MicroRNA-7: expression and function in brain physiological and pathological processes

Juanjuan Zhao,Mengmeng Guo,Guiyou Liang,Ya Zhou,Lin Xu,Dongxu Yue,Chao Chen

doi:10.1186/s13578-020-00436-w

Abstract

MicroRNAs (miRNAs) are a class of small non-coding RNAs that regulate gene expression at the post-transcriptional level and play critical roles in regulating physiological function, and are becoming worldwide research hot spot in brain development and diseases. However, the exact value of miRNAs in brain physiological and pathological processes remain to be fully elucidated, which is vital for the application of miRNAs as diagnostic, prognostic, and therapeutic biomarkers for brain diseases. MicroRNA-7 (miR-7), as a highly expressed miRNA molecule in the mammalian brain, is well documented to play a critical role in development of various diseases. Importantly, accumulating evidence has shown that miR-7 is involved in a range of developmental and pathological processes of brain. Expressively, miR-7, encoded by three genes located different chromosomes, is dominantly expressed in neurons with sensory or neurosecretory. Moreover, the expression of miR-7 is regulated at three levels including gene transcription, process of primary and precursor sequence and formation of mature sequence. Physiologically, miR-7 principally governs the physiological development of Pituitary gland, Optic nervous system and Cerebral cortex. Pathologically, miR-7 can regulate multiple genes thereby manipulating the process of various brain diseases including neurodegenerative diseases, neuroinflammation, and mental disorders and so on. These emerging studies have shown that miR-7, a representative member of miRNA family, might be a novel intrinsic regulatory molecule involved in the physiological and pathological process of brain. Therefore, in-depth studies on the role of miR-7 in brain physiology and pathology undoubtedly not only provide a light on the roles of miRNAs in brain development and diseases, but also are much helpful for ultimate development of therapeutic strategies against brain diseases. In this review, we provide an overview of current scientific knowledge regarding the expression and function of miR-7 in development and disease of brain and raise many issues involved in the relationship between miR-7 and brain physiological and pathological processes.

Highlights

MicroRNA-7, as a unique member of the miRNAs family, has a high degree of conserved mature sequences with a length of 21–23 nt in different species (Fig. 1)
MiR‐7 distribution in brain Many studies have shown that miR-7 and its precursors are expressed in the mammal lens [18], Nucleus accumbens (NACC) and suprachiasmatic nucleus [19] and neocortical and hippocampal regions [11]
Further studies have shown that low Cerebellar degeneration related protein 1 antisense transcription (CDR1as) level can lead to the increased expression of miR-7 which downregulates the activity of ubiquitin conjugating enzyme E2 A (UBE2A), thereby resulting in impaired clearing of toxic amyloid peptides from brain in Alzheimer’s disease (AD), suggesting that miR-7 may be a new target for AD treatment [36, 63]

Summary

Introduction

MicroRNA-7 (miR-7), as a unique member of the miRNAs family, has a high degree of conserved mature sequences with a length of 21–23 nt in different species (Fig. 1).

Results

Conclusion