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Despite all efforts to combat the pandemic of COVID-19, we are still living with high numbers of infected persons, an overburdened health care system, and the lack of an effective and definitive treatment. Understanding the pathophysiology of the disease is crucial for the development of new technologies and therapies for the best clinical management of patients. Since the manipulation of the whole virus requires a structure with an adequate level of biosafety, the development of alternative technologies, such as the synthesis of peptides from viral proteins, is a possible solution to circumvent this problem. In addition, the use and validation of animal models is of extreme importance to screen new drugs and to compress the organism's response to the disease. Peptides derived from recombinant S protein from SARS-CoV-2 were synthesized and validated by in silico, in vitro and in vivo methodologies. Macrophages and neutrophils were challenged with the peptides and the production of inflammatory mediators and activation profile were evaluated. These peptides were also inoculated into the swim bladder of transgenic zebrafish larvae at 6 days post fertilization (dpf) to mimic the inflammatory process triggered by the virus, which was evaluated by confocal microscopy. In addition, toxicity and oxidative stress assays were also developed. In silico and molecular dynamics assays revealed that the peptides bind to the ACE2 receptor stably and interact with receptors and adhesion molecules, such as MHC and TCR, from humans and zebrafish. Macrophages stimulated with one of the peptides showed increased production of NO, TNF-α and CXCL2. Inoculation of the peptides in zebrafish larvae triggered an inflammatory process marked by macrophage recruitment and increased mortality, as well as histopathological changes, similarly to what is observed in individuals with COVID-19. The use of peptides is a valuable alternative for the study of host immune response in the context of COVID-19. The use of zebrafish as an animal model also proved to be appropriate and effective in evaluating the inflammatory process, comparable to humans., (© 2023. The Author(s).)

The Spike protein (S protein) is a critical component in the infection of the new coronavirus (SARS-CoV-2). The objective of this work was to evaluate whether peptides from S protein could cause negative impact in the aquatic animals. The aquatic toxicity of SARS-CoV-2 Spike protein peptides derivatives has been evaluated in tadpoles (n = 50 tadpoles/5 replicates of 10 animals) from species Physalaemus cuvieri (Leptodactylidae). After synthesis, purification, and characterization of peptides (PSDP2001, PSDP2002, PSDP2003) an aquatic contamination has been simulated with these peptides during 24 h of exposure in two concentrations (100 and 500 ng/mL). The control group ("C") was composed of tadpoles kept in polyethylene containers containing de-chlorinated water. Oxidative stress, antioxidant biomarkers and AChE activity were assessed. In both concentrations, PSPD2002 and PSPD2003 increased catalase and superoxide dismutase antioxidants enzymes activities, as well as oxidative stress (nitrite levels, hydrogen peroxide and reactive oxygen species). All three peptides also increased acetylcholinesterase activity in the highest concentration. These peptides showed molecular interactions in silico with acetylcholinesterase and antioxidant enzymes. Aquatic particle contamination of SARS-CoV-2 has cholinesterasic effect in P. cuvieri tadpoles. These findings indicate that the COVID-19 can constitute environmental impact or biological damage potential., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Extracellular vesicles (EVs) are a frontier class of circulating biomarkers for the diagnosis and prognosis of different diseases. These lipid structures afford various biomarkers such as the concentrations of the EVs ( C V ) themselves and carried proteins ( C P ). However, simple, high-throughput, and accurate determination of these targets remains a key challenge. Herein, we address the simultaneous monitoring of C V and C P from a single impedance spectrum without using recognizing elements by combining a multidimensional sensor and machine learning models. This multidetermination is essential for diagnostic accuracy because of the heterogeneous composition of EVs and their molecular cargoes both within the tumor itself and among patients. Pencil HB cores acting as electric double-layer capacitors were integrated into a scalable microfluidic device, whereas supervised models provided accurate predictions, even from a small number of training samples. User-friendly measurements were performed with sample-to-answer data processing on a smartphone. This new platform further showed the highest throughput when compared with the techniques described in the literature to quantify EVs biomarkers. Our results shed light on a method with the ability to determine multiple EVs biomarkers in a simple and fast way, providing a promising platform to translate biofluid-based diagnostics into clinical workflows.

