Abstract 43: The Hypofunctional GPER P16L Variant is Associated With a Gene Dosage-Related Increase in Plasma LDL Cholesterol

Introduction: Estrogen deficiency is linked with dyslipidemia, especially in postmenopausal women, through a poorly understood mechanism. GPER is a recently recognized GPCR which is activated by estrogens. However, the role of GPER in mediating estrogen’s effects on lipid metabolism is unknown. We recently identified a common hypofunctional missense variant of GPER, namely P16L (allele frequency ~ 20%). We studied association of this with plasma LDL cholesterol levels. Further, we studied the role of GPER in regulating expression of the LDL receptor. Methods: Our discovery cohort was a genetically isolated population of Northern European descent (n=415), and our validation cohort consisted of 505 normal, healthy subjects 18-56 years of age from London, Ontario. Genomic DNA was extracted from whole blood and genotyped for GPER using a dedicated TaqMan assay. Additionally we examined the role of GPER on the regulation of LDL receptor expression by treatment with the GPER agonist, G1. Results: In the discovery cohort, the GPER P16L genetic variant was associated with a significant gene-dosage related increase in LDL cholesterol (CC [homozygous wild type] =3.18±0.84 (mean+SD); CT [heterozygote] =3.25±0.80; and TT [homozygous variant] =4.25±0.87 mmol/L, p&lt;0.05). Total cholesterol concentrations followed a similar gradient across genotypes. In the validation cohort, the GPER P16L genetic variant was associated with a similar significant gene-dosage related increase in LDL cholesterol (CC =2.16±0.67; CT [heterozygote] =2.29±0.67; TT =2.40±0.84 mmol/L, p&lt;0.05). In HepG2 cells expressing GPER, G1 mediated a concentration-dependent increase in LDL receptor expression. Pre-treating the cells with the GPER antagonist G15 attenuated the effect of G1 on LDL receptor upregulation. Further, downregulation of GPER expression via infection with a shGPER construct also attenuated G1's effect on LDL receptor upregulation. Conclusion: GPER activation upregulates LDL receptor expression. Further, carrying the hypofunctional P16L genetic variant of GPER, increases plasma LDL cholesterol in humans. In aggregate these data suggest an important role of GPER in regulation of LDL receptor expression and consequently LDL metabolism. </jats:p

Allogenic Fecal Microbiota Transplantation in Patients with Nonalcoholic Fatty Liver Disease Improves Abnormal Small Intestinal Permeability: A Randomized Control Trial

INTRODUCTION:Nonalcoholic fatty liver disease (NAFLD) is an obesity-related disorder that is rapidly increasing in incidence and is considered the hepatic manifestation of the metabolic syndrome. The gut microbiome plays a role in metabolism and maintaining gut barrier integrity. Studies have found differences in the microbiota between NAFLD and healthy patients and increased intestinal permeability in patients with NAFLD. Fecal microbiota transplantation (FMT) can be used to alter the gut microbiome. It was hypothesized that an FMT from a thin and healthy donor given to patients with NAFLD would improve insulin resistance (IR), hepatic proton density fat fraction (PDFF), and intestinal permeability.METHODS:Twenty-one patients with NAFLD were recruited and randomized in a ratio of 3:1 to either an allogenic (n = 15) or an autologous (n = 6) FMT delivered by using an endoscope to the distal duodenum. IR was calculated by HOMA-IR, hepatic PDFF was measured by MRI, and intestinal permeability was tested using the lactulose:mannitol urine test. Additional markers of metabolic syndrome and the gut microbiota were examined. Patient visits occurred at baseline, 2, 6 weeks, and 6 months post-FMT.RESULTS:There were no significant changes in HOMA-IR or hepatic PDFF in patients who received the allogenic or autologous FMT. Allogenic FMT patients with elevated small intestinal permeability (\u3e0.025 lactulose:mannitol, n = 7) at baseline had a significant reduction 6 weeks after allogenic FMT.DISCUSSION:FMT did not improve IR as measured by HOMA-IR or hepatic PDFF but did have the potential to reduce small intestinal permeability in patients with NAFLD

Soluble Epoxide Hydrolase Derived Linoleic Acid Oxylipins, Small Vessel Disease Markers, and Neurodegeneration in Stroke

