Collaterals at angiography guide clinical outcomes after endovascular stroke therapy in HERMES.

BACKGROUND: Robust collateral circulation has been linked with better reperfusion and clinical outcomes. It remains unclear how individual assessments of collateral circulation may be translated into clinical practice. METHODS: The pooled Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials (HERMES) angiography dataset was analyzed by a centralized, independent imaging core blinded to other clinical data. Conventional angiography was acquired immediately prior to endovascular therapy. Collaterals were graded with the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN) system and associated with baseline patient characteristics, reperfusion, and day 90 modified Rankin Score (mRS). Both 90-day all-cause mortality and day 90 mRS were modeled via multivariable logistic regression. RESULTS: Angiography was available in 376/605 (62%) patients. Baseline ASPECTS (Alberta Stroke Program Early CT Score) (p=0.043), history of diabetes mellitus (p=0.048), site of occlusion (p<0.001), and degree of subsequent Thrombolysis in Cerebral Infarction (TICI) reperfusion (p<0.001) were associated with collateral grades. ASITN collateral grade was strongly associated with ordinal mRS from baseline to 90 days in an unadjusted analysis (p<0.001). Multivariable regression demonstrated that collateral status is a strong determinant of mRS outcome in the presence of other predictors (OR=1.37 per grade, 95% CI [1.05 to 1.74], p=0.018). By comparing ORs, 1 unit of ASITN was determined to be approximately equivalent to 4.5 points of NIHSS, 11 years of age, 1.5 points of ASPECTS, or 100 min less delay from onset to puncture, in terms of impact on mRS. CONCLUSIONS: Individual collateral physiology may contribute significantly to reperfusion success and clinical outcomes after acute ischemic stroke. Building a consensus for the role of angiographic collateral assessment in the allocation of adjuvant reperfusion therapies may help galvanize a precision medicine approach in stroke.

Molecular Bidents with Two Electrophilic Warheads as a New Pharmacological Modality.

A systematic strategy to develop dual-warhead inhibitors is introduced to circumvent the limitations of conventional covalent inhibitors such as vulnerability to mutations of the corresponding nucleophilic residue. Currently, all FDA-approved covalent small molecules feature one electrophile, leaving open a facile route to acquired resistance. We conducted a systematic analysis of human proteins in the protein data bank to reveal ∼400 unique targets amendable to dual covalent inhibitors, which we term "molecular bidents". We demonstrated this strategy by targeting two kinases: MKK7 and EGFR. The designed compounds, ZNL-8162 and ZNL-0056, are ATP-competitive inhibitors that form two covalent bonds with cysteines and retain potency against single cysteine mutants. Therefore, molecular bidents represent a new pharmacological modality with the potential for improved selectivity, potency, and drug resistance profile.

Factors Associated with Delays in Initiating Biologic Therapy in Patients with Inflammatory Bowel Disease.

INTRODUCTION: Expeditious initiation of biologic therapy is important in patients with inflammatory bowel disease (IBD). However, initiation of biologics in the outpatient setting may be delayed by various clinical, social, and financial variables. AIM: To evaluate the delay in initiation of an advanced therapy in IBD and to identify factors that contributed to this delay. METHODS: This was a multi-center retrospective study. Outpatients who were initiated on a biologic therapy from 3/1/2019 to 9/30/20 were eligible for the study. Univariate and multivariate linear regression analyses were performed to identify variables associated with a delay in biologic treatment initiation. Delay was defined as the days from decision date (prescription placement) to first infusion or delivery of medication. RESULTS: In total 411 patients (Crohn's disease, n = 276; ulcerative colitis, n = 129) were included in the analysis. The median [interquartile range-(IQR)] delay for all drugs was 20 [12-37] days (infliximab, 19 [13-33] days; adalimumab, 10 [5-26] days; vedolizumab, 21 [14-42] days; and ustekinumab, 21 [14-42] days). Multivariate linear regression analysis identified that the most important variables associated with delays in biologic treatment initiation was self-identification as Black, longer distance from treatment site, and lack of initial insurance coverage approval. CONCLUSION: There may be a significant delay in biologic treatment initiation in patients with IBD. The most important variables associated with this delay included self-identification as Black, longer distance from site, and lack of initial insurance coverage approval.

