Efflux Capacity Research Articles

HDL cholesterol efflux capacity and protein content are associated with vasospasm after aneurysmal subarachnoid hemorrhage

HDL cholesterol efflux capacity and protein content are associated with vasospasm after aneurysmal subarachnoid hemorrhage

HDL proteome associates with hepatic and adipose tissue insulin resistance and cholesterol efflux capacity in metabolic syndrome patients

HDL proteome associates with hepatic and adipose tissue insulin resistance and cholesterol efflux capacity in metabolic syndrome patients

Foam fractionation studies of recombinant human apolipoprotein A-I

Apolipoprotein A-I (apoA-I), the primary protein component of plasma high-density lipoproteins (HDL), is comprised of two structural regions, an N-terminal amphipathic α-helix bundle domain (residues 1–184) and a hydrophobic C-terminal domain (residues 185–243). When a recombinant fusion protein construct [bacterial pelB leader sequence – human apoA-I (1–243)] was expressed in Escherichia coli shaker flask cultures, apoA-I was recovered in the cell lysate. By contrast, when the C-terminal domain was deleted from the construct, large amounts of the truncated protein, apoA-I (1–184), were recovered in the culture medium. Consequently, following pelB leader sequence cleavage in the E. coli periplasmic space, apoA-I (1–184) was secreted from the bacteria. When the pelB-apoA-I (1–184) fusion construct was expressed in a 5 L bioreactor, substantial foam production (~30 L) occurred. Upon foam collection and collapse into a liquid foamate, SDS-PAGE revealed that apoA-I (1–184) was the sole major protein present. Incubation of apoA-I (1–184) with phospholipid vesicles yielded reconstituted HDL (rHDL) particles that were similar in size and cholesterol efflux capacity to those generated with full-length apoA-I. Mass spectrometry analysis confirmed that pelB leader sequence cleavage occurred and that foam fractionation did not result in unwanted protein modifications. The facile nature and scalability of bioreactor-based apolipoprotein foam fractionation provide a novel means to generate a versatile rHDL scaffold protein.

HDL cholesterol efflux capacity and cholesterol loading capacity in long-term fasting: Evidence from a prospective, single-arm interventional study in healthy individuals

Background and aimsLong-term fasting (LF) is increasingly emerging as a non-pharmacological approach to modulate risk factors associated with the development of atherosclerotic cardiovascular diseases (ASCVD). However, protection from ASCVD is more tied to the functionality of high-density lipoprotein (HDL) than its plasma levels. Our prospective interventional study focuses on the functional properties of lipoproteins in modulating cholesterol homeostasis on peripheral cells and examines how LF may influence this and lipoprotein subclass composition. For that purpose, we investigated its impact on HDL-cholesterol efflux capacity (CEC), and on serum cholesterol loading capacity (CLC). MethodsForty healthy subjects (50 % females) underwent medically supervised 9-day fasting (250 kcal/day) in a specialised facility. Thirty-two subjects had a follow-up examination after one month of food reintroduction. ResultsLF was well tolerated and increased self-reported energy levels. Fasting reduced triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and HDL cholesterol (HDL-C). Very-low-density lipoprotein cholesterol (VLDL-C) and LDL3-C showed sustained reductions at follow-up. Only HDL-C, specifically HDL2-C levels, increased at follow-up. Total HDL-CEC decreased during LF and increased above baseline at follow-up. Fasting decreased ATP binding cassette (ABC)A1-mediated HDL-CEC whereas ABCG1-mediated HDL-CEC remained unaffected. Aqueous diffusion increased at follow up. LF decreased serum CLC and then returned to baseline levels. ConclusionsLF not only maintains lipoprotein functionality but also contributes to a favorable shift in the atherogenic risk profile, which persists even after food reintroduction. This further emphasizes the importance of considering HDL functionality alongside traditional lipid measurements to understand the potential for non-pharmacological interventions like LF to promote cardiovascular prevention and health. Trial registration numberNCT05031598.

