Pharmacological inhibition of dynamin II reduces constitutive protein secretion from primary human macrophages

• Published in: PloS one Vol. 9; no. 10; p. e111186
• Main Authors: Kockx, Maaike, Karunakaran, Denuja, Traini, Mathew, Xue, Jing, Huang, Kuan Yen, Nawara, Diana, Gaus, Katharina, Jessup, Wendy, Robinson, Phillip J, Kritharides, Leonard
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 27.10.2014; Public Library of Science (PLoS)
• Subjects: Acrylamides - pharmacology; Animals; Apolipoprotein E; Apolipoproteins; Apolipoproteins E - metabolism; Atherosclerosis; Biological activity; Biology and Life Sciences; Cells, Cultured; Chitinase; CHO Cells; Cricetinae; Cricetulus; Dynamin; Dynamin II - antagonists & inhibitors; Dynamin II - genetics; Dynamin II - metabolism; Exocytosis - drug effects; Fibronectin; Fibronectins; Gel electrophoresis; Golgi cells; Guanosine triphosphatases; Health aspects; Hep G2 Cells; Humans; Indoles - pharmacology; Inflammation; Inhibition; Inhibitors; Isoforms; Kinases; Laboratories; Lysozyme; Macrophages; Macrophages - drug effects; Macrophages - metabolism; Matrix metalloproteinase; Medical research; Membranes; Metalloproteinase; Microtubules; mRNA; Pharmacology; Plasma; Protein biosynthesis; Protein synthesis; Proteins; RNA; Rodents; Secretion; Secretory Pathway; siRNA; Therapeutic applications; Transcription; Sydney New South Wales Australia; Australia
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0111186

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.