RESUMEN
Genome-wide association studies (GWAS) have revealed risk alleles for ulcerative colitis (UC). To understand their cell type specificities and pathways of action, we generate an atlas of 366,650 cells from the colon mucosa of 18 UC patients and 12 healthy individuals, revealing 51 epithelial, stromal, and immune cell subsets, including BEST4+ enterocytes, microfold-like cells, and IL13RA2+IL11+ inflammatory fibroblasts, which we associate with resistance to anti-TNF treatment. Inflammatory fibroblasts, inflammatory monocytes, microfold-like cells, and T cells that co-express CD8 and IL-17 expand with disease, forming intercellular interaction hubs. Many UC risk genes are cell type specific and co-regulated within relatively few gene modules, suggesting convergence onto limited sets of cell types and pathways. Using this observation, we nominate and infer functions for specific risk genes across GWAS loci. Our work provides a framework for interrogating complex human diseases and mapping risk variants to cell types and pathways.
Asunto(s)
Colitis Ulcerosa/patología , Colon/metabolismo , Adulto , Anciano , Anticuerpos Monoclonales/uso terapéutico , Bestrofinas/metabolismo , Antígenos CD8/metabolismo , Estudios de Casos y Controles , Colitis Ulcerosa/tratamiento farmacológico , Colitis Ulcerosa/metabolismo , Colon/patología , Enterocitos/citología , Enterocitos/metabolismo , Femenino , Sitios Genéticos , Estudio de Asociación del Genoma Completo , Humanos , Interleucina-17/metabolismo , Masculino , Persona de Mediana Edad , Factores de Riesgo , Linfocitos T/citología , Linfocitos T/metabolismo , Trombospondinas/metabolismo , Factor de Necrosis Tumoral alfa/inmunología , Factor de Necrosis Tumoral alfa/metabolismo , Adulto JovenRESUMEN
Circular dichroism (CD) spectrum and optical rotation (OR) spectrum, crucial for understanding molecular properties and configurations, present challenges due to limited testing methods and equipment accuracy in the ultraviolet (UV) region. This study proposes a weak measurement system for chiral signals in varying concentrations in the ultraviolet range, optimized using a deep neural network (DNN) model. Introducing different post-selections to detect the circular dichroism spectrum and optical rotation spectrum separately, with contrast as a probe, it achieves a detection resolution of up to 10-6 rad. Moreover, the fitted value of the training data can reach 0.9989, enhancing the prediction accuracy of chiral molecule concentrations. This method exhibits considerable promise for applications in chiral measurement and sensor technologies.
RESUMEN
Common genetic variants interact with environmental factors to impact risk of heritable diseases. A notable example of this is a single-nucleotide variant in the Solute Carrier Family 39 Member 8 (SLC39A8) gene encoding the missense variant A391T, which is associated with a variety of traits ranging from Parkinson's disease and neuropsychiatric disease to cardiovascular and metabolic diseases and Crohn's disease. The remarkable extent of pleiotropy exhibited by SLC39A8 A391T raises key questions regarding how a single coding variant can contribute to this diversity of clinical outcomes and what is the mechanistic basis for this pleiotropy. Here, we generate a murine model for the Slc39a8 A391T allele and demonstrate that these mice exhibit Mn deficiency in the colon associated with impaired intestinal barrier function and epithelial glycocalyx disruption. Consequently, Slc39a8 A391T mice exhibit increased sensitivity to epithelial injury and pathological inflammation in the colon. Taken together, our results link a genetic variant with a dietary trace element to shed light on a tissue-specific mechanism of disease risk based on impaired intestinal barrier integrity.
Asunto(s)
Proteínas de Transporte de Catión/genética , Enfermedad de Crohn/genética , Manganeso/metabolismo , Alelos , Animales , Proteínas de Transporte de Catión/metabolismo , Técnicas de Sustitución del Gen/métodos , Homeostasis/genética , Humanos , Inflamación/genética , Mucosa Intestinal/metabolismo , Intestinos/fisiología , Manganeso/fisiología , Ratones , Mutación Missense/genética , Fenotipo , Factores de RiesgoRESUMEN
Tissue homeostasis is perturbed in a diversity of inflammatory pathologies. These changes can elicit endoplasmic reticulum (ER) stress, protein misfolding, and cell death. ER stress triggers the unfolded protein response (UPR), which can promote recovery of ER proteostasis and cell survival or trigger programmed cell death. Here, we leveraged single-cell RNA sequencing to define dynamic transcriptional states associated with the adaptive versus terminal UPR in the mouse intestinal epithelium. We integrated these transcriptional programs with genome-scale CRISPR screening to dissect the UPR pathway functionally. We identified QRICH1 as a key effector of the PERK-eIF2α axis of the UPR. QRICH1 controlled a transcriptional program associated with translation and secretory networks that were specifically up-regulated in inflammatory pathologies. Thus, QRICH1 dictates cell fate in response to pathological ER stress.
