ABCG1 Research Articles

Therapeutic Potential of Resveratrol and Atorvastatin Following High-Fat Diet Uptake-Induced Nonalcoholic Fatty Liver Disease by Targeting Genes Involved in Cholesterol Metabolism and miR33

The present study was designed to evaluate the effects of resveratrol, atorvastatin, and a combination of resveratrol and atorvastatin on expression levels of genes involved in the cholesterol metabolic pathway in the fatty liver of C57/BL6 mice. A high-fat diet was used to induce fatty liver in C57/BL6 mice treated with resveratrol, atorvastatin, or a combination of resveratrol and atorvastatin. Pathological and biochemical studies were performed. In addition, hepatic gene expressions of ATP-binding cassette transporter A1 (ABCA1), ABCG1, liver X receptor (LXR)α, scavenger receptor B1 (SR-B1), low-density lipoprotein receptor (LDLR), and miR33 were evaluated by the real-time PCR method, and the Western blot method was used to measure the ABCA1, ABCG1, and LXRα protein levels. Resveratrol and atorvastatin reduced fat accumulation in the liver of mice with fatty liver, and this effect was correlated with decreased blood glucose levels, triglyceride, cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol blood levels compared with the positive control (PC) group. In contrast to the animals of the PC group, fatty liver groups that received resveratrol and atorvastatin had a significant effect on the mRNA levels of the ABCA1, ABCG1, LXRα, SR-B1, LDLR, and miR33 genes. Moreover, resveratrol and atorvastatin administration elevated ABCA1 and ABCG1 and reduced LXRα protein expression. Obtained results showed that resveratrol and atorvastatin combination therapy can improve nonalcoholic fatty liver disease by targeting genes involved in cholesterol metabolism and miR33.

Cholestasis in the First Trimester Associated with Rare ABCG5/8 Variants: A Case Study

Background:Obstetric cholestasis, or intrahepatic cholestasis of pregnancy (ICP), is a liver disease that usually presents in the third trimester of pregnancy. It is characterized by pruritis that is associated with elevated liver enzymes and bile acids. This condition can have potentially serious effects on the fetus due to the buildup of serum bile acids resulting from the obstruction of bile flow.
 Case Overview:A 28-year-old patient, who was pregnant for the third time, developed pruritis in the first trimester and presented with blood work that showed elevated total bile acids and liver enzymes. A medical history revealed similar symptoms amongst her female relatives during their pregnancies as well as the patient’s own previous pregnancies, suggesting a genetic component in the etiology of the disease. Genetic testing supported this hypothesis and showed variants of unknown significance that indicated a duplication in the ABCG5 and ABCDG8 genes.
 Discussion:This finding was rather unusual as these genes have not yet been clinically associated with ICP. The ABCG5 and ABCG8 genes code for canicular bile transporters in the liver that transport cholesterol into the bile. Overexpression of these transporters due to the duplication in her genes may result in increased transport of cholesterol into bile, disrupting the regular composition of bile. The resulting increased bile viscosity may cause bile stasis or blockage, and this proposed mechanism can possibly explain the pathophysiology behind this unusual case of cholestasis.
 Conclusion and Potential Impact:ICP can have potential serious effects on the developing fetus, and its etiology is still being understood. The novel ABCG5/8 gene duplication is a novel variant that may lead to earlier onset of ICP than commonly known variants.

Diterpenoids inhibit ox-LDL-induced foam cell formation in RAW264.7 cells by promoting ABCA1 mediated cholesterol efflux.

