OBJECTIVES: To investigate the effect of high glucose on macrophage polarization and the role of immune-responsive gene 1 (IRG1) in mediating its effect. METHODS: RAW264.7 cells were transfected with IRG1-overexpressing plasmid or IRG1 siRNA via electroporation and cultured in either normal or high glucose for 72 h to observe the changes in cell viability and morphology using CCK-8 assay and phase contrast microscopy. The protein levels of IRG1, iNOS, Arg-1, IL-1β and IL-10 in the treated cells were detected with Western blotting, and the fluorescence intensities of iNOS and Arg-1 were detected using immunofluorescence assay. The protein levels of IL-1β and IL-10 in the culture medium were determined with ELISA. RESULTS: High glucose exposure significantly reduced IRG1 and Arg-1 expressions, increased iNOS and IL-1β expressions and IL-1β secretion, and decreased IL-10 level in RAW264.7 cells. Transfection with the IRG1-overexpressing plasmid provided the cells with obvious resistance to high glucose-induced changes in iNOS, Arg-1, IL-1β and IL-10, whereas IRG1 knockdown further enhanced the effects of high glucose exposure on Arg-1 expression and the expression and secretion of IL-10. CONCLUSIONS High glucose promotes M1 polarization of the macrophages possibly through a mechanism to inhibit the expression of IRG1 protein, thus leading to chronic inflammatory response.
Animals ; Mice ; Macrophages/drug effects* ; Glucose/pharmacology* ; Interleukin-10/metabolism* ; Nitric Oxide Synthase Type II/metabolism* ; RAW 264.7 Cells ; Interleukin-1beta/metabolism* ; Arginase/metabolism* ; RNA, Small Interfering/genetics* ; Transfection ; Inflammation

OBJECTIVES: To observe the evolution of intrahepatic macrophage polarization in mice with liver fibrosis induced by iron overload. METHODS: Thirty-two C57BL/6 mice (6-8 weeks) were randomized into control group (n=8) and liver fibrosis model group (n=24) induced by aidly intraperitoneal injection of iron dextran. At the 3rd, 5th, and 7th weeks of modeling, 8 mice in the model group were sacrificed for observing liver fibrosis using Masson, Sirius Red and immunohistochemical staining and detecting serum levels of ALT, AST and the levels of serum iron, ferritin, liver total Fe and ferrous Fe. iNOS⁺/F4/80⁺ cells and CD206⁺/F4/80⁺ cells were detected by double immunofluorescence assay to observe the proportion and distribution of M1 and M2 macrophages. The hepatic expressions of Arg-1, iNOS, IL-6, IL-10, and TNF‑α proteins were detected using Western blotting or ELISA, and the expression of CD206 mRNA was detected using RT-PCR. RESULTS: The mice in the model group showed gradual increase of fibrous tissue hyperplasia in the portal area over time, structural destruction of the hepatic lobules and formation of pseudolobules. With the passage of time during modeling, the rat models showed significantly increased hepatic expressions of α-SMA and COL-1, elevated serum levels of ALT, AST, Fe, ferritin, and increased liver total Fe and ferrous Fe levels. The expressions of M1 polarization markers IL-6, TNF‑α, and iNOS all increased with time and reached their peak levels at the 3rd week; The expressions of M2 polarization markers (IL-10 and Arg-1 proteins and CD206 mRNA) significantly increased in the 3rd week and but decreased in the 5th and 7th weeks. CONCLUSIONS Iron overload promotes M1 polarization of macrophages in mice. Liver fibrosis in the early stage promotes M2 polarization of macrophages but negatively regulate M2 polarization at later stages.
Animals ; Mice ; Mice, Inbred C57BL ; Iron Overload/pathology* ; Macrophages/metabolism* ; Male ; Liver Cirrhosis/etiology* ; Nitric Oxide Synthase Type II/metabolism* ; Interleukin-10/metabolism* ; Liver/pathology* ; Interleukin-6/metabolism* ; Mannose Receptor ; Tumor Necrosis Factor-alpha/metabolism* ; Mannose-Binding Lectins/metabolism* ; Arginase

