GSE168730
The Human Milk Oligosaccharide 3'Sialyllactose Promotes Selective Modulation of Inflammation and Reduces Atherosclerosis Development in Mice
Macrophages contribute to the induction and resolution of inflammation and play a central role in the chronic low-grade inflammation in cardiovascular diseases caused by atherosclerosis. Human milk oligosaccharides (HMOs) are complex unconjugated glycans unique to human milk that benefit infant health and act as innate immune modulators. Here, we identify the HMO 3'sialyllactose (3'SL) as a natural inhibitor of TLR4-induced low-grade inflammation in macrophages and endothelium. Transcriptome analysis in macrophages revealed that 3'SL attenuates a selected set of inflammatory gene expression and promotes activity of genomic regions occupied by LXR and SREBP. These acute anti-inflammatory effects of 3'SL were associated with reduced histone H3K27 acetylation at a subset of LPS-inducible enhancers distinguished by preferential enrichment for NFKB, ATF3, IRF2, BCL6, and other transcription factor recognition motifs. In a murine atherosclerosis model, both subcutaneous and oral administration of 3'SL significantly reduced atherosclerosis development and the associated inflammation. This study provides evidence that 3'SL attenuates inflammation by a transcriptional mechanism to reduce atherosclerosis development in the context of cardiovascular disease. Overall design: H3K27ac, ATAC-Seq, p300, p65, LXR and SREBP ChIP-seq in BMDMs (bone marow-derived macrophages), from C57BL/6J mice, stimulated with or without the human milk oligosaccharide (HMO) 3'sialyllactose (3'SL) at dose of 100µg/ml in presence of 10ng/ml LPS, or with GW3965 for duration as indicated. Data from BMDMs for both p65 ChIP-Seq and ATAC-Seq, under vehicle and LPS (KLA) treatment conditions, were taken from GSE79423 and GSE109965, respectively. For p65 and ATAC-Seq re-analysis of data from GSE79423 and GSE109965 respectively: Relevant raw FASTQ files were mapped to mm10 genome with Bowtie2 with default parameters (Langmead and Salzberg, 2012). HOMER was used to convert aligned reads into “tag directories” for further analysis (Heinz et al., 2010). For p65 peaks were called with HOMER findPeaks for each tag directory with default peak finding parameters -style factor against the corresponding input directory. Peak files across various timepoints for vehicle and KLA treated timepoints were merged using HOMER mergePeaks. Merged peaks were annotated for H3K27ac and p300 signal as indicated. For ATAC-Seq, mm10 mapped, IDR defined peaks from GSE109965, for both vehicle and KLA treatment conditions, were used. Peaks were merged using HOMER mergePeaks, then merged peak file was used for further analysis as indicated in text. Please note that the duplicated sample records of the re-analyzed samples are included for the convenient retrieval of the complete raw data from SRA. ******Please note that the records have been updated on Aug 1st, 2024*****