Daily mitochondrial dynamics in cone photoreceptors
| Autor: | James B. Hurley, William Ge, Brian M. Robbings, Kaitlyn M Rutter, Kristine Tsantilas, Susan E. Brockerhoff, Whitney M. Cleghorn, Kellie C Kuch, Edward D Parker, Daniel C Brock, Michelle M. Giarmarco |
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| Rok vydání: | 2020 |
| Předmět: |
retina
genetic structures Mitochondrial Turnover Dark Adaptation Biology Mitochondrion Endoplasmic Reticulum Mitochondrial Size Mitochondrial Dynamics Animals Zebrafish Multidisciplinary Endoplasmic reticulum photoreceptors Cell Biology Biological Sciences zebrafish biology.organism_classification eye diseases Circadian Rhythm Mitochondria Cell biology circadian Mitochondrial biogenesis Synapses Darkness Retinal Cone Photoreceptor Cells Ultrastructure sense organs |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.2007827117 |
| Popis: | Significance Mitochondria are organelles that make cellular energy. In the retina, mitochondrial health is important for photoreceptor cell function and normal vision. Photoreceptors need more energy at night, but it is unclear how their mitochondria adapt to changing energy demands. We investigated zebrafish cone photoreceptor mitochondria throughout the day. At night cone mitochondria are smaller, more numerous, and more metabolically active. Material from mitochondria is also released from photoreceptors during nighttime, forming stalks and networks outside of the cell. In daytime, photoreceptor mitochondria associate with ER and autophagosomes, organelles that mediate mitochondrial turnover. These daily changes to mitochondrial structure may help photoreceptors adapt to metabolic demands of daytime and nighttime. Cone photoreceptors in the retina are exposed to intense daylight and have higher energy demands in darkness. Cones produce energy using a large cluster of mitochondria. Mitochondria are susceptible to oxidative damage, and healthy mitochondrial populations are maintained by regular turnover. Daily cycles of light exposure and energy consumption suggest that mitochondrial turnover is important for cone health. We investigated the three-dimensional (3D) ultrastructure and metabolic function of zebrafish cone mitochondria throughout the day. At night retinas undergo a mitochondrial biogenesis event, corresponding to an increase in the number of smaller, simpler mitochondria and increased metabolic activity in cones. In the daytime, endoplasmic reticula (ER) and autophagosomes associate more with mitochondria, and mitochondrial size distribution across the cluster changes. We also report dense material shared between cone mitochondria that is extruded from the cell at night, sometimes forming extracellular structures. Our findings reveal an elaborate set of daily changes to cone mitochondrial structure and function. |
| Databáze: | OpenAIRE |
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