RESUMO
In starved larvae of the tobacco hornworm moth Manduca sexta, larval and imaginal tissues stop growing, the former because they lack nutrient-dependent signals but the latter because of suppression by juvenile hormone. Without juvenile hormone, imaginal discs form and grow despite severe starvation. This hormone inhibits the intrinsic signaling needed for disc morphogenesis and does so independently of ecdysteroid action. Starvation and juvenile hormone treatments allowed the separation of intrinsic and nutrient-dependent aspects of disc growth and showed that both aspects must occur during the early phases of disc morphogenesis to ensure normal growth leading to typical-sized adults.
Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Hormônios Juvenis/fisiologia , Manduca/fisiologia , Animais , Ecdisteroides/fisiologia , Larva , Manduca/embriologia , Manduca/crescimento & desenvolvimento , Morfogênese/efeitos dos fármacos , Morfogênese/fisiologia , Piridinas/farmacologiaRESUMO
Human Valpha24+ natural killer T (NKT) cells have an invariant T-cell receptor-alpha chain and are activated in a CD1d-restricted manner. Valpha24+ NKT cells are thought to regulate immune responses and to play important roles in the induction of allograft tolerance. In this report, we analyzed the recovery of Valpha24+ NKT cells after hematopoietic stem cell transplantation and its correlation with graft-versus-host disease (GVHD). Patients who received a dose-reduced conditioning regimen, antithymocyte globulin- or CAMPATH-1H-containing conditioning regimen were excluded. NKT cells were reconstituted within 1 month after transplantation in peripheral blood stem cell transplantation recipients, while their numbers remained low for more than 1 year in bone marrow transplantation (BMT) recipients. The number of Valpha24+ NKT cells in BMT recipients with acute GVHD was lower than that in patients without acute GVHD, and both the CD4+ and CD4- Valpha24+ NKT subsets were significantly reduced. With regard to chronic GVHD, BMT recipients with extensive GVHD had significantly fewer Valpha24+ NKT cells than other patients. Furthermore, the number of CD4+ Valpha24+ NKT cells was also significantly reduced in patients with chronic extensive GVHD. Our results raise the possibility that the number of Valpha24+ NKT cells could be related to the development of GVHD.
Assuntos
Doença Enxerto-Hospedeiro/imunologia , Transplante de Células-Tronco Hematopoéticas , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Adolescente , Adulto , Transplante de Medula Óssea , Feminino , Humanos , Sistema Imunitário/imunologia , Masculino , Pessoa de Meia-Idade , Recuperação de Função Fisiológica/imunologia , Doadores de TecidosRESUMO
Gastric antral vascular ectasia (GAVE) may occur after hematopoietic stem cell transplantation (HSCT) and cause severe and prolonged gastric bleeding. The underlying pathology of transplant-associated GAVE (HSCT-GAVE) is poorly understood and an effective therapeutic strategy has not been established yet. We retrospectively reviewed the medical records of 230 consecutive allogeneic transplant recipients in our institution between January 1997 and June 2002. We identified five patients who developed HSCT-GAVE (2.2%). Four patients had bleeding from HSCT-GAVE and one patient had HSCT-GAVE discovered incidentally. The clinical features of these patients were similar in that they all received conditioning treatment with busulfan and had history of thrombotic microangiopathy. Furthermore, treatment with a beta-blocker apparently improved the outcome of HSCT-GAVE in three patients.
Assuntos
Ectasia Vascular Gástrica Antral/diagnóstico , Ectasia Vascular Gástrica Antral/terapia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Adolescente , Adulto , Antineoplásicos Alquilantes/uso terapêutico , Biópsia , Bussulfano/farmacologia , Endotélio Vascular/patologia , Feminino , Ectasia Vascular Gástrica Antral/etiologia , Humanos , Imunossupressores/uso terapêutico , Masculino , Pessoa de Meia-Idade , Neoplasias/terapia , Estudos Retrospectivos , Fatores de Tempo , Condicionamento Pré-TransplanteRESUMO
A 59-year-old female with an unresectable, large pancreatic tumor (10.0 x 8.0 cm(2) on CT scan) underwent nonmyeloablative allogeneic peripheral-blood stem-cell transplantation from her HLA-identical sibling. Pronounced tumor regression and relief from pain without acute graft-versus-host disease (GVHD) were observed following transplantation. The patient is surviving (more than 300 days) after transplantation, with extensive chronic GVHD, and has tumor regression with an 80% reduction in tumor size. The observed clinical course may suggest a graft-versus-tumor effect on the pancreatic tumor following allogeneic stem-cell transplantation.
