In Vivo Models for Measuring Placental Glutatione-S-transferase (GST-P 7-7) Levels: A Suitable Biomarker for Understanding Cancer Pathogenesis

The Glutatione-S-transferases (GSTs) comprise a family of enzymes closely associated with the cell detoxification of xenobiotics. GSTs exist as homo- or heterodimers and have been grouped into at least seven distinct classes. The main function of GSTs is to catalyze the conjugation of reduced glutathione (GSH) to an electrophilic site of a broad range of potentially toxic and carcinogenic compounds, thereby making such compounds less dangerous and enabling their ready-excretion. Placental GST, known as GST-P 7-7, is the main isoform found in normal placental tissue and comprises 67% of the total GST concentration in this tissue. During development, GST-P 7-7 decreases in concentration and is absent in adult tissues. Interestingly, GST-P 7-7 expression has been detected in adult tissues after exposure to carcinogenic agents in several experimental test systems, being considered a reliable biomarker of exposure and susceptibility in early phases of carcinogenesis. In this article, we review a series of studies involving GST-P 7-7 expression as a suitable tool for understanding cancer pathogenesis, especially cancer risk.

Efeito de um curcumin modificado quimicamente sobre a reabsorção óssea inflamatória e apoptose: estudos in vivo e in vitro

Pós-graduação em Odontologia - FOAR

Anti-inflammatory mechanisms of the annexin A1 protein and its mimetic peptide Ac2-26 in models of ocular inflammation in vivo and in vitro

Annexin A1 (AnxA1) is a protein that displays potent anti-inflammatory properties, but its expression in eye tissue and its role in ocular inflammatory diseases have not been well studied. We investigated the mechanism of action and potential uses of AnxA1 and its mimetic peptide (Ac2-26) in the endotoxin-induced uveitis (EIU) rodent model and in human ARPE-19 cells activated by LPS. In rats, analysis of untreated EIU after 24 and 48 h or EIU treated with topical applications or with a single s.c. injection of Ac2-26 revealed the anti-inflammatory actions of Ac2-26 on leukocyte infiltration and on the release of inflammatory mediators; the systemic administration of Boc2, a formylated peptide receptor (fpr) antagonist, abrogated the peptide's protective effects. Moreover, AnxA1-/- mice exhibited exacerbated EIU compared with wild-type animals. Immunohistochemical studies of ocular tissue showed a specific AnxA1 posttranslational modification in EIU and indicated that the fpr2 receptor mediated the anti-inflammatory actions of AnxA1. In vitro studies confirmed the roles of AnxA1 and fpr2 and the protective effects of Ac2-26 on the release of chemical mediators in ARPE-19 cells. Molecular analysis of NF-κB translocation and IL-6, IL-8, and cyclooxygenase-2 gene expression indicated that the protective effects of AnxA1 occur independently of the NF-κB signaling pathway and possibly in a posttranscriptional manner. Together, our data highlight the role of AnxA1 in ocular inflammation, especially uveitis, and suggest the use of AnxA1 or its mimetic peptide Ac2-26 as a therapeutic approach. Copyright © 2013 by The American Association of Immunologists, Inc.

Protective effects of the galectin-1 protein on in vivo and in vitro models of ocular inflammation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Simulação e análise econômica da produção in vivo e in vitro de embriões em bovinos

The objective of this work was to evaluate the effect of the variables number of recipients, synchronization protocol, reproductive efficiency indicators and pregnancy cost, in the economic effectiveness of in vivo and in vitro bovine embryo production. A simulation application was elaborated to allow the user to insert the input variable parameters. A basic scenario, from the efficiency traditional rates of in vivo (ET) and in vitro production (IVP) techniques of bovine embryos, was introduced in the software as a criterion to compare the results. This software was able to reproduce both ET and IVP scenarios. The embryo production was simulated through stochastic simulation. The optimal number of recipients using sensitivity analysis was determined. The net present value and cost per pregnancy were used as a decision parameter. The synchronization for fixed-time embryo transfer decreased the recipient idleness and, consequently, the final cost of pregnancy, in comparison to the traditional methodology. Foetal sexing must be associated to IVP of bovine embryos. In addition, the optimal recipient number per donor is variable and depends on data inserted in the system.

