RESUMO
BACKGROUND: Idiopathic chylopericardium is a rare disease characterized by filling of the pericardial cavity with chylous fluid and has no evident cause. Secondary chylopericardium usually results from injury or damage to the thoracic duct. The most common causes of secondary chylopericardium are trauma, thoracic or cardiac surgery, and congenital lymphangiomatosis. Conservative or surgical treatment can be pursued; however, surgical treatment is required if conservative treatment is unsuccessful. Pericardiocentesis plays a crucial role in the definitive diagnosis of chylopericardium. However, although a serious complication, its occurrence is infrequent. Non-invasive methods, such as computed tomography (CT), could be useful in predicting the color or characteristics of pericardial effusion. CASE PRESENTATION: A 37-year-old Japanese woman presented to our hospital with a cough that persisted for 1 week. Echocardiography revealed pericardial effusion, which was diagnosed as acute pericarditis and treated with loxoprofen. However, pericardial effusion increased, and the patient presented to the emergency room with cardiac tamponade 1 month later. Pericardiocentesis was performed, which confirmed that the pericardial effusion was chylopericardium. Lymphatic scintigraphy did not show any connection between the thoracic duct and pericardial cavity, and the patient was diagnosed with idiopathic chylopericardium. The patient underwent continuous drainage for 11 days. After completion of cardiac drainage, the patient was discharged from the hospital without any exacerbation. The CT attenuation value of the pericardial fluid was 11.00 Hounsfield units (HU). Compared with the other causes of pericardial effusions encountered at our hospital, the HU on CT scan of pericardial effusion was low in our study and similar to the values on CT scan of chylous ascites reported in previous studies. CONCLUSIONS: Although idiopathic chylopericardium is rare, it should be considered an important cause of pericardial effusion. Pericardiocentesis is necessary for definitive diagnosis; however, the CT findings of pericardial effusion may help predict the presence of chylous fluid.
Assuntos
Tamponamento Cardíaco , Derrame Pericárdico , Feminino , Humanos , Adulto , Derrame Pericárdico/diagnóstico por imagem , Derrame Pericárdico/etiologia , Pericardiocentese/efeitos adversos , Tamponamento Cardíaco/etiologia , Tomografia Computadorizada por Raios X/efeitos adversos , Tomografia/efeitos adversosRESUMO
BACKGROUND: Myocardial abscess is often associated with infective endocarditis (IE), and isolated myocardial abscess without IE is rare. Echocardiography and computed tomography (CT) are often used to diagnose myocardial abscess; however, to the best of our knowledge, diffusion-weighted whole-body magnetic resonance imaging with background body signal suppression (DWIBS) has not been used. Here, we present a case of myocardial abscess without IE that was diagnosed using DWIBS. CASE PRESENTATION: A 72-year-old Japanese man with a history of hypertension, dyslipidemia, and retinitis pigmentosa presented to our hospital with malaise and a fever lasting 10 days. Blood test results showed elevated inflammatory marker levels (white blood cell count 18,700/µL and C-reactive protein level 23.0 mg/dL). Infection was suspected; however, the source of the infection could not be identified. DWIBS, which was performed on day 7 of admission to determine the source of infection, showed a high signal surrounding the right wall, suggesting inflammation. Contrast-enhanced CT performed on day 1 of hospitalization revealed a low-density area in the same region; however, the pathological implications of this finding could not be determined. Based on DWIBS findings, we concluded that the condition presented as a myocardial abscess that was confined specifically to the right atrial wall. Three sets of blood cultures revealed negative findings, and echocardiography showed no vegetation or valve regurgitation. Therefore, the patient was diagnosed with an isolated myocardial abscess uncomplicated with IE. An electrocardiogram on admission showed no P waves, and the patient had a junctional rhythm. However, on day 20 of hospitalization, he developed a complete atrioventricular block. After complete myocardial abscess healing following antibiotic treatment was confirmed, the patient underwent pacemaker implantation. Ten months after surgery, the patient had no signs of infection recurrence. CONCLUSIONS: Based on history and physical examination alone, diagnosis of an isolated myocardial abscess can be challenging. In addition to CT and echocardiography, DWIBS might be helpful for the diagnosis of myocardial abscesses.
