ADAM10 partially protects mice against influenza pneumonia by suppressing specific myeloid cell population.

The influenza virus infection poses a serious health threat worldwide. Myeloid cells play pivotal roles in regulating innate and adaptive immune defense. A disintegrin and metalloproteinase (ADAM) family of proteins contributes to various immune responses; however, the role of a disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) in influenza virus infection remains largely unknown. Herein, we investigated its role, focusing on myeloid cells, during influenza virus infection in mice. ADAM10 gene (Adam10)flox/flox/Lyz2-Cre (Adam10ΔLyz2) and control Adam10flox/flox mice were intranasally infected with 200 plaque-forming units of influenza virus A/H1N1/PR8/34. Adam10ΔLyz2 mice exhibited a significantly higher mortality rate, stronger lung inflammation, and a higher virus titer in the lungs than control mice. Macrophages and inflammatory cytokines, such as TNF-α, IL-1ß, and CCL2, were increased in bronchoalveolar lavage fluid from Adam10ΔLyz2 mice following infection. CD11b+Ly6G-F4/80+ myeloid cells, which had an inflammatory monocyte/macrophage-like phenotype, were significantly increased in the lungs of Adam10ΔLyz2 mice. Adoptive transfer experiments suggested that these cells likely contributed to the poorer prognosis in Adam10ΔLyz2 mice. Seven days after infection, CD11b+Ly6G-F4/80+ lung cells exhibited significantly higher arginase-1 expression levels in Adam10ΔLyz2 mice than in control mice, whereas an arginase-1 inhibitor improved the prognosis of Adam10ΔLyz2 mice. Enhanced granulocyte-macrophage colony-stimulating factor (GM-CSF)/GM-CSF receptor signaling likely contributed to this process. Collectively, these results indicate that myeloid ADAM10 protects against influenza virus pneumonia and may be a promising therapeutic target.

Residual biomass from surfactin production is a source of arginase and adsorbed surfactin that is useful for environmental remediation.

Lipopeptides are important secondary metabolites produced by microbes. They find applications in environmental decontamination and in the chemical, pharmaceutical and food industries. However, their production is expensive. In the present work we propose three strategies to lower the production costs of surfactin. First, the coproduction of surfactin and arginase in a single growth. Second, extract the fraction of surfactin that adsorbs to the biomass and is removed from the growth medium through centrifugation. Third, use microbial biomass for the remediation of organic and inorganic contaminants. The coproduction of surfactin and arginase was evaluated by factorial design experiments using the LB medium supplemented with arginine. The best conditions for surfactin production were 22 h of growth at 37 °C using LB supplemented with arginine 7.3 g/L. Almost similar conditions were found to produce highest levels of arginase, 24 h and 6.45 g/L arginine. Decontamination of phenol and copper from artificial samples was attained by treatment with residues from lipopeptide production. Thus, cell suspensions and wash-waters used to extract surfactin from the biomass. Cell suspensions were used to successfully remove hydroquinone. Cell suspensions and wash-waters containing surfactin were successfully used to recover copper from solution. Specific monitoring methods were used for phenol and metal solutions, respectively a biosensor based on tyrosinase and either atomic absorption flame ionization spectrometry or absorbance coupled to the Arduino™ platform. Therefore, we report three alternative strategies to lower the production costs in lipopeptide production, which include the effective recovery of copper and phenol from contaminated waters using residues from surfactin production. Sustainable and profitable production of surfactin can be achieved by a coproduction strategy of lipopeptides and enzymes. Lipopeptides are collected in the supernatant and enzymes in the biomass. In addition, lipopeptides that coprecipitate with biomass can be recovered by washing. Lipopeptide wash-waters find applications in remediation and cells can also be used for environmental decontamination.

Neutrophil Expression of T and B Immunomodulatory Molecules in HIV Infection.

