Neuroprotective Effects of Geneticin (G418) via Apoptosis
Hypoxic-ischemic (H-I) brain injury during the perinatal period remains the single major cause of acute mortality and chronic disability in newborn infants, leading to permanent neurodevelopmental sequelae.
This study investigated a neuroprotective effect of geneticin (also known as G418 Sulfate) through anti-apoptosis using in vitro cell culture model of anoxia and in vivo animal model of perinatal H-I brain injury. Apoptosis was identified using morphologic analysis by TUNEL assay and immunohistochemistry for caspase-3, and cytologic analysis by Western blot and real-time PCR for bax, bcl-2, and caspase-3.
PURPOSE: Some antibiotics were known to exert neuroprotective effects in the animal model of hypoxic-ischemic (H-I) brain injury, but the mechanism is still unclear. A recent study reported that geneticin (G418), an aminoglycoside antibiotic, increased survival of human breast cancer cells by suppressing apoptosis. We investigated the neuroprotective effects of systemically administrated geneticin via anti-apoptosis following the H-I brain injury.
METHODS: Seven-day-old Sprague-Dawley rat pups were subjected to unilateral (left) common carotid artery occlusion followed by 2.5 hours of hypoxic exposure and the cortical cell culture of rat brain was done under a hypoxic incubator. Apoptosis was measured in the injured hemispheres 7 days after H-I insult and in the injured cells from hypoxic chamber using morphologic analysis by Terminal dUTP Nick-end Labeling(TUNEL) assay and immunohistochemistry for caspase-3, and cytologic analysis by western blot and real time PCR for bax, bcl-2, and caspase-3.
RESULTS: The gross appearance and hematoxylin and eosin stain revealed increased brain volume in the geneticin-treated animal model of perinatal H-I brain injury. The TUNEL assay revealed decreased apoptotic cells after administration of geneticin in the cell culture model of anoxia. Immunohistochemistry showed decreased caspase-3 expression in geneticin-treated cortical cell culture. Western blot and real-time PCR showed decreased caspase-3 expression and decreased ratio of Bax/Bcl-2 expression in geneticin-treated animal model.
CONCLUSION: Geneticin appears to exert a neuroprotective effect against perinatal H-I brain injury at least via anti-apoptosis. However, more experiments are needed in order to demonstrate the usefulness of this antibiotic as a preventive and rescue treatment for H-I brain injuries of neonatal brain.
G-418 Sulfate Salt (Geneticin) is an aminoglycoside antibiotic that is synthesized from Micromonospora rhodorangea and functions by causing a chain of nonsense mutations during translation.
Due to translation G-418 inhibited polypeptide synthesis and protein elongation. G-418 binds to the 80S subunit of the ribosome by blocking the elongation phase of protein synthesis, both in prokaryotic and eukaryotic cells. It also shows activity against protozoa, cecal amoebiasis, and helminthes.
- Ju, Mi, et al. "Neuroprotective effects of geneticin (G418) via apoptosis in perinatal hypoxic-ischemic brain injury." Korean journal of pediatrics 51.2 (2008): 170-180.