Malagon Maria M, Molina Marcelo, Gahete Manuel D, Duran-Prado Mario, Martinez-Fuentes Antonio J, Alcain Francisco J, Tonon Marie-Christine, Leprince Jérôme, Vaudry Hubert, Castaño Justo P, Vazquez-Martinez Rafael
Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14014 Cordoba, Spain.
Peptides. 2008 May;29(5):711-20. doi: 10.1016/j.peptides.2007.12.015. Epub 2008 Jan 17.
The UII and urotensin II-related peptide (URP) genes belong to the same superfamily as the somatostatin gene. It has been previously shown that somatostatin activates the UII-receptor (UTR). In contrast, the possible interaction between UII and URP and somatostatin receptors has remained scarcely analyzed. Herein, we have investigated the effects of UII and URP on cell proliferation and free cytosolic Ca2+ concentration ([Ca2+]i) in CHO-K1 cells stably expressing the porcine somatostatin receptor subtypes sst2 and sst5. Results show that both UII and URP induce stimulation of cell proliferation mediated by sst2 receptors and UII provokes inhibition of cell proliferation mediated by sst5 receptors. UII and URP also provoked an increase of [Ca2+]i in both sst2- and sst5-transfected cells. Together, our present data demonstrate that UII and URP directly activate sst2 and sst5 and thus mimic the effect of somatostatin on its cognate receptors.
尿活性肠肽（UII）和尿紧张素II相关肽（URP）基因与生长抑素基因属于同一超家族。先前的研究表明，生长抑素可激活UII受体（UTR）。相比之下，UII和URP与生长抑素受体之间可能的相互作用几乎未被分析。在此，我们研究了UII和URP对稳定表达猪生长抑素受体亚型sst2和sst5的CHO-K1细胞增殖和游离胞质Ca2+浓度（[Ca2+]i）的影响。结果表明，UII和URP均可通过sst2受体介导刺激细胞增殖，而UII可通过sst5受体介导抑制细胞增殖。UII和URP还可使转染了sst2和sst5的细胞中的[Ca2+]i升高。总之，我们目前的数据表明，UII和URP可直接激活sst2和sst5，从而模拟生长抑素对其同源受体的作用。
