RESUMEN
The transcription factor nuclear factor κB (NF-κB) is activated by proinflammatory cytokines, such as tumor necrosis factor α (TNF-α) and Toll-like receptor (TLR) ligands. Screening of NPDepo chemical libraries identified porphyrin derivatives as anti-inflammatory compounds that strongly inhibited the up-regulation of intercellular adhesion molecule-1 (ICAM-1) expression induced by TNF-α, interleukin-1α, the TLR3 ligand, and TLR4 ligand in human umbilical vein endothelial cells. In the present study, the mechanisms of action of porphyrin derivatives were further elucidated using human lung adenocarcinoma A549 cells. Porphyrin derivatives, i.e., dimethyl-2,7,12,18-tetramethyl-3,8-di(1-methoxyethyl)-21H,23H-porphine-13,17-dipropionate (1) and pheophorbide a (2), inhibited TNF-α-induced ICAM-1 expression and decreased the TNF-α-induced transcription of ICAM-1, vascular cell adhesion molecule-1, and E-selectin genes. 1 and 2 reduced the expression of the NF-κB subunit RelA protein for 1 h, which was not rescued by the inhibition of proteasome- and lysosome-dependent protein degradation. In addition, 1 and 2 decreased the expression of multiple components of the TNF receptor 1 complex, and this was accompanied by the appearance of their cross-linked forms. As common components of the NF-κB signaling pathway, 1 and 2 also cross-linked the α, ß, and γ subunits of the inhibitor of NF-κB kinase complex and the NF-κB subunits RelA and p50. Cellular protein synthesis was prevented by 2, but not by 1. Therefore, the present results indicate that porphyrin derivative 1 reduced the expression and increased the cross-linked forms of cellular components required for the NF-κB signaling pathway without affecting global protein synthesis.
Asunto(s)
Molécula 1 de Adhesión Intercelular , FN-kappa B , Porfirinas , Transducción de Señal , Factor de Necrosis Tumoral alfa , Humanos , Transducción de Señal/efectos de los fármacos , Factor de Necrosis Tumoral alfa/metabolismo , Molécula 1 de Adhesión Intercelular/metabolismo , Molécula 1 de Adhesión Intercelular/genética , FN-kappa B/metabolismo , Porfirinas/farmacología , Porfirinas/química , Células A549 , Selectina E/metabolismo , Selectina E/genética , Regulación de la Expresión Génica/efectos de los fármacosRESUMEN
Eukaryotes produce a large number of cytochrome P450s that mediate the synthesis and degradation of diverse endogenous and exogenous metabolites. Yet, most of these P450s are uncharacterized and global tools to study these challenging, membrane-resident enzymes remain to be exploited. Here, we applied activity profiling of plant, mouse and fungal P450s with chemical probes that become reactive when oxidized by P450 enzymes. Identification by mass spectrometry revealed labeling of a wide range of active P450s, including six plant P450s, 40 mouse P450s and 13 P450s of the fungal wheat pathogen Zymoseptoria tritici. We next used transient expression of GFP-tagged P450s by agroinfiltration to show ER-targeting and NADPH-dependent, activity-based labeling of plant, mouse and fungal P450s. Both global profiling and transient expression can be used to detect a broad range of active P450s to study e.g. their regulation and discover selective inhibitors.
