新生大鼠缺氧缺血后的葡萄糖与中间代谢以及星形胶质细胞-神经元相互作用
Glucose and Intermediary Metabolism and Astrocyte-Neuron Interactions Following Neonatal Hypoxia-Ischemia in Rat.
作者信息
Brekke Eva, Berger Hester Rijkje, Widerøe Marius, Sonnewald Ursula, Morken Tora Sund
机构信息
Department of Neuroscience, Norwegian University of Science and Technology (NTNU), 7489, Trondheim, Norway.
Department of Neurology, Bodø Hospital, Bodø, Norway.
出版信息
Neurochem Res. 2017 Jan;42(1):115-132. doi: 10.1007/s11064-016-2149-9. Epub 2016 Dec 26.
Neonatal hypoxia-ischemia (HI) and the delayed injury cascade that follows involve excitotoxicity, oxidative stress and mitochondrial failure. The susceptibility to excitotoxicity of the neonatal brain may be related to the capacity of astrocytes for glutamate uptake. Furthermore, the neonatal brain is vulnerable to oxidative stress, and the pentose phosphate pathway (PPP) may be of particular importance for limiting this kind of injury. Also, in the neonatal brain, neurons depend upon de novo synthesis of neurotransmitters via pyruvate carboxylase in astrocytes to increase neurotransmitter pools during normal brain development. Several recent publications describing intermediary brain metabolism following neonatal HI have yielded interesting results: (1) Following HI there is a prolonged depression of mitochondrial metabolism in agreement with emerging evidence of mitochondria as vulnerable targets in the delayed injury cascade. (2) Astrocytes, like neurons, are metabolically impaired following HI, and the degree of astrocytic malfunction may be an indicator of the outcome following hypoxic and hypoxic-ischemic brain injury. (3) Glutamate transfer from neurons to astrocytes is not increased following neonatal HI, which may imply that astrocytes fail to upregulate glutamate uptake in response to the massive glutamate release during HI, thus contributing to excitotoxicity. (4) In the neonatal brain, the activity of the PPP is reduced following HI, which may add to the susceptibility of the neonatal brain to oxidative stress. The present review aims to discuss the metabolic temporal alterations observed in the neonatal brain following HI.
新生儿缺氧缺血(HI)及其后续的延迟性损伤级联反应涉及兴奋性毒性、氧化应激和线粒体功能障碍。新生儿脑对兴奋性毒性的易感性可能与星形胶质细胞摄取谷氨酸的能力有关。此外,新生儿脑易受氧化应激影响,而磷酸戊糖途径(PPP)对于限制这类损伤可能尤为重要。另外,在新生儿脑中,神经元在正常脑发育过程中依赖星形胶质细胞通过丙酮酸羧化酶从头合成神经递质来增加神经递质池。最近几篇描述新生儿HI后脑中间代谢的出版物得出了有趣的结果:(1)HI后线粒体代谢出现长时间抑制,这与线粒体作为延迟性损伤级联反应中易损靶点的新证据一致。(2)与神经元一样,HI后星形胶质细胞的代谢也受到损害,星形胶质细胞功能障碍的程度可能是缺氧和缺氧缺血性脑损伤后预后的一个指标。(3)新生儿HI后神经元向星形胶质细胞的谷氨酸转运并未增加,这可能意味着星形胶质细胞在HI期间未能对大量谷氨酸释放做出反应而上调谷氨酸摄取,从而导致兴奋性毒性。(4)在新生儿脑中,HI后PPP的活性降低,这可能增加了新生儿脑对氧化应激的易感性。本综述旨在讨论新生儿HI后脑代谢的时间变化。