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1.
AACE Clin Case Rep ; 9(4): 136-139, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37520756

RESUMO

Background/Objective: Sodium-glucose cotransporter-2 (SGLT2) inhibitors are part of the treatment for hyperglycemia in patients with diabetes. These drugs have shown important benefits including cardiovascular and renal protection among people with diabetes. Case Report: We report a case of a 60-year-old woman with diabetes who presented to the emergency department complaining of left flank pain radiating to the groin. The patient was on multiple antidiabetic medications, including a recently added empagliflozin, considering the difficulty in controlling hyperglycemia. She quickly developed severe sepsis with shock, and imaging studies of the abdomen revealed the presence of encapsulated gas in the left kidney compatible with emphysematous pyelonephritis (EPN). There was no presence of nephrolithiasis or other anatomical or structural abnormality that could have precipitated this focal renal infection.Besides antimicrobials, fluid resuscitation, and vasopressor agents, an emergent surgical nephrectomy, as well as intensive care, was required until the patient fully recovered. Escherichia coli was isolated from the initial blood cultures, and ceftriaxone was administered. The patient was subsequently discharged home in stable condition. Two months later, the patient was readmitted with near-syncope and abdominal pain, which was found to be related to small bowel obstruction. The patient decompensated rapidly and had a cardiac arrest even before surgical evaluation. She was resuscitated and admitted to the intensive care unit but showed no signs of neurologic recovery after the anoxic event. She did not survive this hospitalization. Discussion: The exposure of SGLT2 inhibitors in this patient seemed to have been the precipitating factor for development of complicated pyelonephritis with gas gangrene. EPN is a consequence of a severe renal parenchymal infection, which carries high mortality even with prompt treatment. Conclusion: Use of SGLT2 inhibitors has expanded worldwide as there are clear clinical benefits, but we need to recognize their uncommon yet potentially fatal complications, such as EPN.

2.
Biochim Biophys Acta Mol Cell Res ; 1868(6): 119000, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33675851

RESUMO

A dimer of the heat-shock protein of 90-kDa (Hsp90) represents the critical core of the chaperone complex associated to the glucocorticoid receptor (GR) oligomer. The C-terminal end of the Hsp90 dimer shapes a functional acceptor site for co-chaperones carrying tetratricopeptide repeat (TPR) domains, where they bind in a mutually exclusive and competitive manner. They impact on the biological properties of the GR•Hsp90 complex and are major players of the GR transport machinery. Recently, we showed that the overexpression of a chimeric TPR peptide influences the subcellular distribution of GR. In this study, the functional role of endogenous proteins carrying TPR or TPR-like sequences on GR subcellular distribution was characterized. It is demonstrated that, contrarily to the positive influence of FKBP52 on GR nuclear accumulation, FKBP51 and 14-3-3 impaired this property. While SGT1α showed no significant effect, the overexpression of the Ser/Thr phosphatase PP5 resulted in a nearly equal nuclear-cytoplasmic redistribution of GR rather than its typical cytoplasmic localization in the absence of steroid. This observation led to analyse the influence of the phosphorylation status of GR, which resulted not linked to its nucleo-cytoplasmic shuttling mechanism. Nonetheless, it was evidenced that both PP5 and FKBP52 are related to the anchorage of the GR to nucleoskeleton structures. The influence of these TPR domain proteins on the steroid-dependent transcriptional activity of GR was also characterized. It is postulated that the pleiotropic actions of the GR in different cell types may be the consequence of the relative abundance of different TPR-domain interacting co-chaperones.


