miR-766-5p Attenuates Cigarette Smoke-Induced COPD by Targeting MAPK1

Area of Science:

• Biochemistry
• Molecular Biology
• Pulmonology

Background:

• Chronic obstructive pulmonary disease (COPD) poses a significant health challenge, particularly in older adults, with early diagnosis being difficult.
• MicroRNA-766-5p (miR-766-5p) is known to be dysregulated in COPD, but its precise function and mechanisms are not fully understood.

Purpose of the Study:

• To investigate the diagnostic potential of miR-766-5p in COPD.
• To elucidate the protective mechanisms of miR-766-5p in airway epithelial cells, focusing on its interaction with MAPK1.

Main Methods:

• Serum samples from elderly COPD patients and healthy controls were analyzed for miR-766-5p expression.
• A cigarette smoke extract (CSE)-induced injury model in BEAS-2B cells was used to study the effects of altering miR-766-5p and MAPK1 expression.
• Cell viability, inflammatory markers, oxidative stress, and epithelial-mesenchymal transition (EMT) were assessed.
• A dual-luciferase reporter assay confirmed the direct targeting of MAPK1 by miR-766-5p.

Main Results:

• Serum miR-766-5p levels were significantly lower in COPD patients compared to controls and correlated positively with pulmonary function, indicating diagnostic value.
• Overexpression of miR-766-5p in vitro protected against CSE-induced airway epithelial cell injury, reducing inflammation, oxidative stress, and EMT.
• MAPK1 was identified as a direct target of miR-766-5p, and its overexpression reversed the protective effects of miR-766-5p.

Conclusions:

• miR-766-5p is a promising diagnostic biomarker for COPD due to its reduced levels in patients.
• miR-766-5p exerts protective effects on airway epithelial cells by targeting and inhibiting MAPK1, suggesting a novel therapeutic pathway.