Craig, T.A., Zhang, Y., Magis, A.T., Funk, C.C., Price, N.D., Ekker, S.C., Kumar, R. (2014) Detection of 1,25-Dihydroxyvitamin D-Regulated miRNAs in Zebrafish by Whole Transcriptome Sequencing. Zebrafish. 11(3):207-18.
Abstract The sterol hormone, 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3), regulates gene expression and messenger RNA (mRNA) concentrations in zebrafish in vivo. Since mRNA concentrations and translation are influenced by micro-RNAs (miRNAs), we examined the influence of 1α,25(OH)2D3 on miRNA expression in zebrafish in vivo with whole transcriptome RNA sequencing, searched for miRNA binding sites in 1α,25(OH)2D3-sensitive genes, and performed correlation analyses between 1α,25(OH)2D3-sensitive miRNAs and mRNAs. In vehicle- and 1α,25(OH)2D3-treated, 7-day postfertilization larvae, between 282 and 295 known precursor miRNAs were expressed, and in vehicle- and 1α,25(OH)2D3-treated fish, between 83 and 122 novel miRNAs were detected. Following 1α,25(OH)2D3 treatment, 31 precursor miRNAs were differentially expressed (p<0.05). The differentially expressed miRNAs are predicted to potentially alter mRNAs for metabolic enzymes, transcription factors, growth factors, and Jak-STAT signaling. We verified the role of a 1α,25(OH)2D3-sensitive miRNA, miR125b, by demonstrating alterations in the concentrations of the mRNA of a 1α,25(OH)2D3-regulated gene, Cyp24a1, following transfection of renal cells with a miR125b miRNA mimic. Changes in the Cyp24a1 mRNA concentration by the miR125b miRNA mimic were associated with changes in the protein for Cyp24a1. Our data show that 1α,25(OH)2D3 regulates miRNA in zebrafish larvae in vivo and could thereby influence vitamin D-sensitive mRNA concentrations.