Enzymatic activities during differentiation of the human neuroblastoma cells, LA-N-1 and LA-N-2.
The presence of 10(-5) M retinoic acid (RA) in the culture medium of LA-N-1, a catecholaminergic cell line, and LA-N-2, a cholinergic cell line, enhanced their morphological differentiation. Tyrosine hydroxylase (TH) activity of the LA-N-1 cells was increased in the RA-treated cells compared with control cultures at day 4 and remained elevated. Choline acetyltransferase (ChAT) activity in the LA-N-2 cells gradually increased until 8 days in vitro (DIV) both in the untreated control and the RA treated cultures. This activity in control and treated cells decreased gradually to a constant level of activity. The ChAT activity at 8 DIV of RA-treated LA-N-2 cells was increased 2.1-fold (P less than 0.001) as compared to the control cultures. This increase in ChAT activity was accompanied by a 73% decrease of acetylcholinesterase (AChE) activity in LA-N-2 cells by 8 DIV. AChE activity of LA-N-1 cells was unchanged during the time course of the experiment. Phospholipase-A2 (PL-A2) activity in RA-treated LA-N-2 cells was increased at day 4 as compared with the control cultures. There were no differences observed in phospholipase-D (PL-D), choline kinase and GPC-phosphodiesterases activities in RA-treated and -untreated LA-N-1 and LA-N-2 cells.
Singh
I N
IN
Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
Sorrentino
G
G
McCartney
D G
DG
Massarelli
R
R
Kanfer
J N
JN
D000110:Acetylcholinesterase / Q000378:metabolism*; D000320:Adrenergic Fibers / Q000201:enzymology*; D002454:Cell Differentiation; D002460:Cell Line; D002478:Cells, Cultured; D002795:Choline O-Acetyltransferase / Q000378:metabolism*; D002799:Cholinergic Fibers / Q000201:enzymology*; D006801:Humans; D009447:Neuroblastoma / Q000201:enzymology* / Q000378:metabolism; D010740:Phospholipases / Q000378:metabolism*; D014212:Tretinoin / Q000494:pharmacology*
D014212:Tretinoin; D002795:Choline O-Acetyltransferase; D010740:Phospholipases; D000110:Acetylcholinesterase