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Proteínas de Unión al ADN/metabolismo , Estrés del Retículo Endoplásmico/genética , Regulación de la Expresión Génica , Inflamación/metabolismo , Proteostasis/genética , Factores de Transcripción/metabolismo , Respuesta de Proteína Desplegada/genética , Animales , Apoptosis , Células Cultivadas , Proteínas de Unión al ADN/genética , Factor 2 Eucariótico de Iniciación/metabolismo , Humanos , Inflamación/genética , Inflamación/patología , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Ratones , Organoides , RNA-Seq , Análisis de la Célula Individual , Factores de Transcripción/genética , Transcripción Genética , eIF-2 Quinasa/metabolismoRESUMEN
Polymorphisms in C1orf106 are associated with increased risk of inflammatory bowel disease (IBD). However, the function of C1orf106 and the consequences of disease-associated polymorphisms are unknown. Here we demonstrate that C1orf106 regulates adherens junction stability by regulating the degradation of cytohesin-1, a guanine nucleotide exchange factor that controls activation of ARF6. By limiting cytohesin-1-dependent ARF6 activation, C1orf106 stabilizes adherens junctions. Consistent with this model, C1orf106-/- mice exhibit defects in the intestinal epithelial cell barrier, a phenotype observed in IBD patients that confers increased susceptibility to intestinal pathogens. Furthermore, the IBD risk variant increases C1orf106 ubiquitination and turnover with consequent functional impairments. These findings delineate a mechanism by which a genetic polymorphism fine-tunes intestinal epithelial barrier integrity and elucidate a fundamental mechanism of cellular junctional control.
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Uniones Adherentes/genética , Factores de Intercambio de Guanina Nucleótido/metabolismo , Enfermedades Inflamatorias del Intestino/genética , Fosfoproteínas/metabolismo , Factor 6 de Ribosilación del ADP , Factores de Ribosilacion-ADP/metabolismo , Animales , Células CACO-2 , Células HEK293 , Humanos , Inmunoprecipitación , Mucosa Intestinal/patología , Ratones , Ratones Mutantes , Fosfoproteínas/genética , Polimorfismo Genético , Proteolisis , Riesgo , Ubiquitinación/genéticaRESUMEN
BACKGROUND: There are many contradictory findings about the role of the hormone ghrelin in aversive processing, with studies suggesting that ghrelin signaling can both inhibit and enhance aversion. Here, we characterize and reconcile the paradoxical role of ghrelin in the acquisition of fearful memories. METHODS: We used enzyme-linked immunosorbent assay to measure endogenous acyl-ghrelin and corticosterone at time points surrounding auditory fear learning. We used pharmacological (systemic and intra-amygdala) manipulations of ghrelin signaling and examined several aversive and appetitive behaviors. We also used biotin-labeled ghrelin to visualize ghrelin binding sites in coronal brain sections of amygdala. All work was performed in rats. RESULTS: In unstressed rodents, endogenous peripheral acyl-ghrelin robustly inhibits fear memory consolidation through actions in the amygdala and accounts for virtually all interindividual variability in long-term fear memory strength. Higher levels of endogenous ghrelin after fear learning were associated with weaker long-term fear memories, and pharmacological agonism of the ghrelin receptor during the memory consolidation period reduced fear memory strength. These fear-inhibitory effects cannot be explained by changes in appetitive behavior. In contrast, we show that chronic stress, which increases both circulating endogenous acyl-ghrelin and fear memory formation, promotes profound loss of ghrelin binding sites in the amygdala and behavioral insensitivity to ghrelin receptor agonism. CONCLUSIONS: These studies provide a new link between stress, a novel type of metabolic resistance, and vulnerability to excessive fear memory formation and reveal that ghrelin can regulate negative emotionality in unstressed animals without altering appetite.
