Biology subjects

Witt, S. H.

Publications and source records attributed to Witt, S. H..

8 recordsLinked to original sources

bioRxiv2026

Estrogen receptor alpha regulates alcohol craving in females: convergent evidence from mouse models and human genetics

Alcohol craving and consumption fluctuate across the reproductive cycle in females with alcohol use disorder (AUD), suggesting that estrogen signaling contributes to disease vulnerability. Here, we investigated the role of estrogen receptor alpha (ER; Esr1; ESR1) in alcohol seeking using complementary mouse and human approaches, as this receptor was previously identified as a risk factor for AUD. Female mice were characterized in an IntelliCage-based multidimensional AUD paradigm that stratifies individuals into AUD-prone and AUD-resistant phenotypes. Transcriptomic profiling of the amygdala revealed that Esr1 is a top transcription factor for differentially expressed genes in mice drinking alcohol, and the estrogen signaling pathway was deregulated specifically in AUD-prone mice. Although alcohol exposure did not alter overall Esr1/ER mRNA or protein abundance, both transcript and protein levels positively correlated with cue-induced alcohol seeking, indicating that inter-individual variation in ER signaling predicts relapse-like behavior. Causal manipulations confirmed a functional role of ER. Local knockdown of Esr1 in the basolateral amygdala reduced excitatory synaptic transmission, attenuated alcohol motivation, cue-induced seeking, and relapse drinking, and impaired cue-associated memory recall without affecting anxiety-like behavior. Similarly, ovariectomy decreased amygdala ER expression, altered synaptic protein markers, and reduced alcohol-seeking behaviors, supporting regulation by endogenous ovarian hormones. Extending these findings to humans, ESR1 gene polymorphisms (rs6902771, rs11155819 and rs6557171) were associated with the probability of alcohol binge drinking and alcohol consumption days as well as craving and loss of control in real world in a longitudinal clinical cohort, while ESR1 mRNA blood levels were increased in women with AUD diagnosis. Together, these convergent molecular, circuit, behavioral, and genetic data identify ER signaling in the amygdala as an important modulator of alcohol-seeking behavior induced by alcohol cue and relapse vulnerability, highlighting estrogen pathways as potential therapeutic targets and markers for AUD.

neuroscience↗

bioRxiv2025

Dynamic Epigenetic Changes During Antidepressant Pharmacotherapy in Major Depressive Disorder

Although antidepressants remain the main pharmacological treatment for major depressive disorder (MDD), therapeutic response varies, highlighting the need for molecular markers that predict treatment response, as well as insights into the biological processes underlying antidepressant efficacy. Candidate-gene and cross-sectional epigenome-wide association studies (EWAS) have reported DNA methylation signatures associated with antidepressant response; however, findings remain inconsistent. To date, no longitudinal EWAS has examined methylation trajectories across multiple time points during antidepressant treatment in MDD. Within the Early Medication Change trial, DNA methylation data was generated for 162 patients with MDD (81 responders, 81 non-responders) and 48 matched healthy controls. Patients were assessed at four times across eight-weeks of standardized antidepressant treatment, while controls were assessed twice. Differentially methylated positions (DMPs) and regions (DMRs) were identified using longitudinal EWAS models and the comb-p algorithm. Baseline methylation levels were associated with depressive symptom severity at day 28 and day 56 through two and six DMRs, respectively (e.g., TNRC6C, CAT), whereas no single DMP reached significance. Longitudinal analyses identified one DMP associated with improvement in depressive symptoms (YLMP1) and three DMRs showing methylation changes over time (e.g., GPR126, PM20D1). Combined patient-control analyses revealed additional DMPs and DMRs associated with diagnosis and temporal effects. This study provides first longitudinal evidence of regionally coordinated DNA methylation changes during antidepressant pharmacotherapy, revealing alterations in genes involved in neuroplasticity and inflammatory processes that are associated with clinical response. Replication and functional validation will be essential to determine their relevance for personalized antidepressant treatment.

genomics↗

bioRxiv2024

A multi-omics and cell type-specific characterization of the ventral striatum in human cocaine use disorder

