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1.
J Am Soc Nephrol ; 25(9): 1979-90, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24652793

RESUMEN

Myofibroblasts secrete matrix during chronic injury, and their ablation ameliorates fibrosis. Development of new biomarkers and therapies for CKD will be aided by a detailed analysis of myofibroblast gene expression during the early stages of fibrosis. However, dissociating myofibroblasts from fibrotic kidney is challenging. We therefore adapted translational ribosome affinity purification (TRAP) to isolate and profile mRNA from myofibroblasts and their precursors during kidney fibrosis. We generated and characterized a transgenic mouse expressing an enhanced green fluorescent protein (eGFP)-tagged L10a ribosomal subunit protein under control of the collagen1α1 promoter. We developed a one-step procedure for isolation of polysomal RNA from collagen1α1-eGFPL10a mice subject to unilateral ureteral obstruction and analyzed and validated the resulting transcriptional profiles. Pathway analysis revealed strong gene signatures for cell proliferation, migration, and shape change. Numerous novel genes and candidate biomarkers were upregulated during fibrosis, specifically in myofibroblasts, and we validated these results by quantitative PCR, in situ, and Western blot analysis. This study provides a comprehensive analysis of early myofibroblast gene expression during kidney fibrosis and introduces a new technique for cell-specific polysomal mRNA isolation in kidney injury models that is suited for RNA-sequencing technologies.


Asunto(s)
Riñón/metabolismo , Riñón/patología , Miofibroblastos/metabolismo , Miofibroblastos/patología , Animales , Colágeno Tipo I/genética , Cadena alfa 1 del Colágeno Tipo I , Modelos Animales de Enfermedad , Fibrosis , Perfilación de la Expresión Génica/métodos , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Riñón/lesiones , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos DBA , Ratones Transgénicos , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Proteína Ribosómica L10 , Proteínas Ribosómicas/genética , Proteínas Ribosómicas/metabolismo , Regulación hacia Arriba , Obstrucción Ureteral/genética , Obstrucción Ureteral/metabolismo , Obstrucción Ureteral/patología
2.
Am J Physiol Renal Physiol ; 306(4): F379-88, 2014 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-24338822

RESUMEN

Acute kidney injury (AKI) is common and urgently requires new preventative therapies. Expression of a cyclin-dependent kinase (CDK) inhibitor transgene protects against AKI, suggesting that manipulating the tubular epithelial cell cycle may be a viable therapeutic strategy. Broad spectrum small molecule CDK inhibitors are protective in some kidney injury models, but these have toxicities and epithelial proliferation is eventually required for renal repair. Here, we tested a well-tolerated, novel and specific small molecule inhibitor of CDK4 and CDK6, PD 0332991, to investigate the effects of transient cell cycle inhibition on epithelial survival in vitro and kidney injury in vivo. We report that CDK4/6 inhibition induced G0/G1 cycle arrest in cultured human renal proximal tubule cells (hRPTC) at baseline and after injury. Induction of transient G0/G1 cycle arrest through CDK4/6 inhibition protected hRPTC from DNA damage and caspase 3/7 activation following exposure to the nephrotoxins cisplatin, etoposide, and antimycin A. In vivo, mice treated with PD 0332991 before ischemia-reperfusion injury (IRI) exhibited dramatically reduced epithelial progression through S phase 24 h after IRI. Despite reduced epithelial proliferation, PD 0332991 ameliorated kidney injury as reflected by improved serum creatinine and blood urea nitrogen levels 24 h after injury. Inflammatory markers and macrophage infiltration were significantly decreased in injured kidneys 3 days following IRI. These results indicate that induction of proximal tubule cell cycle arrest with specific CDK4/6 inhibitors, or "pharmacological quiescence," represents a novel strategy to prevent AKI.