Impaired Cholesterol Efflux Capacity rather than Low HDL-C Reflects Oxidative Stress under Acute Myocardial Infarction.

Acute myocardial infarction (AMI) causes irreversible damage to cardiomyocytes due to the discontinuation of oxygen supply and leads to systemic oxidative stress. It has been reported that high-density lipoprotein (HDL) particles have antioxidant capacity, and reduced antioxidant capacity is associated with decreased cholesterol efflux capacity (CEC). The purpose of this study was to clarify the usefulness of CEC measurement in patients with AMI. We investigated the association between CEC and oxidative stress status in a case-control study. This study included 193 AMI cases and 445 age- and sex-matched controls. We examined the associations of CEC with HDL-cholesterol (HDL-C) and oxidized human serum albumin (HSA), an index of systemic oxidative stress status, and the effect of aldehyde dehydrogenase 2 (ALDH2) rs671 polymorphism, which has been reported to affect HDL-C level and risk for MI, on these associations. Both bivariable and multivariable analyses showed that CEC was positively correlated with HDL-C levels in both AMI cases and controls, with a weaker correlation in AMI cases than in controls. In AMI cases, oxidized HSA levels were associated with CEC in both bivariable and multivariable analyses, but not with HDL-C. These associations did not differ among the ALDH2 genotypes. CEC, but not HDL-C level, reflects systemic oxidative stress status in patients with AMI. CEC measurement for patients with AMI may be useful in that it provides information on systemic oxidative stress status as well as atherosclerosis risk.

Cholesterol Efflux Capacity and Its Association with Oxidative Stress in Myocardial Infarction.

Cholesterol Efflux Capacity and Its Association with Oxidative Stress in Myocardial Infarction.

Cholesterol Efflux Capacity and Coronary Plaque Composition Following Non-ST-Elevation Myocardial Infarction

Cholesterol Efflux Capacity and Coronary Plaque Composition Following Non-ST-Elevation Myocardial Infarction

High-Density Lipoprotein Particle Concentration and Size Predict Incident Coronary Artery Disease Events in a Cohort With Type 1 Diabetes.

The cholesterol efflux capacity of high density lipoprotein (HDL) is negatively associated with cardiovascular risk. Small HDL particles account almost quantitatively for cholesterol efflux capacity, perhaps mediated through efflux of cholesterol and outer leaflet plasma membrane phospholipids by ABCA1 (ATP binding cassette subfamily A member 1). People with type 1 diabetes are at increased coronary artery disease (CAD) risk despite normal HDL-cholesterol concentrations. We therefore tested the hypothesis that small HDL particles (HDL-P)-rather than HDL-cholesterol-predict incident CAD in type 1 diabetes. Incident CAD (CAD death, myocardial infarction, or coronary revascularization) was determined in 550 individuals with childhood-onset type 1 diabetes. HDL-P was quantified by calibrated ion mobility analysis and cholesterol efflux capacity was quantified with validated assays. During a median follow-up of 26 years, 36.5% of the participants developed incident CAD, for an incidence density of 181.3 per 10 000 person-years. In multivariable Cox models, neither HDL-cholesterol nor apolipoprotein A1 concentration was significantly associated with CAD risk. In contrast, higher extra-small HDL-P concentrations were significantly associated with decreased CAD risk (hazard ratio [HR], 0.26 [95% CI, 0.14-0.50]). Weaker associations were observed for total HDL-P (HR, 0.88 [95% CI, 0.83-0.93]), small HDL (HR, 0.83 [95% CI, 0.68-1.02]), medium HDL (HR, 0.79 [95% CI, 0.71-0.89]), and large HDL (HR, 0.72 [95% CI, 0.59-0.89]). Although cholesterol efflux capacity was negatively associated with incident CAD, this association was no longer significant after adjustment for total HDL-P. Lower concentrations of total HDL-P and HDL subpopulations were positively associated with incident CAD independently of HDL-cholesterol, apolipoprotein A1, and other common CVD risk factors. Extra-small HDL was a much stronger predictor of risk than the other HDLs. Our data are consistent with the proposal that extra-small HDL plays a critical role in cardioprotection in type 1 diabetes, mediated by macrophage cholesterol efflux by the ABCA1 pathway.

