title: Reduced expression of let-7f activates TGF-β/ALK5 pathway and leads to impaired ischaemia-induced neovascularization after cigarette smoke exposure.
abstract: This study sought to determine the potential role of microRNAs (miRNAs) in the detrimental effects of cigarette smoke on angiogenesis and neovascularization. Using large-scale miRNA profiling and qRT-PCR analyses, we identified let-7f as a pro-angiogenic miRNA which expression is significantly reduced in HUVECs treated with cigarette smoke extracts (CSE), and in the ischemic muscles of mice that are exposed to cigarette smoke (MES). In a mouse model of hindlimb ischaemia, intramuscular injection of let-7f mimic restored ischaemia-induced neovascularization in MES. Doppler flow ratios and capillary density in ischemic muscles were significantly improved in MES treated with let-7f mimic. Clinically, this was associated with reduced ambulatory impairment and hindlimb ischaemic damage. Treatment with let-7f mimic could also rescue pro-angiogenic cell (PAC) number and function (attachment, proliferation, migration) in MES. ALK5 (TGF-βR1), an important modulator of angiogenesis, is a target of let-7f. Here we show that ALK5 is increased in HUVECs exposed to CSE and in the ischaemic muscles of MES. This is associated with a downstream activation of the anti-angiogenic factors SMAD2/3 and PAI-1. Importantly, treatment with let-7f mimic reduces the expression of ALK5, SMAD2/3 and PAI-1 both in vitro and in vivo. Moreover, let-7f overexpression or ALK5 inhibition can rescue angiogenesis in HUVECs exposed to CSE. Cigarette smoke exposure is associated with reduced expression of let-7f and activation of the anti-angiogenic TGF-β/ALK5 pathway. Overexpression of let-7f using a miRNA mimic could constitute a novel therapeutic strategy to improve ischaemia-induced neovascularization in pathological conditions.
authors.affiliation: Department of Cardiovascular Research, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada.
authors.forename: Wahiba
authors.initials: W
authors.lastname: Dhahri
authors.affiliation: Department of Cardiovascular Research, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Dussault
authors.affiliation: Department of Cardiovascular Research, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada.
authors.forename: Paola
authors.initials: P
authors.lastname: Haddad
authors.affiliation: Department of Cardiovascular Research, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada.
authors.forename: Julie
authors.initials: J
authors.lastname: Turgeon
authors.affiliation: Department of Cardiovascular Research, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada.
authors.forename: Sophie
authors.initials: S
authors.lastname: Tremblay
authors.affiliation: Department of Cardiovascular Research, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada.
authors.forename: Kevin
authors.initials: K
authors.lastname: Rolland
authors.affiliation: Department of Cardiovascular Research, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Desjarlais
authors.affiliation: Department of Cardiovascular Research, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada.
authors.forename: Katia Y
authors.initials: KY
authors.lastname: Cáceres-Gorriti
authors.affiliation: Department of Cardiovascular Research, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada.
authors.forename: Raphael
authors.initials: R
authors.lastname: Mathieu
authors.affiliation: Department of Cardiovascular Research, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada.
authors.forename: Alain
authors.identifier: 0000-0002-1101-7698
authors.initials: A
authors.lastname: Rivard
mesh_terms: D000818:Animals; D002452:Cell Count; D005260:Female; D005786:Gene Expression Regulation; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism; D006801:Humans; D007511:Ischemia / Q000235:genetics / Q000473:pathology*; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D009389:Neovascularization, Pathologic / Q000235:genetics* / Q000473:pathology; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism*; D015398:Signal Transduction; D012907:Smoking / Q000009:adverse effects*; D016212:Transforming Growth Factor beta / Q000378:metabolism*
chemical_list: D035683:MicroRNAs; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta; C487931:mirnlet7 microRNA, human; C542687:mirnlet7 microRNA, mouse; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I; C000625841:TGFBR1 protein, human; C000625842:Tgfbr1 protein, mouse
keywords: ALK5; TGF-βR1; angiogenesis; let-7f; microRNA; neovascularization; smoking