Search

Introduction: Schizophrenia is a debilitating disorder that affects a significant proportion of the population and leads to impaired functionality and long-term challenges. The first episode of psychosis (FEP) is a critical intervention stage for improving long-term outcomes. The GAPi program was established in São Paulo, Brazil to provide early intervention services and evaluate biomarkers in individuals with FEP. This article delineates the objectives of the GAPi program, detailing its innovative research protocol, examining the clinical outcomes achieved, and discussing the operational challenges encountered during its initial decade of operation., Methods: The study comprised a prospective cohort of antipsychotic-naïve individuals with first-episode psychosis aged between 16 and 35 years. Participants were recruited from a public psychiatric facility in São Paulo. Emphasizing the initiative's commitment to early intervention, clinical assessments were systematically conducted at baseline and at two months, one year, two years, and five years of treatment to capture both short- and medium-term outcomes. Various assessment tools were utilized, including structured interviews, symptom scales, the Addiction Severity Index, and functional assessments., Results: A total of 232 patients were enrolled in the cohort. Among them, 65.95 % completed the 2-month follow-up. Most patients presented with schizophrenia spectrum disorders, followed by bipolar disorder and major depressive disorder with psychotic features. Treatment response rates and remission rates were evaluated at different time points, with promising outcomes observed. The program also assessed socio-demographic factors, substance use, family history, and genetic and biomarker profiles, providing valuable data for research., Discussion: The GAPi program has emerged as the largest ongoing cohort of antipsychotic-naïve first-episode psychosis in Latin America, contributing to the understanding of early psychosis in low- and middle-income countries. Despite operational challenges, the program has demonstrated efficacy in reducing the duration of untreated psychosis and in improving clinical outcomes. A multidisciplinary approach, including pharmacological treatment, psychosocial interventions, and family involvement, has been instrumental in enhancing treatment adherence and long-term prognosis., Conclusion: The GAPi program represents a valuable model for early intervention in first-episode psychosis and provides insights into the pathophysiology, treatment, and long-term outcomes of individuals with schizophrenia and related disorders. Continued research and resource allocation are essential for addressing operational challenges and expanding early intervention services in low- and middle-income countries., Competing Interests: Declaration of Competing Interest The authors declare that there are no conflicts of interest relevant to the content of this article. This research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Schizophrenia (SCZ) is a severe psychiatric disorder with unclear pathophysiology. Moreover, there is no specific biological marker to help clinicians to define a diagnosis, and medication is decided according to the psychiatrist's experience. In this scenario, microRNAs (miRNAs), which are small noncoding RNA molecules that regulate several genes, emerge as potential peripheral biomarkers to help not only the evaluation of the disease state but also the treatment response. Here, we systematically reviewed indexed literature and evaluated follow-up studies investigating the changes in miRNA expression due to antipsychotic treatment. We also assessed target genes and performed pathway enrichment analysis of miRNAs listed in this systematic review. A total of 11 studies were selected according to research criteria, and we observed that 28 miRNAs play a relevant role in schizophrenia pathogenesis or response to antipsychotic treatment, seven of those of extreme interest as possible biomarkers either for condition or treatment. Predicted targets of the miRNAs reviewed here were previously associated with schizophrenia in genome-wide studies, and pathway analysis showed enrichment for genes related to neural processes. With this review, we expect to highlight the importance of miRNAs in schizophrenia pathogenesis and its treatment and point out interesting miRNAs to future studies., Competing Interests: Declaration of competing interest The authors have nothing to disclose., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Patient response to antipsychotic drugs varies and may be related to clinical and genetic heterogeneity. This study aimed to determine the performance of clinical, genetic, and hybrid models to predict the response of first episode of psychosis (FEP). patients to the antipsychotic risperidone. We evaluated 141 antipsychotic-naïve FEP patients before and after 10 weeks of risperidone treatment. Patients who had a response rate equal to or higher than 50% on the Positive and Negative Syndrome Scale were considered responders (n = 72; 51%). Analyses were performed using a support vector machine (SVM), k-nearest neighbors (kNN), and random forests (RF). Clinical and genetic (with single-nucleotide variants [SNVs]) models were created separately. Hybrid models (clinical+genetic factors) with and without feature selection were created. Clinical models presented greater balanced accuracy 63.3% (confidence interval [CI] 0.46-0.69) with the SVM algorithm than the genetic models (balanced accuracy: 58.5% [CI 0.41-0.76] - kNN algorithm). The hybrid model, which included duration of untreated psychosis, Clinical Global Impression-Severity scale scores, age, cannabis use, and 406 SNVs, showed the best performance (balanced accuracy: 72.9% [CI 0.62-0.84] - RF algorithm). A hybrid model, including clinical and genetic predictors, can provide enhanced predictions of response to antipsychotic treatment., Competing Interests: RAB declares personal fees and non-financial support from Janssen and Ache Laboratórios Farmacêuticos, grants, and personal fees from Roche, outside the submitted work. AG declares personal fees and non-financial support from Janssen, Daiichi Sankyo, Lundbeck, Teva, Cristalia, and Ache Laboratórios Farmacêuticos outside the submitted work. CN declares personal fees and non-financial support from Janssen, Daiichi Sankyo, Lundbeck, Teva, and Ache Laboratórios Farmacêuticos outside the submitted work. No other conflicts of interest declared concerning the publication of this article.