Individual and Joint Associations of High-Sensitivity Troponin I and High-Sensitivity Troponin T with Cardiac Phenotypes and Outcomes in the General Population: An Analysis From the Dallas Heart Study.

High-sensitivity troponin I (hs-cTnI) and T (hs-cTnT) provide complementary information regarding cardiovascular disease risk. The explanation for their distinct risk profiles is incompletely understood. hs-cTnI and hs-cTnT were measured in Dallas Heart Study participants. Associations of hs-cTnI and hs-cTnT with demographics and phenotypes were assessed using linear regression. Associations with incident heart failure, atherosclerotic cardiovascular disease, global cardiovascular disease, and cardiovascular and all-cause mortality were assessed using Cox models. Among 3276 participants (56% women, 50% Black persons, median age 43 years), the correlation between hs-cTnI and hs-cTnT was modest (Spearman rho=0.35). Variables associated with hs-cTnI but not hs-cTnT included hypertension, higher body mass index and total cholesterol, and lower high-density lipoprotein and cholesterol efflux capacity. Older age, male sex, and diabetes were positively associated, and smoking was negatively associated, with hs-cTnT but not hs-cTnI. Hs-cTnI and hs-cTnT were associated with heart failure (hazard ratio [HR] per SD log hs-cTnI 1.53 [95% CI, 1.30-1.81] and HR per SD log hs-cTnT 1.65 [95% CI, 1.40-1.95]), global cardiovascular disease (HR, 1.22 [95% CI, 1.10-1.34] and HR, 1.27 [95% CI, 1.15-1.32]), and all-cause mortality (HR, 1.12 [95% CI, 1.01-1.25], and HR, 1.17 [95% CI, 1.06-1.29]). After adjustment for N-terminal pro-B-type natriuretic peptide and the alternative troponin, both remained associated with heart failure (HR per SD log hs-cTnI 1.32 [95% CI, 1.1-1.58] and HR per log hs-cTnT 1.27 [95% CI, 1.06-1.51]). Hs-cTnI and hs-cTnT are modestly correlated, demonstrate differential associations with cardiac and metabolic phenotypes, and provide complementary information regarding heart failure risk.

Assessing High-Density Lipoprotein: Shifting Focus from Quantity to Quality in Cardiovascular Disease Risk Assessment

High-density lipoprotein cholesterol (HDL) has long been regarded as a protective factor against cardiovascular disease (CVD). However, recent research challenges this notion, suggesting that HDL functionality rather than its quantity may be a more accurate predictor of CVD risk. While epidemiological studies have traditionally found that higher HDL levels are associated with reduced CVD risk, intervention trials aiming to elevate HDL levels have yielded inconsistent results. Moreover, observational studies have reported that unusually high HDL levels are associated with increased mortality rates. These discrepancies underscore the complexity of the role of HDL in CVD. Reverse cholesterol transport, facilitated by HDL, plays a crucial role in preventing atherosclerosis by removing cholesterol from peripheral tissues. Additionally, HDL exhibits anti-inflammatory properties by inhibiting endothelial adhesion molecules and suppressing pro-inflammatory cytokines. Recent studies have highlighted the importance of HDL particle number, size, and functionality in assessing CVD risk. For instance, increased HDL particle number and larger particle size have been associated with reduced CVD risk, independent of HDL cholesterol levels. Furthermore, HDL’s cholesterol efflux capacity has emerged as a promising biomarker for predicting CVD risk, with higher efflux capacity correlating with lower CVD incidence and mortality. This article reviews the latest findings regarding the role of HDL in CVD risk assessment, emphasizing the need to focus on HDL quantity and HDL quality.

