Biology subjects

Hofstra, R. M. W.

Publications and source records attributed to Hofstra, R. M. W..

5 recordsLinked to original sources

bioRxiv2024

Impact of Enteric Neuronal Loss on Intestinal Cell Composition

Hirschsprung disease (HSCR) is a congenital disorder characterized by the absence of an enteric nervous system (ENS) in the distal gut. While the ENS is critical for normal gut function, its broader role in maintaining intestinal homeostasis remains underexplored. Using single-cell RNA sequencing, we investigated the impact of ENS loss on gut composition in wildtype and ret mutant (HSCR model) zebrafish. Significant alterations were identified, including increases in immune cells and shifts in epithelial and extracellular matrix (ECM)-producing cell populations. Immune dysregulation was highlighted by impaired TNF- signaling via NF-{kappa}B, while epithelial cell changes pointed to disrupted energy homeostasis with downregulated fatty acid metabolism and cell cycle pathways. Furthermore, the ECM producing cells showed enriched fibrotic markers. Alterations of the intestinal composition were validated in human HSCR tissues, underscoring the clinical relevance of these findings. These changes can underlie the development of secondary complications and be potentially used to improve patient outcomes.

developmental biology↗

bioRxiv2023

Human enteric glia diversity in health and disease: new avenues for the treatment of Hirschsprung disease

Hirschsprung disease (HSCR) is caused by an absence of the enteric nervous system (ENS), which is crucial for intestinal function. The ENS is composed of enteric neurons and glia, and is mostly derived from migrating vagal neural crest cells. Trunk-derived Schwann cells also play a significant role in postnatal maintenance of the ENS. However, the diversity of the ENS in health and disease remains largely unknown. Here, we performed single cell RNA sequencing on pediatric controls and HSCR individuals, and identified two major classes of enteric glia, being canonical and Schwann-like enteric glia. We show that the latter are the main contributors of enteric glia heterogeneity after birth and importantly, that they are preserved in aganglionic segments of HSCR individuals. In a zebrafish model of HSCR, which also shows preservation of Schwann-like enteric glia, enteric neurogenesis could be stimulated, demonstrating a potential novel therapy for HSCR.

pathology↗

bioRxiv2022

Unbaised intestinal single cell transcriptomics reveals previously uncharacterized enteric nervous system populations in larval zebrafish

The enteric nervous system (ENS) regulates many gastrointestinal functions including peristalsis, immune regulation and uptake of nutrients. Defects in the ENS can lead to severe enteric neuropathies such as Hirschsprung disease (HSCR), which is caused by defective ENS development. Zebrafish have proven to be fruitful in the identification of novel genes involved in ENS development and HSCR pathology. However, the composition and specification of enteric neurons and glial subtypes of the larval zebrafish at a single cell level, remains mainly unexplored. Here, we performed single cell RNA sequencing of zebrafish ENS at 5 days post-fertilization. We identified both vagal neural crest progenitors and Schwann cell precursors, as well as four clusters of early differentiated neurons. Interestingly, since we took an unbiased approach where we sequenced total intestines, an elavl3+/phox2bb- population of neurons and the presence of cx43+/phox2bb- enteric glia were identified in larval zebrafish. These populations have not been described before. Pseudotime analysis supported binary neurogenic branching of ENS differentiation, which happens via a notch-responsive state. Together, our data revealed previously unrecognized ENS populations and serve as a resource to gain new insights on ENS development and specification, proving that the zebrafish is a valuable model organism in the quest towards understanding and treating congenital enteric neuropathies.

developmental biology↗

bioRxiv2021

TALPID3/KIAA0586 regulates multiple aspects of neuromuscular patterning during gastrointestinal development in animal models and human

TALPID3/KIAA0586 is an evolutionary conserved protein, which plays an essential role in protein trafficking. Its role during gastrointestinal (GI) and enteric nervous system (ENS) development has not been studied previously. Here, we analysed chicken, mouse and human embryonic GI tissues with TALPID3 mutations. The GI tract of TALPID3 chicken embryos was shortened and malformed. Histologically, the gut smooth muscle was mispatterned and enteric neural crest cells were scattered throughout the gut wall. Analysis of the Hedgehog pathway and gut extracellular matrix provided causative reasons for these defects. Interestingly, chicken intra-species grafting experiments and a conditional knockout mouse model showed that ENS formation did not require TALPID3, but was dependent on correct environmental cues. Surprisingly, the lack of TALPID3 in enteric neural crest cells (ENCC) affected smooth muscle and epithelial development in a non cell-autonomous manner. Analysis of human gut fetal tissues with a KIAA0586 mutation showed strikingly similar findings compared to the animal models demonstrating conservation of TALPID3 and its necessary role in human GI tract development and patterning

developmental biology↗

bioRxiv2019

Models for infantile hypertrophic pyloric stenosis development in patients with esophageal atresia

Patients born with esophageal atresia (EA) have a 30 times higher prevalence of infantile hypertrophic pyloric stenosis (IHPS). This makes sense from a developmental perspective as both the esophagus and the pyloric sphincter are foregut derived structures. EA and IHPS are variable features in several (monogenetic) syndromes. This, and twin and familial studies, indicates a genetic component for both conditions as single entities. We hypothesized that genetic defects, disturbing foregut morphogenesis, are responsible for this combination of malformations. Non-genetic factors could also contribute, as mice exposed to Adriamycin develop EA and in utero diethylstilbestrol exposure is associated with EA.\n\nWe investigated the copy number profiles and protein coding variants of 15 patients with both EA and IHPS. As all parents were unaffected, we first considered dominant (de novo) or recessive inheritance models but could not identify putatively deleterious mutations or recessive variants. We did identify inherited variants in genes either known to be involved in EA or IHPS or important in foregut morphogenesis in all patients. Unfortunately, variant burden analysis did not show a significant difference with unaffected controls. However, the IHPS associated risk SNP rs1933683 had a significantly higher incidence (OR 3.29, p=0.009).\n\nAlthough the genetic variation in likely candidate genes as well as the predisposing locus near BARX1 (rs1933683) suggest a genetic component, it does not fully explain the abnormalities seen in these patients. Therefore, we hypothesize that a combination of high impact genetic, mechanical and environmental factors together can shift the balance to abnormal development.\n\nSummary statementInstead of one affected gene, the higher incidence of IHPS in EA patients is more likely the result of multiple (epi)genetic and environmental factors together shifting the balance to disease development.

genetics↗