ABCG1 Research Articles

Gegen Qinlian Decoction Modulates Atherosclerosis and Lipid Metabolism Through Cellular Interplay and Signaling Pathways.

The objective of this study is to investigate Gegen Qinlian decoction (GQD) effects on lipid metabolism and explore its mechanism for preventing and treating atherosclerosis. An atherosclerotic rat model was established, and after an 8-week high-fat diet, atherosclerosis and non-alcoholic fatty liver disease were assessed. Subsequently, GQD was administered at low and high doses. Histopathological aortic wall changes, hepatic lipid deposition, and blood lipid changes were evaluated. ELISA indicated the influence of TNF-α and IL-13, and Western blotting revealed MerTK, ABCA1, and LXR-α expression. A foam macrophage model was established, and Cell activity was detected by the MTT method. ELISA indicated the influence of PPAR-γ. The expression of ABCA1, ABCA7, ABCG1, GAS6, MerTK, SCARB1, LXR- α and LXR-β mRNA were detected by qPCR. and Western blotting revealed MerTK and LXR-α expression. The impact of drug-containing serum of GQD on efferocytosis-related factors was studied. GQD improved atherosclerosis and non-alcoholic fatty liver disease and reduced serum low-density lipoprotein levels in the high-dose group. The high- and low-dose groups showed upregulated ABCA1, MerTK, and LXR-α expression in blood vessels and the liver, respectively. GQD decreased serum TNF-α and increased IL-13 levels. PPAR-γ expression was elevated in the high-, and low-dose groups. In the high-and low-dose groups, ABCA7, GAS6, SCARB1, and LXR-α, ABCA1 and MerTK, and ABCG1 gene expression were upregulated, respectively. Both low- and high-dose serum-containing drugs promoted LXR-β gene expression, and LXR-α protein expression was improved in the high-dose group. GQD improves rat atherosclerosis and hepatic lipid metabolism by regulating PPAR-γ, LXR-α, LXR-β, ABCA1, ABCA7, and ABCG1 expression and augmenting cellular intercalation through the GAS6/TAM pathway.

Compound heterozygous variants in the ABCG5 gene in a Korean boy with sitosterolemia.

Compound heterozygous variants in the ABCG5 gene in a Korean boy with sitosterolemia.

Peripheral Blood ABCG1 Gene DNA Methylation: Mediating the Relationship between Dietary Intake of Methyl Donor Nutrients and Stroke Risk

Dysregulation of methyl donor nutrients interferes with DNA methylation and is associated with neurological diseases. ABCG1 gene regulates cholesterol to HDL-C, maintains lipid homeostasis, and has been linked to both methyl nutrition and neurological risks. The aim was to investigate whether there is an effect of ABCG1 DNA methylation on the relationship between intake of methyl donor nutrients and the risk of stroke occurrence. We hypothesize that the intake of methyl donor nutrients may influence stroke occurrence by modulating the methylation status of ABCG1. This study utilized a case-control design and selected 52 stroke patients along with 52 healthy controls from Northwest China. Dietary information was collected using a FFQ, and methylation levels were measured at 29 CpG sites of the ABCG1 gene. A significant linear trend was found between dietary intake of the methyl donor nutrient choline and CpG_19.20 methylation of the ABCG1 gene (β = -0.037, P = 0.033). Additionally, a significant association was observed between CpG_19.20 methylation and the risk of stroke (OR 2.325, 95% CI 1.210 - 4.466). Mediation analysis revealed that choline intake indirectly influenced stroke occurrence through its effect on CpG_19.20 methylation levels in the ABCG1 gene (β = -0.015, SE = 0.013, 95% CI = [-0.053, -0.001]). We found that DNA methylation at specific CpG sites of the peripheral blood ABCG1 gene mediates the association between dietary methyl donor nutrient intake and stroke risk in an adult population from Northwest China. New insights are provided on the prevention and treatment of stroke.

