A2B5-reactive ganglioside expression determines the differentiation stage and capacity of rat insulinoma (RIN) sublines.
We have generated rat insulinoma (RIN) sublines AlGh, m5F, A12, A13 and AhGh with increasing surface expression of the A2B5 ganglioside, a marker of differentiation. We asked whether the capacity of the sublines to differentiate was related to their stage of differentiation, as is characteristic of cells within the normal beta-cell lineage. To answer this, we measured the effect of the differentiation inducer sodium butyrate (NaB, 1 mM) on proliferation, insulin content, secretion and biosynthesis, and the expression of A2B5 and 3G5 gangliosides by the sublines. Six days after exposure to NaB, cell numbers/dish ranged from (1-3) x 10(6) compared to (4-6) x 10(6) in control cultures. By day 2, AlGh, m5F, A12, A13 and AhGh cells exposed to NaB contained 1.5-, 1.4-, 1.4-, 1.2- and 1.0-fold higher amounts of insulin, respectively, and by day 6, 3.6-, 2.3- and 1.0-fold higher, and 1.2- and 2.4-fold lower, amounts of insulin, respectively, than control cells. After 2 days, insulin secretion from AlGh, m5F, A12, A13 and AhGh cells was 1.7-, 1.0-, 1.5-, 1.0- and 1.0-fold higher, respectively, and the rate of (pro)insulin biosynthesis 1.7-, 2.3-, 1.3-, 1.0- and 1.0-fold higher, respectively, than control cells. After 6 days, A2B5 ganglioside expression was increased 3-, 1.9- and 2-fold on m5F, A12 and A13 cells, respectively, but was not significantly altered on AlGh and AhGh cells. 3G5 ganglioside expression was increased 1.5- and 8.4-fold, respectively, on AlGh and m5F cells, but was unaltered on A12, A13 and AhGh cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Bartholomeusz
R K
RK
Burnet Clinical Research Unit, Walter and Eliza Hall Institute of Medical Research, Royal Melbourne Hospital, Parkville, Australia.
Campbell
I L
IL
Harrison
L C
LC
D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division; D002460:Cell Line; D002999:Clone Cells; D005732:Gangliosides / Q000096:biosynthesis*; D007328:Insulin / Q000378:metabolism; D007515:Islets of Langerhans / Q000166:cytology*; D051381:Rats
D005732:Gangliosides; D007328:Insulin; C062875:ganglioside A2B5