title: Zinc affects miR-548n, SMAD4, SMAD5 expression in HepG2 hepatocyte and HEp-2 lung cell lines.
abstract: MicroRNAs affect disease progression and nutrient status. miR-548n increased 57 % in Zn supplemented plasma from adolescent females (ages 9 to 13 years). The purpose of this study was to determine the effects of Zn concentration in cell culture on the expression of miR-548n, SMAD4 and SMAD5 in hepatocyte (HepG2) and lung epithelium (HEp-2) cell lines. Cells were incubated for 48 h in media containing 10 % Chelex 100-treated FBS (0 μM Zn), or with 15 or 50 μM Zn, before isolation of total RNA and cDNA. Expression of miR-548n, SMAD4 and SMAD5 was measured by qPCR. The ΔΔCT method was used to calculate the fold-change, and 15 µM expression levels were used as reference values. HepG2 miR-548n expression decreased 5-fold, and SMAD4 expression increased 4-fold in the absence of Zn, while HEp-2 miR-548n expression increased 10.5-fold, and SMAD5 expression increased 20-fold in the absence of Zn. HEp-2 miR-548n expression increased 23-fold, while SMAD4 expression decreased twofold, in 50 μM Zn-treated cells. However, SMAD4 and SMAD5 expression was not correlated. These data indicate that miR-548n expression is in part regulated by Zn in a cell-specific manner. SMAD4 and SMAD5 are genes in the TGF-β/BMP signaling pathway, and SMAD5 is a putative target for miR-548n; Zn participates in regulating this pathway through controlling SMAD4 and SMAD5 expression. However, SMAD5 expression may be more sensitive to Zn than to miR-548n since SMAD5 expression was not inversely correlated with miR-548n expression.
authors.affiliation: Department of Foods and Nutrition, The University of Georgia, Athens, GA, 30602, USA. agrider1@uga.edu.
authors.forename: Arthur
authors.initials: A
authors.lastname: Grider
authors.affiliation: Department of Foods and Nutrition, The University of Georgia, Athens, GA, 30602, USA.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Lewis
authors.affiliation: Department of Foods and Nutrition, The University of Georgia, Athens, GA, 30602, USA.
authors.forename: Emma M
authors.initials: EM
authors.lastname: Laing
authors.affiliation: Department of Infectious Diseases, College of Veterinary Medicine, The University of Georgia, Athens, GA, 30602, USA.
authors.forename: Abhijeet A
authors.initials: AA
authors.lastname: Bakre
authors.affiliation: Department of Infectious Diseases, College of Veterinary Medicine, The University of Georgia, Athens, GA, 30602, USA.
authors.forename: Ralph A
authors.initials: RA
authors.lastname: Tripp
mesh_terms: D002460:Cell Line; D002648:Child; D019587:Dietary Supplements; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D056945:Hep G2 Cells; D006801:Humans; D035683:MicroRNAs / Q000097:blood / Q000235:genetics*; D009928:Organ Specificity; D020545:Respiratory Mucosa / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction; D051901:Smad4 Protein / Q000235:genetics* / Q000378:metabolism; D051902:Smad5 Protein / Q000235:genetics* / Q000378:metabolism; D019287:Zinc Sulfate / Q000097:blood / Q000494:pharmacology*
chemical_list: C561887:MIRN548 microRNA, human; D035683:MicroRNAs; C497796:SMAD4 protein, human; C497797:SMAD5 protein, human; D051901:Smad4 Protein; D051902:Smad5 Protein; D019287:Zinc Sulfate
keywords: HEp-2; HepG2; SMAD4; SMAD5; Zinc concentration; miRNA-548n