MIAT

MIAT
Name	MIAT
Alt symbols	Rncr2, Gomafu
Locus	22q12.1
Organism	Human
Type	lncRNA
Refseq	NR_003491

MIAT MIAT is a long noncoding RNA (lncRNA) originally identified in screens for myocardial infarction susceptibility and retinal development. It is transcribed as a ~10 kb nuclear-retained transcript expressed in neural and cardiovascular tissues and has been implicated in transcriptional regulation, RNA processing, and disease phenotypes. MIAT interacts with multiple RNA-binding proteins and chromatin regulators and has attracted attention in studies linking noncoding loci to complex traits such as myocardial infarction, schizophrenia, and diabetic retinopathy.

Introduction

MIAT was first associated with risk for myocardial infarction in genome-wide association studies that catalogued loci alongside variants from cohorts analysed by consortia including the Wellcome Trust Case Control Consortium and investigators affiliated with institutes such as the Broad Institute and the National Institutes of Health. Subsequent experimental work in model organisms and cellular systems conducted by teams from universities such as Harvard, Stanford, Kyoto University, and University College London characterized MIAT expression in the retina, brain, heart, and vasculature. MIAT has been referred to in the literature under aliases including Rncr2 in mouse and Gomafu in zebrafish and mammalian neurobiology reports.

Gene and Protein Structure

The MIAT locus on chromosome 22q12.1 encodes a multi-exonic long noncoding transcript lacking conserved open reading frames typical of protein-coding genes described in annotations by RefSeq and Ensembl. The primary transcript contains putative RNA structural motifs and repetitively enriched sequences that bind heterogeneous nuclear ribonucleoproteins (hnRNPs) and splicing regulators characterized in studies using crosslinking-immunoprecipitation performed by laboratories at Cold Spring Harbor Laboratory and Max Planck Institutes. Although MIAT does not encode a protein product, its secondary and tertiary RNA structures have been modelled by groups specializing in RNA structural biology at institutions such as MIT and the University of Cambridge, revealing stem–loop elements and conserved sequence stretches shared with lncRNAs studied by teams at the Salk Institute and Institut Pasteur.

Expression and Regulation

MIAT expression is tissue-selective, with high levels in neuronal populations of the cortex, hippocampus, and retina as reported by consortia including the Allen Institute for Brain Science and the ENCODE Project. Developmental regulation of MIAT has been demonstrated during retinal differentiation protocols used in labs at Johns Hopkins University and the University of California, San Francisco. Transcriptional control elements at the MIAT promoter are bound by transcription factors such as SOX2, POU3F2 (BRN2), and REST in ChIP-seq datasets produced by groups at the European Bioinformatics Institute and the Broad Institute. Post-transcriptional regulation involves interactions with splicing factors like SF1 and SRSF1 and nuclear matrix proteins such as MATR3, documented in experiments from institutions including the University of Tokyo and the Karolinska Institutet.

Biological Function and Mechanisms

MIAT functions as a nuclear scaffold and regulator of alternative splicing and chromatin-associated processes. Mechanistic studies from laboratories at the University of Pennsylvania, Columbia University, and Kyoto University show MIAT binds splicing regulators including QKI and RBFOX1 and modulates alternative splicing patterns of transcripts implicated in synaptogenesis studied in the context of work by the Scripps Research Institute and Cold Spring Harbor Laboratory. MIAT has also been reported to interact with chromatin modifiers such as EZH2 of the Polycomb Repressive Complex 2 in assays performed at institutions like the University of Oxford and Stanford University, influencing local histone modification states and gene expression programs involved in neuronal differentiation characterized by teams at MIT and UC Davis.

Clinical Significance and Disease Associations

Genetic association studies implicate variants in the MIAT locus in susceptibility to myocardial infarction and have been replicated in cohorts from the Framingham Heart Study, CARDIoGRAM, and international consortia. Elevated or dysregulated MIAT expression has been observed in diabetic retinopathy samples processed by clinical groups at Moorfields Eye Hospital and in post-mortem brain tissue from schizophrenia cohorts analysed by the Psychiatric Genomics Consortium and academic centres such as King's College London. Cancer-related studies from Memorial Sloan Kettering Cancer Center and MD Anderson Cancer Center report MIAT dysregulation across glioma and leukemia datasets, implicating MIAT in cell proliferation and apoptosis pathways investigated by laboratories focusing on oncogenic lncRNAs.

Experimental Models and Methods

Functional dissection of MIAT has employed knockout and knockdown strategies in mouse models developed at institutions including the RIKEN Center and the Jackson Laboratory, as well as CRISPR interference and antisense oligonucleotide approaches implemented by groups at the University of California, Berkeley and the Broad Institute. In vitro work uses human induced pluripotent stem cell-derived neurons and retinal organoids produced by teams at the Rockefeller University and Stanford to study MIAT's role in differentiation and synaptogenesis. Biochemical characterization uses RNA immunoprecipitation, single-molecule FISH, and CLIP-seq methodologies established in labs at EMBL, Max Planck, and Harvard Medical School to map MIAT interactions and subnuclear localization.

Therapeutic Potential and Biomarker Research

MIAT is under investigation as a potential biomarker for cardiovascular and ocular disease in translational studies conducted by clinical research groups at Cleveland Clinic, Mayo Clinic, and University College London Hospitals. Therapeutic modulation using antisense oligonucleotides, gapmers, or small molecules targeting MIAT structure has been explored in preclinical studies by biotech firms and academic spinouts associated with Stanford and ETH Zurich. Ongoing multidisciplinary efforts involving regulatory agencies and clinical trial groups aim to establish whether MIAT-guided strategies can augment precision medicine pipelines pioneered by networks such as the All of Us Research Program and international consortia focused on noncoding RNA therapeutics.

Category:Long noncoding RNA