Assuntos
Núcleo Celular/metabolismo , Citoplasma/metabolismo , Chaperonas Moleculares/química , Chaperonas Moleculares/metabolismo , Receptores de Glucocorticoides/metabolismo , Regulação da Expressão Gênica , Células HEK293 , Humanos , Ligação Proteica , Domínios Proteicos , Transporte Proteico , Receptores de Glucocorticoides/genética , Repetições de Tetratricopeptídeos
3.
J Hazard Mater ; 408: 124832, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33421850

RESUMO

A laboratory-scale horizontal subsurface flow constructed wetland system was used to quantify the arsenic removal capacity in the treatment of highly acidic, arsenic and metal-rich water: pH ≈ 2, Fe ≈ 57 mg/L, Pb ≈ 0.9 mg/L, Zn ≈ 12 mg/L. The system was operated in two stages, being As ≈ 2.1 mg/L in stage one, and ≈ 3.7 mg/L in stage 2. Limestone and zeolite were employed as main supporting media to build non-vegetated and vegetated cells with Phragmites australis. The system was very effective in the removal of arsenic and iron (> 96%), and lead (> 94%) throughout the whole experimental period, having the four treatment types a similar performance. The main effect of the media type was on the pH adjustment capacity: limestone cells were able to raise the pH to ≈ 7.1, whereas zeolite cells raised it to ≈ 3.8. The contribution of plant uptake to the overall removal of As, Fe and Zn was minor; accounting for less than 0.02%, 0.07% and 0.7% respectively. As such, pollutants were mainly retained in the wetland beds. Our results suggest that limestone is recommended over zeolite as wetland medium mainly due to its neutralization capacity.

4.
Nat Commun ; 11(1): 5975, 2020 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-33239621

RESUMO

Hop/Stip1/Sti1 is thought to be essential as a co-chaperone to facilitate substrate transfer between the Hsp70 and Hsp90 molecular chaperones. Despite this proposed key function for protein folding and maturation, it is not essential in a number of eukaryotes and bacteria lack an ortholog. We set out to identify and to characterize its eukaryote-specific function. Human cell lines and the budding yeast with deletions of the Hop/Sti1 gene display reduced proteasome activity due to inefficient capping of the core particle with regulatory particles. Unexpectedly, knock-out cells are more proficient at preventing protein aggregation and at promoting protein refolding. Without the restraint by Hop, a more efficient folding activity of the prokaryote-like Hsp70-Hsp90 complex, which can also be demonstrated in vitro, compensates for the proteasomal defect and ensures the proteostatic equilibrium. Thus, cells may act on the level and/or activity of Hop to shift the proteostatic balance between folding and degradation.


Assuntos
Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Proteínas de Choque Térmico/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Células A549 , Técnicas de Inativação de Genes , Células HCT116 , Células HEK293 , Proteínas de Choque Térmico HSP90/genética , Proteínas de Choque Térmico/genética , Humanos , Mutagênese Sítio-Dirigida , Mutação , Complexo de Endopeptidases do Proteassoma/metabolismo , Agregados Proteicos , Dobramento de Proteína , Proteólise , Proteínas de Saccharomyces cerevisiae/genética
5.
J Cell Sci ; 133(12)2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32467326

RESUMO

It has been demonstrated that tetratricopeptide-repeat (TPR) domain proteins regulate the subcellular localization of glucocorticoid receptor (GR). This study analyses the influence of the TPR domain of high molecular weight immunophilins in the retrograde transport and nuclear retention of GR. Overexpression of the TPR peptide prevented efficient nuclear accumulation of the GR by disrupting the formation of complexes with the dynein-associated immunophilin FKBP52 (also known as FKBP4), the adaptor transporter importin-ß1 (KPNB1), the nuclear pore-associated glycoprotein Nup62 and nuclear matrix-associated structures. We also show that nuclear import of GR was impaired, whereas GR nuclear export was enhanced. Interestingly, the CRM1 (exportin-1) inhibitor leptomycin-B abolished the effects of TPR peptide overexpression, although the drug did not inhibit GR nuclear export itself. This indicates the existence of a TPR-domain-dependent mechanism for the export of nuclear proteins. The expression balance of those TPR domain proteins bound to the GR-Hsp90 complex may determine the subcellular localization and nucleocytoplasmic properties of the receptor, and thereby its pleiotropic biological properties in different tissues and cell types.


