RESUMEN
Endothelial cell (EC)-enriched protein coding genes, such as endothelial nitric oxide synthase (eNOS), define quintessential EC-specific physiologic functions. It is not clear whether long noncoding RNAs (lncRNAs) also define cardiovascular cell type-specific phenotypes, especially in the vascular endothelium. Here, we report the existence of a set of EC-enriched lncRNAs and define a role for spliced-transcript endothelial-enriched lncRNA (STEEL) in angiogenic potential, macrovascular/microvascular identity, and shear stress responsiveness. STEEL is expressed from the terminus of the HOXD locus and is transcribed antisense to HOXD transcription factors. STEEL RNA increases the number and integrity of de novo perfused microvessels in an in vivo model and augments angiogenesis in vitro. The STEEL RNA is polyadenylated, nuclear enriched, and has microvascular predominance. Functionally, STEEL regulates a number of genes in diverse ECs. Of interest, STEEL up-regulates both eNOS and the transcription factor Kruppel-like factor 2 (KLF2), and is subject to feedback inhibition by both eNOS and shear-augmented KLF2. Mechanistically, STEEL up-regulation of eNOS and KLF2 is transcriptionally mediated, in part, via interaction of chromatin-associated STEEL with the poly-ADP ribosylase, PARP1. For instance, STEEL recruits PARP1 to the KLF2 promoter. This work identifies a role for EC-enriched lncRNAs in the phenotypic adaptation of ECs to both body position and hemodynamic forces and establishes a newer role for lncRNAs in the transcriptional regulation of EC identity.
Asunto(s)
Cromatina/metabolismo , Células Endoteliales , Neovascularización Fisiológica , ARN Largo no Codificante , Animales , Células Cultivadas , Células Endoteliales/citología , Células Endoteliales/metabolismo , Endotelio Vascular/citología , Hemodinámica , Células Endoteliales de la Vena Umbilical Humana , Humanos , Ratones , Ratones SCID , Neovascularización Fisiológica/genética , Neovascularización Fisiológica/fisiología , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismoRESUMEN
The processes by which cells sense and respond to ambient oxygen concentration are fundamental to cell survival and function, and they commonly target gene regulatory events. To date, however, little is known about the link between the microRNA pathway and hypoxia signaling. Here, we show in vitro and in vivo that chronic hypoxia impairs Dicer (DICER1) expression and activity, resulting in global consequences on microRNA biogenesis. We show that von Hippel-Lindau-dependent down-regulation of Dicer is key to the expression and function of hypoxia-inducible factor α (HIF-α) subunits. Specifically, we show that EPAS1/HIF-2α is regulated by the Dicer-dependent microRNA miR-185, which is down-regulated by hypoxia. Full expression of hypoxia-responsive/HIF target genes in chronic hypoxia (e.g. VEGFA, FLT1/VEGFR1, KDR/VEGFR2, BNIP3L, and SLC2A1/GLUT1), the function of which is to regulate various adaptive responses to compromised oxygen availability, is also dependent on hypoxia-mediated down-regulation of Dicer function and changes in post-transcriptional gene regulation. Therefore, functional deficiency of Dicer in chronic hypoxia is relevant to both HIF-α isoforms and hypoxia-responsive/HIF target genes, especially in the vascular endothelium. These findings have relevance to emerging therapies given that we show that the efficacy of RNA interference under chronic hypoxia, but not normal oxygen availability, is Dicer-dependent. Collectively, these findings show that the down-regulation of Dicer under chronic hypoxia is an adaptive mechanism that serves to maintain the cellular hypoxic response through HIF-α- and microRNA-dependent mechanisms, thereby providing an essential mechanistic insight into the oxygen-dependent microRNA regulatory pathway.
Asunto(s)
Adaptación Fisiológica/fisiología , ARN Helicasas DEAD-box/biosíntesis , Endotelio Vascular/enzimología , Regulación Enzimológica de la Expresión Génica/fisiología , Oxígeno/metabolismo , Ribonucleasa III/biosíntesis , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/biosíntesis , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Hipoxia de la Célula , ARN Helicasas DEAD-box/genética , Endotelio Vascular/citología , Transportador de Glucosa de Tipo 1/biosíntesis , Transportador de Glucosa de Tipo 1/genética , Células Hep G2 , Células Endoteliales de la Vena Umbilical Humana , Humanos , Proteínas de la Membrana/biosíntesis , Proteínas de la Membrana/genética , MicroARNs/biosíntesis , MicroARNs/genética , Proteínas Proto-Oncogénicas/biosíntesis , Proteínas Proto-Oncogénicas/genética , Ribonucleasa III/genética , Proteínas Supresoras de Tumor/biosíntesis , Proteínas Supresoras de Tumor/genética , Factor A de Crecimiento Endotelial Vascular/biosíntesis , Factor A de Crecimiento Endotelial Vascular/genética , Receptor 1 de Factores de Crecimiento Endotelial Vascular/biosíntesis , Receptor 1 de Factores de Crecimiento Endotelial Vascular/genética , Receptor 2 de Factores de Crecimiento Endotelial Vascular/biosíntesis , Receptor 2 de Factores de Crecimiento Endotelial Vascular/genética , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/genética , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/metabolismoRESUMEN
This study compared sex differences in related treatment outcomes and processes in a community sample of outpatient problem gambling treatment-seekers. Participants attended approximately seven sessions of cognitive-behavioral treatment. Women were more likely to have a history of psychiatric comorbidity, prefer non-strategic/non-skill forms of gambling, and have a more rapid progression towards a gambling problem than did men. At the 6-month post-treatment follow-up, men were found to have improved to a significantly greater degree on measures of gambling severity and rates of abstinence in comparison to women. Moreover, men rated treatment components to be more helpful, whereas women found specific gambling-related treatment interventions (e.g., identification of high-risk situations, gambling beliefs and attitudes) to be less helpful. Implications for identifying treatment needs of women seeking problem gambling treatment are discussed.