• Asian-Australasian Journal of Animal Sciences
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• v.33 no.11
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• pp.1714-1724
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• 2020

Objective: MicroRNAs (miRNAs) are the most abundant small RNAs. Approximately 2,000 annotated miRNAs genes have been found to be differentially expressed in ovarian follicles during the follicular development (FD). Many miRNAs exert their regulatory effects on the apoptosis of follicular granulosa cells (FGCs) and FD. However, accurate roles and mechanism of miRNAs regulating apoptosis of FGCs remain undetermined. Methods: In this review, we summarized the regulatory role of each miRNA or miRNA cluster on FGCs apoptosis and FD on the bases of 41 academic articles retrieved from PubMed and web of science and other databases. Results: Total of 30 miRNAs and 4 miRNAs clusters in 41 articles were reviewed and summarized in the present article. Twenty nine documents indicated explicitly that 24 miRNAs and miRNAs clusters in 29 articles promoted or induced FGCs apoptosis through their distinctive target genes. The remaining 10 miRNAs and miRNAs of 12 articles inhibited FGCs apoptosis. MiRNAs exerted modulation actions by at least 77 signal pathways during FGCs apoptosis and FD. Conclusion: We concluded that miRNAs or miRNAs clusters could modulate the apoptosis of GCs (including follicular GCs, mural GCs and cumulus cells) by targeting their specific genes. A great majority of miRNAs show a promoting role on apoptosis of FGCs in mammals. But the accurate mechanism of miRNAs and miRNA clusters has not been well understood. It is necessary to ascertain clearly the role and mechanism of each miRNA or miRNA cluster in the future. Understanding precise functions and mechanisms of miRNAs in FGCs apoptosis and FD will be beneficial in developing new diagnostic and treatment strategies for treating infertility and ovarian diseases in humans and animals.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.10
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• pp.1371-1382
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• 2016

MicroRNAs (miRNAs) are short non-coding RNAs that post-transcriptionally regulate expression of mRNAs in many biological pathways. Liver plays an important role in the feed efficiency of animals and high and low efficient cattle demonstrated different gene expression profiles by microarray. Here we report comprehensive miRNAs profiles by next-gen deep sequencing in Angus cattle divergently selected for residual feed intake (RFI) and identify miRNAs related to feed efficiency in beef cattle. Two microRNA libraries were constructed from pooled RNA extracted from livers of low and high RFI cattle, and sequenced by Illumina genome analyser. In total, 23,628,103 high quality short sequence reads were obtained and more than half of these reads were matched to the bovine genome (UMD 3.1). We identified 305 known bovine miRNAs. Bta-miR-143, bta-miR-30, bta-miR-122, bta-miR-378, and bta-let-7 were the top five most abundant miRNAs families expressed in liver, representing more than 63% of expressed miRNAs. We also identified 52 homologous miRNAs and 10 novel putative bovine-specific miRNAs, based on precursor sequence and the secondary structure and utilizing the miRBase (v. 21). We compared the miRNAs profile between high and low RFI animals and ranked the most differentially expressed bovine known miRNAs. Bovine miR-143 was the most abundant miRNA in the bovine liver and comprised 20% of total expressed mapped miRNAs. The most highly expressed miRNA in liver of mice and humans, miR-122, was the third most abundant in our cattle liver samples. We also identified 10 putative novel bovine-specific miRNA candidates. Differentially expressed miRNAs between high and low RFI cattle were identified with 18 miRNAs being up-regulated and 7 other miRNAs down-regulated in low RFI cattle. Our study has identified comprehensive miRNAs expressed in bovine liver. Some of the expressed miRNAs are novel in cattle. The differentially expressed miRNAs between high and low RFI give some insights into liver miRNAs regulating physiological pathways underlying variation in this measure of feed efficiency in bovines.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.5637-5644
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• 2013

The definite molecular mechanisms underlying the genesis of nasopharyngeal carcinomas (NPCs) remain to be completely elucidated. miRNAs are small non-coding RNAs which are implicated in cell proliferation, apoptosis, and even carcinogenesis through negatively regulating gene expression post-transcriptionally. EBV was the first human virus found to express miRNAs. EBV-encoded BART-miRNAs and dysregulated cellular miRNAs are involved in carcinogenesis of NPC by interfering in the expression of viral and host cell genes related to immune responses and perturbing signal pathways of proliferation, apoptosis, invasion, metastasis and even radio-chemo-therapy sensitivity. Additional studies on the roles of EBV-encoded miRNAs and cellular miRNAs will provide new insights concerning the complicated gene regulated network and shed light on novel strategies for the diagnosis, therapy and prognosis of NPC.

