Date: 10/06/2009

Sandra Voltan, Diego Martines, Marina Elli, Paola Brun, Stefano Longo, Andrea Porzionato, Raffaele DeCaro, Giorgio Palù, Giacomo C. Sturniolo, Lorenzo Morelli, Ignazio Castagliuolo (2008) Gastroenterology 135(4):1216-27.

BACKGROUND & AIMS: Accumulating evidence indicates that the peroxisome proliferator activated receptor (PPAR)-gamma is a major player in maintaining intestinal mucosa homeostasis, but whether PPAR-gamma is directly involved in probiotic-mediated effects and the molecular events involved in its activation are not known. METHODS: We investigated the role of PPAR-gamma in the immunomodulatory effects of Lactobacillus crispatus M247 on intestinal epithelial cells (IEC) and the role of probiotic-derived H(2)O(2) on PPAR-gamma activity. RESULTS: L crispatus M247 supplementation in mice significantly increased PPAR-gamma levels and transcriptional activity in the colonic mucosa. L crispatus M247 induced PPAR-gamma nuclear translocation and enhanced transcriptional activity in epithelial (CMT-93) cells, as demonstrated by the increased luciferase activity of a PPAR-gamma-responsive element, PPAR-gamma-responsive gene up-regulation, and reduced activity of an nuclear factor-kappaB-responsive element. Pharmacologic PPAR-gamma inhibition or silencing by small interfering RNA cancelled the L crispatus M247-mediated effects in CMT-93 cells. Because Lactobacillus strains producing little H(2)O(2) failed to activate PPAR-gamma, we investigated the role of L crispatus M247-derived H(2)O(2) in PPAR-gamma activation. L crispatus M247 induced a transient rise in intracellular H(2)O(2) and PPAR-gamma transcriptional activity was cancelled by antioxidant or H(2)O(2) scavenger. Toll-like receptor (TLR)-2 was not required for PPAR-gamma up-regulation mediated by L crispatus M247 in mice, although the protective effects of L crispatus M247 on dextran sodium sulfate-induced colitis were less pronounced in TLR-2(-/-) mice. CONCLUSIONS: L crispatus M247 uses H(2)O(2) as a signal transducing molecule to induce PPAR-gamma activation in IEC, directly modulating epithelial cell responsiveness to inflammatory stimuli.

Date: 01/04/2010

Ignazio Castagliuolo, Francesca Galeazzi, Susanna Ferrari, Marina Elli, Paola Brun, Andrea Cavaggioni, Deborah Tormen, Giacomo C. Sturniolo, Lorenzo Morelli, and Giorgio Palù
FEMS Immunol Med Microbiol 43(2), 197-204

Date: 01/04/2010

Sandra Voltan,1 Ignazio Castagliuolo,1* Marina Elli,4 Stefano Longo,4 Paola Brun,1 Renata D'Incà,2 Andrea Porzionato,3 Veronica Macchi,3 Giorgio Palù,1 Giacomo C. Sturniolo,2 Lorenzo Morelli,4 and Diego Martines
Clin Vaccine Immunol. 2007 September; 14(9): 1138–1148

Date: 01/04/2010

Siciliano RA, Cacace G, Mazzeo MF, Morelli L, Elli M, Rossi M, Malorni A.
Biochim Biophys Acta. 2008 Feb;1784(2):335-42

Aggregation process affects the ability of Lactobacillus crispatus, a probiotic,
to survive into the gastro-intestinal environment and to adhere to the intestinal
mucosa. To elucidate mechanisms underlying this process, a comparative proteomic
study was carried out on a wild type strain M247 and its spontaneous isogenic
mutant Mu5, which had lost the aggregative phenotype. Results highlighted an
overall lower amount of enzymes involved in carbohydrate transport and metabolism
in strain M247 compared to strain Mu5, suggesting a reduction in the general
growth rate, probably caused by nutrient limitation in cell aggregates,
coherently with the phenotypic traits of the strains. Moreover, the up-regulation
of a putative elongation factor Tu in the wild type M247 strain could suggest a
role of this particular protein in the adhesion mechanism of L. crispatus.