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The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) 3CL protease is a promising target for inhibition of viral replication by interaction with a cysteine residue (Cys145) at its catalytic site. Dalcetrapib exerts its lipid-modulating effect by binding covalently to cysteine 13 of a cholesteryl ester transfer protein. Because 12 free cysteine residues are present in the 3CL protease, we investigated the potential of dalcetrapib to inhibit 3CL protease activity and SARS-CoV-2 replication. Molecular docking investigations suggested that dalcetrapib-thiol binds to the catalytic site of the 3CL protease with a delta G value of −8.5 kcal/mol. Dalcetrapib inhibited both 3CL protease activity in vitro and viral replication in Vero E6 cells with IC50 values of 14.4 ± 3.3 μM and an EC50 of 17.5 ± 3.5 μM (mean ± SD). Near-complete inhibition of protease activity persisted despite 1000-fold dilution after ultrafiltration with a nominal dalcetrapib-thiol concentration of approximately 100 times below the IC50 of 14.4 μM, suggesting stable protease–drug interaction. The inhibitory effect of dalcetrapib on the SARS-CoV-2 3CL protease and viral replication warrants its clinical evaluation for the treatment of COVID-19.

Background: Pharmacogenomic studies have shown that ADCY9 genotype determines the effects of the CETP (cholesteryl ester transfer protein) inhibitor dalcetrapib on cardiovascular events and atherosclerosis imaging. The underlying mechanisms responsible for the interactions between ADCY9 and CETP activity have not yet been determined. Methods: Adcy9 -inactivated ( Adcy9 Gt/Gt ) and wild-type (WT) mice, that were or not transgenic for the CETP gene (CETPtg Adcy9 Gt/Gt and CETPtg Adcy9 WT ), were submitted to an atherogenic protocol (injection of an AAV8 [adeno-associated virus serotype 8] expressing a PCSK9 [proprotein convertase subtilisin/kexin type 9] gain-of-function variant and 0.75% cholesterol diet for 16 weeks). Atherosclerosis, vasorelaxation, telemetry, and adipose tissue magnetic resonance imaging were evaluated. Results: Adcy9 Gt/Gt mice had a 65% reduction in aortic atherosclerosis compared to WT ( P Adcy9 Gt/Gt mice compared to WT animals ( P Adcy9 Gt/Gt mice (versus WT, P Adcy9 Gt/Gt ( P Adcy9 Gt/Gt mice allowed significantly less adhesion of splenocytes compared to WT ( P Adcy9 Gt/Gt mice gained more weight than WT with the atherogenic diet; this was associated with an increase in whole body adipose tissue volume ( P Adcy9 Gt/Gt compared to WT mice ( P P P =0.0572). Adcy9 inactivation–induced effects on atherosclerosis, endothelial function, weight gain, adipose tissue volume, and feed efficiency were lost in CETPtg Adcy9 Gt/Gt mice ( P >0.05 versus CETPtg Adcy9 WT ). Conclusions: Adcy9 inactivation protects against atherosclerosis, but only in the absence of CETP activity. This atheroprotection may be explained by decreased macrophage accumulation and proliferation in the arterial wall, and improved endothelial function and autonomic tone.

Aortic valve stenosis (AVS) is the most common valvular heart disease in the Western world. Therapy based on apolipoprotein A-I (apoA-I), the major protein component of high-density lipoproteins, results in AVS regression in experimental models. Nevertheless, apoA-I degradation by proteases might lead to suboptimal efficacy of such therapy. An activatable probe using a quenched fluorescently labeled full-length apoA-I protein was generated to assess apoA-I-degrading protease activity in plasma derived from 44 men and 20 women with severe AVS (age 65.0 ± 10.4 years) as well as from a rabbit model of AVS. In human and rabbit AVS plasma, apoA-I-degrading protease activity was significantly higher than in controls (humans: 0.038 ± 0.009 vs 0.022 ± 0.005 RFU/s, p

Background Infusions of apolipoprotein A-I (apoA-I), the major protein component of high-density lipoproteins (HDL), result in aortic valve stenosis (AVS) regression in experimental models. Severe AVS can be complicated by acquired von Willebrand syndrome, a haemorrhagic disorder associated with loss of high-molecular-weight von Willebrand factor (vWF) multimers (HMWM), the latter being a consequence of increased shear stress and enhanced vWF-cleaving protease (ADAMTS-13) activity. Although antithrombotic actions of HDL have been described, its effects on ADAMTS-13 and vWF in AVS are unknown. Methods and Results We assessed ADAMTS-13 activity in plasma derived from a rabbit model of AVS (n = 29) as well as in plasma collected from 64 patients with severe AVS (age 65.0 ± 10.4 years, 44 males) undergoing aortic valve replacement (AVR). In both human and rabbit AVS plasma, ADAMTS-13 activity was higher than that in controls (p Conclusion Our data indicate that HDL levels are associated with reduced ADAMTS-13 activity and increased HMWM. HDL-based therapies may reduce the haematologic abnormalities of the acquired von Willebrand syndrome in AVS.

