Myeloid PTP1B deficiency protects against atherosclerosis by improving cholesterol homeostasis through an AMPK-dependent mechanism

Oliver Helk* (Corresponding Author), Ruta Dekeryte, Dawn Thompson, Sarah Kamli-Salino, Sam Philip, Heather Wilson, Nimesh Mody, Mirela Delibegovic* (Corresponding Author)

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Objective
Atherosclerosis is a chronic inflammatory process induced by the influx and entrapment of excess lipoproteins into the intima media of arteries. Previously, our lab demonstrated that systemic PTP1B inhibition protects against atherosclerosis in preclinical LDLR−/− models. Similarly, it was shown that myeloid-specific PTP1B ablation decreases plaque formation and ameliorates dyslipidaemia in the ApoE−/− model of atherosclerosis. We hypothesized that the relevant improvements in dyslipidaemia following modification of PTP1B activation may either result from changes in hepatic cholesterol biosynthesis and/or increased uptake and degradation by liver-resident macrophages. We examined this in animal models and patients with coronary artery disease.

Methods
In this study, we determined the cholesterol-lowering effect of myeloid-PTP1B deletion in mice fed a high-fat high-cholesterol diet and examined effects on total cholesterol levels and lipoprotein profiles. We also determined the effects of PTP1B inhibition to oxLDL-C challenge on foam cell formation and cholesterol efflux in human monocytes/macrophages.

Results
We present evidence that myeloid-PTP1B deficiency significantly increases the affinity of Kupffer cells for ApoB containing lipoproteins, in an IL10-dependent manner. We also demonstrate that PTP1B inhibitor, MSI-1436, treatment decreased foam cell formation in Thp1-derived macrophages and increased macrophage cholesterol efflux to HDL in an AMPK-dependent manner. We present evidence of three novel and distinct mechanisms regulated by PTP1B: an increase in cholesterol efflux from foam cells, decreased uptake of lipoproteins into intra-lesion macrophages in vitro and a decrease of circulating LDL-C and VLDL-C in vivo.

Conclusions
Overall, these results suggest that myeloid-PTP1B inhibition has atheroprotective effects through improved cholesterol handling in atherosclerotic lesions, as well as increased reverse cholesterol transport.

Trial registration Research registry, researchregistry 3235. Registered 07 November 2017, https://www.researchregistry.com/browse-the-registry#home/registrationdetails/5a01d0fce7e1904e93e0aac5/.
Original languageEnglish
Article number715
Number of pages21
JournalJournal of translational medicine
Volume21
Early online date12 Oct 2023
DOIs
Publication statusPublished - 2023

Bibliographical note

Funding
This study was funded by the Development Trust, University of Aberdeen.

Data Availability Statement

Primary data are available upon reasonable request.

The online version contains supplementary material available at https://doi.
org/10.1186/s12967-023-04598-2.

Keywords

  • PTP1B
  • Atherosclerosis
  • Myeloid cells
  • Cholesterol metabolism

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