Youth-derived Lactobacillus rhamnosus with prebiotic xylo-oligosaccharide exhibits anti-hyperlipidemic effects as a novel synbiotic

Changes in dietary patterns and living habits have led to an increasing number of individuals with elevated cholesterol levels. Excessive consumption of high-cholesterol foods can disrupt the body’s lipid metabolism. Numerous studies have firmly established the cholesterol-lowering effects of probiotics and prebiotics, with evidence showing that the synergistic use of synbiotics is functionally more potent than using probiotics or prebiotics alone. Currently, the screening strategy involves screening prebiotics for synbiotic development with probiotics as the core. However, in comparison to probiotics, there are fewer types of prebiotics available, leading to limited resources. Consequently, the combinations of synbiotics obtained are restricted, and probiotics and prebiotics are only relatively suitable. Therefore, in this study, a novel synbiotic screening strategy with prebiotics as the core was developed. The synbiotic combination of Lactobacillus rhamnosus S_82 and xylo-oligosaccharides was screened from the intestinal tract of young people through five generations of xylo-oligosaccharides. Subsequently, the cholesterol-lowering ability of the medium was simulated, and the two carbon sources of glucose and xylo-oligosaccharides were screened out. The results showed that synbiotics may participate in cholesterol-lowering regulation by down-regulating the expression of NPC1L1 gene, down-regulating ACAT2 and increasing the expression of ABCG8 gene in vitro through cell adsorption and cell absorption in vitro, and regulating the intestinal microbiota. Synbiotics hold promise as potential candidates for the prevention of hypercholesterolemia in humans and animals, and this study providing a theoretical foundation for the development of new synbiotic products.

The ATP-binding cassette transporter subfamily G member 4 mediates cuticular hydrocarbon transport to regulate drought tolerance in Acyrthosiphon pisum

ABC transporters are a highly conserved membrane protein class that promote the transport of substances across membranes. Under drought conditions, insects primarily regulate the content of cuticular hydrocarbon (CHC) to retain water and prevent evaporative loss. Involvement of ABC transporter protein G (ABCG) subfamily genes in insect CHC transport has been relatively understudied. In this study, we demonstrated that ABCG4 gene in Acyrthosiphon pisum (ApABCG4) is involved in CHC transport and affects drought tolerance by regulating CHC accumulation. ApABCG4 is strongly expressed in the abdominal cuticle and embryonic stages of A. pisum. Effective silencing of ApABCG4 was achieved using RNAi, and the silencing duration was analyzed. ApABCG4 silencing resulted in a significant decrease in the total and component contents of the CHC and cuticular waxy coatings of A. pisum. Nevertheless, the internal hydrocarbon content remained unchanged. The lack of cuticular hydrocarbons significantly reduced the drought tolerance of A. pisum, shortening its survival time under drought stress. Drought stress caused significant upregulation of ApABCG4. Molecular docking showed that ApABCG4 has a high binding affinity for nine n-alkanes of CHC through electrostatic interactions. These results indicate that ApABCG4 is a novel RNAi target with key applications in aphid biological control.

Family sitosterolemia: Report of two cases in Colombia

Sitosterolemia is an autosomal recessive and very rare disease. Its main characteristic is that there is a greater absorption and a decrease in the excretion of sterols, which leads to them being deposited in tissues. It is given by mutations in the ABCG5 or ABCG8 genes found on chromosome 2p21. In this clinical note, we describe the first two patients with familial sitosterolemia described in Colombia, brothers, one of them with xanthomas in extremities as the only symptom, and the other, completely asymptomatic. Genetic studies were performed as a diagnostic test in both patients, where a pathogenic homozygous variant could be identified in the ABCG8 gene in the first case (symptomatic), and a heterozygous variant in the ABCG8 gene in the second case (asymptomatic), the first patient has responded to treatment with ezetimibe. In conclusion, xanthomas should be studied in depth in pediatric age as they may be the only visible sign of such complex and hereditary diseases as familial sitosterolemia, which can be controlled and prevent cardiovascular complications of the disease.

