Astrocytes regulate brain cholesterol homeostasis, but the astrocyte-specific mechanisms disrupted in Alzheimer’s disease (AD) are poorly understood. By integrating human bulk transcriptomes with single-nucleus RNA sequencing (RNA-seq), we identified adipocyte enhancer-binding protein 1 ( AEBP1 ) as an astrocyte-enriched factor upregulated in AD. In postmortem human tissue and 5×FAD mice, astrocytic AEBP1 levels rise with age and disease progression. Astrocyte-specific AEBP1 knockdown ameliorates, while overexpression worsens, amyloid-β (Aβ) pathology in 5×FAD mice, confirming causality in vivo . In cultured astrocytes, AEBP1 overexpression represses lysosomal acid lipase (LIPA), leading to lipid droplet accumulation, excess cholesteryl ester storage, and lysosomal Aβ retention. LIPA restoration reverses these effects. Hippocampal transcriptomics and metabolomics from AEBP1-knockdown or LIPA-overexpressing 5×FAD mice show converged cholesterol/lipid pathway remodeling, reduced Aβ burden, and cognitive improvement. Mechanistically, AEBP1 sequesters NPAS3 in the cytoplasm, reducing its binding to the Lipa promoter. Thus, the astrocytic AEBP1-NPAS3-LIPA axis links lysosomal cholesterol catabolism to AD pathology.
Renal fibrosis is the common final pathway in many renal diseases regardless of the underlying etiology. Adipocyte enhancer-binding protein 1 (AEBP1) was reported to play a vital role in the development of organ fibrosis, but its role in renal fibrosis has not been reported. Thus, the aim of this study was to investigate the possible function of AEBP1 in renal fibrosis and the mechanism associated with the β-catenin signaling pathway. A total of 83 genes upregulated after unilateral ureteral obstruction (UUO) were screened from two Gene Expression Omnibus (GEO) datasets and subjected to Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Among them, AEBP1 was enriched in collagen binding and the regulation of collagen fibril organization and was confirmed to be upregulated in UUO kidneys and TGF-β1-induced cells. Knockdown of AEBP1 ameliorated renal fibrosis via reducing collagen accumulation, inhibiting epithelial–mesenchymal transition and fibroblast transformation, as evidenced by decreases in the expression of collagen I and III, Col1a1, Col3a1, fibronectin, Snail, α-SMA, as well as collagen-specific staining of kidney tissues, whereas the E-cadherin was increased. Besides, AEBP1 silencing inhibited the expression of β-catenin in nucleus and β-catenin downstream proteins (Axin2, Myc, and Ccnd1). Continuously active β-catenin–S33Y further restored the inhibitory effect of AEBP1 silencing on renal fibrosis. These findings indicate that knockdown of AEBP1 could potentially slow down renal fibrosis by blocking the β-catenin signaling pathway, highlighting the potential of AEBP1 as a therapeutic target for renal fibrosis.
Le Cao,Weilu Gao,Haitao Yang,Ran Zeng,Zongsheng Yin
Inflammation promotes the degradation of the extracellular matrix, which contributes to the development of osteoarthritis (OA). Adipocyte enhancer binding protein 1 (AEBP1) participates in multiple pathological processes related to inflammatory diseases. However, the role of AEBP1 in OA development is unknown. We found a higher AEBP1 expression in articular cartilage of OA patients ( n = 20) compared to their normal controls ( n = 10). Thus, we inferred that AEBP1 might affect OA progression. Then mice with destabilization of the medial meniscus (DMM) surgery and chondrocytes with IL-1β treatment (10 ng/mL) were used to mimic OA. The increased AEBP1 expression was observed in models of OA. AEBP1 knockdown in chondrocytes reversed IL-1β-induced inflammation and extracellular matrix degradation, which was mediated by the inactivation of NF-κB signaling pathway and the increased IκBα activity. Co-immunoprecipitation assay indicated the interaction between AEBP1 and IκBα. Importantly, IκBα knockdown depleted the protective role of AEBP1 knockdown in OA. Moreover, AEBP1 knockdown in mice with OA showed similar results to those in chondrocytes. Collectively, our findings suggest that AEBP1 knockdown alleviates the development of OA, providing a novel strategy for OA treatment.
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