title: Hypoxic stress, hepatocytes and CACO-2 viability and susceptibility to Shigella flexneri invasion.
abstract: Inflammation due to Shigella flexneri can cause damage to the colonic mucosa and cell death by necrosis and apoptosis. This bacteria can reach the bloodstream in this way, and the liver through portal veins. Hypoxia is a condition present in many human diseases, and it may induce bacterial translocation from intestinal lumen. We studied the ability of S. flexneri to invade rat hepatocytes and Caco-2 cells both in normoxic and hypoxic microenvironments, as well as morphological and physiological alterations in these cells after infection under hypoxia. We used the primary culture of rat hepatocytes as a model of study. We analyzed the following parameters in normoxic and hypoxic conditions: morphology, cell viability, bacterial recovery and lactate dehydrogenase (LDH) released. The results showed that there were fewer bacteria within the Caco-2 cells than in hepatocytes in normoxic and hypoxic conditions. We observed that the higher the multiplicity of infection (MOI) the greater the bacterial recovery in hepatocytes. The hypoxic condition decreased the bacterial recovery in hepatocytes. The cytotoxicity evaluated by LDH released by cells was significantly higher in cells submitted to hypoxia than normoxia. Caco-2 cells in normoxia released 63% more LDH than hepatocytes. LDH increased 164% when hepatocytes were submitted to hypoxia and just 21% when Caco-2 cells were in the same condition. The apoptosis evaluated by Tunel was significantly higher in cells submitted to hypoxia than normoxia. When comparing hypoxic cells, we obtained more apoptotic hepatocytes than apoptotic Caco-2 cells. Concluding our results contribute to a better knowledge of interactions between studied cells and Shigella flexneri. These data may be useful in the future to define strategies to combat this virulent pathogen.
authors.affiliation: Laboratory of Bacteriology (LIM 54), Department of Infectious Diseases, Faculty of Medicine, University of Sao Paulo, Sao PauloSP, Brazil, cantalupolima@gmail.com, saniasan@usp.br, dahira@uol.com.br.
authors.forename: Camila Bárbara Cantalupo
authors.initials: CB
authors.lastname: Lima
authors.forename: Sânia Alves Dos
authors.initials: SA
authors.lastname: Santos
authors.forename: Dahir Ramos de
authors.initials: DR
authors.lastname: Andrade Júnior
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D018938:Caco-2 Cells / Q000382:microbiology*; D015687:Cell Hypoxia; D002470:Cell Survival; D005260:Female; D022781:Hepatocytes / Q000382:microbiology*; D006801:Humans; D051381:Rats; D012763:Shigella flexneri / Q000502:physiology*
references.citation: Shock. 1996 Feb;5(2):106-11
references.pmid: 8705386
references.citation: J Leukoc Biol. 1999 Dec;66(6):889-900
references.pmid: 10614769
references.citation: J Immunol. 2005 Nov 15;175(10):6257-63
references.pmid: 16272275
references.citation: Crit Rev Toxicol. 1990;21(2):127-48
references.pmid: 2083032
references.citation: Mol Microbiol. 2009 Jan;71(2):350-68
references.pmid: 19017275
references.citation: Cell Microbiol. 2006 Feb;8(2):339-52
references.pmid: 16441443
references.citation: APMIS. 2010 Feb;118(2):108-14
references.pmid: 20132174
references.citation: Am J Pathol. 1999 Oct;155(4):1065-73
references.pmid: 10514389
references.citation: Gastroenterology. 2011 Oct;141(4):1220-30, 1230.e1-3
references.pmid: 21726511
references.citation: J Parasitol. 2004 Jun;90(3):510-5
references.pmid: 15270094
references.citation: Nature. 2003 Jun 5;423(6940):593-5
references.pmid: 12789320
references.citation: JAMA. 1976 Jun 14;235(24):2628
references.pmid: 775138
references.citation: EMBO J. 2012 May 30;31(11):2448-60
references.pmid: 22562152
references.citation: Nature. 2010 May 20;465(7296):355-8
references.pmid: 20436458
references.citation: Microbes Infect. 2008 Apr;10(4):424-31
references.pmid: 18403240
references.citation: FASEB J. 2002 Aug;16(10):1151-62
references.pmid: 12153983
references.citation: J Hepatol. 2004 Nov;41(5):764-72
references.pmid: 15519649
references.citation: Hepatology. 1989 Feb;9(2):219-28
references.pmid: 2912826
references.citation: Science. 1999 May 21;284(5418):1322-8
references.pmid: 10334981
references.citation: Infect Immun. 1992 Jan;60(1):237-48
references.pmid: 1729185
references.citation: J Anesth. 2011 Feb;25(1):50-6
references.pmid: 21153035
references.citation: J Med Microbiol. 1986 Dec;22(4):335-41
references.pmid: 3098977
references.citation: Infect Immun. 2001 Feb;69(2):1072-83
references.pmid: 11160004
references.citation: Am J Physiol Gastrointest Liver Physiol. 2001 Mar;280(3):G319-23
references.pmid: 11171613
references.citation: In Vitro. 1981 Dec;17(12):1100-10
references.pmid: 6172366
references.citation: Exp Cell Res. 2012 Apr 15;318(7):828-34
references.pmid: 22342953
references.citation: Rev Inst Med Trop Sao Paulo. 2011 Mar-Apr;53(2):107-12
references.pmid: 21537759
references.citation: Am J Physiol Cell Physiol. 2011 May;300(5):C951-67
references.pmid: 21178108
references.citation: Proc Natl Acad Sci U S A. 2010 Nov 9;107(45):19502-7
references.pmid: 20974954
references.citation: Lab Anim Sci. 1996 Feb;46(1):61-6
references.pmid: 8699822
references.citation: Cell Microbiol. 2005 Jan;7(1):115-27
references.pmid: 15617528
references.citation: PLoS One. 2012;7(6):e37475
references.pmid: 22761656
references.citation: Gut. 2011 Apr;60(4):473-84
references.pmid: 21139062