Objective: Evaluate the expression of B and T cell immunomodulatory molecules in polymorphonuclear neutrophils (PMN) in HIV-infected patients. Methods: HIV load, bacterial translocation and neutrophils' expression of T [programmed death ligand, interleukin-10+, arginase 1+] and B [BAFF, APRIL] molecules were analyzed in different cohorts and time points: a control group of 25 healthy individuals and two groups of HIV-infected patients. Group 1 of patients included 35 untreated patients, studied at baseline and after antiretroviral therapy (ART). Group 2 was composed of 25 patients with undetectable viral load after a median of 101 months of ART prior to inclusion in the study. Results: Compared with the control group, group 1 patients showed increased bacterial translocation and their PMN had a significantly higher expression of T and B-cell immunomodulatory molecules, both at baseline and after 12 months of ART. Group 2 patients showed reduced bacterial translocation levels when compared with group 1 patients after 12 months of treatment. PMN expression of B-cell modulators was similar between group 2 patients and healthy controls, although the expression of T-cell modulators remained increased. Conclusion: In HIV-infected patients, the expression of B-cell stimulatory and T-cell suppressive molecules by neutrophils was increased at baseline and after a limited time of therapy. After a prolonged period of ART, only PMNs expression of T-cell immunosuppressive molecules remained elevated.

Changes in arginase isoforms in a murine model of neonatal brain hypoxia-ischemia.

BACKGROUND: Arginases (ARG isoforms, ARG-1/ARG-2) are key regulatory enzymes of inflammation and tissue repair; however, their role after neonatal brain hypoxia (H) and hypoxia-ischemia (HI) remains unknown. METHODS: C57BL/6 mice subjected to the Vannucci procedure on postnatal day (P9) were sacrificed at different timepoints. The degree of brain damage was assessed histologically. ARG spatiotemporal localization was determined via immunohistochemistry. ARG expression was measured by Western blot and activity spectrophotometrically. RESULTS: ARG isoform expression increased during neurodevelopment (P9-P17) in the cortex and hippocampus. This was suppressed with H and HI only in the hippocampus. In the cortex, both isoforms increased with H alone and only ARG-2 increased with HI at 3 days. ARG activity during neurodevelopment remained unchanged, but increased at 1 day with H and not HI. ARG-1 localized with microglia at the injury site as early as 4 h after injury, while ARG-2 localized with neurons. CONCLUSIONS: ARG isoform expression increases with age from P9 to P17, but is suppressed by injury specifically in the hippocampus and not in the cortex. Both levels and activity of ARG isoforms increase with H, while ARG-1 immunolabelling is upregulated in the HI cortex. Evidently, ARG isoforms in the brain differ in spatiotemporal localization, expression, and activity during neurodevelopment and after injury. IMPACT: Arginase isoforms change during neurodevelopment and after neonatal brain HI. This is the first study investigating the key enzymes of inflammation and tissue repair called arginases following murine neonatal brain HI. The highly region- and cell-specific expression suggests the possibility of specific functions of arginases. ARG-1 in microglia at the injury site may regulate neuroinflammation, while ARG-2 in neurons of developmental structures may impact neurodevelopment. While further studies are needed to describe the exact role of ARGs after neonatal brain HI, our study adds valuable data on anatomical localization and expression of ARGs in brain during development and after stroke.

Drupin, a cysteine protease from Ficus drupacea latex accelerates excision wound healing in mice.

Wound healing is a tightly regulated physiological process that restores tissue integrity after injury. Plant latex proteases (PLPs) are considered an integral part in herbal wound care as it interferes at different phases of the wound healing process. Although many studies have reported the involvement of PLPs in healing process, an in-depth investigation is required to understand the molecular mechanism. Hence, the effect of PLPs with fibrinolytic activity on wound healing was investigated systematically using mouse excision wound model. Among 29 latices from Ficus genus tested, Ficus drupacea exhibited potent fibrinolytic activity. Cysteine protease responsible for fibrinolysis was purified from the F. drupacea latex named it as drupin, tested for its wound healing efficacy. The accelerated wound healing was mediated by downregulation of matrix metalloprotease (MMP)-9 without altering MMP-8 expression. Besides, drupin enhanced the rate of collagen synthesis at the wound site by increasing arginase 1 activity. And also, drupin increased the expression of arginase 1 in macrophages and involved in cell proliferation, and migration via MAP kinase and PI3K/Akt pathways. Overall, the present study highlights the interference of drupin in wound healing by increased arginase 1 activity and collagen synthesis, and cell proliferation and migration.

ARG1 functions as a tumor suppressor in breast cancer.

Arginase I (ARG1) is a cytosolic enzyme that catalyzes the hydrolysis of L-arginine to L-ornithine and urea. The association of ARG1 with cancer has mostly been focused on the ARG1 released by tumor-associated myeloid cells in tumor microenvironment. However, the role of ARG1 expressed in cancer cells is unclear. Here, we showed that the expression of ARG1 in human breast cancer (BC) is related to a good prognosis in BC patients. Overexpression of ARG1 suppresses BC cell proliferation and migration in vitro and xenograft tumor growth and development in mouse models. Furthermore, ARG1 expression down-regulates the expression of p-AKT, leading to the de-activation of AKT signal pathway in BC cells. Thus, our results established that in contrast to the role of ARG1 released from tumor-associated myeloid cells in tumor microenvironment that promotes tumor immune escape, ARG1 expressed in BC cells suppresses AKT signaling pathway and functions as a tumor suppressor.

