脳のIRS2信号は,寿命と栄養素の恒常性を調整する
Akiko Taguchi1, Lynn M Wartschow, Morris F White
1Howard Hughes Medical Institute, Division of Endocrinology, Children's Hospital Boston, Harvard Medical School, Boston, MA 02115, USA.
まとめ
インスリン受容体基板-2 (Irs2) のシグナル伝達をマウスで,特に脳で減少させることで,寿命が最大18%延長されました. この介入により,老齢マウスの代謝が改善され,酸化ストレスが軽減されました.
科学分野:
- 老化に関する研究.
- メタボリック経路は
- 神経内分泌学の神経内分泌学
背景:
- インスリンのようなシグナル伝達の減少は,C. elegansやDrosophila. のようなモデル生物の寿命の延長と関連しています.
- 哺乳類の老化と代謝におけるインスリンシグナル伝達の役割を理解することは,介入の開発に不可欠です.
研究 の 目的:
- インスリン受容体基板-2 (Irs2) 信号の減少がマウスの寿命と代謝健康に与える影響を調査する.
- Irs2シグナル伝達の脳特異的な減少が寿命を延長し,代謝パラメータを改善できるかどうかを判断する.
主な方法:
- 減少したIrs2シグナルを送るマウスを生成し,全局的に,特に脳にシグナルを送る.
- 評価された寿命,体重,インスリンレベル,グルコース耐性,身体活動,酸化ストレスマーカー (スーパーオキシドディスミュータゼ-2) を高齢マウスで測定した.
- 食事中に分析された代謝パラメータと下垂体機能.
主要な成果:
- 身体全体および脳特異のIrs2シグナル伝達の減少は,マウスの寿命を最大18%延長しました.
- 22ヶ月の脳特異的なIrs2ノックアウトマウスは,肥満,高インスリン血症,およびグルコース不耐症でしたが,活性化とグルコース酸化が増加しました.
- ヒポタラミック・スーパーオキシド・ディスミュータゼ-2レベルは,脳特異的なIrs2ノックアウトマウスでの食事中に安定したままでした.
結論:
- 老化する脳におけるIrs2シグナリングの低下は,肥満やインスリン抵抗性のある個人にさえも,より健康的な代謝を促進し,寿命を延ばすことができます.
- 脳内のIrs2シグナリングをターゲットにすることは,年齢に関連する代謝低下と酸化ストレスを軽減するための実行可能な戦略である可能性があります.
- 減少したIrs2シグナリングは,代謝機能を改善し,食事による酸化ストレスを軽減することにより,健康的な老化に寄与します.
さらに関連する動画
関連する概念動画
Regulation of the Unfolded Protein Response
Inositol-requiring kinase one or IRE1 is the most conserved eukaryotic unfolded protein response (UPR) receptor. It is a type I transmembrane protein kinase receptor with a distinctive site-specific RNase activity. As the binding mechanics of the misfolded proteins with the N-terminal domain of IRE-1 are unclear, three binding models — direct, indirect, and allosteric -- are proposed for receptor activation. Nevertheless, it is known that once a misfolded protein associates with IRE1, it...
EPS and iPS Cells in Disease Research
Embryonic and induced pluripotent stem cells are excellent models for disease research because of their ability to self-renew and differentiate into most cell types. Somatic cells from a patient are isolated and reprogrammed into induced pluripotent stem cells or iPSCs. These iPSCs are later differentiated into the desired cell type, which mirrors the diseased cell of the patient. In this way, disease models have been created for investigating diseases such as Down syndrome, type I diabetes,...
Neurogenesis and Regeneration of Nervous Tissue
In the CNS, neurogenesis, the birth of new neurons from stem cells, is limited to the hippocampus in adults. In other regions of the brain and spinal cord, neurogenesis is almost non-existent due to inhibitory influences from neuroglia, especially oligodendrocytes, and the absence of growth-stimulating cues. The myelin produced by oligodendrocytes in the CNS inhibits neuronal regeneration. Furthermore, astrocytes proliferate rapidly after neuronal damage, forming scar tissue that physically...
Functional Brain Systems: Reticular Formation
The reticular formation is a complex network of gray and white matter located within the brainstem extending from the medulla to the midbrain.
Within the reticular formation, there are several distinct nuclei that can be classified into three broad categories. The Raphe nuclei are located along the midline of the brainstem. They are primarily known for their role in synthesizing and releasing serotonin, a neurotransmitter involved in regulating mood, appetite, sleep, and circadian rhythms. The...
Within the reticular formation, there are several distinct nuclei that can be classified into three broad categories. The Raphe nuclei are located along the midline of the brainstem. They are primarily known for their role in synthesizing and releasing serotonin, a neurotransmitter involved in regulating mood, appetite, sleep, and circadian rhythms. The...
Regulation of Food Intake
Short-term regulation of food intake primarily involves neural signals from the gastrointestinal (GI) tract, blood nutrient levels, and GI tract hormones. Communication between the gut and brain via vagal nerve fibers plays a significant role in evaluating the contents of the gut. Clinical studies have shown that protein ingestion produces a more prolonged response in these nerve fibers compared to an equivalent amount of glucose. Additionally, the activation of stretch receptors caused by GI...
Gut-Brain Axis
The gut–brain axis is a bidirectional communication system that connects the gastrointestinal tract and the brain. This interaction is mediated through multiple pathways, including the vagus nerve, hormonal signals, immune responses, and chemical messengers produced by gut microbes.Microbial Contributions to Brain FunctionGut microbiota contributes significantly to brain function by producing neuroactive compounds. These include neuroactive compounds that influence neurotransmitters such as...


