Steering the Lipid Transfer To Unravel the Mechanism of Cholesteryl Ester Transfer Protein Inhibition

Tailored quinoline hybrids as promising COX-2/15-LOX dual inhibitors endowed with diverse safety profile: Design, synthesis, SAR, and histopathological study

Complications of the worldwide use of non-steroidal anti-inflammatory drugs (NSAIDs) sparked scientists to design novel harmless alternatives as an urgent need. So, a unique hybridization tactic of quinoline/pyrazole/thioamide (4a-c) has been rationalized and synthesized as potential COX-2/15-LOX dual inhibitors, utilizing relevant reported studies on these pharmacophores. Moreover, we extended these preceding hybrids into more varied functionality, bearing crucial thiazole scaffolds(5a-l). All the synthesized hybrids were evaluatedin vitroas COX-2/15-LOX dual inhibitors. Initially, series4a-cexhibited significant potency towards 15-LOX inhibition (IC50 = 5.454-4.509 μM) compared to meclofenamate sodium (IC50 = 3.837 μM). Moreover, they revealed reasonable inhibitory activities against the COX-2 enzyme in comparison to celecoxib.Otherwise, conjugates 5a-ldisclosed marked inhibitory activity against 15-LOX and strong inhibitory to COX-2. In particular, hybrids5d(IC50 = 0.239 μM, SI = 8.95), 5h(IC50 = 0.234 μM, SI = 20.35) and 5l (IC50 = 0.201 μM, SI = 14.42) revealed more potency and selectivity outperforming celecoxib (IC50 = 0.512 μM, SI = 4.28). In addition, the most potentcompounds, 4a, 5d, 5h, and 5l have been elected for further in vivoevaluation and displayed potent inhibition of edema in the carrageenan-induced rat paw edema test that surpassed indomethacin. Further, compounds5d, 5h, and 5l decreased serum inflammatory markers including oxidative biomarkersiNO, and pro-inflammatory mediators cytokines like TNF-α, IL-6, and PGE. Ulcerogenic liability for tested compounds demonstrated obvious gastric mucosal safety. Furthermore, a histopathological study for compound 5l suggested a confirmatory comprehensive safety profile for stomach, kidney, and heart tissues. Docking and drug-likeness studies offered a good convention with the obtained biological investigation.

Fluorinated Diaryl Sulfonamides: Molecular Modeling, Synthesis, and In Vitro Validation as New CETP Inhibitors

BACKGROUND

Hyperlipidemia, a cardiovascular disease risk factor, is characterized by a rise in low-density lipoprotein (LDL), triglycerides and total cholesterol, and a decrease in high-density lipoprotein (HDL). Cholesteryl ester transfer protein (CETP) enables the transfer of cholesteryl ester from HDL to LDL and very low-density lipoprotein.

OBJECTIVES

CETP inhibition is a promising approach to prevent and treat cardiovascular diseases. By inhibiting lipid transport activity, it increases HDL levels and decreases LDL levels.

MATERIALS AND METHOD

Herein, diaryl sulfonamides 6a-6g and 7a-7g were prepared, and the structure of these compounds was fully determined using different spectroscopic techniques.

RESULTS

These compounds underwent biological evaluation in vitro and showed different inhibitory activities against CETP; 100% inhibitory activity was observed for compounds 7a-7g, while activities of compounds 6a-6g ranged up to 42.6% at 10 μM concentration. Pharmacophore mapping agreed with the bioassay results where the four aromatic ring compounds 7a-7g possessed higher fit values against Hypo4/8 and the shape-complemented Hypo4/8 in comparison to compounds 6a-6g.

CONCLUSION

Docking of the synthesized compounds using libdock and ligandfit engines revealed that compounds 7a-7g formed п-п stacking and hydrophobic interactions with the binding pocket, while compounds 6a-6g missed these hydrophobic interactions with amino acids Leu206, Phe265, and Phe263.

Deciphering structural aspects of reverse cholesterol transport: mapping the knowns and unknowns

Atherosclerosis is a major contributor to the onset and progression of cardiovascular disease (CVD). Cholesterol-loaded foam cells play a pivotal role in forming atherosclerotic plaques. Induction of cholesterol efflux from these cells may be a promising approach in treating CVD. The reverse cholesterol transport (RCT) pathway delivers cholesteryl ester (CE) packaged in high-density lipoproteins (HDL) from non-hepatic cells to the liver, thereby minimising cholesterol load of peripheral cells. RCT takes place via a well-organised interplay amongst apolipoprotein A1 (ApoA1), lecithin cholesterol acyltransferase (LCAT), ATP binding cassette transporter A1 (ABCA1), scavenger receptor-B1 (SR-B1), and the amount of free cholesterol. Unfortunately, modulation of RCT for treating atherosclerosis has failed in clinical trials owing to our lack of understanding of the relationship between HDL function and RCT. The fate of non-hepatic CEs in HDL is dependent on their access to proteins involved in remodelling and can be regulated at the structural level. An inadequate understanding of this inhibits the design of rational strategies for therapeutic interventions. Herein we extensively review the structure-function relationships that are essential for RCT. We also focus on genetic mutations that disturb the structural stability of proteins involved in RCT, rendering them partially or completely non-functional. Further studies are necessary for understanding the structural aspects of RCT pathway completely, and this review highlights alternative theories and unanswered questions.

