RESUMO
BACKGROUND: Although the COVID-19 pandemic has increased the prevalence of cases with olfactory loss, other respiratory viruses can also cause this condition. We aimed to compare the prevalence of acute SARS-CoV-2 infection and other respiratory viruses in patients with sudden smell loss, and to assess the impact of SARS-CoV-2 viral load and co-infection on olfactory symptoms. METHODS: Patients with sudden smell loss were recruited in a multicenter prospective cohort study in 15 hospitals in Brazil. Clinical questionnaire, Connecticut Chemosensory Clinical Research Center (CCCRC) olfactory test and nasopharyngeal swab to perform a PCR-based respiratory viral panel were collected at first visit (day 0) and 30 and 60 days after recruitment. RESULTS: 188 of 213 patients presented positive test result for SARS-CoV-2, among which 65 were co-infected with other respiratory viruses (e.g., rhinovirus, enterovirus, and parainfluenza). 25 had negative test results for SARS-CoV-2. Patients in both SARSCoV-2 and non-SARS-CoV-2 groups had objective anosmia (less than 2 points according to the psychophysical olfactory CCCRC) at day 0, with no significant difference between them. Both groups had significant smell scores improvement after 30 and 60 days, with no difference between them. Co-infection with other respiratory viruses, and SARS-CoV-2 viral load did not impact olfactory scores. CONCLUSION: Patients with sudden smell loss associated with SARS-CoV-2 and other respiratory viruses had similar presentation, with most participants initiating with anosmia, and total or near total recovery after 60 days. SARS-CoV-2 viral load and co-infections with other respiratory viruses were not associated with poorer olfactory outcomes.
Assuntos
COVID-19 , Coinfecção , Transtornos do Olfato , Humanos , SARS-CoV-2 , COVID-19/complicações , Anosmia/complicações , Anosmia/epidemiologia , Estudos Prospectivos , Pandemias , Coinfecção/complicações , Coinfecção/epidemiologia , Transtornos do Olfato/diagnóstico , Transtornos do Olfato/epidemiologia , Transtornos do Olfato/etiologia , OlfatoRESUMO
The identification and SAR development of a series of negative allosteric modulators of the GABAA α5 receptor is described. This novel series of compounds was optimised to provide analogues with high GABAA α5 binding affinity, high α5 negative allosteric modulatory activity, good functional subtype selectivity and low microsomal turnover, culminating in identification of ONO-8590580.
Assuntos
Transtornos Cognitivos/tratamento farmacológico , Descoberta de Drogas , Imidazóis/farmacologia , Piridinas/farmacologia , Receptores de GABA-A/metabolismo , Regulação Alostérica/efeitos dos fármacos , Transtornos Cognitivos/metabolismo , Relação Dose-Resposta a Droga , Humanos , Imidazóis/síntese química , Imidazóis/química , Microssomos Hepáticos/química , Microssomos Hepáticos/metabolismo , Estrutura Molecular , Piridinas/síntese química , Piridinas/química , Relação Estrutura-AtividadeRESUMO
Bacterial haemolytic jaundice caused by Ichthyobacterium seriolicida has been responsible for mortality in farmed yellowtail, Seriola quinqueradiata, in western Japan since the 1980s. In this study, polymorphic analysis of I. seriolicida was performed using three molecular methods: amplified fragment length polymorphism (AFLP) analysis, multilocus sequence typing (MLST) and multiple-locus variable-number tandem repeat analysis (MLVA). Twenty-eight isolates were analysed using AFLP, while 31 isolates were examined by MLST and MLVA. No polymorphisms were identified by AFLP analysis using EcoRI and MseI, or by MLST of internal fragments of eight housekeeping genes. However, MLVA revealed variation in repeat numbers of three elements, allowing separation of the isolates into 16 sequence types. The unweighted pair group method using arithmetic averages cluster analysis of the MLVA data identified four major clusters, and all isolates belonged to clonal complexes. It is likely that I. seriolicida populations share a common ancestor, which may be a recently introduced strain.
