Glycolytic and Oxidative Phosphorylation Defects Precede the Development of Senescence in Primary Human Brain Microvascular Endothelial Cells

Siva S V P Sakamuri; Venkata N Sure; Lahari Kolli; Ning Liu; Wesley R Evans; Jared A Sperling; David W Busija; Xiaoying Wang; Sarah H Lindsey; Walter L Murfee; Ricardo Mostany; Prasad V G Katakam

doi:10.1007/s11357-022-00550-2

Glycolytic and Oxidative Phosphorylation Defects Precede the Development of Senescence in Primary Human Brain Microvascular Endothelial Cells

Geroscience. 2022 Aug;44(4):1975-1994. doi: 10.1007/s11357-022-00550-2. Epub 2022 Apr 4.

Authors

Siva S V P Sakamuri¹, Venkata N Sure², Lahari Kolli², Ning Liu^{3

4}, Wesley R Evans^{2

3}, Jared A Sperling², David W Busija^{2

3}, Xiaoying Wang^{3

4}, Sarah H Lindsey^{2

3}, Walter L Murfee⁵, Ricardo Mostany^{2

3}, Prasad V G Katakam^{2

3

4}

Affiliations

¹ Department of Pharmacology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA, 70112, USA. ssakamuri@tulane.edu.
² Department of Pharmacology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA, 70112, USA.
³ Neuroscience Program, Tulane Brain Institute, Tulane University, 200 Flower Hall, New Orleans, LA, 70118, USA.
⁴ Clinical Neuroscience Research Center, 131 S. Robertson, Suite 1300, New Orleans, LA, 70112, USA.
⁵ J. Clayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA.

Abstract

Alterations of mitochondrial and glycolytic energy pathways related to aging could contribute to cerebrovascular dysfunction. We studied the impact of aging on energetics of primary human brain microvascular endothelial cells (HBMECs) by comparing the young (passages 7-9), pre-senescent (passages 13-15), and senescent (passages 20-21) cells. Pre-senescent HBMECs displayed decreased telomere length and undetectable telomerase activity although markers of senescence were unaffected. Bioenergetics in HBMECs were determined by measuring the oxygen consumption (OCR) and extracellular acidification (ECAR) rates. Cellular ATP production in young HBMECs was predominantly dependent on glycolysis with glutamine as the preferred fuel for mitochondrial oxidative phosphorylation (OXPHOS). In contrast, pre-senescent HBMECs displayed equal contribution to ATP production rate from glycolysis and OXPHOS with equal utilization of glutamine, glucose, and fatty acids as mitofuels. Compared to young, pre-senescent HBMECs showed a lower overall ATP production rate that was characterized by diminished contribution from glycolysis. Impairments of glycolysis displayed by pre-senescent cells included reduced basal glycolysis, compensatory glycolysis, and non-glycolytic acidification. Furthermore, impairments of mitochondrial respiration in pre-senescent cells involved the reduction of maximal respiration and spare respiratory capacity but intact basal and ATP production-related OCR. Proton leak and non-mitochondrial respiration, however, were unchanged in the pre-senescent HBMECs. HBMECS at passages 20-21 displayed expression of senescence markers and continued similar defects in glycolysis and worsened OXPHOS. Thus, for the first time, we characterized the bioenergetics of pre-senescent HBMECs comprehensively to identify the alterations of the energy pathways that could contribute to aging.

Keywords: ATP; Extracellular acidification rate; Glycolysis; Oxidative phosphorylation; Oxygen consumption rate.

Publication types

Research Support, Non-U.S. Gov't
Research Support, N.I.H., Extramural

MeSH terms

Adenosine Triphosphate / metabolism
Brain / metabolism
Endothelial Cells*
Glutamine / metabolism
Glycolysis
Humans
Oxidative Phosphorylation*

Substances

Glutamine
Adenosine Triphosphate

Abstract

Publication types

MeSH terms

Substances

Grants and funding