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1.
Science ; 365(6454): 695-699, 2019 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-31416963

RESUMO

An essential prerequisite for the survival of an organism is the ability to detect and respond to aversive stimuli. Current belief is that noxious stimuli directly activate nociceptive sensory nerve endings in the skin. We discovered a specialized cutaneous glial cell type with extensive processes forming a mesh-like network in the subepidermal border of the skin that conveys noxious thermal and mechanical sensitivity. We demonstrate a direct excitatory functional connection to sensory neurons and provide evidence of a previously unknown organ that has an essential physiological role in sensing noxious stimuli. Thus, these glial cells, which are intimately associated with unmyelinated nociceptive nerves, are inherently mechanosensitive and transmit nociceptive information to the nerve.

2.
Cell ; 177(4): 881-895.e17, 2019 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-31051106

RESUMO

Non-alcoholic fatty liver is the most common liver disease worldwide. Here, we show that the mitochondrial protein mitofusin 2 (Mfn2) protects against liver disease. Reduced Mfn2 expression was detected in liver biopsies from patients with non-alcoholic steatohepatitis (NASH). Moreover, reduced Mfn2 levels were detected in mouse models of steatosis or NASH, and its re-expression in a NASH mouse model ameliorated the disease. Liver-specific ablation of Mfn2 in mice provoked inflammation, triglyceride accumulation, fibrosis, and liver cancer. We demonstrate that Mfn2 binds phosphatidylserine (PS) and can specifically extract PS into membrane domains, favoring PS transfer to mitochondria and mitochondrial phosphatidylethanolamine (PE) synthesis. Consequently, hepatic Mfn2 deficiency reduces PS transfer and phospholipid synthesis, leading to endoplasmic reticulum (ER) stress and the development of a NASH-like phenotype and liver cancer. Ablation of Mfn2 in liver reveals that disruption of ER-mitochondrial PS transfer is a new mechanism involved in the development of liver disease.

3.
Nat Immunol ; 20(5): 581-592, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30962591

RESUMO

Succinate is a signaling metabolite sensed extracellularly by succinate receptor 1 (SUNCR1). The accumulation of succinate in macrophages is known to activate a pro-inflammatory program; however, the contribution of SUCNR1 to macrophage phenotype and function has remained unclear. Here we found that activation of SUCNR1 had a critical role in the anti-inflammatory responses in macrophages. Myeloid-specific deficiency in SUCNR1 promoted a local pro-inflammatory phenotype, disrupted glucose homeostasis in mice fed a normal chow diet, exacerbated the metabolic consequences of diet-induced obesity and impaired adipose-tissue browning in response to cold exposure. Activation of SUCNR1 promoted an anti-inflammatory phenotype in macrophages and boosted the response of these cells to type 2 cytokines, including interleukin-4. Succinate decreased the expression of inflammatory markers in adipose tissue from lean human subjects but not that from obese subjects, who had lower expression of SUCNR1 in adipose-tissue-resident macrophages. Our findings highlight the importance of succinate-SUCNR1 signaling in determining macrophage polarization and assign a role to succinate in limiting inflammation.


Assuntos
Inflamação/imunologia , Macrófagos/imunologia , Obesidade/imunologia , Receptores Acoplados a Proteínas-G/imunologia , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/imunologia , Tecido Adiposo/metabolismo , Animais , Células Cultivadas , Citocinas/genética , Citocinas/imunologia , Citocinas/metabolismo , Perfilação da Expressão Gênica/métodos , Humanos , Inflamação/genética , Inflamação/metabolismo , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Obesidade/genética , Obesidade/metabolismo , Receptores Acoplados a Proteínas-G/deficiência , Receptores Acoplados a Proteínas-G/genética , Ácido Succínico/imunologia , Ácido Succínico/metabolismo , Ácido Succínico/farmacologia , Células THP-1
4.
Int J Mol Sci ; 20(6)2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30897704

