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1.
Z Gerontol Geriatr ; 55(1): 38-43, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34617144

RESUMEN

BACKGROUND: The Comprehensive Geriatric Assessment (CGA) provides essential information about older hospitalized patients but is either not systematically adopted or not adopted at all in clinical routine. As a consequence, critical factors influencing patients' trajectories, like personal resources (geriatric resources, GR), geriatric syndromes (GS), health-related quality of life (HRQoL) and multidimensional prognosis often escape routine diagnostics. OBJECTIVE: To investigate the association between HRQoL and GR/GS as well as its prognostic signature. MATERIAL AND METHODS: In this study 165 inpatients older than 65 years admitted to an internal medicine department of a German large metropolitan hospital were assessed by a CGA-based calculation of the multidimensional prognostic index (MPI). Ten different GR and 17 GS, as well as HRQoL were collected. After 3, 6 and 12 months the patients were followed-up by telephone. RESULTS: The HRQoL was associated with MPI (p < 0.001), number of GS (p < 0.001) and survival days after discharge (p = 0.008). Additionally, significant associations were found between HRQoL and number of GR (p < 0.001). GS displaying risk for physical dependence like instability (p < 0.001) and chronic pain (p = 0.007) and single GR/GS that influence patient's confidence like isolation (p < 0.001), depression (p < 0.001) and emotional resources (p = 0.002) were also associated with HRQoL. CONCLUSION: The HRQoL is significantly associated to specific risk and protective factor profiles of GR and GS. To improve quality of life, targeted, patient-centered diagnostics and treatment of GS as well as stabilization of GR should be encouraged in the management of older, multimorbid patients outside geriatric settings.


Asunto(s)
Pacientes Internos , Calidad de Vida , Anciano , Evaluación Geriátrica , Humanos , Pronóstico , Síndrome
2.
Cell Death Dis ; 6: e1764, 2015 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-25996291

RESUMEN

The tumor suppressor p53 is mainly involved in the transcriptional regulation of a large number of growth-arrest- and apoptosis-related genes. However, a clear understanding of which factor/s influences the choice between these two opposing p53-dependent outcomes remains largely elusive. We have previously described that in response to DNA damage, the RNA polymerase II-binding protein Che-1/AATF transcriptionally activates p53. Here, we show that Che-1 binds directly to p53. This interaction essentially occurs in the first hours of DNA damage, whereas it is lost when cells undergo apoptosis in response to posttranscriptional modifications. Moreover, Che-1 sits in a ternary complex with p53 and the oncosuppressor Brca1. Accordingly, our analysis of genome-wide chromatin occupancy by p53 revealed that p53/Che1 interaction results in preferential transactivation of growth arrest p53 target genes over its pro-apoptotic target genes. Notably, exposure of Che-1(+/-) mice to ionizing radiations resulted in enhanced apoptosis of thymocytes, compared with WT mice. These results confirm Che-1 as an important regulator of p53 activity and suggest Che-1 to be a promising yet attractive drug target for cancer therapy.


Asunto(s)
Proteínas Reguladoras de la Apoptosis/metabolismo , Apoptosis/genética , Proteína BRCA1/metabolismo , Puntos de Control del Ciclo Celular/genética , Proteínas Represoras/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Animales , Proteínas Reguladoras de la Apoptosis/genética , Línea Celular Tumoral , Daño del ADN/genética , Reparación del ADN/genética , Activación Enzimática/genética , Regulación de la Expresión Génica , Células HCT116 , Humanos , Células MCF-7 , Ratones , Ratones Transgénicos , Unión Proteica/genética , Interferencia de ARN , ARN Interferente Pequeño , Proteínas Represoras/genética , Timocitos/patología , Timocitos/efectos de la radiación , Activación Transcripcional/genética , Proteína p53 Supresora de Tumor/genética
3.
Rheumatol Int ; 33(9): 2225-30, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23446441

