Inés Tiscornia

Anti-Inflammatory Lactobacillus rhamnosus CNCM I-3690 Strain Protects against Oxidative Stress and Increases Lifespan in Caenorhabditis elegans

Numerous studies have shown that resistance to oxidative stress is crucial to stay healthy and to reduce the adverse effects of aging. Accordingly, nutritional interventions using antioxidant food-grade compounds or food products are currently an interesting option to help improve health and quality of life in the elderly. Live lactic acid bacteria (LAB) administered in food, such as probiotics, may be good antioxidant candidates. Nevertheless, information about LAB-induced oxidative stress protection is scarce. To identify and characterize new potential antioxidant probiotic strains, we have developed a new functional screening method using the nematode Caenorhabditis elegans as host. C. elegans were fed on different LAB strains (78 in total) and nematode viability was assessed after oxidative stress (3 mM and 5 mM H2O2). One strain, identified as Lactobacillus rhamnosus CNCM I-3690, protected worms by increasing their viability by 30% and, also, increased average worm lifespan by 20%. Moreover, transcriptomic analysis of C. elegans fed with this strain showed that increased lifespan is correlated with differential expression of the DAF-16/insulin-like pathway, which is highly conserved in humans. This strain also had a clear anti-inflammatory profile when co-cultured with HT-29 cells, stimulated by pro-inflammatory cytokines, and co-culture systems with HT-29 cells and DC in the presence of LPS. Finally, this Lactobacillus strain reduced inflammation in a murine model of colitis. This work suggests that C. elegans is a fast, predictive and convenient screening tool to identify new potential antioxidant probiotic strains for subsequent use in humans.

Discovery of new orally effective analgesic and anti-inflammatory hybrid furoxanyl N-acylhydrazone derivatives

We report the design, the synthesis and the biological evaluation of the analgesic and anti-inflammatory activities of furoxanyl N-acylhydrazones (furoxanyl-NAH) by applying molecular hybridization approach. Hybrid compounds with IL-8-release inhibition capabilities were identified. Among them, furoxanyl-NAH, 17, and benzofuroxanyl-derivative, 24, together with furoxanyl-NAH derivative, 31, without IL-8 inhibition displayed both orally analgesic and anti-inflammatory activities. These hybrid derivatives do not have additional LOX- or COX-inhibition activities. For instance, LOX-inhibition by furoxanyl-NAH derivative, 42, emerged as a structural lead to develop new inhibitors. The lack of mutagenicity of the active derivatives 17, 31, and 42, allow us to propose them as candidates for further clinical studies. These results confirmed the success in the exploitation of hybridization strategy for identification of novel N-acylhydrazones (NAH) with optimized activities.

In vitro and in vivo anticancer properties of a Calcarea carbonica derivative complex (M8) treatment in a murine melanoma model

BackgroundMelanoma is the most aggressive form of skin cancer and the most rapidly expanding cancer in terms of worldwide incidence. Chemotherapeutic approaches to treat melanoma have had only marginal success. Previous studies in mice demonstrated that a high diluted complex derived from Calcarea carbonica (M8) stimulated the tumoricidal response of activated lymphocytes against B16F10 melanoma cells in vitro.MethodsHere we describe the in vitro inhibition of invasion and the in vivo anti-metastatic potential after M8 treatment by inhalation in the B16F10 lung metastasis model.ResultsWe found that M8 has at least two functions, acting as both an inhibitor of cancer cell adhesion and invasion and as a perlecan expression antagonist, which are strongly correlated with several metastatic, angiogenic and invasive factors in melanoma tumors.ConclusionThe findings suggest that this medication is a promising non-toxic therapy candidate by improving the immune response against tumor cells or even induce direct dormancy in malignancies.

