Human neutrophil migration and activation by BJcuL, a galactose binding lectin purified from Bothrops jararacussu venom

<p>Abstract</p> <p>Background</p> <p>Neutrophil migration to an inflamed site constitutes the first line of the innate immune response against invading microorganisms. Given the crucial role of endogenous lectins in neutrophil mobilization and activation, lectins from exogenous sources have often been considered as putative modulators of leukocyte function. Lectins purified from snake venom have been described as galactoside ligands that induce erythrocyte agglutination and platelet aggregation. This study evaluated human neutrophil migration and activation by C-type lectin BJcuL purified from <it>Bothrops jararacussu </it>venom.</p> <p>Results</p> <p>Utilizing fluorescence microscopy, we observed that biotinylated-BJcuL was evenly distributed on the neutrophil surface, selectively inhibited by D-galactose. Lectin was able to induce modification in the neutrophil morphology in a spherical shape for a polarized observed by optical microscopy and exposure to BJcuL in a Boyden chamber assay resulted in cell migration. After 30 minutes of incubation with BJcuL we found enhanced neutrophil functions, such as respiratory burst, zymozan phagocytosis and an increase in lissosomal volume. In addition, BJcuL delays late apoptosis neutrophils.</p> <p>Conclusion</p> <p>These results demonstrate that BJcuL can be implicated in a wide variety of immunological functions including first-line defense against pathogens, cell trafficking and induction of the innate immune response since lectin was capable of inducing potent neutrophil activation.</p

Study of wound healing in rat skin treated with extract of Hedera helix, L / Estudo da cura de feridas na pele de rato tratada com extrato de Hedera helix, L

The Hera (Hedera helix L) is part of the ARALIACEAE family, is included in the group of plants that produce saponins, has antifungal action, is hypocholesterolemic, has anti-inflammatory activity, is expectorant, antispasmodic and purifying. It was evaluated, by histological studies, the wound healing action of the extract of Hera leaves on skin wounds, as well as changes in the epithelial tissue and wound healing period. 75 Wistar rats were used and divided into five groups, according to the treatment: negative control (PBS), Hera 10 mg/ml, Hera 30 mg/ml, Hera 50 mg/ml and the positive control (Nebacetin). The animals were anesthetized and undergone through a cut of 4 cm in the dorsal region, exposing their muscle fascias. Right after, daily, the suitable substance to each group was applied in the lesion. After periods of 3, 7, 14, 21 days after the surgery, the animals were killed to collect fragments of the lesion. The material was prepared in stained slides with H&amp;E and toluidine blue for histologic analysis. The results showed that at day 14 of treatment, the animals under effect of 30 mg/ml and 50 mg/ml of Hera extract did not present edema. It was also observed a reduction in vascular congestion in the Hera of 30 mg/ml, Hera 50 mg/ml and Nebacetin groups compared to the other groups analyzed. All groups treated with Hera extract showed a reduction of inflammatory cells in day 14 post-lesion, besides the increase of fibroblast this period, showing acceleration in the chronicity of the lesion. Regarding the number of mast cells, a significant increase in the early lesion, in the 3 and 7 days periods was observed, in Hera 50 mg/ml and 30 mg/ml groups, respectively. According to the results, the Hera extract, especially at concentrations of 30 mg/ml and 50 mg/ml accelerated the healing process; based on the decreased permanence period of the edema and congestion of the vessels, as well as changes in the number of cells related to inflammation of lesions

BJcuL, a lectin purified from Bothrops jararacussu venom, induces apoptosis in human gastric carcinoma cells accompanied by inhibition of cell adhesion and actin cytoskeleton disassembly

We show that BJcuL, a lectin purified from Bothrops jararacussu venom, exerts cytotoxic effects to gastric carcinoma cells MKN45 and AGS. This effect was due to the direct interaction with specific glycans on the cells surface and was observed by cell viability decrease, disorganization of actin filaments and apoptosis. In addition, BJcuL was able to reduce tumor cell adhesion to matrigel, what was inhibited by specific carbohydrate or partially inhibited when cells were pre-incubated with matrigel. Our results suggest that BJcuL was able to promote apoptosis in both tumor cells lines and therefore has a prospect for potential use in cancer therapy. (C) 2011 Elsevier Ltd. All rights reserved.CNP

Intradermal injection of Bothrops cotiara venom in mice in an experimental wound model