Asunto(s)
Lesión Renal Aguda/tratamiento farmacológico , Puntos de Control del Ciclo Celular/efectos de los fármacos , Quinasa 4 Dependiente de la Ciclina/antagonistas & inhibidores , Quinasa 6 Dependiente de la Ciclina/antagonistas & inhibidores , Células Epiteliales/efectos de los fármacos , Túbulos Renales Proximales/efectos de los fármacos , Lesión Renal Aguda/metabolismo , Animales , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Línea Celular , Daño del ADN/efectos de los fármacos , Células Epiteliales/metabolismo , Humanos , Túbulos Renales Proximales/metabolismo , Ratones , Piperazinas/farmacología , Piperazinas/uso terapéutico , Piridinas/farmacología , Piridinas/uso terapéutico
3.
Kidney Int ; 86(3): 481-8, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24088959

RESUMEN

The kidney is a complex organ with over 30 different cell types, and understanding the lineage relationships between these cells is challenging. During nephrogenesis, a central question is how the coordinated morphogenesis, growth, and differentiation of distinct cell types leads to development of a functional organ. In mature kidney, understanding cell division and fate during injury, regeneration and aging are critical topics for understanding disease. Genetic lineage tracing offers a powerful tool to decipher cellular hierarchies in both development and disease because it allows the progeny of a single cell, or group of cells, to be tracked unambiguously. Recent advances in this field include the use of inducible recombinases, multicolor reporters, and mosaic analysis. In this review, we discuss lineage-tracing methods focusing on the mouse model system and consider the impact of these methods on our understanding of kidney biology and prospects for future application.


Asunto(s)
Linaje de la Célula , Genes Reporteros/genética , Riñón/citología , Riñón/embriología , Recombinasas/genética , Animales , Expresión Génica , Técnicas Genéticas , Ratones , Recombinación Genética
4.
J Pathol ; 231(3): 273-89, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24006178

RESUMEN

Fibrosis and scar formation results from chronic progressive injury in virtually every tissue and affects a growing number of people around the world. Myofibroblasts drive fibrosis, and recent work has demonstrated that mesenchymal cells, including pericytes and perivascular fibroblasts, are their main progenitors. Understanding the cellular mechanisms of pericyte/fibroblast-to-myofibroblast transition, myofibroblast proliferation and the key signalling pathways that regulate these processes is essential to develop novel targeted therapeutics for the growing patient population suffering from solid organ fibrosis. In this review, we summarize the current knowledge about different progenitor cells of myofibroblasts, discuss major pathways that regulate their transdifferentiation and discuss the current status of novel targeted anti-fibrotic therapeutics in development.


Asunto(s)
Linaje de la Célula , Transdiferenciación Celular , Cicatriz/metabolismo , Matriz Extracelular/metabolismo , Miofibroblastos/metabolismo , Pericitos/metabolismo , Animales , Proliferación Celular , Cicatriz/inmunología , Cicatriz/patología , Cicatriz/terapia , Matriz Extracelular/patología , Fibrosis , Humanos , Miofibroblastos/inmunología , Miofibroblastos/patología , Pericitos/inmunología , Pericitos/patología , Transducción de Señal
5.
Proc Natl Acad Sci U S A ; 108(22): 9226-31, 2011 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-21576461

RESUMEN

Recently we have established that the kidney tubular epithelium is repaired by surviving epithelial cells. It is not known, however, whether a population of intratubular adult progenitor cells are responsible for this epithelial repair after acute kidney injury. In this study, we used an unbiased DNA analog-based approach that does not rely on candidate markers to track multiple rounds of cell division in vivo. In the proximal tubule, robust thymidine analog incorporation was observed postinjury. Cell division was stochastic and enriched among cells that were injured and dedifferentiated. There was no evidence for the presence of a population of specialized progenitors that repeatedly divide in response to injury. Instead, these results indicate that after injury, new epithelial cells arise from self-duplication of surviving cells, most of which are injured. Because the renal papilla contains DNA label-retaining cells and has been proposed as a stem cell niche, we examined the proliferative behavior of these putative progenitors after ischemia-reperfusion injury. Although label-retaining cells in the renal papilla diminished with time after ischemia-reperfusion injury, they neither proliferated nor migrated to the outer medulla or cortex. Thus, nonlethally injured cells repopulate the kidney epithelium after injury in the absence of any specialized progenitor cell population.