Adiponectin is an adipokine whose plasma levels are inversely correlated to metabolic syndrome components. Adiponectin protects against atherosclerosis and decreases risks in myocardial infarction. Endothelial progenitor cells (EPCs) are a heterogeneous population of circulating cells involved in vascular repair and neovascularization. EPCs number is reduced in patients with cardiovascular disease. We hypothesize that the positive effects of adiponectin against atherosclerosis are explained in part by its interactions with EPCs. Cells were obtained from healthy volunteers' blood by mononuclear cell isolation and plating on collagen-coated dishes. Three sub-populations of EPCs were identified and characterized using flow cytometry. EPCs' expression of adiponectin receptors, AdipoR1, and AdipoR2 was evaluated by quantitative PCR. The effects of recombinant adiponectin on EPCs' susceptibility to apoptosis were assessed. Finally, expression of neutrophil elastase by EPCs and activity of this enzyme on adiponectin processing were assessed. Quantitative PCR analysis of EPCs mRNAs showed that AdipoR1 mRNA is expressed at higher levels than AdipoR2. Expression of AdipoR1 protein was confirmed by western blot. Adiponectin significantly increased survival of two sub-populations of EPCs in conditions of serum deprivation. Such effect could not be demonstrated in the third EPCs sub-population. We also demonstrated that EPCs, particularly one sub-population, express neutrophil elastase. Neutrophil elastase activity was confirmed in EPCs' conditioned media. Adiponectin protects some EPCs sub-populations against apoptosis and therefore could modulate EPCs ability to induce repair of vascular damage. Neutrophil elastase activity of EPCs could locally modulate adiponectin activity by its involvement in the generation of the globular form of adiponectin.

Objective— Studies have shown that high-density lipoprotein (HDL)–raising compounds induce regression of aortic valve stenosis (AVS) in animal models. However, whether patients with AVS have an impaired HDL metabolism is unknown. Approach and Results— A total of 1435 single nucleotide polymorphisms in genes associated with HDL cholesterol levels (in or around GALNT2, LPL, ABCA1, APOA5, SCARB1, LIPC, CETP, LCAT, LIPG, APOC4 , and PLTP ) were genotyped in 382 patients with echocardiography-confirmed AVS (aortic jet velocity ≥2.5 m/s) and 401 controls. After control for multiple testing, none of the genetic variants showed a positive association with case/control status (adjusted P ≥0.05 for all single nucleotide polymorphisms tested). In a subsample of this cohort, HDL cholesterol levels, apolipoprotein AI levels, lecithin-cholesterol acyltransferase activity, pre–β-HDL, HDL size, and 4 parameters of cholesterol efflux capacity were measured in apolipoprotein B–depleted serum samples from 86 patients with and 86 patients without AVS. Cholesterol efflux capacity was measured using J774 macrophages with and without stimulation of ATP-binding cassette A-1 expression by cAMP, and HepG2 hepatocytes for scavenger receptor class B type 1–mediated efflux. None of these parameters were different between cases and controls. However, compared with patients without coronary artery disease, sera from patients with coronary artery disease had lower HDL cholesterol levels, scavenger receptor class B type 1–mediated efflux, and HDL size ( P ≤0.003), independently of the presence or absence of AVS. Conclusions— Results of the present study suggest that, based on HDL genetics and HDL functionality, HDL metabolism does not seem to predict the risk of AVS. Because of our limited sample size, additional studies are needed to confirm these findings.

Background: Studies have shown that low HDL-cholesterol levels may be associated with the progression of aortic valvular calcium and aortic valvular stenosis (AVS), but whether patients with AVS have impaired cholesterol efflux capacities is unknown. Methods and results: We have measured four parameters of cholesterol efflux capacity in apolipoprotein B-depleted serum samples from 48 patients with (aortic jet velocity ≥2.5 m/s, mean age = 72 ± 7 years and 72.7% men) and 51 patients without AVS (aortic jet velocity ≤ 1.7 m/s, mean age 71 ± 7 years and 70.6% men). Cholesterol efflux capacity was measured using J774 macrophages with and without stimulation of ABCA1 expression by cAMP (non-stimulated efflux, total efflux and ABCA1-mediated efflux), and HepG2 hepatocytes to measure SR-BI-mediated efflux. Mean HDL-cholesterol and apolipoprotein A-I levels as well as efflux are shown in the table for patients with vs. without AVS. The Pearson correlation coefficient between HDL-cholesterol levels and SR-B1-dependent efflux was 0.39 (p=0.007) in patients with AVS and 0.68 ( Conclusions: This study provides evidence that serum from patients with AVS may have impaired cholesterol efflux capacities, especially through the SR-B1 pathway. Table. Mean HDL-cholesterol and apolipoprotein A-I levels as well as non-stimulated-, total-, ABCA1-, and SR-B1-dependent cholesterol efflux obtained from patients’ serum with vs. without AVS. Data is shown as mean ± SD. Differences between categories were assessed using a Student unpaired t-test.