Bone resorption and remodeling is an intricately controlled, physiological process that requires the function of osteoclasts. The processes governing both the differentiation and activation of osteoclasts involve signals induced by osteoprotegerin ligand (OPGL), a member of tumor necrosis factor (TNF) superfamily, and its cognate receptor RANK. The molecular mechanisms of the intracellular signal transduction remain to be elucidated. Here we report that mice deficient in TNF receptor-associated factor 6 (TRAF6) are osteopetrotic with defects in bone remodeling and tooth eruption due to impaired osteoclast function. Using in vitro assays, we demonstrate that TRAF6 is crucial not only in IL-1 and CD40 signaling but also, surprisingly, in LPS signaling. Furthermore, like TRAF2 and TRAF3, TRAF6 is essential for perinatal and postnatal survival. These findings establish unexpectedly diverse and critical roles for TRAF6 in perinatal and postnatal survival, bone metabolism, LPS, and cytokine signaling.

SummaryBackground It has been shown that the interleukin (IL)-23/IL-17 axis is critical in the pathogenesis of psoriasis. Objectives To present the primary end point (week 12) and safety and efficacy data up to week 24 from a head-to-head trial (IXORA-S) of the IL-17A inhibitor ixekizumab (IXE) vs. the IL-12/23 inhibitor ustekinumab (UST). Methods Randomized patients received IXE (160-mg starting dose, then 80 mg every 2 weeks for 12 weeks, then 80 mg every 4 weeks, n = 136) or UST (45 mg or 90 mg weight-based dosing per label, n = 166). The primary end point was the proportion of patients reaching ≥ 90% Psoriasis Area and Severity Index improvement (PASI 90). Hommel-adjusted key secondary end points at week 12 included PASI 75, PASI 100, static Physician's Global Assessment (sPGA) score of 0 or 1, sPGA score of 0, Dermatology Life Quality Index (DLQI) score of 0 or 1, ≥ 4-point reduction on the itch numerical rating scale (NRS) and changes in itch NRS and skin pain visual analogue scale. Results At week 12, IXE (n = 99, 72Á8%) was superior to UST (n = 70, 42Á2%) in PASI 90 response (response difference 32Á1%, 97Á5% confidence interval 19Á8À44Á5%, P < 0Á001). Response rates for PASI 75, PASI 100 and sPGA (0,1) were significantly higher for IXE than for UST (adjusted P < 0Á05). At week 24, IXEtreated patients had significantly higher response rates than UST-treated patients for PASI, sPGA and DLQI (unadjusted P < 0Á05). No deaths were reported, and the treatments did not differ with regard to overall incidences of adverse events (P = 0Á299). Conclusions The superior efficacy of IXE demonstrated at week 12 persisted up to week 24. The safety profiles were consistent with those previously reported for both treatments.

Tumor necrosis factor receptor-associated factors (TRAFs) are adaptor proteins important in mediating intracellular signaling. We report here that targeted deletion of traf6 greatly increases the frequency of failure of neural tube closure and exencephaly in traf6 (Ϫ/Ϫ) mice. The penetrance of this defect is influenced by genetic background. Neural tube fusion requires the coordination of several biological processes, including cell migration invoked by contact-dependent signaling, cell proliferation, and programmed cell death (PCD). To gain greater insight into the role of TRAF6 in these processes, neural development and migration within the CNS of traf6 (Ϫ/Ϫ) mice and controls were assessed through temporal examination of a number of immunohistochemical markers. In addition, relative levels of cellular proliferation and PCD were examined throughout embryonic development using bromodeoxyuridine (BrdU) and in situ terminal deoxynucleotidyl transferase-mediated dUTP biotinylated nick end labeling (TUNEL), respectively. The data suggest that loss of TRAF6 does not significantly alter the level of cellular proliferation or the pattern of neural differentiation per se, but rather regulates the level of PCD within specific regions of the developing CNS. Substantial reductions in TUNEL were observed within the ventral diencephalon and mesencephalon in exencephalic traf6 (Ϫ/Ϫ) embryos. Our results demonstrate a novel and prominent role for TRAF6 in the regional control of PCD within the developing CNS. Key words: programmed cell death; TUNEL; CNS; thalamus; diencephalon; neural tube closure; gene targetingTumor necrosis factor receptor (TNFR)-associated factors (TRAFs) belong to a family of intracellular adaptor proteins that mediate signaling downstream of various cell surface receptors, including members of the TNFR superfamily (Arch et al., 1998). TRAF family members have been described in mammals, Drosophila, and Caenorhabditis elegans and are characterized by conserved structural motifs (Rothe et al., 1994;Cao et al., 1996;Muhlenbeck and Scheurich, 1998;Liu et al., 1999). The TRAF C-terminal domain is thought to mediate TRAF-TRAF and TRAF-receptor interactions, whereas the N-terminal RING finger and zinc finger consensus sequences appear to be essential for downstream signal transduction (Rothe et al., 1995;Cao et al., 1996;Takeuchi et al., 1996).The physiological roles of TRAF2, -3, -5, and -6 have been defined using gene-targeted mice (Xu et al., 1996;Yeh et al., 1997;Lomaga et al., 1999;Naito et al., 1999;Nakano et al., 1999). A characteristic phenotype of TRAF-deficient mice is immune system dysfunction that appears to be related to defective activation of kinases such as the c-Jun N-terminal kinases (JNKs) and/or of transcription factors such as nuclear factor kappa B (NF-B). TRAF6 is structurally the most divergent member of the TRAF family (Cao et al., 1996), and the phenotypes exhibited by TRAF6-deficient mice are more varied than those of other TRAF knockout mice. We previously reported that traf6 (Ϫ/Ϫ) m...

