Biomedical subjects

S Bovard-Houppermans

Publications and source records attributed to S Bovard-Houppermans.

3 recordsLinked to original sources

PubMed1994

Fenofibric acid modulates the human apolipoprotein A-IV gene expression in HepG2 cells.

The influence of the hypolipidemic drug, fenofibric acid, on the regulation of apolipoprotein A-IV (apoA-IV) gene expression was investigated in two human cell lines, HepG2 and Caco-2. As shown in the present report, fenofibric acid induces a strong dose-dependent increase of the apoA-IV mRNA level in HepG2 cells, while other apolipoproteins mRNA levels are only slightly modified. In Caco-2 cells, no modification is observed, except for a 2-fold increase of the apoE mRNA level. The increase of the apoA-IV mRNA level could be correlated with a clear enhancement of DNase I hypersensitive sites in the 5' flanking region of the gene in nuclei of HepG2 cells treated with fenofibric acid. Thus, fenofibric acid may act by facilitating the interaction of nuclear regulatory proteins with the DNA in the control regions of the apoA-IV gene.

Apolipoproteins↗

PubMed1994

[Human apolipoprotein A-IV].

Human apolipoprotein A-IV is a member of a family of proteins involved in lipoprotein metabolism. It differs from the other apolipoproteins by physical and chemical properties which allow it to exist in a lipoprotein-free form in plasma. ApoA-IV is synthesised primarily in the intestine and in the liver, and its production is regulated during development. Its expression is also modulated by different effectors such as nutrients and hormones. Its physiological role remains poorly understood. Aside from its implication in reverse cholesterol transport, it could also have a function in the absorption and export of triglycerides; however the relation between these roles remains to be established. Insights into the molecular biology of the apoA-IV gene, which arises from an ancestor gene common to the soluble apolipoprotein genes, will help to clarify the physiological role of this protein.

Apolipoproteins A↗

PubMed1993

Human apolipoprotein A-IV gene expression is modulated by members of the nuclear hormone receptor superfamily.

Human apolipoprotein A-IV (apo A-IV) is essentially synthesized in intestine and to a lower extent in liver. The presence of detectable amounts of apo A-IV messenger in HepG2 and Caco-2 cells enables us to study the transcription regulation of the gene in these cells. A main hypersensitive site to DNase I is detected in the DNA of HepG2 nuclei, in a region situated about 3400 base pairs upstream from the cap site. Transient expression experiments in HepG2, Caco-2 and HeLa cells indicate that HNF-4 activates the transcription of a reporter gene through the -3500/+67 sequence of the apo A-IV gene. This activation is repressed by another transcription factor, Ear3/COUP-TF. On the contrary, HNF-1, whose expression is controlled by HNF-4, is not involved in the regulation of the reporter gene transcription through the -6700/+67 genome sequence. These results indicate that the apo A-IV gene expression is modulated by orphan ligand members of the superfamily of nuclear hormone receptors.

Apolipoproteins A↗