HGF-MET Signaling Shifts M1 Macrophages Toward an M2-Like Phenotype Through PI3K-Mediated Induction of Arginase-1 Expression.

Backgrounds and Aims: Hepatocyte Growth Factor (HGF)-MET signaling is known to promote biological functions such as cell survival, cell motility, and cell proliferation. However, it is unknown if HGF-MET alters the macrophage phenotype. In this study, we aimed to study the effects of HGF-MET signaling on the M1 macrophage phenotype. Methods and Materials: Bone marrow-derived macrophages (BMDMs) isolated from mice were either polarized to an M1 phenotype by IFN-γ and LPS treatment or to an M2 phenotype by IL-4 treatment. Changes in M1 or M2 markers induced by HGF-MET signaling were evaluated. Mechanisms responsible for alternations in the macrophage phenotype and intracellular metabolism were analyzed. Results: c-Met was expressed especially in M1 macrophages polarized by treatment with IFN-γ and LPS. In M1 macrophages, HGF-MET signaling induced the expression of Arg-1 mRNA and secretion of IL-10 and TGF-ß1 and downregulated the mRNA expression of iNOS, TNF-α, and IL-6. In addition, activation of the PI3K pathway and inactivation of NFκB were also observed in M1 macrophages treated with HGF. The increased Arg-1 expression and IL-10 secretion were abrogated by PI3K inhibition, whereas, no changes were observed in TNF-α and IL-6 expression. The inactivation of NFκB was found to be independent of the PI3K pathway. HGF-MET signaling shifted the M1 macrophages to an M2-like phenotype, mainly through PI3K-mediated induction of Arg-1 expression. Finally, HGF-MET signaling also shifted the M1 macrophage intracellular metabolism toward an M2 phenotype, especially with respect to fatty acid metabolism. Conclusion: Our results suggested that HGF treatment not only promotes regeneration in epithelial cells, but also leads to tissue repair by altering M1 macrophages to an M2-like phenotype.

Analysis of Cyclooxygenase 2, Programmed Cell Death Ligand 1, and Arginase 1 Expression in Human Pituitary Adenoma.

BACKGROUND: Cyclooxygenase 2 (COX-2) is a key enzyme in the synthesis of prostaglandins. Recent studies have shown that overexpression of COX-2 can reduce the antitumor effect of the immune system by inhibiting the proliferation of B and T lymphocytes. Programmed cell death ligand 1 (PD-L1) was the first functionally characterized ligand of programmed cell death protein 1. It plays an important role in maintaining peripheral and central immune tolerance by combining with programmed cell death protein 1. Arginase 1 (ARG1) can process L-arginine in the local microenvironment and affect the function of T cells, resulting in immune escape. In this study, COX-2, PD-L1, and ARG1 expression in human pituitary adenoma (PA) and their relationship were investigated, which provided an initial theoretic basis for further study of the immune escape mechanism in PA in cellular and animal experiments. METHODS: The protein expression of COX-2, PD-L1, and ARG1 in 55 PA samples was detected by immunohistochemistry, with 10 normal brain tissues as the control group. The location of COX-2, PD-L1, and ARG1 in PA cells was studied by double immunofluorescence colocalization. The results of immunohistochemistry were further verified by Western blot. RESULTS: The expression of COX-2, PD-L1, and ARG1 in PA was significantly higher than that in normal brain tissue. In functional PA (FPA) and nonfunctional PA (NFPA), there was no significant difference in the expression of COX-2 and PD-L1, whereas ARG1 was higher in NFPA. Moreover, the protein expression level of COX-2 was positively correlated with that of PD-L1 and ARG1, and the expression of PD-L1 was positively correlated with that of ARG1. Immunofluorescence confocal imaging showed that COX-2, PD-L1, and ARG1 were all expressed in the cytoplasm of PA cells, and the physical positions of COX-2, PD-L1, and ARG1 were partially coincident. CONCLUSIONS: These findings indicate that overexpression of COX-2, PD-L1, and ARG1 may be involved in the pathogenesis of PA. ARG1 plays a more important role in the development of NFPA. By upregulating the expression of PD-L1, COX-2 may promote the expression of ARG1, forming the COX-2/PD-L1/ARG1 signal pathway in promoting the occurrence and development of PA. Perhaps further study of the pathogenesis of PA can start with the mechanism of immune escape.

