In a study on mitochondrial biogenesis in apoptotic cells, Chinese researchers observed that mitochondrial biogenesis was significantly enhanced during the early stage of radiation-induced apoptosis.
"It proves biological process observation is important for the study of biological effects," said Prof. HUANG Qing from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences, who led the research team. Relevant result has been published in iScience.
Mitochondrial biogenesis is the physiological response of cells to external stresses that may cause increased energy demand, it is important in maintaining cellular homeostasis. It has been shown mitochondrial biogenesis usually inhibits apoptosis, but it is not clear whether there is mitochondrial biogenesis or changes in the early apoptotic cells. This requires real-time observation of mitochondrial changes during apoptosis.
In this work, the researchers constructed a dual fluorescent reporter system, which can be used for real-time in situ observation of mitochondrial changes. The system was applied to the observation of apoptosis caused by ionizing radiation, and mitochondrial changes were determined by observing changes in the fluorescence ratio of dual fluorescent proteins.
"We detected cell viability, apoptosis, cell cycle, mitochondrial biogenesis, DNA damage repair proteins," said Prof. HUANG, explaining the detailed observation of cellular processes, "and carefully analyzed the process of mitochondrial dynamic changes."
In the end, they found that there was a significant enhancement of mitochondrial biogenesis in the early stage of radiation apoptotic cells, that is, under certain conditions, mitochondrial biogenesis in early stage cells was positively correlated with apoptosis in the later stage. This result revises the previous generalized notion of negative correlation between them.
This work not only provides an effective method to study mitochondrial biogenesis, but also demonstrates how biological effects can be properly assessed at the right time points, highlighting the importance of the observation of dynamic processes in living cells.
This research was mainly supported by the National Natural Science Foundation of China.
Mechanism schematic (Image by SHAO Chengsheng)
In situ observation of biological effects of ionizing radiation by dual fluorescence reporting system (Image by SHAO Changsheng)
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