Because inhibition of integrin signaling induces apoptosis, we investigated whether keratinocytes expressing L L1 and K K6L L4 integrins (enriched for stem cells) are protected from cell death. Keratinocytes rapidly adhering to type IV collagen expressed highest levels of L L1 and K K6L L4 and of the anti-apoptotic stem cell marker p63. Apoptotic cells were signi¢cantly higher in slowly adhering than in rapidly adhering keratinocytes. Anti-L L1 integrin caused a signi¢cant increase in apoptotic cells, while it decreased Bcl-2 levels in stem keratinocytes. Bax and Bad proteins were higher in slowly adhering than in rapidly adhering cells. By contrast, Bcl-2, Bcl-x and Mcl-1 proteins were highest in rapidly adhering keratinocytes and nearly absent in slowly adhering cells. After addition of anti-L L1 integrin, the apoptotic rate was signi¢cantly higher in HaCaT cells not expressing Bcl-2 than in controls. These results indicate that keratinocytes enriched for stem cells are protected from apoptosis via L L1 integrin, in a Bcl-2 dependent manner. ß

Sandoz and Sanofi. A. Cristaudo has been principal investigator in clinical trials sponsored by Abbvie, Leo Pharma and Pfizer. F. Cusano received honoraria as speaker and advisory board member from Sanofi Genzyme. M. Esposito has served as a speaker for Sanofi-Genzyme.

β1-integrin protects keratinocyte stem cells (KSC) from cell-detachment apoptosis (`anoikis'). Here we show that caspase-8 active protein is detected in both young transit amplifying (TA) cells and TA cells, but not in KSC. On suspension, caspases are activated earlier in young TA than in KSC, whereas anti-β1-integrin neutralizing antibody accelerates caspase activation in both KSC and young TA. Caspases 8 and 10 are the first caspases to be activated whereas caspase-8 inhibitor zIETD-fmk delays the activation of Bid, caspase-9 and caspase-3. However, the caspase-9 inhibitor zLEDH-fmk does not block the activation of caspase-8, Bid, caspase-10 and caspase-3. Moreover, caspase-8, but not caspase-9 inhibitor partially prevents keratinocyte anoikis. As FLIP inhibits caspase-8 processing, we retrovirally infected HaCaT keratinocytes with c-FLIPL. Anti-β1-integrin fails to activate caspase-8, Bid, caspase-9 and to induce the release of cytochrome c in c-FLIPL overexpressing keratinocytes. Finally, overexpression of c-FLIPL partially prevents anoikis in both suspended and anti-β1 integrin-treated cells. Taken together, these results indicate that the extrinsic apoptotic pathway triggered by caspase-8 predominates in keratinocyte anoikis. However, the release of cytochrome c and the later activation of caspase-9 seem to suggest that the intrinsic mitochondrial pathway may intervene as a positive feedback loop of caspase activation.

p75 neurotrophin receptor (p75NTR) belongs to the TNF-receptor superfamily and signals apoptosis in many cell settings. In human epidermis, p75NTR is mostly confined to the transit-amplifying (TA) sub-population of basal keratinocytes. Brainderived neurotrophic factor (BDNF) or neurotrophin-4 (NT-4), which signals through p75NTR, induces keratinocyte apoptosis, whereas b-amyloid, a ligand for p75NTR, triggers caspase-3 activation to a greater extent in p75NTR transfected cells. Moreover, p75NTR co-immunoprecipitates with NRAGE, induces the phosphorylation of c-Jun N-terminal kinase (JNK) and reduces nuclear factor kappa B (NF-jB) DNA-binding activity. p75NTR also mediates pro-NGF-induced keratinocyte apoptosis through its co-receptor sortilin. Furthermore, BDNF or b-amyloid cause cell death in TA, but not in keratinocyte stem cells (KSCs) or in p75NTR silenced TA cells. p75NTR is absent in lesional psoriatic skin and p75NTR levels are significantly lower in psoriatic than in normal TA keratinocytes. The rate of apoptosis in psoriatic TA cells is significantly lower than in normal TA cells. BDNF or b-amyloid fail to induce apoptosis in psoriatic TA cells, and p75NTR retroviral infection restores BDNF-or b-amyloid-induced apoptosis in psoriatic keratinocytes. These results demonstrate that p75NTR has a pro-apoptotic role in keratinocytes and is involved in the maintenance of epidermal homeostasis.

Introduction: Treat-to-target strategies are used in several chronic diseases to improve outcomes. Treatment goals have also been suggested for psoriasis, but there is currently no consensus on targets, and guidance is needed to implement this strategy in clinical practice. The project 'Treat to Target Italia' was launched by a scientific board (SB) of 10 psoriasis experts to generate expert consensus recommendations.

Background Brodalumab was efficacious and safe in moderate‐to‐severe plaque‐type psoriasis in the AMAGINE trials; published reports under real‐life conditions are limited. Objectives To evaluate the effectiveness and safety of brodalumab in patients with moderate‐to‐severe plaque‐type psoriasis in a real‐world setting. Methods This observational, retrospective study enrolled adult patients (≥18 years) with moderate‐to‐severe plaque‐type psoriasis who underwent 24 weeks of treatment with brodalumab at 17 Italian dermatological centres. Baseline data included demographics, comorbidities, age of onset and duration of psoriasis and previous treatments. Psoriasis Area and Severity Index (PASI), Physician Global Assessment (PGA), static PGA of Genitalia, Dermatology Life Quality Index and patient satisfaction were assessed at weeks 0, 4, 12 and 24; adverse events were recorded. Results Seventy‐eight patients (mean age 47.9 years, 71.8% male, average disease duration 16.8 years) were enrolled. A rapid and significant reduction in mean PASI score was observed after 4 weeks of treatment, decreasing further at weeks 12 and 24 (all P < 0.0001 vs. baseline). A higher number of cardiometabolic comorbidities and previous therapies were negatively associated with the achievement of PASI 90 at all assessments. Brodalumab was effective in bio‐experienced patients, including those who had failed on anti‐interleukin (IL)‐17 therapies. Quality of life and patient satisfaction increased significantly during treatment (P < 0.0001 and P < 0.01 vs. baseline, respectively). Treatment was interrupted in 9 (11.5%) patients due to adverse events (n = 4), lack of efficacy (n = 3), lost to follow‐up (n = 1) and surgical procedure (n = 1). Conclusions Brodalumab is effective and safe in the treatment of moderate‐to‐severe psoriasis in a real‐world setting, including in patients with failure to anti‐IL17 therapies.

17 β-estradiol/genistein protected fibroblasts/keratinocytes against peroxidation by modulating oxidant/antioxidant system and mitochondria membrane potential, through mechanisms related to ERs and GPER30 and kinases activation.

Significantly lower recurrence rates were recorded in patients treated with classic or Tübingen Mohs' technique. To the best of our knowledge, our case series is the widest treated with MTT ever described in the literature; these data may be useful to guide clinicians in the choice of the gold standard treatment for Dermatofibrosarcoma protuberans.