Fibroblast growth factor 21 inhibits ferroptosis following spinal cord injury by regulating heme oxygenase-1

Interfering with the ferroptosis pathway is a new strategy for the treatment of spinal cord injury.Fibroblast growth factor 21 can inhibit ferro ptosis and promote neurofunctional recovery,while heme oxygenase-1 is a regulator of iron and reactive oxygen species homeostasis.The relationship between heme oxygenase-1and ferroptosis remains controve rsial.In this study,we used a spinal co rd injury rat model to show that the levels of fibroblast growth factor 21 in spinal co rd tissue decreased after spinal cord injury.In addition,there was a significant aggravation of ferroptosis and a rapid increase in heme oxygenase-1 expression after spinal cord injury.Furthe r,heme oxygenase-1 aggravated fe rroptosis after spinal cord injury,while fibroblast growth factor 21 inhibited fe rroptosis by downregulating heme oxygenase-1.Thus,the activation of fibroblast growth factor 21 may provide a potential treatment for spinal co rd injury.These findings could provide a new potential mechanistic explanation for fibroblast growth factor 21 in the treatment of spinal cord injury.

Metformin alleviates spinal cord injury by inhibiting nerve cell ferroptosis through upregulation of heme oxygenase-1 expression

Previous studies have reported upregulation of heme oxygenase-1 in different central nervous system injury models.Heme oxygenase-1 plays a critical anti-inflammatory role and is essential for regulating cellular redox homeostasis.Metformin is a classic drug used to treat type 2 diabetes that can inhibit ferroptosis.Previous studies have shown that,when used to treat cardiovascular and digestive system diseases,metformin can also upregulate heme oxygenase-1 expression.Therefore,we hypothesized that heme oxygenase-1 plays a significant role in mediating the beneficial effects of metformin on neuronal ferroptosis after spinal cord injury.To test this,we first performed a bioinformatics analysis based on the GEO database and found that heme oxygenase-1 was upregulated in the lesion of rats with spinal cord injury.Next,we confirmed this finding in a rat model of T9 spinal cord compression injury that exhibited spinal cord nerve cell ferroptosis.Continuous intraperitoneal injection of metformin for 14 days was found to both upregulate heme oxygenase-1 expression and reduce neuronal ferroptosis in rats with spinal cord injury.Subsequently,we used a lentivirus vector to knock down heme oxygenase-1 expression in the spinal cord,and found that this significantly reduced the effect of metformin on ferroptosis after spinal cord injury.Taken together,these findings suggest that metformin inhibits neuronal ferroptosis after spinal cord injury,and that this effect is partially dependent on upregulation of heme oxygenase-1.

Suppressing high mobility group box-1 release alleviates morphine tolerance via the adenosine5'-monophosphate-activated protein kinase/heme oxygenase-1 pathway

Opioids,such as morphine,are the most potent drugs used to treat pain.Long-term use results in high tolerance to morphine.High mobility group box-1(HMGB1) has been shown to participate in neuropathic or inflammatory pain,but its role in morphine tolerance is unclear.In this study,we established rat and mouse models of morphine tolerance by intrathecal injection of morphine for 7 consecutive days.We found that morphine induced rat spinal cord neurons to release a large amount of HMGB1.HMGB1 regulated nuclear factor κB p65 phosphorylation and interleukin-1β production by increasing Toll-like receptor 4receptor expression in microglia,thereby inducing morphine tolerance.Glycyrrhizin,an HMGB1 inhibito r,markedly attenuated chronic morphine tole rance in the mouse model.Finally,compound C(adenosine 5’-monophosphate-activated protein kinase inhibitor) and zinc protoporphyrin(heme oxygenase-1 inhibitor)alleviated the morphine-induced release of HMGB1 and reduced nuclear factor κB p65 phosphorylation and interleukin-1β production in a mouse model of morphine tolerance and an SH-SY5Y cell model of morphine tole rance,and alleviated morphine tolerance in the mouse model.These findings suggest that morphine induces HMGB1 release via the adenosine 5’-monophosphate-activated protein kinase/heme oxygenase-1 signaling pathway,and that inhibiting this signaling pathway can effectively reduce morphine tole rance.

