Discovery and Validation of a New Class of Small Molecule Toll-Like Receptor 4 (TLR4) Inhibitors

Many inflammatory diseases may be linked to pathologically elevated signaling via the receptor for lipopolysaccharide (LPS), toll-like receptor 4 (TLR4). There has thus been great interest in the discovery of TLR4 inhibitors as potential anti-inflammatory agents. Recently, the structure of TLR4 bound to the inhibitor E5564 was solved, raising the possibility that novel TLR4 inhibitors that target the E5564-binding domain could be designed. We utilized a similarity search algorithm in conjunction with a limited screening approach of small molecule libraries to identify compounds that bind to the E5564 site and inhibit TLR4. Our lead compound, C34, is a 2-acetamidopyranoside (MW 389) with the formula C17H27NO9, which inhibited TLR4 in enterocytes and macrophages in vitro, and reduced systemic inflammation in mouse models of endotoxemia and necrotizing enterocolitis. Molecular docking of C34 to the hydrophobic internal pocket of the TLR4 co-receptor MD-2 demonstrated a tight fit, embedding the pyran ring deep inside the pocket. Strikingly, C34 inhibited LPS signaling ex-vivo in human ileum that was resected from infants with necrotizing enterocolitis. These findings identify C34 and the β-anomeric cyclohexyl analog C35 as novel leads for small molecule TLR4 inhibitors that have potential therapeutic benefit for TLR4-mediated inflammatory diseases. © 2013 Neal et al

Palmitate-induced ER stress and inhibition of protein synthesis in cultured myotubes does not require Toll-like receptor 4

Saturated fatty acids, such as palmitate, are elevated in metabolically dysfunctional condi- tions like type 2 diabetes mellitus. Palmitate has been shown to impair insulin sensitivity and suppress protein synthesis while upregulating proteolytic systems in skeletal muscle. Increased sarco/endoplasmic reticulum (ER) stress and subsequent activation of the unfolded protein response may contribute to the palmitate-induced impairment of muscle protein synthesis. In some cell types, ER stress occurs through activation of the Toll-like receptor 4 (TLR4). Given the link between ER stress and suppression of protein synthesis, we investigated whether palmitate induces markers of ER stress and protein synthesis by activating TLR4 in cultured mouse C2C12 myotubes. Myotubes were treated with vehicle, a TLR4-specific ligand (lipopolysaccharides), palmitate, or a combination of palmitate plus a TLR4-specific inhibitor (TAK-242). Inflammatory indicators of TLR4 activation (IL-6 and TNFα) and markers of ER stress were measured, and protein synthesis was assessed using puromycin incorporation. Palmitate substantially increased the levels of IL-6, TNF-α, CHOP, XBP1s, and ATF 4 mRNAs and augmented the levels of CHOP, XBP1s, phospho- PERK and phospho-eIF2α proteins. The TLR4 antagonist attenuated both acute palmitate and LPS-induced increases in IL-6 and TNFα, but did not reduce ER stress signaling with either 6 h or 24 h palmitate treatment. Similarly, treating myotubes with palmitate for 6 h caused a 43% decline in protein synthesis consistent with an increase in phospho-eIF2α, and the TLR4 antagonist did not alter these responses. These results suggest that palmitate does not induce ER stress through TLR4 in muscle, and that palmitate impairs protein syn- thesis in skeletal muscle in part by induction of ER stress

Understanding the Value of Tumor Markers in Pediatric Ovarian Neoplasms

Purpose The purpose of this study was to determine the diagnostic accuracy of tumor markers for malignancy in girls with ovarian neoplasms. Methods A retrospective review of girls 2–21 years who presented for surgical management of an ovarian neoplasm across 10 children's hospitals between 2010 and 2016 was performed. Patients who had at least one concerning feature on imaging and had tumor marker testing were included in the study. Sensitivity, specificity, and negative and positive predictive values (PPV) of tumor markers were calculated. Results Our cohort included 401 patients; 22.4% had a malignancy. Testing for tumor markers was inconsistent. AFP had high specificity (98%) and low sensitivity (42%) with a PPV of 86%. The sensitivity, specificity, and PPV of beta-hCG was 44%, 76%, and 32%, respectively. LDH had high sensitivity (95%) and Inhibin A and Inhibin B had high specificity (97% and 92%, respectively). Conclusions Tumor marker testing is helpful in preoperative risk stratification of ovarian neoplasms for malignancy. Given the variety of potential tumor types, no single marker provides enough reliability, and therefore a panel of tumor marker testing is recommended if there is concern for malignancy. Prospective studies may help further elucidate the predictive value of tumor markers in a pediatric ovarian neoplasm population

Inter-rater Reliability of Sacral Ratio Measurements in Patients with Anorectal Malformations

© 2020 Elsevier Inc. Background: Anorectal malformations (ARMs) are a spectrum of congenital anomalies with varying prognosis for fecal continence. The sacral ratio (SR) is a measure of sacral development that has been proposed as a method to predict future fecal continence in children with ARM. The aim of this study was to quantify the inter-rater reliability (IRR) of SR calculations by radiologists at different institutions. Materials and methods: x-Rays in the anteroposterior (AP) and lateral planes were reviewed by a pediatric radiologist at each of six different institutions. Subsequently, images were reviewed by a single, central radiologist. The IRR was assessed by calculating Pearson correlation coefficients and intraclass correlation coefficients from linear mixed models with patient and rater-level random intercepts. Results: Imaging from 263 patients was included in the study. The mean inter-rater absolute difference in the AP SR was 0.05 (interquartile range, 0.02-0.10), and in the lateral SR was 0.16 (interquartile range, 0.06-0.25). Overall, the IRR was excellent for AP SRs (intraclass correlation coefficient [ICC], 81.5%; 95% confidence interval, 75.1%-86.0%) and poor for lateral SRs (ICC, 44.0%; 95% CI, 29.5%-59.2%). For both AP and lateral SRs, ICCs were similar when examined by the type of radiograph used for calculation, severity of the ARM, presence of sacral or spinal anomalies, and age at imaging. Conclusions: Across radiologists, the reliability of SR calculations was excellent for the AP plane but poor for the lateral plane. These results suggest that better standardization of lateral SR measurements is needed if they are going to be used to counsel families of children with ARM

Laparoscopy versus laparotomy for pediatric ovarian dermoids

Background: With increased surgeon comfort using laparoscopy, we hypothesized resection of pediatric ovarian dermoids using laparoscopy would yield a shorter length of stay and no increase in morbidity or recurrence compared to laparotomy. Methods: A retrospective review was performed amongst eleven pediatric hospitals. Patients aged 2 to 21 who underwent resection of an ovarian dermoid from 2010 to 2020 were included. Patient characteristics, operative details, and outcomes by approach were evaluated using Chi-squared and Wilcoxon-Mann tests. Results: 466 patients were included, with a median age of 14.4 and median follow-up of 4.0 months. 279 patients underwent laparoscopy (60%), 139 laparotomy (30%), and 48 laparoscopy converted to laparotomy (10%). There were no differences in rates of tumor spillage by approach (p = 0.15). 65% underwent ovarian-sparing surgery and 35% underwent oophorectomy. Length of stay was significantly shorter amongst patients who underwent laparoscopy (1 day versus 2 days for laparotomy and converted, p\u3c0.0001). There were no differences in rates of suspected recurrence or reoperation (p = 0.19 and p = 0.57, respectively). Conclusion: Patients who underwent laparoscopy experienced no differences in the rates of tumor spillage, recurrence, or reoperation and had a shorter length of stay compared to laparotomy. Laparoscopy is an acceptable approach for resection of pediatric ovarian dermoids