Nevena Gajovic

The relationship between the immune system and oral manifestations of inflammatory bowel disease: a review

Inflammatory bowel diseases (IBDs) are chronic, relapsing inflammatory diseases characterized by exacerbations and remissions of the gastrointestinal tract, clinically manifested as Crohn’s disease and ulcerative colitis. The etiology of IBDs is considered to be multi factorial, comprising environmental, immune, microbial and genetic factors. Clinical signs may include abdominal pain, frequent bloody diarrheas, mucorrhea, vomiting, fever, fatigue or weight loss. Changes in the oral cavity often precede intestinal symptoms. Inflammatory bowel disease leads to a significant deterioration of oral health, which indicates that cooperation between the dentist and the gastroenterologist is necessary when considering patients’ welfare. Patients with IBD have an altered immune response, but microorganisms of the oral cavity may also be responsible for its modification. This review paper discusses the correlation between the immune system and inflammatory bowel disease manifestations in the oral cavity.

The frog skin host-defense peptide frenatin 2.1S enhances recruitment, activation and tumoricidal capacity of NK cells

HighlightsThe frog skin‐derived frenatin 2.1S promotes recruitment of cytotoxic NK cells.Frenatin 2.1S enhances activational state and tumoricidal capacities of NK cells.Frenatin 2.1S might be considered as a candidate for antitumor immunotherapy. Abstract Frog skin is a source of peptides with various biological properties. Frenatin 2.1S, derived from norepinephrine‐stimulated skin secretions of the Orinoco lime tree frog Sphaenorhynchus lacteus, exhibits immunostimulatory effects as demonstrated by the promotion of proinflammatory phenotypes of mononuclear cells in mouse peritoneal cavity and spleen. The aim of this study was to identify the populations of host cells sensitive to the action of frenatin 2.1S in vivo and to study its effects on their functional antitumor capacity. A single injection of frenatin 2.1S (100 &mgr;g) in BALB/c mice increased the presence of peritoneal CD11c+ dendritic cells and CD3+ T cells 24 h after administration and there was a significant increase in the number of IL‐17 and CXCR3 expressing inflammatory T cells. Frenatin 2.1S treatment also increased the number of TNF‐&agr; expressing F4/80+ proinflammatory M1 macrophages. The most striking finding of the study is the marked increase of the number of peritoneal natural killer (NK) cells following frenatin 2.1S injection. Further, frenatin 2.1S administration led to activation of NK cells as evaluated by increased expression of NKG2D, FasL, CD69 and CD107a. The increased ratio of interferon‐&ggr; vs. IL‐10 producing NK cells is further indication of the proinflammatory action of frenatin 2.1S. Peptide treatment enhanced the tumoricidal action of peritoneal NK cells on 4T1 mouse mammary carcinoma cells as revealed by the real‐time automated monitoring of cell status. Our data demonstrate that frenatin 2.1S promotes activation and cytotoxic capacity of NK cells and should be regarded as a candidate for antitumor immunotherapy.

Risk factors for hospital infections caused by carbapanem-resistant Acinetobacter baumannii

INTRODUCTION Acinetobacter baumannii is one of major causative agents of severe, life-threatening hospital infections (HIs), especially in intensive care units (ICUs). Our aim was to discover the risk factors associated with the emergence of HIs caused by carbapenem-resistant Acinetobacter baumannii (CRAB), as well as those associated with death in patients who suffer from such infections. METHODOLOGY A prospective cohort study was conducted over a five-year period in the medical-surgical ICU of the Clinical Centre in Kragujevac, Serbia. The study group comprised patients who had HIs caused by CRAB, while the control group comprised patients infected with carbapenem-sensitive Acinetobacter baumannii. RESULTS In total, 137 patients developed HIs caused by Acinetobacter baumannii. The mean age of the patients was 59.65 ± 16.08 years, and 99 (72.26%) of them were males. In 95 patients (69.35%), the infection was caused by CRAB. There were six independent risk factors for CRAB infections: use of mechanical ventilation, previous stay in another department, stay in ICU for more than a month, and previous use of carbapenems, aminoglycosides, and metronidazole. Three independent risk factors were found for death in patients with HIs caused by CRAB: use of mechanical ventilation, previous stay in another department, and previous use of carbapenems. CONCLUSIONS The results of this study can be helpful when identifying patients with risk of HIs caused by CRAB and in planning preventive measures. Modification of known risk factors and appropriate institutional policy of antibiotic utilization are important measures that may decrease the incidence and mortality of such infections.

