title: Differential expression of the 5-HT(3A) and 5-HT(3B) receptor in differentiated NG108-15 cells.
abstract: Previous work from this laboratory has shown that the serotonin (5-HT) induced response is significantly augmented in differentiated NG108-15 (NG) cells treated with dibutyryl cAMP (Bt(2)cAMP) due to qualitative and quantitative changes in the expression of the 5-HT(3) receptor as demonstrated by specific [(3)H] LY-278584 (a selective 5HT(3) receptor antagonist) binding. In this study, we investigated whether there is any change in the relative expression of the 5-HT(3A) and 5-HT(3B) subunits in NG cells differentiated following Bt(2)cAMP treatment cells. The major findings of this study were that the relative amount of 5-HT(3B) subunit mRNA in Bt(2)cAMP-treated NG cells 5 days following Bt(2)cAMP-treatment was greater than that in the untreated cells. In contrast, the relative expression of the 5-HT(3B) subunit protein in the Bt(2)cAMP-treated NG cells was much less than in the untreated cells, but the relative expression of the 5-HT(3A) subunit in the Bt(2)cAMP-treated NG cells was similar to the untreated cells. Therefore, no relationship between mRNA and protein expression for 5-HT(3A) and 5-HT(3B) subunits in Bt(2)cAMP treated and untreated NG cells were observed. It was also found that fluorescent intensity for the 5-HT(3B) subunit in the cell body of the Bt(2)cAMP treated and untreated NG cells gradually decreased from the day 1-5 after Bt(2)cAMP treatment. However, in specific areas such as the varicosity and nerve endings of the Bt(2)cAMP treated cells, staining intensity for the 5-HT(3B) subunits was stronger than in the untreated cells at the all time points, peaking at day 5 post-treatment. These results suggest that the augmented response induced by 5-HT acting via 5-HT(3) receptors in differentiated NG cells may be due to changes in the relative amount of the 5-HT(3B) subunit, particularly the ratio and distribution of the 5-HT(3A) to (3B) subunits.
authors.affiliation: Division of Biochemistry, Kinki University School of Pharmacy, Kowakae, 3-4-1, Higashiosaka 577-8502, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Asano
authors.forename: Akinori
authors.initials: A
authors.lastname: Miyamoto
authors.forename: Mariko
authors.initials: M
authors.lastname: Nakao
authors.forename: Chiyuki
authors.initials: C
authors.lastname: Wakaki
authors.forename: Takuma
authors.initials: T
authors.lastname: Iida
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Funakami
authors.forename: Tetsuyuki
authors.initials: T
authors.lastname: Wada
authors.forename: Seiji
authors.initials: S
authors.lastname: Ichida
mesh_terms: D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002454:Cell Differentiation; D007191:Indazoles; D051379:Mice; D021122:Protein Subunits / Q000096:biosynthesis; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D044406:Receptors, Serotonin, 5-HT3 / Q000096:biosynthesis*; D014326:Tropanes
chemical_list: D007191:Indazoles; D021122:Protein Subunits; D012333:RNA, Messenger; D044406:Receptors, Serotonin, 5-HT3; D014326:Tropanes; C061531:LY 278584; D003994:Bucladesine