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1.
Kidney Int ; 83(2): 213-22, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22913982

RESUMO

Hyperphosphatemia is associated with increased cardiovascular risk in patients with renal disease and in healthy individuals. Here we tested whether high phosphate has a role in the pathophysiology of cardiovascular events by interfering with endothelial function, thereby impairing microvascular function and angiogenesis. Protein expression analysis found downregulation of annexin II in human coronary artery endothelial cells, an effect associated with exacerbated shedding of annexin II-positive microparticles by the cells exposed to high phosphate media. EAhy926 endothelial cells exposed to sera from hyperphosphatemic patients also display decreased annexin II, suggesting a negative correlation between serum phosphate and annexin II expression. By using endothelial cell-based assays in vitro and the chicken chorioallantoic membrane assay in vivo, we found that angiogenesis, vessel wall morphology, endothelial cell migration, capillary tube formation, and endothelial survival were impaired in a hyperphosphatemic milieu. Blockade of membrane-bound extracellular annexin II with a specific antibody mimicked the effects of high phosphate. In addition, high phosphate stiffened endothelial cells in vitro and in rats in vivo. Thus, our results link phosphate and adverse clinical outcomes involving the endothelium in both healthy individuals and patients with renal disease.


Assuntos
Anexina A2/antagonistas & inibidores , Hiperfosfatemia/fisiopatologia , Animais , Anexina A2/análise , Anexina A2/fisiologia , Apoptose , Movimento Celular , Células Cultivadas , Embrião de Galinha , Regulação para Baixo , Humanos , Masculino , Neovascularização Fisiológica , Proteômica , Ratos , Ratos Sprague-Dawley , Insuficiência Renal Crônica/complicações , Rigidez Vascular
2.
Am J Nephrol ; 36(4): 355-61, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23038220

RESUMO

BACKGROUND/AIMS: Recent retrospective studies suggest an association of therapy with erythropoiesis-stimulating agents (ESAs) and increased mortality in renal transplant recipients (RTR). Large artery structure and function are significantly impaired in RTR which contributes to their high cardiovascular morbidity and could be altered by erythropoietin. We aimed to examine the influence of ESA therapy on large artery stiffness and endothelial function in RTR. METHODS: 63 RTR with chronic allograft dysfunction and renal anemia were randomized to a group receiving darbepoetin alfa (Dar) and a control group (Co). At baseline and after 8 months of treatment (cumulative Dar dose 11.1 µg/kg b.w.) brachial and common carotid artery distensibility coefficients, aortic pulse wave velocity, brachial artery flow-mediated and nitroglycerin-mediated vasodilation were measured as well as the following biomarkers of vascular function: vWF, sVCAM, sICAM, E-selectin, t-PA and PAI-1. RESULTS: 23 patients in the Dar group and 17 patients in the Co group were available for per-protocol analysis. Hemoglobin increased significantly from 10.9 to 12.6 g/dl after 8 months in the Dar group, whereas it remained stable at 11.3 g/dl in the Co group. Effects on large artery stiffness, endothelial function and biomarkers of vascular function did not differ significantly between the two groups. CONCLUSION: Therapy with Dar during 8 months did not significantly impact parameters of large artery stiffness and endothelial function in RTR. These data suggest that therapy with erythropoietin does not deteriorate arterial stiffness and endothelial function in RTR.


Assuntos
Endotélio Vascular/efeitos dos fármacos , Eritropoetina/análogos & derivados , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Disfunção Primária do Enxerto/tratamento farmacológico , Rigidez Vascular/efeitos dos fármacos , Anemia/tratamento farmacológico , Anemia/mortalidade , Artéria Braquial/fisiologia , Darbepoetina alfa , Eritropoetina/administração & dosagem , Feminino , Hematínicos/administração & dosagem , Humanos , Falência Renal Crônica/mortalidade , Transplante de Rim/mortalidade , Masculino , Pessoa de Meia-Idade , Disfunção Primária do Enxerto/mortalidade , Fatores de Risco , Transplante Homólogo , Resultado do Tratamento , Vasodilatação/efeitos dos fármacos , Vasodilatação/fisiologia
3.
Nephrol Dial Transplant ; 24(9): 2838-46, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19339340

