Major Lipoprotein Research Articles

Lipid Trajectories Improve Risk Models for Alzheimer’s Disease and Mild Cognitive Impairment

In this retrospective, case-control study, we tested the hypothesis that blood-lipid concentrations during the decade prior to cognitive symptom onset can inform risk prediction for Alzheimer's disease (AD) and stable mild cognitive impairment (MCI). Clinically well-characterized cases were diagnosed using DSM-IV criteria; MCI cases had been stable for ≥5 years; and controls were propensity matched to cases at symptom onset (MCI: 116 cases, 435 controls; AD: 215 cases, 483 controls). Participants were grouped based on (i) longitudinal trajectories and (ii) quintile of variability independent of the mean (VIM) for total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, non-HDL-C, and ln(triglycerides). Risk models evaluated the contributions of lipid trajectory and VIM groups relative to APOE genotype or polygenic risk scores (PRS) for AD and lipid levels and major lipoprotein confounders: age, lipid-lowering medications, comorbidities, and other longitudinal correlates of blood-lipid concentrations. In models with AD-PRS, higher MCI-risk was associated with the two lower HDL-C trajectories [odds ratios: 3.8(1.3−11.3; P=0.014), 3.2(1.1−9.3; P=0.038), relative to the high trajectory], and the lowest VIM quintile of non-HDL-C [odds ratio: 2.2 (1.3−3.8:P=0.004), relative to quintiles 2−5]. Higher AD-risk was associated with the two lower HDL-C trajectories [odds ratios: 2.8(1.5−5.1; P=0.001), 3.7 (2.0−7.0; P<0.001)], and the lowest VIM quintile of TC [odds ratio: 2.5(1.5−4.0: P<0.001)]. Inclusion of lipid-trajectory and VIM groups improved risk-model predictive performance independent of APOE and AD or lipid-level PRS. These results provide important real-world perspectives on how longitudinal levels and variation of blood-lipid concentrations contribute to risk of cognitive decline.

Abstract 2044: Disruption Of DENND5B Attenuates Triglyceride-rich Lipoprotein Secretion From Human Enterocytes And Hepatocytes

Background and Hypothesis: Elevated plasma triacylglycerides (TAGs) are an established risk factor for atherosclerotic cardiovascular disease, and are regulated by dietary absorption via the small intestine and endogenous production by the liver. Our laboratory formerly reported that Dennd5b -deficient mice are protected from diet-induced hepatic steatosis, hyperlipidemia, and atherosclerosis. Electron microscopy imaging of the intestinal epithelium of Dennd5b -/- mice reveals significant lipid accumulation in intracellular chylomicron secretory vesicles, suggesting a post-Golgi chylomicron secretion defect. Given that Dennd5b is expressed by the two major triglyceride-rich lipoprotein (TRL)-secreting organs (liver and small intestine), we hypothesized that disruption of DENND5B attenuates TRL secretion in both of these cell types in humans. Methods and Results: To determine if DENND5B disruption impairs TRL secretion in human cells, we generated DENND5B -/- intestinal epithelial (Caco-2) and hepatocyte (HepG2) cell lines using CRISPR gene editing. Western blots verified DENND5B protein reduction in DENND5B -/- cells. The impact of DENND5B deficiency on TRL secretion was quantified by measuring the cellular and secreted TAG content of DENND5B +/+ and DENND5B -/- cells under standard growth conditions and after oleic acid loading. Caco-2 cells were differentiated on membrane supports for 21 days prior to experiments. DENND5B -/- Caco-2 cells secreted significantly less TAGs compared to wild-type Caco-2 cells (-67.8%, p&lt;0.0001). DENND5B -/- HepG2 cells also had significantly reduced TAG secretion (-91.0%, p&lt;0.0001). Disruption of DENND5B in both cell lines reduced TAG secretion without affecting cellular TAG content. Immunofluorescence microscopy showed intracellular DENND5B protein localization consistent with secretory pathway involvement with detection on a perinuclear structure (likely Golgi), cytosolic vesicles, and plasma membrane. Conclusions: These studies suggest that DENND5B plays a role in TRL secretion from human enterocytes and hepatocytes and provide new model systems for investigating the molecular function of DENND5B in TRL secretion from human cells.

