Abstract Background: Exosomes are nanosized extracellular vesicles secreted by multiple cells in the body, including those located in the respiratory tract and lungs. They are emerging as important inflammatory mediators and can release their contents, especially microRNAs (miRNAs), to both neighboring and distal cells. Mycoplasma gallisepticum (MG) can target host cell and cause chronic respiratory disease (CRD) in chickens. Although exosomal miRNAs have been demonstrated to produce an important effect on microbial pathogenesis and inflammatory response as crucial regulatory noncoding RNAs, the mechanism by which exosomal miRNAs regulate MG-induced inflammation remains to be elucidated. Methods: the expression of exosome-microRNA derived from MG-infected chicken type Ⅱ pneumocytes (CP-Ⅱ) was screened, and the target genes and function of differentially expressed miRNAs (DEGs) were predicted. To verify the inflammatory functions of exosomal gga-miR-451 via targeting YWHAZ, Western blot, ELISA, and RT-qPCR were used in this study. Results: A total of 722 miRNAs were identified from the two exosomal small RNA (sRNA) libraries, and 279 novel miRNAs were discovered; 30 miRNAs (9 up-regulated and 21 down-regulated) were significantly changed (P＜0.05). Function annotation analysis of DEGs showed that the target miRNAs were significantly enriched in treatment group, such as cell cycle, Toll-like receptor signaling pathway and MAPK signaling pathway, etc. The results have also confirmed that gga-miR-451-absent exosomes derived from MG-infected CP-Ⅱ cells increased inflammatory cytokine production in DF-1 (chicken embryo fibroblast) cells, and Wild Type CP-Ⅱ cells-derived-exosomes displayed protective effects. Conclusion: our work suggests that exosomes from MG-infected CP-Ⅱ cells alter the dynamics of the DF-1 cells, and may contribute to pathology of the MG infection via exosomal gga-miR-451 targeting YWHAZ involving in inflammation. This could potentially be used as a biomarker for diagnostics and treatment.
The objective of this study was to evaluate the effect of Allium mongolicum Regel ethanol extract (AME) on the concentration of three branched-chain fatty acids (BCFAs) related to flavor, fermentation parameters and the bacteria and their correlations in the rumen of lambs. A total of thirty 3-month-old male, Small-tailed Han sheep (33.60 ± 1.23 kg) were randomly distributed into 2 groups as follows: control group (CON) was fed a basal diet and AME group was fed a basal diet supplemented with 2.8 g⋅lamb-1⋅d-1A. mongolicum Regel ethanol extract. AME supplementation decreased (P = 0.022) 4-methyloctanoic acid (MOA) content and tended to lower (P = 0.055) 4-methylnonanoic acid (MNA) content in the rumen. Compared to CON group, the ruminal concentrations of valerate and isovalerate were higher (P = 0.046 and P = 0.024, respectively), and propionate was lower (P = 0.020) in the AME group. At the phylum level, the AME group had a lower abundance of Bacteroidetes (P = 0.014) and a higher abundance of Firmicutes (P = 0.020) than the CON group. At the genus level, the relative abundances of Prevotella (P = 0.001), Christensenellaceae_R-7_group (P = 0.003), Succiniclasticum (P = 0.004), and Selenomonas (P = 0.001) were significantly lower in the AME group than in the CON group, while the relative abundances of Ruminococcus (P < 0.001), Quinella (P = 0.013), and Lachnospiraceae_XPB1014_group (P = 0.001) were significantly higher. The relative abundances of Prevotella (P = 0.029, R = 0.685; P = 0.009, R = 0.770), Christensenellaceae_R-7_group (P = 0.019, R = 0.721; P = 0.029, R = 0.685), and Succiniclasticum (P = 0.002, R = 0.842; P = 0.001, R = 0.879) was positively correlated with MOA and MNA levels, and the relative abundance of Lachnospiraceae_XPB1014_group (P = 0.033, R = -0.673) was negatively correlated with MOA. The relative abundance of Christensenellaceae_R-7_group (P = 0.014, R = -0.744) and Prevotellaceae_UCG-003 (P = 0.023, R = -0.706) correlated negatively with the EOA content. In conclusion, these findings suggest that the AME affected the concentration of BCFAs, fermentation parameters and the rumen bacteria in the rumen of lambs.
Mycoplasma gallisepticum (MG), one of the most pathogenic Mycoplasma, has caused tremendous economic loss in the poultry industry. Recently, increasing evidence has suggested that micro ribonucleic acids (miRNAs) are involved in microbial pathogenesis. However, little is known about potential roles of miRNAs in MG infection of chicken. In the present study, using miRNA Solexa sequencing we have found that gga-miR-101-3p was up-regulated in the lungs of MG-infected chicken embryos. Moreover, gga-miR-101-3p regulated expression of the host enhancer of zeste homolog 2 (EZH2) through binding to the 3' un-translated region (3'-UTR) of EZH2 gene. Over-expression of gga-miR-101-3p significantly inhibited EZH2 expression and hence inhibited proliferation of chicken embryonic fibroblast (DF-1 cells) by blocking the G1-to-S phase transition. Similar results were obtained in MG-infected chicken embryos and DF-1 cells, where gga-miR-101-3p was significantly up-regulated, while EZH2 was significantly down-regulated. This study reveals that gga-miR-101-3p plays an important role in MG infection through regulation of EZH2 expression and provides a new insight into the mechanisms of MG pathogenesis.