Primary cutaneous EBV+ extranodal NK/T-cell lymphoma of gamma/delta T-cell lineage in the posttransplantation setting.

Posttransplantation primary cutaneous T-cell lymphomas (PT-CTCL) are a rare complication of sustained immunosuppression in the posttransplant setting. When present, PT-CTCLs are typically EBV- and exhibit features of mycosis fungoides/Sézary syndrome or CD30+ lymphoproliferative disorders. We present a case of a 75-year-old individual who developed skin lesions 30 years after liver transplantation. Pathologic evaluation of the skin biopsy revealed involvement by a clonal, EBV+ T-cell population of gamma/delta lineage with no evidence of systemic disease. Comprehensive genomic profiling was performed, confirming focal one-copy loss of 6q23.3, altogether consistent with the extremely rare and unusual diagnosis of primary cutaneous EBV+ extranodal NK/T-cell lymphoma of gamma/delta T-cell lineage in the posttransplantation setting.

Left atrial appendage closure in patients with atrial fibrillation and acute ischaemic stroke despite anticoagulation.

BACKGROUND: The occurrence of acute ischaemic stroke (AIS) while using oral anticoagulants (OAC) is an increasingly recognised problem among nonvalvular atrial fibrillation (NVAF) patients. We aimed to elucidate the potential role of left atrial appendage closure (LAAC) for stroke prevention in patients with AIS despite OAC use (AIS-despite-OAC). METHODS: We retrospectively collected baseline and follow-up data from consecutive NVAF patients who had AIS-despite-OAC and subsequently underwent endovascular LAAC, between January 2015 and October 2021. The primary outcome measure was the occurrence of AIS after LAAC, and the safety outcome was symptomatic intracerebral haemorrhage (ICH). RESULTS: 29 patients had LAAC specifically because of AIS-despite-OAC. The mean age at the time of the procedure was 73.4±8.7, 13 were female (44.82%). The mean CHA2DS2-VASc score was 5.96±1.32, with an expected AIS risk of 8.44 per 100 patient-years. 14 patients (48%) had two or more past AIS-despite-OAC. After LAAC, 27 patients (93.10%) were discharged on OAC which was discontinued in 17 (58.62%) after transoesophageal echocardiogram at 6 weeks. Over a mean of 1.75±1.0 years follow-up after LAAC, one patient had an AIS (incidence rate (IR) 1.97 per 100 patient-years). One patient with severe cerebral microangiopathy had a small ICH while on direct OAC and antiplatelet 647 days after LAAC. CONCLUSIONS: LAAC in AIS-despite-OAC patients demonstrated a low annual AIS recurrence rate in our cohort (1.97%) compared with the expected IR based on their CHA2DS2-VASc scores (8.44%) and to recent large series of AIS-despite-OAC patients treated with OAC/aspirin only (5.3%-8.9%). These hypothesis-generating findings support randomised trials of LAAC in AIS-despite-OAC patients.

Free-breathing, fat-corrected T1 mapping of the liver with stack-of-stars MRI, and joint estimation of T1, PDFF, R 2 * , and B 1 + .

