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Objectives: To identify the association of the rs121912724 polymorphism in the Apolipoprotein A1 gene with diabetic dyslipidemia and its correlation with serum High-density Lipoprotein Cholesterol (HDL), Triglycerides, (TG) and Low-density Lipoprotein Cholesterol (LDL-C) levels. Methods: Two groups were taken, comprising 150 diabetic dyslipidemia (group I) patients and 150 healthy controls (group II). Demographic and biochemical data were analyzed using Statistical Package for Social Sciences 26 by applying the Student independent t-test. DNA samples of both groups were subjected to TETRA-Amplification Refractory System polymerase chain reaction, and allele A and C of the rs121912724 polymorphism were amplified. The association of the rs121912724 polymorphism with the disease was studied using Fisher's exact test and Cochran-Armitage test. The correlation between the polymorphism and levels of lipid levels was determined using Pearson correlation on SPSS version 27. Results: The levels of HDL-C, LDL-C, and TG were significantly higher than in healthy group (p<0.000). The genotypic count of homozygous AA was 137, 12 of heterozygous AC, and 1 of homozygous CC in group I. The genotypic count of homozygous AA was 138, 12 of heterozygous AC in group II, with no homozygous CC. There was no association of rs121912724 observed with the development of diabetic dyslipidemia, and a negative correlation of rs121912724 with deranged levels of HDL-C, LDL-C, and TG was observed. Conclusion: The rs121912724 polymorphism in the APOA1 gene was not associated with diabetic dyslipidemia. There was no correlation found between the polymorphism and deranged levels of HDL-C, TG, and LDL-C. [ABSTRACT FROM AUTHOR]

Background and Aim: The role of lecithin: cholesterol acyltransferase (LCAT) and oxidized low‐density lipoprotein (ox‐LDL) in endometrial cancer (EC) or EC with concurrent type 2 diabetes is still unclear. This study investigated the LCAT activity, ox‐LDL, and lipid profile in EC patients with or without type 2 diabetes and compared them with healthy individuals and patients with type 2 diabetes alone. Methods: In this cross‐sectional, case–control study, 93 female participants were recruited. The participants were divided into four groups, including EC with type 2 diabetes (n = 19), EC without type 2 diabetes (n = 17), type 2 diabetes (n = 31), and healthy controls (n = 26). Sociodemographic information, the LCAT activity, triglyceride (TG), total cholesterol, high‐density lipoprotein cholesterol (HDL‐C), low‐density lipoprotein cholesterol (LDL‐C), and ox‐LDL levels were collected. One‐way analysis of variance and analysis of covariance, Student's t‐test, Mann–Whitney U‐test, and χ2‐test were used to compare demographic features and laboratory results among studied groups. Regression analyses were also performed to evaluate the interaction effect between EC and type 2 diabetes on serum LCAT activity. Results: The LCAT activity was significantly lower, and ox‐LDL levels were significantly higher in all patient groups compared to the healthy controls (p < 0.001). EC patients had significantly lower LCAT activity and higher ox‐LDL levels than type 2 diabetes and healthy groups (p < 0.05). Higher levels of TG and lower levels of HDL‐C were observed in all patient groups compared to the healthy group (all p < 0.001). Patients with EC and concomitant type 2 diabetes had significantly lower serum LDL‐C levels than healthy and type 2 diabetes groups (p < 0.05). Conclusions: The combination of EC and type 2 diabetes had a subadditive effect on LCAT activity and ox‐LDL level. The lowest LCAT activity and the highest ox‐LDL levels were observed in patients with EC and concurrent type 2 diabetes. Key points: The lecithin: cholesterol acyltransferase (LCAT) activity, oxidized low‐density lipoprotein (ox‐LDL) levels, and lipid profile were evaluated among four groups.The groups were endometrial cancer (EC), type 2 diabetes, EC and concurrent type 2 diabetes, and healthy controls.LCAT and high‐density lipoprotein decreased, and ox‐LDL increased in all three disease groups.The accompaniment of EC and type 2 diabetes significantly increased oxidative stress.The EC group had lower LCAT activity and higher ox‐LDL levels than the type 2 diabetes group. [ABSTRACT FROM AUTHOR]

Objective To observe the DNA methylation in the promoter region of the lecithin cholesterol acyltransferase (LCAT) gene in peripheral blood of patients with carotid atherosclerotic plaque. Methods Fifty-two patients with carotid atherosclerotic plaque (observation group) and 50 healthy subjects without carotid atherosclerotic plaque (control group) during the same period were selected. DNA methylation in the promoter region of the LCAT gene was detected in all subjects to compare the difference of the methylation rate between the two groups. Head and neck CT angiography (CTA) examination was performed in the observation group. The degree of vascular stenosis was compared between methyl‑ ated patients and non-methylated patients in the observation group. Results The DNA methylation rate in the promoter region of the LCAT gene in peripheral blood of the observation group was 65. 38% (34/52), while that of the control group was 36. 00% (18/50), with significant difference in the methylation rate between the two groups (P<0. 05) . Among the 34 methylated patients in the observation group, 21 cases had mild-to-moderate carotid artery stenosis and 13 cases had severe stenosis or occlusion. Among the 18 non-methylated patients in the observation group, 16 cases had mild-to-moderate carotid artery stenosis and 2 cases had severe stenosis or occlusion. There were significant differences in the severity of carotid artery stenosis between methylated and non-methylated patients in the observation group (P<0. 05) . Conclusion The DNA methylation rate in the promoter region of the LCAT gene in peripheral blood of patients with carotid atherosclerotic plaque is higher, and the DNA methylation in the promoter region of the LCAT gene is closely related to the formation of atherosclerotic plaque. [ABSTRACT FROM AUTHOR]