Assuntos
Infecções Bacterianas/veterinária , Bacteroidetes/fisiologia , Doenças dos Peixes/microbiologia , Icterícia/veterinária , Perciformes , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados/veterinária , Animais , Infecções Bacterianas/microbiologia , Bacteroidetes/genética , Japão , Icterícia/microbiologia , Repetições Minissatélites , Tipagem de Sequências Multilocus/veterinária , FilogeniaRESUMO
Laparoscopic transhiatal esophagectomy is a minimally invasive approach for esophageal cancer. However, a transhiatal procedure has not yet been established for en bloc mediastinal dissection. The purpose of this study was to present our novel procedure, hand-assisted laparoscopic transhiatal esophagectomy, with a systematic procedure for en bloc mediastinal dissection. The perioperative outcomes of patients who underwent this procedure were retrospectively analyzed. Transhiatal subtotal mobilization of the thoracic esophagus with en bloc lymph node dissection distally from the carina was performed according to a standardized procedure using a hand-assisted laparoscopic technique, in which the operator used a long sealing device under appropriate expansion of the operative field by hand assistance and long retractors. The thoracoscopic procedure was performed for upper mediastinal dissection following esophageal resection and retrosternal stomach roll reconstruction, and was avoided based on the nodal status and operative risk. A total of 57 patients underwent surgery between January 2012 and June 2013, and the transthoracic procedure was performed on 34 of these patients. In groups with and without the transthoracic procedure, total operation times were 370 and 216 minutes, blood losses were 238 and 139 mL, and the numbers of retrieved nodes were 39 and 24, respectively. R0 resection rates were similar between the groups. The incidence of recurrent laryngeal nerve palsy was significantly higher in the group with the transthoracic procedure, whereas no significant differences were observed in that of pneumonia between these groups. The hand-assisted laparoscopic transhiatal method, which is characterized by a systematic procedure for en bloc mediastinal dissection supported by hand and long device use, was safe and feasible for minimally invasive esophagectomy.
Assuntos
Neoplasias Esofágicas/cirurgia , Esofagectomia/métodos , Laparoscopia Assistida com a Mão/métodos , Excisão de Linfonodo/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Viabilidade , Feminino , Humanos , Masculino , Mediastino/patologia , Mediastino/cirurgia , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do TratamentoRESUMO
OBJECTIVES: To study the occurrence of fever and the behaviours of inflammatory blood markers (C-reactive protein - CRP and procalcitonin - PCT) during episodes of otorrhea due to uncomplicated chronic otitis media in immunocompetent and immunocompromised patients. DESIGN: Prospective study of patients presenting with otorrhea over a 36-month period. SETTING: All patients were treated at Bonsucesso General Hospital, a tertiary referral hospital in Rio de Janeiro, Brazil. PARTICIPANTS: A total of 84 participants, of which 50 were immunocompetent and 34 were immunocompromised. Immunocompetent patients had a total of 106 episodes of otorrhea, and immunocompromised patients had 117 episodes of otorrhea. MAIN OUTCOME MEASURES: Occurrence of fever (axillary temperature over 38(°) C) and elevation of C-reactive protein and procalcitonin levels above the normal ranges. RESULTS: In the immunocompetent group, the levels of procalcitonin were elevated in five of 106 episodes of otorrhea. The C-reactive protein levels were above the normal range in nine of 106 episodes, the same number of episodes in which fever was observed. In the immunocompromised group, procalcitonin was elevated in 38 of 117 episodes of otorrhea, C-reactive protein levels were abnormal in 40 episodes, and fever was detected in 37 episodes. Cases of otorrhea with systemic inflammatory response were significantly more common in immunocompromised patients with associated rhinosinusitis. CONCLUSIONS: Otorrhea due to uncomplicated chronic otitis media rarely causes a systemic inflammatory response in immunocompetent patients. Its occurrence in immunocompromised patients seems to be more related to concurrent rhinosinusitis than to the chronic middle ear inflammation itself.