Traumatic brain injury (TBI) is a prevalent and debilitating condition, which often leads to the development of post-traumatic epilepsy (PTE), a condition that yet lacks preventive strategies. Biperiden, an anticholinergic drug, is a promising candidate that has shown efficacy in murine models of PTE. MicroRNAs (miRNAs), small regulatory RNAs, can help in understanding the biological basis of PTE and act as TBI- and PTE-relevant biomarkers that can be detected peripherally, as they are present in extracellular vesicles (EVs) that cross the blood-brain barrier. This study aimed to investigate miRNAs in serum EVs from patients with TBI, and their association with biperiden treatment and PTE. Blood samples of 37 TBI patients were collected 10 days after trauma and treatment initiation in a double-blind clinical trial. A total of 18 patients received biperiden, with three subjects developing PTE, and 19 received placebo, with two developing PTE. Serum EVs were characterized by size distribution and protein profiling, followed by high-throughput sequencing of the EV miRNome. Differential expression analysis revealed no significant differences in miRNA expression between TBI patients with and without PTE. Interestingly, miR-9-5p displayed decreased expression in biperiden-treated patients compared to the placebo group. This miRNA regulates genes enriched in stress response pathways, including axonogenesis and neuronal death, relevant to both PTE and TBI. These findings indicate that biperiden may alter miR-9-5p expression in serum EVs, which may play a role in TBI resolution., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The pathophysiology of many neuropsychiatric disorders is still poorly understood. Identification of biomarkers for these diseases could benefit patients due to better classification and stratification. Exosomes excreted into the circulatory system can cross the blood-brain barrier and carry a cell type-specific set of molecules. Thus, exosomes are a source of potential biomarkers for many diseases, including neuropsychiatric disorders. Here, we investigated exosomal proteins produced from human-induced pluripotent stem cells (iPSCs) and iPSC-derived neural stem cells, neural progenitors, neurons, astrocytes, microglia-like cells, and brain capillary endothelial cells. Of the 31 exosome surface markers analyzed, a subset of biomarkers were significantly enriched in astrocytes (CD29, CD44, and CD49e), microglia-like cells (CD44), and neural stem cells (SSEA4). To identify molecular fingerprints associated with disease, circulating exosomes derived from healthy control (HC) individuals were compared against schizophrenia (SCZ) patients and late-onset Alzheimer's disease (LOAD) patients. A significant epitope pattern was identified for LOAD (CD1c and CD2) but not for SCZ compared to HC. Thus, analysis of cell type- and disease-specific exosome signatures of iPSC-derived cell cultures may provide a valuable model system to explore proteomic biomarkers for the identification of novel disease profiles.

Snakebite envenomation is classified as a Neglected Tropical Disease. Bothrops jararaca venom induces kidney injury and coagulopathy. HF3, a hemorrhagic metalloproteinase of B. jararaca venom, participates in the envenomation pathogenesis. We evaluated the effects of HF3 in mouse kidney and blood plasma after injection in the thigh muscle, mimicking a snakebite. Transcriptomic analysis showed differential expression of 31 and 137 genes related to kidney pathology after 2 h and 6 h, respectively. However, only subtle changes were observed in kidney proteome, with differential abundance of 15 proteins after 6 h, including kidney injury markers. N-terminomic analysis of kidney proteins showed 420 proteinase-generated peptides compatible with meprin specificity, indicating activation of host proteinases. Plasma analysis revealed differential abundance of 90 and 219 proteins, respectively, after 2 h and 6 h, including coagulation-cascade and complement-system components, and creatine-kinase, whereas a semi-specific search of N-terminal peptides indicated activation of endogenous proteinases. HF3 promoted host reactions, altering the gene expression and the proteolytic profile of kidney tissue, and inducing plasma proteome imbalance driven by changes in abundance and proteolysis. The overall response of the mouse underscores the systemic action of a hemorrhagic toxin that transcends local tissue damage and is related to known venom-induced systemic effects., Competing Interests: Declaration of competing interest The authors have no financial or non-financial interests to disclose. The authors declare that they have no conflicts of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Extracellular vesicles (EVs) are present in numerous peripheral bodily fluids and function in critical biological processes, including cell-to-cell communication. Most relevant to the present study, EVs contain microRNAs (miRNAs), and initial evidence from the field indicates that miRNAs detected in circulating EVs have been previously associated with mental health disorders. Here, we conducted an exploratory longitudinal and cross-sectional analysis of miRNA expression in serum EVs from adolescent participants. We analyzed data from a larger ongoing cohort study, evaluating 116 adolescent participants at two time points (wave 1 and wave 2) separated by three years. Two separate data analyses were employed: A cross-sectional analysis compared individuals diagnosed with Major Depressive Disorder (MDD), Anxiety disorders (ANX) and Attention deficit/Hyperactivity disorder (ADHD) with individuals without psychiatric diagnosis at each time point. A longitudinal analysis assessed changes in miRNA expression over time between four groups showing different diagnostic trajectories (persistent diagnosis, first incidence, remitted and typically developing/control). Total EVs were isolated, characterized by size distribution and membrane proteins, and miRNAs were isolated and sequenced. We then selected differentially expressed miRNAs for target prediction and pathway enrichment analysis. In the longitudinal analysis, we did not observe any statistically significant results. In the cross-sectional analysis: in the ADHD group, we observed an upregulation of miR-328-3p at wave 1 only; in the MDD group, we observed a downregulation of miR-4433b-5p, miR-584-5p, miR-625-3p, miR-432-5p and miR-409-3p at wave 2 only; and in the ANX group, we observed a downregulation of miR-432-5p, miR-151a-5p and miR-584-5p in ANX cases at wave 2 only. Our results identified previously observed and novel differentially expressed miRNAs and their relationship with three mental health disorders. These data are consistent with the notion that these miRNAs might regulate the expression of genes associated with these traits in genome-wide association studies. The findings support the promise of continued identification of miRNAs contained within peripheral EVs as biomarkers for mental health disorders., (© 2023. The Author(s).)