High-density lipoprotein (HDL) is an anti-atherosclerotic lipoprotein. Thanks to the activity of apolipoprotein ApoA1, the principal protein component of HDL, this last is responsible for converting cholesterol into ester form and transporting excessive cholesterol to the liver ("reverse cholesterol transport" RCT). When HDL undergoes oxidation, it becomes dysfunctional and proatherogenic. ApoA1 is a target of oxidation, and its alteration affects RCT and contributes to atherosclerosis development. Until now, the mechanism of HDL oxidation is not fully understood and only hydroxyl radicals seem to induce direct oxidation of protein and lipidic components of lipoproteins. Here we demonstrate that superoxide radical, widely produced in early atherosclerosis, directly oxidizes HDL, and as a consequence, ApoA1 undergoes structural alterations impairing its anti-atherosclerotic functions. Our results highlight in an in vitro system the potential mechanism by which O2·− triggers atherosclerotic pathogenesis in vivo. Our study gets the basis for therapeutic approaches focused on the management of superoxide generation in early atherosclerosis onset. [ABSTRACT FROM AUTHOR]

Abstract Background and Aim The role of lecithin: cholesterol acyltransferase (LCAT) and oxidized low‐density lipoprotein (ox‐LDL) in endometrial cancer (EC) or EC with concurrent type 2 diabetes is still unclear. This study investigated the LCAT activity, ox‐LDL, and lipid profile in EC patients with or without type 2 diabetes and compared them with healthy individuals and patients with type 2 diabetes alone. Methods In this cross‐sectional, case–control study, 93 female participants were recruited. The participants were divided into four groups, including EC with type 2 diabetes (n = 19), EC without type 2 diabetes (n = 17), type 2 diabetes (n = 31), and healthy controls (n = 26). Sociodemographic information, the LCAT activity, triglyceride (TG), total cholesterol, high‐density lipoprotein cholesterol (HDL‐C), low‐density lipoprotein cholesterol (LDL‐C), and ox‐LDL levels were collected. One‐way analysis of variance and analysis of covariance, Student's t‐test, Mann–Whitney U‐test, and χ2‐test were used to compare demographic features and laboratory results among studied groups. Regression analyses were also performed to evaluate the interaction effect between EC and type 2 diabetes on serum LCAT activity. Results The LCAT activity was significantly lower, and ox‐LDL levels were significantly higher in all patient groups compared to the healthy controls (p

Human apolipoprotein C1 (APOC1) is a 57 amino acid long polypeptide that, through its potent inhibition of cholesteryl ester transferase protein, helps regulate the transfer of lipids between lipid particles. We have now determined the structure of APOC1 in four crystal forms by X-ray diffraction. A molecule of APOC1 is a single, slightly bent, α-helix having 13-14 turns and a length of about 80 Å. APOC1 exists as a dimer, but the dimers are not the same in the four crystals. In two monoclinic crystals, two helices closely engage one another in an antiparallel fashion. The interactions between monomers are almost entirely hydrophobic with sparse electrostatic complements. In the third monoclinic crystal, the two monomers spread at one end of the dimer, like a scissor opening, and, by translation along the crystallographic a axis, form a continuous, contiguous sheet through the crystal. In the orthorhombic crystals, two molecules of APOC1 are related by a noncrystallographic 2-fold axis to create an arc of about 120 Å length. This symmetrical dimer utilizes interactions not present in dimers of the monoclinic crystals. Versatility of APOC1 monomer association shown by these crystals is suggestive of physiological function.

Background: Lecithin cholesterol acyltransferase (LCAT) is an important enzyme responsible for free cholesterol (FC) esterification, which is critical for high density lipoprotein (HDL) maturation and the completion of the reverse cholesterol transport (RCT) process. Plasma LCAT activity and concentration showed various patterns under different physiological and pathological conditions. Research on LCAT has grown rapidly over the past 50 years, but there are no bibliometric studies summarizing this field as a whole. This study aimed to use the bibliometric analysis to demonstrate the trends in LCAT publications, thus offering a brief perspective with regard to future developments in this field.Methods: We used the Web of Science Core Collection to retrieve LCAT-related studies published from 1975 to 2020. The data were further analyzed in the number of studies, the journal which published the most LCAT-related studies, co-authorship network, co-country network, co-institute network, co-reference and the keywords burst by CiteSpace V 5.7.Results: 2584 publications contained 55,311 references were used to analyzed. The number of included articles fluctuated in each year. We found that Journal of lipid research published the most LCAT-related studies. Among all the authors who work on LCAT, they tend to collaborate with a relatively stable group of collaborators to generate several major authors clusters which Albers, J. published the most studies (n = 53). The United States of America contributed the greatest proportion (n = 1036) of LCAT-related studies. The LCAT-related studies have been focused on the vascular disease, lecithin-cholesterol acyltransferase reaction, phospholipid, cholesterol efflux, chronic kidney disease, milk fever, nephrotic syndrome, platelet-activating factor acetylhydrolase, reconstituted lpa-i, reverse cholesterol transport. Four main research frontiers in terms of burst strength for LCAT-related studies including “transgenic mice”, “oxidative stress”, “risk”, and “cholesterol metabolism “need more attention.Conclusion: This is the first study that demonstrated the trends and future development in LCAT publications. Further studies should focus on the accurate metabolic process of LCAT dependent or independent of RCT using metabolic marker tracking techniques. It was also well worth to further studying the possibility that LCAT may qualify as a biomarker for risk prediction and clinical treatment.

Background: The etiopathogenesis of abdominal aortic aneurysm (AAA) is still unclarified, but vascular inflammation and matrix metalloproteases activation have a recognized role in AAA development and progression. Circulating lipoproteins are involved in tissue inflammation and repair, particularly through the regulation of intracellular cholesterol, whose excess is associated to cell damage and proinflammatory activation. We analyzed lipoprotein metabolism and function in AAA and in control vasculopathic patients, to highlight possible non-atherosclerosis-related, specific abnormalities. Methods: We measured fluorometrically serum esterified/total cholesterol ratio, as an index of lecithin-cholesterol acyltransferase (LCAT) activity, and cholesteryl ester transfer protein (CETP) activity in patients referred to vascular surgery either for AAA (n=30) or stenotic aortic/peripheral atherosclerosis (n=21) having similar burden of cardiovascular risk factors and disease. We measured high-density lipoprotein (HDL)-cholesterol efflux capacity (CEC), through the ATP-binding cassette G1 (ABCG1) and A1 (ABCA1) pathways and serum cell cholesterol loading capacity (CLC), by radioisotopic and fluorimetric methods, respectively. Results: We found higher LCAT (+23%; p < 0.0001) and CETP (+49%; p < 0.0001) activity in AAA sera. HDL ABCG1-CEC was lower (-16%; p < 0.001) and ABCA1-CEC was higher (+31.7%; p < 0.0001) in AAA. Stratification suggests that smoking may partly contribute to these modifications. CEC and CETP activity correlated with CLC only in AAA. Conclusions: We demonstrated that compared to patients with stenotic atherosclerosis, patients with AAA had altered HDL metabolism and functions involved in their anti-inflammatory and tissue repair activity, particularly through the ABCG1-related intracellular signaling. Clarifying the relevance of this mechanism for AAA evolution might help in developing new diagnostic parameters and therapeutic targets for the early management of this condition. [ABSTRACT FROM AUTHOR]

