中国神经再生研究(英文版) ›› 2024, Vol. 19 ›› Issue (10): 2099-2100.doi: 10.4103/1673-5374.392878

• 观点:退行性病与再生 • 上一篇    下一篇

脑中胆固醇酯积累对神经退行性疾病的致病作用

  

  • 出版日期:2024-10-15 发布日期:2024-01-29

Pathogenic contribution of cholesteryl ester accumulation in the brain to neurodegenerative disorders

Michiko Shirane*   

  1. Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
  • Online:2024-10-15 Published:2024-01-29
  • Contact: Michiko Shirane, PhD, shiram@phar.nagoya-cu.ac.jp.

摘要: https://orcid.org/0000-0002-8297-9245 (Michiko Shirane)

Abstract: Cholesteryl esters (CEs) have been increasingly implicated in neurodegenerative disorders such as Alzheimer’s disease (AD). Alois Alzheimer noted three prominent neuropathologic features in his original analysis of the AD brain: senile plaques, neurofibrillary tangles, and lipid granule accumulation. Senile plaques, which are aggregates of amyloid-beta (Aβ), and neurofibrillary tangles, which are aggregates of phosphorylated tau, have been regarded as more consistent characteristics of the AD brain compared with lipid granule accumulation and thus have been studied more intensively (Foley, 2010). However, more recent large-scale genetic studies have revealed that a major risk factor for late-onset AD (LOAD) is the APOE4 variant allele of the gene for apolipoprotein E (APOE), a protein that plays an important role in cholesterol metabolism and lipid transport. In addition, individuals who harbor variants of the gene for triggering receptor expressed on myeloid cells 2 (TREM2), an immune receptor protein expressed in microglia, have also been known to be at higher risk for the development of LOAD. Such findings have led to an increased focus on defective lipid metabolism and inflammation in the brain as potential pathological mechanisms of LOAD (Shi and Holtzman, 2018). The accumulation of CEs has also recently been identified in postmortem brain tissue of individuals with LOAD as well as in the brain of AD model mice, such as those that overexpress the Aβ precursor protein (APP) or which are deficient in APOE or TREM2 (Chan et al., 2012; Nugent et al., 2020). Furthermore, the accumulation of phosphorylated tau as well as the release of Aβ was shown to be promoted by CEs in neurons that were derived from induced pluripotent stem cells of individuals with AD and which harbored an extra copy of the APP gene (van der Kant et al., 2019). CEs are highly hydrophobic lipids and are the main components of both high-density lipoprotein (HDL) outside of cells and lipid droplets (LDs) within cells. Potential causes of CE accumulation in the AD brain include impairment of the clearance of phagocytosed cholesterol contained in myelin debris, as has been demonstrated in TREM2-deficient mice, as well as defective cholesterol transport in the brain, as has been shown in APOE-deficient mice (Nugent et al., 2020).