This study was designed to investigate the correlation between autophagy and polarization of macrophages in atherosclerosis (AS) plaque in arteriosclerosis obliterans amputees. Femoral artery specimens from arteriosclerosis obliterans amputees were performed hematoxylin and eosin (HE) staining, oil red O and immunofluorescence staining to observe the morphology of atherosclerotic plaque, phenotype of macrophages and autophagy in plaque; using real-time quantitative RT-PCR technology to detect the mRNA level of M1 and M2 type markers in arterial tissue; to analyze polarized signal pathway and autophagy protein levels in macrophages by Western blotting. Arterial specimens staining showed obvious lipid deposition and obvious infiltration of amount of foam cells and inflammatory cells. Macrophages were mainly expression M1 type in percentage in fibrous plaque. Although both M1 and M2 macrophages were upregulated in atheromatous plaque, the increase was dominant in M2 type in percentage. The level of autophagy was significantly higher in the atheromatous plaque than that of fibrous plaque. The expression of tumor necrosis factor- α (TNF-α), monocyte chemotactic protein-1 (MCP-1), inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6) and interleukin-12 (IL-12) mRNA was significantly higher in fibrous plaque than that of atheromatous plaque (P < 0.01 or 0.05), and arginase-1 (Arg-1), transforming growth factor-β (TGF-β), CD163 and interleukin-10 (IL-10) mRNA was significantly lower than that in atheromatous plaque (P < 0.01). The levels of p-STAT1 and NF-κB were significantly increased in fibrous plaque (P < 0.01), while p-STAT6 expression was significantly increased in atheromatous plaque (P < 0.01). The level of LC3-II was significantly higher in atheromatous plaque than that in fibrous plaque (P < 0.01). Macrophages in early atherosclerotic plaque were induced to M1 type through p-STAT1/NF-κB pathway and expressed moderate levels of autophagy; while macrophages in advanced plaques were induced to polarization of M2 type through p-STAT6 pathway. M2 macrophages expressed a higher level of autophagy than M1 macrophages.
Amputees ; Arginase ; metabolism ; Arteriosclerosis Obliterans ; pathology ; Atherosclerosis ; pathology ; Autophagy ; Cell Polarity ; Chemokine CCL2 ; metabolism ; Foam Cells ; cytology ; Humans ; Interleukin-10 ; metabolism ; Interleukin-12 ; metabolism ; Interleukin-6 ; metabolism ; Macrophages ; cytology ; NF-kappa B ; metabolism ; Nitric Oxide Synthase Type II ; metabolism ; Phenotype ; STAT6 Transcription Factor ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism ; Up-Regulation

PURPOSE: Oxidative stress during CO2 pneumoperitoneum is reported to be associated with decreased bioactivity of nitric oxide (NO). However, the changes in endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), and arginase during CO2 pneumoperitoneum have not been elucidated. MATERIALS AND METHODS: Thirty male Sprague-Dawley rats were randomized into three groups. After anesthesia induction, the abdominal cavities of the rats of groups intra-abdominal pressure (IAP)-10 and IAP-20 were insufflated with CO2 at pressures of 10 mm Hg and 20 mm Hg, respectively, for 2 hours. The rats of group IAP-0 were not insufflated. After deflation, plasma NO was measured, while protein expression levels and activity of eNOS, iNOS, arginase (Arg) I, and Arg II were analyzed with aorta and lung tissue samples. RESULTS: Plasma nitrite concentration and eNOS expression were significantly suppressed in groups IAP-10 and IAP-20 compared to IAP-0. While expression of iNOS and Arg I were comparable between the three groups, Arg II expression was significantly greater in group IAP-20 than in group IAP-0. Activity of eNOS was significantly lower in groups IAP-10 and IAP-20 than in group IAP-0, while iNOS activity was significantly greater in group IAP-20 than in groups IAP-0 and IAP-10. Arginase activity was significantly greater in group IAP-20 than in groups IAP-0 and IAP-10. CONCLUSION: The activity of eNOS decreases during CO2 pneumoperitoneum, while iNOS activity is significantly increased, a change that contributes to increased oxidative stress and inflammation. Moreover, arginase expression and activity is increased during CO2 pneumoperitoneum, which seems to act inversely to the NO system.
Animals ; Aorta/*physiology ; Arginase/*antagonists & inhibitors ; Enzyme Inhibitors/administration & dosage/pharmacology ; Inflammation/etiology/*prevention & control ; Injections, Subcutaneous ; Lung Injury/etiology/prevention & control ; Male ; Nitric Oxide/metabolism ; Nitric Oxide Synthase Type II/*metabolism ; Nitric Oxide Synthase Type III/*metabolism ; Oxidative Stress/*drug effects ; Pneumoperitoneum/*complications/drug therapy ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the expression of arginase-1 (Arg-1), glypican-3 (GPC3), hepatocyte paraffin antigen 1 (HepPar-1) and alpha-fetoprotein (AFP) in hepatocellular carcinoma (HCC), benign liver lesions (BLL) and metastatic carcinoma (MC), and their applications in diagnosis and differential diagnosis.