Background: Very few predictive models in Psychiatry had their performance validated in independent external samples. A previously developed multivariable demographic model for attention-deficit/hyperactivity disorder (ADHD) accurately predicted young adulthood ADHD using clinical and demographical information collected in childhood in three samples from developed countries, but failed to replicate its performance in a sample from a developing country. Furthermore, consolidated risk factors for ADHD were not included among its predictors., Methods: Participants were 1905 children and adolescents from a community-based sample and followed from ages 6 to 14 years at baseline to ages 14 to 23 years (mean age 18) at follow-up. We applied the intercept and weights of the original model to the data, calculating the predicted probability of each participant according to the set of predictors collected in childhood, and compared the estimates with the actual outcome (ADHD) collected during adolescence and young adulthood. We explored the performance of the original model, and of models including novel predictors (prematurity, family history of ADHD, and polygenic risk score for ADHD)., Results: The observed area under the curve of the original model was .76 (95% Confidence Interval .70 to .82). The multivariable demographical model outperformed single variable models using only prematurity, family history, or the ADHD PRS. Adding either of these variables, or all at once, did not improve the performance of the original demographical model., Conclusions: Our findings suggest that the originally developed ADHD predictive model is suitable for use in different settings for clinical and research purposes., (© 2022 Association for Child and Adolescent Mental Health.)

Background: Spiders of the genus Loxosceles are distributed throughout tropical and temperate regions worldwide. Loxosceles spp. bites may evolve to necrosis, with or without intravascular hemolysis. There is no consensus regarding the best treatment to prevent necrosis. The objective of this study was to evaluate the factors associated with the development of necrosis and the impact that antivenom administration has on the evolution of cutaneous loxoscelism., Methodology/principal Findings: This was a prospective observational study carried out at a referral center for envenoming. Over a 6-year period, we included 146 patients with a presumptive or definitive diagnosis of loxoscelism. Depending on the symptom severity, a polyvalent anti-arachnid antivenom was administered or not-in 74 cases (50.7%) and 72 cases (49.3%), respectively. Cutaneous and systemic manifestations were assessed at admission and weekly thereafter. Adverse reactions to the antivenom were also evaluated. Cutaneous loxoscelism was observed in 141 cases (96.6%), and the spider was identified in 29 (19.9%). The mean time from bite to antivenom administration was 41.6 ± 27.4 h. After discharge, 130 patients (90.9%) were treated with corticosteroids, antihistamines and analgesics being prescribed as needed. The probability of developing necrosis was significantly lower among the patients who were admitted earlier, as well as among those who received antivenom (p = 0.0245). Among the 74 patients receiving antivenom, early and delayed adverse reactions occurred in seven (9.5%) and four (5.4%), respectively. Local infection was observed only in three (2.3%) of the 128 patients for whom that information was available., Conclusions/significance: Necrosis after a Loxosceles sp. bite appears to more common when hospital admission is delayed or when antivenom is not administered. In addition, the administration of a polyvalent anti-arachnid antivenom appears to be safe, with a relatively low rate of adverse reactions., Competing Interests: The authors have declared that no competing interests exist.

Viperidae snakes are the most important agents of snakebites in Brazil. The protein composition of snake venoms has been frequently analyzed by means of electrophoretic techniques, but the interaction of proteins in venoms has barely been addressed. An electrophoretic technique that has gained prominence to study this type of interaction is blue native polyacrylamide gel electrophoresis (BN-PAGE), which allows for the high-resolution separation of proteins in their native form. These protein complexes can be further discriminated by a second-dimension gel electrophoresis (SDS-PAGE) from lanes cut from BN-PAGE. Once there is no study on the use of bidimensional BN/SDS-PAGE with snake venoms, this study initially standardized the BN/SDS-PAGE technique in order to evaluate protein interactions in Bothrops atrox , Bothrops erythromelas , and Bothrops jararaca snake venoms. Results of BN/SDS-PAGE showed that native protein complexes were present, and that snake venom metalloproteinases and venom serine proteinases maintained their enzymatic activity after BN/SDS-PAGE. C-type lectin-like proteins were identified by Western blotting. Therefore, bidimensional BN/SDS-PAGE proved to be an easy, practical, and efficient method for separating functional venom proteins according to their assemblage in complexes, as well as to analyze their biological activities in further details.

Treatment-resistant schizophrenia (TRS) occurs in one-third of the patients, but the molecular determinants of poor antipsychotic response remain unclear. We compared genetic data of patients with TRS (n = 63) with non-TRS (n = 111) by polygenic risk scores (PRS) calculated by PRSice software using PGC2_SCZ (Psychiatric Genomics Consortium - Schizophrenia) data. TRS criteria followed the International Psychopharmacology Algorithm Project SCZ algorithm. Statistical clustering and functional enrichment analyses of genes harboring TRS-linked variants were performed. Individuals on the top three deciles of schizophrenia PRS distribution exhibited higher odds of being refractory to antipsychotics than those on the bottom three deciles. Clusters of interacting variant-harboring genes were identified among the association signals. They are upregulated in the dorsolateral prefrontal, orbitofrontal, temporal, and inferior parietal areas during adolescence and early adulthood. Similar gene modules were found using transcriptional data from the same brain regions in individuals with schizophrenia. Genes were enriched among markers of cortical interneurons and somatosensory pyramidal cells. Finally, the enrichment of the clustered genes in drug-response expression signatures revealed compounds that could be employed to identify novel antipsychotic targets. In conclusion, we identified variant-harboring genes that may predispose SCZ patients to poor antipsychotic response and found statistically enriched clusters which provided functional and spatiotemporal context for TRS, suggesting that genotypic variation may converge to biological alterations at the interplay between actin dynamics and synaptic organization., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Schizophrenia has a heritability of 60-80% 1 , much of which is attributable to common risk alleles. Here, in a two-stage genome-wide association study of up to 76,755 individuals with schizophrenia and 243,649 control individuals, we report common variant associations at 287 distinct genomic loci. Associations were concentrated in genes that are expressed in excitatory and inhibitory neurons of the central nervous system, but not in other tissues or cell types. Using fine-mapping and functional genomic data, we identify 120 genes (106 protein-coding) that are likely to underpin associations at some of these loci, including 16 genes with credible causal non-synonymous or untranslated region variation. We also implicate fundamental processes related to neuronal function, including synaptic organization, differentiation and transmission. Fine-mapped candidates were enriched for genes associated with rare disruptive coding variants in people with schizophrenia, including the glutamate receptor subunit GRIN2A and transcription factor SP4, and were also enriched for genes implicated by such variants in neurodevelopmental disorders. We identify biological processes relevant to schizophrenia pathophysiology; show convergence of common and rare variant associations in schizophrenia and neurodevelopmental disorders; and provide a resource of prioritized genes and variants to advance mechanistic studies., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Human brain structure changes throughout the lifespan. Altered brain growth or rates of decline are implicated in a vast range of psychiatric, developmental and neurodegenerative diseases. In this study, we identified common genetic variants that affect rates of brain growth or atrophy in what is, to our knowledge, the first genome-wide association meta-analysis of changes in brain morphology across the lifespan. Longitudinal magnetic resonance imaging data from 15,640 individuals were used to compute rates of change for 15 brain structures. The most robustly identified genes GPR139, DACH1 and APOE are associated with metabolic processes. We demonstrate global genetic overlap with depression, schizophrenia, cognitive functioning, insomnia, height, body mass index and smoking. Gene set findings implicate both early brain development and neurodegenerative processes in the rates of brain changes. Identifying variants involved in structural brain changes may help to determine biological pathways underlying optimal and dysfunctional brain development and aging., (© 2022. The Author(s), under exclusive licence to Springer Nature America, Inc.)

