👤 Wesley K Thompson

Due to its proximity to cells of the central nervous system, cerebrospinal fluid (CSF) is an important source of novel biomarkers for neurological diseases. Membrane-bound extracellular vesicles (EVs) are enriched for proteins of intracellular and membrane origin, implicated in the pathogenesis of some neurological diseases, and secreted into CSF. Proteomic profiling of CSF-EVs, however, is limited by the large volumes required for typical EV isolation protocols. We appraised the performance of tetraspanin (CD81, CD63, CD9)-based immunocapture for EV isolation from 200 to 1000 µL CSF sample and compared to size-exclusion chromatography (SEC). EVs were profiled by library-free data independent-acquisition (DIA) mass spectrometry to assess protein depth and abundance of specific EV markers and known co-isolates. Abundance and precursor peptide locations for potential neuronal-specific immunocapture targets described in the literature were also assessed. Immunocapture was effective using CSF volumes as low as 200 µL, consistently detecting core EV markers and reducing relative levels of non-vesicular proteins such as Apolipoprotein B (APOB) and galectin 3 binding protein (LGALS3BP) compared with size-exclusion chromatography (SEC). Proteomic depth reached 811 ± 14 protein groups in EVs from 200 µL CSF, increasing to 1285 ± 224 when using feature alignment across runs with up to 1000 µL starting volume. These included eleven candidate biomarkers of neurological diseases that were detected in all preparation methods, with additional candidates detected by immunocapture only. Increased depth was observed for both transmembrane and secreted proteins using immunocapture compared with SEC, with proportional enrichment of transmembrane proteins. This work demonstrates the effectiveness of tetraspanin immunocapture for proteomic profiling of EVs in small volumes of CSF that can be adapted to use with cell-type-specific markers of choice. Show less

The APOE-ε4 allele is the strongest genetic risk factor for late-onset Alzheimer's disease. However, APOE-ε4 is not deterministic, highlighting the need to identify additional genetic and environmental factors. APOE-ε4 has been linked to accelerated cognitive decline, so we sought to investigate genetic factors that modify APOE-ε4-associated cognitive decline. We conduct cross-ancestry APOE-ε4-stratified and interaction GWAS using harmonized cognitive data from 32,778 participants, including 29,354 non-Hispanic White and 3,424 non-Hispanic Black individuals. Our primary outcome is late-life cognition, measured using harmonized composite scores for memory, executive function, and language, modeled as continuous traits reflecting both normative cognitive aging and disease-related decline. We identify two genome-wide significant loci in APOE-ε4 carriers, reaching genome-wide significance for executive function. These loci also demonstrate nominal associations across the other domains, suggesting broad effects on cognition. In non-carriers, we identify a genome-wide significant association at ITGB8 restricted to executive function, and another locus associated with language. We further link these loci to SEMA6D, GRIN3A, and ITGB8 through expression and methylation databases. Post-GWAS analyses implicate additional genes including SLCO1A2, and DNAH11. Genetic correlation analyses reveal differences by APOE-ε4 status for immune-related traits, suggesting immune-related predispositions may exacerbate cognitive risk in APOE-ε4 carriers. Show less

The Timed Up and Go (TUG) is a 20-foot gait assessment, with TUG-dual task (DT) serial subtractions to determine dual-task cost. Alzheimer's disease (AD) risk is established using plasma biomarkers and APOE genotyping. We investigated: 1) TUG/TUG-DT differences between AD low-risk cognitively unimpaired (CU) older adults (N = 74), AD high-risk CU older adults (N = 87), and mild cognitively impaired (MCI) older adults (N = 33) and 2) the relationship between TUG/TUG-DT performance and plasma biomarkers. One hundred and ninety-four older adults ages 55-80 completed TUG/TUG-DT, a fasting blood draw, and APOE genotyping. Scores on the Clinical Dementia Rating Scale (CU = 0; CI = ≥0.5) and Montreal Cognitive Assessment (CU ≥ 24; CI = ≤23) determined whether participants were placed into the CU low-risk, CU high-risk, or MCI groups. Risk level for CU participants were assessed by APOE genotyping. Those participants who carried at least one copy of the APOE ε4 allele were designated to the high-risk group (n = 87). Participants with no APOE ε4 allele were assigned to the low-risk group (n = 75). MCI participants took longer to perform the TUG than CU participants ( Step count may be more sensitive, compared to speed alone, in identifying those in preclinical AD stages. Gait metrics (speed and efficiency) played a key role as a clinical manifestation of early AD pathophysiology determined by blood-based biomarker concentration. Combining these assessments offers a multidimensional, cost-effective approach for preclinical-AD screening and potential early intervention. Show less

