ABSTRACT
Abstract MiRNA (or microRNA) is a subclass of non-coding RNAs that is responsible for post-transcriptional gene regulation. It has approximately 22 nucleotides and regulates gene expression in plants and animals at the post-transcriptional level, by the cleavage of a target mRNA or by suppression of its translation. Although many of the processes and mechanisms have not yet been fully elucidated, there is a strong association between miRNA expression and several diseases. It is known that miRNAs are expressed in the cardiovascular system, but their role in cardiovascular diseases (CVDs) has not been clearly established. In this non-systematic review of the literature, we first present the definition of miRNAs and their action at the cellular level. Afterward, we discuss the role of miRNAs as circulating biomarkers of CVDs, and then their role in cardiac remodeling and atherosclerosis. Despite the complexity and challenges, it is crucial to identify deregulated miRNAs in CVDs, as it allows a better understanding of underlying cellular and molecular mechanisms and helps in the development of more accurate diagnostic and prognostic circulating biomarkers, and new therapeutic strategies for different stages of CVDs.
Resumo O miRNA (ou microRNA) constitui uma subclasse de RNAs não codificantes responsáveis pela regulação gênica pós-transcricional. Ele possui aproximadamente 22 nucleotídeos e regula a expressão gênica em plantas e animais ao nível pós-transcricional, pela clivagem de um mRNA alvo ou da repressão de sua tradução. Embora muitos processos e mecanismos ainda não estejam completamente elucidados, existe uma forte associação entre a expressão de miRNAs e diversas doenças que acometem o organismo. Os miRNAs são expressos no sistema cardiovascular, contudo o seu papel no desenvolvimento das doenças cardiovasculares (DCVs) ainda não está totalmente elucidado. Diante disso, realizou-se uma revisão não sistemática da literatura a fim de se discutir a relação entre os miRNAs e as DCVs. Nesta revisão, primeiramente é discutido o que são os miRNAs e a sua ação a nível celular. Após, é discutido o papel dos miRNAs como biomarcadores circulantes de DCVs e então o seu papel no remodelamento cardíaco e na aterosclerose. Apesar da complexidade e dos desafios, a identificação dos miRNAs desregulados nas DCVs é crucial, uma vez que possibilita uma melhor compressão dos mecanismos celulares e moleculares envolvidos, assim como auxilia o desenvolvimento de marcadores circulantes de diagnóstico e prognóstico mais acurados e de novas estratégias terapêuticas para os diferentes estágios da DCV.
Subject(s)
Humans , Cardiovascular Diseases/physiopathology , MicroRNAs/physiology , Biomarkers , Cardiovascular Diseases/genetics , Cardiovascular Diseases/metabolism , Gene Expression Regulation/genetics , Ventricular Remodeling/genetics , MicroRNAs/genetics , Atherosclerosis/physiopathology , Atherosclerosis/genetics , Atherosclerosis/metabolismABSTRACT
Background Limbal stem cells (LSCs) deficiency leads to many ocular surface diseases,such as pterygium and so on.ATP-binding cassette transporter B5 (ABCB5) is a recently discovered marker of LSCs.Understanding the expression changes of ABCB5 in pterygium tissue has an important clinical significance for pterygium.Objective This study was to investigate the expression changes of ABCB5 in pterygium tissue.Methods Thirty-seven pterygium tissue specimens were collected from primary pterygium patients who received pterygium surgery,and 22 normal conjunctival tissue specimens were obtained from the strabismus patients and retinal detachment patients during surgery in 474 Hospital of Chinese PLA from January 2015 to November 2015.Immunochemistry was employed to detect the cxpression and location of ABCB5 in the specimens,and the protein and mRNA expressions of ABCB5 were detected by Western blot and real-time fluorescence quantitative PCR,respectively.The results were compared between normal conjunctival tissues and pterygium tissue.Results ABCB5 protein was expressed in the cytoplasm and nuclei of stratified squamous epithelium of 22 normal counjunctival tissue specimens,especially in the basal layer cells,and showed obvious polarity in normal conjunctiva.In pterygium group,ABCB5 protein was positively expressed in 91.89％ specimens (34/37) and the expression was absent in 8.11％ specimens (3/37).The relative expression levels of ABCB5 protein were 0.90±0.31 and 0.59±0.41,and those of ABCB5 mRNA were 1.01±0.26 and 0.65±0.32 in the normal conjunctival tissues and pterygium tissue,respectively,showing significant differences between them (protein:t =-0.266,P =0.011;mRNA:t =-4.560,P =0.000).Conclusions Down-regulation of ABCB5 in pterygium indicates the decreasing and losing of LSCs,which may play an important role in the development of pterygium.ABCB5 may be a useful indicator for the prediction of development and recurrence of pterygium and has an important implication for treating evaluation,and it may also be a target for the management of pterygium.