The venom of the Brazilian pit viper Bothrops jararaca (BjV) is a complex mixture of molecules, and snake venom metalloproteinases (SVMP) and serine proteinases (SVSP) are the most abundant protein families found therein. Toxins present in BjV trigger most of the deleterious disturbances in hemostasis observed in snakebites, i.e., thrombocytopenia, hypofibrinogenemia and bleedings. The treatment of patients bitten by snakes still poses challenges and the bioflavonoid rutin has already been shown to improve hemostasis in an experimental model of snakebite envenomation. However, rutin is poorly soluble in water; in this study, it was succinylated to generate its water-soluble form, rutin succinate (RS), which was analyzed comparatively regarding the chemical structure and characteristic features of rutin. Biological activities of rutin and RS were compared on hemostatic parameters, and against toxic activities of crude BjV in vitro . In vivo , C57BL/6 mice were injected i.p. with either BjV alone or pre-incubated with rutin, RS or 1,10-phenanthroline (o-phe, an SVMP inhibitor), and the survival rates and hemostatic parameters were analyzed 48 h after envenomation. RS showed the characteristic activities described for rutin - i.e., antioxidant and inhibitor of protein disulfide isomerase - but also prolonged the clotting time of fibrinogen and plasma in vitro . Differently from rutin, RS inhibited typical proteolytic activities of SVMP, as well as the coagulant activity of BjV. Importantly, both rutin and RS completely abrogated the lethal activity of BjV, in the same degree as o-phe. BjV induced hemorrhages, falls in RBC counts, thrombocytopenia and hypofibrinogenemia in mice. Rutin and RS also improved the recovery of platelet counts and fibrinogen levels, and the development of hemorrhages was totally blocked in mice injected with BjV incubated with RS. In conclusion, RS has anticoagulant properties and is a novel SVMP inhibitor. Rutin and RS showed different mechanisms of action on hemostasis. Only RS inhibited directly BjV biological activities, even though both flavonoids neutralized B. jararaca toxicity in vivo . Our results showed clearly that rutin and RS show a great potential to be used as therapeutic compounds for snakebite envenomation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Sachetto, Miyamoto, Tashima, de Souza and Santoro.)

Lack of diversity regarding genetic and environmental backgrounds weakens the generalization and clinical applicability of research findings on psychotic disorders. Notably, Latin Americans have been generally neglected in genetic studies, comprising less than 2% of genome-wide association study samples. But Latin American populations represent a unique opportunity for research, given the exceptionally high ethnic admixture of this group. Increasing genetic diversity is essential to improve the fine mapping of known regions associated with psychotic disorders, discover novel genetic associations, and replicate studies. Additionally, Latin America is characterized by massive social, political, and economic inequalities, all known risk factors for mental health issues, including psychotic disorders. This article aims to 1) discuss the challenges and advantages of studying Latin America's particular genetic makeup and environmental context; 2) review previous studies conducted in the region; and 3) describe three Latin American research initiatives in progress: the Neuropsychiatric Genetics of Psychosis in Mexican Populations (NeuroMEX), the Paisa, and the Latin American Network for the Study of Early Psychosis (ANDES) studies.

