BackgroundThe hypothalamus plays a pivotal role in numerous mechanisms highly relevant to the maintenance of body homeostasis, such as the control of food intake and energy expenditure. Impairment of these mechanisms has been associated with the metabolic disturbances involved in the pathogenesis of obesity. Since rodent species constitute important models for metabolism studies and the rat hypothalamus is poorly characterized by proteomic strategies, we performed experiments aimed at constructing a two-dimensional gel electrophoresis (2-DE) profile of rat hypothalamus proteins.ResultsAs a first step, we established the best conditions for tissue collection and protein extraction, quantification and separation. The extraction buffer composition selected for proteome characterization of rat hypothalamus was urea 7 M, thiourea 2 M, CHAPS 4%, Triton X-100 0.5%, followed by a precipitation step with chloroform/methanol. Two-dimensional (2-D) gels of hypothalamic extracts from four-month-old rats were analyzed; the protein spots were digested and identified by using tandem mass spectrometry and database query using the protein search engine MASCOT. Eighty-six hypothalamic proteins were identified, the majority of which were classified as participating in metabolic processes, consistent with the finding of a large number of proteins with catalytic activity. Genes encoding proteins identified in this study have been related to obesity development.ConclusionThe present results indicate that the 2-DE technique will be useful for nutritional studies focusing on hypothalamic proteins. The data presented herein will serve as a reference database for studies testing the effects of dietary manipulations on hypothalamic proteome. We trust that these experiments will lead to important knowledge on protein targets of nutritional variables potentially able to affect the complex central nervous system control of energy homeostasis.

Our study shows that high-intensity RT protocol changes left ventricle proteome, modifying metabolic profile of heart tissue and inducing the expression of proteins that acts against cardiac injury. We hypothesize that these adaptations occur to prevent the onset of cardiac dysfunction. Despite highly significant, it remains to be determined whether these adaptations are sufficient to further keep left ventricle function and exert cardioprotection, and whether this panel will be shifted towards maladaptation, and heart failure.

Os dispositivos biorreabsorvíveis são alternativas para fixação interna das fraturas. Durante o tratamento estes dispositivos mantêm a fixação e degradam-se gradualmente não necessitando de uma cirurgia de remoção, reduzindo o custo de tratamento quando comparadas aos dispositivos metálicos. O objetivo desse trabalho foi estudar a interação polímero/tecido utilizando pinos de PLGA e PDS após implantes em coelhos Nova Zelândia. Separou-se os animais em 3 grupos os quais foram sacrificados após 3, 6 e 12 semanas de implantação e o material obtido foi submetido à análise histológica. As análises histológicas com implantes de PLGA mostraram após 3 semanas a formação de um tecido com características mesenquimatosas e com 12 semanas a formação de uma estrutura óssea madura. Já nos implantes de PDS de 3 semanas houve uma maior invasão de tecido mesenquimal comparado ao PLGA e após 12 semanas, ocorreu uma degradação avançada, com tecido proliferativo mesenquimal e ósseo. Assim, concluiu-se que ocorreram resultados positivos à resposta tecidual/implante e foi relevante a observação da ausência de células responsáveis pela resposta inflamatória. As análises demonstraram que o copolímero de PLGA apresentou propriedades osteoindutivas mais adequadas que os de PDS, apresentando biocompatibilidade aceitável para aplicação ortopédica.

Background/Aims: Nephrotoxicity is a prominent component of the profile of chemotherapeutic agents and to date proteomics has represented the main technique to identify protein profiles in response to xenobiotic exposure. Methods: We made use of two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight analysis to evaluate chemotoxicity effects of cisplatin (CPT) and carboplatin (CB) on proteins from human renal proximal tubule epithelial cells (HK-2). Results: Tandem mass spectrometry analysis showed that ATP synthase subunit α and serine hydroxymethyltransferase were only expressed in HK-2 cells exposed to CPT. Since CPT causes damage in cellular respiration, we suggest that this might be a protective adaptation to CPT-induced nephrotoxicity. Thioredoxin-dependent peroxide reductase disappeared in the CPT group and was upregulated in the CB group, suggesting that CB exposure stimulates preventive apoptotic mechanisms. We suggest a relationship between chemotherapeutic agent-induced nephrotoxicity and cell respiration. The identification of proteins differentially expressed in HK-2 cells, when exposed to CPT and CB, not only supplies important information to understand the molecular action mechanisms, which are triggered by metal-based drugs in cell nephrotoxicity, but also can lead to the design of more effective anticancer drugs. Conclusion: These results provide important insights into the investigation of possible biomarker(s) of toxicity that could eventually reduce the side effects of chemotherapeutic agents.

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Proteomic techniques are a powerful tool in nephrology research and allows the identification of important biomarkers. Using two‐dimensional polyacrilamide gel electrophoresis (2‐DE), we identified an alteration of protein expression in human renal tubular epithelial cells (HK‐2) induced by the treatment with anticancer drugs. HK‐2 were randomized in control (CT‐not treated), cisplatin (CPT‐100 µM) and carboplatin (CB‐50 µM). Sample protein (500 µg) was applied to a IPG strip (pH 3.0‐ 10.0), and electrophoresis ran under denaturing conditions. Gels were stained with coomassie G‐250, scanned and analysed by PdQuest software. Analysis showed a total of 124 spots in CT, 122 in CPT and 127 in CB. Using quantitative analysis (minimum difference of 5x expression between CT and treated groups) we identified a down‐regulation of 8 spots between CT and CPT groups, and also a down‐regulation of 12 spots of CPT and CB, compared with CT group. There was an up‐regulation of spots on CB and CPT groups (14 and 12 spots, respectively) compared with CT, and there was a correpondence on the up‐regulation of 11 spots, between both treatments and CT. Qualitative analysis (100x background) showed that some proteins are only expressed on CT (5 spots), CPT (12 spots) or CB (7 spots) groups. Our results, show that the treatment with anticancer drugs may induce alterations on protein expression in renal cells, which may be related to chemotherapy nephrotoxicity. The identification of these proteins may bring important information for new drug development.Financial support: Fapesp

Kidney transplant is the best treatment for patients with end stage renal failure. Acute rejection (AR) is the major impediment to success in renal transplantation. We aimed to identify biomarkers candidates for acute renal rejection using plasma using LC‐MSE.Analysis was performed with plasma from 25 renal transplant patients with stable renal graft function ‐ control group (Ct) ‐ and 9 patients with acute graft rejection ‐ rejection group (Rej).We have detected 19 proteins overexpressed in the Rej group compared to Ct group, 02 proteins were underexpressed and 04 that were present only in the Rej group. Among the 19 overexpressed proteins we have selected 03 candidates for AR biomarkers in this model of renal graft. This overexpression was confirmed by Western Blotting. They are: alpha‐1 antitrypsin (A1AT) also known as SERPIN1, alpha‐2 antiplasmin (A2AP) called SERPINF2 and serum amyloid A (SAA). These proteins are involved in the acute phase response and are strongly associated among itself. With this study we identified a number of new targets in plasma that can be used in the future to monitor the patient. These proteins may be validated in the future as markers of acute rejection in renal transplantation. This is the first study using the technique of LC‐MSE to investigate proteomic changes in plasma of kidney transplant patients. (Supported Fapesp).

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