Arginase is upregulated in healthy women infected by oncogenic HPV types

INTRODUCTION

The implication of arginase enzyme in Human Papillomavirus (HPV) infections has not been clearly elucidated. The present study investigates whether HPV infection is correlated with changes in plasmatic arginase activity and cervical ARG1 and ARG2 mRNA expression among infected women negative for intraepithelial lesions (NIL).

MATERIEL AND METHODS

The present study included 300 women. The plasmatic arginase activity was evaluated by a colorimetric assay. Cervical HPV was detected by real-time PCR. The circulating viral load and ARG1 and ARG2 mRNA expression quantification were performed by quantitative real-time PCR.

RESULTS

A significant increase in plasma arginase activity and ARG1 and ARG2 mRNA expression levels in cervical cells was observed among HPV-positive women compared to the HPV-negative group. The highest levels were significantly associated with oncogenic HPV, and increased arginase activity was associated with a high HPV circulating viral load. Moreover, the highest levels of arginase activity were observed in oncogenic HPV-positive inflammatory smears.

DISCUSSION

These data suggest that HPV could modulate arginase activity and expression, which may restrict arginine bioavailability and inhibit this amino acid's antiviral properties.

CONCLUSION

Our findings revealed that arginase activity and isoform gene expression were upregulated in women with HPV infection, particularly the oncogenic HPV types.

Optimization of the arginase activity assay micromethod for macrophages and sera

OBJECTIVE

We optimized the spectrophotometric micromethod for the determination of arginase activity based on the Corraliza et al. modification of Schimke's method. Arginase activity in sera from patients suffering from human African trypanosomiasis, in macrophage lysates from trypanosome-infected mice, and in purified bovine liver arginase was compared using the conventional and optimized micromethods.

RESULTS

The sensitivity of both micromethods was comparable. However, our optimized method has the following advantages: it uses small sample volumes (6 µl per assay vs. 50 µl) and reagent volumes (200 µl vs. 400 µl), it can be carried out in a single microplate well, thereby minimizing handling, and it requires fewer materials and utilizes readily available equipment. Our optimized method proved to be applicable and well suited for small-volume samples and resource-poor laboratories.

Elevated levels of arginase activity are related to inflammation in patients with COPD exacerbation

Introduction

Within the pathogenesis of the chronic obstructive pulmonary disease (COPD) there are interactions between different inflammatory mediators that are enhanced during an exacerbation. Arginase is present in bronchial epithelial cells, endothelial, fibroblasts and alveolar macrophages, which make it a probable key enzyme in the regulation of inflammation and remodelling. We aimed to find a potential relationship between arginase activity, inflammatory mediators in COPD patients in stable phase and during exacerbations.

Methods

We performed a prospective, observational study of cases and controls, with 4 study groups (healthy controls, stable COPD, COPD during an exacerbation and COPD 3 months after exacerbation). We measured arginase, inflammation markers (IL-6, IL-8, TNF-∝, IFN-γ and C reactive protein), and mediators of immunity: neutrophils, monocytes, total TCD3 + lymphocytes (CD3ζ), CD4 + T cells, CD8 + T cells, NK cells.

Results

A total of 49 subjects were recruited, average age of 69.73 years (59.18% male). Arginase activity is elevated during an exacerbation of COPD, and this rise is related to an increase in IL-6 production. The levels of IL-6 and IL-8 remained elevated in patients with COPD at 3 months after hospital exacerbation.

We did not find a clear relationship between arginase activity, immunity or with the degree of obstruction in COPD patients.

Conclusions

Arginase activity is elevated during an exacerbation of COPD, and it could be related to an increase in the production of IL-6. Levels of IL-6, IL-8, and arginase activity remain elevated in patients with COPD at 3 months after hospital exacerbation. Arginase activity could contribute to the development of COPD.

