OBJECTIVE: To investigate effects of antioxidant stress protein heme oxygenase-1 (HO-1) on lipopolysaccharide (LPS)-induced endoplasmic reticulum stress (ERS) of rat hepatocytes. METHODS: The BRL cells (rat hepatocyte cell line) were cultured. The hepatocytes were treated with LPS, LPS+HO-1 siRNA, HO-1 siRNA and PBS solution, respectively. The cell viability was measured by trypan blue exclusion test. The apoptosis cells were detected by the fluorescent dye Hoechst 33258. Expressions of GRP78, CHOP, caspase-12 and HO-1 were detected by Western blotting. RESULTS: LPS caused an increase of HO-1 protein expression of rat hepatocytes in a dose-dependent and time-dependent manner, a up-regulation of GRP78, CHOP and caspase-12, a decrease in cell viability, and an increase in apoptosis rate of hepatocytes. Pretreatment of HO-1 siRNA inhibited the up-regulation of LPS-induced HO-1, however, aggravated ERS and cellular injury. CONCLUSION HO-1 inhibites ERS-mediated cellular injury of rat hepatocytes induced by LPS.
Animals ; Apoptosis/physiology* ; Endoplasmic Reticulum/metabolism* ; Endoplasmic Reticulum Stress/physiology* ; Heme Oxygenase-1/pharmacology* ; Hepatocytes/metabolism* ; Lipopolysaccharides/pharmacology* ; Rats

We investigated the expression of heme oxygenase-1 (HO-1) gene and production of endogenous carbon monoxide (CO) in the rat lung tissue at different time points of chronic hypoxic pulmonary hypertension and the effect of hemin on the expression of HO-1 gene and pulmonary hypertension. A rat model of hypoxic pulmonary hypertension was recreated by exposure to intermittent normobaric hypoxic environment (10% O2). Reverse transcriptase polymerase chain reaction (RT-PCR) was performed to determine the level of HO-1 mRNA in the rat lung tissue and double wave length spectrophotometry was used to evaluate the quantity of COHb in arterial blood. Cardiac catheterization was employed to measure the right ventricular systolic pressure (RVSP) and HE staining was performed in dissected lung tissue to observe the pathological changes of the intra-acinar pulmonary arteries (IAPA). It was found that (1) There was a low level of HO-1 mRNA in normal rat lung tissue, but the level of HO-1 mRNA increased by 2-4 times in the lung tissue of hypoxic rats (P<0.01). The quantity of COHb was 2-3 times those of control group (P<0.01 or P<0.05). These were accompanied by the increased of RVSP and the thickened IAPA; (2) Hemin could keep the HO-1 mRNA and COHb in the hypoxic rat lung tissue at a high level, and partially suppressed the increase of rat RVSP, thereby ameliorating the pathological changes of IAPA. In conclusion, the upregulation of the expression of HO-1 gene and production of CO in the rat lung of hypoxic pulmonary hypertension plays a role of inhibition in the development of hypoxic pulmonary hypertension. Hemin has a therapeutic effect on hypoxic pulmonary hypertension.
Animals ; Carbon Monoxide ; metabolism ; physiology ; Heme Oxygenase (Decyclizing) ; biosynthesis ; genetics ; Heme Oxygenase-1 ; Hypertension, Pulmonary ; etiology ; metabolism ; Hypoxia ; complications ; Lung ; metabolism ; Myocytes, Smooth Muscle ; drug effects ; pathology ; Pulmonary Artery ; metabolism ; pathology ; RNA, Messenger ; biosynthesis ; genetics ; Rats

Animals ; Antioxidants ; metabolism ; Apoptosis ; Carbon Monoxide ; physiology ; Heme Oxygenase-1 ; physiology ; Hemoglobins ; metabolism ; Humans ; Iron ; metabolism ; Nitric Oxide Synthase ; metabolism ; Oxidative Stress

