Metabolic alterations induced by ischemia in primary cultures of astrocytes

ITQB PhD Seminars

Title: Metabolic alterations induced by ischemia in primary cultures of astrocytes: merging 13C NMR spectroscopy and metabolic flux analysis

Speaker: Ana Isabel Porém Amaral

Laboratory: Animal Cell Technology

Abstract:
Disruption of brain energy metabolism is the hallmark of cerebral ischemia, a major cause of death worldwide. Astrocytes play a key role in the regulation of brain metabolism and their vulnerability to ischemia has been described. This work aimed to quantify the effects of an ischemic insult in astrocytic metabolism. Primary cultures of astrocytes were subjected to 5 hours of oxygen and glucose deprivation in a bioreactor. Flux distributions, before and after ischemia, were estimated by metabolic flux analysis using isotopic information and the consumption/secretion rates of relevant extracellular metabolites as constraints. During ischemia and early recovery, 30% of cell death was observed; several metabolic alterations were also identified reflecting a metabolic response by the surviving cells. In the early recovery (~10 h), astrocytes up-regulated glucose utilization by 30% and increased the pentose phosphate pathway and TCA cycle fluxes. Additionally, a similar enhancement in branched-chain amino acids catabolism suggested the importance of anaplerotic molecules to the fast recovery of the energetic state, which was corroborated by measured cellular ATP levels. Glycolytic metabolism was predominant in the late recovery. In summary, this work demonstrates that astrocytic metabolic plasticity is implicated in the recovery from ischemia, through the adaptation of key energy metabolism pathways.

Short CV
2005 – Graduated in Biochemistry by the University of Lisbon
2004 to 2006 - Research Student at the Animal Cell Technology Lab, ITQB-UNL/IBET
2007 - PhD Student at the Animal Cell Technology Lab, ITQB-UNL/IBET under the supervision of Dr. Paula M. Alves