Assuntos
Adenocarcinoma/terapia , Neoplasias Pancreáticas/terapia , Transplante de Células-Tronco/métodos , Vidarabina/análogos & derivados , Adenocarcinoma/diagnóstico por imagem , Ciclofosfamida/uso terapêutico , Feminino , Doença Enxerto-Hospedeiro/prevenção & controle , Teste de Histocompatibilidade , Humanos , Doadores Vivos , Pessoa de Meia-Idade , Neoplasias Pancreáticas/diagnóstico por imagem , Irmãos , Fatores de Tempo , Tomografia Computadorizada por Raios X , Condicionamento Pré-Transplante/métodos , Resultado do Tratamento , Vidarabina/uso terapêuticoRESUMO
We report a patient with fatal hepatitis B virus (HBV) reactivation after treatment for chronic graft-versus-host disease (GVHD) following allogeneic peripheral blood stem cell transplantation to treat chronic myelogenous leukemia. The presence of antibodies to hepatitis B surface antigen (HBsAb) prior to transplantation indicated previous HBV infection. Liver damage first developed 8 months after transplantation with the disappearance of HBsAb. Hepatitis B antigen was first noted during an examination of liver damage that occurred 22 months after transplantation. Retrospective examination of serum by real-time detection polymerase chain reaction (RTD-PCR) revealed HBV in both the first and second episodes of liver damage (89 copies/mL and 2 x 10(6) copies/mL, respectively). HBV may have been reactivated, leading to fatal liver damage in this HBsAb-positive patient. We propose that RTD-PCR-based analysis should be performed to diagnose liver dysfunction after hematopoietic stem cell transplantation.
Assuntos
Doença Enxerto-Hospedeiro/complicações , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Vírus da Hepatite B/crescimento & desenvolvimento , Ativação Viral , Anticorpos Antivirais/sangue , Células Sanguíneas/citologia , Células Sanguíneas/transplante , Doença Crônica , Evolução Fatal , Doença Enxerto-Hospedeiro/tratamento farmacológico , Hepatite B/diagnóstico , Hepatite B/etiologia , Hepatite B/patologia , Vírus da Hepatite B/imunologia , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/complicações , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Falência Hepática/etiologia , Falência Hepática/patologia , Falência Hepática/virologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , RNA Viral/sangue , Transplante Homólogo/efeitos adversosRESUMO
Bone marrow transplantation (BMT) may be complicated by coagulation abnormalities. The present study evaluated whether platelets might be activated in patients who had undergone BMT without significant coagulopathy. The patients selected had received allogeneic BMTs a median of 39 months before the study (range, 11-124 months) and had not received cyclosporine, FK506 (tacrolimus), or other medication affecting cyclo-oxygenase for at least 3 months prior to the collection of blood samples. Furthermore, patients had platelet counts greater than 100 x 10(9) cells/L and normal serum creatinine levels. Twenty-five healthy volunteers acted as controls. Platelet aggregation studies and a mepacrine assay of platelets showed abnormal aggregation and decreased staining in some patients. The platelet storage-pool adenosine 5'-triphosphate (ATP) level in 15 patients after BMT was 0.45+/-0.24 micromol per 10(11) platelets, whereas the level in 18 controls was 1.03+/-0.36 micromol per 10(11) platelets (P = .00078). The total ATP levels of platelets in patients and controls were 4.33+/-1.14 and 5.63+/-1.51 micromol per 10(11) platelets, respectively (P = .016). With the exception of 1 patient, plasma levels of thrombomodulin and von Willebrand factor were all within the normal range. The average plasma level of 11-dehydrothromboxane B2 was significantly increased in 15 patients after BMT compared with controls, 20.6+/-8.2 and 10.3+/-1.2 pg/mL, respectively (P = .0004). These findings suggest a long-term process of platelet activation in patients after BMT and, following the cessation of cyclosporine, development of acquired storage-pool disorder of platelets.