Introduction: Atherosclerosis is the main cause of many cardiovascular diseases and contributes to morbidity and mortality worldwide. The formation of macrophage-derived foam cells plays a critical role in the early stage of atherosclerosis pathogenesis. Diterpenoids found in the flowers of Callicarpa rubella Lindl., a traditional Chinese medicine, have been reported to have anti-inflammatory activity. However, little is known about the effects of these diterpenoids on macrophage foam cell formation. Methods: A macrophage-derived foam cell formation model was established by treating RAW264.7 cells with oxidized low-density lipoprotein (ox-LDL) for 24 h. Oil red O staining were used to detect the intracellular lipids. The cholesterol efflux capacity was assayed by labeling cells with 22-NBD-cholesterol. Western blots and real-time PCRs were performed to quantify protein and mRNA expressions. Results: Two diterpenoid molecules, 14α-hydroxyisopimaric acid (C069002) and isopimaric acid (C069004), extracted from the flowers of Callicarpa rubella Lindl., significantly attenuated ox-LDL-induced foam cell formation in RAW264.7 macrophages. Further investigation showed that these two diterpenoids could promote cholesterol efflux from RAW264.7 macrophages to apolipoprotein A-I or high-density lipoproteins, which was associated with upregulated expression of ATP-binding cassette A1/G1 (ABCA1/G1), liver X receptor-α (LXRα), and peroxisome proliferator-activated receptor-γ (PPARγ). Unexpectedly, the diterpenoids C069002 and C069004 failed to enhance the mRNA transcription of the ABCG1 gene in macrophage-derived foam cells induced by ox-LDL. To evaluate the effects of diterpenoids on macrophage foam cell formation and determine the underlying mechanism, two drugs (lovastatin and rosiglitazone) were used as positive controls. Although both drugs could reduce macrophage foam cell formation and promote cholesterol efflux, they each had distinctive abilities to modulate the expression of cholesterol efflux-related genes. In contrast to lovastatin, rosiglitazone showed a similar influence on the expression of cholesterol efflux-related genes (including ABCA1, LXRα, and PPARγ) as the diterpenoids regardless of the presence or absence of ox-LDL, implying a similar mechanism by which they may exert atheroprotective effects. Conclusion: Our research indicates that diterpenoids effectively inhibit ox-LDL-induced macrophage foam cell formation by promoting cholesterol efflux from macrophages via the PPARγ-LXRα-ABCA1 pathway. Further investigation of diterpenoids as potential drugs for the treatment of atherosclerosis is warranted.

Screening for Pathogenic Genetic Variants of APOA1 and ABCG1 Genes Associated with Dyslipidemia in Type 2 Diabetic Patients

Screening for Pathogenic Genetic Variants of APOA1 and ABCG1 Genes Associated with Dyslipidemia in Type 2 Diabetic Patients

Clinical analysis of 4 children with hereditary hypercholesterolemia

Objective: To investigate the clinical characteristics of hereditary hypercholesterolemia in childhood. Methods: The clinical data including general conditions, clinical manifestations, laboratory tests, and genetic testing results of 4 children with hereditary hypercholesterolemia who admitted to Henan Children's Hospital from January 2020 to December 2020 were retrospectively analyzed. Results: There were 4 female children aged 5.5,1.5,6.3,3.1 years, all presented with skin xanthoxoma as the chief complaint. Plasma total cholesterol (range 11.8 to 20.9 mmol/L) and low density lipoprotein-cholesterol (range 8.2 to 13.7 mmol/L) were significantly elevated. The serum β-glutamate levels in case 1 (241.2 μmol/L) and case 2 (164.2 μmol/L) increased significantly. Genetic analysis revealed compound heterozygous variants of ABCG8 gene in case 1 and ABCG5 gene in case 2 who were diagnosed with sitosterolemia. Case 3 and 4 who all had family history of hypercholesterolemia and compound heterozygous variants of LDLR gene were diagnosed with familial hypercholesterolemia. After diet treatment, the blood lipids returned normal and the skin xanoma subsided in case 1 and 2. In case 3 and 4, the blood lipids gradually decreased after diet and rosuvastatin treatment. Conclusions: Xanthomatosis is the common clinical manifestation of sitosterolemia and familial hypercholesterolemia. Family history, blood plant sterol profile, genetic variation, and changes in blood lipids after early dietary treatment are helpful for disease identification.

Genetic analysis of a rare form of dyslipidemia: De novo ABCG5/APOB mutations in Greece

Background and Aims : Sitosterolemia is a rare autosomal recessive inherited metabolic disorder of lipids, characterized by increased levels of plant sterols in plasma. It is caused by mutations in gABCG5 or ABCG8 genes and recent studies have revealed the fact that heterozygous mutation carriers also exhibit milder manifestations.

