Isolated Peptide from Spider Venom Modulates Dendritic Cells In Vitro: A Possible Application in Oncoimmunotherapy for Glioblastoma.

Dendritic cells (DCs) vaccine is a potential tool for oncoimmunotherapy. However, it is known that this therapeutic strategy has failed in solid tumors, making the development of immunoadjuvants highly relevant. Recently, we demonstrated that Phoneutria nigriventer spider venom (PnV) components are cytotoxic to glioblastoma (GB) and activate macrophages for an antitumor profile. However, the effects of these molecules on the adaptive immune response have not yet been evaluated. This work aimed to test PnV and its purified fractions in DCs in vitro. For this purpose, bone marrow precursors were collected from male C57BL6 mice, differentiated into DCs and treated with venom or PnV-isolated fractions (F1-molecules < 3 kDa, F2-3 to 10 kDa and F3->10 kDa), with or without costimulation with human GB lysate. The results showed that mainly F1 was able to activate DCs, increasing the activation-dependent surface marker (CD86) and cytokine release (IL-1ß, TNF-α), in addition to inducing a typical morphology of mature DCs. From the F1 purification, a molecule named LW9 was the most effective, and mass spectrometry showed it to be a peptide. The present findings suggest that this molecule could be an immunoadjuvant with possible application in DC vaccines for the treatment of GB.

Nursing students' opinion on the use of Escape ZOOM® as a learning strategy: Observational study.

The teaching-learning process has gone through major changes due to the COVID-19 pandemics and it has been left to professors to adapt the teaching process and find ways to keep students engaged. There has been a need to establish collaborative and active strategies for working in the online environment. The development of a game for both teaching and evaluating de interdisciplinary learning content on an online platform may create a gameful experience and stimulating environment that makes complex learning goals achievable. To analyze how nursing students feel in relation to their participation and learning in an Escape Room activity taking place in an online environment. This is a descriptive and exploratory cross-sectional cohort study. The study was carried out in a higher education institution. The sample consisted of 73 students. After implementation of Escape Zoom® in the first semester of 2021, adapted questionnaires to assess students' satisfaction and perception of learning were applied. In the Educational Practices Questionnaire, all statements obtained greater than 70% agreement, which revealed students' satisfaction, especially with learning with colleagues. As for learning, 93.2% of students' statements expressed that the Escape Zoom® favors teamwork and 91.8% of student's statements agreed that the activity is effective for learning and would recommend it to other colleagues. The Escape Zoom® is an effective teaching strategy, perceived with satisfaction by students as a form of learning with colleagues, in a game-oriented way. It also has the potential to promote the development of soft skills.

First case report of Ctenus medius envenomation: Clinical features of a patient bitten three times by the same spider.

A 22 years old undergraduate student was injured three times by a C. medius spider while wearing pants. Right foot and internal lower leg were bitten in three sites, leading to local pain and oedema, besides a total leg paresthesia as immediate symptoms. A series of photographs of the sites were taken since day 0 until resolution in day 10. Two hours after the accident, the victim received intravenous promethazine. Despite cessation of pain and paresthesia after 24 hours, an intense erythema and itching emerged reaching the maximum in day 4, when the victim returned to hospital and received topic dexamethasone and oral dexchlorpheniramine. The regression was complete in day 10. This accident opened room for discussion of empiric drug choice for immediate and subsequent symptoms of unknown envenomations, as good as a reference for further accidents with this common spider. Biological aspects such as venom composition and spider control of delivered venom amount are also discussed.

Components from spider venom activate macrophages against glioblastoma cells: new potential adjuvants for anticancer immunotherapy.

