Prostaglandin E2 stimulates progression-related gene expression in early colorectal adenoma cells

Upregulation of cyclooxygenase-2 (COX-2) and prostaglandin-dependent vascularisation in small adenomatous polyps is an essential part of colon carcinogenesis. To study the underlying cellular mechanisms, LT97 and Caco2 human colorectal tumour cells not expressing endogenous COX-2 were exposed to 1 μM prostaglandin E2 (PGE2) in their medium. At 30 min after addition, expression of c-fos was stimulated 5-fold and 1.3-fold, respectively, depending on the activation of both extracellular signal-regulated kinase and p38. The amount of c-jun in nuclear extracts was increased 20% in LT97 cells. Expression of COX-2 was upregulated 1.7-fold in LT97 cells and 1.5-fold in Caco2 2 h after prostaglandin (PG) addition by a p38-mediated pathway. The known PGE2 target gene vascular endothelial growth factor (VEGF) was not modulated. Effects of sustained PGE2 production were studied in VACO235 cells that have high endogenous COX-2 and in LT97 cells infected with an adenovirus expressing COX-2. Prostaglandin E2 secretion into the medium was 1–2 nM and 250 pM, respectively. Expression of both VEGF and c-fos was high in VACO235 cells. In LT97 cells, COX-2 upregulated c-fos expression and c-jun content in nuclear extracts 1.7- and 1.2-fold, respectively, in a PG-dependent way. This shows that exogenous PGE2 as well as COX-2 overexpression affect signalling and gene expression in a way that enhances tumour progression

A Novel DC Therapy with Manipulation of MKK6 Gene on Nickel Allergy in Mice

BACKGROUND: Although the activation of dermal dendritic cells (DCs) or Langerhans cells (LCs) via p38 mitogen-activated protein kinase (MAPK) plays a crucial role in the pathogenesis of metal allergy, the in vivo molecular mechanisms have not been identified and a possible therapeutic strategy using the control of dermal DCs or LCs has not been established. In this study, we focused on dermal DCs to define the in vivo mechanisms of metal allergy pathogenesis in a mouse nickel (Ni) allergy model. The effects of DC therapy on Ni allergic responses were also investigated. METHODS AND FINDING: The activation of dermal DCs via p38 MAPK triggered a T cell-mediated allergic immune response in this model. In the MAPK signaling cascade in DCs, Ni potently phosphorylated MAP kinase kinase 6 (MKK6) following increased DC activation. Ni-stimulated DCs could prime T cell activation to induce Ni allergy. Interestingly, when MKK6 gene-transfected DCs were transferred into the model mice, a more pronounced allergic reaction was observed. In addition, injection of short interfering (si) RNA targeting the MKK6 gene protected against a hypersensitivity reaction after Ni immunization. The cooperative action between T cell activation and MKK6-mediated DC activation by Ni played an important role in the development of Ni allergy. CONCLUSIONS: DC activation by Ni played an important role in the development of Ni allergy. Manipulating the MKK6 gene in DCs may be a good therapeutic strategy for dermal Ni allergy

New Model of Macrophage Acquisition of the Lymphatic Endothelial Phenotype

Macrophage-derived lymphatic endothelial cell progenitors (M-LECPs) contribute to new lymphatic vessel formation, but the mechanisms regulating their differentiation, recruitment, and function are poorly understood. Detailed characterization of M-LECPs is limited by low frequency in vivo and lack of model systems allowing in-depth molecular analyses in vitro. Our goal was to establish a cell culture model to characterize inflammation-induced macrophage-to-LECP differentiation under controlled conditions.Time-course analysis of diaphragms from lipopolysaccharide (LPS)-treated mice revealed rapid mobilization of bone marrow-derived and peritoneal macrophages to the proximity of lymphatic vessels followed by widespread (∼50%) incorporation of M-LECPs into the inflamed lymphatic vasculature. A differentiation shift toward the lymphatic phenotype was found in three LPS-induced subsets of activated macrophages that were positive for VEGFR-3 and many other lymphatic-specific markers. VEGFR-3 was strongly elevated in the early stage of macrophage transition to LECPs but undetectable in M-LECPs prior to vascular integration. Similar transient pattern of VEGFR-3 expression was found in RAW264.7 macrophages activated by LPS in vitro. Activated RAW264.7 cells co-expressed VEGF-C that induced an autocrine signaling loop as indicated by VEGFR-3 phosphorylation inhibited by a soluble receptor. LPS-activated RAW264.7 macrophages also showed a 68% overlap with endogenous CD11b(+)/VEGFR-3(+) LECPs in the expression of lymphatic-specific genes. Moreover, when injected into LPS- but not saline-treated mice, GFP-tagged RAW264.7 cells massively infiltrated the inflamed diaphragm followed by integration into 18% of lymphatic vessels.We present a new model for macrophage-LECP differentiation based on LPS activation of cultured RAW264.7 cells. This system designated here as the "RAW model" mimics fundamental features of endogenous M-LECPs. Unlike native LECPs, this model is unrestricted by cell numbers, heterogeneity of population, and ability to change genetic composition for experimental purposes. As such, this model can provide a valuable tool for understanding the LECP and lymphatic biology

