O-GlcNAc glycosylation (or O-GlcNAcylation) is a dynamic, inducible posttranslational modification found on proteins associated with neurodegenerative diseases such as α-synuclein, amyloid precursor protein, and tau. Deletion of the O-GlcNAc transferase (ogt) gene responsible for the modification causes early postnatal lethality in mice, complicating efforts to study O-GlcNAcylation in mature neurons and to understand its roles in disease. Here, we report that forebrain-specific loss of OGT in adult mice leads to progressive neurodegeneration, including widespread neuronal cell death, neuroinflammation, increased production of hyperphosphorylated tau and amyloidogenic Aβ-peptides, and memory deficits. Furthermore, we show that human cortical brain tissue from Alzheimer’s disease patients has significantly reduced levels of OGT protein expression compared with cortical tissue from control individuals. Together, these studies indicate that O-GlcNAcylation regulates pathways critical for the maintenance of neuronal health and suggest that dysfunctional O-GlcNAc signaling may be an important contributor to neurodegenerative diseases.

Adults with psoriasis have a greater risk of developing metabolic syndrome (MetS) and cardiovascular disease (CVD), but few studies have investigated the prevalence of MetS and other risk factors for CVD in children with psoriasis. In an assessor-blinded study, 20 children ages 9-17 years with a current or previously documented history of psoriasis involving 5% or more of their body surface area or psoriatic arthritis were compared with a cohort of age- and sex-matched controls with benign nevi, warts, or acne. MetS, our primary endpoint, was defined by the presence of abnormal values in at least three of the following measures: triglycerides, high-density lipoprotein cholesterol (HDL-C), fasting blood glucose (FBG), waist circumference, and blood pressure. Secondary endpoints included high-sensitivity C-reactive protein (hs-CRP), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C). Thirty percent (6/20) of children with psoriasis met the criteria for MetS, compared with 5% (1/20) of the control group (p < 0.05). Subjects with psoriasis had higher mean FBG (91.1 mg/dL) than the control group (82.9 mg/dL) (p = 0.01). There were no statistically significant differences in the other four components of MetS, BMI, BMI percentile, hs-CRP, TC, or LDL-C. The results of this trial demonstrate that children with psoriasis have higher rates of MetS than age- and sex-matched controls. It may therefore be important to evaluate children with psoriasis for components of MetS to prevent future CVD morbidity and mortality.

IMPORTANCE Methotrexate is a first-line systemic agent for treating of psoriasis, although its onset of effects is slower and overall it is less effective than tumor necrosis factor blockers. OBJECTIVE To differentiate the response of psoriatic disease to adalimumab and methotrexate sodium. DESIGN, SETTING, AND PARTICIPANTS Single-center, randomized, assessor-blind, 2-arm clinical trial of 30 patients from the outpatient dermatology center of Tufts Medical Center, enrolled from August 18, 2009, to October 11, 2011. Patients aged 18 to 85 years with chronic plaque-type psoriasis, a minimum Physician Global Assessment score of 3 (higher scores indicate more severe disease), and a psoriatic plaque of at least 2 cm were randomized in a 1:1 fashion to receive subcutaneous adalimumab or oral methotrexate. Skin biopsy specimens obtained at baseline and weeks 1, 2, 4, and 16 were given a histologic grade by blinded assessors to evaluate treatment response. Analyses were conducted from April 16, 2013, to January 5, 2015. INTERVENTIONS A 16-week course of subcutaneous adalimumab (40 mg every 2 weeks after a loading dose) or low-dosage oral methotrexate sodium (7.5–25 mg/wk). MAIN OUTCOMES AND MEASURES Changes in genomic, immunohistochemical, and messenger RNA (mRNA) profiles. RESULTS Methotrexate responders experienced significant downregulation of helper T-cell– related (TH1, TH17, and TH22) mRNA expression compared with methotrexate nonresponders. Comparisons among adalimumab-treated patients were limited by the number of nonresponders (n = 1). Between adalimumab and methotrexate responders, we found no significant differences in gene expression at any study point or in the expression of T-cell–related mRNA at week 16. Adalimumab responders demonstrated early downregulation of chemokine (C-C motif) ligand 20 (CCL20) mRNA (mean [SE] at week 2, −1.83 [0.52], P < .001; week 16, −3.55 [0.54], P < .001) compared with late downregulation for methotrexate responders (week 2, 0.02 [0.51], P = .96; week 16, −2.96 [0.51], P < .001). Similar differences were observed with interleukin 22 (IL22) mRNA showing early downregulation for adalimumab responders (week 2, −3.17 [1.00], P < .001; week 16, −3.58 [1.00], P < .001) compared with late downregulation for methotrexate responders (week 2, −0.44 [0.68], P = .64; week 16, −5.14 [0.68], P < .001). Analysis of variance findings for key mRNA and immunohistochemical marker expression over the study course were significant only for CCL20 (P = .03) and IL22 (P = .006) mRNA comparing adalimumab and methotrexate responders. CONCLUSIONS AND RELEVANCE Methotrexate is an immunomodulator with effects on helper T-cell signaling in psoriasis. Similar genomic and immunohistochemical response signatures and levels of mRNA downregulation at study completion among adalimumab and methotrexate responders suggest a disease-driven instead of therapeutic-driven pathway regulation. Adalimumab and methotrexate responses are differentiated by patterns of normalization of CCL20 and IL22 mRNA expres...