Assuntos
Hospedeiro Imunocomprometido , Otite Média Supurativa/complicações , Síndrome de Resposta Inflamatória Sistêmica/etiologia , Doença Crônica , Humanos , Otite Média com Derrame/etiologia , Estudos ProspectivosRESUMO
This study was designed to determine the efficacy of esophagectomy preceded by the laparoscopic transhiatal approach (LTHA) with regard to the perioperative outcomes of esophageal cancer. The esophageal hiatus was opened by hand-assisted laparoscopic surgery, and carbon dioxide was introduced into the mediastinum. Dissection of the distal esophagus was performed up to the level of the tracheal bifurcation. En bloc dissection of the posterior mediastinal lymph nodes was performed using LTHA. Next, cervical lymphadenectomy, reconstruction via a retrosternal route with a gastric tube and anastomosis from a cervical approach were performed. Finally, a small thoracotomy (around 10 cm in size) was made to extract the thoracic esophagus and allow upper mediastinal lymphadenectomy to be performed. The treatment outcomes of 27 esophageal cancer patients who underwent LTHA-preceding esophagectomy were compared with those of 33 patients who underwent the transthoracic approach preceding esophagectomy without LTHA (thoracotomy; around 20 cm in size). The intrathoracic operative time and operative bleeding were significantly decreased by LTHA. The total operative time did not differ between the two groups, suggesting that the abdominal procedure was longer in the LTHA group. The number of resected lymph nodes did not differ between the two groups. Postoperative respiratory complications occurred in 18.5% of patients treated with LTHA and 30.3% of those treated without it. The increase in the number of peripheral white blood cells and the duration of thoracic drainage were significantly decreased by this method. Our surgical procedure provides a good surgical view of the posterior mediastinum, markedly shortens the intrathoracic operative time, and decreases the operative bleeding without increasing major postoperative complications.
Assuntos
Neoplasias Esofágicas/cirurgia , Esofagectomia , Laparoscopia Assistida com a Mão/métodos , Idoso , Perda Sanguínea Cirúrgica , Carcinoma de Células Escamosas/cirurgia , Drenagem , Feminino , Humanos , Leucócitos Mononucleares , Excisão de Linfonodo , Masculino , Mediastino/cirurgia , Duração da Cirurgia , Pneumonia/etiologia , Complicações Pós-Operatórias , Toracotomia , Fatores de TempoRESUMO
BACKGROUND: Neuroimmunological disorders are involved in the pathogenesis of atopic dermatitis (AD), partly through enhanced sensory nerve-skin mast cell interaction. Cell adhesion molecule 1 (CADM1) is a mast-cell adhesion molecule that mediates the adhesion to, and communication with, sympathetic nerves. OBJECTIVES: To investigate the role of mast cell CADM1 in the pathogenesis of AD, CADM1 expression levels by comparing between lesional and nonlesional skin mast cells of an AD mouse model, which was developed by repeated application of trinitrochlorobenzene, and to examine, in cocultures, how the alterations in CADM1 detected in lesional mast cells might affect the sensory nerve-mast cell interaction. METHODS: AD-like lesional and nonlesional skin mast cells were collected separately by laser capture microdissection. CADM1 expression was examined by reverse transcription-polymerase chain reaction and CADM1 immunohistochemistry. In cocultures, adhesion between dorsal root ganglion (DRG) neurites and IC2 mast cells was analysed by loading a femtosecond laser-induced impulsive force on neurite-attendant IC2 cells, while cellular communication was monitored as the IC2 cellular response ([Ca(2+)]i increase) after nerve-specific stimulant-induced DRG activation. RESULTS: AD-like lesional mast cells expressed three-fold more CADM1 transcripts than nonlesional cells. This was supported at the protein level, shown by immunohistochemistry. In coculture, CADM1 overexpression in IC2 cells strengthened DRG neurite-IC2 cell adhesion and doubled the population of IC2 cells responding to DRG activation. A function-blocking anti-CADM1 antibody abolished these effects in a dose-dependent manner. CONCLUSIONS: Increased expression of CADM1 in mast cells appeared to be a cause of enhanced sensory nerve-mast cell interaction in a hapten-induced mouse model of AD.
