Project description:High Density Lipoproteins (HDLs) have long been considered as "good cholesterol," beneficial to the whole body and, in particular, to cardio-vascular health. However, HDLs are complex particles that undergoes dynamic remodeling through interactions with various enzymes and tissues throughout their life cycle, making the complete understanding of its functions and roles more complicated than initially expected. In this review, we explore the novel understanding of HDLs' behavior in health and disease as a multifaceted class of lipoprotein, with different size subclasses, molecular composition, receptor interactions, and functionality. Further, we report on emergent HDL-based therapeutics tested in small and larger scale clinical trials and their mixed successes.
Project description:Previous studies demonstrated that pomegranate, which is a source of several bioactive molecules, induces modifications of high-density lipoproteins (HDL) lipid composition and functionality. However, it remains unclear whether the beneficial effects of pomegranate are related to improvement in the lipid components of HDL. Therefore, in this placebo-controlled study, we characterized the size and lipid composition of HDL subclasses and assessed the functionality of these lipoproteins after 30 days of supplementation with a pomegranate microencapsulated (MiPo) in New Zealand white rabbits. We observed a significant decrease in plasma cholesterol, triglycerides, and non-HDL sphingomyelin, as well as increases in HDL cholesterol and HDL phospholipids after supplementation with MiPo. Concomitantly, the triglycerides of the five HDL subclasses isolated by electrophoresis significantly decreased, whereas phospholipids, cholesterol, and sphingomyelin of HDL subclasses, as well as the HDL size distribution remained unchanged. Of particular interest, the triglycerides content of HDL, estimated by the triglycerides-to-phospholipids ratio, decreased significantly after MiPo supplementation. The modification on the lipid content after the supplementation was associated with an increased resistance of HDL to oxidation as determined by the conjugated dienes formation catalyzed by Cu2+. Accordingly, paraoxonase-1 (PON1) activity determined with phenylacetate as substrate increased after MiPo. The effect of HDL on endothelial function was analyzed by the response to increasing doses of acetylcholine of aorta rings co-incubated with the lipoproteins in an isolated organ bath. The HDL from rabbits that received placebo partially inhibited the endothelium-dependent vasodilation. In contrast, the negative effect of HDL on endothelial function was reverted by MiPo supplementation. These results show that the beneficial effects of pomegranate are mediated at least in part by improving the functionality of HDL, probably via the reduction of the content of triglycerides in these lipoproteins.
Project description:Atopic dermatitis is a common inflammatory skin disease with a strong heritable component. Pathogenetic models consider keratinocyte differentiation defects and immune alterations as scaffolds, and recent data indicate a role for autoreactivity in at least a subgroup of patients. FLG (encoding filaggrin) has been identified as a major locus causing skin barrier deficiency. To better define risk variants and identify additional susceptibility loci, we densely genotyped 2,425 German individuals with atopic dermatitis (cases) and 5,449 controls using the Immunochip array followed by replication in 7,196 cases and 15,480 controls from Germany, Ireland, Japan and China. We identified four new susceptibility loci for atopic dermatitis and replicated previous associations. This brings the number of atopic dermatitis risk loci reported in individuals of European ancestry to 11. We estimate that these susceptibility loci together account for 14.4% of the heritability for atopic dermatitis.
Project description:BackgroundStructural abnormalities in the brain of patients with atopic dermatitis (AD) have been reported; however, the cause has not been determined yet. Herein, we used Mendelian randomization (MR) to reveal the causal effect of AD on brain structure.MethodsThis study utilized summary statistics from genome-wide association studies (GWASs) to investigate a collection of cerebral structural measures, encompassing cortical thickness (CT), cortical surface area (CA), and subcortical volumes in T1 images. A comprehensive GWAS meta-analysis identified a total of 20 independent single nucleotide polymorphisms linked to AD, surpassing the genome-wide significance threshold (p < 5 × 10⁻⁸). MR estimates were aggregated through the application of the inverse variance weighted method. Additional complementary analyses (i.e., MR-Egger and weighted median approaches) were conducted to further assess the robustness of the obtained results. Sensitivity analysis and multivariate MR (MVMR) while adjusting for brain structural changes risk factors (i.e., depression and anxiety) were performed to assess the reliability and stability of observed causality.ResultsGenetically determined AD exhibited a causal link with reduced caudate volumes (IVW-MR: β = -0.186, p = 0.001, p-corrected = 0.009). Furthermore, we identified potential causal associations between AD and reduced CT in the cingulate region (posterior cingulate, IVW-MR: β = -0.065, p = 0.018, p-corrected = 0.551; isthmus cingulate, IVW-MR: β = -0.086, p = 0.003, p-corrected = 0.188), as well as abnormal cortical surface area (CA) in the supramarginal (IVW-MR: β = -0.047, p = 0.044, p-corrected = 0.714) and isthmus cingulate (IVW-MR: β = 0.053, p = 0.018, p-corrected = 0.714). Additional supplementary analyses yielded consistent outcomes. There was no evidence of horizontal pleiotropy. MVMR analysis showed that the causal effects of AD on abnormal brain structure remained significant while adjusting for depression and anxiety.ConclusionThis MR study provided suggestive evidence that decreased caudate nucleus, posterior cingulate cortex, isthmus cingulate cortex and supramarginal gyrus are suggestively associated with higher AD risk. Future investigation into the brain regions is recommended, which helps to clarify the underlying mechanisms and point to new therapies against AD.