Bound Phospholipids Assist Cholesteryl Ester Transfer in the Cholesteryl Ester Transfer Protein

Cholesteryl ester transfer protein (CETP) is a plasma glycoprotein that assists the transfer of cholesteryl esters (CEs) from antiatherogenic high-density lipoproteins (HDLs) to proatherogenic low-density lipoproteins (LDLs), initiating cholesterol plaques in the arteries. Consequently, inhibiting the activity of CETP is therefore being pursued as a novel strategy to reduce the risk of cardiovascular diseases (CVDs). The crystal structure of CETP has revealed the presence of two CEs running in the hydrophobic tunnel and two plugged-in phospholipids (PLs) near the concave surface. Other than previous animal models that rule out the PL transfer by CETP and PLs in providing the structural stability, the functional importance of bound phospholipids in CETP is not fully explored. Here, we employ a series of molecular dynamics (MD) simulations, steered molecular dynamics (SMD) simulations, and free energy calculations to unravel the effect of PLs on the functionality of the protein. Our results suggest that PLs play an important role in the transfer of neutral lipids by transforming the unfavorable bent conformation of CEs into a favorable linear conformation to facilitate the smooth transfer. The results also suggest that the making and breaking interactions of the hydrophobic tunnel residues with CEs with a combined effort from PLs are responsible for the transfer of CEs. Further, the findings demonstrate that the N-PL has a more pronounced effort on CE transfer than C-PL but efforts from both PLs are essential in the transfer. Thus, we propose that the functionally important PLs can be considered with potential research interest in targeting cardiovascular diseases.

Thiomethylphenyl benzenesulfonamides as potential cholesteryl ester transfer protein inhibitors: Synthesis, molecular modeling and biological evaluation

Background:

The number of lipid disorders cases has risen dramatically around the world as a result of poor dietary habits, hereditary risk factors, or other diseases or medicines. Cholesteryl ester transfer protein (CETP) is a 476 amino acid lipophilic glycoprotein that helps transport cholesteryl esters and phospholipids from proatherogenic LDL and VLDL to atheroprotective HDL. CETP inhibition increases HDL cholesterol, lowers LDL cholesterol and triglycerides, rendering it a promising therapy option for hyperlipidemia and its comorbidities.

Methods:

In this research, fourteen benzenesulfonamides 7a-7g and 8a-8g were synthesized and identified using 1H-NMR, 13C-NMR, IR and MS. The in vitro biological evaluation of 7a-7g and 8a-8g revealed CETP inhibitory activities ranging from 15.6 to 100% at 10 μM concentration.

Results:

Four aromatic rings compounds bearing either m-CH3 (8c) or p-Cl (8g) were the most potent compounds with 100% CETP inhibition, while the most active compound was 7c bearing three aromatic rings and m-CH3 with an IC50 of 0.12 μM. LibDock displayed that benzeneulfonamides can form hydrophobic interactions with the side chains of Leu129, Cys13, Ala202, Val198, Leu217 and Ile215 and participate in п-п stacking with Phe441, Phe197 and Arg201 in the binding pocket of CETP.

Conclusion:

Pharmacophore mapping showed significant matching with the pharmacophoric features of Hypo4/8 and shape-complemented Hypo4/8 of CETP inhibitors for potent compounds.

Role of lipid metabolism and systemic inflammation in the development of atherosclerosis in animal models

Systemic inflammation makes a significant contribution to the pathogenesis of atherosclerosis and has been the subject of numerous studies. Works aiming to analyze the mechanisms of atherosclerosis development often include experiments on animals. A primary task of such research is the characterization, justification, and selection of an adequate model. Aim. To evaluate the peculiarities of lipid metabolism and systemic inflammation in chronic obstructive pulmonary disease (COPD) in the development of atherosclerosis in animal models. Materials and Methods. Analyses of cross-links between species-specific peculiarities of lipid metabolism and the immune response, as well as a bioinformatic analysis of differences in Toll-like receptor 4 (TLR4) in mice, rats, and rabbits in comparison with its human homolog, were carried out. A search for and analysis of the amino acid sequences of human, mouse, rat, and rabbit TLR4 was performed in the International database GenBank of National Center of Biotechnical Information and in The Universal Protein Resource (UniProt) database. Multiple alignments of the TLR4 amino acid sequences were implemented in the Clustal Omega program, version 1.2.4. Reconstruction and visualization of molecular phylogenetic trees were performed using the MEGA7 program according to the Neighbor-Joining and Maximum Parsimony methods. Results. Species-specific differences of the peculiarities of lipid metabolism and the innate immune response in humans, mice, and rabbits were shown that must be taken into account in analyses of study results. Conclusion.Disorders in lipid metabolism and systemic inflammation mediated by the innate immune system participating in the pathogenesis of atherosclerosis in COPD possess species-specific differences that should be taken into account in analyses of study results.