Bothropic envenomation induces hemorrhage, coagulant disturbances and necrosis. Regarding therapies against the local damage caused by the venom, there is little information on tissue changes until the complete healing. In the current study, local damage was evaluated by examination of morphological inflammatory alterations, mast cell count, and analysis of collagen deposition. Bleeding was evident four hours after inoculation. After 24 hours, a large area of injury appeared presenting disorganized tissue, significant hemorrhage and acute inflammation. After three days, the damaged area was extensive, with a large amount of inflammatory cells and the presence of scab. In seven days, healing and reepithelization process started. And, 21 days later, the epithelium showed less infiltration and no skin appendages. The number of mast cells was similar to control after four hours, with a drop of 50% at 24 hours, followed by an increase until the 21st day. No differences of collagen deposition were observed among experimental groups. Taken together, wound healing after intradermal injection of Bothrops cotiara venom in mice follows similar parameters to wounds caused by other bothropic venoms. The present work reveals the importance of experimental wound models to the study of neutralizing agents against venom toxins

Marine Actinomycetes-Derived Secondary Metabolites Overcome TRAIL-Resistance via the Intrinsic Pathway through Downregulation of Survivin and XIAP

International audienc

A remote, fully oriented personalized program of physical exercise for women in follow-up after breast cancer treatment improves body composition and physical fitness

This study aimed to evaluate the efficacy of an individualized remote exercise program on the improvement of body composition and physical fitness of a heterogeneous group of patients who completed breast cancer treatment. This prospective study included 107 women aged 18 to 60, shortly after curative treatment for localized breast cancer, at the Erasto Gaertner Cancer Hospital (HEG) in Curitiba, PR, Brazil. Body composition, maximal oxygen consumption, and muscle resistance were evaluated after nine months of intervention while considering adherence to the program, level of physical activity, presence of binge eating disorder, tumor classification, and treatment type. Seventy-eight women (72.8%) adhered to the training program. Adherent participants showed significant changes in body mass ([-4.3 ​± ​3.6] kg; p ​< ​0.000 1), body mass index ([-1.6 ​± ​1.5] kg·m−2; p ​< ​0.000 1), body fat (−3.4% ​± ​3.1%; p ​< ​0.000 1), maximal oxygen consumption ([7.5 ​± ​2.0] ml·kg−1·min−1); p ​< ​0.000 1), and abdominal resistance ([11.2 ​± ​2.8] reps; p ​< ​0.000 1). In contrast, these variables did not change significantly in the non-adherent group. Among the adherent participants, those subclassified in the severe binge group showed a more noticeable reduction in body mass, body mass index, and body fat (p ​< ​0.05) than those in the non-binge group. Individualized remotely-guided physical exercise programs can improve the body composition and physical fitness of women undergoing post-breast cancer surveillance, regardless of pathological history or treatment

Death Receptor-Induced Apoptosis Signalling Regulation by Ezrin Is Cell Type Dependent and Occurs in a DISC-Independent Manner in Colon Cancer Cells

International audienceEzrin belongs to the ERM (ezrin-radixin-moesin) protein family and has been demonstrated to regulate early steps of Fas receptor signalling in lymphoid cells, but its contribution to TRAIL-induced cell death regulation in adherent cancer cells remains unknown. In this study we report that regulation of FasL and TRAIL-induced cell death by ezrin is cell type depen-dant. Ezrin is a positive regulator of apoptosis in T-lymphoma cell line Jurkat, but a negative regulator in colon cancer cells. Using ezrin phosphorylation or actin-binding mutants, we provide evidence that negative regulation of death receptor-induced apoptosis by ezrin occurs in a cytoskeleton-and DISC-independent manner, in colon cancer cells. Remarkably, inhibition of apoptosis induced by these ligands was found to be tightly associated with regulation of ezrin phosphorylation on serine 66, the tumor suppressor gene WWOX and activation of PKA. Deficiency in WWOX expression in the liver cancer SK-HEP1 or the pancreatic Mia PaCa-2 cell lines as well as WWOX silencing or modulation of PKA activation by pharmacological regulators, in the colon cancer cell line SW480, abrogated regulation of TRAIL signalling by ezrin. Altogether our results show that death receptor pro-apoptotic signalling regulation by ezrin can occur downstream of the DISC in colon cancer cells

Proposal of a low-cost protocol for colorimetric semi-quantification of secretory phospholipase by Candida albicans grown in planktonic and biofilm phases

Biofilms are aggregates of microorganisms living in multilayered structures inside polymeric matrices onto surfaces. These biofilms may subvert the physiological properties of adjacent tissues causing morphofunctional failure. Many studies have shown that the expression of virulence attributes is maximized when microbes form such communities. This study evaluated the differential phospholipasic activity of Candida albicans SC5314 grown in planktonic phase and in biofilm. We propose two distinct protocols for the colorimetric evaluation of phosphatidylcholine hydrolysis in neutral and acidic conditions. The results showed that both protocols are suitable for the proposed intention and that 72\ua0h-old planktonic cultures of C. albicans SC5314 secrete higher quantities of neutral (6.42-fold) and acidic (3.85-fold) phospholipases than biofilms