Assuntos
Transplante de Medula Óssea/efeitos adversos , Deficiência do Pool Plaquetário/etiologia , Trifosfato de Adenosina/análise , Adolescente , Adulto , Idoso , Biomarcadores/sangue , Plaquetas/química , Plaquetas/patologia , Feminino , Humanos , Masculino , Ativação Plaquetária , Transplante Homólogo/efeitos adversosRESUMO
We describe the case of a 51-year-old patient with relapsed myelodysplastic syndrome after allogeneic bone marrow transplantation (BMT), who underwent allogeneic peripheral blood stem cell transplantation (PBSCT) after conditioning with a novel regimen consisting of fludarabine, busulfan, and antithymocyte globulin. The second PBSCT was performed early, at 3 months after the initial allogeneic BMT, but it was well tolerated and complete hematologic remission was documented. The patient did not experience any early transplantation-related organ toxicity but died from opportunistic infection 6 months after the second transplantation. Our experience suggests that this novel regimen may induce remission and could be offered to patients relapsing after the first transplantation; however, the fludarabine-containing regimen might be accompanied by profound immunosuppression.
Assuntos
Transplante de Células-Tronco Hematopoéticas/métodos , Síndromes Mielodisplásicas/terapia , Condicionamento Pré-Transplante/efeitos adversos , Vidarabina/administração & dosagem , Antineoplásicos/administração & dosagem , Antineoplásicos/toxicidade , Transplante de Medula Óssea , Evolução Fatal , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Infecções/etiologia , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/complicações , Recidiva , Condicionamento Pré-Transplante/métodos , Transplante Homólogo/efeitos adversos , Transplante Homólogo/métodos , Vidarabina/análogos & derivados , Vidarabina/toxicidadeRESUMO
The cDNAs for two members of the nuclear receptor superfamily were isolated from the tobacco hornworm, Manduca sexta. The deduced amino acid sequence of MHR4 shows 93-95% identity in the DNA-binding domain and the first portion of the hinge (D) region with the germ cell nuclear factor (GCNF)-related factors (GRFs) of the silkworm, Bombyx mori, and the mealworm, Tenebrio molitor, and with a genomic sequence from the fruit fly, Drosophila melanogaster. Northern blot hybridization showed that a 7.5 kb MHR4 mRNA appeared in Manduca abdominal epidermis just as the ecdysteroid titer began to decline during the larval molt, disappeared about 12 h later, then transiently reappeared shortly before larval ecdysis. During the pupal and adult molts, a similar pattern of expression was seen (the very end of the adult molt was not studied). At peak times of expression in the epidermis, MHR4 mRNA was also present in fat body and the central nervous system (CNS). The deduced amino acid sequence of Manduca FTZ-F1 is 100% and 96% identical to that of B. mori and Drosophila betaFTZ-F1, respectively, in the DNA-binding domain and the adjacent hinge region including the FTZ-F1 box. Northern blot analysis showed that the >9.5 kb betaFTZ-F1 mRNA appeared in Manduca epidermis during the decline of the ecdysteroid titer in the larval, pupal and adult molts as the first peak of MHR4 mRNA declined, then it disappeared in the larval and pupal molts before the second peak of MHR4 appeared. betaFTZ-F1 mRNA was also found in fat body and the CNS at the time of peak expression in the epidermis during the larval and pupal molts. Both MHR4 and betaFTZ-F1 mRNAs were found in the testis during the onset of spermatogenesis in the prepupal period.
Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Insetos/genética , Manduca/genética , Receptores Citoplasmáticos e Nucleares/genética , Fatores de Transcrição/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , DNA Complementar , Epiderme/metabolismo , Fatores de Transcrição Fushi Tarazu , Expressão Gênica , Proteínas de Homeodomínio , Masculino , Dados de Sequência Molecular , RNA Mensageiro , Fator Esteroidogênico 1 , Testículo/metabolismo , Distribuição TecidualRESUMO
During the last larval molt in Manduca sexta, a number of transcription factors are sequentially expressed. Unlike E75A and MHR3, whose mRNAs are induced when the ecdysteroid titer increases, the expression of MHR4 mRNA occurs transiently at the onset of the decline of ecdysteroid titer followed by betaFTZ-F1 mRNA expression when the ecdysteroid titer becomes low. When day 2 fourth epidermis was exposed to 20-hydroxyecdysone (20E) in vitro, MHR4 mRNA appeared between 12 and 21 h, peaked at 24 h, and then declined. Using the protein synthesis inhibitors cycloheximide and anisomycin both in vivo and in vitro, we found that the MHR4 transcript was directly induced by 20E and required the presence of 20E for its expression. The accumulation of MHR4 mRNA, however, did not occur until a 20E-induced inhibitory protein(s) disappeared. This control of MHR4 expression is unique among the ecdysone-induced transcription factors. When the epidermis was cultured with 20E, betaFTZ-F1 mRNA was not induced until after the removal of 20E as previously found for Drosophila and the silkworm Bombyx mori. The presence of juvenile hormone had no effect on accumulation of either transcript.
