RESUMO
The pathobiology of chronic obstructive pulmonary disease (COPD) is not completely understood. The aim of this study was to assess the expression of hypoxia inducible factor (HIF)-1α in lung tissue from patients with COPD/emphysema. Lung tissue samples from 26 patients were included in this study. Seven samples were obtained from patients with normal lung function, the remainder of the samples were taken from patients with moderate COPD (n = 6; stage I and II Global Initiative for Chronic Obstructive Lung Disease classification) and severe COPD (n = 13; stage III and IV). We analysed mRNA and protein expression in the lung tissue samples and found that: 1) HIF-1α and histone deacetylase 2 proteins were significantly decreased and were correlated; 2) HIF-1α and vascular endothelial growth factor (VEGF) proteins, and forced expiratory volume in 1 s % predicted were correlated in all patients; 3) the changes in VEGF and HIF-1α protein levels in all patients were not age-related and not related to the pack-yr smoking history; and 4) the reduced HIF-1α protein expression was seen in lung endothelial cells and alveolar septal cells by immunohistochemistry. In conclusion, reduced expression of HIF-1α protein in severe COPD is consistent with the concept of a lung structure maintenance programme which is impaired on a molecular level.
Assuntos
Enfisema/metabolismo , Regulação da Expressão Gênica , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Pulmão/metabolismo , Doença Pulmonar Obstrutiva Crônica/metabolismo , Idoso , Núcleo Celular/metabolismo , Estudos de Coortes , Citoplasma/metabolismo , Feminino , Perfilação da Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
The etiology and pathogenesis of the vascular lesions characterizing primary pulmonary hypertension (PPH), an often fatal pulmonary vascular disease, are largely unknown. Plexiform lesions composed of proliferating endothelial cells occur in between 20 and 80% of the cases of this irreversible pulmonary vascular disease. Recently, technology to assess monoclonality has allowed the distinction between cellular proliferation present in neoplasms from that in reactive nonneoplastic tissue. To determine whether the endothelial cell proliferation in plexiform lesions in PPH is monoclonal or polyclonal, we assessed the methylation pattern of the human androgen receptor gene by PCR (HUMARA) in proliferated endothelial cells in plexiform lesions from female PPH patients (n = 4) compared with secondary pulmonary hypertension (PH) patients (n = 4). In PPH, 17 of 22 lesions (77%) were monoclonal. However, in secondary PH, all 19 lesions examined were polyclonal. Smooth muscle cell hyperplasia in pulmonary vessels (n = 11) in PPH and secondary PH was polyclonal in all but one of the examined vessels. The monoclonal expansion of endothelial cells provides the first marker that allows the distinction between primary and secondary PH. Our data of a frequent monoclonal endothelial cell proliferation in PPH suggests that a somatic genetic alteration similar to that present in neoplastic processes may be responsible for the pathogenesis of PPH.
Assuntos
Endotélio/patologia , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/patologia , Pulmão/patologia , Adulto , Pré-Escolar , Células Clonais , DNA/análise , DNA/genética , DNA/metabolismo , Endotélio/citologia , Feminino , Humanos , Hiperplasia/genética , Hiperplasia/patologia , Hipertensão Pulmonar/genética , Hipertrofia/patologia , Pessoa de Meia-Idade , Músculo Liso/citologia , Músculo Liso/patologia , Neovascularização Patológica/genética , Neovascularização Patológica/patologia , Reação em Cadeia da Polimerase , Receptores Androgênicos/análise , Receptores Androgênicos/genéticaRESUMO
Cellular senescence is an initial barrier for carcinogenesis. However, the signaling mechanisms that trigger cellular senescence are incompletely understood, particularly in vivo. Here we identify Wnt7a as a novel upstream inducer of cellular senescence. In two different mouse strains (C57Bl/6J and FVB/NJ), we show that the loss of Wnt7a is a major contributing factor for increased lung tumorigenesis owing to reduced cellular senescence, and not reduced apoptosis, or autophagy. Wnt7a-null mice under de novo conditions and in both the strains display E-cadherin-to-N-cadherin switch, reduced expression of cellular senescence markers and reduced expression of senescence-associated secretory phenotype, indicating a genetic predisposition of these mice to increased carcinogen-induced lung tumorigenesis. Interestingly, Wnt7a induced an alternate senescence pathway, which was independent of ß-catenin, and distinct from that of classical oncogene-induced senescence mediated by the well-known p16(INK4a) and p19(ARF) pathways. Mechanistically, Wnt7a induced cellular senescence via inactivation of S-phase kinase-associated protein 2, an important alternate regulator of cellular senescence. Additionally, we identified Iloprost, a prostacyclin analog, which initiates downstream signaling cascades similar to that of Wnt7a, as a novel inducer of cellular senescence, presenting potential future clinical translational strategies. Thus pro-senescence therapies using either Wnt7a or its mimic, Iloprost, might represent a new class of therapeutic treatments for lung cancer.