Project description:We quantified differential microRNA (miRNA) expression on human HDL before and after incubation with human coronary artery endothelial cells. These data were used to determine which miRNAs are altered on HDL (taken up or effluxed to) by human coronary artery endothelial cells.
Project description:ObjectiveDamage to the vascular endothelium is strongly implicated in the pathogenesis of idiopathic inflammatory myopathies (IIM). Normally, high-density lipoprotein (HDL) protects the vascular endothelium from damage from oxidized phospholipids, which accumulate under conditions of oxidative stress. The current work evaluated the antioxidant function of HDL in IIM patients.MethodsHDL's antioxidant function was measured in IIM patients using a cell-free assay, which assesses the ability of isolated patient HDL to inhibit oxidation of low-density lipoproteins and is reported as the HDL inflammatory index (HII). Cholesterol profiles were measured for all patients, and subgroup analysis included assessment of oxidized fatty acids in HDL and plasma MPO activity. A subgroup of IIM patients was compared with healthy controls.ResultsThe antioxidant function of HDL was significantly worse in patients with IIM (n = 95) compared with healthy controls (n = 41) [mean (S.d.) HII 1.12 (0.61) vs 0.82 (0.13), P < 0.0001]. Higher HII associated with higher plasma MPO activity [mean (S.d.) 13.2 (9.1) vs 9.1 (4.6), P = 0.0006] and higher oxidized fatty acids in HDL. Higher 5-hydroxyeicosatetraenoic acid in HDL correlated with worse diffusion capacity in patients with interstitial lung disease (r = -0.58, P = 0.02), and HDL's antioxidant function was most impaired in patients with autoantibodies against melanoma differentiation-associated protein 5 (MDA5) or anti-synthetase antibodies. In multivariate analysis including 182 IIM patients, higher HII was associated with higher disease activity and DM diagnosis.ConclusionThe antioxidant function of HDL is abnormal in IIM patients and may warrant further investigation for its role in propagating microvascular inflammation and damage in this patient population.
Project description:In this work, we developed a targeted glycoproteomic method to monitor the site-specific glycoprofiles and quantities of the most abundant HDL-associated proteins using Orbitrap LC-MS for (glyco)peptide target discovery and QqQ LC-MS for quantitative analysis. We conducted a pilot study using the workflow to determine whether HDL protein glycoprofiles are altered in healthy human participants in response to dietary glycan supplementation.
Project description:Dyslipidemia is a typical trait of patients with chronic kidney disease (CKD) and it is typically characterized by reduced high-density lipoprotein (HDL)-cholesterol(c) levels. The low HDL-c concentration is the only lipid alteration associated with the progression of renal disease in mild-to-moderate CKD patients. Plasma HDL levels are not only reduced but also characterized by alterations in composition and structure, which are responsible for the loss of atheroprotective functions, like the ability to promote cholesterol efflux from peripheral cells and antioxidant and anti-inflammatory proprieties. The interconnection between HDL and renal function is confirmed by the fact that genetic HDL defects can lead to kidney disease; in fact, mutations in apoA-I, apoE, apoL, and lecithin-cholesterol acyltransferase (LCAT) are associated with the development of renal damage. Genetic LCAT deficiency is the most emblematic case and represents a unique tool to evaluate the impact of alterations in the HDL system on the progression of renal disease. Lipid abnormalities detected in LCAT-deficient carriers mirror the ones observed in CKD patients, which indeed present an acquired LCAT deficiency. In this context, circulating LCAT levels predict CKD progression in individuals at early stages of renal dysfunction and in the general population. This review summarizes the main alterations of HDL in CKD, focusing on the latest update of acquired and genetic LCAT defects associated with the progression of renal disease.
Project description:Decades of epidemiological studies have established the strong inverse relationship between high-density lipoprotein (HDL)-cholesterol concentration and cardiovascular disease. Recent evidence suggests that HDL particle functions, including anti-inflammatory and antioxidant functions, and cholesterol efflux capacity may be more strongly associated with cardiovascular disease protection than HDL cholesterol concentration. These HDL functions are also relevant in non-cardiovascular diseases, including acute and chronic kidney disease. This review examines our current understanding of the kidneys' role in HDL metabolism and homeostasis, and the effect of kidney disease on HDL composition and functionality. Additionally, the roles of HDL particles, proteins, and small RNA cargo on kidney cell function and on the development and progression of both acute and chronic kidney disease are examined. The effect of HDL protein modification by reactive dicarbonyls, including malondialdehyde and isolevuglandin, which form adducts with apolipoprotein A-I and impair proper HDL function in kidney disease, is also explored. Finally, the potential to develop targeted therapies that increase HDL concentration or functionality to improve acute or chronic kidney disease outcomes is discussed.
Project description:Circulating lipoproteins may offer interesting properties as therapeutic carriers for cytokines and hormones, in terms of both stability and bio-distribution. The fusion of apolipoprotein A-I with interleukin-15 (IL-15) targets the latter to high-density lipoproteins (HDLs). The bioactivity of this chimera can be further enhanced by creating triple fusions with IL-15 receptor α domain involved in IL-15 trans-presentation.