The DNA Damage Signal for Mdm2 Regulation, Trp53 Induction, and Sunburn Cell Formation In Vivo Originates from Actively Transcribed Genes

The stratum corneum and DNA repair do not completely protect keratinocytes from ultraviolet B. A third defense prevents cells with DNA photoproducts from becoming precancerous mutant cells: apoptosis of ultraviolet-damaged keratinocytes (“sunburn cells”). As signals for ultraviolet-induced apoptosis, some studies implicate DNA photoproducts in actively transcribed genes; other studies implicate non-nuclear signals. We traced and quantitated the in vivo DNA signal through several steps in the apoptosis-signaling pathway in haired mice. Homozygous inactivation of Xpa, Csb, or Xpc nucleotide excision repair genes directed the accumulation of DNA photoproducts to specific genome regions. Repair-defective Xpa−/− mice were 7–10-fold more sensitive to sunburn cell induction than wild-type mice, indicating that 86–90% of the ultraviolet B signal for keratinocyte apoptosis involved repairable photoproducts in DNA; the remainder involves unrepaired DNA lesions or nongenomic targets. Csb−/− mice, defective only in excising photoproducts from actively transcribed genes, were as sensitive as Xpa−/−, indicating that virtually all of the DNA signal originates from photoproducts in active genes. Conversely, Xpc−/− mice, defective in repairing the untranscribed majority of the genome, were as resistant to apoptosis as wild type. Sunburn cell formation requires the Trp53 tumor suppressor protein; 90–96% of the signal for its induction in vivo involved transcribed genes. Mdm2, which regulates the stability of Trp53 through degradation, was induced in vivo by low ultraviolet B doses but was suppressed at erythemal doses. DNA photoproducts in actively transcribed genes were involved in ≈ 89% of the Mdm2 response

Phase 3 trials of ixekizumab in moderate-to-severe plaque psoriasis

BACKGROUND Two phase 3 trials (UNCOVER-2 and UNCOVER-3) showed that at 12 weeks of treatment, ixekizumab, a monoclonal antibody against interleukin-17A, was superior to placebo and etanercept in the treatment of moderate-to-severe psoriasis. We report the 60-week data from the UNCOVER-2 and UNCOVER-3 trials, as well as 12-week and 60-week data from a third phase 3 trial, UNCOVER-1. METHODS We randomly assigned 1296 patients in the UNCOVER-1 trial, 1224 patients in the UNCOVER-2 trial, and 1346 patients in the UNCOVER-3 trial to receive subcutaneous injections of placebo (placebo group), 80 mg of ixekizumab every 2 weeks after a starting dose of 160 mg (2-wk dosing group), or 80 mg of ixekizumab every 4 weeks after a starting dose of 160 mg (4-wk dosing group). Additional cohorts in the UNCOVER-2 and UNCOVER-3 trials were randomly assigned to receive 50 mg of etanercept twice weekly. At week 12 in the UNCOVER-3 trial, the patients entered a long-term extension period during which they received 80 mg of ixekizumab every 4 weeks through week 60; at week 12 in the UNCOVER-1 and UNCOVER-2 trials, the patients who had a response to ixekizumab (defined as a static Physicians Global Assessment [sPGA] score of 0 [clear] or 1 [minimal psoriasis]) were randomly reassigned to receive placebo, 80 mg of ixekizumab every 4 weeks, or 80 mg of ixekizumab every 12 weeks through week 60. Coprimary end points were the percentage of patients who had a score on the sPGA of 0 or 1 and a 75% or greater reduction from baseline in Psoriasis Area and Severity Index (PASI 75) at week 12. RESULTS In the UNCOVER-1 trial, at week 12, the patients had better responses to ixekizumab than to placebo; in the 2-wk dosing group, 81.8% had an sPGA score of 0 or 1 and 89.1% had a PASI 75 response; in the 4-wk dosing group, the respective rates were 76.4% and 82.6%; and in the placebo group, the rates were 3.2% and 3.9% (P<0.001 for all comparisons of ixekizumab with placebo). In the UNCOVER-1 and UNCOVER-2 trials, among the patients who were randomly reassigned at week 12 to receive 80 mg of ixekizumab every 4 weeks, 80 mg of ixekizumab every 12 weeks, or placebo, an sPGA score of 0 or 1 was maintained by 73.8%, 39.0%, and 7.0% of the patients, respectively. Patients in the UNCOVER-3 trial received continuous treatment of ixekizumab from weeks 0 through 60, and at week 60, at least 73% had an sPGA score of 0 or 1 and at least 80% had a PASI 75 response. Adverse events reported during ixekizumab use included neutropenia, candidal infections, and inflammatory bowel disease. CONCLUSIONS In three phase 3 trials involving patients with psoriasis, ixekizumab was effective through 60 weeks of treatment. As with any treatment, the benefits need to be weighed against the risks of adverse events. The efficacy and safety of ixekizumab beyond 60 weeks of treatment are not yet known