Assuntos
Senescência Celular , Neoplasias Pulmonares/patologia , Proteínas Supressoras de Tumor/fisiologia , Proteínas Wnt/fisiologia , beta Catenina/fisiologia , Animais , Linhagem Celular Tumoral , Senescência Celular/efeitos dos fármacos , Humanos , Iloprosta/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Quinases Associadas a Fase S/fisiologia , Transdução de SinaisRESUMO
Acute interstitial pneumonitis (AIP) is an acute, idiopathic interstitial lung disease characterized by rapidly progressive diffuse pulmonary infiltrates and hypoxemia requiring hospitalization. The case-fatality ratio is high. Previous reports suggested that survivors of the acute event have a favorable outcome. We undertook this study to examine the natural history of survivors. We had observed several patients who experienced recurrent episodes of AIP and chronic progressive interstitial lung disease. We sought to determine longitudinal survival in these patients and to compare our experience with that in the medical literature. Overall, we identified 13 biopsy-proven cases of AIP. The mean patient age was 54 years in our review, which is identical to previous reports. Twelve patients were hospitalized and all 12 required mechanical ventilation. Overall hospital survival was 67%. All patients demonstrated abnormalities in gas exchange at presentation. Radiographs typically demonstrated bilateral patchy densities that progressed to a diffuse alveolar filling pattern in nearly all cases. All biopsy specimens showed organizing diffuse alveolar damage. Longitudinal data were available for 7 patients. Two died of AIP recurrences. A third died of complications of heart failure shortly after hospital discharge. One patient progressed to end-stage lung disease and required lung transplantation. Two patients experienced persistent pulmonary symptoms, accompanied in 1 by progressive lung fibrosis. One patient had nearly complete recovery of lung function 2 years following AIP. (Follow-up information was unavailable for 2 survivors.) In our literature review, 5 of 7 patients reported experienced some recovery of lung function. One case of progressive interstitial lung disease requiring lung transplantation was reported. The reported mortality was much higher than in our experience (74% versus 33%). The mean time from symptom onset to death was 26 days, compared with 34 days in our experience. The use of corticosteroids did not appear to influence survival, although this has not been tested in a rigorous manner. The better survival in our series may be related in part to a survivor selection bias. In contrast to previous reports, we found that survivors of AIP may experience recurrences and chronic, progressive interstitial lung disease. We did not identify any clinical or pathologic features that predict mortality in these patients. Likewise, there were no features that predicted the longitudinal course in survivors. Further study to identify causal factors is required in the hope of preventing morbidity and mortality related to this disease.
Assuntos
Doenças Pulmonares Intersticiais/complicações , Doenças Pulmonares Intersticiais/mortalidade , Doença Aguda , Adulto , Idoso , Biópsia , Causas de Morte , Tosse/etiologia , Cianose/etiologia , Progressão da Doença , Dispneia/etiologia , Feminino , Febre/etiologia , Seguimentos , Humanos , Doenças Pulmonares Intersticiais/diagnóstico , Doenças Pulmonares Intersticiais/terapia , Masculino , Pessoa de Meia-Idade , Prognóstico , Recidiva , Respiração Artificial , Análise de Sobrevida , Tomografia Computadorizada por Raios XRESUMO
Recent information is limited regarding pathological features of the malignant lymphomas of Africa, other than Burkitt's lymphoma. In this study, we apply modern techniques and nomenclature to classify 73 lymphomas from a central histopathology laboratory serving 40 mission hospitals in Kenya. We were particularly interested in the frequency of recently recognized lymphomas and the incidence of Epstein-Barr virus in various lymphoma subtypes. Malignant lymphomas accounted for 12% of all surgical pathology specimens processed in the laboratory over the 21-month period included in the study. Patient age ranged from 4 to 97 years (median, 35 years). The male-to-female ratio was 2.5:1. Sixty lymphomas (82%) were non-Hodgkin's, and 13 (18%) were Hodgkin's disease. Of the non-Hodgkin's lymphomas (NHLs), 52 (87%) were B-lineage, including 21 (35% of NHLs) Burkitt's lymphomas (only one from the jaw), 11 (18%) diffuse large B cell lymphomas; nine (15%) small lymphocytic lymphomas, six (10%) Burkitt's-like lymphomas, two (3%) follicular lymphomas (two of two expressed bcl-2 protein; one of two showed bcl-2 major breakpoint region rearrangement), two (3%) mantle cell lymphomas, and one extranodal marginal zone lymphoma. Of the eight T cell lymphomas, six were precursor T-cell type, and the remaining two were peripheral T cell lymphomas, unspecified. The median age of the 13 patients (18% of lymphomas) with Hodgkin's disease was 23 years (range, 9 to 97 years). Six were nodular sclerosis, four were mixed cellularity, one case each was lymphocyte depletion, lymphocyte predominance, and unclassified Hodgkin's disease. Hodgkin's cells in 6 of the 12 nonlymphocyte predominance cases were positive for CD20, and in three of the six for CD45 as well. Epstein-Barr virus was identified using in situ hybridization for EBER 1 in the malignant cells of 22 of 39 informative lymphomas, including each of 17 Burkitt's lymphomas, and three of seven diffuse large B cell lymphomas. Of note, none of five Burkitt's-like lymphomas expressed EBER 1. One of two informative cases of peripheral T cell lymphoma, and four of nine cases of Hodgkin's disease were EBER 1 positive. In summary, T cell lymphomas and recently recognized B-lineage non-Hodgkin's lymphoma subtypes do not appear to be particularly common in East Africa.
