👤 Anna Berg

To systematically examine the available literature on circulating biomarkers of performance resilience in a military environment, with the goal of identifying the most promising circulating biomarkers. The construct 'resilience' is hypothesized to play an important role in increasing Special Operations Forces' and other military personnel's capacity for withstanding exposure to various military-specific stressors. However, objectively measuring resilience is challenging. Some of the most important and well-studied circulating biomarkers that affect military-specific resilience are cortisol, dehydroepiandrosterone (sulfate) [DHEA(S)], noradrenaline, serotonin, neuropeptide-Y (NPY) and brain-derived neurotrophic factor. Despite growing evidence, the available knowledge is yet to be summarized and reviewed while considering the intensity and duration of military-specific stressors, military experience, and methodological differences between studies. Cortisol, Insulin-like growth factor-1 (IGF-1), NPY and DHEA(S) provide a physiological window into military-specific resilience. In general, individuals who exhibit a pronounced but controlled biomarker response to an acute stressor, combined with a quick recovery to baseline, demonstrate physiological flexibility that is associated with greater military-specific resilience. Future research will need to determine relative thresholds for the acute stressor-related change in circulating biomarkers and relative timing to stressor, to correctly interpret 'a pronounced but controlled biomarker response' and 'quick recovery to baseline'. Show less

Familial chylomicronemia syndrome (FCS) is a rare autosomal recessive disorder characterized by extreme hypertriglyceridemia (>1000 mg/dL), recurrent pancreatitis, and lipoprotein lipase (LPL) deficiency. FCS is caused by biallelic loss-of-function variants in LPL or in 4 other genes encoding its cofactors and regulators, including LMF1 (lipase maturation factor 1). Variants in LMF1 are rare and present only in 1% to 2% of the FCS cases. To assess in 3 patients with severe hypertriglyceridemia and recurrent pancreatitis and in whom a homozygous LMF1 duplication, initially classified as a variant of uncertain significance (VUS) was identified, post-heparin LPL activity. We collected demographics, fasting lipid profiles, and body mass index, and performed next-generation sequencing using a targeted panel that included canonical FCS genes. A homozygous in-frame duplication in LMF1 (c.914₉₂₈dup; p.Ser309_Phe310dup) was identified. Variants were classified according to American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) guidelines and cross-referenced with public archive of reports of the relationships among human variations and phenotypes (ClinVar), The Human Gene Mutation Database at the Institute of Medical Genetics in Cardiff (HGMD), Leiden Open Variation Database (LOVD), The Single Nucleotide Polymorphism database (dbSNP), The Genome Aggregation Database (gnomAD), and in-house databases. LPL activity was assessed in post-heparin plasma using a radiometric assay. All 3 patients were homozygous for c.914₉₂₈dup (this variant was classified as a VUS) and exhibited markedly reduced LPL activity (<20% of normal). Clinical manifestations were consistent with FCS, including extreme triglyceride elevations and recurrent pancreatitis. One patient died from fulminant pancreatitis. The combined clinical, biochemical, and genetic evidence supports the reclassification of LMF1 c.914₉₂₈dup (p.Ser309_Phe310dup) as likely pathogenic according to ACMG/AMP guidelines and indicates its association with severe pancreatitis. Show less

A case of a 29-year-old female patient with a history of a single episode of hypertriglyceridemia-induced pancreatitis 4 years prior is reported. She had been treated with fibrates until 2 months before conception and required hospitalization at 33 weeks of gestation due to severe hypertriglyceridemia (6690 mg/dL) and gestational diabetes. Upon hospital admission, there was no evidence of pancreatitis. A comprehensive treatment approach was initiated, combining a low-fat diet, fibrates, omega-3 fatty acids (2 g/d), and continuous insulin infusion. This regimen resulted in a significant reduction of triglyceride levels to 960 mg/dL. The pregnancy progressed to full term without any maternal-fetal complications. Genetic analysis revealed 2 compound heterozygous mutations in the APOA5 gene, which encodes apolipoprotein AV. Notably, these specific mutations have not been previously reported as causative factors for familial chylomicronemia syndrome (FCS). The diagnosis of FCS was confirmed by the patient's markedly reduced lipoprotein lipase activity of 3.2%. Show less