Asunto(s)
Sistema Enzimático del Citocromo P-450 , Proteínas Fúngicas , Proteoma , Animales , Sistema Enzimático del Citocromo P-450/metabolismo , Sistema Enzimático del Citocromo P-450/genética , Ratones , Proteoma/metabolismo , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genética , Ascomicetos/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genéticaRESUMEN
Plant phytohormone pathways are regulated by an intricate network of signaling components and modulators, many of which still remain unknown. Here, we report a forward chemical genetics approach for the identification of functional SA agonists in Arabidopsis thaliana that revealed Neratinib (Ner), a covalent pan-HER kinase inhibitor drug in humans, as a modulator of SA signaling. Instead of a protein kinase, chemoproteomics unveiled that Ner covalently modifies a surface-exposed cysteine residue of Arabidopsis epoxide hydrolase isoform 7 (AtEH7), thereby triggering its allosteric inhibition. Physiologically, the Ner application induces jasmonate metabolism in an AtEH7-dependent manner as an early response. In addition, it modulates PATHOGENESIS RELATED 1 (PR1) expression as a hallmark of SA signaling activation as a later effect. AtEH7, however, is not the exclusive target for this physiological readout induced by Ner. Although the underlying molecular mechanisms of AtEH7-dependent modulation of jasmonate signaling and Ner-induced PR1-dependent activation of SA signaling and thus defense response regulation remain unknown, our present work illustrates the powerful combination of forward chemical genetics and chemical proteomics for identifying novel phytohormone signaling modulatory factors. It also suggests that marginally explored metabolic enzymes such as epoxide hydrolases may have further physiological roles in modulating signaling.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Humanos , Arabidopsis/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Epóxido Hidrolasas/metabolismo , Proteínas de Arabidopsis/metabolismo , Ácido Salicílico/metabolismo , Regulación de la Expresión Génica de las PlantasRESUMEN
Congenital tooth agenesis is one of the most common anomalies in humans. Many genetic factors are involved in tooth development, including MSX1, PAX9, WNT10A, and LRP6. Thus, mutations in these genes can cause congenital tooth agenesis in humans. In this study, we identified a novel nonsense WNT10A variant, NM_025216.3(WNT10A_v001):c.1090A > T, which produces a C-terminal truncated gene product, p.(Lys364*), in a sporadic form of congenital tooth agenesis. The variant was not found in the healthy parents and thus was considered to cause congenital tooth agenesis in the case.
RESUMEN
Metacaspases are essential cysteine proteases present in plants, fungi, and protists that are regulated by calcium binding and proteolytic maturation through mechanisms not yet understood. Here, we developed and validated activity-based probes for the three main metacaspase types, and used them to study calcium-mediated activation of metacaspases from their precursors in vitro. By combining substrate-inspired tetrapeptide probes containing an acyloxymethylketone (AOMK) reactive group, with purified representatives of type-I, type-II, and type-III metacaspases, we were able to demonstrate that labeling of mature metacaspases is strictly dependent on calcium. The probe with the highest affinity for all metacaspases also labels higher molecular weight proteoforms of all three metacaspases only in the presence of calcium, displaying the active, unprocessed metacaspase intermediates. Our data suggest that metacaspase activation proceeds through previously unknown active intermediates that are formed upon calcium binding, before precursor processing.
RESUMEN
Reactivity-based chemical proteomics is a powerful technology based on the use of tagged chemicals that covalently react with surface-exposed residues on proteins in native proteomes. Reactivity profiling involves the purification, identification, and quantification of labeled peptides by LC-MS/MS. Here, we have detailed a protocol for reactivity profiling of Cys residues using iodoacetamide probes, displaying >1000 reactive Cys residues in the proteome of phytopathogen Pseudomonas syringae pv. tomato DC3000 (PtoDC3000). Comparative reactivity profiling of PtoDC3000 treated with or without hydrogen peroxide (H2O2) identified ~200 H2O2-sensitive Cys residues in antioxidant enzymes, metabolic enzymes, and transcription regulators. Interestingly, half of these H2O2-sensitive Cys residues are more reactive in response to H2O2 and several proteins have multiple Cys residues with opposite reactivities in response to H2O2 exposure.