Abstract Background Mycoplasma gallisepticum ( MG ) is one of the most important pathogens that causes chronic respiratory disease (CRD) in chickens. Exosomes secreted from cells have been well documented to deliver miRNAs to recipient cells to modulate cellular function. The purpose of this current study was to explore the functions of exosomal miR-181a-5p in MG infection and the underlying mechanisms. Results Here, we found that miR-181a-5p expression in vivo and in vitro was significantly upregulated after MG infection. Exosomes enriched in MG-infected chicken type-II pneumocytes (CP-II) could selectively load miR-181a-5p and transfer it into recipient DF-1 cells. PPM1B was further identified as the target gene of miR-181a-5p. Overexpression of miR-181a-5p and/or knockdown of PPM1B activated the TLR2-mediated MyD88/NF-κB signaling pathways, whereas inhibition of miR-181a-5p and the overexpression of PPM1B led to the opposite results. In addition, depressing miR-181a-5p significantly reduced the expression of tumor necrosis factors alpha (TNF-α) and interleukin-1β (IL-1β) by MG-induced. Upregulated miR-181a-5p promoted cell proliferation and cell cycle progression and inhibited apoptosis to resist MG infection. Moreover, overexpression of miR-181a-5p significantly depressed pMAG1.2 expression by directly inhibiting PPM1B. Conclusions Taken together, we conclude that the newly identified primary CP-II cells exosomal miR-181a-5p activates the TLR2-mediated MyD88/NF-κB pathway by directly targeting PPM1B to promote pro-inflammatory cytokines expression for defending against MG infection in recipient DF-1 cells.
Mycoplasma gallisepticum (MG) is the pathogen of chronic respiratory disease (CRD), hallmarked by vigorous inflammation in chickens, causing the poultry industry enormous losses. miRNAs have emerged as important regulators of animal diseases. Previous miRNA sequencing data has demonstrated that miR-130b-3p is up-regulated in MG-infected chicken embryo lungs. Therefore, we aimed to investigate the function of miR-130b-3p in MG infection of chickens. RT-qPCR results confirmed that miR-130b-3p was up-regulated both in MG-infected chicken embryo lungs and chicken embryonic fibroblast cells (DF-1 cells). Furthermore, functional studies showed that overexpression of miR-130b-3p promoted MG-infected DF-1 cell proliferation and cell cycle, whereas inhibition of miR-130b-3p weakened these cellular processes. Luciferase reporter assay combined with gene expression data supported that phosphatase and tensin homolog deleted on chromosome ten (PTEN) was a direct target of miR-130b-3p. Additionally, overexpression of miR-130b-3p resulted in up-regulations of phosphatidylinositol-3 kinase (PI3K), serine/threonine kinase (AKT), and nuclear factor-κB (NF-κB), whereas inhibition of miR-130b-3p led to the opposite results. Altogether, upon MG infection, up-regulation of miR-130b-3p activates the PI3K/AKT/NF-κB pathway, facilitates cell proliferation and cell cycle via down-regulating PTEN. This study helps to understand the mechanism of host response to MG infection.
Respiratory diseases represent a significant economic and health burden worldwide, affecting millions of individuals each year in both human and animal populations. MicroRNAs (miRNAs) play crucial roles in gene expression regulation and are involved in various physiological and pathological processes. Exosomal miRNAs and cellular miRNAs have been identified as key regulators of several immune respiratory diseases, such as chronic respiratory diseases (CRD) caused by Mycoplasma gallisepticum (MG), Mycoplasma pneumoniae pneumonia (MMP) caused by the bacterium Mycoplasma pneumoniae, coronavirus disease 2019 (COVID-19), chronic obstructive pulmonary disease (COPD), asthma, and acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Consequently, miRNAs seem to have the potential to serve as diagnostic biomarkers and therapeutic targets in respiratory diseases. In this review, we summarize the current understanding of the functional roles of miRNAs in the above several respiratory diseases and discuss the potential use of miRNAs as stable diagnostic biomarkers and therapeutic targets for several immune respiratory diseases, focusing on the identification of differentially expressed miRNAs and their targeting of various signaling pathways implicated in disease pathogenesis. Despite the progress made, unanswered questions and future research directions are discussed to facilitate personalized and targeted therapies for patients with these debilitating conditions.
Mongolian sheep are characteristically cold-tolerant. However, their cold adaptive processes, such as the physiological feedback adjustments that occur during the cold season, remain unexplored. Therefore, the present study aimed to evaluate the physiological adaptations of Mongolian sheep in cold plateau environments. A comparative analysis of the serum biochemical parameters, immune response, antioxidant capacity, and glucose and lipid metabolism of grazing Mongolian sheep in the cold and warm seasons was conducted. The results showed that in the cold season, the glucose and lipid metabolism and thermogenesis of the grazing Mongolian sheep were notably enhanced. Moreover, the immune responses were stimulated by increased levels of cytokines, such as IL-2, IL-1β, and IL-6, during the cold season. However, the antioxidant defense system was damaged; this damage was mainly characterized by decreased activity of antioxidant enzymes and an increased level of MDA during the cold season. Overall, glucose metabolism, lipid metabolism, thermogenesis, and immune responses were stimulated to meet the requirements of organismal metabolic regulation to enable grazing Mongolian sheep to physiologically adapt to cold climatic conditions.
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