RESUMO

BACKGROUND: Induction of heat shock proteins (HSP), i.e. of the major family member HSP70, is an important cytoprotective-resistance mechanism for monocytes/ macrophages (Mphi). Patients on haemodialysis present with a high infectious morbidity and enhanced carcinoma incidence. Renal insufficiency-related alteration of microbicidal and tumoricidal functions of Mphi, major effectors of the immune system, might promote these diseases. METHODS: Freshly isolated Mphi from Sprague-Dawley rats 2 weeks after 5/6-nephrectomy and from patients on intermittent haemodialysis (IHD) were stimulated by heat shock (HS) and compared to stimulated Mphi of control rats or healthy volunteers (CTR). Expression of HSP72 (inducible HSP70) was assessed by RT-PCR, and/or flow cytometry. Apoptosis of Mphi was detected by flow cytometry (CD14/annexin V-labelling). RESULTS: In rat Mphi, baseline HSP72 expression was similar in both groups, but its induction was significantly impaired in renal insufficiency (214 +/- 68% less HSP70-mRNA versus CTR, n = 6). In patients, HSF-1-mRNA and HSP72-mRNA/protein response to HS was significantly lower, but not affected by dialysis session itself. In parallel, apoptosis of Mphi of patients was enhanced (+83 +/- 29% constitutive apoptotic Mphi versus CTR, n = 8), and HS-dependent protection from apoptosis with and without serum depletion (48 h depletion: HS, +275 +/- 37% apoptotic Mphi versus CTR, n = 6; full medium: +166 +/- 62% versus CTR, n = 8, P < 0.05) was inferior. CONCLUSIONS: Impaired HSP72 stress response of Mphi in patients on haemodialysis might contribute to the observed immune dysfunction and, therefore, to the increased susceptibility to infection and malignancy. Stress impairment is not restricted to uraemia but is already present in a rat model of chronic kidney disease.


Assuntos
Proteínas de Choque Térmico HSP72/biossíntese , Monócitos/metabolismo , Diálise Renal/efeitos adversos , Adolescente , Adulto , Idoso , Animais , Apoptose , Sequência de Bases , Estudos de Casos e Controles , Primers do DNA/genética , Proteínas de Ligação a DNA/biossíntese , Proteínas de Ligação a DNA/genética , Modelos Animais de Doenças , Feminino , Proteínas de Choque Térmico HSP72/genética , Fatores de Transcrição de Choque Térmico , Resposta ao Choque Térmico/genética , Resposta ao Choque Térmico/imunologia , Resposta ao Choque Térmico/fisiologia , Humanos , Técnicas In Vitro , Falência Renal Crônica/genética , Falência Renal Crônica/imunologia , Falência Renal Crônica/metabolismo , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Monócitos/efeitos dos fármacos , Monócitos/imunologia , Monócitos/patologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genética , Ureia/farmacologia , Adulto Jovem
4.
Transpl Int ; 22(11): 1073-80, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19624495

RESUMO

Whether the use of angiotensin-converting enzyme inhibitor or angiotensin receptor blocker inhibitor (ACEI/ARB) is beneficial in renal transplant recipients remains controversial. In this retrospective study on 505 renal transplant recipients, we analyzed blood pressure and graft survival according to antihypertensive treatment with ACE-I/ARB and/or calcium channel blockers (CCB) over a period of 10 years. Patients were stratified according to their blood pressure 1 year after transplantation [controlled (130/80 mmHg; non-CTR, 324 patients)] and according to antihypertensive treatment (ACE-I/ARB and/or CCB taken for at least 2 years). One year after transplantation, 88.4% of CTR and 96.6% of non-CTR received antihypertensive treatment (P < 0.05). Graft survival was longer in CTR than in non-CTR (P < 0.05). Importantly, graft survival was longer in patients who received long-term treatment with ACEI/ARB, CCB, or a combination of ACEI/ARB and CCB (P < 0.001). The beneficial effect of ACEI/ARB therapy was more pronounced in non-CTR compared with that of CTR. We conclude that blood pressure control is a key target for long-term graft survival in renal transplant patients. Long-term ACEI/ARB and CCB therapy is beneficial for graft survival, especially in patients with diabetes and/or albuminuria.


Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Sobrevivência de Enxerto/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Transplante de Rim , Complicações Pós-Operatórias/tratamento farmacológico , Adolescente , Adulto , Idoso , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Anti-Hipertensivos/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Nefropatias Diabéticas/epidemiologia , Nefropatias Diabéticas/fisiopatologia , Feminino , Seguimentos , Rejeição de Enxerto , Humanos , Hipertensão/prevenção & controle , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/prevenção & controle , Reoperação , Estudos Retrospectivos , Adulto Jovem
5.
BMC Genomics ; 9: 71, 2008 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-18261221

RESUMO

BACKGROUND: Microarray analysis provides a powerful approach to identify gene expression alterations following transplantation. In patients the heterogeneity of graft specimens, co-morbidity, co-medications and the challenges in sample collection and preparation complicate conclusions regarding the underlying mechanisms of graft injury, rejection and immune regulation. RESULTS: We used a rat kidney transplantation model with strict transplant and sample preparation procedures to analyze genome wide changes in gene expression four days after syngeneic and allogeneic transplantation. Both interventions were associated with substantial changes in gene expression. After allogeneic transplantation, genes and pathways related to transport and metabolism were predominantly down-regulated consistent with rejection-mediated graft injury and dysfunction. Up-regulated genes were primarily related to the acute immune response including antigen presentation, T-cell receptor signaling, apoptosis, interferon signaling and complement cascades. We observed a cytokine and chemokine expression profile consistent with activation of a Th1-cell response. A novel finding was up-regulation of several regulatory and protective genes after allogeneic transplantation, specifically IL10, Bcl2a1, C4bpa, Ctla4, HO-1 and the SOCS family. CONCLUSION: Our data indicate that in parallel with the predicted activation of immune response and tissue injury pathways, there is simultaneous activation of pathways for counter regulatory and protective mechanisms that would balance and limit the ongoing inflammatory/immune responses. The pathophysiological mechanisms behind and the clinical consequences of alterations in expression of these gene classes in acute rejection, injury and dysfunction vs. protection and immunoregulation, prompt further analyses and open new aspects for therapeutic approaches.