Assuntos
Moléculas de Adesão Celular/metabolismo , Dermatite Atópica/metabolismo , Imunoglobulinas/metabolismo , Mastócitos/metabolismo , Células Receptoras Sensoriais/fisiologia , Animais , Adesão Celular , Molécula 1 de Adesão Celular , Moléculas de Adesão Celular/fisiologia , Comunicação Celular/fisiologia , Células Cultivadas , Dermatite Atópica/induzido quimicamente , Pavilhão Auricular , Gânglios Espinais/fisiologia , Haptenos/toxicidade , Imunoglobulinas/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Neuritos/fisiologia , Cloreto de Picrila/toxicidade , Venenos de Escorpião/farmacologiaRESUMO
The formation of the Ontong Java Nui super oceanic plateau (OJN), which is based on the model that the submarine Ontong Java Plateau (OJP), Manihiki Plateau (MP), and Hikurangi Plateau (HP) were once its contiguous fragments, could have been the largest globally consequential volcanic event in Earth's history. This OJN hypothesis has been debated given the paucity of evidence, for example, the differences in crustal thickness, the compositional gap between MP and OJP basalts and the apparent older age of both plateaus relative to HP remain unresolved. Here we investigate the geochemical and 40Ar-39Ar ages of dredged rocks recovered from the OJP's eastern margin. Volcanic rocks having compositions that match the low-Ti MP basalts are reported for the first time on the OJP and new ~ 96-116 Ma and 67-68 Ma 40Ar-39Ar age data bridge the temporal gap between OJP and HP. These results provide new evidence for the Ontong Java Nui hypothesis and a framework for an integrated tectonomagmatic evolution of the OJP, MP, and HP. The isotopic data imply four mantle components in the source of OJN that are also expressed in present-day Pacific hotspots sources, indicating origin from (and longevity of) the Pacific Large Low Shear-wave Velocity Province.
Assuntos
Tosse/etiologia , Bulbo/fisiopatologia , Neuromielite Óptica/complicações , Administração Oral , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Bulbo/diagnóstico por imagem , Bulbo/efeitos dos fármacos , Neuromielite Óptica/diagnóstico por imagem , Neuromielite Óptica/tratamento farmacológico , Neuromielite Óptica/fisiopatologia , Esteroides/administração & dosagem , Resultado do TratamentoRESUMO
Although many variants of the parathyroid hormone 1 receptor (PTH1R) gene are known to be associated with primary failure of eruption (PFE), the mechanisms underlying the link remains poorly understood. We here performed functional analyses of PTH1R variants reported in PFE patients-namely, 356C>T (P119L), 395C>T (P132L), 439C>T (R147C), and 1148G>A (R383Q)-using HeLa cells with a lentiviral vector-mediated genetic modification. Two particular variants, P119L and P132L, had severe reduction in a level of N-linked glycosylation when compared with wild-type PTH1R, whereas the other 2 showed modest alteration. PTH1R having P119L or P132L showed marked decrease in the affinity to PTH1-34, which likely led to severely impaired cAMP accumulation upon stimulation in cells expressing these mutants, highlighting the importance of these 2 amino acid residues for ligand-mediated proper functioning of PTH1R. To further gain insights into PTH1R functions, we established the induced pluripotent stem cell (iPSC) lines from a patient with PFE and the heterozygous P132L mutation. When differentiated into osteoblastic-lineage cells, PFE-iPSCs showed no abnormality in mineralization. The mRNA expression of RUNX2, SP7, and BGLAP, the osteoblastic differentiation-related genes, and that of PTH1R were augmented in both PFE-iPSC-derived cells and control iPSC-derived cells in the presence of bone morphogenetic protein 2. Also, active vitamin D3 induced the expression of RANKL, a major key factor for osteoclastogenesis, equally in osteoblastic cells derived from control and PFE-iPSCs. In sharp contrast, exposure to PTH1-34 resulted in no induction of RANKL mRNA expression in the cells expressing P132L variant PTH1R, consistent with the idea that a type of heterozygous PTH1R gene mutation would spoil PTH-dependent response in osteoblasts. Collectively, this study demonstrates a link between PFE-associated genetic alteration and causative functional impairment of PTH1R, as well as a utility of iPSC-based disease modeling for future elucidation of pathogenesis in genetic disorders, including PFE.