Extracellular Vesicles Secreted by Adipose Tissue during Obesity and Type 2 Diabetes Mellitus Influence Reverse Cholesterol Transport-Related Gene Expression in Human Macrophages.

Obesity is a risk factor for type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). Adipose tissue (AT) extracellular vesicles (EVs) could play a role in obesity and T2DM associated CVD progression via the influence of their specific cargo on gene expression in recipient cells. The aim of this work was to evaluate the effects of AT EVs of patients with obesity with/without T2DM on reverse cholesterol transport (RCT)-related gene expression in human monocyte-derived macrophages (MDMs) from healthy donors. AT EVs were obtained after ex vivo cultivation of visceral and subcutaneous AT (VAT and SAT, respectively). ABCA1, ABCG1, PPARG, LXRβ (NR1H2), and LXRα (NR1H3) mRNA levels in MDMs as well as in origine AT were determined by a real-time PCR. T2DM VAT and SAT EVs induced ABCG1 gene expression whereas LXRα and PPARG mRNA levels were simultaneously downregulated. PPARG mRNA levels also decreased in the presence of VAT EVs of obese patients without T2DM. In contrast ABCA1 and LXRβ mRNA levels tended to increase with the addition of obese AT EVs. Thus, AT EVs can influence RCT gene expression in MDMs during obesity, and the effects are dependent on T2DM status.

H2S is involved in drought-mediated stomatal closure through PLDα1 in Arabidopsis.

PLDα1 promoted H2S production by positively regulating the expression of LCD. Stomatal closure promoted by PLDα1 required the accumulation of H2S under drought stress. Phospholipase Dα1 (PLDα1) acting as one of the signal enzymes can respond to drought stress. It is well known that hydrogen sulfide (H2S) plays an important role in plant responding to biotic or abiotic stress. In this study, the functions and relationship between PLDα1 and H2S in drought stress resistance in Arabidopsis were explored. Our results indicated that drought stress promotes PLDα1 and H2S production by inducing the expression of PLDα1 and LCD genes. PLDα1 and LCD enhanced plant tolerance to drought by regulating membrane lipid peroxidation, proline accumulation, H2O2 content and stomatal closure. Under drought stress, the H2O2 content of PLDα1-deficient mutant (pldα1), L-cysteine desulfhydrase (LCD)-deficient mutant (lcd) was higher than that of ecotype (WT), the stomatal aperture of pldα1 and lcd was larger than that of WT. The transcriptional and translational levels of LCD were lower in pldα1 than that in WT. Exogenous application of the H2S donor NaHS or GYY reduced the stomatal aperture of WT, pldα1, PLDα1-CO, and PLDα1-OE lines, while exogenous application of the H2S scavenger hypotaurine (HT) increased the stomatal aperture. qRT-PCR analysis of stomatal movement-related genes showed that the expression of CAX1, ABCG5, SCAB1, and SLAC1 genes in pldα1 and lcd were down-regulated, while ACA1 and OST1 gene expression was significantly up-regulated. Thus, PLDα1 and LCD are required for stomatal closure to improve drought stress tolerance.

Hif-1α expression targets the TMA/Fmo3/TMAO axis to participate in gallbladder cholesterol stone formation in individuals living in plateau regions