The Effect of Combined Training on ABCG5 and ABCG8 in Coronary Artery Bypass Graft Patients

Aims Coronary heart disease is one of the leading causes of mortality in modern societies. The disease is associated with the lack of physical activity and the expression of some genes involved in blood cholesterol transportation. Adenosine triphosphate (ATP)-binding cassette transporters G5/G8) ABCG5 and ABCG8) is the expression of adenosine triphosphate-dependent box protein genes 5 and 8, a member of the ABC transporter family, playing a crucial role in high-density lipoprotein cholesterol and lipoproteins metabolism. The action of ABCG5/8 is to remove cholesterol and decrease its toxicity. The increased activity of these two factors may prevent atherosclerosis. This study aims to investigate the effect of eight weeks of aerobic resistance training on ABCG5 and ABCG8 gene expression in coronary artery bypass grafting (CABG) patients. Methods & Materials The research population included 30 men voluntarily selected and randomly divided into an experimental (n=15) and control (n=15) group. The experimental group performed aerobic resistance training for eight weeks (3 sessions per week) and the control group had no exercise. The blood samples were taken 48 hours before the beginning of the first training session and 48 hours after the last training session while all subjects were fasting. Semi-quantitative polymerase chain reaction (PCR) was used to measure the expression of ABCG5 and ABCG8 genes. To analyze the data, independent and paired t tests were used at the significant level of 0.05 in SPSS software, version 21. Findings The present study results showed that the aerobic resistance training group experienced a significant increase in the messenger ribonucleic acid (mRNA) expression of ABCG5 and ABCG8 genes as a result of eight weeks of aerobic resistance training compared to the control group. Conclusion Based on the findings of the present study, it is possible to suggest that aerobic resistance training increases the expression of ABCG5 and ABCG8 genes, and improves the cholesterol transportation process, which may improve recovery of coronary artery bypass grafting (CABG) patients and prevent cardiovascular diseases.

*A Novel ABCG8 Variant and Apo(A) Short Isoform Associated with Premature Atherosclerosis and Familial Hypercholesterolemia Phenocopy.

Lead Author's Financial Disclosures Nothing to disclose. Study Funding None. Background/Synopsis We report a patient with a rare ABCG8 mutation, that when combined with Apo(a) short isoforms may represent a familial hypercholesterolemia (FH) phenocopy. Objective/Purpose A 44-year-old African American male with prior myocardial infarction (MI) at the age 24 with subsequent coronary artery bypass graft who had rapid progression of atherosclerosis despite having a corrected LDL of zero. Methods Lp(a) was 127 mg/dL and LDL was 40 mg/dL and he had been on evolocumab and rosuvastatin. The corrected LDL accounts for the cholesterol contained in Lp(a) using the formula LDLcorr =LDL- 0.3x Lp(a) mass. Thus, his LDLcorr was zero. He underwent genetic testing with GBinsight which demonstrated he had Apo(a) short isoforms, which is associated with elevated Lp(a). He was also heterozygous for an extremely rare ABCG8 variant p.Gly212Glu (rs1318623110) which has not been previously reported. This variant is predicted to be deleterious and Gly212 is highly conserved across vertebrates. Mutations in ABCG5 or ABCG8 can be associated with increased LDL and risk for CAD. In addition, elevation of Lp(a) can be associated with 3 to 4 folds increased risk. This novel mutation, along with the elevated Lp(a) may help to explain his FH phenocopy presentation. Results We hypothesized that his premature disease progression may have been secondary to inflammation, atherogenesis or prothrombosis associated with Lp(a) with the added potentially deleterious effect of the ABCG8 mutation. His clinical course with his first MI at age 24 mimics that of FH, thus making him a phenocopy. We enrolled him in the randomized Lp(a)HORIZON trial evaluating the effect of pelacarsen in lowering Lp(a). However, he subsequently had an episode of unstable angina requiring additional intervention. Conclusions When assessing patients with suspected FH, mutations in genes other than LDLR, APOB, and PCSK9 should be evaluated. In this case, a mutation in ABCG8 gene along with Apo(a) short form isoforms may help explain the patient's disease progression and FH phenocopy presentation. In addition, ezetimibe may be beneficial in patients with ABCG5/8 mutation. His marked disease progression despite having a LDLcorr of zero highlights the importance of considering factors other than just LDL. Nothing to disclose.

Bariatric Surgery-induced High-density Lipoprotein Functionality Enhancement Is Associated With Reduced Inflammation.