Assuntos
Fibrilação Atrial , Endocardite Bacteriana , Endocardite , Masculino , Humanos , Idoso , Imageamento por Ressonância Magnética , Abscesso/diagnóstico por imagem , Abscesso/terapia , Imagem Corporal Total , Imagem de Difusão por Ressonância Magnética/métodosRESUMO
Background and objective: Unilateral agenesis of pulmonary arteries (UAPA) is a rare disease, with approximately 400 cases reported to date. UAPA is often associated with congenital heart disease, and the uncomplicated form is isolated UAPA, which accounts for approximately 30% of all cases of UAPA. The incidence of pulmonary hypertension due to UAPA has been reported to range from 19 to 44%. There is no consensus treatment for pulmonary hypertension associated with UAPA. We present the first reported case in which a three-drug combination, comprising of iloprost inhalation, riociguat, and ambrisentan, was administered to a patient with UAPA, and was followed-up for 3 years post-diagnosis. Case presentation: A 68-year-old Japanese woman presented to our hospital with dyspnea and chest discomfort. She underwent chest radiography, blood tests, and echocardiography; however, the cause of the patient's symptoms could not be identified. During regular follow-up, an echocardiography 21 months after the initial visit revealed elevated right ventricular pressure (peak tricuspid regurgitation velocity: 5.2 m/s and right ventricular systolic pressure: 120 mmHg) and a diagnosis of pulmonary hypertension was made. Contrast-enhanced computed tomography (CT) of the chest and a pulmonary blood flow scintigram were performed to investigate the cause of pulmonary hypertension, and isolated UAPA was diagnosed. The patient was treated with a three-drug combination of iloprost inhalation, riociguat, and ambrisentan and followed up for 3 years with good therapeutic outcomes. Conclusions: We present a case of pulmonary hypertension caused by isolated UAPA. Although rare, this disease can lead to pulmonary hypertension and should be treated cautiously. While there is no consensus regarding the treatment of this disease, a three-drug combination of iloprost inhalation, riociguat, and oral ambrisentan proved effective.
Assuntos
Cardiopatias Congênitas , Hipertensão Pulmonar , Pneumopatias , Feminino , Humanos , Idoso , Artéria Pulmonar/anormalidades , Hipertensão Pulmonar/complicações , Hipertensão Pulmonar/tratamento farmacológico , Seguimentos , Iloprosta/uso terapêutico , Cardiopatias Congênitas/complicaçõesRESUMO
Background: Cardiopulmonary disorders are the most common cause of central cyanosis, and methemoglobinemia is often overlooked in the differential diagnosis of patients with central cyanosis. In most cases, methemoglobinemia is acquired and hereditary congenital methemoglobinemia is rare. Only a few case reports of congenital methemoglobinemia can be found in PubMed. To date, only four cases of congenital methemoglobinemia diagnosed after the age of 50 years have been reported. Case Presentation: A 79-year-old Japanese woman presented at our hospital with the chief complaints of dyspnea and cyanosis. She exhibited cyanosis of the lips and extremities, and her SpO2 was 80%, with oxygen administration at 5 L/min. Blood gas analysis revealed a PaO2 of 325.4 mmHg and methemoglobin level of 36.9%. The SpO2 and PaO2 values were dissociated, and methemoglobin levels were markedly elevated. Genetic analysis revealed a nonsynonymous variant in the gene encoding nicotinamide adenine dinucleotide cytochrome (NADH) B5 reductase 3 (CYB5R3), and the patient was diagnosed with congenital methemoglobinemia. Conclusions: It is important to consider methemoglobinemia in the differential diagnosis of patients with central cyanosis. At 79 years of age, our patient represents the oldest patient with this diagnosis. This report indicates that it is crucial to consider the possibility of methemoglobinemia regardless of the patient's age.
