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Published on: April 29, 2015
MiR-20a-5p Targeting the TGFBR2 Gene Regulates Inflammatory Response of Chicken Macrophages Infected with Avian
Xinqi Cao1, Jiayi Ge1, Yuyi Ma1
1College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China.
Abstract:
Avian pathogenic E. coli (APEC) causes localized and systemic infections and are a threat to human health. microRNAs (miRNAs) play critical roles in inflammation and immune regulation following pathogen invasion. However, the related regulatory mechanism remains unclear. This study aimed to elucidate the involvement of chicken microRNA-20a-5p (gga-miR-20a-5p) in host defense against APEC in chickens and the underlying mechanisms. We evaluated the expression levels of gga-miR-20a-5p in chicken tissues and cells and observed a significant decrease in expression following APEC infection. Dual luciferase reporter assays showed that gga-miR-20a-5p directly targeted transforming growth factor-beta receptor 2 (TGFBR2), specifically by binding to the 3'-untranslated region (3'UTR) of TGFBR2. Overexpression of gga-miR-20a-5p markedly reduced both the mRNA and protein levels of TGFBR2, whereas inhibition of gga-miR-20a-5p significantly increased expression. Mechanistic investigations revealed that overexpression of gga-miR-20a-5p also attenuated the expression levels of the pro-inflammatory cytokines IL8, TNFα, IL6, and IL1β, whereas inhibition of gga-miR-20a-5p had the opposite effects. Collectively, our findings suggest that gga-miR-20a-5p regulates the immune response during APEC infection by targeting TGFBR2, thereby suppressing inflammatory cytokine production. This study provides valuable insights into the role of gga-miR-20a-5p in the host defense against APEC.
Insights
Chicken microRNA-20a-5p (gga-miR-20a-5p) plays a key role in host defense against avian pathogenic E. coli (APEC). This microRNA targets TGFBR2, reducing inflammation and protecting chickens from APEC infection.
Area of Science:
- Immunology
- Molecular Biology
- Veterinary Science
Background:
- Avian pathogenic Escherichia coli (APEC) poses significant threats to poultry health and potentially human health.
- MicroRNAs (miRNAs) are crucial regulators of immune responses during pathogen invasion, but their specific roles in APEC infections are not fully understood.
Purpose of the Study:
- To investigate the role of chicken microRNA-20a-5p (gga-miR-20a-5p) in the host defense against APEC.
- To elucidate the molecular mechanisms underlying gga-miR-20a-5p's function in chickens infected with APEC.
Main Methods:
- Quantitative real-time PCR (qRT-PCR) to assess gga-miR-20a-5p expression levels in chicken tissues and cells post-APEC infection.
- Dual-luciferase reporter assays to confirm direct targeting of transforming growth factor-beta receptor 2 (TGFBR2) by gga-miR-20a-5p.
- Western blotting and qRT-PCR to evaluate the effects of gga-miR-20a-5p manipulation on TGFBR2 and pro-inflammatory cytokine expression (IL8, TNFα, IL6, IL1β).
Main Results:
- APEC infection led to a significant decrease in gga-miR-20a-5p expression in chicken tissues and cells.
- gga-miR-20a-5p was confirmed to directly target the 3'-untranslated region (3'UTR) of TGFBR2 mRNA.
- Overexpression of gga-miR-20a-5p reduced TGFBR2 expression and attenuated the production of pro-inflammatory cytokines, while inhibition had opposite effects.
Conclusions:
- gga-miR-20a-5p acts as a negative regulator of the inflammatory response during APEC infection by targeting TGFBR2.
- This microRNA plays a protective role in host defense against APEC by suppressing inflammatory cytokine production.
- The findings offer insights into the gga-miR-20a-5p-TGFBR2 pathway as a potential target for managing APEC infections in poultry.
