title: Pharmacological inhibition of dynamin II reduces constitutive protein secretion from primary human macrophages.
abstract: Dynamins are fission proteins that mediate endocytic and exocytic membrane events and are pharmacological therapeutic targets. These studies investigate whether dynamin II regulates constitutive protein secretion and show for the first time that pharmacological inhibition of dynamin decreases secretion of apolipoprotein E (apoE) and several other proteins constitutively secreted from primary human macrophages. Inhibitors that target recruitment of dynamin to membranes (MiTMABs) or directly target the GTPase domain (Dyngo or Dynole series), dose- and time- dependently reduced the secretion of apoE. SiRNA oligo's targeting all isoforms of dynamin II confirmed the involvement of dynamin II in apoE secretion. Inhibition of secretion was not mediated via effects on mRNA or protein synthesis. 2D-gel electrophoresis showed that inhibition occurred after apoE was processed and glycosylated in the Golgi and live cell imaging showed that inhibited secretion was associated with reduced post-Golgi movement of apoE-GFP-containing vesicles. The effect was not restricted to macrophages, and was not mediated by the effects of the inhibitors on microtubules. Inhibition of dynamin also altered the constitutive secretion of other proteins, decreasing the secretion of fibronectin, matrix metalloproteinase 9, Chitinase-3-like protein 1 and lysozyme but unexpectedly increasing the secretion of the inflammatory mediator cyclophilin A. We conclude that pharmacological inhibitors of dynamin II modulate the constitutive secretion of macrophage apoE as a class effect, and that their capacity to modulate protein secretion may affect a range of biological processes.
authors.affiliation: Atherosclerosis Laboratory, ANZAC Research Institute, University of Sydney, Sydney, Australia.
authors.forename: Maaike
authors.initials: M
authors.lastname: Kockx
authors.affiliation: Centre for Vascular Research, University of New South Wales, Sydney, Australia; University of Ottawa Heart Institute, Ottawa, Canada.
authors.forename: Denuja
authors.initials: D
authors.lastname: Karunakaran
authors.affiliation: Atherosclerosis Laboratory, ANZAC Research Institute, University of Sydney, Sydney, Australia.
authors.forename: Mathew
authors.initials: M
authors.lastname: Traini
authors.affiliation: Children's Medical Research Institute, University of Sydney, Sydney, Australia.
authors.forename: Jing
authors.initials: J
authors.lastname: Xue
authors.affiliation: Centre for Vascular Research, University of New South Wales, Sydney, Australia.
authors.forename: Kuan Yen
authors.initials: KY
authors.lastname: Huang
authors.affiliation: Atherosclerosis Laboratory, ANZAC Research Institute, University of Sydney, Sydney, Australia.
authors.forename: Diana
authors.initials: D
authors.lastname: Nawara
authors.affiliation: Centre for Vascular Research, University of New South Wales, Sydney, Australia.
authors.forename: Katharina
authors.initials: K
authors.lastname: Gaus
authors.affiliation: Atherosclerosis Laboratory, ANZAC Research Institute, University of Sydney, Sydney, Australia.
authors.forename: Wendy
authors.initials: W
authors.lastname: Jessup
authors.affiliation: Children's Medical Research Institute, University of Sydney, Sydney, Australia.
authors.forename: Phillip J
authors.initials: PJ
authors.lastname: Robinson
authors.affiliation: Department of Cardiology and ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia.
authors.forename: Leonard
authors.initials: L
authors.lastname: Kritharides
mesh_terms: D000178:Acrylamides / Q000494:pharmacology; D000818:Animals; D001057:Apolipoproteins E / Q000378:metabolism*; D016466:CHO Cells; D002478:Cells, Cultured; D006224:Cricetinae; D003412:Cricetulus; D034285:Dynamin II / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D005089:Exocytosis / Q000187:drug effects*; D056945:Hep G2 Cells; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D055571:Secretory Pathway
chemical_list: C541935:2-cyano-N-octyl-3-(1-(3-dimethylaminopropyl)-1H-indol-3-yl)acrylamide; D000178:Acrylamides; D001057:Apolipoproteins E; D007211:Indoles; D034285:Dynamin II