MR Imaging Findings in Anti-Leucine-Rich Glioma Inactivated Protein 1 Encephalitis: A Systematic Review and Meta-analysis.

BACKGROUND: Antibodies against leucine-rich glioma inactivated protein 1 (LGI1) constitute a common form of autoimmune encephalitis. On MR imaging, it may show T2 FLAIR hyperintensities of the medial temporal lobe (T2 FLAIR-MTL), involve the basal ganglia, or be unremarkable. PURPOSE: We performed a systematic review and meta-analysis to obtain prevalence estimates of abnormal findings on MR imaging in anti-LGI1 encephalitis. A human brain map of the LGI1 microarray gene expression was derived from the Allen Human Brain Atlas. DATA SOURCES: PubMed and Web of Science were searched with the terms "LGI1" and "encephalitis" from inception to April 7, 2022. STUDY SELECTION: Thirty-one research publications, encompassing case series and retrospective cohort and case-control studies, with >10 patients with anti-LGI1 encephalitis and MR imaging data were included. DATA ANALYSIS: Pooled prevalence estimates were calculated using Freeman-Tukey double-arcsine transformation. Meta-analysis used DerSimonian and Laird random effects models. DATA SYNTHESIS: Of 1318 patients in 30 studies, T2 FLAIR-MTL hyperintensities were present in 54% (95% CI, 0.48-0.60; I2 = 76%). Of 394 patients in 13 studies, 27% showed bilateral (95% CI, 0.19-0.36; I2 = 71%) and 24% unilateral T2 FLAIR-MTL abnormalities (95% CI, 0.17-0.32; I2 = 61%). Of 612 patients in 15 studies, basal ganglia abnormalities were present in 10% (95% CI, 0.06-0.15; I2 = 67%). LGI1 expression was highest in the amygdala, hippocampus, and caudate nucleus. LIMITATIONS: Only part of the spectrum of MR imaging abnormalities in anti-LGI1 encephalitis could be included in a meta-analysis. MR imaging findings were not the main outcomes in most studies, limiting available information. I2 values ranged from 62% to 76%, representing moderate-to-large heterogeneity. CONCLUSIONS: T2 FLAIR-MTL hyperintensities were present in around one-half of patients with anti-LGI1. The prevalence of unilateral and bilateral presentations was similar, suggesting unilaterality should raise the suspicion of this disease in the appropriate clinical context. Around 10% of patients showed basal ganglia abnormalities, indicating that special attention should be given to this region. LGI1 regional expression coincided with the most frequently reported abnormal findings on MR imaging. Regional specificity might be partially determined by expression levels of the target protein.

A single and short exposure to heated tobacco vapor or cigarette smoke affects macrophage activation and polarization.

The toxicity of heated tobacco products (HTP) on the immune cells remains unclear. Here, U937-differentiated macrophages were exposed to a single and short-term exposure (30 minutes) of HTP vapor or cigarette smoke (CS) in an air-liquid interface (ALI) system to evaluate the effects on macrophages' early activation and polarization. In our system, HTP released lower amounts of polycyclic aromatic hydrocarbons (PAHs), but higher nicotine levels than CS into the cell culture supernatant. Both tobacco products triggered the expression of the α-7 nicotinic receptor (α7 nAChR) and reactive oxygen species (ROS) production. When challenged with a bacterial product, lipopolysaccharide (LPS), cells exposed to HTP or CS failed to respond properly and enhance ROS production upon LPS stimuli. Furthermore, both tobacco products also impaired bacterial phagocytosis and the exposures triggered higher IL-1ß secretion. The α7 nAChR antagonist treatment rescued the effects caused only by HTP exposure. The CS-exposed group switched macrophage to the pro-inflammatory M1, while HTP polarized to the suppressive M2 profile. Associated, data highlight that HTP and CS exposures similarly activate macrophages; nonetheless, the α7 nAChR pathway is only involved in HTP actions, and the distinct subsequent polarization caused by HTP or CS may influence the outcome of host defense.