Enamel defects associated with coeliac disease: putative role of antibodies against gliadin in pathogenesis

Enamel defects in the permanent teeth of patients with coeliac disease (CD) are often reported as an atypical manifestation, sometimes being suggestive of an undiagnosed atypical disease. We proposed to explore the pathogenesis of these oral defects, which are poorly studied. Sequence analyses of proteins from gluten (gliadins) and of proline-rich enamel proteins (amelogenin and ameloblastin) suggested the presence of common antigenic motifs. Therefore, we analyzed, by ELISA and western blotting, the reactivity of sera from patients with CD against gliadin and enamel-derived peptides. Correlation analyses between the levels of specific antibodies against gliadin and enamel derived peptides and inhibition experiments confirmed the presence of cross-reactive antibodies. Immunoblot analysis revealed that the most prominent component in enamel matrix derivative (of approximately 18.6 kDa), identified by an amelogenin-specific antibody, is recognized by sera from patients with CD; in addition, several fractions of pure gliadin were recognized by amelogenin-specific antibody. In agreement, sera from mice immunized with enamel matrix-derived proteins generated antibodies that recognized a peptide (of approximately 21.2 kDa) derived from gliadin. In conclusion, antibodies against gliadin generated in patients with CD can react in vitro with a major enamel protein. The involvement of anti-gliadin serum in the pathogenesis of enamel defects in children with untreated CD can be hypothesized on the basis of these novel results.

HT-29 and Caco-2 Reporter Cell Lines for Functional Studies of Nuclear Factor Kappa B Activation

The NF-κB is a transcription factor which plays a key role in regulating biological processes. In response to signals, NF-κB activation occurs via phosphorylation of its inhibitor, which dissociates from the NF-κB dimer allowing the translocation to the nucleus, inducing gene expression. NF-κB activation has direct screening applications for drug discovery for several therapeutic indications. Thus, pathway-specific reporter cell systems appear as useful tools to screen and unravel the mode of action of probiotics and natural and synthetic compounds. Here, we describe the generation, characterization, and validation of human epithelial reporter cell lines for functional studies of NF-κB activation by different pro- and anti-inflammatory agents. Caco-2 and HT-29 cells were transfected with a pNF-κB-hrGFP plasmid which contains the GFP gene under the control of NF-κB binding elements. Three proinflammatory cytokines (TNF-α, IL-1β, and LPS) were able to activate the reporter systems in a dose-response manner, which corresponds to the activation of the NF-κB signaling pathway. Finally, the reporter cell lines were validated using lactic acid bacteria and a natural compound. We have established robust Caco-2-NF-κB-hrGFP and HT-29-NF-κB-hrGFP reporter cell lines which represent a valuable tool for primary screening and identification of bacterial strains and compounds with a potential therapeutic interest.

Human monocyte-derived dendritic cells from leukoreduction system chambers after plateletpheresis are functional in an in vitro co-culture assay with intestinal epithelial cells.

The dendritic cells (DC) found in the intestine are involved both in the maintenance of tolerance towards commensal microbiota, and in the generation of protective immune responses against pathogens, thus contributing to gut immune homeostasis. There is an increasing interest in the use of lactic acid bacteria (LAB) as probiotics; among their beneficial effects we highlight the modulation of the immune system which is one of their fundamental properties. As these effects are strain-dependent, it is important to have in vitro systems that include DC and intestinal epithelial cells (IEC), which are crucial for intestinal homeostasis, to identify candidates by means of bacterial screening. Obtaining enough human cells, necessary to simultaneously test several bacteria, is a major challenge for researchers. In this study we analyzed the usefulness of the cellular fraction retained in leukoreduction system chambers following plateletpheresis (PP) as a source of DC. We compared the capacity of peripheral blood mononuclear cells (PBMC) from buffy coats (BC) or PP to generate DC using a short differentiation protocol. The functionality of the DC obtained was analyzed in co-cultures together with intestinal epithelial HT-29 cells, stimulating with LPS alone or with two LAB commonly used in the food industry, Streptococcus thermophilus and Lactobacillus delbrueckii. DC surface markers CD86, HLA-DR and cytokine production were measured. The behavior of DC derived from PP was similar to the behavior observed for DC derived from BC. When we tested the response of DC to bacteria, we found significant differences in cytokine secretion, especially for IL-10, suggesting that the system has the ability to discriminate LAB with different immunomodulatory properties. We also found that DC derived from both sources displayed a similar ability to phagocyte bacteria. In conclusion, we hereby propose a modification of the two-day protocol for obtaining human DC previously described, using PP as an alternative source of PBMC, to be used in co-culture systems with IEC. The novelty of this protocol is the combination of the blood monocyte source with a simple and fast differentiation method to obtain DC, and their use in a combined culture with IEC and LAB to model microbial-host interaction. Since the initial PP volume is ten times lower than that of BC, the use of PP minimizes biological residue generation and reagent consumption. In addition, monocyte-derived DC from PP were suitable for use in co-culture assays as a first screening step to study the immunomodulatory properties of LAB.