Dietary n-3 alpha-linolenic and n-6 linoleic acids modestly lower serum lipoprotein(a) concentration but differentially influence other atherogenic lipoprotein traits: A randomized trial

Background and aimsLipoprotein(a) [Lp(a)] is a causal, genetically determined cardiovascular risk factor. Limited evidence suggests that dietary unsaturated fat may increase serum Lp(a) concentration by 10–15 %. Linoleic acid may increase Lp(a) concentration through its endogenous conversion to arachidonic acid, a process regulated by the fatty acid desaturase (FADS) gene cluster. We aimed to compare the Lp(a) and other lipoprotein trait-modulating effects of dietary alpha-linolenic (ALA) and linoleic acids (LA). Additionally, we examined whether FADS1 rs174550 genotype modifies Lp(a) responses. MethodsA genotype-based randomized trial was performed in 118 men homozygous for FADS1 rs174550 SNP (TT or CC). After a 4-week run-in period, the participants were randomized to 8-week intervention diets enriched with either Camelina sativa oil (ALA diet) or sunflower oil (LA diet) 30–50 mL/day based on their BMI. Serum lipid profile was measured at baseline and at the end of the intervention. ResultsALA diet lowered serum Lp(a) concentration by 7.3 % (p = 0.003) and LA diet by 9.5 % (p < 0.001) (p = 0.089 for between-diet difference). Both diets led to greater absolute decreases in individuals with higher baseline Lp(a) concentration (p < 0.001). Concentrations of LDL cholesterol (LDL-C), non-HDL-C, remnant-C, and apolipoprotein B were lowered more by the ALA diet (p < 0.01). Lipid or lipoprotein responses were not modified by the FADS1 rs174550 genotype. ConclusionsA considerable increase in either dietary ALA or LA from vegetable oils has a similar Lp(a)-lowering effect, whereas ALA may lower other major atherogenic lipids and lipoproteins to a greater extent than LA. Genetic differences in endogenous PUFA conversion may not influence serum Lp(a) concentration.

Role of LpnA in Francisella tularensis Susceptibility to Resazurin

Francisella tularensis is classified by the Centers for Disease Control and Prevention as a Category A bioterrorism agent due to its low infectious dose, ease of aerosolization, and high mortality rate. Given there is no licensed tularemia vaccine and the possibility of antibiotic-resistant F. tularensis strains, there is an urgent need to develop new treatments against this bacterium. Resazurin (Rz) has bactericidal activity against F. tularensis and other gram-negative bacteria including the human pathogens Neisseria gonorrhoeae and Helicobacter pylori. However, the mechanism of action for Rz has yet to be determined. To identify targets of Rz, we screened for Rz-resistant (Rzr) mutants of F. tularensis LVS. Whole genome sequencing was performed on 42 Rzr isolates and all contained mutations within the coding regions of FTL_0421 and FTL_1504. FTL_0421 encodes for LpnA, the major lipoprotein in F. tularensis. The FTL_0421 mutation in Rzr1 resulted in loss of LpnA expression which correlated with increased sensitivity to osmotic stress. To investigate the individual role of lpnA in Rz-resistance, a deletion mutant (ΔlpnA) was generated using standard molecular genetics techniques. An agar dilution assay was then performed to determine the Rz susceptibility of the ΔlpnA strain. A minimum inhibitory concentration (MIC) of 2.75μg/mL was achieved for the ΔlpnA and the LVS wild-type strain. This data suggests mutation of lpnA alone is not sufficient to confer resistance to resazurin. In the future, we will investigate whether lpnA in combination with other genes like FTL_1504 play a role in resazurin susceptibility in F. tularensis. (Supported by NIH Grant P20GM103434 to the West Virginia IDeA Network for Biomedical Research Excellence &amp; the NASA Space Grant Consortium)

Targeting NPC1 in Renal Cell Carcinoma

Rapidly proliferating cancer cells have a greater requirement for cholesterol than normal cells. Tumor cells are largely dependent on exogenous lipids given that their growth requirements are not fully met by endogenous pathways. Our current study shows that ccRCC cells have redundant mechanisms of cholesterol acquisition. We demonstrate that all major lipoproteins (i.e., LDL, HDL, and VLDL) have a comparable ability to support the growth of ccRCC cells and are equally effective in counteracting the antitumor activities of TKIs. The intracellular trafficking of exogenous lipoprotein-derived cholesterol appears to be distinct from the movement of endogenously synthesized cholesterol. De novo synthetized cholesterol is transported from the endoplasmic reticulum directly to the plasma membrane and to the acyl-CoA: cholesterol acyltransferase, whereas lipoprotein-derived cholesterol is distributed through the NPC1-dependent endosomal trafficking system. Expression of NPC1 is increased in ccRCC at mRNA and protein levels, and high expression of NPC1 is associated with poor prognosis. Our current findings show that ccRCC cells are particularly sensitive to the inhibition of endolysosomal cholesterol export and underline the therapeutic potential of targeting NPC1 in ccRCC.

