title: Identification of microRNAs 758 and 33b as potential modulators of ABCA1 expression in human atherosclerotic plaques.
abstract: OBJECTIVE
  Adenosine triphosphate (ATP)-binding cassette (ABC) transporters A1 and G1 are the main transporters involved in macrophage cholesterol efflux. The understanding of the molecular mechanism(s) of their regulation in atherosclerosis is crucial for potential therapeutic approaches. Preclinical studies support a role for microRNAs in the posttranscriptional regulation of these transporters; however, no evidence is still available on human atherosclerosis. Thus, the aim of this study was to investigate the modulation of the ABCA1 and ABCG1 pathway in human atherosclerotic plaques and microRNA involvement in its modulation.
  
  
  RESULTS
  Thirty-one human atherosclerotic plaques were obtained from patients undergoing carotid endarterectomy for high-grade (>70%) vessel stenosis, and divided into normocholesterolemic (n = 15) and hypercholesterolemic groups (n = 16) according to the presence/absence of hypercholesterolemia. Both ABCA1 and ABCG1 messenger RNAs (mRNAs) were significantly upregulated in carotid plaques from hypercholesterolemic patients as assessed by real-time polymerase chain reaction (RT-PCR). Despite this result, no difference was found at the protein levels analyzed by Western blot, thus suggesting a strong posttranscriptional modulation. MicroRNA microarray and subsequent validation by RT-PCR showed a significant upregulation of ABCA1-linked miR-758 and miR-33b in plaques from hypercholesterolemic patients.
  
  
  CONCLUSIONS
  We provide evidence of a strong posttranscriptional regulation of ABCA1 and ABCG1 expression in human atherosclerotic plaques from hypercholesterolemic patients. This effect is potentially due to the concomitant increase of miR-33b and miR-758, two well-established regulators of ABCA1 and ABCG1 expression. The identification of miR-33b and miR-758 as putative key regulators of ABCA1 protein expression within human atherosclerotic plaques provides further data for the realization of new anti-atherosclerotic drugs with specific targets based on anti-miRNA technologies.
authors.affiliation: Geriatric Clinic, European Center of Excellence on Atherosclerosis, Hypertension and Dyslipidemia, Chieti, Italy; Clinical Research Center, Center of Excellence on Aging (Ce.S.I.), Chieti, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Mandolini
authors.affiliation: Geriatric Clinic, European Center of Excellence on Atherosclerosis, Hypertension and Dyslipidemia, Chieti, Italy; Clinical Research Center, Center of Excellence on Aging (Ce.S.I.), Chieti, Italy; Institute for Cardiovascular Prevention, Ludwig-Maximilians University, Munich, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Santovito
authors.affiliation: Geriatric Clinic, European Center of Excellence on Atherosclerosis, Hypertension and Dyslipidemia, Chieti, Italy; Clinical Research Center, Center of Excellence on Aging (Ce.S.I.), Chieti, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Marcantonio
authors.affiliation: Center of Predictive Molecular Medicine, Center of Excellence on Aging (Ce.S.I.), Chieti, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Buttitta
authors.affiliation: Geriatric Clinic, European Center of Excellence on Atherosclerosis, Hypertension and Dyslipidemia, Chieti, Italy; Clinical Research Center, Center of Excellence on Aging (Ce.S.I.), Chieti, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Bucci
authors.affiliation: Vascular Surgery Unit - "G. d'Annunzio" University, Chieti, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Ucchino
authors.affiliation: Geriatric Clinic, European Center of Excellence on Atherosclerosis, Hypertension and Dyslipidemia, Chieti, Italy; Clinical Research Center, Center of Excellence on Aging (Ce.S.I.), Chieti, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Mezzetti
authors.affiliation: Geriatric Clinic, European Center of Excellence on Atherosclerosis, Hypertension and Dyslipidemia, Chieti, Italy; Clinical Research Center, Center of Excellence on Aging (Ce.S.I.), Chieti, Italy. Electronic address: fcipollone@unich.it.
authors.forename: F
authors.initials: F
authors.lastname: Cipollone
mesh_terms: D064286:ATP Binding Cassette Transporter 1 / Q000235:genetics / Q000378:metabolism*; D000070998:ATP Binding Cassette Transporter, Subfamily G, Member 1; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism; D000368:Aged; D000369:Aged, 80 and over; D001692:Biological Transport; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D005260:Female; D006801:Humans; D006937:Hypercholesterolemia / Q000097:blood / Q000235:genetics; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D058226:Plaque, Atherosclerotic / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D015854:Up-Regulation
chemical_list: C577836:ABCA1 protein, human; C419353:ABCG1 protein, human; D064286:ATP Binding Cassette Transporter 1; D000070998:ATP Binding Cassette Transporter, Subfamily G, Member 1; D018528:ATP-Binding Cassette Transporters; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; C550416:MIRN33a microRNA, human; C569441:MIRN758 microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger
keywords: ABC transporter; Atherosclerosis; Carotid endarterectomy; Cholesterol efflux; MicroRNA