The incidence of gallbladder cholesterol stones (GCS) increases rapidly among people living in high-altitude hypoxic environments compared to those in normoxic areas. Upregulation of hepatic hypoxia inducible factor 1α (Hif-1α) plays a key role in the formation of GCS. High plasma trimethylamine-N-oxide (TMAO) levels are positively correlated with the occurrence of GCS. We hypothesized that HIF-1α may upregulate TMAO levels by promoting the transcription of flavin-containing monooxygenase 3 (Fmo3), which eventually leads to GCS formation. Our study shows that in women, high plasma total cholesterol and apolipoprotein B were positively correlated with cholecystolithiasis and hypoxia. Hif-1α binds to the Fmo3 promoter and promotes Fmo3 expression. Hypoxia and lithogenic diet induce the expression of Hif-1α, Fmo3, TMAO and cholesterol tube transporters in the livers of mice, disturb the proportion of bile and plasma components, and induce the formation of GCS. In cell experiments, silencing Hif-1α downregulates the expression of Fmo3, TMAO and cholesterol tube transporters. In a mouse model of hypoxic cholecystolithiasis, silencing Hif-1α downregulates the expression of related genes, restores the proportion of bile and plasma lipid components, and reduces the formation of GCS. Our study shows that Hif-1α binds to the promoter region of Fmo3 and promotes Fmo3 transcription. Thus, it mediates the transcriptional activation of the TMA/Fmo3/TMAO pathway, upregulates the expression of ATP-binding cassettes (Abc) g5 and g8, and participates in the regulation of the occurrence of GCS in the plateau region.

Evaluation of the role of metabolizing enzymes and transporter variants in ezetimibe pharmacokinetics.

Ezetimibe inhibits cholesterol uptake by modulation of intestinal sterol absorption. Currently, although some studies have shown alterations in ezetimibe levels caused by alterations in the ABCG5, ABCG8, NPC1L1 or UGT1A1 genes, there are no pharmacogenetic guidelines to confirm these biomarkers. The aim of this work was to evaluate the effect of 49 variants in 22 pharmacogenes related to metabolism and transport. A total of 96 healthy volunteers from four bioequivalence clinical trials of ezetimibe as monotherapy or in combination with simvastatin were studied. Blood samples were extracted for unconjugated ezetimibe plasma quantification and genotyping. No association of metabolizing enzyme variants with ezetimibe pharmacokinetic parameters was found. The results show some trends in the univariate analysis for ABCB1 rs2032582 or ABCC2 rs2273697 and Cmax (p univariate (p uv ) = 0.056 and 0.087, respectively), which finally reach significance in the multivariate analysis (p multivariate (p mv ) = 0.049 and 0.048, respectively). Nevertheless, these results need to be validated in future studies.

Sitosterolemia caused by mutations in the ABCG8 gene. First case report in Colombia

Introduction: Sitosterolemia is an autosomal recessive disease caused by mutations in the ABCG5 or ABCG8 genes. It is characterized by reduced excretion of plant sterols and cholesterol, leading to the development of hypercholesterolemia, xanthomas, and premature atherosclerosis. The present article reports the first case of this disease in Colombia. Case presentation: A 5-year-old child, son of non-consanguineous parents, who was under active treatment with ezetimibe and cholestyramine was taken (April 2021) to the human genetics service of a healthcare institution in Bogotá, Colombia, for assessment due to multiple xanthomas and elevated LDL cholesterol levels. Familial hypercholesterolemia had been ruled out. A next-generation gene sequencing (NGS) analysis detected a mutation in the ABCG8 gene, so he was diagnosed with sitosterolemia. Pharmacological treatment (ezetimibe and cholestyramine) was continued and dietary modifications were started. In the last follow-up visit of the patient to the human genetics service (March 2022), an improvement in the lipid profile was observed. In addition, 9 months later (December 2022), a decrease in the size of the xanthomas was reported in an evaluation by the pediatric endocrinology service. Conclusion: Sitosterolemia is a rare disease that should be considered in pediatric patients with multiple xanthomas and in whom familial hypercholesterolemia has been ruled out. Performing NGS of the genes involved is important to make a timely diagnosis and initiate appropriate treatment, which will improve the prognosis and quality of life of these patients.

Molecular and computational characterization of ABCB11 and ABCG5 variants in Tunisian patients with neonatal/infantile low-GGT intrahepatic cholestasis: Genetic diagnosis and genotype-phenotype correlation assessment.