Assuntos
Rejeição de Enxerto/genética , Rejeição de Enxerto/imunologia , Transplante de Rim/efeitos adversos , Transplante de Rim/imunologia , Doença Aguda , Animais , Apresentação de Antígeno/genética , Quimiocinas/genética , Ativação do Complemento/genética , Citocinas/genética , Perfilação da Expressão Gênica , Genes MHC da Classe II , Marcadores Genéticos , Interferons/genética , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Ratos , Ratos Endogâmicos BN , Ratos Endogâmicos Lew , Transdução de Sinais/genética , Células Th1/imunologia , Transplante Homólogo , Transplante Isogênico
6.
Nephrol Dial Transplant ; 23(7): 2280-5, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18194979

RESUMO

BACKGROUND: Antihypertensive drugs may have differential, pressure-independent effects on hypertension-associated alterations of arterial function. We compared the effects of a 12-week therapy with the AT(1)-receptor antagonist valsartan (Val) versus the beta-blocker metoprolol (Met) on arterial stiffness and endothelial function in mildly hypertensive patients at rest and during generalized sympathetic stimulation. METHODS: Sixty-eight patients (37 male, 31 female, 46 +/- 6 years) were randomized to Val (80-160 mg/d) or Met (50-100 mg/d). Effects of therapy on endothelial function, brachial and carotid artery distensibility coefficients, pulse wave velocity, carotid intima-media thickness and elastic modulus were assessed at rest and during the cold pressor test. RESULTS: Fifty-two patients were available for per protocol analysis. Blood pressure was comparably reduced in both treatment groups. Effects on endothelial function and large artery elastic wall properties did not differ significantly between the two antihypertensive treatment regimens. Trends did not differ significantly between groups for any parameter including carotid intima-media thickness and elastic modulus. CONCLUSION: Short-term treatment with Val and Met had similar effects on large artery functional vessel wall properties in a population of mildly hypertensive patients.


Assuntos
Anti-Hipertensivos/uso terapêutico , Artéria Braquial/fisiopatologia , Artérias Carótidas/fisiopatologia , Endotélio Vascular/fisiopatologia , Hipertensão/tratamento farmacológico , Metoprolol/uso terapêutico , Tetrazóis/uso terapêutico , Valina/análogos & derivados , Adulto , Anti-Hipertensivos/farmacologia , Velocidade do Fluxo Sanguíneo/fisiologia , Pressão Sanguínea/fisiologia , Relação Dose-Resposta a Droga , Método Duplo-Cego , Elasticidade , Feminino , Humanos , Hipertensão/fisiopatologia , Masculino , Metoprolol/farmacologia , Pessoa de Meia-Idade , Sistema Nervoso Simpático/fisiologia , Tetrazóis/farmacologia , Túnica Íntima/diagnóstico por imagem , Túnica Média/diagnóstico por imagem , Ultrassonografia , Valina/farmacologia , Valina/uso terapêutico , Valsartana
7.
J Surg Res ; 148(2): 126-35, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18456280

RESUMO

BACKGROUND: Cytoprotective proteins, such as heme oxygenase-1 (HO-1), play a decisive role in ischemia-reperfusion injury during kidney transplantation. The aim of this study was to investigate the impact of heme oxygenase-1 on microcirculation and on ischemia-reperfusion injury in an isogenic kidney transplantation rat model. MATERIALS AND METHODS: Seventy male Lewis rats were distributed into three groups. In Group 1(control), the kidneys were only mobilized. In Groups 2 and 3, bilateral nephrectomy was performed, and a kidney from another Lewis rat was orthotopically transplanted on the left side. The donor animals in Group 3 received preconditioning with the HO-1 inductor hemin. 24 h after reperfusion graft function and morphology were examined. Microcirculation was investigated by in vivo microscopy of the renal surface 1 h after reperfusion. RESULTS: HO-1 preconditioning led to significantly lower serum creatinine and serum urea, as well as less histological damage and inducible nitric oxide synthase expression. Microcirculation was improved by a significant enlargement of the vascular diameter and an increase of the capillary flow. CONCLUSIONS: Treatment with hemin improves microcirculation by induction of HO-1 and reduces ischemia-reperfusion injury after kidney transplantation. HO-1 induction was shown to be a promising approach in the preconditioning of donor kidneys.