PURPOSE: Quantitative T1 mapping has the potential to replace biopsy for noninvasive diagnosis and quantitative staging of chronic liver disease. Conventional T1 mapping methods are confounded by fat and B 1 + $$ {B}_1^{+} $$ inhomogeneities, resulting in unreliable T1 estimations. Furthermore, these methods trade off spatial resolution and volumetric coverage for shorter acquisitions with only a few images obtained within a breath-hold. This work proposes a novel, volumetric (3D), free-breathing T1 mapping method to account for multiple confounding factors in a single acquisition. THEORY AND METHODS: Free-breathing, confounder-corrected T1 mapping was achieved through the combination of non-Cartesian imaging, magnetization preparation, chemical shift encoding, and a variable flip angle acquisition. A subspace-constrained, locally low-rank image reconstruction algorithm was employed for image reconstruction. The accuracy of the proposed method was evaluated through numerical simulations and phantom experiments with a T1/proton density fat fraction phantom at 3.0 T. Further, the feasibility of the proposed method was investigated through contrast-enhanced imaging in healthy volunteers, also at 3.0 T. RESULTS: The method showed excellent agreement with reference measurements in phantoms across a wide range of T1 values (200 to 1000 ms, slope = 0.998 (95% confidence interval (CI) [0.963 to 1.035]), intercept = 27.1 ms (95% CI [0.4 54.6]), r2 = 0.996), and a high level of repeatability. In vivo imaging studies demonstrated moderate agreement (slope = 1.099 (95% CI [1.067 to 1.132]), intercept = -96.3 ms (95% CI [-82.1 to -110.5]), r2 = 0.981) compared to saturation recovery-based T1 maps. CONCLUSION: The proposed method produces whole-liver, confounder-corrected T1 maps through simultaneous estimation of T1, proton density fat fraction, and B 1 + $$ {B}_1^{+} $$ in a single, free-breathing acquisition and has excellent agreement with reference measurements in phantoms.

Monolithic optical resonator for ultrastable laser and photonic millimeter-wave synthesis.

Optical resonators are indispensable tools in optical metrology that usually benefit from an evacuated and highly-isolated environment to achieve peak performance. Even in the more sophisticated design of Fabry-Perot (FP) cavities, the material choice limits the achievable quality factors. For this reason, monolithic resonators are emerging as promising alternative to traditional designs, but their design is still at preliminary stage and far from being optimized. Here, we demonstrate a monolithic FP resonator with 4.5 cm3 volume and 2 × 105 finesse. In the ambient environment, we achieve 18 Hz integrated laser linewidth and 7 × 10-14 frequency stability measured from 0.08 s to 0.3 s averaging time, the highest spectral purity and stability demonstrated to date in the context of monolithic reference resonators. By locking two separate lasers to distinct modes of the same resonator, a 96 GHz microwave signals is generated with phase noise -100 dBc/Hz at 10 kHz frequency offset, achieving orders of magnitude improvement in the approach of photonic heterodyne synthesis. The compact monolithic FP resonator is promising for applications in spectrally-pure, high-frequency microwave photonic references as well as optical clocks and other metrological devices. ©2024. All rights reserved.

Did childhood adversity increase the vulnerability of university students to the negative mental health impact of the COVID-19 pandemic?

OBJECTIVE: To examine a potential synergistic effect of history of childhood adversity and COVID-19 pandemic exposure on the association with mental health concerns in undergraduate students. Participants: We used U-Flourish Survey data from 2019 (pre-pandemic) and 2020 (during-pandemic) first-year cohorts (n = 3,149) identified at entry to a major Canadian University. METHODS: Interactions between childhood adversity (physical and sexual abuse, and peer bullying) and COVID-19 pandemic exposure regarding mental health concern (depressive and anxiety symptoms, suicidality, and non-suicidal self-harm) were examined on an additive scale. RESULTS: We found a positive additive interaction between physical abuse and pandemic exposure in relation to suicidality (combined effect was greater than additive effect (risk difference 0.54 vs. 0.36)). Conversely, less than additive interactions between peer bullying and pandemic regarding depression and anxiety were observed. CONCLUSIONS: Childhood adversities have diverse reactions to adult stressor depending on the nature of the childhood adversity and the mental health outcomes.

Physical activity during COVID-19 in people with systemic sclerosis: A Scleroderma Patient-centred Intervention Network COVID-19 Cohort longitudinal study.