Analysis of omarigliptin forced degradation products by ultra-fast liquid chromatography, mass spectrometry, and in vitro toxicity assay.

Omarigliptin (OMG) is an antidiabetic drug indicated for the treatment of type 2 diabetes mellitus. Forced degradation studies are practical experiments to evaluate the stability of drugs and to establish degradation profiles. Herein, we present the investigation of the degradation products (DPs) of OMG formed under various stress conditions. OMG was subjected to hydrolytic (alkaline and acidic), oxidative, thermal, and photolytic forced degradation. A stability-indicating ultra-fast liquid chromatography method was applied to separate and quantify OMG and its DPs. Five DPs were adequately separated and detected in less than 6 min, while other published methods detected four DPs. MS was applied to identify and obtain information on the structural elucidation of the DPs. Three m/z DPs confirmed previously published research, and two novel DPs were described in this paper. The toxicity of OMG and its DPs were investigated for the first time using in vitro cytotoxicity assays, and the sample under oxidative conditions presented significant cytotoxicity. Based on the results from forced degradation studies, OMG was found to be labile to hydrolysis, oxidation, photolytic, and thermal stress conditions. The results of this study contribute to the quality control and stability profile of OMG.

Interaction of Statherin-Derived Peptide with the Surface of Hydroxyapatite: Perspectives Based on Molecular Dynamics Simulations.

INTRODUCTION: Statherin-derived peptide (StatpSpS) has shown promise against erosive tooth wear. To elucidate its interaction with the hydroxyapatite (HAP) surface, the mechanism related to adsorption of this peptide with HAP was investigated through nanosecond-long all-atom molecular dynamics simulations. METHODS: StatpSpS was positioned parallel to the HAP surface in 2 orientations: 1 - neutral and negative residues facing the surface and 2 - positive residues facing the surface. A system containing StatpSpS without HAP was also simulated as control. In the case of systems with HAP, both partially restrained surface and unrestrained surface were constructed. Structural analysis, interaction pattern, and binding-free energy were calculated. RESULTS: In the peptide system without the HAP, there were some conformational changes during the simulation. In the presence of the surface, only moderate changes were observed. Many residues exhibited short and stable distances to the surface, indicating strong interaction. Specially, the residues ASP1 and SER2 have an important role to anchor the peptide to the surface, with positively charged residues, mainly arginine, playing a major role in the further stabilization of the peptide in an extended conformation, with close contacts to the HAP surface. CONCLUSION: The interaction between StatpSpS and HAP is strong, and the negative charged residues are important to the anchoring of the peptide in the surface, but after the initial placement the peptide rearranges itself to maximize the interactions between positive charged residues.

Conversion from seismic to underwater sound waves along the Louisville Seamount Chain.

The conversion from seismic to ocean-acoustic waves occurs in different places on the bottom of the ocean, often hundreds to thousands of kilometers away from the epicenter. Here, we investigate this conversion process by studying 15 large-magnitude earthquakes that occurred between 2014 and 2022 along the Kermadec Arc in the southwestern Pacific Ocean. To pinpoint the location where seismic-to-acoustic conversion takes places, we analyze hydroacoustic signals recorded by a hydrophone triplet station of the International Monitoring System in the Juan Fernández archipelago. Results from direction-of-arrival and travel-time calculations indicate that the location of the conversion zone largely matches segments of the Louisville Seamount Chain, its lateral extent ranging from approximately 300 to 1800 km, and its location depending on the geometry between earthquake epicenter and the seamounts.

Dimensional crossover in Kardar-Parisi-Zhang growth.