Ketogenic diet alleviates cognitive dysfunction and neuroinflammation in APP/PS1 mice via the Nrf2/HO-1 and NF-κB signaling pathways

Alzheimer's disease is a progressive neurological disorder characterized by cognitive decline and chronic inflammation within the brain.The ketogenic diet,a widely recognized therapeutic intervention for refractory epilepsy,has recently been proposed as a potential treatment for a variety of neurological diseases,including Alzheimer's disease.However,the efficacy of ketogenic diet in treating Alzheimer's disease and the underlying mechanism remains unclear.The current investigation aimed to explore the effect of ketogenic diet on cognitive function and the underlying biological mechanisms in a mouse model of Alzheimer's disease.Male amyloid precursor protein/presenilin 1(APP/PS1)mice were randomly assigned to either a ketogenic diet or control diet group,and received their respective diets for a duration of 3 months.The findings show that ketogenic diet administration enhanced cognitive function,attenuated amyloid plaque formation and proinflammatory cytokine levels in APP/PS1 mice,and augmented the nuclear factor-erythroid 2-p45 derived factor 2/heme oxygenase-1 signaling pathway while suppressing the nuclear factor-kappa B pathway.Collectively,these data suggest that ketogenic diet may have a therapeutic potential in treating Alzheimer's disease by ameliorating the neurotoxicity associated with Aβ-induced inflammation.This study highlights the urgent need for further research into the use of ketogenic diet as a potential therapy for Alzheimer's disease.

Quercetin protects against diabetic retinopathy in rats by inducing heme oxygenase-1 expression

Quercetin is a widely-occurring flavonoid that protects against cancer, and improves memory and cardiovascular functions.However, whether quercetin exhibits therapeutic effects in diabetic retinopathy remains unclear.In this study, we established a rat model of streptozocininduced diabetic retinopathy.Seventy-two hours later, the rats were intraperitoneally administered 150 mg/kg quercetin for 16 successive weeks.Quercetin markedly increased the thickness of the retinal cell layer, increased the number of ganglion cells, and decreased the overexpression of the pro-inflammatory factors interleukin-1β, interleukin-18, interleukin-6 and tumor necrosis factor-α in the retinal tissue as well as the overexpression of high mobility group box-1 and the overactivation of the NLRP3 inflammasome.Furthermore, quercetin inhibited the overexpression of TLR4 and NF-κBp65, reduced the expression of the pro-angiogenic vascular endothelial growth factor and soluble intercellular adhesion molecule-1, and upregulated the neurotrophins brain-derived neurotrophic factor and nerve growth factor.Intraperitoneal injection of the heme oxygenase-1 inhibitor zinc protoporphyrin blocked the protective effect of quercetin.These findings suggest that quercetin exerts therapeutic effects in diabetic retinopathy possibly by inducing heme oxygenase-1 expression.This study was approved by the Animal Ethics Committee of China Medical University, China(approval No.2016 PS229K) on April 8, 2016.

Heme oxygenase-1 protects donor livers from ischemia/reperfusion injury:The role of Kupffer cells

AIM:To examine whether heme oxygenase (HO)-1 overexpression would exert direct or indirect effects on Kupffer cells activation, which lead to aggravation of reperfusion injury.METHODS: Donors were pretreated with cobalt protoporphyrin (CoPP) or zinc protoporphyrin (ZnPP), HO-1 inducer and antagonist, respectively. Livers were stored at 4℃ for 24 h before transplantation. Kupffer cells were isolated and cultured for 6 h after liver reperfusion.RESULTS: Postoperatively, serum transaminases were significantly lower and associated with less liver injury when donors were pretreated with CoPP, as compared with the ZnPP group. Production of the cytokines tumor necrosis factor-α and interleukin-6 generated by Kupffer cells decreased in the CoPP group. The CD14 expression levels (RT-PCR/Western blots) of Kupffer cells from CoPP-pretreated liver grafts reduced.CONCLUSION: The study suggests that the potential utility of HO-1 overexpression in preventing ischemia/reperfusion injury results from inhibition of Kupffer cells activation.