Establishing a fluorescence-based technique for ABC transporters functional analysis in metabolism of insecticides in a Lepidopteron

The insecticide resistance development poses challenges to the pest control effectiveness. As phase III detoxification enzyme, ATP-binding cassette (ABC) transporters play a crucial role in conferring resistance by facilitating the elimination of insecticides. However, the precise involvement of ABCs in insecticides metabolism remains unclear. In this study, a competitive assay utilizing microinjection of the ABC substrate Texas Red (TR) was established in Lepidoptera for the first time to investigate the contribution of ABCs to the detoxification process of Cydia pomonella towards lambda-cyhalothrin (LCT) and abamectin (ABM). Results revealed that the elimination of TR was hindered by ABC inhibitor verapamil, LCT, or a combination of both, implying a shared subsets of ABCs involved in the transportation of TR and LCT. Moreover, the application of ABM alone led to marked inhibition of TR elimination, with verapamil not further exacerbating this inhibitory effect, indicating that ABM exhibited a highly competitive ABC substrate characteristic and has a strong interaction with them. Furthermore, silencing key resistance associated ABC genes through RNAi resulted in increased mortality of larvae under LCT or ABM exposure, affecting TR elimination and ATP hydrolysis. These findings imply that ABC genes are critical for the active transport function of ABCs energized by ATP, ultimately reducing larvae tolerance to insecticides. In conclusion, our findings not only validated the feasibility of a competitive bioassay using fluorescent ABC substrate in lepidopteran larvae but also highlighted that ABCs in enhancing the efflux capacity of C. pomonella larvae, facilitating the binding and transportation of insecticides and their metabolites.

Highlights of Cardiovascular Disease Prevention Studies Presented at the 2024 American College of Cardiology Conference.

To summarize selected late-breaking science on cardiovascular (CV) disease prevention presented at the 2024 Scientific Session of the American College of Cardiology (ACC) conference. The LIBerate-HR trial showed the efficacy and safety of lerodalcibep, a subcutaneous injection that prevents binding of Pro-Protein Convertase Subtilisin/Kexin (PCSK) 9 to low-density lipoprotein (LDL)-receptors resulting in LDL-cholesterol (LDL-C) lowering in patients at very high risk or high risk of atherosclerotic CV disease (ASCVD). The AEGIS-II randomized patients with type 1 myocardial infarction (MI) with multivessel coronary artery disease and additional CV risk factors and found no benefit in major adverse CV events (MACE) with CSL112, an apolipoprotein A1 infusion shown to increase cholesterol efflux capacity. The Bridge-TIMI 73a trial showed a significant reduction in triglyceride (TG) levels with olezarsen, an antisense mRNA, in patients with moderate hyperTG with elevated CV risk. The BE ACTIVE trial showed significant improvement in step counts in patients given behavioral and financial incentives. The DRIVE study showed a significant increase in the prescription of either sodium-glucose co-transporter-2 inhibitors or glucagon-like peptide-1 receptor agonists in patients with type 2 diabetes mellitus (T2DM) at elevated CV or renal risk with a remote team-based, non-licensed navigator and clinical pharmacist approach. The TACTiC trial showed increased and sustained use of statin therapy by patient-driven use of a web-based portal that calculated the ASCVD risk score and gave prompts. The VICTORIAN-INITIATE trial showed efficacy and safety in early use of inclisiran in patients with ASCVD who did not reach target LDL-C < 70mg/dL despite maximally tolerated statin therapy. The ARISE-HF trial showed no difference in change of peak oxygen consumptionwith the use of an oral aldose reductase inhibitor, AT-001, in patients with well-controlled T2DM and diabetic cardiomyopathy with high-risk features compared to placebo. The PREVENT trial showed a significant reduction in target vessel failure at 2years in patients with non-flow limiting vulnerable plaques with percutaneous coronary intervention and optimal medical therapy (OMT) compared to OMT alone. The late-breaking clinical science presented at the 2024 Scientific Session of the ACC paves the way for an evidence-based alternative to statin therapy and provides data on several common clinical scenarios encountered in daily practice.