Intestinal remnant chylomicrons (CMs) are involved in cardiovascular residual risk and the atherogenic process. Microsomal triglyceride transfer protein (MTTP) catalyzes the assembly of lipids to apolipoprotein B48, generating CMs. Dysbiosis could alter this behavior. This study investigated the chemical composition of CMs and their associations with intestinal MTTP and gut fat depots in a diet-induced dysbiosis animal model. Male Wistar rats were fed either a standard diet (control, n=10) or a high-fat high-sucrose diet (HFSD, n=10) for 14 weeks. Measurements included serum glucose, lipid-lipoprotein profile, free fatty acids (FFAs), lipopolysaccharide (LPS) and the Compared to control, HFSD rats showed higher levels of LPS, triglycerides (TGs), non-high-density lipoprotein cholesterol (HDL-C) levels, TG/HDL-C ratio, FFAs, and the F/B ratio. HFSD CMs showed increased TG and phospholipids. TJ proteins levels were lower in the HFSD group, while histological scores showed no differences. CIF was increased in the HFSD group. No significant differences in apoB mRNA were found. MTTP expression was higher in the HFSD group, and directly correlated with CM-TG and inversely correlated with CIF. Our findings imply that gut TG content may constitute an important determinant of the secretion of TG-rich CMs, promoted by MTTP, with increased atherogenic potential. Show less

Endosomal system dysfunction within neurons is a prominent early feature of Alzheimer's disease (AD) pathology. Multiple AD risk factors are regulators of endocytosis and known to cause hyperactivity of the early endosome small GTPase rab5, resulting in neuronal endosomal pathway disruption and cholinergic neurodegeneration. Adaptor protein containing Pleckstrin homology domain, Phosphotyrosine binding domain, Leucine zipper motif (APPL1), an important rab5 effector protein and signaling molecule has been shown in vitro to interface between endosomal and neuronal dysfunction through a rab5-activating interaction with the BACE1-generated C-terminal fragment of amyloid precursor protein (APP-βCTF), a pathogenic APP fragment generated within endosomal compartments. To understand the contribution of APPL1 to AD-related endosomal dysfunction in vivo, we generated a transgenic mouse model overexpressing human APPL1 within neurons (Thy1-APPL1). Strongly supporting the important endosomal regulatory roles of APPL1 and their relevance to AD etiology, Thy1-APPL1 mice (both sexes) develop enlarged neuronal early endosomes and increased synaptic endocytosis due to increased rab5 activation. We demonstrated pathophysiological consequences of APPL1 overexpression, including functional changes in hippocampal long-term potentiation (LTP) and long-term depression (LTD), degeneration of large projection cholinergic neurons of the basal forebrain, and impaired hippocampal-dependent memory. Our evidence shows that neuronal APPL1 elevation modeling its functional increase in the AD brain induces a cascade of AD-related pathological effects within neurons, including early endosome anomalies, synaptic dysfunction, and selective neurodegeneration. Our in vivo model highlights the contributions of APPL1 to the pathobiology and neuronal consequences of early endosomal pathway disruption and its potential value as a therapeutic target. Show less

Endosomal system dysfunction within neurons is a prominent early feature of Alzheimer's disease (AD) pathology. Multiple AD risk factors are regulators of endocytosis and are known to cause hyper-activity of the early-endosome small GTPase rab5, resulting in neuronal endosomal pathway disruption and cholinergic neurodegeneration. Adaptor protein containing Pleckstrin homology domain, Phosphotyrosine binding domain, Leucine zipper motif (APPL1), an important rab5 effector protein and signaling molecule, has been shown Neuronal endosome dysfunction appears early in Alzheimer's disease (AD) and is linked to memory loss. Genes and risk factors associated with AD often increase rab5 activity, a protein that disrupts endosomal signalling when hyperactivated. APPL1, a key rab5 partner, worsens this dysfunction via its interaction with APP-βCTF, a protein fragment associated with AD. To explore APPL1's role, we created a genetically modified mouse that overexpresses APPL1 in neurons. This model provides the first Show less

G-quadruplexes (G4s) are prevalent DNA structures that regulate transcription but also threaten genome stability. How G4 dynamics are controlled remains poorly understood. Here, we report that RNA transcripts govern G4 landscapes through coordinated G-loop assembly and disassembly. G-loop assembly involves activation of the ATM and ATR kinases, followed by homology-directed invasion of RNA opposite the G4 strand mediated by BRCA2 and RAD51. Disassembly of the G-loop resolves the G4 structure through DHX36-FANCJ-mediated G4 unwinding, which triggers nucleolytic incision and subsequent hybrid strand renewal by DNA synthesis. Inhibition of G-loop disassembly causes global G4 and R-loop accumulation, leading to transcriptome dysregulation, replication stress, and genome instability. These findings establish an intricate G-loop assembly-disassembly mechanism that controls G4 landscapes and is essential for cellular homeostasis and survival. Show less