Heme oxygenase-1 protects rat liver against warm ischemia/reperfusion injury via TLR2/TLR4-triggered signaling pathways

AIM:To investigate the efficacy and molecularmechanisms of induced heme oxygenase(HO)-1 in protecting liver from warm ischemia/reperfusion(I/R)injury.METHODS:Partial warm ischemia was produced in the left and middle hepatic lobes of SD rats for 75min,followed by 6 h of reperfusion.Rats were treated with saline,cobalt protoporphyrin(Co PP)or zinc protoporphyrin(Zn PP)at 24 h prior to the ischemia insult.Blood and samples of ischemic lobes subjected to ischemia were collected at 6 h after reperfusion.Serum transaminases level,plasma lactate dehydrogenase and myeloperoxidase activity in liver were measured.Liver histological injury and inflammatory cell infiltration were evaluated by tissue section and liver immunohistochemical analysis.We used quantitative reverse transcription polymerase chain reaction to analyze liver expression of inflammatory cytokines and chemokines.The cell lysates were subjected to immunoprecipitation with anti-Toll-IL-1R-containing adaptor inducing interferon-β(TRIF)and anti-myeloid differentiation factor 88(My D88),and then the immunoprecipitates were analyzed by SDS-PAGE and immunoblotted with the indicated antibodies.RESULTS:HO-1 protected livers from I/R injury,as evidenced by diminished liver enzymes and wellpreserved tissue architecture.In comparison with Zn PP livers 6 h after surgery,Co PP treatment livers showed a significant increase inflammatory cell infiltration of lymphocytes,plasma cells,neutrophils and macrophages.The Toll-like receptor(TLR)-4 and TANK binding kinase1 protein levels of rats treated with Co PP significantly reduced in TRIF-immunoprecipitated complex,as compared with Zn PP treatment.In addition,pretreatment with Co PP reduced the expression levels of TLR2,TLR4,IL-1R-associated kinase(IRAK)-1 and tumor necrosis factor receptor-associated factor 6 in My D88-immunoprecipitated complex.The inflammatory cytokines and chemokines m RNA expression rapidly decreased inCo PP-pretreated liver,compared with the Zn PP-treated group.However,the expression of negative regulators Tollinteracting protein,suppressor of cytokine signaling-1,IRAK-M and Src homology 2 domain-containing inositol-5-phosphatase-1 in Co PP treatment rats were markedly up-regulated as compared with Zn PP-treated rats.CONCLUSION:HO-1 protects liver against I/R injury by inhibiting TLR2/TLR4-triggered My D88-and TRIFdependent signaling pathways and increasing expression of negative regulators of TLR signaling in rats.

Inhibiting heme oxygenase-1 attenuates rat liver fibrosis by removing iron accumulation

