Anna De Filippis

Polydatin, a natural precursor of resveratrol, induces β-Defensin production and reduces inflammatory response.

It is well known that human keratinocytes produce the anti-microbial peptide β-defensin 2. Its production is enhanced by pathogenic microorganisms or other environmental stressors. In this study, we evaluated the effect of resveratrol, a polyphenol found in several dietary source as grape seed, and its natural precursor, polydatin on heat-stressed human keratinocytes. By reverse transcription-polymerase chain reaction and enzyme-linked immunoadsorbent assay, we demonstrated that resveratrol used in combination with polydatin was able to modulate interleukin (IL)-6, IL-8 and tumor necrosis factor-alpha gene expression. In addition, our data show that resveratrol and polydatin increased the heat shock protein (Hsp)70B′ gene expression, a Hsp that plays an important role in the cytoprotection and repair of cells and tissues. Worthy of note, polydatin used alone or in combination with resveratrol, increased the release of human β-defensin 2. These results highlighted the ability of polydatin and resveratrol to reinforce cytoprotective response in stress conditions and suggest their use in cosmetic or pharmaceutical preparations.

Effects of AV119, a natural sugar from avocado, on Malassezia furfur invasiveness and on the expression of HBD-2 and cytokines in human keratinocytes

Abstract:  AV119 is a patented blend of two sugars from avocado that can induce human β‐defensin‐2 production by normal human keratinocytes. In this study, we analysed the effect of AV119 on growth and invasiveness of Malassezia furfur, a dimorphic, lipid‐dependent yeast that is part of the normal human cutaneous commensal flora. The ability to modulate the expression of the proinflammatory and immunomodulatory cytokines in normal human keratinocytes was also investigated. Microbiological assay demonstrated that this sugar induced the aggregation of yeast cells and inhibited the invasiveness of M. furfur, without affecting its growth. Real‐time PCR analysis demonstrated that AV119 was able to modulate the HBD‐2 response in treated keratinocytes, reaching a maximum after 48‐h treatment, and to induce the recovery of a satisfactory proinflammatory response in human keratinocytes. As AV119 can induce aggregation of yeast cells, thus inhibiting their penetration into the keratinocytes, the sugar could be used in the preparation of cosmetics or pharmacological drugs to inhibit colonization of the skin by pathogenic strains of M. furfur.

The Helicobacter pylori protein HspB interferes with Nrf2/Keap1 pathway altering the antioxidant response of Ags cells.

Helicobacter pylori infection causes chronic oxidative stress on gastric mucosa, thereby causing mucosal damage and increasing the risk of gastric adenocarcinoma. Nrf2 is an important transcription factor, regulating the antioxidant response in the cells. Nrf2 signaling is repressed by Keap1 at basal condition and induced by oxidative stress. The aim of our study was to analyze whether the H. pylori proteins interfered in the Nrf2/Keap1 pathway.

5-Aminolaevulinic acid and photodynamic therapy reduce HSV-1 replication in HaCat cells through an apoptosis-independent mechanism

Background: Photodynamic therapy (PDT) involves the use of a photosensitizing agent, which may require metabolic synthesis (i.e. a prodrug), followed by light activation. Numerous studies have advanced PDT as a means for treating bacteria, fungi and viruses. In this study, the photoinactivation of Herpes simplex virus type 1 (HSV‐1) in human keratinocytes using 5‐aminolaevulinic acid (5‐ALA) was investigated.

3‐O‐methylfunicone produced by penicillium pinophilum affects cell motility of breast cancer cells, downregulating αvβ5 integrin and inhibiting metalloproteinase‐9 secretion

Recent evidence assigns integrins and metalloproteinases (MMPs) an important role in regulating tumor cell progression. Here, we demonstrate that 3‐O‐methylfunicone (OMF), a secondary metabolite produced by Penicillium pinophilum, affects cell proliferation and motility of breast cancer MCF‐7 cells, downregulating αvβ5 integrin, and inhibiting MMP‐9 secretion. This effect was absent when the non‐tumoral MCF‐10 cell line was used. Inhibition of cell motility was also associated to modifications in cell shape and in the distribution of tubulin fibers of OMF‐treated MCF‐7 cells. In addition, a possible effect on survivin and hTERT was also investigated. We found that OMF strongly inhibits survivin and hTERT gene expression. The results of this study indicate that OMF‐induced inhibition of cell motility may be mediated through the modulation of αvβ5 integrin and MMP‐9 secretion. In addition, the inhibition of typical markers of tumor progression such as hTERT and survivin in MCF‐7 and their inactivity towards MCF10 provide strong evidence for a potential use of OMF in anticancer therapy.

Innate immune response in human keratinocytes infected by a feline isolate of Malassezia pachydermatis

Malassezia pachydermatis is a normal inhabitant of canine and feline skin that can spread to other pets. The outer layer or epidermis is made up primarily of keratinocytes, which are capable of releasing various factors and expressing receptors that are significantly involved in the immune regulation. Little is known about the mechanism by which M. pachydermatis overcomes the natural barrier of the skin. The aim of this study was to evaluate the direct in vitro interaction between human keratinocytes and a clinical strain of live M. pachydermatis isolated as a pure culture from an otitic cat. Human keratinocytes (HaCat) were infected with M. pachydermatis to analyse the modulation of the innate immune response. Gene expression was analysed by real-time PCR. We demonstrated that M. pachydermatis invaded HaCat cells and modulated the expression of TLR2 after 24h infection, while HBD-2, IL-1β TNF-α, IL-6 and IL-8 were modulated both at 24 and 48 h. Thus, our results demonstrated that M. pachydermatis is able to stimulate the innate immune response in infected human keratinocytes indicating a possible role of this yeast as a human opportunistic pathogen.