Arginase/nitric oxide modifications using live non-pathogenic Leishmania tarentolae as an effective delivery system inside the mammalian macrophages

Recombinant live delivery system based on chemokine IFN-γ-inducible protein-10 kDa (CXCL 10 or IP-10), as a suitable immunotherapy tool, have been used for the treatment of Leishmania infections. This chemokine can defeat Leishmania spp. infection via producing nitric oxide (NO) for parasite killing. This study was performed to investigate the effects of IP-10 on the infected human macrophages by L. tarentolae expressing IP-10. We also quantified the arginase activity and NO production in the co-cultured human macrophages with L. tarentolae expressing IP-10 as compared with wild L. tarentolae. The results elucidate that in the infected cells with L. tarentolae expression of IP-10 the arginase activity decreased, and inversely, NO production intensely increased. Altogether, L. tarentolae expressing IP-10 shows a favorable therapeutic tool to improve the treatment of Leishmania infection. This work suggests that L. tarentolae expressing IP-10 cause specific effects on the metabolic pathways of the macrophage host, which might enable the host cells in killing of parasites and decreasing the survival of them against Leishmania infection.

The potential role of nicotinamide on Leishmania tropica: An assessment of inhibitory effect, cytokines gene expression and arginase profiling

Leishmaniasis represents a major health concern worldwide which has no effective treatment modality. Nicotinamide (NAm) has been used for a wide range of applications from anticancer to antimicrobial usage. This study aimed to assess the effect of NAm combination on Leishmania tropica Inhibition, as well as on cytokines gene expression and arginase (ARG) activity in L. tropica-infected macrophages in an in vitro model. The leishmanicidal effects of NAm and Glucantime (meglumine antimoniate, MA) alone and in combination (NAm/MA) were evaluated using a colorimetric assay and macrophage model. Additionally, immunomodulatory effects and enzymatic activity were assessed by analyzing Th1 and Th2 cytokines gene expression and ARG level, respectively, in infected macrophages treated with NAm and MA, alone and in combination. Findings indicated that the NAm/MA combination demonstrated greater inhibitory effects on L. tropica promastigotes and amastigotes compared with each drug individually. Docking results proved the affinity of NAm to IFN-γ, which can affirm the increased levels of IFN-γ, IL-12p40 and TNF-α as well as reductions in IL-10 secretion with a dose-response effect, especially in the combination group. The NAm/MA combination also showed a significant reduction in the level of ARG activity at all concentrations used compared to each drug individually. These findings indicate higher effectiveness of NAm plus MA in reducing parasite growth, promoting immune response and inhibiting ARG level. This combination should be considered as a potential therapeutic regimen for treatment of volunteer patients with anthroponotic cutaneous leishmaniasis (ACL) in future control programs.

Assessment of leukocyte activity in mice devoid of the glucocorticoid receptor in the noradrenergic system (GRDBHCre)

Disturbances in brain monoamines, overactivity of the hypothalamo-pituitary adrenal (HPA) axis and pro-inflammatory tendency in the immune system are the key features of depressive disorders. Recently, several murine lines with mutations in glucocorticoid receptors (GRs) have been generated and these animals may be utilized for study depressive-like disorders. In the present study, we have investigated whether selective ablation of GRs in noradrenergic neurons affects functional properties of leukocytes and redirects them towards pro-inflammatory activity. Transgenic mice selectively devoid of GRs on noradrenergic cells were constructed using the Cre/loxP approach. Peritoneal leukocytes were collected from mutant and wild type (WT) animals of both sexes and were cultured in vitro for 24h both in basal conditions and after application of selected pro- or anti-inflammatory stimuli. Metabolic activity and adherence were measured in basal conditions. Nitric oxide (NO) synthesis and arginase (ARG) activity were assessed as the markers of functional status of the cells. Because adult mutant mice lack adrenal medulla and thereby peripheral adrenaline, we modulated pro- and anti-inflammatory culture conditions by addition of noradrenaline (10-6M). Finally, effects of in vivo pro-inflammatory challenge (with intraperitoneal administration of lipopolysaccharide) on properties of leukocytes were assessed 24h (in both sexes) and 48h later (in males only). The experiments indicated that selective ablation of GR in noradrenergic neurons did not affect fundamental properties of peritoneal leukocytes and exerted effects only under conditions of selected pro- or anti-inflammatory stimuli in vitro. Stronger response to pro-inflammatory stimulation in terms of NO synthesis and ARG activity may suggest pro-inflammatory tendency in mutant mice. In vivo inflammatory challenge failed to show any effect of GR ablation on selected parameters of leukocyte activity. Both in vitro studies and in vivo challenge revealed mainly sex-related differences in leukocyte activity.