Many inherited conditions cause hepatocellular cholestasis in infancy, including progressive familial intrahepatic cholestasis (PFIC), a heterogeneous group of diseases with highly overlapping symptoms. In our study, six unrelated Tunisian infants with PFIC suspicion were the subject of a panel-target sequencing followed by an exhaustive bioinformatic and modeling investigations. Results revealed five disease-causative variants including known ones: (the p.Asp482Gly and p.Tyr354 * in the ABCB11 gene and the p.Arg446 * in the ABCC2 gene), a novel p.Ala98Cys variant in the ATP-binding cassette subfamily G member 5 (ABCG5) gene and a first homozygous description of the p.Gln312His in the ABCB11 gene. The p.Gln312His disrupts the interaction pattern of the bile salt export pump as well as the flexibility of the second intracellular loop domain harboring this residue. As for the p.Ala98Cys, it modulates both the interactions within the first nucleotide-binding domain of the bile transporter and its accessibility. Two additional potentially modifier variants in cholestasis-associated genes were retained based on their pathogenicity (p.Gly758Val in the ABCC2 gene) and functionality (p.Asp19His in the ABCG8 gene). Molecular findings allowed a PFIC2 diagnosis in five patients and an unexpected diagnosis of sisterolemia in one case. The absence of genotype/phenotype correlation suggests the implication of environmental and epigenetic factors as well as modifier variants involved directly or indirectly in the bile composition, which could explain the cholestasis phenotypic variability.

A Descriptive Analysis of Patients with ABCG8 Mutation and Anemia. a Meta-Analysis and Systematic Review of an Uncommon Cause of Unexplained Anemia

Background Sitosterolemia is a rare inherited condition caused by elevated levels of plant sterols in the plasma. The genetic basis of the condition is characterized by homozygous and compound heterozygous mutations in ABCG5 and ABCG8 genes. The condition is very rare that information about this in literature is limited to case reports, case series and translational observational studies. A scarce occurrence in this already infrequent condition are hematological abnormalities such as hemolytic anemia, stomatocytosis, and macrothrombocytopenia. Basic details of the disease such are frequency of occurrence, demographic details of patients, and degree and type of anemia are not available. We conducted a meta-analysis and systematic review to answer these questions regarding patients who have hemolytic anemia and ABCG8 mutation. The study was also prompted by a clinical experience that our group encountered, of an adult male who had chronic severe hemolysis, at times requiring transfusion support, in whom, extensive investigation failed to reveal a cause for the hemolysis. The patient was ultimately found to have a mutation in the ABCG8 gene. Methods A controlled vocabulary encompassing ABCG8, sitosterolemia, phytosterolemia, anemia and hemolysis was used to perform a systematic search in PubMed, Embase, Scopus and Cochrane, from inception to July 2023. No restrictions on date, language, status, or outcomes were applied. 532 records were identified after duplicates were removed using Mendeley 1.19.8. The titles and abstracts were screened independently by 2 reviewers. We only included studies pertaining to patients with sitosterolemia, ABCG8 mutation and anemia of any cause or severity. Studies associated with ABCG5 mutation alone or lacked anemia were excluded. 13 reports were shortlisted for the final analysis (Observational studies-6, case series-4, case reports-3). Descriptive statistics were utilized to study the patient characteristics. The proportion of patients having both anemia and any ABCG8 mutation among all cases of sitosterolemia was determined using the DerSimonian-Laird random effects model with OpenMeta. Results From the 13 reports that we found in available literature, we identified 19 cases of ABCG8 mutation and anemia. From the random-effects proportions model, the chance of this event occurring among patients with sitosterolemia was 6.8% [0.068, 95% Confidence Interval (CI) 0.016-0.120, p=0.010] (I 2 24.68%) (14/145) (figure 1). Various characteristics of the cohort analyzed, including the different ABCG8 mutations, are summarized in figure 2. The mean age of the patients was 26 years (Age range: 0.1-61 years) and included neonates, pediatric, and adult patients. There were 7 females and 7 males among those whose sex were reported. 9/13 studies documented elevated sterols, while 8/13 clearly stated hemolysis as the cause of anemia. The hemoglobin ranged between 6.1 to 12.6 g/dl with a mean of 10.2 g/dl. Thrombocytopenia and stomatocytosis were frequently reported. Splenomegaly and xanthomas were other common associations. One example demonstrated an improvement in anemia after ezetimibe therapy, while splenectomy and supportive care was utilized in a couple of other reports to treat hemolysis. Conclusions To the best of our knowledge, we provide the first report of the prevalence of anemia, specifically in patients with sitosterolemia caused by a mutation in the ABCG8 gene. At 6.8%, this is an extremely rare occurrence in an already infrequent disease. A high index of suspicion is required to arrive at this diagnosis. The age distribution demonstrates a peculiar aspect of the disease, that it can occur very early in infancy, as well as in adults, likely triggered by environmental factors in an already predisposed patient. Unexplained hemolytic anemia, especially if associated with thrombocytopenia, splenomegaly and xanthomas should prompt testing for sterol levels and genomic sequencing to identify pathogenic variants of ABCG8 or ABCG5. The degree of anemia was mild in our analysis and hence unlikely to lead to significant mortality or morbidity. Heterogeneity between the various reports is a limitation of our analysis. While we specifically focused on ABCG8 and anemia, future research can also include ABCG5 related anemia and attempt to compare the two cohorts.

