Biology subjects

Wijnen, R. M. H.

Publications and source records attributed to Wijnen, R. M. H..

3 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↗

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↗