Two-dimensional (2D) Kardar-Parisi-Zhang (KPZ) growth is usually investigated on substrates of lateral sizes L_{x}=L_{y}, so that L_{x} and the correlation length (ξ) are the only relevant lengths determining the scaling behavior. However, in cylindrical geometry, as well as in flat rectangular substrates L_{x}≠L_{y} and, thus, the surfaces can become correlated in a single direction, when ξ∼L_{x}≪L_{y}. From extensive simulations of several KPZ models, we demonstrate that this yields a dimensional crossover in their dynamics, with the roughness scaling as W∼t^{ß_{2D}} for t≪t_{c} and W∼t^{ß_{1D}} for t≫t_{c}, where t_{c}∼L_{x}^{1/z_{2D}}. The height distributions (HDs) also cross over from the 2D flat (cylindrical) HD to the asymptotic Tracy-Widom Gaussian orthogonal ensemble (Gaussian unitary ensemble) distribution. Moreover, 2D to one-dimensional (1D) crossovers are found also in the asymptotic growth velocity and in the steady-state regime of flat systems, where a family of universal HDs exists, interpolating between the 2D and 1D ones as L_{y}/L_{x} increases. Importantly, the crossover scalings are fully determined and indicate a possible way to solve 2D KPZ models.

Differential atrophy along the longitudinal hippocampal axis in Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that primarily affects the hippocampus. Since hippocampal studies have highlighted a differential subregional regulation along its longitudinal axis, a more detailed analysis addressing subregional changes along the longitudinal hippocampal axis has the potential to provide new relevant biomarkers. This study included structural brain MRI data of 583 participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Cognitively normal (CN) subjects, mild cognitively impaired (MCI) subjects and AD patients were conveniently selected considering the age and sex match between clinical groups. Structural MRI acquisitions were pre-processed and analysed with a new longitudinal axis segmentation method, dividing the hippocampus in three subdivisions (anterior, intermediate, and posterior). When normalizing the volume of hippocampal sub-divisions to total hippocampus, the posterior hippocampus negatively correlates with age only in CN subjects (r = -.31). The longitudinal ratio of hippocampal atrophy (anterior sub-division divided by the posterior one) shows a significant increase with age only in CN (r = .25). Overall, in AD, the posterior hippocampus is predominantly atrophied early on. Consequently, the anterior/posterior hippocampal ratio is an AD differentiating metric at early disease stages with potential for diagnostic and prognostic applications.

Development of an innovative analytical method for forensic detection of cocaine, antidepressants, and metabolites in postmortem blood using magnetic nanoparticles.

Cocaine and antidepressants rank high globally in substance consumption, emphasizing their impact on public health. The determination of these compounds and related substances in biological samples is crucial for forensic toxicology. This study focused on developing an innovative analytical method for the determination of cocaine, antidepressants, and their related metabolites in postmortem blood samples, using unmodified commercial Fe3O4 nanoparticles as a sorbent for dispersive magnetic solid-phase extraction (m-d-SPE), coupled with liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) analysis. An aliquot of 100 µL of whole blood and 5 µL of the internal standard pool were added to 30 mg of nanoparticles. The nanoparticles were separated from the sample using a neodymium magnet inserted into a 3D-printed microtube rack. The liquid was then discarded, followed by desorption with 300 µL of 1/1/1 acetonitrile/methanol/ethyl acetate. The sample was vortexed and separated, and 1.5 µL of the organic supernatant was injected into the LC-MS/MS. The method was acceptably validated and successfully applied to 263 postmortem blood samples. All samples evaluated in this study were positive for at least one substance. The most frequent analyte was benzoylecgonine, followed by cocaine and cocaethylene. The most common antidepressants encountered in the analyzed samples were citalopram and fluoxetine, followed by fluoxetine's metabolite norfluoxetine. This study describes the first report of this sorbent in postmortem blood analysis, demonstrating satisfactory results for linearity, precision, accuracy, and selectivity for all compounds. The method's applicability was confirmed, establishing it as an efficient and sustainable alternative to traditional techniques for forensic casework.

Non-targeted isomer-sensitive N-glycome analysis reveals new layers of organ-specific diversity in mice.

