American Diabetes Association
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The role of activator protein-1 (AP-1) complex in diabetes associated atherosclerosis: Insights from single cell RNA sequencing

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posted on 2024-06-21, 17:08 authored by Abdul Waheed Khan, Misbah Aziz, Karly C Sourris, Man KS Lee, Aozhi Dai, Anna MD Watson, Scott Maxwell, Arpeeta Sharma, Ying Zhou, Mark E Cooper, Anna C Calkin, Andrew J Murphy, Sara Baratchi, Karin AM Jandeleit-Dahm

Abstract

Despite advances in the treatment of atherosclerotic cardiovascular disease, it remains the leading cause of death in patients with diabetes. Even when risk factors are mitigated, the disease progresses, and thus newer targets need to be identified that directly inhibit the underlying pathobiology of atherosclerosis in diabetes. A single cell sequencing approach was utilised to distinguish the proatherogenic transcriptional profile in aortic cells in diabetes using a streptozotocin induced-diabetic Apoe-/- mouse model. Human carotid endarterectomy specimens from individuals with and without diabetes were also evaluated via immunohistochemical analysis. Further mechanistic studies were performed in human aortic endothelial cells and human THP-1 derived macrophages. We then performed a preclinical study using an AP-1 inhibitor in a diabetic Apoe-/- mouse model. Single cell RNA sequencing analysis identified the AP-1 complex as a novel target in diabetes-associated atherosclerosis. AP-1 levels were elevated in carotid endarterectomy specimens from diabetic when compared to non-diabetic individuals. AP-1 was validated as a mechanosensitive transcription factor via immunofluorescence staining for regional heterogeneity of endothelial cells of the aortic region exposed to turbulent blood flow and by performing microfluidics experiments in HAECs. AP-1 inhibition with T-5224 blunted endothelial cell activation as assessed by a monocyte adhesion assay and expression of genes relevant to endothelial function. Furthermore, AP-1 inhibition attenuated foam cell formation. Critically, treatment with T-5224 attenuated atherosclerosis development in diabetic Apoe-/- mice. This study has identified the AP-1 complex as a novel target, inhibition of which treats the underlying pathobiology of atherosclerosis in diabetes.

Article Highlights

· Cell-specific transcriptional profile of vascular cells in diabetes-associated atherosclerosis is not known.

· Single cell sequencing analysis not only defined the transcriptional profile of vascular cells in diabetes but also identified the AP-1 complex as one of the important transcription factor complexes in flow mediated endothelial cell activation and foam cell formation.

· Although, previous studies have implicated AP-1 in atherosclerosis, our study has defined the role of AP-1 as a central regulator of a gene expression program linked to endothelial dysfunction and foam cell formation in diabetes.

· Importantly, inhibition of AP-1 transcription activity with T-5224 attenuated atherosclerosis development in vivo in diabetes.

Funding

Department of Education and Training > Australian Research Council LP190100728, DO200101248

Department of Health and Aged Care, Australian Government > National Health and Medical Research Council App1163233

National Heart Foundation of Australia 102492 105631

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