Cytochrome P450 1A1 enhances Arginase-1 expression, which reduces LPS-induced mouse peritonitis by targeting JAK1/STAT6.

The polarization of macrophages is critical to inflammation and tissue repair, with unbalanced macrophage polarization associated with critical dysfunctions of the immune system. Cytochrome P450 1A1 (CYP1A1) is a hydroxylase mainly controlled by the inflammation-limiting aryl hydrocarbon receptor (AhR), which plays a critical role in mycoplasma infection, oxidative stress injury, and cancer. Arginase-1 (Arg-1) is a surrogate for polarized alternative macrophages and is important to the production of nitric oxide (NO) by the modulation of arginine. In the present study, we found CYP1A1 to be upregulated in IL-4-stimulated mouse peritoneal macrophages (PMs) and human peripheral blood monocytes. Using CYP1A1-overexpressing RAW264.7 cells (CYP1A1/RAW) we found that CYP1A1 augmented Arg-1 expression by strengthening the activation of the JAK1/STAT6 signaling pathway in macrophages treated with IL-4. 15(S)-HETE, a metabolite of CYP1A1 hydroxylase, was elevated in IL-4-induced CYP1A1/RAW cells. Further, in macrophages, the loss-of-CYP1A1-hydroxylase activity was associated with reduced IL-4-induced Arg-1 expression due to impaired 15(S)-HETE generation. Of importance, CYP1A1 overexpressing macrophages reduced the inflammation associated with LPS-induced peritonitis. Taken together, these findings identified a novel signaling axis, CYP1A1-15(S)-HETE-JAK1-STAT6, that may be a promising target for the proper maintenance of macrophage polarization and may also be a means by which to treat immune-related disease due to macrophage dysfunction.

Safflower Yellow Improves Synaptic Plasticity in APP/PS1 Mice by Regulating Microglia Activation Phenotypes and BDNF/TrkB/ERK Signaling Pathway.

Alzheimer's disease (AD) is a common neurodegenerative disease that is always accompanied by synaptic loss in the brain. Safflower yellow (SY) is the extract of safflower, a traditional Chinese medicine, which has shown neuroprotective effects in recent studies. However, the mechanism of SY in protecting synapses remains unclear. In this study, we are going to study the mechanism of how SY treats AD in terms of synaptic plasticity. We found, via behavioral experiments, that SY treatment could improve the abilities of learning and memory in APP/PS1 mice. In addition, using Golgi staining and HE staining, we found that SY treatment could reduce the loss of dendritic spines in the pathological condition and could maintain the normal physiological state of the cells in cortex and in hippocampus. In addition, the results of immunofluorescence staining and western blotting showed that SY treatment could significantly increase the expression of synapse-related proteins. Moreover, after being treated with SY, the expression of iNOS (marker of M1 microglia) declined remarkably, and the level of Arginase-1 (marker of M2 microglia) increased significantly. Finally, we found BDNF/TrkB/ERK signaling cascade was activated. These results indicate that SY enhances synaptic plasticity in APP/PS1 mice by regulating microglia activation phenotypes and BDNF/TrkB/ERK signaling pathway.

The Diagnostic Value of Arginase-1, FTCD, and MOC-31 Expression in Early Detection of Hepatocellular Carcinoma (HCC) and in Differentiation Between HCC and Metastatic Adenocarcinoma to the Liver.