Assuntos
Herpesvirus Humano 4/isolamento & purificação , Doença de Hodgkin/epidemiologia , Linfoma não Hodgkin/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD/análise , Biomarcadores Tumorais/análise , Criança , Pré-Escolar , Feminino , Doença de Hodgkin/patologia , Humanos , Imuno-Histoquímica , Quênia/epidemiologia , Linfoma não Hodgkin/química , Linfoma não Hodgkin/patologia , Masculino , Pessoa de Meia-Idade , Mucina-1/análiseRESUMO
Patients with primary pulmonary hypertension develop vascular lesions characterized by proliferated blood channels, the so-called plexiform lesions. These lesions are often associated with concentric intimal obliteration of pulmonary vessels. We report that the lungs of three patients with scleroderma-associated pulmonary hypertension showed a predominance of obliterative-concentric lesions, with relatively few plexiform or combined lesions. In contrast, plexiform lesions predominated in the lungs obtained from three patients with human immunodeficiency virus (HIV)-associated pulmonary hypertension; pure obliterative-concentric lesions were infrequent. Both plexiform and concentric obliterative lesions stained strongly positive for the endothelial cell marker factor VIII-related antigen. Muscle-specific actin immunostaining highlighted the smooth muscle cells of the tunica media of plexiform vessels, but not the luminal layers of the concentric-obliterative lesions. Proliferating cells, as determined by immunostaining with the MIB-1 antibody, were only detected in the plexiform vascular lesions. We postulate that concentric-obliterative lesions and plexiform lesions are temporally and etiologically related. A scaffolding of proliferating endothelial cells could be the common denominator of both lesions. Our hypothesis that there exists a chronological continuum, proceeding from early, proliferative plexiform lesions to late, nonproliferative concentric-obliterative lesions in primary and secondary pulmonary hypertension, may lead to better targeted treatment strategies and disease classification.
Assuntos
Infecções por HIV/complicações , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/patologia , Pulmão/patologia , Escleroderma Sistêmico/complicações , Actinas/análise , Adulto , Antígenos CD/análise , Antígenos de Diferenciação Mielomonocítica/análise , Complexo CD3/análise , Divisão Celular , Endotélio Vascular/química , Endotélio Vascular/imunologia , Endotélio Vascular/patologia , Fator VIII/análise , Feminino , Infecções por HIV/imunologia , Humanos , Hipertensão Pulmonar/imunologia , Imuno-Histoquímica , Antígeno Ki-67/análise , Antígenos Comuns de Leucócito/análise , Pulmão/irrigação sanguínea , Pulmão/química , Pulmão/imunologia , Masculino , Pessoa de Meia-Idade , Músculo Liso Vascular/química , Músculo Liso Vascular/patologia , Escleroderma Sistêmico/imunologiaRESUMO
Delayed pulmonary toxicity syndrome, characterized by interstitial pneumonia and pulmonary fibrosis, is common following high-dose bischloroethylnitrosourea (BCNU) (carmustine, [1,3-bis (2-chloroethyl)-1-nitrosourea]) containing chemotherapeutic regimens. Depending upon the treatment protocol, it may develop in over 70% of patients. Early and aggressive corticosteroid treatment leads to improvement in the majority of patients. However, up to 8% of affected patients may fail to respond to corticosteroids and develop progressive respiratory failure leading to death. No alternatives to corticosteroids have thus far been shown useful. We report the symptomatic and physiological improvement of a patient with severe steroid-resistant delayed pulmonary toxicity syndrome, following treatment with interferon-gamma.
