Depletion of PINK1 affects mitochondrial metabolism, calcium homeostasis and energy maintenance
Depletion of PINK1 affects mitochondrial metabolism, calcium homeostasis and energy maintenance
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DOI：
10.1242/jcs.078303
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发表时间：
2011-04-01
影响因子：
4
通讯作者：
Baekelandt, Veerle
中科院分区：
文献类型：
--
作者：
Heeman, Bavo;Van den Haute, Chris;Baekelandt, Veerle
编码线粒体PTEN诱导的推定激酶1（PINK1）的基因的功能缺失突变是早发性家族性帕金森病（PD）的主要原因。最近的研究强调了PINK1在通过线粒体自噬清除去极化线粒体中的重要功能。然而，PINK1在生理条件下线粒体和细胞功能中的作用仍然不完全清楚。在这里，我们研究线粒体和细胞钙（Ca2+）稳态PINK1敲除和PINK1敲除小鼠细胞，无论是在基础代谢条件下和生理刺激后，使用无偏自动活单细胞成像结合细胞器特异性荧光探针。我们的数据表明，PINK1的耗竭诱导线粒体网络的适度碎片化，线粒体膜去极化和活性氧的产生增加。这导致在生理刺激后线粒体对Ca2+的摄取减少。因此，具有PINK1敲低或敲除的细胞显示受损的线粒体ATP合成，其在ATP需求增加的条件下加剧，从而影响胞质Ca 2+挤出。通过体内生物发光成像，在PINK1基因敲除小鼠的大脑中证实了能量维持的损伤。我们的研究结果表明PINK1在生理条件下调节线粒体稳态和能量代谢中起着关键作用。
Loss-of-function mutations in the gene encoding the mitochondrial PTEN-induced putative kinase 1 (PINK1) are a major cause of early-onset familial Parkinson's disease (PD). Recent studies have highlighted an important function for PINK1 in clearing depolarized mitochondria by mitophagy. However, the role of PINK1 in mitochondrial and cellular functioning in physiological conditions is still incompletely understood. Here, we investigate mitochondrial and cellular calcium (Ca2+) homeostasis in PINK1-knockdown and PINK1-knockout mouse cells, both in basal metabolic conditions and after physiological stimulation, using unbiased automated live single-cell imaging in combination with organelle-specific fluorescent probes. Our data reveal that depletion of PINK1 induces moderate fragmentation of the mitochondrial network, mitochondrial membrane depolarization and increased production of reactive oxygen species. This results in reduced uptake of Ca2+ by mitochondria after physiological stimulation. As a consequence, cells with knockdown or knockout of PINK1 display impaired mitochondrial ATP synthesis, which is exacerbated under conditions of increased ATP demand, thereby affecting cytosolic Ca2+ extrusion. The impairment in energy maintenance was confirmed in the brain of PINK1-knockout mice by in vivo bioluminescence imaging. Our findings demonstrate a key role for PINK1 in the regulation of mitochondrial homeostasis and energy metabolism under physiological conditions.