N-glycosylation is one of the most common protein modifications in eukaryotes, with immense importance at the molecular, cellular, and organismal level. Accurate and reliable N-glycan analysis is essential to obtain a systems-wide understanding of fundamental biological processes. Due to the structural complexity of glycans, their analysis is still highly challenging. Here we make publicly available a consistent N-glycome dataset of 20 different mouse tissues and demonstrate a multimodal data analysis workflow that allows for unprecedented depth and coverage of N-glycome features. This highly scalable, LC-MS/MS data-driven method integrates the automated identification of N-glycan spectra, the application of non-targeted N-glycome profiling strategies and the isomer-sensitive analysis of glycan structures. Our delineation of critical sub-structural determinants and glycan isomers across the mouse N-glycome uncovered tissue-specific glycosylation patterns, the expression of non-canonical N-glycan structures and highlights multiple layers of N-glycome complexity that derive from organ-specific regulations of glycobiological pathways.

Excess of body weight is associated with accelerated T-cell senescence in hospitalized COVID-19 patients.

BACKGROUND: Several risk factors have been involved in the poor clinical progression of coronavirus disease-19 (COVID-19), including ageing, and obesity. SARS-CoV-2 may compromise lung function through cell damage and paracrine inflammation; and obesity has been associated with premature immunosenescence, microbial translocation, and dysfunctional innate immune responses leading to poor immune response against a range of viruses and bacterial infections. Here, we have comprehensively characterized the immunosenescence, microbial translocation, and immune dysregulation established in hospitalized COVID-19 patients with different degrees of body weight. RESULTS: Hospitalised COVID-19 patients with overweight and obesity had similarly higher plasma LPS and sCD14 levels than controls (all p < 0.01). Patients with obesity had higher leptin levels than controls. Obesity and overweight patients had similarly higher expansions of classical monocytes and immature natural killer (NK) cells (CD56+CD16-) than controls. In contrast, reduced proportions of intermediate monocytes, mature NK cells (CD56+CD16+), and NKT were found in both groups of patients than controls. As expected, COVID-19 patients had a robust expansion of plasmablasts, contrasting to lower proportions of major T-cell subsets (CD4 + and CD8+) than controls. Concerning T-cell activation, overweight and obese patients had lower proportions of CD4+CD38+ cells than controls. Contrasting changes were reported in CD25+CD127low/neg regulatory T cells, with increased and decreased proportions found in CD4+ and CD8+ T cells, respectively. There were similar proportions of T cells expressing checkpoint inhibitors across all groups. We also investigated distinct stages of T-cell differentiation (early, intermediate, and late-differentiated - TEMRA). The intermediate-differentiated CD4 + T cells and TEMRA cells (CD4+ and CD8+) were expanded in patients compared to controls. Senescent T cells can also express NK receptors (NKG2A/D), and patients had a robust expansion of CD8+CD57+NKG2A+ cells than controls. Unbiased immune profiling further confirmed the expansions of senescent T cells in COVID-19. CONCLUSIONS: These findings suggest that dysregulated immune cells, microbial translocation, and T-cell senescence may partially explain the increased vulnerability to COVID-19 in subjects with excess of body weight.

Psychosis in Alzheimer's disease is associated with specific changes in brain MRI volume, cognition and neuropathology.

Psychosis in Alzheimer's Disease (AD) is prevalent and indicates poor prognosis. However, the neuropathological, cognitive and brain atrophy patterns underlying these symptoms have not been fully elucidated. In this study, we evaluated 178 patients with AD neuropathological change (ADNC) and ante-mortem volumetric brain magnetic resonance imaging (MRI). Presence of psychosis was determined using the Neuropsychiatric Inventory Questionnaire. Clinical Dementia Rating Sum-of-boxes (CDR-SB) was longitudinally compared between groups with a follow-up of 3000 days using mixed-effects multiple linear regression. Neuropsychological tests closest to the time of MRI and brain regional volumes were cross-sectionally compared. Psychosis was associated with lower age of death, higher longitudinal CDR-SB scores, multi-domain cognitive deficits, higher neuritic plaque severity, Braak stage, Lewy Body pathology (LB) and right temporal lobe regional atrophy. Division according to the presence of LB showed differential patterns of AD-typical pathology, cognitive deficits and regional atrophy. In conclusion, psychosis in ADNC with and without LB has clinical value and associates with subgroup patterns of neuropathology, cognition and regional atrophy.