ImportanceOnce-daily roflumilast cream, 0.3%, a potent phosphodiesterase 4 inhibitor, demonstrated efficacy and was well tolerated in a phase 2b trial of patients with psoriasis.ObjectiveTo evaluate the efficacy of roflumilast cream, 0.3%, applied once daily for 8 weeks in 2 trials of patients with plaque psoriasis.Design, Setting, and ParticipantsTwo phase 3, randomized, double-blind, controlled, multicenter trials (DERMIS-1 [trial 1; n = 439] and DERMIS-2 [trial 2; n = 442]) were conducted at 40 centers (trial 1) and 39 centers (trial 2) in the US and Canada between December 9, 2019, and November 16, 2020, and between December 9, 2019, and November 23, 2020, respectively. Patients aged 2 years or older with plaque psoriasis involving 2% to 20% of body surface area were enrolled. The dates of final follow-up were November 20, 2020, and November 23, 2020, for trial 1 and trial 2, respectively.InterventionsPatients were randomized 2:1 to receive roflumilast cream, 0.3% (trial 1: n = 286; trial 2: n = 290), or vehicle cream (trial 1: n = 153; trial 2: n = 152) once daily for 8 weeks.Main Outcomes and MeasuresThe primary efficacy end point was Investigator Global Assessment (IGA) success (clear or almost clear status plus ≥2-grade improvement from baseline [score range, 0-4]) at week 8, analyzed using a Cochran-Mantel-Haenszel test stratified by site, baseline IGA score, and intertriginous involvement. There were 9 secondary outcomes, including intertriginous IGA success, 75% reduction in Psoriasis Area and Severity Index (PASI) score, and Worst Itch Numeric Rating Scale score of 4 or higher at baseline achieving 4-point reduction (WI-NRS success) at week 8 (scale: 0 [no itch] to 10 [worst imaginable itch]; minimum clinically important difference, 4 points).ResultsAmong 881 participants (mean age, 47.5 years; 320 [36.3%] female), mean IGA scores in trial 1 were 2.9 [SD, 0.52] for roflumilast and 2.9 [SD, 0.45] for vehicle and in trial 2 were 2.9 [SD, 0.48] for roflumilast and 2.9 [SD, 0.47]) for vehicle. Statistically significantly greater percentages of roflumilast-treated patients than vehicle-treated patients had IGA success at week 8 (trial 1: 42.4% vs 6.1%; difference, 39.6% [95% CI, 32.3%-46.9%]; trial 2: 37.5% vs 6.9%; difference, 28.9% [95% CI, 20.8%-36.9%]; P &lt; .001 for both). Of 9 secondary end points, statistically significant differences favoring roflumilast vs vehicle were observed for 8 in trial 1 and 9 in trial 2, including intertriginous IGA success (71.2% vs 13.8%; difference, 66.5% [95% CI, 47.1%-85.8%] and 68.1% vs 18.5%; difference, 51.6% [95% CI, 29.3%-73.8%]; P &lt; .001 for both), 75% reduction in PASI score (41.6% vs 7.6%; difference, 36.1% [95% CI, 28.5%-43.8%] and 39.0% vs 5.3%; difference, 32.4% [95% CI, 24.9%-39.8%]; P &lt; .001 for both), WI-NRS success (67.5% vs 26.8%; difference, 42.6% [95% CI, 31.3%-53.8%] and 69.4% vs 35.6%; difference, 30.2% [95% CI, 18.2%-42.2%]; P &lt; .001 for both). The incidence of treatment-emergent adverse events was 25.2% with roflumilast vs 23.5% with vehicle in trial 1 and 25.9% with roflumilast vs 18.4% with vehicle in trial 2. The incidence of serious adverse events was 0.7% with roflumilast vs 0.7% with vehicle in trial 1 and 0% with roflumilast vs 0.7% with vehicle in trial 2.Conclusions and RelevanceAmong patients with chronic plaque psoriasis, treatment with roflumilast cream, 0.3%, compared with vehicle cream resulted in better clinical status at 8 weeks. Further research is needed to assess efficacy compared with other active treatments and to assess longer-term efficacy and safety.Trial RegistrationClinicalTrials.gov Identifiers: NCT04211363, NCT04211389