A Wortmannin-sensitive Signal Transduction Pathway Is Involved in the Stimulation of Insulin Release by Vasoactive Intestinal Polypeptide and Pituitary Adenylate Cyclase-activating Polypeptide (*)

Vasoactive intestinal polypeptide (VIP), pituitary adenylate cyclase-activating polypeptide-27 (PACAP-27), and PACAP-38 stimulated insulin release with EC values of 0.15, 0.15, and 0.06 nM respectively, as expected for the VIP2/PACAP3 receptor subtype. Secretion was stimulated promptly and peaked at 6-10 min. At 30 min, the secretion rate was still 2-3-fold higher than the control rate. The peptides increased cyclic AMP and [Ca] transiently so that at 30 min they had returned to control values. Therefore, an additional signal is required to explain the prolonged stimulation of release. The prolonged effects, but not the acute effects of VIP and PACAP on insulin release were inhibited by low concentrations of wortmannin, a phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor. While wortmannin inhibited PI 3-kinase activity in cell lysates, no activation by the peptides was seen. Therefore, the wortmannin-sensitive pathway is either dependent on basal PI 3-kinase activity, or another target for wortmannin is responsible for inhibition of the peptide-stimulated secretion. It is concluded that the acute stimulation of insulin release by VIP and PACAP is mediated by increased cyclic AMP and [Ca], whereas the sustained release is mediated by a novel wortmannin-sensitive pathway.

[1]  S. Volinia,et al.  Cloning and characterization of a G protein-activated human phosphoinositide-3 kinase. , 1995, Science.

[2]  F. Leyva-Cobián,et al.  Wortmannin, an inhibitor of phospholipase D activation, selectively blocks major histocompatibility complex class II‐restricted antigen presentation , 1994, European journal of immunology.

[3]  J. Dodge,et al.  Wortmannin, a potent and selective inhibitor of phosphatidylinositol-3-kinase. , 1994, Cancer research.

[4]  P. Hawkins,et al.  A novel phosphoinositide 3 kinase activity in myeloid-derived cells is activated by G protein βγ subunits , 1994, Cell.

[5]  J. Miyazaki,et al.  Cloning and functional characterization of a third pituitary adenylate cyclase-activating polypeptide receptor subtype expressed in insulin-secreting cells. , 1994, Proceedings of the National Academy of Sciences of the United States of America.

[6]  K. Catt,et al.  Inhibition of agonist-stimulated inositol 1,4,5-trisphosphate production and calcium signaling by the myosin light chain kinase inhibitor, wortmannin. , 1994, The Journal of biological chemistry.

[7]  M. Nakata,et al.  Pituitary adenylate cyclase activating polypeptide is an extraordinarily potent intra-pancreatic regulator of insulin secretion from islet beta-cells. , 1994, The Journal of biological chemistry.

[8]  Y. Nonomura,et al.  Inhibition of histamine secretion by wortmannin through the blockade of phosphatidylinositol 3-kinase in RBL-2H3 cells. , 1993, The Journal of biological chemistry.

[9]  J. Fahrenkrug Transmitter role of vasoactive intestinal peptide. , 1993, Pharmacology & toxicology.

[10]  C. Vlahos,et al.  Signal transduction in neutrophil activation Phosphatidylinositol 3‐kinase is stimulated without tyrosine phosphorylation , 1992, FEBS letters.

[11]  R. Håkanson,et al.  Vascular effects of pituitary adenylate cyclase activating peptide: a comparison with vasoactive intestinal peptide , 1992, Regulatory Peptides.

[12]  R. Sillard,et al.  Demonstration of [125I]VIP binding sites and effects of VIP on cAMP-formation in rat insulinoma (RINm5F and RIN14B) cells , 1992, Regulatory Peptides.

[13]  I. Takahashi,et al.  Wortmannin, a microbial product inhibitor of myosin light chain kinase. , 1992, The Journal of biological chemistry.

[14]  S. Ohashi,et al.  Pituitary adenylate cyclase activating polypeptide stimulates insulin release from the isolated perfused rat pancreas. , 1992, Life sciences.

[15]  A. Arimura,et al.  Effect of pituitary adenylate cyclase activating polypeptide on rat pancreatic exocrine secretion , 1991, Peptides.

[16]  G. McKnight,et al.  Role of cyclic adenosine 3',5'-monophosphate-dependent protein kinase in hormone-stimulated beta-endorphin secretion in AtT20 cells. , 1991, Molecular endocrinology.

[17]  S. Koh Signal transduction through the vasoactive intestinal peptide receptor stimulates phosphorylation of the tyrosine kinase pp60c-src. , 1991, Biochemical and biophysical research communications.

[18]  L. Cantley,et al.  Purification and characterization of phosphoinositide 3-kinase from rat liver. , 1990, The Journal of biological chemistry.

[19]  N. Minamino,et al.  Isolation of a neuropeptide corresponding to the N-terminal 27 residues of the pituitary adenylate cyclase activating polypeptide with 38 residues (PACAP38). , 1990, Biochemical and biophysical research communications.

[20]  G. Zimmerman,et al.  Activation of human neutrophil phospholipase D by three separable mechanisms , 1990, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[21]  H. Onda,et al.  A novel peptide which stimulates adenylate cyclase: molecular cloning and characterization of the ovine and human cDNAs. , 1990, Biochemical and biophysical research communications.

[22]  A. Laurenza,et al.  Forskolin: a specific stimulator of adenylyl cyclase or a diterpene with multiple sites of action? , 1989, Trends in pharmacological sciences.

[23]  M. Culler,et al.  Isolation of a novel 38 residue-hypothalamic polypeptide which stimulates adenylate cyclase in pituitary cells. , 1989, Biochemical and biophysical research communications.

[24]  P. Taylor,et al.  Transient increase in phosphatidylinositol 3,4-bisphosphate and phosphatidylinositol trisphosphate during activation of human neutrophils. , 1989, The Journal of biological chemistry.

[25]  J. Conlon,et al.  Binding sites for peptide-histidine-isoleucine (PHI) on rat insulinoma-derived RINm5F cells , 1988, Molecular and Cellular Endocrinology.

[26]  B. Dewald,et al.  Two transduction sequences are necessary for neutrophil activation by receptor agonists. , 1988, The Journal of biological chemistry.

[27]  F M Matschinsky,et al.  Ca2+, cAMP, and phospholipid-derived messengers in coupling mechanisms of insulin secretion. , 1987, Physiological reviews.

[28]  M. White,et al.  Common elements in growth factor stimulation and oncogenic transformation: 85 kd phosphoprotein and phosphatidylinositol kinase activity , 1987, Cell.

[29]  M. Molitch,et al.  Vasoactive intestinal peptide is a physiological mediator of prolactin release in the rat. , 1985, Endocrinology.

[30]  R Y Tsien,et al.  Calcium homeostasis in intact lymphocytes: cytoplasmic free calcium monitored with a new, intracellularly trapped fluorescent indicator , 1982, The Journal of cell biology.

[31]  C. Wollheim,et al.  Regulation of insulin release by calcium. , 1981, Physiological reviews.

[32]  M. M. Bradford A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. , 1976, Analytical biochemistry.