Given that lipoprotein lipase (LPL) activity assays are not standardized for clinical use, we aimed to define reference values applicable to our clinical setting and identify a cut-off point to help distinguish Familial Chylomicronemia Syndrome from Multifactorial Chylomicronemia Syndrome, particularly in patients with inconclusive genetic findings. We evaluated 28 patients with a history of TG levels above 880 mg/dL (10 mmol/L), and assessed their likelihood of FCS using the Moulin score. LPL activity was measured in post-heparin plasma using a radiometric assay. Thirty normotriglyceridemic controls were used to define reference values. Genetic testing for FCS canonical genes and lipid profile was performed in all sHTG patients. The reference value for LPL activity was 33.3 (18.7-70.3) mIU, with a cut-off of 8.42 mIU (25 % of the median of NTG) to distinguish FCS from MCS. Eighteen patients without genetic variants in canonical genes, a Moulin score <9 and LPL activity >25 % of NTG, were classified as MCS. Five genetic diagnosed FCS patients, with a Moulin score>10 presented LPL activity <25 % of NTG. Four patients with inconclusive genetic results and a Moulin score>10 were classified as FCS according to LPL activity. LPL activity in patients with sHTG could be useful for differentiating FCS and MCS, particularly in patients with ambiguous or negative genetic findings, highlighting the need for specialized laboratory support in diagnostics. Show less

Familial chylomicronemia syndrome (FCS) is an autosomal recessive disorder that affects approximately 1 to 10 individuals per million and is caused by variants in the genes encoding for the lipoprotein lipase (LPL) enzyme. In addition to its heterogeneous clinical presentation, FCS is characterized by a higher risk of life-threatening, recurrent acute pancreatitis and type 3 diabetes. Since available evidence on FCS in Latin America is limited, there is a clear need for a consensus document that provides relevant recommendations to guide the management of suspected cases and optimize disease diagnosis across the region. A panel of specialists from Latin America with extensive experience in the diagnosis of chylomicronemia was invited to participate in the creation of this document. The modified Delphi technique was used to reach group consensus through multiple rounds of questionnaires using statistical techniques and controlled feedback. Results and discussion: Seventeen recommendations on diagnosis of FCS were generated. This consensus reflects the collaborative efforts of Latin American scientific societies and is essential to suspect and diagnose FCS. The organizations that support this document, including Sociedad Argentina de Lípidos, Federación Argentina de Sociedades de Endocrinología, Fundación Bioquímica Argentina, Corporación Grupo Chileno de Trabajo en Ateroesclerosis, Asociación Colombiana de Endocrinología, Diabetes y Metabolismo, Departamento de Aterosclerose da Sociedade Brasileira de Cardiología, and Sociedad Mexicana de Nutrición y Endocrinología, are a robust support network that might aid the adoption of these recommendations in local healthcare systems. Show less

Familial chylomicronemia syndrome (FCS) is a rare monogenic disorder characterized by severe hypertriglyceridemia caused by pathogenic variants in genes involved in triglyceride metabolism. Glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1) plays a critical role in the lipolytic processing of triglyceride-rich lipoproteins. We present 3 unrelated cases of FCS with a newly identified homozygous complex insertion-deletion variant in GPIHBP1, namely c.460₄₆₁delinsAAA, p.Ala154Lysfs*153. All 3 cases presented with severe hypertriglyceridemia, a high FCS clinical score, and significantly reduced lipoprotein lipase (LPL) activity (being 6.6 mUI the value corresponding to 20% of normal activity). These observations expand the spectrum of pathogenic GPIHBP1 variants in FCS. The identification of GPIHBP1 variant reinforces the causal link between GPIHBP1 mutations and LPL deficiency, as evidenced by diminished LPL activity, and further expands the genetic landscape of FCS. Show less

Prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) is higher in men than in women. Hormonal and genetic causes may account for the sex differences in MASLD. Current human in vitro liver models do not sufficiently take the influence of biological sex and sex hormones into consideration. Primary human hepatocytes (PHHs) were isolated from liver specimen of female and male donors and cultured with sex hormones (17β-estradiol, testosterone and progesterone) for up to 72 h. mRNA expression levels of 8 hepatic lipid metabolism genes were analyzed by RT-qPCR. Sex hormones and their metabolites were determined in cell culture supernatants by LC-MS analyses. A sex-specific expression was observed for LDLR (low density lipoprotein receptor) with higher mRNA levels in male than female PHHs. All three sex hormones were metabolized by PHHs and the effects of hormones on gene expression levels varied depending on hepatocyte sex. Only in female PHHs, 17β-estradiol treatment affected expression levels of PPARA (peroxisome proliferator-activated receptor alpha), LIPC (hepatic lipase) and APOL2 (apolipoprotein L2). Further changes in mRNA levels of female PHHs were observed for ABCA1 (ATP-binding cassette, sub-family A, member 1) after testosterone and for ABCA1, APOA5 (apolipoprotein A-V) and PPARA after progesterone treatment. Only the male PHHs showed changing mRNA levels for LDLR after 17β-estradiol and for APOA5 after testosterone treatment. Male and female PHHs showed differences in their expression levels of hepatic lipid metabolism genes and their responsiveness towards sex hormones. Thus, cellular sex should be considered, especially when investigating the pathophysiological mechanisms of MASLD. Show less