Assuntos
Corticosteroides/efeitos adversos , Neoplasias da Mama/tratamento farmacológico , Carmustina/efeitos adversos , Interferon gama/uso terapêutico , Pulmão/efeitos dos fármacos , Pulmão/patologia , Fibrose Pulmonar/induzido quimicamente , Antineoplásicos Alquilantes/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias da Mama/radioterapia , Feminino , Humanos , Pessoa de Meia-Idade , Fibrose Pulmonar/radioterapia , Testes de Função Respiratória , Síndrome , Fatores de Tempo , Resultado do TratamentoRESUMO
Dysfunctional endothelial cells have a central and critical role in the initiation and progression of severe pulmonary hypertension. The elucidation of the mechanisms involved in the control of endothelial cell proliferation and cell death in the pulmonary vasculature, therefore, is fundamentally important in the pathogenesis of severe pulmonary hypertension and of great interest for a better understanding of endothelial cell biology. Because the intravascular growth of endothelial cells resulting in tumorlets is unique to severe pulmonary hypertension, this phenomenon can teach researchers about the factors involved in the formation and maintenance of the normal endothelial cell monolayer. Clearly, in severe pulmonary hypertension, the "law of the endothelial cell monolayer" has been broken. The ultimate level of such a control is at the altered gene expression pattern that is conducive to endothelial cell growth and disruption of pulmonary blood flow. Secondary pulmonary hypertension certainly also is associated with proliferated pulmonary endothelial cells and plexiform lesions that are histologically indistinguishable from those in PPH. What is then the difference in the mechanisms of endothelial cell proliferation between primary and secondary pulmonary hypertension? The authors believe that PPH is a disease caused by somatic mutations in key angiogenesis- or apoptosis-related genes such as the TGF-beta receptor-2 and Bax. The loss of these important cell growth control mechanisms allows for the clonal expansion of endothelial cells from a single cell that has acquired a selective growth advantage. On the other hand, the proliferated endothelial cells in secondary pulmonary hypertension are polyclonal. It follows from this finding that local (vascular) factor(s) (such as increased shear stress), rather than mutations, play a major role in triggering endothelial cell proliferation. In PPH and secondary pulmonary hypertension, the researcher can postulate that the pulmonary vascular bed contains progenitor-like cells with the capacity of dysregulated growth. The main difference in the pathogenesis of primary and secondary pulmonary endothelial cell proliferation therefore may be the initial mechanism involved in the recruitment of an endothelial progenitor-like cell. In PPH, anorexigen-associated, and familial PPH, the proliferation of endothelial cells occurs from a mutated single cell, whereas in secondary pulmonary hypertension, several progenitor-like cells would be activated to grow. The abnormal endothelial cells in both forms of severe pulmonary hypertension expand because of the expression of angiogenesis-related molecules such as VEGF, VEGFR-2, HIF-1 alpha, and HIF-beta. Also important for the expansion of these cells is the down-regulation of expression of apoptosis-related mediators such as TGF-beta receptor-2 or Bax. The success of any therapy for severe pulmonary hypertension requires that the underlying process of endothelial cell proliferation could be controlled or reversed.
Assuntos
Endotélio Vascular/fisiopatologia , Hipertensão Pulmonar/fisiopatologia , Animais , Coagulação Sanguínea/fisiologia , Sistema Enzimático do Citocromo P-450/metabolismo , Fatores de Crescimento Endotelial/metabolismo , Endotélio Vascular/patologia , Humanos , Hipertensão Pulmonar/genética , Hipertensão Pulmonar/patologia , Oxirredutases Intramoleculares/metabolismo , Linfocinas/metabolismo , Repetições de Microssatélites , Músculo Liso Vascular/patologia , Músculo Liso Vascular/fisiopatologia , Mutação , Óxido Nítrico/metabolismo , Isoformas de Proteínas/metabolismo , Artéria Pulmonar/patologia , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular , VasoconstriçãoRESUMO
AIMS: To identify individual histopathological features within usual interstitial pneumonia pattern that predict responsiveness to immunosuppressive therapy. METHODS AND RESULTS: Fifty-six retrospectively confirmed usual interstitial pneumonia pattern surgical lung biopsy specimens from subjects with idiopathic pulmonary fibrosis treated with corticosteroid and cytotoxic therapy were included. Eleven prospectively defined histopathological features were evaluated by two expert pulmonary pathologists. Regression analysis identified predictors of response to therapy, as defined by the change in percent predicted forced vital capacity over 6 months. Additional end-points were change in dyspnoea score over 6 months, and survival time. Improvement in percent predicted forced vital capacity was associated with lymphoplasmacytic inflammation, while worsening of percent predicted forced vital capacity was associated with the presence of organizing pneumonia and fibroblast foci. Worsening dyspnoea was associated with fibroblast foci. Survival time was associated with age and baseline percent predicted forced vital capacity, but not with any individual histopathological feature. CONCLUSIONS: In pathological usual interstitial pneumonia pattern, the presence of lymphoplasmacytic inflammation predicts responsiveness to immunomodulatory therapy, while airspace organization predicts lack of response.
