title: Lactobacillus plantarum 299v Prevents Caspase-Dependent Apoptosis In Vitro.
abstract: Selective microbes used as probiotics can enhance epithelial cell protection. We have previously shown that a Lactobacillus plantarum strain 299v (Lp299v) has the ability to induce mucin genes. In the current study, we utilized a cytokine model of inflammation in cell culture to study the modulation of apoptosis by this probiotic. HT-29 cells were pre-incubated with the Lp299v or L. plantarum strain adh- (Lpadh-), a non-adherent derivative of Lp299v. Cells were challenged with a mixture of cytokines (TNF-α, IFN-γ, and IL-1a) to imitate conditions of inflammation. To assess for cell death, we evaluated TUNEL, multi-caspase, and caspase-3 and caspase-7 activity assays. There was a marked decrease in apoptosis as measured by TUNEL(+) cells in samples pre-treated with Lp299v (18.7 ± 4.1%, p < 0.01) and Lpadh- (16.6 ± 3.2%, p < 0.05) prior to cytokine exposure when compared to cells (43.6 ± 6.2%) exposed to the cytokine mixture. Lp299v pre-incubation with HT-29 cells reduced caspase(+) cells in the multi-caspase activity assay (3.6 ± 0.6%, p < 0.05) compared to cells exposed to cytokines (68.9 ± 5.1%) whereas Lpadh- did not (46.8 ± 17.5%, p > 0.05). Similarly, caspase-3, caspase-7 activity was also reduced by Lp299v. Selected probiotics may confer an exogenous protective effect at the mucosal-luminal interface for intestinal epithelial cells via alteration of caspase-dependent apoptotic pathways.
authors.affiliation: Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada.|Children's Hospital of Eastern Ontario Research Institute, 401 Smyth Road, Ottawa, ON, K1H 8L1, Canada.
authors.forename: Natalie S
authors.initials: NS
authors.lastname: Dykstra
authors.affiliation: Children's Hospital of Eastern Ontario Research Institute, 401 Smyth Road, Ottawa, ON, K1H 8L1, Canada.
authors.forename: Lucie
authors.initials: L
authors.lastname: Hyde
authors.affiliation: Department of Pediatrics, University of Ottawa, Ottawa, Canada.|Children's Hospital of Eastern Ontario Research Institute, 401 Smyth Road, Ottawa, ON, K1H 8L1, Canada.
authors.forename: Alexander
authors.initials: A
authors.lastname: MacKenzie
authors.affiliation: Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada. dmack@cheo.on.ca.|Department of Pediatrics, University of Ottawa, Ottawa, Canada. dmack@cheo.on.ca.|Children's Hospital of Eastern Ontario Research Institute, 401 Smyth Road, Ottawa, ON, K1H 8L1, Canada. dmack@cheo.on.ca.
authors.forename: David R
authors.initials: DR
authors.lastname: Mack
keywords: Mucin; Necrotizing enterocolitis; Probiotics; Programmed cell death; TUNEL