HuR and Its Interactions with Noncoding RNAs in Gut Epithelium Homeostasis and Diseases

The mammalian intestinal epithelium is a rapidly self-renewing tissue in the body and its homeostasis is tightly controlled by numerous factors at multiple levels. The RNA-binding protein HuR (human antigen R) is intimately involved in many aspects of gut mucosal pathobiology and plays an important role in maintaining integrity of the intestinal epithelium by regulating stability and translation of target mRNAs. Nonetheless, deregulation of HuR expression and altered binding affinity of HuR for target transcripts occur commonly in various gut mucosal disorders. In this review, we highlight the essential role of HuR in the intestinal epithelium homeostasis and discuss recent results that interactions between HuR and noncoding RNAs (ncRNAs), including circular RNAs, long ncRNAs, small vault RNAs, and microRNAs, influence gut mucosal regeneration and regulate barrier function in various pathophysiological conditions. These exciting discoveries advance our knowledge of HuR biological function in the gut mucosa and also create a fundamental basis for developing novel therapies to protect intestinal epithelial integrity in critically ill patients.