Assuntos
Linfócitos/patologia , Pneumonia/patologia , Fibrose Pulmonar/diagnóstico , Fibrose Pulmonar/tratamento farmacológico , Humanos , Pessoa de Meia-Idade , Prognóstico , Resultado do TratamentoRESUMO
Lymphoid interstitial pneumonia (LIP) is rare and its clinical course incompletely described. The aim of this study was to examine the clinical features, associations and prognosis of surgical lung biopsy-proven LIP. The study group consisted of 15 subjects encountered over a 14-yr period. The majority of subjects were females (n = 11) and the mean age was 47 yrs (range 17-78 yrs). Underlying systemic immune disorders were frequent, including Sjögren's syndrome (n = 8), rheumatoid arthritis, systemic lupus erythematosus, polymyositis, common variable immunodeficiency and dysproteinaemia. Only three patients were classified as "idiopathic". Presenting symptoms were dominated by dyspnoea and cough. Restrictive physiology, reduced diffusion capacity (62.5+/-18.4% predicted) and bronchoalveolar lavage lymphocytosis (30.5+/-29.1% pred) were noted. Thirteen patients received corticosteroid therapy. Of the nine whose response could be assessed, four showed clinical improvement and four were stable. Overall, median survival was 11.5 yrs. Of the seven patients who died, respiratory problems were the primary cause of death in three. Conversion to lymphoma was not identified. In conclusion, histopathological lymphoid interstitial pneumonia is commonly associated with immune system dysregulation, with idiopathic lymphoid interstitial pneumonia being extremely rare. Clinical stability or improvement with corticosteroids can be expected; however, survival remains impaired.
Assuntos
Doenças Autoimunes , Doenças do Sistema Imunitário , Doenças Pulmonares Intersticiais , Linfocitose , Adolescente , Adulto , Doenças Autoimunes/complicações , Doenças Autoimunes/tratamento farmacológico , Doenças Autoimunes/mortalidade , Doenças Autoimunes/patologia , Feminino , Humanos , Doenças do Sistema Imunitário/complicações , Doenças do Sistema Imunitário/tratamento farmacológico , Doenças do Sistema Imunitário/mortalidade , Doenças do Sistema Imunitário/patologia , Doenças Pulmonares Intersticiais/complicações , Doenças Pulmonares Intersticiais/tratamento farmacológico , Doenças Pulmonares Intersticiais/mortalidade , Doenças Pulmonares Intersticiais/patologia , Linfocitose/complicações , Linfocitose/tratamento farmacológico , Linfocitose/mortalidade , Linfocitose/patologia , Masculino , Pessoa de Meia-Idade , Doenças Raras/tratamento farmacológico , Doenças Raras/mortalidade , Doenças Raras/patologiaRESUMO
Loss of PKC-epsilon limits the magnitude of acute hypoxic pulmonary vasoconstriction (HPV) in the mouse. Therefore, we hypothesized that loss of PKC-epsilon would decrease the contractile and/or structural response of the murine pulmonary circulation to chronic hypoxia (Hx). However, the pattern of lung vascular responses to chronic Hx may or may not be predicted by the acute HPV response. Adult PKC-epsilon wild-type (PKC-epsilon(+/+)), heterozygous null, and homozygous null (PKC-epsilon(-/-)) mice were exposed to normoxia or Hx for 5 wk. PKC-epsilon(-/-) mice actually had a greater increase in right ventricular (RV) systolic pressure, RV mass, and hematocrit in response to chronic Hx than PKC-epsilon(+/+) mice. In contrast to the augmented PA pressure and RV hypertrophy, pulmonary vascular remodeling was increased less than expected (i.e., equal to PKC-epsilon(+/+) mice) in both the proximal and distal PKC-epsilon(-/-) pulmonary vasculature. The contribution of increased vascular tone to this pulmonary hypertension (PHTN) was assessed by measuring the acute vasodilator response to nitric oxide (NO). Acute inhalation of NO reversed the increased PA pressure in hypoxic PKC-epsilon(-/-) mice, implying that the exaggerated PHTN may be due to a relative deficiency in nitric oxide synthase (NOS). Despite the higher PA pressure, chronic Hx stimulated less of an increase in lung endothelial (e) and inducible (i) NOS expression in PKC-epsilon(-/-) than PKC-epsilon(+/+) mice. In contrast, expression of nNOS in PKC-epsilon(+/+) mice decreased in response to chronic Hx, while lung levels in PKC-epsilon(-/-) mice remained unchanged. In summary, loss of PKC-epsilon results in increased vascular tone, but not pulmonary vascular remodeling in response to chronic Hx. Blunting of Hx-induced eNOS and iNOS expression may contribute to the increased vascular tone. PKC-epsilon appears to be an important signaling intermediate in the hypoxic regulation of each NOS isoform.