FRI094 Case Report: Treatment Of Sitosterolemia With Ezetimibe - 17 Years Of Follow-up

Abstract Disclosure: J.V. Coutinho: None. A.S. Costa: None. M.M. Issa: None. N.P. Paim: None. E.P. Quedas: None. V.S. Nunes: None. A.L. Jorge: None. E.R. Nakandakare: None. A.F. Carrilho: None. Background: Sitosterolemia is a rare autosomal recessive disease caused by inactivating mutations in the ABCG5 or ABCG8 genes. It is characterized by the accumulation of plant sterols in tissues in the form of xanthomas and vascular atheroma. Ezetimibe has been used to decrease serum sterol levels, but its role in xanthomas and arterial atherosclerosis progression remains undetermined. We present a patient diagnosed with sitosterolemia done at age 23 years and followed for 17 years on treatment with ezetimibe 20 mg daily. Clinical case: A 23-year-old man showed typical xanthomas on the extensor surfaces of his hands and Achilles tendons, in addition to splenomegaly and thrombocytopenia. Serum cholesterol and triglyceride levels were normal and sitosterolemia was suspected by a tendon biopsy. The diagnosis was confirmed by high serum concentrations of β-sitosterol and campesterol, and the patient was advised to follow a low plant-sterol diet and to take ezetimibe 20 mg daily. Seven years later, there was no change in xanthoma size, abdominal ultrasound showed normal spleen, and plasma lipid levels were: total cholesterol (TC) 147 mg/dL, HDL cholesterol (HDL) 44 mg/dL, LDL cholesterol (LDL) 61 mg/dL, triglycerides (Tg) 206 mg/dL, desmosterol 0. 137 µg/mL (n < 1.6 µg/mL), lanosterol 0.368 µg/mL (n < 2.2 µg/mL), campesterol 39.65 µg/mL (n < 5.5 µg/mL), β-sitosterol 87.53 µg/mL (n < 1.7 µg/mL) and platelet count 109,000/mL. Seventeen years after diagnosis, at age 40, there was no significant change in xanthoma size and the patient remained without cardiovascular symptoms (normal echocardiography and exercise stress test), however ultrasound showed bilateral carotid-intimal-medial thickening (0.1 on the right and 0.17 on the left, n < 0.1) and serum lipid concentrations were: TC 203 mg/dL, LDL 130 mg/dL, HDL 46 mg/dL, Tg 145 mg/dL, campesterol 21.34 µg/mL (n < 5.5 µg/mL) and β-sitosterol 65.13 µg/mL (n < 1.7 µg/mL). Then, atorvastatin 20 mg daily was added to ezetimibe. In addition, genomic DNA sequencing revealed a compound heterozygous mutation of the ABCG5 gene (NM_022436:exon1:c.64C>T:p.Q22* and NM_022436:exon9:c.1217G>A:p.R406Q). Conclusion: treatment with ezetimibe prevented the growth of xanthomas, however it was not able to normalize plasma levels of campesterol and β-sitosterol. Furthermore, the small carotid intimal-medial thickening found raised the question about the role of plant sterols in atherosclerosis. Presentation: Friday, June 16, 2023