Background Cerebral small vessel disease is associated with higher ratios of soluble-epoxide hydrolase derived linoleic acid diols (12,13-dihydroxyoctadecenoic acid [DiHOME]&nbsp;and 9,10-DiHOME) to their parent epoxides (12(13)-epoxyoctadecenoic acid [EpOME]&nbsp;and 9(10)-EpOME); however, the relationship has not yet been examined in stroke. Methods and Results Participants with mild to moderate small vessel stroke or large vessel stroke were selected based on clinical and imaging&nbsp;criteria. Metabolites were quantified by ultra-high-performance liquid chromatography-mass spectrometry. Volumes of stroke, lacunes, white matter hyperintensities, magnetic resonance imaging visible perivascular spaces, and free water diffusion were quantified from structural and diffusion magnetic resonance imaging (3 Tesla). Adjusted linear regression models were used for analysis. Compared with&nbsp;participants with large vessel stroke (n=30), participants with small vessel stroke (n=50) had a higher 12,13-DiHOME/12(13)-EpOME ratio (β=0.251, P=0.023). The 12,13-DiHOME/12(13)-EpOME ratio was associated with more lacunes (β=0.266, P=0.028) but not with large vessel stroke volumes. Ratios of 12,13-DiHOME/12(13)-EpOME and 9,10-DiHOME/9(10)-EpOME were associated with greater volumes of white matter hyperintensities (β=0.364, P&lt;0.001; β=0.362, P&lt;0.001) and white matter MRI-visible perivascular spaces (β=0.302, P=0.011; β=0.314, P=0.006). In small vessel stroke, the 12,13-DiHOME/12(13)-EpOME ratio was associated with higher white matter free water diffusion (β=0.439, P=0.016), which was specific to the temporal lobe in exploratory regional analyses. The 9,10-DiHOME/9(10)-EpOME ratio was associated with temporal lobe atrophy (β=-0.277, P=0.031). Conclusions Linoleic acid markers of cytochrome P450/soluble-epoxide hydrolase activity were associated with small versus large vessel stroke, with small vessel disease markers consistent with blood brain barrier and neurovascular-glial disruption, and temporal lobe atrophy. The findings may indicate a novel modifiable risk factor for small vessel disease and related neurodegeneration

PCSK9 inhibition with evolocumab (AMG 145) in heterozygous familial hypercholesterolaemia (RUTHERFORD-2): a randomised, double-blind, placebo-controlled trial

Background Heterozygous familial hypercholesterolaemia is characterised by low cellular uptake of LDL cholesterol, increased plasma LDL cholesterol concentrations, and premature cardiovascular disease. Despite intensive statin therapy, with or without ezetimibe, many patients are unable to achieve recommended target levels of LDL cholesterol. We investigated the effect of PCSK9 inhibition with evolocumab (AMG 145) on LDL cholesterol in patients with this disorder. Methods This multicentre, randomised, double-blind, placebo-controlled trial was undertaken at 39 sites (most of which were specialised lipid clinics, mainly attached to academic institutions) in Australia, Asia, Europe, New Zealand, North America, and South Africa between Feb 7 and Dec 19,2013.331 eligible patients (18-80 years of age), who met clinical criteria for heterozygous familial hypercholesterolaemia and were on stable lipid-lowering therapy for at least 4 weeks, with a fasting LDL cholesterol concentration of 2.6 mmol/L or higher, were randomly allocated in a 2:2:1:1 ratio to receive subcutaneous evolocumab 140 mg every 2 weeks, evolocumab 420 mg monthly, or subcutaneous placebo every 2 weeks or monthly for 12 weeks. Randomisation was computer generated by the study sponsor, implemented by a computerised voice interactive system, and stratified by LDL cholesterol concentration at screening (higher or lower than 4.1 mmol/L) and by baseline ezetimibe use (yes/no). Patients, study personnel, investigators, and Amgen study staff were masked to treatment assignments within dosing frequency groups. The coprimary endpoints were percentage change from baseline in LDL cholesterol at week 12 and at the mean of weeks 10 and 12, analysed by intention-to-treat. This trial is registered with ClinicalTrials.gov, number NCT01763918. Findings Of 415 screened patients, 331 were eligible and were randomly assigned to the four treatment groups: evolocumab 140 mg every 2 weeks (n=111), evolocumab 420 mg monthly (n=110), placebo every 2 weeks (n=55), or placebo monthly (n=55). 329 patients received at least one dose of study drug. Compared with placebo, evolocumab at both dosing schedules led to a significant reduction in mean LDL cholesterol at week 12 (every-2-weeks dose: 59.2% reduction [95% CI 53.4-65.1], monthly dose: 61.3% reduction [53.6-69.0]; both p<0.0001) and at the mean of weeks 10 and 12 (60.2% reduction [95% CI 54.5-65.8] and 65.6% reduction [59.8-71.3]; both p<0.0001). Evolocumab was well tolerated, with rates of adverse events similar to placebo. The most common adverse events occurring more frequently in the evolocumab-treated patients than in the placebo groups were nasopharyngitis (in 19 patients [9%] vs five [5%] in the placebo group) and muscle-related adverse events (ten patients [5%] vs 1 [1%]). Interpretation In patients with heterozygous familial hypercholesterolaemia, evolocumab administered either 140 mg every 2 weeks or 420 mg monthly was well tolerated and yielded similar and rapid 60% reductions in LDL cholesterol compared with placebo