Expression and localization of somatostatin receptor types 3, 4 and 5 in the wild-type, SSTR1 and SSTR1/SSTR2 knockout mouse cochlea

Abstract

Somatostatin (SST) is a peptide hormone that exerts inhibitory effects mediated through binding to specific cell surface G protein-coupled receptors, of which five distinct subtypes (SSTR1-SSTR5) have been characterized. Our study performed on mouse cochlear hair cells shows the expression and localization of the three receptors (SSTR3-SSTR5) in wild-type (WT), single-knockout (SSTR1 KO) and double-knockout SSTR1/SSTR2 (DKO) mice. Similar SSTRs expression were observed in the inner hair cells (IHC), outer hair cells (OHC) and supporting cells of cultivated P7 mouse organ of Corti (OC) explants as well as in cultivated cochlear neuroepithelial supporting cells (NEsc). We found differences in the expression of SSTR3-5 in WT, SSTR1 KO and DKO mouse cochlea, which might be explained as a compensatory effect in the cochlea after the loss of SSTR1 and/or SSTR2.

International Union of Basic and Clinical Pharmacology. CV. Somatostatin Receptors: Structure, Function, Ligands, and New Nomenclature

“…SST 5 is present in the rat retina, where its activation protects from AMPA–induced neurotoxicity ( Kiagiadaki et al, 2010 ). SST 5 is also present in cochlea, but its role and relevance are not yet known ( Radojevic and Bodmer, 2014 ). In the reproductive tract, SST 5 is present in Sertoli cells, where its expression is developmentally regulated ( Riaz et al, 2013 ).…”

Pasireotide prevents nuclear factor of activated T cells nuclear translocation and acts as a protective agent in aminoglycoside‐induced auditory hair cell loss

“…; Bodmer et al . ; Radojevic and Bodmer ) and demonstrated that Sstr1–5 are expressed in both the outer and inner HCs of the OC, and in a subset of supporting cells. We also demonstrated that somatostatin protects HCs from gentamicin‐induced HC death in vitro , and that octreotide protects HCs from gentamicin toxicity via the activation of Akt signaling (Brand et al .…”

“…SST has been explored as a treatment for hormonal imbalance, diseases of disrupted cell proliferation, and dysregulated neuronal signaling (Harris 1990(Harris , 1994. We previously studied the somatostatinergic system in the mammalian inner ear (Radojevic et al 2011;Bodmer et al 2012;Radojevic and Bodmer 2014) and demonstrated that Sstr1-5 are expressed in both the outer and inner HCs of the OC, and in a subset of supporting cells. We also demonstrated that somatostatin protects HCs from gentamicin-induced HC death in vitro, and that octreotide protects HCs from gentamicin toxicity via the activation of Akt signaling (Brand et al 2014).…”

Identification of Somatostatin Receptor Subtype 1 (SSTR1) Gene Polymorphism and Their Association with Growth Traits in Hulun Buir Sheep

“…To discover the potential functional mutations related to the growth traits in Hulun Buir sheep, we conducted exon sequencing of the SSTR1 gene, The ovine SSTR1 gene transcript has three exons and two introns (ENSOART00020017811.1) located on chromosome 18 (GenBank, Gene ID: 443202), encoding 1089 bp base (47398442–47400840) and 362 amino acid residues [ 33 ]. As a receptor of somatostatin, the SSTR1 gene plays an important role in many physiological processes, such as cell anti-proliferation, and inhibition of gastrointestinal motility and regulates a variety of signal transduction pathways [ 34 ]. Four SNPs (A345G, A285G, C309T and G951C) were all in Hardy–Weinberg equilibrium, which indicated an adequate population size of Hulun Buir sheep under random mating (or without selection) in the experiment [ 35 ].…”