多层次线粒体晶体重塑将Opa1下调与老年心脏中OXPHOS容量减少联系在一起
Isidora Molina-Riquelme1, Gonzalo Barrientos1, Leonhard Breitsprecher2
1Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago de Chile 8331150, Chile.
概括
心脏衰老与线粒体功能障碍有关. 这项研究揭示了线粒体晶状体结构的变化,而不是蛋白质水平,损害心脏功能,作为早期衰老信号.
科学领域:
- 心血管生物学 心血管生物学
- 线粒体生物学 线粒体生物学
- 衰老研究研究 衰老研究
背景情况:
- 心血管疾病是导致死亡的主要原因,与衰老密切相关.
- 线粒体功能障碍是心血管衰老的一个关键特征.
- 心脏ATP的产生依赖于线粒体晶体内的氧化酸化 (OXPHOS).
研究的目的:
- 研究人类和老鼠心中的线粒体晶状体结构的与年龄相关的变化.
- 为了与线粒体功能和衰老相关联的结构晶状体变化.
- 为了识别心脏衰老的早期标志物.
主要方法:
- 使用了多个尺度的电子显微镜,包括传输电子显微镜 (TEM) 和串行块面扫描电子显微镜 (SBF-SEM).
- 采用电子断层扫描来分析晶状体的连接性和窗体化.
- 评估Opa1蛋白水平和最大的OXPHOS呼吸.
主要成果:
- 老人和老鼠的心脏显示了形密度和宽度的下降.
- 在老年小鼠中观察到形重塑,连接性减少和化增加.
- Opa1的下调与OXPHOS最大呼吸的减少相关.
- 这些结构变化独立于主要的OXPHOS蛋白质变化发生.
结论:
- 单单是线粒体晶状体结构的改变就会损害心脏氧化代谢.
- 晶状体的结构变化是心脏衰老的早期指标,在更广泛的线粒体形态变化之前.
- 向形结构可能为与年龄有关的心血管衰退提供治疗策略.
相关概念视频
Mitochondria
19.5K
Mitochondria are eukaryotic cellular organelles that are known to produce energy through a process called oxidative phosphorylation. Besides their primary function, mitochondria are involved in various cellular processes, including cell growth, differentiation, signaling, metabolism, and senescence. Age-related changes cause a decline in mitochondrial quality and integrity due to increased mitochondrial mutations and oxidative damage. Thus, aging can severely impact mitochondrial functions,...
19.5K
Mitochondrial Membranes
16.5K
A single mitochondrion is a bean-shaped organelle enclosed by a double-membrane system. The outer membrane of mitochondria is smooth and contains many porins - the integral membrane transporters. Porins enable free diffusion of ions and small uncharged molecules through the outer mitochondrial membrane but limit the transport of molecules larger than 5000 Daltons. Further, the outer mitochondrial membrane forms a unique structure called membrane contact sites with other subcellular organelles,...
16.5K
Electron Transport Chain: Complex I and II
18.3K
The mitochondrial electron transport chain (ETC) is the main energy generation system in the eukaryotic cells. However, mitochondria also produce cytotoxic reactive oxygen species (ROS) due to the large electron flow during oxidative phosphorylation. While Complex I is one of the primary sources of superoxide radicals, ROS production by Complex II is uncommon and may only be observed in cancer cells with mutated complexes.
ROS generation is regulated and maintained at moderate levels necessary...
ROS generation is regulated and maintained at moderate levels necessary...
18.3K
The Inner Mitochondrial Membrane
4.5K
The inner mitochondrial membrane is the primary site of ATP synthesis. The inner membrane domain that forms a smooth layer adjacent to the outer membrane is called the inner boundary membrane. This domain contains membrane transporters that drive metabolites in and out of the mitochondria. In contrast, the inner membrane network that invaginates into the matrix space is called the cristae membrane. This domain accounts for principle mitochondrial function as it accommodates the protein...
4.5K
The Supercomplexes in the Crista Membrane
2.9K
The mitochondrial cristae membrane is the primary site for the oxidative phosphorylation (OXPHOS) process of energy conversion mediated through respiratory complexes I to V. These complexes have been widely studied for decades, and it has been proven that they form supramolecular structures called respiratory supercomplexes (SC). These higher-order complexes may be crucial in maintaining the biochemical structure and improving the physiological activity of the individual complexes while...
2.9K
Translocation of Proteins into the Mitochondria
11.8K
Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
11.8K


