The effect of pyrroloquinoline quinone on apoptosis and autophagy in traumatic brain injury.

BACKGROUND:

Pyrroloquinoline quinoe is an anionic, water-soluble compound with antioxidant characteristic. The role of pyrroloquinoline quinoe in pharmacology and nutrition has attracted wide attention of researchers. Although a few experiments have confirmed that pyrroloquinoline quinoe plays an obvious effective role in neuroprotection. There are little reports about the effect of pyrroloquinoline quinoe in traumatic brain injury. Traumatic brain injury is one of the leading causes of adult disability and death in the world. So far, there are no effective treatment methods because its complex pathophysiology.

METHODS:

In the present study, a model of traumatic brain injury in rat was established to study the role of pyrroloquinoline quinoe in central nervous system injury.

RESULTS:

The results showed that the protein expression of cleaved-Caspase 3/Caspase 3 was increased after traumatic brain injury and treatment with 2mM pyrroloquinoline quinoe decreased the expression. Terminal-deoxynucleoitidyl transferase mediated nick end labeling(TUNEL) staining displayed that the TUNEL positive signals were up-regulated after traumatic brain injury and down-regulated after treatment with 2mM pyrroloquinoline quinoe. The protein expression of LC3Ⅱ/LC3Ⅰ or lysosome-associated membrane protein 2(LAMP2) was elevated after traumatic brain injury and reduced after administration with 2mM pyrroloquinoline quinoe. Transmission electron microscopy showed that the number of autophagosomes was increased markedly after traumatic brain injury and administration with 2mM pyrroloquinoline quinoe decreased it. Electroencephalogram indicated that pyrroloquinoline quinoe improved brain electrophysiological function after traumatic brain injury. The results of CCK-8 test showed that pyrroloquinoline quinone(PQQ) could increase the viability of primary astrocyte treated with Glutamate. Lactate dehydrogenase(LDH) assay demonstrated that PQQ decreased LDH content in primary astrocyte exposed to Glutamate.

CONCLUSION:

Pyrroloquinoline quinoe could play a neuroprotective role after traumatic brain injury in rat, which might be through inhibiting apoptosis and autophagy caused by traumatic brain injury.