RESUMEN
We investigated endothelin-1 (ET-1) receptor expression on normal human keratinocytes (HK). We show that HK express the ETB receptor isoform and respond to ET-1 with a 2.7-fold increase in intracellular free calcium. HK did not respond to ET-1 with increased proliferation; however, 30 nM ET-1 caused a 51.7% decrease in ET-1 accumulation in HK-conditioned medium. We propose that HK ET-1 receptors function in autocrine regulation of ET-1 secretion.
Asunto(s)
Endotelinas/metabolismo , Queratinocitos/metabolismo , Receptores de Endotelina/fisiología , División Celular , Células Cultivadas , Medios de Cultivo Condicionados , Humanos , Queratinocitos/citología , Unión Proteica , Receptor de Endotelina BRESUMEN
Northern blot and RNAse protection assays previously failed to detect bombesin-like peptide (BLP) receptors in normal human lung tissue, but by RT/PCR cultured human bronchial epithelial (HBE) cells expressed all three BLP receptor subtypes, predominantly neuromedin B (NMB) receptor. By RT/PCR, we found expression of all three BLP receptor subtypes by human lung tissue and confirmed NMB receptor expression in six out of six HBE samples. However, transformed HBE BEAS B2B cells expressed only gastrin-releasing peptide (GRP) receptors; saturable, high-affinity (Kd = 3.5 nM) specific [125I]GRP binding confirmed functional GRP receptor, with M(r) = 75 kDa and immunologic cross-reactivity with GRP receptor from human small-cell lung carcinoma (SCLC) NCI-H345 cells. Altered regulation of BLP receptors may accompany transformation of normal lung cells to cancer.
Asunto(s)
Bronquios/metabolismo , Receptores de Bombesina/metabolismo , Células 3T3 , Animales , Secuencia de Bases , Células Cultivadas , Cartilla de ADN/genética , ADN Complementario/genética , Epitelio/metabolismo , Fibroblastos/metabolismo , Humanos , Ratones , Ratones Endogámicos BALB C , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Receptores de Bombesina/genética , Homología de Secuencia de Ácido NucleicoRESUMEN
The recently devised methods for surgical sampling of chorio-retinal tissue permits morphological evaluation of retina in various diseases. In the present report it is demonstrated, that the retinal pigment epithelium in such samples can be isolated as a viable cell population, and that the cell mass can be increased sufficiently in culture to permit biochemical as well as morphological studies. This procedure thereby expands the diagnostic potential of the sample tissue.