Genetic susceptibility to metabolic associated fatty liver disease (MAFLD) is complex and poorly characterized. Accurate characterization of the genetic background of hepatic fat content would provide insights into disease etiology and causality of risk factors. We performed genome-wide association study (GWAS) on two noninvasive definitions of hepatic fat content: magnetic resonance imaging proton density fat fraction (MRI-PDFF) in 16,050 participants and fatty liver index (FLI) in 388,701 participants from the United Kingdom (UK) Biobank (UKBB). Heritability, genetic overlap, and similarity between hepatic fat content phenotypes were analyzed, and replicated in 10,398 participants from the University Medical Center Groningen (UMCG) Genetics Lifelines Initiative (UGLI). Meta-analysis of GWASs of MRI-PDFF in UKBB revealed five statistically significant loci, including two novel genomic loci harboring CREB3L1 (rs72910057-T, P = 5.40E-09) and GCM1 (rs1491489378-T, P = 3.16E-09), respectively, as well as three previously reported loci: PNPLA3, TM6SF2, and APOE. GWAS of FLI in UKBB identified 196 genome-wide significant loci, of which 49 were replicated in UGLI, with top signals in ZPR1 (P = 3.35E-13) and FTO (P = 2.11E-09). Statistically significant genetic correlation (rg) between MRI-PDFF (UKBB) and FLI (UGLI) GWAS results was found (rg = 0.5276, P = 1.45E-03). Novel MRI-PDFF genetic signals (CREB3L1 and GCM1) were replicated in the FLI GWAS. We identified two novel genes for MRI-PDFF and 49 replicable loci for FLI. Despite a difference in hepatic fat content assessment between MRI-PDFF and FLI, a substantial similar genetic architecture was found. FLI is identified as an easy and reliable approach to study hepatic fat content at the population level. Show less

The onset of puberty is associated with a shift in the circadian timing of sleep, leading to delayed sleep initiation [i.e., later sleep onset time (SOT)] due to later bedtimes and/or longer sleep onset latency (SOL). Several genome-wide association studies (GWAS) have identified genes that may be involved in the etiology of sleep phenotypes. However, circadian rhythms are also epigenetically regulated; therefore, epigenetic biomarkers may provide insight into the physiology of the pubertal sleep onset shift and the pathophysiology of prolonged or delayed sleep initiation. The gene-wide analysis indicated differential methylation within or around 1818 unique genes across the sleep initiation measurements using self-report, actigraphy (ACT), and polysomnography (PSG), while GWAS-informed analysis yielded 67 genes. Gene hits were identified for bedtime (PSG), SOL (subjective, ACT and PSG) and SOT (subjective and PSG). DNA methylation within 12 genes was associated with both subjective and PSG-measured SOL, 31 with both ACT- and PSG-measured SOL, 19 with both subjective and ACT-measured SOL, and one gene (SMG1P2) had methylation sites associated with subjective, ACT- and PSG-measured SOL. Objective and subjective sleep initiation in adolescents is associated with altered DNA methylation in genes previously identified in adult GWAS of sleep and circadian phenotypes. Additionally, our data provide evidence for a potential epigenetic link between habitual (subjective and ACT) SOL and in-lab SOT and DNA methylation in and around genes involved in circadian regulation (i.e., RASD1, RAI1), cardiometabolic disorders (i.e., FADS1, WNK1, SLC5A6), and neuropsychiatric disorders (i.e., PRR7, SDK1, FAM172A). If validated, these sites may provide valuable targets for early detection and prevention of disorders involving prolonged or delayed SOT, such as insomnia, delayed sleep phase, and their comorbidity. Show less

Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are closely related progressive disorders with no available disease-modifying therapy, neuropathologically characterized by intraneuronal aggregates of misfolded α-synuclein. To explore the role of DNA methylation changes in PD and DLB pathogenesis, we performed an epigenome-wide association study (EWAS) of 322 postmortem frontal cortex samples and replicated results in an independent set of 200 donors. We report novel differentially methylated replicating loci associated with Braak Lewy body stage near TMCC2, SFMBT2, AKAP6 and PHYHIP. Differentially methylated probes were independent of known PD genetic risk alleles. Meta-analysis provided suggestive evidence for a differentially methylated locus within the chromosomal region affected by the PD-associated 22q11.2 deletion. Our findings elucidate novel disease pathways in PD and DLB and generate hypotheses for future molecular studies of Lewy body pathology. Show less

