Disease relevance of Entpd1

• Ischemia followed by reperfusion times over 30 min were associated with loss of glomerular ATPDase activity [1].
• Lipopolysaccharide alters ecto-ATP-diphosphohydrolase and causes relocation of its reaction product in experimental intrahepatic cholestasis [2].
• In contrast to the decrease in ecto-apyrase activity, there were increases in alkaline phosphatase activity and bilirubin concentration, markers of cholestasis [2].
• Furthermore, hypothyroidism increased the expression of NTPDase1 and 5'-nucleotidase, whereas hyperthyroidism decreased the expression of 5'-nucleotidase in hippocampus of adult rats [3].
• Total RNA was isolated from cultured glioma C6 cells and the cDNA was analyzed by Real Time-PCR with primers for the NTPDase family [4].

High impact information on Entpd1

• Hepatic expression of NTPDase2 was determined and contrasted to NTPDase1 using confocal immunofluorescence, immunoelectron microscopy, reverse-transcription polymerase chain reaction, Northern blot analysis, Western blot analysis, and functional assays [5].
• NTPDase2 was expressed in the periportal region surrounding intrahepatic bile ducts, whereas NTPDase1 was found in hepatic arteries, portal veins, and hepatic central veins, consistent with its known vascular distribution [5].
• Rat CD39, a membrane-bound ectonucleoside triphosphate diphosphohydrolase that hydrolyzes extracellular nucleoside tri- and diphosphates, has seven potential N-glycosylation sites at asparagine residues 73, 226, 291, 333, 375, 429, and 458 [6].
• Using enzyme histochemistry and immunostaining, we demonstrate that NTPDase2 is associated with nonmyelinating Schwann cells of the rat sciatic nerve, whereas NTPDase1 is restricted to blood vessel walls [7].
• Using PCR we identified the mRNA of all members of the ecto-nucleoside triphosphate diphosphohydrolase family investigated (NTPDase1 to NTPDase3, NTPDase5/6), of ecto-nucleotide pyrophosphatase/phosphodiesterase3 (NPP3), tissue-non-specific alkaline phosphatase and ecto-5'-nucleotidase [8].

Biological context of Entpd1

• Enzymes that can be involved in the extracellular hydrolysis chain are ecto-ATP diphosphohydrolase (ecto-apyrase), ecto-ATPase, ecto-ADPase and 5'-nucleotidase [9].
• Mammalian ecto-ATP diphosphohydrolase is a member of a family of apyrases sharing four "apyrase conserved regions" that presumably participate in the formation of the catalytic site [9].
• In contrast to NTPDase1, substrate specificity of NTPDase2 was altered with prolonged expression time, resulting in a decrease in the ATPase/ADPase activity ratio from 10 : 1 to 2.5 : 1 [10].
• Southern analysis of the mouse genome suggests that there may be a single copy of the ecto-apyrase gene [11].
• Semi-quantitative immunohistochemistry in the cochlea exposed to 110 dB SPL localized the increased NTPDase1 and NTPDase2 immunostaining in the stria vascularis and up-regulation of NTPDase2 in the intraganglionic spiral bundle [12].

Anatomical context of Entpd1

• As revealed by Northern analysis of rat tissues, the ecto-ATPase is co-expressed with ecto-ATP diphosphohydrolase in heart, kidney, spleen, thymus, lung, skeletal muscle and brain [9].
• The participation of ecto-ATP diphosphohydrolase (CD39; ecto-NTPDase) and ecto-5'-nucleotidase (CD73) activities in the nucleotide hydrolysis by salivary gland cells from rats was evaluated [13].
• Determination of native oligomeric state and substrate specificity of rat NTPDase1 and NTPDase2 after heterologous expression in Xenopus oocytes [10].
• This study characterized the effect of noise exposure on regulation of NTPDase1 and NTPDase2 expression in the cochlea using a combination of real-time RT-PCR, immunohistochemistry and functional studies [12].
• In contrast, NTPDase1 was down-regulated in the cell bodies of the spiral ganglion neurones [12].

Associations of Entpd1 with chemical compounds

• The effect of glutamate on the ATPase and ADPase activities in rat hippocampal slices of different ages was also studied since adenosine, the final product of an enzymatic chain that includes NTPDase 1 and 5'-nucleotidase, can act upon A1 receptors in turn decreasing the release of glutamate [14].
• ATP diphosphohydrolase (NTPDase 1) in rat hippocampal slices and effect of glutamate on the enzyme activity in different phases of development [14].
• As revealed by application of blue native PAGE and a comparison of glutaraldehyde cross-linking, native NTPDase1 and NTPDase2 occur in oligomeric form [10].
• NTPDase1 preferentially occurred as a dimer that could be dissociated into monomeric forms in the presence of Coomassie Brilliant blue G-250 and dithiothreitol whereas NTPDase2 revealed higher oligomeric forms up to tetramers, largely resistant to dithiothreitol [10].
• The inhibition of NTPDase by heparin was observed at three different pH values (6.0, 8.0 and 10.0) [15].

Other interactions of Entpd1

• An ecto-ATPase and an ecto-ATP diphosphohydrolase are expressed in rat brain [9].
• Whereas ecto-apyrase hydrolyzes nucleoside 5'-diphosphates at a rate approximately 20-30% lower than nucleoside-5'-triphosphates, ecto-ATPase hydrolyzes nucleoside-5'-diphosphates only to a marginal extent [16].
• Ecto-apyrase is enriched in brain postsynaptic density membrane fractions and is localized in proximity to synaptophysin, the marker of synaptic vesicles [17].
• We have shown that ecto-apyrase protein is expressed in primary neurons and astrocytes in cell culture (T.-F. Wang, P.A. Rosenberg, G. Guidotti, 1997. Mol. Brain Res. 1997, 47: 295-302) [17].
• New benzodiazepines alter acetylcholinesterase and ATPDase activities [18].

Analytical, diagnostic and therapeutic context of Entpd1

• Cobra Venom Factor (CVF) inhibited ATPDase activity and potentiated the deleterious effects of reperfusion [1].
• Our results suggest that NTPDase-1/cd39 influences pathways of vascular injury in cardiac xenografts [19].
• Alterations in cd39 mRNA transcripts and NTPDase activity expression were evaluated in wild-type grafts in untreated rats and then following complement depletion and immunosuppression [19].
• RESULTS: NTPDase biochemical activity in wild-type xenografts rapidly decreased after transplantation but soon rebounded with graft survival [19].

References