RESUMO

It has been proposed that one of the mechanisms of taxane-site ligand-mediated tubulin activation is modulation of the structure of a switch element (the M-loop) from a disordered form in dimeric tubulin to a folded helical structure in microtubules. Here, we used covalent taxane-site ligands, including cyclostreptin, to gain further insight into this mechanism. The crystal structure of cyclostreptin-bound tubulin reveals covalent binding to ßHis229, but no stabilization of the M-loop. The capacity of cyclostreptin to induce microtubule assembly compared to other covalent taxane-site agents demonstrates that the induction of tubulin assembly is not strictly dependent on M-loop stabilization. We further demonstrate that most covalent taxane-site ligands are able to partially overcome drug resistance mediated by ßIII-tubulin (ßIII) overexpression in HeLa cells, and compare their activities to pironetin, an interfacial covalent inhibitor of tubulin assembly that displays invariant growth inhibition in these cells. Our findings suggest a relationship between a diminished interaction of taxane-site ligands with ßIII-tubulin and ßIII tubulin-mediated drug resistance. This supports the idea that overexpression of ßIII increases microtubule dynamicity by counteracting the enhanced microtubule stability promoted by covalent taxane-site binding ligands.


Assuntos
Microtúbulos/química , Compostos Policíclicos/química , Tubulina (Proteína)/química , Resistencia a Medicamentos Antineoplásicos , Ácido Edético/química , Células HeLa , Humanos , Espectrometria de Massas , Taxoides/química
5.
Reumatol. clín. (Barc.) ; 15(1): 34-42, ene.-feb. 2019. tab
Artigo em Inglês | IBECS | ID: ibc-176075

RESUMO

Objectives: The course and long-term outcome of pure membranous lupus nephritis (MLN) are little understood. The aims of this study are to evaluate the clinical features, course, outcome and prognostic indicators in pure MLN and to determine the impact of ethnicity and the type of health insurance on the course and prognosis of pure MLN. Methods: We conducted a retrospective review of medical records of 150 patients with pure MLN from Spain and the USA. Results: Mean age was 34.2±12.5 and 80% were women. Sixty-eight percent of patients had nephrotic syndrome at diagnosis. The average serum creatinine was 0.98±0.78mg/dl. Six percent of patients died and 5.3% developed end-stage renal disease (ESRD). ESRD was predicted by male sex, hypertension, dyslipidemia, high basal 24h-proteinuria, high basal serum creatinine and a low basal creatinine clearance. Age, cardiac insufficiency, peripheral artheriopathy, hemodialysis and not having received mycophenolate mofetil or antimalarials for MLN predicted death. Conclusions: Pure MLN frequently presents with nephrotic syndrome, high proteinuria and normal serum creatinine. Its prognosis is favourable in maintaining renal function although proteinuria usually persists over time. Baseline cardiovascular disease and not having a health insurance are related with poor prognosis


Objetivos: Los conocimientos sobre el curso y el desenlace a largo plazo de la nefritis lúpica membranosa (NLM) pura son todavía escasos. El objetivo de este estudio es evaluar las características clínicas, curso, desenlace e indicadores pronósticos de la NLM y determinar el impacto de la etnicidad y tipo de cobertura sanitaria en el curso y pronóstico de la NLM. Métodos: Se realizó una revisión retrospectiva de las historias de 150 pacientes con NLM de España y Estados Unidos. Resultados: La edad media fue 34,2±12,5 y el 80% eran mujeres. El 68% de los pacientes tenían síndrome nefrótico al diagnóstico. La creatinina sérica media fue 0,98±0,78mg/dl. El 6% de los pacientes fallecieron y el 5,3% desarrollaron insuficiencia renal terminal (IRT). El sexo masculino, la hipertensión, la dislipemia, la alta proteinuria basal, la alta creatininemia y un aclaramiento de creatinina reducido predijeron el desarrollo de IRT. La edad, la insuficiencia cardíaca, la arteriopatía periférica, la hemodiálisis y el no haber recibido micofenolato de mofetilo o antimaláricos predijeron el fallecimiento. Conclusiones: La NLM pura suele debutar con síndrome nefrótico, alta proteinuria y creatininemia normal. Su pronóstico es favourable en términos de mantenimiento de la función renal aunque la proteinuria habitualmente persiste durante el seguimiento. La enfermedad cardiovascular basal y no tener cobertura sanitaria se relacionan con mal pronóstico