Epicardial adipose tissue (EAT) contributes to coronary artery disease (CAD). EAT presents a specific lipidomic signature, showing increased ceramides and other proinflammatory lipids content. Besides, LPL (lipoprotein lipase) activity in EAT would contribute to its expansion, supplying fatty acids to the tissue. Our aim was to evaluate the relations between LPL activity, regulators of LPL, and ceramides in EAT from CAD patients. We studied patients undergoing coronary bypass graft (CAD, n=25) and patients without CAD (no CAD, n=14). EAT and subcutaneous AT (SAT) were obtained, tissue LPL activity and its regulator's expression (ANGPTL4, GPIHBP1 [glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1], and PPARγ [peroxisomal proliferator-activated receptor γ]) were assessed. Tissue lipidomes were evaluated by UHPLC-MS, in positive and negative ionization modes. LPL activity was higher in EAT from CAD ( The association between LPL activity, total ceramide, and the atherogenic ceramide ratios highlights the importance of the enzyme and these bioactive lipids contributing to the different metabolic profile of EAT in CAD. Show less

In this study, the effect of heterozygous germline mutations in the heparan sulfate (HS) glycosaminoglycan chain co-polymerases EXT1 and EXT2 on glomerular barrier function and the endothelial glycocalyx in humans is investigated. Heparan sulfate (HS) glycosaminoglycans are deemed essential to the glomerular filtration barrier, including the glomerular endothelial glycocalyx. Animal studies have shown that loss of HS results in a thinner glycocalyx. Also, decreased glomerular HS expression is observed in various proteinuric renal diseases in humans. A case report of a patient with an EXT1 mutation indicated that this could result in a specific renal phenotype. This patient suffered from multiple osteochondromas, an autosomal dominant disease caused by mono-allelic germline mutations in the EXT1 or EXT2 gene. These studies imply that HS is indeed essential to the glomerular filtration barrier. However, loss of HS did not lead to proteinuria in various animal models. We demonstrate that multiple osteochondroma patients do not have more microalbuminuria or altered glycocalyx properties compared to age-matched controls (n = 19). A search for all Dutch patients registered with both osteochondroma and kidney biopsy (n = 39) showed that an EXT1 or EXT2 mutation does not necessarily lead to specific glomerular morphological phenotypic changes. In conclusion, this study shows that a heterozygous mutation in the HS backbone elongating enzymes EXT1 and EXT2 in humans does not result in (micro)albuminuria, a specific renal phenotype or changes to the endothelial glycocalyx, adding to the growing knowledge on the role of EXT1 and EXT2 genes in pathophysiology. Show less

Genome-wide association studies have identified genetic variation in genomic loci associated with susceptibility to Parkinson's disease (PD), the most common neurodegenerative movement disorder worldwide. We used allelic expression profiling of genes located within PD-associated loci to identify cis-regulatory variation affecting gene expression. DNA and RNA were extracted from post-mortem superior frontal gyrus tissue and whole blood samples from PD patients and controls. The relative allelic expression of transcribed SNPs in 12 GWAS risk genes was analysed by real-time qPCR. Allele-specific expression was identified for 9 out of 12 genes tested (GBA, TMEM175, RAB7L1, NUCKS1, MCCC1, BCKDK, ZNF646, LZTS3, and WDHD1) in brain tissue samples. Three genes (GPNMB, STK39 and SIPA1L2) did not show significant allele-specific effects. Allele-specific effects were confirmed in whole blood for three genes (BCKDK, LZTS3 and MCCC1), whereas two genes (RAB7L1 and NUCKS1) showed brain-specific allelic expression. Our study supports the hypothesis that changes to the cis-regulation of gene expression is a major mechanism behind a large proportion of genetic associations in PD. Interestingly, allele-specific expression was also observed for coding variants believed to be causal variants (GBA and TMEM175), indicating that splicing and other regulatory mechanisms may be involved in disease development. Show less

Several inflammatory molecules participate in the immune response to malaria. Interleukin (IL)-18 is an inflammatory cytokine activated by NLRP3 inflammasomes. In clinical falciparum malaria, with and without HIV co-infection, data on IL-18 and in particular on its binding protein, IL-18bp, is scarce. Clinical data and blood samples were collected from adults in Mozambique with P. falciparum infection, with (n = 70) and without (n = 61) HIV co-infection, from HIV-infected patients with similar symptoms without malaria (n = 58) and from healthy controls (n = 52). In vitro studies were performed in endothelial cells using hemozoin crystals. (i) IL-18 and IL-18bp were markedly up-regulated during falciparum malaria with particular high levels in malaria patients co-infected with HIV and severe malaria disease. (ii) In the malaria group as a whole, both IL-18 and IL-18bp were positively correlated with disease severity, parasitemia, and endothelial cell activation as assessed by vWF in plasma. (iii) Whereas there was no change in IL-18 levels in malaria patients co-infected with HIV during follow-up, the patients with malaria only had slightly increased IL-18 levels. Further, the IL-18pb levels declined and thereby contributed to an increase in IL-18/IL-18bp ratio in all subgroups of malaria patients. (iv) IL-27, previously shown to be up-regulated in this malaria cohort, markedly induced a release of IL-18bp from endothelial cells in vitro, and notably, this presumably anti-inflammatory effect was counteracted by hemozoin. Our findings suggest that the IL-18 system could be an important mediator in the immune pathogenesis during falciparum malaria, potentially also representing a target for therapy. Show less