Medium-term protocols for in vivo evaluation of chemical modifiers of carcinogenesis

Cancer development is a long-term multistep process which allows interventional measure before the clincial disease emerges. the detection of natural substances which can block the process of carcinogenesis is a important as the identification of anti-tumoral drugs since they might be used in chemoprevention of cancer in high-risk groups. In vivo rodent models of chemical caecinogenesis have been used to study plant-derived inhibitors of carcinofenesis such as indols, coumarins, isothiocyanates, flavones, phenols and allyl-sulfides. Since the standard in vivo rodent bioassay is prolonged and expensive, shorter reliable protocols are needed. Two in vivo medium-term protocols for evaluation of modifiers of carcinogenesis are presented, one related to liver and the other to bladder cancer. Both protocols use rats, last 8 and 36 weeks and are based on the two-step concept of carcinogenesis: initiation and promotion. The protocols use respectively the development of altered foci of hepatocytes expressing immunochistochemically the placental form of gluthation S-transferase and the appearence of pre-neoplastic urothelium and papillomas as the end-points. the use of these protocols for detection of plantpderived inhibitors of carcinogenesis appear warranted.

Mapping eIF5A binding sites for Dys1 and Lia1: In vivo evidence for regulation of eIF5A hypusination

The evolutionarily conserved factor eIF5A is the only protein known to undergo hypusination, a unique posttranslational modification triggered by deoxyhypusine synthase (Dys1). Although eIF5A is essential for cell viability, the function of this putative translation initiation factor is still obscure. To identify eIF5A-binding proteins that could clarify its function, we screened a two-hybrid library and identified two eIF-5A partners in S. cerevisiae: Dys1 and the protein encoded by the gene YJR070C, named Lia1 (Ligand of eIF5A). The interactions were confirmed by GST pulldown. Mapping binding sites for these proteins revealed that both eIF5A domains can bind to Dys1, whereas the C-terminal domain is sufficient to bind Lia1. We demonstrate for the first time in vivo that the N-terminal α-helix of Dys1 can modulate enzyme activity by inhibiting eIF5A interaction. We suggest that this inhibition be abrogated in the cell when hypusinated and functional eIF5A is required. © 2003 Published by Elsevier B.V. on behalf of the Federation of European Biochemical Societies.

The use of planarians as in vivo animal model to study laser biomodulation effects

A variety of effects is attributed to the photo stimulation of tissues, such as improved healing of ulcers, analgesic and anti-inflammatory effects, stimulation of the proliferation of cells of different origins and stimulation of bone repair. Some investigations that make qualitative evaluations, like wound healing and evaluation of pain and edema, can be conducted in human subjects. However, deeper investigations on the mechanisms of action of the light stimulus and other quantitative works that requires biopsies or destructive analysis has to be carried out in animal models or in cell cultures. In this work, we propose the use of planarians as a model to study laser-tissue interaction. Contrasting with cell cultures and unicellular organisms, planarians are among the simplest organism having tissue layers, central nerve system, digestive and excretory system that might have been platforms for the evolution of the complex and highly organized tissues and organs found in higher organisms. For the present study, 685 nm laser radiation was employed. Planarians were cut transversally, in a plane posterior to the auricles. The body fragments were left to regenerate and the proliferation dynamics of stem cells was studied by using histological analysis. Maximum cell count was obtained for the laser treated group at the 4th experimental day. At that experimental time, we also had the largest difference between the irradiated and the non-irradiated control group. We concluded that the studied flatworm could be an interesting animal model for in vivo studies of laser-tissue interactions.

EIF5A dimerizes not only in vitro but also in vivo and its molecular envelope is similar to the EF-P monomer

The protein eukaryotic initiation factor 5A (eIF5A) is highly conserved among archaea and eukaryotes, but not in bacteria. Bacteria have the elongation factor P (EF-P), which is structurally and functionally related to eIF5A. eIF5A is essential for cell viability and the only protein known to contain the amino acid residue hypusine, formed by post-translational modification of a specific lysine residue. Although eIF5A was initially identified as a translation initiation factor, recent studies strongly support a function for eIF5A in the elongation step of translation. However, the mode of action of eIF5A is still unknown. Here, we analyzed the oligomeric state of yeast eIF5A. First, by using size-exclusion chromatography, we showed that this protein exists as a dimer in vitro, independent of the hypusine residue or electrostatic interactions. Protein-protein interaction assays demonstrated that eIF5A can form oligomers in vitro and in vivo, in an RNA-dependent manner, but independent of the hypusine residue or the ribosome. Finally, small-angle X-ray scattering (SAXS) experiments confirmed that eIF5A behaves as a stable dimer in solution. Moreover, the molecular envelope determined from the SAXS data shows that the eIF5A dimer is L-shaped and superimposable on the tRNAPhe tertiary structure, analogously to the EF-P monomer. © 2012 Springer-Verlag.