RESUMEN

In systemic sclerosis (SSc), kidney damage is a major clinical problem which can lead to a deleterious outcome. Recently, in diabetes mellitus, early detection of proteinuria and treatment with angiotensin-converting enzyme (ACE) inhibitors has been shown to slow progression of kidney disease and to improve prognosis. In this study, we investigated the spontaneous course of proteinuria in SSc and the effects of ACE inhibitor therapy. Proteinuria was determined in SSc patients with urine protein electrophoresis. SSc patients with proteinuria (n = 31) were followed over a median of 12 months. Of all 31 patients with pathologic urine protein electrophoresis investigated in this study, 9 patients (29 %) had additional microalbuminuria and 4 patients (12.9 %) showed increased total urinary protein. ACE inhibitor treatment was subsequently given to 23 patients. A total of 8 patients remained untreated for various reasons. Proteinuria resolved in 74 % of patients treated with ACE inhibitors, whereas in the untreated group, remission was observed only in 25 % (p = 0.014). Improvement of proteinuria was predominantly achieved in patients with recently diagnosed proteinuria and short disease duration. In patients with SSc and proteinuria, initiation of ACE inhibitor therapy resulted in a significant decrease in proteinuria.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Proteinuria/tratamiento farmacológico , Esclerodermia Sistémica/complicaciones , Adulto , Anciano , Albuminuria/tratamiento farmacológico , Femenino , Humanos , Masculino , Persona de Mediana Edad
4.
Dtsch Med Wochenschr ; 137(10): 476-8, 2012 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-22374655

RESUMEN

HISTORY AND CLINICAL FINDINGS: A 39-year-old man complained of unspecific chest pains four years after kidney transplantation. INVESTIGATIONS: Laboratory tests revealed a slow increase of retentions values; the value of soluble IL-2 receptor was slightly elevated. Computed tomography of the chest confirmed mediastinal and bilateral hilar masses. The broncho-alveolar lavage (BAL) showed a marked increase of the CD4/CD8 T-lymphocyte ratio and the aspiration cytology of these lymphadenopathies revealed the cytopathological characteristics of sarcoidosis. TREATMENT AND CLINICAL COURSE: An asymptomatic stage I sarcoidosis was diagnosed, and the immunosuppressive treatment with cyclosporine, mycophenolatmofetil and prednisone was retained. The patient has remained asymptomatic for now six months. CONCLUSION: When bilateral hilar / mediastinal lymphadenopathies occur after organ transplantation with immunosuppression de novo sarcoidosis should be taken into account.


Asunto(s)
Inmunosupresores/uso terapéutico , Trasplante de Riñón/efectos adversos , Sarcoidosis Pulmonar/tratamiento farmacológico , Sarcoidosis Pulmonar/etiología , Adulto , Humanos , Masculino , Sarcoidosis Pulmonar/prevención & control , Resultado del Tratamiento
6.
Dtsch Med Wochenschr ; 136(19): 1014-20, 2011 May.
Artículo en Alemán | MEDLINE | ID: mdl-21544793

RESUMEN

The improved understanding of genetic kidney diseases has given rise to a more detailed understanding of kidney function within the last decade. Insights into the pathophysiological principles of frequent kidney diseases - partly inherited, partly acquired - have been obtained by the investigation of rare genetic disorders and can now serve as a starting point for the development of novel therapeutic strategies. In this way various clinical multicenter trials, which are based on the observations made in basic science have been established for the very common autosomal dominant polycystic kidney disease. Furthermore, the influence of genetic aspects on frequent kidney diseases, e. g. diabetic nephropathy, is becoming more obvious. This article aims to give an overview over essential recent development in the field of genetic kidney diseases.


Asunto(s)
Enfermedades Renales/genética , Enfermedades Raras , Adulto , Anciano , Alelos , Niño , Análisis Mutacional de ADN , Enfermedad de Fabry/diagnóstico , Enfermedad de Fabry/genética , Enfermedad de Fabry/fisiopatología , Pruebas Genéticas , Tasa de Filtración Glomerular/genética , Tasa de Filtración Glomerular/fisiología , Glomeruloesclerosis Focal y Segmentaria/diagnóstico , Glomeruloesclerosis Focal y Segmentaria/genética , Glomeruloesclerosis Focal y Segmentaria/fisiopatología , Humanos , Recién Nacido , Enfermedades Renales/diagnóstico , Enfermedades Renales/fisiopatología , Nefritis Hereditaria/diagnóstico , Nefritis Hereditaria/genética , Nefritis Hereditaria/fisiopatología , Síndrome Nefrótico/diagnóstico , Síndrome Nefrótico/genética , Síndrome Nefrótico/fisiopatología , Fenotipo , Podocitos/fisiología , Riñón Poliquístico Autosómico Dominante/diagnóstico , Riñón Poliquístico Autosómico Dominante/genética , Polimorfismo Genético/genética , Proteinuria/diagnóstico , Proteinuria/genética , Proteinuria/fisiopatología , Análisis de Secuencia de ADN
7.
Dtsch Med Wochenschr ; 136(7): 325-30, 2011 Feb.
Artículo en Alemán | MEDLINE | ID: mdl-21302208

