Publications by authors named "Richard Hemmi Valente"

Metabolic reprogramming is a ubiquitous feature of transformed cells, comprising one of the hallmarks of cancer and enabling neoplastic cells to adapt to new environments. Accumulated evidence reports on the failure of some neoplastic cells to convert mannose-6-phosphate into fructose-6-phosphate, thereby impairing tumor growth in cells displaying low levels of mannose-6-phosphate isomerase (MPI). Thus, we performed functional analyses and profiled the proteome landscape and the repertoire of substrates of proteases (degradome) of melanoma cell lines with distinct mutational backgrounds submitted to treatment with mannose.

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Monoxenous trypanosomatid Strigomonas culicis harbors an endosymbiotic bacterium, which enables the protozoa to survive without heme supplementation. The impact of HO resistance and symbiont elimination on intracellular heme and Fe availability was analyzed through a comparison of WT strain with both WT HO-resistant (WTR) and aposymbiotic (Apo) protozoa. The relative quantification of the heme biosynthetic pathway through label-free parallel reaction monitoring targeted mass spectrometry revealed that HO resistance does not influence the abundance of tryptic peptides.

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Article Synopsis
  • Histoplasmosis is a serious fungal infection that can be life-threatening for people with HIV/AIDS and those with weakened immune systems, and current treatments can have harmful drug interactions and side effects.
  • A study evaluated mebendazole, an existing drug, to see if it could effectively kill or inhibit histoplasmosis fungi, finding it inhibited the growth of multiple strains at low concentrations.
  • Proteomics analysis showed that mebendazole treatment altered protein profiles in yeast, impacting metabolic processes and suggesting it could be a promising option for treating histoplasmosis.
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Complex protein mixtures typically generate many tandem mass spectra produced by different peptides coisolated in the gas phase. Widely adopted proteomic data analysis environments usually fail to identify most of these spectra, succeeding at best in identifying only one of the multiple cofragmenting peptides. We present PatternLab V (PLV), an updated version of PatternLab that integrates the YADA 3 deconvolution algorithm to handle such cases efficiently.

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contains seeds with a high oil content, suitable for biodiesel production. After oil extraction, the remaining mass can be a rich source of enzymes. However, data from the literature describing physicochemical characteristics for a monomeric esterase from the seed did not fit the electrostatic catapult model for esterases/lipases.

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Sepsis results from a dyshomeostatic response to infection, which may lead to hyper or hypoimmune states. Monocytes are central regulators of the inflammatory response, but our understanding of their role in the genesis and resolution of sepsis is still limited. Here, we report a comprehensive exploration of monocyte molecular responses in a cohort of patients with septic shock via proteomic profiling.

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In proteomics, the identification of peptides from mass spectral data can be mathematically described as the partitioning of mass spectra into clusters (i.e., groups of spectra derived from the same peptide).

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Species of the genus cause a systemic infection in human patients. Yeast cells of spp. produce melanin in the presence of L-dihydroxyphenylalanine and during infection, which may impact the pathogen's survival in the host.

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Histoplasmosis is one of the most frequent systemic mycosis in HIV patients. In these patients, histoplasmosis has high rates of morbidity/mortality if diagnosis and treatment are delayed. Despite its relevance, there is a paucity of information concerning the interaction between and the human host, especially regarding the B-cell response, which has a direct impact on the diagnosis.

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During their life cycle, trypanosomatids are exposed to stress conditions and adapt their energy and antioxidant metabolism to colonize their hosts. Strigomonas culicis is a monoxenous protist found in invertebrates with an endosymbiotic bacterium that completes essential biosynthetic pathways for the trypanosomatid. Our research group previously generated a wild-type HO-resistant (WTR) strain that showed improved mitochondrial metabolism and antioxidant defenses, which led to higher rates of Aedes aegypti infection.

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Background: Worldwide, breast cancer is the main cause of cancer mortality in women. Most cases originate in mammary ductal cells that produce the nipple aspirate fluid (NAF). In cancer patients, this secretome contains proteins associated with the tumor microenvironment.

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Background: -Glucosidases are components of the cellulase system, a family of enzymes that hydrolyze the -1,4 linkages of cellulose. These proteins have been extensively studied due to the possibility of their use in various biotechnological processes. They have different affinities for substrates (depending on their source) and their activities can be used for saccharification of different types of biomass.