Assuntos
Humanos , Masculino , Feminino , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Nefrite Lúpica/epidemiologia , Glomerulonefrite Membranosa/epidemiologia , Lúpus Eritematoso Sistêmico/complicações , Estudos Retrospectivos , Proteinúria/epidemiologia , Avaliação de Resultados da Assistência ao Paciente , Lúpus Eritematoso Sistêmico/etnologia , Creatinina/sangue
6.
Nat Commun ; 9(1): 3399, 2018 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-30143614

RESUMO

It is unclear how the mitochondrial fusion protein Optic atrophy 1 (OPA1), which inhibits cristae remodeling, protects from mitochondrial dysfunction. Here we identify the mitochondrial F1Fo-ATP synthase as the effector of OPA1 in mitochondrial protection. In OPA1 overexpressing cells, the loss of proton electrochemical gradient caused by respiratory chain complex III inhibition is blunted and this protection is abolished by the ATP synthase inhibitor oligomycin. Mechanistically, OPA1 and ATP synthase can interact, but recombinant OPA1 fails to promote oligomerization of purified ATP synthase reconstituted in liposomes, suggesting that OPA1 favors ATP synthase oligomerization and reversal activity by modulating cristae shape. When ATP synthase oligomers are genetically destabilized by silencing the key dimerization subunit e, OPA1 is no longer able to preserve mitochondrial function and cell viability upon complex III inhibition. Thus, OPA1 protects mitochondria from respiratory chain inhibition by stabilizing cristae shape and favoring ATP synthase oligomerization.

7.
Cell Rep ; 23(12): 3685-3697.e4, 2018 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-29925008

RESUMO

Post-translational modifications hugely increase the functional diversity of proteomes. Recent algorithms based on ultratolerant database searching are forging a path to unbiased analysis of peptide modifications by shotgun mass spectrometry. However, these approaches identify only one-half of the modified forms potentially detectable and do not map the modified residue. Moreover, tools for the quantitative analysis of peptide modifications are currently lacking. Here, we present a suite of algorithms that allows comprehensive identification of detectable modifications, pinpoints the modified residues, and enables their quantitative analysis through an integrated statistical model. These developments were used to characterize the impact of mitochondrial heteroplasmy on the proteome and on the modified peptidome in several tissues from 12-week-old mice. Our results reveal that heteroplasmy mainly affects cardiac tissue, inducing oxidative damage to proteins of the oxidative phosphorylation system, and provide a molecular mechanism explaining the structural and functional alterations produced in heart mitochondria.

8.
J Nat Prod ; 81(3): 494-505, 2018 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-29023132

RESUMO

The marine natural product zampanolide and analogues thereof constitute a new chemotype of taxoid site microtubule-stabilizing agents with a covalent mechanism of action. Zampanolide-ligated tubulin has the switch-activation loop (M-loop) in the assembly prone form and, thus, represents an assembly activated state of the protein. In this study, we have characterized the biochemical properties of the covalently modified, activated tubulin dimer, and we have determined the effect of zampanolide on tubulin association and the binding of tubulin ligands at other binding sites. Tubulin activation by zampanolide does not affect its longitudinal oligomerization but does alter its lateral association properties. The covalent binding of zampanolide to ß-tubulin affects both the colchicine site, causing a change of the quantum yield of the bound ligand, and the exchangeable nucleotide binding site, reducing the affinity for the nucleotide. While these global effects do not change the binding affinity of 2-methoxy-5-(2,3,4-trimethoxyphenyl)-2,4,6-cycloheptatrien-1-one (MTC) (a reversible binder of the colchicine site), the binding affinity of a fluorescent analogue of GTP (Mant-GTP) at the nucleotide E-site is reduced from 12 ± 2 × 105 M-1 in the case of unmodified tubulin to 1.4 ± 0.3 × 105 M-1 in the case of the zampanolide tubulin adduct, indicating signal transmission between the taxane site and the colchicine and nucleotide sites of ß-tubulin.

9.
J Cell Sci ; 130(23): 4013-4027, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29061881

RESUMO

Cadherin-based intercellular adhesions are essential players in epithelial homeostasis, but their dynamic regulation during tissue morphogenesis and remodeling remain largely undefined. Here, we characterize an unexpected role for the membrane-anchored metalloproteinase MT2-MMP in regulating epithelial cell quiescence. Following co-immunoprecipitation and mass spectrometry, the MT2-MMP cytosolic tail was found to interact with the zonula occludens protein-1 (ZO-1) at the apical junctions of polarized epithelial cells. Functionally, MT2-MMP localizes in the apical domain of epithelial cells where it cleaves E-cadherin and promotes epithelial cell accumulation, a phenotype observed in 2D polarized cells as well as 3D cysts. MT2-MMP-mediated cleavage subsequently disrupts apical E-cadherin-mediated cell quiescence resulting in relaxed apical cortical tension favoring cell extrusion and re-sorting of Src kinase activity to junctional complexes, thereby promoting proliferation. Physiologically, MT2-MMP loss of function alters E-cadherin distribution, leading to impaired 3D organoid formation by mouse colonic epithelial cells ex vivo and reduction of cell proliferation within intestinal crypts in vivo Taken together, these studies identify an MT2-MMP-E-cadherin axis that functions as a novel regulator of epithelial cell homeostasis in vivo.


Assuntos
Caderinas/metabolismo , Homeostase/fisiologia , Mucosa Intestinal/metabolismo , Metaloproteinase 15 da Matriz/metabolismo , Junções Aderentes/metabolismo , Caderinas/genética , Movimento Celular/fisiologia , Proteínas do Citoesqueleto/metabolismo , Células Epiteliais/metabolismo , Humanos , Junções Intercelulares/metabolismo , Junções Íntimas/metabolismo
10.
Rev. colomb. reumatol ; 24(3): 153-158, jul.-set. 2017. tab
Artigo em Inglês | LILACS-Express | ID: biblio-900870

RESUMO

Abstract Objective: To evaluate the performance of the most widely used SpA classification criteria in a Colombian group of patients with chronic low back pain. Methods: We assessed the ASAS and the European Spondyloarthropathy Study Group (ESSG) classification criteria in a group of 133 patients who attended consecutively over a period of six months at outpatient clinic of low back pain. All the patients were evaluated with the same protocol. The patients were divided into two groups according to the diagnosis. The diagnosis was compared with the diagnosis made by a expert rheumatologist blinded to patient information. Results: 81 patients with SpA and 52 with other diagnoses were included. There were no differences in age and age of onset of symptoms between the two groups. The SpA group included 55 males and more common clinical findings were: enthesitis, arthritis, sacroiliitis, HLA-B27-positive, previous infection, and dactylitis. The sensitivity and specificity of criteria were: ASAS criteria 96% of sensibility and 80% of specificity, and ESSG criteria 95% and 100% respectively. The agreement between the classification criteria and the diagnosis established by the rheumatologist showed a Cohen's kappa index of 0.938 for ESSG criteria (95% CI: 0.877-0.998) and 0.790 for the ASAS criteria (95% CI: 0.682-0.898). Conclusion: In a Colombian group of SpA patients, the new ASAS classification criteria have a good concordance with clinical diagnosis but are not superior to the ESSG criteria.


