Retinoic acid temporally orchestrates colonization of the gut by vagal neural crest cells

The enteric nervous system arises from neural crest cells that migrate as chains into and along the primitive gut, subsequently differentiating into enteric neurons and glia. Little is known about the mechanisms governing neural crest migration en route to and along the gut in vivo. Here, we report that Retinoic Acid (RA) temporally controls zebrafish enteric neural crest cell chain migration. In vivo imaging reveals that RA loss severely compromises the integrity and migration of the chain of neural crest cells during the window of time window when they are moving along the foregut. After loss of RA, enteric progenitors accumulate in the foregut and differentiate into enteric neurons, but subsequently undergo apoptosis resulting in a striking neuronal deficit. Moreover, ectopic expression of the transcription factor meis3 and/or the receptor ret, partially rescues enteric neuron colonization after RA attenuation. Collectively, our findings suggest that retinoic acid plays a critical temporal role in promoting enteric neural crest chain migration and neuronal survival upstream of Meis3 and RET in vivo

Retinoic acid temporally orchestrates colonization of the gut by vagal neural crest cells

The enteric nervous system arises from neural crest cells that migrate as chains into and along the primitive gut, subsequently differentiating into enteric neurons and glia. Little is known about the mechanisms governing neural crest migration en route to and along the gut in vivo. Here, we report that Retinoic Acid (RA) temporally controls zebrafish enteric neural crest cell chain migration. In vivo imaging reveals that RA loss severely compromises the integrity and migration of the chain of neural crest cells during the window of time window when they are moving along the foregut. After loss of RA, enteric progenitors accumulate in the foregut and differentiate into enteric neurons, but subsequently undergo apoptosis resulting in a striking neuronal deficit. Moreover, ectopic expression of the transcription factor meis3 and/or the receptor ret, partially rescues enteric neuron colonization after RA attenuation. Collectively, our findings suggest that retinoic acid plays a critical temporal role in promoting enteric neural crest chain migration and neuronal survival upstream of Meis3 and RET in vivo

A pediatric airway atlas and its application in subglottic stenosis

Young children with upper airway problems are at risk for hypoxia, respiratory insufficiency and long term morbidity. Computational models and quantitative analysis would reveal airway growth patterns and benefit clinical care. To capture expected growth patterns we propose a method to build a pediatric airway atlas as a function of age. The atlas is based on a simplified airway model in combination with kernel regression. We show experimental results on children with subglottic stenosis to demonstrate that our method is able to track and measure the stenosis in pediatric airways

Generation of T Follicular Helper Cells Is Mediated by Interleukin-21 but Independent of T Helper 1, 2, or 17 Cell Lineages

SummaryAfter activation, CD4+ helper T (Th) cells differentiate into distinct effector subsets. Although chemokine (C-X-C motif) receptor 5-expressing T follicular helper (Tfh) cells are important in humoral immunity, their developmental regulation is unclear. Here we show that Tfh cells had a distinct gene expression profile and developed in vivo independently of the Th1 or Th2 cell lineages. Tfh cell generation was regulated by ICOS ligand (ICOSL) expressed on B cells and was dependent on interleukin-21 (IL-21), IL-6, and signal transducer and activator of transcription 3 (STAT3). However, unlike Th17 cells, differentiation of Tfh cells did not require transforming growth factor β (TGF-β) or Th17-specific orphan nuclear receptors RORα and RORγ in vivo. Finally, naive T cells activated in vitro in the presence of IL-21 but not TGF-β signaling preferentially acquired Tfh gene expression and promoted germinal-center reactions in vivo. This study thus demonstrates that Tfh is a distinct Th cell lineage

Dietary Cholesterol Promotes Adipocyte Hypertrophy and Adipose Tissue Inflammation in Visceral, But Not Subcutaneous, Fat in Monkeys

Objective—Excessive caloric intake is associated with obesity and adipose tissue dysfunction. However, the role of dietary cholesterol in this process is unknown. The aim of this study was to determine whether increasing dietary cholesterol intake alters adipose tissue cholesterol content, adipocyte size, and endocrine function in nonhuman primates. Approach and Results—Age-matched, male African Green monkeys (n=5 per group) were assigned to one of three diets containing 0.002 (Lo), 0.2 (Med) or 0.4 (Hi) mg cholesterol/Kcal. After 10 weeks of diet feeding, animals were euthanized for adipose tissue, liver, and plasma collection. With increasing dietary cholesterol, free cholesterol (FC) content and adipocyte size increased in a step-wise manner in visceral, but not subcutaneous fat, with a significant association between visceral adipocyte size and FC content (r2=0.298; n=15; p=0.035). In visceral fat, dietary cholesterol intake was associated with: 1) increased pro-inflammatory gene expression and macrophage recruitment, 2) decreased expression of genes involved in cholesterol biosynthesis and lipoprotein uptake, and 3) increased expression of proteins involved in FC efflux. Conclusions—Increasing dietary cholesterol selectively increases visceral fat adipocyte size, FC and macrophage content, and proinflammatory gene expression in nonhuman primates

Engineered resistance to Zika virus in transgenic Aedes aegypti expressing a polycistronic cluster of synthetic small RNAs

Recent Zika virus (ZIKV) outbreaks have highlighted the necessity for development of novel vector control strategies to combat arboviral transmission, including genetic versions of the sterile insect technique, artificial infection with Wolbachia to reduce population size and/or vectoring competency, and gene drive-based methods. Here, we describe the development of mosquitoes synthetically engineered to impede vector competence to ZIKV. We demonstrate that a polycistronic cluster of engineered synthetic small RNAs targeting ZIKV is expressed and fully processed in Aedes aegypti, ensuring the formation of mature synthetic small RNAs in the midgut where ZIKV resides in the early stages of infection. Critically, we demonstrate that engineered Ae. aegypti mosquitoes harboring the anti-ZIKV transgene have significantly reduced viral infection, dissemination, and transmission rates of ZIKV. Taken together, these compelling results provide a promising path forward for development of effective genetic-based ZIKV control strategies, which could potentially be extended to curtail other arboviruses

Association of Premorbid GLP-1RA and SGLT-2i Prescription Alone and in Combination with COVID-19 Severity

Introduction People with type 2 diabetes are at heightened risk for severe outcomes related to COVID-19 infection, including hospitalization, intensive care unit admission, and mortality. This study was designed to examine the impact of premorbid use of glucagon-like peptide-1 receptor agonist (GLP-1RA) monotherapy, sodium-glucose cotransporter-2 inhibitor (SGLT-2i) monotherapy, and concomitant GLP1-RA/SGLT-2i therapy on the severity of outcomes in individuals with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Methods Utilizing observational data from the National COVID Cohort Collaborative through September 2022, we compared outcomes in 78,806 individuals with a prescription of GLP-1RA and SGLT-2i versus a prescription of dipeptidyl peptidase 4 inhibitors (DPP-4i) within 24 months of a positive SARS-CoV-2 PCR test. We also compared concomitant GLP-1RA/SGLT-2i therapy to GLP-1RA and SGLT-2i monotherapy. The primary outcome was 60-day mortality, measured from the positive test date. Secondary outcomes included emergency room (ER) visits, hospitalization, and mechanical ventilation within 14 days. Using a super learner approach and accounting for baseline characteristics, associations were quantified with odds ratios (OR) estimated with targeted maximum likelihood estimation (TMLE). Results Use of GLP-1RA (OR 0.64, 95% confidence interval [CI] 0.56–0.72) and SGLT-2i (OR 0.62, 95% CI 0.57–0.68) were associated with lower odds of 60-day mortality compared to DPP-4i use. Additionally, the OR of ER visits and hospitalizations were similarly reduced with GLP1-RA and SGLT-2i use. Concomitant GLP-1RA/SGLT-2i use showed similar odds of 60-day mortality when compared to GLP-1RA or SGLT-2i use alone (OR 0.92, 95% CI 0.81–1.05 and OR 0.88, 95% CI 0.76–1.01, respectively). However, lower OR of all secondary outcomes were associated with concomitant GLP-1RA/SGLT-2i use when compared to SGLT-2i use alone. Conclusion Among adults who tested positive for SARS-CoV-2, premorbid use of either GLP-1RA or SGLT-2i is associated with lower odds of mortality compared to DPP-4i. Furthermore, concomitant use of GLP-1RA and SGLT-2i is linked to lower odds of other severe COVID-19 outcomes, including ER visits, hospitalizations, and mechanical ventilation, compared to SGLT-2i use alone

Broad Dengue Neutralization in Mosquitoes Expressing an Engineered Antibody

With dengue virus (DENV) becoming endemic in tropical and subtropical regions worldwide, there is a pressing global demand for effective strategies to control the mosquitoes that spread this disease. Recent advances in genetic engineering technologies have made it possible to create mosquitoes with reduced vector competence, limiting their ability to acquire and transmit pathogens. Here we describe the development of Aedes aegypti mosquitoes synthetically engineered to impede vector competence to DENV. These mosquitoes express a gene encoding an engineered single-chain variable fragment derived from a broadly neutralizing DENV human monoclonal antibody and have significantly reduced viral infection, dissemination, and transmission rates for all four major antigenically distinct DENV serotypes. Importantly, this is the first engineered approach that targets all DENV serotypes, which is crucial for effective disease suppression. These results provide a compelling route for developing effective genetic-based DENV control strategies, which could be extended to curtail other arboviruses