RESUMEN

Glomerular diseases are among the most common renal pathologies leading frequently to end-stage renal disease. Clinical disease can be divided into five different groups the features of which are determined by the underlying pathophysiology. One of these five clinical syndromes is the nephrotic syndrome, which is characterized by proteinuria > 3.5 g/day accompanied by hypalbuminemia, hyperlipoproteinemia and pronounced edema. The nephrotic syndrome may be the clinical manifestation of a row of underlying diseases. The pathophysiological basics had remained elusive for decades, yet recently significant progress which allows for establishing new therapeutic strategies has been made. A major breakthrough in understanding the function of the glomerular filter unit has been possible in the last years through both genetic and cell biological studies, which have revealed a crucial role for the visceral epithelial cells of the glomerulus - the podocytes. By now various factors have been found causing podocyte damage, such as toxines, immunological phenomena or systemic disease like diabetes mellitus.


Asunto(s)
Síndrome Nefrótico/terapia , Antagonistas de Receptores de Angiotensina/uso terapéutico , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Antihipertensivos/uso terapéutico , Presión Sanguínea/efectos de los fármacos , Presión Sanguínea/fisiología , Terapia Combinada , Dieta con Restricción de Proteínas , Dieta Hiposódica , Edema/etiología , Edema/fisiopatología , Edema/terapia , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Hiperlipoproteinemias/etiología , Hiperlipoproteinemias/fisiopatología , Hiperlipoproteinemias/terapia , Hipoalbuminemia/etiología , Hipoalbuminemia/fisiopatología , Hipoalbuminemia/terapia , Hipoglucemiantes/uso terapéutico , Glomérulos Renales/fisiopatología , Síndrome Nefrótico/etiología , Síndrome Nefrótico/fisiopatología , Podocitos/fisiología , Guías de Práctica Clínica como Asunto , Sistema Renina-Angiotensina/efectos de los fármacos , Sistema Renina-Angiotensina/fisiología , Factores de Riesgo , Cese del Hábito de Fumar , Pérdida de Peso/fisiología
8.
Transplant Proc ; 41(6): 2533-8, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19715969

RESUMEN

BACKGROUND: Optimal treatment of polyomavirus-induced allograft nephropathy (PVAN) with immunosuppressive and antiviral therapy is uncertain at present. Reduced immunosuppression is accompanied by increased risk of rejection, and antiviral agents are nephrotoxic. Leflunomide has immunosuppressive and antiviral properties and may be an alternative treatment agent. We report a two-center experience with use of leflunomide for treatment of PVAN. PATIENTS AND METHODS: Thirteen renal allograft recipients were diagnosed with biopsy-proven PVAN. Treatment consisted of lowering the calcineurin-inhibitor trough level, discontinuing mycophenolate mofetil therapy, and initiating leflunomide therapy. In 8 of the 13 patients, the serum concentration of the leflunomide active metabolite A771726 was monitored. RESULTS: Exchange of mycophenolate mofetil with leflunomide in patients with PVAN was well tolerated and safe, with no serious adverse effects or episodes of graft rejection. Mean follow-up after transplantation was 717 days, and after initiation of leflunomide therapy was 465 days. With the modified therapy, 12 patients cleared the virus at a mean of 109 days. One graft was lost due to refractory rejection accompanied by a decreasing viral load. In the other 12 patients, graft function stabilized or improved (mean [median] creatinine concentration at diagnosis, 2.39 [2.5] mg/mL, vs 2.27 [2.0] mg/dL at follow-up). Leflunomide concentration did not correlate with treatment efficiency. CONCLUSIONS: Treatment of PVAN with leflunomide, a low-dose calcineurin inhibitor, and prednisone seems to reduce viral load and stabilize renal graft function without increasing the risk of rejection. Even low serum concentrations of leflunomide support viral elimination and prevention of graft rejection.