Recombinant IL-4/13A and IL-4/13B induce arginase activity and down-regulate nitric oxide response of primary goldfish (Carassius auratus L.) macrophages

We report on the expression analysis and functional characterization of IL-4/13A and IL-4/13B in goldfish. Quantitative analysis indicated the highest expression in the heart, spleen, brain, and kidney, with comparable expression patterns for both IL-4/13A and IL-4/13B. The mRNA levels of IL-4/13A and IL-4/13B in the immune cells examined were highest in macrophage and monocytes. Assessment of spleen mRNA following infection with Trypanosoma carassii, a prominent protozoan pathogen of fish, revealed decrease in IL-4/13B and arginase expression 14 days post infection, followed by an increase in IL-4/13B and arginase-2 at 28 days post infection. Recombinant forms of IL-4/13A and IL-4/13B induced an increase in arginase activity in macrophages in a dose-dependent manner. Recombinant IL-4/13A and IL-4/13B also induced significant increase in mRNA levels of arginase -2 in macrophages at 6, 12, 18 and 24 h after treatment. Furthermore, treatment with both IL-4/13 recombinants interfered with the IFNγ-induced nitric oxide response of macrophages. Our results suggest a conserved role of IL-4/IL-13 in induction of alternative activation phenotype in teleost macrophages.

Significance of arginase determination in body fluids of patients with hepatocellular carcinoma and liver cirrhosis before and after surgical treatment

OBJECTIVE

To assess the utility of arginase activity and expression in diagnosis of liver diseases.

DESIGN AND METHODS

Arginase activity, sensitivity and specificity were determined in serum of 140 patients including 50 with HCC, 60 with LC, 30 with choledocholithiasis (CDL) and 90 healthy controls. In HCC and LC arginase activity in serum was studied before and after tumor resection or liver transplantation. Arginase sensitivity in HCC was compared to that of alpha-fetoprotein (AFP) and aminotransferases (AST, ALT). In LC the activity was determined also in bile before and after transplantation. The expression of arginase isoenzymes in serum was studied by Western blotting.

RESULTS

In HCC and LC the preoperative arginase activity was significantly higher compared to controls, and it decreased after surgery. The sensitivity of arginase in HCC was much higher than that of AFP, AST and ALT (96, 40, 20 and 18%, respectively). In HCC it was higher than in LC (93%) and CDL (33%). The specificity of arginase was above 80%. In bile of cirrhotic patients the highest activity was immediately after liver transplantation. It decreased with time but increased dramatically at the time of the graft rejection. Arginase AII was present in serum of HCC and LC but not the control cases.

CONCLUSIONS

The increase of arginase activity in serum accompanied by the presence of isoenzyme AII can be useful in HCC and LC diagnosis. The determination of arginase activity in bile may be helpful in monitoring liver graft recipients.

Arginase activity and lecithin/sphingomyelin (l/s) ratio in the amniotic fluid of pregnant women

Arginase activity is important in polyamines and nitric oxide production which are required for the normal growth of placenta and embryo. A considerable arginase activity is observed in amniotic fluid in women at the end of pregnancy. Lecithin to sphingomyelin (L/S) ratio is widely used in order to assess fetal lung immaturity and prevention of neonatal respiratory distress syndrome, the major cause of neonatal morbidity and mortality. The purpose of our study was to determine if there is a relationship between arginase activity and L/S ratio in amniotic fluid. The study included 170 pregnant women, 18-43 years old, with normal and pathological pregnancy. The arginase activity was measured on the basis of the determination of the amount of liberated ornithine from arginine as substrate. The L/S ratio was done by using a thin layer chromatography. Increased level of arginase activity correlates with the fetal lung maturity. Arginase activity and L/S values may be useful biochemical data, for intrauterine baby maturity.