👤 Maureen Fitzgerald

Genome-wide association studies (GWAS) have successfully identified genetic loci associated with major depressive disorder (MDD), yet the complex gene networks underpinning this polygenic risk remain largely uncharacterised. Here, we elucidate the neurobiological mechanisms of MDD by analyzing co-expression networks of 94 risk genes in the human prefrontal cortex. By linking these networks to individual symptoms, we identify the FADS1 (fatty acid desaturase 1) network as a central integrator across symptom clusters. We find that the FADS1 network functions primarily in astrocytes to regulate fatty acid metabolism and influence oligodendrocyte-related cell states. Furthermore, we identify FGF2 as a synaptic effector of this pathway and highlight PPARα (peroxisome proliferator-activated receptor alpha) as a putative therapeutic target. These results establish astrocyte fatty acid metabolism as a critical mechanistic contributor to MDD and a promising avenue for treatment. Show less

Elevated plasma lipoprotein(a) [Lp(a)] is a causal risk factor for the development of atherosclerotic cardiovascular disease (ASCVD). However, commonly used ASCVD clinical risk-assessment tools in primary care do not include the measurement of Lp(a) levels, potentially under-estimating individual risk. Here we describe the case of a late-40s, asymptomatic, normotensive, non-smoking veteran athlete with a moderately raised low density lipoprotein cholesterol (LDL-C) level and a calculated 10-year QRISK3 score of 4.1%. Despite his low calculated QRISK3 score, significantly elevated Lp(a) levels led to advanced cardiovascular imaging, which revealed severe stenosis (75%, CAD-RADS 4A) of the left anterior descending coronary artery. This case demonstrates the limitations of conventional cardiovascular risk tools and highlights the importance of Lp(a) measurement for identifying and managing high-risk patients. Show less

Lipoprotein(a) [Lp(a)] is a well recognised contributor in the development of cardiovascular disease. Unlike other lipoproteins, Lp(a) levels are primarily genetically determined, and in most individuals remain largely stable throughout life. Elevated Lp(a) is common in the general population, and various international guidelines now recommend at least one lifetime measurement of Lp(a) and its inclusion into an individual's cardiovascular risk assessment. Despite this, Lp(a) is still rarely measured, even in patients with known cardiovascular risk factors. Critically, the therapeutic landscape for Lp(a)-lowering medications is rapidly evolving with multiple drugs showing considerable promise in late-stage clinical trials. The strength and consistency of the evidence now cement Lp(a) as an essential biomarker of cardiovascular health. Failure to incorporate measurement of Lp(a) into clinical practice will continue to underestimate an individual's risk of CVD. Now is the time for Lp(a) to move from a neglected biomarker to a widely known and measured essential component of cardiovascular risk assessment. Show less

Microtubule-actin cross-linking factor 1 (MACF1) is a large protein of the spectraplakin family, which is essential for brain development. MACF1 interacts with microtubules through the growth arrest-specific 2 (Gas2)-related (GAR) domain. Heterozygous MACF1 missense variants affecting the zinc-binding residues in this domain result in a distinctive cortical and brain stem malformation. Evidence for other MACF1-associated disorders is still limited. Here, we present a cohort of 45 individuals with heterozygous or bi-allelic MACF1 variants to explore the phenotypic spectrum and assess possible pathogenic relevance. We observe that de novo heterozygous missense variants in the EF-hand domains also result in distinctive brain malformation and provide experimental evidence that variants in the EF-hand/GAR module increase microtubule binding, suggestive of a toxic gain of function. Notably, no phenotype-genotype correlation was possible for the remaining heterozygous variants in other domains. A clinical review of eight families with bi-allelic variants reveals a possible complex neurodevelopmental syndrome of the central and peripheral nervous systems. In these individuals, bi-allelic variants mostly affect the Plakin domain. Furthermore, RNA sequencing and chromatin immunoprecipitation (ChIP) analyses of human fetal brain tissue reveal five MACF1 isoforms with region-specific expression, differing in their exon 1 transcription start sites but splicing to a common exon 2. This differential expression explains the frontal-predominant lissencephaly in an individual with a homozygous stop-gain in exon 1 (MACF1-204: c.70C>T [p.Arg24∗]), as this isoform is preferentially expressed in the frontal cortex. We conclude that MACF1-related disorders are strictly linked to domain function and the level of transcript expression, explaining the observed wide clinical heterogeneity. Show less

