Andre Souza Mecawi

The etiological heterogeneity of autism spectrum disorder (ASD) complicates identifying core molecular mechanisms. We systematically integrated scRNA‐seq data from 11 diverse genetic and environmental mouse ( Mus musculus ) models, encompassing > 300,000 cells across multiple brain regions and developmental stages. Using advanced computational harmonization (RPCA), we identified robust convergent transcriptomic signatures that transcend model‐specific variability. Our findings reveal widespread alterations in neuronal communication pathways, specifically increased excitatory‐inhibitory signaling involving PTN, SLIT, and PTPR pathways. Furthermore, cell–cell communication analysis via NicheNet prioritized ligand‐receptor pairs associated with altered circuit excitability, offering a predictive blueprint of dysregulated intercellular crosstalk. Crucially, we identified significant glial involvement characterized by astrocyte function inhibition, marked by Aqp4 and Kcnj10 downregulation related to impaired water/potassium homeostasis and mature oligodendrocyte metabolic dysregulation through Olig family upregulation and enhanced oxidative phosphorylation. Differentially expressed genes (DEGs) significantly overlapped with SFARI‐listed high‐confidence risk genes, particularly within excitatory neuronal subtypes. Comparison with human postmortem single‐nucleus data from the prefrontal and parietal cortices demonstrated conserved signatures related to impaired synaptic protein synthesis (GRIN2B, CAMK2A) and oligodendrocyte‐mediated neurodevelopmental deficits (NRXN, DLGAP). This study confirms that E/I imbalance and glial dysfunction are universal cellular pathologies in ASD, providing a robust, large‐scale reference for identifying novel therapeutic targets with single‐cell resolution.

Early‐life experiences critically shape neuroendocrine systems involved in emotional and social behaviours. The oxytocin (OXT) and vasopressin (AVP) systems are particularly sensitive to environmental influences during the perinatal period, a developmental window characterized by high neural plasticity. However, the long‐term effects of perinatal environmental enrichment (PEE) on hypothalamic OXT and AVP neuroplasticity and their relationship with emotional behaviour remain poorly understood. Therefore, this study investigated whether PEE induces persistent behavioural, structural, and neurochemical changes in OXT and AVP neurons in male and female mice. Male and female mice reared in either PEE or non‐enriched environment (NE) conditions were evaluated in adulthood using the elevated plus maze, light/dark box, and sociability/social novelty preference tests. Morphometric analyses assessed soma and nuclear size, as well as OXT and AVP immunoreactivity in neurons of the paraventricular nucleus (PVN) of the hypothalamus. PEE reduced anxiety‐like behaviour, as evidenced by increased open‐arm exploration in the elevated plus maze, particularly in males, and reduced latency to enter the light compartment in the light/dark box. These behavioural effects were accompanied by reduced soma and nuclear dimensions of AVP neurons in PEE males, as well as increased nuclear size and OXT immunoreactivity in both sexes. Correlation analyses showed that smaller AVP neuronal profiles were associated with reduced anxiety‐related behavioural measures, whereas larger OXT neuronal dimensions were associated with reduced risk‐assessment behaviours. Perinatal environmental enrichment induces long‐lasting, sex‐dependent structural and neurochemical plasticity in hypothalamic OXT and AVP systems, which may contribute to the enduring modulation of anxiety‐related behaviours.