BACKGROUND: Early detection of small HCC and differentiation between HCC from AC metastatic to the liver is very essential for surgical pathologists, due to different treatment modalities. Immunohistochemistry plays a very important role in such conditions. In our study, we aimed to identify the diagnostic benefits of Arginase-1, FTCD& MOC-31 in the early detection of HCC in normal or cirrhotic liver, differentiation between HCC and metastatic ACs to the liver, and for early detection of small micro-metastases from ACs to liver. MATERIALS AND METHODS: We included 20 samples from liver cirrhosis, 10 samples from normal liver tissue, 30 samples from primary HCCs in the liver, and 30 samples from metastatic ACs to the liver. We have evaluated Arginase-1, FTCD, and MOC-31 expression using immunohistochemistry. RESULTS: The sensitivity of Arginase-1 expression in differentiation between HCC and metastatic carcinoma was 93.3% and the specificity was 93.3%. The sensitivity of FTCD expression in differentiation between HCC and normal or cirrhotic liver and early detection of well-differentiated HCC was 90% and the specificity was 86.7%. The sensitivity of MOC-31 expression in differentiation between HCC and metastatic carcinoma was 90% and the specificity was 90%. The sensitivity of combination of panel of Arginase 1 + FTCD + MOC 31 expression in differentiation between HCC, metastatic carcinoma, and normal and cirrhotic liver was 93.3% and the specificity was 93.3%. CONCLUSIONS: The combination of Arginase 1 + FTCD + MOC 31 expression was helpful in diagnosing most cases of HCC and metastatic carcinoma with high sensitivity and specificity.

Endothelin-1 increases expression and activity of arginase 2 via ETB receptors and is co-expressed with arginase 2 in human atherosclerotic plaques.

BACKGROUND AND AIMS: Endothelin-1 (ET-1) and arginase are both suggested to be involved in the inflammatory processes and development of endothelial dysfunction in atherosclerosis. However, information regarding the roles of ET-1 and arginase, as well as the interactions between the two in human atherosclerosis, is scarce. We investigated the expression of ET-1 and its receptors, ETA and ETB, as well as arginase in human carotid atherosclerotic plaques and determined the functional interactions between ET-1 and arginase in endothelial cells and THP-1-derived macrophages. METHODS: Carotid plaques and blood samples were retreived from patients undergoing surgery for symptomatic or asymptomatic carotid stenosis. Plaque gene and protein expression was determined and related to clinical characteristics. Functional interactions between ET-1 and arginase were investigated in endothelial cells and THP-1 cells. RESULTS: Expression of ET-1 and ETB receptors was increased in plaques from patients with symptomatic carotid artery disease. ET-1 was co-localized with arginase 1 and arginase 2 in the necrotic core, together with macrophage markers CD163 and CD68. Arginase 2, ET-1 and ETB receptors were expressed in endothelial cells as well as in smooth muscle cells in the fibrous cap. ET-1 increased arginase 2 mRNA expression and arginase activity in endothelial cells and arginase activity in macrophages. Moreover, ET-1 stimulated formation of reactive oxygen species (ROS) in THP-1-derived macrophages via an arginase-dependent mechanism. CONCLUSIONS: This is the first study that demonstrates co-localization of ET-1 and arginase 2 in human atherosclerotic plaques. ET-1 stimulated arginase 2 expression and activity in endothelial cells, as well as arginase activity and ROS formation in macrophages via an arginase-dependent mechanism. These results indicate an important interaction between the ET pathway and arginase in human atherosclerotic plaques.

Clinical value of ARG1 in acute myocardial infarction patients: Bioinformatics-based approach.

BACKGROUND: In this study, we aimed to explore key genes as biomarker for diagnosis AMI through using Bioinformatics tools. METHODS: GSE4648 and GSE60993 were downloaded from Gene Expression Omnibus (GEO). DEGs in GSE4648 and GSE60993 were selected to run GO enrichment, KEGG pathway, and PPI network. Hub genes in DEGS of GSE4648 and GSE60993 were selected out according to Molecular Complex Detection (MCODE) and overlapping genes were further screened out. Finally, the most important gene of coincide genes was used for deeper clinical study of patients with AMI. RESULTS: A total of 41 and 173 DEGs were screened out in GSE4648 and GSE60993 respectively. GO and KEGG analysis showed similar biological process, cellular Component and molecular function of these two group DEGs. PPI network of these two group DEGs were built and 19 key genes of GSE4648 were selected out according to MCODE, while 48 key genes of GSE60993 were selected out. Overlapping genes of these 19 and 48 genes included PLAUR, ARG1, FOS, and IL1R2, and fold change (FC) of ARG1 was the biggest. Therefore, ARG1 was detected in 46 controls and 115 AMI patients by ELISA, and ARG1 was significantly upregulated in AMI group. Pearson correlation analysis indicated ARG1 was positive correlated with gensini score (R = 0.378). ROC curve revealed that area under ROC curve (AUC) of ARG1 was 77.6%. CONCLUSION: Therefore, ARG1 might play an important role in the development of AMI and could be used as biomarker of AMI.

Near-Infrared-Triggered Dynamic Surface Topography for Sequential Modulation of Macrophage Phenotypes.

