Small molecules exploiting structural differences within microRNA-200 precursors family members reverse a type 2 diabetes phenotype

Abstract

AbstractMicroRNA families are pervasive in the human transcriptome, but specific targeting of individual members is a challenge because of sequence homology. Many of the secondary structures of the precursors to these miRs (pre-miRs), however, are quite different. Here, we demonstrate both in vitro and in cellulis that design of structure-specific small molecules can inhibit specific miR family members to modulate a disease pathway. In particular, the miR-200 family consists five miRs, miR-200a, −200b, −200c, −141, and - 429, and is associated with Type II Diabetes (T2D). We designed a small molecule that potently and selectively targets pre-miR-200c’s structure. The compound reverses a pro-apoptotic effect in a pancreatic β-cell model. In contrast, oligonucleotides targeting the RNA’s sequence inhibit all family members. Global proteomics analysis further demonstrates selectivity for miR-200c. Collectively, these studies establish that miR-200c plays an important role in T2D and that small molecules targeting RNA structure can be an important complement to oligonucleotides targeting sequence.Significance StatementThe most common way to develop medicines targeting RNA is by using oligonucleotides that target its sequence by using base pairing. Some RNAs, however, have similar sequences and thus are impossible to target selectively by using oligonucleotides. Here, we show that a class of RNAs that have similar sequences emerge from precursors that have very different structures. Exploiting these structural differences afforded a selective compound. In particular, the selective small molecule targets a member of the microRNA (miR)-200 family, the overexpression of which is linked to diabetes and pancreatic cell death. Selective inhibition of family member miR-200c alleviates pancreatic cell death, and thus the small molecule provides a path to the treatment of diabetes.