Assuntos
Receptores de Glucocorticoides , Repetições de Tetratricopeptídeos , Transporte Ativo do Núcleo Celular , Núcleo Celular/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Poro Nuclear/metabolismo , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo , Proteínas de Ligação a Tacrolimo/genética , Proteínas de Ligação a Tacrolimo/metabolismo
6.
Nat Commun ; 10(1): 1833, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-31015428

RESUMO

In response to extracellular signals, many signalling proteins associated with the plasma membrane are sorted into endosomes. This involves endosomal fusion, which depends on the complexes HOPS and CORVET. Whether and how their subunits themselves modulate signal transduction is unknown. We show that Vps11 and Vps18 (Vps11/18), two common subunits of the HOPS/CORVET complexes, are E3 ubiquitin ligases. Upon overexpression of Vps11/Vps18, we find perturbations of ubiquitination in signal transduction pathways. We specifically demonstrate that Vps11/18 regulate several signalling factors and pathways, including Wnt, estrogen receptor α (ERα), and NFκB. For ERα, we demonstrate that the Vps11/18-mediated ubiquitination of the scaffold protein PELP1 impairs the activation of ERα by c-Src. Thus, proteins involved in membrane traffic, in addition to performing their well-described role in endosomal fusion, fine-tune signalling in several different ways, including through ubiquitination.


Assuntos
Proteínas Correpressoras/metabolismo , Endossomos/metabolismo , Fatores de Transcrição/metabolismo , Complexos Ubiquitina-Proteína Ligase/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Proteína Tirosina Quinase CSK , Receptor alfa de Estrogênio/metabolismo , Células HEK293 , Humanos , Células MCF-7 , NF-kappa B/metabolismo , Transdução de Sinais/fisiologia , Ubiquitinação/fisiologia , Proteínas Wnt/metabolismo , Quinases da Família src/metabolismo
7.
PLoS One ; 14(2): e0208287, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30726209

RESUMO

The molecular chaperone Hsp90 is an essential and highly abundant central node in the interactome of eukaryotic cells. Many of its large number of client proteins are relevant to cancer. A hallmark of Hsp90-dependent proteins is that their accumulation is compromised by Hsp90 inhibitors. Combined with the anecdotal observation that cancer cells may be more sensitive to Hsp90 inhibitors, this has led to clinical trials aiming to develop Hsp90 inhibitors as anti-cancer agents. However, the sensitivity to Hsp90 inhibitors has not been studied in rigorously matched normal versus cancer cells, and despite the discovery of important regulators of Hsp90 activity and inhibitor sensitivity, it has remained unclear, why cancer cells might be more sensitive. To revisit this issue more systematically, we have generated an isogenic pair of normal and oncogenically transformed NIH-3T3 cell lines. Our proteomic analysis of the impact of three chemically different Hsp90 inhibitors shows that these affect a substantial portion of the oncogenic program and that indeed, transformed cells are hypersensitive. Targeting the oncogenic signaling pathway reverses the hypersensitivity, and so do inhibitors of DNA replication, cell growth, translation and energy metabolism. Conversely, stimulating normal cells with growth factors or challenging their proteostasis by overexpressing an aggregation-prone sensitizes them to Hsp90 inhibitors. Thus, the differential sensitivity to Hsp90 inhibitors may not stem from any particular intrinsic difference between normal and cancer cells, but rather from a shift in the balance between cellular quiescence and activity.


Assuntos
Antineoplásicos/farmacologia , Carcinogênese/efeitos dos fármacos , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Animais , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , Humanos , Camundongos , Chaperonas Moleculares/genética , Células NIH 3T3 , Proto-Oncogenes/genética , Transdução de Sinais/efeitos dos fármacos
8.
Adv Cancer Res ; 129: 1-30, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26915999

RESUMO

The molecular chaperone Hsp90 has attracted a lot of interest in cancer research ever since cancer cells were found to be more sensitive to Hsp90 inhibition than normal cells. Why that is has remained a matter of debate and is still unclear. In addition to increased Hsp90 dependence for some mutant cancer proteins and modifications of the Hsp90 machinery itself, a number of other characteristics of cancer cells probably contribute to this phenomenon; these include aneuploidy and overall increased numbers and levels of defective and mutant proteins, which all contribute to perturbed proteostasis. Work over the last two decades has demonstrated that many cancer-related proteins are Hsp90 clients, and yet only few of them have been extensively investigated, selected either on the basis of their obvious function as cancer drivers or because they proved to be convenient biomarkers for monitoring the effects of Hsp90 inhibitors. The purpose of our review is to go beyond these "usual suspects." We established a workflow to select poorly studied proteins that are related to cancer processes and qualify as Hsp90 clients. By discussing and taking a fresh look at these "unusual suspects," we hope to stimulate others to revisit them as novel therapeutic targets or diagnostic markers.