Emerging evidence suggests an association between impaired high-density lipoprotein (HDL) functionality and cardiovascular disease (CVD). HDL is essential for reverse cholesterol transport (RCT) and reduces inflammation and oxidative stress principally via paraoxonase-1 (PON1). RCT depends on HDL's capacity to accept cholesterol (cholesterol efflux capacity [CEC]) and active transport through ATP-binding cassette (ABC) A1, G1, and scavenger receptor-B1 (SR-B1). We have studied the impact of Roux-en-Y gastric bypass (RYGB) in morbidly obese subjects on RCT and HDL functionality. Biomarkers associated with increased CVD risk including tumour necrosis factor-α (TNF-α), high-sensitivity C-reactive protein (hsCRP), myeloperoxidase mass (MPO), PON1 activity, and CEC in vitro were measured in 44 patients before and 6 and 12 months after RYGB. Overweight but otherwise healthy (mean body mass index [BMI] 28 kg/m2) subjects acted as controls. Twelve participants also underwent gluteal subcutaneous adipose tissue biopsies before and 6 months after RYGB for targeted gene expression (ABCA1, ABCG1, SR-B1, TNF-α) and histological analysis (adipocyte size, macrophage density, TNF-α immunostaining). Significant (P < 0.05) improvements in BMI, HDL-cholesterol, hsCRP, TNF-α, MPO mass, PON1 activity, and CEC in vitro were observed after RYGB. ABCG1 (fold-change, 2.24; P = 0.005) and ABCA1 gene expression increased significantly (fold-change, 1.34; P = 0.05). Gluteal fat adipocyte size (P < 0.0001), macrophage density (P = 0.0067), and TNF-α immunostaining (P = 0.0425) were reduced after RYBG and ABCG1 expression correlated inversely with TNF-α immunostaining (r = -0.71; P = 0.03). RYGB enhances HDL functionality in association with a reduction in adipose tissue and systemic inflammation.

A systematic review and metaanalysis of observational studies on the effects of epigenetic factors on serum triglycerides.

Epigenetic modifications might be associated with serum triglycerides (TG) levels. This study aims to systematically review the studies on the relationship between the methylation of specific cytosine-phosphate-guanine (CpG) sites and serum TG levels. This systematic review and meta-analysis study was conducted according to the PRISMA 2020 (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. A systematic literature search was conducted in Medline database (PubMed), Scopus, and Cochrane library up to end of 2020. All observational studies (cross-sectional, case-control, and cohort) were included. Studies that assessed the effect of DNA methylation of different CpG sites of ABCG1, CPT1A, and SREBF1 genes on serum TG levels were selected. The National Institutes of Health (NIH) checklist was used to assess the quality of included articles. Among 2790 articles, ten studies were included in the quantitative analysis and fourteen studies were included in the systematic review. DNA methylation of ABCG1 gene had significant positive association with TG levels (β = 0.05, 95% CI = 0.04, 0.05, P heterogeneity < 0.001). There was significant inverse association between DNA methylation of CPT1A gene and serum TG levels (β = -0.03, 95% CI = -0.03, -0.02, P heterogeneity < 0.001). DNA methylation of SREBF1 gene was positively and significantly associated with serum TG levels (β = 0.03; 95% CI = 0.02-0.04, P heterogeneity < 0.001). DNA methylation of ABCG1 and SREBF1 genes has positive association with serum TG level, whereas this association is opposite for CPT1A gene. The role of epigenetic factors should be considered in some populations with high prevalence of hypertriglyceridemia.

Abstract 452: Classification And Effect Of Correctors On ABCG8 Sitosterolemia Associated Cytosolic Mutants

