Dennison, T. | bioRxiv Science

bioRxiv2025

Human Milk Oligosaccharides Modulate Inflammatory Responses and Lipid Metabolism in a Human Intestinal Organoid Model

Human milk oligosaccharides (HMOs) are a major component of human breast milk and have significant protective effects on infant gut health. HMOs are also present in the amniotic fluid surrounding the developing fetus in the womb. Beginning at 10 weeks of gestational age, HMOs enter the fetal gut through the swallowing of amniotic fluid. The effects of this earliest exposure to HMOs on the gut epithelium, which pre-term infants partially miss, remains unknown. In this study, we investigate the effect of a blend of HMOs, including 2-fucosyllactose (2FL), 3-sialyllactose (3SL), and difucosyllactose (DFL), on intestinal epithelial cells, examining their role in steady-state conditions and during inflammation. By utilizing advanced intestinal epithelial organoid models derived from fetal and pediatric donors, we reveal developmental-stage-specific responses to this HMO blend, as well as its potential to mitigate inflammatory damage. These findings offer important insights into the role of HMOs in early-life nutrition and gut health, lending compelling evidence to support their inclusion in infant nutrition strategies.

cell biology↗

bioRxiv2019

Loss of MLKL Decreases Necrotic Core but Increases Macrophage Lipid Accumulation In Atherosclerosis

ObjectivesDuring the advancement of atherosclerosis, the cellularity of the plaque is governed by the influx of monocyte-derived macrophages and their turnover via apoptotic and non-apoptotic forms of cell death. Previous reports have demonstrated that programmed necrosis, or necroptosis, of macrophages within the plaque contribute to necrotic core formation. Knockdown or inhibition of the necrosome components RIPK1 and RIPK3 slow the progression of atherosclerosis, and activation of the terminal step of necroptosis, MLKL, has been demonstrated in advanced human atherosclerotic plaques. However, whether MLKL directly contributes to lesion development and necrotic core formation has not been investigated.\n\nApproaches and ResultsMLKL expression was knocked down in atherogenic Apoe- knockout mice via subcutaneous administration of antisense oligonucleotides (ASO). During advanced atherogenesis, Mlkl knockdown potently reduced cell death in the plaque, with a significant reduction in the necrotic core. However, total lesion area in the aortic sinus remained unchanged. Furthermore, treatment with the MLKL ASO unexpectedly reduced circulating cholesterol levels compared to control ASO, while staining for lipids within the plaque was significantly increased. Peritoneal macrophages transfected with the MLKL ASO showed increased lipid loading upon incubation with modified cholesterol-rich lipoproteins. In lipid-loaded macrophages, MLKL co-localized with Rab7, a marker of the late endosome.\n\nConclusionsThese studies confirm the requirement for MLKL as the executioner of necroptosis, and as such a significant contributor to the necrotic core during atherogenesis. We also identified a previously unknown role for MLKL in interacting with endosomal trafficking components to regulate lipid uptake in macrophages during atherogenesis.

pathology↗