Asunto(s)
Túbulos Renales Proximales/metabolismo , Animales , Diferenciación Celular , División Celular , Movimiento Celular , Proliferación Celular , Supervivencia Celular , ADN/metabolismo , Antígeno Ki-67/biosíntesis , Masculino , Ratones , Ratones Endogámicos C57BL , Daño por Reperfusión , Células Madre/citología , Procesos Estocásticos , Timidina/química , Factores de Tiempo
6.
J Am Soc Nephrol ; 24(9): 1399-412, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23766539

RESUMEN

Injury to the adult kidney induces a number of developmental genes thought to regulate repair, including Wnt4. During kidney development, early nephron precursors and medullary stroma both express Wnt4, where it regulates epithelialization and controls smooth muscle fate, respectively. Expression patterns and roles for Wnt4 in the adult kidney, however, remain unclear. In this study, we used reporters, lineage analysis, and conditional knockout or activation of the Wnt/ß-catenin pathway to investigate Wnt4 in the adult kidney. Proliferating, medullary, interstitial myofibroblasts strongly expressed Wnt4 during renal fibrosis, whereas tubule epithelia, except for the collecting duct, did not. Exogenous Wnt4 drove myofibroblast differentiation of a pericyte-like cell line, suggesting that Wnt4 might regulate pericyte-to-myofibroblast transition through autocrine signaling. However, conditional deletion of Wnt4 in interstitial cells did not reduce myofibroblast proliferation, cell number, or myofibroblast gene expression during fibrosis. Because the injured kidney expresses multiple Wnt ligands that might compensate for the absence of Wnt4, we generated a mouse model with constitutive activation of canonical Wnt/ß-catenin signaling in interstitial pericytes and fibroblasts. Kidneys from these mice exhibited spontaneous myofibroblast differentiation in the absence of injury. Taken together, Wnt4 expression in renal fibrosis defines a population of proliferating medullary myofibroblasts. Although Wnt4 may be dispensable for myofibroblast transformation, canonical Wnt signaling through ß-catenin stabilization is sufficient to drive spontaneous myofibroblast differentiation in interstitial pericytes and fibroblasts, emphasizing the importance of this pathway in renal fibrosis.


Asunto(s)
Médula Renal/irrigación sanguínea , Miofibroblastos/fisiología , Daño por Reperfusión/fisiopatología , Transducción de Señal/fisiología , Obstrucción Ureteral/fisiopatología , Proteína Wnt4/fisiología , beta Catenina/fisiología , Animales , Diferenciación Celular/fisiología , Proliferación Celular , Células Cultivadas , Modelos Animales de Enfermedad , Eliminación de Gen , Técnicas In Vitro , Médula Renal/patología , Médula Renal/fisiopatología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Miofibroblastos/patología , Daño por Reperfusión/patología , Obstrucción Ureteral/patología , Urotelio/patología , Urotelio/fisiopatología , Proteína Wnt4/genética , Proteína Wnt4/farmacología
7.
J Neurosci ; 29(35): 10835-42, 2009 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-19726641

RESUMEN

Hippocampus-dependent memory requires a cAMP signal that is generated by Ca2+-stimulated adenylyl cyclases (AC1, AC8). Young transgenic mice overexpressing AC1 in the forebrain (AC1+ mice) have enhanced hippocampal long-term potentiation, superior memory for novel object recognition and more persistent remote contextual memory. To determine whether increasing AC1 expression improves memory when older mice are trained, we analyzed fear, recognition, and spatial memory in mice aged to 25 months. Here we report that young adult AC1+ mice have enhanced social recognition memory, and normal fear and spatial memory. Surprisingly, aged AC1+ mice had poorer spatial memory than age-matched wild-type littermates. These data suggest that the decrease in Ca2+-stimulated adenylyl cyclase activity during aging of wild-type mice may be an adaptive mechanism required to maintain spatial memory function.