Epigenome, transcriptome, and proteome analyses of postmortem brains have revealed initial molecular insights into cocaine use disorder (CUD). However, the inter-relationship between these -omics and the contribution of individual cell types remain largely unknown. We present an in-depth analysis of molecular changes in the ventral striatum in CUD at multi-omics and single-cell resolution. Integrative multi-omics analyses of microRNA-seq, RNA-seq, and proteomics datasets in 41 individuals and single-nuclei RNA-seq in a subset of 16 individuals revealed conserved deregulation of metabolic pathways, oxidative phosphorylation, and glutamatergic signaling. Cell type-specific analyses identified inverse metabolic pathway deregulation patterns in glial and neuronal cells, notably in astrocytes and medium spiny neurons (MSNs). Characterizing astrocyte-neuron crosstalk revealed altered glutamatergic and cell adhesion signaling in CUD. By applying a comprehensive multi-omics analytical framework, our study provides novel insights into CUD-associated molecular changes in the ventral striatum, suggesting astrocytes, MSNs, and their crosstalk as particularly perturbed in CUD.

neuroscience↗

bioRxiv2021

Real-time individual benefit from social interactions before and during the lockdown: The crucial role of personality, neurobiology and genes.

BackgroundSocial integration is a major resilience factor for staying healthy. However, the COVID-19-pandemic led to unprecedented restrictions in social life. The consequences of these social lockdowns on momentary well-being are yet not fully understood. MethodWe investigated the individual affective benefit from social interactions in a longitudinal birth cohort study. We used two real-time, real-life ecological momentary assessments once before and once during the initial lockdown of the pandemic (N~6800 total observations) to determine the protective role of social interactions on well-being. Moreover, we used a multimethod approach combining the ecological assessment data with individual risk and resilience factors to analyze the moderating mechanisms of personality, neurobiology and genes. ResultsSocial contacts were linked to higher positive affect both during normal times and during the COVID-19 pandemic, highlighting the beneficial role of social embedding. Moreover, this relationship was moderated by amygdala volume, neuroticism and polygenic risk for schizophrenia. In detail, participants with a larger left amygdala volume and higher trait neuroticism exhibited an affective benefit from more social interactions prior to the pandemic. This pattern changed during the pandemic with participants with smaller amygdala volumes and lower neurotic traits showing a social affective gain during the pandemic. Moreover, participants with low genetic risk for schizophrenia showed an affective benefit from social interactions irrespective of the time point. ConclusionOur results highlight the protective role of social integration on momentary well-being. Thereby, we offer new insights into how this relationship is differently affected by a persons, neurobiology, personality, and genes under adverse circumstances.

neuroscience↗

bioRxiv2021

Connection Failure: Differences in White Matter Microstructure are associated with 5-HTTLPR but not with Risk-Seeking for Losses

In a previous study (Neukam, Kroemer et al. 2018), we found for the 5-HTTLPR genotype higher risk-seeking for losses in S/S vs. L/L carrier, which could not be explained by acutely changed central serotonin levels. This finding alternatively may be the result of reduced top-down control from the frontal cortex due to altered signal pathways involving the amygdala and ventral striatum. The serotonergic system is known to be involved in neurodevelopment and neuroplasticity. Therefore, the aim of this study was to investigate whether structural differences in white matter can explain the differences in risk-seeking behaviour that we observed in our previous study and whether 5-HTTLPR groups differ in their white matter microstructure. These differences can be detected using diffusion-weighted imaging (DWI). We assumed lower structural connectivity in S/S compared to L/L carrier, and a negative relationship between risk-seeking for losses and connectivity. We used DWI to compute diffusion parameters for the frontostriatal and uncinate tract in 175 individuals (39 S/S, 80 S/L, 56 L/L). Results showed no significant relationship between diffusion parameters and risk-seeking for losses. Furthermore, we did not find significant differences in diffusion parameters of the S/S vs. L/L group. There were only group differences in the frontostriatal tract showing stronger structural connectivity in the S/L group, which is also reflected in the whole brain approach. Therefore, the data do not support our hypothesis that the association between 5- HTTLPR and risk-seeking for losses is related to differences in white matter pathways implicated in decision-making.

neuroscience↗

bioRxiv2019

Longitudinal transcriptome-wide gene expression analysis of sleep deprivation treatment showsinvolvement of circadian genes and immune pathways

