Previous studies have reported that low molecular mass HA and highly polymerized HA respectively elicited pro- and anti-inflammatory responses by modulating the toll-like receptor 4 (TLR-4) and the TLR-2. The activation of TLR-4 and TLR-2 mediated by collagen-induced arthritis (CIA) induces the myeloid differentiation primary response protein (MyD88) and the tumor necrosis factor receptor-associated factor 6 (TRAF6), and ends with the liberation of NF-kB which, in turn, stimulates pro-inflammatory cytokine production. The aim of this study was to investigate the influence of high molecular weight HA at different concentrations on TLR-4 and TLR-2 modulation in CIA in mice. Arthritis was induced in mice via intradermal injection of an emulsion containing bovine type II collagen in complete Freund's adjuvant. Mice were treated with HA intraperitoneally daily for 30days. CIA increased TLR-4, TLR-2, MyD88 and TRAF6 mRNA expression and the related protein in the cartilage of arthritic joints. High levels of both mRNA and related protein were also detected for tumor necrosis factor alpha (TNF-α), interleukin 1-beta (IL-1-β), interleukin-17 (IL-17), matrix metalloprotease-13 (MMP-13) and inducible nitric oxide synthase (iNOS) in the joint of arthritic mice. HA treatment significantly limited CIA incidence and decreased all the parameters up-regulated by CIA. The improvement of biochemical parameters was also supported by histological analysis, plasma and synovial fluid HA levels. These results suggest that the TLR-4 and TLR-2 play an important role in the arthritis mechanism and the interaction/block of HA at high molecular mass may reduce inflammation and cartilage injury.

BAY 11-7082 antagonizes I-κB kinase-β preventing nuclear translocation of nuclear factor-κB (NF-κB); it also inhibits NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation. NF-κB is involved in psoriasis, whereas the role of NLRP3 is controversial. We investigated BAY 11-7082 effects in an experimental model of psoriasis-like dermatitis. Psoriasis-like lesions were induced by a topical application of imiquimod (IMQ) cream (62.5 mg/day) on the shaved back skin of C57BL/6 and NLRP3 knockout (KO) mice for 7 consecutive days. Sham psoriasis animals were challenged with Vaseline cream. Sham and IMQ animals were randomized to receive BAY 11-7082 (20 mg/kg/i.p.) or its vehicle (100 μl/i.p of 0.9% NaCl). Skin of IMQ animals developed erythema, scales, thickening and epidermal acanthosis. IMQ skin samples showed increased expression of pNF-κB and NLRP3 activation. BAY 11-7082 blunted epidermal thickness, acanthosis and inflammatory infiltrate. BAY 11-7082 reduced pNF-κB, NLRP3, tumour necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-1β expression, blunted the phosphorylation of signal transducer and activators of transcription 3 (STAT3) and decreased IL-23 levels. In addition, BAY 11-7082 reawakened the apoptotic machinery. NLRP3 KO animals showed a reduced total histological score but persistent mild acanthosis, dermal thickness and expression of pNF-κB and pSTAT3, following IMQ application. Our data suggest that BAY 11-7082 might represent an interesting approach for the management of psoriasis-like dermatitis depending on the dual inhibition of NF-κB and NLRP3.

Background: Nail involvement is a frequent event in the course of psoriasis causing severe distress. While systemic cyclosporin (CsA) represents a well-established therapy of psoriasis, its topical use is limited by the difficult penetration of the molecule through the skin and the nail because of its highly lipophilic nature. Objectives: We carried out a prospective randomized placebo-controlled study in order to analyze the effectiveness and tolerability of topical oil-dissolved 70% CsA solution in nail psoriasis. Methods: Sixteen adult patients with nail psoriasis, divided randomly into two groups of 8 patients (group A and group B), were treated respectively with a 70% maize-oil-dissolved oral CsA solution and maize oil alone. To compare the therapeutic effectiveness, all patients were evaluated, before starting the treatment and after 12 weeks of therapy, by the same dermatologists. The patients were also asked to assess the severity of their nail involvement at baseline and at the end of the treatment. Results: In group A, 3 patients came to a complete resolution of nail lesions and 5 showed a substantial improvement of the overall severity score. In group B, a slight improvement was noted in only 1 patient. All the patients of group A judged positively the results of the therapy, while in group B only 1 patient reported a moderate improvement. Conclusion: Our results show that topical therapy with oral CsA solution is a safe, effective and cosmetically highly acceptable treatment modality for nail psoriasis. The ability of CsA to influence keratinocyte proliferation and T-cell lymphokine release, reducing the cornification of the upper layers of the epidermis, may prevent the typical alterations observed in nail psoriasis.

In order to ascertain whether erythropoietin plays a role in early and late repair processes following ischaemic skin flap injury, a dorsal, caudally based skin flap was created in rats. The rats were successively divided into four groups. Group 1 was not treated. The other groups were treated with a subcutaneous administration of 0.9% NaCl saline solution (group 2), a subcutaneous administration of vehicle (group 3) or a subcutaneous administration of 300 IU/kg/day of recombinant human erythropoietin (group 4). We evaluated the possible relationships between neutrophil accumulation, myeloperoxidase activity and content in flap tissue, flap survival, flap temperature (using telethermography) and flap revascularization (using videocapillaroscopy). Necrosis in the flap was significantly less extensive in group 4 than in groups 1, 2 and 3. A significant increase in neutrophil infiltration occurred between the 1st and 24th hour in these groups, but this was not observed in group 4. These findings were confirmed by biochemical data of myeloperoxidase activity and malonyldialdehyde content. Between the 1st and 7th days, we recorded an increase of about 20% in flap temperature in groups 1, 2 and 3, whereas no significant variation was observed in group 4. On the 7th day, videocapillaroscopic findings showed an increase in the mean vascularization index in group 4. Our findings suggest that recombinant human erythropoietin administration can improve the wound healing process, in both early and late stages of injury, by reducing inflammatory response, increasing the density of capillaries in ischaemic flaps and allowing earlier repair of a damaged area.