Assuntos
Proteínas de Ligação a DNA/genética , Ecdisterona/farmacologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Manduca/embriologia , Fatores de Transcrição/genética , Animais , Fatores de Transcrição Fushi Tarazu , Proteínas de Homeodomínio , Proteínas de Insetos , Larva/metabolismo , Manduca/metabolismo , RNA Mensageiro/análise , Receptores Citoplasmáticos e Nucleares , Fator Esteroidogênico 1RESUMO
The case of a 34-year-old man with relapsing Ph+ acute lymphoblastic leukemia (ALL), which occurred five months after allogeneic bone marrow transplantation, is described. He was originally treated with aggressive chemotherapy, which put him in hematological remission, and he subsequently received donor leukocyte infusion (DLI) form the original donor. To assess the efficacy of this adoptive immunotherapy, we monitored minor-BCR/ABL (m-BCR/ABL) mRNA levels using the recently established real-time quantitative RT-PCR (RQ-PCR) assay. The results were compared with those obtained using conventional qualitative RT-PCR assays run in parallel. RQ-PCR, but not RT-PCR-based, minimum residual disease (MRD) detection showed a good correlation with the rapid changes documented during the post-DLI clinical course. Currently, six months after DLI, the patient continues to be in remission, which is consistent with the undetectable levels of m-BCR/ABL mRNA in the leukemic clone using RQ-PCR found in this study. Thus, monitoring of m-bcr/abl transcripts using RQ-PCR provides more useful information on a clinical assessment of MRD.
RESUMO
MHR3, an ecdysone-induced transcription factor, was shown to appear in the abdominal epidermis of the tobacco hornworm Manduca sexta in a pattern-specific manner as the 20-hydroxyecdysone (20E) titer rises for the larval molt. The crochet epidermis that forms the hooked setae on the proleg is first to show MHR3 mRNA and protein followed sequentially by the spiracle, the dorsal intrasegmental annuli, the interannular regions, and finally the trichogen and tormogen cells. The protein appears in the nuclei about 8 h before the onset of cuticle formation, is present during the outgrowth of the setae, and disappears after epicuticle formation. In vitro studies showed that MHR3 mRNA induction in the crochet epidermis by 20E was more sensitive (EC(50) = 10(-6) M; 50% induction by 2 h exposure to 4 x 10(-6) M 20E) and did not require protein synthesis for maximal accumulation compared to the dorsal epidermis. The ecdysone receptor complex is present in both tissues at the outset of the molt and therefore is not a determining factor in these responses. Thus, in addition to the ecdysone receptor complex, region-specific factors govern both sensitivity and timing of responsiveness of MHR3 to 20E to ensure that this transcription factor will be present when needed for its differentiative role.
Assuntos
Proteínas de Insetos/genética , Manduca/crescimento & desenvolvimento , Manduca/genética , Fatores de Transcrição/genética , Animais , Ecdisteroides , Ecdisterona/metabolismo , Ecdisterona/farmacologia , Epiderme/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Hibridização In Situ , Proteínas de Insetos/metabolismo , Larva/crescimento & desenvolvimento , Larva/metabolismo , Manduca/metabolismo , Mosaicismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Esteroides/metabolismo , Esteroides/metabolismo , Fatores de Transcrição/metabolismoRESUMO
Hepatic veno-occlusive disease (VOD) is a major complication after hematopoietic stem cell transplantation (HSCT). Aetiological determinants, diagnosis and treatment remain unclear. Changes in coagulation-fibrinolysis parameters and N-terminal propeptide for type III procollagen (P-III-P) have been studied in patients with or without VOD after HSCT. We prospectively measured protein C activity, tissue plasminogen activator (t-PA), antithrombin III (AT-III), plasminogen activity (PLG), thrombin-antithrombin III (TAT), alpha2-plasmin inhibitor (alpha2-PI),fibrinogen (Fbg) and P-III-P in 44 consecutive adult patients undergoing allogeneic HSCT. Each parameter was determined before conditioning, on day 0 of HSCT and weekly for 5 weeks. Five of the 44 patients developed VOD at a median post HSCT of day 3 (range, day 3 to 12). On repeated analysis of variance (ANOVA), there were significant differences between patients with and without VOD in P-III-P (P < 0.0001), protein C (P < 0.0001), t-PA (P < 0.0001), PLG (P < 0.0001), AT-III(P < 0.0001), Fbg (P < 0.0001), alpha2-PI (P = 0.0002). Levels of P-III-P were significantly higher in patients with VOD than without VOD, before preparative chemotherapy (P < 0.005) and on days 0 and 7 (P < 0.001). On day 0, levels of t-PA were significantly higher in patients with VOD than without VOD (P < 0.05). On day 7, levels of protein C were significantly lower in patients with VOD than without VOD (P < 0.01). On day 0, there were trends of differences (P = 0.0515) between patients with and without VOD in the levels of protein C. These results suggest P-III-P, t-PA and protein C are predictive markers for VOD after HSCT in adults. Moreover, the serum P-III-P level before start of conditioning might indicate patients at risk for developing VOD.