Cytokines control immune related events and are critically involved in a plethora of patho-physiological processes including autoimmunity and cancer development. In rare cases, single nucleotide polymorphisms (SNPs) or single nucleotide variations (SNVs) in cytokine receptors eventually cause detrimental ligand-independent, constitutive activation of signal transduction. Most SNPs have, however, no or only marginal influences on gene expression, protein stability, localization and function and thereby only slightly affecting pathogenesis probability. The SNP database (dbSNP) is an archive for a broad collection of polymorphisms in which SNPs are categorized and marked with a locus accession number "reference SNP" (rs). Here, we engineered an algorithm to directly align dbSNP information to DNA and protein sequence information to clearly illustrate a genetic SNP landscape exemplified for all tall cytokine receptors of the IL-6/IL-12 family, including IL-23R, IL-12Rβ1, IL-12Rβ2, gp130, LIFR, OSMR and WSX-1. This information was complemented by a comprehensive literature summary and structural insights of relevant disease-causing SNPs in cytokine/cytokine receptor interfaces. In summary, we present a general strategy with potential to apply to other cytokine receptor networks. Show less

We conducted cohort- and race-specific epigenome-wide association analyses of mitochondrial deoxyribonucleic acid (mtDNA) copy number (mtDNA CN) measured in whole blood from participants of African and European origins in five cohorts (n = 6182, mean age = 57-67 years, 65% women). In the meta-analysis of all the participants, we discovered 21 mtDNA CN-associated DNA methylation sites (CpG) (P < 1 × 10-7), with a 0.7-3.0 standard deviation increase (3 CpGs) or decrease (18 CpGs) in mtDNA CN corresponding to a 1% increase in DNA methylation. Several significant CpGs have been reported to be associated with at least two risk factors (e.g. chronological age or smoking) for cardiovascular disease (CVD). Five genes [PR/SET domain 16, nuclear receptor subfamily 1 group H member 3 (NR1H3), DNA repair protein, DNA polymerase kappa and decaprenyl-diphosphate synthase subunit 2], which harbor nine significant CpGs, are known to be involved in mitochondrial biosynthesis and functions. For example, NR1H3 encodes a transcription factor that is differentially expressed during an adipose tissue transition. The methylation level of cg09548275 in NR1H3 was negatively associated with mtDNA CN (effect size = -1.71, P = 4 × 10-8) and was positively associated with the NR1H3 expression level (effect size = 0.43, P = 0.0003), which indicates that the methylation level in NR1H3 may underlie the relationship between mtDNA CN, the NR1H3 transcription factor and energy expenditure. In summary, the study results suggest that mtDNA CN variation in whole blood is associated with DNA methylation levels in genes that are involved in a wide range of mitochondrial activities. These findings will help reveal molecular mechanisms between mtDNA CN and CVD. Show less

Artificial light exposure is associated with dyslipidemia in humans, which is a major risk factor for the development of atherosclerotic cardiovascular disease. However, it remains unclear whether artificial light at night can exacerbate atherosclerosis. In this study, we exposed female APOE*3-Leiden.CETP mice, a well-established model for human-like lipid metabolism and atherosclerosis, to either a regular light-dark cycle or to constant bright light for 14 weeks. Mice exposed to constant light demonstrated a minor reduction in food intake, without any effect on body weight, body composition, or the weight of metabolic organs. Constant light increased the plasma levels of proatherogenic non-high-density lipoprotein (HDL) cholesterol but did not increase the size or severity of atherosclerotic lesions in the aortic root. Mice exposed to constant light did show lower immune cell counts, which could explain the absence of an effect of atherosclerosis despite increased non-HDL cholesterol levels. Behavioral analysis demonstrated variability in the response of mice to the light intervention. Constant light completely blunted behavioral rhythms in some mice, while others extended their behavioral period. However, rhythm strength was not an important determinant of atherosclerosis. Altogether, these results demonstrate that constant bright light does not affect atherosclerosis in APOE*3-Leiden.CETP mice. Whether artificial light exposure contributes to cardiovascular disease risk in humans remains to be investigated. Show less

