Lower Plasma Cholesterol Research Articles

222-LB: Switching Palmitoyl and Oleoyl Position in Sn-2 and Sn-3 of a Triacylglycerol Led to Differential Body Weight Gain Rates and Hepatic Gene Expressions in Mice Fed a High-Fat Diet

Alterations of fatty acid metabolism have been associated with diabetes. Triacylglycerol (TAG) can be obtained from dietary sources and synthesized de novo. The composition and location of the fatty acyl groups in a TAG can affect its physicochemical features such as melting temperature, and physiological characteristics such as digestion, absorption, and lipid metabolism. We hypothesize that the TAG fatty acyl position affects the body weight gain and lipid metabolism of mice in a high-fat diet (HFD) setting. Twenty-seven 6-week-old male C57/BL6J mice were randomly assigned to 3 dietary treatment groups, 1,2-dipalmitoyl-3-oleoylglycerol (PPO, 36 % w/w diet) , 1,3-dipalmitoyl-2-oleoylglycerol (POP, 36% w/w diet) , and the chow diet control groups. Mice in each group were fed their respective diet for 6 weeks, and food intake and body weight were measured daily. Mice fed the PPO diet had significantly higher food intake, calories intake and body wight gain rate, and lower liver to body weight ratio than those fed the POP diet. Mice fed the chow diet had significantly higher total grams of food intake, but lower calories intake, liver and epididymal fat weight, and body weight gain rate than those fed the PPO, but not the POP, diet. Mice in the PPO group had significantly higher serum glucose than that in other two groups, whereas mice fed the chow diet had significantly lower plasma cholesterol level than those HFD groups. The plasma TAG levels were not different among them. The hepatic levels of insulin receptor substrate 1, and fatty acid synthase, and phosphorylated acetyl CoA carboxylase in mice fed the chow diet are significantly higher than those fed the PPO or POP diet, whereas the hepatic expression level of stearoyl CoA desaturase 1 in mice fed the POP diet was lower than those fed the PPO or chow diet. We conclude that feeding a HFD affects the expression levels of hepatic proteins for lipid metabolism in mice. In addition, the position of fatty acyl group in a TAG affects the food intake, the body weight gain rate and lipid homeostasis in mice. Disclosure X. Hu: None. T. Wang: None. G. Chen: None.

Abstract 437: Carnitine Palmitoyltransferase 1a Modulates Lipoprotein Metabolism

Background: Nonalcoholic fatty liver disease (NAFLD) affects almost 1 billion people worldwide and is associated with risk factors such as obesity and dyslipidemia. Studies show linked variants and methylation status of carnitine palmitoytransferase 1a (CPT1a) to disrupt very low-density lipoprotein (VLDL) cholesterol and triglyceride (TG) levels. We exhibit liver-specific deletion of CPT1a in mice lowers plasma cholesterol and TG while exacerbating NAFLD and inflammation. Methods: Eight-week old Cpt1a floxed mice with the human apoB100 transgene (Cpt1a fl/fl /B100 Tg ) were administered control adenoassociated virus (AAV) or AAV encoding Cre-recombinase under control of a liver specific promoter (TBG-Cre). Control and Cpt1a liver-specific knock out (LKO) mice were placed on low-fat control or western-type diet (WTD; 42% kcal fat, 0.2% cholesterol) for 16 weeks. Body weights were recorded weekly and body composition by MRI was performed at the study midpoint and end. Tissues and plasma were collected and analyzed for lipid composition and gene and protein expression by QPCR and immunoblotting, respectively. Results: CPT1a LKO mice had lower plasma cholesterol and TG irrespective of diet. The reduction in plasma cholesterol was limited to the LDL pool in FPLC-fractionated plasma. Hepatic TG was elevated in mice fed WTD and LKO Cpt1a mice. Loss of hepatic Cpt1a had no effect on hepatic cholesterol in male mice, but increased total and free cholesterol by 2- and 2.5-fold, respectively, in females. The rise in hepatic free cholesterol in female Cpt1a LKO mice associated with increases in Kupffer cell ( Clec4f ) and collagen ( Col1a1 ) gene expression. Free cholesterol levels were not related to differences in transcripts for enzymes involved in cholesterol synthesis or secretion ( Srebp2, Hmgcr, Hmgcs, Soat2, Mttp ), hepatic clearance ( Ldlr ), metabolism ( Cpy7a1, Cyp8b1 ), or biliary secretion ( Abcg5, Abcg8 ). Conclusions: Liver-specific deletion of CPT1a reduces plasma LDL-cholesterol and increases cholesterol levels in female, but not male mice. The increase in hepatic free cholesterol did not alter expression of cholesterol-responsive genes, suggesting cholesterol accumulation outside of the regulatory pool.