Assuntos
Metemoglobinemia , Humanos , Feminino , Idoso , Pessoa de Meia-Idade , Metemoglobinemia/diagnóstico , Metemoglobinemia/genética , Metemoglobinemia/congênito , Metemoglobina/análise , Citocromo-B(5) Redutase/genética , Cianose/genéticaRESUMO
Epithelial ovarian cancer is classified into four major histological subtypes: serous, clear cell, endometrioid and mucinous. Ovarian clear cell carcinoma (OCCC) responds poorly to conventional chemotherapies and shows poor prognosis. Thus, there is a need to develop new drugs for the treatment of OCCC. In this study, we performed CRISPR/Cas9 screens against OCCC cell lines and identified candidate genes important for their proliferation. We found that quite different genes are required for the growth of ARID1A and PIK3CA mutant and wild-type OCCC cell lines, respectively. Furthermore, we found that the epigenetic regulator KDM2A and the translation regulator PAIP1 may play important roles in the growth of ARID1A and PIK3CA mutant, but not wild-type, OCCC cells. The results of our CRISPR/Cas9 screening may be useful in elucidating the molecular mechanism of OCCC tumorigenesis and in developing OCCC-targeted drugs.
RESUMO
Ovarian cancer is the fifth most common cause of cancer-related death in women. Ovarian clear cell carcinoma (OCCC) is a chemotherapy-resistant epithelial ovarian cancer with poor prognosis. As a basis for the development of therapeutic agents that could improve the prognosis of OCCC, we performed a screen for proteins critical for the tumorigenicity of OCCC using the CRISPR/Cas9 system. Here we show that knockdown of the phosphate exporter XPR1/SLC53A1 induces the growth arrest and apoptosis of OCCC cells in vitro. Moreover, we show that knockdown of XPR1/SLC53A1 inhibits the proliferation of OCCC cells xenografted into immunocompromised mice. These results suggest that XPR1/SLC53A1 plays a critical role in the tumorigenesis of OCCC cells. We speculate that XPR1/SLC53A1 might be a promising molecular target for the therapeutic treatment of OCCC.
Assuntos
Adenocarcinoma de Células Claras , Neoplasias Ovarianas , Adenocarcinoma de Células Claras/patologia , Animais , Carcinoma Epitelial do Ovário/genética , Feminino , Humanos , Camundongos , Neoplasias Ovarianas/patologia , Fosfatos/uso terapêutico , PrognósticoRESUMO
Long non-coding RNAs (lncRNAs) are aberrantly expressed in many disease conditions, including cancer. Accumulating evidence indicates that some lncRNAs may play critical roles in cancer progression and metastasis. Here, we identify a set of lncRNAs that are upregulated in metastatic subpopulations isolated from colon cancer HCT116 cells in vivo and show that one of these lncRNAs, which we name CALIC, is required for the metastatic activity of colon cancer cells. We show that CALIC associates with the RNA-binding protein hnRNP-L and imparts specificity to hnRNP-L-mediated gene expression. Furthermore, we demonstrate that the CALIC/hnRNP-L complex upregulates the tyrosine kinase receptor AXL and that knockdown of CALIC or AXL using shRNA in colon cancer cells attenuates their ability to form metastases in mice. These results suggest that the CALIC/hnRNP-L complex enhances the metastatic potential of colon cancer cells.