Psychotic experiences (PE) are forms of hallucinations and delusions neither reaching the intensity and functional impairment required to be regarded as full psychotic symptoms nor a psychotic disorder. Here we investigated the ability to predict PE using multiple models (regressions, mediation and moderation) using polygenic risk score for psychotic experiences (PE-PRS), polygenic risk score for schizophrenia (SCZ-PRS), and polyenvironmental risk score (PERS) in youth from a Brazilian sample. The scores were not able to predict outcome, either when both scores were combined (PERS + PE-PRS and PERS + SCZ-PRS) or separately. Our results show that there is no association between PE and PRS or PERS among adolescents in our Brazilian sample. The lack of association may be a result of the absence of better representativeness regarding genetic and environmental factors of our population., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Schizophrenia is a severe and multifactorial disorder with an unknown causative pathophysiology. Abnormalities in neurodevelopmental and aging processes have been reported. Relative telomere length (RTL) and DNA methylation age (DMA), well-known biomarkers for estimating biological age, are both commonly altered in patients with schizophrenia compared to healthy controls. However, few studies investigated these aging biomarkers in first-episode psychosis (FEP) and in antipsychotic-naïve patients. To cover the existing gap regarding DMA and RTL in FEP and antipsychotic treatment, we aimed to verify whether those aging markers could be associated with psychosis and treatment response. Thus, we evaluated these measures in the blood of FEP antipsychotic-naïve patients and healthy controls (HC), as well as the response to antipsychotics after 10 weeks of treatment with risperidone. RTL was measured in 392 subjects, being 80 FEP and 312 HC using qPCR, while DMA was analyzed in a subset of 60 HC, 60 FEP patients (antipsychotic-naïve) and 59 FEP-10W (after treatment) using the "Multi-tissue Predictor"and the Infinium HumanMethylation450 BeadChip Kit. We observed diminished DMA and longer RTL in FEP patients before treatment compared to healthy controls, indicating a decelerated aging process in those patients. We found no statistical difference between responder and non-responder patients at baseline for both markers. An increased DMA was observed in patients after 10 weeks of treatment, however, after adjusting for blood cell composition, no significant association remained. Our findings indicate a decelerated aging process in the early phases of the disease., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Schizophrenia is a severe psychiatric disorder with high heritability. Consortia efforts and technological advancements have led to a substantial increase in knowledge of the genetic architecture of schizophrenia over the past decade. In this article, we provide an overview of the current understanding of the genetics of schizophrenia, outline remaining challenges, and summarise future directions of research. World-wide collaborations have resulted in genome-wide association studies (GWAS) in over 56 000 schizophrenia cases and 78 000 controls, which identified 176 distinct genetic loci. The latest GWAS from the Psychiatric Genetics Consortium, available as a pre-print, indicates that 270 distinct common genetic loci have now been associated with schizophrenia. Polygenic risk scores can currently explain around 7.7% of the variance in schizophrenia case-control status. Rare variant studies have implicated eight rare copy-number variants, and an increased burden of loss-of-function variants in SETD1A, as increasing the risk of schizophrenia. The latest exome sequencing study, available as a pre-print, implicates a burden of rare coding variants in a further nine genes. Gene-set analyses have demonstrated significant enrichment of both common and rare genetic variants associated with schizophrenia in synaptic pathways. To address current challenges, future genetic studies of schizophrenia need increased sample sizes from more diverse populations. Continued expansion of international collaboration will likely identify new genetic regions, improve fine-mapping to identify causal variants, and increase our understanding of the biology and mechanisms of schizophrenia.

Patients bitten by snakes consistently manifest a bleeding tendency, in which thrombocytopenia, consumption coagulopathy, mucous bleeding, and, more rarely, thrombotic microangiopathy, are observed. Von Willebrand factor (VWF) is required for primary hemostasis, and some venom proteins, such as botrocetin (a C-type lectin-like protein) and snake venom metalloproteinases (SVMP), disturb the normal interaction between platelets and VWF, possibly contributing to snakebite-induced bleedings. To understand the relationship among plasma VWF, platelets, botrocetin and SVMP from Bothrops jararaca snake venom (BjV) in the development of thrombocytopenia, we used (a) Wistar rats injected s.c. with BjV preincubated with anti-botrocetin antibodies (ABA) and/or Na2-EDTA (a SVMP inhibitor), and (b) VWF knockout mice (Vwf-/-) injected with BjV. Under all conditions, BjV induced a rapid and intense thrombocytopenia. In rats, BjV alone reduced the levels of VWF:Ag, VWF:CB, high molecular weight multimers of VWF, ADAMTS13 activity, and factor VIII. Moreover, VWF:Ag levels in rats that received BjV preincubated with Na2-EDTA and/or ABA tended to recover faster. In mice, BjV caused thrombocytopenia in both Vwf-/- and C57BL/6 (background control) strains, and VWF:Ag levels tended to decrease in C57BL/6, demonstrating that thrombocytopenia was independent of the presence of plasma VWF. These findings showed that botrocetin present in BjV failed to affect the extent or the time course of thrombocytopenia induced by envenomation, but it contributed to decrease the levels and function of plasma VWF. Thus, VWF alterations during B. jararaca envenomation are an ancillary event, and not the main mechanism leading to decreased platelet counts., Competing Interests: The authors have declared that no competing interests exist.

Background: Thalamic volume measures have been linked to obsessive-compulsive disorder (OCD) in children and adolescents. However, it is unclear if alterations in thalamic volumes occur before or after symptom onset and if there is a relation to the presence of sub-clinical obsessive-compulsive symptoms (OCS). Here, we explore the relationship between OCS and the rate of thalamic volume change in a cohort of children and youth at high risk to develop a mental disorder. A secondary aim was to determine if there is a relationship between OCS and the individual's OCD polygenic risk score (OCD-PRS) and between the rate of thalamic volume change and the OCD-PRS. Methods: The sample included 378 children enrolled in the longitudinal Brazilian High-Risk Cohort for Mental Conditions. Participants were assessed for OCS and the symmetrized percent change (SPC) of thalamic volume across two time-points separated by 3 years, along with the OCD-PRS. Zero-altered negative binomial models were used to analyze the relationship between OCS and thalamic SPC. Multiple linear regressions were used to examine the relationship between thalamic SPC and OCD-PRS. Results: A significant relationship between OCS and the right thalamus SPC ( p = 0.042) was found. There was no significant relationship between changes in thalamic volume SPC and OCD-PRS. Conclusions: The findings suggest that changes in the right thalamic volume over the course of 3 years in children may be associated to OCS. Future studies are needed to confirm these results and further characterize the specific nature of OCS symptoms associated with thalamic volumes., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Ravagnani Salto, Santoro, Hoexter, Jackowski, Pan, Rosário, Belangero, Alvarenga, Doretto, Fumo, Batistuzzo, Macul Ferreira de Barros, Timpano, Ota, Rohde, Miguel, Leckman and Zugman.)