Assuntos
Carcinogênese/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Chaperonas Moleculares/metabolismo , Neoplasias/metabolismo , Fatores de Transcrição/metabolismo , Fator Apoptótico 1 Ativador de Proteases/metabolismo , Biomarcadores Farmacológicos/metabolismo , Proteínas de Ciclo Celular/metabolismo , DNA (Citosina-5-)-Metiltransferase 1 , DNA (Citosina-5-)-Metiltransferases/metabolismo , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Carioferinas/metabolismo , Neoplasias/terapia , Proteínas Oncogênicas/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , RecQ Helicases/genética , RecQ Helicases/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Proteínas Repressoras/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Proteína Exportina 1
9.
Mol Cell Biol ; 36(8): 1310-21, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26884463

RESUMO

Hsp90 is the ATP-consuming core component of a very abundant molecular chaperone machine that handles a substantial portion of the cytosolic proteome. Rather than one machine, it is in fact an ensemble of molecular machines, since most mammalian cells express two cytosolic isoforms of Hsp90 and a subset of up to 40 to 50 cochaperones and regulate their interactions and functions by a variety of posttranslational modifications. We demonstrate that the Hsp90 ensemble is fundamentally remodeled during muscle differentiation and that this remodeling is not just a consequence of muscle differentiation but possibly one of the drivers to accompany and to match the vast proteomic changes associated with this process. As myoblasts differentiate into myotubes, Hsp90α disappears and only Hsp90ß remains, which is the only isoform capable of interacting with the novel muscle-specific Hsp90 cochaperone Aarsd1L. Artificially maintaining Hsp90α or knocking down Aarsd1L expression interferes with the differentiation of C2C12 myotubes. During muscle differentiation, Aarsd1L replaces the more ubiquitous cochaperone p23 and in doing so dampens the activity of the glucocorticoid receptor, one of the Hsp90 clients relevant to muscle functions. This cochaperone switch protects muscle cells against the inhibitory effects of glucocorticoids and may contribute to preventing muscle wasting induced by excess glucocorticoids.


Assuntos
Alanina-tRNA Ligase/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Desenvolvimento Muscular , Alanina-tRNA Ligase/genética , Animais , Linhagem Celular , Expressão Gênica , Humanos , Camundongos , Fibras Musculares Esqueléticas/citologia , Fibras Musculares Esqueléticas/metabolismo
10.
Oncotarget ; 7(6): 6552-65, 2016 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-26735887

RESUMO

Runx1 participation in epithelial mammary cells is still under review. Emerging data indicates that Runx1 could be relevant for breast tumor promotion. However, to date no studies have specifically evaluated the functional contribution of Runx1 to control gene expression in mammary epithelial tumor cells. It has been described that Runx1 activity is defined by protein context interaction. Interestingly, Foxp3 is a breast tumor suppressor gene. Here we show that endogenous Runx1 and Foxp3 physically interact in normal mammary cells and this interaction blocks Runx1 transcriptional activity. Furthermore we demonstrate that Runx1 is able to bind to R-spondin 3 (RSPO3) and Gap Junction protein Alpha 1 (GJA1) promoters. This binding upregulates Rspo3 oncogene expression and downregulates GJA1 tumor suppressor gene expression in a Foxp3-dependent manner. Moreover, reduced Runx1 transcriptional activity decreases tumor cell migration properties. Collectively, these data provide evidence of a new mechanism for breast tumor gene expression regulation, in which Runx1 and Foxp3 physically interact to control mammary epithelial cell gene expression fate. Our work suggests for the first time that Runx1 could be involved in breast tumor progression depending on Foxp3 availability.