METHODSImmunohistochemical study (EnVision method) for Arg-1, GPC3, HepPar-1 and AFP was carried out in three groups of liver lesions, including 85 cases of HCC, 35 cases of BLL and 19 cases of MC. The relationship between expression of Arg-1, GPC3, HepPar-1 and AFP and clinicopathologic features in HCC was also analyzed.

RESULTSThe positive expression rate of Arg-1 was 90.6% (79/85) in HCC and 100% (35/35) in BLL. Arg-1 expression was observed in 1 of the 19 cases of MC studied. The positive expression rate of GPC3 was 82.4% (70/85) in HCC, 5.3% (1/19) in MC and 0 (0/35) in BLL. The positive expression rate of AFP was 47.1% (40/85) in HCC and 0 in BLL or MC. The positive expression rate of HepPar-1 was 72.9% (62/85) in HCC, 100% (35/35) in BLL and 2/19 in MC. Arg-1 has a higher sensitivity in highlighting hepatocellular lesions than AFP and HepPar-1 (P=0.000 versus P=0.002). The specificity of GPC3 expression in HCC was 98.1%.

CONCLUSIONSArg-1 is a sensitive hepatocellular marker in delineation of liver lesions.GPC3 is a relatively specific marker in diagnosis of HCC.

Adenocarcinoma ; metabolism ; secondary ; Adult ; Aged ; Antibodies, Monoclonal ; metabolism ; Antibodies, Neoplasm ; metabolism ; Antigens, Neoplasm ; immunology ; Arginase ; metabolism ; Biomarkers, Tumor ; metabolism ; Breast Neoplasms ; metabolism ; pathology ; Carcinoma, Hepatocellular ; diagnosis ; metabolism ; pathology ; Diagnosis, Differential ; Female ; Glypicans ; metabolism ; Humans ; Liver Diseases ; diagnosis ; metabolism ; Liver Neoplasms ; diagnosis ; metabolism ; pathology ; Male ; Middle Aged ; Rectal Neoplasms ; metabolism ; pathology ; Survival Rate ; alpha-Fetoproteins ; metabolism

Myeloid-derived suppressor cells (MDSCs) play a crucial role in T cell dysfunction, which is related to poor outcome in patients with severe trauma. Cyclooxygenase-2 (Cox-2) contributes to immune disorder in trauma and infection via production of prostaglandin E2. However, the role of Cox-2 in the accumulation and function of MDSCs after traumatic stress has not been fully elucidated. In the present study, we treated murine trauma model with NS398, a selective Cox-2 inhibitor. Then the percentages of CD11b+/Gr-1+ cells, proliferation and apoptosis of CD4+ T cells were determined. Arginase activity and arginase-1 (Arg-1) protein expression of splenic CD11b+/Gr-1+ cells, and delayed-type hypersensitivity (DTH) response were analyzed. The results showed that Cox-2 blockade significantly decreased the percentages of CD11b+/Gr-1+ cells in the spleen and bone marrow 48 and 72 h after traumatic stress. NS398 inhibited arginase activity and down-regulated the Arg-1 expression of splenic CD11b+/Gr-1+ cells. Moreover, NS398 could promote proliferation and inhibit apoptosis of CD4+ T cells. It also restored DTH response of traumatic mice. Taken together, our data revealed that Cox-2 might play a pivotal role in the accumulation and function of MDSC after traumatic stress.
Animals ; Apoptosis ; drug effects ; Arginase ; biosynthesis ; CD11b Antigen ; biosynthesis ; CD4-Positive T-Lymphocytes ; drug effects ; metabolism ; Cell Proliferation ; drug effects ; Cyclooxygenase 2 ; biosynthesis ; Cyclooxygenase 2 Inhibitors ; administration & dosage ; Gene Expression Regulation ; drug effects ; Humans ; Mice ; Myeloid Progenitor Cells ; metabolism ; pathology ; Nitrobenzenes ; administration & dosage ; Stress Disorders, Traumatic ; drug therapy ; genetics ; pathology ; Sulfonamides ; administration & dosage

OBJECTIVETo study the role of arginase-1 (Arg-1) expression in differential diagnosis of hepatocellular carcinoma (HCC), Arg-1 staining pattern in clear cell neoplasm (HCC and non-HCC) and Arg-1 expression in non-hepatocellular tumors.