BackgroundThe etiopathogenesis of abdominal aortic aneurysm (AAA) is still unclarified, but vascular inflammation and matrix metalloproteases activation have a recognized role in AAA development and progression. Circulating lipoproteins are involved in tissue inflammation and repair, particularly through the regulation of intracellular cholesterol, whose excess is associated to cell damage and proinflammatory activation. We analyzed lipoprotein metabolism and function in AAA and in control vasculopathic patients, to highlight possible non-atherosclerosis-related, specific abnormalities.MethodsWe measured fluorometrically serum esterified/total cholesterol ratio, as an index of lecithin-cholesterol acyltransferase (LCAT) activity, and cholesteryl ester transfer protein (CETP) activity in patients referred to vascular surgery either for AAA (n=30) or stenotic aortic/peripheral atherosclerosis (n=21) having similar burden of cardiovascular risk factors and disease. We measured high-density lipoprotein (HDL)-cholesterol efflux capacity (CEC), through the ATP-binding cassette G1 (ABCG1) and A1 (ABCA1) pathways and serum cell cholesterol loading capacity (CLC), by radioisotopic and fluorimetric methods, respectively.ResultsWe found higher LCAT (+23%; p < 0.0001) and CETP (+49%; p < 0.0001) activity in AAA sera. HDL ABCG1-CEC was lower (−16%; p < 0.001) and ABCA1-CEC was higher (+31.7%; p < 0.0001) in AAA. Stratification suggests that smoking may partly contribute to these modifications. CEC and CETP activity correlated with CLC only in AAA.ConclusionsWe demonstrated that compared to patients with stenotic atherosclerosis, patients with AAA had altered HDL metabolism and functions involved in their anti-inflammatory and tissue repair activity, particularly through the ABCG1-related intracellular signaling. Clarifying the relevance of this mechanism for AAA evolution might help in developing new diagnostic parameters and therapeutic targets for the early management of this condition.

To investigate the effects of doxorubicin injection on the levels of lipoprotein lipase and leci-thin cholesterol acyltransferase (LCAT) in rats with nehpmtic syndrome (NS). Sixty-four SD rats were randomly divided into four groups, namely: matched group, low-dose adriamycin group, medium-dose adriamycin group and high-dose adriamycin group. The four groups of rats were injected with adriamycin through the tail vein at one time at 0 mg/kg, 2 mg/kg, 4 mg/kg, 8 mg/kg, the changes in rat kidney lipoprotein lipase and LCAT levels were detected at different time points after modeling. The body weight, daily feed intake, blood creatinine and urea nitrogen of the low-dose doxorubicin group, medium-dose doxorubicin group and high-dose doxorubicin group were lower than those of the matched group (P<0.05) at 7 d, 14 d, 21 d after modeling, the 24 h urine protein were higher than that of the matched group (P<0.05), and there were adose-dependence, the difference compared among the three groups were statistically significant (P<0.05). The relative expression levels of renal lipoprotein lipase and lecithin cholesterol acylase in the low-dose doxorubicin group, medium-dose doxorubicin group, and high-dose doxorubicin group were lower than those in the matched group at 21 d and 28 d after modeling (P<0.05). and there were dose-dependence, the difference compared among the three groups were statistically significant (P<0.05). A small dose of doxorubicin can inhibit the expression of lipoprotein lipase and LCAT in rat kidneys, and can quickly and effectively establish rat model of nephrotic syndrome with good simulation effect. [ABSTRACT FROM AUTHOR]

Abstract Background The functionality of high-density lipoproteins (HDL) is a better cardiovascular risk predictor than HDL concentrations. One of the key elements of HDL functionality is its apolipoprotein composition. Lecithin-cholesterol acyl transferase (LCAT) and cholesterol-ester transfer protein (CETP) are enzymes involved in HDL-mediated reverse cholesterol transport. This study assessed the concentration and activity of LCAT and CETP in HDL subspecies defined by their content of apolipoproteins E (apoE) and C-III (apoC-III) in humans. Methods Eighteen adults (ten women and eight men, mean age 55.6, BMI 26.9 Kg/m2, HbA1c 5.4%) were studied. HDL from each participant were isolated and divided into four subspecies containing respectively: No apoE and no apoC-III (E-C-), apoE but not apoC-III (E + C-), apoC-III but no apoE (E-C+) and both apoE and apoC-III (E + C+). The concentration and enzymatic activity of LCAT and CETP were measured within each HDL subspecies using immunoenzymatic and fluorometric methods. Additionally, the size distribution of HDL in each apolipoprotein-defined fraction was determined using non-denaturing electrophoresis and anti-apoA-I western blotting. Results HDL without apoE or apoC-III was the predominant HDL subtype. The size distribution of HDL was very similar in all the four apolipoprotein-defined subtypes. LCAT was most abundant in E-C- HDL (3.58 mg/mL, 59.6% of plasma LCAT mass), while HDL with apoE or apoC-III had much less LCAT (19.8, 12.2 and 8.37% of plasma LCAT respectively for E + C-, E-C+ and E + C+). LCAT mass was lower in E + C- HDL relative to E-C- HDL, but LCAT activity was similar in both fractions, signaling a greater activity-to-mass ratio associated with the presence of apoE. Both CETP mass and CETP activity showed only slight variations across HDL subspecies. There was an inverse correlation between plasma LCAT activity and concentrations of both E-C+ pre-beta HDL (r = − 0.55, P = 0.017) and E-C- alpha 1 HDL (r = − 0.49, P = 0.041). Conversely, there was a direct correlation between plasma CETP activity and concentrations of E-C+ alpha 1 HDL (r = 0.52, P = 0.025). Conclusions The presence of apoE in small HDL is correlated with increased LCAT activity and esterification of plasma cholesterol. These results favor an interpretation that LCAT and apoE interact to enhance anti-atherogenic pathways of HDL.