Assuntos
Heme Oxigenase-1/metabolismo , Transplante de Rim/fisiologia , Rim/irrigação sanguínea , Traumatismo por Reperfusão/prevenção & controle , Animais , Creatinina/sangue , Modelos Animais de Doenças , Heme Oxigenase-1/genética , Hemina/farmacologia , Precondicionamento Isquêmico/métodos , Rim/patologia , Transplante de Rim/patologia , Masculino , Microcirculação/fisiologia , Óxido Nítrico Sintase/metabolismo , Ratos , Ratos Endogâmicos Lew , Traumatismo por Reperfusão/fisiopatologia , Ureia/sangue
8.
Oncogene ; 24(48): 7127-34, 2005 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-16170378

RESUMO

B-Myb is a highly conserved vertebrate member of the Myb transcription factor family, which is expressed in virtually all proliferating cells. A large body of evidence suggests that B-Myb plays an important role in cell cycle regulation; however, the exact nature of its function has not yet been clarified. We have used gene targeting in chicken DT40 cells, a cell line exhibiting very high rates of homologous recombination, to create cells expressing endogenous B-myb in a doxycyclin-dependent manner. We find that the cells proliferate well in the absence of B-Myb, suggesting that B-Myb is not essential for cell proliferation per se. However, cells lacking B-Myb are more sensitive to DNA-damage induced by UV-irradiation and alkylation. Our work provides the first direct evidence for a novel function of B-Myb in the response to DNA-damage. The cells described here should be a useful model to characterize this function in more detail.


Assuntos
Galinhas/genética , Dano ao DNA , Genes myb , Proteínas Proto-Oncogênicas c-myb/genética , Proteínas Proto-Oncogênicas c-myb/metabolismo , Animais , Apoptose , Ciclo Celular , Linhagem Celular , Proliferação de Células , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Células Clonais , Doxiciclina/farmacologia , Regulação da Expressão Gênica , Marcação de Genes , Engenharia Genética , Análise em Microsséries , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-myb/deficiência , RNA Mensageiro/metabolismo , Recombinação Genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Raios Ultravioleta
9.
J Hypertens ; 24(5): 957-64, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16612259

RESUMO

BACKGROUND: It has been suggested that the increase in blood pressure observed in transplant patients treated with cyclosporine is mediated by cyclosporine-induced sympathoexcitation. However, the chronic effects of cyclosporine on sympathetic outflow in renal transplant patients have not been investigated. Therefore we studied sympathetic nerve activity and blood pressure before and 6 months after the withdrawal of cyclosporine in renal transplant patients. METHODS: Twenty-four renal transplant patients with histologically confirmed chronic allograft nephropathy (age 48 +/- 3 years, 60 +/- 10 months after transplantation) were included in the prospective study and randomly assigned to either withdrawal (n = 12) or continuation (n = 12) of cyclosporine. Both groups received mycophenolate mofetil and prednisolone as additional immunosuppressants. At entry and 6 months later blood pressure, muscle sympathetic nerve activity (MSNA), and plasma norepinephrine were measured. To assess the potential influence of the diseased native kidneys, three renal transplant patients who had their native kidneys removed were studied before and after cyclosporine withdrawal. RESULTS: Mean arterial pressure decreased significantly in the cyclosporine-withdrawal group (95 +/- 4 versus 105 +/- 4 mmHg 6 versus 0 months, P < 0.05) but not in the cyclosporine-continuation group (103 +/- 3 versus 105 +/- 4 mmHg, NS). However, plasma norepinephrine and MSNA did not change significantly in either group (MSNA 43 +/- 4 versus 44 +/- 3 and 38 +/- 5 versus 39 +/- 4 bursts/min in the cyclosporine-withdrawal and cyclosporine-continuation groups, NS). Graft function remained stable in both groups and in transplant patients who had their native kidneys removed MSNA did not decrease after cyclosporine withdrawal. CONCLUSION: The withdrawal of cyclosporine in renal transplant patients, receiving relatively low doses of cyclosporine, resulted in a substantial decrease in blood pressure. However, MSNA and norepinephrine did not change. This suggests that cyclosporine treatment does not cause chronic sympathetic activation that could explain the cyclosporine-induced blood pressure elevation in renal transplant patients.