SAT009 Investigating The Role Of Hepatic Small Heterodimer Partner In Regulating Gallstone Formation

Abstract Disclosure: N.M. Dang: None. S. Anakk: None. Nuclear receptor, Small Heterodimer partner (Shp) regulates bile acid homeostasis by inhibiting transcription of Cholesterol 7 alpha-hydroxylase (Cyp7a1), the rate-limiting enzyme involved in converting cholesterol to bile acids, within the liver. Bile acid regulation prevents the formation of gallstones as cholesterol is excreted into bile along with bile acids and phospholipids. How hepatic Shp affects the development of gallstones and the mechanisms underlying these effects remain unclear. Here we used a liver-specific knockout mouse model and a lithogenic diet model to uncover potential liver-to-gallbladder crosstalk that contributes to gallstone development. Previously, we had shown that the knockout of Shp alters bile acid composition, resulting in higher percentages of secondary bile acid, deoxycholic acid. This increased the hydrophobic index of hepatic bile acids and also implicated a trend for a subsequent increase in the hydrophobicity of biliary bile. Higher hydrophobicity is sufficient to increase susceptibility to developing gallstones by promoting cholesterol nucleation. Of note, the expression of transporter genes Abcg5 and Aqp1 were altered in the gallbladder of hepatic Shp knockout mice, indicating a potential change in their bile composition. The enterokine, Fgf15 is known to stimulate gallbladder filling through its interaction with its receptor, Fgfr4. Recently, the Fgf15-Fgfr4 axis was shown to prevent degradation of the SHP protein such that impeding this axis led to higher Cyp7a1 transcript, increased bile acid levels, and altered gallbladder filling. Taken together, these findings suggest that hepatic Shp acts as a central node that regulates bile acid transport, homeostasis, and composition within the gall bladder and thus can prevent gallstone development. Elucidating Shp-mediated liver-to-gallbladder crosstalk is important for understanding the contribution of liver dysfunction towards gallbladder diseases and gallstones. Presentation: Saturday, June 17, 2023

VIGS as a strategy to reverse aphid wing induction by Y-satellite RNA of cucumber mosaic virus.

Y-satellite RNA (Y-sat) of cucumber mosaic virus upregulates the expression of the aphid ABCG4 gene, which promotes aphid wing formation. We used ABCG4 virus-induced gene silencing (VIGS) to prevent the wing-induction mechanism of Y-sat and thus inhibited aphid wing formation. Of the aphids on plants with VIGS of ABCG4, only about 30% had wings, and 60-70% of the winged aphids were small and likely impaired in flying ability. In addition, we showed that double-stranded RNAs (dsRNAs) and small RNAs were transferred from the plant to the aphid to adequately silence aphid genes. Supplying ABCG4 dsRNA by VIGS to aphids is thus a potential strategy to inhibit aphid wing formation.

Genetic Characteristics of Latvian Patients with Familial Hypercholesterolemia: The First Analysis from Genome-Wide Sequencing.