Literature has reported elevated concentrations of copeptin (CPP), a marker of arginine vasopressin (AVP) secretion, preceding the clinical features of the life-threatening condition, preeclampsia (PE). Those findings pointed to a possible role for the hypothalamic-neurohypophyseal system (HNS) in its pathophysiology. This systematic review and meta-analysis reports CPP levels in women with PE, exploring the AVP system not as a primary driver of the disease, but as a dynamic physiological feature associated with its clinical progression. The search terms used were “preeclampsia-AND-vasopressin-OR-copeptin-OR-oxytocin” in five databases: Google Scholar, Embase, Scopus, PubMed, and Semantic Scholar. Study quality was assessed using the Newcastle-Ottawa Scale. A Gaussian Mixture Model (GMM) algorithm was applied to blind predict the preeclamptic or healthy normotensive pregnancies by the CPP concentration, after performing a Kernel Principal Component Analysis (kPCA). Thirty-nine registries were selected, of which twenty were observational studies documenting CPP concentrations across all three trimesters, encompassing 1025 cases in 2446 pregnancies. Observational and experimental studies have associated the development of PE with circulating CPP levels and pharmacological manipulations involving AVP. Such an association was not found for oxytocin. Continental comparisons reveal a potential gene-environment link, showing a greater effect of higher concentrations of CPP on preeclamptic cases in Asian and African people. Furthermore, gestational hypertension has been associated with single nucleotide polymorphisms (SNPs) in the AVP and ERAP2 genes. Notably, ERAP2 encodes an endopeptidase that cleaves and inactivates AVP. It is essential to improve the early detection of this condition by understanding how genetic and geographic factors influence PE causes. Systematic review registration: https://www.crd.york.ac.uk/prospero/ , identifier CRD420251111755.

The Wistar Audiogenic Rat (WAR) strain is a genetically selected model of reflex epilepsy, susceptible to mesencephalic and, following chronic stimulation, limbic seizures. In this study, we examined the molecular underpinnings of this seizure progression by assessing gene expression profiles of pre‐synaptic serotonergic components in Dorsal Raphe Nucleus (DRN) and post‐synaptic receptors in the Basolateral Amygdala (BLA), Central Amygdala (CeA), and Hippocampus (HIP). Concurrently, we evaluated mRNA expression of Galanin (Gal) and Prodynorphin (Pdyn) in the Supraoptic Nucleus (SON) and their respective receptors in the BLA, CeA, and HIP. WARs and control Wistar rats underwent a ten‐day audiogenic kindling (AK) protocol, involving twice‐daily exposure to a high‐intensity acoustic stimulus to induce seizures. WARs were sub‐grouped based on their behavioral phenotype (seizure scales) into limbic‐recruited seizures (LiR) and non‐limbic‐recruited (n‐LiR). Quantitative PCR analysis of brain micropunches revealed a significant failure of adaptive plasticity in WARs. Unlike control rats, which showed a robust upregulation of serotonergic (5‐HT‐ergic) components in the DRN in response to the chronic stress of the kindling protocol, WARs had a significantly blunted pre‐synaptic response. Rats that did not show limbic seizures showed compensatory upregulation of amygdala 5‐HT receptors, a mechanism that failed in rats that developed chronic seizures. Furthermore, WARs showed elevated hypothalamic galanin but reduced limbic receptor expression. The opioid system was also imbalanced, with an increase in the pro‐convulsant mu‐opioid receptor. Critically, Pdyn expression was strongly and negatively correlated with limbic seizure severity. Collectively, these findings suggest that the progression to limbic epilepsy, already demonstrated in behavioral and EEG protocols in this model, is driven by a widespread failure of plasticity across interconnected neuromodulatory networks, rather than a single molecular defect, highlighting novel targets for therapeutic intervention. image