Background: The most common glomerular disorder in children is nephrotic syndrome, associated with high morbidity despite notable advances in its treatment. Many of the nephrotic syndrome complications, including the increased risk of atherosclerosis and thromboembolism, can be linked to dysregulated lipid metabolism and dyslipidemia. Paraoxonase enzyme is responsible for the most of antioxidant properties of HDL, thus preventing the formation of atherogenic ox-LDL molecules, and Lecithin Cholesterol acyltransferase is intimately involved in HDL maturation and is a key component of the reverse cholesterol transport pathway, which removes excess cholesterol molecules from the peripheral tissues to the liver for excretion. Objective: The present study aimed to investigate the serum activities of paraoxonase-1(PON-1) and lecithin cholesterol acyltransferase (LCAT) in children with nephrotic syndrome in an active phase (as newly diagnosed or old cases with acute relapse) also, to study any correlation exists between paraoxonase-1 activity and lipid profile. Methods: This study consists of Group 1 with 40 cases of nephrotic syndrome in the age group of (2-14 years) and Group 2 with 40 age and sex-matched healthy controls. Lipid profile and paraoxonase activity, Lecithin Cholesterol acyltransferase activities were measured in both groups' serum samples. Results: Statistical analysis by student's t-test showed that the mean levels of Total Cholesterol, Triglycerides, LDL were significantly increased in Group 1 when compared to Group 2 (p

Background: The functionality of high-density lipoproteins (HDL) is a better cardiovascular risk predictor than HDL concentrations. One of the key elements of HDL functionality is its apolipoprotein composition. Lecithin-cholesterol acyl transferase (LCAT) and cholesterol-ester transfer protein (CETP) are enzymes involved in HDL-mediated reverse cholesterol transport. This study assessed the concentration and activity of LCAT and CETP in HDL subspecies defined by their content of apolipoproteins E (apoE) and C-III (apoC-III) in humans. Methods: Eighteen adults (ten women and eight men, mean age 55.6, BMI 26.9 Kg/m2, HbA1c 5.4%) were studied. HDL from each participant were isolated and divided into four subspecies containing respectively: No apoE and no apoC-III (E-C-), apoE but not apoC-III (E + C-), apoC-III but no apoE (E-C+) and both apoE and apoC-III (E + C+). The concentration and enzymatic activity of LCAT and CETP were measured within each HDL subspecies using immunoenzymatic and fluorometric methods. Additionally, the size distribution of HDL in each apolipoprotein-defined fraction was determined using non-denaturing electrophoresis and anti-apoA-I western blotting. Results: HDL without apoE or apoC-III was the predominant HDL subtype. The size distribution of HDL was very similar in all the four apolipoprotein-defined subtypes. LCAT was most abundant in E-C- HDL (3.58 mg/mL, 59.6% of plasma LCAT mass), while HDL with apoE or apoC-III had much less LCAT (19.8, 12.2 and 8.37% of plasma LCAT respectively for E + C-, E-C+ and E + C+). LCAT mass was lower in E + C- HDL relative to E-C- HDL, but LCAT activity was similar in both fractions, signaling a greater activity-to-mass ratio associated with the presence of apoE. Both CETP mass and CETP activity showed only slight variations across HDL subspecies. There was an inverse correlation between plasma LCAT activity and concentrations of both E-C+ pre-beta HDL (r = − 0.55, P = 0.017) and E-C- alpha 1 HDL (r = − 0.49, P = 0.041). Conversely, there was a direct correlation between plasma CETP activity and concentrations of E-C+ alpha 1 HDL (r = 0.52, P = 0.025). Conclusions: The presence of apoE in small HDL is correlated with increased LCAT activity and esterification of plasma cholesterol. These results favor an interpretation that LCAT and apoE interact to enhance anti-atherogenic pathways of HDL. [ABSTRACT FROM AUTHOR]

A coronary artery disease (CAD) is a leading cause of death worldwide that occurs due to deposition of fatty streaks on the artery wall as a plaque. Pivotal role of proteins in heart disease pathogenesis lead the present study to screen proteins having altered expression in CAD patients plasma by proteomic approach. We used two-dimensional gel electrophoresis followed by identification of differential proteins by Matrix Assisted Laser Desorption Ionization-Time of Flight (MALDI-TOF). Apolipoprotein A-I (apoA-I) has been recognized as significantly down regulated protein as compared to healthy control that has been validated by Western blot and enzyme linked immunosorbent assay in 200 North Indian CAD plasma. The in-silico studies of apoA-I was carried out to investigate the effect of single amino acid substitution (A164S) on the function and the stability of apoA-1. Functional analysis indicated that apoA-I helps in reverse cholesterol transportation (RCT) by activating lecithin cholesterol acyltransferase (LCAT) enzyme. Crystallographic structure of apoA-I was taken from protein data bank (PDB), mutation was carried out by Swiss PDB viewer (SPDBV) and its effect was analysed with DUET, I-Mutant2.0, MuPro, Folding Rate Change serevr (RaCe), MuPro, Sorting Intolerant from Tolerant server (SIFT), Site Directed Mutator (SDM) and Tango servers. This analysis indicated that A164S mutation considerably affect the stability and function of apoA-I and may play an important role during its interaction with LCAT. Studied mutation may also lead to the apoA-I aggregation thus present study implicated that this mutation may hamper the apoA-I and LCAT interaction which may lead to CAD progression. [ABSTRACT FROM AUTHOR]

Lecithin:cholesterol acyltransferase (LCAT) and LCAT-activating compounds are being investigated as treatments for coronary heart disease (CHD) and familial LCAT deficiency (FLD). Herein we report the crystal structure of human LCAT in complex with a potent piperidinylpyrazolopyridine activator and an acyl intermediate-like inhibitor, revealing LCAT in an active conformation. Unlike other LCAT activators, the piperidinylpyrazolopyridine activator binds exclusively to the membrane-binding domain (MBD). Functional studies indicate that the compound does not modulate the affinity of LCAT for HDL, but instead stabilizes residues in the MBD and facilitates channeling of substrates into the active site. By demonstrating that these activators increase the activity of an FLD variant, we show that compounds targeting the MBD have therapeutic potential. Our data better define the substrate binding site of LCAT and pave the way for rational design of LCAT agonists and improved biotherapeutics for augmenting or restoring reverse cholesterol transport in CHD and FLD patients.