Disruption of circadian rhythm by means of shift work has been associated with cardiovascular disease in humans. However, causality and underlying mechanisms have not yet been established. In this study, we exposed hyperlipidemic APOE*3-Leiden.CETP mice to either regular light-dark cycles, weekly 6 hours phase advances or delays, or weekly alternating light-dark cycles (12 hours shifts), as a well-established model for shift work. We found that mice exposed to 15 weeks of alternating light-dark cycles displayed a striking increase in atherosclerosis, with an approximately twofold increase in lesion size and severity, while mice exposed to phase advances and delays showed a milder circadian disruption and no significant effect on atherosclerosis development. We observed a higher lesion macrophage content in mice exposed to alternating light-dark cycles without obvious changes in plasma lipids, suggesting involvement of the immune system. Moreover, while no changes in the number or activation status of circulating monocytes and other immune cells were observed, we identified increased markers for inflammation, oxidative stress, and chemoattraction in the vessel wall. Altogether, this is the first study to show that circadian disruption by shifting light-dark cycles directly aggravates atherosclerosis development. Show less

The immune response during falciparum malaria mediates both harmful and protective effects on the host; however the participating molecules have not been fully defined. Interleukin (IL)-27 is a pleiotropic cytokine exerting both inflammatory and anti-inflammatory effects, but data on IL-27 in malaria patients are scarce. Clinical data and blood samples were collected from adults in Mozambique with P. falciparum infection, with (n = 70) and without (n = 61) HIV-1 co-infection, from HIV-infected patients with similar symptoms without malaria (n = 58) and from healthy controls (n = 52). In vitro studies were performed in endothelial cells and PBMC using hemozoin crystals. Samples were analyzed using enzyme immunoassays and quantitative PCR. (i) IL-27 was markedly up-regulated in malaria patients compared with controls and HIV-infected patients without malaria, showing no relation to HIV co-infection. (ii) IL-27 was correlated with P. falciparum parasitemia and von Willebrand factor as a marker of endothelial activation, but not with disease severity. (iii) In vitro, IL-27 modulated the hemozoin-mediated cytokine response in endothelial cells and PBMC with enhancing effects on IL-6 and attenuating effects on IL-8. Our findings show that IL-27 is regulated during falciparum malaria, mediating both inflammatory and anti-inflammatory effects, potentially playing an immune-regulatory role during falciparum malaria. Show less

Impaired lysosomal degradation of α-synuclein and other cellular constituents may play an important role in Parkinson's disease (PD). Rare genetic variants in the glucocerebrosidase (GBA) gene were consistently associated with PD. Here we examine the association between rare variants in lysosomal candidate genes and PD. We investigated the association between PD and rare genetic variants in 23 lysosomal candidate genes in 4096 patients with PD and an equal number of controls using pooled targeted next-generation DNA sequencing. Genewise association of rare variants in cases or controls was analyzed using the optimized sequence kernel association test with Bonferroni correction for the 23 tested genes. We confirm the association of rare variants in GBA with PD and report novel associations for rare variants in ATP13A2, LAMP1, TMEM175, and VPS13C. Rare variants in selected lysosomal genes, first and foremost GBA, are associated with PD. Rare variants in ATP13A2 and VPC13C previously linked to monogenic PD and more common variants in TMEM175 and VPS13C previously linked to sporadic PD in genome-wide association studies are associated with PD. © 2020 International Parkinson and Movement Disorder Society. Show less

Epicardial adipose tissue (EAT) is a visceral AT, surrounding myocardium and coronary arteries. Its volume is higher in Type 2 diabetic (DM2) patients, associated with cardiovascular disease risk. Lipoprotein lipase (LPL) hydrolyses triglycerides (TG) from circulating lipoproteins, supplying fatty acids to AT, contributing to its expansion. We aimed to evaluate LPL expression and activity in EAT from DM2 and no DM2 patients, and its regulators ANGPTL4, GPIHBP1 and PPARγ levels, together with VLDLR expression and EAT LPL association with VLDL characteristics. We studied patients undergoing coronary by-pass graft (CABG) divided into CABG-DM2 (n = 21) and CABG-noDM2 (n = 29), and patients without CABG (No CABG, n = 30). During surgery, EAT and subcutaneous AT (SAT) were obtained, in which LPL activity, gene and protein expression, its regulators and VLDLR protein levels were determined. Isolated circulating VLDLs were characterized. EAT LPL activity was higher in CABG-DM2 compared to CABG-noDM2 and No CABG (p=0.002 and p<0.001) and in CABG-noDM2 compared to No CABG (p=0.02), without differences in its expression. ANGPTL4 levels were higher in EAT from No CABG compared to CABG-DM2 and CABG-noDM2 (p<0.001). GPIHBP1 levels were higher in EAT from CABG-DM2 and CABG-noDM2 compared to No CABG (p= 0.04). EAT from CABG-DM2 presented higher PPARγ levels than CABG-noDM2 and No CABG (p=0.02 and p=0.03). No differences were observed in VLDL composition between groups, although EAT LPL activity was inversely associated with VLDL-TG and TG/protein index (p<0.05). EAT LPL regulation would be mainly post-translational. The higher LPL activity in DM2 could be partly responsible for the increase in EAT volume. Show less