Major lipids and lipoprotein levels and risk of blood pressure elevation: a Mendelian Randomisation study

BackgroundQuantitative nuclear magnetic resonance (NMR) metabolomics techniques provide detailed measurements of lipoprotein particle concentration. Metabolic dysfunction often represents a cluster of conditions, including dyslipidaemia, hypertension, and diabetes, that increase the risk of cardiovascular diseases (CVDs). However, the causal relationship between lipid profiles and blood pressure (BP) remains unclear. We performed a Mendelian Randomisation (MR) study to disentangle and prioritize the potential causal effects of major lipids, lipoprotein particles, and circulating metabolites on BP and pulse pressure (PP). MethodsWe employed single-nucleotide polymorphisms (SNPs) associated with major lipids, lipoprotein particles, and other metabolites from the UK Biobank as instrumental variables. Summary-level data for BP and PP were obtained from the Genetic Epidemiology Research on Adult Health and Aging (GERA) cohort. Two-sample MR and MR Bayesian model averaging approaches (MR-BMA) were conducted to analyse and rank causal associations. FindingsGenetically predicted TG was the most likely causal exposure among the major lipids to increase systolic blood pressure (SBP) and diastolic blood pressure (DBP), with marginal inclusion probabilities (MIPs) of 0.993 and 0.847, respectively. Among the majority of lipoproteins and their containing lipids, including major lipids, genetically elevated TG in small high-density lipoproteins (S_HDL_TG) had the strongest association with the increase of SBP and DBP, with MIPs of 0.416 and 0.397, respectively. HDL cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were potential causal factors for PP elevation among the major lipids (MIP = 0.927 for HDL-C and MIP = 0.718 for LDL-C). Within the sub-lipoproteins, genetically predicted atherogenic lipoprotein particles (i.e., sub-very low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), and LDL particles) had the most likely causal impact on increasing PP. InterpretationThis study provides genetic evidence for the causality of lipids on BP indicators. However, the effect size on SBP, DBP, and PP varies depending on the lipids’ components and sizes. Understanding this potential relationship may inform the potential benefits of comprehensive management of lipid profiles for BP control. FundingKey Research and Development Program of Hubei Province, Science and Technology Innovation Project of Huanggang Central Hospital of Yangtze University, the Hubei Industrial Technology Research Institute of Heart-Brain Diseases, and the Hubei Provincial Engineering Research Centre of Comprehensive Care for Heart-Brain Diseases.

Isoform‐ and cellular metabolism‐specific apolipoprotein E (ApoE) lipidation in astrocytes

AbstractBackgroundApolipoprotein E (ApoE) is the major lipoprotein in the brain and connects the metabolic interactions between astrocytes and neurons. The E4 variant (APOE4) affects this function and represents a genetic predisposition for Alzheimer’s disease (AD), but the molecular mechanisms remain unclear.MethodWe have integrated cell‐free in vitro assays, a new cell system based on isogenic iPSC‐derived astrocytes and lipidomics to study ApoE lipidation, and how this is affected by genetic polymorphism.ResultWe show that ApoE produces different types of lipoprotein particles via distinct lipidation pathways. ApoE forms high‐density lipoprotein (HDL)‐like, cholesterol‐rich particles via the ATP‐binding cassette transporter 1 (ABCA1), a mechanism largely unaffected by ApoE polymorphism. Alternatively, ectopic accumulation of fat in astrocytes, a stress‐associated condition, redirects ApoE toward the assembly and secretion of triacylglycerol‐rich lipoprotein particles, a process boosted by the APOE4 variant. We demonstrate in vitro that ApoE can detect triacylglycerol in membranes and spontaneously assemble lipoprotein particles (10‐20 nm) rich in unsaturated triacylglycerol, and that APOE4 has remarkable properties behaving as a strong triacylglycerol binder. Fatty APOE4 astrocytes have reduced ability to clear toxic fatty acids from the extracellular milieu, because APOE4 reroutes them back to secretion.ConclusionThe molecular mechanisms discussed here provide a new model explaining the interaction between genetic polymorphism and environmental factors, such as dyslipidaemia or aging, in the aetiology of late‐onset AD, as well as inspire possible new strategies for therapeutic intervention.Graphical abstract from https://doi.org/10.1016/j.celrep.2022.110435.