AIM:To investigate the effects of the heme oxygenase(HO)-1/carbon monoxide system on iron deposition and portal pressure in rats with hepatic fibrosis induced by bile duct ligation(BDL).METHODS:Male Sprague-Dawley rats were divided randomly into a Sham group,BDL group,Fe group,deferoxamine(DFX) group,zinc protoporphyrin(ZnPP) group and cobalt protoporphyrin(CoPP) group.The levels of HO-1 were detected using different methods.The serum carboxyhemoglobin(COHb),iron,and portal vein pressure(PVP) were also quantified.The plasma and mRNA levels of hepcidin were measured.Hepatic fibrosis and its main pathway were assessed using Van Gieson's stain,hydroxyproline,transforming growth factor-β1(TGF-β1),nuclear factor-E2-related factor 2(Nrf2),matrix metalloproteinase-2(MMP-2) and tissue inhibitor of metalloproteinase-1(TIMP-1).RESULTS:Serum COHb and protein and mRNA expression levels of HO-1 and Nrf2 were increased in the BDL group compared with the Sham group and were much higher in the CoPP group.The ZnPP group showed lower expression of HO-1 and Nrf2 and lower COHb.The levels of iron and PVP were enhanced in the BDL group but were lower in the ZnPP and DFX groups and were higher in the CoPP and Fe groups.Hepcidin levels were higher,whereas superoxide dismutase levels were increased and malonaldehyde levels were decreased in the ZnPP and DFX groups.The ZnPP group also showed inhibited TGF-β1 expression and regulated TIMP-1/MMP-2 expression,as well as obviously attenuated liver fibrosis.CONCLUSION:Reducing hepatic iron deposition and CO levels by inhibiting HO-1 activity though the Nrf2/Keap pathway could be helpful in improving hepatic fibrosis and regulating PVP.

Effects of heme oxygenase-1-modified bone marrow mesenchymal stem cells on microcirculation and energy metabolism following liver transplantation

AIM To investigate the effects of heme oxygenase-1(HO-1)-modified bone marrow mesenchymal stem cells(BMMSCs)on the microcirculation and energy metabolism of hepatic sinusoids following reduced-size liver transplantation(RLT)in a rat model.METHODS BMMSCs were isolated and cultured in vitro using an adherent method,and then transduced with HO-1-bearing recombinant adenovirus to construct HO-1/BMMSCs.A rat acute rejection model following 50%RLT was established using a two-cuff technique.Recipients were divided into three groups based on the treatment received:normal saline(NS),BMMSCs and HO-1/BMMSCs.Liver function was examined at six time points.The levels of endothelin-1(ET-1),endothelial nitric-oxide synthase(e NOS),inducible nitric-oxide synthase(i NOS),nitric oxide(NO),and hyaluronic acid(HA)were detected using an enzyme-linked immunosorbent assay.The portal vein pressure(PVP)was detected by Power Lab ML880.The expressions of ET-1,i NOS,e NOS,and von Willebrand factor(v WF)protein in the transplanted liver were detected using immunohistochemistry and Western blotting.ATPase in the transplanted liver was detected by chemical colorimetry,and the ultrastructural changes were observed under a transmission electron microscope.RESULTS HO-1/BMMSCs could alleviate the pathological changes and rejection activity index of the transplanted liver,and improve the liver function of rats following 50%RLT,with statistically significant differences compared with those of the NS group and BMMSCs group(P<0.05).In term of the microcirculation of hepatic sinusoids:The PVP on POD7 decreased significantly in the HO-1/BMMSCs and BMMSCs groups compared with that of the NS group(P<0.01);HO-1/BMMSCs could inhibit the expressions of ET-1 and i NOS,increase the expressions of e NOS and inhibit amounts of NO production,and maintain the equilibrium of ET-1/NO(P<0.05);and HO-1/BMMSCs increased the expression of v WF in hepatic sinusoidal endothelial cells(SECs),and promoted the degradation of HA,compared with those of the NS group and BMMSCs group(P<0.05).In term of the energy metabolism of the transplanted liver,HO-1/BMMSCs repaired the damaged mitochondria,and improved the activity of mitochondrial aspartate aminotransferase(ASTm)and ATPase,compared with the other two groups(P<0.05).CONCLUSION HO-1/BMMSCs can improve the microcirculation of hepatic sinusoids significantly,and recover the energy metabolism of damaged hepatocytes in rats following RLT,thus protecting the transplanted liver.

