Abstract
MicroRNAs (miRNA) are short, noncoding RNA sequences that regulate gene expression by blocking protein translation or inducing messenger RNA (mRNA) degradation. miRNA is found in various tissues with variable expression, and changes in expression are related to various disease processes. Evidence suggests that changes in miRNA expression are critical for the normal development of kidney tissue. Alternatively, in diseases such as diabetic nephropathy, polycystic kidney disease, and lupus nephritis, specific miRNAs may enhance disease manifestations in a myriad of ways, ranging from activation of fibrotic pathways to anatomic changes that abet proteinuria. The variable expression of miRNA in kidney tissue, whether in the context of normal development or disease processes, makes miRNAs a valuable new tool for understanding, diagnosing, and discovering therapeutic options for pathologic processes that affect the kidney.