"SuperAgers" are oldest-old adults (ages 80+) whose memory performance more closely resembles middle-aged adults. The present study examined apolipoprotein E (APOE) allele frequency in non-Hispanic Black (NHB) and non-Hispanic White (NHW) SuperAgers compared to controls and Alzheimer's disease dementia cases. In 18,080 participants from eight cohorts, harmonized clinical diagnostics and memory, executive function, and language domain scores were used to identify SuperAgers, cases, and controls across age-defined bins. NHW SuperAgers had significantly lower frequency of APOE-ε4 alleles and higher frequency of APOE-ε2 alleles compared to all cases and controls, including oldest-old controls. Similar patterns were found in a small yet substantial sample of NHB SuperAgers; however, not all comparisons with controls reached significance. We demonstrated strong evidence that APOE allele frequency relates to SuperAger status. Further research is needed with a larger sample of NHB SuperAgers to determine if mechanisms conferring cognitive resilience differ across race groups. Apolipoprotein E (APOE) allele frequency differs between SuperAgers and cases APOE allele frequency differs between non-Hispanic White SuperAgers and controls The relationship of APOE and non-Hispanic Black SuperAger status is unclear. Show less

Ambient air pollution exposures increase risk for Alzheimer's disease (AD) and related dementias, possibly due to structural changes in the medial temporal lobe (MTL). However, previous MRI studies examining exposure effects on the MTL were cross-sectional and mostly focused on the hippocampus, yielding mixed results. We addressed these limitations using longitudinal data collected from 653 cognitively unimpaired community-dwelling women from the Women's Health Initiative Memory Study with two MRI scans (M Show less

Lysophosphatidic acid (LPA) is a cell-signaling lipid that has been proposed as an early-stage biomarker for ovarian cancer (OC). Diagnosing OC in Stage I is critical to improving patient outcomes, increasing the survival rate from 30% (when diagnosed in late stages of the disease) to over 90%. This significant improvement is due to the success of early interventions; however, current diagnostic methods are not as effective at early-stage detection, with only 15% of cases diagnosed in Stage I and over 70% diagnosed in Stage III or IV. There is a strong need for LPA detection that is sensitive, specific, rapid, low-cost, and automated to truly validate its effectiveness as a diagnostic characteristic for OC. We report the preliminary development and characterization of one such biosensor, which makes use of the advantages of magnetic particles and chemiluminescence for quick, sensitive detection of LPA. The sensor has proven to be viable, with a positive response to LPA concentration, a measurement time of 5 s after incubation, and an LOD of 3.5 nM. Show less

Adherence to antiretroviral therapy is essential for achieving viral suppression. Plasma separation cards (HemaSep; HS-DBS) provide advantages for pharmacokinetic (PK) analysis and adherence monitoring, including simplified sample collection. This study compared the PK of dolutegravir (DTG), nucleoside reverse transcriptase inhibitors (NRTIs), and their intracellular metabolites in the dried plasma and cellular fractions of HS-DBS against the appropriate gold-standard matrices: liquid plasma for parent drugs and Whatman DBS (WM-DBS) for NRTI metabolites. The APT-POCT-01 clinical trial (NCT04302896) is an open-label study assessing drug concentrations following cessation in healthy volunteers. Participants were randomized (1:1) to receive DTG/FTC/TAF or DTG/3TC/TDF for 15 days. Paired liquid plasma (L-pL), HS-DBS, and WM-DBS samples were collected on Day 15 and following treatment cessation (0-336 hours post-final dose). 29 individuals were included in the PK analysis (15-TDF/14-TAF). Tenofovir diphosphate (TFV-DP) was quantifiable up to 14 days post-cessation in HS-DBS (TAF/TDF) and WM-DBS (TDF) (HS-DBS t½ > 17 days, WM-DBS t½ = 15 days). 3TC-TP and FTC-TP were eliminated more rapidly. Nucleoside di/triphosphate concentrations were 3-7-fold higher, with prolonged half-lives (TFV-DP, FTC-TP), compared with WM-DBS. TFV-DP levels were ~12-fold higher with TDF compared to TAF. For NRTI and DTG, HS-plasma resulted in 1.8-fold higher exposures compared to L-pL. Measurable HS-DBS concentrations were correlated with L-pL and WM-DBS, with Bland-Altman analysis indicating agreement between methods. This study provides important insights into the elimination kinetics of NRTI, their intracellular metabolites and DTG. Plasma separation cards are a promising alternative for adherence monitoring, enabling simultaneous quantification of parent and intracellular moieties from a single sample. Differences in TFV-DP levels between TDF and TAF regimens, and DBS sampling method, underscore the need for matrix and regimen-specific interpretation to validate adherence benchmarks. Show less

Myosin-19 (Myo19) is a mitochondrially localized actin-based motor important for regulating mitochondrial homeostasis, including the stabilization of mitochondrial-endoplasmic reticulum (mitoER) contact sites. Thus, proper regulation of Myo19 is likely required to maintain mitochondrial health and function, but little is known about regulatory mechanisms. Non-muscle tropomyosins are known to differentially regulate members of the myosin superfamily, leading us to hypothesize that tropomyosins may regulate Myo19-actin filament interactions. Here, we show that the interaction of Myo19 with actin filaments is inhibited by the association of Tropomyosin 3.1 (Tpm3.1) and 1.7 (Tpm1.7) with F-actin. This inhibition is highly cooperative, as both Tpm isoforms induce an all-or-none stalling of Myo19-driven filaments in in vitro gliding assays. In HeLa cells, Tpm3.1 is associated with actin filaments in close proximity to mitochondria. This localization is dynamic, as Tpm3.1 interacts with the mitochondrially-associated actin wave in interphase cells. These findings point toward a tropomyosin-based regulatory mechanism that spatially regulates Myo19 activity in a dynamic manner. Show less