We investigated the expression of heme oxygenase-1 (HO-1) gene and production of endogenous carbon monoxide (CO) in the rat lung tissue at different time points of chronic hypoxic pulmonary hypertension and the effect of hemin on the expression of HO-1 gene and pulmonary hypertension. A rat model of hypoxic pulmonary hypertension was recreated by exposure to intermittent normobaric hypoxic environment (10% O2). Reverse transcriptase polymerase chain reaction (RT-PCR) was performed to determine the level of HO-1 mRNA in the rat lung tissue and double wave length spectrophotometry was used to evaluate the quantity of COHb in arterial blood. Cardiac catheterization was employed to measure the right ventricular systolic pressure (RVSP) and HE staining was performed in dissected lung tissue to observe the pathological changes of the intra-acinar pulmonary arteries (IAPA). It was found that (1) There was a low level of HO-1 mRNA in normal rat lung tissue, but the level of HO-1 mRNA increased by 2-4 times in the lung tissue of hypoxic rats (P<0.01). The quantity of COHb was 2-3 times those of control group (P<0.01 or P<0.05). These were accompanied by the increased of RVSP and the thickened IAPA; (2) Hemin could keep the HO-1 mRNA and COHb in the hypoxic rat lung tissue at a high level, and partially suppressed the increase of rat RVSP, thereby ameliorating the pathological changes of IAPA. In conclusion, the upregulation of the expression of HO-1 gene and production of CO in the rat lung of hypoxic pulmonary hypertension plays a role of inhibition in the development of hypoxic pulmonary hypertension. Hemin has a therapeutic effect on hypoxic pulmonary hypertension.
Anoxia/complications ; Carbon Monoxide/*metabolism ; Carbon Monoxide/physiology ; Heme Oxygenase (Decyclizing)/*biosynthesis ; Heme Oxygenase (Decyclizing)/genetics ; Heme Oxygenase-1 ; Hypertension, Pulmonary/etiology ; Hypertension, Pulmonary/*metabolism ; Lung/metabolism ; Myocytes, Smooth Muscle/drug effects ; Myocytes, Smooth Muscle/pathology ; Pulmonary Artery/metabolism ; Pulmonary Artery/*pathology ; RNA, Messenger/biosynthesis ; RNA, Messenger/genetics

OBJECTIVETo examine whether TLR-4 has an effect on hemorrhage induced changes in lung, and to investigate the change of heme oxygenase-1 (HO-1) on acute lung injury (ALI) induced by hemorrhagic shock in mice.

METHODSForty-eight male mice, including C3H/HeN mice and C3H/HeJ mice, were randomly divided into sham group (n=12), hemorrhagic shock group with twelve mice in each phase. Blood pressure (BP) was monitored continuously by attaching carotid artery catheter to a strain gauge pressure transducer/ polygraph. Arterial blood samples were taken for blood gas analysis. A mouse model of non-lethal hemorrhagic shock and resuscitation was used to observe pulmonary myeloperoxidase (MPO) activity and wet/dry weight ratio (W/D). The expression of HO-1 was observed by means of RT-PCR and immunohistochemistry. IL-6 and IL-10 in lung tissue homogenate were assayed by enzyme-linked immunosorbent assay (ELISA). The pulmonary pathologic changes were observed under electron microscope and light microscope.

RESULTSCompared with sham group, the expression of HO-1 in lung tissue was significantly higher in Hem 24 h and Hem 48 h of C3H/HeN mice (P less than 0.01). The expression of HO-1 mRNA and the levels of IL-6, IL-10 and MPO in lung tissue were markedly increased in Hem 24 h (P less than 0.01 or P less than 0.05); Compared with C3H/HeN mice, the expression of HO-1 mRNA and the levels of IL-6 and IL-10 in C3H/HeJ mice significantly decreased in Hem 24 h and Hem 48 h (P less than 0.01 or P less than 0.05), and the W/D, MPO in C3H/HeJ mice were obviously lower in Hem 24 h (P less than 0.05). The injuries of lung tissues after hemorrhagic shock have been demonstrated by histological examination with electron microscope and light microscope.

CONCLUSIONSTLR-4 and HO-1 might modulate the balance of pro- and anti-inflammatory processes in inflammatory reaction of hemorrhagic shock-induced ALI, and the activation of Toll-like receptor might induce the transcription activity of HO-1, which may play a key role in acute lung injury.

Acute Disease ; Animals ; Heme Oxygenase-1 ; metabolism ; Lung ; pathology ; physiopathology ; Male ; Mice ; Mice, Inbred C3H ; Random Allocation ; Shock, Hemorrhagic ; physiopathology ; Toll-Like Receptor 4 ; physiology

Excess energy intake, without a compensatory increase of energy expenditure, leads to obesity. Several molecules are involved in energy homeostasis regulation and new ones are being discovered constantly. Appetite regulating hormones such as ghrelin, peptide tyrosine-tyrosine and amylin or incretins such as the gastric inhibitory polypeptide have been studied extensively while other molecules such as fibroblast growth factor 21, chemerin, irisin, secreted frizzle-related protein-4, total bile acids, and heme oxygenase-1 have been linked to energy homeostasis regulation more recently and the specific role of each one of them has not been fully elucidated. This mini review focuses on the above mentioned molecules and discusses them in relation to their regulation by the macronutrient composition of the diet as well as diet-induced weight loss.
Appetite ; Bile Acids and Salts ; Diet ; Energy Intake ; Energy Metabolism ; Fibroblast Growth Factors ; Gastric Inhibitory Polypeptide ; Ghrelin ; Heme Oxygenase-1 ; Homeostasis* ; Incretins ; Islet Amyloid Polypeptide ; Obesity ; Physiology* ; Weight Loss*

OBJECTIVETo study the potential function and mechanism of heme oxygenase-1 (HO-1) in regulating platelet reactivity and arterial thrombosis.

