Cholesterol Efflux Efficiency of Reconstituted HDL Is Affected by Nanoparticle Lipid Composition

Targeting Nanoplatform for Atherosclerosis Inhibition and Degradation via a Dual-Track Reverse Cholesterol Transport Strategy

As a main cause of serious cardiovascular diseases, atherosclerosis is characterized by deposited lipid and cholesterol crystals (CCs), which is considered as a great challenge to the current treatments. In this study, a dual-track reverse cholesterol transport strategy is used to overcome the cumulative CCs in the atherosclerotic lesions via a targeting nanoplatform named as LPLCH. Endowed with the active targeting ability to the plaques, the nanoparticles can be efficiently internalized and achieve a pH-triggered charge conversion for the escape from lysosomes. During this procedure, the liver X receptor (LXR) agonists loaded in nanoparticles are replaced by the deposited lysosomal CCs, leading to a LXR mediated up-regulation of ATP-binding cassette transporte ABCA1/G1 with the local CCs carrying at the same time. Thus, the cumulative CCs are removed in a dual-track way of ABCA1/G1 mediated efflux and nanoparticle-based carrying. The in vivo investigations indicate that LPLCH exhibits a favorable inhibition on the plaque progression and a further reversal of formed lesions when under a healthy diet. And the RNA-sequencing suggests that the cholesterol transport also synergistically activates the anti-inflammation effect. The dual-track reverse cholesterol transport strategy performed by LPLCH delivers an exciting candidate for the effective inhibition and degradation of atherosclerosis.

High-Density Lipoprotein function is modulated by the SARS-CoV-2 spike protein in a lipid-type dependent manner

There is a close relationship between the SARS-CoV-2 virus and lipoproteins, in particular high-density lipoprotein (HDL). The severity of the coronavirus disease 2019 (COVID-19) is inversely correlated with HDL plasma levels. It is known that the SARS-CoV-2 spike (S) protein binds the HDL particle, probably depleting it of lipids and altering HDL function. Based on neutron reflectometry (NR) and the ability of HDL to efflux cholesterol from macrophages, we confirm these observations and further identify the preference of the S protein for specific lipids and the consequent effects on HDL function on lipid exchange ability. Moreover, the effect of the S protein on HDL function differs depending on the individuals lipid serum profile. Contrasting trends were observed for individuals presenting low triglycerides/high cholesterol serum levels (LTHC) compared to high triglycerides/high cholesterol (HTHC) or low triglycerides/low cholesterol serum levels (LTLC). Collectively, these results suggest that the S protein interacts with the HDL particle and, depending on the lipid profile of the infected individual, it impairs its function during COVID-19 infection, causing an imbalance in lipid metabolism.

Boosting Cholesterol Efflux from Foam Cells by Sequential Administration of rHDL to Deliver MicroRNA and to Remove Cholesterol in a Triple-Cell 2D Atherosclerosis Model

Cardiovascular disease, the leading cause of mortality worldwide, is primarily caused by atherosclerosis, which is characterized by lipid and inflammatory cell accumulation in blood vessels and carotid intima thickening. Although disease management has improved significantly, new therapeutic strategies focused on accelerating atherosclerosis regression must be developed. Atherosclerosis models mimicking in vivo-like conditions provide essential information for research and new advances toward clinical application. New nanotechnology-based therapeutic opportunities have emerged with apoA-I nanoparticles (recombinant/reconstituted high-density lipoproteins, rHDL) as ideal carriers to deliver molecules and the discovery that microRNAs participate in atherosclerosis establishment and progression. Here, a therapeutic strategy to improve cholesterol efflux is developed based on a two-step administration of rHDL consisting of a first dose of antagomiR-33a-loaded rHDLs to induce adenosine triphosphate-binding cassette transporters A1 overexpression, followed by a second dose of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine rHDLs, which efficiently remove cholesterol from foam cells. A triple-cell 2D-atheroma plaque model reflecting the cellular complexity of atherosclerosis is used to improve efficiency of the nanoparticles in promoting cholesterol efflux. The results show that sequential administration of rHDL potentiates cholesterol efflux indicating that this approach may be used in vivo to more efficiently target atherosclerotic lesions and improve prognosis of the disease.

Phospholipid nanoparticles: Therapeutic potentials against atherosclerosis via reducing cholesterol crystals and inhibiting inflammation

Background

Atherosclerosis-related cardiovascular diseases (CVDs) are the leading cause of mortality worldwide. Cholesterol crystals (CCs) induce inflammation in atherosclerosis and are associated with unstable plaques and poor prognosis, but no drug can remove CCs in the clinic currently.