Immunomodulation has been considered an important approach in the treatment of malignant tumours. However, the modulation of innate immune cells remains an underexplored tool. Studies from our group demonstrated that the Phoneutria nigriventer spider venom (PnV) administration increased the infiltration of macrophage in glioblastoma, in addition to decreasing the tumour size in a preclinical model. The hypothesis that PnV would be modulating the innate immune system led us to the main objective of the present study: to elucidate the effects of PnV and its purified fractions on cultured macrophages. Results showed that PnV and the three fractions activated macrophages differentiated from bone marrow precursors. Further purification generated 23 subfractions named low weight (LW-1 to LW-12) and high weight (HW-1 to HW-11). LW-9 presented the best immunomodulatory effect. Treated cells were more phagocytic, migrated more, showed an activated morphological profile and induced an increased cytotoxic effect of macrophages on tumour cells. However, while M1-controls (LPS) increased IL-10, TNF-alpha and IL-6 release, PnV, fractions and subfractions did not alter any cytokine, with the exception of LW-9 that stimulated IL-10 production. These findings suggest that molecules present in LW-9 have the potential to be used as immunoadjuvants in the treatment of cancer.

Spider venom components decrease glioblastoma cell migration and invasion through RhoA-ROCK and Na+/K+-ATPase ß2: potential molecular entities to treat invasive brain cancer.

BACKGROUND: Glioblastoma (GB) cells have the ability to migrate and infiltrate the normal parenchyma, leading to the formation of recurrent tumors often adjacent to the surgical extraction site. We recently showed that Phoneutria nigriventer spider venom (PnV) has anticancer effects mainly on the migration of human GB cell lines (NG97 and U-251). The present work aimed to investigate the effects of isolated components from the venom on migration, invasiveness, morphology and adhesion of GB cells, also evaluating RhoA-ROCK signaling and Na+/K+-ATPase ß2 (AMOG) involvement. METHODS: Human (NG97) GB cells were treated with twelve subfractions (SFs-obtained by HPLC from PnV). Migration and invasion were evaluated by scratch wound healing and transwell assays, respectively. Cell morphology and actin cytoskeleton were shown by GFAP and phalloidin labeling. The assay with fibronectin coated well plate was made to evaluate cell adhesion. Western blotting demonstrated ROCK and AMOG levels and a ROCK inhibitor was used to verify the involvement of this pathway. Values were analyzed by the GraphPad Prism software package and the level of significance was determinate using one-way analysis of variance (ANOVA) followed by Dunnett's multiple comparisons test. RESULTS: Two (SF1 and SF11) of twelve SFs, decreased migration and invasion compared to untreated control cells. Both SFs also altered actin cytoskeleton, changed cell morphology and reduced adhesion. SF1 and SF11 increased ROCK expression and the inhibition of this protein abolished the effects of both subfractions on migration, morphology and adhesion (but not on invasion). SF11 also increased Na+/K+-ATPase ß2. CONCLUSION: All components of the venom were evaluated and two SFs were able to impair human glioblastoma cells. The RhoA effector, ROCK, was shown to be involved in the mechanisms of both PnV components. It is possible that AMOG mediates the effect of SF11 on the invasion. Further investigations to isolate and biochemically characterize the molecules are underway.

Pharmacological Characterization of the Edema Caused by Vitalius dubius (Theraphosidae, Mygalomorphae) Spider Venom in Rats.

