title: Species Difference in Sensitivity of Human and Mouse P2X7 Receptors to Inhibitory Effects of Divalent Metal Cations.
abstract: P2X7 receptor (P2X7R), a purinergic receptor, is involved in pathophysiological events such as inflammation and cell death, and thus is an attractive target for therapeutic approaches. It is reported that divalent metal cations (DMCs) inhibit P2X7R activation and that there are species differences in their inhibitory effects. To extrapolate the findings in experimental animals to humans, these species differences have to be clarified, but species differences in the sensitivity of P2X7R to DMCs between man and mouse have not been demonstrated. Here we performed direct comparison of the inhibitory effects of DMCs on human and mouse P2X7R activation. Cell lines constitutively expressing human and mouse P2X7R were used, and their P2X7R activation was evaluated as means of YO-PRO-1 dye uptake. MgCl2, NiCl2, ZnCl2, CuCl2and CaCl2dose-dependently decreased agonist-induced YO-PRO-1 uptake via both human and mouse P2X7Rs. Apparent differences in the inhibitory profiles for NiCl2and CaCl2between them were found, and the IC50values of DMCs were in the order of CaCl2>MgCl2>NiCl2≈ZnCl2>CuCl2for both human and mouse P2X7Rs. In this study, we demonstrate that human P2X7R exhibits different sensitivity to nickel and calcium compared with the case of the mouse one, while there is no species difference in the sensitivity of their P2X7Rs to magnesium, zinc and copper, suggesting that the effects of magnesium, zinc and copper on P2X7R-associated pathophysiological events in humans might be predicted from those in mice.
authors.affiliation: Department of Environmental Biochemistry, Kyoto Pharmaceutical University.
authors.forename: Makiko
authors.initials: M
authors.lastname: Fujiwara
authors.forename: Kenshi
authors.initials: K
authors.lastname: Ohbori
authors.forename: Akihiro
authors.initials: A
authors.lastname: Ohishi
authors.forename: Kentaro
authors.initials: K
authors.lastname: Nishida
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Uozumi
authors.forename: Kazuki
authors.initials: K
authors.lastname: Nagasawa
mesh_terms: D000818:Animals; D001583:Benzoxazoles / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology*; D002413:Cations, Divalent / Q000494:pharmacology*; D003300:Copper / Q000494:pharmacology*; D057809:HEK293 Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D008274:Magnesium / Q000494:pharmacology*; D051379:Mice; D009532:Nickel / Q000494:pharmacology*; D011806:Quinolinium Compounds / Q000378:metabolism; D058486:Receptors, Purinergic P2X7 / Q000235:genetics* / Q000378:metabolism; D013045:Species Specificity; D015032:Zinc / Q000494:pharmacology*
chemical_list: D001583:Benzoxazoles; D002413:Cations, Divalent; D011806:Quinolinium Compounds; D058486:Receptors, Purinergic P2X7; C089813:YO-PRO 1; D003300:Copper; D009532:Nickel; D008274:Magnesium; D015032:Zinc; D002118:Calcium