Probes for INS

Intestinal epithelial stem cells (ISCs) are responsible for intestinal epithelial barrier renewal; thereby, ISCs play a critical role in intestinal pathophysiology research. While transgenic ISC reporter mice are available, advanced translational studies lack a large animal model. This study validates ISC isolation in a new porcine Leucine Rich Repeat Containing G Protein-Coupled Receptor 5 (LGR5) reporter line and demonstrates the use of these pigs as a novel colorectal cancer (CRC) model. We applied histology, immunofluorescence, fluorescence-activated cell sorting, flow cytometry, gene expression quantification, and 3D organoid cultures to whole tissue and single cells from the duodenum, jejunum, ileum, and colon of LGR5-H2B-GFP and wild-type pigs. Ileum and colon LGR5-H2B-GFP, healthy human, and murine biopsies were compared by mRNA fluorescent in situ hybridization (FISH). To model CRC, adenomatous polyposis coli (APC) mutation was induced by CRISPR/Cas9 editing in porcine LGR5-H2B-GFP colonoids. Crypt-base, green fluorescent protein (GFP) expressing cells co-localized with ISC biomarkers. LGR5-H2B-GFPhi cells had significantly higher LGR5 expression (p < .01) and enteroid forming efficiency (p < .0001) compared with LGR5-H2B-GFPmed/lo/neg cells. Using FISH, similar LGR5, OLFM4, HOPX, LYZ, and SOX9 expression was identified between human and LGR5-H2B-GFP pig crypt-base cells. LGR5-H2B-GFP/APCnull colonoids had cystic growth in WNT/R-spondin-depleted media and significantly upregulated WNT/β-catenin target gene expression (p < .05). LGR5+ ISCs are reproducibly isolated in LGR5-H2B-GFP pigs and used to model CRC in an organoid platform. The known anatomical and physiologic similarities between pig and human, and those shown by crypt-base FISH, underscore the significance of this novel LGR5-H2B-GFP pig to translational ISC research.

In adults, hepatocytes are mainly replenished from the existing progenitor pools of hepatocytes and cholangiocytes during chronic liver injury. However, it is unclear whether other cell types in addition to classical hepatocytes and cholangiocytes contribute to hepatocyte regeneration after chronic liver injuries. Here, we identified a new biphenotypic cell population that contributes to hepatocyte regeneration during chronic liver injuries. We found that a cell population expressed Gli1 and EpCAM (EpCAM+Gli1+), which was further characterized with both epithelial and mesenchymal identities by single-cell RNA sequencing. Genetic lineage tracing using dual recombinases revealed that Gli1+ nonhepatocyte cell population could generate hepatocytes after chronic liver injury. EpCAM+Gli1+ cells exhibited a greater capacity for organoid formation with functional hepatocytes in vitro and liver regeneration upon transplantation in vivo. Collectively, these findings demonstrate that EpCAM+Gli1+ cells can serve as a new source of liver progenitor cells and contribute to liver repair and regeneration.

Single-cell RNA sequencing (scRNA-seq) approaches have transformed our ability to resolve cellular properties across systems, but are currently tailored toward large cell inputs (>1,000 cells). This renders them inefficient and costly when processing small, individual tissue samples, a problem that tends to be resolved by loading bulk samples, yielding confounded mosaic cell population read-outs. Here, we developed a deterministic, mRNA-capture bead and cell co-encapsulation dropleting system, DisCo, aimed at processing low-input samples (<500 cells). We demonstrate that DisCo enables precise particle and cell positioning and droplet sorting control through combined machine-vision and multilayer microfluidics, enabling continuous processing of low-input single-cell suspensions at high capture efficiency (>70%) and at speeds up to 350 cells per hour. To underscore DisCo's unique capabilities, we analyzed 31 individual intestinal organoids at varying developmental stages. This revealed extensive organoid heterogeneity, identifying distinct subtypes including a regenerative fetal-like Ly6a+ stem cell population that persists as symmetrical cysts, or spheroids, even under differentiation conditions, and an uncharacterized 'gobloid' subtype consisting predominantly of precursor and mature (Muc2+) goblet cells. To complement this dataset and to demonstrate DisCo's capacity to process low-input, in vivo-derived tissues, we also analyzed individual mouse intestinal crypts. This revealed the existence of crypts with a compositional similarity to spheroids, which consisted predominantly of regenerative stem cells, suggesting the existence of regenerating crypts in the homeostatic intestine. These findings demonstrate the unique power of DisCo in providing high-resolution snapshots of cellular heterogeneity in small, individual tissues.

Barrier epithelia depend upon resident stem cells for homeostasis, defense, and repair. Epithelial stem cells of small and large intestines (ISCs) respond to their local microenvironments (niches) to fulfill a continuous demand for tissue turnover. The complexity of these niches and underlying communication pathways are not fully known. Here, we report a lymphatic network at the intestinal crypt base that intimately associates with ISCs. Employing in vivo loss of function and lymphatic:organoid cocultures, we show that crypt lymphatics maintain ISCs and inhibit their precocious differentiation. Pairing single-cell and spatial transcriptomics, we apply BayesPrism to deconvolve expression within spatial features and develop SpaceFold to robustly map the niche at high resolution, exposing lymphatics as a central signaling hub for the crypt in general and ISCs in particular. We identify WNT-signaling factors (WNT2, R-SPONDIN-3) and a hitherto unappreciated extracellular matrix protein, REELIN, as crypt lymphatic signals that directly govern the regenerative potential of ISCs.