METHODSHO-1-deficient (HO-1(-/-)) mice were generated by gene knock-out technique, and the genotyping of the mice was performed by PCR analysis of tail DNA. Thrombus formation was induced by applying FeCl(3) to the exposed carotid artery, and the occlusion time was monitored for each animal. Western blot and chemical assays were used to detect HO-1 and cGMP levels in platelets. Platelet aggregation induced by ADP was also studied.

RESULTSThe difference between mean occlusion time of wild-type mice [(15.56 +/- 1.25) min, n = 16] and HO-1(-/-) mice [(12.85 +/- 0.55) min, n = 14] was not statistically significant. However, after challenge with hemin, which induces HO-1 expression, mean occlusion time was significantly longer in wild-type mice [(16.25 +/- 1.20) min, n = 15] than in HO-1(-/-) mice [(11.96 +/- 0.98) min, n = 19; P < 0.05]. Hemin administration which induced oxidative stress could markedly elevate HO-1 level and cGMP concentration in platelet, while suppress ADP induced platelet aggregation in wild type mice.

CONCLUSIONUnder conditions that stimulate HO-1 production, platelet-dependent thrombus formation is inhibited by HO-1 through the pathway of cGMP expression. It suggests that enhanced platelet HO-1 expression in response to physiological stress may represent an adaptive response mechanism to down-regulate platelet activation under pro-thrombotic conditions.

Animals ; Blood Platelets ; metabolism ; physiology ; Cyclic GMP ; blood ; Female ; Heme Oxygenase-1 ; blood ; genetics ; physiology ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Oxidative Stress ; physiology ; Platelet Aggregation ; Thrombosis ; metabolism ; physiopathology

Heme oxygenase-1 (HO-1) has been described as an inducible protein that is capable of cytoprotection via radical scavenging and the prevention of apoptosis. Chronic exposure to hyperglycemia can lead to cellular dysfunction that may become irreversible over time, and this process has been termed glucose toxicity. Yet little is known about the relation between glucose toxicity and HO-1 in the islets. The purposes of the present study were to determine whether prolonged exposure of pancreatic islets to a supraphysiologic glucose concentration disrupts the intracellular balance between reactive oxygen species (ROS) and HO-1, and so this causes defective insulin secretion; we also wanted to evaluate a protective role for HO-1 in pancreatic islets against high glucose levels. The intracellular peroxide levels of the pancreatic islets (INS-1 cell, rat islet) were increased in the high glucose media (30 mM glucose or 50 mM ribose). The HO-1 expression was induced in the INS-1 cells by the high glucose levels. Both the HO-1 expression and glucose stimulated insulin secretion (GSIS) was decreased simultaneously in the islets by treatment of the HO-1 antisense. The HO-1 was upregulated in the INS-1 cells by hemin, an inducer of HO-1. And, HO-1 upregulation induced by hemin reversed the GSIS in the islets at a high glucose condition. These results suggest HO-1 seems to mediate the protective response of pancreatic islets against the oxidative stress that is due to high glucose conditions.
Reactive Oxygen Species ; Rats, Wistar ; Rats ; Peroxides/metabolism ; Oxidative Stress ; Male ; Islets of Langerhans/*metabolism ; Insulin/secretion ; Hemin/metabolism ; Heme Oxygenase-1/metabolism/*physiology ; Glucose/metabolism/*pharmacology ; *Gene Expression Regulation ; Flow Cytometry ; Animals

BACKGROUNDOne effect of solid tumors is severe hypoxia of local tissues. Heme oxygenase-1 (HO-1) is highly expressed in a variety of human tumor tissues; its induction and activity are closely related to growth of solid tumors. Hypoxia inducible factor-1 (HIF-1) is a transcription factor that regulates hypoxia signal transduction and plays a central role in tumor hypoxia regulation. However, whether and how changes in HO-1 activity affect HIF-1 gene expression has not been reported previously.

