Alternative titles; symbols
HGNC Approved Gene Symbol: MIR96
Cytogenetic location: 7q32.2 Genomic coordinates (GRCh38) : 7:129,774,692-129,774,769 (from NCBI)
Location | Phenotype |
Phenotype MIM number |
Inheritance |
Phenotype mapping key |
---|---|---|---|---|
7q32.2 | Deafness, autosomal dominant 50 | 613074 | Autosomal dominant | 3 |
MicroRNAs (miRNAs), such as MIR96, are noncoding regulatory RNAs of 18 to 24 nucleotides that influence translation and stability of target mRNAs. MIR183 (611608), MIR96, and MIR182 (611607) are transcribed in tandem as a single polycistronic primary transcript (Xu et al., 2007).
Using quantitative PCR and Northern blot analyses, Weston et al. (2006) detected expression of mature Mirn183, Mirn96, and Mirn182 in mouse inner ear, but not in brain or heart. RT-PCR detected the primary transcript encoding these miRNAs in inner ear and adult eye. In situ hybridization localized Mirn183, Mirn96, and Mirn182 expression to the inner and outer hair cells of the cochlea and in hair cells of the cristae, utricle, and saccule of the vestibular endorgans.
By microarray analysis and quantitative RT-PCR, Xu et al. (2007) found that Mirn183, Mirn96, and Mirn182 were highly expressed in adult mouse retina. Qualitative RT-PCR showed that these miRNAs exhibited at least a 10-fold increase in expression in mouse retina from postnatal day 1 to adult. In situ hybridization of adult mouse retina revealed expression of these miRNAs in photoreceptors and interneurons in the inner nuclear layer, with little or no expression in the ganglion cell layer. RT-PCR also showed expression of Mirn183, Mirn96, and Mirn182 in mouse olfactory epithelium and lingual epithelium. Xu et al. (2007) noted that Mirn183, Mirn96, and Mirn182 share significant identity, particularly in their seed sequences.
Xu et al. (2007) observed circadian variation in expression of Mirn182 and Mirn96 that was nearly inverse to that of Adcy6 (600294), a putative target mRNA. Reporter gene assays confirmed that Mirn182 and Mirn96 targeted the 3-prime UTR of Adcy6. The 3-prime UTR of Mitf (156845) also contains putative Mirn182- and Mirn96-binding sites, and expression of an Mitf reporter was reduced in the presence of Mirn182 or Mirn96. A lack of additive inhibition when the 2 miRNAs were cotransfected suggested that they compete for the same target sites in Adcy6 and Mitf.
Using expression arrays and quantitative RT-PCR, Krol et al. (2010) showed that expression of Mir211 (613753), Mir204 (610942), and the Mir183/Mir96/Mir182 cluster was reversibly up- and downregulated in mouse retina during light and dark adaptation, respectively. Increased accumulation of these miRNAs upon light adaptation occurred independently of circadian rhythm. The half-lives of these and other miRNAs appeared to be much shorter in retinal neurons than in rod bipolar cells or Muller glia cells. Similar rapid miRNA decay was observed in cultured rodent neurons and mouse embryonic stem cell-derived neurons. Inhibitor studies revealed that miRNA turnover was stimulated by neuronal activity. In silico analysis identified Atp1b3 (601867), Slc1a1 (133550), and Paip2b (611018) as potential targets of the Mir183/Mir96/Mir182 cluster in retina. Expression of Slc1a1 increased with dark adaptation in mouse retina, concomitant with low expression of Mir183/Mir96/Mir182. Reporter gene assays and other studies confirmed regulation of Slc1a1 mRNA by the Mir183/Mir96/Mir182 cluster.
Upton et al. (2012) found that sustained IRE1-alpha (604033) RNase activation caused rapid decay of select microRNAs (miR17, 609416; miR34a, 611172; miR96; and miR125b, 610105) that normally repress translation of caspase-2 (600639) mRNA, and thus sharply elevated protein levels of this initiator protease of the mitochondrial apoptotic pathway. In cell-free systems, recombinant IRE1-alpha endonucleolytically cleaved microRNA precursors at sites distinct from DICER (606241). Thus, Upton et al. (2012) concluded that IRE1-alpha regulates translation of a proapoptotic protein through terminating microRNA biogenesis, and noncoding RNAs are a part of the endoplasmic reticulum stress response.