Snake venom thrombin-like enzymes (SVTLEs) are serine proteinases that clot fibrinogen. SVTLEs are distributed mainly in venoms from snakes of the Viperidae family, comprising venomous pit viper snakes. Bothrops snakes are distributed throughout Central and South American and are responsible for most venomous snakebites. Most Bothrops snakes display thrombin-like activity in their venoms, but it has been shown that some species do not present it. In this work, to understand SVTLE polymorphism in Bothrops snake venoms, we studied individual samples from two species of medical importance in Brazil: Bothrops jararaca, distributed in Southeastern Brazil, which displays coagulant activity on plasma and fibrinogen, and Bothrops erythromelas, found in Northeastern Brazil, which lacks direct fibrinogen coagulant activity but shows plasma coagulant activity. We tested the coagulant activity of venoms and the presence of SVTLE genes by a PCR approach. The SVTLE gene structure in B. jararaca is similar to the Bothrops atrox snake, comprising five exons. We could not amplify SVTLE sequences from B. erythromelas DNA, except for a partial pseudogene. These genes underwent a positive selection in some sites, leading to an amino acid sequence diversification, mostly in exon 2. The phylogenetic tree constructed using SVTLE coding sequences confirms that they are related to the chymotrypsin/kallikrein family. Interestingly, we found a B. jararaca specimen whose venom lacked thrombin-like activity, and its gene sequence was a pseudogene with SVTLE structure, presenting nonsense and frameshift mutations. Our results indicate an association of the lack of thrombin-like activity in B. jararaca and B. erythromelas venoms with mutations and deletions of snake venom thrombin-like enzyme genes., Competing Interests: The authors have declared that no competing interest exist.

Admixed populations are routinely excluded from genomic studies due to concerns over population structure. Here, we present a statistical framework and software package, Tractor, to facilitate the inclusion of admixed individuals in association studies by leveraging local ancestry. We test Tractor with simulated and empirical two-way admixed African-European cohorts. Tractor generates accurate ancestry-specific effect-size estimates and P values, can boost genome-wide association study (GWAS) power and improves the resolution of association signals. Using a local ancestry-aware regression model, we replicate known hits for blood lipids, discover novel hits missed by standard GWAS and localize signals closer to putative causal variants.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection spreaded rapidly worldwide, as far as it has become a global pandemic. Therefore, the introduction of serological tests for determination of IgM and IgG antibodies has become the main diagnostic tool, useful for tracking the spread of the virus and for consequently allowing its containment. In our study we compared point of care test (POCT) lateral flow immunoassay (FIA) vs automated chemiluminescent immunoassay (CLIA), in order to assess their specificity and sensibility for COVID-19 antibodies detection., Results: We find that different specificities and sensitivities for IgM and IgG tests. Notably IgM POCT FIA method vs CLIA method (gold standard) has a low sensitivity (0.526), while IgG POCT FIA method vs CLIA method (gold standard) test has a much higher sensitivity (0.937); further, with respect of IgG, FIA and CLIA could arguably provide equivalent information., Conclusions: FIA method could be helpful in assessing in short time, the possible contagiousness of subjects that for work reasons cannot guarantee "social distancing".

Aim: We investigated the DNA methylation profile over LINE-1 in antipsychotic-naive, first-episode psychosis-patients (n = 69) before and after 2 months of risperidone treatment and in healthy controls (n = 62). Materials & methods: Patients were evaluated using standardized scales and classified as responders and nonresponders. DNA from blood was bisulfite converted and LINE-1 fragments were amplified and pyrosequencing was performed. Results: Lower LINE-1 methylation was observed in antipsychotic-naive first-episode psychosis patients than in healthy controls. Lower DNA methylation levels before treatment were associated with poor risperidone responses. A positive correlation was observed between LINE-1 methylation levels and positive symptoms response. Conclusion: Our study brings new insight regarding how epigenomic studies and clinical correlation studies can supplement psychosis treatment.

Few studies have addressed gene expression of hemostasis-related factors during acute thrombo-hemorrhagic diseases. Bites by the lanced-headed viper Bothrops jaracaca induce rapid hemostatic disturbances in victims, leading to systemic bleedings, thrombocytopenia and consumption coagulopathy. Although circulating levels of coagulation factors recover rapidly after administration of specific antivenom therapy, it is unclear if B. jararaca venom (BjV) upregulates the mRNA synthesis of hepatic hemostasis-related factors, or if the recovery occurs under basal conditions after the neutralization of venom components by antivenom. Thus, we aimed to investigate if BjV regulates gene expression of important hemostasis-related factors synthetized by the liver. On that account, Swiss mice were injected with saline or BjV (1.6 mg/kg b.w, s.c.), and after 3, 6 and 24 h blood samples and liver fragments were collected to analyze mRNA expression by real-time qPCR. Increased gene expression of fibrinogen chains, haptoglobin and STAT3 was observed during envenomation, particularly at 3 and 6 h. At 24h, mRNA levels of F10 were raised, while those of Serpinc1, Proc and Adamts13 were diminished. Surprisingly, F3 mRNA levels were steadily decreased at 3 h. Gene expression of Thpo, F7, F5 Tfpi, Mug1 was unaltered. mRNA levels of Vwf, P4hb, F8, F2, Plg, and Serpinf2 were minimally altered, but showed important associations with Nfkb1 gene expression. In conclusion, snakebite envenomation upregulates hepatic mRNA synthesis particularly of fibrinogen chains, and acute-phase markers. This response explains the fast recovery of fibrinogen levels after antivenom administration to patients bitten by B. jararaca snakes., Competing Interests: The authors declare that no competing interests exist.

We aimed to identify blood gene expression patterns associated to psychopathological trajectories retrieved from a large community, focusing on the emergence and remission of general psychiatric symptoms. Hundred and three individuals from the Brazilian High-Risk Cohort Study (BHRCS) for mental disorders were classified in four groups according to Child Behavior Checklist (CBCL) total score at the baseline (w0) and after 3 years (w1): low-high (L-H) (N = 27), high-low (H-L) (N = 12), high-high (H-H) (N = 34) and low-low (L-L) groups (N = 30). Blood gene expression profile was measured using Illumina HT-12 Beadchips, and paired analyses comparing w0 and w1 were performed for each group. Results: 98 transcripts were differentially expressed comparing w0 and w1 in the L-H, 33 in the H-L, 177 in the H-H and 273 in the L-L. Of these, 66 transcripts were differentially expressed exclusively in the L-H; and 6 only in the H-L. Cross-Lagged Panel Models analyses revealed that RPRD2 gene expression at w1 might be influenced by the CBCL score at w0. Moreover, COX5B, SEC62, and NDUFA2 were validated with another technique and were also differentially regulated in postmortem brain of subjects with mental disorders, indicating that they might be important not only to specific disorders, but also to general psychopathology and symptoms trajectories. Whereas genes related to metabolic pathways seem to be associated with the emergence of psychiatric symptoms, mitochondrial inner membrane genes might be important over the course of normal development. These results suggest that changes in gene expression can be detected in blood in different psychopathological trajectories.