Design, Development, and Validation of a First, Low-cost, Three-dimensional (3D) Printed Optical Urethrotomy Simulation Model.

OBJECTIVE: To develop and validate a low-cost, portable, and reusable simulation model for optical internal urethrotomy (OIU) training. METHODS: A 3D-printed low-cost simulation model for OIU was designed locally and the final model was evaluated by trainees and trainers at the urology boot camps (UK, Belgium, Portugal, Poland). Participants were asked to complete a questionnaire, using a 6-item 5-point Likert Scale, to assess the model's anatomic realism. RESULTS: A total of 27 trainees and 9 trainers evaluated the model. The model's anatomy and color were rated as the most realistic features, with 88.9% and 11.1% of respondents rating them as good and excellent, respectively. There were no significant differences between consultants and trainees in their assessment of any of the simulation properties of the OIU model. CONCLUSION: Our study introduces an innovative, lifelike, and cost-effective simulation model for OIU training. Our model provides a realistic simulation of OIU. We feel that our low-cost and reusable model fills the gap in simulation-based training for young trainees in urology.

Enhancement of colorectal cancer therapy through interruption of the HSF1-HSP90 axis by p53 activation or cell cycle inhibition.

The stress-associated molecular chaperone system is an actionable target in cancer therapies. It is ubiquitously upregulated in cancer tissues and enables tumorigenicity by stabilizing hundreds of oncoproteins and disturbing the stoichiometry of protein complexes. Most inhibitors target the key component heat-shock protein 90 (HSP90). However, although classical HSP90 inhibitors are highly tumor-selective, they fail in phase 3 clinical oncology trials. These failures are at least partly due to an interference with a negative feedback loop by HSP90 inhibition, known as heat-shock response (HSR): in response to HSP90 inhibition there is compensatory synthesis of stress-inducible chaperones, mediated by the transcription factor heat-shock factor 1 (HSF1). We recently identified that wildtype p53 (p53) actively reduces the HSR by repressing HSF1 via a p21-CDK4/6-MAPK-HSF1 axis. Here we test the hypothesis that in HSP90-based therapies simultaneous p53 activation or direct cell cycle inhibition interrupts the deleterious HSF1-HSR axis and improves the efficiency of HSP90 inhibitors. Indeed, we find that the clinically relevant p53 activator Idasanutlin suppresses the HSF1-HSR activity in HSP90 inhibitor-based therapies. This combination synergistically reduces cell viability and accelerates cell death in p53-proficient colorectal cancer (CRC) cells, murine tumor-derived organoids and patient-derived organoids (PDOs). Mechanistically, upon combination therapy human CRC cells strongly upregulate p53-associated pathways, apoptosis, and inflammatory immune pathways. Likewise, in the chemical AOM/DSS CRC model in mice, dual HSF1-HSP90 inhibition strongly represses tumor growth and remodels immune cell composition, yet displays only minor toxicities in mice and normal mucosa-derived organoids. Importantly, inhibition of the cyclin dependent kinases 4 and 6 (CDK4/6) under HSP90 inhibition phenocopies synergistic repression of the HSR in p53-proficient CRC cells. Even more important, in p53-deficient (mutp53-harboring) CRC cells, an HSP90 inhibition in combination with CDK4/6 inhibitors similarly suppresses the HSF1-HSR system and reduces cancer growth. Likewise, p53-mutated PDOs strongly respond to dual HSF1-HSP90 pathway inhibition and thus, providing a strategy to target CRC independent of the p53 status. In sum, activating p53 (in p53-proficient cancer cells) or inhibiting CDK4/6 (independent of the p53 status) provide new options to improve the clinical outcome of HSP90-based therapies and to enhance colorectal cancer therapy.

