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*

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

OBJECTIVETo study the effect of heme oxygenase-1 (HO-1) on peribiliary vascular plexus (PVP) in rat bile duct ischemia/reperfusion injury.

METHODSTotal 128 male SD rats were randomly divided into saline group (Saline), empty virus group (Adv), induced group (Adv-HO-1) and suppressed group (HO-1 siRNA), and there were 32 rats in each group. Rats were injected using 0.5 ml of saline, empty adenovirus, HO-1 adenovirus and siRNA adenovirus (2×10(9) TU/rat) via the dorsal penile vein 24 hours before surgery. Liver function was analyzed at 1 hour and 1, 7, 14 days after reperfusion. HO-1, hypoxiainducible factor-1α (HIF-1α), stromal cell derived factor-1α (SDF-1α) and vascular endothelial growth factor (VEGF) protein content was analyzed by Western blot. The endothelial progenitor cells (EPCs) ratio in the liver and peripheral blood was detected by flow cytometry. Small vascular around the bile duct was observed by α-smooth muscle actin and von Willebrand factor double immunofluorescence staining.

RESULTSReduced liver injury and higher expression of HIF-1α, SDF-1α and VEGF in the induced group after surgery (q = 5.68-7.52, P < 0.01). EPCs ratio in the liver and peripheral blood was significantly higher in the induced group than saline group (q = 12.14 and 15.26, P < 0.01), and the suppressed group at 7 days after surgery were less than saline group significantly (q = 4.83 and 5.07, P < 0.01). In comparison to the suppressed group, higher density of small vascular around the bile duct was seen in the liver tissue of induced group.

CONCLUSIONSHO-1 can induce the expression of HIF-1α, SDF-1α and VEGF, and mobilize the release of EPCs to the peripheral from the bone marrow. EPCs migrate to the liver and promote damaged PVP repair and regeneration.

Animals ; Bile Ducts ; blood supply ; Chemokine CXCL12 ; metabolism ; Endothelial Cells ; cytology ; Heme Oxygenase (Decyclizing) ; physiology ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Male ; Neovascularization, Physiologic ; RNA, Small Interfering ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; physiopathology ; Stem Cells ; cytology ; Vascular Endothelial Growth Factor A ; metabolism

BACKGROUNDBone marrow hematopoietic function suppression is one of the most common side effects of chemotherapy. After chemotherapy, the bone marrow structure gets destroyed and the cells died, which might cause the hematopoietic function suppression. Heme oxygenase-1 (HO-1) is a key enzyme of antioxidative metabolism that associates with cell proliferation and resistance to apoptosis. The aim of this study was to restore or resist the bone marrow from the damage of chemotherapy by the HO-1 expression of mouse mesenchymal stem cells (mMSCs) homing to the mice which had the chemotherapy-induced bone marrow suppression.

METHODSOne hundred and sixty female Balb/c mice (6-8-weeks old) were randomly divided into four groups. Each group was performed in 40 mice. The control group was intraperitoneally injected for 5 days and tail intravenously injected on the 6th day with normal saline. The chemotherapy-induced bone marrow suppression was established by intraperitoneally injecting cyclophosphamide (CTX) into the mice which performed as the chemotherapy group. The mMSCs were tail intravenously injected into 40 chemotherapically damaged mice which served as the mMSCs group. The difference between the HO-1 group and the mMSCs group was the injected cells. The HO-1 group was tail intravenously injected into the mMSCs that highly expressed HO-1 which was stimulated by hemin. The expression of HO-1 was analyzed by Western blotting and RT-PCR. Cell proliferation was measured using the 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. Histopathologic examinations were performed 1 week after injection.

RESULTSCompared with the control group, the expression levels of HO-1 mRNA and protein were significantly higher in the HO-1 group (all P < 0.05), even obviously than the mMSCs group. CTX treatment induced apoptosis and inhibited proliferation. After injected, the white blood cell (WBC), red blood cell (RBC) and platelet (PLT) declined fast and down to the bottom at the 7th day. The bone marrow structure was destroyed incomplete. In vitro, the survival rate of cells in chemotherapy group was less than 50% after 24 hours. In contrast, mMSCs could do a favor to the cellular cleavage and proliferation. They slowed down the cell mortality and more than 50% cells survived after 24 hours. The effects of blocking apoptosis and bone marrow recovery could be more effective in the HO-1 group. In the HO-1 group, it had observed that the bone marrow structure became complete and the hemogram closed to normal at 7th day.