Simvastatin reduces melanoma progression in a murine model

Statins are a class of drugs that inhibit the rate-limiting step in the cholesterol biosynthetic pathway and show an anticancer effect, probably through the inhibition of cell proliferation. To date, the exact mechanism of cancer cell growth arrest induced by statins is not known. We report that simvastatin is able to induce apoptosis in melanoma cells but not in normal cells and also able to contrast the growth of tumor in an experimental melanoma murine model. We observed a delay in the tumor development in almost the 50% of the simvastatin administered animals and a strong reduction of the tumor volume with a differences of ∼150% compared to the controls. Also the survival rate was significantly higher in mice that received the drug with a survival increase of ∼130% compared to the controls. The tumor growth reduction in mice was supported by the results of cell migration assay, confirming that simvastatin clearly reduced cell migration. Moreover, simvastatin induced a strong downregulation of NonO gene expression, an important growth factor involved in the splicing regulation. This result could explain the decrease of melanoma cells proliferation, suggesting a possible action mechanism. The results derived from our experiments may sustain the many reports on the anticancer inhibitory property of statins and encourage new studies on this drug for a possible use in therapy, probably in combination with conventional chemotherapy.

Cell-growth and migration inhibition of human mesothelioma cells induced by 3-O-Methylfunicone from Penicillium pinophilum and cisplatin

SummaryMalignant pleural mesothelioma is a fatal malignancy linked to asbestos exposure. The main challenge for mesothelioma treatment is to go beyond the drug resistance, in particular against cisplatin (CDDP), one of the most used chemotherapeutic drug. 3-O-methylfunicone (OMF) is a metabolite produced by the fungus Penicillium pinophilum; its antiproliferative properties have been previously studied in vitro. Particularly, OMF is able to inhibit mesothelioma cell motility. To improve the effects of CDDP by-passing the resistance of mesothelioma cells to this drug, in the present study we investigated the combined treatment of OMF with CDDP respectively in an established mesothelioma cell line (NCI) and primary mesothelioma cells (Mest). As compared to the effect of single treatments, the combination of OMF and CDDP resulted in a stronger inhibition of NCI and Mest cell proliferation. OMF combination with CDDP was also able to affect the migratory ability of NCI and Mest cells by down-regulating αv and β5 expression and reducing metalloproteinase 2 (MMP-2) production. In addition, this association was effective in modulating VEGF gene expression. This finding highlights the possibility to use OMF and CDDP together to regulate angiogenesis and tumour progression in mesothelioma.

Captopril modulates acetylcholinesterase in human keratinocytes

Human keratinocytes synthesize and secrete non-neuronal acetylcholine, which acts as a local cell signaling molecule, regulating functions like proliferation, cell adhesion, motility, desmosomal cell contact, and glandular activity. The keratinocyte acetylcholine axis is composed of the enzymes mediating acetylcholine synthesis (acetyltransferase) and degradation (acetylcholinesterase), and two classes of acetylcholine receptors. In this study we investigated the effect of captopril, an ACE-inhibitor, on acetylcholinesterase and acetylcholine secretion in human keratinocytes. We analyzed the level of acetylcholinesterase in HaCat and NHEK cells by RT-PCR and Western blotting analysis. In addition, the effect of captopril on AChE activity was evaluated. We found that captopril induces a strong AChE up-regulation leading to ACh degradation and reduced secretion. Our results suggest that acantholysis induced by ACE-inhibitors might be linked to altered level of Ach.

Vitamin D reduces the inflammatory response by Porphyromonas gingivalis infection by modulating human β-defensin-3 in human gingival epithelium and periodontal ligament cells

Abstract Periodontitis is a multifactorial polymicrobial infection characterized by a destructive inflammatory process. Porphyromonas gingivalis, a Gram‐negative black‐pigmented anaerobe, is a major pathogen in the initiation and progression of periodontitis; it produces several virulence factors that stimulate human gingival epithelium (HGE) cells and human periodontal ligament (HPL) cells to produce various inflammatory mediators. A variety of substances, such as vitamin D, have growth‐inhibitory effects on some bacterial pathogens and have shown chemo‐preventive and anti‐inflammatory activity. We used a model with HGE and HPL cells infected with P. gingivalis to determine the influence of vitamin D on P. gingivalis growth and adhesion and the immunomodulatory effect on TNF‐&agr;, IL‐8, IL‐12 and human‐&bgr;‐defensin 3 production. Our results demonstrated, firstly, the lack of any cytotoxic effect on the HGE and HPL cells when treated with vitamin D; in addition, vitamin D inhibited P. gingivalis adhesion and infectivity in HGE and HPL cells. Our study then showed that vitamin D reduced TNF‐&agr;, IL‐8, IL‐12 production in P. gingivalis‐infected HGE and HPL cells. In contrast, a significant upregulation of the human‐&bgr;‐defensin 3 expression in HGE and HPL cells induced by P. gingivalis was demonstrated. Our results indicate that vitamin D specifically enhances the production of the human‐&bgr;‐defensin 3 antimicrobial peptide and exerts an inhibitory effect on the pro‐inflammatory cytokines, thus suggesting that vitamin D may offer possible therapeutic applications for periodontitis. HighlightsVitamin D inhibits Porphyromonas gingivalis infectivity in human gingival epithelium and periodontal ligament cellsVitamin D reduces TNF‐&agr;, IL‐8, IL‐12 production in infected cells with Porphyromonas gingivalisVitamin D enhances the production of the human‐&bgr;‐defensin 3 in infected cells with Porphyromonas gingivalis