Introduction: Hypertension is a multifactorial condition of unknown cause that affects more than 1.28 billion adults worldwide and impacts the sexes differently. The hypothalamic paraventricular nucleus (PVN) plays a central role in blood pressure (BP) regulation by modulating sympathetic tone and releasing neuropeptides that affect the cardiovascular function. In this study, we investigated the transcriptomic profile of the PVN in hypertensive strains and across sexes, aiming to identify novel sex-specific molecular pathways involved in the regulation of BP. Methods: To accomplish this goal, we sequenced RNA from the PVNs of normotensive Wistar rats and Spontaneously Hypertensive Rats (SHR), both male and female. We also performed a cardiovascular assessment based on blood pressure (BP) measurements and their variability. Results: Cardiovascular assessment revealed higher SBP in SHRs than in Wistar rats; while males exhibited greater autonomic regulation associated with vasomotor and neurohumoral mechanisms, while females maintained comparable SBP levels primarily through an increase in heart rate, reflecting distinct autonomic adaptations. Hypertension also impacted gene expression, with influences from both the hypertensive state and sex. Compared with female SHRs, male SHRs presented a marked increase in differentially expressed genes (DEGs). Key upregulated genes in males, including Brain-Derived Neurotrophic Factor (Bdnf) and Hypocretin (Hcrt) , have already been linked to elevated BP, and Angiotensin II Receptor Type 1 (Agtr1a) is possibly associated with increased SBP-VLF variability, which serves as an indirect measure of enhanced sympathetic tone. In contrast, the female transcriptomic signature was characterized by the upregulation of anti-inflammatory pathways, with upregulation of NLR Family CARD Domain Containing 3 (Nlrc3) and Paired Ig-like Receptor B (Pirb) , and downregulation of Absent in Melanoma 2 (Aim2) , and S100 Calcium Binding Protein B (S100b). Notably, genes associated with neuroinflammation, such as the downregulation of Annexin A1 (Anxa1) and the upregulation of Solute Carrier Family 11 Member 1 (Slc11a1) , were consistently altered in both sexes. Conclusion: These results provide new insights into the cardiovascular and molecular basis of sex differences in hypertension, suggesting distinct neurohumoral autonomic profile in males, whereas in females a greater anti-inflammatory component. These findings offer a valuable framework for developing future sex-specific therapeutic strategies.

Background: Hypertension is a polygenic, complex disease that impacts men and women differently; whilst the incidence of high blood pressure (BP) is roughly equal over a lifetime, men typically are at higher risk of developing the disease earlier in life, before 50 years of age. There is adequate evidence that the brain is critical for the BP setpoint. The paraventricular nucleus (PVN) of the hypothalamus is an integrative structure that can influence not only neurohumoral responses to blood pressure changes, but also sympathetic drive. Here we manipulate the androgenic status of both male and female spontaneously hypertensive rats (SHRs) to determine how this changes gene expression within the PVN of these animals. Methods: SHR (8-weeks old) were either sham-operated or orchiectomized, whereas all females were oophorectomized, half of which received 10 mg testosterone propionate subcutaneously. Mean arterial pressure (MAP) and testosterone (T) were measured by carotid cannulation and ELISA respectively. Sequencing was performed on hand-punched PVN sections and subjected to robust bioinformatic analysis. Results: in total, 6,571 differentially regulated genes (DRGs) are regulated in the PVN of male and female rats. High T (endogenous or replaced) correlates with higher MAP in both sexes. Orchidectomy-induced T depletion resulted in the significant regulation of 5,104 genes, involved in thousands of biological roles, including ones related to hormone and sex-hormone signalling. In the female SHR, testosterone replacement in oophorectomized animals induced the regulation of 1,727 genes, sharing many biological functions with those in the high T males. We validated key genes by qPCR to determine false discovery rate. Conclusions: T status in hypertensive rats correlates with MAP, and consistent changes in PVN transcriptome.

Autism Spectrum Disorder (ASD) presents profound clinical and etiological heterogeneity, complicating the identification of core pathophysiological mechanisms. Single-cell RNA sequencing (scRNA-seq) offers cellular resolution but integrating findings across diverse studies remains challenging. Here, we constructed a unified single-cell reference framework by integrating scRNA-seq data from 11 distinct genetic and environmental ASD animal models, encompassing over 300.000 cells across various brain regions and developmental stages. Comparative analyses revealed convergent differentially expressed genes (DEGs) across neuronal and glial populations. Cross-model comparisons validated the integration, showing significant concordance between the unified dataset and individual studies, particularly for neuronal populations, and demonstrating how environmental models like valproic acid exposure recapitulate some of the transcriptomic alterations seen in genetic models. Cell communication analyses support widespread excitatory-inhibitory imbalance and with predicted signaling involving ligands like Pdgfa and Reln . Furthermore, we identified significant glial dysfunction, notably downregulation of crucial functional genes in astrocytes and signatures of metabolic dysregulation in mature oligodendrocytes. Cross-referencing with the SFARI database confirmed significant overlap with high-confidence ASD risk genes, with notable dysregulated in specific cell types included Ermn (upregulated in multiple glia), Foxg1 (downregulated in L5/6 NP neurons) and Mef2c (downregulated in MEIS2-like interneurons). Comparison with human scRNA-seq postmortem data revealed conserved dysregulation, highlighting enrichment of presynaptic/postsynaptic translation processes in neurons (implicating CACNAIA , GRIN2B , CAMK2A , ribosomal proteins) along with enrichment for neurodevelopmental disorder pathways in mature oligodendrocytes, involving NRXN and DLGAP gene networks. This integrative study provides unprecedented insight into the convergent cellular and molecular pathologies underlying ASD, establishing a valuable resource for understanding shared mechanisms and identifying new potential therapeutic targets.