Bites by tarantulas (Theraphosidae, Mygalomorphae) in humans can result in mild clinical manifestations such as local pain, erythema, and edema. Vitalius dubius is a medium-sized, nonaggressive theraphosid found in southeastern Brazil. In this work, we investigated the mediators involved in the plasma extravasation caused by V. dubius venom in rats. The venom caused dose-dependent (0.1-100 µg/site) edema in rat dorsal skin. This edema was significantly inhibited by ((S)1-{2-[3(3-4-dichlorophenyl)-1-(3-iso-propoxyphenylacetyl)piperidine-3-yl]ethyl}-4-phenyl-1-azoniabicyclo[2.2.2]octone, chloride) (SR140333, a neurokinin NK1 receptor antagonist), indomethacin [a nonselective cyclooxygenase (COX) inhibitor], cyproheptadine (a serotonin 5-hydroxytryptamine1/2 and histamine H1 receptor antagonist), and N(ω)-nitro-L-arginine methyl ester (a nitric oxide synthase inhibitor). In contrast, mepyramine (a histamine H1 receptor antagonist), D-Arg-[Hyp(3),Thi(5),D-Tic(7),Oic(8)-]-BK (JE 049, a bradykinin B2 receptor antagonist), and ((S)-N-methyl-N-[4-(4-acetylamino-4-phenylpiperidino)-2-(3,4-di-chlorophenyl)butyl]benzamide) (SR48968, a neurokinin NK2 receptor antagonist) had no effect on the venom-induced increase in vascular permeability. In rat hind paws, the venom-induced edema was attenuated by ketoprofen (a nonselective COX inhibitor) administered 15 minutes postvenom. Preincubation of venom with commercial antiarachnid antivenom attenuated the venom-induced edema. These results suggest that the enhanced vascular permeability evoked by V. dubius venom involves serotonin, COX products, neurokinin NK1 receptors, and nitric oxide formation. The attenuation of hind paw edema by ketoprofen suggests that COX inhibitors could be useful in treating the local inflammatory response to bites by these spiders.

VdTX-1, a reversible nicotinic receptor antagonist isolated from venom of the spider Vitalius dubius (Theraphosidae).

Theraphosid spider venoms can block neurotransmission in vertebrate nerve-muscle preparations in vitro, but few of the components involved have been characterized. In this work, we describe the neuromuscular activity of venom from the Brazilian theraphosid Vitalius dubius and report the purification and pharmacological characterization of VdTX-1, a 728 Da toxin that blocks nicotinic receptors. Neuromuscular activity was assayed in chick biventer cervicis preparations and muscle responses to exogenous ACh and KCl were determined before and after incubation with venom or toxin. Changes in membrane resting potential were studied in mouse diaphragm muscle. The toxin was purified by a combination of filtration through Amicon® filters, cation exchange HPLC and RP-HPLC; toxin purity and mass were confirmed by mass spectrometry. Venom caused progressive neuromuscular blockade and muscle contracture; the blockade but not the contracture was reversible by washing. Venom attenuated contractures to exogenous ACh and KCl. Filtration yielded low (LM, <5 kDa) and high (HM, >5 kDa) fractions, with the latter reproducing the contracture seen in venom but with a slight and progressive twitch blockade. The LM fraction caused reversible blockade and attenuated contractures to ACh, but had no effect on contractures to KCl. VdTX-1 (728 Da) purified from the LM fraction was photosensitive and reduced the E(max) to ACh in biventer cervicis muscle without affecting the EC50; VdTX-1 also abolished carbachol-induced depolarizations. V. dubius venom contains at least two components that affect vertebrate neurotransmission. One component, VdTX-1, blocks nicotinic receptors non-competitively to produce reversible blockade without muscle contracture.

Histological and functional renal alterations caused by Bothrops alternatus snake venom: expression and activity of Na+/K+-ATPase.

BACKGROUND: Acute renal failure is a serious complication of human envenoming by Bothrops snakes. The ion pump Na+/K+-ATPase has an important role in renal tubule function, where it modulates sodium reabsorption and homeostasis of the extracellular compartment. Here, we investigated the morphological and functional renal alterations and changes in Na+/K+-ATPase expression and activity in rats injected with Bothrops alternatus snake venom. METHODS: Male Wistar rats were injected with venom (0.8 mg/kg, i.v.) and renal function was assessed 6, 24, 48 and 72 h and 7 days post-venom. The rats were then killed and renal Na+/K+-ATPase activity was assayed based on phosphate release from ATP; gene and protein expressions were assessed by real time PCR and immunofluorescence microscopy, respectively. RESULTS: Venom caused lobulation of the capillary tufts, dilation of Bowman's capsular space, F-actin disruption in Bowman's capsule and renal tubule brush border, and deposition of collagen around glomeruli and proximal tubules that persisted seven days after envenoming. Enhanced sodium and potassium excretion, reduced proximal sodium reabsorption, and proteinuria were observed 6 h post-venom, followed by a transient decrease in the glomerular filtration rate. Gene and protein expressions of the Na+/K+-ATPase α1 subunit were increased 6h post-venom, whereas Na+/K+-ATPase activity increased 6 h and 24 h post-venom. CONCLUSIONS: Bothrops alternatus venom caused marked morphological and functional renal alterations with enhanced Na+/K+-ATPase expression and activity in the early phase of renal damage. GENERAL SIGNIFICANCE: Enhanced Na+/K+-ATPase activity in the early hours after envenoming may attenuate the renal dysfunction associated with venom-induced damage.

