Format

Send to

Choose Destination
Mol Neurobiol. 2018 Aug;55(8):7025-7037. doi: 10.1007/s12035-017-0840-8. Epub 2018 Jan 30.

Disruption of De Novo Serine Synthesis in Müller Cells Induced Mitochondrial Dysfunction and Aggravated Oxidative Damage.

Author information

1
State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China.
2
Save Sight Institute, The University of Sydney, 8 Macquarie Street, Sydney, NSW, 2000, Australia.
3
School of Optometry and Vision Sciences, University of New South Wales, Sydney, NSW, Australia.
4
West Virginia University Health Sciences Center, Morgantown, WV, USA.
5
Faculty of Pharmacy, The University of Sydney, Sydney, NSW, Australia.
6
Save Sight Institute, The University of Sydney, 8 Macquarie Street, Sydney, NSW, 2000, Australia. ling.zhu@sydney.edu.au.

Abstract

De novo serine synthesis plays important roles in normal mitochondrial function and cellular anti-oxidative capacity. It is reported to be mainly activated in glial cells of the central nervous system, but its role in retinal Müller glia remains unclear. In this study, we inhibited de novo serine synthesis using CBR-5884, a specific inhibitor of phosphoglycerate dehydrogenase (PHGDH, a rate limiting enzyme in de novo serine metabolism) in MIO-M1 cells (immortalized human Müller cells) and huPMCs (human primary Müller cells) under mild oxidative stress. Alamar blue and LDH (lactate dehydrogenase) assays showed significantly reduced metabolic activities and increased cellular damage of Müller cells, when exposed to CBR-5884 accompanied by mild oxidative stress; however, CBR-5884 alone had little effect. The increased cellular damage was partially reversed by supplementation with exogenous serine/glycine. HSP72 (an oxidative stress marker) and reactive oxygen species (ROS) levels were significantly increased; glutathione and NADPH/NADP+ levels were pronouncedly reduced under PHGDH inhibition accompanied by oxidative stress. JC-1 staining and Seahorse respiration experiments showed that inhibition of de novo serine synthesis in Müller cells can also increase mitochondrial stress and decrease mitochondrial ATP production. qPCR and Western blot demonstrated an increased expression of HSP60 (a key mitochondrial stress-related gene), and this was further validated in human retinal explants. Our study suggests that de novo serine synthesis is important for Müller cell survival, particularly when they are exposed to mild oxidative stress, possibly by maintaining mitochondrial function and generating glutathione and NADPH to counteract ROS.

KEYWORDS:

De novo serine synthesis; Glutathione; Mitochondrial dysfunction; Müller cells; Oxidative stress; Phosphoglycerate dehydrogenase

PMID:
29383682
DOI:
10.1007/s12035-017-0840-8
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Springer
Loading ...
Support Center