A validated dilute-and-shoot LC-MS-MS urine screening for the analysis of 95 illicit drugs and medicines: Insights from clinical and forensic Brazilian cases.

Urine toxicological analysis is a relevant tool in both clinical and forensic scenarios, enabling the diagnosis of acute poisonings, elucidation of deaths, verification of substance use in the workplace and identification of drug-facilitated crimes. For these analyses, the dilute-and-shoot technique associated with liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS) is a promising alternative since it has demonstrated satisfactory results and broad applicability. This study developed and validated a comprehensive LC-MS-MS screening method to analyze 95 illicit drugs and medicines in urine samples and application to clinical and forensic Brazilian cases. The dilute-and-shoot protocol was defined through multivariate optimization studies and was set using 100 µL of sample and 300 µL of solvent. The total chromatographic run time was 7.5 min. The method was validated following the recommendations of the ANSI/ASB Standard 036 Guideline. The lower limits of quantification varied from 20 to 100 ng/mL. Within-run and between-run precision coefficient of variations% were <20%, and bias was within ± 20%. Only 4 of the 95 analytes presented significant ionization suppression or enhancement (>25%). As proof of applicability, 839 urine samples from in vivo and postmortem cases were analyzed. In total, 90.9% of the analyzed samples were positive for at least one substance, and 78 of the 95 analytes were detected. The most prevalent substances were lidocaine (40.2%), acetaminophen (38.0%) and benzoylecgonine (31.5%). The developed method proved to be an efficient and simplified alternative for analyzing 95 therapeutic and illicit drugs in urine samples. Additionally, the results obtained from sample analysis are essential for understanding the profile of Brazilian substance use, serving as a valuable database for the promotion of health and safety public policies.

Integrative open workflow for confident annotation and molecular networking of metabolomics MSE/DIA data.

Liquid chromatography coupled with high-resolution mass spectrometry data-independent acquisition (LC-HRMS/DIA), including MSE, enable comprehensive metabolomics analyses though they pose challenges for data processing with automatic annotation and molecular networking (MN) implementation. This motivated the present proposal, in which we introduce DIA-IntOpenStream, a new integrated workflow combining open-source software to streamline MSE data handling. It provides 'in-house' custom database construction, allows the conversion of raw MSE data to a universal format (.mzML) and leverages open software (MZmine 3 and MS-DIAL) all advantages for confident annotation and effective MN data interpretation. This pipeline significantly enhances the accessibility, reliability and reproducibility of complex MSE/DIA studies, overcoming previous limitations of proprietary software and non-universal MS data formats that restricted integrative analysis. We demonstrate the utility of DIA-IntOpenStream with two independent datasets: dataset 1 consists of new data from 60 plant extracts from the Ocotea genus; dataset 2 is a publicly available actinobacterial extract spiked with authentic standard for detailed comparative analysis with existing methods. This user-friendly pipeline enables broader adoption of cutting-edge MS tools and provides value to the scientific community. Overall, it holds promise for speeding up metabolite discoveries toward a more collaborative and open environment for research.

Infected Thrombosed Popliteal Artery Aneurysm With Cutaneous Fistula.