Resumen Objetivo: Evaluar el acuerdo entre los criterios de clasificación para SpA y el diagnóstico de un experto reumatólogo en un grupo de pacientes con dolor lumbar. Métodos: Se evaluó el comportamiento de los criterios de ASAS y del ESSG en 133 pacientes que acudieron de forma consecutiva durante seis meses a la clínica ambulatoria de dolor lumbar. Todos los pacientes se evaluaron con el mismo protocolo. Los pacientes fueron divididos en dos grupos de acuerdo con el diagnóstico. Posteriormente se estableció del acuerdo diagnóstico con el de un experto reumatólogo ciego a la información previa de los pacientes. Resultados: 81 pacientes con SpA y 52 con otros diagnósticos fueron incluidos. No hubo diferencias en la edad y la edad de aparición de los síntomas. El grupo SpA incluyó a 55 varones y los hallazgos más comunes fueron: entesitis, artritis, sacroileitis, infección previa, HLA-B27, y dactilitis. La sensibilidad y especificidad de los criterios fueron: ASAS 96% de sensibilidad y 80% de especificidad, y ESSG 95% y 100% respectivamente. El acuerdo entre los criterios de clasificación y el diagnóstico del reumatólogo mostró un índice kappa de 0,938 con criterios ESSG (IC del 95%: 0,877-0,998) y 0,790 para los criterios ASAS (IC del 95%: 0,682-0,898). Conclusión: En un grupo de pacientes colombianos SpA, los nuevos criterios de clasificación ASAS tienen una buena concordancia con el diagnóstico clínico, pero no son superiores a los criterios ESSG.

11.
Science ; 357(6346)2017 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-28684471

RESUMO

Adrenaline is a fundamental circulating hormone for bodily responses to internal and external stressors. Chromaffin cells of the adrenal medulla (AM) represent the main neuroendocrine adrenergic component and are believed to differentiate from neural crest cells. We demonstrate that large numbers of chromaffin cells arise from peripheral glial stem cells, termed Schwann cell precursors (SCPs). SCPs migrate along the visceral motor nerve to the vicinity of the forming adrenal gland, where they detach from the nerve and form postsynaptic neuroendocrine chromaffin cells. An intricate molecular logic drives two sequential phases of gene expression, one unique for a distinct transient cellular state and another for cell type specification. Subsequently, these programs down-regulate SCP-gene and up-regulate chromaffin cell-gene networks. The AM forms through limited cell expansion and requires the recruitment of numerous SCPs. Thus, peripheral nerves serve as a stem cell niche for neuroendocrine system development.


Assuntos
Medula Suprarrenal/embriologia , Diferenciação Celular , Células Cromafins/citologia , Células-Tronco Multipotentes/citologia , Células-Tronco Neurais/citologia , Células Neuroendócrinas/citologia , Células de Schwann/citologia , Medula Suprarrenal/citologia , Animais , Diferenciação Celular/genética , Movimento Celular , Proliferação de Células , Regulação da Expressão Gênica no Desenvolvimento , Camundongos , Camundongos Mutantes , Proteína Proteolipídica de Mielina/genética , Crista Neural/citologia , Nervos Periféricos/citologia , Fatores de Transcrição SOXE/genética , Nicho de Células-Tronco/genética , Transcrição Genética
12.
Cell Death Dis ; 8(5): e2802, 2017 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-28518147

RESUMO

Adipose tissue (AT) has a central role in obesity-related metabolic imbalance through the dysregulated production of cytokines and adipokines. In addition to its known risk for cardiovascular disease and diabetes, obesity is also a major risk for cancer. We investigated the impact of obesity for the expression of survivin, an antiapoptotic protein upregulated by adipokines and a diagnostic biomarker of tumor onset and recurrence. In a cross-sectional study of 111 subjects classified by body mass index, circulating levels of survivin and gene expression in subcutaneous AT were significantly higher in obese patients and positively correlated with leptin. Within AT, survivin was primarily detected in human adipocyte-derived stem cells (hASCs), the adipocyte precursors that determine AT expansion. Remarkably, survivin expression was significantly higher in hASCs isolated from obese patients that from lean controls and was increased by proinflammatory M1 macrophage soluble factors including IL-1ß. Analysis of survivin expression in hASCs revealed a complex regulation including epigenetic modifications and protein stability. Surprisingly, obese hASCs showed survivin promoter hypermethylation that correlated with a significant decrease in its mRNA levels. Nonetheless, a lower level of mir-203, which inhibits survivin protein translation, and higher protein stability, was found in obese hASCs compared with their lean counterparts. We discovered that survivin levels determine the susceptibility of hASCs to apoptotic stimuli (including leptin and hypoxia). Accordingly, hASCs from an obese setting were protected from apoptosis. Collectively, these data shed new light on the molecular mechanisms governing AT expansion in obesity through promotion of hASCs that are resistant to apoptosis, and point to survivin as a potential new molecular player in the communication between AT and tumor cells. Thus, inhibition of apoptosis targeting survivin might represent an effective strategy for both obesity and cancer therapy.


