ABSTRACT
Inflammatory bowel disease (IBD) manifests in two forms—ulcerative colitis (UC) or Crohn’s disease (CD). This is due to various environmental cues in a genetically susceptible individual, leading to a dysregulated inflammatory response. Contributing factors in the pathogenesis of IBD are microbial, environmental, genetic and epigenetic in nature. MicroRNAs, a class of endogenous, non-coding, small RNAs, are considered an epigenetic factor responsible for modulating target gene expression. Studies have revealed that deregulation of miRNA expression can be profiled in different tissues of mucosa in affected UC or CD patients, using microarray technique followed by real time analysis. Functional studies have revealed that they target various signaling molecules in the inflammatory pathways, culminating in differential activation of NF-κB--the key molecule in the pathogenesis of this disease. MiRNA are also responsible in mediating the interaction between microbial factors and host immune response that triggers the signaling pathways. Detection of miRNA in serum samples has paved the way to develop biomarkers for an early diagnosis of the disease and to help monitor progression from UC or CD to colorectal cancer (CRC). The presence of single nucleotide polymorphism in miRNA has been found to alter the function of miRNA. Possible clinical applications of miRNA as therapeutics are now being explored.