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Despite numerous studies concerning morphology and venom production and secretion in the main venom gland (and some data on the accessory gland) of the venom glandular apparatus of Viperidae snakes, the primary duct has been overlooked. We characterized the primary duct of the snake by morphological analysis, immunohistochemistry and proteomics. The duct has a pseudostratified epithelium with secretory columnar cells with vesicles of various electrondensities, as well as mitochondria-rich, dark, basal, and horizontal cells.

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Snake venoms are sources of molecules with proven and potential therapeutic applications. However, most activities assayed in venoms (or their components) are of hemorrhagic, hypotensive, edematogenic, neurotoxic or myotoxic natures. Thus, other relevant activities might remain unknown.

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Unlabelled: In Viperidae snakes, it has been attributed to the main venom gland, a component of the venom gland apparatus, the function of synthesizing all venom toxins and storing them inside a basal-central lumen. However, the role of the accessory gland is still unknown. Here, we analyzed the proteome and the transcriptome of the accessory gland during venom production and secretion cycle.

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Primary culture of snake venom gland secretory cells could be a good model to study the mechanism(s) of toxin(s) production. These cells can produce and secrete venom to the medium with a hemorrhagic activity comparable to that induced by venom collected from snakes. Production of new venom is triggered by the sympathetic outflow, through the release of noradrenaline, but the importance of this neurotransmitter on toxin synthesis has not been addressed.

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Background: The obligate intracellular protozoan Trypanosoma cruzi is the causative agent of Chagas disease, a neglected illness affecting millions of people in Latin America that recently entered non-endemic countries through immigration, as a consequence of globalization. The chemotherapy for this disease is based mainly on benznidazole and nifurtimox, which are very efficient nitroderivatives against the acute stage but present limited efficacy during the chronic phase. Our group has been studying the trypanocidal effects of naturally occurring quinones and their derivatives, and naphthoimidazoles derived from β-lapachone N1, N2 and N3 were the most active.

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Background: Lung inflammation is a major consequence of the systemic inflammatory response caused by severe sepsis. Increased migration of γδ T lymphocytes into the lungs has been previously demonstrated during experimental sepsis; however, the involvement of the γδ T cell subtype Vγ4 has not been previously described.

Methods: Severe sepsis was induced by cecal ligation and puncture (CLP; 9 punctures, 21G needle) in male C57BL/6 mice.

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Unlabelled: NAF is a breast fluid that is closely related to the tumor microenvironment and a valuable sample for studying breast cancer. To perform an in-depth proteomic analysis of this sample, aliquots of a single NAF digest were analyzed by the following peptide-centric fractionation strategies: a) 30-cm reversed-phase (RP) column on-line with an LTQ-Orbitrap XL; b) off-line strong cation-exchange (SCX) column; and c) pI-based OFFGEL fractionation. All fractions from approaches (b) and (c) were further analyzed on a 10-cm RP column hyphenated to the same mass spectrometer.

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Unlabelled: Chagas disease is a neglected disease, caused by the protozoan Trypanosoma cruzi. This kinetoplastid presents a cycle involving different forms and hosts, being trypomastigotes the main infective form. Despite various T.

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Breast cancer is the leading cause of cancer related deaths in women. Most breast cancers stem from mammary ductal cells that secrete nipple aspirate fluid (NAF), a biological sample that contains proteins associated with the tumor microenvironment. In this study, NAF samples from both breasts of 7 Brazilian patients with unilateral breast cancer were analyzed.

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Unlabelled: Viperidae venom glands have a basal-central lumen where the venom produced by secretory cells is stored. We have shown that the protein composition of venom gland changes during the venom production cycle. Here, we analyzed the venom gland proteins during the venom production cycle by proteomic approach.

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Angiostrongylus costaricensis is a nematode that causes abdominal angiostrongyliasis, a widespread human parasitism in Latin America. This study aimed to characterize the protease profiles of different developmental stages of this helminth. First-stage larvae (L1) were obtained from the faeces of infected Sigmodon hispidus rodents and third-stage larvae (L3) were collected from mollusks Biomphalaria glabrata previously infected with L1.

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Excessive training (i.e. overtraining, OT) may result in underperformance, which can be characterized by the time needed to re-establish performance (i.

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