Asunto(s)
Adenilil Ciclasas/genética , Envejecimiento/genética , Regulación Enzimológica de la Expresión Génica/fisiología , Memoria/fisiología , Prosencéfalo/enzimología , Conducta Espacial/fisiología , Adaptación Fisiológica/genética , Adenilil Ciclasas/biosíntesis , Adenilil Ciclasas/fisiología , Animales , Calcio/fisiología , Masculino , Aprendizaje por Laberinto/fisiología , Trastornos de la Memoria/enzimología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos
8.
J Neurosci ; 29(8): 2393-403, 2009 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-19244515

RESUMEN

Cocaine sensitization is produced by repeated exposure to the drug and is thought to reflect neuroadaptations that contribute to addiction. Here, we identify the Ca(2+)/calmodulin-stimulated adenylyl cyclases, type 1 (AC1) and type 8 (AC8), as novel regulators of this behavioral plasticity. We show that, whereas AC1 and AC8 single knock-out mice (AC1(-/-) and AC8(-/-)) exhibit Ca(2+)-stimulated adenylyl cyclase activity in striatal membrane fractions, AC1/8 double-knock-out (DKO) mice do not. Furthermore, DKO mice are acutely supersensitive to low doses of cocaine and fail to display locomotor sensitization after chronic cocaine treatment. Because of the known role for the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase signaling pathway in cocaine-induced behavioral plasticity and its coupling to calcium-stimulated cAMP signaling in the hippocampus, we measured phosphorylated ERK (pERK) levels in the striatum. Under basal conditions, pERK is upregulated in choline acetyltransferase-positive interneurons in DKO mice relative to wild-type (WT) controls. After acute cocaine treatment, pERK signaling is significantly suppressed in medium spiny neurons (MSNs) of DKO mice relative to WT mice. In addition to the lack of striatal ERK activation by acute cocaine, signaling machinery downstream of ERK is uncoupled in DKO mice. We demonstrate that AC1 and AC8 are necessary for the phosphorylation of mitogen and stress-activated kinase-1 (pMSK1) at Ser376 and Thr581 and cAMP response element-binding protein (pCREB) at Ser133 after acute cocaine treatment. Our results demonstrate that the Ca(2+)-stimulated adenylyl cyclases regulate long-lasting cocaine-induced behavioral plasticity via activation of the ERK/MSK1/CREB signaling pathway in striatonigral MSNs.


Asunto(s)
Adenilil Ciclasas/metabolismo , Cocaína/administración & dosificación , Inhibidores de Captación de Dopamina/administración & dosificación , Actividad Motora/efectos de los fármacos , Adenilil Ciclasas/deficiencia , Análisis de Varianza , Animales , Conducta Animal/efectos de los fármacos , Proteína de Unión a CREB/metabolismo , Calcio/farmacología , Calmodulina/metabolismo , Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Actividad Motora/fisiología , Proteínas Quinasas S6 Ribosómicas 90-kDa/metabolismo , Serina/metabolismo , Transducción de Señal/efectos de los fármacos , Treonina/metabolismo , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/genética
9.
Hippocampus ; 20(4): 492-8, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19557767

RESUMEN

Activity-dependent changes in gene-expression are believed to underlie the molecular representation of memory. In this study, we report that in vivo activation of neurons rapidly induces the CREB-regulated microRNA miR-132. To determine if production of miR-132 is regulated by neuronal activity its expression in mouse brain was monitored by quantitative RT-PCR (RT-qPCR). Pilocarpine-induced seizures led to a robust, rapid, and transient increase in the primary transcript of miR-132 (pri-miR-132) followed by a subsequent rise in mature microRNA (miR-132). Activation of neurons in the hippocampus, olfactory bulb, and striatum by contextual fear conditioning, odor-exposure, and cocaine-injection, respectively, also increased pri-miR-132. Induction kinetics of pri-miR-132 were monitored and found to parallel those of immediate early genes, peaking at 45 min and returning to basal levels within 2 h of stimulation. Expression levels of primary and mature-miR-132 increased significantly between postnatal Days 10 and 24. We conclude that miR-132 is an activity-dependent microRNA in vivo, and may contribute to the long-lasting proteomic changes required for experience-dependent neuronal plasticity.