Assuntos
Adenocarcinoma/metabolismo , Neoplasias da Mama/metabolismo , Conexina 43/metabolismo , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Regulação Neoplásica da Expressão Gênica , Trombospondinas/metabolismo , Adenocarcinoma/genética , Adenocarcinoma/patologia , Animais , Apoptose , Western Blotting , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Movimento Celular , Proliferação de Células , Imunoprecipitação da Cromatina , Feminino , Imunofluorescência , Humanos , Técnicas Imunoenzimáticas , Imunoprecipitação , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Confocal , Microscopia de Fluorescência , Regiões Promotoras Genéticas/genética , Células Tumorais Cultivadas , Cicatrização , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Biochem J ; 467(1): 77-90, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25588078

RESUMO

Mitogen-activated protein kinase (MAPK) pathways constitute key regulatory elements linking extracellular stimuli to nuclear gene expression. Immediate-early responsive genes (IEGs) of the activator protein 1 (AP-1) family, such as fos, achieve peak expression levels shortly after cells are stimulated with growth factors and sharply decrease thereafter. Several AU-rich binding proteins (AUBPs), including HuR (Hu-antigen R, Elav-like protein 1, ELAVL1) and KSRP (far upstream element-binding protein 2, KHSRP) bind to a fos AU-rich element (ARE) present in the 3'-UTR (untranslated region) of fos mRNA regulating its stability by a still poorly defined mechanism. We show in the present study that, whereas HuR binds and stabilizes transcribed reporter mRNAs bearing the fos 3'-UTR, KSRP counteracts this effect. Furthermore, we found that fos mRNA stability and HuR phosphorylation status are dependent on the activity of p38 MAPK in both epithelial cells and fibroblasts upon proliferative stimulation. Analysing PPI (protein-protein interaction) networks, we performed a thorough query of interacting proteins for p38 MAPKs, HuR and other AUBPs upon growth factor stimulation. This revealed novel HuR interactors including inhibitors of protein phosphatase 2 (PP2A) activity. Over-expression of two of these interactors, pp32 and APRIL (acidic leucine-rich nuclear phosphoprotein 32 family member B, ANP32B) and pharmacological inhibition of PP2A stabilized a fos reporter mRNA. Our results indicate that p38 MAPK regulates fos mRNA decay by affecting the state of phosphorylation of HuR while controlling yet to be fully elucidated PP regulatory networks.


Assuntos
Proteínas ELAV/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Mitógenos/farmacologia , Proteínas Proto-Oncogênicas c-fos/metabolismo , Estabilidade de RNA/efeitos dos fármacos , RNA Mensageiro/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Regiões 3' não Traduzidas/efeitos dos fármacos , Animais , Proliferação de Células/efeitos dos fármacos , Proteínas ELAV/genética , Proteína Semelhante a ELAV 1 , Células HEK293 , Células HeLa , Humanos , Camundongos , Mutação , Células NIH 3T3 , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-fos/química , Proteínas Proto-Oncogênicas c-fos/genética , RNA Mensageiro/química , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Transativadores/química , Transativadores/genética , Transativadores/metabolismo
12.
Curr Protein Pept Sci ; 15(3): 245-55, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24694366

RESUMO

The HSP90 chaperone is a highly conserved protein from bacteria to higher eukaryotes. In eukaryotes, this chaperone participates in different large complexes, such as the HSP90 heterocomplex, which has important biological roles in cell homeostasis and differentiation. The HSP90-heterocomplex is also named the HSP90/HSP70 cycle because different co-chaperones (HIP, HSP40, HOP, p23, AHA1, immunophilins, PP5) participate in this complex by assembling sequentially, from the early to the mature complex. In this review, we analyze the conservation and relevance of HSP90 and the HSP90-heterocomplex in several protozoan parasites, with emphasis in Plasmodium spp., Toxoplasma spp., Leishmania spp. and Trypanosoma spp. In the last years, there has been an outburst of studies based on yeast two-hybrid methodology, co-immunoprecipitation-mass spectrometry and bioinformatics, which have generated a most comprehensive protein-protein interaction (PPI) network of HSP90 and its co-chaperones. This review analyzes the existing PPI networks of HSP90 and its co-chaperones of some protozoan parasites and discusses the usefulness of these powerful tools to analyze the biological role of the HSP90-heterocomplex in these parasites. The generation of a T. gondii HSP90 heterocomplex PPI network based on experimental data and a recent Plasmodium HSP90 heterocomplex PPI network are also included and discussed. As an example, the putative implication of nuclear transport and chromatin (histones and Sir2) as HSP90-heterocomplex interactors is here discussed.