Assuntos
Receptor Tipo 1 de Hormônio Paratireóideo/genética , Doenças Dentárias , Erupção Dentária , Células HeLa , Humanos , Mutação , Hormônio ParatireóideoRESUMO
Ehrlich ascites tumor cells were found to be very insensitive to diphtheria toxin. We formed 37 hybrids from Ehrlich tumor cells and diphtheria toxin-sensitive human fibroblasts. The effects of diphtheria toxin on protein synthesis in those hybrids were examined. The hybrids were divided into three groups on the basis of toxin sensitivity. Group A hybrids were as sensitive to diphtheria toxin as human fibroblasts, Group C were as resistant as Ehrlich tumor cells, and Group B had intermediate sensitivity. Group A hybrids had diphtheria toxin-binding sites but Group B and C had no detectable binding sites. Elongation factor-2 of all the hybrids was susceptible to ADP-ribosylation by fragment A of diphtheria toxin. Cells of Group A and B became more sensitive to CRM 45 (cross-reacting material 45 of diphtheria toxin) after they were exposed to low pH (pH = 4.5). The resistance of Group C to CRM 45 was not affected by the same treatment. Group A and B hybrids and human fibroblasts had similar sensitivities to a hybrid toxin composed of wheat germ agglutinin and fragment A of diphtheria toxin, but Group C and Ehrlich tumor cells were resistant to this hybrid toxin. All the hybrids and Ehrlich tumor cells were more sensitive to a hybrid toxin composed of wheat germ agglutinin and subunit A of ricin than were human fibroblasts. On subcloning of Group B hybrids, one Group C hybrid was obtained, but no Group A hybrid. These facts suggest that Ehrlich ascites tumor cells differ from human fibroblasts in the expression of a factor(s) that is involved in entry of fragment A of diphtheria toxin into the cytoplasm after the toxin binds to its surface receptors.
Assuntos
Carcinoma de Ehrlich/metabolismo , Toxina Diftérica/metabolismo , Células Híbridas/metabolismo , Receptores de Superfície Celular , Receptores Colinérgicos/metabolismo , Adenosina Difosfato Ribose/metabolismo , Animais , Membrana Celular/metabolismo , Toxina Diftérica/toxicidade , Fibroblastos/metabolismo , Fator de Crescimento Semelhante a EGF de Ligação à Heparina , Humanos , Peptídeos e Proteínas de Sinalização Intercelular , Cinética , Masculino , Camundongos , Fator 2 de Elongação de Peptídeos , Fatores de Alongamento de Peptídeos/metabolismo , Biossíntese de Proteínas/efeitos dos fármacos , Pele/metabolismoRESUMO
Androgens play an important role in the growth of prostate cancer, but the molecular mechanism that underlies development of resistance to antiandrogen therapy remains unknown. Cyclin E has now been shown to increase the transactivation activity of the human androgen receptor (AR) in the presence of its ligand dihydrotestosterone. The enhancement of AR activity by cyclin E was resistant to inhibition by the antiandrogen 5-hydroxyflutamide. Cyclin E was shown to bind directly to the COOH terminus portion of the AB domain of the AR, and to enhance its AF-1 transactivation function. These results suggest that cyclin E functions as a coactivator of the AR, and that aberrant expression of cyclin E in tumors may contribute to persistent activation of AR function, even during androgen ablation therapy.
Assuntos
Ciclina E/fisiologia , Receptores Androgênicos/metabolismo , Transativadores/metabolismo , Linhagem Celular , Glutationa Transferase/genética , Células HeLa , Humanos , Ligantes , Receptores Androgênicos/genética , Proteínas Recombinantes de Fusão/metabolismo , TransfecçãoRESUMO
Pieces of chicken heart or skeletal muscle were placed in a dilute solution of the antimicrobial agent 2-phenoxyethanol and stored at room temperature. Under these conditions, the serum albumin, lactate dehydrogenase, and malate dehydrogenase in these tissues survived in easily detectable amounts for at least 2 weeks. The surviving proteins appeared to be identical with those of fresh tissues in physical, catalytic, and immunological properties. Phenoxyethanol also preserved heart and muscle proteins of representatives of other vertebrate classes. Tissue samples collected in the analysis by biochemical taxonomists.