Assuntos
Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Hepatopatia Veno-Oclusiva/etiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Fragmentos de Peptídeos/sangue , Pró-Colágeno/sangue , Estudos Prospectivos , Proteína C/análise , Fatores de Risco , Ativador de Plasminogênio Tecidual/análiseRESUMO
To estimate the length of hospitalization following bone marrow transplantation(BMT), we conducted a retrospective study of 190 patients who had received allogeneic BMTs at our institution. By our criteria, patients were considered ready for discharge if they were afebrile, did not need intravenous chemotherapy or blood transfusions more than 2 times per week, had maintained these conditions for 1 week or more, and also had no medical history of hepatic veno-occlusive disease, grade-II-or-higher graft-versus-host disease, interstitial pneumonitis, or severe hepato-renal dysfunction. The median length of hospitalization was 108.5 days. Of 82 patients who satisfied our discharge criteria by their 70th hospital day, 10 experienced mild complications during the next 30 hospital days. Of 89 patients who were considered ready for discharge by the 40th hospital day, 30 and 38 experienced complications during the next 30 and 60 hospital days, respectively, and 16 required emergency treatment. No significant baseline characteristics distinguished the patients who experienced complications from those who did not, either after 40 or 70 hospital days. This compounded the difficulty of predicting the development of complications in patients who satisfied our discharge criteria. Although management on an outpatient basis should be safe and feasible for BMT patients who meet our discharge criteria by the 70th day of hospitalization, caution is advised for early discharges after only 40 hospital days.
Assuntos
Transplante de Medula Óssea , Tempo de Internação , Adolescente , Adulto , Criança , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Alta do Paciente/normas , Estudos Retrospectivos , Transplante HomólogoRESUMO
Of 264 patients aged 15 years or more who underwent hematopoietic stem cell transplantation between 1989 and September 1998 at the Tokyo Metropolitan Komagome Hospital, 47 were infected by the varicella-zoster virus (VZV). In 2 patients, visceral disease preceded cutaneous dissemination. One of these patients exhibited gastrointestinal symptoms followed by disseminated skin rash 6 days later. In the other patient, epigastralgia developed and was followed by seizures secondary to meningitis; the appearance of a skin rash 5 days after these initial symptoms yielded the diagnosis. Early diagnosis and treatment of VZV infection are important, especially for patients who present with visceral symptoms suspected to be due to VZV.