Assuntos
Tecido Adiposo/patologia , Apoptose , Progressão da Doença , Proteínas Inibidoras de Apoptose/metabolismo , Obesidade/metabolismo , Células-Tronco/patologia , Tecido Adiposo/metabolismo , Adulto , Antropometria , Epigênese Genética , Feminino , Humanos , Inflamação/patologia , Proteínas Inibidoras de Apoptose/sangue , Proteínas Inibidoras de Apoptose/genética , Masculino , Pessoa de Meia-Idade , Biossíntese de Proteínas , Survivina , Transcrição Genética
13.
Reumatol Clin ; 2017 May 18.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-28528869

RESUMO

OBJECTIVES: The course and long-term outcome of pure membranous lupus nephritis (MLN) are little understood. The aims of this study are to evaluate the clinical features, course, outcome and prognostic indicators in pure MLN and to determine the impact of ethnicity and the type of health insurance on the course and prognosis of pure MLN. METHODS: We conducted a retrospective review of medical records of 150 patients with pure MLN from Spain and the USA. RESULTS: Mean age was 34.2±12.5 and 80% were women. Sixty-eight percent of patients had nephrotic syndrome at diagnosis. The average serum creatinine was 0.98±0.78mg/dl. Six percent of patients died and 5.3% developed end-stage renal disease (ESRD). ESRD was predicted by male sex, hypertension, dyslipidemia, high basal 24h-proteinuria, high basal serum creatinine and a low basal creatinine clearance. Age, cardiac insufficiency, peripheral artheriopathy, hemodialysis and not having received mycophenolate mofetil or antimalarials for MLN predicted death. CONCLUSIONS: Pure MLN frequently presents with nephrotic syndrome, high proteinuria and normal serum creatinine. Its prognosis is favourable in maintaining renal function although proteinuria usually persists over time. Baseline cardiovascular disease and not having a health insurance are related with poor prognosis.

14.
PLoS Biol ; 15(4): e2000653, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28394935

RESUMO

The actin cytoskeleton coordinates the organization of signaling microclusters at the immune synapse (IS); however, the mechanisms involved remain poorly understood. We show here that nitric oxide (NO) generated by endothelial nitric oxide synthase (eNOS) controls the coalescence of protein kinase C-θ (PKC-θ) at the central supramolecular activation cluster (c-SMAC) of the IS. eNOS translocated with the Golgi to the IS and partially colocalized with F-actin around the c-SMAC. This resulted in reduced actin polymerization and centripetal retrograde flow of ß-actin and PKC-θ from the lamellipodium-like distal (d)-SMAC, promoting PKC-θ activation. Furthermore, eNOS-derived NO S-nitrosylated ß-actin on Cys374 and impaired actin binding to profilin-1 (PFN1), as confirmed with the transnitrosylating agent S-nitroso-L-cysteine (Cys-NO). The importance of NO and the formation of PFN1-actin complexes on the regulation of PKC-θ was corroborated by overexpression of PFN1- and actin-binding defective mutants of ß-actin (C374S) and PFN1 (H119E), respectively, which reduced the coalescence of PKC-θ at the c-SMAC. These findings unveil a novel NO-dependent mechanism by which the actin cytoskeleton controls the organization and activation of signaling microclusters at the IS.