Assuntos
Ciclosporina/uso terapêutico , Imunossupressores/uso terapêutico , Transplante de Rim , Sistema Nervoso Simpático/efeitos dos fármacos , Idoso , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculos/inervação , Músculos/fisiologia , Ácido Micofenólico/análogos & derivados , Ácido Micofenólico/uso terapêutico , Nefrectomia , Norepinefrina/sangue , Prednisolona/uso terapêutico , Sistema Nervoso Simpático/fisiologia , Fatores de Tempo , Transplante Homólogo
10.
Virchows Arch ; 449(2): 192-9, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16738898

RESUMO

Light microscopic alterations reflecting both previous and preservation-induced changes in the donor organ are usually not very distinctive. The ischemia/reperfusion-associated injury depends primarily on the conditions of donor organ preservation. The present study examined human kidney biopsies with special attention paid to the molecular mechanisms of preservation-induced injury preceding reperfusion. Stress-associated proteins hemeoxygenase-1 (HO-1), heat shock protein 70 (HSP 70), and metallothionein (MT) were studied in human zero-hour biopsies of transplanted kidneys prior to reperfusion in 29 patients. Protein expression was evaluated by semiquantitative immunohistochemistry and Western blotting for HO-1 and HSP 70. These findings were correlated with terminal deoxynucleotidyltransferase-mediated 2'-deoxyuridine 5'-triphosphate-digoxigenin nick end labeling (TUNEL) staining and follow up. Compared to controls, MT and HSP 70 expression was significantly higher at zero hour. In contrast, HO-1 and the number of TUNEL-positive cells were not elevated. MT and HO-1 immunoexpression were inversely associated with graft function, and hence, were of prognostic relevance. MT and HSP 70 were sensitive to the duration of cold ischemia. MT and HO-1 are suitable indicators for tissue injury during ischemia and may serve as new predictive markers that need to be validated in further independent studies.


Assuntos
Proteínas de Choque Térmico HSP70/análise , Heme Oxigenase-1/análise , Transplante de Rim , Rim/química , Adulto , Idoso , Idoso de 80 Anos ou mais , Apoptose , Biópsia , Humanos , Imuno-Histoquímica , Rim/patologia , Metalotioneína/análise , Pessoa de Meia-Idade
11.
Br J Pharmacol ; 137(7): 1116-24, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12429585

RESUMO

1. In inflammatory kidney diseases procoagulatory activity (PCA) becomes evident. Glomerular fibrin deposits and capillary microthrombi are histopathological hallmarks in most forms of glomerulonephritis. 2. Therefore in this study the expression of tissue factor (TF) as the main inducer of thrombogenesis was examined in cultured human mesangial cells (MC) in response to proinflammatory stimuli such as interleukin-1 (IL-1 beta), tumour necrosis factor alpha (TNF-alpha) and lipopolysaccharide (LPS). Also main signalling pathways were investigated. 3. IL-1 beta, TNF-alpha and LPS induced TF in MC in a time and dose dependent manner on mRNA and protein levels. Highest activity was found after 12 h of stimulation. Induction of TF was completely blockable by BAPTA-AM, a chelator of intracellular [Ca(2+)](i) as well as calphostin, a protein kinase C (PKC) inhibitor. Activation of the protein kinase A (PKA) pathway had no influence on basal TF expression, but down-regulated cytokine-induced TF. The PKA blocker, KT5720, increased TF formation significantly. Since TF exerts its activity primarily on the surface of cells and after release of encrypted receptors we further tested TF activity in MC supernatants. IL-1 beta did not significantly increase TF activity in supernatants of intact cells. However, when MC were rendered apoptotic by oxidative metabolites, IL-1 beta treated MC released highly stimulated TF activity into the supernatants, suggesting that a paracrine activation of the coagulatory cascade can take place under such conditions. 4. Inflammatory mediators up-regulate TF expression in MC by a PKC dependent pathway whereas PKA can serve as a negative feed-back link. Apoptosis of inflammatory MC may trigger to spread PCA.


Assuntos
Apoptose , Carbazóis , Ácido Egtázico/análogos & derivados , Mesângio Glomerular/efeitos dos fármacos , Mediadores da Inflamação/farmacologia , Proteína Quinase C/metabolismo , Tromboplastina/genética , Cálcio/metabolismo , Linhagem Celular , Células Cultivadas , Quelantes/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , Ácido Egtázico/farmacologia , Inibidores Enzimáticos/farmacologia , Ensaio de Imunoadsorção Enzimática , Regulação da Expressão Gênica/efeitos dos fármacos , Mesângio Glomerular/citologia , Mesângio Glomerular/metabolismo , Humanos , Peróxido de Hidrogênio/farmacologia , Indóis/farmacologia , Interleucina-1/farmacologia , Lipopolissacarídeos/farmacologia , Naftalenos/farmacologia , Proteína Quinase C/antagonistas & inibidores , Pirróis/farmacologia , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Tromboplastina/metabolismo , Fatores de Tempo , Fator de Necrose Tumoral alfa/farmacologia
12.
J Nephrol ; 15(6): 709-12, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12495289

RESUMO

IgA nephropathy is one of the most common forms of glomerulonephritis. Macroscopic or microscopic hematuria with mild proteinuria are the main symptoms. Without complicating factors, IgA nephropathy has a favourable long-term prognosis. We report a case of reversible acute renal failure (ARF) as a complication of mild IgA nephropathy while oral anticoagulants were administered. Diagnosis was based on a renal biopsy showing marked granular mesangial IgA-deposition. In addition, numerous tubules were extended and completely obstructed by red blood cell casts. After hemodialysis treatment and parallel anti-inflammatory steroids and after stopping anticoagulation, renal function gradually improved up to complete remission. This report indicates that anticoagulatory treatment may have negative effects on the long-term prognosis of IgA nephropathy with respect to development of ARF or tubulo-interstitial inflammation.


