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circAtp9b knockdown alleviates LPS-caused inflammation provided that microRNA-27a is upregulated
Jianwei Sun1, Xijuan Wang1, Dandan Wang1
1Neonatal Intensive Care Unit, Henan Provincial People's Hospital, Zhengzhou 450003, Henan, China.
Background:
The etiology of pneumonia is associated with gram-negative bacteria in malnourished children. To anatomize the molecular mechanisms, we focused on the modulatory function of circular RNA-Atp9b (circAtp9b) on inflammation in which microRNA-27a (miR-27a) might be implicated.
Methods:
MRC-5 cells were stimulated by lipopolysaccharide (LPS) to exhibit inflammatory lesions assessed by viability and apoptosis as well as the cleavage of caspase-3, production of interleukin-6 and tumor necrosis factor alpha, and generation of reactive oxygen species (ROS). circAtp9b and miR-27a were quantified by qRT-PCR. circAtp9b- or miR-27a-silenced MRC-5 cells were established to study their roles in inflammation. Moreover, the change of NF-κB and JNK pathways was monitored.
Results:
LPS was observed to induce adverse inflammatory injuries by repressing viability and fortified apoptosis with cleavage of caspase-3, production of cytokines, formation of ROS and abundance of circAtp9b. The results suggested circAtp9b silence prevented MRC-5 cells from LPS-elicited insults, which was accompanied by blockage of NF-κB and JNK. circAtp9b silence restored miR-27a which was repressed by LPS. miR-27a knockdown abrogated the protective capacities of circAtp9b silence with activation of NF-κB and JNK in response to LPS.
Conclusion:
LPS triggered adverse inflammation response by elevating the biogenesis of circAtp9b which caused a repressive role in miR-27a expression.
Insights
Circular RNA-Atp9b (circAtp9b) exacerbates inflammation by suppressing microRNA-27a (miR-27a) in response to lipopolysaccharide (LPS). Silencing circAtp9b protects against LPS-induced inflammation by restoring miR-27a levels.
Area of Science:
- Molecular Biology
- Cellular Biology
- Immunology
Background:
- Pneumonia etiology in malnourished children linked to gram-negative bacteria.
- Investigating molecular mechanisms of inflammation involving circular RNA-Atp9b (circAtp9b) and microRNA-27a (miR-27a).
Purpose of the Study:
- To elucidate the modulatory role of circAtp9b in lipopolysaccharide (LPS)-induced inflammation.
- To determine the involvement of miR-27a in the circAtp9b-mediated inflammatory response.
Main Methods:
- MRC-5 cells stimulated with LPS to induce inflammatory lesions.
- Assessed cell viability, apoptosis, caspase-3 cleavage, cytokine production (IL-6, TNF-α), and ROS generation.
- Quantified circAtp9b and miR-27a via qRT-PCR; utilized silenced cell lines to study inflammatory roles.
- Monitored NF-κB and JNK pathway activation.
Main Results:
- LPS induced inflammation, decreasing viability, increasing apoptosis, cytokine production, ROS, and circAtp9b abundance.
- circAtp9b silencing protected cells from LPS insults, inhibiting NF-κB and JNK pathways.
- circAtp9b silencing restored LPS-repressed miR-27a; miR-27a knockdown abolished protective effects, activating NF-κB and JNK.
Conclusions:
- LPS triggers inflammation by upregulating circAtp9b biogenesis.
- circAtp9b exerts a repressive effect on miR-27a expression during LPS-induced inflammation.
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