MicroRNA-210 Downregulates ISCU and Induces Mitochondrial Dysfunction and Neuronal Death in Neonatal Hypoxic-Ischemic...

Area of Science:

• Neuroscience
• Molecular Biology
• Biochemistry

Background:

• Neonatal hypoxic-ischemic (HI) brain injury leads to mortality and neurological deficits.
• Previous studies showed microRNA-210 (miR-210) increases post-HI and its inhibition is neuroprotective.
• The precise molecular mechanisms of miR-210's neuroprotective role in HI injury were unclear.

Purpose of the Study:

• To elucidate the molecular mechanisms by which miR-210 contributes to oxidative brain injury after neonatal HI.
• To investigate the role of iron-sulfur cluster assembly protein (ISCU) in miR-210-mediated neuroprotection.
• To determine if targeting miR-210-ISCU interaction can ameliorate HI-induced brain damage.

Main Methods:

• Utilized in vivo neonatal rat models and in vitro primary cortical neuron cultures.
• Employed oxygen-glucose deprivation (OGD) to mimic ischemic conditions.
• Assessed miR-210, ISCU levels, mitochondrial function, oxidative stress, and neuronal apoptosis.

Main Results:

• Neonatal HI and OGD increased miR-210, which downregulated ISCU, leading to mitochondrial dysfunction and oxidative stress.
• Inhibition of miR-210 protected against HI/OGD-induced neuronal injury, mitochondrial dysfunction, and oxidative stress by preserving ISCU.
• Silencing ISCU mimicked miR-210's detrimental effects, while ISCU knockdown counteracted miR-210 inhibition's neuroprotection.

Conclusions:

• Neonatal HI induces oxidative brain injury partly through miR-210-mediated downregulation of ISCU, causing mitochondrial dysfunction.
• Inhibition of miR-210 demonstrates neuroprotective effects by restoring ISCU levels and mitigating mitochondrial damage.
• Targeting the miR-210-ISCU pathway represents a potential therapeutic strategy for neonatal hypoxic-ischemic brain injury.