n-Butyrate induces plasminogen activator inhibitor type 1 messenger RNA in cultured Hep G2 cells

Abstract

n-Butyrate, a short-chain aliphatic carboxylic acid with pleiotropic actions, is present at high concentrations in the portal circulation and thus may play an important role in the regulation of specific gene expression in the mammalian liver. We report here that n-butyrate can increase substantially the level of plasminogen activator inhibitor type 1 (PAI-1) messenger RNA (mRNA) in Hep G2 cells, up to eightfold above control cultures. Maximal effects occurred at a concentration of 3 mmol/L n-butyrate and with a treatment period of 8 to 12 hours. Increases in PAI-1 mRNA were accompanied by modest increases (twofold) in the encoded protein as assessed by specific enzyme-linked immunosorbent assay and by [35S]methionine incorporation into immunoprecipitable PAI-1 in the culture medium. Nuclear run-on studies showed that the rate of transcription of the PAI-1 gene did not appear altered by treatment with 3 mmol/L n-butyrate for 6 hours. The increases in steady-state PAI-1 mRNA caused by exposure to n-butyrate can be blocked by cycloheximide. Enhanced stability of mature PAI-1 transcript could not be demonstrated in Hep G2 cells treated with the carboxylic acid. We have reported previously that n-butyrate can reduce the level of beta-galactoside alpha 2,6-sialyltransferase expression in Hep G2 cells. That effect was attenuated with inhibitors of protein and RNA synthesis and was mediated at the post-transcriptional level. Thus, n-butyrate can influence the expression of multiple genes in this hepatoblastoma cell through its actions on events that appear to be posttranscriptional. These observations may be relevant to the normal physiology of the mammalian liver because of the high concentrations of n-butyrate and related compounds to which the organ is ordinarily exposed.

Activation of transiently transfected reporter genes in 3T3 Swiss cells by the inducers of differentiation/apoptosis – dimethylsulfoxide, hexamethylene bisacetamide and trichostatin A

“…in the signal of the Charcot-Leyden crystal gene using HL-60 cells exposed to SB for 48 h. The exposure time (48 h) indicates that the increase is not a primary effect of SB. Smith et al [43], on the other hand, reported a decrease in the signal of the plasminogen activator inhibitor type 1 gene using Hep G2 cells treated with n-butyrate. As butyrate did not affect [41] (or even decreased [43]) the stability of the mRNAs in experiments using actinomycin D, neither transcriptional activation nor stabilization of the mRNA accounted for the increase in the steady-state level of the mRNA [43].…”

Baculovirus ETL promoter acts as a shuttle promoter between insect cells and mammalian cells1

“…Butyrate did not enhance the activity of the ETL promoter in mammalian cells Several studies have shown that histone deacetylase (HDAC) inhibitors, such as butyrate, can effectively enhance protein expression in mammalian cells [18,19] . To clarify whether the baculovirus early genedependent ETL promoter can also be enhanced by butyrate, we added 10 mmol/L butyrate to the COS-1 cell culture medium after transduction with vAcR-IR-G or vGS-EV71 ( Figure 5).…”

Taguchi Experimental Design for Optimization of Recombinant Human Growth Hormone Production in CHO Cell Lines and Comparing its Biological Activity with Prokaryotic Growth Hormone

“…Sodium butyrate (NaBu) is one of the most commonly used chemical additives in mammalian cell culture and is a known protein enhancer in CHO cells. NaBu improves productivity of recombinant proteins in CHO cells by hyperacetylation of histones, especially H4 by inactivation of histone deacetylase and changes in chromatin structure [16], NaBu causes over expression of mRNAs coding for a variety of proteins [17,18]. However, increased apoptosis was also observed by the addition of NaBu in these cultures [19].…”