The relationship between ApoE4 and lipid dysregulation in glia of the PS19 mouse model of tauopathy

AbstractBackgroundApolipoprotein E4 (apoE), the major lipoprotein in the brain, plays an essential role in brain`s lipid homeostasis; furthermore, the presence of the apoE4 allele is the strongest genetic risk factor for developing late‐onset AD compared to most common apoE3 and protective apoE2 alleles. Recent studies in iPSC microglia and astrocytes demonstrate that apoE modulates cholesterol dysfunction and inflammatory responses in an isoform‐specific fashion. However, it is not known if lipid accumulation in glia mediates toxic effects in vivo in the context of tauopathy and neurodegeneration.MethodIn this work we used the combination unbiased lipidomics coupled with immunostainings to dissect the role of apoE and apoE isoforms in glial lipid metabolism of tauopathy P301S tau transgenic mice with a targeted replacement of murine apoE with human ApoE4, ApoE3, or ApoE KO. We further treated the P301S/ApoE4 mice with the LXR agonist GW3965 to test if promoting cholesterol efflux in P301S mice would reduce tau pathology and neurodegeneration in this model.ResultsBy performing unbiased lipidomic analysis of forebrain samples, we demonstrate that P301S/ApoE KI mice accumulate significant amounts of specific cholesteryl esters, oxidized sterols and endolysosomal BMP lipids in an ApoE‐isoform and Tau‐dependent manner. We further show that microglia from aged 9.5 months old P301S/ApoE4 mice accumulate significant amounts of neutral BODIPY‐positive lipid inclusions within lysosomes. Next, we demonstrate that the oral administration of the LXR agonist GW3965 for 3 months significantly reduces p‐tau‐positive AT8 immunostaining in cortex and hippocampus, protects from associated brain neurodegeneration, and improves nesting behavior in 9.5 months old P301S/ApoE4 mice. Using bulk RNA sequencing and immunostaining, we show that LXR agonist diet induces changes in cholesterol biosynthesis and metabolism that result in a significant reduction of neuroinflammatory responses in aged P301S/ApoE4 mice. Lastly, using unbiased lipidomics of forebrain tissues we demonstrate that P301S/ApoE4 mice on LXR diet exhibit significantly lower levels of cholesterol esters when compared to tau transgenic animals on control diet.ConclusionsTogether, we demonstrate that ApoE4 promotes lipid accumulation in glia in the setting of tauopathy and that reducing the accumulation of these lipids by LXR activation is neuroprotective.

The Rrp2-RpoN-RpoS pathway plays an important role in the blood-brain barrier transmigration of the Lyme disease pathogen.

Lyme disease, caused by Borrelia (or Borreliella) burgdorferi, is a complex multisystemic disorder that includes Lyme neuroborreliosis resulting from the invasion of both the central and peripheral nervous systems. However, factors that enable the pathogen to cross the blood-brain barrier (BBB) and invade the central nervous system (CNS) are still not well understood. The objective of this study was to identify the B. burgdorferi factors required for BBB transmigration. We utilized a transwell BBB model based on human brain-microvascular endothelial cells and focused on investigating the Rrp2-RpoN-RpoS pathway, a central regulatory pathway that is essential for mammalian infection by B. burgdorferi. Our results demonstrated that the Rrp2-RpoN-RpoS pathway is crucial for BBB transmigration. Furthermore, we identified OspC, a major surface lipoprotein controlled by the Rrp2-RpoN-RpoS pathway, as a significant contributor to BBB transmigration. Constitutive production of OspC in a mutant defective in the Rrp2-RpoN-RpoS pathway did not rescue the impairment in BBB transmigration, indicating that this pathway controls additional factors for this process. Two other major surface lipoproteins controlled by this pathway, DbpA/B and BBK32, appeared to be dispensable for BBB transmigration. In addition, both the surface lipoprotein OspA and the Rrp1 pathway, which are required B. burgdorferi colonization in the tick vector, were found not required for BBB transmigration. Collectively, our findings using in vitro transwell assays uncover another potential role of the Rrp2-RpoN-RpoS pathway in BBB transmigration of B. burgdorferi and invasion into the CNS.

Possible effect of mutations on serological detection of Borrelia burgdorferi sensu stricto ospC major groups: An in-silico study.

