RESUMO
Dopamine axons are the only axons known to grow during adolescence. Here, using rodent models, we examined how two proteins, Netrin-1 and its receptor, UNC5C, guide dopamine axons towards the prefrontal cortex and shape behaviour. We demonstrate in mice ( Mus musculus ) that dopamine axons reach the cortex through a transient gradient of Netrin-1 expressing cells - disrupting this gradient reroutes axons away from their target. Using a seasonal model (Siberian hamsters; Phodopus sungorus ) we find that mesocortical dopamine development can be regulated by a natural environmental cue (daylength) in a sexually dimorphic manner - delayed in males, but advanced in females. The timings of dopamine axon growth and UNC5C expression are always phase-locked. Adolescence is an ill-defined, transitional period; we pinpoint neurodevelopmental markers underlying this period.
RESUMO
[Figure: see text].
Assuntos
RNA Circular/metabolismo , Disfunção Ventricular/metabolismo , Remodelação Ventricular , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Moléculas de Adesão Celular Neuronais/genética , Moléculas de Adesão Celular Neuronais/metabolismo , Células Cultivadas , Colágeno/metabolismo , Fibrose , Humanos , Camundongos , Miócitos Cardíacos/metabolismo , Miofibroblastos/metabolismo , Ligação Proteica , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , RNA Circular/genética , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Disfunção Ventricular/genéticaRESUMO
Significant progress has been made in circular RNA (circRNA) research in recent years. Increasing evidence suggests that circRNAs play important roles in many cellular processes, and their dysregulation is implicated in the pathogenesis of various diseases. CircRNAs are highly stable and usually expressed in a tissue- or cell type-specific manner. Therefore, they are currently being explored as potential therapeutic targets. Gain-of-function and loss-of-function approaches are typically performed using circRNA expression plasmids and RNA interference-based strategies, respectively. These strategies have limitations that can be mitigated using nanoparticle and exosome delivery systems. Furthermore, recent developments show that the cre-lox system can be used to knockdown circRNAs in a cell-specific manner. While still in the early stages of development, the CRISPR/Cas13 system has shown promise in knocking down circRNAs with high specificity and efficiency. In this review, we describe circRNA properties and functions and highlight their significance in disease. We summarize strategies that can be used to overexpress or knockdown circRNAs as a therapeutic approach. Lastly, we discuss major challenges and propose future directions for the development of circRNA-based therapeutics.
Assuntos
Sistemas CRISPR-Cas , Técnicas de Silenciamento de Genes , Terapia Genética , RNA Circular , Humanos , RNA Circular/biossíntese , RNA Circular/genéticaRESUMO
Circular RNAs (circRNAs) are RNAs with a unique circular structure that is generated from back-splicing processes. These circular molecules were discovered more than 40 years ago but failed to raise scientific interest until lately. Increasing studies have found that these circular RNAs might not just be byproducts of the splicing process but possess important regulatory functions through different cellular events. Most circular RNAs are currently being studied in the field of cancer, and many of them have been confirmed to be involved in the process of tumorigenesis. However, many circular RNAs are implicated in the developmental stages of diseases other than cancer. In this review, we focus on discussing the role of circular RNAs in non-cancer diseases, especially in cardiovascular diseases. Following the summary of the life cycle of circRNAs, we provide input on studying circRNA-protein interactions based on our experience, which modulate protein translocation. Furthermore, we outline the potential of circRNAs to be potent biomarkers, effective therapeutic targets, and potential treatments in cardiovascular diseases as well as other non-cancer fields.
Assuntos
Doenças Cardiovasculares/genética , Marcadores Genéticos , RNA Circular/genética , Doenças Cardiovasculares/tratamento farmacológico , Doenças Cardiovasculares/metabolismo , Diagnóstico Precoce , Humanos , Terapia de Alvo Molecular , Transporte Proteico , Proteínas/metabolismo , RNA Circular/metabolismoRESUMO
Circular RNAs (circRNAs) are a large class of noncoding RNAs, generated from a process called back-splicing, that possess critical regulatory functions in many cellular events. A large body of literature has reported various circRNA functions and their underlying mechanisms, including sponging miRNA, exerting transcriptional and translational regulation, interacting with proteins, and translating into peptides and proteins. CircRNA dysregulation has been implicated in many cancers, including lung, breast, liver, gastric, colorectal, and ovarian cancer. They are detectable in bodily fluids and relatively stable, making them potential cancer biomarker candidates. Furthermore, targeting circRNA expression levels is a potential therapeutic approach for treating cancers. In this review, we describe the functional mechanisms of circRNAs and discuss limitations of current mechanism studies. Following this, we outline the potential of circRNAs to be effective biomarkers in various cancers and present circRNA-based therapeutic approaches. Finally, we discuss challenges in using circRNAs as diagnostic and therapeutic tools and propose future research directions.
