TY - JOUR
T1 - Glucose stimulation of pancreatic β-cell lines induces expression and secretion of dynorphin
AU - Josefsen, Knud
AU - Buschard, Karsten
AU - Sørensen, Lone Reinholdt
AU - Wøllike, Michael
AU - Ekman, Rolf
AU - Birkenbach, Mark
PY - 1998
Y1 - 1998
N2 - To investigate adaptive responses of pancreatic β-cells to hyperglycemia, genes induced by glucose stimulation were identified by subtraction cloning. Among 53 clones representing differentially expressed genes, 20 encoded the endogenous opioid precursor, prodynorphin. The amino acid sequence of murine prodynorphin is identical to the rat protein in sequences comprising the opioid peptides and 86% identical in the remainder of the molecule. Stimulation of MIN6 cells increased prodynorphin RNA levels to more than 20-fold in proportion to physiological glucose concentrations. Similar induction levels were observed in murine βTC3 and rat Rinm5F β- cell lines. Prodynorphin RNA expression increased within 1 h of glucose stimulation, achieved maximal levels by 4 h, and remained elevated for at least 24 h. By using RIA, MIN6 cells were shown to contain and secrete increased amounts of dynorphin-A following glucose stimulation. Treatment of MIN6 cells with KCl, forskolin, or isobutyl-methyl-xanthine strongly induced prodynorphin RNA expression, suggesting that induction may be related to secretion-coupled signaling pathways. The induction of prodynorphin in several β-cell lines is consistent with previous demonstrations of β-cell synthesis of other endogenous opioids, including β-endorphin, and suggests that opioids may have a potentially significant role in regulating β-cell secretion.
AB - To investigate adaptive responses of pancreatic β-cells to hyperglycemia, genes induced by glucose stimulation were identified by subtraction cloning. Among 53 clones representing differentially expressed genes, 20 encoded the endogenous opioid precursor, prodynorphin. The amino acid sequence of murine prodynorphin is identical to the rat protein in sequences comprising the opioid peptides and 86% identical in the remainder of the molecule. Stimulation of MIN6 cells increased prodynorphin RNA levels to more than 20-fold in proportion to physiological glucose concentrations. Similar induction levels were observed in murine βTC3 and rat Rinm5F β- cell lines. Prodynorphin RNA expression increased within 1 h of glucose stimulation, achieved maximal levels by 4 h, and remained elevated for at least 24 h. By using RIA, MIN6 cells were shown to contain and secrete increased amounts of dynorphin-A following glucose stimulation. Treatment of MIN6 cells with KCl, forskolin, or isobutyl-methyl-xanthine strongly induced prodynorphin RNA expression, suggesting that induction may be related to secretion-coupled signaling pathways. The induction of prodynorphin in several β-cell lines is consistent with previous demonstrations of β-cell synthesis of other endogenous opioids, including β-endorphin, and suggests that opioids may have a potentially significant role in regulating β-cell secretion.
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U2 - 10.1210/endo.139.10.6233
DO - 10.1210/endo.139.10.6233
M3 - Article
C2 - 9751516
AN - SCOPUS:0031765094
SN - 0013-7227
VL - 139
SP - 4329
EP - 4336
JO - Endocrinology
JF - Endocrinology
IS - 10
ER -