Assuntos
Proteínas de Choque Térmico HSP90/metabolismo , Mapeamento de Interação de Proteínas/métodos , Proteínas de Protozoários/metabolismo , Sequência de Aminoácidos , Animais , Sequência Conservada , Proteínas de Choque Térmico HSP90/química , Humanos , Dados de Sequência Molecular , Proteínas de Protozoários/química
13.
Parasitology ; 141(9): 1138-47, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24560345

RESUMO

Hsp90 is a widely distributed and highly conserved molecular chaperone that is ubiquitously expressed throughout nature, being one of the most abundant proteins within non-stressed cells. This chaperone is up-regulated following stressful events and has been involved in many cellular processes. In Toxoplasma gondii, Hsp90 could be linked with many essential processes of the parasite such as host cell invasion, replication and tachyzoite-bradyzoite interconversion. A Protein-Protein Interaction (PPI) network approach of TgHsp90 has allowed inferring how these processes may be altered. In addition, data mining of T. gondii phosphoproteome and acetylome has allowed the generation of the phosphorylation and acetylation map of TgHsp90. This review focuses on the potential roles of TgHsp90 in parasite biology and the analysis of experimental data in comparison with its counterparts in yeast and humans.


Assuntos
Regulação da Expressão Gênica/fisiologia , Proteínas de Choque Térmico HSP90/metabolismo , Toxoplasma/metabolismo , Ciclo Celular , Proteínas de Choque Térmico HSP90/genética , Processamento de Proteína Pós-Traducional , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Toxoplasma/citologia , Toxoplasma/genética
14.
PLoS One ; 8(11): e80425, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24312219

RESUMO

The molecular chaperone Hsp90-dependent proteome represents a complex protein network of critical biological and medical relevance. Known to associate with proteins with a broad variety of functions termed clients, Hsp90 maintains key essential and oncogenic signalling pathways. Consequently, Hsp90 inhibitors are being tested as anti-cancer drugs. Using an integrated systematic approach to analyse the effects of Hsp90 inhibition in T-cells, we quantified differential changes in the Hsp90-dependent proteome, Hsp90 interactome, and a selection of the transcriptome. Kinetic behaviours in the Hsp90-dependent proteome were assessed using a novel pulse-chase strategy (Fierro-Monti et al., accompanying article), detecting effects on both protein stability and synthesis. Global and specific dynamic impacts, including proteostatic responses, are due to direct inhibition of Hsp90 as well as indirect effects. As a result, a decrease was detected in most proteins that changed their levels, including known Hsp90 clients. Most likely, consequences of the role of Hsp90 in gene expression determined a global reduction in net de novo protein synthesis. This decrease appeared to be greater in magnitude than a concomitantly observed global increase in protein decay rates. Several novel putative Hsp90 clients were validated, and interestingly, protein families with critical functions, particularly the Hsp90 family and cofactors themselves as well as protein kinases, displayed strongly increased decay rates due to Hsp90 inhibitor treatment. Remarkably, an upsurge in survival pathways, involving molecular chaperones and several oncoproteins, and decreased levels of some tumour suppressors, have implications for anti-cancer therapy with Hsp90 inhibitors. The diversity of global effects may represent a paradigm of mechanisms that are operating to shield cells from proteotoxic stress, by promoting pro-survival and anti-proliferative functions. Data are available via ProteomeXchange with identifier PXD000537.