Aims: To review the formation, catabolism, and the possible atherogenic properties of Lp-X.Data Synthesis: The conversion of cholesterol to bile acids is regulated by several mechanisms including cholesterol 7 alpha hydroxylase, fibroblast growth factor 19, and farnesoid X receptors. During cholestasis these mechanisms are altered and there is an accumulation of bile acids and cholesterol in plasma. The hypercholesterolemia observed in cholestasis is due to the presence of an anomalous lipoprotein called lipoprotein-X (Lp-X). Lp-X is a lipoprotein rich in phospholipid and free cholesterol present in plasma of patients with cholestasis and, with some variations, in patients with lecithin-cholesterol-acyl-transferase deficiency (LCAT), and after lipid infusion. Lp-X is formed from a bile lipoprotein moving to the blood vessels where it incorporates small quantities of triglycerides, apo-C and esterified cholesterol and becomes a "mature" Lp-X. The activity of the phosphatidilcholine canalicular transporter Mdr2 P-glycoprotein (homologous to the human ABCB4) is essential for LpX appearance, since its suppression abolishes Lp-X formation. However, the concentration of Lp-X in plasma is determined also by the degree of the cholestasis, the residual liver function, and the LCAT deficiency. The Lp-X catabolism seems to be mediated by the reticuloendothelial system and possibly the kidney.Conclusions: Lp-X might be considered a defense mechanism against the toxic effect of free cholesterol in cholestasis. The frequency of cardiovascular events in patients affected by primary biliary cholangitis, in whom the Lp-X is present in high concentration, are not increased. Further studies could now clarify the remaining open questions on the role of Lp-X in the dyslipidemia of cholestasis. [ABSTRACT FROM AUTHOR]

Background: HDL function may be more important than HDL concentration in determining risk for cardiovascular disease. In addition, HDL is a carrier of carotenoids and antioxidant enzymes, which protect HDL and LDL particles against oxidation.Objective: The goal of this study was to determine the impact of consuming 0-3 eggs/d on LDL and HDL particle size, HDL function, and plasma antioxidants in a young, healthy population.Methods: Thirty-eight healthy men and women [age 18-30 y, body mass index (in kg/m2) 18.5-29.9] participated in this 14-wk crossover intervention. Subjects underwent a 2-wk washout (0 eggs/d) followed by sequentially increasing intake of 1, 2, and 3 eggs/d for 4 wk each. After each period, fasting blood was collected for analysis of lipoprotein subfractions, plasma apolipoprotein (apo) concentration, lutein and zeaxanthin concentration, and activities of lecithin-cholesterol acyltransferase, cholesteryl ester transfer protein, and paraoxonase-1.Results: Compared with intake of 0 eggs/d, consuming 1-3 eggs/d resulted in increased large-LDL (21-37%) and large-HDL (6-13%) particle concentrations, plasma apoAI (9-15%), and lecithin-cholesterol acyltransferase activity (5-15%) (P < 0.05 for all biomarkers). Intake of 2-3 eggs/d also promoted an 11% increase in apoAII (P < 0.05) and a 20-31% increase in plasma lutein and zeaxanthin (P < 0.05), whereas intake of 3 eggs/d resulted in a 9-16% increase in serum paraoxonase-1 activity compared with intake of 1-2 eggs/d (P < 0.05). Egg intake did not affect cholesteryl ester transfer protein activity.Conclusions: Intake of 1 egg/d was sufficient to increase HDL function and large-LDL particle concentration; however, intake of 2-3 eggs/d supported greater improvements in HDL function as well as increased plasma carotenoids. Overall, intake of ≤3 eggs/d favored a less atherogenic LDL particle profile, improved HDL function, and increased plasma antioxidants in young, healthy adults. This trial was registered at clinicaltrials.gov as NCT02531958. [ABSTRACT FROM AUTHOR]

Background Humans with familial lecithin:cholesterol acyltransferase (LCAT) deficiency (FLD) have extremely low or undetectable high-density lipoprotein cholesterol (HDL-C) levels and by early adulthood develop many manifestations of the disorder, including corneal opacities, anemia, and renal disease. Objective To determine if infusions of recombinant human LCAT (rhLCAT) could reverse the anemia, halt progression of renal disease, and normalize HDL in FLD. Methods rhLCAT (ACP-501) was infused intravenously over 1 hour on 3 occasions in a dose optimization phase (0.3, 3.0, and 9.0 mg/kg), then 3.0 or 9.0 mg/kg every 1 to 2 weeks for 7 months in a maintenance phase. Plasma lipoproteins, lipids, LCAT levels, and several measures of renal function and other clinical labs were monitored. Results LCAT concentration peaked at the end of each infusion and decreased to near baseline over 7 days. Renal function generally stabilized or improved and the anemia improved. After infusion, HDL-C rapidly increased, peaking near normal in 8 to 12 hours; analysis of HDL particles by various methods all revealed rapid sequential disappearance of preβ-HDL and small α-4 HDL and appearance of normal α-HDL. Low-density lipoprotein cholesterol increased more slowly than HDL-C. Of note, triglyceride routinely decreased after meals after infusion, in contrast to the usual postprandial increase in the absence of rhLCAT infusion. Conclusions rhLCAT infusions were well tolerated in this first-in-human study in FLD; the anemia improved, as did most parameters related to renal function in spite of advanced disease. Plasma lipids transiently normalized, and there was rapid sequential conversion of small preβ-HDL particles to mature spherical α-HDL particles. [ABSTRACT FROM AUTHOR]