Abstract 119: Into The Wormhole: Understanding SR-B1’s Cholesterol Transport Functions Through Structural Studies

Scavenger receptor Class B type 1 (SR-B1) is a glycosylated integral membrane protein that serves as the primary receptor for high density lipoprotein (HDL) and plays a central role in the reverse cholesterol transport pathway (RCT). In RCT, HDL removes cholesterol within atherosclerotic plaques and delivers it to the liver for excretion. HDL-cholesterol is delivered into hepatocytes through interaction with SR-B1, highlighting the need to improve our understanding of SR-B1 structure-function relationships to effectively lower plasma cholesterol levels and cardiovascular disease risk. Currently, structural information about SR-B1 remains limited to a structure of short transmembrane-spanning peptide segment, homology models, and transient transfection studies in cultured cells. Towards our long-term goal of resolving a full-length structure of human SR-B1, we have expressed and purified full-length human SR-B1 from an Sf9 insect cell baculoviral infection system. To verify function, human full-length SR-B1 expressed in plated Sf9 cells displayed a significant increase in DiI-HDL binding and DiI-lipid uptake compared to empty vector controls. Using PFO-PAGE, we demonstrated that SR-B1 forms dimers and higher order oligomers in Sf9 cells. After functional verification, we successfully incorporated purified protein into detergent micelles. Thermal shift assays revealed purified SR-B1 remained stable over a 6-week period. Purified SR-B1 also maintained the ability to bind to apolipoprotein A-I (the main protein component of HDL) and holoparticle HDL with high affinity (K D = 42.77 ± 7.15 μg/mL) by microscale thermophoresis (MST). Additionally, SR-B1 was able to bind oxidized low density lipoprotein (oxLDL). Further, while glycosylation remains important for SR-B1 expression, we are the first to demonstrate by MST that SR-B1’s glycosylation status did not impact HDL binding affinity (K D of 42.77 ± 7.15 μg/mL for glycosylated vs. 41.25 ± 4.92 μg/mL for unglycosylated SR-B1). Availability of functional purified human SR-B1 is a critical step towards a high-resolution structure and these studies lay the foundation for understanding the dynamics of SR-B1-mediated cholesterol transport and novel ways to modulate cardiovascular disease risk.

Abstract 206: Into The Wormhole: Understanding SR-B1’s Cholesterol Transport Functions Through Structural Studies

Scavenger receptor Class B type 1 (SR-B1) is a glycosylated integral membrane protein that serves as the primary receptor for high density lipoprotein (HDL) and plays a central role in the reverse cholesterol transport pathway (RCT). In RCT, HDL removes cholesterol within atherosclerotic plaques and delivers it to the liver for excretion. HDL-cholesterol is delivered into hepatocytes through interaction with SR-B1, highlighting the need to improve our understanding of SR-B1 structure-function relationships to effectively lower plasma cholesterol levels and cardiovascular disease risk. Currently, structural information about SR-B1 remains limited to a structure of short transmembrane-spanning peptide segment, homology models, and transient transfection studies in cultured cells. Towards our long-term goal of resolving a full-length structure of human SR-B1, we have expressed and purified full-length human SR-B1 from an Sf9 insect cell baculoviral infection system. To verify function, human full-length SR-B1 expressed in plated Sf9 cells displayed a significant increase in DiI-HDL binding and DiI-lipid uptake compared to empty vector controls. Using PFO-PAGE, we demonstrated that SR-B1 forms dimers and higher order oligomers in Sf9 cells. After functional verification, we successfully incorporated purified protein into detergent micelles. Thermal shift assays revealed purified SR-B1 remained stable over a 6-week period. Purified SR-B1 also maintained the ability to bind to apolipoprotein A-I (the main protein component of HDL) and holoparticle HDL with high affinity (K D = 42.77 ± 7.15 μg/mL) by microscale thermophoresis (MST). Additionally, SR-B1 was able to bind oxidized low density lipoprotein (oxLDL). Further, while glycosylation remains important for SR-B1 expression, we are the first to demonstrate by MST that SR-B1’s glycosylation status did not impact HDL binding affinity (K D of 42.77 ± 7.15 μg/mL for glycosylated vs. 41.25 ± 4.92 μg/mL for unglycosylated SR-B1). Availability of functional purified human SR-B1 is a critical step towards a high-resolution structure and these studies lay the foundation for understanding the dynamics of SR-B1-mediated cholesterol transport and novel ways to modulate cardiovascular disease risk.