Electroacupuncture pretreatment enhances the calcium efflux activity of Na+/Ca2+ exchanger to attenuate cerebral injury by PI3K/Akt-mediated NCX1 upregulation after focal cerebral ischaemia

Electroacupuncture pretreatment is considered as an optimal strategy for inducing cerebral ischaemic tolerance. However, the underlying neuroprotective mechanism of this approach has never been explored from the perspective of calcium homeostasis. Intracellular calcium overload is a key inducer of cascade neuronal injury in the early stage after cerebral ischaemia attack and the Na+/Ca2+ exchanger (NCX) is the main plasma membrane calcium extrusion pathway maintaining post-ischaemic calcium homeostasis. This study aims to investigate whether the regulation of NCX-mediated calcium transport contributes to the cerebroprotective effect of electroacupuncture pretreatment against ischaemic injury and to elucidate the underlying mechanisms involved in this process. Following five days of repeated electroacupuncture stimulation on Baihui (GV20), Neiguan (PC6), and Sanyinjiao (SP6) acupoints in rats, in vivo and in vitro models of cerebral ischaemia were induced through middle cerebral artery occlusion and oxygen/glucose deprivation (OGD), respectively. Firstly, we verified the neuroprotective effect of electroacupuncture pretreatment from the perspective of neurological score, infarct volume and neuronal apoptosis. Our findings from brain slice patch-clamp indicated that electroacupuncture pretreatment enhanced the Ca2+ efflux capacity of NCX after OGD. NCX1 expression in the ischaemic penumbra exhibited a consistent decline from 1 to 24 h in MCAO rats. Electroacupuncture pretreatment upregulated the expression of NCX1, especially at 24 h, and silencing NCX1 by short hairpin RNA (shRNA) administration reversed the protective effect of electroacupuncture pretreatment against cerebral ischaemic injury. Furthermore, we administered LY294002, a phosphatidylinositol 3 kinase (PI3K) inhibitor, prior to inducing ischaemia to investigate the upstream regulatory mechanism of electroacupuncture pretreatment on NCX1 expression. Electroacupuncture pretreatment activates PI3K/Akt pathway, leading to an increase in the expression of NCX1, which facilitates calcium extrusion and exerts a neuroprotective effect against cerebral ischaemia. These findings provided a novel insight into the prevention of ischemic stroke and other similar conditions characterized by brain ischaemia or hypoperfusion.

Novel Insights of ANGPTL-3 on Modulating Cholesterol Efflux Capacity Induced by HDL Particle.

Angiopoietin-like protein 3 (ANGPTL-3) modulates lipid metabolism and the risk of coronary artery disease (CAD), especially stable angina (SA), via suppressing lipoprotein lipase (LPL). However, whether there are other mechanisms is not elucidated yet. The current research explored the modulatory roles of ANGPTL-3 on high-density lipoprotein (HDL), which further affects atherosclerotic development. A total of 200 individuals were enrolled in the present study. Serum ANGPTL- 3 levels were detected via enzyme-linked immunosorbent assays (ELISA). Cholesterol efflux capacity induced by HDL particles was detected through H3-cholesterol loading THP-1 cell. The serum ANGPTL-3 levels presented no significant discordance between the SA group and the non-SA group, whereas the serum ANGPTL-3 levels in type 2 diabetes mellitus (T2DM) group were significantly elevated compared with those in the non-T2DM group [428.3 (306.2 to 736.8) ng/ml vs. 298.2 (156.8 to 555.6) ng/ml, p <0.05]. Additionally, the serum ANGPTL-3 levels were elevated in patients with low TG levels compared to those in patients with high TG levels [519.9 (377.6 to 809.0) ng/ml vs. 438.7 (329.2 to 681.0) ng/ml, p <0.05]. By comparison, the individuals in the SA group and T2DM group presented decreased cholesterol efflux induced by HDL particles [SA: (12.21±2.11)% vs. (15.51±2.76)%, p <0.05; T2DM: (11.24±2.13)% vs. (14.65± 3.27)%, p <0.05]. In addition, the serum concentrations of ANGPTL-3 were inversely associated with the cholesterol efflux capacity of HDL particles (r=-0.184, p <0.05). Through regression analysis, the serum concentrations of ANGPTL-3 were found to be an independent modulator of the cholesterol efflux capacity of HDL particles (standardized β=-0.172, p <0.05). ANGPTL-3 exhibited a negative modulatory function on cholesterol efflux capacity induced by HDL particles.