Assuntos
Preservação Biológica , Animais , Aves , Galinhas , Classificação , L-Lactato Desidrogenase/análise , Lagartos , Malato Desidrogenase/análise , Músculos/análise , Músculos/enzimologia , Miocárdio/análise , Miocárdio/enzimologia , Coelhos , Salmonidae , Albumina Sérica/análiseRESUMO
OBJECTIVE AND DESIGN: We monitored the membrane fusion of liposomes to determine if the minimal components of soluble N-ethyl maleimide-sensitive factor attachment protein receptor (SNARE), which is involved in mast cell exocytosis, have fusogenic activity. METHODS: Three core components of SNARE were reconstituted into liposomes. Membrane fusion between liposomes containing vesicle associated membrane protein (VAMP) -7 or -8 and liposomes containing synaptosomal-associated protein 23 kDa (SNAP23) and syntaxin-3 or -4 was monitored by fluorescence resonance energy transfer. RESULTS: The combination of SNAP23/syntaxin-3/VAMP-8 showed the most efficient liposome-liposome fusogenic activity. Liposomes with VAMP-7 exhibited poor fusogenic activity regardless of the syntaxin isoform. CONCLUSION: The core components of SNAP23, syntaxin-3, and VAMP-8 appear to be minimal machinery to induce membrane fusion, while VAMP-7 appears to be unessential for membrane fusion.
Assuntos
Exocitose/fisiologia , Lipossomos/metabolismo , Mastócitos/fisiologia , Fusão de Membrana/fisiologia , Proteínas SNARE/metabolismo , Animais , Linhagem Celular , Lipossomos/química , Mastócitos/citologia , RatosRESUMO
Liomyomas of the nasal cavity and paranasal sinuses are rare. They make up less than 1% of all leiomyomas in the human body. This is due to the paucity of smooth muscle in the nose. They are classified in three groups: leiomyoma, angiomyoma and epithelioid leiomyoma. Only 15 cases of vascular leiomyomas have been found in the literature. The treatment of choice is surgical excision. Hereby we present a new case and review the literature.
Assuntos
Angiomioma/diagnóstico , Cavidade Nasal , Neoplasias Nasais/diagnóstico , Adulto , Angiomioma/cirurgia , Biópsia , Feminino , Humanos , Neoplasias Nasais/cirurgia , Tomografia Computadorizada por Raios XRESUMO
Cathepsin K inhibitors are new drugs with the potential for the treatment of osteoporosis because they sustain bony remodelling better than bone resorption inhibitors such as bisphosphonates. The treatment of osteoporosis with inhibitors of bony resorption is associated with osteonecrosis of the jaw, as the deterioration in bony quality that they induce is thought to be one of its causes. The quality of bone is delineated by structural and material characteristics (which include the degree and quality of mineralisation, and depends on the content of proteoglycan and the structural integrity of the bony collagen).1,2 Animal and clinical studies have shown that cathepsin K inhibitors improve the mineral density and structural characteristics of bone, but their effect on the rest remains unknown. We therefore hypothesised that these inhibitors will affect the material characteristics of newly-formed mandibular bone. To verify our hypothesis, we used Raman microspectroscopy to examine such bone in rats that were given a cathepsin K inhibitor, and found unusual crystallinity and an increased substitution of carbonate (CO32-) in its crystal structure.
Assuntos
Compostos de Bifenilo/farmacologia , Densidade Óssea/efeitos dos fármacos , Catepsina K/antagonistas & inibidores , Mandíbula/efeitos dos fármacos , Animais , Feminino , Mandíbula/diagnóstico por imagem , Ratos , Ratos Wistar , Tomografia Computadorizada por Raios XRESUMO
Bone quality is defined by structural and material characteristics. Most studies on the mandible have focused on the analysis of structural characteristics, with insufficient investigation of material characteristics. This study tested whether zoledronate affects the material characteristics of newly formed mandibular bone. Thirty-six female Wistar rats were assigned to three groups: sham-ovariectomized rats (SHAM, n=12), ovariectomized rats (OVX, n=12), and ovariectomized rats treated with zoledronate (ZOL, n=12). The left side of the mandibular ramus of all rats was drilled bicortically. Twenty-eight days after surgery, all surviving rats were euthanized and all mandibles were removed. Raman microspectroscopy was performed, and five spectra per specimen of newly formed mandibular bone were analysed. Compared with OVX rats, the mineral/matrix ratio in ZOL rats was significantly increased (5.43±1.88 vs. 7.86±2.05), while crystallinity (0.055±0.002 vs. 0.050±0.002), relative proteoglycan content (0.43±0.10 vs. 0.31±0.05), and collagen structural integrity (1.16±0.21 vs. 0.72±0.06) were significantly decreased. These changes in material characteristics may explain why rats that received zoledronate exhibited peculiar biological phenomena such as bisphosphonate-related osteonecrosis of the jaw.