METHODSHypoxia-inducible models were established using gastric cancer cell lines (SGC-7901) in a hypoxia incubator. Cells were placed in four groups: Group A, transfected by plasmid harboring HO-1 shRNA; Group B, transfected with scrambled shRNA vector; Group C, treated with hemin; and Group D, exposed to hypoxia only. Expressions of HO-1 and HIF-1 mRNAs were quantified by reverse transcription-polymerase chain reaction. Expressions of HO-1 and HIF-1 proteins were determined by immunohistochemistry and Western blotting.

RESULTSmRNA and protein levels of HO-1 and HIF-1 in the control group were significantly higher than in Group A (P < 0.01), but lower than in Group C (P < 0.01). Chromatin immunoprecipitation analysis showed that HIF-1 was identified as the direct HO-1 target gene.

CONCLUSIONWhile affected by HIF-1, HO-1 up-regulation promotes the expression of HIF-1 and the down-regulation of HO-1 suppresses the expression of HIF-1 gene.

Blotting, Western ; Cell Hypoxia ; genetics ; physiology ; Cell Line, Tumor ; Chromatin Immunoprecipitation ; Heme Oxygenase-1 ; genetics ; metabolism ; Humans ; Hypoxia-Inducible Factor 1 ; genetics ; metabolism ; Immunohistochemistry ; RNA, Small Interfering ; Reverse Transcriptase Polymerase Chain Reaction

BACKGROUNDMesenchymal stem cells (MSCs) transplantation may partially restore heart function in the treatment of acute myocardial infarction (AMI). The aim of this study was to explore the beneficial effects of MSCs modified with heme xygenase-1 (HO-1) on post-infarct swine hearts to determine whether the induction of therapeutic angiogenesis is modified by the angiogenic cytokines released from the implanted cells.

METHODSIn vitro, MSCs were divided into four groups: (1) non-transfected MSCs (MSCs group), (2) MSCs transfected with the pcDNA3.1-Lacz plasmid (Lacz-MSCs group), (3) MSCs transfected with pcDNA3.1-hHO-1 (HO-1-MSCs group), and (4) MSCs transfected with pcDNA3.1-hHO-1 and pretreatment with an HO inhibitor, tin protoporphyrin (SnPP) (HO-1-MSCs + SnPP group). Cells were cultured in an airtight incubation bottle for 24 hours, in which the oxygen concentration was maintained at < 1%, followed by 12 hours of reoxygenation. After hypoxia/reoxygen treatment, ELISA was used to measure transforming growth factor (TGF-β) and fibroblast growth factor (FGF-2) in the supernatant. In vivo, 28 Chinese mini-pigs were randomly allocated to the following treatment groups: (1) control group (saline), (2) Lacz-MSCs group, (3) HO-1-MSCs group, and (4) HO-1-MSCs + SnPP group. About 1 × 10(7) of autologous stem cells or an identical volume of saline was injected intracoronary into porcine hearts 1 hour after MI. Magnetic resonance imaging (MRI) assay and postmortem analysis were assessed four weeks after stem cell transplantation.

RESULTSPost hypoxia/reoxygenation in vitro, TGF-β in the supernatant was significantly increased in the HO-1-MSCs ((874.88 ± 68.23) pg/ml) compared with Lacz-MSCs ((687.81 ± 57.64) pg/ml, P < 0.001). FGF-2 was also significantly increased in the HO-1-MSCs ((1106.48 ± 107.06) pg/ml) compared with the Lacz-MSCs ((853.85 ± 74.44) pg/ml, P < 0.001). In vivo, at four weeks after transplantation, HO-1 gene transfer increased the capillary density in the peri-infarct area compared with the Lacz-MSCs group (14.24 ± 1.66/HPFs vs. 11.51 ± 1.34/HPFs, P < 0.001). Arteriolar density was also significantly higher in HO-1-MSCs group than in the Lacz-MSCs group (7.86 ± 2.00/HPFs vs. 6.45 ± 1.74/HPFs, P = 0.001). At the same time, the cardiac function was significantly improved in the HO-1-MSCs group compared with the Lacz-MSCs group ((53.17 ± 3.55)% vs. (48.82 ± 2.98)%, P < 0.05). However, all these effects were significantly abrogated by SnPP.

CONCLUSIONMSCs provided a beneficial effect on cardiac function after ischemia/reperfusion by the induction of therapeutic angiogenesis, and this effect was amplified by HO-1 overexpression.

Animals ; Blotting, Western ; Cell Differentiation ; genetics ; physiology ; Heme Oxygenase-1 ; genetics ; metabolism ; Magnetic Resonance Imaging ; Mesenchymal Stromal Cells ; cytology ; enzymology ; metabolism ; Myocardial Reperfusion Injury ; enzymology ; metabolism ; Swine ; Swine, Miniature