Assuntos
Neoplasias do Colo/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/genética , Proteínas Proto-Oncogênicas/genética , RNA Longo não Codificante/genética , Receptores Proteína Tirosina Quinases/genética , Ribonucleoproteínas/genética , Animais , Proliferação de Células , Neoplasias do Colo/metabolismo , Neoplasias do Colo/mortalidade , Neoplasias do Colo/patologia , Progressão da Doença , Feminino , Células HCT116 , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/secundário , Metástase Linfática , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Ligação Proteica , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas/metabolismo , RNA Longo não Codificante/antagonistas & inibidores , RNA Longo não Codificante/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Receptores Proteína Tirosina Quinases/metabolismo , Ribonucleoproteínas/metabolismo , Transdução de Sinais , Análise de Sobrevida , Ensaios Antitumorais Modelo de Xenoenxerto , Receptor Tirosina Quinase AxlRESUMO
The purpose of this study was to determine whether chronic estrogen replacement in ovariectomized rats inhibits the pressor response to psychological stress by attenuating the activation of the renin-angiotensin system. Female Wistar rats aged 9 wk were ovariectomized. After 4 wk, the rats were randomly assigned to be implanted subcutaneously with pellets containing either 17ß-estradiol (E2) or placebo (Pla). After 4 wk of treatment, the rats underwent cage-switch stress and, in a separate experiment, a subset received an infusion of angiotensin II. The cage-switch stress rapidly elevated blood pressure (BP) and heart rate (HR) as measured by radiotelemetry in both groups. However, the BP and HR responses to the stress were significantly attenuated in the E2 group compared with the Pla group. An angiotensin II type 1 receptor blocker, losartan, given in drinking water, abolished the difference in the pressor response to stress between the two groups. Moreover, the stress-induced elevation in plasma renin activity and angiotensin II concentration was significant in the Pla group, but not in the E2 group. In addition, the expression of renin mRNA in the kidney was lower in the E2 group relative to the Pla group. Finally, we found that intravenous angiotensin II infusion increased BP and decreased HR to a similar degree in both groups. These results suggest that the inhibitory effects of estrogen on psychological stress-induced activation of the renin-angiotensin system could be at least partially responsible for the suppression of the pressor responses to psychological stress seen in estrogen-replaced ovariectomized rats.
Assuntos
Pressão Sanguínea/fisiologia , Terapia de Reposição de Estrogênios , Frequência Cardíaca/fisiologia , Sistema Renina-Angiotensina/fisiologia , Estresse Fisiológico/fisiologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Estradiol/farmacologia , Feminino , Frequência Cardíaca/efeitos dos fármacos , Ovariectomia , Ratos , Ratos Wistar , Sistema Renina-Angiotensina/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacosRESUMO
The patient received endovascular therapy for a superficial femoral artery occlusion. Placement of a SMART stent distal to the lesion was successful, but deployment issues occurred with the Innova stent, requiring forceful retraction and causing elongation. The "cut and peel technique" was developed as a bailout strategy for such cases.
RESUMO
Nuclear expression of protein kinase CK2α is reportedly elevated in human carcinomas, but mechanisms underlying its variable localization in cells are poorly understood. This study demonstrates a functional connection between nuclear CK2 and gene expression in relation to cell proliferation. Growth stimulation of quiescent human normal fibroblasts and phospho-proteomic analysis identified a pool of CK2α that is highly phosphorylated at serine 7. Phosphorylated CK2α translocates into the nucleus, and this phosphorylation appears essential for nuclear localization and catalytic activity. Protein signatures associated with nuclear CK2 complexes reveal enrichment of apparently unique transcription factors and chromatin remodelers during progression through the G1 phase of the cell cycle. Chromatin immunoprecipitation-sequencing profiling demonstrated recruitment of CK2α to active gene loci, more abundantly in late G1 phase than in early G1, notably at transcriptional start sites of core histone genes, growth stimulus-associated genes, and ribosomal RNAs. Our findings reveal that nuclear CK2α complexes may be essential to facilitate progression of the cell cycle, by activating histone genes and triggering ribosomal biogenesis, specified in association with nuclear and nucleolar transcriptional regulators.
Assuntos
Redes Reguladoras de Genes , Histonas , Humanos , Ciclo Celular/genética , Proliferação de Células/genética , ProteômicaRESUMO
Certain cancers, such as ovarian clear cell carcinoma (OCCC), display high levels of genetic variation between patients, making it difficult to develop effective therapies. In order to identify novel genes critical to OCCC growth, we carried out a comprehensive CRISPR-Cas9 knockout screen against cell growth using an OCCC cell line and a normal ovarian surface epithelium cell line. We identified the gene encoding DHX38/PRP16, an ATP-dependent RNA helicase involved in splicing, as critical for the growth and tumorigenesis of OCCC. DHX38/PRP16 knockdown in OCCC cells, but not normal cells, induces apoptosis and impairs OCCC tumorigenesis in a mouse model. Our results suggest that DHX38/PRP16 may play a role in OCCC tumorigenesis and could potentially be a promising therapeutic target.