TGF-Β as a Marker of Ulcerative Colitis and Disease Severity

Abstract Ulcerative colitis (UC) represents chronic inflammation of the large intestine. Immune response plays an important role in disease genesis and progression. Activated leukocytes secrete several cytokines that actively regulate the inflammatory response in UC. The aim of this study was to determine levels of cytokines IL-17, IL-27, IFN-γ and TGF-β in patients with UC and to test them as biomarkers for disease. The blood samples of 24 patients with ulcerative colitis without previous treatment and 37 healthy individuals were analyzed. Serum levels of IL-17, IL-27, IFN-γ and TGF-β were measured using sensitive enzyme-linked immunosorbent assay (ELISA) kits. Serum levels of IL-17, IL-27, IFN-γ and TGF-β were increased in patients with UC, compared to healthy controls (p=0.022; p=0.001; p=0.001; and p=0.002; respectively). Ratios of cytokines IL-27/IL-17, IFN-γ/TGF-β and IL-17/TGF-β were significantly higher in group of patients with UC (p=0.002; p=0.002; p=0.003; respectively). Serum value of TGF-β higher than 20 pg/ml presents a highly sensitive and specific marker for UC. We believe that increased production and predominance of immunosupressive TGF-β may represent compensatory mechanism for ongoing pro-inflammatory processes in UC.

Fecal Galectin-3: A New Promising Biomarker for Severity and Progression of Colorectal Carcinoma

Background and Objectives The aim of the study was to determine systemic and fecal values of galectin-3 and pro- and anti-inflammatory cytokines in patients with CRC and the relationship with clinicopathological aspects. Methods Concentrations of galectin-3, TNF-α, TGF-β, IL-10, and IL-1β were analyzed in samples of blood and stool of 60 patients with CRC. Results Systemic concentration of TNF-α was significantly lower in patients with severe diseases (advanced TNM stage, nuclear grade, and poor histological differentiation) as in patients with more progressive CRC (lymph and blood vessel invasion, presence of metastasis). Fecal values of anti-inflammatory cytokines TGF-β and IL-10 were increased in patients with severe stadium of CRC. Fecal concentration of Gal-3 was enhanced in CRC patients with higher nuclear grade, poor tumor tissue differentiation, advanced TNM stage, and metastatic disease. Gal-3/TNF-α ratio in sera and feces had a higher trend in patients with severe and advanced diseases. Positive correlation between fecal Gal-3 and disease severity, tumor progression, and biomarkers AFP and CEA, respectively, was also observed. Conclusions Predomination of Gal-3 in patients with advanced diseases may implicate on its role in limiting ongoing proinflammatory processes. The fecal values of Gal-3 can be used as a valuable marker for CRC severity and progression.

Potential Hepatoprotective Role of Galectin-3 during HCV Infection in End-Stage Renal Disease Patients