Facial wrinkling is a prominent sign of aging, yet individuals exhibit unique trajectories of biological aging, contributing to the variability in facial appearance. Here, we present a pioneering study exploring the association between lifestyle choices, DNA methylation, and SNP genotypes with a range of facial skin aging phenotypes. The study demonstrated that age-related facial skin phenotypes are influenced by multiple environmental stressors. Epigenome-wide association analyses identified differentially methylated cytosines mapped to 151 loci, including novel genes associated with facial wrinkles, such as EDAR (cg02925966, p = 4.96 × 10 Show less

Preeclampsia is a heterogeneous syndrome of diverse etiologies and molecular pathways leading to distinct clinical subtypes. Herein, we aimed to characterize the extracellular vesicle (EV)-associated and soluble fractions of the maternal plasma proteome in patients with preeclampsia and to assess their value for disease prediction. This case-control study included 24 women with term preeclampsia, 23 women with preterm preeclampsia, and 94 healthy pregnant controls. Blood samples were collected from cases on average 7 weeks before the diagnosis of preeclampsia and were matched to control samples. Soluble and EV fractions were separated from maternal plasma; EVs were confirmed by cryo-EM, NanoSight, and flow cytometry; and 82 proteins were analyzed with bead-based, multiplexed immunoassays. Quantile regression analysis and random forest models were implemented to evaluate protein concentration differences and their predictive accuracy. Preeclampsia subgroups defined by molecular profiles were identified by hierarchical cluster analysis. Significance was set at p < 0.05 or false discovery rate-adjusted q < 0.1. In preterm preeclampsia, PlGF, PTX3, and VEGFR-1 displayed differential abundance in both soluble and EV fractions, whereas angiogenin, CD40L, endoglin, galectin-1, IL-27, CCL19, and TIMP1 were changed only in the soluble fraction (q < 0.1). The direction of changes in the EV fraction was consistent with that in the soluble fraction for nine proteins. In term preeclampsia, CCL3 had increased abundance in both fractions (q < 0.1). The combined EV and soluble fraction proteomic profiles predicted preterm and term preeclampsia with an AUC of 78% (95% CI, 66%-90%) and 68% (95% CI, 56%-80%), respectively. Three clusters of preeclampsia featuring distinct clinical characteristics and placental pathology were identified based on combined protein data. Our findings reveal distinct alterations of the maternal EV-associated and soluble plasma proteome in preterm and term preeclampsia and identify molecular subgroups of patients with distinct clinical and placental histopathologic features. Show less

Fermented foods and ingredients, including furmenties derived from lactic acid bacteria (LAB) in dairy products, can modulate the immune system. Here, we describe the use of reconstituted skimmed milk powder to generate novel fermentates from Show less

Fermented foods have long been known to have immunomodulatory capabilities, and fermentates derived from the lactic acid bacteria of dairy products can modulate the immune system. We have used skimmed milk powder to generate novel fermentates using Show less

Immune checkpoint inhibitors (ICIs) that target programmed cell death 1 (PD-1) have revolutionized cancer treatment by enabling the restoration of suppressed T-cell cytotoxic responses. However, resistance to single-agent ICIs limits their clinical utility. Combinatorial strategies enhance their antitumor effects, but may also enhance the risk of immune related adverse effects of ICIs. Prostaglandin (PG) E Show less

