Evaluation of Murine Host Sex as a Biological Variable in Transplanted Human Intestinal Organoid Development

BACKGROUND

Human intestinal organoids (HIOs), when transplanted into immunocompromised mice (tHIOs), demonstrate significant growth and maturation. While both male and female mice are reported to be viable hosts for these experiments, a direct comparison of sex-related differences in tHIO structure and development has not been performed.

AIMS

We sought to identify host sex-related differences in tHIO engraftment, morphology, and epithelial and mesenchymal development.

METHODS

HIOs were generated in vitro and transplanted beneath the kidney capsule of NSG male and female mice. tHIOs were harvested at 8-9 weeks. Anthropometric measurements were captured. tHIOs were divided in half and histology or RT-qPCR performed. Morphology was evaluated and epithelial architecture graded on a scale of 1 (absence of crypts/villi) to 4 (elongated crypt-villus axis). RT-qPCR and immunofluorescence microscopy were performed for epithelial and mesenchymal differentiation markers.

RESULTS

Host survival and tHIO engraftment were equivalent in male and female hosts. tHIO weight and length were also equivalent between groups. The number of lumens per tHIOs from male and female hosts was similar, but the mean lumen circumference was larger for tHIOs from male hosts. tHIOs from male hosts were more likely to demonstrate higher grades of epithelial development. However, both groups showed similar differentiation into secretory and absorptive epithelial lineages. Markers for intestinal identity, mesenchymal development, and brush border enzymes were also expressed similarly between groups.

CONCLUSIONS

While male host sex was associated with larger tHIO lumen size and mucosal maturation, tHIOs from both groups had similar engraftment, growth, and epithelial and mesenchymal cytodifferentiation.

Limosilactobacillus reuteri DS0384 promotes intestinal epithelial maturation via the postbiotic effect in human intestinal organoids and infant mice

Little is known about the modulatory capacity of the microbiota in early intestinal development. We examined various intestinal models that respond to gut microbial metabolites based on human pluripotent stem cell-derived human intestinal organoids (hIOs): physiologically relevant in vitro fetal-like intestine, intestinal stem cell, and intestinal disease models. We found that a newly isolated Limosilactobacillus reuteri strain DS0384 accelerated maturation of the fetal intestine using 3D hIO with immature fetal characteristics. Comparative metabolomic profiling analysis revealed that the secreted metabolite N-carbamyl glutamic acid (NCG) is involved in the beneficial effect of DS0384 cell-free supernatants on the intestinal maturation of hIOs. Experiments in an intestinal stem cell spheroid model and hIO-based intestinal inflamed model revealed that the cell-free supernatant from DS0384 comprising NCG promoted intestinal stem cell proliferation and was important for intestinal protection against cytokine-induced intestinal epithelial injury. The probiotic properties of DS0384 were also evaluated, including acid and bile tolerance and ability to adhere to human intestinal cells. Seven-day oral administration of DS0384 and cell-free supernatant promoted the intestinal development of newborn mice. Moreover, NCG exerted a protective effect on experimental colitis in mice. These results suggest that DS0384 is a useful agent for probiotic applications and therapeutic treatment for disorders of early gut development and for preventing intestinal barrier dysfunction.

Using Bioengineered Fluorescence for Selective In Vivo and Ex Vivo Tracking of Intestinal Organoids Derived from Human Pluripotent Stem Cells

For current and future applications of human intestinal organoids (hIOs) to various aspects of in vivo research and their potential clinical use, an efficient noninvasive system is needed to directly visualize the stage of intestinal differentiation and graft-host interactions and for further safety monitoring and efficacy. Here, we describe a detailed method for monitoring and histologically identifying implanted hIO-expressing eGFP and mCherry fluorescence under the kidney capsule of immunodeficient mice with fluorescence imaging (FLI). We then describe the orthotropic transplantation method of hIOs and methods to confirm successful engraftment in the small intestines of immunodeficient mice. These methods provide an approach for tracking the location of intestinal cells in hIOs in vivo and ex vivo using a fluorescent reporter system from the beginning of engraftment to various subsequent experiments.

In Vivo Transplantation of Human Intestinal Organoids Enhances Select Tight Junction Gene Expression

BACKGROUND

Short bowel syndrome is a potentially fatal condition with inadequate management options. Tissue-engineered small intestine (TESI) is a promising solution, but confirmation of TESI function will be crucial before human application. We sought to define intestinal epithelial barrier function in human intestinal organoid (HIO)-derived TESI.

MATERIALS AND METHODS

HIOs were generated in vitro from human embryonic stem cells. After 1 mo, HIOs were collected for analysis or transplanted into the kidney capsule of immunocompromised mice. Transplanted HIOs (tHIOs) were harvested for analysis at 4 or 8 wk. Reverse transcription quantitative polymerase chain reaction and immunofluorescent staining were performed for tight junction components: claudin 3 (CLDN3), claudin 15 (CLDN15), occludin (OCLN), and zonula occludens-1, or tight junction protein-1 (TJP1/ZO-1).

RESULTS

Four-week-old tHIOs demonstrated significantly (P < 0.05) higher levels of CLDN15 (6x), OCLN (4x), and TJP1/ZO-1 (3x) normalized to GAPDH than in vitro HIOs. Eight-week-old tHIOs demonstrated significantly (P < 0.05) higher expression levels of CLDN3 (26x), CLDN15 (29x), OCLN (4x), and TJP1/ZO-1 (5x) than in vitro HIOs. There was no significant difference in expression of these tight junction components between 4- and 8-week-old tHIOs. Immunofluorescent staining revealed the presence of claudin 3, claudin 15, occludin, and zonula occludens-1 in both in vitro HIOs and tHIOs; however, the morphology appeared more mature in tHIOs.

CONCLUSIONS

In vitro HIOs have lower levels of tight junction mRNA, and tight junction proteins appear morphologically immature. Transplantation facilitates maturation of the HIOs and enhances select tight junction gene expression.