Immune response is critical to tissue repair. Designing biomaterials with immunomodulatory functions has become a promising strategy to facilitate tissue repair. Considering the key roles of macrophages in tissue repair and the significance of the balance of M1 and M2, smart biomaterials, which can harness macrophage phenotypes dynamically to match the tissue healing process on demand, have attracted a lot of attention to be set apart from the traditional anti-inflammatory biomaterials. Here, we prepare a gold nanorod-contained shape memory polycaprolactone film with dynamic surface topography, which has the ability to be transformed from flat to microgrooved under near-infrared (NIR) irradiation. Based on the close relationships between the morphologies and the phenotypes of macrophages, the NIR-triggered surface transformation induces the elongation of macrophages, and consequently the upregulated expressions of arginase-1 and IL-10 in vitro, indicating the change of macrophage phenotypes. The sequential modulation of macrophage phenotypes by dynamic surface topography is further confirmed in an in vivo implantation test. The healing-matched modulation of macrophage phenotypes by dynamic surface topography without the stimuli of cytokines offers an effective and noninvasive strategy to manipulate tissue regenerative immune reactions to achieve optimized healing outcomes.

Transcription factor Fra-1 targets arginase-1 to enhance macrophage-mediated inflammation in arthritis.

The polarization of macrophages is regulated by transcription factors such as nuclear factor kappa B (NF-κB) and activator protein 1 (AP-1). In this manuscript, we delineated the role of the transcription factor Fos-related antigen 1 (Fra-1) during macrophage activation and development of arthritis. Network level interaction analysis of microarray data derived from Fra-1- or Fra-2-deficient macrophages revealed a central role of Fra-1, but not of Fra-2 in orchestrating the expression of genes related to wound response, toll-like receptor activation and interleukin signaling. Chromatin-immunoprecipitation (ChIP)-sequencing and standard ChIP analyses of macrophages identified arginase 1 (Arg1) as a target of Fra-1. Luciferase reporter assays revealed that Fra-1 down-regulated Arg1 expression by direct binding to the promoter region. Using macrophage-specific Fra-1- or Fra-2- deficient mice, we observed an enhanced expression and activity of Arg1 and a reduction of arthritis in the absence of Fra-1, but not of Fra-2. This phenotype was reversed by treatment with the arginase inhibitor Nω-hydroxy-nor-L-arginine, while ʟ-arginine supplementation increased arginase activity and alleviated arthritis, supporting the notion that reduced arthritis in macrophage-specific Fra-1-deficient mice resulted from enhanced Arg1 expression and activity. Moreover, patients with active RA showed increased Fra-1 expression in the peripheral blood and elevated Fra-1 protein in synovial macrophages compared to RA patients in remission. In addition, the Fra-1/ARG1 ratio in synovial macrophages was related to RA disease activity. In conclusion, these data suggest that Fra-1 orchestrates the inflammatory state of macrophages by inhibition of Arg1 expression and thereby impedes the resolution of inflammation.

Overexpression of Arginase-1 is an indicator of poor prognosis in patients with colorectal cancer.

AIM: Arginase-1 (Arg-1) metabolizes l-arginine to l-ornithine and urea. It has been documented to have a role in various malignancies. However, the relationship between Arg-1 expression and clinicopathological characteristics of colorectal cancer (CRC) patients remains to be elucidated. The present study aimed to analyze the expression and prognostic value of Arg-1 in patients with CRC. MATERIAL AND METHODS: The mRNA and protein expressions of Arg-1 in fresh colorectal cancer tissue specimens and the corresponding noncancerous tissue specimens were examined by RT-qPCR (n = 24) and western blot analysis (n = 17). Arg-1 expression levels were determined in paraffin-embedded CRC tissue specimens (n = 236) by immunohistochemistry. The associations of Arg-1 expression and clinicopathological features and clinical prognosis in 236 CRC patients were analyzed. RESULTS: The expression levels of Arg-1 were significantly higher in the CRC tissues compared with the matched noncancerous tissues, and elevated Arg-1 expression was remarkably associated with stage III-IV tumors (P = 0.007), lymph node metastasis (P = 0.019) and a plasma albumin concentration <35 g/l (P = 0.022). Kaplan-Meier analysis indicated that Arg-1 overexpression was associated with adverse prognoses for overall survival (OS) (P < 0.001) and disease-free survival (DFS) (P < 0.001) in all cases. Further analysis revealed that the patients with high Arg-1 expression had significantly shorter OS and DFS at the advanced stages (III + IV) (P = 0.032 for OS, and P = 0.012 for DFS) but not at the early stages (I + II) (P = 0.194 for OS, and P = 0.065 for DFS). Multivariate analysis revealed that Arg-1 overexpression was an independent prognostic factor for OS (P = 0.002) and DFS (P < 0.001) in patients with CRC. CONCLUSION: The data indicated that Arg-1 overexpression in CRC may be a marker that can discriminate subgroups of patients with a poor prognosis.

