MODULATION OF HUMAN MICROVASCULAR ENDOTHELIAL-CELL BIOENERGETIC STATUS AND GLUTATHIONE LEVELS DURING PROLIFERATIVE AND DIFFERENTIATED GROWTH

Citation
Sr. Mallery et al., MODULATION OF HUMAN MICROVASCULAR ENDOTHELIAL-CELL BIOENERGETIC STATUS AND GLUTATHIONE LEVELS DURING PROLIFERATIVE AND DIFFERENTIATED GROWTH, Journal of cellular biochemistry, 53(4), 1993, pp. 360-372
Citations number
51
Categorie Soggetti
Biology
ISSN journal
07302312
Volume
53
Issue
4
Year of publication
1993
Pages
360 - 372
Database
ISI
SICI code
0730-2312(1993)53:4<360:MOHMEB>2.0.ZU;2-A
Abstract
During angiogenesis, formerly differentiated human microvascular endot helial cells (HMECs) return to a proliferative growth state. Many fund amental questions regarding HMEC function, such as how HMECS adapt to changes in bioenergetic requirements upon return to proliferative grow th, remained unanswered. In this study, we evaluated whether modificat ions in HMEC bioenergetic profiles and glutathione (GSH) levels accomp anied the cellular transition between differentiated and proliferative growth. To provide insight into the continuum of cellular adaptations that occur during this transition, we used a method recently develope d in our laboratory that induces a state of morphological and function al predifferentiation in HMECs. Cellular morphology, in conjunction wi th flow cytometric DNA analyses and HMEC functional assays (the direct ed migration and intercellular association involved in microtubule for mation) were employed to validate the HMEC culture state of growth. An alysis of the HPLC nucleotide profiles disclosed several findings comm on to all culture growth states. These uniform findings, e.g., cellula r energy charges > 0.90, and highly reduced redox states, revealed tha t cultured HMECs maintain high rates of oxidative metabolism. However, there were also significant, culture growth state related differences in the nucleotide profiles. Proliferative HMECs were shown to possess significantly higher (relative to both large vessel endothelial cells , and differentiated HMECs) levels of GSH and specific nucleotides whi ch were related with a return to the active cell cycle-ATP, GTP, UTP, and CTP, and NADPH. Further, the nucleotide profiles and GSH levels of the predifferentiated HMECs were determined to be intermediate betwee n-levels obtained for the proliferative and differentiated HMECs. The results of this study demonstrate that the capacity to modulate their cellular bioenergetic status during growth state transitions is one of the adaptations that enable HMECs to retain a growth state reciprocit y. In addition, our findings also show that HMECs, especially during t he proliferative growth state, are biochemically distinct from endothe lial cells harvested from large vessels, and therefore suggest that HM ECs are the cells of choice to employ when studying diseases that affe ct the human microvasculature. (C) 1993 Wiley-Liss, Inc.