The Effects of Somatostatin on Immune Cells, Functions and Diseases

摘要: Somatostatin (SST) is a ubiquitous neuropeptide hormone that was first extracted from bovine hypothalamus as an inhibitor of growth secretion (Brazeau et al. 1973). The SST gene very ancient present in all vertebrate classes (Tostivint 2004). Since its discovery 1973, has stimulated plethora studies investigating multiple physiological actions great variety tissues. continued scientific interest been evident over the years including cloning family five somatostatin receptors (SSTRs) 1992 (Yamada 1992; O’Carroll Panetta 1994), characterization related corticostatin 1996 (de Lecea 1996; Tostivint 1996), and development hundreds synthetic analogues, some them with clinical applications. exists two bioactive forms, 14 amino acid peptide 1973) cogener somatostatin-14 extended at N-terminus called somatostatin-28 (Pradayrol 1980) (Fig. 7.1). widely distributed central peripheral nervous system but also endocrine pancreas, gut thyroid, prostate, placenta, adrenals, kidneys skin (Luft 1974; Arimura 1975; Dubois Hokfelt Orci Pelletier Polak Patel Reichlin 1978; Johansson Nordlind 1984). sympathetic sensory neurons innervating lymphoid organs may thus influence functional responses lymphocytes antigen-presenting cells (Aguila 1991; Felten 1985). expressed both cortical medullary thymic epithelial (Solomou 2002). suppresses synthesis factors such insulin-like factor 1. inhibits gastrointestinal hormones include gastrin, cholecystokinin, serotonin, glucagon, vasoactive intestinal peptide, others (Alberti 1973; Koerker Zhang Philippe 1993; Nelson-Piercy 1994; Kleinman 1995; Ballian 2006; Corleto 2010). There evidence several test systems can modulate to mitogens T cell antigen receptor (TCR)/CD3 stimulation even influences adhesion motility lymphocytes. stimulates extracellular matrix components (ECM) (Levite 1998). proliferation directly by regulating tyrosine kinase, phosphatase, nitric oxide synthase, cyclic guanosine 3′, 5′-cyclic monophosphate–dependent protein RAS/extracellular signal–regulated kinase signalling pathways (Pyronnet 2008). antiangiogenic properties induce apoptosis (Sharma Srikant 1998; Woltering 2003; Pyronnet Glucagons, growth-releasing hormone, neurotensin, corticotrophin-releasing calcitonin gene-related bombesin are potent stimulators secretion, while opiate GABA inhibitors (Patel Epelbaum 1994). Inflammatory cytokines have shown regulatotory effects on secretion: IL-1, IL-6, IL-10; INF-γ, TNF-α stimulate whereas TGF-β release (Scarborough 1989; Quintela 1997; Elliott