Hydrogen-rich water protects against inflammatory bowel disease in mice by inhibiting endoplasmic reticulum stress and promoting heme oxygenase-1 expression

AIM To investigate the therapeutic effect of hydrogen-rich water(HRW) on inflammatory bowel disease(IBD) and to explore the potential mechanisms involved.METHODS Male mice were randomly divided into the following four groups: control group, in which the mice received equivalent volumes of normal saline(NS) intraperitoneally(ip); dextran sulfate sodium(DSS) group, in which the mice received NS ip(5 m L/kg body weight, twice per day at 8 am and 5 pm) for 7 consecutive days after IBD modeling; DSS + HRW group, in which the mice received HRW(in the same volume as the NS treatment) for 7 consecutive days after IBD modeling; and DSS + HRW + Zn PP group, in which the mice received HRW(in the same volume as the NS treatment) and ZnP P [a heme oxygenase-1(HO-1) inhibitor, 25 mg/kg] for 7 consecutive days after IBD modeling. IBD was induced by feeding DSS to the mice, and blood and colon tissues were collected on the 7th d after IBD modeling to determine clinical symptoms, colonic inflammation and the potential mechanisms involved.RESULTS The DSS + HRW group exhibited significantly attenuated weight loss and a lower extent of disease activity index compared with the DSS group on the 7th d(P < 0.05). HRW exerted protective effects against colon shortening and colonic wall thickening in contrast to the DSS group(P < 0.05). The histological study demonstrated milder inflammation in the DSS + HRW group, which was similar to normal inflammatory levels, and the macroscopic and microcosmic damage scores were lower in this group than in the DSS group(P < 0.05). The oxidative stress parameters, including MDA and MPO in the colon, were significantly decreased in the DSS + HRW group compared with the DSS group(P < 0.05). Simultaneously, the protective indicators, superoxide dismutase and glutathione, were markedly increased with the use of HRW. Inflammatory factors were assessed, and the results showed that the DSS + HRW group exhibited significantly reduced levels of TNF-α, IL-6 and IL-1β compared with the DSS group(P < 0.05). In addition, the pivotal proteins involved in endoplasmic reticulum(ER) stress, including p-e IF2α, ATF4, XBP1 s and CHOP, were dramatically reduced after HRW treatment in contrast to the control group(P < 0.05). Furthermore, HRW treatment markedly up-regulated HO-1 expression, and the use of Zn PP obviously reversed the protective role of HRW. In the DSS + HRW + ZnP P group, colon shortening and colonic wall thickening were significantly aggravated, and the macroscopic damage scores were similar to those of the DSS + HRW group(P < 0.05). The histological study also showed more serious colonic damage that was similar to the DSS group.CONCLUSION HRW has a significant therapeutic potential in IBD by inhibiting inflammatory factors, oxidative stress and ER stress and by up-regulating HO-1 expression.

Induction of Heme Oxygenase-1 in Human Hepatocytes to Protect Them From Ethanol-induced Cytotoxicity

Background/Aim We investigated the relationship between ethanol exposure and heme oxygenase (HO-1) in human hepatocytes in order to ascertain if induction of HO-1 can prevent ethanol induced cellular damage. Methods Dose-dependent (25-100 mmol/L) and time-dependent (0-24 h) ethanol exposure were used in the present study. HO-1 mRNA and protein expression were detected by PT-PCR and Western blot respectively. HO-1 activity was indicated by bilirubin and Fe2+ formation. Cytotoxicity was investigated by means of lactate dehydrogenate (LDH) and aspartate transaminase (AST) level in culture supernatants, as well as the intracellular formation of malondialdehyde (MDA), cellular glutathione (GSH) status and CYP 2E1 activity. Results We first demonstrated a dose-dependent response between ethanol exposure and HO-1 mRNA and protein expression in human hepatocytes. We further observed a time-dependent increase of HO-1 mRNA expression using 100 mmol/L ethanol starting 30 minutes after ethanol exposure, reaching its maximum between 3 h and 9 h. Being similar to what had been demonstrated with the mRNA level, increased protein expression started at 6 h after ethanol exposure, and kept continuous elevated over 18 h. In addition, we found that ethanol exposure to hepatocytes markedly increased HO-1 enzyme activity in a time-dependent manner measured as bilirubin and Fe2+ formation in human hepatocytes. Our results clearly showed that ethanol exposure caused a significant increase of LDH, AST, and MDA levels, while the antioxidant GSH was time-dependently reduced. Furthermore, we demonstrated that pre-administration of cobalt protoporphyrin (CoPP) induced HO-1 in human hepatocytes, and prevented an increase of MDA and a decrease of GSH. These effects could be partially reversed by zinc protoporphyrin (ZnPP), an antagonist of HO-1 induction. Conclusion HO-1 expression in cells or organs could lead to new strategies for better prevention and treatment of ethanol-induced oxidative damage in human liver.

