title: Apolipoprotein M.
abstract: Apolipoprotein M (ApoM) is a novel apolipoprotein that was discovered in 1999 and is bound primarily to high-density lipoproteins (HDLs) in the plasma. Multiple factors may influence its expression at both the post-transcriptional and the transcriptional levels both in vivo and ex vivo as follows: hepatocyte nuclear factor-1α, 4α (HNF-1α, 4α), liver receptor homolog-1 (LRH-1), forkhead box A2 (Foxa2) and platelet activating factor (PAF) upregulate its expression; liver X receptor (LXR), retinoid X receptor (RXR), farnesoid X receptor (FXR), small heterodimer partner (SHP) and the majority of cytokines downregulate its expression. However, mechanisms underlying these processes remain unknown. Structurally, there exists a characterized hydrophobic binding pocket within the apoM protein, which enables it to bind functional lipids such as Sphingosine-1-Phosphate (S1P). Functionally, it facilitates the formation of preβ-HDL and enhances an avalanche of atheroprotective effects exerted by HDL. Moreover, in patients with diabetes, the levels of plasma apoM may decrease, whereas the augmentation of apoM decreases plasma glucose levels and magnifies the secretion of insulin. This article offers a panorama of the progress made in the research regarding the characteristics of apoM, particularly the regulation of its expression and its functions.
authors: Institute of Cardiovascular Disease, Key Lab for Arteriosclerology of Hunan Province, University of South China, Hengyang City 421001 Hunan Province, China.
authors: Kun
authors: K
authors: Ren
authors: Institute of Cardiovascular Disease, Key Lab for Arteriosclerology of Hunan Province, University of South China, Hengyang City 421001 Hunan Province, China.
authors: Zhen-Li
authors: ZL
authors: Tang
authors: Institute of Cardiovascular Disease, Key Lab for Arteriosclerology of Hunan Province, University of South China, Hengyang City 421001 Hunan Province, China.
authors: Yue
authors: Y
authors: Jiang
authors: Institute of Cardiovascular Disease, Key Lab for Arteriosclerology of Hunan Province, University of South China, Hengyang City 421001 Hunan Province, China.
authors: Yan-Mei
authors: YM
authors: Tan
authors: Institute of Cardiovascular Disease, Key Lab for Arteriosclerology of Hunan Province, University of South China, Hengyang City 421001 Hunan Province, China. Electronic address: ghyi6108@163.com.
authors: Guang-Hui
authors: GH
authors: Yi
mesh_terms: D000818:Animals; D001053:Apolipoproteins / Q000097:blood*; D000075243:Apolipoproteins M; D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000097:blood* / Q000175:diagnosis*; D051538:Hepatocyte Nuclear Factor 1-alpha / Q000097:blood; D053442:High-Density Lipoproteins, Pre-beta / Q000097:blood; D006801:Humans; D054834:Lipocalins / Q000097:blood*; D008075:Lipoproteins, HDL / Q000097:blood; D008246:Lysophospholipids / Q000097:blood; D013110:Sphingosine / Q000031:analogs & derivatives / Q000097:blood
chemical_list: C400523:APOM protein, human; D001053:Apolipoproteins; D000075243:Apolipoproteins M; D015415:Biomarkers; D051538:Hepatocyte Nuclear Factor 1-alpha; D053442:High-Density Lipoproteins, Pre-beta; D054834:Lipocalins; D008075:Lipoproteins, HDL; D008246:Lysophospholipids; C060506:sphingosine 1-phosphate; D013110:Sphingosine
keywords: Apolipoprotein M; Function; Regulation