Early diagnosis of sepsis and discrimination from SIRS is crucial for clinicians to provide appropriate care, management and treatment to critically ill patients. We describe identification of mRNA biomarkers from peripheral blood leukocytes, able to identify severe, systemic inflammation (irrespective of origin) and differentiate Sepsis from SIRS, in adult patients within a multi-center clinical study. Participants were recruited in Intensive Care Units (ICUs) from multiple UK hospitals, including fifty-nine patients with abdominal sepsis, eighty-four patients with pulmonary sepsis, forty-two SIRS patients with Out-of-Hospital Cardiac Arrest (OOHCA), sampled at four time points, in addition to thirty healthy control donors. Multiple clinical parameters were measured, including SOFA score, with many differences observed between SIRS and sepsis groups. Differential gene expression analyses were performed using microarray hybridization and data analyzed using a combination of parametric and non-parametric statistical tools. Nineteen high-performance, differentially expressed mRNA biomarkers were identified between control and combined SIRS/Sepsis groups (FC>20.0, p<0.05), termed 'indicators of inflammation' (I°I), including CD177, FAM20A and OLAH. Best-performing minimal signatures e.g. FAM20A/OLAH showed good accuracy for determination of severe, systemic inflammation (AUC>0.99). Twenty entities, termed 'SIRS or Sepsis' (S°S) biomarkers, were differentially expressed between sepsis and SIRS (FC>2·0, p-value<0.05). The best performing signature for discriminating sepsis from SIRS was CMTM5/CETP/PLA2G7/MIA/MPP3 (AUC=0.9758). The I°I and S°S signatures performed variably in other independent gene expression datasets, this may be due to technical variation in the study/assay platform. Show less

Apolipoprotein A4 (APOA4) is one of the most abundant and versatile apolipoproteins facilitating lipid transport and metabolism. APOA4 is synthesized in the small intestine, packaged onto chylomicrons, secreted into intestinal lymph and transported via circulation to several tissues, including adipose. Since its discovery nearly 4 decades ago, to date, only platelet integrin αIIbβ3 has been identified as APOA4 receptor in the plasma. Using co-immunoprecipitation coupled with mass spectrometry, we probed the APOA4 interactome in mouse gonadal fat tissue, where ApoA4 gene is not transcribed but APOA4 protein is abundant. We demonstrate that lipoprotein receptor-related protein 1 (LRP1) is the cognate receptor for APOA4 in adipose tissue. LRP1 colocalized with APOA4 in adipocytes; it interacted with APOA4 under fasting condition and their interaction was enhanced during lipid feeding concomitant with increased APOA4 levels in plasma. In 3T3-L1 mature adipocytes, APOA4 promoted glucose uptake both in absence and presence of insulin in a dose-dependent manner. Knockdown of LRP1 abrogated APOA4-induced glucose uptake as well as activation of phosphatidylinositol 3 kinase (PI3K)-mediated protein kinase B (AKT). Taken together, we identified LRP1 as a novel receptor for APOA4 in promoting glucose uptake. Considering both APOA4 and LRP1 are multifunctional players in lipid and glucose metabolism, our finding opens up a door to better understand the molecular mechanisms along APOA4-LRP1 axis, whose dysregulation leads to obesity, cardiovascular disease, and diabetes. Show less