Lutein and Zeaxanthin Enhance, Whereas Oxidation, Fructosylation, and Low pH Damage High-Density Lipoprotein Biological Functionality.

High-density lipoproteins (HDLs) are key regulators of cellular cholesterol homeostasis but are functionally altered in many chronic diseases. The factors that cause HDL functional loss in chronic disease are not fully understood. It is also unknown what roles antioxidant carotenoids play in protecting HDL against functional loss. The aim of this study was to measure how various disease-associated chemical factors including exposure to (1) Cu2+ ions, (2) hypochlorous acid (HOCL), (3) hydrogen peroxide (H2O2), (4) sialidase, (5) glycosidase, (6) high glucose, (7) high fructose, and (8) acidic pH, and the carotenoid antioxidants (9) lutein and (10) zeaxanthin affect HDL functionality. We hypothesized that some of the modifications would have stronger impacts on HDL particle structure and function than others and that lutein and zeaxanthin would improve HDL function. HDL samples were isolated from generally healthy human plasma and incubated with the corresponding treatments listed above. Cholesterol efflux capacity (CEC), lecithin-cholesterol acyl transferase (LCAT) activity, and paraoxonase-1 (PON1) activity were measured in order to determine changes in HDL functionality. Median HDL particle diameter was increased by acidic pH treatment and reduced by HOCl, high glucose, high fructose, N-glycosidase, and lutein treatments. Acidic pH, oxidation, and fructosylation all reduced HDL CEC, whereas lutein, zeaxanthin, and sialidase treatment improved HDL CEC. LCAT activity was reduced by acidic pH, oxidation, high fructose treatments, and lutein. PON1 activity was reduced by sialidase, glycosidase, H2O2, and fructose and improved by zeaxanthin and lutein treatment. These results show that exposure to oxidizing agents, high fructose, and low pH directly impairs HDL functionality related to cholesterol efflux and particle maturation, whereas deglycosylation impairs HDL antioxidant capacity. On the other hand, the antioxidants lutein and zeaxanthin improve or preserve both HDL cholesterol efflux and antioxidant activity but have no effect on particle maturation.

High-density lipoprotein metrics during midlife and future subclinical atherosclerosis in women: the SWAN HDL study.

The clinical utility of high-density lipoprotein cholesterol (HDL-C) in risk classification is limited, especially in midlife women. Novel metrics of HDL may better reflect this risk. We clustered a comprehensive profile of HDL metrics into favorable and unfavorable clusters and assessed how these two clusters are related to future subclinical atherosclerosis (carotid intima media thickness [cIMT], interadventitial diameter [IAD], and carotid plaque presence) in midlife women. Four hundred sixty-one women (baseline age: 50.4 [2.7] years; 272 White, 137 Black, 52 Chinese) from the Study of Women's Health Across the Nation HDL ancillary study who had baseline measures of HDL cholesterol efflux capacity (HDL-CEC), lipid contents (HDL-phospholipids [HDL-PL] and HDL triglycerides [HDL-Tg]), and HDL particle (HDL-P) distribution and size, followed by carotid ultrasound (average 12.9 [SD: 2.6] years later), were included. Using latent cluster analysis, women were clustered into a favorable (high HDL-CEC, HDL-PL, large and medium HDL-P, less HDL-Tg and small HDL-P, larger size) or an unfavorable HDL cluster (low HDL-CEC, HDL-PL, large and medium HDL-P, more HDL-Tg, and small HDL-P, smaller size) and then linked to future subclinical atherosclerosis using linear or logistic regression. The favorable HDL cluster was associated with lower cIMT, IAD, and odds of carotid plaque presence. These associations were attenuated by body mass index, except in Chinese women where the association with cIMT persisted (0.72 [0.63, 0.83]). The association between favorable HDL clusters and a better postmenopausal subclinical atherosclerosis profile is largely explained by body mass index; however, racial/ethnic differences may exist.