Assuntos
Actinas/metabolismo , Sinapses Imunológicas/enzimologia , Isoenzimas/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Profilinas/metabolismo , Proteína Quinase C/metabolismo , Processamento de Proteína Pós-Traducional , Linfócitos T/metabolismo , Substituição de Aminoácidos , Linhagem Celular , Células Cultivadas , Cisteína/metabolismo , Ativação Enzimática , Complexo de Golgi/enzimologia , Complexo de Golgi/imunologia , Complexo de Golgi/metabolismo , Humanos , Sinapses Imunológicas/imunologia , Sinapses Imunológicas/metabolismo , Isoenzimas/química , Isoenzimas/genética , Proteínas Luminescentes/antagonistas & inibidores , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Mutação , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/antagonistas & inibidores , Óxido Nítrico Sintase Tipo III/genética , Profilinas/genética , Proteína Quinase C/química , Proteína Quinase C/genética , Proteína Quinase C-theta , Transporte Proteico , Pseudópodes , Interferência de RNA , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Linfócitos T/citologia , Linfócitos T/imunologia
15.
Int J Rheumatol ; 2017: 3143069, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28286523

RESUMO

Background. Clinical, laboratory, and radiologic parameters are used for diagnosis and classification of spondyloarthritis (SpA). Magnetic resonance imaging (MRI) of sacroiliac (SI) joints is being increasingly used to detect early sacroiliitis. We decided to evaluate the interobserver agreement in MRI findings of SI joints of SpA patients between a local radiologist, a rheumatologist, and an expert radiologist in musculoskeletal diseases. Methods. 66 MRI images of the SI joints of patients with established diagnosis of SpA were evaluated. Agreement was expressed in Cohen's kappa. Results. Interobserver agreement between a local radiologist and an expert radiologist was fair (κ = 0.37). Only acute findings showed a moderate agreement (κ = 0.45), while chronic findings revealed 76.5% of disagreement (κ = 0.31). A fair agreement was observed in acute findings (κ = 0.38) as well as chronic findings (κ = 0.38) between a local radiologist and a rheumatologist. There was a substantial agreement between an expert radiologist and a rheumatologist (κ = 0.73). In acute findings, a 100% agreement was achieved. Also chronic and acute plus chronic findings showed high levels of agreement (κ = 0.73 and 0.62, resp.). Conclusions. Our study shows that rheumatologists may have similar MRI interpretations of SI joints in SpA patients as an expert radiologist.

17.
Cell Rep ; 17(11): 3024-3034, 2016 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-27974214

RESUMO

The mitochondrial contact site and cristae organizing system (MICOS) and Optic atrophy 1 (OPA1) control cristae shape, thus affecting mitochondrial function and apoptosis. Whether and how they physically and functionally interact is unclear. Here, we provide evidence that OPA1 is epistatic to MICOS in the regulation of cristae shape. Proteomic analysis identifies multiple MICOS components in native OPA1-containing high molecular weight complexes disrupted during cristae remodeling. MIC60, a core MICOS protein, physically interacts with OPA1, and together, they control cristae junction number and stability, OPA1 being epistatic to MIC60. OPA1 defines cristae width and junction diameter independently of MIC60. Our combination of proteomics, biochemistry, genetics, and electron tomography provides a unifying model for mammalian cristae biogenesis by OPA1 and MICOS.


Assuntos
Epistasia Genética , GTP Fosfo-Hidrolases/genética , Mitocôndrias/genética , Atrofia Óptica Autossômica Dominante/genética , Apoptose/genética , Humanos , Mitocôndrias/patologia , Atrofia Óptica Autossômica Dominante/patologia , Proteoma/genética , Proteômica
18.
Nature ; 539(7630): 579-582, 2016 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-27775717

RESUMO

Respiratory chain complexes can super-assemble into quaternary structures called supercomplexes that optimize cellular metabolism. The interaction between complexes III (CIII) and IV (CIV) is modulated by supercomplex assembly factor 1 (SCAF1, also known as COX7A2L). The discovery of SCAF1 represented strong genetic evidence that supercomplexes exist in vivo. SCAF1 is present as a long isoform (113 amino acids) or a short isoform (111 amino acids) in different mouse strains. Only the long isoform can induce the super-assembly of CIII and CIV, but it is not clear whether SCAF1 is required for the formation of the respirasome (a supercomplex of CI, CIII2 and CIV). Here we show, by combining deep proteomics and immunodetection analysis, that SCAF1 is always required for the interaction between CIII and CIV and that the respirasome is absent from most tissues of animals containing the short isoform of SCAF1, with the exception of heart and skeletal muscle. We used directed mutagenesis to characterize SCAF1 regions that interact with CIII and CIV and discovered that this interaction requires the correct orientation of a histidine residue at position 73 that is altered in the short isoform of SCAF1, explaining its inability to interact with CIV. Furthermore, we find that the CIV subunit COX7A2 is replaced by SCAF1 in supercomplexes containing CIII and CIV and by COX7A1 in CIV dimers, and that dimers seem to be more stable when they include COX6A2 rather than the COX6A1 isoform.