Juvenile neuronal ceroid lipofuscinosis (JNCL) is a fatal lysosomal storage disease caused by autosomal-recessive mutations in CLN3 for which no treatment exists. Symptoms appear between 5 and 10 years of age, beginning with blindness and seizures, followed by progressive cognitive and motor decline and premature death (late teens to 20s). We explored a gene delivery approach for JNCL by generating two self-complementary adeno-associated virus 9 (scAAV9) constructs to address CLN3 dosage effects using the methyl-CpG-binding protein 2 (MeCP2) and β-actin promoters to drive low versus high transgene expression, respectively. This approach was based on the expectation that low CLN3 levels are required for cellular homeostasis due to minimal CLN3 expression postnatally, although this had not yet been demonstrated in vivo One-month-old Cln3(Δex7/8) mice received one systemic (intravenous) injection of scAAV9/MeCP2-hCLN3 or scAAV9/β-actin-hCLN3, with green fluorescent protein (GFP)-expressing viruses as controls. A promoter-dosage effect was observed in all brain regions examined, in which hCLN3 levels were elevated 3- to 8-fold in Cln3(Δex7/8) mice receiving scAAV9/β-actin-hCLN3 versus scAAV9/MeCP2-hCLN3. However, a disconnect occurred between CLN3 levels and disease improvement, because only the scAAV9 construct driving low CLN3 expression (scAAV9/MeCP2-hCLN3) corrected motor deficits and attenuated microglial and astrocyte activation and lysosomal pathology. This may have resulted from preferential promoter usage because transgene expression after intravenous scAAV9/MeCP2-GFP injection was primarily detected in NeuN(+) neurons, whereas scAAV9/β-actin-GFP drove transgene expression in GFAP(+) astrocytes. This is the first demonstration of a systemic delivery route to restore CLN3 in vivo using scAAV9 and highlights the importance of promoter selection for disease modification in juvenile animals. Juvenile neuronal ceroid lipofuscinosis (JNCL) is a fatal lysosomal storage disease caused by CLN3 mutations. We explored a gene delivery approach using two self-complementary adeno-associated virus 9 (scAAV9) constructs to address CLN3 dosage effects using the methyl-CpG-binding protein 2 (MeCP2) and β-actin promoters. hCLN3 levels were elevated 3- to 8-fold in Cln3(Δex7/8) mice receiving scAAV9/β-actin-hCLN3 versus scAAV9/MeCP2-hCLN3 after a single systemic injection. However, only scAAV9/MeCP2-hCLN3 corrected motor deficits and attenuated glial activation and lysosomal pathology. This may reflect preferential promoter usage because transgene expression with scAAV9/MeCP2-green fluorescent protein (GFP) was primarily in neurons, whereas scAAV9/β-actin-GFP drove transgene expression in astrocytes. This is the first demonstration of systemic delivery for CLN3 using scAAV9 and highlights the importance of promoter selection for disease modification in juvenile animals. Show less

Vascular endothelial growth factor (VEGF) is an angiogenic and neurotrophic factor, secreted by endothelial cells, known to impact various physiological and disease processes from cancer to cardiovascular disease and to be pharmacologically modifiable. We sought to identify novel loci associated with circulating VEGF levels through a genome-wide association meta-analysis combining data from European-ancestry individuals and using a dense variant map from 1000 genomes imputation panel. Six discovery cohorts including 13,312 samples were analyzed, followed by in-silico and de-novo replication studies including an additional 2,800 individuals. A total of 10 genome-wide significant variants were identified at 7 loci. Four were novel loci (5q14.3, 10q21.3, 16q24.2 and 18q22.3) and the leading variants at these loci were rs114694170 (MEF2C, P = 6.79 x 10(-13)), rs74506613 (JMJD1C, P = 1.17 x 10(-19)), rs4782371 (ZFPM1, P = 1.59 x 10(-9)) and rs2639990 (ZADH2, P = 1.72 x 10(-8)), respectively. We also identified two new independent variants (rs34528081, VEGFA, P = 1.52 x 10(-18); rs7043199, VLDLR-AS1, P = 5.12 x 10(-14)) at the 3 previously identified loci and strengthened the evidence for the four previously identified SNPs (rs6921438, LOC100132354, P = 7.39 x 10(-1467); rs1740073, C6orf223, P = 2.34 x 10(-17); rs6993770, ZFPM2, P = 2.44 x 10(-60); rs2375981, KCNV2, P = 1.48 x 10(-100)). These variants collectively explained up to 52% of the VEGF phenotypic variance. We explored biological links between genes in the associated loci using Ingenuity Pathway Analysis that emphasized their roles in embryonic development and function. Gene set enrichment analysis identified the ERK5 pathway as enriched in genes containing VEGF associated variants. eQTL analysis showed, in three of the identified regions, variants acting as both cis and trans eQTLs for multiple genes. Most of these genes, as well as some of those in the associated loci, were involved in platelet biogenesis and functionality, suggesting the importance of this process in regulation of VEGF levels. This work also provided new insights into the involvement of genes implicated in various angiogenesis related pathologies in determining circulating VEGF levels. The understanding of the molecular mechanisms by which the identified genes affect circulating VEGF levels could be important in the development of novel VEGF-related therapies for such diseases. Show less