Introduction/Objective: People with systemic sclerosis (SSc) face barriers to physical activity. Few studies have described physical activity in SSc, and none have explored physical activity longitudinally during COVID-19. We evaluated physical activity from April 2020 to March 2022 among people with SSc. Methods: The Scleroderma Patient-centred Intervention Network (SPIN) COVID-19 Cohort was launched in April 2020 and included participants from the ongoing SPIN Cohort plus external enrolees. Participants completed measures bi-weekly through July 2020, then every 4 weeks afterwards (28 assessments). Physical activity was assessed via the self-reported International Physical Activity Questionnaire-Elderly. Analyses included estimated means with 95% confidence intervals for physical activity across assessments. Missing data were imputed for main analyses. Sensitivity analyses included evaluating only participants who completed >90% of items for >21 of 28 possible assessments ('completers') and stratified analyses by sex, age, country and SSc subtype. Results: A total of 800 people with SSc enrolled. Mean age was 55.6 (standard deviation (SD) = 12.6) years. Physical activity significantly decreased from April 2020 to March 2021 (standardized mean difference (SMD) = -0.17, 95% confidence interval (CI) = -0.26 to -0.07) and was stable from March 2021 to March 2022 (SMD = -0.05, 95% CI = -0.15 to 0.05). Results were similar for completers and subgroups. The proportion of participants who met World Health Organization minimum physical activity recommendations of at least 150 min of moderate-to-vigorous activity per week ranged from 63% to 82% across assessments. Conclusion: Physical activity decreased by a relatively small amount, on average, across the pandemic. Most participants met recommended physical activity levels.

Strength and muscle mass development after a resistance-training period at terrestrial and normobaric intermittent hypoxia.

This study investigated the effect of a resistance training (RT) period at terrestrial (HH) and normobaric hypoxia (NH) on both muscle hypertrophy and maximal strength development with respect to the same training in normoxia (N). Thirty-three strength-trained males were assigned to N (FiO2 = 20.9%), HH (2,320 m asl) or NH (FiO2 = 15.9%). The participants completed an 8-week RT program (3 sessions/week) of a full body routine. Muscle thickness of the lower limb and 1RM in back squat were assessed before and after the training program. Blood markers of stress, inflammation (IL-6) and muscle growth (% active mTOR, myostatin and miRNA-206) were measured before and after the first and last session of the program. Findings revealed all groups improved 1RM, though this was most enhanced by RT in NH (p = 0.026). According to the moderate to large excess of the exercise-induced stress response (lactate and Ca2+) in HH and N, results only displayed increases in muscle thickness in these two conditions over NH (ES > 1.22). Compared with the rest of the environmental conditions, small to large increments in % active mTOR were only found in HH, and IL-6, myostatin and miR-206 in NH throughout the training period. In conclusion, the results do not support the expected additional benefit of RT under hypoxia compared to N on muscle growth, although it seems to favour gains in strength. The greater muscle growth achieved in HH over NH confirms the impact of the type of hypoxia on the outcomes.

Discordance between a deep learning model and clinical-grade variant pathogenicity classification in a rare disease cohort.

Genetic testing has become an essential component in the diagnosis and management of a wide range of clinical conditions, from cancer to developmental disorders, especially in rare Mendelian diseases. Efforts to identify rare phenotype-associated variants have predominantly focused on protein-truncating variants, while the interpretation of missense variants presents a considerable challenge. Deep learning algorithms excel in various applications across biomedical tasks1,2, yet accurately distinguishing between pathogenic and benign genetic variants remains an elusive goal3-5. Specifically, even the most sophisticated models encounter difficulties in accurately assessing the pathogenicity of missense variants of uncertain significance (VUS). Our investigation of AlphaMissense (AM)5, the latest iteration of deep learning methods for predicting the potential functional impact of missense variants and assessing gene essentiality, reveals important limitations in its ability to identify pathogenic missense variants within a rare disease cohort. Indeed, AM struggles to accurately assess the pathogenicity of variants in intrinsically disordered regions (IDRs), leading to unreliable gene-level essentiality scores for certain genes containing IDRs. This limitation highlights the challenges in applying AM faces in the context of clinical genetics6.

Antibodies targeting Crimean-Congo hemorrhagic fever virus GP38 limit vascular leak and viral spread.