Patients born with congenital porto-systemic shunts have been shown to have a high risk of benign and malignant liver tumors in otherwise healthy livers. This study aimed to evaluate the genetic landscape of liver tumors in patients with congenital porto-systemic shunts (CPSS) and correlate genotype with histological findings. Nodules from patients with CPSS and sporadic pediatric focal nodular hyperplasia (FNH) or FNH-like nodules were evaluated histologically and sequenced for a panel of 50 genes using next-generation sequencing. Thirty-eight nodules from 17 patients with CPSS were histologically classified as hepatoblastomas ( CPSS is strongly associated with nodules containing variants in Show less

There is a need for effective tools to stratify and modify cardiovascular risk associated with elevated lipoprotein(a) [Lp(a)] and oxidized phospholipids (OxPL). The objective of this analysis was to explore the modifying effects of low-grade inflammation on Lp(a)- and OxPL-associated risk in a secondary prevention cohort. Levels of Lp(a), OxPL associated with apolipoprotein(a) (OxPL-apo[a]) and apolipoprotein B (OxPL-apoB) were determined in the placebo-arm of the low-dose colchicine 2 trial. Patients were between 35 and 82 years, had established chronic coronary syndrome (CCS), and were clinically stable for at least six months prior to randomization. The outcome was the incidence of the composite endpoint of spontaneous myocardial infarction, ischemic stroke, or ischemia-driven coronary revascularization stratified by biomarker levels using a Cox regression model. There was a significant interaction between Lp(a) and IL-6 <3.2 ng/L (median) and IL-6 ≥3.2 ng/L for the composite endpoint (HR 0.90; 95 %CI 0.78-1.03 vs HR 1.18; 95 %CI 1.01-1.39, P In patients with CCS, Lp(a), OxPL-apo(a) and OxPL-apoB associated cardiovascular risk was only pertinent in those with elevated IL-6 but not hsCRP levels. Show less

Inflammatory lipoprotein(a) [Lp(a)] and oxidized phospholipids (OxPLs) on lipoproteins convey residual cardiovascular disease risk. The low-dose colchicine 2 (LoDoCo2) trial showed that colchicine reduced the risk of cardiovascular events occurring on standard therapies in patients with chronic coronary syndrome (CCS). We explored the effects of colchicine on Lp(a)- and oxidized lipoprotein-associated risk in a LoDoCo2 biomarker subpopulation. Lipoprotein(a) and OxPLs on apolipoprotein(a) [OxPL-apo(a)] and apolipoprotein B-100 (OxPL-apoB) levels were determined in the biomarker population of the LoDoCo2 trial (n = 1777). The Cox regression analysis was used to compare the risk of the primary endpoint, consisting of myocardial infarction, ischaemic stroke, or ischaemia-driven revascularization by biomarker levels. Interactions between treatment, Lp(a), and OxPL levels were evaluated. Lipoprotein(a), OxPL-apo(a), and OxPL-apoB levels were similar between the colchicine and placebo groups. Consistent risk reduction by colchicine was observed in those with Lp(a) < 125 nmol/L and ≥125 nmol/L and the highest OxPL-apo(a) tertile compared with the lowest (Pinteraction = 0.92 and 0.66). The absolute risk reduction for those with Lp(a) ≥ 125 nmol/L appeared higher compared with those with Lp(a) < 125 nmol/L (4.4% vs. 2.4%). A treatment interaction for colchicine was found in those with the highest OxPL-apoB tertile vs. the lowest (Pinteraction = 0.04). In patients with CCS, colchicine reduces cardiovascular disease risk in those with and without elevated Lp(a) but absolute benefits appeared higher in those with Lp(a) ≥ 125 nmol/L. Patients with higher levels of OxPL-apoB experienced greater benefit of colchicine, suggesting that colchicine may be more effective in subjects with heightened oxidation-driven inflammation. Show less