Overexpression of carbamoyl-phosphate synthase 1 significantly improves ureagenesis of human liver HepaRG cells only when cultured under shaking conditions.

Hyperammonemia is an important contributing factor to hepatic encephalopathy in end-stage liver failure patients. Therefore reducing hyperammonemia is a requisite of bioartificial liver support (BAL). Ammonia elimination by human liver HepaRG cells occurs predominantly through reversible fixation into amino acids, whereas the irreversible conversion into urea is limited. Compared to human liver, the expression and activity of the three urea cycle (UC) enzymes carbamoyl-phosphate synthase1 (CPS1), ornithine transcarbamoylase (OTC) and arginase1, are low. To improve HepaRG cells as BAL biocomponent, its rate limiting factor of the UC was determined under two culture conditions: static and dynamic medium flow (DMF) achieved by shaking. HepaRG cells increasingly converted escalating arginine doses into urea, indicating that arginase activity is not limiting ureagenesis. Neither was OTC activity, as a stable HepaRG line overexpressing OTC exhibited a 90- and 15.7-fold upregulation of OTC transcript and activity levels, without improvement in ureagenesis. However, a stable HepaRG line overexpressing CPS1 showed increased mitochondrial stress and reduced hepatic differentiation without promotion of the CPS1 transcript level or ureagenesis under static-culturing conditions, yet, it exhibited a 4.3-fold increased ureagenesis under DMF. This was associated with increased CPS1 transcript and activity levels amounting to >2-fold, increased mitochondrial abundance and hepatic differentiation. Unexpectedly, the transcript levels of several other UC genes increased up to 6.8-fold. We conclude that ureagenesis can be improved in HepaRG cells by CPS1 overexpression, however, only in combination with DMF-culturing, suggesting that both the low CPS1 level and static-culturing, possibly due to insufficient mitochondria, are limiting UC.

Arginase II Contributes to the Ca2+/CaMKII/eNOS Axis by Regulating Ca2+ Concentration Between the Cytosol and Mitochondria in a p32-Dependent Manner.

Background Arginase II activity contributes to reciprocal regulation of endothelial nitric oxide synthase ( eNOS ). We tested the hypotheses that arginase II activity participates in the regulation of Ca2+/Ca2+/calmodulin-dependent kinase II / eNOS activation, and this process is dependent on mitochondrial p32. Methods and Results Downregulation of arginase II increased the concentration of cytosolic Ca2+ ([Ca2+]c) and decreased mitochondrial Ca2+ ([Ca2+]m) in microscopic and fluorescence-activated cell sorting analyses, resulting in augmented eNOS Ser1177 phosphorylation and decreased eNOS Thr495 phosphorylation through Ca2+/Ca2+/calmodulin-dependent kinase II . These changes were observed in human umbilical vein endothelial cells treated with small interfering RNA against p32 (sip32). Using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, fluorescence immunoassay, and ion chromatography, inhibition of arginase II reduced the amount of spermine, a binding molecule, and the release of Ca2+ from p32. In addition, arginase II gene knockdown using small interfering RNA and knockout arginase II -null mice resulted in reduced p32 protein level. In the aortas of wild-type mice, small interfering RNA against p32 induced eNOS Ser1177 phosphorylation and enhanced NO -dependent vasorelaxation. Arginase activity, p32 protein expression, spermine amount, and [Ca2+]m were increased in the aortas from apolipoprotein E (ApoE-/-) mice fed a high-cholesterol diet, and intravenous administration of small interfering RNA against p32 restored Ca2+/Ca2+/calmodulin-dependent kinase II -dependent eNOS Ser1177 phosphorylation and improved endothelial dysfunction. The effects of arginase II downregulation were not associated with elevated NO production when tested in aortic endothelia from eNOS knockout mice. Conclusions These data demonstrate a novel function of arginase II in regulation of Ca2+-dependent eNOS phosphorylation. This novel mechanism drives arginase activation, mitochondrial dysfunction, endothelial dysfunction, and atherogenesis.