Assuntos
Injúria Renal Aguda/induzido quimicamente , Anticoagulantes/efeitos adversos , Glomerulonefrite por IGA/patologia , Hematúria/induzido quimicamente , Trombose Venosa/tratamento farmacológico , Injúria Renal Aguda/terapia , Anticoagulantes/uso terapêutico , Biópsia por Agulha , Feminino , Seguimentos , Glomerulonefrite por IGA/complicações , Hematúria/fisiopatologia , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Diálise Renal/métodos , Medição de Risco , Índice de Gravidade de Doença , Resultado do Tratamento , Trombose Venosa/complicações
13.
Front Biosci (Schol Ed) ; 6(1): 75-91, 2014 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-24389263

RESUMO

Monocytes interact and cross-talk with platelets in many settings including inflammation, hemostasis, or vascular disorders. These interactions are important for the regulation of life span of both. During inflammatory diseases, there is a rapid recruitment of monocytes and platelets to the site of inflammation and endothelial injury where they act side-by-side. Adherence between monocytes/macrophages (Mphi) and platelets occur in the vessel wall and atherosclerotic plaque, but it is also shown in the blood stream where it has been called platelet satellitism. This phenomenon has been attributed to thrombotic disorders such as stroke. Furthermore, we discovered consequences for leukocyte apoptosis after the interaction with platelets. Herein, we reviewed the complex mechanism and interactions regulating the life span of both types of blood cells. We also provide a distinct focus on apoptosis of platelets and Mphi.


Assuntos
Plaquetas/citologia , Comunicação Celular/fisiologia , Monócitos/citologia , Animais , Plaquetas/fisiologia , Humanos , Monócitos/fisiologia
14.
PLoS One ; 6(9): e24046, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21931640

RESUMO

BACKGROUND: Kidney transplantation (RTx) leads to amelioration of endothelial function in patients with advanced renal failure. Endothelial progenitor cells (EPCs) may play a key role in this repair process. The aim of this study was to determine the impact of RTx and immunosuppressive therapy on the number of circulating EPCs. METHODS: We analyzed 52 RTx patients (58±13 years; 33 males, mean ± SD) and 16 age- and gender-matched subjects with normal kidney function (57±17; 10 males). RTx patients received a calcineurin inhibitor (CNI)-based (65%) or a CNI-free therapy (35%) and steroids. EPC number was determined by double positive staining for CD133/VEGFR2 and CD34/VEGFR2 by flow cytometry. Stromal cell-derived factor 1 alpha (SDF-1) levels were assessed by ELISA. Experimentally, to dissociate the impact of RTx from the impact of immunosuppressants, we used the 5/6 nephrectomy model. The animals were treated with a CNI-based or a CNI-free therapy, and EPCs (Sca+cKit+) and CD26+ cells were determined by flow cytometry. RESULTS: Compared to controls, circulating number of CD34+/VEGFR2+ and CD133+/VEGFR2+ EPCs increased in RTx patients. There were no correlations between EPC levels and statin, erythropoietin or use of renin angiotensin system blockers in our study. Indeed, multivariate analysis showed that SDF-1--a cytokine responsible for EPC mobilization--is independently associated with the EPC number. 5/6 rats presented decreased EPC counts in comparison to control animals. Immunosuppressive therapy was able to restore normal EPC values in 5/6 rats. These effects on EPC number were associated with reduced number of CD26+ cells, which might be related to consequent accumulation of SDF-1. CONCLUSIONS: We conclude that kidney transplantation and its associated use of immunosuppressive drugs increases the number of circulating EPCs via the manipulation of the CD26/SDF-1 axis. Increased EPC count may be associated to endothelial repair and function in these patients.


Assuntos
Células Endoteliais/citologia , Transplante de Rim/efeitos adversos , Células-Tronco/citologia , Animais , Inibidores de Calcineurina , Contagem de Células , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Imunossupressores/farmacologia , Masculino , Ratos , Ratos Sprague-Dawley , Células-Tronco/efeitos dos fármacos
16.
Front Biosci (Landmark Ed) ; 14(7): 2432-47, 2009 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-19273210

RESUMO

Monocytes interact and cross-talk with platelets in many settings including inflammation, hemeostasis, or vascular disorders. These interactions are important for the regulation of life span of both. During inflammatory diseases, there is a rapid targeting of monocytes and platelets to points of inflammation and endothelial injury where they lie side-by-side. Adherence between monocytes/macrophages (Mphi) and platelets occur in the vessel wall and atherosclerotic plaque, but it is also shown in the blood stream where it has been called platelet satellitism. This phenomenon has been attributed to thrombotic disorders such as stroke. Furthermore, we discovered consequences for leukocyte apoptosis after the interaction with platelets. Herein, we reviewed the complex mechanism and interactions regulating the life span of both types of blood cells. We also provide a distinct focus on apoptosis of platelets and Mphi.