Neuronal Ceroid Lipofuscinoses (NCLs), also known as Batten disease, are a group of inherited neurodegenerative disorders that mostly arise in childhood. Each of the NCLs is a genetically distinct disease caused by variants in at least 13 different genes (CLN1-CLN14). NCLs are neurodegenerative, and symptoms can include a combination of childhood dementia, epileptic seizures, motor decline and vision loss, and eventually lead to premature death. There is currently no cure for any subtype of NCL, however, enzyme replacement therapy is available for CLN2 disease, and several treatment strategies are being explored for other NCL subtypes. Early diagnosis and initiation of supportive services (e.g. health, education, social services) are essential to preserve quality of life. Only a few studies have investigated family experiences with NCL, many of which are international in scope. A mixed-method research study was conducted in the UK to understand family experiences in CLN2 and CLN3 disease. It involved an initial literature review, followed by in-depth qualitative interviews. Interview data were analysed using a thematic analysis. Thirteen families (n = 13) participated in the interviews. This represented 16 parents (11 mothers and 5 fathers) of 18 children (10 diagnosed with CLN3 disease and 8 diagnosed with CLN2 disease). Findings were analysed jointly across CLN2 and CLN3 disease. Six overarching themes emerged from the analysis: difficulty in recognising early symptoms; the shock of a diagnosis; the demands of caring for complex and ever-changing needs; a constant battle to access appropriate and timely support services; the extensive impact on the unaffected sibling; and the all-encompassing impact on the family. This study contributes novel UK specific data on family experiences and unmet needs in CLN2 and CLN3 disease. More needs to be done to ensure NCLs are diagnosed early, and timely local support services are made available to protect quality of life for both the affected children and their families. Show less

To evaluate optic nerve head (ONH) morphology in children with craniosynostosis versus healthy controls. Single-center, prospective cohort study. Handheld optical coherence tomography (OCT) was performed in 110 eyes of 58 children (aged 0-13 years) with craniosynostosis. Inclusion criteria were as follows: normal intracranial pressure on invasive overnight monitoring, or clinically stable intracranial pressure. The latter was defined as stable VA within 1 logMAR line and no papilledema on fundoscopy for at least 4 months following OCT, and normal/stable visual evoked potentials. Control data for 218 eyes of 218 children were obtained from a published normative dataset. The main outcome measures were disc width, cup width, rim width, and retinal nerve layer thickness (nasal and temporal). Outcome measures were compared using three-way linear mixed model regression analysis (fibroblast growth factor receptor [FGFR] 1/2-associated craniosynostosis, non-FGFR 1/2-associated craniosynostosis, and controls). Out of 63 eligible children with craniosynostosis, handheld OCT imaging was successful in 110 eyes of 58 children (92%). Of these, 22 (38%) were female. Median subject age at OCT examination was 53 months (range: 2-157; IQR: 39-73). Twelve children (21%) had FGFR1/2-associated syndromes (Crouzon, n = 6; Apert, n = 4; Pfeiffer, n = 2). Control data were available for 218 eyes of 218 healthy children. 122 controls (56%) were female. Median control age at OCT examination was 20 months (range: 0-163; IQR: 6-59). When comparing ONH morphology in craniosynostosis (n = 58) versus controls (n = 218), disc width was 6% greater (P = .001), temporal cup width was 13% smaller (P = .027), rim width was 16% greater (P < .001) and temporal retinal nerve fiber layer was 11% smaller (P = .027). When comparing FGFR1/2-associated syndromes (Crouzon, Apert, and Pfeiffer syndromes, n = 12) to the rest of the craniosynostosis group (n = 46), disc width was 10% smaller (P = .014) and temporal cup width was 38% smaller (P = .044). This cohort demonstrated morphological differences of the ONH in craniosynostosis, most markedly in Crouzon, Apert, and Pfeiffer syndromes. These findings could help improve ophthalmological monitoring and surgical decision-making in children with craniosynostosis. Further work on longitudinal ONH changes in syndromic and nonsyndromic craniosynostosis would be valuable. Show less

Endothelial-to-mesenchymal transition (EndMT) is a biological process through which lung vascular endothelial cells (ECs) transdifferentiate into mesenchymal-like cells. EndMT has recently been implicated in the development and progression of pulmonary vascular remodeling in pulmonary hypertension (PH); however, its underlying regulatory mechanisms remain incompletely understood. MicroRNAs (miRNAs) are key post-transcriptional regulators of EC gene expression and cellular responses to various stimuli. Notably, microRNA-153 (miR-153) has been shown to directly target SNAI1 to modulate epithelial-to-mesenchymal transition (EMT), a process closely related to EndMT and extensively studied in cancer. Whether miR-153 also participates in EndMT regulation, however, remains unknown. In this study, we demonstrate that 72-hour hypoxic exposure induces SNAI1-mediated EndMT in human lung vascular ECs. Hypoxia also increased cell proliferation and disrupted intercellular junctions, leading to enhanced endothelial permeability. Reduced miR-153 expression was observed in both hypoxia- and TGF-β1-induced EndMT, as well as in ECs isolated from PH patients exhibiting an EndMT phenotype. Similar to hypoxia, TGF-β1 promoted EC permeability. Loss of miR-153 enhanced SNAI1-mediated EndMT, endothelial survival, and permeability under normoxic conditions, whereas miR-153 overexpression attenuated EndMT induced by hypoxia or TGF-β1. However, miR-153 restoration did not completely recover endothelial barrier integrity disrupted by these stimuli. In conclusion, miR-153 serves as a critical regulator of EndMT, maintaining endothelial identity and barrier function. Therapeutic delivery of miR-153 may therefore represent a novel strategy to inhibit EndMT and attenuate pulmonary vascular remodeling in PH. Show less