There is limited data on the genetic characteristics of patients with familial hypercholesterolemia (FH) in Latvia. We aim to describe monogenic variants in patients from the Latvian Registry of FH (LRFH). Whole genome sequencing with 30× coverage was performed in unrelated index cases from the LRFH and the Genome Database of Latvian Population. LDLR, APOB, PCSK9, LDLRAP1, ABCG5, ABCG8, LIPA, LPA, CYP27A1, and APOE genes were analyzed. Only variants annotated as pathogenic (P) or likely pathogenic (LP) using the FH Variant Curation Expert Panel guidelines for LDLR and adaptations for APOB and PCSK9 were reported. Among 163 patients, the mean highest documented LDL-cholesterol level was 7.47 ± 1.60 mmol/L, and 79.1% of patients had LDL-cholesterol ≥6.50 mmol/L. A total of 15 P/LP variants were found in 34 patients (diagnostic yield: 20.9%): 14 in the LDLR gene and 1 in the APOB gene. Additionally, 24, 54, and 13 VUS were detected in LDLR, APOB, and PCSK9, respectively. No P/LP variants were identified in the other tested genes. Despite the high clinical likelihood of FH, confirmed P/LP variants were detected in only 20.9% of patients in the Latvian cohort when assessed with genome-wide next generation sequencing.

Flindissone, a Limonoid Isolated from Trichilia prieuriana, Is an LXR Agonist.

In this study, the ability of six limonoids from Trichilia prieuriana (Meliaceae) to activate the liver X receptor (LXR) was assessed. One of these limonoids, flindissone, was shown to activate LXR by reporter-gene assays. Flindissone is a ring-intact limonoid, structurally similar to sterol-like LXR ligands. In endogenous cellular settings, flindissone showed an activity profile that is characteristic of LXR agonists. It induced cholesterol efflux in THP-1 macrophages by increasing the cholesterol transporter ABCA1 and ABCG1 gene expression. In HepG2 cells, flindissone induced the expression of IDOL, an LXR-target gene that is associated with the downregulation of the LDL receptor. However, unlike synthetic and similarly to sterol-based LXR agonists, flindissone did not induce the expression of the SREBP1c gene, a major transcription factor regulating de novo lipogenesis. Additionally, flindissone also appeared to be able to inhibit post-translational activation of SREBP1c. The results presented here reveal a natural product as a new LXR agonist and point to an additional property of T. prieuriana and other plant extracts containing flindissone.

Combined effects of lead and manganese on locomotor activity and microbiota in zebrafish

Exposure to lead (Pb) and manganese (Mn) during early life influences neurodevelopment and increases the risk of neurodegenerative disorders. However, the level of developmental neurotoxicity due to combined exposure to the two metals remains unclear. Although the microbiota plays an essential part in the development of the nervous system via the gut–brain axis, there is a paucity of information regarding the interactions between exposure to Pb and Mn, the destruction of the microbiome, and neurodevelopmental impacts. To fill in this knowledge gap, we investigated the developmental neurotoxicity and effects on the microbiota of Pb (0.05 mg·L−1) alone and in combination with Mn (0.3 mg·L−1) in zebrafish larvae. Our results revealed that combined exposure precipitated higher malformation rates and lower locomotor activity levels than exposure to either Pb or Mn alone. Additionally, when we separated the combined exposure group from the other groups by applying unsupervised principal coordinates analysis (PCoA) and linear discriminant analysis (LEfSe) of microflora sequencing results, we observed extensive alterations in microbial abundances under combined-exposure conditions. Functional prediction analysis showed that combined exposure contributed to altered amino acid and lipid metabolism, and also that combined exposure to Pb and Mn reflected the greatest number of differentially activated biological pathways compared to the other three groups. ATP-binding cassette G (ABCG) genes and genes related to serotonin signaling and metabolism were altered following combined Pb and Mn exposure and exhibited disparate trends vis-à-vis Pb or Mn exposure alone. According to the results, the combined exposure to Pb and Mn led to more severe effects on both zebrafish locomotor activity and gut microbial composition. We suggest that the microbiota contributes to the combined neurotoxicity by increasing ABCG5 and ABCG8 gene expression.

Hypermethylation and reduced expression of lipoprotein metabolism genes ABCG1, LIPC and PLTP in Obese and Diabetic subjects: Potential risk factors for Coronary artery disease

Hypermethylation and reduced expression of lipoprotein metabolism genes ABCG1, LIPC and PLTP in Obese and Diabetic subjects: Potential risk factors for Coronary artery disease