Background: Sitosterolemia is a rare form of Familial Hypercholesterolemia (FH) which is unique from other forms of FH due to the accumulation of phytosterols in the plasma and tissues. Sitosterolemia is autosomal recessive and caused by mutations in either the ABCG5 or ABCG8 gene. ABCG5 and ABCG8 form a heterodimer (ABCG5/ABCG8) that functions at the apical surface of hepatocytes and enterocytes to promote cholesterol and phytosterol excretion. Small molecule modulators classified as either correctors or potentiators have therapeutic benefit when used to treat mutants of ABCB4 (PFIC3) or ABCC7 (Cystic Fibrous) that have impaired folding, stability, or activity. There are over 40 missense mutations in ABCG5/ABCG8 which have been clinically confirmed in patients with Sitosterolemia. Methods: We developed a classification system for ABCG5 and ABCG8 mutations based on the underlying molecular defect for ABCG5/ABCG8 dysfunction (maturation, trafficking, activity, etc.). We used site directed mutagenesis to introduce ABCG8 missense mutations located in the N-terminal, cytosolic domain of human ABCG8. Normal and mutant ABCG5/ABCG8 constructs were transiently transfected into a human hepatocyte cell line, Huh-7, and analyzed for heterodimerization, trafficking beyond the ER, and localization at the cell surface. Results: Of the ABCG8 cytosolic mutants studied, R184H, L196Q, L228P, and R263Q failed to traffic beyond the ER to form a stable heterodimer (class II) while P231T, T400K, N409D, N409I, and P415H were trafficking competent. Conclusions: Forty four percent (4 of 9) of cytosolic, ABCG8 mutations that cause Sitosterolemia are due to failures in complex formation and trafficking beyond the ER. Fifty six (5 of 9) percent were trafficking competent, indicating a stable ABCG5/G8 complex, but loss of activity due to impaired ATP hydrolysis or substrate binding. ABCG8 mutants may be potentially restored by proteostatic regulators and/or potentiators &amp; correctors that have shown to be effective in disease-causing mutations in other ABC transporters.

Captopril and Spironolactone can Attenuate Diabetic Nephropathy in Wistar Rats by Targeting ABCA1 and microRNA-33.

Nephropathy diabetes is one of the important causes of death and a more prevalent cause of end-stage renal disease. The present study investigated the effect of applying spironolactone and captopril and their combination on some renal performance indices and cholesterol-efflux-related gene expression in nephropathy diabetic rats. Intraperitoneal injection of streptozotocin was used to induce diabetes in rats. FBS, creatinine, and BUN were assayed using the calorimetry technique; also, urine microalbumin was assayed by ELISA. Hepatic gene expressions of ABCA1, ABCG1, and miR-33 were evaluated by the real-time PCR method. FBS levels in the captopril-treated group were significantly decreased compared with the untreated diabetic group. BUN levels of treated groups with captopril and a combination of captopril + spironolactone were significantly increased. GFR of both treated diabetic groups with captopril and spironolactone was significantly lower than an untreated diabetic group. ABCA1 gene expression in hepatic cells of the combination of spironolactone + captopril treated group was significantly increased compared to other treated and untreated diabetic groups. The hepatic expression of the ABCG1 gene in the treated and untreated diabetic groups was significantly lower than in the control group. Treatment of the diabetic group with only combination therapy decreased the hepatic gene expression of miR-33 significantly. Obtained results suggest that S+C combination therapy can improve nephropathy and diabetes disorders by targeting the ABCA1 and miR-33 gene expression. It is suggested that miR-33 and ABCA1 genes evaluation could be a new therapeutic strategy for nephropathy diabetes remediation.

Identification and action mechanism of lipid regulating components from Rhei Radix et rhizoma

Ethnopharmacological relevanceRhei Radix et Rhizoma is widely used in Traditional Chinese Medicine to attack stagnation, clear damp heat, relieve fire, cool blood, remove blood stasis and detoxify recorded in Chinese Pharmacopoeia. Modern pharmacological research has showed the extract of Rhei Radix et Rhizoma has the effect of lowering blood lipids, but the main active components and their mechanisms are still not clear. Aim of the studyTo reveal the lipid regulating components from Rhei Radix et Rhizoma and preliminarily explore their related action mechanisms. Materials and methodsA rat model of dyslipidemia was established by administration of a high-fat emulsion via gavage, and the intervention effect of different polar fractions of Rhei Radix et Rhizoma on rat blood lipids as well as their related action mechanisms were preliminarily investigated. The effective components were inferred based on the above tests and identified by high performance liquid chromatography in comparison with reference substances, their UV absorption and high resolution mass spectra characteristics. ResultsThe extract with dichloromethane fraction (DF) containing rhubarb free anthraquinones (aloe-emodin, rhein, emodin, chrysophanol and physcion) significantly regulated the disordered blood lipids, lowered TC and LDLC, reversed TG and increased HDLC level in dyslipidemic rats and also showed lipid-lowering effect on lipid abnormalities in HepG2 cells. DF could alter the signaling pathways such as PPARα and AMPK implicated in lipid metabolism, and it down-regulated the mRNA expression of liver APOA2, SCD-1, HMGCR, SREBP-2 and PCSK9, but up-regulated the expressions of liver APOE, LPL and intestinal ABCG8. Besides, it could change the composition of Firmicutes, Bacteroidetes and Proteobacteria in dyslipidemic rat feces samples. ConclusionsRhubarb free anthraquinones have a significant regulating effect on the levels of serum TC, LDLC and HDLC, and probably possess a bidirectional regulatory effect on TG level in dyslipidemic rats. These effects may be achieved by regulating the expressions of the liver PPARα and SREBP target genes, PCSK9 and the intestinal ABCG8 genes, which are involved in blood cholesterol transport, liver lipid metabolism and intestinal cholesterol excretion. Rhubarb free anthraquinones may also affect energy metabolism by changing the composition of gut microflora related to lipid metabolism in dyslipidemic rats.