Evaluation the antihyprlipidemic effect of apigenin flavonoid in mice

The study’s aim was to examine the antihyperlipidemic effect of apigenin in mice as a model. Healthy adult albino mice of either sex were selected to use for this study. Four groups of animals were formed of 5 mice each. Animals Group 1 served as a negative control and fed the standard diet and tap water. Groups 2,3 and 4 were fed fatty diet and 1% water with H2O2 for 90 days to induce hyperlipidemia. After hyperlipidemic induction, group 2 served as a positive control, whereas group 3 was treated orally with apigenin 50 mg/kg/day for 14 constitutive days. Group 4 was treated by rosuvastatin (an antihyprlipidemic drug) orally at 7 mg/kg for 14 constitutive days. Blood samples were collected from all of the animals at the beginning of the study to measure the lipid profile. Then these were rechecked again after 12 weeks of feeding a high-fat diet, and then at the end of the experiment for the treated groups. The results demonstrated that the apigenin at 50mg/kg significantly reduced hyperlipidemia manifested by decreased TC, LDL-C, Triglyceride and elevation of HDL-C in comparison with the positive control group. The results, obtained by apigenin were the in accordance with those of the standard drug rosuvastatin for TC and LDL-C. This study concluded that apigenin lowered plasma cholesterol and triglycerides levels in mice.

Long-Term Dietary Taurine Lowers Plasma Levels of Cholesterol and Bile Acids.

Cholesterol is an essential lipid in vertebrates, but excess blood cholesterol promotes atherosclerosis. In the liver, cholesterol is metabolized to bile acids by cytochrome P450, family 7, subfamily a, polypeptide 1 (CYP7A1), the transcription of which is negatively regulated by the ERK pathway. Fibroblast growth factor 21 (FGF21), a hepatokine, induces ERK phosphorylation and suppresses Cyp7a1 transcription. Taurine, a sulfur-containing amino acid, reportedly promotes cholesterol metabolism and lowers blood and hepatic cholesterol levels. However, the influence of long-term feeding of taurine on cholesterol levels and metabolism remains unclear. Here, to evaluate the more chronic effects of taurine on cholesterol levels, we analyzed mice fed a taurine-rich diet for 14–16 weeks. Long-term feeding of taurine lowered plasma cholesterol and bile acids without significantly changing other metabolic parameters, but hardly affected these levels in the liver. Moreover, taurine upregulated Cyp7a1 levels, while downregulated phosphorylated ERK and Fgf21 levels in the liver. Likewise, taurine-treated Hepa1-6 cells, a mouse hepatocyte line, exhibited downregulated Fgf21 levels and upregulated promoter activity of Cyp7a1. These results indicate that taurine promotes cholesterol metabolism by suppressing the FGF21/ERK pathway followed by upregulating Cyp7a1 expression. Collectively, this study shows that long-term feeding of taurine lowers both plasma cholesterol and bile acids, reinforcing that taurine effectively prevents hypercholesterolemia.

SR-B1's Next Top Model: Structural Perspectives on the Functions of the HDL Receptor.

Purpose of ReviewThe binding of high-density lipoprotein (HDL) to its primary receptor, scavenger receptor class B type 1 (SR-B1), is critical for lowering plasma cholesterol levels and reducing cardiovascular disease risk. This review provides novel insights into how the structural elements of SR-B1 drive efficient function with an emphasis on bidirectional cholesterol transport.Recent FindingsWe have generated a new homology model of full-length human SR-B1 based on the recent resolution of the partial structures of other class B scavenger receptors. Interrogating this model against previously published observations allows us to generate structurally informed hypotheses about SR-B1’s ability to mediate HDL-cholesterol (HDL-C) transport. Furthermore, we provide a structural perspective as to why human variants of SR-B1 may result in impaired HDL-C clearance.SummaryA comprehensive understanding of SR-B1’s structure–function relationships is critical to the development of therapeutic agents targeting SR-B1 and modulating cardiovascular disease risk.