BackgroundTherapeutic sleep deprivation (SD) rapidly induces robust, transient antidepressant effects in a large proportion of major mood disorder patients suffering from a depressive episode, but underlying biological factors remain poorly understood. Research suggests that these patients may have altered circadian molecular genetic clocks and that SD functions through resetting dysregulated genes; additional factors may be involved, warranting further investigation. Leveraging advances in microarray technology enabling the transcriptome-wide assessment of gene expression, this study aimed to examine gene expression changes accompanying SD and recovery sleep in patients suffering from an episode of depression. MethodsPatients (N=78) and controls (N=15) underwent SD, with blood taken at the same time of day before, after one night of SD and after recovery sleep. A transcriptome-wide gene-by-gene approach was used, with a targeted look also taken at circadian genes. Furthermore, gene set enrichment, and longitudinal gene set analyses including the time point after recovery sleep, were conducted. ResultsCircadian genes were significantly affected by SD, with patterns suggesting that molecular clocks of responders and non-responders, as well as patients and controls respond differently to chronobiologic stimuli. Notably, gene set analyses revealed a strong widespread effect of SD on pathways involved in immune function and inflammatory response, such as those involved in cytokine and especially in interleukin signalling. Longitudinal gene set analyses showed that in responders these pathways were upregulated after SD; in non-responders, little response was observed. ConclusionsOur findings emphasize the close relationship between circadian, immune and sleep systems and their link to etiology of depression at the transcriptomic level.

epidemiology↗

bioRxiv2018

Bipolar multiplex families have an increased burden of common risk variants for psychiatric disorders

Multiplex families with a high prevalence of a psychiatric disorder are often examined to identify rare genetic variants with large effect sizes. In the present study, we analysed whether the risk for bipolar disorder (BD) in BD multiplex families is influenced by common genetic variants. Furthermore, we investigated whether this risk is conferred mainly by BD-specific risk variants or by variants also associated with the susceptibility to schizophrenia or major depression. In total, 395 individuals from 33 Andalusian BD multiplex families as well as 438 subjects from an independent, sporadic BD case-control cohort were analysed. Polygenic risk scores (PRS) for BD, schizophrenia, and major depression were calculated and compared between the cohorts. Both the familial BD cases and unaffected family members had significantly higher PRS for all three psychiatric disorders than the independent controls, suggesting a high baseline risk for several psychiatric disorders in the families. Moreover, familial BD cases showed significantly higher BD PRS than unaffected family members and sporadic BD cases. A plausible hypothesis is that, in multiplex families with a general increase in risk for psychiatric disease, BD development is attributable to a high burden of common variants that confer a specific risk for BD. The present analyses, therefore, demonstrated that common genetic risk variants for psychiatric disorders are likely to contribute to the high incidence of affective psychiatric disorders in the multiplex families. The PRS explained only part of the observed phenotypic variance and rare variants might have also contributed to disease development.

genetics↗

bioRxiv2018

Response to Therapeutic Sleep Deprivation: A Naturalistic Study of Clinical and Genetic Factors and Post-Treatment Depressive Symptom Trajectory

Research has shown that therapeutic sleep deprivation (SD) has rapid antidepressant effects in the majority of depressed patients. Investigation of factors preceding and accompanying these effects may facilitate the identification of the underlying biological mechanisms. This exploratory study aimed to examine clinical and genetic factors predicting response to SD and determine the impact of SD on illness course. Mood and tiredness during SD were also assessed via visual analogue scales (VAS). Depressed inpatients (n = 78) and healthy controls (n = 15) underwent ~36hrs of SD. Response to SD was defined as a score of [≤]2 on the Clinical Global Impression Scale for Global Improvement. Depressive symptom trajectories were evaluated for up to a month using self/expert ratings. Impact of genetic burden was calculated using polygenic risk scores for major depressive disorder. 72% of patients responded to SD. Responders and nonresponders did not differ in baseline self/expert depression symptom ratings, but mood subjectively measured by VAS scale differed. Response was associated with lower age (p = 0.007) and later age at life-time disease onset (p = 0.003). Higher genetic burden of depression was observed in non-responders than healthy controls. Up to a month post-SD, depressive symptoms decreased in both patients groups, but more in responders, in whom effects were sustained. The present findings suggest that re-examining SD with a greater focus on biological mechanisms will lead to better understanding of mechanisms of depression.

epidemiology↗