Assuntos
Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Herpes Zoster/etiologia , Aciclovir/uso terapêutico , Adulto , Antivirais/uso terapêutico , Feminino , Herpes Zoster/diagnóstico , Herpes Zoster/tratamento farmacológico , Humanos , Masculino , Resultado do TratamentoRESUMO
This report describes a patient with acute-type adult T cell leukemia/lymphoma (ATLL) successfully treated by autologous CD34+ peripheral blood stem cell transplantation after fractionated total body irradiation and high-dose cytarabine and cyclophosphamide. A newly established inverse polymerase chain reaction method was used to demonstrate the disappearance of ATLL clonal cells. The patient achieved a sustained molecular remission after transplantation, but died from opportunistic infection 4 months after transplantation. Thus, autologous CD34+ peripheral blood stem cell transplantation is promising for this type of malignancy. However, a prudent clinical attitude toward immunological fragility after transplantation is needed for better outcome.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Leucemia de Células T/terapia , Antígenos CD34 , Feminino , Humanos , Leucemia de Células T/genética , Leucemia de Células T/patologia , Pessoa de Meia-Idade , Células-Tronco Neoplásicas , Reação em Cadeia da Polimerase , Indução de Remissão , Transplante AutólogoRESUMO
MHR3, a homolog of the retinoid orphan receptor (ROR), is a transcription factor in the nuclear hormone receptor family that is induced by 20-hydroxyecdysone (20E) in the epidermis of the tobacco hornworm, Manduca sexta. Its 2.7-kb 5' flanking region was found to contain four putative ecdysone receptor response elements (EcREs) and a monomeric (GGGTCA) nuclear receptor binding site. Activation of this promoter fused to a chloramphenicol acetyltransferase (CAT) reporter by 2 micrograms of 20E per ml in Manduca GV1 cells was similar to that of endogenous MHR3, with detectable CAT by 3 h. When the ecdysone receptor B1 (EcR-B1) and Ultraspiracle 1 (USP-1) were expressed at high levels under the control of a constitutive promoter, CAT levels after a 3-h exposure to 20E increased two- to sixfold. In contrast, high expression of EcR-B1 and USP-2 caused little increase in CAT levels in response to 20E. Moreover, expression of USP-2 prevented activation by EcR-B1-USP-1. Deletion experiments showed that the upstream region, including the three most proximal putative EcREs, was responsible for most of the 20E activation, with the EcRE3 at -671 and the adjacent GGGTCA being most critical. The EcRE1 at -342 was necessary but not sufficient for the activational response but was the only one of the three putative EcREs to bind the EcR-B1-USP-1 complex in gel mobility shift assays and was responsible for the silencing action of EcR-B1-USP-1 in the absence of hormone. EcRE2 and EcRE3 each specifically bound other protein(s) in the cell extract, but not EcR and USP, and so are not EcREs in this cellular context. When cell extracts were used, the EcR-B1-USP-2 heterodimer showed no binding to EcRE1, and the presence of excess USP-2 prevented the binding of EcR-B1-USP-1 to this element. In contrast, in vitro-transcribed-translated USP-1 and USP-2 both formed heterodimeric complexes with EcR-B1 that bound ponasterone A with the same Kd (7 x 10(-10) M) and bound to both EcRE1 and heat shock protein 27 EcRE. Thus, factors present in the cell extract appear to modulate the differential actions of the two USP isoforms.
Assuntos
Proteínas de Ligação a DNA/metabolismo , Ecdisona , Genes de Insetos , Receptores de Esteroides/genética , Fatores de Transcrição/metabolismo , Animais , Sequência de Bases , Linhagem Celular , DNA Complementar , Dimerização , Proteínas de Drosophila , Ecdisterona/farmacologia , Regulação da Expressão Gênica , Manduca/genética , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Isoformas de Proteínas , RNARESUMO
In this study using guinea pigs, we investigated the effects of diesel exhaust (DE) containing diesel exhaust particulate (DEP) on 1) vascular permeability induced by histamine, 2) nasal mucosal permeability to horseradish peroxidase (HRP), and 3) eosinophilic epithelial infiltration. The vascular permeability induced by histamine was enhanced significantly and dose-dependently in DE-exposed guinea pigs. The HRP reaction products in epithelial cells and intercellular spaces were significantly and dose-dependently increased in those guinea pigs. Eosinophil infiltration into the epithelial layer was significantly increased in guinea pigs exposed to DE containing 3.2 mg/m3 DEP, and the reactivity of the nasal mucosa to histamine solution applied on the nasal mucosa was significantly enhanced in those guinea pigs. These findings suggest that DE may play an important role not only in promoting nasal hyperreactivity induced by the enhancement of absorption of antigen through the nasal epithelium, but also in inducing eosinophil infiltration in nasal mucosa and enhancing nasal mucosal reactivity.