Asunto(s)
Proteína de Unión a Elemento de Respuesta al AMP Cíclico/genética , MicroARNs/genética , Plasticidad Neuronal/genética , Neuronas/fisiología , Convulsiones/genética , Transcripción Genética/genética , Animales , Aprendizaje por Asociación/fisiología , Conducta Animal/fisiología , Expresión Génica/genética , Hipocampo/fisiología , Masculino , Ratones , Pilocarpina , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Convulsiones/inducido químicamente
10.
J Neurosci ; 28(42): 10720-33, 2008 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-18923047

RESUMEN

Transcriptional dysregulation is a central pathogenic mechanism in Huntington's disease, a fatal neurodegenerative disorder associated with polyglutamine (polyQ) expansion in the huntingtin (Htt) protein. In this study, we show that mutant Htt alters the normal expression of specific mRNA species at least partly by disrupting the binding activities of many transcription factors which govern the expression of the dysregulated mRNA species. Chromatin immunoprecipitation (ChIP) demonstrates Htt occupation of gene promoters in vivo in a polyQ-dependent manner, and furthermore, ChIP-on-chip and ChIP subcloning reveal that wild-type and mutant Htt exhibit differential genomic distributions. Exon 1 Htt binds DNA directly in the absence of other proteins and alters DNA conformation. PolyQ expansion increases Htt-DNA interactions, with binding to recognition elements of transcription factors whose function is altered in HD. Together, these findings suggest mutant Htt modulates gene expression through abnormal interactions with genomic DNA, altering DNA conformation and transcription factor binding.


Asunto(s)
Proteínas de Unión al ADN/fisiología , ADN/metabolismo , Proteínas del Tejido Nervioso/fisiología , Proteínas Nucleares/fisiología , Péptidos/fisiología , Regiones Promotoras Genéticas/fisiología , Transcripción Genética/fisiología , Animales , Línea Celular Transformada , ADN/antagonistas & inhibidores , ADN/química , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Humanos , Proteína Huntingtina , Enfermedad de Huntington/genética , Enfermedad de Huntington/metabolismo , Enfermedad de Huntington/patología , Ratones , Ratones Transgénicos , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Conformación de Ácido Nucleico , Péptidos/química , Péptidos/genética , Unión Proteica/fisiología , Factores de Transcripción/antagonistas & inhibidores , Factores de Transcripción/metabolismo
12.
Cell Stem Cell ; 16(1): 51-66, 2015 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-25465115

RESUMEN

Mesenchymal stem cells (MSCs) reside in the perivascular niche of many organs, including kidney, lung, liver, and heart, although their roles in these tissues are poorly understood. Here, we demonstrate that Gli1 marks perivascular MSC-like cells that substantially contribute to organ fibrosis. In vitro, Gli1(+) cells express typical MSC markers, exhibit trilineage differentiation capacity, and possess colony-forming activity, despite constituting a small fraction of the platelet-derived growth factor-ß (PDGFRß)(+) cell population. Genetic lineage tracing analysis demonstrates that tissue-resident, but not circulating, Gli1(+) cells proliferate after kidney, lung, liver, or heart injury to generate myofibroblasts. Genetic ablation of these cells substantially ameliorates kidney and heart fibrosis and preserves ejection fraction in a model of induced heart failure. These findings implicate perivascular Gli1(+) MSC-like cells as a major cellular origin of organ fibrosis and demonstrate that these cells may be a relevant therapeutic target to prevent solid organ dysfunction after injury.


Asunto(s)
Fibrosis/patología , Factores de Transcripción de Tipo Kruppel/metabolismo , Animales , Antígenos/metabolismo , Aorta/efectos de los fármacos , Aorta/patología , Aorta/fisiopatología , Vasos Sanguíneos/efectos de los fármacos , Vasos Sanguíneos/metabolismo , Vasos Sanguíneos/patología , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/metabolismo , Diferenciación Celular/efectos de los fármacos , Linaje de la Célula/efectos de los fármacos , Células Cultivadas , Ensayo de Unidades Formadoras de Colonias , Toxina Diftérica/farmacología , Células Endoteliales/citología , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Fibrosis/metabolismo , Ventrículos Cardíacos/efectos de los fármacos , Ventrículos Cardíacos/patología , Ventrículos Cardíacos/fisiopatología , Homeostasis/efectos de los fármacos , Humanos , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/ultraestructura , Ratones , Miofibroblastos/citología , Miofibroblastos/metabolismo , Neovascularización Fisiológica/efectos de los fármacos , Especificidad de Órganos/efectos de los fármacos , Pericitos/efectos de los fármacos , Pericitos/metabolismo , Pericitos/patología , Proteoglicanos/metabolismo , Receptor beta de Factor de Crecimiento Derivado de Plaquetas/metabolismo , Nicho de Células Madre/efectos de los fármacos , Proteína con Dedos de Zinc GLI1
13.
J Clin Invest ; 125(8): 2935-51, 2015 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-26193634