The outer surface protein C (OspC) of the agent of Lyme disease, Borrelia burgdorferi sensu stricto, is a major lipoprotein surface-expressed during early-phase human infections. Antibodies to OspC are used in serological diagnoses. This study explored the hypothesis that serological test sensitivity decreases as genetic similarity of ospC major groups (MGs) of infecting strains, and ospC A (the MG in the strain B31 used to prepare antigen for serodiagnosis assays) decreases. We used a previously published microarray dataset to compare serological reactivity to ospC A (measured as pixel intensity) versus reactivity to 22 other ospC MGs, within a population of 55 patients diagnosed by two-tier serological testing using B. burgdorferi s.s. strain B31 as antigen, in which the ospC MG is OspC A. The difference in reactivity of sera to ospC A and reactivity to each of the other 22 ospC MGs (termed 'reactivity difference') was the outcome variable in regression analysis in which genetic distance of the ospC MGs from ospC A was the explanatory variable. Genetic distance was computed for the whole ospC sequence, and 9 subsections, from Neighbour Joining phylogenetic trees of the 23 ospC MGs. Regression analysis was conducted using genetic distance for the full ospC sequence, and the subsections individually. There was a significant association between the reactivity difference and genetic distance of ospC MGs from ospC A: increased genetic distance reduced reactivity to OspC A. No single ospC subsection sequence fully explained the relationship between genetic distance and reactivity difference. An analysis of single nucleotide polymorphisms supported a biological explanation via specific amino acid modifications likely to change protein binding affinity. This adds support to the hypothesis that genetic diversity of B. burgdorferi s.s. (here specifically OspC) may impact serological diagnostic test performance. Further prospective studies are necessary to explore the clinical implications of these findings.

Comparison of on-Statin Lipid and Lipoprotein Levels for the Prediction of First Cardiovascular Event in Type 2 Diabetes Mellitus.

A substantial cardiovascular disease risk remains even after optimal statin therapy. Comparative predictiveness of major lipid and lipoprotein parameters for cardiovascular events in patients with type 2 diabetes mellitus (T2DM) who are treated with statins is not well documented. From the Korean Nationwide Cohort, 11,900 patients with T2DM (≥40 years of age) without a history of cardiovascular disease and receiving moderate- or high-intensity statins were included. The primary outcome was the first occurrence of major adverse cardiovascular events (MACE) including ischemic heart disease, ischemic stroke, and cardiovascular death. The risk of MACE was estimated according to on-statin levels of low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), highdensity lipoprotein cholesterol (HDL-C), and non-HDL-C. MACE occurred in 712 patients during a median follow-up period of 37.9 months (interquartile range, 21.7 to 54.9). Among patients achieving LDL-C levels less than 100 mg/dL, the hazard ratios for MACE per 1-standard deviation change in ontreatment values were 1.25 (95% confidence interval [CI], 1.07 to 1.47) for LDL-C, 1.31 (95% CI, 1.09 to 1.57) for non-HDL-C, 1.05 (95% CI, 0.91 to 1.21) for TG, and 1.16 (95% CI, 0.98 to 1.37) for HDL-C, after adjusting for potential confounders and lipid parameters mutually. The predictive ability of on-statin LDL-C and non-HDL-C for MACE was prominent in patients at high cardiovascular risk or those with LDL-C ≥70 mg/dL. On-statin LDL-C and non-HDL-C levels are better predictors of the first cardiovascular event than TG or HDL-C in patients with T2DM.

Disturbed lipid profile in common variable immunodeficiency - a pathogenic loop of inflammation and metabolic disturbances.

The relationship between metabolic and inflammatory pathways play a pathogenic role in various cardiometabolic disorders and is potentially also involved in the pathogenesis of other disorders such as cancer, autoimmunity and infectious diseases. Common variable immunodeficiency (CVID) is the most common primary immunodeficiency in adults, characterized by increased frequency of airway infections with capsulated bacteria. In addition, a large proportion of CVID patients have autoimmune and inflammatory complications associated with systemic inflammation. We summarize the evidence that support a role of a bidirectional pathogenic interaction between inflammation and metabolic disturbances in CVID. This include low levels and function of high-density lipoprotein (HDL), high levels of triglycerides (TG) and its major lipoprotein very low-density lipoprotein (VLDL), and an unfavorable fatty acid (FA) profile. The dysregulation of TG, VLDL and FA were linked to disturbed gut microbiota profile, and TG and VLDL levels were strongly associated with lipopolysaccharides (LPS), a marker of gut leakage in blood. Of note, the disturbed lipid profile in CVID did not include total cholesterol levels or high low-density lipoprotein levels. Furthermore, increased VLDL and TG levels in blood were not associated with diet, high body mass index and liver steatosis, suggesting a different phenotype than in patients with traditional cardiovascular risk such as metabolic syndrome. We hypothesize that these metabolic disturbances are linked to inflammation in a bidirectional manner with disturbed gut microbiota as a potential contributing factor.