METHODSSeventy-eight cases of HCC (including 8 cases of clear cell type and 70 cases of non- clear cell type) and 246 cases of non-hepatocellular neoplasms (including 29 cases of metastatic tumors such as breast cancer, nasopharyngeal carcinoma and neuroendocrine carcinoma, 77 cases of tumors with clear cell changes such as malignant melanoma, clear cell renal cell carcinoma and alveolar soft part sarcoma, and 140 cases of other types of tumors such as ovarian endometrioid adenocarcinoma, pituitary tumor and thyroid papillary carcinoma) were studied.Immunohistochemical study for Arg-1 was performed on the paraffin-embedded tumor tissue.

RESULTSIn HCC, Arg-1 demonstrated both cytoplasmic and nuclear staining, with an overall sensitivity of 96.2% (75/78).In well, moderately and poorly differentiated HCC, the sensitivity was 15/15, 100% (41/41) and 86.4% (19/22), respectively. That was in contrast to negative staining for Arg-1 in all the 29 cases of metastatic tumors studied. The sensitivity, specificity, positive predictive value and negative predictive value of Arg-1 in distinguishing HCC from metastatic tumors was 96.2%, 100%, 100% and 90.6%, respectively. Cytoplasmic and membranous staining was observed in clear cell type of HCC. The overall sensitivity of Arg-1 expression in the 77 cases of tumors with clear cell changes was 14.3% (11/77), including 8/15 for malignant melanoma, 2/4 for ovarian clear cell carcinoma and 1/1 gall bladder adenocarcinoma with clear cell component.In malignant melanoma and ovarian clear cell carcinoma, only cytoplasmic staining was demonstrated. There was no expression of Arg-1 in the 140 cases of other tumor types studied.

CONCLUSIONSArg-1 is a sensitive and specific marker for HCC.It is a potentially useful immunohistochemical marker in distinguishing HCC from metastatic tumors. Though also expressed in malignant melanoma and ovarian clear cell carcinoma, Arg-1 shows a different staining pattern as compared with that in HCC.

Adenocarcinoma ; enzymology ; Adult ; Aged ; Arginase ; metabolism ; Carcinoma, Hepatocellular ; enzymology ; pathology ; secondary ; Cell Differentiation ; Diagnosis, Differential ; Female ; Gallbladder Neoplasms ; enzymology ; Humans ; Liver Neoplasms ; enzymology ; pathology ; secondary ; Male ; Melanoma ; enzymology ; Middle Aged ; Ovarian Neoplasms ; enzymology ; Stomach Neoplasms ; enzymology ; pathology

BACKGROUNDHemorrhagic shock is usually associated with complicated immune and inflammatory responses, which are sometimes crucial for the prognosis. As regulators of the immune and inflammatory system; proliferation, migration, distribution and activation of myeloid-derived suppressor cells (MDSCs) are intimately linked to the inflammation cascade.

METHODSIn a model of severe hemorrhagic shock, thirty-five rats were randomly divided into control, sham, normal saline resuscitation (NS), hypertonic saline resuscitation (HTS), and hydroxyethyl starch resuscitation (HES), with seven in each group. MDSCs were analyzed by flow cytometric staining of CD11b/c(+)Gra(+) in peripheral blood mononuclear cells (PBMC), spleen cell suspensions, and bone marrow nucleated cells (BMNC). Simultaneously, the expressions of arginase-1 (ARG-1) and inducible nitric oxide synthase (iNOS) mRNA in MDSCs were evaluated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR).

RESULTSIn the early stage after hemorrhagic shock, fluid resuscitation and emergency treatment, the MDSCs in the PBMC of NS, HTS and HES groups markedly increased, and MDSCs in BMNC of these groups decreased accordingly, significantly different to the control group. In hemorrhagic shock rats infused with HTS at the early resuscitation stage, MDSCs in PBMC increased about 2 and 4 folds, and MDSCs in BMNC decreased about 1.3 and 1.6 folds, as compared to the sham group respectively, with statistically significant difference. Furthermore, compared to the NS and HES groups, the MDSCs in PBMC of HTS group increased 1.6 and 1.8 folds with statistically significant differences; the MDSCs decrease in BMNC was not significant. However, there was no statistically significant difference in MDSCs of spleen among the five groups. In addition, compared to the control, sham, NS and HES groups, the ARG-1 and iNOS mRNA of MDSCs in PBMC, spleen and BMNC in the HTS group had the highest level of expression, but no statistically significant differences were noted.

