Particulate ligands, including cholesterol crystals and amyloid fibrils, induce production of interleukin 1β (IL-1β) dependent on the cytoplasmic sensor NLRP3 in atherosclerosis, Alzheimer's disease ...and diabetes. Soluble endogenous ligands, including oxidized low-density lipoprotein (LDL), amyloid-β and amylin peptides, accumulate in such diseases. Here we identify an endocytic pathway mediated by the pattern-recognition receptor CD36 that coordinated the intracellular conversion of those soluble ligands into crystals or fibrils, which resulted in lysosomal disruption and activation of the NLRP3 inflammasome. Consequently, macrophages that lacked CD36 failed to elicit IL-1β production in response to those ligands, and targeting CD36 in atherosclerotic mice resulted in lower serum concentrations of IL-1β and accumulation of cholesterol crystals in plaques. Collectively, our findings highlight the importance of CD36 in the accrual and nucleation of NLRP3 ligands from within the macrophage and position CD36 as a central regulator of inflammasome activation in sterile inflammation.
Objective
There is a paucity of validated diagnostic interviews for avoidant/restrictive food intake disorder (ARFID) to aid identification and classification of cases for both clinical and research ...purposes. To evaluate the factor structure, construct validity, and criterion validity of the Pica ARFID and Rumination Disorder Interview (PARDI; ARFID module), we administered the PARDI to 129 children and adolescents ages 9–23 years (M = 16.1) with ARFID (n = 84), subclinical ARFID (n = 11), and healthy controls (n = 34).
Method
We used exploratory factor analysis to examine the factor structure of the PARDI in children, adolescents, and young adults with an ARFID diagnosis, the Kruskal‐Wallis analysis of variance and Spearman correlations to test the construct validity of the measure, and non‐parametric receiver operating characteristic curves to evaluate the criterion validity of the PARDI.
Results
Exploratory factor analysis yielded a 3‐factor structure: (1) concern about aversive consequences of eating, (2) low appetite/low interest in food, and (3) sensory sensitivity. Participants with ARFID demonstrated significantly higher levels of sensory sensitivity, low appetite/low‐food interest, and concern about aversive consequences of eating symptoms relative to control participants. The construct validity for each PARDI subscale was supported and clinical cutoffs for the low appetite/low interest in food (1.1) and sensory sensitivity subscales (0.6) were established.
Discussion
These data present evidence for the factor structure and validity of the PARDI diagnostic interview for diagnosing ARFID in children, adolescents, and young adults, supporting the use of this tool to facilitate ARFID clinical assessment and research.
Public Significance
Due to the paucity of validated diagnostic interviews for avoidant/restrictive food intake disorder (ARFID), we evaluated the factor structure and validity of the Pica ARFID and Rumination Disorder Interview (ARFID module). Findings suggest that the interview assesses 3 components of ARFID: concern about aversive consequences of eating, low‐appetite, and sensory sensitivity, and that clinical threshold scores on the latter two subscales can be used to advance ARFID assessment.
Phagocytosis is a fundamental cellular process that is pivotal for immunity as it coordinates microbial killing, innate immune activation and antigen presentation. An essential step in this process ...is phagosome acidification, which regulates many functions of these organelles that allow phagosomes to participate in processes that are essential to both innate and adaptive immunity. Here we report that acidification of phagosomes containing Gram-positive bacteria is regulated by the NLRP3 inflammasome and caspase-1. Active caspase-1 accumulates on phagosomes and acts locally to control the pH by modulating buffering by the NADPH oxidase NOX2. These data provide insight into a mechanism by which innate immune signals can modify cellular defenses and establish a new function for the NLRP3 inflammasome and caspase-1 in host defense.
A coding polymorphism (Thr300Ala) in the essential autophagy gene, autophagy related 16-like 1 (ATG16L1), confers increased risk for the development of Crohn disease, although the mechanisms by which ...single disease-associated polymorphisms contribute to pathogenesis have been difficult to dissect given that environmental factors likely influence disease initiation in these patients. Here we introduce a knock-in mouse model expressing the Atg16L1 T300A variant. Consistent with the human polymorphism, T300A knock-in mice do not develop spontaneous intestinal inflammation, but exhibit morphological defects in Paneth and goblet cells. Selective autophagy is reduced in multiple cell types from T300A knock-in mice compared with WT mice. The T300A polymorphism significantly increases caspase 3- and caspase 7-mediated cleavage of Atg16L1, resulting in lower levels of full-length Atg16Ll T300A protein. Moreover, Atg16L1 T300A is associated with decreased antibacterial autophagy and increased IL-1β production in primary cells and in vivo. Quantitative proteomics for protein interactors of ATG16L1 identified previously unknown nonoverlapping sets of proteins involved in ATG16L1dependent antibacterial autophagy or IL-1β production. These findings demonstrate how the T300A polymorphism leads to cell typeand pathway-specific disruptions of selective autophagy and suggest a mechanism by which this polymorphism contributes to disease.