Assessment of a new biological complex efficacy on dysseborrhea, inflammation, and Propionibacterium acnes proliferation

Sandra Trompezinski,1 Sophie Weber,1 Benoît Cadars,2 Florence Larue,1 Nathalie Ardiet,1 Marlène Chavagnac-Bonneville,2 Michèle Sayag,2 Eric Jourdan2 1NAOS, Aix-en Provence, 2Direction Scientifique Bioderma (NAOS), Lyon, France Introduction: Acne vulgaris is a common chronic inflammatory disease of the pilosebaceous unit triggered by Propionibacterium acnes. A bakuchiol, Ginkgo biloba extract, and mannitol (BGM) complex has been developed to provide patients with acne with a specific dermocosmetic to be used adjunctively with conventional treatments. Objective: The aim of these studies was to assess the antibacterial, anti-inflammatory, and antioxidative potential of BGM complex and its individual compounds as well as its impact on sebum composition. Methods: The antibacterial, anti-inflammatory, and antioxidative potential of BGM complex and its compounds was assessed through in vitro, ex vivo, and clinical studies. The clinical benefit of BGM complex formulated in a cream was assessed in subjects prone to acne through sebum composition analysis and photometric assessments. Results: Results from the studies showed that the BGM complex has significant antibacterial, anti-inflammatory, and antioxidative properties. At similar concentrations, bakuchiol has up to twice the antioxidative potential than vitamin E. In subjects, BGM complex regulated the sebum composition in acne patients by increasing the level of sapienic and linolenic acid and reducing the level of oleic acid. The reduced number of porphyrins on the skin surface showed that it is also effective against P. acnes. Conclusion: BGM complex provides a complete adjunctive care in patients with acne by targeting etiopathogenic factors of acne: dysseborrhea, inflammation, and P. acnes proliferation. Keywords: acne, antibacterial, anti-inflammatory, antioxidation, cosmetics, sebu

Impact of Leave-on Skin Care Products on the Preservation of Skin Microbiome: An Exploration of Ecobiological Approach

Sylvie Callejon,1,2 Félix Giraud,1,2 Florence Larue,1 Armonie Buisson,1 Léa Mateos,1,2 Laurence Grare,1 Aurélie Guyoux,1 Eric Perrier,2 Nathalie Ardiet,1 Sandra Trompezinski1,2 1NAOS Group, Research and Development Department, Aix-en-Provence, France; 2NAOS Institute of Life Science, Aix-en-Provence, FranceCorrespondence: Sandra Trompezinski, 355 Rue Pierre Simon Laplace, 13593 Aix-en-Provence Cedex 03, Aix-en-Provence, France, Tel +33 4 42 60 73 65, Email [email protected]: Skincare products are used daily to maintain a healthy skin, although their skin microbiome impact is still poorly known. Preserving the natural resources and mechanisms of the skin ecosystem is essential, and a novel approach based on these premises, called ecobiology, has recently emerged in skincare. We evaluated the impact on the skin microbiome of three types of leave-on face skincare products: a hydrophilic solution, a micellar solution, and an oil-in-water emulsion.Patients and Methods: Samples for microbial profiling were obtained from 20 Caucasian females twenty-four hours and four days following daily application of the skincare products and compared to an untreated area. The bacterial diversity and the abundance of the skin microbiome were analyzed by 16S rRNA gene sequencing using an Illumina MiSeq platform.Results: Our results confirmed the skin microbiome diversity and the prevalence of Cutibacterium spp. and Staphylococcus spp. at sebaceous sites. The bacterial diversity and abundance were not affected by the products, and no dissimilarities versus the control nor between each product were noted at both times.Conclusion: These preliminary results demonstrate for the first time that three types of leave-on face skincare products have no impact on the human skin microbiome and can be considered to be “microbiome friendly”.Keywords: cosmetic product, ecobiology, microbiome friendl