Assuntos
Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Proteoma , Proteômica , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Análise por Conglomerados , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Proteínas Oncogênicas/genética , Proteínas Oncogênicas/metabolismo , Mapeamento de Interação de Proteínas , Mapas de Interação de Proteínas , Proteólise , Reprodutibilidade dos Testes , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo
15.
Sci Transl Med ; 5(182): 182ra55, 2013 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-23616122

RESUMO

Estrogens and progesterones are major drivers of breast development but also promote carcinogenesis in this organ. Yet, their respective roles and the mechanisms underlying their action in the human breast are unclear. Receptor activator of nuclear factor κB ligand (RANKL) has been identified as a pivotal paracrine mediator of progesterone function in mouse mammary gland development and mammary carcinogenesis. Whether the factor has the same role in humans is of clinical interest because an inhibitor for RANKL, denosumab, is already used for the treatment of bone disease and might benefit breast cancer patients. We show that progesterone receptor (PR) signaling failed to induce RANKL in PR(+) breast cancer cell lines and in dissociated, cultured breast epithelial cells. In clinical specimens from healthy donors and intact breast tissue microstructures, hormone response was maintained and RANKL expression was under progesterone control, which increased RNA stability. RANKL was sufficient to trigger cell proliferation and was required for progesterone-induced proliferation. The findings were validated in vivo where RANKL protein expression in the breast epithelium correlated with serum progesterone levels and the protein was expressed in a subset of luminal cells that express PR. Thus, important hormonal control mechanisms are conserved across species, making RANKL a potential target in breast cancer treatment and prevention.


Assuntos
Mama/metabolismo , Progesterona/metabolismo , Ligante RANK/metabolismo , Feminino , Humanos , Técnicas In Vitro , Ligante RANK/genética , Receptores de Progesterona/genética , Receptores de Progesterona/metabolismo
16.
Recent Pat Biotechnol ; 7(1): 2-8, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23002958

RESUMO

Diseases caused by protozoan parasites are still an important health problem. These parasites can cause a wide spectrum of diseases, some of which are severe and have high morbidity or mortality if untreated. Since they are still uncontrolled, it is important to find novel drug targets and develop new therapies to decrease their remarkable social and economic impact on human societies. In the past years, human HSP90 has become an interesting drug target that has led to a large number of investigations both at state organizations and pharmaceutical companies, followed by clinical trials. The finding that HSP90 has important biological roles in some protozoan parasites like Plasmodium spp, Toxoplasma gondii and trypanosomatids has allowed the expansion of the results obtained in human cancer to these infections. This review summarizes the latest important findings showing protozoan HSP90 as a drug target and presents three patents targeting T. gondii, P. falciparum and trypanosomatids HSP90.


Assuntos
Antiprotozoários/farmacologia , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Proteínas de Choque Térmico HSP90/metabolismo , Patentes como Assunto , Proteínas de Protozoários/metabolismo , Animais , Proteínas de Choque Térmico HSP90/química , Terapia de Alvo Molecular , Plasmodium/efeitos dos fármacos , Plasmodium/metabolismo , Proteínas de Protozoários/química , Toxoplasma/efeitos dos fármacos , Toxoplasma/metabolismo
17.
Breast Cancer Res ; 14(4): 210, 2012 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-22809143

RESUMO

The ovarian hormones estrogen and progesterone orchestrate postnatal mammary gland development and are implicated in breast cancer. Most of our understanding of the molecular mechanisms of estrogen receptor (ER) and progesterone receptor (PR) signaling stems from in vitro studies with hormone receptor-positive cell lines. They have shown that ER and PR regulate gene transcription either by binding to DNA response elements directly or via other transcription factors and recruiting co-regulators. In addition they cross-talk with other signaling pathways through nongenomic mechanisms. Mouse genetics combined with tissue recombination techniques have provided insights about the action of these two hormones in vivo. It has emerged that hormones act on a subset of mammary epithelial cells and relegate biological functions to paracrine factors. With regards to hormonal signaling in breast carcinomas, global gene expression analyses have led to the identification of gene expression signatures that are characteristic of ERα-positive tumors that have stipulated functional studies of hitherto poorly understood transcription factors. Here, we highlight what has been learned about ER and PR signaling nodes in these different systems and attempt to lay out in which way the insights may converge.