The Oncogenic Role of ARG1 in Progression and Metastasis of Hepatocellular Carcinoma.

ARG1, which encodes Arginase1, is expressed in the liver cytoplasm and plays a major role in the hepatic urea cycle. The past research works shed light on the fact that ARG1 participates in anti-inflammation, tumor immunity, and immunosuppression-related diseases. Nevertheless, the concrete role and clinical significance of ARG1 in the progression of hepatocellular carcinoma (HCC) remain unclear. Herein, we aimed at examining the expression and clinicopathological significance of ARG1 in HCC, together with determining the effect of ARG1 on the progression and metastasis of HCC. In the current study, evaluation of the expression of ARG1 and clinicopathological significance of ARG1 was carried out in the human HCC tissues microarray, and the ARG1 overexpression vector and shRNA-ARG1 plasmids were constructed for the assessment of the concrete effect of ARG1 on cellular behaviors of Huh7 cells. As our data revealed, ARG1 was significantly downregulated in HCC, and the higher expression of ARG1 was positively correlated with more aggressive tumor growth, size, ALT, and GGT level. Significantly, we found that the high expression of ARG1 was correlated with poor DFS of HCC patients. Besides, in vitro study revealed that overexpression of ARG1 could enhance arginase activity, cell viability, migration, and invasion of Huh7 cells, and loss-of-function of ARG1 by shRNA interference could inhibit these cellular behaviors. Additionally, overexpression of ARG1 led to a significant increase in the expression of Vimentin, N-cadherin, and ß-catenin both at protein and mRNA levels, which promotes the EMT process. On the other hand, these proteins' expression was significantly downregulated in ARG1 silenced Huh7 cells. Besides, the level of E-cadherin protein was upregulated in ARG1 knocked down cells. In conclusion, ARG1 might play a pivotal role as an oncogene in the progression of HCC through promoting the EMT process.

Calcitonin gene-related peptide decreases IL-1beta, IL-6 as well as Ym1, Arg1, CD163 expression in a brain tissue context-dependent manner while ameliorating experimental autoimmune encephalomyelitis.

Activation states of immune cells (among them, the so-called pro- or anti-inflammatory states) influence the pathogenesis of multiple sclerosis (MS). The neuropeptide calcitonin gene-related peptide (CGRP) can exert a pro- or anti-inflammatory role in a context-dependent manner. In mice CGRP was found to attenuate the development of experimental autoimmune encephalomyelitis (EAE, a common MS animal model). We analyzed CGRP effects on the expression of cytokines and markers of activation states, as well as its intracellular cascade, following intrathecal administration during EAE immunization. Real Time quantitative-PCR (RT-PCR) showed that IL-1beta and IL-6 (associated to a pro-inflammatory state in EAE), but also Ym1 (also known as Chil3), Arg1 and CD163 (associated to an anti-inflammatory state in EAE) were decreased in the encephalon (devoid of cerebellum). In the cerebellum itself, IL-1beta and Ym1 were decreased. TNF-alpha (associated to a pro-inflammatory state in EAE), but also IL-10 (associated to another type of anti-inflammatory state) and BDNF were unchanged in these two regions. No changes were detected in the spinal cord. Additional tendencies toward a change (as revealed by RT-PCR) were again decreases: IL-10 in the encephalon and Arg1 in the spinal cord. CGRP decreased percentage of Ym1+/CD68+ immunoreactive cells and cell density of infiltrates in the cervical spinal cord pia mater. Instead, Ym1 in the underlying parenchyma and at thoracic and lumbar levels, as well as Arg1, were unchanged. In cultured microglia the neuropeptide decreased Ym1, but not Arg1, immunoreactivity. Inducible NOS (iNOS) was unchanged in spinal cord microglia and astrocytes. The neuropeptide increased the activation of ERK1/2 in the astrocytes of the spinal cord and in culture, but did not influence the activation of ERK1/2 or p38 in the spinal cord microglia. Finally, in areas adjacent to infiltration sites CGRP-treated microglia showed a larger ramification radius. In conclusion, CGRP-induced EAE amelioration was associated to a concomitant, context-dependent decrease in the expression of markers belonging to both pro- or anti-inflammatory activation states of immune cells. It can be hypothesized that CGRP-induced EAE attenuation is obtained through a novel mechanism that promotes down-regulation of immune cell activation that facilitates the establishment of a beneficial environment in EAE provided possibly also by other factors.