Assuntos
Adenocarcinoma de Células Claras , Neoplasias Ovarianas , Fatores de Processamento de RNA , Adenocarcinoma de Células Claras/genética , Adenocarcinoma de Células Claras/metabolismo , Adenocarcinoma de Células Claras/patologia , Animais , Sistemas CRISPR-Cas/genética , Carcinogênese/genética , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Neoplasias Ovarianas/tratamento farmacológico , Fatores de Processamento de RNA/genética , Fatores de Processamento de RNA/metabolismo , Fatores de Processamento de RNA/uso terapêuticoRESUMO
Paternal environmental factors can epigenetically influence gene expressions in offspring. We demonstrate that restraint stress, an experimental model for strong psychological stress, to fathers affects the epigenome, transcriptome, and metabolome of offspring in a MEKK1-dATF2 pathway-dependent manner in Drosophila melanogaster. Genes involved in amino acid metabolism are upregulated by paternal restraint stress, while genes involved in glycolysis and the tricarboxylic acid (TCA) cycle are downregulated. The effects of paternal restraint stress are also confirmed by metabolome analysis. dATF-2 is highly expressed in testicular germ cells, and restraint stress also induces p38 activation in the testes. Restraint stress induces Unpaired 3 (Upd3), a Drosophila homolog of Interleukin 6 (IL-6). Moreover, paternal overexpression of upd3 in somatic cells disrupts heterochromatin in offspring but not in offspring from dATF-2 mutant fathers. These results indicate that paternal restraint stress affects metabolism in offspring via inheritance of dATF-2-dependent epigenetic changes.
Assuntos
Fator 2 Ativador da Transcrição/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/fisiologia , Epigenoma , Células Germinativas/fisiologia , Metaboloma , Transcriptoma , Fator 2 Ativador da Transcrição/metabolismo , Animais , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Pai , MAP Quinase Quinase Quinase 1/fisiologia , Masculino , Transdução de Sinais/fisiologiaRESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMO
Gonocyte-to-spermatogonia transition is a critical fate determination process to initiate sperm production throughout the lifecycle. However, the molecular dynamics of this process has not been fully elucidated mainly due to the asynchronized differentiation stages of neonatal germ cells. In this study, we employed single cell RNA sequencing analyses of P1.5-5.5 germ cells to clarify the temporal dynamics of gene expression during gonocyte-to-spermatogonia transition. The analyses identified transcriptional modules, one of which regulates spermatogonial gene network in neonatal germ cells. Among them, we identified Dec2, a bHLH-type transcription factor, as a transcriptional repressor for a spermatogonial differentiation factor Sohlh1. Deficiency of Dec2 in mice induces significant reduction of undifferentiated spermatogonia, and transplantation assay using Dec2-depleted cells also demonstrated the impaired efficiency of engraftment, suggesting its role in maintaining spermatogonial stem cells (SSCs). Collectively, this study revealed the intrinsic role of a new SSC factor Dec2, which protects germ cells from inadequate differentiation during neonatal testis development.
Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Regulação da Expressão Gênica no Desenvolvimento , Espermatogênese/genética , Espermatogônias/fisiologia , Fatores de Transcrição/metabolismo , Animais , Animais Recém-Nascidos , Diferenciação Celular/genética , Masculino , Camundongos , Camundongos Transgênicos , Análise de Célula Única , Células-Tronco/fisiologia , Testículo/citologia , Testículo/crescimento & desenvolvimento , Fatores de Transcrição/genéticaRESUMO
An ATP-binding cassette transporter LolCDE complex of Escherichia coli releases lipoproteins destined to the outer membrane from the inner membrane as a complex with a periplasmic chaperone, LolA. Interaction of the LolA-lipoprotein complex with an outer membrane receptor, LolB, then causes localization of lipoproteins to the outer membrane. As far as examined, formation of the LolA-lipoprotein complex strictly depends on ATP hydrolysis by the LolCDE complex in the presence of LolA. It has been speculated, based on crystallographic and biochemical observations, that LolA undergoes an ATP-dependent conformational change upon lipoprotein binding. Thus, preparation of a large amount of the LolA-lipoprotein complex is difficult. Moreover, lipoproteins bound to LolA are heterogeneous. We report here that the coexpression of LolA and outer membrane-specific lipoprotein Pal from a very efficient plasmid causes the unusual accumulation of the LolA-Pal complex in the periplasm. The complex was purified to homogeneity and shown to be a functional intermediate of the lipoprotein localization pathway. In vitro incorporation of Pal into outer membranes revealed that a single molecule of LolB catalyzes the incorporation of more than 100 molecules of Pal into outer membranes. Moreover, the LolB-dependent incorporation of Pal was not affected by excess-free LolA, indicating that LolB specifically interacts with liganded LolA. Finally, the LolB depletion caused the accumulation of a significant amount of Pal in the periplasm, thereby establishing the conditions for preparation of the homogeneous LolA-lipoprotein complex.
