involucrin and delphinidin

Psoriasis is a chronic inflammatory disorder of skin and joints for which conventional treatments that are effective in clearing the moderate-to-severe disease are limited due to long-term safety issues. This necessitates exploring the usefulness of botanical agents for treating psoriasis. We previously showed that delphinidin, a diet-derived anthocyanidin endowed with antioxidant and anti-inflammatory properties, induces normal epidermal keratinocyte differentiation and suggested its possible usefulness for the treatment of psoriasis [1].. To investigate the effect of delphinidin (0-20 μM; 2-5 days) on psoriatic epidermal keratinocyte differentiation, proliferation and inflammation using a three-dimensional reconstructed human psoriatic skin equivalent (PSE) model.. PSEs and normal skin equivalents (NSEs) established on fibroblast-contracted collagen gels with respective psoriatic and normal keratinocytes and treated with/without delphinidin were analyzed for histology, expression of markers of differentiation, proliferation and inflammation using histomorphometry, immunoblotting, immunochemistry, qPCR and cultured supernatants for cytokine with a Multi-Analyte ELISArray Kit.. Our data show that treatment of PSE with delphinidin induced (1) cornification without affecting apoptosis and (2) the mRNA and protein expression of markers of differentiation (caspase-14, filaggrin, loricrin, involucrin). It also decreased the expression of markers of proliferation (Ki67 and proliferating cell nuclear antigen) and inflammation (inducible nitric oxide synthase and antimicrobial peptides S100A7-psoriasin and S100A15-koebnerisin, which are often induced in psoriatic skin). ELISArray showed increased release of psoriasis-associated keratinocyte-derived proinflammatory cytokines in supernatants of the PSE cultures, and this increase was significantly suppressed by delphinidin.. These observations provide a rationale for developing delphinidin for the management of psoriasis.

Topics: Anthocyanins; Anti-Inflammatory Agents; Caspases; Cell Differentiation; Cells, Cultured; Cytokines; Filaggrin Proteins; Humans; Keratinocytes; Membrane Proteins; Models, Biological; Protein Precursors; Psoriasis; RNA, Messenger; S100 Calcium Binding Protein A7; S100 Proteins; Skin

Delphinidin (Del), [3,5,7,3'-,4'-,5'-hexahydroxyflavylium], an anthocyanidin and a potent antioxidant abundantly found in pigmented fruits and vegetables exhibits proapoptotic effects in many cancer cells. Here, we determined the effect of Del on growth, apoptosis and differentiation of normal human epidermal keratinocytes (NHEKs) in vitro in submerged cultures and examined its effects in a three-dimensional (3D) epidermal equivalent (EE) model that permits complete differentiation reminiscent of in vivo skin. Treatment of NHEKs with Del (10-40 μm; 24-48 h) significantly enhanced keratinocyte differentiation. In Del-treated cells, there was marked increase in human involucrin (hINV) promoter activity with simultaneous increase in the mRNA and protein expressions of involucrin and other epidermal differentiation markers including procaspase-14 and transglutaminase-1 (TGM1), but without any effect on TGM2. Del treatment of NHEKs was associated with minimal decrease in cell viability, which was not associated with apoptosis as evident by lack of modulation of caspases, apoptosis-related proteins including Bcl-2 family of proteins and poly(ADP-ribose) polymerase cleavage. To establish the in vivo relevance of our observations in submerged cultures, we then validated these effects in a 3D EE model, where Del was found to significantly enhance cornification and increase the protein expression of cornification markers including caspase-14 and keratin 1. For the first time, we show that Del induces epidermal differentiation using an experimental system that closely mimics in vivo human skin. These observations suggest that Del could be a useful agent for dermatoses associated with epidermal barrier defects including aberrant keratinization, hyperproliferation or inflammation observed in skin diseases like psoriasis and ichthyoses.

Topics: Anthocyanins; Antioxidants; Apoptosis; Caspases; Cell Culture Techniques; Cell Differentiation; Cell Proliferation; Cells, Cultured; Dose-Response Relationship, Drug; Epidermal Cells; Foreskin; Fruit; Gene Expression; Humans; Infant, Newborn; Keratinocytes; Male; Organ Culture Techniques; Promoter Regions, Genetic; Protein Precursors; Vegetables