Crimean-Congo hemorrhagic fever virus (CCHFV) is a priority pathogen transmitted by tick bites, with no vaccines or specific therapeutics approved to date. Severe disease manifestations include hemorrhage, endothelial dysfunction, and multiorgan failure. Infected cells secrete the viral glycoprotein GP38, whose extracellular function is presently unknown. GP38 is considered an important target for vaccine and therapeutic design as GP38-specific antibodies can protect against severe disease in animal models, albeit through a currently unknown mechanism of action. Here, we show that GP38 induces endothelial barrier dysfunction in vitro, and that CCHFV infection, and GP38 alone, can trigger vascular leak in a mouse model. Protective antibodies that recognize specific antigenic sites on GP38, but not a protective neutralizing antibody binding the structural protein Gc, potently inhibit endothelial hyperpermeability in vitro and vascular leak in vivo during CCHFV infection. This work uncovers a function of the secreted viral protein GP38 as a viral toxin in CCHFV pathogenesis and elucidates the mode of action of non-neutralizing GP38-specific antibodies.

Individual Patient Data Meta-Analysis Estimates the Minimal Detectable Change of the Geriatric Depression Scale-15.

OBJECTIVE: To use individual participant data meta-analysis (IPDMA) to estimate the minimal detectable change (MDC) of the Geriatric Depression Scale-15 (GDS-15) and to examine whether MDC may differ based on participant characteristics and study-level variables. STUDY DESIGN AND SETTING: This was a secondary analysis of data from an IPDMA on the depression screening accuracy of the GDS. Datasets from studies published in any language were eligible for the present study if they included GDS-15 scores for participants aged 60 or older. MDC of the GDS-15 was estimated via random-effects meta-analysis using 2.77 (MDC95) and 1.41 (MDC67) standard errors of measurement (SEM). Subgroup analyses were used to evaluate differences in MDC by participant age and sex. Meta-regression was conducted to assess for differences based on study-level variables, including mean age, proportion male, proportion with major depression, and recruitment setting. RESULTS: 5,876 participants (mean age 76 years, 40% male, 11% with major depression) from 21 studies were included. The MDC95 was 3.81 points (95% confidence interval [CI] 3.59, 4.04), and MDC67 was 1.95 (95% CI 1.83, 2.03). The difference in MDC95 was 0.26 points (95% CI 0.04, 0.48) between ≥ 80-year-olds and < 80-year-olds; MDC95 was similar for females and males (0.05, 95% CI -0.12, 0.22). The MDC95 increased by 0.29 points (95% CI 0.17, 0.41) per 10% increase in proportion of participants with major depression; mean age had a small association (0.04 points, 95% CI 0.00 to 0.09) with MDC95, but sex and recruitment setting were not significantly associated. CONCLUSIONS: The MDC95 was 3.81 points and MDC67 was 1.95 points. MDC95 increased with the proportion of participants with major depression. Results can be used to evaluate individual changes in depression symptoms and as a threshold for assessing minimal clinical important difference estimates.

Comparison of Patient Health Questionnaire-9, Edinburgh Postnatal Depression Scale and Hospital Anxiety and Depression - Depression subscale scores by administration mode: An individual participant data differential item functioning meta-analysis.

Administration mode of patient-reported outcome measures (PROMs) may influence responses. We assessed if Patient Health Questionnaire-9 (PHQ-9), Edinburgh Postnatal Depression Scale (EPDS) and Hospital Anxiety and Depression Scale - Depression subscale (HADS-D) item responses and scores were associated with administration mode. We compared (1) self-administration versus interview-administration; within self-administration (2) research or medical setting versus private; and (3) pen-and-paper versus electronic; and within interview-administration (4) in-person versus phone. We analysed individual participant data meta-analysis datasets with item-level data for the PHQ-9 (N = 34,529), EPDS (N = 16,813), and HADS-D (N = 16,768). We used multiple indicator multiple cause models to assess differential item functioning (DIF) by administration mode. We found statistically significant DIF for most items on all measures due to large samples, but influence on total scores was negligible. In 10 comparisons conducted across the PHQ-9, EPDS, and HADS-D, Pearson's correlations and intraclass correlation coefficients between latent depression symptom scores from models that did or did not account for DIF were between 0.995 and 1.000. Total PHQ-9, EPDS, and HADS-D scores did not differ materially across administration modes. Researcher and clinicians who evaluate depression symptoms with these questionnaires can select administration methods based on patient preferences, feasibility, or cost.