Low-grade inflammation is associated with a heterogeneous lipoprotein subclass profile in an apparently healthy population sample

Background and aimsPrevention measures for cardiovascular diseases (CVD) have shifted their focus from lipoproteins to the immune system. However, low-grade inflammation and dyslipidemia are tightly entangled. The objective of this study was to assess the relations between a broad panel of inflammatory biomarkers and lipoprotein subclass parameters.MethodsWe utilized data from the population-based Study of Health in Pomerania (SHIP-TREND, n = 403). Plasma concentrations of 37 inflammatory markers were measured by a bead-based assay. Furthermore, we employed nuclear magnetic resonance spectroscopy to measure total cholesterol, total triglycerides, total phospholipids as well as the fractional concentrations of cholesterol, triglycerides, phospholipids, ApoA1, ApoA2 and ApoB in all major lipoprotein subclasses. Associations between inflammatory biomarkers and lipoprotein subclasses were analyzed by adjusted linear regression models.ResultsAPRIL, BAFF, TWEAK, sCD30, Pentraxin-3, sTNFR1, sTNFR2, Osteocalcin, Chitinase 3-like 1, IFN-alpha2, IFN-gamma, IL-11, IL-12p40, IL-29, IL-32, IL-35, TSLP, MMP1 and MMP2 were related with lipoprotein subclass components, forming two distinct clusters. APRIL had inverse relations to HDL-C (total and subclasses) and HDL Apo-A1 and Apo-A2 content. MMP-2 was inversely related to VLDL-C (total and subclasses), IDL-C as well as LDL5/6-C and VLDL-TG, IDL-TG, total triglycerides as well as LDL5/5-TG and HDL4-TG. Additionally, we identified a cluster of cytokines linked to the Th1-immune response, which were associated with an atherogenic lipoprotein profile.ConclusionOur findings expand the existing knowledge of inflammation-lipoprotein interactions, many of which are suggested to be involved in the pathogeneses of chronic non-communicable diseases. The results of our study support the use of immunomodulatory substances for the treatment and possibly prevention of CVD.

Increased Plasma Levels of Triglyceride-Enriched Lipoproteins Associate with Systemic Inflammation, Lipopolysaccharides, and Gut Dysbiosis in Common Variable Immunodeficiency

PurposeTriglycerides (TG) and their major transport lipoprotein in the circulation (VLDL) appear to be related to inflammation. Patients with common variable immunodeficiency (CVID) have inflammatory complications associated with gut microbial dysbiosis. We hypothesized that CVID patients have disturbed TG/VLDL profiles associated with these clinical characteristics.MethodsWe measured plasma concentrations of TGs, inflammatory markers, and lipopolysaccharide (LPS) in 95 CVID patients and 28 healthy controls. Additionally, in 40 CVID patients, we explored plasma lipoprotein profiling, fatty acid, gut microbial dysbiosis, and diet.ResultsTG levels were increased in CVID patients as compared to healthy controls (1.36 ± 0.53 mmol/l versus 1.08 ± 0.56 [mean, SD], respectively, P = 0.008), particularly in the clinical subgroup “Complications,” characterized by autoimmunity and organ-specific inflammation, compared to “Infection only” (1.41 mmol/l, 0.71[median, IQR] versus [1.02 mmol/l, 0.50], P = 0.021). Lipoprotein profile analyses showed increased levels of all sizes of VLDL particles in CVID patients compared to controls. TG levels correlated positively with CRP (rho = 0.256, P = 0.015), IL-6 (rho = 0.237, P = 0.021), IL-12 (rho = 0.265, P = 0.009), LPS (r = 0.654, P = 6.59 × 10−13), CVID-specific gut dysbiosis index (r = 0.315, P = 0.048), and inversely with a favorable fatty acid profile (docosahexaenoic acid [rho = − 0.369, P = 0.021] and linoleic acid [rho = − 0.375, P = 0.019]). TGs and VLDL lipids did not appear to be associated with diet and there were no differences in body mass index (BMI) between CVID patients and controls.ConclusionWe found increased plasma levels of TGs and all sizes of VLDL particles, which were associated with systemic inflammation, LPS, and gut dysbiosis in CVID, but not diet or BMI.