Mulberry (Morus alba L.) ethanol extract attenuates lipid metabolic disturbance and adipokine imbalance in high-fat fed rats.

An imbalanced adipokine profile in obesity increases the susceptibility to obesity-related cardiometabolic alterations, including type 2 diabetes, hypertension, dyslipidemia, and non-alcoholic fatty liver disease. The mulberry plant has been reported to have health benefits, such as hypolipidemic and hepatoprotective effects. This study examined the effects of a mulberry (Morus alba L.) fruit ethanol extract (MBEE) on dyslipidemia, liver steatosis, and adipokine imbalance in response to a high-fat diet. Male Sprague-Dawley rats were assigned to one of 4 groups containing 6 rats each and fed either a control diet (CON), a high-fat diet (HFD), or a high-fat diet with MBEE of 150 mg/kg/day (LMB) or 300 mg/kg/day (HMB). The triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activities were measured spectrophotometrically. The leptin, adiponectin, and plasminogen activator inhibitor-1 (PAI-1) levels were determined by an enzyme-linked immunosorbent assay. The plasma TG levels were similar in the 4 groups. Plasma cholesterol and low-density lipoprotein cholesterol (LDL-C) levels and TC/HDL-C ratio increased in the HFD group compared with the CON group, whereas those values decreased in the LMB group (P < 0.05), indicating that MBEE had a plasma lipid-lowering effect. HDL-C decreased in the HFD group, but MBEE did not affect the HDL-C level. The HFD rats significantly increased hepatic TG and cholesterol levels and plasma ALT and AST activities compared to the CON group. The hepatic TG level and ALT and AST activities were reduced markedly by the MBEE treatment. The HFD group showed a higher PAI-1 level, whereas MBEE treatment, especially in the HMB group, significantly reduced leptin level, and leptin/adiponectin and PAI-1/adiponectin ratios. These findings suggest that MBEE altered the imbalance between the pro- and anti-inflammatory adipokines to a more anti-inflammatory state. MBEE could protect against abnormal lipid metabolism and hepatic steatosis induced by a high-fat diet, lowering plasma cholesterol, LDL-C and TC/HDL-C, and hepatic TG. These findings are associated with the regulating effect of MBEE on the leptin/adiponectin and PAI-1/adiponectin ratios.

Fragrant rapeseed oil consumption prevents blood cholesterol accumulation via promoting fecal bile excretion and reducing oxidative stress in high cholesterol diet fed rats

• Long-term effect of three rapeseed oils fed in hypercholesterolemic rats was tested. • Fragrant rapeseed oils lowered plasma cholesterol and boosted fecal bile acid efflux. • Fragrant rapeseed oils altered liver redox status and increased EPA and DHA output. • Such beneficial impact probably owed to high α-linolenic acid and polyphenols levels. We investigated the compositional changes and effects of long-term supplementation on blood lipids in three rapeseed oils [refined (RO), roasted at 120 °C (FO-120) and roasted at 150 °C (FO-150)]. Sixty Sprague-Dawley rats were fed either a basal diet or one of five high-cholesterol diets comprising lard, lard with cholestyramine, or three rapeseed oils for 12 weeks. Results showed that FO-120 and FO-150 alleviated plasma total cholesterol and increased fecal bile acid excretion, but RO had no significant effect. In the liver, cholesterol synthesis and conversion mRNA expression were altered by FO-120 or FO-150 feeding, like the inhibition of Hmgcr and activation of Cyp7a1 . Furthermore, FO-120 or FO-150 increased hepatic eicosapentaenoic and docosahexaenoic acid production and favorably improved hepatic redox status. Overall, the hypocholesterolemic effects may be attributed to their high levels of α-linolenic acid and polyphenols, linked closely to regulating cholesterol metabolism, promoting highly-unsaturated fatty acids synthesis, and reducing oxidative stress.

