요약: 일단의 과학자들이 신경세포들이 어떻게 뇌의 성장 과정 동안에 낮은 에너지 환경에 적응하는지를 발견했다. 그들의 연구는 언젠가 알츠하이머병과 파킨슨병과 같은 신경병성 질환들과 신경 세포 손상을 위한 치료를 찾는 것을 도울지도 모른다.
그림. 미토콘드리아(Mitochondria)는 생명을 유지하기 위해서 몸이 필요로 하는 에너지의 90퍼센트 이상을 만드는 일을 책임진다. ATP 에너지는 미토콘드리아가 포도당과 산소를 물과 이산화탄소로 바꿀 때 만들어진다. ATP가 어떻게 만들어지고 복잡한 뉴런 수지상 돌기로 전달되는지는 수수께끼이다.
일본에 있는 교토대(Kyoto University)의 통합 세포-물질 과학연구소(Institute for Integrated Cell-Material Sciences (iCeMS))의 과학자들이 뇌의 성장 과정 동안에 신경 세포들이 어떻게 낮은 에너지 환경에 적응하는지를 밝혔다. Journal of Neuroscience에 실린 그들의 연구는 언젠가 알츠하이머병과 파킨슨병과 같은 신경병성 질환들과 신경세포 손상을 위한 치료를 찾는 것을 도울지도 모른다.
뇌에 있는 뉴런은 높은 부피와 표면적으로 확장하는 복잡한 수지상 돌기 때문에 매우 높은 에너지 수요를 가진다. 또한 뉴런이 조직에 혈액 공급을 제한했을 때 처음으로 죽어서, 세포 대사를 위해서 필요한 산소와 포도당의 부족을 유래하는 것이 알려져 있다. 그러나 –이른바 세포의 “발전소”인—미토콘드리아가 제때에 전달되지 않아서 에너지 분토에 지연이 발생하여, 다양한 신경병성 질환들로 이어질지도 모르는, 발달 중인 뇌에서 낮은 에너지 수준의 환경에 세포들이 어떻게 적응하는지에 대해서는 거의 알려져 있지 않다.
그 수수께끼를 밝히기 위해서, 연구팀은 일주일에 걸쳐서 살아있는, 자라고 있는 신경 세포에서 미토콘드리아와 에너지 소비를 연구했다. “만약 뉴런이 낮은 ATP 에너지 수준에서 자라려고 한다면, 변형되고 심지어는 세포의 생명을 위태롭게 할 수도 있을 것”이라고 그 연구에 관여한 Kansai Fukumitsu가 말했다. “세포의 뿌리에 있는 단일 미토콘드리아는 신경의 끝에 에너지를 공급하기에 충분하지 않기 때문에 세포는 미토콘드리아를 그것의 가장 바깥 가지에 분포시켜서 에너지가 부족한 곳에 동력을 전달한다”고 Fukumitsu가 설명했다.
ATP 에너지 농도가 낮은 부위에서, 화학적 변화들은 분자 단백질들에 의해서 일어나고, 이것은 수지상 돌기가 더 자라는 것을 멈춘다. “우리는 공동으로 효소들을 만들어서 세포 생존을 위해서 절박하게 필요한 에너지 분자들을 할당하는 두 가지 단백질 분자들을 발견했다”고 iCeMS에서 나온 연구의 주조사자인 Mineko Kengaku는 말했다.
미래에, Kengaku와 그녀의 공동저자들은 에너지 부족 상태에서 신경 세포 대사를 정확히 알아냄으로써 치유불가능한 질병들을 위한 치료법을 상상하고 있다. “만약 우리가 건강하지 않은 뉴런에 대해서 더 잘 이해할 수 있다면, 우리는 그것들에 의해서 발생하는 병적 이상을 치유하기 위한 방법을 찾을지도 모른다”고 연구팀은 말했다.
Journal Reference: K. Fukumitsu, K. Fujishima, A. Yoshimura, Y. K. Wu, J. Heuser, M. Kengaku.Synergistic Action of Dendritic Mitochondria and Creatine Kinase Maintains ATP Homeostasis and Actin Dynamics in Growing Neuronal Dendrites.Journal of Neuroscience, 2015; 35 (14): 5707 DOI: 10.1523/JNEUROSCI.4115-14.2015
Mapping energy metabolism of growing nerve cells to better understand neuronal disorders
Date:April 10, 2015
Source: Institute for Integrated Cell-Material Sciences, Kyoto University
Summary:A group of scientists has discovered how nerve cells adjust to low energy environments during the brain's growth process. Their study may one day help find treatments for nerve cell damage and neurodegenerative disorders such as Alzheimer's and Parkinson's diseases.Share This
Mitochondria are responsible for creating more than 90 percent of the energy needed by the body to sustain life and support growth. ATP energy is produced when the mitochondria transfers glucose and oxygen into water and carbon dioxide. How ATP is produced and delivered to intricate neuronal dendrites has been a mystery.