Assuntos
Glândulas Mamárias Humanas/crescimento & desenvolvimento , Glândulas Mamárias Humanas/metabolismo , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo , Transdução de Sinais , Adulto , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Receptor alfa de Estrogênio/metabolismo , Feminino , Regulação da Expressão Gênica , Humanos , Comunicação Parácrina
18.
Int J Biol Macromol ; 50(3): 725-33, 2012 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-22209934

RESUMO

Toxoplasma gondii is an obligate intracellular protozoan parasite in which 36 predicted Hsp40 family members were identified by searching the T. gondii genome. The predicted protein sequence from the gene ID TGME49_065310 showed an amino acid sequence and domain structure similar to Saccharomyces cerevisiae Sis1. TgSis1 did not show differences in its expression profile during alkaline stress by microarray analysis. Furthermore, TgSis1 showed to be a cytosolic Hsp40 which co-immunoprecipitated with T. gondii Hsp70 and Hsp90. Structural modeling of the TgSis1 peptide binding fragment revealed structural and electrostatic properties different from the experimental model of human Sis1-like protein (Hdj1). Based on these differences; we propose that TgSis1 may be a potentially attractive drug target for developing a novel anti-T. gondii therapy.


Assuntos
Citosol/metabolismo , Proteínas de Choque Térmico HSP40/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Proteínas de Protozoários/metabolismo , Toxoplasma/citologia , Toxoplasma/metabolismo , Sequência de Aminoácidos , Bases de Dados Genéticas , Proteínas de Choque Térmico HSP40/química , Proteínas de Choque Térmico HSP40/genética , Humanos , Espaço Intracelular/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Conformação Proteica , Estrutura Terciária de Proteína , Transporte Proteico , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Análise de Sequência , Estresse Fisiológico , Toxoplasma/genética
19.
PLoS One ; 6(10): e26044, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22022502

RESUMO

Understanding the functions of proteins requires information about their protein-protein interactions (PPI). The collective effort of the scientific community generates far more data on any given protein than individual experimental approaches. The latter are often too limited to reveal an interactome comprehensively. We developed a workflow for parallel mining of all major PPI databases, containing data from several model organisms, and to integrate data from the literature for a protein of interest. We applied this novel approach to build the PPI network of the human Hsp90 molecular chaperone machine (Hsp90Int) for which previous efforts have yielded limited and poorly overlapping sets of interactors. We demonstrate the power of the Hsp90Int database as a discovery tool by validating the prediction that the Hsp90 co-chaperone Aha1 is involved in nucleocytoplasmic transport. Thus, we both describe how to build a custom database and introduce a powerful new resource for the scientific community.


Assuntos
Bases de Dados de Proteínas , Proteínas de Choque Térmico HSP90/metabolismo , Mapas de Interação de Proteínas , Transporte Ativo do Núcleo Celular , Animais , Humanos , Camundongos , Ligação Proteica , Reprodutibilidade dos Testes
20.
BioData Min ; 4(1): 15, 2011 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-21672238

RESUMO

BACKGROUND: To make sense out of gene expression profiles, such analyses must be pushed beyond the mere listing of affected genes. For example, if a group of genes persistently display similar changes in expression levels under particular experimental conditions, and the proteins encoded by these genes interact and function in the same cellular compartments, this could be taken as very strong indicators for co-regulated protein complexes. One of the key requirements is having appropriate tools to detect such regulatory patterns. RESULTS: We have analyzed the global adaptations in gene expression patterns in the budding yeast when the Hsp90 molecular chaperone complex is perturbed either pharmacologically or genetically. We integrated these results with publicly accessible expression, protein-protein interaction and intracellular localization data. But most importantly, all experimental conditions were simultaneously and dynamically visualized with an animation. This critically facilitated the detection of patterns of gene expression changes that suggested underlying regulatory networks that a standard analysis by pairwise comparison and clustering could not have revealed. CONCLUSIONS: The results of the animation-assisted detection of changes in gene regulatory patterns make predictions about the potential roles of Hsp90 and its co-chaperone p23 in regulating whole sets of genes. The simultaneous dynamic visualization of microarray experiments, represented in networks built by integrating one's own experimental with publicly accessible data, represents a powerful discovery tool that allows the generation of new interpretations and hypotheses.

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