Asunto(s)
Antivirales/uso terapéutico , Virus BK/efectos de los fármacos , Isoxazoles/uso terapéutico , Trasplante de Riñón/efectos adversos , Infecciones por Polyomavirus/prevención & control , Biopsia , Relación Dosis-Respuesta a Droga , Monitoreo de Drogas/métodos , Rechazo de Injerto/epidemiología , Humanos , Inmunosupresores/uso terapéutico , Isoxazoles/sangre , Trasplante de Riñón/patología , Leflunamida , Ácido Micofenólico/análogos & derivados , Ácido Micofenólico/uso terapéutico , Factores de Riesgo , Carga Viral
9.
Clin Nephrol ; 71(3): 321-5, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19281745

RESUMEN

Alport syndrome is a progressive hereditary renal disease. Mutations in the genes encoding for three members of the type IV collagen protein family have been found to be the cause of the disease. Alport syndrome is often associated with sensorineural hearing loss and ocular abnormalities, and patients suffering from typical Alport syndrome usually develop end stage renal disease during adolescence or young adulthood. Here we report on a family with atypical Alport disease initially presenting as hereditary focal and segmental glomerulosclerosis. Genetic testing identified a previously undescribed COL4A5 mutation as cause of the disease.


Asunto(s)
Colágeno Tipo IV/genética , Mutación , Nefritis Hereditaria/genética , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Linaje
10.
J Biol Chem ; 276(45): 41543-6, 2001 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-11562357

RESUMEN

Mutations of NPHS1 or NPHS2, the genes encoding for the glomerular podocyte proteins nephrin and podocin, cause steroid-resistant proteinuria. In addition, mice lacking CD2-associated protein (CD2AP) develop a nephrotic syndrome that resembles NPHS mutations suggesting that all three proteins are essential for the integrity of glomerular podocytes. Although the precise glomerular function of either protein remains unknown, it has been suggested that nephrin forms zipper-like interactions to maintain the structure of podocyte foot processes. We demonstrate now that nephrin is a signaling molecule, which stimulates mitogen-activated protein kinases. Nephrin-induced signaling is greatly enhanced by podocin, which binds to the cytoplasmic tail of nephrin. Mutational analysis suggests that abnormal or inefficient signaling through the nephrin-podocin complex contributes to the development of podocyte dysfunction and proteinuria.


Asunto(s)
Proteínas de la Membrana/fisiología , Proteínas/fisiología , Secuencia de Bases , Humanos , Péptidos y Proteínas de Señalización Intracelular , Proteínas Quinasas Activadas por Mitógenos/fisiología , Datos de Secuencia Molecular , Proteínas/química , Factor de Transcripción AP-1/fisiología , Proteínas Quinasas p38 Activadas por Mitógenos
11.
Proc Natl Acad Sci U S A ; 98(17): 9784-9, 2001 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-11493697

RESUMEN

Juvenile nephronophthisis type 1 is caused by mutations of NPHP1, the gene encoding for nephrocystin. The function of nephrocystin is presently unknown, but the presence of a Src homology 3 domain and its recently described interaction with p130(Cas) suggest that nephrocystin is part of the focal adhesion signaling complex. We generated a nephrocystin-specific antiserum and analyzed the interaction of native nephrocystin with endogenous proteins. Immunoprecipitation of nephrocystin revealed that nephrocystin forms protein complexes with p130(Cas), proline-rich tyrosine kinase 2 (Pyk2), and tensin, indicating that these proteins participate in a common signaling pathway. Expression of nephrocystin resulted in phosphorylation of Pyk2 on tyrosine 402 as well as activation of downstream mitogen-activated protein kinases, such as ERK1 and ERK2. Our findings suggest that nephrocystin helps to recruit Pyk2 to cell matrix adhesions, thereby initiating phosphorylation of Pyk2 and Pyk2-dependent signaling. A lack of functional nephrocystin may compromise Pyk2 signaling in a subset of renal epithelial cells.


