum: (23.9 ± 2.4) pg/ml, lung tissue homogenate: (69.2 ± 3.0) pg/ml, BALF: (17.8 ± 5.3) pg/ml], IL-8 [serum:(103 ± 50) pg/ml, BALF: (114 ± 35) pg/ml] and TNF-α [serum: (423 ± 48) pg/ml, BALF: (216 ± 134) pg/ml] and prevented emphysema development.

CONCLUSION

HO-1 has anti-inflammatory effects and can prevent smoke-induced emphysema development.

[Clinical significance of circulating hypoxia inducible factor-1α and hemeoxygenase-1 in patients with liver cirrhosis]

OBJECTIVE

To explore the levels of circulating hypoxia inducible factor-1α (HIF-1α) and hemeoxygenase-1 (HO-1) in liver cirrhosis and to explore their diagnostic values as noninvasive methods.

METHODS

The levels of circulating HIF-1α and HO-1 were quantitatively detected in 34 patients with liver cirrhosis and 10 healthy controls by ELISA from May 2012 to May 2013. The diagnostic values were analyzed by ROC curve and their correlation with clinicopathological characters were also compared.

RESULTS

The serum levels of HIF-1α and HO-1 were significantly higher than those in healthy controls ((10.99 ± 0.24) vs (5.79 ± 0.84) µg/L, (63.04 ± 1.87) vs (16.35 ± 2.07) µg/L, both P < 0.01). No significant difference existed among Child-Pugh classification. The expressions of HIF-1α and HO-1 had a linear correlation between each other, and closely related with rebleeding and portal thrombosis during a one-year follow-up (all P < 0.05). The area under ROC curve of HIF-1α and HO-1 was 0.894 and 0.994 respectively. With 9.45 µg/L as a critical point for HIF-1α, the diagnosis of liver cirrhosis might be predicted with a positive predictive value of 91.2%. And HO-1 >31.86 µg/L predicted the diagnosis of liver cirrhosis with a sensitivity of 97.1% and a specificity of 100%.

CONCLUSION

The serum levels of HIF-1α and HO-1 may serve as useful molecular markers for a noninvasive diagnosis of liver cirrhosis.

Hispolon inhibition of inflammatory apoptosis through reduction of iNOS/NO production via HO-1 induction in macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Phellinus linteus (Berkeley & Curtis), a well-known medical fungus, has long been used as a traditional medicine in Oriental countries to treat various diseases, and hispolon (HIS) is one of its bioactive components. HIS is known to possess potent antineoplastic and antiviral properties; however, its effect on inflammatory apoptosis is still undefined.

MATERIALS AND METHODS

RAW264.7 macrophages were incubated with HIS for 30 min followed by LPS, LTA, or PGN stimulation for 12h. The expression of indicated proteins AP-1 and NF-κB transcriptional activities was examined by Western blotting using specific antibodies. Levels of NO and ROS were examined by Griess reaction, and DCHF-DA staining via flow cytometric analysis, respectively. AP-1 and NF-κB transcriptional activities were detected by luciferase reporter assay. Knockdown of HO-1 protein expression was performed by transfection of macrophages with HO-1 siRNA. Pharmacological inhibitors including ROS scavenger NAC, JNK inhibitor SP600125, NF-κB inhibitor BAY117082 were applied for mechanism study.

RESULTS

HIS showed concentration-dependent inhibition of LPS, LTA, and PGN-induced iNOS protein expressions and NO production by RAW264.7 macrophages. Accordingly, HIS protected RAW264.7 cells from LPS-, LTA-, and PGN-induced apoptosis. Increased HO-1 by HIS was detected at both protein and mRNA levels along with an increase in intracellular peroxide, and this was inhibited by the translational inhibitor, cycloheximide (CHX), the transcriptional inhibitor, actinomycin D (Act D), and the reactive oxygen species scavenger, N-acetylcysteine (NAC). A mechanistic study indicated that inhibition of c-Jun N-terminal kinase (JNK) protein phosphorylation, and activator protein (AP)-1 and nuclear factor (NF)-κB activation were involved in the anti-inflammatory actions of HIS in macrophages. A structure-activity relationship analysis showed that HIS expressed the most potent effect of inhibiting iNOS and apoptosis elicited by LPS, LTA, and PGN with a significant increase in HO-1 protein in macrophages.

CONCLUSIONS

Evidence supporting HIS prevention of inflammatory apoptosis via blocking NO production and inducing HO-1 protein expression in macrophages is provided, and the hydroxyl at position C3 is a critical substitution for the anti-inflammatory actions of HIS.

Upregulation of heat shock protein 32 with hemin alleviates acute heat-induced hepatic injury in mice

Heat shock protein 32 (HSP32) is a stress response protein that can be induced by heat stress in the liver, and its induction can act as an important cellular defence mechanism against heat-induced liver injury. To investigate the functional role of HSP32 in protecting liver tissue against heat stress in mice and the mechanism by which it achieves this protective effect, HSP32 expression and carbon monoxide (CO) contents in a model of mice subjected to acute, transient heat exposure were examined. Furthermore, functional and histological parameters of liver damage and the possible involvement of oxidative stress to induce oxidative deterioration of liver functions and caspase-3 expression were also investigated in this study. We found that heat treatment of mice produced severe hepatic injury, whereas upregulation of HSP32 with hemin pretreatment prevented mice from liver damage. In contrast, addition of Sn-protoporphyrin (SnPP) to inhibit HSP32 expression completely reversed its hepatoprotective effect. It is concluded that upregulation of HSP32 by hemin could alleviate acute heat-induced hepatocellular damage in mice, and its by-product CO seems to play a more important role in hepatoprotective mechanism.