Sato Miho, Nakahara Keiko, Goto Shintaro, Kaiya Hiroyuki, Miyazato Mikiya, Date Yukari, Nakazato Masamitsu, Kangawa Kenji, Murakami Noboru
Department of Veterinary Physiology, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2155, Japan.
Biochem Biophys Res Commun. 2006 Nov 24;350(3):598-603. doi: 10.1016/j.bbrc.2006.09.088. Epub 2006 Sep 26.
Expressions of the growth hormone secretagogue receptor (GHS-R) mRNA and its protein were confirmed in rat fetal spinal cord tissues by RT-PCR and immunohistochemistry. In vitro, over 3 nM ghrelin and des-acyl ghrelin induced significant proliferation of primary cultured cells from the fetal spinal cord. The proliferating cells were then double-stained using antibodies against the neuronal precursor marker, nestin, and the cell proliferation marker, 5-bromo-2'-deoxyuridine (BrdU), and the nestin-positive cells were also found to be co-stained with antibody against GHS-R. Furthermore, binding studies using [125I]des-acyl ghrelin indicated the presence of a specific binding site for des-acyl ghrelin, and confirmed that the binding was displaced with unlabeled des-acyl ghrelin or ghrelin. These results indicate that ghrelin and des-acyl ghrelin induce proliferation of neuronal precursor cells that is both dependent and independent of GHS-R, suggesting that both ghrelin and des-acyl ghrelin are involved in neurogenesis of the fetal spinal cord.
通过逆转录聚合酶链反应（RT-PCR）和免疫组织化学方法，在大鼠胎儿脊髓组织中证实了生长激素促分泌素受体（GHS-R）mRNA及其蛋白的表达。在体外，超过3 nM的胃饥饿素和去酰基胃饥饿素可诱导胎儿脊髓原代培养细胞显著增殖。然后使用针对神经元前体标志物巢蛋白和细胞增殖标志物5-溴-2'-脱氧尿苷（BrdU）的抗体对增殖细胞进行双重染色，并且还发现巢蛋白阳性细胞与抗GHS-R抗体共染色。此外，使用[125I]去酰基胃饥饿素的结合研究表明存在去酰基胃饥饿素的特异性结合位点，并证实该结合可被未标记的去酰基胃饥饿素或胃饥饿素取代。这些结果表明，胃饥饿素和去酰基胃饥饿素诱导神经元前体细胞增殖，这既依赖于GHS-R，也独立于GHS-R，提示胃饥饿素和去酰基胃饥饿素均参与胎儿脊髓的神经发生。