Cutaneous loxoscelism caused by Loxosceles anomala.

A previously healthy 35-year-old female was bitten on the anterior right thigh by a brown spider while dressing her trousers; the spider was stored and later identified as an adult female Loxosceles anomala. Clinical evolution involved a relatively painless bite with mild itching, followed by local, indurated swelling and a transient, generalized erythrodermic rash at 24 h post-bite. The local discomfort was progressive, and involved changes in the lesion pattern, with pain of increasing intensity. The patient was admitted 60 h post-bite, showing an irregular blue plaque surrounded by an erythematous halo lesion, located over an area of indurated swelling. Considering the presumptive diagnosis of cutaneous loxoscelism, she was treated with five vials of anti-arachnidic antivenom i.v. without adverse effects. There was progressive improvement, with no dermonecrosis or hemolysis; complete lesion healing was observed by Day 55. The clinical features and outcome were compatible with cutaneous loxoscelism and similar to those reported for other Loxosceles species.

Venom apparatus of the Brazilian tarantula Vitalius dubius Mello-Leitão 1923 (Theraphosidae).

Tarantula venoms are a cocktail of proteins and peptides that have been increasingly studied in recent years. In contrast, less attention has been given to analyzing the structure of the paired cephalic glands that produce the venom. We have used light, electron, and confocal microscopy to study the organization and structure of the venom gland of the Brazilian tarantula Vitalius dubius. The chelicerae are hairy chitinous structures, each with a single curved hollow fang that opens via an orifice on the anterior surface. Internally, each chelicera contains striated muscle fiber bundles that control fang extension and retraction, and a cylindrical conical venom gland surrounded by a thick well-developed layer of obliquely arranged muscle fibers. Light microscopy of longitudinal and transverse sections showed that the gland secretory epithelium consists of a sponge-like network of slender epithelial cell processes with numerous bridges and interconnections that form lacunae containing secretion. This secretory epithelium is supported by a basement membrane containing elastic fibers. The entire epithelial structure of the venom-secreting cells is reinforced by a dense network of F-actin intermediate filaments, as shown by staining with phalloidin. Neural elements (axons and acetylcholinesterase activity) are also associated with the venom gland. Transmission electron microscopy of the epithelium revealed an ultrastructure typical of secretory cells, including abundant rough and smooth endoplasmic reticulum, an extensive Golgi apparatus, and numerous mitochondria.

Milking and partial characterization of venom from the Brazilian spider Vitalius dubius (Theraphosidae).

The theraphosid spider genus Vitalius contains several species found in southeastern Brazil. In this work, we used electrostimulation to obtain venom from Vitalius dubius and examined its general composition. Male spiders yielded significantly less (p < 0.05) venom (12.5 +/- 0.7 mg of liquid/spider, n = 16; mean +/- S.E.M.) than female spiders (25.5 +/- 2.0 mg of liquid/spider, n = 11). However, when corrected for spider weight, males yielded slightly more venom (2.89 +/- 0.16 mg/g vs. 2.45 +/- 0.76 mg/g for males and females, respectively, p < 0.05). Venom yield correlated linearly with spider weight for spiders weighing up to approximately 12-13 g, but decreased in very heavy females. There was a marked decrease in venom yield after the first milking. The protein concentration of pooled venom was 18.3 +/- 2.4 mg/ml (n = 4) and accounted for 16.6 +/- 4.7% of the dry venom weight. The venom contained high hyaluronidase activity (275 +/- 24 TRU/mg of protein, n = 4), with a molecular mass of approximately 45 kDa estimated by zymography. SDS-PAGE revealed a few proteins with molecular masses >14 kDa but showed two staining bands of peptides <14 kDa. The venom reacted in ELISA with affinity-purified IgG from commercial arachnidic antivenom. Immunoblotting with this IgG detected proteins of 30-140 kDa only. Fractionation of the venom by reverse-phase chromatography resulted in five major and eight minor peaks.