Background: Extracellular vesicles (EVs) are small membrane-bound vesicles of growing interest in vetetinary parasitology. The aim of the present report was to provide the first isolation, quantification and protein characterization of EVs from buffalo ( Bubalus bubalis) sera infected with Theileria spp., Methods: Infected animals were identified through optical microscopy and PCR. EVs were isolated from buffalo sera by size-exclusion chromatography and characterized using western blotting analysis, nanoparticle tracking analysis and transmission electron microscopy. Subsequently, the proteins from isolated vesicles were characterized by mass spectrometry., Results: EVs from buffalo sera have shown sizes in the 124-140 nm range and 306 proteins were characterized. The protein-protein interaction analysis has evidenced biological processes and molecular function associated with signal transduction, binding, regulation of metabolic processes, transport, catalytic activity and response to acute stress. Five proteins have been shown to be differentially expressed between the control group and that infected with Theileria spp., all acting in the oxidative stress pathway., Conclusions: EVs from buffaloes infected with Theileria spp. were successfully isolated and characterized. This is an advance in the knowledge of host-parasite relationship that contributes to the understanding of host immune response and theileriosis evasion mechanisms. These findings may pave the way for searching new EVs candidate-markers for a better production of safe biological products derived from buffaloes., Competing Interests: Competing interests: The authors declare that they have no competing interests. Lucilene Delazari dos Santos and Rui Seabra Ferreira Jr. authors of this article are associate editors of Journal of Venomous Animals and Toxins including Tropical Diseases. They did not get involved in the peer review process of this manuscript.

Biological properties of natural products are an important research target and essential oils (EO) from aromatic plants with antimicrobial properties are well documented. However, their uses are limited, and the mechanisms underlying their antibacterial activity are still not well known. Therefore, our objective was to evaluate the antibacterial activities of Origanum vulgare EO, thymol and carvacrol against Salmonella Enteritidis ATCC 13076 strain, particularly regarding the bacterial proteic profile, enzymatic activities and DNA synthesis. Bacterial expressed proteins were evaluated using an untreated assay control and treatments with sublethal concentrations of oregano EO, carvacrol and thymol. The same protein extracts were also assayed for oxidative stress and energy metabolism enzyme activities, as well as effect on DNA synthesis. Protein expression outcomes revealed by 2D-SDS-PAGE, from antimicrobial actions, showed a stress response with differential expressions of chaperones and cellular protein synthesis mediated by the bacterial signaling system. In addition, Salmonella used a similar mechanism in defense against oxidative stress, for its survival. Thus, the antibacterial inhibitory activity of EO was preferentially associated with the presence of thymol and there was interference in protein regulation as well as DNA synthesis affected by these compounds. SIGNIFICANCE: Antimicrobial activity of essential oils (EO) is already known. In this way, the understanding of how this activity occurs is a fundamental part to provide the practical and rational use of these substances. In the current scenario, where the emergence of resistant bacteria or even multiresistant bacteria against conventional antimicrobials, the search for alternatives becomes essential, since the discovery of new inhibitory substances does not occur at the same speed. The anti-Salmonella action allied to the knowledge about the biological processes affected by O. vulgare EO contribute to these bioactive compounds being effectively used as agents in the safety and shelf life of food in a future product, packaging or process where the antibacterial activity is safe and best used., Competing Interests: Declaration of Competing Interest The authors state that no conflict of interest exists., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Chronic venous ulcers affect the quality of life of patients around the world. The aims of this study were to identify the proteins expressed in chronic venous ulcer exudates, to categorize them according to their roles and to correlate them with the clinical and epidemiological aspects of the disease. The study population consisted of 37 ulcers from 28 patients, and the inflammatory exudates of these thirty-seven ulcers were subjected to tryptic digestion and mass spectrometry analysis. Twenty-three patients were female (62.2%), and five (37.8%) were male. The patients had a mean age of 70 (±10.1) years. Of the patients, 73% adhered to compression and rest, 81.1% reported a history of primary varices, 54.1% reported a history of systemic arterial hypertension, 54.1% reported a history of devitalized tissue in the wound bed and 64.9% reported ulcers with more than ten years of evolution. Seventy-six proteins were identified, and they were grouped according to their primary role in the healing process. Eight correlations between clinical and epidemiological data and protein expression were noteworthy: diabetes mellitus vs. Ig gamma-2 and apolipoprotein-A1 and albumin; congestive heart failure vs. Ig lambda-2; colonization vs. actin; compressive therapy vs. Ig kappa; systemic arterial hypertension vs. alpha-2-macroglobulin and apolipoprotein-A1; area of ulcer vs. apolipoprotein-A1; race vs. heavy chain Ig and Ig γ-1 chain; age and race vs. Ig γ-1 chain. These associations may help to elucidate the prognosis and chronicity of chronic venous ulcers based on secreted proteins., (Copyright © 2018. Published by Elsevier B.V.)