Introduction: Popliteal artery aneurysms (PAAs) pose some challenges in their surgical management and are often treated by exclusion and bypass procedures. However, post-operative complications, such as endoleaks and sac growth, can occur, potentially leading to serious consequences. Endoleaks, characterised by persistent flow within the aneurysm sac after repair, can cause sac expansion, increasing the risk of adverse outcomes, including the formation of cutaneous fistulae, a rare but potentially severe complication. Report: A 75 year old male with a history of previous bilateral PAA exclusion with a left femoropopliteal bypass using reversed great saphenous vein (GSV) graft in 2012 and a right femoropopliteal bypass using a PTFE prosthesis in 2017, both through medial approach, presented with pain and ulceration in the left popliteal region. Previous angiography had shown residual arterial flow through collateral vessels, requiring thrombin injection. Bilateral bypass thrombosis had also occurred after discontinuing anticoagulation. Computed tomography angiography confirmed a complicated excluded left popliteal aneurysm with superinfection. The patient underwent elective surgery, involving partial aneurysmectomy, endoaneurysmorrhaphy, and fistulectomy through a posterior approach. Post-operatively, the patient experienced resolution of symptoms and inflammatory signs. Discussion: The optimal approach for treating PAAs remains a subject of debate, with some experts advocating the posterior approach to prevent sac growth. However, others support the medial approach, reporting satisfactory results. In this case, the medial approach resulted in incomplete exclusion, leading to sac expansion and a cutaneous fistula. Timely re-intervention through the posterior approach successfully resolved the complication. This report highlights a rare but serious complication of incomplete PAA exclusion. Vigilant post-operative surveillance and intervention are crucial to manage such cases effectively. Further research is warranted to determine the optimal approach for PAA repair and prevent associated complications.

Adoption of digital twins as a sustainable energy solution: Determinants to adoption in household.

Digital Twin (DT) consists of a recent technology that can enable sustainability. However, Digital Twins are still in early stages of adoption, especially in households, and so the determinants to this adoption have not yet been determined. The aim of this study is to fill this research gap through providing a conceptual model of the drivers to the adoption of Digital Twins in households and it's relation to well-being. This study is developed as a mixed-methods research. The model is produced qualitatively, based on literature discoveries and key findings from interviews with experts and possible consumers. Afterwards, the model was validated with data collected through a questionnaire with 149 respondents. Results show that a set of informational, social, environmental and utility factors can influence the intention to adopt Digital Twins as a sustainable energy solution, and consequently the perceived well-being.

APOE genotype dictates lipidomic signatures in primary human hepatocytes.

Apolipoprotein E (APOE) genetic variants are most notably known for their divergent impact on the risk of developing Alzheimer's disease. While APOE genotype has been consistently shown to modulate lipid metabolism in a variety of cellular contexts, the effect of APOE alleles on the lipidome in hepatocytes is unknown. In this study, we investigated the contribution of APOE alleles to lipidomic profiles of donor-derived primary human hepatocytes from 77 subjects. Lipidomic data obtained by liquid chromatography-mass spectrometry were analyzed across ε2/ε3, ε3/ε3, and ε3/ε4 genotypes to reveal how APOE modulates lipid relative levels over age and between groups. Hepatic APOE concentration, measured by ELISA, was assessed for correlation with lipid abundance in subjects grouped as per APOE genotype and sex. APOE genotype-specific differential lipidomic signatures associated with age for multiple lipid classes but did not differ between sexes. Compared to ε2/ε3, ε3/ε4 hepatocytes had higher abundance of acylcarnitines (AC) and acylphosphatidylglycerol (AcylPG) as a class, as well as higher medium and long-chain ACs, AcylPG, phosphatidylglycerol (PG), bis(monoacylglycerol)phosphate (BMP), monoacylglycerol (MG) and diacylglycerol (DG) species. The ε3/ε4 hepatocytes also exhibited a higher abundance of medium and long-chain ACs compared to the ε3/ε3 hepatocytes. Only in the ε3/ε4 hepatocytes, APOE concentration was lower and showed a negative correlation with BMP levels, specifically in females. APOE genotype dictates a differential lipidome in primary human hepatocytes. The lipids involved suggest mitochondrial dysfunction with accompanying alterations in neutral lipid storage, reflective of a general disturbance of free fatty acid metabolism in human hepatocytes with the ε4 allele.