Effects of sericin on heme oxygenase-1 expression in the hippocampus and cerebral cortex of type 2 diabetes mellitus rats

Previous studies have demonstrated that sericin effectively reduces blood glucose, and protects islet cells, as well as the gonads and kidneys. However, whether sericin improves diabetes mellitus-induced structural and functional problems in the central nervous system remains poorly understood. Rat models of type 2 diabetes mellitus were established by intraperitoneal injection of streptozotocin. The present study observed histological changes in the hippocampus and cerebral cortex, as well as heme oxygenase-1 expression, and explored sericin effects on the central nervous system in diabetic rats. Pathological damage to neural cells in the rat hippocampus and cerebral cortex was relieved following intragastric administration of sericin at a dose of 2.4 g/kg for 35 consecutive days. Heme oxygenase-1 protein and mRNA expressions were decreased in the hippocampus and cerebral cortex of diabetes mellitus rats after sericin treatment. The results suggest that sericin plays a protective effect on the nervous system by decreasing the high expression of heme oxygenase-1 following diabetes mellitus.

Atorvastatin Attenuates TNF-alpha Production via Heme Oxygenase-1 Pathway in LPS-stimulated RAW264.7 Macrophages

Objective To assess the effect of atorvastatin on lipopolysaccharide （LPS）-induced TNF-a production in RAW264.7 macrophages. Methods RAW264.7 macrophages were treated in different LPS concentrations or at different time points with or without atorvastatin. TNF-a level in supernatant was measured. Expressions of TNF-a mRNA and protein and heme oxygenase-1 （HO-1） were detected by ELISA, PCR, and Western blot, respectively. HO activity was assayed. Results LPS significantly increased the TNF-a expression and secretion in a dose- and time-dependent manner. The HO-1 activity and HO-1 expression level were significantly higher after atorvastatin treatment than before atorvastatin treatment and attenuated by SB203580 and PD98059 but not by SP600125, suggesting that the ERK and p38 mitogen-activated protein kinase （MAPK） pathways participate in regulating the above-mentioned effects of atorvastatin. Moreover, the HO-1 activity suppressed by SnPP or the HO-1 expression inhibited by siRNA significantly attenuated the effect of atorvastatin on TNF-c~ expression and production in LPS-stimulated macrophages. Conclusion Atorvastatin can attenuate LPS-induced TNF-e expression and production by activating HO-1 via the ERK and p38 MAPK pathways, suggesting that atorvastatin can be used in treatment of inflammatory diseases such as sepsis, especially in those with atherosclerotic diseases.

1,2,3,4,6-penta-O-galloyl-β-D-glucose Protects PC12 Cells from MPP^+-mediated Cell Death by Inducing Heme Oxygenase-1 in an ERK- and Akt-dependent Manner

