In situ observation of mitochondrial biogenesis as the early event of apoptosis

Chang-Sheng Shao; Xiu-Hong Zhou; Yu-Hui Miao; Peng Wang; Qian-Qian Zhang; Qing Huang

doi:10.1016/j.isci.2021.103038

In situ observation of mitochondrial biogenesis as the early event of apoptosis

iScience. 2021 Aug 27;24(9):103038. doi: 10.1016/j.isci.2021.103038. eCollection 2021 Sep 24.

Authors

Chang-Sheng Shao^{1

2}, Xiu-Hong Zhou³, Yu-Hui Miao⁴, Peng Wang¹, Qian-Qian Zhang^{1

2}, Qing Huang^{1

2}

Affiliations

¹ CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences (CAS), P. O. Box 1138, Hefei 230031, P.R. China.
² Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, China.
³ Center of Biology, Anhui Agricultural University, Hefei, China.
⁴ Department of Medical Oncology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.

Abstract

Mitochondrial biogenesis is a cell response to external stimuli which is generally believed to suppress apoptosis. However, during the process of apoptosis, whether mitochondrial biogenesis occurs in the early stage of the apoptotic cells remains unclear. To address this question, we constructed the COX8-EGFP-ACTIN-mCherry HeLa cells with recombinant fluorescent proteins respectively tagged on the nucleus and mitochondria and monitored the mitochondrial changes in the living cells exposed to gamma-ray radiation. Besides in situ detection of mitochondrial fluorescence changes, we also examined the cell viability, nuclear DNA damage, reactive oxygen species (ROS), mitochondrial superoxide, citrate synthase activity, ATP, cytoplasmic and mitochondrial calcium, mitochondrial mass, mitochondrial morphology, and protein expression related to mitochondrial biogenesis, as well as the apoptosis biomarkers. As a result, we confirmed that significant mitochondrial biogenesis took place preceding the radiation-induced apoptosis, and it was closely correlated with the apoptotic cells at late stage. The involved mechanism was also discussed.

Keywords: Biochemistry methods; Biomolecular engineering; Cell biology.