Asunto(s)
Proteínas de Microfilamentos/metabolismo , Fosfoproteínas/metabolismo , Procesamiento Proteico-Postraduccional , Proteínas Tirosina Quinasas/metabolismo , Proteínas/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Animales , Western Blotting , Células Cultivadas , Proteína Sustrato Asociada a CrK , Proteínas del Citoesqueleto , Células Epiteliales/metabolismo , Quinasa 2 de Adhesión Focal , Humanos , Túbulos Renales Colectores/citología , Sistema de Señalización de MAP Quinasas , Sustancias Macromoleculares , Proteínas de la Membrana , Ratones , Fosforilación , Fosfotirosina/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , Proteína p130 Similar a la del Retinoblastoma , Tensinas , Dominios Homologos src
12.
Biochem Biophys Res Commun ; 281(4): 917-23, 2001 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-11237748

RESUMEN

The cystic fibrosis transmembrane conductance regulator (CFTR) has been shown previously to be regulated by inhibitory G proteins. In the present study, we demonstrate inhibition of CFTR by alphaG(i2) and alphaG(i1), but not alphaG(0), in Xenopus oocytes. We further examined whether regulators of G protein signaling (RGS) proteins interfere with alphaG(i)-dependent inhibition of CFTR. Activation of CFTR by IBMX and forskolin was attenuated in the presence of alphaG(i2), indicating inhibition of CFTR by alphaG(i2) in Xenopus oocytes. Coexpression of the proteins RGS3 and RGS7 together with CFTR and alphaG(i2) partially recovered activation by IBMX/forskolin. 14-3-3, a protein that is known to interfere with RGS proteins, counteracted the effects of RGS3. These data demonstrate the regulation of CFTR by alphaG(i) in Xenopus oocytes. Because RGS proteins interfere with the G protein-dependent regulation of CFTR, this may offer new potential pathways for pharmacological intervention in cystic fibrosis.


Asunto(s)
Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/fisiología , Proteínas de Unión al GTP , Proteínas Activadoras de GTPasa , Proteínas RGS/fisiología , Proteínas Represoras , 1-Metil-3-Isobutilxantina/farmacología , Proteínas 14-3-3 , Inhibidores de Adenilato Ciclasa , Adenilil Ciclasas/metabolismo , Animales , Canales de Cloruro/fisiología , Colforsina/farmacología , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Femenino , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/genética , Humanos , Potenciales de la Membrana/efectos de los fármacos , Oocitos/metabolismo , Oocitos/fisiología , Proteínas RGS/genética , ARN Complementario/administración & dosificación , ARN Complementario/genética , Factores de Tiempo , Tirosina 3-Monooxigenasa/genética , Tirosina 3-Monooxigenasa/fisiología , Xenopus laevis
13.
J Biol Chem ; 275(36): 28167-72, 2000 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-10862767

RESUMEN

Regulator of G protein signaling (RGS) proteins function as GTPase-activating proteins (GAPs) that stimulate the inactivation of heterotrimeric G proteins. We have recently shown that RGS proteins may be regulated on a post-translational level (Benzing, T., Brandes, R., Sellin, L., Schermer, B., Lecker, S., Walz, G., and Kim, E. (1999) Nat. Med. 5, 913-918). However, mechanisms controlling the GAP activity of RGS proteins are poorly understood. Here we show that 14-3-3 proteins associate with RGS7 and RGS3. Binding of 14-3-3 is mediated by a conserved phosphoserine located in the Galpha-interacting portion of the RGS domain; interaction with 14-3-3 inhibits the GAP activity of RGS7, depends upon phosphorylation of a conserved residue within the RGS domain, and results in inhibition of GAP function. Collectively, these data indicate that phosphorylation-dependent binding of 14-3-3 may act as molecular switch that controls the GAP activity keeping a substantial fraction of RGS proteins in a dormant state.


Asunto(s)
Proteínas de Unión al GTP , Proteínas Activadoras de GTPasa/metabolismo , Proteínas/metabolismo , Proteínas RGS/metabolismo , Proteínas Represoras , Tirosina 3-Monooxigenasa , Proteínas 14-3-3 , Secuencia de Aminoácidos , Sitios de Unión , Línea Celular , Humanos , Cinética , Datos de Secuencia Molecular , Mutagénesis Insercional , Mutagénesis Sitio-Dirigida , Fosforilación , Proteínas RGS/química , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Estaurosporina/farmacología , Transfección
14.
Nat Med ; 5(8): 913-8, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10426315

RESUMEN

The central nervous dysfunctions of lethargy, fever and anorexia are manifestations of sepsis that seem to be mediated by increased cytokine production. Here we demonstrate that tumor necrosis factor (TNF)-alpha, an essential mediator of endotoxin-induced sepsis, prevents the proteasome-dependent degradation of RGS7, a regulator of G-protein signaling. The stabilization of RGS7 by TNF-alpha requires activation of the stress-activated protein kinase p38 and the presence of candidate mitogen-activated protein kinase phosphorylation sites. In vivo, RGS7 is rapidly upregulated in mouse brain after exposure to either endotoxin or TNF-alpha, a response that is nearly abrogated in mice lacking TNF receptor 1. Our findings indicate that TNF-mediated upregulation of RGS7 may contribute to sepsis-induced changes in central nervous function.