This study examined the ability of 1,2,3,4,6-penta-O-galloyl-β-D-glucose (β-PGG) to induce the expression of heme oxygenase-1 (HO-1) in the PC12 cells and its regulation in the PC12 cells.One week before treatment with the drug,nerve growth factor (NGF) was added to the cultures at a final concentration of 50 ng/mL to induce neuronal differentiation.After drug treatment,HO-1 gene transcription was analyzed by reverse transcription polymerase chain reaction (RT-PCR).Expression of HO-1 and NF-E2-related factor2 (Nrf2) and activation of extracellular signal-regulated kinase (ERK) and Akt were detected by Western blotting.The viability of the PC12 cells treated with different medicines was examined by MTT assay.The oxidative stress in the PC12 cells was evaluated qualitatively and quantitatively by DCFH-DA.The results showed that β-PGG up-regulated HO-1 expression and this increased expression provided neuroprotection against MPP+-induced oxidative injury.Moreover,β-PGG induced Nrf2 nuclear translocation,which was found to be upstream of β-PGG-induced HO-1 expression,and the activation of ERK and Akt,a pathway that is involved in β-PGG-induced Nrf2 nuclear translocation,HO-1 expression and neuroprotection.In conclusion,β-PGG up-regulates HO-1 expression by stimulating Nrf2 nuclear translocation in an ERK-and Akt-dependent manner,and HO-1 expression by β-PGG may provide the PC12 cells with an acquired antioxidant defense capacity to survive the oxidative stress.

Heme oxygenase-1 system and gastrointestinal tumors

Heme oxygenase-1(HO-1) system catabolizes heme into three products:carbon monoxide,biliverdin/bilirubin and free iron.It is involved in many physiological and pathophysiological processes.A great deal of data has demonstrated the roles of HO-1 in the formation,growth and metastasis of tumors.The interest in this system by investigators involved in gastrointestinal tumors is fairly recent,and few papers on HO-1 have touched upon this subject.This review focuses on the current understanding of the physiological significance of HO-1 induction and its possible roles in the gastrointestinal tumors studied to date.The implications for possible therapeutic manipulation of HO-1 in gastrointestinal tumors are also discussed.

Heme oxygenase-1 inhibits neuropathic pain in rats with diabetic mellitus

A diabetes mellitus model was established through single intraperitoneal injection of streptozotocin into rats. Seven days later, model rats were intraperitoneally administered zinc protoporphyrin, a heme oxygenase-1 inducer, and cobalt protoporphyrin, a heme oxygenase-1 inhibitor, once every two days, for 5 successive weeks. After administration, the paw withdrawal mechanical threshold of diabetic mellitus rats significantly decreased, the myelin sheath of the sciatic nerve thickened or showed vacuole defects, the number of spinal dorsal horn neurons reduced, some neurons degenerated and were necrotic, and heme oxygenase-1 was visible in the cytoplasm of spinal dorsal hom neurons. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling demonstrated that the number of apoptotic neurons increased, which could be inhibited by cobalt protoporphyrin, however, zinc protoporphyrin led to an opposite effect. Our experimental findings indicate that heme oxygenase-1 attenuates neuropathic pain in diabetic mellitus rats through amelioration of peripheral neuropathy and inhibition of spinal dorsal horn neuron apoptosis.

Effect of Hypertonic Versus Isotonic Saline Resuscitation on Heme Oxygenase-1 Expression in Visceral Organs Following Hemorrhagic Shock in Rats

To compare the early effects of hypertonic and isotonic saline resuscitation on heme oxygenase-1 （HO-1） expression in organs of rats with hemorrhagic shock. Rats were randomly divided into hypertonic saline resuscitation （HTS）, normal saline resuscitation （NS） and sham groups. HO-1 mRNA, protein expression and apoptosis were evaluated in organs. In the HTS group, significant difference was noted in HO-1 protein in small intestinal mucosa and liver compared with the NS and sham groups, and in HO-1 mRNA in liver and kidney compared with the sham group. The apoptosis of small intestinal mucosa, liver, heart, and lung was significantly lower in the HTS group than that in the NS group. In this study, small volume resuscitation with HTS can efficiently up-regulate the expression level of HO-1 in small intestinal mucosa and liver, which may be one of the mechanisms alleviating organ damage.

