MicroRNAs as diagnosis and prognosis markers of ulcerative colitis and Crohn's disease in patients with inflammatory bowel disease

Abstract

The correct distinction between Ulcerative Colitis (RCU) and Crohn's Disease (CD), the two major subtypes of Inflammatory Bowel Disease (IBD), is determinant for decision-making of the best treatment and therapeutic that was used to prevent aggravation of disease and increase the remission time of the patients' symptoms. The correct distinction between Ulcerative Colitis (UC) and Crohn's Disease (CD), the two main subtypes of Inflammatory Bowel Disease (IBD), is decisive for the decision making of the best treatment and therapeutic procedures that should be used to avoid aggravation of disease and increase the time of remission of symptoms in patients. To date there is no gold standard of examination for differential diagnosis and characterization of the prognosis of IBD in humans, which leads to incorrect classifications and repetition of invasive examinations. In clinical practice, the optimization of standard diagnostic approaches based on clinical characteristics, biomarkers, radiology, endoscopy and histopathology produces only marginal benefits, and it is necessary to create new techniques that combine ease of execution and less aggressive practices. Although recently identified prognostic factors are used to improve treatment and reduce future complications for patients, none of these markers is superior to the evaluation of clinical and endoscopic phenotypic characteristics. On the other hand, new tools involving genetics, epigenetics, metabolomics and proteomics may be fundamental for the differential diagnosis and prognosis of IBD in humans, especially since they allow a molecular classification of the different types and stages of IBD. Numerous efforts have been made in this direction; however, there are few data that allow characterization of the profile of these patients, as there is a huge lack of approaches and tools that can be used as predictors of prognosis of these diseases. In this context, one of the most modern and innovative strategies involved in diagnosis, prognosis, pathogenesis and therapy has been based on the determination of the role of microRNAs in IBD. MicroRNAs (miRNAs) are a single class of small non-coding RNAs with 18 to 24 nucleotides that exert different effects by regulating the expression of genes and proteins without DNA sequence changes. It is estimated that miRNAs are responsible for regulating the expression of approximately 30% of genes in the human genome and since the initial discovery and characterization in 1993, the number of miRNAs recorded in the miRBase database has grown enormously. The role of miRNAs in the etiology, diagnosis, prognosis and treatment of IBD has been extensively revised, however, functional miRNAs are rarely available, most of which are restricted to a small number of miRNAs. To date, no comparative studies of miRNAs performed directly on the mucosa of patients with different IBD subtypes have been found. It is in this context that the present project proposes to study the diversity of microRNAs in patients with inflammatory bowel disease previously diagnosed with RCU or CD and to verify if there is a differential pattern of these microRNAs in each of these subtypes of disease and that represent a potential tool for the diagnosis of future IBD patients. In addition, the evaluation of these microRNAs in patients with RCU and DC will be accompanied by the simultaneous analysis of different mediators of inflammatory bowel response. (AU)