Alterations in the Hemato-biochemical, Endocrine, Somatic Cell Count and Milk Composition in Lactating Tarai Buffaloes during Different Lactation Stages

Background: Tarai buffalo is indigenous buffalo breed of Uttarakhand state, dual purpose, well adapt to hot-humid climatic condition of Tarai area. This study aimed to evaluate the alterations in the hemato-biochemical, endocrine, milk somatic cell count and milk composition in lactating Tarai buffaloes. Methods: Thirty-six healthy Tarai buffaloes were selected from four different Gujjar farms and divided into four groups consisting nine buffaloes in each group as early (60±30 days), mid (120±30 days) and late (180±30 days) lactation stages and dry buffaloes. Both blood and milk samples were collected once from each lactation stage of selected animals. Hematological parameters and milk composition were evaluated by standard procedures and methods. Biochemical and endocrine parameters were evaluated using commercially available kits as per manufacturer’s protocol. Milk somatic cell count (SCC) was done by direct microscopic counts using Newman Lampert stain. Result: It observed significantly (p less than 0.05) higher TLC value but lower plasma glucose, cholesterol, calcium, phosphorus and urea levels during early lactation stage. Significantly (p less than 0.05) declined in plasma total protein during late lactation stage and triglyceride in dry cows. Plasma hormone significantly (p less than 0.05) higher in cortisol during early lactation while higher T4 and insulin in late lactation stages. Milk fat, urea and total solids were significantly (p less than 0.05) decreased during early lactation and again increased during late lactation while milk SCC significantly (p less than 0.05) higher during early and late lactation stages.

Hepatic TM6SF2 Is Required for Lipidation of VLDL in a Pre-Golgi Compartment in Mice and Rats.

Background & AimsSubstitution of lysine for glutamic acid at residu 167 in Transmembrane 6 superfamily member 2 (TM6SF2) is associated with fatty liver disease and reduced plasma lipid levels. Tm6sf2-/- mice replicate the human phenotype but were not suitable for detailed mechanistic studies. As an alternative model, we generated Tm6sf2-/- rats to determine the subcellular location and function of TM6SF2.MethodsTwo lines of Tm6sf2-/- rats were established using gene editing. Lipids from tissues and from newly secreted very low density lipoproteins (VLDLs) were quantified using enzymatic assays and mass spectrometry. Neutral lipids were visualized in tissue sections using Oil Red O staining. The rate of dietary triglyceride (TG) absorption and hepatic VLDL-TG secretion were compared in Tm6sf2-/- mice and in their wild-type littermates. The intracellular location of TM6SF2 was determined by cell fractionation. Finally, TM6SF2 was immunoprecipitated from liver and enterocytes to identify interacting proteins.ResultsTm6sf2-/- rats had a 6-fold higher mean hepatic TG content (56.1 ± 28.9 9 vs 9.8 ± 3.9 mg/g; P < .0001) and lower plasma cholesterol levels (99.0 ± 10.5 vs 110.6 ± 14.0 mg/dL; P = .0294) than their wild-type littermates. Rates of appearance of dietary and hepatic TG into blood were reduced significantly in Tm6sf2-/- rats (P < .001 and P < .01, respectively). Lipid content of newly secreted VLDLs isolated from perfused livers was reduced by 53% (TG) and 62% (cholesterol) (P = .005 and P = .01, respectively) in Tm6sf2-/- mice. TM6SF2 was present predominantly in the smooth endoplasmic reticulum and endoplasmic reticulum–Golgi intermediate compartments, but not in Golgi. Both apolipoprotein B-48 and acyl-CoA synthetase long chain family member 5 physically interacted with TM6SF2.ConclusionsTM6SF2 acts in the smooth endoplasmic reticulum to promote bulk lipidation of apolipoprotein B–containing lipoproteins, thus preventing fatty liver disease.

Knowledge as to cholesterol reduction and use of phytosterol-enriched dietary foods in the general population: Insights from the Hamburg City Health Study

