Interaction of mTOR and iNOS pathways in protection against Ischemia/Reperfusion injury

Area of Science:

• Neuroscience
• Pharmacology
• Cellular Biology

Background:

• Mammalian target of rapamycin (mTOR) signaling is crucial for cellular functions and intracellular events during ischemia/reperfusion (I/R) injury.
• Chronic morphine (CM) treatment enhances mTOR phosphorylation, suggesting a neuroprotective role against I/R injury.

Purpose of the Study:

• To investigate the interplay between mTOR and inducible nitric oxide synthase (iNOS) expression.
• To determine the neuroprotective effects of CM on hippocampal neurons against I/R injury in morphine-dependent mice.

Main Methods:

• Morphine dependence was induced in BALB/c mice over 5 days.
• Global brain ischemia was induced by bilateral common carotid artery occlusion for 30 minutes.
• The effects of CM and mTOR inhibitor (rapamycin) on iNOS expression, nitric oxide (NO) production, and malondialdehyde activity were assessed in hippocampal tissue.

Main Results:

• CM preconditioning attenuated iNOS expression, NO production, and malondialdehyde activity in hippocampal tissue following I/R injury.
• Pretreatment with rapamycin reversed these protective effects of CM.
• These findings indicate that CM exerts its effects via the mTOR signaling pathway.

Conclusions:

• CM preconditioning confers neuroprotection against I/R injury in the hippocampus.
• The mTOR signaling pathway is essential for mediating the effects of CM on iNOS expression and oxidative stress.
• Targeting the mTOR pathway may represent a therapeutic strategy for mitigating I/R injury.