Among the most common lipid abnormalities, a low level of high-density lipoprotein-cholesterol (HDL-C) is one of the first risk factors identified for coronary heart disease. Lecithin cholesterol acyltransferase (LCAT) has a pivotal role in the formation and maturation of HDL-C and in reverse cholesterol transport. To identify genetic loci associated with low HDL-C in a population-based cohort in Tehran, the promoter, coding regions and exon/intron boundaries of LCAT were amplified and sequenced in consecutive individuals (n=150) who had extremely low or high HDL-C levels but no other major lipid abnormalities. A total of 14 single-nucleotide polymorphisms (SNPs) were identified, of which 10 were found to be novel; the L393L, S232T and 16:67977696 C>A polymorphisms have been previously reported in the SNP Database (as rs5923, rs4986970 and rs11860115, respectively) and the non-synonymous R47M mutation has been reported in the Catalogue of Somatic Mutations in Cancer (COSM972635). Three of the SNPs identified in the present study (position 6,531 in exon 5, position 6,696 in exon 5 and position 5,151 in exon 1) led to an amino acid substitution. The most common variants were L393L (4886C/T) in exon 6 and Q177E, a novel mutation, in exon 5, and the prevalence of the heterozygous genotype of these two SNPs was significantly higher in the low HDL-C groups. Univariate conditional logistic regression odds ratios (ORs) were nominally significant for Q177E (OR, 5.64; P=0.02; 95% confidence interval, 1.2-26.2). However, this finding was attenuated following adjustment for confounders. Further studies using a larger sample size may enhance the determination of the role of these SNPs. [ABSTRACT FROM AUTHOR]

Background High density lipoproteins (HDL) have many cardioprotective roles; however, in subjects with type 2 diabetes (T2D) these cardioprotective properties are diminished. Conversely, increased fruit and vegetable (F&V) intake may reduce cardiovascular disease risk, although direct trial evidence of a mechanism by which this occurs in subjects with T2D is lacking. Therefore, the aim of this study was to examine if increased F&V consumption influenced the carotenoid content and enzymes associated with the antioxidant properties of HDL in subjects with T2D. Methods Eighty obese subjects with T2D were randomised to a 1- or ⩾6-portion/day F&V diet for 8- weeks. Fasting serum was collected pre- and post-intervention. HDL was subfractionated into HDL2 and HDL3 by rapid ultracentrifugation. Carotenoids were measured in serum, HDL2 and HDL3 by high performance liquid chromatography. The activity of paraoxonase-1 (PON- 1) was measured in serum, HDL2 and HDL3 by a spectrophotometric assay, while the activity of lecithin cholesterol acyltransferase (LCAT) was measured in serum, HDL2 and HDL3 by a fluorometric assay. Results In the ⩾6- vs. 1-portion post-intervention comparisons, carotenoids increased in serum, HDL2 and particularly HDL3, (α-carotene, p = 0.008; β-cryptoxanthin, p = 0.042; lutein, p = 0.012; lycopene, p = 0.016), as did the activities of PON-1 and LCAT in HDL3 (p = 0.006 and 0.044, respectively). Conclusion To our knowledge, this is the first study in subjects with T2D to demonstrate that increased F&V intake augmented the carotenoid content and influenced enzymes associated with the antioxidant properties of HDL. We suggest that these changes would enhance the cardioprotective properties of this lipoprotein. [ABSTRACT FROM AUTHOR]

Background: Lecithin cholesterol acyltransferase (LCAT) is an important enzyme responsible for free cholesterol (FC) esterification, which is critical for high density lipoprotein (HDL) maturation and the completion of the reverse cholesterol transport (RCT) process. Plasma LCAT activity and concentration showed various patterns under different physiological and pathological conditions. Research on LCAT has grown rapidly over the past 50 years, but there are no bibliometric studies summarizing this field as a whole. This study aimed to use the bibliometric analysis to demonstrate the trends in LCAT publications, thus offering a brief perspective with regard to future developments in this field. Methods: We used the Web of Science Core Collection to retrieve LCAT-related studies published from 1975 to 2020. The data were further analyzed in the number of studies, the journal which published the most LCAT-related studies, co-authorship network, co-country network, co-institute network, co-reference and the keywords burst by CiteSpace V 5.7. Results: 2584 publications contained 55,311 references were used to analyzed. The number of included articles fluctuated in each year. We found that Journal of lipid research published the most LCAT-related studies. Among all the authors who work on LCAT, they tend to collaborate with a relatively stable group of collaborators to generate several major authors clusters which Albers, J. published the most studies ( n = 53). The United States of America contributed the greatest proportion ( n = 1036) of LCAT-related studies. The LCAT-related studies have been focused on the vascular disease, lecithin-cholesterol acyltransferase reaction, phospholipid, cholesterol efflux, chronic kidney disease, milk fever, nephrotic syndrome, platelet-activating factor acetylhydrolase, reconstituted lpa-i, reverse cholesterol transport. Four main research frontiers in terms of burst strength for LCAT-related studies including "transgenic mice", "oxidative stress", "risk", and "cholesterol metabolism "need more attention. Conclusion: This is the first study that demonstrated the trends and future development in LCAT publications. Further studies should focus on the accurate metabolic process of LCAT dependent or independent of RCT using metabolic marker tracking techniques. It was also well worth to further studying the possibility that LCAT may qualify as a biomarker for risk prediction and clinical treatment., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Gao, Wu, Sun, Zhang, Shi, Lu, Qian, Yin, Zhao, Qin and Xue.)