• IMMUNE NETWORK
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• v.11 no.5
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• pp.227-244
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• 2011

MicroRNAs (miRNAs) are small noncoding RNA molecules that negatively regulate gene expression via degradation or translational repression of their target messenger RNAs (mRNAs). Recent studies have clearly demonstrated that miRNAs play critical roles in several biologic processes, including cell cycle, differentiation, cell development, cell growth, and apoptosis and that miRNAs are highly expressed in regulatory T (Treg) cells and a wide range of miRNAs are involved in the regulation of immunity and in the prevention of autoimmunity. It has been increasingly reported that miRNAs are associated with various human diseases like autoimmune disease, skin disease, neurological disease and psychiatric disease. Recently, the identification of miRNAs in skin has added a new dimension in the regulatory network and attracted significant interest in this novel layer of gene regulation. Although miRNA research in the field of dermatology is still relatively new, miRNAs have been the subject of much dermatological interest in skin morphogenesis and in regulating angiogenesis. In addition, miRNAs are moving rapidly center stage as key regulators of neuronal development and function in addition to important contributions to neurodegenerative disorder. Moreover, there is now compelling evidence that dysregulation of miRNA networks is implicated in the development and onset of human neruodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, Tourette's syndrome, Down syndrome, depression and schizophrenia. In this review, I briefly summarize the current studies about the roles of miRNAs in various autoimmune diseases, skin diseases, psychoneurological disorders and mental stress.

• Journal of Animal Science and Technology
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• v.64 no.2
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• pp.312-329
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• 2022

Feed cost is the main factor affecting the economic benefits of pig industry. Improving the feed efficiency (FE) can reduce the feed cost and improve the economic benefits of pig breeding enterprises. Liver is a complex metabolic organ which affects the distribution of nutrients and regulates the efficiency of energy conversion from nutrients to muscle or fat, thereby affecting feed efficiency. MicroRNAs (miRNAs) are small non-coding RNAs that can regulate feed efficiency through the modulation of gene expression at the post-transcriptional level. In this study, we analyzed miRNA profiling of liver tissues in High-FE and Low-FE pigs for the purpose of identifying key miRNAs related to feed efficiency. A total 212~221 annotated porcine miRNAs and 136~281 novel miRNAs were identified in the pig liver. Among them, 188 annotated miRNAs were co-expressed in High-FE and Low-FE pigs. The 14 miRNAs were significantly differentially expressed (DE) in the livers of high-FE pigs and low-FE pigs, of which 5 were downregulated and 9 were upregulated. Kyoto Encyclopedia of Genes and Genomes analysis of liver DE miRNAs in high-FE pigs and low-FE pigs indicated that the target genes of DE miRNAs were significantly enriched in insulin signaling pathway, Gonadotropin-releasing hormone signaling pathway, and mammalian target of rapamycin signaling pathway. To verify the reliability of sequencing results, 5 DE miRNAs were randomly selected for quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The qRT-PCR results of miRNAs were confirmed to be consistent with sequencing data. DE miRNA data indicated that liver-specific miRNAs synergistically acted with mRNAs to improve feed efficiency. The liver miRNAs expression analysis revealed the metabolic pathways by which the liver miRNAs regulate pig feed efficiency.

• Tuberculosis and Respiratory Diseases
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• v.77 no.2
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• pp.60-64
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• 2014

MicroRNAs (miRNAs) are a class of small noncoding RNAs that modulate target gene activity, and are aberrantly expressed in most types of cancer as well in lung cancer. A miRNA can potentially target a diverse set of mRNAs; further, it plays a critical role in lung tumorigenesis as well as affects patient outcome. Previous studies focused mainly on abnormal miRNAs expressions in lung cancer tissues. Interestingly, circulating miRNAs were identified in human plasma and serum in 2008. Since then, considerable effort has been directed to the study of circulating miRNAs as one of the biomarkers of lung cancer. miRNAs expression of tissues and blood in lung cancer patients is being analyzed by more researchers. Recently, to overcome the high false-positivity of low-dose chest computed tomography scan, miRNAs in lung cancer screening are being investigated. This article summarizes the recent researches regarding clinical applications of miRNAs in the diagnosis and management of lung cancer.