Assuntos
Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Lipoproteínas/metabolismo , Peptidoglicano/metabolismo , Proteínas Periplásmicas de Ligação/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Proteínas da Membrana Bacteriana Externa/isolamento & purificação , Membrana Celular/metabolismo , Proteínas de Escherichia coli/isolamento & purificação , Lipoproteínas/isolamento & purificação , Peptidoglicano/isolamento & purificação , Periplasma/metabolismo , Proteínas Periplásmicas de Ligação/isolamento & purificaçãoRESUMO
Aberrant activation of Wnt/ß-catenin signaling is a major driving force in colon cancer. Wnt/ß-catenin signaling induces the expression of the transcription factor c-Myc, leading to cell proliferation and tumorigenesis. c-Myc regulates multiple biological processes through its ability to directly modulate gene expression. Here, we identify a direct target of c-Myc, termed MYU, and show that MYU is upregulated in most colon cancers and required for the tumorigenicity of colon cancer cells. Furthermore, we demonstrate that MYU associates with the RNA binding protein hnRNP-K to stabilize CDK6 expression and thereby promotes the G1-S transition of the cell cycle. These results suggest that the MYU/hnRNP-K/CDK6 pathway functions downstream of Wnt/c-Myc signaling and plays a critical role in the proliferation and tumorigenicity of colon cancer cells.
Assuntos
Ciclo Celular , Quinase 6 Dependente de Ciclina/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , RNA Longo não Codificante/metabolismo , Via de Sinalização Wnt , Animais , Sequência de Bases , Carcinogênese/genética , Carcinogênese/patologia , Linhagem Celular Tumoral , Proliferação de Células , Células Clonais , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , Ribonucleoproteínas Nucleares Heterogêneas Grupo K/metabolismo , Humanos , Camundongos Nus , RNA Longo não Codificante/genética , Regulação para Cima/genéticaRESUMO
8-Hydroxy-2'-deoxyguanosine (8-OH-dG), which has been regarded as a potential marker of oxidative DNA damage induced by reactive oxygen species, was measured in human urine by a commercial ELISA using a monoclonal antibody N45.1 and by high-performance liquid chromatography (HPLC) coupled to an electrochemical detector (HPLC-ECD) to evaluate whether the ELISA system is applicable to human monitoring studies. The urine samples were collected from 120 healthy men ages 18-58 in a steel-manufacturing company. A good correlation (r = 0.833; P < 0.0001) was observed between the two methods on HPLC-purified 8-OH-dG fractions from 23 urine samples. The mean value (+/-SD) of 8-OH-dG (microg/g creatinine) was 5.47 (+/-2.97) by HPLC-ECD assay and 5.50 (+/-2.36) by ELISA. However, the correlation (r) between the two methods on 120 original urine samples was 0.460 [P < 0.001; mean value (+/-SD) of 8-OH-dG (microg/g creatinine) was 4.46 (+/-2.03) by the HPLC assay and 9.33 (+/-3.23) by ELISA]. ELISA estimates were about 2-fold higher than the HPLC estimates on original urine. For an unknown reason, 10% of the urine samples showed more than a 4-fold increase in value by ELISA. It is suggested that the ELISA system is applicable for comparative human monitoring studies. Prepurification of 'samples is required to determine the absolute value of 8-OH-dG in individual urine samples by ELISA.