Electrochemical immunosensor utilizing a multifunctional 3D nanocomposite coating with antifouling capability for urinary bladder cancer diagnosis

Currently available point-of-care tests for Bladder Cancer (BC) are qualitative and prone to high false positives, thus preventing them from replacing clinical cystoscopy as reliable stand-alone diagnostics. In this study, we have targeted this unmet need by developing a label-free electrochemical impedimetric immunosensor for detection of APO-A1, a major high-density lipoprotein that is overexpressed in the urine of early-stage bladder cancer patients. The immunosensor utilizes a novel multifunctional 3D nanocomposite coating consisting of a porous bovine serum albumin (BSA) matrix embedded with a network of highly conductive and biocompatible gold coated silver nanowires (Au@AgNWs). The main components of this nanocomposite coating and their specific functions include: (i) A 3D porous BSA matrix to enable oriented antibody conjugation and prevent non-specific protein adsorption while allowing diffusion of analyte with minimal hindrance as compared to traditional antifouling coatings (ii) Embedded Au@AgNWs that enhance biocompatibility and improve charge transfer to the underlying electrode. The nanocomposite coating demonstrated minimal decrease in electrochemical performance even after 1-month of incubation in 1% BSA, human serum and human urine. Furthermore, the low-cost and disposable screen-printed electrochemical immunosensor exhibited excellent feasibility for sensitive and specific APO-A1 detection in the clinically relevant sensing range of 100 pg/mL to 250 ng/mL with high reproducibility (n = 5, RSD=2.2%) and an impressive LOD of 22 pg/mL. These results highlight the potential of the proposed immunosensor to enable reliable early diagnosis of bladder cancer at the point-of-care and serve as a viable alternative to cystoscopy.

ASSESSMENT OF LIPID LEVELS TO GAUGE HEALTH

The age where the girls need additional nutrition for the development for their body is termed as adolescence. Childhood undernourishment is considered as a concerned issue in India, especially in slums. Considering the undernourishment, major lipoproteins like, total cholesterol (Tc), low density lipoprotein (LDL-c), high density lipoproteins (HDL-c), very low-density lipoprotein (VLDL-c) and triglycerides (TG) were estimated for nutritional status in the adolescent population also pertaining its use as a screening method for disease diagnosis. The study comprised 50 healthy and 50 underprivileged Adolescents as group II and 2 respectively within the age of 14-18 years. The study parameters were evaluated and the results indicated signicant difference in both the study groups.

Particle Size Distribution of Plasma Lipoproteins in Donkeys from Death Valley Compared to a Sampling of Horses.

Simple SummaryDonkeys, like horses, belong to the Equidae family. Though they share some physical attributes, much of their physiology is quite different from horses. Both horses and donkeys can develop clinical issues associated with obesity; insulin dysregulation; and altered lipid metabolism, often termed equine metabolic syndrome or donkey metabolic syndrome, respectively. Unlike large breed horses, however, donkeys, ponies, and miniature horses are more susceptible to developing dyslipidemias. This study aimed to use a novel Lipoprint® assay to compare the lipid profiles of apparently healthy donkeys and large-breed horses to establish a baseline for future work that may lead to the use of this test methodology for the evaluation and monitoring of equids with endocrine disorders.The clinical evaluation of lipid metabolism in equids is often limited to the measurement of total cholesterol and triglyceride concentrations. This provides a limited picture of metabolic state and general health, given the continuous exchange of lipid species between various lipoproteins. Major lipoprotein classes in equids include high-density lipoprotein (HDL), intermediate-density lipoprotein (IDL), low-density lipoprotein (LDL), very low-density lipoprotein (VLDL), and chylomicrons (CM). Unlike large breed horses, donkeys are highly susceptible to hepatic lipidosis. Currently, serum triglyceride concentrations serve as a surrogate marker of hepatic lipid exportation. Both VLDL, indicative of hepatic exportation, and its metabolic end-product, LDL, are rich in triglycerides, and contribute to this value. Diagnostic assays that distinguish VLDL from LDL could be useful in better recognizing the hepatic pathology in donkeys. The compositional differences of lipoproteins across species limit the use of commercially available assays developed for the measurement of human lipoproteins in domestic animals. In this study, we evaluated a high-resolution polyacrylamide gel electrophoresis method (Lipoprint®) for separating major lipoprotein classes and sub-fractionating LDL and HDL based on particle size in a large group of donkeys, and compared the pattern to a representative set of horses. Donkeys proved an HDL-rich species, with HDL accounting for the bulk of all lipoproteins (average 78.45%, SD 6.6%, range 92.2–55%). VLDL accounted for a large portion of the total (average 21.6%, SD 6.6%, range 37.1–7.8%), with minimal amounts of LDL detected. The horses tested had higher proportions of VLDL as compared to donkeys (31.7% and 21.6%, respectively p = 0.00008). The later finding draws into question the purported relationship between VLDL, high triglycerides, and hepatic lipidosis, given the incidence of the disease in donkeys is far higher than in horses.