Dynamics of cytochrome P450 inducers in polluted sites of São Paulo city reservoirs.

The first analysis of water pollutants using biomarkers at the Guarapiranga Reservoir, which supplies water for one-third of the population of the São Paulo megalopolis (Brazil), is reported. Studies were performed before and after the start of water pumping to the Guarapiranga from the highly polluted Billings reservoir. Billings's water was purified by passing through the natural wetland located near Guarapiranga. Liver enzymes of Oreochromis niloticus (tilopias) obtained from both reservoirs served as biomarkers of pollution in a comparison with animals obtained from a reference site. Enhanced levels of total cytochromes P450 (3.4 times) and b5 (2.7 times) and activity of cytochrome c (P450) reductase (2.2 times) were observed in specimens collected near the water influx from the Billings before the pumping started. However, these parameters were significantly decreased 3 months later. This effect is probably due to dilution of pollutants because of the increased level of water in the Guarapiranga.

Comparison of liver mixed-function oxygenase and antioxidant enzymes in vertebrates.

We performed a comparative analysis of cytochrome P450, cytochrome b5, MFO associated enzymes and cytosolic antioxidant enzymes in hepatic microsomes and cytosolic fractions prepared from five animal species representing three vertebrate classes living in tropical conditions (Brazil). The data obtained show that rats have higher hepato-somatic index, specific cytochrome b5 concentration, and NADPH-dependent cytochrome c (P450) activity compared to ectothermic species, SOD activity similar to those in amphibians, and specific concentration of cytochrome P450 and catalase activity lower than in a toad, but higher than in fishes and a frog. Our data indicate that tropical fishes may have reduced xenobiotic-metabolizing ability compared to the rat and amphibians. In contrast to fish and rat, amphibians have a low ratio (< 0.5) of cytochrome b5 concentration to that of P450. Most species showed cytochrome b5 sensitivity to oxygen. Thus, the use of sodium dithionate as a reducer, rather than NADPH, may be preferential in b5 determinations.

Comparison of the cytotoxicity of two nitroheterocyclic drugs (NHCD) towards transformed and non-transformed cells.

The cytotoxicity of two nitroheterocyclic compounds (NHCD), Nitracrine, 1-nitro-9(3'3'-dimethylaminopropylamino) acridine (Polfa, Poland) and Quinifuryl, 2-(5'-nitro-2'-furanyl) ethenyl-4-[N-[4-(N,N-diethylamino)-1'-methylbutyl] carbamoyl] quinoline (Dr. N. M. Sukhova, Institute of Organic Synthesis, Riga, Latvian Republic), towards two lines of leukaemic cells and a line of non-transformed cells, was determined under normoxia conditions. Although both drugs showed significant cytotoxicity to all cell lines (LC(50) for 24h, < or = 2 microM) with that of Nitracrine exceeding Quinifuryl, their toxicity towards murine leukaemia P388 was substantially higher, compared to murine fibroblasts NIH3T3. In addition, the rate of cell death was also two- to three-fold higher in case of P388 cells versus NIH3T3. Interestingly, human erythroleukaemia K562 cells were shown to uptake the drugs 10 min after their addition to the tissue culture medium, while the LC(50) values were reached after a substantial delay of 3h. This delay might be due to the intracellular transformation of drugs required for cell killing.