miR-214-PTEN pathway is a potential mechanism for stress-induced immunosuppression affecting chicken immune response to avian influenza virus vaccine.

Stress-induced immunosuppression (SIIS) is one of common problems in the intensive poultry industry, affecting the effect of vaccine immunization and leading to high incidences of diseases. In this study, the expression characteristics and regulatory mechanisms of miR-214 in the processes of SIIS and its influence on the immune response to avian influenza virus (AIV) vaccine in chicken were explored. The qRT-PCR results showed that serum circulating miR-214 was significantly differentially expressed (especially on 2, 5, and 28 days post immunization (dpi)) in the processes, so had the potential as a molecular marker. MiR-214 expressions from multiple tissues were closely associated with the changes in circulating miR-214 expression levels. MiR-214-PTEN regulatory network was a potential key regulatory mechanism for the heart, bursa of Fabricius, and glandular stomach to participate in the process of SIIS affecting AIV immune response. This study can provide references for further understanding of stress affecting immune response.

MicroRNA and mRNA sequencing analyses reveal key hepatic metabolic and signaling pathways responsive to maternal undernutrition in full-term fetal pigs.

Maternal undernutrition is highly prevalent in developing countries, leading to severe fetus/infant mortality, intrauterine growth restriction, stunting, and severe wasting. However, the potential impairments of maternal undernutrition to metabolic pathways in offspring are not defined completely. In this study, 2 groups of pregnant domestic pigs received nutritionally balanced gestation diets with or without 50% feed intake restriction from 0 to 35 gestation days and 70% from 35 to 114 gestation days. Full-term fetuses were collected via C-section on day 113/114 of gestation. MicroRNA and mRNA deep sequencing were analyzed using the Illumina GAIIx system on fetal liver samples. The mRNA-miRNA correlation and associated signaling pathways were analyzed via CLC Genomics Workbench and Ingenuity Pathway Analysis Software. A total of 1189 and 34 differentially expressed mRNA and miRNAs were identified between full-nutrition (F) and restricted-nutrition (R) groups. The correlation analyses showed that metabolic and signaling pathways such as oxidative phosphorylation, death receptor signaling, neuroinflammation signaling pathway, and estrogen receptor signaling pathways were significantly modified, and the gene modifications in these pathways were associated with the miRNA changes induced by the maternal undernutrition. For example, the upregulated (P<.05) oxidative phosphorylation pathway in R group was validated using RT-qPCR, and the correlational analysis indicated that miR-221, 103, 107, 184, and 4497 correlate with their target genes NDUFA1, NDUFA11, NDUFB10 and NDUFS7 in this pathway. These results provide the framework for further understanding maternal malnutrition's negative impacts on hepatic metabolic pathways via miRNA-mRNA interactions in full-term fetal pigs.

MiR-375: A novel multifunctional regulator.

MiR-375, a primitively described beta cell-specific miRNA, is confirmed to function as multi-functional regulator in diverse typical cellular pathways according to the follow-up researches. Based on the existing studies, miR-375 can regulate many functional genes and ectopic expressions of miR-375 are usually associated with pathological changes, and its expression regulation mechanism is mainly related to promoter methylation or circRNA. In this review, the regulatory functions of miR-375 in immunity, such as its relevance with macrophages, T helper cells and autoimmune diseases were briefly discussed. Also, the functions of miR-375 involved in inflammation, development and virus replication were reviewed. Finally, the mechanisms and application prospects of miR-375 in cancers were analyzed. Studies show that the application of miR-375 as therapeutic target and biomarker has a broad developing space in future. We hope this paper can provide reference for its further study.

Immune function of miR-214 and its application prospects as molecular marker.

MicroRNAs are a class of evolutionary conserved non-coding small RNAs that play key regulatory roles at the post-transcriptional level. In recent years, studies have shown that miR-214 plays an important role in regulating several biological processes such as cell proliferation and differentiation, tumorigenesis, inflammation and immunity, and it has become a hotspot in the miRNA field. In this review, the regulatory functions of miR-214 in the proliferation, differentiation and functional activities of immune-related cells, such as dendritic cells, T cells and NK cells, were briefly reviewed. Also, the mechanisms of miR-214 involved in tumor immunity, inflammatory regulation and antivirus were discussed. Finally, the value and application prospects of miR-214 as a molecular marker in inflammation and tumor related diseases were analyzed briefly. We hope it can provide reference for further study on the mechanism and application of miR-214.