Asunto(s)
Encéfalo/efectos de los fármacos , Proteínas de Caenorhabditis elegans , Proteínas Quinasas Activadas por Mitógenos , Proteínas/metabolismo , Proteínas RGS , Factor de Necrosis Tumoral alfa/farmacología , Animales , Antígenos CD/genética , Encéfalo/fisiología , Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Línea Celular , Cisteína Endopeptidasas/efectos de los fármacos , Cisteína Endopeptidasas/metabolismo , Femenino , Proteínas de Unión al GTP/metabolismo , Humanos , Leupeptinas/farmacología , Lipopolisacáridos/farmacología , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Complejos Multienzimáticos/efectos de los fármacos , Complejos Multienzimáticos/metabolismo , Fosforilación , Complejo de la Endopetidasa Proteasomal , Proteína Quinasa C/metabolismo , Proteínas/genética , Receptores del Factor de Necrosis Tumoral/genética , Receptores Tipo I de Factores de Necrosis Tumoral , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Regulación hacia Arriba , Proteínas Quinasas p38 Activadas por Mitógenos
15.
Proc Natl Acad Sci U S A ; 96(11): 6371-6, 1999 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-10339594

RESUMEN

Regulators of G protein signaling (RGS) proteins accelerate the intrinsic GTPase activity of certain Galpha subunits and thereby modulate a number of G protein-dependent signaling cascades. Currently, little is known about the regulation of RGS proteins themselves. We identified a short-lived RGS protein, RGS7, that is rapidly degraded through the proteasome pathway. The degradation of RGS7 is inhibited by interaction with a C-terminal domain of polycystin, the protein encoded by PKD1, a gene involved in autosomal-dominant polycystic kidney disease. Furthermore, membranous expression of C-terminal polycystin relocalized RGS7. Our results indicate that rapid degradation and interaction with integral membrane proteins are potential means of regulating RGS proteins.


Asunto(s)
Proteínas/genética , Proteínas/metabolismo , Proteínas RGS , Secuencia de Aminoácidos , Linfocitos B/metabolismo , Sitios de Unión , Cisteína Endopeptidasas/metabolismo , Proteínas de Unión al GTP/química , Proteínas de Unión al GTP/metabolismo , Biblioteca de Genes , Humanos , Datos de Secuencia Molecular , Complejos Multienzimáticos/metabolismo , Riñón Poliquístico Autosómico Dominante/genética , Riñón Poliquístico Autosómico Dominante/metabolismo , Complejo de la Endopetidasa Proteasomal , Biosíntesis de Proteínas , Proteínas/química , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Canales Catiónicos TRPP , Transcripción Genética , Ubiquitinas/metabolismo
16.
Circulation ; 99(15): 2034-40, 1999 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-10209009