Recent advances in mass cytometry allow simultaneous measurements of up to 50 markers at single-cell resolution. However, the high dimensionality of mass cytometry data introduces computational ...challenges for automated data analysis and hinders translation of new biological understanding into clinical applications. Previous studies have applied machine learning to facilitate processing of mass cytometry data. However, manual inspection is still inevitable and becoming the barrier to reliable large-scale analysis.
We present a new algorithm called utomated ell-type iscovery and lassification (ACDC) that fully automates the classification of canonical cell populations and highlights novel cell types in mass cytometry data. Evaluations on real-world data show ACDC provides accurate and reliable estimations compared to manual gating results. Additionally, ACDC automatically classifies previously ambiguous cell types to facilitate discovery. Our findings suggest that ACDC substantially improves both reliability and interpretability of results obtained from high-dimensional mass cytometry profiling data.
A Python package (Python 3) and analysis scripts for reproducing the results are availability on https://bitbucket.org/dudleylab/acdc .
brian.kidd@mssm.edu or joel.dudley@mssm.edu.
Supplementary data are available at Bioinformatics online.
Replacement of the central, para-substituted fluorophenyl ring in the γ-secretase inhibitor 1 (BMS-708,163) with the bicyclo1.1.1pentane motif led to the discovery of compound 3, an equipotent ...enzyme inhibitor with significant improvements in passive permeability and aqueous solubility. The modified biopharmaceutical properties of 3 translated into excellent oral absorption characteristics (∼4-fold ↑ C max and AUC values relative to 1) in a mouse model of γ-secretase inhibition. In addition, SAR studies into other fluorophenyl replacements indicate the intrinsic advantages of the bicyclo1.1.1pentane moiety over conventional phenyl ring replacements with respect to achieving an optimal balance of properties (e.g., γ-secretase inhibition, aqueous solubility/permeability, in vitro metabolic stability). Overall, this work enhances the scope of the 1.1.1-bicycle beyond that of a mere “spacer” unit and presents a compelling case for its broader application as a phenyl group replacement in scenarios where the aromatic ring count impacts physicochemical parameters and overall drug-likeness.
As an ancient disease with high fatality, cholera has likely exerted strong selective pressure on affected human populations. We performed a genome-wide study of natural selection in a population ...from the Ganges River Delta, the historic geographic epicenter of cholera. We identified 305 candidate selected regions using the composite of multiple signals (CMS) method. The regions were enriched for potassium channel genes involved in cyclic adenosine monophosphate-mediated chloride secretion and for components of the innate immune system involved in nuclear factor κB (NF-κB) signaling. We demonstrate that a number of these strongly selected genes are associated with cholera susceptibility in two separate cohorts. We further identify repeated examples of selection and association in an NF-κB/inflammasome-dependent pathway that is activated in vitro by Vibrio cholerae. Our findings shed light on the genetic basis of cholera resistance in a population from the Ganges River Delta and present a promising approach for identifying genetic factors influencing susceptibility to infectious diseases.
Autophagy has been postulated to play role in mammalian host defense against fungal pathogens, although the molecular details remain unclear. Here, we show that primary macrophages deficient in the ...autophagic factor LC3 demonstrate diminished fungicidal activity but increased cytokine production in response to Candida albicans stimulation. LC3 recruitment to fungal phagosomes requires activation of the fungal pattern receptor dectin-1. LC3 recruitment to the phagosome also requires Syk signaling but is independent of all activity by Toll-like receptors and does not require the presence of the adaptor protein Card9. We further demonstrate that reactive oxygen species generation by NADPH oxidase is required for LC3 recruitment to the fungal phagosome. These observations directly link LC3 to the inflammatory pathway against C. albicans in macrophages.
The phagocyte oxidative burst, mediated by Nox2 NADPH oxidase-derived reactive oxygen species, confers host defense against a broad spectrum of bacterial and fungal pathogens. Loss-of-function ...mutations that impair function of the Nox2 complex result in a life-threatening immunodeficiency, and genetic variants of Nox2 subunits have been implicated in pathogenesis of inflammatory bowel disease (IBD). Thus, alterations in the oxidative burst can profoundly impact host defense, yet little is known about regulatory mechanisms that fine-tune this response. Here we report the discovery of regulatory nodes controlling oxidative burst by functional screening of genes within loci linked to human inflammatory disease. Implementing a multi-omics approach, we define transcriptional, metabolic and ubiquitin-cycling nodes controlled by Rbpj, Pfkl and Rnf145, respectively. Furthermore, we implicate Rnf145 in proteostasis of the Nox2 complex by endoplasmic reticulum-associated degradation. Consequently, ablation of Rnf145 in murine macrophages enhances bacterial clearance, and rescues the oxidative burst defects associated with Ncf4 haploinsufficiency.
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