Background: Psychiatric symptomatology during late childhood and early adolescence tends to persist later in life. In the present longitudinal study, we aimed to identify changes in genome-wide DNA methylation patterns that were associated with the emergence of psychopathology in youths from the Brazilian High-Risk Cohort (HRC) for psychiatric disorders. Moreover, for the differentially methylated genes, we verified whether differences in DNA methylation corresponded to differences in mRNA transcript levels by analyzing the gene expression levels in the blood and by correlating the variation of DNA methylation values with the variation of mRNA levels of the same individuals. Finally, we examined whether the variations in DNA methylation and mRNA levels were correlated with psychopathology measurements over time., Methods: We selected 24 youths from the HRC who presented with an increase in dimensional psychopathology at a 3-year follow-up as measured by the Child Behavior Checklist (CBCL). The DNA methylation and gene expression data were compared in peripheral blood samples (n = 48) obtained from the 24 youths before and after developing psychopathology. We implemented a methodological framework to reduce the effect of chronological age on DNA methylation using an independent population of 140 youths and the effect of puberty using data from the literature., Results: We identified 663 differentially methylated positions (DMPs) and 90 differentially methylated regions (DMRs) associated with the emergence of psychopathology. We observed that 15 DMPs were mapped to genes that were differentially expressed in the blood; among these, we found a correlation between the DNA methylation and mRNA levels of RB1CC1 and a correlation between the CBCL and mRNA levels of KMT2E. Of the DMRs, three genes were differentially expressed: ASCL2, which is involved in neurogenesis; HLA-E, which is mapped to the MHC loci; and RPS6KB1, the gene expression of which was correlated with an increase in the CBCL between the time points., Conclusions: We observed that changes in DNA methylation and, consequently, in gene expression in the peripheral blood occurred concurrently with the emergence of dimensional psychopathology in youths. Therefore, epigenomic modulations might be involved in the regulation of an individual's development of psychopathology.

Research suggested accumulation of tau proteins might lead to the degeneration of functional networks. Studies investigating the impact of genetic risk for Alzheimer's disease (AD) on early brain connections might shed light on mechanisms leading to AD development later in life. Here, we aim to investigate whether the polygenic risk score for Alzheimer's disease (AD-PRS) influences the connectivity among regions susceptible to tau pathology during childhood and adolescence. Participants were youth, aged 6-14 years, and recruited in Porto Alegre (discovery sample, n = 332) and São Paulo (replication sample, n = 304), Brazil. Subjects underwent genotyping and 6-min resting state funcional magnetic resonance imaging. Connections between the local maxima of tau pathology networks were used as dependent variables. The AD-PRS was associated with the connectivity between the right precuneus and the right superior temporal gyrus (discovery sample: β = 0.180, p adjusted  = 0.036; replication sample: β = 0.202, p = 0.031). This connectivity was also associated with inhibitory control (β = 0.157, p adjusted  = 0.035) and moderated the association between the AD-PRS and both immediate and delayed recall. These findings suggest the AD-PRS may affect brain connectivity in youth, which might impact memory performance and inhibitory control in early life., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Redox-related plasma proteins are candidate reporters of protein signatures associated with endothelial structure/function. Thiol-proteins from protein disulfide isomerase (PDI) family are unexplored in this context. Here, we investigate the occurrence and physiological significance of a circulating pool of PDI in healthy humans. We validated an assay for detecting PDI in plasma of healthy individuals. Our results indicate high inter-individual (median = 330 pg/mL) but low intra-individual variability over time and repeated measurements. Remarkably, plasma PDI levels could discriminate between distinct plasma proteome signatures, with PDI-rich (>median) plasma differentially expressing proteins related to cell differentiation, protein processing, housekeeping functions and others, while PDI-poor plasma differentially displayed proteins associated with coagulation, inflammatory responses and immunoactivation. Platelet function was similar among individuals with PDI-rich vs. PDI-poor plasma. Remarkably, such protein signatures closely correlated with endothelial function and phenotype, since cultured endothelial cells incubated with PDI-poor or PDI-rich plasma recapitulated gene expression and secretome patterns in line with their corresponding plasma signatures. Furthermore, such signatures translated into functional responses, with PDI-poor plasma promoting impairment of endothelial adhesion to fibronectin and a disturbed pattern of wound-associated migration and recovery area. Patients with cardiovascular events had lower PDI levels vs. healthy individuals. This is the first study describing PDI levels as reporters of specific plasma proteome signatures directly promoting contrasting endothelial phenotypes and functional responses., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)

We investigated the role of DGCR2, a corticogenesis-related gene, on schizophrenia (SZ) and its subphenotypes, including brain morphology. A total of 221 SZ patients, 263 controls and 70 antipsychotic-naïve first episode of psychosis (FEP) were genotyped for 17 DGCR2 polymorphisms. While no association between DGCR2 polymorphisms and SZ was found, the missense variant rs2072123 was associated to left rostral anterior cingulate thickness, showing that DGCR2 seems not to be associated directly with the SZ but might be influencing the brain morphology. We also showed a DGCR2 downregulation in SZ patients when compared to controls and FEP., (Copyright © 2019. Published by Elsevier B.V.)

