| 摘要: | 粒線體自噬作用是細胞損傷調控機制之一，其作用為去除失去功能及多餘的粒線體，以利控制粒線體的數量及能量代謝的平衡。在粒線體大片段缺失而導致突變的皮膚纖維母細胞中，相關之粒線體清除機制顯得尤為重要，透過清除突變型的粒線體，使體內相關基因之表達保持平衡，可以減緩過多的代償作用或基因缺失所導致的細胞能量生成缺陷。由先前研究發現，粒線體衍胜? (mitochondrial- derived pepetide, MDP)之一的人類素 (Humanin) 為細胞保護和能量生成的調節訊息分子，人類素可經由細胞內和細胞外活化路徑，有效調節粒線體至細胞核逆行訊息，以此來應對嚴重的粒線體損傷和細胞壓力。本研究的研究主旨在探究人類素可否有效調控粒線體的自噬作用，以期加快清除體內突變之粒線體，使患者不會因過多突變型的粒線體堆積而導致相關疾病。本研究透過體外培養含粒線體基因斷損突變患者-Pearson症患者的初代纖維母細胞 (patient fibroblasts, PF) 以及與健康對照組 (normal fibroblasts, NF) 或是Detriol559 (Det) 人類表皮纖維母細胞株為實驗細胞模式，進行了解人類素 (Humanin)，對於粒線體突變型之皮膚纖維母細胞的影響。由先前的研究中發現，透過病患纖維母細胞與健康對照組之比較，人類素能有效降低因粒線體基因損害所導致的粒線體DNA拷貝數代償增加，以及降低粒線體DNA突變量。在本研究中，人類素顯著增加了病患纖維母細胞內的ATP含量，同時有效維持細胞內的膜電位水平，增加粒線體呼吸鏈複合體 (respiratory complex) 相關蛋白之表達，並經由 Parkin-PINK1 訊息路徑加速粒線體自噬作用 (mitophagy) 清除損傷粒線體，進而維持細胞之能量功能。本研究結果確認粒線體衍生?人類素可以增強粒線體自噬作用清除損害粒線體的相關分子機制，並希望做為開發未來治療粒線體損傷相關疾病的方法。
Mitophagy is one of the regulatory mechanisms of cell damage. Its function is to remove dysfunctional and redundant mitochondria, so as to control the number of mitochondria and the balance of energy metabolism. In skin fibroblasts that are mutated due to the loss of large mitochondrial fragments, the relevant mitochondrial clearance mechanism is particularly important. By clearing the mutant mitochondria, the expression of related genes in the body can be kept in balance without excessive. The compensatory effect or gene non-expression caused by the deletion, and previous studies have found that Humanin, one of the mitochondrial-derived peptides (MDP), acts as a signal for cellular protection and energy regulation in organisms, and can effectively regulate mitophagy, in order to speed up the removal of mutated mitochondria in the body, so that patients will not cause related diseases due to excessive accumulation of mutated mitochondria.
Study mitochondria by culturing primary fibroblasts patient fibroblasts (PF)with mitochondrial mutations in vitro and comparing them with healthy controls (normal fibroblast, NF) or Immortalised cell line Detriol559 (Det) that observed the treatment of mitochondrial derived peptide-Humanin, the effect on mitochondrial mutants. Humanin and SHLPs regulate cell survival and growth via distinct pathways. Humanin can effectively mediate the retrograde message through intracellular and extracellular activation and protection pathways to deal with severe mitochondrial damage and cellular stress. And in our previous studies, we knew that humanin can effectively reduce the compensatory increase in mitochondrial DNA copy number and decrease the mutate road in patient fibroblasts.
In this study, humanin increased the ATP level, and effectively maintained the membrane potential level in the patient's fibroblasts. Making the cells with normal mitochondrial function, less prone to apoptosis and accelerating damage to mitochondria body clearance, and increase the expression of mitochondria-related proteins to maintain the normal function of cells. The purpose of this study is to clarify the molecular mechanism of mitochondrial-derived peptides to clear damaged mitochondria, and hope to develop future treatments for mitochondrial damage diseases. |