Wang et al. (2013) found that MIR185 (615576), MIR96, and MIR223 (300694) downregulated expression of the hepatic scavenger receptor SRBI (SCARB1; 601040), which has a role in uptake of high density lipoprotein cholesterol (HDLC) in human hepatic cell lines. The 3-prime UTR of SRBI contains independent binding sites for MIR96, MIR185, and MIR223, and the 3 miRNAs showed an additive effect in inhibiting expression of a reporter gene containing the SRBI 3-prime UTR. Transfection of MIR185 and MIR96 mimics, but not an MIR223 mimic, markedly reduced SRBI mRNA levels in phorbol ester-stimulated human THP-1 macrophage-like cells and suppressed HDLC uptake. In apoE (107741)-knockout mice on a high-fat diet, elevated hepatic Srbi coincided with decreased Mir96 and Mir185 content (the 3-prime UTR of rodent Srbi does not have an Mir223 target site). Wang et al. (2013) concluded that these miRNAs have a role in regulating cholesterol uptake by repressing expression of SRBI.
Xu et al. (2007) determined that the MIRN183-MIRN96-MIRN182 cluster spans about 4.3 kb. The 5-prime upstream region contains a CpG island and has binding sites for sensory organ-related transcription factors, including OLF1 (EBF; 164343), OTX1 (600036), and PAX2 (167409).
By genomic sequence analysis, Xu et al. (2007) mapped the MIRN183-MIRN96-MIRN182 cluster to chromosome 7q32.2. They mapped the mouse cluster to a region of chromosome 6A3 that shares homology of synteny with human chromosome 7q32.2.
Mencia et al. (2009) identified heterozygous point mutations in the seed region of MIR96, a miRNA expressed in hair cells of the inner ear, that result in autosomal dominant progressive hearing loss. The identified mutations have a strong impact on MIR96 biogenesis and result in a significant reduction of mRNA targeting. Mencia et al. (2009) proposed that these mutations alter the regulatory role of MIR96 in maintaining gene expression profiles in hair cells required for their normal function.
Lewis et al. (2009) reported a new ENU-induced mouse mutant, 'diminuendo' (Dmdo), with a single base change in the seed region of Mirn96. Heterozygotes showed progressive loss of hearing and hair cell anomalies, whereas homozygotes had no cochlear responses. Most microRNAs are believed to downregulate target genes by binding to specific sites on their mRNAs, so mutation of the seed should lead to target gene upregulation. Microarray analysis revealed 96 transcripts with significantly altered expression in homozygotes; notably, Slc26a5 (604943), Ocm (164795), Gfi1 (600871), Ptprq (603317), and Pitpnm1 (608794) were downregulated. Hypergeometric P-value analysis showed that hundreds of genes were upregulated in mutants. Different genes, with target sites complementary to the mutant seed, were downregulated.
Schluter et al. (2018) analyzed homozygous Dmdo/Dmdo mice and found a significant reduction in size of auditory hindbrain nuclei due to decreased cell size compared with wildtype littermates, pointing to developmental arrest in Dmdo/Dmdo mice. Further analysis showed that these effects were an auditory-specific effect of the Dmdo mutation, not a broader phenomenon. Electrophysiologic analysis in medial nucleus of the trapezoid body (MNTB) showed that the Dmdo mutation selectively affected firing behavior in MNTB neurons, as more neurons in Dmdo/Dmdo MNTB responded with a sustained firing pattern upon depolarization compared with the single-firing pattern in control animals. Immunoreactivity analysis demonstrated that this observed firing pattern was due to reduced expression of voltage-gated potassium channels in Dmdo/Dmdo mice. Immunolabeling of synaptic vesicle glycoprotein-2 (SV2A; 185860) showed that the mature synaptic structure of Dmdo/Dmdo calyx of Held had morphologic changes that caused arrested synapse development, altering the short-term plasticity at high frequencies in synaptic transmission and thereby affecting evoked synaptic transmission.
In a large 5-generation Spanish family segregating autosomal dominant nonsyndromic progressive hearing loss (DFNA50; 613074), initially described by Modamio-Hoybjor et al. (2004), Mencia et al. (2009) identified a heterozygous G-to-A transition at nucleotide 13 of the MIR96 precursor sequence. The mutation replaced the fourth nucleotide within the conserved 7-nucleotide seed region of the mature sequence. This mutation segregated absolutely with the phenotype in the family and was not detected in 462 unrelated normal-hearing Spanish controls.
