HIF1α Attenuated the Lung Ischemia-Reperfusion Injury by Activating the miR-485/Notch1 Signalling

Area of Science:

• Cell Biology
• Molecular Biology
• Physiology

Background:

• Lung ischemia-reperfusion (I/R) injury is a significant clinical challenge after lung transplantation and cardiac surgery.
• Pulmonary microvascular endothelial cells (PMVECs) are central to I/R injury pathogenesis.
• Understanding protective mechanisms in PMVECs is crucial for developing therapeutic interventions.

Purpose of the Study:

• To investigate the role of hypoxia-inducible factor 1-alpha (HIF1α) in protecting PMVECs against I/R injury.
• To elucidate the involvement of Notch1 signaling and microRNA-485 (miR-485) in the HIF1α-mediated protective effects.
• To identify key molecular targets and pathways regulated by HIF1α in the context of I/R injury.

Main Methods:

• Utilized cell culture models of hypoxia/reoxygenation (H/R) in PMVECs.
• Employed gene overexpression and knockdown techniques for HIF1α, miR-485, and Numb.
• Assessed cell viability, apoptosis, mitophagy, and mitochondrial function.
• Analyzed Notch1 signaling pathway activation (Hes1 expression and promoter activity).
• Performed bioinformatic analysis and luciferase reporter assays to identify miR-485 targets.

Main Results:

• HIF1α overexpression enhanced PMVEC viability and reduced apoptosis under H/R conditions.
• HIF1α activated Notch1 signaling and alleviated H/R-induced mitophagy and mitochondrial dysfunction.
• HIF1α transcriptionally upregulated miR-485 expression.
• miR-485 overexpression rescued PMVEC function impaired by HIF1α inhibition and targeted Numb mRNA.

Conclusions:

• The HIF1α-miR-485-Numb axis plays a critical role in protecting PMVECs from I/R injury.
• Targeting this pathway presents a promising therapeutic strategy for mitigating lung I/R injury.
• Further research into this axis could lead to novel treatments for lung transplantation complications.