Change of Beclin-1 dependent on ATP, [Ca2+]i and MMP in PC12 cells following oxygen-glucose deprivation-reoxygenation injury

Authors

  • Zhentao Mo,

    1. The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510405, People's Republic of China
    2. Department of Pharmacology, Zunyi Medical College, Zunyi 563000, People's Republic of China
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  • Yongqi Fang,

    Corresponding author
    1. The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510405, People's Republic of China
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  • Yuping He,

    1. The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510405, People's Republic of China
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  • Xuehong Ke

    1. The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510405, People's Republic of China
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(email fangyq2@163.com)

Abstract

Autophagy is usually up-regulated to provide more ATP in response to starvation or OGD (oxygen-glucose deprivation), but the relationship between autophagy and ATP, [Ca2+]i (intracellular free Ca2+ concentration) or MMP (mitochondrial membrane potential) during reoxygenation is not yet fully clear. The role of autophagy is unknown in PC12 cells subjected to 2 h OGD with different time points of reoxygenation. In the present study, we showed that Beclin-1 was up-regulated beginning at 0 h reoxygenation peaking at 24 h and lasting for 48 h. Cell viability was decreased from 0 to 48 h reoxygenation, reaching its minimum at 10 h reoxygenation. ATP was decreased from 0 to 10 h reoxygenation, reaching its minimum at 4 h reoxygenation. A significant negative correlation was observed between ATP and Beclin-1 (r = −0.61, P<0.05) at 0 h reoxygenation, but ATP was not significant related (r = 0.24, P>0.05) to Beclin-1 at 24 h reoxygenation. Besides, Nimodipine, a calcium antagonist, significantly reduced [Ca2+]i and Beclin-1, but increased MMP in OGD/R-treated cells. At 24 h reoxygenation, Beclin-1 expression reached its maximum, cell viability continued to increase, and ATP was higher than that before OGD. These results suggest that energy metabolism dysfunction can induce autophagy during OGD in PC12 cells. Increased [Ca2+]i and decreased MMP may induce autophagy during reoxygenation in PC12 cells. Autophagy may be a protective effect on PC12 cells treated with different time points of reoxygenation after 2 h OGD.

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