Assuntos
Mucosa Nasal/metabolismo , Emissões de Veículos/efeitos adversos , Animais , Permeabilidade da Membrana Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Eosinófilos/metabolismo , Epitélio/patologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/biossíntese , Cobaias , Histamina/metabolismo , Técnicas Imunoenzimáticas , Interleucina-8/metabolismo , Masculino , Mucosa Nasal/patologiaRESUMO
BACKGROUND: Histamine is the most important chemical mediator in the pathogenesis of nasal allergy. Diesel exhaust particulates (DEPs) are common air pollutants from diesel engine-powered car exhaust and cause chronic airway diseases. Recently we observed that the nasal reactivity to histamine was enhanced in diesel exhaust-exposed guinea-pigs. It was also revealed that epithelial cells and endothelial cells in the airway produce certain cytokines in response to histamine. OBJECTIVE: We examined the effects of DEP extract on the expression of histamine H1 receptor (H1R) mRNA in human nasal epithelial cells (HNECs) and human mucosal microvascular endothelial cells (HMMECs), and on the production of IL-8 and GM-CSF induced by histamine. METHODS: HNECs and HMMECs were isolated from human nasal mucosa specimens. HNEC and HMMEC monolayers were cultured in the presence or absence of DEP extract. The change in the expression of H1R mRNA was then evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) and the Southern blot analysis. To investigate the effects of DEP extract on the histamine-induced cytokine production, HNEC and HMMEC monolayers were cultured in the presence or absence of DEP extract for 3-24 h. After three washes with PBS, they were then incubated with 10(-6) mol/L histamine for 24 h. The amounts of IL-8 and GM-CSF in the culture media were measured by enzyme-linked immunoabsorbent assay. RESULTS: DEP extract increased the expression of H1R mRNA in both HNECs and HMMECs. The amount of IL-8 and GM-CSF, induced by histamine, was significantly higher in DEP extract pretreated HNECs and HMMECs than nontreated HNECs and HMMECs. CONCLUSION: These results strongly suggest that DEP accelerates the inflammatory change by not only directly upregulating H1R expression but also increasing histamine-induced IL-8 and GM-CSF production.
Assuntos
Fator Estimulador de Colônias de Granulócitos e Macrófagos/biossíntese , Interleucina-8/biossíntese , Mucosa Nasal/efeitos dos fármacos , RNA Mensageiro/efeitos dos fármacos , Receptores Histamínicos/genética , Emissões de Veículos/efeitos adversos , Sobrevivência Celular/efeitos dos fármacos , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Expressão Gênica/efeitos dos fármacos , Histamina/farmacologia , Humanos , Mucosa Nasal/citologia , Mucosa Nasal/metabolismo , RNA Mensageiro/metabolismo , Fatores de Tempo , Regulação para CimaRESUMO
Insect molting and metamorphosis are orchestrated by ecdysteroids with juvenile hormone (JH) preventing the actions of ecdysteroids necessary for metamorphosis. During the molt and metamorphosis of the dorsal abdominal epidermis of the tobacco hornworm, Manduca sexta, the isoforms involved in the ecdysone receptor (EcR)/Ultraspiracle (USP) complex change with the most dramatic switch being the loss of USP-1 and the appearance of USP-2 during the larval and pupal molts. We show here that this switch in USP isoforms is mediated by high 20-hydroxyecdysone (20E) and that the presence of JH is necessary for the down-regulation of USP-1 mRNA. The decrease of USP-1 mRNA in day 2 fourth instar larval epidermis in vitro required exposure to a high concentration (10(-5) M) of 20E equivalent to the peak ecdysteroid concentration in vivo, whereas the increase of USP-2 mRNA occurred at lower concentrations (effective concentrations, EC50=6.3x10(-7) M). During the pupal molt of allatectomized larvae which lack JH, USP-2 mRNA increased normally with the increasing ecdysteroid titer, whereas USP-1 mRNA remained high until pupation. When day 2 fifth instar larval epidermis was exposed to 500 ng/ml 20E in the absence of JH to cause pupal commitment of the cells by 24 h, USP-1 RNA remained at its high preculture level for 12 h, then increased two- to threefold by 24 h. The increase was prevented by the presence of 1 microgram/ml JH I which also prevents the pupal commitment of the cells. By contrast, USP-2 mRNA increased steadily with the same EC50 as in fourth stage epidermis, irrespective of the presence or absence of JH. Under the same conditions, mRNAs for both EcR-B1 and EcR-A isoforms were up-regulated by 20E, each in its own time-dependent manner, similar to that seen in vivo. These initial mRNA increases were unaffected by the presence of JH I, but those seen after 12 h exposure to 20E were prevented by JH, indicating a difference in response between larvally and pupally committed cells. The presence of JH which maintained larval commitment of the cells also prolonged the half-life of the EcR proteins in these cells. These results indicate that both EcR and USP RNAs are regulated by 20E and can be modulated by JH in a complex manner with only that of USP-2 apparently unaffected.