I-BIO 정기세미나 개최(2008.5.20)
2008-1학기 시스템생명공학부 정기세미나
♠ 제 목 : What is zinc doing in the brain?
♠ 연 사 : 고재영 교수 ( 울산대 의과대학/서울아산병원 신경과 )
♠ 일 시 : 2008년 5월 20일(화) 오후 4시 30분
♠ 장 소 : 지곡연구동 304호
Zinc is one of the most abundant transition metals in the brain. A substantial fraction (20 30 %) of brain zinc is located inside presynaptic vesicles of certain glutamatergic terminals in a free or loosely bound state. This vesicle zinc is released with neuronal activity or depolarization, probably serving physiologic functions such as modulation of synaptic transmission and plasticity.
However, with excess release, as may occur in a variety of pathologic conditions, presynaptic vesicle zinc may translocate to and accumulate in postsynaptic neurons, which events may contribute to selective neuronal cell death. Intracellular mechanisms of zinc neurotoxicity may include disturbances in energy metabolism, increases in oxidative stress, and activation of apoptosis cascades. Zinc inhibits glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and depletes nicotinamide adenine dinucleotide (NAD+) and adenosine triphosphate (ATP), partily via the PARP pathway. On the other hand, zinc activates protein kinase C (PKC), extracellular signal-regulated kinase (Erk-1/2), and NADPH oxidase; these events result in oxidative neuronal injury and lysosomal membrane permeabilization (LMP). Zinc can also trigger caspase activation and apoptosis via the p75NTRpathway. In addition to the neurotoxic effect, zinc may contribute to the pathogenesis of chronic neurodegenerative diseases. For example, in Alzheimer’s disease, mature amyloid plaques are found to contain high levels of zinc, suggesting the role of zinc in the process of plaque maturation. Moreover, deletion of synaptic zinc by knocking out ZnT3 gene results in markedly reduced amyloid plaque load in APP Tg2576 mice.
Although significantly more information is available now than 10 years ago, zinc neurobiology is still at its early stage. Further studies may be needed to comprehensively understand the role of brain zinc in physiology and pathology. .
Supported by NRL, Brain Frontier Program, and Star Faculty Program.
※ 문의처 : 신소재공학과 제정호 교수 ( T.279-2143 )
시스템생명공학부 행정실 ( T.279-8405~6 )