Photodynamic Therapy (PDT) is a non-invasive treatment successfully used for neoplastic, inflammatory and infectious skin diseases. One of its strengths is represented by the high safety profile, even in elderly and/or immuno-depressed subjects. PDT, however, may induce early and late onset side effects. Erythema, pain, burns, edema, itching, desquamation, and pustular formation, often in association with each other, are frequently observed in course of exposure to the light source and in the hours/days immediately after the therapy. In particular, pain is a clinically relevant short-term complication that also reduces long-term patient satisfaction. Rare complications are urticaria, contact dermatitis at the site of application of the photosensitizer, and erosive pustular dermatosis. Debated is the relationship between PDT and carcinogenesis: the eruptive appearance of squamous cell carcinoma (SCC) in previously treated areas has been correlated to a condition of local and/or systemic immunosuppression or to the selection of PDT-resistant SCC. Here we review the literature, with particular emphasis to the pathogenic hypotheses underlying these observations.

BACKGROUND AND PURPOSE Ovariectomy accelerates age‐related skin changes as adequate oestrogen levels are required to control structural integrity and functional capacity of skin. Genistein, a soy‐derived isoflavone, has been tested in anti‐ageing cosmetic preparations with interesting results on skin elasticity, photoaging and skin cancer prevention. We investigated the effects of genistein aglycone and compared them with systemic raloxifene hydrochloride and 17‐α‐ethinyloestradiol on skin changes in aged, ovariectomized (OVX) rats. EXPERIMENTAL APPROACH Six months after ovariectomy, rats were randomly allocated to different groups and treated, daily, with genistein aglycone (1 and 10 mg·kg−1 s.c.), raloxifene hydrochloride (0.05 and 0.5 mg·kg−1 s.c.) or 17‐α‐ethinyloestradiol (0.003 and 0.03 mg·kg−1 s.c.) for 12 weeks. Controls were untreated OVX and sham OVX rats. At the end of the treatment period, a skin biopsy was carried out and skin samples were assessed for molecular, histological and functional changes. KEY RESULTS Skin samples of untreated OVX rats showed a decrease in TGF‐β1, VEGF, MMP‐2, MMP‐9, tissue inhibitor of metalloproteinase (TIMP)‐1 and TIMP‐2 compared with sham OVX rats. All the treatments significantly restored this depressed molecular profile revealed in OVX rats. Genistein aglycone, 1 mg·kg−1, also significantly increased the thickness of collagen and breaking strength of skin in the OVX rats. CONCLUSIONS AND IMPLICATIONS Relatively long‐term, systemic treatment with genistein aglycone shows comparable efficacy to oestrogen in reversing some molecular, histological and functional changes of the skin associated with ovariectomy in aged rats. This suggests that genistein aglycone might be an effective alternative therapy for the management of age‐related skin changes in postmenopausal women.

Background: Subacute cutaneous lupus erythematosus (SCLE) is a distinct subset of cutaneous lupus erythematosus clinically characterized by psoriasiform and/or annular lesions and by a mild or absent systemic involvement. Objective: The Italian Group of Immunodermatology of the Italian Society of Dermatology and Venereology reviewed the cases of SCLE seen in 10 years (1987–1996). Patients: Forty-six women and 12 men have been retrospectively studied, 42% had annular lesions, 39% psoriasiform ones and 16% both. Results: Lesions were mainly localized on the neck and face and relapsed in spring and autumn. Seventeen patients had 4 or more American College of Rheumatology criteria and could be classified as having systemic lupus erythematosus. The most frequent histopathological alterations were epidermal atrophy, hydropic degeneration of the basal layer and perivascular lymphocytic infiltrate. Deposits of immunoglobulins and C3 at the dermo-epidermal junction on the clinically involved skin were present in 86% of the patients. Dust-like particles in the epidermis were only found in 3% of cases. Anti-Ro/SSA antibodies were found in 71% of the cases and anti-dsDNA only in 5% of cases. Conclusions: SCLE is a particular subset of cutaneous lupus erythematosus with peculiar clinical and immunopathological features.

β-caryophyllene (BCP) is a cannabinoid receptor 2 (CB2) agonist that tempers inflammation. An interaction between the CB2 receptor and peroxisome proliferator-activated receptor gamma (PPAR-γ) has been suggested and PPAR-γ activation exerts anti-arthritic effects. The aim of this study was to characterize the therapeutic activity of BCP and to investigate PPAR-γ involvement in a collagen antibody induced arthritis (CAIA) experimental model. CAIA was induced through intraperitoneal injection of a monoclonal antibody cocktail and lipopolysaccharide (LPS; 50 μg/100 μL/ip). CAIA animals were then randomized to orally receive either BCP (10 mg/kg/100 μL) or its vehicle (100 μL of corn oil). BCP significantly hampered the severity of the disease, reduced relevant pro-inflammatory cytokines, and increased the anti-inflammatory cytokine IL-13. BCP also decreased joint expression of matrix metalloproteinases 3 and 9. Arthritic joints showed increased COX2 and NF-ĸB mRNA expression and reduced expression of the PPARγ coactivator-1 alpha, PGC-1α, and PPAR-γ. These conditions were reverted following BCP treatment. Finally, BCP reduced NF-ĸB activation and increased PGC-1α and PPAR-γ expression in human articular chondrocytes stimulated with LPS. These effects were reverted by AM630, a CB2 receptor antagonist. These results suggest that BCP ameliorates arthritis through a cross-talk between CB2 and PPAR-γ.