Asunto(s)
Cisteína , Solanum lycopersicum , Cromatografía Liquida , Cisteína/química , Peróxido de Hidrógeno/metabolismo , Solanum lycopersicum/metabolismo , Oxidación-Reducción , Proteoma/metabolismo , Pseudomonas syringae/metabolismo , Espectrometría de Masas en Tándem/métodosRESUMEN
Plants encode > 100 metalloproteases representing > 19 different protein families. Tools to study this large and diverse class of proteases have not yet been introduced into plant research. We describe the use of hydroxamate-based photoaffinity probes to explore plant proteomes for metalloproteases. We detected labelling of 23 metalloproteases in leaf extracts of the model plant Arabidopsis thaliana that belong to nine different metalloprotease families and localize to different subcellular compartments. The probes identified several chloroplastic FtsH proteases, vacuolar aspartyl aminopeptidase DAP1, peroxisomal metalloprotease PMX16, extracellular matrix metalloproteases and many cytosolic metalloproteases. We also identified nonproteolytic metallohydrolases involved in the release of auxin and in the urea cycle. Studies on tobacco plants (Nicotiana benthamiana) infected with the bacterial plant pathogen Pseudomonas syringae uncovered the induced labelling of PRp27, a secreted protein with implicated metalloprotease activity. PRp27 overexpression increases resistance, and PRp27 mutants lacking metal binding site are no longer labelled, but still show increased immunity. Collectively, these studies reveal the power of broad-range metalloprotease profiling in plants using hydroxamate-based probes.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Metaloproteínas , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Metaloproteasas/metabolismo , Metaloproteínas/metabolismo , Enfermedades de las Plantas , Pseudomonas syringae/metabolismo , Nicotiana/metabolismoRESUMEN
BACKGROUND: High signal intensity in the endolymphatic duct (ED) is occasionally observed on magnetic resonance imaging (MRI) in ears that have otological disorders. OBJECTIVE: The signal intensity (SI) in the ED on post-contrast MRI was investigated in subjects with various otological disorders, and the meaning of high SI in the ED was evaluated. MATERIAL AND METHODS: 392 patients with otological disorders and 21 controls without otological symptoms underwent 3 T MRI. The SIs of the ED and the cerebellum were measured, the SI ratio (SIR) was calculated, and ears with SIR ≥4 were identified. RESULTS: A high SIR was identified in the ED of 3.7% of ears affected by definite Meniere's disease (dMD), 100% of ears affected by large vestibular aqueduct syndrome (LVAS), and 7.1% of ears with no otological symptoms. On the whole, a significant relationship was found between the existence of vestibular or cochlear EH and the SIR in the ED. CONCLUSION: The MRI finding of high SI in the ED may indicate the mechanism of inner ear disturbances in ears with otological disorders, especially in those with LVAS, and it may suggest an underlying disorder in some ears in which otological symptoms are not apparent.
Asunto(s)
Conducto Endolinfático/diagnóstico por imagen , Pérdida Auditiva Sensorineural/diagnóstico por imagen , Enfermedades del Laberinto/diagnóstico por imagen , Imagen por Resonancia Magnética , Estudios de Casos y Controles , Conducto Endolinfático/fisiología , Conducto Endolinfático/fisiopatología , Pérdida Auditiva Sensorineural/fisiopatología , Humanos , Enfermedades del Laberinto/fisiopatología , Valores de ReferenciaRESUMEN
A number of regulatory nascent peptides have been shown to regulate gene expression by causing programmed ribosome stalling during translation. Nascent peptide emerges from the ribosome through the exit tunnel, and one-third of the way along which ß-loop structures of ribosomal proteins uL4 and uL22 protrude into the tunnel to form the constriction region. Structural studies have shown interactions between nascent peptides and the exit tunnel components including the constriction region. In eukaryotes, however, there is a lack of genetic studies for the involvement of the constriction region in ribosome stalling. Here, we established transgenic Arabidopsis lines that carry mutations in the ß-loop structure of uL4. Translation analyses using a cell-free translation system derived from the transgenic Arabidopsis carrying the mutant ribosome showed that the uL4 mutations reduced the ribosome stalling of four eukaryotic stalling systems, including those for which stalled structures have been solved. Our data, which showed differential effects of the uL4 mutations depending on the stalling systems, explained the spatial allocations of the nascent peptides at the constriction that were deduced by structural studies. Conversely, our data may predict allocation of the nascent peptide at the constriction of stalling systems for which structural studies are not done.
Asunto(s)
Péptidos/genética , Biosíntesis de Proteínas/genética , Proteínas Ribosómicas/química , Ribosomas/genética , Secuencia de Aminoácidos/genética , Arabidopsis/química , Arabidopsis/genética , Sistema Libre de Células , Células Eucariotas/química , Células Eucariotas/metabolismo , Péptidos/química , Genética Inversa , Proteínas Ribosómicas/genética , Ribosomas/químicaRESUMEN
Plants protect their wounds against pathogen invasion by releasing damage signals that induce immune responses in neighboring cells. A new study shows that a conserved bioactive peptide is released from its cytoplasmic precursor upon wounding by a metacaspase that is activated by calcium influx into the injured cell.