Concerns over the replicability and reproducibility of published research have grown in many research fields, but empirical data to inform policies are still scarce. Biomedical research in Brazil expanded rapidly over the last three decades, with no systematic assessment of the replicability of its findings. With this in mind, we set up the Brazilian Reproducibility Initiative, a multicenter replication of published experiments from Brazilian science using three common experimental methods: the MTT assay, the reverse transcription polymerase chain reaction (RT-PCR) and the elevated plus maze (EPM). A total of 56 laboratories performed 143 replications of 56 experiments; of these, 90 replications of 45 experiments were considered valid by an independent committee. Replication rates for these experiments varied between 20 and 44% according to five predefined criteria. In median terms, ratios between group means were 58% lower in replications than in original experiments, while coefficients of variation were 82% higher. Effect size decrease was smaller for MTT experiments, original results with less variability and those considered more challenging to replicate, while t values for replications were positively correlated with researcher predictions about replicability, and negatively correlated with the rate of publications by the original article’s last author. Deviations from preregistered protocols were very common in replications, most frequently due to reasons inherent to the experimental model or related to infrastructure and logistics. Our results highlight factors that limit the replicability of results published by researchers in Brazil and suggest ways by which this scenario can be improved.

This study investigated the effects of WD on mouse homeostasis, focusing on energy substrates and skeletal muscle protein metabolism. Our findings revealed a shift toward reduced dependence on carbohydrate degradation and increased reliance on lipid oxidation, or even protein oxidation, as energy sources, since we observed increased proteolysis in one muscle phenotype. Despite body mass loss, soleus and EDL muscle masses were differently affected. These results indicate the procatabolic potential of short-term WD in mice.

Although it is well established that fibromyalgia (FM) syndrome is characterized by chronic diffuse musculoskeletal hyperalgesia, very little is known about the effect of this pathology on muscle tissue plasticity. Therefore, the present study aimed to characterize the putative alterations in skeletal muscle mass in female rats subjected to a FM model by inducing chronic diffuse hyperalgesia (CDH) through double injections of acidic saline (pH 4.0) into the left gastrocnemius muscle at 5‐day intervals. To determine protein turnover, the total proteolysis, proteolytic system activities and protein synthesis were evaluated in oxidative soleus muscles of pH 7.2 (control) and pH 4.0 groups at 7 days after CDH induction. All animals underwent behavioural analyses of mechanical hyperalgesia, strength and motor performance. Our results demonstrated that, in addition to hyperalgesia, rats injected with acidic saline exhibited skeletal muscle loss, as evidenced by a decrease in the soleus fibre cross‐sectional area. This muscle loss was associated with increased proteasomal proteolysis and expression of the atrophy‐related gene (muscle RING‐finger protein‐1), as well as reduced protein synthesis and decreased protein kinase B/S6 pathway activity. Although the plasma corticosterone concentration did not differ between the control and pH 4.0 groups, the removal of the adrenal glands attenuated hyperalgesia, but it did not prevent the increase in muscle protein loss in acidic saline‐injected animals. The data suggests that the stress‐related hypothalamic–pituitary–adrenal axis is involved in the development of hyperalgesia, but is not responsible for muscle atrophy observed in the FM model induced by intramuscular administration of acidic saline. Although the mechanisms involved in the attenuation of hyperalgesia in rats injected with acidic saline and subjected to adrenalectomy still need to be elucidated, the results found in this study suggest that glucocorticoids may not represent an effective therapeutic approach to alleviate FM symptoms.