Background and aimsDietary approaches to lowering cholesterol appear to be common knowledge. However, the marketing of phytosterol-enriched products and their recommendation by guidelines for individuals at increased risk of cardiovascular disease have given rise to concern, since phytosterols may be atherogenic and inappropriately used by healthy individuals of higher social status at low cardiovascular risk. Hence, we have investigated awareness of cholesterol lowering lifestyle measures and attitudes towards consumption of phytosterol-enriched foods. MethodsData from validated questionnaires supplemented by queries on cholesterol lowering and phytosterol-enriched products were analyzed using data of 7223 participants of the Hamburg City Health Study, an ongoing cohort study of the general population aged 45–74 years. Results95.9% of the participants agreed that lifestyle may lower cholesterol and 76.6% claimed knowledge of measures that lower plasma cholesterol. As to effective approaches, 80.2% suggested physical activity, 67.8% reducing dietary fat, followed by sugar-sweetened beverages or stress, increasing water consumption, or dietary fiber and only 16.2% stated statins and 9.3% phytosterol-enriched products. Compared to nonusers, the 2.0% female and 2.8% male individuals regularly using phytosterol-enriched products had a lower educational status, higher cardiovascular risk, but no difference in income and were characterized by adverse dietary habits. The study has been registered in ClinicalTrial.gov (NCT03934957). ConclusionsIn the general population awareness of hypercholesterolemia is high but knowledge on how to lower plasma cholesterol does not necessarily follow scientific evidence. There is a trend towards the use of phytosterol-enriched products by individuals at increased cardiovascular risk independent of income.

Simvastatin regulates the proliferation, apoptosis, migration and invasion of human acute myeloid leukemia cells via miR-19a-3p/HIF-1α axis

ABSTRACT Statins are mainly used to lower plasma cholesterol level. In addition, the anti-leukemia effect of statins has been reported, but the mechanism remains unclear. This study aimed to explore the bioregulation of simvastatin and its mechanism in acute leukemia cell lines. Cell viability was detected by CCK-8 analysis. Apoptosis was detected through flow cytometry. Cell invasion and migration both were observed by transwell and wound healing separately. RT-qPCR and Western blot were used for determination of genes and proteins. We found that that simvastatin could regulate the biological functions of acute myeloid leukemia (AML) cells, including its proliferation, migration, invasion and apoptosis, which may be carried out by down-regulating miR-19a-3p. Overexpression of miR-19a-3p had the opposite effect in AML cells, suggesting simvastatin-inhibited AML by reducing miR-19a-3p expression. Following researches showed that HIF-1α was directly regulated by the target of miR-19a-3p. Simvastatin could reverse the adverse effects caused by miR-19a-3p mimics. Conversely, the increased expression of Mcl-1, the inhibition of caspase-3 could promote the growth of AML cells. In conclusion, simvastatin could inhibit the proliferation, migration, invasion and promote apoptosis in AML cells through miR-19a-3p/HIF-1α axis.

Targeting mangiferin loaded N-succinyl chitosan-alginate grafted nanoparticles against atherosclerosis – A case study against diabetes mediated hyperlipidemia in rat

Mangiferin (MGF), from Mangifera indica is well reported for its hypoglycemic activity and hypolipidemic activity. However, MGF suffers therapeutic limitation due to poor solubility causing disparaging bioavailability. Herein to address this problem, we have incorporated MGF in alginate grafted N-succinylated chitosan (NSC) nanomatrix. Characterization by molecular docking, FT-IR and 2D-NMR (COSY) has revealed that MGF could reinforce interaction with NSC. The OH and CH2OH groups of MGF may set interactions with pyranosic OH, CH2OH, NH2 (or NH-succinyl and COOH-succinyl) of NSC. The NSC-MGF nanoconjugate revealed a spherical particle geometry of 100 ∼ 200 nm size. The encapsulated MGF showed 100% release in vitro. In vivo, NSC-MGF nanoconjugate revealed blood glucose lowering from 300 mg/dL to ∼ 90 mg/dL as well as ∼ 37% lowering of total plasma cholesterol. This is well comparative to the earlier reports which acknowledged only 1 ∼ 36% lowering of plasma cholesterol with MGF. Furthermore, NSC-MGF lowered serum trigyceride to ∼ 61%, while in earlier studies, only 10 ∼ 40% serum triglycerides reduction was found with solitary MGF.