MUC5B silencing reduces chemo-resistance of MCF-7 breast tumor cells and impairs maturation of dendritic cells

Mucins participate in cancer progression by regulating cell growth, adhesion, signaling, apoptosis or chemo-resistance to drugs. The secreted mucin MUC5B, the major component of the respiratory tract mucus, is aberrantly expressed in breast cancer, where it could constitute a cancer biomarker. In this study we evaluated the role of MUC5B in breast cancer by gene silencing the MUC5B expression with short hairpin RNA on MCF-7 cells. We found that MUC5B-silenced MCF-7 cells have a reduced capacity to grow, adhere and form cell colonies. Interestingly, MUC5B knock-down increased the sensitivity to death induced by chemotherapeutic drugs. We also show that MUC5B silencing impaired LPS-maturation of DCs, and production of cytokines. Furthermore, MUC5B knock-down also influenced DC-differentiation and activation since it resulted in an upregulation of IL-1β, IL-6 and IL-10, cytokines that might be involved in cancer progression. Thus, MUC5B could enhance the production of LPS-induced cytokines, suggesting that the use of MUC5B-based cancer vaccines combined with DC-maturation stimuli, could favor the induction of an antitumor immune response.

Pro-inflammatory Ca ++ -activated K + channels are inhibited by hydroxychloroquine

Antimalarials have demonstrated beneficial effects in Systemic Lupus Erithematosus and Rheumatoid Arthritis. However, the mechanisms and the molecular players targeted by these drugs remain obscure. Although hydroxychloroquine (HCQ) is a known ion channel inhibitor, this property has not been linked to its anti-inflammatory effects. We aimed to study whether HCQ inhibits pro-inflammatory ion channels. Electrophysiology experiments demonstrated that HCQ inhibited Ca++-activated K+ conductance in THP-1 macrophages in a dose-dependent manner. In macrophages, ATP-induced K+ efflux plays a key role in activating the NLRP3 inflammasome. ATP-induced IL-1beta secretion was controlled by the KCa1.1 inhibitor iberiotoxin. NS1619 and NS309 (KCa1.1 and KCa3.1 activators respectively) induced the secretion of IL-1beta. This effect was inhibited by HCQ and also by iberiotoxin and clotrimazol (KCa3.1 inhibitor), arguing against off-target effect. In vitro, HCQ inhibited IL-1beta and caspase 1 activation induced by ATP in a dose-dependent manner. HCQ impaired K+ efflux induced by ATP. In vivo, HCQ inhibited caspase 1-dependent ATP-induced neutrophil recruitment. Our results show that HCQ inhibits Ca++-activated K+ channels. This effect may lead to impaired inflammasome activation. These results are the basis for i) a novel anti-inflammatory mechanism for HCQ and ii) a new strategy to target pro-rheumatic Ca++-activated K+ channels.

Data for comparative proteomics analysis of the antitumor effect of CIGB-552 peptide in HT-29 colon adenocarcinoma cells

CIGB-552 is a second generation antitumor peptide that displays potent cytotoxicity in lung and colon cancer cells. The nuclear subproteome of HT-29 colon adenocarcinoma cells treated with CIGB-552 peptide was identified and analyzed [1]. This data article provides supporting evidence for the above analysis.

Evaluation of hexane and ethyl acetate extracts of the sponge Jaspis diastra collected from Mauritius Waters on HeLa cells

Based on previous screening results, the cytotoxic effect of the hexane (JDH) and ethyl acetate extracts (JDE) of the marine sponge Jaspis diastra were evaluated on HeLa cells and the present study aimed at determining their possible mechanism of cell death.