Words similar to sp-a
Example sentences for: sp-a
How can you use “sp-a” in a sentence? Here are some example sentences to help you improve your vocabulary:
In cultured human muscle cells, only the PI 3-kinase - p70 S6 kinase pathway, and not the MAPK pathway, mediates insulin up-regulation of p85α PI 3-kinase gene expression [ 26 ] . Similarly, in L6 myotubes, insulin induces hexokinase II gene transcription via the rapamycin-sensitive PI 3-kinase pathway, but not via the MAPK pathway [ 27 ] . The PI 3-kinase - p70 S6 kinase pathway, but not the MAPK pathway, mediates insulin induction of glucose-6-phosphate dehydrogenase gene expression in primary rat hepatocytes [ 28 ] . In H411E liver cells, insulin down-regulates cAMP-induced phosphoenolpyruvate carboxykinase gene transcription via the PI 3-kinase pathway, but not via the MAPK pathway [ 29 ] . Phosphorylated p70 S6 kinase has been shown to be present in the nucleus in insulin-treated cells [ 30 ] . Moreover, it has been shown that p70 S6 kinase phosphorylates and activates members of the cAMP response element modulator family of transcription factors [ 31 ] . These data raise the possibility that transcriptional regulation of SP-A gene expression occurs via the PI 3-kinase - p70 S6 kinase pathway.
We found that wortmannin and rapamycin had no effect on basal SP-A mRNA levels, at any concentration tested.
However, 2 μM LY294002 abolished the inhibitory effects of insulin, but did not affect basal SP-A mRNA levels.
Chess and coworkers have shown that transforming growth factor-α and hepatocyte growth factor increase the phosphorylation of p44/p42 MAPK in H441 cells [ 23 ] . Epidermal growth factor, which binds to the same receptor as transforming growth factor-α, increases SP-A content in human fetal lung [ 24 ] . Hepatocyte growth factor has also been shown to upregulate the synthesis of SP-A in rat type II cells [ 25 ] . Thus, phosphorylation of p44/42 MAPK may be involved in the up-regulation of SP-A gene expression, results consistent with our observation that inhibition of basal levels of p44/42 MAPK phosphorylation may decrease SP-A gene expression.
In summary, our studies are suggestive that in lung epithelial cells, SP-A gene transcription is inhibited by insulin via the rapamycin-sensitive PI 3-kinase pathway, but not the p44/42 MAPK pathway.
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