Assuntos
Plaquetas/citologia , Senescência Celular , Monócitos/citologia , Animais , Humanos
17.
World J Biol Psychiatry ; 10(4 Pt 2): 609-11, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-17965988

RESUMO

Hyponatremia is a well-known side effect of antidepressant treatment with serotonin reuptake inhibitors (SSRI) or combined serotonin and noradrenaline reuptake inhibitors (SNRI), and is linked to the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) in most cases. In contrast, only very few data are available on hyponatremia following treatment with selective noradrenaline reuptake inhibitors (NaRI). In this report, we describe the case of a patient who developed severe hyponatremia after treatment with reboxetine. However, extensive laboratory testing did not reveal inappropriate secretion of ADH, suggesting that SIADH did not account for hyponatremia in our case. Proposing further examination of the underlying pathomechanism of hyponatremia as a side effect of NaRIs, we discuss the importance of careful monitoring of serum sodium levels in patients treated with NaRIs.


Assuntos
Antidepressivos/efeitos adversos , Transtorno Depressivo Maior/tratamento farmacológico , Hiponatremia/induzido quimicamente , Síndrome de Secreção Inadequada de HAD/induzido quimicamente , Morfolinas/efeitos adversos , Idoso , Antidepressivos/uso terapêutico , Transtorno Depressivo Maior/sangue , Diagnóstico Diferencial , Relação Dose-Resposta a Droga , Feminino , Humanos , Hiponatremia/sangue , Hiponatremia/diagnóstico , Síndrome de Secreção Inadequada de HAD/sangue , Síndrome de Secreção Inadequada de HAD/diagnóstico , Morfolinas/uso terapêutico , Reboxetina , Recidiva , Sódio/sangue
18.
J Hypertens ; 27(3): 517-26, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19330906

RESUMO

BACKGROUND: Nebivolol (NEB) is a [beta]1-receptor blocker with nitric oxide-dependent vasodilating properties. NEB-induced nitric oxide release is mediated through the estrogen receptor. METHOD: Here, we tested the hypothesis that NEB decreases endothelial cell stiffness and that these effects can be abolished by both endothelial nitric oxide synthase and estrogen receptor blockade. Human endothelial cells (EAHy-926) were incubated with vehicle, NEB 0.7 nmol/l, metoprolol 200 nmol/l, 17[beta]-estradiol (E2) 15 nmol/l, the estrogen receptor antagonists tamoxifen 100 nmol/l and ICI 182780 (ICI) 100 nmol/l, the nitric oxide synthase inhibitor N[omega]-nitro-L-arginine methyl ester 1 mmol/l and combinations of NEB and E2 with either tamoxifen, ICI or N[omega]-nitro-L-arginine methyl ester as well as metoprolol and ICI. Atomic force microscopy was performed to measure cellular stiffness, cell volume and apical surface. Presence of estrogen receptor protein in EAHy-926 was confirmed by western blot analysis; quantification of ER[alpha] and ER[beta] total RNA was performed by semiquantitative PCR. RESULTS: Both NEB as well as E2 decreased cellular stiffness to a similar extent (NEB: 0.83 +/- 0.03 pN/nm, E2: 0.87 +/- 0.03 pN/nm, vehicle: 2.19 +/- 0.07 pN/nm), whereas metoprolol had no effect on endothelial stiffness (2.07 +/- 0.04 pN/nm, all n = 60, P < 0.01). The decrease in stiffness occurred as soon as 5 min after starting NEB incubation. The effects are mediated through nongenomic ER[beta] pathways, as ER[alpha] is not translated into measurable protein levels in EAHy-926. Furthermore, NEB increased cell volume by 48 +/- 4% and apical surface by 34 +/- 3%. E2 had comparable effects. Tamoxifen, ICI and N[omega]-nitro-L-arginine methyl ester substantially diminished the effects of NEB and E2. CONCLUSION: NEB decreases cellular stiffness and causes endothelial cell growth. These effects are nitric oxide-dependent and mediated through nongenomic ER[beta] pathways. The morphological and functional alterations observed in endothelial cells may explain improved endothelial function with NEB treatment.


