Characterization of peripheral human cannabinoid receptor (hCB2) expression and pharmacology using a novel radioligand, [35S]Sch225336.
Studies to characterize the endogenous expression and pharmacology of peripheral human cannabinoid receptor (hCB2) have been hampered by the dearth of authentic anti-hCB2 antibodies and the lack of radioligands with CB2 selectivity. We recently described a novel CB2 inverse agonist, N-[1(S)-[4-[[4-methoxy-2-[(4methoxyphenyl)sulfonyl] phenyl]sulfonyl] phenyl]ethyl]methane-sulfonamide (Sch225336), that binds hCB2 with high affinity and excellent selectivity versus hCB1. The precursor primary amine of Sch225336 was prepared and reacted directly with [(35)S]mesyl chloride (synthesized from commercially obtained [(35)S]methane sulfonic acid) to generate [(35)S]Sch225336. [(35)S]Sch225336 has high specific activity (>1,400 Ci/mmol) and affinity for hCB2 (65 pm). Using [(35)S]Sch225336, we assayed hemopoietic cells and cell lines to quantitate the expression and pharmacology of hCB2. Lastly, we used [(35)S]Sch225336 for detailed autoradiographic analysis of CB2 in lymphoid tissues. Based on these data, we conclude that [(35)S]Sch225336 represents a unique radioligand for the study of CB2 endogenously expressed in blood cells and tissues.
Gonsiorek
Waldemar
W
Department of Inflammation, Schering-Plough Research Institute, Kenilworth, New Jersey 07033, USA.
Hesk
David
D
Chen
Shu-Cheng
SC
Kinsley
David
D
Fine
Jay S
JS
Jackson
James V
JV
Bober
Loretta A
LA
Deno
Gregory
G
Bian
Hong
H
Fossetta
James
J
Lunn
Charles A
CA
Kozlowski
Joseph A
JA
Lavey
Brian
B
Piwinski
John
J
Narula
Satwant K
SK
Lundell
Daniel J
DJ
Hipkin
R William
RW
D000818:Animals; D001345:Autoradiography; D015153:Blotting, Western; D016466:CHO Cells; D006224:Cricetinae; D018922:HL-60 Cells; D006801:Humans; D008214:Lymphocytes / Q000737:chemistry; D011869:Radioligand Assay; D043885:Receptor, Cannabinoid, CB2 / Q000819:agonists* / Q000032:analysis*; D013154:Spleen / Q000737:chemistry; D013449:Sulfonamides / Q000378:metabolism*
D043885:Receptor, Cannabinoid, CB2; C514445:Sch225336; D013449:Sulfonamides