Could microRNAs contribute to the maintenance of β cell identity?

•microRNAs are genome-encoded RNAs that confer sequence-based post-transcriptional silencing.•In vivo evidence demonstrates that microRNAs are crucial for insulin synthesis.•microRNAs silence genes that otherwise interfere with normal β cell function.•We suggest that microRNAs play a role in the maintenance of adult β cell identity.

Normal physiology depends on defined functional output of differentiated cells. However, differentiated cells are often surprisingly fragile. As an example, phenotypic collapse and dedifferentiation of β cells were recently discovered in the pathogenesis of type 2 diabetes (T2D). These discoveries necessitate the investigation of mechanisms that function to maintain robust cell type identity. microRNAs (miRNAs), which are small non-coding RNAs, are known to impart robustness to development. miRNAs are interlaced within networks, that include also transcriptional and epigenetic regulators, for continuous control of lineage-specific gene expression. In this Opinion article, we provide a framework for conceptualizing how miRNAs might participate in adult β cell identity and suggest that miRNAs may function as important genetic components in metabolic disorders, including diabetes.