The Mediator complex regulates transcription by connecting enhancers to promoters. High Mediator binding density defines super enhancers, which regulate cell-identity genes and oncogenes. Protein interactions of Mediator may explain its role in these processes but have not been identified comprehensively. Here, we purify Mediator from neural stem cells (NSCs) and identify 75 protein-protein interaction partners. We identify super enhancers in NSCs and show that Mediator-interacting chromatin modifiers colocalize with Mediator at enhancers and super enhancers. Transcription factor families with high affinity for Mediator dominate enhancers and super enhancers and can explain genome-wide Mediator localization. We identify E-box transcription factor Tcf4 as a key regulator of NSCs. Tcf4 interacts with Mediator, colocalizes with Mediator at super enhancers and regulates neurogenic transcription factor genes with super enhancers and broad H3K4me3 domains. Our data suggest that high binding-affinity for Mediator is an important organizing feature in the transcriptional network that determines NSC identity. Show less

The tumor-suppressing function of SMAD4 is frequently subverted during mammary tumorigenesis, leading to cancer growth, invasion, and metastasis. A long-standing concept is that SMAD4 is not regulated by phosphorylation but ubiquitination. Our search for signaling pathways regulated by breast tumor kinase (BRK), a nonreceptor protein tyrosine kinase that is up-regulated in ~80% of invasive ductal breast tumors, led us to find that BRK competitively binds and phosphorylates SMAD4 and regulates transforming growth factor-β/SMAD4 signaling pathway. A constitutively active BRK (BRK-Y447F) phosphorylates SMAD4, resulting in its recognition by the ubiquitin-proteasome system, which accelerates SMAD4 degradation. Activated BRK-mediated degradation of SMAD4 is associated with the repression of tumor suppressor gene Show less

Lipoprotein lipase (LPL) and endothelial lipase (EL) are involved in lipoprotein metabolism. In insulin-resistance, their behavior is altered. Peroxisome proliferator-activated receptors (PPAR) and apoproteins (apo)CII and CIII could be partly responsible for these alterations. To evaluate this response, we assessed Lpl and Lipg expression, protein levels, and enzyme activity in adipose tissue (AT) and heart in an obesity model. Besides, we assessed the role of PPAR and apoC. Male Wistar rats were fed with standard diet (Control, n = 14) or high-fat diet (HFD, n = 14) for 14 weeks. Glucose and lipoprotein profiles were measured. Histological studies were performed in heart and epididymal AT. Lpl and Lipg were assessed by reverse transcription polymerase chain reaction (RT-qPCR), protein levels by Western Blot, and activities by radiometric assays. Cardiac and AT PPAR expression were measured by Western Blot and hepatic Apoc2 and Apoc3 mRNA by RT-qPCR. In HFD, fat deposits were observed in hearts, whereas AT presented a higher adipocyte size. In heart and AT, no differences were found in Lipg mRNA between groups, while AT Lpl mRNA and LPL protein were decreased in HFD, without differences in heart. In both tissues, EL protein levels and activity were increased and inversely associated with decreased LPL activity, being partially responsible for the atherogenic lipoprotein profile in HFD. PPARγ expression in AT was decreased in HFD, without differences in cardiac PPARδ expression and hepatic apoC mRNA. The increase in EL activity could be an alternative pathway for fatty acid release from lipoproteins and uptake in tissues with decreased LPL activity. In AT, PPARγ could be involved in enzyme regulation. Show less

Many favorable metabolic effects have been attributed to thermogenic activity of brown adipose tissue (BAT). Yet, time of day has rarely been considered in this field of research. Here, we show that a diurnal rhythm in BAT activity regulates plasma lipid metabolism. We observed a high-amplitude rhythm in fatty acid uptake by BAT that synchronized with the light/dark cycle. Highest uptake was found at the onset of the active period, which coincided with high lipoprotein lipase expression and low angiopoietin-like 4 expression by BAT. Diurnal rhythmicity in BAT activity determined the rate at which lipids were cleared from the circulation, thereby imposing the daily rhythm in plasma lipid concentrations. In mice as well as humans, postprandial lipid excursions were nearly absent at waking. We anticipate that diurnal BAT activity is an important factor to consider when studying the therapeutic potential of promoting BAT activity. Show less