No abstract

Nomination of new oncology targets has been greatly aided by advances in genetic screening and profiling, but developing potent, selective small molecule inhibitors against these targets remains a resource intensive pursuit. To significantly de-risk this process we applied a chemical biology strategy to model pharmacological inhibition of the MASTL kinase and showed that selective enzymatic inhibition accurately mimicked targeted genetic perturbation. Specifically, we engineered an electrophile-sensitive version of MASTL through a single amino acid substitution, Asp117Cys, within the ATP-binding site hinge region. Only 11 human kinases contain a cysteine handle in this particular hinge position (H10), which drastically limits the scope of off-targets prone to any H10 Cys-selective covalent inhibitors but also demonstrates that an H10 Cys is not incompatible with kinase activity. Furthermore, endogenous H10 Cys kinases include several targets of successful covalent inhibitor development campaigns (e.g. EGFR, JAK3 and BTK). This broad availability of optimized compounds allowed us to quickly screen and identify potent inhibitors of the MASTL Asp117Cys recombinant mutant. MASTL overexpression is observed across a broad spectrum of solid tumors, so to directly examine how its inhibition would impact cancer cell growth, Asp117Cys was created in the endogenous MASTL gene through CRISPR-directed gene editing. Pancreatic cancer cells homozygous for MASTL Asp117Cys showed clear dose-dependent growth inhibition when treated with a T790M mutant-specific EGFR covalent inhibitor (PF-06459988). Moreover, inhibitor treatment induced a visible phenotype of large multi-nucleated cells that phenocopies genetic perturbation of MASTL and aligns with MASTL's functional role regulating mitotic division. These inhibitor induced effects were not observed in unmodified parental cells and affinity purification experiments utilizing an alkyne probe of PF-06459988 confirmed binding specifically in engineered Asp117Cys mutant cells. When these Asp117Cys mutant cells are propagated as mouse xenografts, their in vivo tumor growth rate is indistinguishable from parental, but PF-06459988 treatment selectively induces tumor growth inhibition of mutant cells, thus demonstrating that selective enzymatic inhibition is sufficient to drive anti-tumor effects. Herein our application of an electrophile-sensitive mutant demonstrates how existing, optimized covalent small molecule inhibitors can be repurposed as chemical probes against engineered kinase domains. This engineered system provides a valuable orthogonal benchmark in advance of a drug discovery campaign, reveals target-dependent biology, and is likely to translate to additional kinase targets due to structural conservation within this enzymatic domain. Citation Format: Jon A. Oyer, Ted W. Johnson, Andrew C. Wang, Michael F. Maestre, Ana Flores-Bojorquez, Roksolana Melnychuk, Sergei Timofeevski, Sherry Niessen, Zhenxiong Wang, Jian Li, Wade C. Diehl, Koleen J. Eisele, Nathan V. Lee, Aihua Zou, Carl Davis, Eric C. Greenwald, Jacob DeForest, Martha Ornelas, Bryan Li, Stephanie Scales, Penney L. Khamphavong, Catherine M. Ambler, Yun Huang, Romelia Salomon-Ferrer, Samantha E. Greasley, Ben Bolanos, Neil Grodsky, Lawrence Lum, Todd L. VanArsdale, Indrawan J. McAlpine. Engineering electrophile-sensitive kinase mutants to accelerate oncology target validation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 330.