Assuntos
Hipóxia/enzimologia , Pulmão/irrigação sanguínea , Pulmão/enzimologia , Proteína Quinase C-épsilon/metabolismo , Circulação Pulmonar , Animais , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/genética , Feminino , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/genética , Hipertensão Pulmonar/enzimologia , Hipertensão Pulmonar/genética , Hipertensão Pulmonar/patologia , Hipóxia/genética , Hipóxia/patologia , Pulmão/patologia , Masculino , Camundongos , Camundongos Knockout , Óxido Nítrico/administração & dosagem , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/biossíntese , Óxido Nítrico Sintase Tipo III , Proteína Quinase C-épsilon/deficiência , Proteína Quinase C-épsilon/genética , Circulação Pulmonar/efeitos dos fármacos , Circulação Pulmonar/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genéticaRESUMO
Irradiation with parallel arrays of thin, planar slices of X-ray beams (microplanar beams, or microbeams) spares normal tissue, including the central nervous system (CNS), and preferentially damages tumors. The effects are mediated, at least in part, by the tissue's microvasculature that seems to effectively repair itself in normal tissue but fails to do so in tumors. Consequently, the therapeutic index of single-fraction unidirectional microbeam irradiations has been shown to be larger than that of single-fraction unidirectional unsegmented beams in treating the intracranial rat 9L gliosarcoma tumor model (9LGS) and the subcutaneous murine mammary carcinoma EMT-6. This paper presents results demonstrating that individual microbeams, or arrays of parallel ones, can also be used for targeted, selective cell ablation in the CNS, and also to induce demyelination. The results highlight the value of the method as a powerful tool for studying the CNS through selective cell ablation, besides its potential as a treatment modality in clinical oncology.
RESUMO
Chronic obstructive lung disease affects the entire lung, not just the airways. Although pulmonary hypertension (PH) has long been recognised in a subset of patients with COLD, the important pathophysiological questions remain unanswered. Oxygen supplementation, however, has been shown to blunt the exercise-induced PH in these patients. Hypercoagulability has also been described in patients with COLD. This may, in part, be due to the inflammatory aspects of COLD exacerbation events. In addition to perivascular inflammation, the pathology of vessels in COLD includes intimal thickening, muscularisation of arterioles, in situ thrombosis, loss of capillaries and precapillary arterioles, and vascular congestion and stasis. Recent work describes apoptosis of septal endothelial cells and decreased expression of vascular endothelial growth factor (VEGF) and one of its receptors, VEGFRII, in lungs from patients with emphysema. Based on this work, a rat model was developed that shows chronic blockade of VEGF receptors leads to septal cell apoptosis and results in emphysema and PH. This animal model has led to prevention trials using 1) a broad-spectrum caspase inhibitor, 2) a superoxide dismutase mimetic, and 3) alpha1-antitrypsin. These findings highlight the importance of vascular endothelial growth factor, apoptosis, oxidative stress and protease activity in the pathogenesis of emphysema. They also underscore the importance of the vasculature in what is traditionally thought of as an airways disease. Future treatment strategies need to address the vascular components of chronic obstructive lung disease.
Assuntos
Artéria Pulmonar/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Animais , Coagulação Sanguínea , Endotélio Vascular/fisiopatologia , Humanos , Hipertensão/patologia , Hipertensão/fisiopatologia , Inflamação , Artéria Pulmonar/patologia , Doença Pulmonar Obstrutiva Crônica/sangue , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/patologia , Enfisema Pulmonar/patologia , Enfisema Pulmonar/fisiopatologia , Receptores de Fatores de Crescimento do Endotélio Vascular/fisiologia , Trombose/etiologia , Trombose/fisiopatologiaRESUMO
To investigate the role of mast cells (MC) and their fibrogenic growth factors in silicosis, we performed quantitative immunohistochemistry for MC tryptase and for basic fibroblast growth factor (bFGF) in lung tissue from silicotic and control subjects. Anti-bFGF antibody was bound to lung MC, basement membrane, endothelial cells, and smooth-muscle cells. Morphometric analysis revealed that the volume density (V(v)) of MC was increased in silicotic lung and that the V(v) of bFGF-positive (bFGF(+)) cells was significantly higher than normal in silicotic lung. Most MC contained bFGF (rho = 0.88, p < 0.001). The V(v) of collagen/reticulin fibers was increased in silicosis and correlated with the V(v) of bFGF(+) cells (rho = 0.81, p < 0.001). Immature silicotic nodules contained bFGF(+) MC throughout the loose array of collagen/reticulin fibers. In large, mature nodules, the density of collagen/reticulin fibers was higher, and bFGF(+) MC were found only in the nodule periphery. Because of this circumferential MC alignment in silicotic nodules, we observed a negative correlation between the V(v) of bFGF(+) MC and the density of collagen/reticulin fibers in silicotic nodules (rho = -0.80, p < 0.001) and between the V(v) of all other nodule-associated cells and the density of collagen/reticulin fibers in the hypocellular nodule centers (rho = -0.84, p < 0.001). We conclude that MC that produce bFGF may play an important role in the development of silicosis.