Credit: Mineko Kengaku, Kyoto University's Institute for Integrated Cell-Material Sciences (iCeMS)[Click to enlarge image] Mitochondria are responsible for creating more than 90 percent of the energy needed by the body to sustain life and support growth. ATP energy is produced when the mitochondria transfers glucose and oxygen into water and carbon dioxide. How ATP is produced and delivered to intricate neuronal dendrites has been a mystery.Credit: Mineko Kengaku, Kyoto University's Institute for Integrated Cell-Material Sciences (iCeMS)
Scientists from Kyoto University's Institute for Integrated Cell-Material Sciences (iCeMS) in Japan have have discovered how nerve cells adjust to low energy environments during the brain's growth process. Their study, published in the Journal of Neuroscience, may one day help find treatments for nerve cell damage and neurodegenerative disorders such as Alzheimer's and Parkinson's diseases.
Neurons in the brain have extraordinarily high energy demands due to its complex dendrites that expand to high volume and surface areas. It is also known that neurons are the first to die from restriction of blood supply to tissues, causing a shortage of oxygen and glucose needed for cellular metabolism. Little was known, however, on how cells adjust to low energy level environments in the developing brain, when mitochondria--the so-called "power plant" of the cell--do not get delivered on time, and a lag in the energy distribution occurs, which may lead to a variety of neurodegenerative disorders.
To unlock the mystery, the research team studied mitochondria and energy consumption in a live, growing nerve cell over the course of a week.
"If neurons try to grow in low ATP energy levels, they could end up deformed, and even worse, put the life of the cell itself at stake," said Kansai Fukumitsu, who was involved in the study. "Since a single mitochondria in the root of the cell is not enough to supply energy to the nerve ends, the cell distributes mitochondria to its most outer branches to deliver power where energy levels are scarce."
In areas of low ATP energy concentrations, chemical changes were brought by molecular proteins, which stopped the dendrites from growing further.
"We found two protein molecules that synergistically produced enzymes to allocate energy molecules where it is direly needed for cellular survival," says Mineko Kengaku, the principal investigator of the study from iCeMS.
In the future, Kengaku and her co-authors envision treatments for incurable diseases by mapping the nerve cell metabolism in an energy-deprived state. "If we can get a better understanding of an unhealthy neuron, we may someday find ways to cure pathologies caused by them."
Mapping energy metabolism of growing nerve cells to better understand neuronal disorders
Publication InformationRelated LinksApril 8, 2015
Kyoto, Japan - Scientists from Kyoto University's Institute for Integrated Cell-Material Sciences (iCeMS) in Japan have discovered how nerve cells adjust to low energy environments during the brain's growth process. Their study, published in the Journal of Neuroscience, may one day help find treatments for nerve cell damage and neurodegenerative disorders such as Alzheimer's and Parkinson's diseases.
Neurons in the brain have extraordinarily high energy demands due to its complex dendrites that expand to high volume and surface areas. It is also known that neurons are the first to die from restriction of blood supply to tissues, causing a shortage of oxygen and glucose needed for cellular metabolism. Little was known, however, on how cells adjust to low energy level environments in the developing brain, when mitochondria--the so-called "power plant" of the cell--do not get delivered on time, and a lag in the energy distribution occurs, which may lead to a variety of neurodegenerative disorders.
To unlock the mystery, the team studied mitochondria and energy consumption in a live, growing nerve cell over the course of a week.
"If neurons try to grow in low ATP energy levels, they could end up deformed, and even worse, put the life of the cell itself at stake," said Kansai Fukumitsu, who was involved in the study. "Since a single mitochondria in the root of the cell is not enough to supply energy to the nerve ends, the cell distributes mitochondria to its most outer branches to deliver power where energy levels are scarce."
In areas of low ATP energy concentrations, chemical changes were brought by molecular proteins, which stopped the dendrites from growing further.
"We found two protein molecules that synergistically produced enzymes to allocate energy molecules where it is direly needed for cellular survival," says Mineko Kengaku, the principal investigator of the study from iCeMS.
In the future, Kengaku and her co-authors envision treatments for incurable diseases by mapping the nerve cell metabolism in an energy-deprived state. "If we can get a better understanding of an unhealthy neuron, we may someday find ways to cure pathologies caused by them."
Mitochondria produce energy that cells need in order to function. ATP energy is produced when the mitochondria transfers glucose and oxygen into water and carbon dioxide. How ATP is produced and delivered to intricate neuronal dendrites has been a mystery.