RESUMEN

Chronic kidney disease is characterized by interstitial fibrosis and proliferation of scar-secreting myofibroblasts, ultimately leading to end-stage renal disease. The hedgehog (Hh) pathway transcriptional effectors GLI1 and GLI2 are expressed in myofibroblast progenitors; however, the role of these effectors during fibrogenesis is poorly understood. Here, we demonstrated that GLI2, but not GLI1, drives myofibroblast cell-cycle progression in cultured mesenchymal stem cell-like progenitors. In animals exposed to unilateral ureteral obstruction, Hh pathway suppression by expression of the GLI3 repressor in GLI1+ myofibroblast progenitors limited kidney fibrosis. Myofibroblast-specific deletion of Gli2, but not Gli1, also limited kidney fibrosis, and induction of myofibroblast-specific cell-cycle arrest mediated this inhibition. Pharmacologic targeting of this pathway with darinaparsin, an arsenical in clinical trials, reduced fibrosis through reduction of GLI2 protein levels and subsequent cell-cycle arrest in myofibroblasts. GLI2 overexpression rescued the cell-cycle effect of darinaparsin in vitro. While darinaparsin ameliorated fibrosis in WT and Gli1-KO mice, it was not effective in conditional Gli2-KO mice, supporting GLI2 as a direct darinaparsin target. The GLI inhibitor GANT61 also reduced fibrosis in mice. Finally, GLI1 and GLI2 were upregulated in the kidneys of patients with high-grade fibrosis. Together, these data indicate that GLI inhibition has potential as a therapeutic strategy to limit myofibroblast proliferation in kidney fibrosis.


Asunto(s)
Arsenicales/farmacología , Puntos de Control del Ciclo Celular/efectos de los fármacos , Glutatión/análogos & derivados , Enfermedades Renales/tratamiento farmacológico , Riñón/metabolismo , Factores de Transcripción de Tipo Kruppel/antagonistas & inhibidores , Miofibroblastos/metabolismo , Piridinas/farmacología , Pirimidinas/farmacología , Animales , Puntos de Control del Ciclo Celular/genética , Línea Celular , Fibrosis , Glutatión/farmacología , Humanos , Riñón/patología , Enfermedades Renales/genética , Enfermedades Renales/metabolismo , Enfermedades Renales/patología , Factores de Transcripción de Tipo Kruppel/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Ratones , Ratones Noqueados , Miofibroblastos/patología , Proteína con Dedos de Zinc GLI1 , Proteína Gli2 con Dedos de Zinc
14.
Curr Pathobiol Rep ; 1(4)2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24319648

RESUMEN

Chronic injury to the kidney causes kidney fibrosis with irreversible loss of functional renal parenchyma and leads to the clinical syndromes of chronic kidney disease (CKD) and end-stage renal disease (ESRD). Regardless of the type of initial injury, kidney disease progression follows the same pathophysiologic processes characterized by interstitial fibrosis, capillary rarefaction and tubular atrophy. Myofibroblasts play a pivotal role in fibrosis by driving excessive extracellular matrix (ECM) deposition. Targeting these cells in order to prevent the progression of CKD is a promising therapeutic strategy, however, the cellular source of these cells is still controversial. In recent years, a growing amount of evidence points to resident mesenchymal cells such as pericytes and perivascular fibroblasts, which form extensive networks around the renal vasculature, as major contributors to the pool of myofibroblasts in renal fibrogenesis. Identifying the cellular origin of myofibroblasts and the key regulatory pathways that drive myofibroblast proliferation and transdifferentiation as well as capillary rarefaction is the first step to developing novel anti-fibrotic therapeutics to slow or even reverse CKD progression and ultimately reduce the prevalence of ESRD. This review will summarize recent findings concerning the cellular source of myofibroblasts and highlight recent discoveries concerning the key regulatory signaling pathways that drive their expansion and progression in CKD.