Endothelial-to-mesenchymal transition (EndMT) is a biological process that converts endothelial cells to mesenchymal cells with increased proliferative and migrative abilities. EndMT has been implicated in the development of pulmonary vascular remodeling in pulmonary arterial hypertension (PAH), a fatal and progressive lung vascular disease. Transforming growth factor β Show less

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) have clinical, pathological and genetic overlapping. Lipid pathways are implicated in ALS. This study examined the effect of blood lipid levels on ALS, FTD risk, and survival in ALS. A systematic review and meta-analysis of high and low-density lipoprotein cholesterol (HDL-c and LDL-c), total cholesterol, triglycerides, apolipoproteins B and A1 levels with ALS was performed. Two-sample Mendelian randomisation (MR) analysis sought the causal effects of these exposures on ALS, FTD, and survival in ALS. The effect of lipid-lowering drugs was also examined using genetic proxies for targets of lipid-lowering medications. Three cohort studies met the inclusion criteria for meta-analysis. Meta-analysis indicated an association between higher LDL-c (HR These data support the influence of LDL-c and total cholesterol on ALS risk and apolipoprotein B on the risk of ALS and FTD. Potential APOB inhibition might decrease the risk of sporadic ALS and FTD. Further work in monogenic forms of ALS and FTD is necessary to determine whether blood lipids influence penetrance and phenotype. Show less

Guidelines recommend low-dose colchicine for secondary prevention in cardiovascular disease, but uncertainty remains concerning its efficacy for stroke, efficacy in key subgroups and about uncommon but serious safety outcomes. In this trial-level meta-analysis, we searched bibliographic databases and trial registries form inception to May 16, 2024. We included randomised trials of colchicine for secondary prevention of ischaemic stroke and major adverse cardiovascular events (MACE: ischaemic stroke, myocardial infarction, coronary revascularisation, or cardiovascular death). Secondary outcomes were serious safety outcomes and mortality. A fixed-effect inverse-variance model was used to generate a pooled estimate of relative risk (RR) with 95% confidence intervals (CI). This study is registered with PROSPERO, CRD42024540320. Six trials involving 14,934 patients with prior stroke or coronary disease were included. In all patients, colchicine compared with placebo or no colchicine reduced the risk for ischaemic stroke by 27% (132 [1.8%] events versus 186 [2.5%] events, RR 0.73 [95% CI 0.58-0.90]) and MACE by 27% (505 [6.8%] events versus 693 [9.4%] events, with RR 0.73 [0.65-0.81]). Efficacy was consistent in key subgroups (females versus males, age below versus above 70, with versus without diabetes, statin versus non-statin users). Colchicine was not associated with an increase in serious safety outcomes: hospitalisation for pneumonia (109 [1.5%] versus 106 [1.5%], RR 0.99 [0.76-1.30]), cancer (247 [3.5%] versus 255 [3.6%], RR 0.97 [0.82-1.15]), and gastro-intestinal events (153 [2.1%] versus 135 [1.9%]), RR 1.15 [0.91-1.44]. There was no difference in all-cause death (201 [2.7%] versus 181 [2.4%], RR 1.09 [0.89-1.33]), cardiovascular death (70 [0.9%] versus 80 [1.1%], RR 0.89 [0.65-1.23]), or non-cardiovascular death (131 [1.8%] versus 101 [1.4%], RR 1.26 [0.98-1.64]). In patients with prior stroke or coronary disease, colchicine reduced ischaemic stroke and MACE, with consistent treatment effect in key subgroups, and did not increase serious safety events or death. There was no funding source for this study. Show less

Childhood malnutrition is a major global health problem with long-term sequelae, including non-communicable diseases (NCDs). Mechanisms are unknown but may involve metabolic programming, resulting from "short-term" solutions to optimise survival by compromising non-priority organs. As key players in lipid metabolism, desaturases have been shown to be predictive of NCDs. We hypothesised that the association between specific desaturase activities and NCD risk determinants (including body composition, serum glucose, insulin levels, and blood pressure) are influenced by childhood post-malnutrition weight gain. 278 Afro-Caribbean adults with well-documented clinical history of severe malnutrition in childhood were studied. Extensive metabolic analyses including body composition (DXA), fasting serum glucose and lipidomics (n = 101), and fasting serum insulin (n = 83) were performed in malnutrition survivors and matched community controls (n = 90). Established lipid ratios were used as proxies of desaturase activities: CE 16:1/CE 16:0 for stearoyl-CoA desaturase (SCD1), LysoPC 20:4/20:3 for fatty acid desaturase 1 (FADS1), and LysoPC 20:3/18:2 for FADS2. Compared to community controls, adult malnutrition survivors (mean ± SD) age 28.3 ± 7.8 and BMI 23.6 ± 5.2 had higher SCD1 and FADS1 activity, (B ± SE) 0.07 ± 0.02 and 0.7 ± 0.08, respectively, but lower FADS2 activities (B ± SE) -0.05 ± 0.01, adjusted for sex and age (p < 0.0005). SCD1 was positively associated with adult BMI and body fat percentage, and negatively associated with lean mass and height. Stratification based on weight gain during nutritional rehabilitation among malnutrition survivors might signal the potential associations between weight gain during that critical period, desaturase activities, and some of adult metabolic parameters, with the lowest tertiles (slowest catch-up weight gain) performing more similarly to controls. In adult survivors of early-life severe acute malnutrition, desaturase activity is associated with markers of NCD risk, especially adiposity. These associations seem to be strengthened by faster weight gain during nutritional rehabilitation. Show less