Assuntos
Antagonistas Adrenérgicos beta/farmacologia , Anti-Hipertensivos/farmacologia , Benzopiranos/farmacologia , Células Endoteliais/efeitos dos fármacos , Receptor beta de Estrogênio/metabolismo , Etanolaminas/farmacologia , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Arginina/análogos & derivados , Arginina/farmacologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular , Linhagem Celular Tumoral , Tamanho Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Elasticidade/efeitos dos fármacos , Células Endoteliais/ultraestrutura , Estradiol/análogos & derivados , Estradiol/farmacologia , Antagonistas de Estrogênios/farmacologia , Moduladores de Receptor Estrogênico/farmacologia , Receptor beta de Estrogênio/antagonistas & inibidores , Estrogênios/farmacologia , Feminino , Fulvestranto , Genes Reporter , Humanos , Metoprolol/farmacologia , Nanotecnologia/métodos , Nebivolol , Óxido Nítrico/metabolismo , Nitritos/análise , Tamoxifeno/farmacologia , Fatores de Tempo , Transfecção
19.
Pflugers Arch ; 456(1): 51-60, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18172604

RESUMO

Vascular actions of steroid hormones have gained increasing importance. Indeed, some steroid hormones favorably influence vascular structure and function, whereas others are detrimental. This review will focus on the endothelial effects of steroid hormones. In the first part, we summarize data from in vivo studies elucidating the regulation of endothelial function by steroid hormones. Accumulating data argue for an improvement of endothelium-derived relaxation and impaired vascular contraction by estradiol, whereas testosterone, progesterone, and aldosterone have contrary effects. In the second part, we present data from novel atomic force microscopy studies performed in living endothelial cells under the influence of steroid hormones. These studies provide insight into structural and functional alterations of endothelial cells characterized by changes in volume, apical surface, and stiffness. We summarize the available evidence that changes in shape of endothelial cells translate into changes of endothelial cell stiffness. Under the influence of estradiol, endothelial cells become spherical with consecutive improvement of elasticity, whereas aldosterone flattens endothelial cell-shape leading to increased stiffness. Both, endothelial cell shape and stiffness are major determinants of endothelial nitric oxide production. These studies emphasize the great potential of atomic force microscopy to investigate the function of living endothelial cells.


Assuntos
Endotélio Vascular/fisiologia , Hormônios Esteroides Gonadais/fisiologia , Microscopia de Força Atômica , Animais , Forma Celular/fisiologia , Elasticidade , Endotélio Vascular/citologia , Endotélio Vascular/ultraestrutura , Humanos , Óxido Nítrico/fisiologia
20.
Am J Physiol Cell Physiol ; 290(6): C1521-31, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16394027

RESUMO

Polyspecific organic cation transporters (OCTs) have a large substrate binding pocket with different interaction domains. To determine whether OCT regulation is substrate specific, suitable fluorescent organic cations were selected by comparing their uptake in wild-type (WT) human embryonic kidney (HEK)-293 cells and in HEK-293 cells stably transfected with hOCT2. N-amidino-3,5-diamino-6-chloropyrazine-carboxamide (amiloride) and 4-[4-(dimethylamino)-styryl]-N-methylpyridinium (ASP) showed concentration-dependent uptake in hOCT2 at 37 degrees C. After subtraction of unspecific uptake determined in WT at 37 degrees C or in hOCT2 at 8 degrees C saturable specific uptake of both substrates was measured. Km values of hOCT2-mediated uptake of 95 microM amiloride and 24 microM ASP were calculated. Inhibition of amiloride and ASP uptake by several organic cations was also measured [IC50 (in microM) for amiloride and ASP, respectively, tetraethylammonium (TEA) 98 and 30, cimetidine 14 and 26, and tetrapentylammonium (TPA) 7 and 2]. Amiloride and ASP uptake were significantly reduced by inhibition of Ca2+/CaM complex (-55 +/- 5%, n = 10 and -63 +/- 2%, n = 15, for amiloride and ASP, respectively) and stimulation of PKC (-54 +/- 5%, n = 14, and -31 +/- 6%, n = 26) and PKA (-16 +/- 5%, n = 16, and -18 +/- 4%, n = 40), and they were increased by inhibition of phosphatidylinositol 3-kinase (+28 +/- 6%, n = 8, and +55 +/- 17%, n = 16). Inhibition of Ca2+/CaM complex resulted in a significant decrease of Vmax (160-99 photons/s) that can be explained in part by a reduction of the membrane-associated hOCT2 (-22 +/- 6%, n = 9) as determined using FACScan flow cytometry. The data indicate that saturable transport by hOCT2 can be measured by the fluorescent substrates amiloride and ASP and that transport activity for both substrates is regulated similarly. Inhibition of the Ca2+/CaM complex causes changes in transport capacity via hOCT2 trafficking.


Assuntos
Modelos Biológicos , Proteínas de Transporte de Cátions Orgânicos/metabolismo , Transdução de Sinais/fisiologia , Amilorida/metabolismo , Ligação Competitiva , Transporte Biológico , Western Blotting , Cálcio/metabolismo , Calmodulina/metabolismo , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Microscopia Confocal , Microscopia de Fluorescência , Transportador 2 de Cátion Orgânico , Técnicas de Patch-Clamp , Transporte Proteico/fisiologia , Piridinas/metabolismo , Especificidade por Substrato
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