Evaluation of Objective Signs and Subjective Symptoms of Dry Eye Disease in Patients with Inflammatory Bowel Disease

Aim. To evaluate tear film parameters and relationship of objective clinical signs and subjective symptoms of dry eye disease (DED) in inflammatory bowel disease (IBD) subgroups. Methods. 39 patients with Crohn’s disease (CD), 26 patients with ulcerative colitis (UC), and 39 control persons with no ocular symptoms or surface disorders were included in this prospective, case-control, and cross-sectional study. The ocular surface disease index (OSDI) questionnaire was applied to evaluate dry eye symptoms, and objective tests of DED were performed on both eyes of each subject. Results. The average of OSDI scores was 30.59 (±16.68) in CD patients, 24.67 (±23.48) in UC patients, and 11.19 (±5.8) in controls. Except for tear film breakup time (tBUT) and Schirmer-I values other objective parameters were better in UC patients, than in CD patients. CD patients rather than UC patients tend to develop DED. This was associated with immunosuppressant and TNF-α inhibitor use. Conclusions. Clinicians must be aware of the spectrum of DED involvement in IBD and suggest using artificial tears in order to decrease severity of ocular complications

The prevalence of obesity is increased in patients with late compared with early onset psoriasis.

PURPOSE We compared the clinical and epidemiologic characteristics of early and late onset psoriasis with an emphasis on potential differences in the comorbidities associated with each subtype. METHODS An observational, multicenter study was performed, and associations between the age at the time of diagnosis and binary comorbidity outcomes were evaluated using multiple logistic regression analysis adjusted for age and other relevant confounders. RESULTS An increased prevalence of positive family history, psoriatic arthritis, and depression was observed in patients with early onset psoriasis. On the other hand, late onset psoriasis was more frequently associated with obesity and elevated waist circumference compared with early onset form. Elderly psoriatic patients (at the age of 75 years) with late onset psoriasis are at an especially high risk for obesity compared with individuals at the same age with an early onset disease. CONCLUSIONS The increased frequency of psoriasis in the family of early onset patients may suggest that manifestation of psoriasis at younger age is driven by strong genetic influence. However, such a remarkable association of abdominal obesity with late onset psoriasis may suggest that obesity can be one of the acquired factors that may predispose for the development of psoriasis in the elderly

The atopic skin-like microenvironment modulates the T-cell-polarising cytokine production of myeloid dendritic cells, as determined by laser scanning cytometry.

Because it is not known exactly when or where myeloid dendritic cells (mDCs) acquire their atopic dermatitis (AD)-specific T-cell-polarising ability in patients with this condition, we used laser scanning cytometry (LSC) to determine whether isolated peripheral blood mDCs from AD patients differed from cells from controls in their cytokine expression profiles de novo and after stimulation with Staphylococcus enterotoxin B (SEB) and thymic stromal lymphopoietin (TSLP), which represents an AD-like microenvironment. Unstimulated mDCs from AD patients showed pluripotent T-cell-polarising capacity, and the surrounding skin microenvironment was essential for the distinctive, disease-specific activity of mDCs (Th2-Th22 bias). We also emphasise that LSC is an attractive technique to study the effect of new DC-targeted therapeutic modalities in AD

PPAR? nuclear receptor coupled arachidonic acid signaling is involved in differentiation and lipid production of human sebocytes

The transcriptional basis of sebocyte differentiation and lipid-producing mechanisms is mostly unclear. Peroxisome proliferator-activated receptor-gamma (PPAR?), a lipid activated transcription factor, has been implicated in lipid metabolism of various cell types. Here, we show that PPAR?? is differentially expressed in normal and pathological human sebocytes, and appears to have roles in their differentiation process. These were demonstrated in laser microdissected normal human sebaceous glands (SG) and SZ95 cells (immortalized sebocyte cell line) utilizing RT-qPCR, immunhistochemistry, for lipid analyses quantitative fluorimetry and mass spectrometry based analytical approaches. We have observed that PPAR? and its target genes, ADRP and PGAR, are expressed in and associated with the differentiation levels of sebocytes. Also, PPAR? is present in normal and hyperplastic SG, whereas its expression levels gradually decrease in cases obtained from SG adenoma and SG carcinoma cells, reflecting a maturation-linked expression pattern. Furthermore, in SZ95 sebocytes, natural lipids including arachidonic acid and arachidonic acid derivate keto-metabolites (e.g. 5-KETE, 12-KETE) appear to regulate PPAR? signaling pathways, which in turn modulate phospholipid biosynthesis and induce neutral lipid synthesis. Collectively, our findings highlight the importance of novel endogenous ligand-activated PPAR? signaling in human sebocyte biology and suggest that PPAR? might be a candidate target for the clinical management of SG disorder