Potential role of miR-155-5p in fat deposition and skeletal muscle development of chicken.

miR-155 has multiple functions in many physiological and pathological processes. However, little is known about the expression characteristics of avian miR-155. In the present study, partial pri-miR-155 sequences were cloned from AA+ broiler, Sanhuang broiler and Hy-Line Brown layer, respectively. Stem-loop qRT-PCR was performed to detect the miR-155-5p spatiotemporal expression profiles of each chicken breed, and the target genes of miR-155-5p were predicted in Gene Oncology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The results showed that the partial pri-miR-155 sequences of different breeds of chicken were high conserved. The expression patterns of miR-155-5p between broiler and layer were basically similar, and miR-155-5p was expressed highly in immune related tissues (spleen, thymus and bursa). In the same old chicken (14 days old), miR-155-5p expression activity of fat tissue all had higher level in the three chicken breeds, but the expression activities in skeletal muscle of broilers were significantly lower than that of layer (P<0.05). In different development stages of Hy-Line Brown layer, miR-155-5p expression activities in skeletal muscle of 14-day-old and 10-month-old layers were significantly lower than that of 24-month-old layer (P<0.05). Fat related target genes (ACOX1, ACOT7, FADS1, SCD and HSD17B12) and skeletal muscle related target genes (CCNT2, DMD, CFL2, MAPK14, FLNB, ZBTB18 and CDK5) of miR-155-5p were predicted, respectively. The results indicate that miR-155-5p may be an important factor inhibiting the fat deposition and skeletal muscle development in chicken.

[Progress in microRNAs associated with major avian viruses].

Recently, avian viral diseases have become one of the main models to study mechanisms of viral infections and pathogenesis. The study of regulatory relationships and mechanisms between viruses and microRNAs has also become the focus. In this review, we briefly summarize the general situations of microRNAs encoded by avian herpesviruses. Also, we analyze the regulatory relationships between tumorigenicity of avian herpesviruses and microRNAs. Additionally, the possible applications for prevention and treatment of viral diseases (such as infectious bursal disease, avian influenza and avian leucosis) using the regulatory mechanisms of microRNAs are also discussed.

Cloning and expression pattern of akirin2 gene in broiler.

Akirin2 is an important nuclear factor which plays functions in innate immune response, myogenesis, muscle development, and carcinogenesis. In this study, akirin2 genes were cloned from 4-day-old Sanhuang and AA(+) broiler, and its expression patterns were analyzed by RT-PCR. The results showed that there were four SNPs in the 5'-terminal region of akirin2 coding sequences. Expression profile analysis showed that the akirin2 transcripts were constitutively expressed in 15 tissues tested, and similar expression patterns were found between the two breeds of broilers. In addition, one of the interesting findings was that the akirin2 gene is highly expressed in blood and lowly expressed in heart, respectively. These data can serve as a foundation for further studying functions of akirin2 gene.

[The function and application of animal microRNA-181].

MicroRNAs (miRNAs) are a type of non-coding RNAs which are short (17-25nt) and highly conservative in evolution. They can regulate gene expression by preventing target mRNA translation or inducing degradation via oligonucleotides complementary to target mRNA. Here, we briefly summarize the functions and regulatory mechanisms of microRNA-181 (miR-181) in cell proliferation, apoptosis and differentiation, and discuss the miR-181-mediated regulation of immune response in lymphocyte proliferation and differentiation, autoimmunity, inflammation and virus infection. Also, we analyze the functions of miR-181 in tumorigenesis, tumor development, diagnosis, treatment and prognosis. Finally, we discuss the application prospects of miR-181. The functional studies of miR-181 family members have important significance in understanding the mechanisms of biological events, pathogenesis of diseases, and finding new ways to diagnose and treat related diseases.

[Efficient packaging retrovirus and construction of transgenic chicken technical platform].

Transgenic chicken and oviduct bioreactor are growing to be one of the hotspot of scientific study in the field of biology. The most successful method of producing transgenic chicken is pseudotyped retrovirus vector system, but no one has reported the production of transgenic chicken by retrovirus system recently in our country. In order to accelerate our study in this field, we introduced the relevant technical methods such as packaging retrovirus and vesicular stomatitis virus G glycoprotein (VSV-G) pseudotyped retrovirus, optimizing the conditions of packaging retrovirus, concentrating VSV-G pseudotyped retrovirus, helper virus assays, and microinjection of retrovirus. Furthermore, we successfully conducted in vivo study for detecting the marker gene EGFP of chicken embryo as well as in vitro study for detecting that gene of chicken embryo myoblast (CFM), thus we have provided an applied technical platform for studies of transgenic chicken in the future.