Asunto(s)
Calcio , Plantas , PéptidosRESUMEN
Though they are rare in nature, anthropogenic 1,3,5-triazines have been used in herbicides as chemically stable scaffolds. Here, we show that small 1,3,5-triazines selectively target ascorbate peroxidases (APXs) in Arabidopsis (Arabidopsis thaliana), tomato (Solanum lycopersicum), rice (Oryza sativa), maize (Zea mays), liverwort (Marchantia polymorpha), and other plant species. The alkyne-tagged 2-chloro-4-methyl-1,3,5-triazine probe KSC-3 selectively binds APX enzymes, both in crude extracts and in living cells. KSC-3 blocks APX activity, thereby reducing photosynthetic activity under moderate light stress, even in apx1 mutant plants. This suggests that APX enzymes in addition to APX1 protect the photosystem against reactive oxygen species. Profiling APX1 with KCS-3 revealed that the catabolic products of atrazine (a 1,3,5-triazine herbicide), which are common soil pollutants, also target APX1. Thus, KSC-3 is a powerful chemical probe to study APX enzymes in the plant kingdom.
Asunto(s)
Arabidopsis/enzimología , Arabidopsis/metabolismo , Ascorbato Peroxidasas/metabolismo , Arabidopsis/genética , Ascorbato Peroxidasas/genética , Atrazina/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Regulación de la Expresión Génica de las Plantas/fisiología , Hepatophyta/genética , Hepatophyta/metabolismo , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , Oryza/genética , Oryza/metabolismo , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Zea mays/genética , Zea mays/metabolismoRESUMEN
Plants and animals recognize conserved flagellin fragments as a signature of bacterial invasion. These immunogenic elicitor peptides are embedded in the flagellin polymer and require hydrolytic release before they can activate cell surface receptors. Although much of flagellin signaling is understood, little is known about the release of immunogenic fragments. We discovered that plant-secreted ß-galactosidase 1 (BGAL1) of Nicotiana benthamiana promotes hydrolytic elicitor release and acts in immunity against pathogenic Pseudomonas syringae strains only when they carry a terminal modified viosamine (mVio) in the flagellin O-glycan. In counter defense, P. syringae pathovars evade host immunity by using BGAL1-resistant O-glycans or by producing a BGAL1 inhibitor. Polymorphic glycans on flagella are common to plant and animal pathogenic bacteria and represent an important determinant of host immunity to bacterial pathogens.
Asunto(s)
Flagelina/inmunología , Flagelina/metabolismo , Interacciones Huésped-Patógeno/inmunología , Nicotiana/enzimología , Nicotiana/microbiología , Polímeros/metabolismo , Pseudomonas syringae/inmunología , beta-Galactosidasa/metabolismo , Glicosilación , Hidrólisis , Polisacáridos/química , Polisacáridos/metabolismo , Pseudomonas syringae/patogenicidad , Nicotiana/genética , Nicotiana/inmunología , beta-Galactosidasa/genéticaRESUMEN
Plants have evolved complex systems to rapidly respond to severe stress conditions, such as heat, cold, and dehydration. Dehydration-responsive element-binding protein 2A (DREB2A) is a key transcriptional activator that induces many heat- and drought-responsive genes, increases tolerance to both heat and drought stress, and suppresses plant growth in Arabidopsis thaliana. DREB2A expression is induced by stress, but stabilization of the DREB2A protein in response to stress is essential for activating the expression of downstream stress-inducible genes. Under nonstress growth conditions, an integral negative regulatory domain (NRD) destabilizes DREB2A, but the mechanism by which DREB2A is stabilized in response to stress remains unclear. Here, based on bioinformatics, mutational, MS, and biochemical analyses, we report that Ser/Thr residues in the NRD are phosphorylated under nonstress growth conditions and that their phosphorylation decreases in response to heat. Furthermore, we found that this phosphorylation is likely mediated by casein kinase 1 and is essential for the NRD-dependent, proteasomal degradation of DREB2A under nonstress conditions. These observations suggest that inhibition of NRD phosphorylation stabilizes and activates DREB2A in response to heat stress to enhance plant thermotolerance. Our study reveals the molecular basis for the coordination of stress tolerance and plant growth through stress-dependent transcriptional regulation, which may allow the plants to rapidly respond to fluctuating environmental conditions.