Purpurogallin carboxylic acid exhibits synergistic effects with 5‑fluorouracil on liver cancer cells in vitro by targeting ABCG2.

Purpurogallin carboxylic acid (PCA) is a natural phenol compound derived from Macleaya microcarpa (Maxim.) Fedde, which exerts particular antioxidant and anti-inflammatory capacities. However, the effects and mechanisms of PCA on liver cancer cells remain unknown. Therefore, network pharmacology and computer virtual docking were used to identify the target-proteins of PCA. In addition, surface plasmon resonance, protease activity and rhodamine excretion assays were carried out to evaluate the effects of PCA on the activity of ATP binding cassette subfamily G member 2 (ABCG2). The synergistic effects of PCA and 5-fluorouracil (5-FU) on liver cancer cell proliferation, cell cycle arrest, colony formation and spheroid formation abilities in vitro were determined by Cell Counting Kit-8 (CCK-8) assay, flow cytometry, western blot analysis, colony formation and spheroid formation assays, respectively. ABCG2 was identified as a potential target of PCA, with a high docking score. The equilibrium dissociation constant of PCA for ABCG2 protein was 1.84 µM, while the median inhibitory concentration of this protein was 3.09 µM. In addition, the results demonstrated that PCA could significantly reduce the drug efflux capacity of liver cancer cells. CCK-8 assays revealed that liver cancer cell treatment with 10 µM PCA and 10 µM 5-FU exhibited the most potent synergistic effects on liver cancer cell proliferation at 48 h. Additionally, cell co-treatment with PCA and 5-FU also significantly attenuated the colony and spheroid formation abilities of liver cancer cells in vitro, while it promoted their arrest at the G1 phase of the cell cycle. Furthermore, ABCG2 silencing in liver cancer cells notably abrogated the synergistic effects of PCA and 5-FU. In conclusion, the present study demonstrated that PCA exhibited synergistic effects with 5-FU on liver cancer cells in vitro via targeting ABCG2. Therefore, PCA combined with 5-FU may be a potential strategy for liver cancer therapy.

Cholesterol esterification is hampered in alzheimer’s disease and cholesteryl esters composition is consequently altered

Introduction and Aim: Several epidemiological studies indicate a strong inverse association between the risk of developing Alzheimer’s disease (AD) and plasma HDL-C levels. The mechanism by which plasma HDL influence the pathogenesis and progression of AD is still unsolved and since cholesterol esterification is a crucial step in HDL metabolism it could be involved. The purpose of this study was to evaluate cholesterol esterification and HDL subclasses in plasma and cerebrospinal fluid (CSF) of Alzheimer’s Disease (AD) patients. Methods: The study enrolled 70 AD patients and 74 cognitively-normal controls comparable for age and sex. Lipids and lipoprotein profile, cholesterol esterification, and cholesterol efflux capacity (CEC) were evaluated in plasma and CSF using assays set for measurement in plasma, which were appropriately modified for CSF. Results: AD patients have normal plasma lipids, but significantly reduced unesterified cholesterol and unesterified/total cholesterol ratio. Lecithin:cholesterol acyltransferase (LCAT) activity and cholesterol esterification rate (CER), two measures of the efficiency of the esterification process, were reduced by 29% and 16%, respectively, in plasma of AD patients. Plasma HDL subclass distribution in AD patients was comparable to that of controls, but the content of small discoidal preβ-HDL particles was significantly reduced. In agreement with the reduced preβ-HDL particles, cholesterol efflux capacity mediated by the transporters ABCA1 and ABCG1 was reduced in AD patients’ plasma. The CSF unesterified to total cholesterol ratio was increased in AD patients, and CSF CER and CEC from astrocytes were significantly reduced in AD patients. In the AD group, a significant positive correlation was observed between plasma unesterified cholesterol and unesterified/total cholesterol ratio with Aβ1-42 CSF content. Conclusions: Taken together data indicate that cholesterol esterification is hampered in plasma and CSF of AD patients, and that plasma cholesterol esterification biomarkers (unesterified cholesterol and unesterified/total cholesterol ratio) are significantly associated to disease biomarkers (i.e., CSF Aβ1-42).