Assuntos
Conservadores da Densidade Óssea/farmacologia , Mandíbula/efeitos dos fármacos , Mandíbula/ultraestrutura , Ácido Zoledrônico/farmacologia , Animais , Biomarcadores/análise , Densidade Óssea/efeitos dos fármacos , Feminino , Fêmur/diagnóstico por imagem , Fêmur/efeitos dos fármacos , Imageamento Tridimensional , Mandíbula/diagnóstico por imagem , Ovariectomia , Ratos , Ratos Wistar , Análise Espectral Raman , Microtomografia por Raio-XRESUMO
Nuclear factor kappa B (NF-kappaB), which exists as heterodimeric complexes composed of p50 and p65, has been shown to play an important role in cell survival processes. In the present study, we found for the first time that NF-kappaB has an ability to induce the ubiquitin-dependent proteasomal degradation of proapoptotic p73alpha. The activation of NF-kappaB in tumor necrosis factor alpha (TNF-alpha)-stimulated H1299 cells resulted in a significant reduction in the amounts of the endogenous p73alpha. Consistent with these results, TNF-alpha-mediated downregulation of p73alpha was observed in wild-type (WT) mouse embryonic fibroblasts (MEFs) but not in p65-deficient MEFs. Ectopic expression of NF-kappaB decreased a half-life of p73alpha by increasing its ubiquitination levels, and thereby inhibiting the transcriptional activity as well as proapoptotic function of p73alpha, whereas NF-kappaB had undetectable effects on p53. Immunoprecipitation experiments demonstrated that, under our experimental conditions, NF-kappaB does not bind to p73alpha in mammalian cultured cells. In contrast to WT p65, the COOH-terminal deletion mutant of p65 (p65DeltaC) failed to reduce the expression levels of p73alpha, suggesting that NF-kappaB-mediated proteolytic degradation of p73alpha requires the transcriptional activity of NF-kappaB. Taken together, our present results imply that NF-kappaB-mediated degradation of proapoptotic p73 is a novel inhibitory mechanism of p73 that regulates cell survival and death.
Assuntos
Proteínas de Ligação a DNA/metabolismo , NF-kappa B/metabolismo , Proteínas Nucleares/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina/metabolismo , Animais , Células COS , Linhagem Celular Tumoral , Chlorocebus aethiops , Regulação para Baixo , Embrião de Mamíferos/citologia , Fibroblastos/metabolismo , Deleção de Genes , Humanos , Camundongos , Subunidade p50 de NF-kappa B/genética , Subunidade p50 de NF-kappa B/metabolismo , Processamento de Proteína Pós-Traducional , Sinaptotagmina I/genética , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Proteína Tumoral p73RESUMO
Class II major histocompatibility genes are expressed at high levels in B lymphocytes and are gamma interferon (IFN-gamma) inducible in many other cells. Previously, we observed that DRA promoter sequences from positions -150 to +31 determine the tissue specificity of this class II gene. Moreover, Z and X boxes located between positions -145 and -87 conferred B-cell specificity and IFN-gamma inducibility upon a heterologous promoter. In this study, sequences from positions -145 to -35 in the DRA promoter were systematically mutated by using oligonucleotide cassettes. Z (-131 to -125), pyrimidine (-116 to -109), X (-108 to -95), Y (-73 to -61), and octamer (-52 to -45) boxes were required for B-cell specificity and, with the exception of the octamer box, for IFN-gamma inducibility. Z box and sequences flanking Z and X boxes helped to determine low levels of expression in T and uninduced cells. In phenotypically distinct cells, shared and distinct proteins bound to these conserved upstream sequences. However, few correlations between expression and DNA-binding proteins could be made. Similar proteins bound to Z and X boxes, and the Z box most likely represents a duplication of the X box.