CONCLUSIONSHO-1 played an important role in promoting the recovery of CTX-induced hematopoietic damage. We suggest that HO-1 is able to restore the functions of chemotherapy-induced hematopoietic damage.

Animals ; Apoptosis ; drug effects ; Blood Platelets ; drug effects ; Blotting, Western ; Bone Marrow ; drug effects ; enzymology ; Cell Proliferation ; drug effects ; Cells, Cultured ; Cyclophosphamide ; toxicity ; Erythrocytes ; drug effects ; Female ; Heme Oxygenase-1 ; genetics ; metabolism ; Leukocytes ; drug effects ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells ; enzymology ; physiology ; Mice ; Mice, Inbred BALB C ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo establish the method for cotransferring human A20 gene and human heme oxygenase-1 (HO-1) gene into the isolated rat islets using lentiviral transfection system, and to study the protective effect of A20 and HO-1 protein against the apoptosis induced by cycloheximide (CHX) and TNF-α, and finally to explore the underlying mechanism.

METHODThe A20 gene and HO-1 gene were cloned and inserted into the lentiviral transfection system. The efficacy of gene transfer was measured by the intensity of the enhanced green fluorescent protein (EGFP) fluorescence-positive islets. Western blot was applied to verify the expression of the A20 and HO-1 genes. To induce apoptosis in vitro, the isolated islets were treated with CHX+TNF-α, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and the fluorescence-activated cell sorting (FACS) methods were used to evaluate the apoptosis of the islet cells and Western blot was used to detect caspase-3 activation.

RESULT(1) A20 and HO-1 genes were introduced into the isolated islets by lentiviral transfection, both of the genes were highly expressed in the islets after 96 hours culture detected by Western blot method. (2) The insulin levels in the cell culture medium from A20 and/or HO-1 transgenic islets were significantly higher than that in non-transgenic controls (P < 0.01). (3)After CHX + TNF-alpha treatment, the cell culture medium insulin concentration in the A20 gene transfected group [(93.58 ± 4.12)µg/ml], HO-1 gene transfected group [(88.98 ± 4.77) µg/ml ] and A20/HO-1 co-transfected group [(103.33 ± 3.16) µg/ml] were significantly higher than that in the EGFP group [(9.03 ± 0.65) µg/ml ] and the control group [(8.86 ± 0.38) µg/ml] (P < 0.001). Minimum expression level of the activated caspase-3 was found in the A20/HO-1 co-transfected group.

CONCLUSIONThe lentiviral gene transfer system was an efficient and stable gene transfer vector, the over-expressed A20 and HO-1 protein delivered via lentivirus could preserve rats' islets function and act against the apoptosis induced by CHX and TNF-α.

Animals ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cell Line ; DNA-Binding Proteins ; genetics ; metabolism ; Female ; Flow Cytometry ; Genetic Vectors ; Heme Oxygenase-1 ; genetics ; metabolism ; Humans ; Insulin ; metabolism ; Intracellular Signaling Peptides and Proteins ; genetics ; metabolism ; Islets of Langerhans ; drug effects ; enzymology ; physiology ; Lentivirus ; genetics ; Male ; Nuclear Proteins ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Transfection ; methods ; Tumor Necrosis Factor alpha-Induced Protein 3 ; Tumor Necrosis Factor-alpha ; pharmacology

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

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.
Age Factors ; Blotting, Western ; *Cell Aging ; Cell Cycle ; Cells, Cultured ; Enzyme Induction ; Fibroblasts/physiology ; G1 Phase ; Heme Oxygenase-1/metabolism ; Humans ; Hydrogen Peroxide/pharmacology ; *Oxidative Stress ; Oxidoreductases Acting on CH-CH Group Donors/*metabolism ; Protein Kinase Inhibitors/metabolism ; RNA, Small Interfering ; Reactive Oxygen Species/metabolism ; beta-Galactosidase/genetics/metabolism

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

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

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