101. Inorganic polyphosphate induces accelerated tube formation of HUVEC endothelial cells
- Author
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Rafael Muñoz-Espí, Shunfeng Wang, Heinz C. Schröder, Maximilian Ackermann, Werner E. G. Müller, Qingling Feng, Meik Neufurth, and Xiaohong Wang
- Subjects
0301 basic medicine ,Angiogenesis ,Matrix (biology) ,Biology ,Gene Expression Regulation, Enzymologic ,Umbilical vein ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,Adenosine Triphosphate ,0302 clinical medicine ,Polyphosphates ,Cell Line, Tumor ,Human Umbilical Vein Endothelial Cells ,Extracellular ,Humans ,Molecular Biology ,Cells, Cultured ,Pharmacology ,Tube formation ,Apyrase ,Cell Biology ,Alkaline Phosphatase ,digestive system diseases ,Cell biology ,030104 developmental biology ,Matrix Metalloproteinase 9 ,Microscopy, Fluorescence ,chemistry ,Biochemistry ,030220 oncology & carcinogenesis ,Microvessels ,Microscopy, Electron, Scanning ,Matrix Metalloproteinase 2 ,Molecular Medicine ,Alkaline phosphatase ,Adenosine triphosphate - Abstract
In this study, the effect of inorganic polyphosphate (polyP) on the initial phase of angiogenesis and vascularization was investigated, applying the HUVEC cell tube formation assay. PolyP is a physiological and high energy phosphate polymer which has been proposed to act as a metabolic fuel in the extracellular space with only a comparably low ATP content. The experiments revealed that polyP accelerates tube formation of human umbilical vein endothelial cells (HUVEC), seeded onto a solidified basement membrane extract matrix which contains polyP-metabolizing alkaline phosphatase (ALP) activity. This effect is abolished by co-addition of apyrase, which degrades ATP to AMP and inorganic phosphate. The assumption that ATP, derived from polyP, activates HUVEC cells leading to tube formation was corroborated by experiments showing that addition of polyP to the cells causes a strong rise of ATP level in the culture medium. Finally, we show that at a later stage of cultivation of HUVEC cells, after 3 d, polyP causes a strong enhancement of the expression of the genes encoding for the two major matrix metalloproteinases (MMPs) released by endothelial cells during tube formation, MMP-9 and MMP-2. This stimulatory effect is again abrogated by addition of apyrase together with polyP. From these results, we propose that polyP is involved either directly or indirectly in energy supply, via ALP-mediated transfer of energy-rich phosphate under ATP formation. This ATP is utilized for the activation and oriented migration of endothelial cells and for the matrix organization during the initial phases of tube formation.
- Published
- 2017