Multisystem inflammatory syndrome in children (MIS-C) is a hyperinflammatory condition caused by recent infection with severe acute respiratory syndrome coronavirus 2, but the underlying immunological mechanisms driving this distinct syndrome are unknown. We utilized high-dimensional flow cytometry, cell-free (cf) DNA, and cytokine and chemokine profiling to identify mechanisms of critical illness distinguishing MIS-C from severe acute coronavirus disease 2019 (SAC). Compared to SAC, MIS-C patients demonstrated profound innate immune cell death and features of emergency myelopoiesis (EM), an understudied phenomenon observed in severe inflammation. EM signatures were characterized by fewer mature myeloid cells in the periphery and decreased expression of HLA-DR and CD86 on antigen-presenting cells. Interleukin 27 (IL-27), a cytokine known to drive hematopoietic stem cells toward EM, was increased in MIS-C, and correlated with immature cell signatures in MIS-C. Upon recovery, EM signatures decreased and IL-27 plasma levels returned to normal levels. Despite profound lymphopenia, we report a lack of cfDNA released by adaptive immune cells and increased CCR7 expression on T cells indicative of egress out of peripheral blood. Immune cell signatures of EM combined with elevated innate immune cell-derived cfDNA levels distinguish MIS-C from SAC in children and provide mechanistic insight into dysregulated immunity contributing toward MIS-C, offering potential diagnostic and therapeutic targets. Show less

Although fish exposed to municipal wastewater effluents (MWWE) show higher lipid accumulation, whether this is due to adipogenesis is unclear. The objective here was to identify molecular markers of adipogenesis in zebrafish (Danio rerio) larvae for use as high throughput screening tools for environmental contaminants, including obesogens in MWWE. Zebrafish larvae were fed a commercial diet at a maintenance level (5 % body mass) or in excess (25 or 50 % body mass) from day 6 to 30 days post-fertilization (dpf) to stimulate adipogenesis. We monitored fat accumulation and markers of lipid metabolism, including peroxisome proliferator-activated receptor γ (ppar γ), fatty acid synthase (fas), ELOVL fatty acid elongase 2 (elovl2), diacylglycerol O-acyltransferase 2 (dgat2), leptin (lepa and lepb), leptin receptor (lepr), and lipoprotein lipase (lpl). Excess feeding led to a higher growth rate, protein content and an increase in igf1 transcript abundance. Also, these larvae had higher triglyceride levels and accumulated lipids droplets in the abdominal cavity and viscera. The molecular markers of adipogenesis, including fas, elovl2, and dgat2, were upregulated, while the transcript abundance of lpl, a lipolytic gene, was transiently lower due to excess feeding. The increased adiposity seen at 30 dpf due to excess feeding coincided with a lower lep but not lepr transcript abundance in zebrafish. Our results demonstrate that excess feeding alters the developmental programming of key genes involved in lipid homeostasis, leading to excess lipid accumulation in zebrafish larvae. Overall, fas, elovl2, lpl, and dgat2, but not lep or ppar γ, have the potential to be biomarkers of adipogenesis in zebrafish larvae. Show less

Congenital myasthenic syndromes (CMS) are a rare group of inherited disorders caused by gene defects associated with the neuromuscular junction and potentially treatable with commonly available medications such as acetylcholinesterase inhibitors and β2 adrenergic receptor agonists. In this study, we identified and genetically characterized the largest cohort of CMS patients from India to date. Genetic testing of clinically suspected patients evaluated in a South Indian hospital during the period 2014-19 was carried out by standard diagnostic gene panel testing or using a two-step method that included hotspot screening followed by whole-exome sequencing. In total, 156 genetically diagnosed patients (141 families) were characterized and the mutational spectrum and genotype-phenotype correlation described. Overall, 87 males and 69 females were evaluated, with the age of onset ranging from congenital to fourth decade (mean 6.6 ± 9.8 years). The mean age at diagnosis was 19 ± 12.8 (1-56 years), with a mean diagnostic delay of 12.5 ± 9.9 (0-49 years). Disease-causing variants in 17 CMS-associated genes were identified in 132 families (93.6%), while in nine families (6.4%), variants in genes not associated with CMS were found. Overall, postsynaptic defects were most common (62.4%), followed by glycosylation defects (21.3%), synaptic basal lamina genes (4.3%) and presynaptic defects (2.8%). Other genes found to cause neuromuscular junction defects (DES, TEFM) in our cohort accounted for 2.8%. Among the individual CMS genes, the most commonly affected gene was CHRNE (39.4%), followed by DOK7 (14.4%), DPAGT1 (9.8%), GFPT1 (7.6%), MUSK (6.1%), GMPPB (5.3%) and COLQ (4.5%). We identified 22 recurrent variants in this study, out of which eight were found to be geographically specific to the Indian subcontinent. Apart from the known common CHRNE variants p.E443Kfs*64 (11.4%) and DOK7 p.A378Sfs*30 (9.3%), we identified seven novel recurrent variants specific to this cohort, including DPAGT1 p.T380I and DES c.1023+5G>A, for which founder haplotypes are suspected. This study highlights the geographic differences in the frequencies of various causative CMS genes and underlines the increasing significance of glycosylation genes (DPAGT1, GFPT1 and GMPPB) as a cause of neuromuscular junction defects. Myopathy and muscular dystrophy genes such as GMPPB and DES, presenting as gradually progressive limb girdle CMS, expand the phenotypic spectrum. The novel genes MACF1 and TEFM identified in this cohort add to the expanding list of genes with new mechanisms causing neuromuscular junction defects. Show less