RESUMEN

BACKGROUND: ACE (kininase II) inhibitors have been shown to exert their beneficial cardiovascular effects via the inhibition of both angiotensin II formation and bradykinin breakdown. Because recent evidence suggests that ACE inhibitors may also interfere with B2 kinin receptor signaling and thus enhance the vascular response to bradykinin, we examined whether the distribution of B2 kinin receptors within the plasma membrane of native endothelial cells is affected by an ACE inhibitor. METHODS AND RESULTS: Localization of the B2 kinin receptor in membranes prepared from native porcine aortic endothelial cells was evaluated by means of specific [3H]bradykinin binding and immunoprecipitation of the B2 receptor from isolated membranes. Effects of bradykinin and ramiprilat on intracellular signaling were determined by monitoring the activation of the extracellularly regulated kinases Erk1 and Erk2 as well as [Ca2+]i increases in fura 2-loaded endothelial cells. Stimulation of native endothelial cells with bradykinin 100 nmol/L resulted in the time-dependent sequestration of the B2 receptor to caveolin-rich (CR) membranes, which was maximal after 5 minutes. Pretreatment with ramiprilat 100 nmol/L for 15 minutes significantly attenuated the recovery of B2 kinin receptors in CR membranes while increasing that from membranes lacking caveolin. This effect was not due to the inhibition of bradykinin degradation, because no effect was seen in the presence of an inhibitory concentration of the synthetic ACE substrate hippuryl-L-histidyl-L-leucine. Ramiprilat also decreased [3H]bradykinin binding to CR membranes when applied either before or after bradykinin stimulation. Moreover, ramiprilat resulted in reactivation of the B2 receptor in bradykinin-stimulated cells and induced a second peak in [Ca2+]i and reactivation of Erk1/2. CONCLUSIONS: The ACE inhibitor ramiprilat interferes with the targeting of the B2 kinin receptor to CR membrane domains in native endothelial cells. Therefore, effects other than the inhibition of kininase II may account for the effects of ramiprilat and other ACE inhibitors on the vascular system.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Endotelio Vascular/efectos de los fármacos , Proteínas de la Membrana/metabolismo , Proteínas Quinasas Activadas por Mitógenos , Ramipril/análogos & derivados , Receptores de Bradiquinina/metabolismo , Animales , Aorta , Transporte Biológico/efectos de los fármacos , Bradiquinina/análogos & derivados , Bradiquinina/farmacología , Señalización del Calcio/efectos de los fármacos , Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Endotelio Vascular/metabolismo , Proteína Quinasa 1 Activada por Mitógenos , Proteína Quinasa 3 Activada por Mitógenos , Ramipril/farmacología , Receptor de Bradiquinina B2 , Receptores de Bradiquinina/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Porcinos
17.
Mol Cell Biol ; 19(5): 3423-34, 1999 May.
Artículo en Inglés | MEDLINE | ID: mdl-10207066

RESUMEN

Autosomal dominant polycystic kidney disease (ADPKD) is caused by germ line mutations in at least three ADPKD genes. Two recently isolated ADPKD genes, PKD1 and PKD2, encode integral membrane proteins of unknown function. We found that PKD2 upregulated AP-1-dependent transcription in human embryonic kidney 293T cells. The PKD2-mediated AP-1 activity was dependent upon activation of the mitogen-activated protein kinases p38 and JNK1 and protein kinase C (PKC) epsilon, a calcium-independent PKC isozyme. Staurosporine, but not the calcium chelator BAPTA [1,2-bis(o-aminophenoxy)ethane-N,N,N', N'-tetraacetate], inhibited PKD2-mediated signaling, consistent with the involvement of a calcium-independent PKC isozyme. Coexpression of PKD2 with the interacting C terminus of PKD1 dramatically augmented PKD2-mediated AP-1 activation. The synergistic signaling between PKD1 and PKD2 involved the activation of two distinct PKC isozymes, PKC alpha and PKC epsilon, respectively. Our findings are consistent with others that support a functional connection between PKD1 and PKD2 involving multiple signaling pathways that converge to induce AP-1 activity, a transcription factor that regulates different cellular programs such as proliferation, differentiation, and apoptosis. Activation of these signaling cascades may promote the full maturation of developing tubular epithelial cells, while inactivation of these signaling cascades may impair terminal differentiation and facilitate the development of renal tubular cysts.


Asunto(s)
Proteínas de la Membrana/genética , Proteínas Quinasas Activadas por Mitógenos , Riñón Poliquístico Autosómico Dominante/genética , Proteínas Quinasas Dependientes de Calcio-Calmodulina/genética , Línea Celular , Proteínas de Unión al ADN/genética , Ácido Egtácico/análogos & derivados , Ácido Egtácico/farmacología , Proteínas de Unión al GTP/genética , Regulación de la Expresión Génica/genética , Humanos , Proteínas Quinasas JNK Activadas por Mitógenos , Mutación/genética , Fosforilación , Proteína Quinasa C/metabolismo , Proteínas/genética , Proteínas Proto-Oncogénicas c-jun/genética , Transducción de Señal , Estaurosporina/farmacología , Canales Catiónicos TRPP , Factor de Transcripción AP-1/genética
18.
J Biol Chem ; 274(8): 4947-53, 1999 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-9988738

RESUMEN

Two distinct signaling pathways, involving Wnt signaling and polycystin, have been found to be critical for normal kidney development. Renal tubulogenesis requires the presence of certain Wnt proteins, whereas mutations in polycystin impede the terminal differentiation of renal tubular epithelial cells, causing the development of large cystic kidneys that characterize autosomal dominant polycystic kidney disease. Polycystin is an integral membrane protein, consisting of several extracellular motifs indicative of cell-cell and cell-matrix interactions, coupled through multiple transmembrane domains to a functionally active cytoplasmic domain. We report here that expression of the C-terminal cytoplasmic domain of polycystin stabilizes soluble endogenous beta-catenin and stimulates TCF-dependent gene transcription in human embryonic kidney cells. Microinjection of the polycystin C-terminal cytoplasmic domain induces dorsalization in zebrafish. Our findings suggest that polycystin has the capacity to modulate Wnt signaling during renal development.