Abstract P115: Building A Structurally Sound System To Understand SR-BI Function

The interaction of scavenger receptor BI (SR-BI) and high density lipoproteins (HDL) is the key step for the bodily removal of cholesterol. The HDL/SR-BI interaction is one of the concluding steps of the reverse cholesterol transport (RCT) pathway. In RCT, cholesterol within atherosclerotic plaques is taken up by HDL particles, which then dock on SR-BI at the surface of the liver, where cholesterol can be delivered converted into bile for excretion. Humans with mutations in the gene encoding SR-BI display elevated HDL-cholesterol levels and an increased risk of cardiovascular disease (CVD). Therefore, understanding the interaction between HDL and SR-BI is crucial to discovering ways to lower plasma cholesterol and modulate CVD risk. Due to the importance of SR-BI, the goal of these studies is to resolve a structure of functional full-length human SR-BI. We have expressed and purified full-length SR-BI using an insect cell Sf9 system. In order to assess SR-BI’s functions within this system, Sf9 cells were infected with baculovirus encoding empty vector or SR-BI, or left uninfected and plated into culture dishes. Expression of SR-BI significantly increased HDL cellular association and uptake of HDL-cholesteryl esters compared to empty vector and uninfected cells. Additionally, free cholesterol efflux was increased upon SR-BI expression. Lastly, SR-BI in Sf9 cells maintained its ability to form higher order oligomers in cells, which is crucial, as SR-BI oligomerization is important in cholesterol transport. Additionally, size exclusion chromatography shows that purified SR-BI is able to form oligomers in micelles. Lastly, using microscale thermophoresis, we demonstrated that purified SR-BI binds to its ligands (apolipoprotein A-I, holoparticle HDL, and oxidized LDL) with high affinity, regardless of the glycosylation state of SR-BI. Together, these assays represent the first steps in resolving a high-resolution structure of human full-length SR-BI and provide promise for delineating the ways in which the HDL/SR-BI relationship allows for efficient cholesterol clearance.

Clinical Relevance of VEGFA (rs3025039) +936 C>T Polymorphism in Primary Myelofibrosis: Susceptibility, Clinical Co-Variates, and Outcomes.

We evaluated the association of VEGFA rs3025039 polymorphism with clinical co-variates and outcomes in 849 subjects with primary myelofibrosis (PMF) and 250 healthy controls. Minor T-allele frequency was higher in subjects with JAK2V617F compared with those without JAK2V617F (18% vs. 13%; p = 0.014). In subjects with JAK2V617F, the TT genotype was associated at diagnosis with lower platelet concentrations (p = 0.033), higher plasma LDH concentration (p = 0.005), higher blood CD34-positive cells (p = 0.027), lower plasma cholesterol concentration (p = 0.046), and higher concentration of high-sensitivity C-reactive protein (p = 0.018). These associations were not found in subjects with PMF without JAK2V617F. In subjects with the TT genotype, risk of death was higher compared with subjects with CC/CT genotypes (HR = 2.12 [1.03, 4.35], p = 0.041). Finally, the TT genotype was associated with higher frequency of deep vein thrombosis in typical sites (12.5% vs. 2.5%; OR = 5.46 [1.51, 19.7], p = 0.009). In conclusion, in subjects with PMF, the VEGFA rs3025039 CT or TT genotypes are more common in those with JAK2V617F than in those without JAK2V67F mutation and are associated with disease severity, poor prognosis, and risk of deep vein thrombosis.

Serum opacity factor normalizes dysfunctional HDL phenotype in SRB1 -/- mice

Background and Aims: Although plasma HDL-C levels negatively correlate with atherosclerotic cardiovascular disease (ACVD), attempts to reduce ACVD risk by raising plasma HDL have disappointed. The SRB1-/- mouse is an extreme model of HDL dsyfunctionality; compared to WT mice, SRB1-/- mice have higher plasma HDL with a free cholesterol (FC)-rich surface (60 vs. 15 mol%). HDL dysfunctionality among SRB1-/- mice is associated with atherosusceptibility and female infertility. Liver-specific SRB1 expression in SRB1-/- mice normalizes HDL size and FC content. Thus, the SRB1-/- mouse phenotype is due to lack of hepatic clearance of dysfunctional HDL. Serum opacity factor (SOF) is a bacterial protein that catalyzes the quantitative disproportionation of HDL into a cholesteryl ester-rich micro emulsion (CERM), neo HDL, and lipid-free apo AI. The CERM contains apo E and all HDL-CE. Injection of SOF into WT mice lowers plasma cholesterol by diverting the CERM to hepatic LDLR. Our studies will determine whether normalizing dysfunctional HDL in SRB1-/- mice by SOF leads to phenotypical changes in female infertility and atherosclerosis in a high-fat diet model.

