Dataset Information

Lipid Droplet-Associated Hydrolase Mobilizes Oxysterol Stores and Inhibits Atheroma Growth and Progression

ABSTRACT: Lipid droplets (LDs) of foam cells within atheroma contain abundant cholesterol, but also serve as reservoirs of central bioactive lipids. The mechanisms of storage and mobilization of many of these lipids remain obscure. LD-associated hydrolase (LDAH) localizes to LDs, has a lipase structure, and is abundant in atheroma. However, its lipid substrates and role in atherogenesis are unknown. Using knockout and transgenic mice we found that LDAH protects against atherosclerosis. Myeloid LDAH expression is sufficient to inhibit lesion progression and promote stable architectures, less necrotic, and richer in fibrillar collagen. Lipidomics coupled with RNA sequencing revealed that LDAH facilitates mobilization of esters of oxysterols that are liver X receptor agonists, leading to induction of cholesterol efflux transporters, reduced foam cell inflammation, and pro-fibrotic gene signatures. These studies identify LDAH as a novel player in neutral hydrolysis of esterified regulatory sterols that promotes atheroprotective and pro-stabilizing mechanisms beyond mass cholesterol removal.

ORGANISM(S): Mus musculus

PROVIDER: GSE157947 | GEO | 2020/11/10

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Background: Cardiovascular diseases remain the leading cause of morbidity and mortality worldwide, most of which are caused by atherosclerosis. Discerning processes that participate in macrophage-to-foam cell formation are critical for understanding the basic mechanisms underlying atherosclerosis. To explore the molecular mechanisms of foam cell formation, the differentially expressed proteins were identified. Methods: In this paper, human monocytes, macrophage colony-stimulating factor induced macrophages, and oxidized low-density lipoprotein induced foam cells were cultured, and tandem mass tag (TMT) labeling combined with mass spectrometry (MS) were performed to find associations between foam cell transformation and proteome profiles. Results: Totally, 5146 quantifiable proteins were identified, among which 1515 and 182 differentially expressed proteins (DEPs) were found in macrophage/monocyte and foam cell/macrophage, respectively, using a cutoff of 1.5-fold change. Subcellular localization analysis revealed that downregulated DEPs of macrophages/monocytes were mostly located in the nucleus and upregulated DEPs of foam cells/macrophages mostly located in the plasma membrane and extracellular. Functional analysis of DEPs demonstrated that cholesterol metabolism related proteins were upregulated in foam cells, whereas the immune response-related proteins were downregulated in foam cells. The protein-interaction network showed that the DEPs with the highest interaction intensity between macrophages and foam cells were mainly concentrated in lysosomes and the endoplasmic reticulum. Conclusions: This study for the first time to perform quantitative proteomic investigation by TMT labeling and LC-MS/MS to identify differentially expressed proteins in human monocyte, macrophage, and foam cell. The results confirmed cholesterol metabolism was upregulated in foam cells, while immune response was suppressed, which suggested that foam cells were not the population that promote inflammation. In addition, KEGG enrichment analysis and protein-protein interaction indicated that the differentially expressed proteins locating in the endoplasmic reticulum and lysosomes may be key targets to regulate foam cell formation. These data provide a basis for identifying the potential proteins associated with the molecular mechanism involved in the transformation of macrophages to foam cells.

Dataset Information

Lipid Droplet-Associated Hydrolase Mobilizes Oxysterol Stores and Inhibits Atheroma Growth and Progression

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure