title: Hypercholesterolemia and apolipoprotein B expression: regulation by selenium status.
abstract: BACKGROUND
  Apolipoprotein B (apoB) contains ligand-binding domain for the binding of LDL to LDL-R site, which enables the removal of LDL from circulation. Our recent data showed that selenium (Se) is involved in the lipid metabolism. The present study was aimed to understand the effect of Se deficiency (0.02 ppm) and selenium supplementation (1 ppm) on apoB expression in liver during hypercholesterolemia in male Sprague Dawley rats. Animals were fed with control and high cholesterol diet (2%) for 1 and 2 months. ApoB levels by ELISA and protein expression by western blot was done. Hepatic LDL receptor (LDL-R) activity (in vivo) and mRNA expression by RT-PCR was monitored.
  
  
  RESULTS
  In selenium deficiency and on high cholesterol diet (HCD) feeding apoB levels increased and LDL-R expression decreased significantly after 2 months. On 1 ppm selenium supplementation apoB expression significantly decreased and LDL-R expression increased after 2 months. But after one month of treatment there was no significant change observed in apoB and LDL-R expression.
  
  
  CONCLUSIONS
  So the present study demonstrates that Se deficiency leads to up regulation of apoB expression during experimental hypercholesterolemia. Selenium supplementation upto 1 ppm leads to downregulation of apoB expression. Further, this study will highlight the nutritional value of Se supplementation in lipid metabolism.
authors.affiliation: Department of Biophysics, Panjab University, Chandigarh-160014, India. sanjivdhingra@gmail.com
authors.forename: Sanjiv
authors.initials: S
authors.lastname: Dhingra
authors.forename: Mohinder P
authors.initials: MP
authors.lastname: Bansal
mesh_terms: D000818:Animals; D001055:Apolipoproteins B / Q000096:biosynthesis*; D002784:Cholesterol / Q000097:blood; D002791:Cholesterol, Dietary / Q000008:administration & dosage; D008078:Cholesterol, LDL / Q000097:blood; D015536:Down-Regulation / Q000187:drug effects; D005979:Glutathione Peroxidase / Q000378:metabolism; D006937:Hypercholesterolemia / Q000378:metabolism*; D007453:Iodide Peroxidase / Q000378:metabolism; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011973:Receptors, LDL / Q000096:biosynthesis; D012643:Selenium / Q000008:administration & dosage* / Q000097:blood / Q000172:deficiency*; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D015854:Up-Regulation
chemical_list: D001055:Apolipoproteins B; D002791:Cholesterol, Dietary; D008078:Cholesterol, LDL; D011973:Receptors, LDL; D014284:Triiodothyronine; D002784:Cholesterol; C109812:iodothyronine deiodinase type I; D007453:Iodide Peroxidase; D005979:Glutathione Peroxidase; D012643:Selenium; D013974:Thyroxine