title: Dysregulation of gene expression in ABCC6 knockdown HepG2 cells.
abstract: ABCC6 protein is an ATP-dependent transporter that is mainly found in the basolateral plasma membrane of hepatocytes. ABCC6 deficiency is the primary cause of several forms of ectopic mineralization syndrome. Mutations in the human ABCC6 gene cause pseudoxanthoma elasticum (PXE), an autosomal recessive disease characterized by ectopic calcification of the elastic fibers in dermal, ocular and vascular tissues. Mutations in the mouse ABCC6 gene were also associated with dystrophic cardiac calcification. Reduced levels of ABCC6 protein were found in a β-thalassemic mouse model. Moreover, some cases of generalized arterial calcification in infancy are due to ABCC6 mutations. In order to study the role of ABCC6 in the pathogenesis of ectopic mineralization, the expressions of genes involved in this process were evaluated in HepG2 cells upon stable knockdown of ABCC6 by small hairpin RNA (shRNA) technology. ABCC6 knockdown in HepG2 cells causes a significant upregulation of the genes promoting mineralization, such as TNAP, and a parallel downregulation of genes with anti-mineralization activity, such as NT5E, Fetuin A and Osteopontin. Although the absence of ABCC6 has been already associated with ectopic mineralization syndromes, this study is the first to show a direct relationship between reduced ABCC6 levels and the expression of pro-mineralization genes in hepatocytes.
authors.affiliation: Department of Sciences, University of Basilicata, Viale dell'Ateneo Lucano 10, 85100, Potenza, Italy.
authors.forename: Rocchina
authors.initials: R
authors.lastname: Miglionico
authors.forename: Maria Francesca
authors.initials: MF
authors.lastname: Armentano
authors.forename: Monica
authors.initials: M
authors.lastname: Carmosino
authors.forename: Antonella Maria
authors.initials: AM
authors.lastname: Salvia
authors.forename: Flavia
authors.initials: F
authors.lastname: Cuviello
authors.forename: Faustino
authors.initials: F
authors.lastname: Bisaccia
authors.forename: Angela
authors.initials: A
authors.lastname: Ostuni
mesh_terms: D015720:5'-Nucleotidase / Q000235:genetics / Q000378:metabolism; D000469:Alkaline Phosphatase; D002114:Calcinosis / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D058851:GPI-Linked Proteins / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D015971:Gene Expression Regulation, Enzymologic; D055785:Gene Knockdown Techniques; D056945:Hep G2 Cells; D006801:Humans; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D015720:5'-Nucleotidase; D000469:Alkaline Phosphatase; D002352:Carrier Proteins; D058851:GPI-Linked Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C102029:ABCC6 protein, human; C548267:ALPL protein, human; C548241:NT5E protein, human