title: PI3K-dependent host cell actin rearrangements are required for Cronobacter sakazakii invasion of human brain microvascular endothelial cells.
abstract: Cronobacter sakazakii (C. sakazakii) is an opportunistic pathogen that can cause neonatal sepsis and meningitis. The mechanism involved in the pathogenesis of C. sakazakii meningitis remains largely unknown. Previous studies indicated that bacterial invasion of brain microvascular endothelial cells is required for penetration into the central nervous system. In this study, we found that C. sakazakii invasion of human brain microvascular endothelial cells (HBMEC) was significantly inhibited by cytochalasin D, a disrupting agent of actin microfilaments. Disassembly of actin stress fibers and cortical actin fibers was observed in HBMEC infected with C. sakazakii. C. sakazakii infection leads to increased Akt phosphorylation in HBMEC, which was blocked by treatment with PI3K inhibitors. Meanwhile, PI3K and Akt inhibitors significantly inhibited C. sakazakii invasion of HBMEC. Our further results illustrated that the C. sakazakii-induced Akt activation and C. sakazakii invasion were attenuated in HBMEC transfected with dominant-negative PI3K (Δp110). More importantly, the actin filaments rearrangements in HBMEC induced by C. sakazakii were effectively blocked by PI3K inhibitors treatment and transfection with Δp110. Taken together, our findings demonstrated that PI3K-mediated actin rearrangements are required for C. sakazakii invasion of HBMEC.
authors.affiliation: Department of Developmental Biology, Key Laboratory of Cell Biology, Ministry of Public Health, China Medical University, Heping District, Shenyang, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Wei-Dong
authors.initials: WD
authors.lastname: Zhao
authors.forename: Ke
authors.initials: K
authors.lastname: Zhang
authors.forename: Wen-Gang
authors.initials: WG
authors.lastname: Fang
authors.forename: Ying
authors.initials: Y
authors.lastname: Hu
authors.forename: Shao-Hui
authors.initials: SH
authors.lastname: Wu
authors.forename: Yu-Hua
authors.initials: YH
authors.lastname: Chen
mesh_terms: D000199:Actins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002478:Cells, Cultured; D015638:Cytochalasin D / Q000633:toxicity; D042783:Endothelial Cells / Q000382:microbiology*; D004755:Enterobacteriaceae / Q000472:pathogenicity*; D006801:Humans; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation
chemical_list: D000199:Actins; D015638:Cytochalasin D; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors
references.citation: Eur J Clin Microbiol Infect Dis. 2002 Aug;21(8):613-6
references.pmid: 12226694
references.citation: J Biol Chem. 2000 Nov 24;275(47):36769-74
references.pmid: 10973983
references.citation: Pediatr Infect Dis J. 1988 Mar;7(3):196-9
references.pmid: 3282215
references.citation: J Cell Sci. 2008 Mar 1;121(Pt 5):551-9
references.pmid: 18287584
references.citation: Int J Food Microbiol. 1997 Feb;34(2):103-13
references.pmid: 9039558
references.citation: Microb Pathog. 2003 Jul;35(1):35-42
references.pmid: 12860457
references.citation: Cell Microbiol. 2002 Aug;4(8):503-14
references.pmid: 12174085
references.citation: Clin Infect Dis. 2006 Apr 1;42(7):996-1002
references.pmid: 16511766
references.citation: Microbiology (Reading). 2007 Oct;153(Pt 10):3538-3547
references.pmid: 17906151
references.citation: Infect Immun. 2004 Jul;72(7):3743-51
references.pmid: 15213114
references.citation: Microb Pathog. 2008 Sep;45(3):181-91
references.pmid: 18606523
references.citation: J Food Prot. 2003 Mar;66(3):370-5
references.pmid: 12636287
references.citation: Proc Natl Acad Sci U S A. 1993 Jul 15;90(14):6884-8
references.pmid: 8341714
references.citation: Nature. 2003 Apr 17;422(6933):775-81
references.pmid: 12700772
references.citation: Foodborne Pathog Dis. 2009 May;6(4):495-501
references.pmid: 19415974
references.citation: Cell Microbiol. 2009 Jun;11(6):863-71
references.pmid: 19290913
references.citation: J Biol Chem. 2003 Feb 7;278(6):3694-704
references.pmid: 12446712
references.citation: Dev Cell. 2005 Jul;9(1):3-17
references.pmid: 15992537
references.citation: BMC Microbiol. 2004 Nov 25;4:43
references.pmid: 15563736
references.citation: Acta Paediatr. 2001 Mar;90(3):356-8
references.pmid: 11332182
references.citation: Microbes Infect. 2000 Aug;2(10):1237-44
references.pmid: 11008113
references.citation: Infect Immun. 2008 Feb;76(2):562-70
references.pmid: 18070906
references.citation: BMC Microbiol. 2006 Jun 26;6:58
references.pmid: 16800879
references.citation: Nat Rev Microbiol. 2008 Aug;6(8):625-34
references.pmid: 18604221
references.citation: FEBS Lett. 2010 Jan 4;584(1):27-32
references.pmid: 19903481
references.citation: J Immunol. 2009 May 1;182(9):5778-88
references.pmid: 19380826
references.citation: Pediatr Res. 2007 Dec;62(6):664-9
references.pmid: 17957161
references.citation: J Clin Microbiol. 2001 Jan;39(1):293-7
references.pmid: 11136786
references.citation: J Biol Chem. 2009 Jul 17;284(29):19427-36
references.pmid: 19473971
references.citation: Nature. 2007 Oct 18;449(7164):827-34
references.pmid: 17943119
references.citation: Lett Appl Microbiol. 2009 Aug;49(2):153-9
references.pmid: 19486285