Identification and transcriptional profile of Culex quinquefasciatus Say (Diptera: Culicidae) lipophorin in different stages.

Lipophorin is a major hemolymph lipoprotein found in insects with a molecular native mass of 700 kDa. In mosquitoes,two different types of apolipoproteins are characterized, apolipophorin-I (ApoLp-I, ~250 kDa) and apolipophorin-II (ApoLp-II, ~80 kDa). This concentration depends on the stage of development and the age of the insects. Lipophorins are best studied in mosquitoes of the genus Aedes and Anopheles. In this study, we analyze the lipophorin sequence and show the lipophorin purification of the Culexquinquefasciatus and the transcriptional profile of the lipophorin gene in different life cycle stages. Similar amino acid composition and molecular weights are founded in three mosquitoes species lipophorins amino acid sequence. The two subunits of purified lipophorin (Apo I and Apo II) showed molecular masses of approximately 248 and 93 kDa, like that found in other mosquitoes. A gradual increase in the lipophorin expression gene was obtained during the previtellogenic period and after feeding we obtained peak expression at 24 h after feeding. With our results, we conclude that C. quinquefasciatusprotein sequence has the same characteristics as those observed in other mosquitoes and that the expression of its apolipophorins is induced by blood feeding.

A Defect in Lipoprotein Modification by Lgt Leads to Abnormal Morphology and Cell Death in Escherichia coli That Is Independent of Major Lipoprotein Lpp.

ABSTRACTLgt is an essential enzyme in proteobacteria and therefore a potential target for novel antibiotics. The effect of Lgt depletion on growth, morphology, and viability was studied in Escherichia coli to assess whether absence of Lgt leads to cell death. Two Lgt depletion strains were used in which lgt was under the control of an arabinose-inducible promoter that allowed regulation of Lgt protein levels. Reduced levels of Lgt led to severe growth and morphological defects that could be restored by expressing lgt in trans, demonstrating that only Lgt is responsible for the distorted phenotypes. In the absence of major lipoprotein Lpp, growth defects were partially restored when low levels of Lgt were still present; however, lgt could not be deleted in the absence of Lpp. Our results demonstrate that Lpp is not the main cause of cell death under conditions of Lgt depletion and that other lipoproteins are important in cell envelope biogenesis and cell viability. Specific inhibitors of Lgt are thus promising for the development of novel antibiotics.IMPORTANCE Incomplete maturation and envelope mislocalization of lipoproteins, through inhibition or mutations in lipoprotein modification enzymes or transport to the outer membrane, are lethal in proteobacteria. Resistance to small-molecule inhibition or the appearance of suppressor mutations is often directly correlated with the presence of abundant outer membrane lipoprotein Lpp. Our results show that Lgt, the first enzyme of the lipoprotein modification pathway, is still required for growth and viability in the absence of Lpp and thus is necessary for the function of other essential lipoproteins in the cell envelope. This adds credence to the hypothesis that Lgt is essential in proteobacteria and an attractive target for the development of novel antibiotics.

Apolipoprotein A1 Enhances Endothelial Cell Survival in an In Vitro Model of ALS.

Altered lipoprotein metabolism is considered a pathogenic component of amyotrophic lateral sclerosis (ALS). Apolipoprotein A1 (ApoA1), a major high-density lipoprotein (HDL) protein, is associated with prevention of vascular damage. However, ApoA1’s effects on damaged endothelium in ALS are unknown. This study aimed to determine therapeutic potential of ApoA1 for endothelial cell (EC) repair under a pathologic condition reminiscent of ALS. We performed in vitro studies using mouse brain ECs (mBECs) exposed to plasma from symptomatic G93A SOD1 mice. Dosage effects of ApoA1, including inhibition of the phosphoinoside 3-kinase (PI3K)/Akt signaling pathway and integration of ApoA1 into mBECs were examined. Also, human bone marrow-derived endothelial progenitor cells (hBM-EPCs) and mBECs were co-cultured without cell contact to establish therapeutic mechanism of hBM-EPC transplantation. Results showed that ApoA1 significantly reduced mBEC death via the PI3K/Akt downstream signaling pathway. Also, ApoA1 was incorporated into mBECs as confirmed by blocked ApoA1 cellular integration. Co-culture system provided evidence that ApoA1 was secreted by hBM-EPCs and incorporated into injured mBECs. Thus, our study findings provide important evidence for ApoA1 as a potential novel therapeutic for endothelium protection in ALS. This in vitro study lays the groundwork for further in vivo research to fully determine therapeutic effects of ApoA1 in ALS.