Summary: Objective: Recent data suggest that obesity and related metabolic aberrations are associated with osteoarthritis (OA) development, a phenomenon that is attributed at least in part to the consumption of lipid-rich diets. To date, the molecular mechanisms that govern the lipid-OA connection remain largely unknown. Given the important role of high-density lipoprotein (HDL) in plasma and tissue lipid metabolism, the main purpose of the present study was to investigate the role of HDL metabolism in the pathobiology of OA. Methods: We used apolipoprotein A-I (apoA-I)−/− mice that lack classical apoA-I containing HDL, LCAT−/− mice that have only immature HDL and relatively reduced HDL-cholesterol levels and control C57BL/6 mice. Mice were placed on chow or western-type (WTD) and monitored for 24 weeks. Knee joints were removed and articular cartilage was isolated for further analyses. Results: The LCAT−/− mice were significantly more sensitive to the development of diet-induced obesity compared to the C57BL/6 and apoA-I−/− mice. Morphological, biochemical and molecular analyses revealed that the LCAT−/− obese mice developed OA, while the C57BL/6 mice that were fed WTD did not. Notably, apoA-I−/− mice that received WTD also developed OA although their body-weight gain was similar to their wild-type counterparts. Interestingly, bone marrow from LCAT−/− and apoA-I−/− mice contained significantly increased number of adipocytes, compared to the other groups. Conclusions: Our findings suggest that perturbations in HDL metabolism predispose to OA following chronic insult with WTD and raise the challenging possibility that HDL has a causative relation to OA in patients with metabolic syndrome. [ABSTRACT FROM AUTHOR]

Apolipoprotein A-I and Apolipoprotein E promote different steps of reverse cholesterol transport, including lecithin-cholesterol acyltransferase stimulation. Our aim was to study the changes in the levels of Apolipoprotein A-I, Apolipoprotein E, and lecithin-cholesterol acyltransferase activity during atherosclerosis progression in rabbits. Quantitative echocardiographic parameters were analyzed in order to evaluate, for the first time, whether atherosclerosis progression in rabbit is associated to apolipoproteins changes and alteration of indices of cardiac function, such as systolic strain and strain rate of the left ventricle. Atherosclerosis was induced by feeding rabbits for 8 weeks with 2 % cholesterol diet. The HDL levels of cholesterol and cholesteryl esters were measured by HPLC. The lecithin-cholesterol acyltransferase activity was evaluated both ex vivo, as cholesteryl esters/cholesterol molar ratio, and in vitro. Apolipoproteins levels were analyzed by ELISA. The HDL levels of cholesterol and cholesteryl esters increased, during treatment, up to 3.7- and 2.5-fold, respectively, compared to control animals. The lecithin-cholesterol acyltransferase activity in vitro was halved after 4 weeks. During cholesterol treatment, Apolipoprotein A-I level significantly decreased, whereas Apolipoprotein E concentration markedly increased. The molar ratio Apolipoprotein E/Apolipoprotein A-I was negatively correlated with the enzyme activity, and positively correlated with both increases in the intima-media thickness of common carotid wall and cardiac dysfunction signs, such as systolic strain and strain rate of the left ventricle. [ABSTRACT FROM AUTHOR]

Context: Long pepper, Piper longum Linn. (Piperaceae), is widely used in traditional Mongolian medicine for treating hyperlipidemia and coronary heart disease. Objective: To investigate the hypolipidemic effects of a new piperine derivative GB-N isolated from long pepper in high-fat diet-fed rats. Methods: The levels of serum total cholesterol, triacylglycerols (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were determined by enzymatic colorimetric method. The levels of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA), CYP7A1, lecithin cholesterol acyltransferase (LCAT) and LDL receptor (LDLR) mRNA and protein expression were detected by real-time polymerase chain reaction and western blot analysis. Results and discussion: Compared with model rats, oral administration of GB-N at doses of 2.5-10 mg/kg to hyperlipidemic rats could significantly decrease the levels of serum TG from 1.54 mmol/L in hyperlipidemic rats to 0.94-1.02 mmol/L, with an increase in serum HDL-C levels from 0.40 mmol/L in hyperlipidemic rats to 1.21-2.26 mmol/L. Treatment with GB-N (10 mg/kg) could also significantly upregulate levels of hepatic HMG-CoA reductase, CYP7A1, LCAT and LDLR mRNA and protein expression. Conclusion: GB-N had hypolipidemic activity via regulating lipid metabolism pathways in liver of hyperlipidemic rats and could be explored as a potential agent for the prevention of hyperlipidemia diseases. [ABSTRACT FROM AUTHOR]

Lecithin cholesterol acyl transferase (LCAT) is a plasma enzyme that esterifies cholesterol and raises high-density lipoprotein cholesterol, but its role in atherosclerosis is not clearly established. Studies of various animal models have yielded conflicting results, but studies done in rabbits and non-human primates, which more closely simulate human lipoprotein metabolism, indicate that LCAT is likely atheroprotective. Although suggestive, there are also no biomarker studies that mechanistically link LCAT with cardiovascular disease. Imaging studies of patients with LCAT deficiency have also not yielded a clear answer to the role of LCAT in atherosclerosis. Recombinant LCAT, however, is currently being developed as a therapeutic product for enzyme replacement therapy of patients with genetic disorders of LCAT for the prevention and/or treatment of renal disease, but it may also have value for the treatment of acute coronary syndrome. [ABSTRACT FROM AUTHOR]

Abstract: The solvatochromic fluorescent probe 8-anilino-1-naphthalenesulfonate (ANS) has been used to study the hydrophobicity and conformational dynamics of lecithin:cholesterol acyltransferase (LCAT). The ANS to LCAT binding constant was estimated from titrations with ANS, keeping a constant concentration of LCAT (2μM). Apparent binding constant was found to be dependent on the excitation. For the direct excitation of ANS at 375nm the binding constant was 4.7μM−1 and for UV excitation at 295nm was 3.2μM−1. In the later case, not only ANS but also tryptophan (Trp) residues of LCAT is being excited. Fluorescence spectra and intensity decays show an efficient energy transfer from tryptophan residues to ANS. The apparent distance from Trp donor to ANS acceptor, estimated from the changes in donor lifetime was about 3nm and depends on the ANS concentration. Steady-state and time-resolved fluorescence emission and anisotropies have been characterized. The lifetime of ANS bound to LCAT was above 16ns which is characteristic for it being in a hydrophobic environment. The ANS labeled LCAT fluorescence anisotropy decay revealed the correlation time of 42ns with a weak residual motion of 2.8ns. These characteristics of ANS labeled LCAT fluorescence show that ANS is an excellent probe to study conformational changes of LCAT protein and its interactions with other macromolecules. [Copyright &y& Elsevier]