Hepatitis C virus infection (HCV), one of the greatest causes of liver disease, is a frequent complication in patients with end-stage renal disease (ESRD) on dialysis. ESRD is defined as decreased glomerular filtration and also accompanied by impaired function of the immune system. Galectin-3 is a β-galactoside-binding lectin, involved in various biological processes including pathogenesis of chronic renal disease. The aim of our study was to estimate disease severity in ESRD HCV+ patients and analyze the serum concentrations of IL-1β, IL-4, IL-23, and IL-6; anti-HCV antibodies; and galectin-3. Also, we attempted to determine potential correlation between galectin-3 level and parameters of disease severity ALT and AST. Our results showed decreased levels of ALT and AST (p = 0.00), demonstrating less liver destruction in ESRD HCV+ patients in comparison to HCV+ patients. Increased levels of IL-6 (p = 0.03) implicate a hepatoprotective role of IL-6 in these patients. Also, level of galectin-3 (p = 0.00) in the serum of ESRD HCV+ patients was higher than that of HCV+ patients. This alteration was accompanied with negative correlation between galectin-3 and AST and ALT, respectively (p = 0.029; p = 0.033). The presence of increased systemic levels of IL-6 and Gal-3 in ESRD HCV+ patients may be an attempt to counteract or limit ongoing proinflammatory processes and to downregulate chronic inflammation, suggesting the new aspects of HCV infection in ESRD patients.

Platinum Complexes with Edda (Ethylenediamine -N, N - Diacetate) Ligands as Potential Anticancer Agents

Abstract The design of platinum based drugs is not a new field of interest. Platinum complexes are widely used as anticancer agents and currently, approximately 30 platinum(II) and platinum(IV) entered into some of the phases of clinical trials. A special place in today’s research belongs to platinum complexes with diammine ligands. A large number of edda (ethylenediamine- N, N’-diacetate)-type ligands and their corresponding metal complexes has been successfully synthesized. This article summarizes recent progress in research on edda-type-platinum complexes. Some of these agents achieves better effect compared to the gold standard (cisplatin). It has been shown that there is a possible relationship between the length of the ligand ester group carbon chain and its cytotoxic effect. In most cases the longer the ester chain is the greater is the antitumor activity. Of particular interest are the noticeable effects of some new platinum compound with edda-type ligand on cell lines that are known to have a high level of cisplatin-resistance. Exanimate complexes appear to have a different mode of mechanism of action compared with cisplatin which includes apoptotic and necrotic cell death. There are indications that further investigations of these compounds may be very useful in overcoming the problems associated global cancer statistic.

Indoleamine 2,3-dioxygenase-dependent expansion of T-regulatory cells maintains mucosal healing in ulcerative colitis

Background: Dendritic cell (DC)-derived indolamine 2,3-dioxygenase (IDO) degrades tryptophan to kynurenine, which promotes conversion of inflammatory T cells in immunosuppressive regulatory T cells (Tregs). We analyzed the significance of the IDO:Treg axis for inducing and maintaining mucosal healing in ulcerative colitis (UC). Methods: Dextran sodium sulphate (DSS)-induced colitis in BALB/c mice (model for mucosal healing) and C57BL/6 mice (model for persistent disease) was used. Serum, fecal samples and colon-infiltrating immune cells of 65 patients with UC with mucosal healing or persistent colitis were analyzed. Results: Significantly higher serum levels of kynurenine and downregulated inflammatory cytokines were noticed in DSS-treated BALB/c mice compared with C57BL/6 mice. Increased IDO activity and attenuated capacity for antigen presentation and production of inflammatory cytokines, observed in BALB/c DCs, was followed by a significantly lower number of inflammatory T helper 1 (Th1) and Th17 cells and a notably increased number of Tregs in the colons of DSS-treated BALB/c mice. DCs and Tregs were crucially important for the maintenance of mucosal healing since their depletion aggravated colitis. Mucosal healing, followed by an increase in kynurenine and intestinal Tregs, was re-established when BALB/c DCs were transferred into DC-depleted or Treg-depleted DSS-treated BALB/c mice. This phenomenon was completely abrogated by the IDO inhibitor. Significantly higher serum and fecal levels of kynurenine, accompanied by an increased presence of intestinal Tregs, were noticed in patients with UC with mucosal healing and negatively correlated with disease severity, fecal calprotectin, colon-infiltrating interferon γ and interleukin-17-producing cells, serum and fecal levels of inflammatory cytokines. Conclusion: IDO-dependent expansion of endogenous Tregs should be further explored as a new approach for the induction and maintenance of mucosal healing in patients with UC.