Paracoccidoides brasiliensis 30 kDa Adhesin: Identification as a 14-3-3 Protein, Cloning and Subcellular Localization in Infection Models

Paracoccidoides brasiliensis adhesion to lung epithelial cells is considered an essential event for the establishment of infection and different proteins participate in this process. One of these proteins is a 30 kDa adhesin, pI 4.9 that was described as a laminin ligand in previous studies, and it was more highly expressed in more virulent P. brasiliensis isolates. This protein may contribute to the virulence of this important fungal pathogen. Using Edman degradation and mass spectrometry analysis, this 30 kDa adhesin was identified as a 14-3-3 protein. These proteins are a conserved group of small acidic proteins involved in a variety of processes in eukaryotic organisms. However, the exact function of these proteins in some processes remains unknown. Thus, the goal of the present study was to characterize the role of this protein during the interaction between the fungus and its host. To achieve this goal, we cloned, expressed the 14-3-3 protein in a heterologous system and determined its subcellular localization in in vitro and in vivo infection models. Immunocytochemical analysis revealed the ubiquitous distribution of this protein in the yeast form of P. brasiliensis, with some concentration in the cytoplasm. Additionally, this 14-3-3 protein was also present in P. brasiliensis cells at the sites of infection in C57BL/6 mice intratracheally infected with P. brasiliensis yeast cells for 72 h (acute infections) and 30 days (chronic infection). An apparent increase in the levels of the 14-3-3 protein in the cell wall of the fungus was also noted during the interaction between P. brasiliensis and A549 cells, suggesting that this protein may be involved in host-parasite interactions, since inhibition assays with the protein and this antibody decreased P. brasiliensis adhesion to A549 epithelial cells. Our data may lead to a better understanding of P. brasiliensis interactions with host tissues and paracoccidioidomycosis pathogenesis. © 2013 Silva et al.

In vivo analgesic activity, toxicity and phytochemical screening of the hydroalcoholic extract from the leaves of Psidium cattleianum Sabine

Ethnopharmacological relevance: Psidium cattleianum Sabine is extensively used in Brazilian traditional medicine to treat several diseases including painful disorders. Aim of the study to investigate the toxicity and the possible analgesic activities of the hydroalcoholic extract from the leaves of Psidium cattleianum Sabine (ELPCS), to support its use in folk medicine. To screen the major phytochemical constituents of this extract and evaluate their antioxidant activity. Materials and methods: ELPCS was assessed for its antioxidant activity using the DPPH model. Its analgesic activity was examined using mouse models of acetic acid-induced writhing and hot plate paw licking models. The major phytochemical constituents of the extract were screened; their toxicity on LLC-MK2 mammalian cells was evaluated. Results: ELPCS exhibited significant peripheral analgesic activity at doses of 60, 80, 100, 200 and 400 mg/kg in mice, but it did not display central analgesic activity and not was toxic to LLC-MK2 cell (LD 50>400 μg/mL). The extract exhibited free radical scavenging activity as evidenced by IC 50 values (15.9 μg/mL) obtained by the DPPH method. Phytochemical screening detected flavonoids, saponins, cardiac glycosides, anthraquinones, and tannins. Conclusions: The results of the experimental studies proved the analgesic activity of ELPCS and supported the traditional use of this plant. © 2013 Elsevier B.V. All rights reserved.

Influência do FK-506 sobre a expressão de RANKL e OPG na doença periodontal induzida: estudo in vivo e in vitro

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Criotolerância de embriões Bos Taurus Indicus e Bos Taurus Taurus produzidos in vitro e in vivo

Pós-graduação em Medicina Veterinária - FMVZ

Platelet-Rich Plasma, Low-Level Laser Therapy, or Their Combination Promotes Periodontal Regeneration in Fenestration Defects: A Preliminary In Vivo Study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Modelos in vitro e in vivo aplicados à avaliação de toxicidade e eficácia de fitocosmético: Serjania marginata Casar. (Sapindaceae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)