Project description:While cells in the human body function in an environment where the blood supply constantly de-livers nutrients and removes waste, cells in conventional tissue culture well platforms are grown with a static pool of media above them and often lack maturity, limiting their utility to study cell biology in health and disease. In contrast, organ-chip microfluidic systems allow the growth of cells under constant flow, more akin to the in vivo situation. Here, we differentiated human induced pluripotent stem cells into dopamine neurons and assessed cellular properties in conventional multi-well cultures and organ-chips. We show that organ-chip cultures, compared to multi-well cultures, provide an overall greater proportion and homogeneity of dopaminergic neurons as well as increased levels of maturation markers. These organ-chips are an ideal platform to study mature dopamine neurons to better understand their biology in health and ultimately in neurological disorders.
Project description:Environmental Enteric Dysfunction (EED) is a chronic inflammatory condition of the intestine characterized by villus blunting, compromised intestinal barrier function, and reduced nutrient absorption. Here, we show that key genotypic and phenotypic features of EED-associated intestinal injury can be reconstituted in a human intestine-on-a-chip (Intestine Chip) microfluidic culture device lined by organoid-derived intestinal epithelial cells from EED patients and cultured in nutrient deficient medium lacking niacinamide and tryptophan (-N/-T). Exposure of EED Intestine Chips to -N/-T deficiencies resulted in transcriptional changes similar to those seen in clinical EED patient samples including congruent changes in six of the top ten upregulated genes. Exposure of EED Intestine Chips or chips lined by healthy intestinal epithelium (healthy Intestine Chips) to -N/-T medium resulted in severe villus blunting and barrier dysfunction, as well as impairment of fatty acid uptake and amino acid transport.
Project description:Organ-on-chip technology has accelerated in vitro preclinical research of the vascular system, and a key strength of this platform is its promise to impact personalized medicine by providing a primary human cell-culture environment where endothelial cells are directly biopsied from individual tissue or differentiated through stem cell biotechniques. But these methods are difficult to adopt in labs, and often result in impurity and heterogeneity of cells. This limits the power of organ-chips in making accurate physiological predictions. In this study, we report the use of blood-derived endothelial cells as alternatives to primary and iPSC-derived endothelial cells. Briefly, the genotype, phenotype and organ-chip functional characteristics of blood-derived outgrowth endothelial cells were compared against commercially available and most used primary endothelial cells and iPSC-derived endothelial cells. Through RNA sequencing we observe differences in gene expression profiles between different sources of endothelial cells, however blood-derived cells are relatively closer to primary cells than iPSC-derived suggesting that blood-derived endothelial cells may serve as an equally effective cell source for functional studies and organ-chips compared to primary cells or iPSC-derived cells.
Project description:In vitro neuronal models are essential for studying neurological physiology, disease mechanisms and potential treatments. Most in vitro models lack controlled vasculature, despite its necessity in brain physiology and disease. Organ-on-chip models offer microfluidic culture systems with dedicated micro-compartments for neurons and vascular cells. Such multi-cell type organs-on-chips can emulate neurovascular unit (NVU) physiology, however there is a lack of systematic data on how individual cell types are affected by culturing on microfluidic systems versus conventional culture plates. This information can provide perspective on initial findings of studies using organs-on-chip models, and further optimizes these models in terms of cellular maturity and neurovascular physiology. Here, we analysed the transcriptomic profiles of co-cultures of human induced pluripotent stem cell (hiPSC)-derived neurons and rat astrocytes, as well as one-day monocultures of human endothelial cells, cultured on microfluidic chips. For each cell type, large gene expression changes were observed when cultured on microfluidic chips compared to conventional culture plates. Endothelial cells showed decreased cell division, neurons and astrocytes exhibited increased cell adhesion, and neurons showed increased maturity when cultured on a microfluidic chip. Our results demonstrate that culturing NVU cell types on microfluidic chips changes their gene expression profiles, presumably due to distinct surface-to-volume ratios and substrate materials. These findings inform further NVU organ-on-chip model optimization and support their future application in disease studies and drug testing.
Project description:iPSCs were differentiated to human liver organoids as previously described. Human liver organoids were dispersed into single-cell suspension with trypsin (0.25%) and transferred to both channels in an dual-channel organ on chip system and cultured in hepatocyte maturation media. Media flow was regulated to 30 µL/hr for both channels. After 7 days of culture, liver chips were treated with vehicle control, or DILI-related compounds APAP, FIAU, tenofovir, or a tenofovir-inarigivir combination. scRNA sequencing was performed on intact HLOs and liver chips treated with each condition to compare HLOs pre- and post-chip and provide mechanistic DILI insight of treatments. Each sample generated between 440 and 860 million barcoded reads corresponding to an estimated 4,600 to 25,000 cells per sample
Project description:Cas9 screen to enhance survival of postmitotic dopamine neurons in vivo. We identified TP53-mediated apoptotic cell death as major contributor to dopamine neuron loss and uncovered a causal link of TNFa-NFκB signaling in limiting cell survival. A surface marker screen enabled the purification of midbrain dopamine neurons obviating the need for genetic reporters. Combining cell sorting with adalimumab pretreatment, a clinically approved TNFa inhibitor, enabled efficient engraftment of postmitotic dopamine neurons leading to extensive re-innervation and functional recovery in a preclinical PD mouse model. Thus, transient TNFa inhibition may present a clinically relevant strategy to enhance survival of human PSC-derived lineages in PD and beyond.
Project description:Engineered microfluidic organ-chips enable increased cellular diversity and function of human stem cell-derived tissues grown in vitro. These three dimensional (3D) cultures, however, are met with unique challenges in visualization and quantification of cellular proteins. Due to the dense 3D nature of cultured nervous tissue, classical methods of immunocytochemistry are complicated by sub-optimal light and antibody penetrance as well as image acquisition parameters. In addition, complex polydimethylsiloxane scaffolding surrounding the tissue of interest can prohibit high resolution microscopy and spatial analysis. Hyperhydration tissue clearing methods have been developed to mitigate similar challenges of in vivo tissue imaging. Here, we describe an adaptation of this approach to efficiently clear human pluripotent stem cell-derived neural tissues grown on organ-chips. We also describe critical imaging considerations when designing signal intensity-based approaches to complex 3D architectures inherent in organ-chips. To determine morphological and anatomical features of cells grown in organ-chips, we have developed a reliable protocol for chip sectioning and high-resolution microscopic acquisition and analysis.