Risk Factors for Carbapenem-Resistant Klebsiella pneumoniae Hospital Infection in the Intensive Care Unit

Abstract Carbapenem-resistant Klebsiella pneumoniae (CR-Kp) has become a major threat to patients in hospitals, increasing mortality, length of stay and costs. The aim of this study was to discover risk factors for the development of hospital infections (HIs) caused by CR-Kp. A prospective cohort study was conducted in the Medical-Surgical Intensive Care Unit of the Clinical Centre in Kragujevac, Kragujevac, Serbia, from January 1, 2011, to December 31, 2015. The “cases” were patients with HIs caused by CR-Kp, while the “controls” were patients infected with carbapenem-sensitive Klebsiella pneumoniae (CS-Kp). The significance of multiple putative risk factors for HIs caused by CR-Kp was tested using multivariate logistic regression. Although univariate analyses pointed to many risk factors, with a significant influence on the occurrence of hospital CR-Kp infections, the multivariate logistic regression identified five independent risk factors: use of mechanical ventilation (OR=6.090; 95% CI=1.030-36.020; p=0.046); length of antibiotic therapy before HIs (days) (OR=1.080; 95% CI=1.003-1.387; p=0.045); previous use of carbapenems (OR=7.005; 95% CI=1.054-46.572; p=0.044); previous use of ciprofloxacin (OR=20.628; 95% CI=2.292-185.687; p=0.007) and previous use of metronidazole (OR=40.320; 95% CI=2.347-692.795; p=0.011) HIs caused by CR-Kp are strongly associated with the use of mechanical ventilation and the duration of the previous use of certain antibiotics (carbapenems, ciprofloxacin and metronidazole).

The organic ester O,O'-diethyl-(S,S)-ethylenediamine-N,N'-di-2-(3-cyclohexyl)propanoate dihydrochloride attenuates murine breast cancer growth and metastasis

Pharmacological treatment of cancer is mostly limited by drug-toxicity and resistance. It has been noticed that new organic ester ligand, O,O’-diethyl-(S,S)-ethylenediamine-N,N’-di-2-(3-cyclohexyl)propanoate dihydrochloride (named DE-EDCP) showed effective cytotoxic capacities against several human and mouse cancer cell lines. However, its effects on tumor growth and metastasis are unexplored. The aim of present study was to examine the ability of DE-EDCP to inhibit 4T1 murine breast cancer growth and progression and to explore possible molecular mechanisms. DE-EDCP exhibited significant tumoricidal activity on human and murine breast cancer cell lines. Further, marked reduction of murine breast cancer growth and progression by DE-EDCP was shown. DE-EDCP exhibits fewer side-effects compared to cisplatin as a conventional chemotherapeutic. Results obtained from in vivo and in vitro experiments indicate that DE-EDCP induces apoptosis and inhibits proliferation of 4T1 cells. DE-EDCP increases percentage of 4T1 cells in late apoptosis, expression of pro-apoptotic Bax and caspase-3, while decreases expression of anti-apoptotic Bcl-2. DE-EDCP treatment increased the percentage of TUNEL-positive nuclei and reduced Ki-67 expression in breast cancer tissue. DE-EDCP decreased expression of cyclin D3 and Ki-67, increased expression of cyclin-dependent kinase inhibitors p16, p21 and p27 and arrested 4T1 cells in G0/G1 cell cycle phase. Expression of STAT3 and downstream regulated molecules, NANOG and SOX2, was reduced in 4T1 cells after DE-EDCP treatment. In conclusion, DE-EDCP impairs breast cancer growth and progression by triggering cancer cell death and inhibition of cancer cell proliferation. DE-EDCP might be of interest in the development of the new anticancer agent.