Assuntos
Membranas Mitocondriais/metabolismo , Isoformas de Proteínas/metabolismo , Animais , Complexo IV da Cadeia de Transporte de Elétrons/química
19.
Nature ; 535(7613): 561-5, 2016 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-27383793

RESUMO

Human mitochondrial DNA (mtDNA) shows extensive within population sequence variability. Many studies suggest that mtDNA variants may be associated with ageing or diseases, although mechanistic evidence at the molecular level is lacking. Mitochondrial replacement has the potential to prevent transmission of disease-causing oocyte mtDNA. However, extension of this technology requires a comprehensive understanding of the physiological relevance of mtDNA sequence variability and its match with the nuclear-encoded mitochondrial genes. Studies in conplastic animals allow comparison of individuals with the same nuclear genome but different mtDNA variants, and have provided both supporting and refuting evidence that mtDNA variation influences organismal physiology. However, most of these studies did not confirm the conplastic status, focused on younger animals, and did not investigate the full range of physiological and phenotypic variability likely to be influenced by mitochondria. Here we systematically characterized conplastic mice throughout their lifespan using transcriptomic, proteomic,metabolomic, biochemical, physiological and phenotyping studies. We show that mtDNA haplotype profoundly influences mitochondrial proteostasis and reactive oxygen species generation,insulin signalling, obesity, and ageing parameters including telomere shortening and mitochondrial dysfunction, resulting in profound differences in health longevity between conplastic strains.


Assuntos
Envelhecimento/genética , Núcleo Celular/genética , DNA Mitocondrial/genética , Variação Genética/genética , Metabolismo/genética , Mitocôndrias/genética , Mitocôndrias/metabolismo , Envelhecimento/fisiologia , Animais , Feminino , Genoma Mitocondrial/genética , Haplótipos , Insulina/metabolismo , Longevidade/genética , Masculino , Metabolismo/fisiologia , Metabolômica , Camundongos , Camundongos Congênicos , Mitocôndrias/patologia , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Obesidade/genética , Obesidade/metabolismo , Fenótipo , Proteômica , Espécies Reativas de Oxigênio/metabolismo , Encurtamento do Telômero , Transcriptoma , Resposta a Proteínas não Dobradas
20.
Sci Rep ; 6: 27351, 2016 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-27272971

RESUMO

The mitochondria-associated membrane (MAM) is a specialized subdomain of the endoplasmic reticulum (ER) which acts as an intracellular signaling hub. MAM dysfunction has been related to liver disease. We report a high-throughput mass spectrometry-based proteomics characterization of MAMs from mouse liver, which portrays them as an extremely complex compartment involved in different metabolic processes, including steroid metabolism. Interestingly, we identified caveolin-1 (CAV1) as an integral component of hepatic MAMs, which determine the relative cholesterol content of these ER subdomains. Finally, a detailed comparative proteomics analysis between MAMs from wild type and CAV1-deficient mice suggests that functional CAV1 contributes to the recruitment and regulation of intracellular steroid and lipoprotein metabolism-related processes accrued at MAMs. The potential impact of these novel aspects of CAV1 biology on global cell homeostasis and disease is discussed.


Assuntos
Caveolina 1/metabolismo , Retículo Endoplasmático/metabolismo , Hepatócitos/metabolismo , Metabolismo dos Lipídeos , Mitocôndrias/metabolismo , Animais , Fracionamento Celular , Espectrometria de Massas , Camundongos Endogâmicos C57BL , Proteoma/análise
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