Miro proteins are universally conserved mitochondrial calcium-binding GTPases that regulate a multitude of mitochondrial processes, including transport, clearance, and lipid trafficking. The exact role of Miro in these functions is unclear but involves binding to a variety of client proteins. How this binding is operated at the molecular level and whether and how it is important for mitochondrial health, however, remains unknown. Here, we show that known Miro interactors-namely, CENPF, Trak, and MYO19-all use a similar short motif to bind the same structural element: a highly conserved hydrophobic pocket in the first calcium-binding domain of Miro. Using these Miro-binding motifs, we identified direct interactors de novo, including MTFR1/2/1L, the lipid transporters Mdm34 and VPS13D, and the ubiquitin E3-ligase Parkin. Given the shared binding mechanism of these functionally diverse clients and its conservation across eukaryotes, we propose that Miro is a universal mitochondrial adaptor coordinating mitochondrial health. Show less

Endothelial-to-mesenchymal transition (EndMT) is a biological process that converts endothelial cells to mesenchymal cells with increased proliferative and migrative abilities. EndMT has been implicated in the development of pulmonary vascular remodeling in pulmonary arterial hypertension (PAH), a fatal and progressive lung vascular disease. Transforming growth factor β EndMT has been reported to contribute to the pathogenesis of PH. In this study we aimed to determine the role of Ca Show less

Melanocortin 4 receptor (MC4R) activity in the hypothalamus is crucial for regulation of metabolism and food intake. The peptide ligands for the MC4R are associated with feeding, energy expenditure, and also with complex behaviors that orchestrate energy intake and expenditure, but the downstream neuroanatomical and neurochemical targets associated with these behaviors are elusive. In addition to strong expression in the hypothalamus, the MC4R is highly expressed in the medial prefrontal cortex, a region involved in executive function and decision-making. Using viral techniques in genetically modified male mice combined with molecular techniques, we identify and define the effects on feeding behavior of a novel population of MC4R expressing neurons in the infralimbic (IL) region of the cortex. Here, we describe a novel population of MC4R-expressing neurons in the IL of the mouse prefrontal cortex that are glutamatergic, receive input from melanocortinergic neurons, and project to multiple regions that coordinate appetitive responses to food-related stimuli. The neurons are stimulated by application of MC4R-specific peptidergic agonist, THIQ. Deletion of MC4R from the IL neurons causes increased food intake and body weight gain and impaired executive function in simple food-related behavior tasks. Together, these data suggest that MC4R neurons of the IL play a critical role in the regulation of food intake in male mice. Show less

Alzheimer's disease (AD) is the most common cause of dementia and is characterized by amyloid-β (Aβ) peptides and hyperphosphorylated Tau proteins. Evidence indicates that AD and type 2 diabetes mellitus (T2DM) share pathophysiological characteristics, including impaired insulin sensitivity. Large-leaf yellow tea (LYT) has been widely recognized for its health benefits, and we previously found that LYT can improve peripheral insulin resistance. This study aimed to investigate the protective effects and underlying mechanisms of LYT in the 5xFAD mouse model of AD. HPLC and spectrophotometric methods determined the chemical composition of the LYT extract. 5xFAD mice were treated with LYT supplementation (2 and 4 mg/ml) in drinking water for six months. Barnes and Y mazes were used to evaluate cognitive function, and the open field test assessed anxiety-like behavior. Immunofluorescence, silver, and Nissl staining were used to evaluate the pathological effects of LYT extract. A FRET-based assay assessed β-site APP cleavage enzyme 1 (BACE1) activity, ELISA measured Aβ levels in the brain, and Western blot analyses explored protein expression levels. Our results revealed that LYT significantly attenuated memory impairment and anxiety levels and alleviated cerebral neural damage. A reduction of senile plaques was also observed in both the cortex and hippocampus. LYT significantly inhibited the activity of BACE1, which resulted in a lower Aβ protein level. In addition, LYT enhanced insulin receptor substrate 1 (IRS-1)-mediated phosphorylation of phosphoinositide 3-kinase (PI3K) and protein kinase B (AKT), further suppressed glycogen synthase kinase-3β (GSK3β), and ultimately inhibited hyperphosphorylation of the protein Tau. The inhibitory effect of the LYT extract on the phosphorylation of Tau and BACE1 activity was dose-dependent. LYT improves cognitive ability and reduces Aβ production by inhibiting BACE1 activity. Decreases of Tau protein hyperphosphorylation upon LYT treatment appear to be associated with the regulation of the IRS-1/PI3K/AKT/GSK3β axis. Thus, the findings of this study also provide new evidence that LYT regulates insulin signaling pathways within the central nervous system. Show less