Methods

We generated a phospholipid-based and high-density lipoprotein (HDL)-like nanoparticle, miNano, and determined CC-dissolving capacity, cholesterol efflux property, and anti-inflammation effects of miNano in vitro. Both normal C57BL/6J and Apoe-deficient mice were used to explore the accumulation of miNano in atherosclerotic plaques. The efficacy and safety of miNano administration to treat atherosclerosis were evaluated in the Ldlr-deficient atherosclerosis model. The CC-dissolving capacity of miNano was also detected using human atherosclerotic plaques ex vivo.

Findings

We found that miNano bound to and dissolved CCs efficiently in vitro, and miNano accumulated in atherosclerotic plaques, co-localized with CCs and macrophages in vivo. Administration of miNano inhibited atherosclerosis and improved plaque stability by reducing CCs and macrophages in Ldlr-deficient mice with favorable safety profiles. In macrophages, miNano prevented foam cell formation by enhancing cholesterol efflux and suppressed inflammatory responses via inhibiting TLR4-NF-κB pathway. Finally, in an ex vivo experiment, miNano effectively dissolved CCs in human aortic atherosclerotic plaques.

Interpretation

Together, our work finds that phospholipid-based and HDL-like nanoparticle, miNano, has the potential to treat atherosclerosis by targeting CCs and stabilizing plaques.

Funding

This work was supported by the National Institutes of Health HL134569, HL109916, HL136231, and HL137214 to Y.E.C, HL138139 to J.Z., R21NS111191 to A.S., by the American Heart Association 15SDG24470155, Grant Awards (U068144 from Bio-interfaces and G024404 from M-BRISC) at the University of Michigan to Y.G., by the American Heart Association 19PRE34400017 and Rackham Helen Wu award to M.Y., NIH T32 GM07767 to K. H., Barbour Fellowship to D.L.

(r)HDL in theranostics: how do we apply HDL's biology for precision medicine in atherosclerosis management?

High-density lipoproteins (HDL) are key players in cholesterol metabolism homeostasis since they are responsible for transporting excess cholesterol from peripheral tissues to the liver. Imbalance in this process, due to either excessive accumulation or impaired clearance, results in net cholesterol accumulation and increases the risk of cardiovascular disease (CVD). Therefore, significant effort has been focused on the development of therapeutic tools capable of either directly or indirectly enhancing HDL-guided reverse cholesterol transport (RCT). More recently, in light of the emergence of precision nanomedicine, there has been renewed research interest in attempting to take advantage of the development of advanced recombinant HDL (rHDL) for both therapeutic and diagnostic purposes. In this review, we provide an update on the different approaches that have been developed using rHDL, focusing on the rHDL production methodology and rHDL applications in theranostics. We also compile a series of examples highlighting potential future perspectives in the field.

Targeting macrophages using nanoparticles: a potential therapeutic strategy for atherosclerosis

Atherosclerosis is one of the leading causes of vascular diseases, with high morbidity and mortality worldwide. Macrophages play a critical role in the development and local inflammatory responses of atherosclerosis, contributing to plaque rupture and thrombosis. Considering their central roles, macrophages have gained considerable attention as a therapeutic target to attenuate atherosclerotic progression and stabilize existing plaques. Nanoparticle-based delivery systems further provide possibilities to selectively and effectively deliver therapeutic agents into intraplaque macrophages. Although challenges are numerous and clinical application is still distant, the design and development of macrophage-targeting nanoparticles will generate new knowledge and experiences to improve therapeutic outcomes and minimize toxicity. Hence, the review aims to discuss various strategies for macrophage modulation and the development and evaluation of macrophage targeting nanomedicines for anti-atherosclerosis.

High Density Lipoprotein Cholesterol Efflux Capacity and Atherosclerosis in Cardiovascular Disease: Pathophysiological Aspects and Pharmacological Perspectives

Over the years, the relationship between high-density lipoprotein (HDL) and atherosclerosis, initially highlighted by the Framingham study, has been revealed to be extremely complex, due to the multiple HDL functions involved in atheroprotection. Among them, HDL cholesterol efflux capacity (CEC), the ability of HDL to promote cell cholesterol efflux from cells, has emerged as a better predictor of cardiovascular (CV) risk compared to merely plasma HDL-cholesterol (HDL-C) levels. HDL CEC is impaired in many genetic and pathological conditions associated to high CV risk such as dyslipidemia, chronic kidney disease, diabetes, inflammatory and autoimmune diseases, endocrine disorders, etc. The present review describes the current knowledge on HDL CEC modifications in these conditions, focusing on the most recent human studies and on genetic and pathophysiologic aspects. In addition, the most relevant strategies possibly modulating HDL CEC, including lifestyle modifications, as well as nutraceutical and pharmacological interventions, will be discussed. The objective of this review is to help understanding whether, from the current evidence, HDL CEC may be considered as a valid biomarker of CV risk and a potential pharmacological target for novel therapeutic approaches.