• IMMUNE NETWORK
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• v.11 no.6
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• pp.309-323
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• 2011

MicroRNAs (miRNAs) are a class of naturally occurring small non-coding RNAs of about 22 nucleotides that have recently emerged as important regulators of gene expression at the posttranscriptional level. Recent studies provided clear evidence that microRNAs are abundant in the lung, liver and kidney and modulate a diverse spectrum of their functions. Moreover, a large number of studies have reported links between alterations of miRNA homeostasis and pathological conditions such as infectious diseases, sickle cell disease and endometrium diseases as well as lung, liver and kidney diseases. As a consequence of extensive participation of miRNAs in normal functions, alteration and/or abnormalities in miRNAs should have importance in human diseases. Beside their important roles in patterning and development, miRNAs also orchestrated responses to pathogen infections. Particularly, emerging evidence indicates that viruses use their own miRNAs to manipulate both cellular and viral gene expression. Furthermore, viral infection can exert a profound impact on the host cellular miRNA expression profile, and several RNA viruses have been reported to interact directly with cellular miRNAs and/or to use these miRNAs to augment their replication potential. Here I briefly summarize the newly discovered roles of miRNAs in various human diseases including infectious diseases, sickle cell disease and enodmetrium diseases as well as lung, liver and kidney diseases.

• Molecules and Cells
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• v.38 no.10
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• pp.895-903
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• 2015

Non-coding microRNAs (miRNAs) regulate the translation of target messenger RNAs (mRNAs) involved in the growth and development of a variety of cells, including primordial germ cells (PGCs) which play an essential role in germ cell development. However, the target mRNAs and the regulatory networks influenced by miRNAs in PGCs remain unclear. Here, we demonstrate a novel miRNAs control PGC development through targeting mRNAs involved in various cellular pathways. We reveal the PGC-enriched expression patterns of nine miRNAs, including miR-10b, -18a, -93, -106b, -126-3p, -127, -181a, -181b, and -301, using miRNA expression analysis along with mRNA microarray analysis in PGCs, embryonic gonads, and postnatal testes. These miRNAs are highly expressed in PGCs, as demonstrated by Northern blotting, miRNA in situ hybridization assay, and miRNA qPCR analysis. This integrative study utilizing mRNA microarray analysis and miRNA target prediction demonstrates the regulatory networks through which these miRNAs regulate their potential target genes during PGC development. The elucidated networks of miRNAs disclose a coordinated molecular mechanism by which these miRNAs regulate distinct cellular pathways in PGCs that determine germ cell development.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.6
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• pp.757-766
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• 2019

Objective: MicroRNAs are a class of endogenous small regulatory RNAs that regulate cell proliferation, differentiation and apoptosis. Recent studies on miRNAs are mainly focused on mice, human and pig. However, the studies on miRNAs in skeletal muscle of sheep are not comprehensive. Methods: RNA-seq technology was used to perform genomic analysis of miRNAs in prenatal and postnatal skeletal muscle of sheep. Targeted genes were predicted using miRanda software and miRNA-mRNA interactions were verified by quantitative real-time polymerase chain reaction. To further investigate the function of miRNAs, candidate targeted genes were enriched for analysis using gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment. Results: The results showed total of 1,086 known miRNAs and 40 new candidate miRNAs were detected in prenatal and postnatal skeletal muscle of sheep. In addition, 345 miRNAs (151 up-regulated, 94 down-regulated) were differentially expressed. Moreover, miRanda software was performed to predict targeted genes of miRNAs, resulting in a total of 2,833 predicted targets, especially miR-381 which targeted multiple muscle-related mRNAs. Furthermore, GO and KEGG pathway analysis confirmed that targeted genes of miRNAs were involved in development of skeletal muscles. Conclusion: This study supplements the miRNA database of sheep, which provides valuable information for further study of the biological function of miRNAs in sheep skeletal muscle.

• Food Science of Animal Resources
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• v.35 no.4
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• pp.459-465
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• 2015

Bovine milk provides essential nutrients, including immunologically important molecules, as the primary source of nutrition to newborns. Recent studies showed that RNAs from bovine milk contain immune-related microRNAs (miRNA) that regulate various immune systems. To evaluate the biological and immunological activity of miRNAs from milk products, isolation methods need to be established. Six methods for extracting total RNAs from bovine colostrums were adopted to evaluate the isolating efficiency and expression of miRNAs. Total RNA from milk was presented in formulation of small RNAs, rather than ribosomal RNAs. Column-combined phenol isolating methods showed high recovery of total RNAs, especially the commercial columns for biofluid samples, which demonstrated outstanding efficiency for recovering miRNAs. We also evaluated the quantity of five immune-related miRNAs (miR-93, miR-106a, miR-155, miR-181a, miR-451) in milk processed by temperature treatments including low temperature for long time (LTLT, 63℃ for 30 min)-, high temperature for short time (HTST, 75℃ for 15 s)-, and ultra heat treatment (UHT, 120-130℃ for 0.5-4 s). All targeted miRNAs had significantly reduced levels in processed milks compared to colostrum and raw mature milk. Interestingly, the amount of immune-related miRNAs from HTST milk was more resistant than those of LTLT and UHT milks. Our present study examined defined methods of RNA isolation and quantification of immune-specific miRNAs from small volumes of milk for use in further analysis.