Heparin Sulfate in Normal Islets (Alcina blue and Histochemistry staining) Invading mononuclear cells of NOD mice express heparanase NOD DM Prevention with inhibitor heparanase Ziokowski..Simeonovic: Heparan sulfate and heparanase play key roles in mouse beta cell survival and autoimmune diabetes JCI 122: , 2012
Schematic Representation of the Putative Steps in the Mechanism of Insulin Exocytosis & ß-Granule Trafficking in Pancreatic ß-cells SNAP/ NSF Complex Disassociation & Recycling ATP Insulin Secretory Granules Storage Pool Pre-Docking (+ Rab3A/Rab27/RIM2/munc18/ piccolo/bassoon/Exos) READILY RELEASABLE POOL Fusion Pore Ca 2+ (VAMP2/Syntaxin/SNAP-25/ synaptotagmin/syncollin) Multigranular Body Degradation Transport (+ microtubles/microfilaments/ATP/ MAP-2/kinesin/Rab3A/kinase/phosphatase) Plasma Membrane Docked (VAMP2/Syntaxin/ SNAP-25) Primed ATP (VAMP2/Syntaxin/ SNAP-25/CAPS) Rhodes
Primary DCV sorting Secondary DCV sorting DCV fusion Crystallisation & exocytosis Kiss & run retrieval Endosomal fusions Constitutive-like release Golgi cargo aggregation Membrane Traffic BDC -Hutton
K R R R Split 32,33 proinsulin CPH K R R R Proinsulin PC1PC2 K R R R Split 65,66 proinsulin CPE Insulin Des 31,32 proinsulin K R PC2 Des 64,65 proinsulin R R PC1 R R Diarginyl insulin CPE Proinsulin Processing BDC -Hutton
110aa Preproglucagon Preproinsulin A|F 1 KTRR|E 33 KR|G 66 Ins B-chain C-peptide Ins A-Chain 180aa Q|R 1 KR|H 33 KR|N 64 KR|H 72 R|H 78 RGRR|D 111 GRR|H 125 RK 160 GlicentinGlucagon OxyntomodulinGLP-1GLP-2 GLP-1 (7-37amide) 116aa Preprosomatostatin G|A 25 F|L 34 Q|R 89 Antrin ? SS-14 Somatostatin 28 RERK|A aa Prepro Pancreatic polypeptide E|P 33 RPRYGKR|H 69 Pancreatic polypeptide Islet Prohormones BDC -Hutton
Localization of PC1 with Islet Hormones PC1 Glucagon Insulin BDC -Hutton
Localization of Islet PC2 with islet hormones PC2 Glucagon Insulin BDC -Hutton
CPE Glucagon Insulin Localization of CPE with islet hormones BDC -Hutton
Chromogranin A 457aa A|L 19 KK|H 97 KR|E 134 GGK|S 322 S|L 260 RKGESR|S 272 AR|A 380 Vasostatin I Betagranin (Vasostatin II) RR|G 393 WE14Pancreastatin VR|G 413 AKR|E 228 KR|W 342 KR|l 358 RR|G 457 RR AEDQELESLSAIEAELEKVAHQLQAL RR AEDQELESLSAIEAELEKVAHQLQAL ESLSAIEAELEKVAHQLQALRR FRAR AYGFRDPGPQL RRG AYGFRDPGPQL YGFRDPGPQL GFRDPGPQL FRDPGPQLR KR WSRMDQLAKELTAE KR WSRMDQLAKELTAE MDQLAKELT WSRMDQLAKEL SRMDQLAKELT RWSRMDQLAKELTAE KRLE GEDDPDRSMKLS FRAR CgA products BDC -Hutton
89aa Preproamylin A|T 23 KR|K 34 GKR|N 74 IAPP amide PC1 PC2 Proamylin Processing BDC -Hutton
7B2 Insulin Glucagon Localization of 7B2 with islet hormones BDC -Hutton
proSAAS Glucagon Insulin Localization of proSAAS with islet hormones BDC -Hutton
Extrapancreatic insulin-producing cells in multiple organs in diabetes Kojima et al. PNAS 2004; 101: Proinsulin mRNA and proinsulin protein induced with multiple forms of hyperglycemia in marrow derived CD45+ murine cells (in liver, adipose tissue, spleen, bone marrow and thymus[some acinar pancreas but not remnant islets]) STZ rat and mice; ob/ob mice/IP glucose X 3 days Transgenic GFP driven by mouse insulin promoter gave complete concordance with presence proinsulin Bone marrow transplantation experiments (bta galactosidase postive cells)indicated bone marrow derivation-Post glucose injections 30% of bone marrow cells positive for proinsulin and 75% of proinsulin positive cells beta galactosidase positive. Proinsulin and somatostatin protein in same cells of liver of glucose injected mice. BDC