Asunto(s)
Enfermedades Renales Poliquísticas/metabolismo , Proteínas/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Transducción de Señal , Transactivadores , Proteínas de Pez Cebra , Animales , Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Línea Celular , Linaje de la Célula , Citoplasma/metabolismo , Proteínas del Citoesqueleto/metabolismo , Embrión no Mamífero/citología , Glucógeno Sintasa Quinasa 3 , Humanos , Proteínas Proto-Oncogénicas c-jun/metabolismo , Canales Catiónicos TRPP , Ubiquitinas/metabolismo , Proteínas Wnt , Pez Cebra/embriología , beta Catenina
19.
Clin Nephrol ; 49(6): 385-8, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9696436

RESUMEN

A 28-year-old woman was kidney transplanted. She had an inapparent hepatitis B virus (HBV) infection 2 years previously. At the time of transplantation she was hepatitis B surface antigen (HBsAg) negative, anti-HBs, anti-HBc, anti-HBe and anti-HCV antibody positive and her transaminase activities were within the normal range. The donor of the kidney allograft was HBV negative. Twelve weeks after transplantation a life-threatening liver failure occurred with a rapid rise of alanine aminotransferase (ALT) to 1427 U/l and a decrease of the prothrombin time to 25% of normal value. Anti-HBs had become negative, anti-HBc and anti-HBe titers had decreased. HBsAg became positive, associated with a HBV DNA of 3 x 10(8) genome equivalents/ml. Azathioprine and prednisone were withdrawn and foscarnet therapy was started. This therapy led to a decrease of ALT activity associated with an elimination of HBsAg and HBV DNA. Eight months after transplantation liver function tests were within the normal range. Graft rejection did not occur despite low or intermittent cessation of immunosuppressive therapy.


Asunto(s)
Hepatitis B/etiología , Trasplante de Riñón/efectos adversos , Adulto , Femenino , Hepatitis B/diagnóstico , Hepatitis B/terapia , Humanos , Recurrencia
20.
Dtsch Med Wochenschr ; 123(16): 493-6, 1998 Apr 17.
Artículo en Alemán | MEDLINE | ID: mdl-9589023

RESUMEN

HISTORY AND CLINICAL FINDINGS: A 30-year-old previously healthy man suddenly developed double vision, unsteady gait and some difficulty in speech articulation. Within 4 weeks he had become markedly ataxic, unable to walk, stand or sit down unaided. Neurological examination indicated a severe cerebellar syndrome. There were no other abnormal findings on physical examination. INVESTIGATIONS: There was no pleocytosis and no oligoclonal bands in cerebrospinal fluid (CSF). A test for anti-Purkinje cell antibodies was negative in both CSF and serum. Computed tomography and nuclear magnetic imaging (NMI) of the brain were normal. TREATMENT AND COURSE: As a para- or postinfectious or paraneoplastic process was suspected. I.v. immunoglobulin and oral corticosteroids were administered, but without improvement. 13 month later, a mediastinal mass was noted on a chest radiogram. This led to the diagnosis of a stage IA Hodgkin's disease. Retrospectively the cerebellar degeneration was most likely a paraneoplastic change related to the Hodgkin's disease. However, an independent second disease cannot be excluded. While the treatment of Hodgkin's disease was successful, the neurological symptoms remained unchanged. Severe cerebellar atrophy was demonstrated on NMI. CONCLUSION: In case of cerebellar atrophy of undetermined aetiology a paraneoplastic cause should be considered and an underlying malignant disease looked for.


Asunto(s)
Enfermedades Cerebelosas/complicaciones , Cerebelo/patología , Enfermedad de Hodgkin/complicaciones , Síndromes Paraneoplásicos/complicaciones , Adulto , Atrofia , Ataxia Cerebelosa/complicaciones , Humanos , Imagen por Resonancia Magnética , Masculino
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