Hepatic steatosis signifies onset of metabolic dysfunction-associated fatty liver disease (MAFLD) caused by disrupted metabolic homeostasis compromising liver function. Regular consumption of common beans reduces the risk of metabolic impairment, but its effective dose, the impact of biological sex, and underlying mechanisms of action are unknown. We fed female and male C57BL6/J mice with obesogenic yet isocaloric diets containing 0%, 17.5%, 35%, and 70% of total dietary protein derived from cooked whole common beans. Liver tissue was collected for histopathology, lipid quantification, and RNA-seq analyses. Beans qualitatively and quantitatively diminished hepatic fat deposition at the 35% dose in female and 70% dose in male mice. Bean-induced differentially expressed genes (DEGs) most significantly mapped to hepatic steatosis and revealed dose-responsive inhibition of Show less

Mitochondrial homeostasis requires a dynamic balance of fission and fusion. The actin cytoskeleton promotes fission, and we found that the mitochondrially localized myosin, myosin 19 (Myo19), is integral to this process. Myo19 knockdown induced mitochondrial elongation, whereas Myo19 overexpression induced fragmentation. This mitochondrial fragmentation was blocked by a Myo19 mutation predicted to inhibit ATPase activity and strong actin binding but not by mutations predicted to affect the working stroke of the motor that preserve ATPase activity. Super-resolution imaging indicated a dispersed localization of Myo19 on mitochondria, which we found to be dependent on metaxins. These observations suggest that Myo19 acts as a dynamic actin-binding tether that facilitates mitochondrial fragmentation. Myo19-driven fragmentation was blocked by depletion of either the CAAX splice variant of the endoplasmic reticulum (ER)-anchored formin INF2 or the mitochondrially localized F-actin nucleator Spire1C (a splice variant of Spire1), which together polymerize actin at sites of mitochondria-ER contact for fission. These observations imply that Myo19 promotes fission by stabilizing mitochondria-ER contacts; we used a split-luciferase system to demonstrate a reduction in these contacts following Myo19 depletion. Our data support a model in which Myo19 tethers mitochondria to ER-associated actin to promote mitochondrial fission. Show less

Researchers have long investigated a hypothesized interaction between genetic risk and stressful life events in the etiology of depression, but studies on the topic have yielded inconsistent results. We conducted a genome-wide by environment interaction study (GWEIS) in 18,532 patients with depression from hospital-based settings and 20,184 population controls. All individuals were drawn from the iPSYCH2012 case-cohort study, a nationally representative sample identified from Danish national registers. Information on stressful life events including family disruption, serious medical illness, death of a first-degree relative, parental disability, and child maltreatment was identified from the registers and operationalized as a time-varying count variable. Hazard ratios for main and interaction effects were estimated using Cox regressions weighted to accommodate the case-cohort design. Our replication sample included 22,880 depression cases and 50,378 controls from the UK Biobank. The GWEIS in the iPSYCH2012 sample yielded three novel, genome-wide-significant ( In this large, population-based GWEIS, we did not find any replicable hits for interaction. Future gene-by-stress research in depression should focus on establishing even larger collaborative GWEISs to attain sufficient power. Show less

Neuroblastoma (NB) is a heterogeneous cancer of the sympathetic nervous system, which accounts for 7-10% of paediatric malignancies worldwide. Due to the lack of targetable molecular aberrations in NB, most treatment options remain relatively nonspecific. Here, we investigated the therapeutic potential of BCI, an inhibitor of DUSP1 and DUSP6, in cultured NB cells. BCI was cytotoxic in a range of NB cell lines and induced a short-lived activation of the AKT and stress-inducible MAP kinases, although ERK phosphorylation was unaffected. Furthermore, a phosphoproteomic screen identified significant upregulation of JNK signalling components and suppression in mTOR and R6K signalling. To assess the specificity of BCI, CRISPR-Cas9 was employed to introduce insertions and deletions in the DUSP1 and DUSP6 genes. Surprisingly, BCI remained fully cytotoxic in NB cells with complete loss of DUSP6 and partial depletion of DUSP1, suggesting that BCI exerts cytotoxicity in NB cells through a complex mechanism that is unrelated to these phosphatases. Overall, these data highlight the risk of using an inhibitor such as BCI as supposedly specific DUSP1/6, without understanding its full range of targets in cancer cells. Show less