Nitinol Staple Use in Primary Arthrodesis of Lisfranc Fracture-Dislocations.

BACKGROUND: Primary arthrodesis of Lisfranc fracture-dislocations is a reliable treatment option, yet concerns remain about nonunion. Nitinol staple use has recently proliferated in midfoot arthrodesis. The purpose of this study is to examine the union rate of primary arthrodesis of acute Lisfranc fracture-dislocations treated with nitinol staples compared with traditional plate-and-screw fixation. The secondary objective is to assess the difference in operative times and reoperation rates. METHODS: Midfoot fracture-dislocations treated with primary arthrodesis by 7 foot and ankle orthopaedic surgeons were reviewed. Of 160 eligible patients, 121 patients (305 joints) met the required 4-month minimum radiographic follow-up. Radiographic outcomes were analyzed at the individual joint level. Each joint was classified as either staples alone (45 patients, 154 joints), staples plus plates and screws (hybrid) (45 patients, 40 joints), or plates and screws alone (31 patients, 111 joints). The primary outcome was arthrodesis union at each joint fused. RESULTS: Nonunion was more common (9.0%, 10/111) among joints fixed with plate and screws than with hybrid (2.5%, 1/40) or staples only (1.3%, 2/154) (P = .0085). Multivariable regression demonstrated that autograft use was independent associated with union (P = .0035) and plate-and-screw only fixation was an independent risk factor for nonunion (P = .0407). Median operating room and tourniquet times were shorter for hybrid (92 and 83 minutes) and staple only (67 and 63 minutes) constructs compared to plate-and-screw only fixation (105 and 95 minutes) (P ≤ .0001 and .0003). There was no difference in reoperation rates among patients with different fixation types. CONCLUSION: We found that use of nitinol compression staple and bone autograft in primary arthrodesis of Lisfranc and midfoot fracture-dislocations was associated with both improved union rates and shorter tourniquet and operative times compared to traditional plate-and-screw fixation techniques. LEVEL OF EVIDENCE: Level III, therapeutic.

Revaccination outcomes among adolescents and adults with suspected hypersensitivity reactions following COVID-19 vaccination: A Canadian immunization research network study.

BACKGROUND: COVID-19 vaccination has been associated with anaphylaxis and hypersensitivity reactions. Infectious disease physicians and allergists in the Canadian Special Immunization Clinic (SIC) Network developed guidance for evaluating patients with adverse events following immunization (AEFI) including suspected hypersensitivity. This study evaluated management and adverse event recurrence following subsequent COVID-19 vaccinations. METHODS: Individuals aged 12 years and older enrolled at participating SICs before February 28, 2023 who were referred for suspected or diagnosed hypersensitivity reaction following COVID-19 vaccination, or for prevaccination assessment of suspected allergy to a COVID-19 vaccine component were included. De-identified clinical assessments and revaccination data, captured in a centralized database, were analyzed. The Brighton Collaboration case definition (BCCD) for anaphylaxis (2023 version) was applied. RESULTS: The analysis included 206 participants from 13 sites: 26 participants referred for pre-vaccination assessment and 180 participants referred for adverse events following COVID-19 vaccination (15/180 [8.3%] with BCCD confirmed anaphylaxis, 84 [46.7%] with immediate hypersensitivity symptoms not meeting BCCD, 33 [18.3%] with other diagnosed hypersensitivity reactions, and 48 [26.7%] participants with a final diagnosis of non-hypersensitivity AEFI). Among participants referred for AEFIs following COVID-19 vaccination, 166/180 (92.2%) were recommended for COVID-19 revaccination after risk assessment, of whom 158/166 (95.2%) were revaccinated (all with a COVID-19 mRNA vaccine). After revaccination, 1/15 (6.7%) participants with prior anaphylaxis, 1/77 (1.3%) with immediate hypersensitivity not meeting criteria for anaphylaxis and 1/24 (4.2%) with other physician diagnosed hypersensitivity developed recurrent AEFI symptoms that met the BCCD for anaphylaxis. All 26 participants referred pre-vaccination, including 9 (34.6%) with history of polyethylene glycol-asparaginase reactions, were vaccinated without occurrence of immediate hypersensitivity symptoms. CONCLUSIONS: Most individuals in this national cohort who experienced a hypersensitivity event following COVID-19 vaccination and were referred for specialist review were revaccinated without AEFI recurrence, suggesting that specialist evaluation can facilitate safe revaccination.

