Sleep deprivation impairs calcium signaling in mouse splenocytes and leads to a decreased immune response

Background: Sleep is a physiological event that directly influences health by affecting the immune system, in which calcium (Ca2+) plays a critical signaling role. We performed live cell measurements of cytosolic Ca2+ mobilization to understand the changes in Ca2+ signaling that occur in splenic immune cells after various periods of sleep deprivation (SD).Methods: Adult male mice were subjected to sleep deprivation by platform technique for different periods (from 12 to 72 h) and Ca2+ intracellular fluctuations were evaluated in splenocytes by confocal microscopy. We also performed spleen cell evaluation by flow cytometry and analyzed intracellular Ca2+ mobilization in endoplasmic reticulum and mitochondria. Additionally. Ca2+ channel gene expression was evaluatedResults: Splenocytes showed a progressive loss of intracellular Ca2+ maintenance from endoplasmic reticulum (ER) stores. Transient Ca2+ buffering by the mitochondria was further compromised. These findings were confirmed by changes in mitochondrial integrity and in the performance of the store operated calcium entry (SOCE) and stromal interaction molecule 1 (STIM1) Ca2+ channels.Conclusions and general significance: These novel data suggest that SD impairs Ca2+ signaling, most likely as a result of ER stress, leading to an insufficient Ca2+ supply for signaling events. Our results support the previously described immunosuppressive effects of sleep loss and provide additional information on the cellular and molecular mechanisms involved in sleep function. (C) 2012 Elsevier B.V. All rights reserved.AFIP (Associacao Fundo de Incentivo a Pesquisa)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo UNIFESP, Dept Psychobiol, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Dept Biosci, Santos, SP, BrazilUniversidade Federal de São Paulo UNIFESP, Dept Biochem, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Dept Psychobiol, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Dept Biosci, Santos, SP, BrazilUniversidade Federal de São Paulo UNIFESP, Dept Biochem, São Paulo, BrazilFAPESP: 05/04366-3FAPESP: CEPID 98/14303-6Web of Scienc

Metabolites from Marine Sponges and Their Potential to Treat Malarial Protozoan Parasites Infection: A Systematic Review

Malaria is an infectious disease caused by protozoan parasites of the Plasmodium genus through the bite of female Anopheles mosquitoes, affecting 228 million people and causing 415 thousand deaths in 2018. Artemisinin-based combination therapies (ACTs) are the most recommended treatment for malaria; however, the emergence of multidrug resistance has unfortunately limited their effects and challenged the field. In this context, the ocean and its rich biodiversity have emerged as a very promising resource of bioactive compounds and secondary metabolites from different marine organisms. This systematic review of the literature focuses on the advances achieved in the search for new antimalarials from marine sponges, which are ancient organisms that developed defense mechanisms in a hostile environment. The principal inclusion criterion for analysis was articles with compounds with IC50 below 10 µM or 10 µg/mL against P. falciparum culture. The secondary metabolites identified include alkaloids, terpenoids, polyketides endoperoxides and glycosphingolipids. The structural features of active compounds selected in this review may be an interesting scaffold to inspire synthetic development of new antimalarials for selectively targeting parasite cell metabolism

PVALB diminishes [Ca2+] and alters mitochondrial features in follicular thyroid carcinoma cells through AKT/GSK3 beta pathway

We have identified previously a panel of markers (C1orf24, ITM1 and PVALB) that can help to discriminate benign from malignant thyroid lesions. C1orf24 and ITM1 are specifically helpful for detecting a wide range of thyroid carcinomas, and PVALB is particularly valuable for detecting the benign Hurthle cell adenoma . Although these markers may ultimately help patient care, the current understanding of their biological functions remains largely unknown. In this article, we investigated whether PVALB is critical for the acquisition of Hurthle cell features and explored the molecular mechanism underlying the phenotypic changes. Through ectopic expression of PVALB in thyroid carcinoma cell lines (FTC-133 and WRO), we demonstrated that PVALB sequesters free cytoplasmic Ca-2+,Ca- which ultimately lowers calcium levels and precludes endoplasmic reticulum (ER) Ca2+ refilling. These results were accompanied by induced expression of PERK, an ER stress marker. Additionally, forced expression of PVALB reduces Ca2+ inflow in the mitochondria, which can in turn cause changes in mitochondria morphology, increase mitochondria number and alter subcellular localization. These findings share striking similarity to those observed in Hurthle cell tumors. Moreover, PVALB inhibits cell growth and induces cell death, most likely through the AKT/GSK-3 beta. Finally, PVALB expression coincides with Ca2+ deposits in HCA tissues. Our data support the hypothesis that the loss of PVALB plays a role in the pathogenesis of thyroid tumors.Sao Paulo State Research Foundation - FAPESP [2013/03867-5, 2014/06570-6, 2009/54598-9]Brazilian Research Council (CNPq)FAPESPCNPqUniv Fed Sao Paulo, Dept Morphol & Genet, Div Genet, Genet Bases Thyroid Tumors Lab, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Biophys, Enzymol Lab, Sao Paulo, BrazilInst Biol, Ctr Res & Dev Anim Hlth, Lab Electron Microscopy, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Pathol, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Biosci, Cell Signaling Lab Plasmodium, Santos, SP, BrazilUniv Fed Sao Paulo, Dept Morphol & Genet, Div Genet, Genet Bases Thyroid Tumors Lab, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Biophys, Enzymol Lab, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Pathol, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Biosci, Cell Signaling Lab Plasmodium, Santos, SP, BrazilFAPESP:2013/03867-52014/06570-62009/54598-9Web of Scienc

Cysteine-protease activity elicited by Ca2+ stimulus in Plasmodium

Bloodstage malaria parasites require proteolytic activity for key processes as invasion, hemoglobin degradation and merozoite escape from red blood cells (RBCs). We investigated by confocal microscopy the presence of cysteine-protease activity elicited by calcium stimulus in Plasmodium chabaudi and Plasmodium falciparum in free trophozoites or for the later parasite within RBC using fluorescence resonance energy transfer (FRET) peptides. Peptide probes access, to either free or intraerythrocytic parasites, was also tested by selecting a range of fluorescent peptides (653-3146 Da molecular mass) labeled with Abz or FITC. in the present work we show that Ca2+ stimulus elicited by treatment with either melatonin, thapsigargin, ionomicin or nigericin, promotes an increase of substrate hydrolysis, which was blocked by the specific cysteine-protease inhibitor E-64 and the intracellular Ca2+ chelator, BAPTA. When parasites were treated with cytoplasmic Ca2+ releasing compounds, a cysteine-protease was labeled in the parasite cytoplasm by the fluorescent specific irreversible inhibitor, Ethyl-Eps-Leu-Tyr-Cap-Lys(Abz)-NH2, where Ethyl-Eps is Ethyl-(2S,3S)-oxirane-2,3-dicarboxylate. in summary, we demonstrate that P. chabaudi and P. falciparum have a cytoplasmic dependent cysteine-protease activity elicited by Ca2+. (c) 2005 Elsevier B.V. All rights reserved.Univ São Paulo, Inst Biociencias, Dept Physiol, BR-05508900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biophys, Escola Paulista Med, São Paulo, BrazilUniv São Paulo, Inst Ciencias Biomed, Dept Parasitol, BR-05508900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biophys, Escola Paulista Med, São Paulo, BrazilWeb of Scienc