CONCLUSIONSIn this model of rat with severe and controlled hemorrhagic shock, small volume resuscitation with HTS contributes to dramatically early migration and redistribution of MDSCs from bone marrow to peripheral circulation, compared to resuscitation with NS or HES.

Animals ; Arginase ; genetics ; metabolism ; Blood Pressure ; physiology ; Disease Models, Animal ; Flow Cytometry ; Fluid Therapy ; methods ; Leukocytes, Mononuclear ; metabolism ; Male ; Nitric Oxide Synthase Type II ; metabolism ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Saline Solution, Hypertonic ; therapeutic use ; Shock, Hemorrhagic ; immunology ; metabolism ; therapy

The incidence of cardiovascular disease is predicted to increase as the population ages. There is accumulating evidence that arginase upregulation is associated with impaired endothelial function. Here, we demonstrate that arginase II (ArgII) is upregulated in aortic vessels of aged mice and contributes to decreased nitric oxide (NO) generation and increased reactive oxygen species (ROS) production via endothelial nitric oxide synthase (eNOS) uncoupling. Inhibiting ArgII with small interfering RNA technique restored eNOS coupling to that observed in young mice and increased NO generation and decreased ROS production. Furthermore, enhanced vasoconstrictor responses to U46619 and attenuated vasorelaxation responses to acetylcholine in aged vasculature were markedly improved following siRNA treatment against ArgII. These results might be associated with increased L-arginine bioavailability. Collectively, these results suggest that ArgII may be a valuable target in age-dependent vascular diseases.
15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid/pharmacology ; Aging ; Animals ; Aorta/enzymology/physiopathology ; Arginase/genetics/*metabolism ; Endothelium, Vascular/*enzymology/physiopathology ; Enzyme Induction ; Gene Knockdown Techniques ; Mice ; Mice, Inbred C57BL ; Nitric Oxide/metabolism ; Nitric Oxide Synthase Type III/*metabolism ; RNA, Small Interfering/genetics ; Reactive Oxygen Species/metabolism ; Up-Regulation ; Vasoconstriction/drug effects

Arginase competitively inhibits nitric oxide synthase (NOS) via use of the common substrate L-arginine. Arginase II has recently reported as a novel therapeutic target for the treatment of cardiovascular diseases such as atherosclerosis. Here, we demonstrate that piceatannol-3'-O-beta-D-glucopyranoside (PG), a potent component of stilbenes, inhibits the activity of arginase I and II prepared from mouse liver and kidney lysates, respectively, in a dose-dependent manner. In human umbilical vein endothelial cells, incubation of PG markedly blocked arginase activity and increased NOx production, as measured by Griess assay. The PG effect was associated with increase of eNOS dimer ratio, although the protein levels of arginase II or eNOS were not changed. Furthermore, isolated mice aortic rings treated with PG showed inhibited arginase activity that resulted in increased nitric oxide (NO) production upto 78%, as measured using 4-amino-5-methylamino-2',7'-difluorescein (DAF-FM) and a decreased superoxide anions up to 63%, as measured using dihydroethidine (DHE) in the intact endothelium. PG showed IC50 value of 11.22 microM and 11.06 microM against arginase I and II, respectively. PG as an arginase inhibitor, therefore, represents a novel molecule for the therapy of cardiovascular diseases derived from endothelial dysfunction and may be used for the design of pharmaceutical compounds.
Animals ; Aorta/drug effects/metabolism ; Arginase/*antagonists & inhibitors/metabolism ; Dose-Response Relationship, Drug ; Endothelial Cells/drug effects/enzymology ; Enzyme Activation/drug effects ; Glucosides/chemistry/*pharmacology ; Humans ; Mice ; Mice, Inbred C57BL ; Nitrates/metabolism ; Nitric Oxide/biosynthesis ; Nitric Oxide Synthase Type III/*metabolism ; Nitrites/metabolism ; Reactive Oxygen Species/metabolism ; Rheum/*chemistry ; Stilbenes/chemistry/*pharmacology