Bacterial serum opacity factor catalyzes the discordant distribution of plasma proteins: Analysis by asymmetric flow flow-field fractionation (AF4)

Background and Aims: Serum opacity factor (SOF), a highly stable bacterial protein, converts HDL to three products, lipid-free APOA1, lipoprotein remnants (neo HDL), and large cholesteryl ester rich microemulsions (CERM). SOF has potential cardioprotective activities: both neo HDL and APOA1 support macrophage-free cholesterol efflux, and low-dose SOF in mice lowers plasma cholesterol (>50%) via the APOE-mediated targeting of CERM to hepatic receptors for disposal. Previous studies characterized the SOF reaction vs.

Rutin and Quercetin Decrease Cholesterol in HepG2 Cells but Not Plasma Cholesterol in Hamsters by Oral Administration.

Rutin (R) and quercetin (Q) are two widespread dietary flavonoids. Previous studies regarding the plasma cholesterol-lowering activity of R and Q generated inconsistent results. The present study was therefore carried out to investigate the effects of R and Q on cholesterol metabolism in both HepG2 cells and hypercholesterolemia hamsters. Results from HepG2 cell experiments demonstrate that both R and Q decreased cholesterol at doses of 5 and 10 µM. R and Q up-regulated both the mRNA and protein expression of sterol regulatory element binding protein 2 (SREBP2), low-density lipoprotein receptor (LDLR), and liver X receptor alpha (LXRα). The immunofluorescence study revealed that R and Q increased the LDLR expression, while only Q improved LDL-C uptake in HepG2 cells. Results from hypercholesterolemia hamsters fed diets containing R (5.5 g/kg diet) and Q (2.5 g/kg diet) for 8 weeks demonstrate that both R and Q had no effect on plasma total cholesterol. In the liver, only Q reduced cholesterol significantly. The discrepancy between the in vitro and in vivo studies was probably due to a poor bioavailability of flavonoids in the intestine. It was therefore concluded that R and Q were effective in reducing cholesterol in HepG2 cells in vitro, whereas in vivo, the oral administration of the two flavonoids had little effect on plasma cholesterol in hamsters.

Why to ignore alternative therapies in human population?

After having a meal, cholesterol is digested and absorbed in small intestine then the metabolism and storage occurred in the liver. The cholesterol may be secreted by the liver whenever the requirement of cholesterol is needed by the body. Cholesterol is not present in the food which is derived from the plants. We in this study have compared hypolipidemic effects of Fenugreek, Curcuma longa, and Lemon. Study was conducted at Jinnah Hospital Lahore-Pakistan from January 2016 to May 2016. Ninety hyperlipidemic patients of age group 19 to 70 were included in the study. Exclusion criteria were diabetic, alcoholic additives, hypertensive patients and those whose kidney or liver functions were impaired. Consent was taken from all participants. Their base line lipid profile was taken in biochemistry laboratory of the hospital. They were divided in three groups i.e. 30 patients in each group. Group-I was advised to take 500 mg of Curcuma longa (haldi) mixed in fresh milk without cream, thrice daily for two months. Group-II patients were advised to take 100 grams of Fenugreek leaves mixed with salad in each meal (thrice daily) for the period of two months. Group-III patients were advised to take 40 ml of fresh lemon juice mixed with 40 ml mineral water thrice daily for two months. They all were advised not to take heavy meal rich with any type of fat like junk food etc. One hour daily brisk walk was advised to all participants. 15 days follow up visit was scheduled for them. After two months their lipid profile was re-determined. When results were compiled and statistically analyzed by applying paired ‘t’ test, it revealed that Curcuma longa decreased total cholesterol, TG, LDL cholesterol 16.10, 20.01, and 17.59 mg/dl respectively. Fenugreek decreased total cholesterol, TGs, and LDL cholesterol 14.70, 17.33, and 17.06 mg/dl respectively. Lemon in two months therapy decreased total cholesterol, TGs, and LDL cholesterol 15.45, 10.13, and 11.97 mg/dl respectively. None of the above mentioned herbs raised HDL cholesterol significantly. It was concluded from this research work that Curcuma longa, Fenugreek leaves and Lemon are mild to moderately effective hypolipidemic herbs to lower total plasma cholesterol, triglycerides, and LDL cholesterol but have no potential to raise HDL cholesterol when analyzed.