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Degradation of extracellular nucleotides and their analogs in HeLa and HUVEC cell cultures

100%

Gendaszewska-Darmach E., Maszewska M., Zaklos M., Koziolkiewicz M.

Acta Biochimica Polonica

2003

tom 50

nr 4

The use of nucleotides and their analogs in the pharmacological studies of nucleotide receptors (P2 class) should be preceded by detailed studies on their degradation connected with ecto-enzymes of a given cell type. In the present studies we have analyzed stability of some phosphorothioate and phosphonate analogs of ATP and ADP in the HeLa epitheloid carcinoma and endothelial HUVEC cells cultures. Our studies have revealed that ecto-nucleotide pyrophosphatase (E-NPP) is one of the main enzymes involved in the extracellular degradation of ATP and other nucleotides in the HeLa cells. On the other hand, the ecto-ATPDase is responsible for the hydrolysis of extracellular nucleotides in human endothelial cell cultures, while the E-NPP-like enzymes of the HUVEC cells are not essential to this degradation. The concerted action of the aforementioned ecto-enzymes and nucleotide pyrophosphatase, 5 -nucleo- tidase and adenosine deaminase present in fetal bovine serum (FBS) supplied to the culture medium, results in partial or complete degradation of the phosphorothioate (ATPγS) and phosphonate analogs of adenosine nucleotides (α,β-methylene-ATP and β,γ-methylene-ATP) in the cell cultures. Only ADPβS appears to be resistant to these enzymes. The influence of some nucleotides and their analogs on the proliferation of the HeLa cells in presence or absence of FBS is also discussed.

Cross-talk between the ATP and ADP nucleotide receptor signalling pathways in glioma C6 cells

84%

Czajkowski R., Baranska J.

Acta Biochimica Polonica

2002

tom 49

nr 4

In this review we summarize the present status of our knowledge on the enzymes involved in the extracellular metabolism of nucleotides and the receptors involved in nucleotide signalling. We focus on the mechanism of the ATP and ADP signalling pathways in glioma C6, representative of the type of nonexcitable cells. In these cells, ATP acts on the P2Y2 receptor coupled to phospholipase C, whereas ADP on two distinct P2Y receptors: P2Y1 and P2Y12. The former is linked to phospholipase C and the latter is negatively coupled to adenylyl cyclase. The possible cross-talk between the ATP-, ADP- and adenosine-induced pathways, leading to simultaneous regulation of inositol 1,4,5-trisphosphate and cAMP mediated signalling, is discussed.

Ograniczanie wyników

2 Acta Biochimica Polonica

1 Baranska J.

1 Czajkowski R.

1 Gendaszewska-Darmach E.

1 Koziolkiewicz M.

1 Maszewska M.

1 Zaklos M.

1 2003

1 2002

Wyniki wyszukiwania

Degradation of extracellular nucleotides and their analogs in HeLa and HUVEC cell cultures

Cross-talk between the ATP and ADP nucleotide receptor signalling pathways in glioma C6 cells