TUDCA alleviates atherosclerosis by inhibiting AIM2 inflammasome and enhancing cholesterol efflux capacity in macrophage

Cholesterol efflux capacity (CEC) dysfunction in macrophages is important in atherosclerosis. However, the mechanism underlying CEC dysfunction remains unclear. We described the characteristics of ATF4 and inflammasome activation in macrophages during atherosclerosis through scRNA sequencing analysis. Then model of hyperlipemia was established in ApoE-/- mice; some were treated with tauroursodeoxycholic acid (TUDCA). TUDCA decreased the ATF4, Hspa, and inflammasome activation, reduced plaque area of the artery, and promoted CEC in macrophages. Furthermore, TUDCA abolished oxLDL-induced foam cell formation by inhibiting activation of the PERK/eIF2α/ATF4 and AIM2 inflammasome in macrophages. Further assays revealed ATF4 binding to AIM2 promoter, promoting its transcriptional activity significantly. Then we discovered that ATF4 affected AIM2-mediated foam cell formation by targeting ABCA1, which could be blocked by TUDCA. Our study demonstrated that TUDCA alleviates atherosclerosis by inhibiting AIM2 inflammasome and enhancing CEC of macrophage, which provided possibilities for the development of therapies.

Atherosclerosis Residual Lipid Risk-Overview of Existing and Future Pharmacotherapies.

Patients with atherosclerotic disease remain at increased risk of future events despite receiving optimal medical treatment. This residual risk is widely heterogeneous, but lipoprotein particles and their content play a major role in determining future cardiovascular events. Beyond low-density lipoprotein cholesterol (LDL-c), other lipoprotein particles have not demonstrated similar contribution to the progression of atherosclerosis. Statins, ezetimibe, and more recently, proprotein convertase subtilisin kexin 9 (PCSK9) inhibitors and bempedoic acid have confirmed the causal role of LDL-c in the development of atherosclerosis. Data on high-density lipoprotein cholesterol (HDL-c) suggested a possible causal role for atherosclerosis; nonetheless, HDL-c-raising treatments, including cholesteryl-ester transfer protein (CETP) inhibitors and niacin, failed to confirm this relationship. On the other hand, mendelian randomisation revealed that triglycerides are more implicated in the development of atherosclerosis. Although the use of highly purified eicosapentaenoic acid (EPA) was associated with a reduction in the risk of adverse cardiovascular events, this beneficial effect did not correlate with the reduction in triglycerides level and has not been consistent across large phase 3 trials. Moreover, other triglyceride-lowering treatments, such as fibrates, were not associated with a reduction in future cardiovascular risk. Studies assessing agents targeting angiopoietin-like 3 (lipoprotein lipase inhibitor) and apolipoprotein C3 antisense will add further insights into the role of triglycerides in atherosclerosis. Emerging lipid markers such as lipoprotein (a) and cholesterol efflux capacity may have a direct role in the progression of atherosclerosis. Targeting these biomarkers may provide incremental benefits in reducing cardiovascular risk when added to optimal medical treatment. This Review aims to assess available therapies for current lipid biomarkers and provide mechanistic insight into their potential role in reducing future cardiovascular risk.