Asunto(s)
Adaptación Fisiológica , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Respuesta al Choque Térmico/fisiología , Calor , Factores de Transcripción/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Mutación , Fosforilación , Factores de Transcripción/genéticaRESUMEN
With nearly 140 α-glycosidases in 14 different families, plants are well equipped with enzymes that can break the α-glucosidic bonds in a large diversity of molecules. Here, we introduce activity-based protein profiling (ABPP) of α-glycosidases in plants using α-configured cyclophellitol aziridine probes carrying various fluorophores or biotin. In Arabidopsis (Arabidopsis thaliana), these probes label members of the GH31 family of glycosyl hydrolases, including endoplasmic reticulum-resident α-glucosidase-II Radial Swelling3/Priority for Sweet Life5 (RSW3/PSL5) and Golgi-resident α-mannosidase-II Hybrid Glycosylation1 (HGL1), both of which trim N-glycans on glycoproteins. We detected the active state of extracellular α-glycosidases such as α-xylosidase XYL1, which acts on xyloglucans in the cell wall to promote cell expansion, and α-glucosidase AGLU1, which acts in starch hydrolysis and can suppress fungal invasion. Labeling of α-glycosidases generates pH-dependent signals that can be suppressed by α-glycosidase inhibitors in a broad range of plant species. To demonstrate its use on a nonmodel plant species, we applied ABPP on saffron crocus (Crocus sativus), a cash crop for the production of saffron spice. Using a combination of biotinylated glycosidase probes, we identified and quantified 67 active glycosidases in saffron crocus stigma, of which 10 are differentially active. We also uncovered massive changes in hydrolase activities in the corms upon infection with Fusarium oxysporum using multiplex fluorescence labeling in combination with probes for serine hydrolases and cysteine proteases. These experiments demonstrate the ease with which active α-glycosidases and other hydrolases can be analyzed through ABPP in model and nonmodel plants.
Asunto(s)
Colorantes Fluorescentes/química , Glicósido Hidrolasas/química , Proteínas de Plantas/metabolismo , Proteómica/métodos , Acarbosa/farmacología , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Biotinilación , Carbocianinas/química , Dominio Catalítico , Crocus/enzimología , Inhibidores Enzimáticos/farmacología , Fusarium/patogenicidad , Galactosamina/análogos & derivados , Galactosamina/farmacología , Glucosidasas/antagonistas & inhibidores , Glucosidasas/química , Glucosidasas/metabolismo , Glicósido Hidrolasas/antagonistas & inhibidores , Glicósido Hidrolasas/metabolismo , Concentración de Iones de Hidrógeno , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/análisis , Proteínas de Plantas/químicaRESUMEN
Quinacrine has been used for therapeutic drugs in some clinical settings. In the present study, we demonstrated that quinacrine decreased the expression of intercellular adhesion molecule-1 (ICAM-1) induced by tumor necrosis factor (TNF)-α and interleukin-1 (IL-1) α in human lung adenocarcinoma A549 cells. Quinacrine inhibited ICAM-1 mRNA expression and nuclear factor κB (NF-κB)-responsive luciferase reporter activity following a treatment with TNF-α and IL-1α. In the NF-κB signaling pathway, quinacrine did not markedly affect the TNF-α-induced degradation of the inhibitor of NF-κB or the TNF-α-induced phosphorylation of the NF-κB subunit, p65, at Ser-536 and its subsequent translocation to the nucleus. In contrast, a chromatin immunoprecipitation assay showed that quinacrine prevented the binding of p65 to the ICAM-1 promoter following TNF-α stimulation. Moreover, TNF-α and the Fas ligand effectively reduced the viability of A549 cells in the presence of quinacrine only. Quinacrine down-regulated the constitutive and TNF-α-induced expression of c-FLIP and Mcl-1 in A549 cells. These results revealed that quinacrine inhibits ICAM-1 transcription by blocking the DNA binding of p65 and sensitizes A549 cells to TNF-α and the Fas ligand.
