Antenatal Ureaplasma infection induces ovine small intestinal goblet cell defects: a strong link with NEC pathology

ABSTRACT

Disruption of the intestinal mucus barrier and intestinal epithelial endoplasmic reticulum (ER) stress contribute to necrotizing enterocolitis (NEC). Previously, we observed intestinal goblet cell loss and increased intestinal epithelial ER stress following chorioamnionitis. Here, we investigated how chorioamnionitis affects goblet cells by assessing their cellular characteristics. Importantly, goblet cell features are compared with those in clinical NEC biopsies. Mucus thickness was assessed as read-out of goblet cell function. Fetal lambs were intra-amniotically (IA) infected for 7d at 122 gestational age with Ureaplasma parvum serovar-3, the main microorganism clinically associated with chorioamnionitis. After preterm delivery, mucus thickness, goblet cell numbers, gut inflammation, epithelial proliferation and apoptosis and intestinal epithelial ER stress were investigated in the terminal ileum. Next, goblet cell morphological alterations (TEM) were studied and compared to human NEC samples. Ileal mucus thickness and goblet cell numbers were elevated following IA UP exposure. Increased pro-apoptotic ER stress, detected by elevated CHOP-positive cell counts and disrupted organelle morphology of secretory cells in the intestinal epithelium, was observed in IA UP exposed animals. Importantly, comparable cellular morphological alterations were observed in the ileum from NEC patients. In conclusion, UP-driven chorioamnionitis leads to a thickened ileal mucus layer and mucus hypersecretion from goblet cells. Since this was associated with pro-apoptotic ER stress and organelle disruption, mucus barrier alterations seem to occur at the expense of goblet cell resilience and may therefore predispose to detrimental intestinal outcomes. The remarkable overlap of these in utero findings with observations in NEC patients underscores their clinical relevance.

KEYWORDS:

• Chorioamnionitis
• NEC
• TEM
• mucus
• ER stress
• goblet cell

Acknowledgments

The authors would like to thank Ruben Visschers, Hamit Cakir and Olivier Theeuws for their help with collecting human intestinal samples and Nico Kloosterboer for his excellent technical support. In addition, we also would like to thank Elly van Donselaar for her insight in the TEM methodology and Hans Duimel and the other members of the microscopy CORE laboratory at FHML for their support in the TEM work.

Authors contribution statement:

Conceptualization: CG, MH, TW.; methodology: CG, IL, CLI, KM, LK, GB, WW, TW; software: CG, KM; validation: CG, IL, KM, LK, TW; formal analysis: CG, IL, KM, LK; investigation: CG, IL, CLI, KM, LK, OS, GB, WG, LZ, TW; resources: MH, BK, WG, LZ, TW; data curation: CG, IL, KM; writing original article: CG, IL, TW; writing—review and editing: MH, CLI, LK, BW, WW, OS, GB, WG, LZ; visualization: CG, IL, KM; supervision: TW; project administration: MH, CG, KM; funding acquisition, MH, LZ, TW. All authors have read and agreed to the published version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Ethics approval statement:

Animal experiments were approved by the animal experimentation committee of Maastricht University (registration number PV2015–005–02). The human part of this study was approved by the Medical Ethical Committee of Maastricht University Medical Centre (registration number 1–5–185). All parents gave written informed consent.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/21688370.2022.2158016

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was financially supported by the ‘Kinderonderzoeksfonds Limburg’, (TW), NUTRIM: School of Nutrition and Translational Research in Metabolism and the NUTRIM graduate programme (IL). Data availability statement: The data presented in this study are available in this article and in the Supplementary Materials.