Altered immunoreactivity of HPC-1/syntaxin 1A in proliferated nerve fibers in the human aganglionic colon of Hirschsprung's disease.

To clarify the pathogenesis of excessive proliferation of extrinsic nerve fibers in the aganglionic colon of patients with Hirschsprung's disease (HD), we immunohistochemically determined the role that exocytosis-related proteins play in the regulation of exocytosis using the antibody to HPC-1/syntaxin 1A, an exocytosis-related protein. Localization of exocytosis-related proteins (HPC-1/syntaxin 1A, N-ethylmalemide-sensitive fusion protein (NSF), soluble NSF attachment protein (SNAP), synaptotagmin, synaptobrevin, and synaptosome-associated protein 25 (SNAP-25)) was determined in surgical specimens obtained from normal proximal and aganglionic distal segments of the colon of 7 infant patients with HD. In the normal ganglionic colon, Auerbach's plexus, Meisner's plexus, nerve fibers in the muscle layer, and ganglion cells were immunopositive for all six kinds of antisera.

Non-functional role of syntaxin 2 in insulin exocytosis by pancreatic beta cells.

This study was designed in order to examine the expression and functional role of syntaxin 2/epimorphin in pancreatic beta cells. Northern blot analysis revealed that syntaxin 2 mRNA was able to be detected in mouse beta TC3 cells, but not in isolated mouse islets. In agreement with this result, immunoblot analysis detected an appreciable amount of syntaxin 2 protein in beta TC3 cells, but not in mouse islets.