Assuntos
Fator 2 de Crescimento de Fibroblastos/análise , Mastócitos/patologia , Silicose/patologia , Idoso , Idoso de 80 Anos ou mais , Biópsia , Humanos , Pulmão/patologia , Masculino , Pessoa de Meia-Idade , Valores de ReferênciaRESUMO
Emphysema due to cigarette smoking is characterized by a loss of alveolar structures. We hypothesize that the disappearance of alveoli involves apoptosis of septal endothelial cells and a decreased expression of lung vascular endothelial growth factor (VEGF) and its receptor 2 (VEGF R2). By terminal transferase dUTP nick end labeling (TUNEL) in combination with immunohistochemistry, we found that the number of TUNEL+ septal epithelial and endothelial cells/lung tissue nucleic acid (microg) was increased in the alveolar septa of emphysema lungs (14.2 +/- 2.0/microg, n = 6) when compared with normal lungs (6.8 +/- 1.3/microg, n = 7) (p < 0.01) and with primary pulmonary hypertensive lungs (2.3 +/- 0.8/microg, n = 5) (p < 0.001). The cell death events were not significantly different between healthy nonsmoker (7.4 +/- 1.9/microg) and smoker (5.7 +/- 0.7/microg) control subjects. The TUNEL results were confirmed by single-stranded DNA and active caspase-3 immunohistochemistry, and by DNA ligation assay. Emphysema lungs (n = 12) had increased levels of oligonucleosomal-length DNA fragmentation when compared with normal lungs (n = 11). VEGF, VEGF R2 protein, and mRNA expression were significantly reduced in emphysema. We propose that epithelial and endothelial alveolar septal death due to a decrease of endothelial cell maintenance factors may be part of the pathogenesis of emphysema.
Assuntos
Apoptose , Enfisema/metabolismo , Enfisema/patologia , Fatores de Crescimento Endotelial/biossíntese , Receptores ErbB/biossíntese , Linfocinas/biossíntese , Adolescente , Adulto , Idoso , Enfisema/genética , Fatores de Crescimento Endotelial/análise , Receptores ErbB/análise , Feminino , Humanos , Marcação In Situ das Extremidades Cortadas , Linfocinas/análise , Masculino , Pessoa de Meia-Idade , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio VascularRESUMO
Inflammatory infiltrates and endothelial cell proliferation have been appreciated in plexiform and concentric lesions, which characterize the vascular remodeling in primary pulmonary hypertension (PPH). Leukotriene production by perivascular and alveolar macrophages relies on activation of 5-lipoxygenase (5-LO), with translocation of the enzyme to the nuclear membrane, and association with the 5-LO activating protein (FLAP). Using immunohistochemical staining, we localized and semi-quantitatively estimated the abundance of 5-LO and FLAP in lungs obtained from patients with PPH, patients with interstitial lung disease (ILD), and normal control subjects. Expression of 5-LO and FLAP was prominent in alveolar macrophages in both the normal and PPH lungs; however, alveolar macrophages were more frequently clustered in the vicinity of remodeled blood vessel in PPH. Medium- and small-size pulmonary arteries in PPH showed more abundant FLAP expression than in control and ILD lungs. 5-LO expression in small arteries in PPH was more intense than in control and ILD patients. Endothelial cells in plexiform and concentric lesions in PPH expressed both 5-LO and FLAP. In situ hybridization confirmed the presence of 5-LO transcripts in macrophages and endothelial cells of the remodeled vessels in PPH. We propose that the overexpression of 5-LO and FLAP represents evidence for the participation of inflammation in the process of PPH vasculopathy or, alternatively, that the overabundance of the enzymes involved in generation of inflammatory mediators may themselves be related to vascular cell proliferation and cell growth.
Assuntos
Araquidonato 5-Lipoxigenase/análise , Proteínas de Transporte/análise , Regulação Enzimológica da Expressão Gênica , Hipertensão Pulmonar/enzimologia , Macrófagos Alveolares/enzimologia , Proteínas de Membrana/análise , Artéria Pulmonar/enzimologia , RNA Mensageiro/análise , Proteínas Ativadoras de 5-Lipoxigenase , Araquidonato 5-Lipoxigenase/genética , Proteínas de Transporte/genética , Estudos de Casos e Controles , Humanos , Hipertensão Pulmonar/imunologia , Hipertensão Pulmonar/patologia , Imuno-Histoquímica , Inflamação , Doenças Pulmonares Intersticiais/enzimologia , Proteínas de Membrana/genéticaRESUMO
Prostacyclin is a powerful vasodilator and inhibits platelet adhesion and cell growth. We hypothesized that a decrease in expression of the critical enzyme PGI2 synthase (PGI2-S) in the lung may represent an important manifestation of pulmonary endothelial dysfunction in severe pulmonary hypertension (PH). Immunohistochemistry and Western blot analysis were used to assess lung PGI2-S protein expression, and in situ hybridization was used to assess PGI2-S mRNA expression. In the normal pulmonary circulation (n = 7), PGI2-S was expressed in 48% of small, 67% of medium, and 76% of large pulmonary arteries as assessed by immunohistochemistry. PPH (n = 12), cirrhosis-associated (n = 4) and HIV-associated PH (n = 2) lungs exhibited a marked reduction in PGI2-S expression, involving all size ranges of pulmonary arteries. Vessels with concentric lesions showed complete lack of PGI2-S expression. Congenital heart (n = 4) and CREST (n = 2) cases exhibited a more variable immunohistological pattern of PGI2-S expression. These results were complemented by in situ hybridization and Western blots of representative lung samples. We conclude that the different sizes of the pulmonary arteries express PGI2-S differently and that the loss of expression of PGI2-S represents one of the phenotypic alterations present in the pulmonary endothelial cells in severe PH.
Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Hipertensão Pulmonar/enzimologia , Oxirredutases Intramoleculares/metabolismo , Pulmão/enzimologia , Adulto , Western Blotting , Síndrome CREST/complicações , Pré-Escolar , Feminino , Infecções por HIV/complicações , Cardiopatias Congênitas/complicações , Humanos , Hipertensão Pulmonar/complicações , Imuno-Histoquímica , Hibridização In Situ , Cirrose Hepática/complicações , Masculino , Pessoa de Meia-IdadeRESUMO
The plexiform lesions of severe pulmonary hypertension (PH) are complex vascular structures composed primarily of endothelial cells. In this study, we use immunohistochemical markers to identify the various cell layers of pulmonary vessels and to identify different endothelial cell phenotypes in pulmonary arteries affected by severe PH. Our computerized three-dimensional reconstructions of nine vessels in five patients with severe PH demonstrate that plexiform (n = 14) and concentric-obliterative (n = 6) lesions occur distal to branch points of small pulmonary arteries. And, whereas plexiform lesions occur as solitary lesions, concentric-obliterative lesions appear to be only associated with, and proximal to, plexiform structures. The endothelial cells of plexiform lesions express intensely and uniformly the vascular endothelial growth factor (VEGF) receptor KDR and segregate phenotypically into cyclin-kinase inhibitor p27/kip1-negative cells in the central core of the plexiform lesion and p27/kip1-positive cells in peripheral areas adjacent to incipient blood vessel formation. Using immunohistochemistry and three-dimensional reconstruction techniques, we show that plexiform lesions are dynamic vascular structures characterized by at least two endothelial cell phenotypes. Plexiform arteriopathy is not merely an end stage or postthrombotic change--it may represent one stage in an ongoing, angiogenic endothelial cell growth process.
Assuntos
Proteínas de Ciclo Celular , Simulação por Computador , Endotélio/metabolismo , Hipertensão Pulmonar/metabolismo , Hipertensão Pulmonar/patologia , Artéria Pulmonar/anatomia & histologia , Proteínas Supressoras de Tumor , Actinas/análise , Adulto , Biomarcadores , Divisão Celular , Inibidor de Quinase Dependente de Ciclina p27 , Fatores de Crescimento Endotelial/análise , Endotélio/anatomia & histologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imuno-Histoquímica , Pulmão/anatomia & histologia , Pulmão/patologia , Linfocinas/análise , Masculino , Proteínas Associadas aos Microtúbulos/análise , Pessoa de Meia-Idade , Modelos Biológicos , Músculo Liso/anatomia & histologia , Músculo Liso/metabolismo , Artéria Pulmonar/patologia , Receptores Proteína Tirosina Quinases/análise , Receptores de Fatores de Crescimento/análise , Receptores de Fatores de Crescimento do Endotélio Vascular , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular , Fator de von Willebrand/análiseRESUMO
Pulmonary arteries of patients with severe pulmonary hypertension (SPH) presenting in an idiopathic form (primary PH-PPH) or associated with congenital heart malformations or collagen vascular diseases show plexiform lesions. It is postulated that in lungs with SPH, endothelial cells in plexiform lesions express genes encoding for proteins involved in angiogenesis, in particular, vascular endothelial growth factor (VEGF) and those involved in VEGF receptor-2 (VEGFR-2) signalling. On immunohistochemistry and in situ hybridization, endothelial cells in the plexiform lesions expressed VEGF mRNA and protein and overexpressed the mRNA and protein of VEGFR-2, and the transcription factor subunits HIF-1alpha and HIF-1beta of hypoxia inducible factor, which are responsible for the hypoxia-dependent induction of VEGF. When compared with normal lungs, SPH lungs showed decreased expression of the kinases PI3 kinase and src, which, together with Akt, relay the signal transduction downstream of VEGFR-2. Because markers of angiogenesis are expressed in plexiform lesions in SPH, it is proposed that these lesions may form by a process of disordered angiogenesis.