Differentiation-dependent expression of the Na+/glucose cotransporter (SGLT1) in LLC-PK1 cells: role of protein kinase C activation and ongoing transcription.
AUTOR(ES)
Shioda, T
RESUMO
We examined changes in the mRNA level of SGLT1, a Na+/glucose cotransporter, by the differentiation status of LLC-PK1 renal epithelial cells. Proliferating (undifferentiated) cells revealed no detectable SGLT1 mRNA by Northern blot analysis. However, when cells became confluent and differentiated into polarized monolayers, there was an abrupt appearance of the SGLT1 mRNA. When confluent (differentiated) cells were dedifferentiated by reseeding at a subconfluent density, SGLT1 mRNA levels decreased quickly to nondetectable levels (t1/2 = 1.5 h), while the mRNA levels of gamma-glutamyltranspeptidase, another differentiation marker, decreased only slowly (t1/2 > 40 h). This decrease in SGLT1 mRNA was completely blocked by H-7, a protein kinase inhibitor. Since protein kinase C was highly activated in the undifferentiated cells and treatment of differentiated cells with a phorbol ester also induced quick and complete loss of SGLT1 mRNA (t1/2 = 1.5 h) but not of gamma-glutamyltranspeptidase mRNA, protein kinase C activation appears to be involved in the dedifferentiation-induced decrease in SGLT1 mRNA. Although the phorbol ester-induced decrease in the SGLT1 mRNA level was blocked completely by inhibition of transcription, inhibitors of translation blocked the decrease in mRNA levels only partially.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=45347Documentos Relacionados
- Sodium butyrate increases glucose transporter expression in LLC-PK1 cells.
- Regulation of glucose transporters in LLC-PK1 cells: effects of D-glucose and monosaccharides.
- ATP receptor regulation of adenylate cyclase and protein kinase C activity in cultured renal LLC-PK1 cells.
- Toxicidade da polimixina B em células LLC-PK1 e a enzima heme oxigenase-1
- Optical measurements of intracellular pH in single LLC-PK1 cells: demonstration of Cl-HCO3 exchange.