Assuntos
Cromatografia Líquida de Alta Pressão , Dano ao DNA , Desoxiguanosina/análogos & derivados , Desoxiguanosina/urina , Ensaio de Imunoadsorção Enzimática , 8-Hidroxi-2'-Desoxiguanosina , Adolescente , Adulto , Biomarcadores/análise , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Manejo de Espécimes , UrináliseRESUMO
BACKGROUND: Ischemia-reperfusion injury (IRI) is the main cause of acute renal failure in both allograft and native kidney. Studies using T cell knockout mice have established an important role for T cells in renal IRI. T cell depletion strategies are effective in human allograft rejection. However, it is not known whether those are effective in renal IRI. Therefore, the effect of T cell depletion in a murine model of renal IRI using well-characterized antibodies (Abs) that have been effective in preventing experimental allograft rejection was studied. METHODS: T cell depleting Abs to CD4 (GK1.5), CD8 (2.43) or pan-T cells (30.H12) were purified from hybridoma culture supernatant. Thymectomized C57BL/6 mice, treated with different combinations of T cell depleting Abs, underwent 30 min of bilateral renal IRI, followed by assessment of renal function, structure, and degree of T cell depletion in spleen, lymph nodes, and peripheral blood by flow cytometry. RESULTS: Mice given both GK1.5 and 2.43 had considerable CD4 and CD8 cell depletion but no protection of renal function after ischemia-reperfusion (I/R) as measured by the rise in serum creatinine. However, when GK1.5 and 2.43 was administered combined with 30.H12, which more effectively depleted CD4 T cell numbers, a significant protection of renal function and structure was observed after I/R. Antibody combinations did not significantly alter other leukocyte populations. CONCLUSIONS: These data demonstrate that T cell depletion can improve the course of experimental renal IRI. However, more aggressive T cell depletion strategies were required compared with that needed to prevent experimental allograft rejection.
Assuntos
Isquemia/terapia , Rim/irrigação sanguínea , Depleção Linfocítica/métodos , Traumatismo por Reperfusão/prevenção & controle , Linfócitos T/imunologia , Animais , Antígenos CD4/imunologia , Antígenos CD8/imunologia , Rejeição de Enxerto/prevenção & controle , Rim/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , TimectomiaAssuntos
Anticorpos Anti-Idiotípicos/farmacologia , Nefropatias/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Nefrite Lúpica/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/imunologia , Animais , Modelos Animais de Doenças , Rim/metabolismo , Rim/patologia , Nefropatias/metabolismo , Nefropatias/patologia , Nefrite Lúpica/patologia , Camundongos , Camundongos Endogâmicos NZB , Microscopia de Fluorescência , Fatores de Tempo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
Outer membrane-specific lipoproteins of Escherichia coli are released from the inner membrane through the action of Lol-CDE, which leads to the formation of a complex between the lipoprotein and LolA, a periplasmic chaperone. LolA then transfers lipoproteins to LolB, a receptor in the outer membrane. The structures of LolA and LolB are very similar, having an incomplete beta-barrel covered with an alpha-helical lid forming a hydrophobic cavity inside. The cavity of LolA, but not that of LolB, is closed and thus inaccessible to the bulk solvent. Previous studies suggested that Arg at position 43 of LolA is critical for maintaining this closed structure. We show here, through a crystallographic study, that the cavity of the LolA(R43L) mutant, in which Leu replaces Arg-43, is indeed open to the external milieu. We then found that the binding of a fluorescence probe distinguishes the open/close state of the cavity. Furthermore, it was revealed that the hydrophobic cavity of LolA opens upon the binding of lipoproteins. Such a liganded LolA was found to be inactive in the release of lipoproteins from the inner membrane. On the other hand, the liganded LolA became fully functional when lipoproteins were removed from LolA by detergent treatment or transferred to LolB. Free LolA thus formed was inaccessible to a fluorescence probe. These results, taken together, reveal the LolA cycle, in which the hydrophobic cavity undergoes opening and closing upon the binding and release of lipoproteins, respectively.