Nesfatin-1 and nesfatin-1-like peptide attenuate hepatocyte lipid accumulation and nucleobindin-1 disruption modulates lipid metabolic pathways.

Nesfatin-1 (NESF-1) has been shown to modulate lipid metabolism. We have identified a nesfatin-1-like-peptide (NLP) processed from a related precursor nucleobindin 1 (NUCB1). Here we determined if NLP, like NESF-1, regulates lipid accumulation in vitro, and tested if the disruption of nucb1 gene affects hepatic lipid metabolism genes in mice. Hepatocytes (HepG2/C3A cells) express NLP and NESF-1 and both peptides significantly reduced lipogenic enzyme mRNAs and enhanced beta-oxidation enzyme mRNAs. Lipid contents in oleic acid induced HepG2/C3A cells were attenuated by NESF-1 and NLP. The inhibitory effect on cellular lipid content was blocked by compound C, an inhibitor of AMPK. The disruption of nucb1 gene affected lipid metabolism-related enzyme mRNAs, endogenous nucb2 mRNA and AMPK phosphorylation. The lipid-lowering effects identified here highlights the potential of nucleobindins and peptides processed from them to address lipid disorders, and its possible benefits in metabolic disease management.

Sterol O-acyltransferase (SOAT/ACAT) activity is required to form cholesterol crystals in hepatocyte lipid droplets.

OBJECTIVE: Excess cholesterol storage can induce the formation of cholesterol crystals in hepatocyte lipid droplets. Such crystals distinguish metabolic dysfunction associated steatohepatitis (MASH) from simple steatosis and may underlie its pathogenesis by causing cell damage that triggers liver inflammation. The mechanism linking cholesterol excess to its crystallization in lipid droplets is unclear. As cholesteryl esters localize to and accumulate in lipid droplets more readily than unesterified free cholesterol, we investigated whether cholesterol esterification by sterol O-acyltransferase (SOAT), also known as acyl co-A cholesterol acyltransferase (ACAT), is required for hepatocyte lipid droplet crystal formation. METHOD: Cholesterol crystals were measured in cholesterol loaded Hep3B hepatocytes, RAW264.7 macrophages, and mouse liver using polarizing light microscopy. We examined the effect of blocking SOAT activity on crystal formation and compared these results to features of cholesterol metabolism and the progression to intracellular crystal deposits. RESULTS: Cholesterol loading of Hep3B cells caused robust levels of lipid droplet localized crystal formation in a dose- and time-dependent manner. Co-treatment with SOAT inhibitors and genetic ablation of SOAT1 blocked crystal formation. SOAT inhibitor also blocked crystal formation in low density lipoprotein (LDL) treated Hep3B cells, acetylated LDL treated RAW 264.7 macrophages, and in the liver of mice genetically predisposed to hepatic cholesterol overload and in mice with cholesterol enriched diet-induced MASH. CONCLUSION: SOAT1-mediated esterification may underlie cholesterol crystals associated with MASH by concentrating it in lipid droplets. These findings imply that inhibiting hepatocyte SOAT1 may be able to alleviate cholesterol associated MASH. Moreover, that either a lipid droplet localized cholesteryl ester hydrolase is required for cholesterol crystal formation, or the crystals are composed of cholesteryl ester.