The Effect of Combined Training Courses on the Expression of ABCG4 Gene and Interleukin-10 in Men after Coronary Artery Bypass Grafting

The Effect of Combined Training Courses on the Expression of ABCG4 Gene and Interleukin-10 in Men after Coronary Artery Bypass Grafting

Features of chinese patients with sitosterolemia

BackgroundSitosterolemia is a lipid disorder characterized by the accumulation of phytosterols in plasma and organs, caused by mutations in the ABCG5 and/or ABCG8 genes. The disease is frequently misdiagnosed and mistreated as familial hypercholesterolemia (FH). To gain a better understanding of the disease, the current status of diagnosis and treatment of Chinese patients with sitosterolemia was reviewed and summarized.MethodLiterature search was performed. The clinical features and molecular characteristics of Chinese patients with sitosterolemia were analysed. Four children with sitosterolemia and the treatment experience were described.ResultsFifty-five patients with sitosterolemia have been reported in China. These patients were aged from 3 months to 67 years at diagnosis, and the median was 8 years of age. Several complications, such as xanthomas in 47 patients (85%), thrombocytopenia in 17 patients (31%), anemia in 14 patients (25%), and cardiovascular damage in 12 patients (22%), were observed. Thirty-nine patients (71%) exhibited mutations in the ABCG5 gene, 15 patients (27%) showed mutations in ABCG8, and variations in both genes occurred in one patient (2%). A patient with two clinically rare diseases, namely, sitosterolemia and glycogen storage disease type VI (GSD VI)), is reported here for the first time. The four reported patients were treated with low cholesterol and phytosterol-limited diet alone or combined with cholestyramine. Even though decreases were observed for total plasma cholesterol (TC) and low-density-lipoprotein cholesterol (LDL-C), and these levels were as low as normal in some patients, the levels of plant sterols remained above the normal range. However, TC, LDL-C and plant sterol levels remained at high levels in patients treated with a control diet control only.ConclusionsThe analysis reveals that different from Caucasians carrying mainly variations in ABCG8, most Chinese patients have mutations in the ABCG5 gene, and Arg446Ter, Gln251Ter, anArg389His might be hot-spot mutations in Chinese patients. The current survey provides clinical data to enable the development of a standardized protocol for the diagnosis and treatment of sitosterolemia in China.

Knockout of ABC Transporter ABCG4 Gene Confers Resistance to Cry1 Proteins in Ostrinia furnacalis.

Ostrinia furnacalis is an important borer on maize. Long-term and large-scale planting of transgenic corn has led O. furnacalis evolving resistance and reducing the control effect. Recently, high levels of resistance to Bt Cry1 toxins have been reported to be genetically linked to the mutation or down-regulation of ABC transporter subfamily G gene ABCG4 in O. furnacalis. In order to further determine the relationship between ABCG4 gene and the resistance to Cry1 toxins in O. furnacalis, the novel CRISPR/Cas9 genome engineering system was utilized to successfully construct ABCG4-KO knockout homozygous strain. Bioassay results indicated that an ABCG4-KO strain had a higher resistance to Cry1 proteins compared with a susceptible strain (ACB-BtS). The result indicates that the ABCG4 gene may act as a receptor of the Bt Cry1 toxin in O. furnacalis. Furthermore, the development time was significantly changed in the early stage ABCG4-KO larvae, and the population parameters were also significantly changed. In summary, our CRISPR/Cas9-mediated genome editing study presents evidence that ABCG4 gene is a functional receptor for Bt Cry1 toxins, laying the foundation for further clarification of the Bt resistance mechanism.