Abstract: In families, well-known monogenic high-density lipoprotein cholesterol (HDL-C) disorders characterized by extreme HDL-C levels on both ends of the continuum occur in multiple HDL pathways and can confer increased risk for atherosclerotic disease. Polygenic HDL-C variants have been more difficult to identify. In many family and twin studies in different populations, HDL-C levels have been shown to be highly heritable, explaining, on average, between 40% and 60% of between-individual variation. This review of abnormal HDL in families addresses known monogenic HDL disorders and HDL-C heritability in the general population, and presents novel data on the heritability of HDL-C in families with a history of premature coronary artery disease. We conclude that levels of HDL-C and HDL abnormalities are largely under genetic control and environmental and behavioral factors alone have only a modest impact. While rare, monogenic disorders offer considerable insight into the genetics of HDL regulation. Moderate to high heritability estimates across different family populations suggest that future genetic studies will be successful in identifying HDL genetic trait loci and that translational studies will ultimately lead to therapies that optimize the cardiovascular protective benefits of HDL. [Copyright &y& Elsevier]

Lecithin cholesterol acyltransferase (LCAT) is a key enzyme in the metabolism of high density lipoprotein (HDL), which has been found inversely correlated with atherosclerosis. Adenovirus mediated overexpression of human LCAT (hLCAT) in hamsters resulted in increased levels of plasma total cholesterol, HDL cholesterol, phospholipids and enlarged particle size of HDL. It also increased cholesterol and total bile acid concentrations in bile. Hepatic mRNA level of cholesterol 7α-hydroxylase increased 2.7-fold in hamsters. However, such effects were not observed in mice in a parallel experiment. This study suggests that overexpression of hLCAT in hamsters facilitated reverse cholesterol transport. Similar metabolic changes in humans might modify atherogenic risk. [Copyright &y& Elsevier]

Lecithin cholesterol acyltransferase (LCAT) is a lipid-modification enzyme that catalyzes the transfer of the acyl chain from the second position of lecithin to the hydroxyl group of cholesterol (FC) on plasma lipoproteins to form cholesteryl acylester and lysolecithin. Familial LCAT deficiency is an intractable autosomal recessive disorder caused by inherited dysfunction of the LCAT enzyme. The disease appears in two different phenotypes depending on the position of the gene mutation: familial LCAT deficiency (FLD, OMIM 245900) that lacks esterification activity on both HDL and ApoB-containing lipoproteins, and fish-eye disease (FED, OMIM 136120) that lacks activity only on HDL. Impaired metabolism of cholesterol and phospholipids due to LCAT dysfunction results in abnormal concentrations, composition and morphology of plasma lipoproteins and further causes ectopic lipid accumulation and/or abnormal lipid composition in certain tissues/cells, and serious dysfunction and complications in certain organs. Marked reduction of plasma HDL-cholesterol (HDL-C) and corneal opacity are common clinical manifestations of FLD and FED. FLD is also accompanied by anemia, proteinuria and progressive renal failure that eventually requires hemodialysis. Replacement therapy with the LCAT enzyme should prevent progression of serious complications, particularly renal dysfunction and corneal opacity. A clinical research project aiming at gene/cell therapy is currently underway.

Lecithin:cholesterol acyltransferase (LCAT) and LCAT-activating compounds are being investigated as treatments for coronary heart disease (CHD) and familial LCAT deficiency (FLD). Herein we report the crystal structure of human LCAT in complex with a potent piperidinylpyrazolopyridine activator and an acyl intermediate-like inhibitor, revealing LCAT in an active conformation. Unlike other LCAT activators, the piperidinylpyrazolopyridine activator binds exclusively to the membrane-binding domain (MBD). Functional studies indicate that the compound does not modulate the affinity of LCAT for HDL, but instead stabilizes residues in the MBD and facilitates channeling of substrates into the active site. By demonstrating that these activators increase the activity of an FLD variant, we show that compounds targeting the MBD have therapeutic potential. Our data better define the substrate binding site of LCAT and pave the way for rational design of LCAT agonists and improved biotherapeutics for augmenting or restoring reverse cholesterol transport in CHD and FLD patients., Competing Interests: KM, SY, BB, LC, AG, WY, LF, DM, AS, AR, AJ, JT No competing interests declared

Rationale: Low high-density lipoprotein-cholesterol (HDL-C) in patients with coronary heart disease (CHD) may be caused by rate-limiting amounts of lecithin:cholesterol acyltransferase (LCAT). Raising LCAT may be beneficial for CHD, as well as for familial LCAT deficiency, a rare disorder of low HDL-C., Objective: To determine safety and tolerability of recombinant human LCAT infusion in subjects with stable CHD and low HDL-C and its effect on plasma lipoproteins., Methods and Results: A phase 1b, open-label, single-dose escalation study was conducted to evaluate safety, tolerability, pharmacokinetics, and pharmacodynamics of recombinant human LCAT (ACP-501). Four cohorts with stable CHD and low HDL-C were dosed (0.9, 3.0, 9.0, and 13.5 mg/kg, single 1-hour infusions) and followed up for 28 days. ACP-501 was well tolerated, and there were no serious adverse events. Plasma LCAT concentrations were dose-proportional, increased rapidly, and declined with an apparent terminal half-life of 42 hours. The 0.9-mg/kg dose did not significantly change HDL-C; however, 6 hours after doses of 3.0, 9.0, and 13.5 mg/kg, HDL-C was elevated by 6%, 36%, and 42%, respectively, and remained above baseline ≤4 days. Plasma cholesteryl esters followed a similar time course as HDL-C. ACP-501 infusion rapidly decreased small- and intermediate-sized HDL, whereas large HDL increased. Pre-β-HDL also rapidly decreased and was undetectable ≤12 hours post ACP-501 infusion., Conclusions: ACP-501 has an acceptable safety profile after a single intravenous infusion. Lipid and lipoprotein changes indicate that recombinant human LCAT favorably alters HDL metabolism and support recombinant human LCAT use in future clinical trials in CHD and familial LCAT deficiency patients., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01554800., (© 2015 American Heart Association, Inc.)