15.
J Biol Chem ; 281(24): 16672-80, 2006 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-16595660

RESUMEN

Interactions between mutant huntingtin (Htt) and a variety of transcription factors including specificity proteins (Sp) have been suggested as a central mechanism in Huntington disease (HD). However, the transcriptional activity induced by Htt in neurons that triggers neuronal death has yet to be fully elucidated. In the current study, we characterized the relationship of Sp1 to Htt protein aggregation and neuronal cell death. We found increased levels of Sp1 in neuronal-like PC12 cells expressing mutant Htt, primary striatal neurons, and brain tissue of HD transgenic mice. Sp1 levels were also elevated when 3-nitropropionate (3-NP) was used to induce cell death in PC12 cells. To assess the effects of knocking down Sp1 in HD pathology, we used Sp1 siRNA, a heterozygous Sp1 knock-out mouse, and mithramycin A, a DNA-intercalating agent that inhibits Sp1 function. The three approaches consistently yielded reduced levels of Sp1 which ameliorated toxicity caused by either mutant Htt or 3-NP. In addition, when HD mice were crossed with Sp1 heterozygous knock-out mice, the resulting offspring did not experience the loss of dopamine D2 receptor mRNA characteristic of HD mice, and survived longer than their HD counterparts. Our data suggest that enhancement of transcription factor Sp1 contributes to the pathology of HD and demonstrates that its suppression is beneficial.


Asunto(s)
Enfermedad de Huntington/genética , Fármacos Neuroprotectores/farmacología , Factor de Transcripción Sp1/biosíntesis , Factor de Transcripción Sp1/fisiología , Regulación hacia Arriba , Animales , Modelos Animales de Enfermedad , Femenino , Enfermedad de Huntington/metabolismo , Masculino , Ratones , Ratones Transgénicos , Neuronas/metabolismo , Células PC12 , Ratas
16.
Neurobiol Dis ; 22(2): 233-41, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16442295

RESUMEN

Huntington's disease (HD) is a neurodegenerative disease caused by expansion of a polyglutamine tract within the huntingtin protein. Transcriptional dysregulation has been implicated in HD pathogenesis; recent evidence suggests a defect in Sp1-mediated transcription. We used chromatin immunoprecipitation (ChIP) assays followed by real-time PCR to quantify the association of Sp1 with individual genes. We find that, despite normal protein levels and normal to increased overall nuclear binding activity, Sp1 has decreased binding to specific promoters of susceptible genes in transgenic HD mouse brain, in striatal HD cells, and in human HD brain. Genes whose mRNA levels are decreased in HD have abnormal Sp1-DNA binding, whereas genes with unchanged mRNA levels have normal levels of Sp1 association. Moreover, the altered binding seen with Sp1 is not found with another transcription factor, NF-Y. These findings suggest that mutant huntingtin dissociates Sp1 from target promoters, inhibiting transcription of specific genes.


Asunto(s)
Química Encefálica/genética , Encéfalo/metabolismo , Regulación hacia Abajo/genética , Regulación de la Expresión Génica/genética , Enfermedad de Huntington/genética , Factor de Transcripción Sp1/genética , Animales , Sitios de Unión/genética , Encéfalo/fisiopatología , Células Cultivadas , Humanos , Proteína Huntingtina , Enfermedad de Huntington/metabolismo , Enfermedad de Huntington/fisiopatología , Ratones , Ratones Transgénicos , Proteínas del Tejido Nervioso/genética , Proteínas Nucleares/genética , Regiones Promotoras Genéticas/genética , Unión Proteica/genética , Elementos Reguladores de la Transcripción/genética , Factor de Transcripción Sp1/metabolismo , Activación Transcripcional/genética
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