ABCA1 and ABCG1 DNA methylation in epicardial adipose tissue of patients with coronary artery disease

BackgroundRecent studies have focused on the potential role of epicardial adipose tissue (EAT) in the development of coronary artery disease (CAD). ABCA1 and ABCG1 transporters regulate cell cholesterol content and reverse cholesterol transport. We aimed to determine whether DNA methylation and mRNA levels of the ABCA1 and ABCG1 genes in EAT and subcutaneous adipose tissue (SAT) were associated with CAD.MethodsPaired EAT and SAT samples were collected from 82 patients undergoing elective cardiac surgery either for coronary artery bypass grafting (CAD group, N = 66) or valve surgery (NCAD group, N = 16). ABCA1 and ABCG1 mRNA levels in EAT and SAT samples were analyzed using real time polymerase chain reaction, ABCA1 protein levels in EAT samples were assessed by western blotting. ABCA1 and ABCG1 DNA methylation analysis was performed in 24 samples from the CAD group and 9 samples from the NCAD group via pyrosequencing.ResultsDNA methylation levels in the ABCA1 promoter and ABCG1 cg27243685 and cg06500161 CpG sites were higher in EAT samples from patients with CAD compared with NCAD (21.92% vs 10.81%, p = 0.003; 71.51% vs 68.42%, p = 0.024; 46.11% vs 37.79%, p = 0.016, respectively). In patients with CAD, ABCA1 and ABCG1 DNA methylation levels were higher in EAT than in SAT samples (p < 0.05). ABCA1 mRNA levels in EAT samples were reduced in the subgroup of patients with CAD and concomitant carotid artery disease or peripheral artery disease compared with the NCAD group (p = 0.024). ABCA1 protein levels in EAT samples tended to be lower in CAD patients than in the NCAD group (p = 0.053). DNA methylation levels at the ABCG1 cg27243685 site positively correlated with plasma triglyceride concentration (r = 0.510, p = 0.008), body mass index (r = 0.556, p = 0.013) and waist-to-hip ratio (r = 0.504, p = 0.012) in SAT samples.ConclusionCAD is associated with ABCA1 and ABCG1 DNA hypermethylation in EAT. CAD with concomitant carotid artery disease or peripheral artery disease is accompanied by decreased ABCA1 gene expression in EAT. DNA methylation levels at the ABCG1 cg27243685 locus in SAT are associated with hypertriglyceridemia and obesity.

Misdiagnosis of sitosterolemia in a patient as Evans syndrome and familial hypercholesterolemia

Sitosterolemia is a rare form of dyslipidemia that has diverse clinical manifestations, and insufficient knowledge of the disease frequently leads to a delay in diagnosis. We report a case of sitosterolemia in a 26-year-old Chinese woman, characterized by anemia, thrombocytopenia, persistent hypercholesterolemia, premature atherosclerosis, extensive xanthoma, and arthralgia-tenosynovitis. Successive misdiagnoses of Evans syndrome and familial hypercholesterolemia had been made, and the patient had responded minimally to steroid therapy, splenectomy, and statin treatment; therefore, she was referred to our hospital. On admission, a peripheral blood smear revealed the presence of abnormally shaped erythrocytes and giant platelets. Multiple atherosclerotic lesions, sites of tenosynovitis, and carotid sheath xanthomas were identified on ultrasonography. Compound heterozygous mutations of the ABCG5 gene, including a hot variant (c.1,336, exon10 C>T, p.(R446*)) and a novel variant (c.1,325-3(IVS9)_c.1325-2(IVS9)delCA) were separately identified in her parents by pedigree analysis. Plant sterols analysis by high performance liquid chromatography method revealed remarkably elevated plasma plant sterol concentrations after drug withdrawal but reduced rapidly after restarting ezetimibe during follow-up period. After 21 months of treatment with ezetimibe and a low-plant sterol diet, her hematologic abnormalities, tenosynovitis, and hypercholesterolemia had significantly improved; and ultrasonography showed that her skin and carotid sheath xanthomas had resolved or shrunk. This case demonstrates that morphological changes in blood cells on a peripheral blood smear, ultrasonographic findings and ABCG5/ABCG8 gene screening are valuable, and plant sterol analysis in serum is crucial to confirm diagnosis and assess treatment adequacy for sitosterolemia.