The strong male predominance in Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) remains inadequately explained, but sex hormones might be involved. We hypothesized that single nucleotide polymorphisms (SNPs) in the androgen pathway influence risk of developing BE and EAC. This genetic-epidemiological analysis included 14 studies from Australia, Europe and North America. Polymorphisms in 16 genes coding for the androgen pathway were analyzed using a gene-based approach: versatile gene-based test association study. This method evaluates associations between a trait and all SNPs within a specific gene rather than each SNP marker individually as in a conventional GWAS. The data were stratified for sex, body-mass index, waist-to-hip ratio, tobacco smoking and gastroesophageal reflux status. Included were data from 1,508 EAC patients, 2,383 BE patients and 2,170 control participants. SNPs within the gene CYP17A1 were associated with risk of BE in the sexes combined (p = 0.002) and in males (p = 0.003), but not in females separately (p = 0.3). This association was found in tobacco smokers (p = 0.003) and in BE patients without reflux (p = 0.004), but not in nonsmokers (p = 0.2) or those with reflux (p = 0.036). SNPs within JMJD1C were associated with risk of EAC in females (p = 0.001). However, none of these associations replicated in a subsequent sample. Fourteen other genes studied did not reach statistically significant levels of association with BE, EAC or the combination of BE and EAC, after correcting for the number of genes included in the analysis. In conclusion, genetic variants in the androgen-related genes CYP17A1 and JMJD1C might be associated with risk of BE and EAC, respectively, but replication data with larger sample sizes are needed. Show less

Colorectal cancer is one of the most common cancers worldwide with almost 700,000 deaths every year. Detection of colorectal cancer at an early stage significantly improves patient survival. Cancer-specific autoantibodies found in sera of cancer patients can be used for pre-symptomatic detection of the disease. In this study we assess the zinc finger proteins ZNF346, ZNF638, ZNF700 and ZNF768 as capture antigens for the detection of autoantibodies in colorectal cancer. Sera from 96 patients with colorectal cancer and 35 control patients with no evidence of cancer on colonoscopy were analysed for the presence of ZNF-specific autoantibodies using an indirect ELISA. Autoantibodies to individual ZNF proteins were detected in 10-20% of colorectal cancer patients and in 0-5.7% of controls. A panel of all four ZNF proteins resulted in an assay specificity of 91.4% and sensitivity of 41.7% for the detection of cancer patients in a cohort of non-cancer controls and colorectal cancer patients. Clinicopathological and survival analysis revealed that ZNF autoantibodies were independent of disease stage and did not correlate with disease outcome. Since ZNF autoantibodies were shared between patients and corresponding ZNF proteins showed similarities in their zinc finger motifs, we performed an in silico epitope sequence analysis. Zinc finger proteins ZNF700 and ZNF768 showed the highest sequence similarity with a bl2seq score of 262 (E-value 1E-81) and their classical C2H2 ZNF motifs were identified as potential epitopes contributing to their elevated immunogenic potential. Our findings show an enhanced and specific immunogenicity to zinc finger proteins, thereby providing a multiplexed autoantibody assay for minimally invasive detection of colorectal cancer. Show less