The study of patients with schizophrenia (SZ) at different clinical stages may help clarify what effects could be due to the disease itself, to the pharmacological treatment, or to the disease progression. We compared expression levels of targeted genes in blood from individuals in different stages of SZ: clinical high risk for psychosis (CHR), first episode of psychosis (FEP), and chronic SZ (CSZ). Then, we further verified whether single-nucleotide polymorphisms (SNPs) could be related to gene expression differences. We investigated 12 genes in 394 individuals (27 individuals with CHR, 70 antipsychotic-naive individuals with FEP, 157 CSZ patients, and 140 healthy controls (HCs)). For a subsample, genotype data were also available, and we extracted SNPs that were previously associated with the expression of selected genes in whole blood or brain tissue. We generated a mediation model in which a putative cause (SNP) is related to a presumed effect (disorder) via an intermediate variable (gene expression). MBP and NDEL1 were upregulated in FEP compared to all other groups; DGCR8 was downregulated in FEP compared to HC and CHR; DGCR2 was downregulated in CSZ compared to FEP and HCs; DISC1 was upregulated in schizophrenia compared to controls or FEP, possibly induced by the rs3738398 and rs10864693 genotypes, which were associated with DISC1 expression; and UFD1 was upregulated in CSZ and CHR compared to FEP and HC. Our results indicated changes in gene expression profiles throughout the different clinical stages of SZ, reinforcing the need for staging approaches to better capture SZ heterogeneity.

We evaluated the effects of the interaction between child maltreatment (CM) and single nucleotide polymorphisms (SNPs) on development of mental disorders (MD) and psychopathology. We genotyped 720 individuals from a Brazilian community school-based prospective study, focusing on SNPs in 21 genes known to be associated with mental disorders. CM was assessed via a multi-informant-measure, which was previously validated. To test G × CM, we used linear or logistic models depending on variable evaluated (MD or dimensional psychopathology). After Bonferroni multiple comparison correction, we did not find any statistically significant association of G × CM with either MD or psychopathology., (Copyright © 2019. Published by Elsevier B.V.)

Victims of Bothrops jararaca snakebites manifest bleedings, blood incoagulability, platelet dysfunction, and thrombocytopenia, and the latter has been directly implicated in the genesis of hemorrhagic diathesis. We addressed herein the direct effects of B. jararaca venom (BjV) on ex vivo platelet aggregation and granule secretion in washed human and mouse platelets. BjV directly aggregated platelets, but the extent of platelet aggregation was lower in human than mouse platelets. On the other hand, BjV (24.4 μg/mL) and thrombin (0.1 U/mL) induced a similar extent of ATP and platelet factor 4 (PF4) secretion in both species. BjV-induced platelet aggregation was independent of the platelet dense body content, as in pearl mouse (Ap3b1 -/- ) platelets, whose dense bodies are deficient in adenine nucleotides and serotonin, the extent of platelet aggregation was superior to that induced in BALB/c or C57BL/6 mice. BjV-induced β-hexosaminidase secretion in human platelets was less intense than that evoked by thrombin, and the contrary was observed in mouse platelets. Irreversible inactivation of platelet cyclooxygenase 1 by acetylsalicylic acid did not reduce BjV-induced platelet aggregation. BjV exerted no cytotoxic activity in human and mouse platelets, as evaluated by lactate dehydrogenase loss. Eptifibatide, which inhibits the binding of fibrinogen to platelet glycoprotein complex GPIIb-IIIa, differently blocked BjV-induced platelet aggregation in mice and humans. BjV-induced platelet aggregation did not depend on snake venom serine proteinases nor metalloproteinases in mice, whilst serine proteinases were rather important for platelet aggregation in humans. Our results show that BjV induces direct activation, aggregation, and secretion in human and mouse platelets, but it exerts diverse responses in them, which should be considered in comparative studies to understand pathophysiological events during Bothrops envenomation., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Context: Bothrops snakes are the most frequent agents of snakebites in South and Central America. Acute kidney injury (AKI) is one of its complications and has multifactorial origin. Thrombotic microangiopathy (TMA)-induced AKI in snakebites is uncommon and is not described in Bothrops envenomation., Case Details: We report two cases of patients bitten by young Bothrops jararaca who developed AKI induced by TMA. Both patients evolved with mild envenomation and received the specific antivenom within 4 h after the snakebite. None of them had hypotension or shock, bleeding or secondary infection. Patient 1 (P1) was diabetic and using oral hypoglycemic drugs, and patient 2 (P2) was hypertensive without regular use of medication. On admission, both patients had levels of fibrinogen lower than 35 mg/dL, D-dimer higher than 10,000 ng/mL. They evolved with AKI, thrombocytopenia, normal coagulation assays, anemia, lactate dehydrogenase (LDH) elevation, low haptoglobin levels, negative direct antiglobulin test, and presence of schizocytes in peripheral blood. Only P1 required renal replacement therapy, and plasmapheresis was not required. Both patients were discharged and did not require outpatient dialysis, and subsequently had normal creatinine levels., Discussion: TMA may occur in Bothrops jararaca envenomation, even in mild cases that received early specific antivenom.

Von Willebrand disease (VWD) is a common cause of bleeding worldwide. Analysis of von Willebrand factor (VWF) multimer distribution (VWF:MD) is essential to properly classify and treat different types of VWD, and it is performed using a SDS agarose gel electrophoresis followed by Western blotting, a handmade technique that demands days to be completed and requires skillful execution. Aiming both to facilitate gel production and to shorten the preparation time, we developed an uncomplicated technique to provide agility in the analysis of VWF:MD, so that it can be easily accomplished in the routine practice of hemostasis laboratories. On that account, we used a commercial vertical mini-gel electrophoresis system for SDS-PAGE and a semi-dry transfer system, which allowed us to analyze VWF:MD of various samples in a period shorter than 12 h. This technique differentiated VWF:MD in human and animal plasmas under normal, congenital and acquired (experimental envenomation by Bothrops jararaca snake) conditions. This optimized method is cheap, rapid, reproducible, easy to be performed, and uses electrophoresis and Western blotting systems available in most laboratories. All these advantages encourage hemostasis professionals to use it in their routine practices. In order to facilitate the setup and accomplishment of the whole procedure step by step, videos were appended to the article., (Copyright © 2019 Elsevier Ltd. All rights reserved.)