Evidence of Immunological Abnormalities in Sitosterolemia

Objectives: Mutations involving the ABCG8 gene cause sitosterolemia (STSL), a rare metabolic disease due to an abnormal plasmatic plant sterols level. STSL hematological findings include stomatocytic hemolysis and macrothrombocytopenia. So far, few cases of leukopenia have been reported and there are no studies that consider inflammatory activity. The purpose of our study is to evaluate immunological abnormalities in STSL and the effect of dietary and pharmacological treatment. Study Design: In a sitosterolemic patient presenting leukopenia and increased inflammatory indexes were evaluated in vitro interleukin 1B secretion from monocytes and type 1 interferon (IFN) signature. Besides, Stimulation Indexes (SI) of patient’s and two Healthy Controls’ (HCs) T-helper lymphocytes in response to proliferative stimuli were assessed, when incubated in enriched medium alternately with patient plasma or with AB Rh+ group control plasma. SI (compared to the same HCs) and IFN signature have been evaluated again three (T3) and six (T6) months apart, after patient received therapy. Results: Following treatment with Ezetimibe (EZE) and adequate diet, lower plasmatic plant sterols levels and progressive improvement of hematological and immunological abnormalities were observed. These data were confirmed by the negativization of IFN signature at T3 and by the progressive normalization at T3 and T6 of SI in patient’s and HCs’ T-helper lymphocytes incubated in patient’s plasma-enriched medium. Conclusion: High plasmatic phytosterols levels due to STSL seems to affect white blood cells proliferation and trigger pro-inflammatory process, justifying leukopenia and increased phlogosis indexes observed in our patient. These hypotheses are supported by normalization of clinical and laboratory data during EZE therapy. Take-home Message: Immunological abnormalities should be considered among the hematological manifestations of sitosterolemia, moreover high levels of plasma phytosterols could be a pro-inflammatory trigger. Treatment with ezetimibe seems to reverse these manifestations.

Genetic factors associated with alterations in liver function test results in adult hospitalized patients treated with parenteral nutrition: A substudy of a clinical trial

ObjectivesThe presence of phytosterols in vegetable-based lipid emulsions has been associated with alterations in the results of liver function tests (LFTs). Serum levels of phytosterols are under strict genetic control. T-allele carriers in rs41360247 and C-allele carriers in rs4245791 of ABCG8genes are associated with higher phytosterolemia. The objective of this study was to determine the association between these single-nucleotide polymorphisms (SNPs) and LFT result alterations in an adult hospitalized population treated with parenteral nutrition. MethodsThis is a substudy of a previous clinical trial (EudraCT 2014-003597-17). It included adult hospitalized patients who had received at least 7 d of parenteral nutrition with 0.8 g/kg/d of an olive/soybean lipid emulsion, randomized 1:1 to receive the same olive/soybean emulsion or 100% fish oil at a dose of 0.4 g/kg/d for 7 d. Plasma phytosterols and their fractions, rs41360247 and rs4245791 of ABCG8 genes, and LFT were determined. Analyses of variance were performed to determine the association between the SNPs and LFT values, as well as total phytosterol values and their fractions. Simple linear regressions were performed to analyze LFT variations and the different interactions of the SNPs studied with phytosterols and their fractions. Interactions of the synergic variable plasma phytosterol and its fractions with SNPs allow us to study the interaction of the SNPs with phytosterols with a regression. ResultsWe included 19 participants. In the multivariate model, total phytosterols, sitosterol, and lanosterol were positively associated with increases in γ-glutamyltransferase. Significant increases with stigmasterol were associated with the T allele of rs41360247, whereas campesterol showed only a tendency to increase that was not significant. Increases in alkaline phosphatase were associated with T-rs41360247 independent of the presence of phytosterols. With stigmasterol, C-allele carriers of rs4245791 showed a tendency to increase, and also for sitosterol and lanosterol, although independent of the SNP analyzed. Increases in alanine aminotransferase were positively associated with total phytosterol and sitostanol, whereas lanosterol and stigmasterol were associated with the presence of the T allele of rs41360247. ConclusionsWith both SNPs rs41360247 and rs4245791, the alteration in parameters of liver function in adult patients with short-term parenteral nutrition is conditional.