Objectives: The aim of the study was to compare, using a proteomic approach, cervicovaginal fluid (CVF) proteins of women with bacterial vaginosis (BV) with those presenting normal microbiota., Materials and Methods: A total of 309 reproductive-aged women were cross-sectionally enrolled. Participants were tested for vaginal candidosis, Trichomonas vaginalis, Chlamydia trachomatis, and Neisseria gonorrhoeae and excluded if positive. Vaginal microbiota was classified microscopically according to Nugent criteria in normal, intermediate, and BV. Randomly selected CVF samples of 29 women with BV and an equal number with normal microbiota were subjected to proteomic analysis. Thus, a total of 58 CVF samples were evaluated using shotgun liquid chromatography-tandem mass spectrometry in a Q-Tof PREMIER API mass spectrometer (MicroMass/Waters) for peptide detection and relative quantification., Results: Of the 309 women enrolled, 63 (20.4%) were excluded after testing positive for at least one of the tested co-infections or because of low-quality samples. Microscopic classification of vaginal microbiota on the remaining 246 samples revealed that 132 women (53.6%) had normal microbiota, 33 (13.4%) had intermediate microbiota, and 81 (33.0%) had BV. Proteomic analysis of CVF of 58 randomly selected women with normal microbiota (n = 29) or BV (n = 29) successfully identified 74 proteins. In addition, the comparison of abundance of those proteins between the groups showed that the following five (6.7%) were enriched in BV: neutrophil elastase, kaliocin-1, neutrophil defensin-1, Ig lambda-2 chain C regions, and protein S100-A7. All of which have a recognized role in host's immunity., Conclusions: Exclusive finding of BV affects immunity-related CVF components of reproductive-aged women.

The proteomic approach has aroused the interest of veterinary medicine researchers, especially regarding the production of biopharmaceuticals and diagnosis of diseases in farm animals. Water buffaloes have gained prominence in the world economy due to the quality of their milk, meat, and leather, in addition to being an important donor of blood components. This work aimed to identify and characterize the proteins present in the blood plasma of Murrah buffaloes (Bubalus bubalis) through 2D electrophoresis, in gel protein digestion followed by mass spectrometry technique and for albumin depletion, in solution protein digestion followed by shotgun analysis. Our results showed the identification of 112 protein spots and 35 individual proteins, respectively. The abundant proteins were represented by albumin, fibrinogen-α, fibrinogen-β, fibrinogen-γ, immunoglobulins in general, α-1-antiproteinase, α-1B-glycoprotein, α-2-HS-glycoprotein, α-macroglobulin, apolipoprotein A1, antithrombin-III, endopin 2B, fetuin-B, retinol-binding protein, serotransferrin, transthyretin and vitamin D-binding protein. Most of these proteins are related to the signaling pathways of the complement system and coagulation cascade. The results allowed a better understanding of the protein composition of these blood components, thus promoting studies on animal health in the search for molecular markers of zoonotic diseases in buffaloes., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Hemostatic and adhesive agents date back to World War II, when homologous fibrin sealant came onto scene. Considering that infectious diseases can be transmitted via human blood, a new heterologous fibrin sealant was standardized in the 1990s. Its components were a serine protease (a thrombin-like enzyme) extracted from the venom of Crotalus durissus terrificus snakes and a fibrinogen-rich cryoprecipitate extracted from the blood of Bubalus bubalis buffaloes. This new bioproduct has been used as a coagulant, sealant, adhesive and recently as a candidate scaffold for mesenchymal stem cells and bone and cartilage repair. This review discusses the composition of a new heterologous fibrin sealant, and cites published articles related to its preclinical applications aiming at repairing nervous system traumas and regenerating bone marrow. Finally, we present an innovative safety trial I/II that found the product to be a safe and clinically promising candidate for treating chronic venous ulcers. A multicenter clinical trial, phase II/III, with a larger number of participants will be performed to prove the efficacy of an innovative biopharmaceutical product derived from animal venom.