Modulation of rhodopsin gene expression and signaling mechanisms evoked by endothelins in goldfish and murine pigment cell lines

AUTOR(ES)

Lopes, G.J.D., Góis, C.C., Lima, L.H.R.G., Castrucci, A.M.L.

FONTE

Brazilian Journal of Medical and Biological Research

DATA DE PUBLICAÇÃO

2010-09

RESUMO

Endothelins (ETs) and sarafotoxins (SRTXs) belong to a family of vasoconstrictor peptides, which regulate pigment migration and/or production in vertebrate pigment cells. The teleost Carassius auratus erythrophoroma cell line, GEM-81, and Mus musculus B16 melanocytes express rhodopsin, as well as the ET receptors, ETB and ETA, respectively. Both cell lines are photoresponsive, and respond to light with a decreased proliferation rate. For B16, the doubling time of cells kept in 14-h light (14L):10-h darkness (10D) was higher compared to 10L:14D, or to DD. The doubling time of cells kept in 10L:14D was also higher compared to DD. Using real-time PCR, we demonstrated that SRTX S6c (12-h treatment, 100 pM and 1 nM; 24-h treatment, 1 nM) and ET-1 (12-h treatment, 10 and 100 pM; 24- and 48-h treatments, 100 pM) increased rhodopsin mRNA levels in GEM-81 and B16 cells, respectively. This modulation involves protein kinase C (PKC) and the mitogen-activated protein kinase cascade in GEM-81 cells, and phospholipase C, Ca2+, calmodulin, a Ca2+/calmodulin-dependent kinase, and PKC in B16 cells. Cells were kept under constant darkness throughout the gene expression experiments. These results show that rhodopsin mRNA levels can be modulated by SRTXs/ETs in vertebrate pigment cells. It is possible that SRTX S6c binding to the ETB receptors in GEM-81 cells, and ET-1 binding to ETA receptors in B16 melanocytes, although activating diverse intracellular signaling mechanisms, mobilize transcription factors such as c-Fos, c-Jun, c-Myc, and neural retina leucine zipper protein. These activated transcription factors may be involved in the positive regulation of rhodopsin mRNA levels in these cell lines.

Documentos Relacionados

• Expressão gênica e protéica de rodopsina em células pigmentares e mecanismos de sinalização intracelular da sua modulação por endotelinas
• Frequent hereditable shutdown of murine retrovirus gene expression in murine cell lines.
• Immunoglobulin gene expression and DNA methylation in murine pre-B cell lines.
• Tissue- and stage-specific modulation of Wingless signaling by the segment polarity gene lines
• Expression of a drug resistance gene in human neuroblastoma cell lines: modulation by retinoic acid-induced differentiation.