Asunto(s)
Adenocarcinoma/genética , Antineoplásicos/farmacología , Molécula 1 de Adhesión Intercelular/genética , Neoplasias Pulmonares/genética , Quinacrina/farmacología , Factor de Transcripción ReIA/metabolismo , Transcripción Genética/efectos de los fármacos , Células A549 , Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/metabolismo , Adenocarcinoma del Pulmón , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Sinergismo Farmacológico , Proteína Ligando Fas/farmacología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Molécula 1 de Adhesión Intercelular/metabolismo , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/metabolismo , Regiones Promotoras Genéticas/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
DEHYDRATION-RESPONSIVE ELEMENT BINDING PROTEIN 2A (DREB2A) acts as a key transcription factor in both drought and heat stress tolerance in Arabidopsis and induces the expression of many drought- and heat stress-inducible genes. Although DREB2A expression itself is induced by stress, the posttranslational regulation of DREB2A, including protein stabilization, is required for its transcriptional activity. The deletion of a 30-aa central region of DREB2A known as the negative regulatory domain (NRD) transforms DREB2A into a stable and constitutively active form referred to as DREB2A CA. However, the molecular basis of this stabilization and activation has remained unknown for a decade. Here we identified BTB/POZ AND MATH DOMAIN proteins (BPMs), substrate adaptors of the Cullin3 (CUL3)-based E3 ligase, as DREB2A-interacting proteins. We observed that DREB2A and BPMs interact in the nuclei, and that the NRD of DREB2A is sufficient for its interaction with BPMs. BPM-knockdown plants exhibited increased DREB2A accumulation and induction of DREB2A target genes under heat and drought stress conditions. Genetic analysis indicated that the depletion of BPM expression conferred enhanced thermotolerance via DREB2A stabilization. Thus, the BPM-CUL3 E3 ligase is likely the long-sought factor responsible for NRD-dependent DREB2A degradation. Through the negative regulation of DREB2A stability, BPMs modulate the heat stress response and prevent an adverse effect of excess DREB2A on plant growth. Furthermore, we found the BPM recognition motif in various transcription factors, implying a general contribution of BPM-mediated proteolysis to divergent cellular responses via an accelerated turnover of transcription factors.
Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Regulación de la Expresión Génica de las Plantas , Regiones Promotoras Genéticas , Termotolerancia , Factores de Transcripción/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Deshidratación , Respuesta al Choque Térmico , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/crecimiento & desarrollo , Plantas Modificadas Genéticamente/metabolismo , Proteolisis , Estrés Fisiológico , Ubiquitina-Proteína Ligasas/genéticaRESUMEN
CONCLUSIONS: The presence of endolymphatic hydrops (EH) in the vestibule on magnetic resonance imaging (MRI) might be a high-risk factor for complications in cases that are candidates for stapes surgery. OBJECTIVE: Pre-operative detection of EH could be valuable in cases that are candidates for stapes surgery to prevent unpredictable complications following surgery. Pre-operative MRI findings and post-operative findings following stapes surgery were compared to evaluate the efficacy of such MRI evaluation for the management of cases with otosclerosis. SUBJECTS AND METHODS: Sixteen cases who underwent pre-operative evaluation by 3T MRI performed 4 h after intravenous injection of gadolinium and stapes surgery for otosclerosis were recruited. Imaging data concerning the degree of EH in the vestibule and cochlea were compared with post-operative clinical findings for all cases. RESULTS: Mild EH in the cochlea or the vestibule was observed in eight ears and one ear, respectively, whereas one ear showed significant EH both in the cochlea and the vestibule. The post-operative course was uneventful in 12 of 14 cases with no EH in the vestibule, and the other two cases had a short period of dizziness, but two cases with EH in the vestibule had a long period of dizziness.