In a 3-generation Spanish family segregating nonsyndromic progressive autosomal dominant hearing loss (DFNA50; 613074), Mencia et al. (2009) identified a heterozygous C-to-A transition at nucleotide 14 of the MIR96 precursor sequence. This variant replaces the fifth nucleotide of the conserved seed region of the mature sequence. This mutation segregated with the phenotype in the family and was not identified in 462 normal-hearing Spanish controls.
Krol, J., Busskamp, V., Markiewicz, I., Stadler, M. B., Ribi, S., Richter, J., Duebel, J., Bicker, S., Fehling, H. J., Schubeler, D., Oertner, T. G., Schratt, G., Bibel, M., Roska, B., Filipowicz, W. Characterizing light-regulated retinal microRNAs reveals rapid turnover as a common property of neuronal microRNAs. Cell 141: 618-631, 2010. [PubMed: 20478254] [Full Text: https://doi.org/10.1016/j.cell.2010.03.039]
Lewis, M. A., Quint, E., Glazier, A. M., Fuchs, H., De Angelis, M. H., Langford, C., van Dongen, S., Abreu-Goodger, C., Piipari, M., Redshaw, N., Dalmay, T., Moreno-Pelayo, M. A., Enright, A. J., Steel, K. P. An ENU-induced mutation of miR-96 associated with progressive hearing loss in mice. Nature Genet. 41: 614-618, 2009. [PubMed: 19363478] [Full Text: https://doi.org/10.1038/ng.369]
Mencia, A., Modamio-Hoybjor, S., Redshaw, N., Morin, M., Mayo-Merino, F., Olavarrieta, L., Aguirre, L. A., del Castillo, I., Steel, K. P., Dalmay, T., Moreno, F., Moreno-Pelayo, M. A. Mutations in the seed region of human miR-96 are responsible for nonsyndromic progressive hearing loss. Nature Genet. 41: 609-613, 2009. [PubMed: 19363479] [Full Text: https://doi.org/10.1038/ng.355]
Modamio-Hoybjor, S., Moreno-Pelayo, M. A., Mencia, A., del Castillo, I., Chardenoux, S., Morais, D., Lathrop, M., Petit, C., Moreno, F. A novel locus for autosomal dominant nonsyndromic hearing loss, DFNA50, maps to chromosome 7q32 between the DFNB17 and DFNB13 deafness loci. J. Med. Genet. 41: e14, 2004. Note: Electronic Article. [PubMed: 14757864] [Full Text: https://doi.org/10.1136/jmg.2003.012500]
Schluter, T., Berger, C., Rosengauer, E., Fieth, P., Krohs, C., Ushakov, K., Steel, K. P., Avraham, K. B., Hartmann, A. K., Felmy, F., Nothwang, H. G. miR-96 is required for normal development of the auditory hindbrain. Hum. Molec. Genet. 27: 860-874, 2018. [PubMed: 29325119] [Full Text: https://doi.org/10.1093/hmg/ddy007]
Upton, J.-P., Wang, L., Han, D., Wang, E. S., Huskey, N. E., Lim, L., Truitt, M., McManus, M. T., Ruggero, D., Goga, A., Papa, F. R., Oakes, S. A. IRE1-alpha cleaves select microRNAs during ER stress to derepress translation of proapoptotic caspase-2. Science 338: 818-822, 2012. [PubMed: 23042294] [Full Text: https://doi.org/10.1126/science.1226191]
Wang, L., Jia, X.-J., Jiang, H.-J., Du, Y., Yang, F., Si, S.-Y., Hong, B. MicroRNAs 185, 96, and 223 repress selective high-density lipoprotein cholesterol uptake through posttranscriptional inhibition. Molec. Cell. Biol. 33: 1956-1964, 2013. [PubMed: 23459944] [Full Text: https://doi.org/10.1128/MCB.01580-12]
Weston, M. D., Pierce, M. L., Rocha-Sanchez, S., Beisel, K. W., Soukup, G. A. MicroRNA gene expression in the mouse inner ear. Brain Res. 1111: 95-104, 2006. [PubMed: 16904081] [Full Text: https://doi.org/10.1016/j.brainres.2006.07.006]
Xu, S., Witmer, P. D., Lumayag, S., Kovacs, B., Valle, D. MicroRNA (miRNA) transcriptome of mouse retina and identification of a sensory organ-specific miRNA cluster. J. Biol. Chem. 282: 25053-25066, 2007. [PubMed: 17597072] [Full Text: https://doi.org/10.1074/jbc.M700501200]