Over-expression of Heme Oxygenase-1 Does not Protect Porcine Endothelial Cells from Human Xenoantibodies and Complement-mediated Lysis

Accommodated organs can survive in the presence of anti-organ antibodies and complement. Heme oxygenase-1 （HO-1） is essential to ensure accommodation in concordant xenotransplant models. However, whether induction of HO-1 over-expression could protect porcine endothelial cells （PECs） against human xenoantibodies and complement-mediated lysis and induce an in vitro accommodation is still unknown. The SV40-immortalized porcine aorta-derived endothelial cell line （iPEC） was pre-incubated with 20, 50, or 80 μmol/L of cobalt-protoporphyrins IX （CoPPIX） for 24 h, and the HO-1 expression in iPECs was analyzed by using Western blotting. CoPPIX-treated or untreated iPECs were incubated with normal human AB sera, and complement-dependent cytotoxicity （CDC） was measured by both flow cytometry and lactate dehydrogenase （LDH） release assay. In vitro treatment with CoPPIX significantly increased the expression of HO-1 in iPECs in a dose-dependent manner. Over-expression of HO-1 was successfully achieved by incubation of iPECs with either 50 or 80 μmol/L of CoPPIX. However, HO-1 over-expression did not show any protective effects on iPECs against normal human sera-mediated cell lysis. In conclusion, induction of HO-1 over-expression alone is not enough to pro- tect PECs from human xenoantibodies and complement-mediated humoral injury. Additionally, use of other protective strategies is needed to achieve accommodation in pig-to-primate xenotransplantation.

Is glial heme oxygenase-1 suppression in neurodegenerative disorders permissive for neural repair?

＇Core＇ neuropathology of degenerative central nervous system （CNS） disorders The common human neurodegenerative disorders （Alzheimer＇s disease （AD）, Parkinson＇s disease （PD）, amyotrophic lateral sclerosis, etc.） vary with respect to risk factors, ages of onset, sex predilections, neuraxial regions affected, hallmark cellular inclusions, behavioral and neurological symptoms, and responses to treatment. Despite these differences, there appears to be a set of ＇core＇ neuropathological features shared among these and related entities. Common to these conditions are 1） pathological deposition of non-transferrin bound iron, 2） oxidative stress and associated protein, lipid and nucleic acid modifications, 3） mitochondrial membrane damage and bioenergetic failure, and 4） macroautophagy in the affected neural tissues.

Sinapic acid ameliorates D-galactosamine/lipopolysaccharideinduced fulminant hepatitis in rats:Role of nuclear factor erythroidrelated factor 2/heme oxygenase-1 pathways

BACKGROUND Sinapic acid(SA)has been shown to have various pharmacological properties such as antioxidant,antifibrotic,anti-inflammatory,and anticancer activities.Its mechanism of action is dependent upon its ability to curb free radical production and protect against oxidative stress-induced tissue injuries.AIM To study the hepatoprotective effects of SA against lipopolysaccharide(LPS)/Dgalactosamine(D-GalN)-induced acute liver failure(ALF)in rats.METHODS Experimental ALF was induced with an intraperitoneal(i.p.)administration of 8μg LPS and 800 mg/kg D-GalN in normal saline.SA was administered orally once daily starting 7 d before LPS/D-GalN treatment.RESULTS Data showed that SA ameliorates acute liver dysfunction,decreases serum levels of alanine transaminase(ALT),and aspartate aminotransferase(AST),as well as malondialdehyde(MDA)and NO levels in ALF model rats.However,pretreatment with SA(20 mg/kg and 40 mg/kg)reduced nuclear factor kappalight-chain-enhancer of activated B cells(NF-κB)activation and levels of inflammatory cytokines(tumor necrosis factor-αand interleukin 6).Also,SA increased the activity of the nuclear factor erythroid-related factor 2/heme oxygenase-1(Nrf2/HO-1)signaling pathway.CONCLUSION In conclusion,SA offers significant protection against LPS/D-GalN-induced ALF in rats by upregulating Nrf2/HO-1 and downregulating NF-κB.