Asunto(s)
Hidropesía Endolinfática/diagnóstico por imagen , Imagen por Resonancia Magnética , Otosclerosis/cirugía , Complicaciones Posoperatorias/etiología , Cirugía del Estribo , Adulto , Anciano , Hidropesía Endolinfática/complicaciones , Femenino , Humanos , Masculino , Persona de Mediana Edad , Cuidados PreoperatoriosRESUMEN
CONCLUSION: All definite Meniere's disease (MD) had endolymphatic hydrops (EH) at least in the cochlea or the vestibule. Symptoms of MD may appear after formation of EH. It is assumed that the probability of immediate progression to bilateral MD from unilateral MD is very low in patients without EH on the non-affected side. OBJECTIVE: To evaluate the EH on both sides in patients with unilateral and bilateral MD, and to investigate factors with progression to bilateral MD including the degree of EH, hearing level, and the duration of MD. PATIENTS AND METHODS: The study included 29 patients with unilateral definite MD and 12 patients with bilateral definite MD. The endolymphatic space size was visualized by using 3-Tesla magnetic resonance imaging. RESULTS: All patients with unilateral and bilateral MD had significant or mild EH at least in the cochlea or the vestibule on the affected side. On the non-affected side, EH was not observed at all in eight patients, but asymptomatic EH was observed in the cochlea in 14 patients and in the vestibule in 16 patients. There was no relationship between the EH on the non-affected side and the duration of MD.
Asunto(s)
Oído Interno/patología , Enfermedad de Meniere/patología , Progresión de la Enfermedad , Oído Interno/diagnóstico por imagen , Femenino , Audición , Humanos , Imagen por Resonancia Magnética , Masculino , Enfermedad de Meniere/diagnóstico por imagen , Enfermedad de Meniere/fisiopatología , Persona de Mediana EdadRESUMEN
The active proteome dictates plant physiology. Yet, active proteins are difficult to predict based on transcript or protein levels, because protein activities are regulated post-translationally in their microenvironments. Over the past 10 years, activity-based protein profiling (ABPP) is increasingly used in plant science. ABPP monitors the activities of hundreds of plant proteins using tagged chemical probes that react with the active site of proteins in a mechanism-dependent manner. Since labeling is covalent and irreversible, labeled proteins can be detected and identified on protein gels and by mass spectrometry using tagged fluorophores and/or biotin. Here, we discuss general concepts, approaches and practical considerations of ABPP, before we summarize the discoveries made using 40 validated probes representing 14 chemotypes that can monitor the active state of >4,500 plant proteins. These discoveries and new opportunities indicate that this emerging functional proteomic technology is a powerful discovery tool that will have an increasing impact on plant science.
Asunto(s)
Proteínas de Plantas/metabolismo , Plantas/metabolismo , Proteoma/metabolismo , Proteómica/métodos , Complejo de la Endopetidasa Proteasomal/metabolismo , Coloración y EtiquetadoRESUMEN
OBJECTIVES/HYPOTHESIS: Pathologic third window lesions, such as superior semicircular canal dehiscence syndrome (SCDS) or large vestibular aqueduct syndrome (LVAS), cause several auditory and vestibular symptoms, which might affect perilymphatic pressure and induce endolymphatic hydrops (EH). In this study, the existence of EH in subjects with SCDS or LVAS was investigated using contrast-enhanced magnetic resonance imaging (MRI). STUDY DESIGN: Case series at university hospital. METHODS: Seventeen ears from nine subjects who were diagnosed as having SCDS (five ears from three cases) or LVAS (12 ears from six cases) were studied. Ears were evaluated by 3-T MRI performed 4 hours after intravenous injection of gadodiamide hydrate. Imaging data concerning the degree of EH in the cochlea and the vestibule were compared with clinical symptoms and hearing levels for all ears. RESULTS: All ears showed air-bone gaps at low frequencies on pure tone audiometry. None of the subjects with SCDS had episodes of acute sensorineural hearing loss (SNHL) or vestibular symptoms, except for one patient who complained of head vibration induced by loud noise. Conversely, five of six subjects with LVAS had episodes of acute SNHL or vestibular symptoms. Four of five ears with SCDS showed severe EH in the cochlea, and two ears showed mild EH in the vestibule. All ears with LVAS showed mild to severe EH in both the cochlea and vestibule. CONCLUSIONS: The present study demonstrated the existence of EH in ears with pathologic third window lesions, which might affect patients' auditory or vestibular symptoms. LEVEL OF EVIDENCE: 4 Laryngoscope, 126:1446-1450, 2016.