Apolipoprotein E deficiency potentiates macrophage against Staphylococcus aureus in mice with osteomyelitis via regulating cholesterol metabolism

Mincheng Lu; Ruiyi He; Chao Li; Zixian Liu; Yuhui Chen; Bingsheng Yang; Xianrong Zhang; Bin Yu

doi:10.3389/fcimb.2023.1187543

Apolipoprotein E deficiency potentiates macrophage against Staphylococcus aureus in mice with osteomyelitis via regulating cholesterol metabolism

Front Cell Infect Microbiol. 2023 Jul 17:13:1187543. doi: 10.3389/fcimb.2023.1187543. eCollection 2023.

Authors

Mincheng Lu^{1

2}, Ruiyi He^{1

2}, Chao Li^{1

2}, Zixian Liu^{1

2}, Yuhui Chen^{1

2}, Bingsheng Yang^{1

2}, Xianrong Zhang^{1

2}, Bin Yu^{1

2}

Affiliations

¹ Division of Orthopedics and Traumatology, Department of Orthopedics, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China.
² Guangdong Provincial Key Laboratory of Bone and Cartilage Regenerative Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China.

Abstract

Introduction: Staphylococcus aureus (S. aureus) osteomyelitis causes a variety of metabolism disorders in microenvironment and cells. Defining the changes in cholesterol metabolism and identifying key factors involved in cholesterol metabolism disorders during S. aureus osteomyelitis is crucial to understanding the mechanisms of S. aureus osteomyelitis and is important in designing host-directed therapeutic strategies.

Methods: In this study, we conducted in vitro and in vivo experiments to define the effects of S. aureus osteomyelitis on cholesterol metabolism, as well as the role of Apolipoprotein E (ApoE) in regulating cholesterol metabolism by macrophages during S. aureus osteomyelitis.

Results: The data from GSE166522 showed that cholesterol metabolism disorder was induced by S. aureus osteomyelitis. Loss of cholesterol from macrophage obtained from mice with S. aureus osteomyelitis was detected by liquid chromatography-tandem mass spectrometry(LC-MS/MS), which is consistent with Filipin III staining results. Changes in intracellular cholesterol content influenced bactericidal capacity of macrophage. Subsequently, it was proven by gene set enrichment analysis and qPCR, that ApoE played a key role in developing cholesterol metabolism disorder in S. aureus osteomyelitis. ApoE deficiency in macrophages resulted in increased resistance to S. aureus. ApoE-deficient mice manifested abated bone destruction and decreased bacteria load. Moreover, the combination of transcriptional analysis, qPCR, and killing assay showed that ApoE deficiency led to enhanced cholesterol biosynthesis in macrophage, ameliorating anti-infection ability.

Conclusion: We identified a previously unrecognized role of ApoE in S. aureus osteomyelitis from the perspective of metabolic reprogramming. Hence, during treating S. aureus osteomyelitis, considering cholesterol metabolism as a potential therapeutic target presents a new research direction.

Keywords: Apolipoprotein E; Staphylococcus aureus; cholesterol metabolism; infection; macrophages; osteomyelitis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Apolipoproteins E / genetics
Cholesterol / metabolism
Chromatography, Liquid
Macrophages / metabolism
Mice
Osteomyelitis* / microbiology
Staphylococcal Infections* / microbiology
Staphylococcus aureus
Tandem Mass Spectrometry

Substances

Cholesterol
Apolipoproteins E

Grants and funding

This study was supported by the National Natural Science Foundation of China (82272517), and Science and Technology Project of Guangzhou (202201011339).