Aditya Mithal

Objectives: Inflammatory bowel diseases (IBDs) are chronic inflammatory conditions of the gastrointestinal tract, comprising ulcerative colitis (UC) and Crohn’s disease (CD). Earlier onset of IBD symptoms has been linked to a higher prevalence of depression and anxiety. Evidence supports that cortisol abnormalities correlate with the development and severity of autoimmune diseases. The primary aim of this study was to investigate the correlation of morning salivary cortisol levels with self-reported mood (depression and anxiety) and quality of life in patients with IBD. Methods: This was a prospective, single-center study including outpatients with IBD. Enrolled patients provided a one-time morning salivary cortisol sample and electronically completed a one-time survey encompassing self-reported quality of life (Short Inflammatory Bowel Disease Questionnaire (SIBDQ)) and mood (Patient Health Questionnaire 8 (PHQ-8), General Anxiety Disorder-7 (GAD-7)). Results: A total of 36 patients (UC, n = 21) were included in the study. There was no correlation between morning salivary cortisol and depressive symptoms (PHQ-8: r = 0.007, p = 0.968) or quality of life (SIBDQ: r = −0.095, p = 0.606). However, there was a trend towards a positive correlation between self-reported anxiety symptoms by GAD-7 and salivary cortisol (r = 0.347, p = 0.052). A subgroup analysis showed a positive correlation between morning salivary cortisol and GAD-7 scores in patients with UC (r = 0.535, p = 0.015), but not in patients with CD (r = 0.064, p = 0.843). Conclusions: This pilot study is the first to associate cortisol with anxiety symptom severity in UC. Further research is needed to investigate the link between salivary cortisol, neuropsychiatric disease, and IBD outcomes.

Cystic fibrosis is a monogenic lung disease caused by dysfunction of the cystic fibrosis transmembrane conductance regulator anion channel, resulting in significant morbidity and mortality. The progress in elucidating the role of CFTR using established animal and cell-based models led to the recent discovery of effective modulators for most individuals with CF. However, a subset of individuals with CF do not respond to these modulators and there is an urgent need to develop novel therapeutic strategies. In this study, we generate a panel of airway epithelial cells using induced pluripotent stem cells from individuals with common or rare CFTR variants representative of three distinct classes of CFTR dysfunction. To measure CFTR function we adapt two established in vitro assays for use in induced pluripotent stem cell-derived airway cells. In both a 3-D spheroid assay using forskolin-induced swelling as well as planar cultures composed of polarized mucociliary airway epithelial cells, we detect genotype-specific differences in CFTR baseline function and response to CFTR modulators. These results demonstrate the potential of the human induced pluripotent stem cell platform as a research tool to study CF and in particular accelerate therapeutic development for CF caused by rare variants.

Cystic fibrosis (CF) is a monogenic lung disease caused by dysfunction of the cystic fibrosis transmembrane regulator (CFTR) anion channel, resulting in significant morbidity and mortality. The progress in elucidating the role of the CFTR channel using established animal and cell-based models led to the recent discovery of effective CFTR modulators for most individuals with CF. However, a subset of individuals with CF do not respond to these modulators and there is an urgent need to develop novel therapeutic strategies. In this study, we assembled a panel of iPSCs derived from individuals with common or rare variants representative of three distinct classes of CFTR dysfunction. To measure CFTR function in patient-specific iPSCs we adapted two established in vitro assays of CFTR function to iPSC-derived airway cells. In both a 3-D spheroid assay using forskolin-induced swelling as well as planar cultures composed of polarized mucociliary airway epithelial cells, we quantified CFTR baseline function and response to CFTR modulators and detected genotype-specific differences. Our results demonstrate the potential of the human iPSC platform as a research tool to study cystic fibrosis and in particular accelerate therapeutic development for CF caused by rare mutations.

Liver damage and an exacerbated inflammatory response are hallmarks of Ebola virus (EBOV) infection. Little is known about the intrinsic response to infection in human hepatocytes and their contribution to the observed inflammatory response. Here, we present an iPSC-derived hepatocyte platform to define the hepato-intrinsic response to EBOV infection. Transcriptomics analysis revealed a delayed host response with minimal transcriptomic changes at one day post infection (dpi) followed by a general downregulation of genes associated with hepatic functions and upregulation of interferon signaling at two and three dpi. Using RNA-FISH, we showed at single cell resolution that IFNβ and CXCL10 were mainly expressed in bystander cells or cells with weak EBOV mRNA signal intensity. We did not observe an inflammatory signature at any timepoint. In conclusion, iPSC-derived hepatocytes are an immune competent platform to study intrinsic responses to EBOV infection that have not been observed in EBOV-infected hepatocarcinoma cell lines.

Efficient generation of human induced pluripotent stem cell (hiPSC)-derived human intestinal organoids (HIOs) would facilitate the development of in vitro models for a variety of diseases that affect the gastrointestinal tract, such as inflammatory bowel disease or Cystic Fibrosis. Here, we report a directed differentiation protocol for the generation of mesenchyme-free HIOs that can be primed towards more colonic or proximal intestinal lineages in serum-free defined conditions. Using aCDX2^eGFPiPSC knock-in reporter line to track the emergence of hindgut progenitors, we follow the kinetics ofCDX2expression throughout directed differentiation, enabling the purification of intestinal progenitors and robust generation of mesenchyme-free organoids expressing characteristic markers of small intestinal or colonic epithelium. We employ HIOs generated in this way to measureCFTRfunction using cystic fibrosis patient-derived iPSC lines before and after correction of theCFTRmutation, demonstrating their future potential for disease modeling and therapeutic screening applications.