title: Manipulation of metallothionein expression in the regenerating rat liver using antisense oligonucleotides.
abstract: Metallothioneins (MTs) are low molecular weight, zinc-binding proteins that by activating zinc metalloenzymes participate in the regulation of growth and development. The present study was designed to examine the roles of MTs in cell proliferation using an in vivo model of liver regeneration following partial hepatectomy (PH) in rats. The levels of MT-I and MT-II were studied with respect to regulation of proliferative potential, cell cycle checkpoint activity, and oxidative stress in the rat PH model. We synthesized a 17-mer antisense phosphorothioate oligodeoxynucleotide (S-ODN), named aMT, complimentary to the start site of the MT-I mRNA sequence and an appropriate control. Both S-ODNs were administered intraperitoneally at the dose of 5 mg/kg following 70% PH. MT became induced 57.4 +/- 9.8-fold following PH and the said effect became attenuated dramatically following administration of aMT. In addition, PH rats treated with aMT exhibited decreased rate of liver regeneration as measured by expression of proliferating cell nuclear antigen and elevated cell cycle checkpoint activity as determined by expression of p53. The results of these studies suggest that MT isoforms with their high thiol contents do play an important role in cellular functions and especially during stressful states induced by a broad range of mediators generating free radicals.
authors.affiliation: Department of Pharmacology, University of Nebraska College of Medicine, Omaha 68198-6260, USA.
authors.forename: V
authors.initials: V
authors.lastname: Arora
authors.forename: P L
authors.initials: PL
authors.lastname: Iversen
authors.forename: M
authors.initials: M
authors.lastname: Ebadi
mesh_terms: D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases; D002455:Cell Division / Q000187:drug effects*; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D019362:Cytochrome P-450 CYP2B1 / Q000378:metabolism; D051544:Cytochrome P-450 CYP3A; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D008115:Liver Regeneration / Q000187:drug effects*; D008297:Male; D008668:Metallothionein / Q000096:biosynthesis* / Q000235:genetics; D009596:Nitrophenols / Q000378:metabolism; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects*; D010089:Oxidoreductases, N-Demethylating / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis; D019287:Zinc Sulfate / Q000494:pharmacology
chemical_list: D009596:Nitrophenols; D016376:Oligonucleotides, Antisense; D018809:Proliferating Cell Nuclear Antigen; D016159:Tumor Suppressor Protein p53; D019287:Zinc Sulfate; D003577:Cytochrome P-450 Enzyme System; D008668:Metallothionein; D001189:Aryl Hydrocarbon Hydroxylases; D019363:Cytochrome P-450 CYP1A1; D019362:Cytochrome P-450 CYP2B1; D051544:Cytochrome P-450 CYP3A; D010089:Oxidoreductases, N-Demethylating; C024836:4-nitrophenol