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Amígdala del Cerebelo/metabolismo , Miedo/fisiología , Ghrelina/fisiología , Consolidación de la Memoria/fisiología , Memoria/fisiología , Amígdala del Cerebelo/efectos de los fármacos , Animales , Condicionamiento Clásico/fisiología , Corticosterona/sangre , Ingestión de Alimentos/fisiología , Miedo/efectos de los fármacos , Ghrelina/sangre , Indoles/farmacología , Masculino , Memoria/efectos de los fármacos , Ratas , Receptores de Ghrelina/agonistas , Receptores de Ghrelina/antagonistas & inhibidores , Receptores de Ghrelina/metabolismo , Compuestos de Espiro/farmacología , Estrés Psicológico/metabolismoRESUMEN
BACKGROUND: Prior exposure to stress is a risk factor for developing posttraumatic stress disorder (PTSD) in response to trauma, yet the mechanisms by which this occurs are unclear. Using a rodent model of stress-based susceptibility to PTSD, we investigated the role of serotonin in this phenomenon. METHODS: Adult mice were exposed to repeated immobilization stress or handling, and the role of serotonin in subsequent fear learning was assessed using pharmacologic manipulation and western blot detection of serotonin receptors, measurements of serotonin, high-speed optogenetic silencing, and behavior. RESULTS: Both dorsal raphe serotonergic activity during aversive reinforcement and amygdala serotonin 2C receptor (5-HT2CR) activity during memory consolidation were necessary for stress enhancement of fear memory, but neither process affected fear memory in unstressed mice. Additionally, prior stress increased amygdala sensitivity to serotonin by promoting surface expression of 5-HT2CR without affecting tissue levels of serotonin in the amygdala. We also showed that the serotonin that drives stress enhancement of associative cued fear memory can arise from paired or unpaired footshock, an effect not predicted by theoretical models of associative learning. CONCLUSIONS: Stress bolsters the consequences of aversive reinforcement, not by simply enhancing the neurobiological signals used to encode fear in unstressed animals, but rather by engaging distinct mechanistic pathways. These results reveal that predictions from classical associative learning models do not always hold for stressed animals and suggest that 5-HT2CR blockade may represent a promising therapeutic target for psychiatric disorders characterized by excessive fear responses such as that observed in PTSD.
Asunto(s)
Miedo/fisiología , Consolidación de la Memoria/fisiología , Receptor de Serotonina 5-HT2C/metabolismo , Proteínas de Transporte de Serotonina en la Membrana Plasmática/metabolismo , Serotonina/metabolismo , Estrés Psicológico/fisiopatología , Amígdala del Cerebelo/efectos de los fármacos , Amígdala del Cerebelo/metabolismo , Animales , Aprendizaje por Asociación/efectos de los fármacos , Aprendizaje por Asociación/fisiología , Condicionamiento Psicológico/efectos de los fármacos , Condicionamiento Psicológico/fisiología , Modelos Animales de Enfermedad , Núcleo Dorsal del Rafe/metabolismo , Electrochoque , Miedo/efectos de los fármacos , Masculino , Consolidación de la Memoria/efectos de los fármacos , Ratones Endogámicos C57BL , Ratones Transgénicos , Modelos Neurológicos , Modelos Psicológicos , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Optogenética , Restricción Física , Antagonistas del Receptor de Serotonina 5-HT2/farmacología , Proteínas de Transporte de Serotonina en la Membrana Plasmática/genética , Trastornos por Estrés Postraumático/metabolismoRESUMEN
Though growth hormone (GH) is synthesized by hippocampal neurons, where its expression is influenced by stress exposure, its function is poorly characterized. Here, we show that a regimen of chronic stress that impairs hippocampal function in rats also leads to a profound decrease in hippocampal GH levels. Restoration of hippocampal GH in the dorsal hippocampus via viral-mediated gene transfer completely reversed stress-related impairment of two hippocampus-dependent behavioral tasks, auditory trace fear conditioning, and contextual fear conditioning, without affecting hippocampal function in unstressed control rats. GH overexpression reversed stress-induced decrements in both fear acquisition and long-term fear memory. These results suggest that loss of hippocampal GH contributes to hippocampal dysfunction following prolonged stress and demonstrate that restoring hippocampal GH levels following stress can promote stress resilience.