2. Academic Validation
  3. Soluble LDL-receptor is induced by TNF-α and inhibits hepatocytic clearance of LDL-cholesterol

Soluble LDL-receptor is induced by TNF-α and inhibits hepatocytic clearance of LDL-cholesterol

  • J Mol Med (Berl). 2023 Dec;101(12):1615-1626. doi: 10.1007/s00109-023-02379-4.
Mulugeta M Zegeye 1,  Sravya S Nakka 2,  Jonas S O Andersson 3,  Stefan Söderberg 4,  Liza U Ljungberg 5,  Ashok K Kumawat 5,  Allan Sirsjö 5
Affiliations

Affiliations

  • 1 Cardiovascular Research Centre, School of Medical Sciences, Örebro University Södra Grev, Rosengatan 32, 703 62, Örebro, Sweden. mulugeta.m.zegeye@oru.se.
  • 2 Department of Infectious Diseases, Sahlgrenska University Hospital, Region Västra Götaland, Gothenburg, Sweden.
  • 3 Department of Public Health and Clinical Medicine, Skellefteå Research Unit, Umeå University, 931 86, Skellefteå, Sweden.
  • 4 Department of Public Health and Clinical Medicine, Medicine Unit, Umeå University, Umeå, Sweden.
  • 5 Cardiovascular Research Centre, School of Medical Sciences, Örebro University Södra Grev, Rosengatan 32, 703 62, Örebro, Sweden.
PMID: 37861809 DOI: 10.1007/s00109-023-02379-4
Abstract

Defective LDL-C clearance and hence its elevation in the circulation is an established risk factor for cardiovascular diseases (CVDs) such as myocardial infarction (MI). A soluble LDL-receptor (sLDL-R) has been detected in human plasma which correlates strongly with circulating LDL-C and classical conditions that promote chronic inflammation. However, the mechanistic interplay between sLDL-R, inflammation, and CVDs remains to be investigated. Here, we report that stimulation of HepG2 cells with TNF-α induces the release of sLDL-R into culture supernatants. In addition, TNF-α induces gene expression of peptidases ADAM-17 and MMP-14 in HepG2 cells, and inhibiting these peptidases using TMI 1 significantly reduces the TNF-α induced sLDL-R release. We found that a soluble form of recombinant LDL-R (100 nM) can strongly bind to LDL-C and form a stable complex (KD = E-12). Moreover, incubation of HepG2 cells with this recombinant LDL-R resulted in reduced LDL-C uptake in a dose-dependent manner. In a nested case-control study, we found that baseline sLDL-R in plasma is positively correlated with plasma total Cholesterol level. Furthermore, a twofold increase in plasma sLDL-R was associated with a 55% increase in the risk of future MI [AOR = 1.55 (95% CI = 1.10-2.18)]. Nevertheless, mediation analyses revealed that a significant proportion of the association is mediated by elevation in plasma Cholesterol level (indirect effect β = 0.21 (95% CI = 0.07-0.38). Collectively, our study shows that sLDL-R is induced by a pro-inflammatory cytokine TNF-α via membrane shedding. Furthermore, an increase in sLDL-R could inhibit hepatic clearance of LDL-C increasing its half-life in the circulation and contributing to the pathogenesis of MI. KEY MESSAGES: TNF-α causes shedding of hepatocytic LDL-R through induction of ADAM-17 and MMP-14. sLDL-R binds strongly to LDL-C and inhibits its uptake by hepatocytic cells. Plasma sLDL-R is positively correlated with TNF-α and Cholesterol. Plasma sLDL-R is an independent predictor of myocardial infarction (MI). Plasma Cholesterol mediates the association between sLDL-R and MI.

Keywords

ADAM-17; Chronic inflammation; Hypercholesterolemia; MMP-14; Mediation analyses; Myocardial infarction.

Figures
Products