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Reinhardt, P.

Publications and source records attributed to Reinhardt, P..

9 recordsLinked to original sources

Impaired Control Symptoms in Alcohol Use Disorder Show Convergent Associations Across Behavioral and Neural Markers of Inhibitory Control and Drinking Behavior

Background: Deficits in inhibitory control are considered a central feature of alcohol use disorder (AUD), yet behavioral and neuroimaging findings have been inconsistent. One potential explanation is the marked heterogeneity of AUD, which encompasses multiple symptom dimensions that may differ in their underlying neurocognitive mechanisms. In this study, we investigated whether behavioral and neural markers of inhibitory control are associated with specific DSM-5 AUD symptom domains. Methods: A total of 589 participants (432 with non-treatment seeking AUD, 157 controls) completed a Stop-Signal Task (SST) during fMRI. Associations between DSM-5 symptom domains (impaired control over alcohol use, risky use, social problems, physical dependence) and SST performance, inhibition-related brain activation, and alcohol consumption were examined. Real-life drinking behavior was additionally assessed over 12 months using ecological momentary assessment (EMA). Results: Greater impaired control symptom severity was associated with poorer performance on go trials and diminished post-error slowing during SST. At the neural level, higher impaired control symptom severity was associated with reduced activation across fronto-insular, parietal, cingulate, supplementary motor, and cerebellar regions. In contrast, other symptom domains showed little to no associations with inhibition-related behavioral or neural measures. Higher impaired control symptom severity was associated with greater alcohol consumption across questionnaire-based and EMA-based assessments. Conclusions: In this large cohort, altered behavioral performance and recruitment of inhibition-related brain regions in the SST was selectively linked to impaired control symptoms. These findings highlight the importance of symptom-based approaches for understanding heterogeneity in addiction and may inform the development of more targeted interventions.

neuroscience↗

Brain Functional Connectivity Signatures of Craving Across Substance Use Disorders: A Transdiagnostic Approach

Craving is a hallmark feature of substance use disorders (SUDs) and a major risk factor for relapse, yet reliable biomarkers that enable individual-level prediction remain scarce. Here, we applied connectome-based predictive modeling (CPM) to resting-state functional magnetic resonance imaging (fMRI) data in a transdiagnostic sample of individuals with cannabis, opioid, or tobacco use disorder (n = 78). Using CPM, we identified a distributed functional brain network that reliably predicted self-reported craving. Computational lesion analyses revealed key contributions from the right medial orbitofrontal cortex, right dorsal posterior cingulate cortex, and left lateral medial frontal gyrus. Importantly, the craving network generalized across two independent datasets. In alcohol-dependent patients (n = 41), the identified craving network, along with its positive and negative subnetworks, predicted distinct cognitive and motivational components of craving. In a second external dataset of smokers (n = 28), the craving network predicted both nicotine craving after abstinence as well as intra-individual changes in craving between sated and craving states. Together, these findings provide evidence for a robust, transdiagnostic craving signature in SUDs. Future work should assess the networks predictive utility for longitudinal outcomes such as relapse risk and treatment response.

neuroscience↗

NGN2 Expression and Regional Patterning Allow Rapid Differentiation from hiPSCs to DRG-Like Neurons Responsive to Type 2 Cytokines

Itch or pruritus, is a sensation that elicits scratching behaviour and is a major symptom and cause of morbidity in skin diseases such as atopic dermatitis (AD), allergic contact dermatitis (ACD), prurigo nodularis (PN), and urticaria. Itch is often triggered by inflammatory stimuli in the skin including type 2 cytokines such as IL-4, IL-13, and/or IL-31. Several therapies targeting type 2 immune pathways have been developed to treat pruritus; however, itch improvement in many patients remains to be improved. Thus, additional approaches to modulate sensory neuron activity are needed. Ex vivo or even in vitro study of the molecular mechanisms underlying primary sensory neuron activation is challenging since harvesting neurons from dorsal root ganglia (DRG) in patients can only be done from cadavers. Herein, we describe rapid human sensory neurons generation (2 days to precursor cells) by in vitro differentiation of human induced pluripotent stem cells (hiPSC) from simultaneous application of patterning factors with NGN2 overexpression. We show that these hiPSC-derived sensory neurons possess key characteristics of primary sensory neurons. They express key neuronal markers, such as TRKA receptors, TRPV1 and TRPA1 channels, and functionally respond to the TRPV1 agonist capsaicin. In addition, they express key type 2 cytokine receptors such as interleukin (IL)-4R and IL31-R, known to promote itch in AD and PN. Moreover, these cells are functional as our sensory neurons respond to IL-4, IL-13 and IL-31 stimulation. Collectively, these data demonstrate that our protocol generates a phenotypic profile consistent with native somatosensory neurons that can facilitate development of novel approaches to model and treat pruritic disease.

neuroscience↗

Induction of Human Pruriceptors from Pluripotent Stem Cells via Transcription Factors

Pruriception is crucial for defense against external stimuli but can lead to chronic pruritus, a debilitating condition affecting millions worldwide. Our understanding of the cellular and molecular mechanisms behind the sensation of itch has been hindered by the lack of functional human models. Here, we address this limitation by developing a protocol to generate induced pruriceptors (iPruriceptors) from human pluripotent stem cells (hPSCs). We compared two differentiation approaches: a direct method via forced expression of transcription factors (TFs) in hPSCs, and a 2-step process through expression of TFs in hPSC-derived neural crest cells (NCCs). The 2-step protocol proved superior in inducing a transcriptional program that closely resembles that of human pruriceptors. Our optimized protocol employs forced expression of NGN1 and ISL1 to drive differentiation from NCCs into pruriceptors, enhancing the expression of known pruritogen receptors such as IL31RA, which pairs with OSMR, and HRH1. The induction of this transcriptional program leads to functional maturation of iPruriceptors. Accordingly, iPruriceptors exhibit robust responses to itch stimuli and in vivo-like itch pharmacology such as treatment with ABT-317, a JAK1 inhibitor tool compound, similar to those targeting intensive pruritus in atopic dermatitis (AD). Importantly, iPruriceptors can be generated without viral vectors or safe-harbor gene editing, using a PiggyBac-based transfection method that simplifies scalability. Our protocol offers a robust platform for investigating itch biology, modeling chronic pruritus, and enabling high-throughput screening for therapeutic target discovery. HighlightsO_LINGN1 and ISL1 forced expression in NCCs induces rapid differentiation to iPruriceptors C_LIO_LIiPruriceptors share transcriptional profile of primary human pruriceptors C_LIO_LIiPruriceptors have electrophysiological responses to known pruritogens C_LIO_LIiPruriceptors have JAK1-dependent IL-31/-13 responses blocked by ABT-317 C_LI

neuroscience↗

New Insights on Bridging Integrator 1 Protein Isoforms as a Risk Increasing Gene in Alzheimer's Disease

INTRODUCTIONGenome-wide association studies (GWAS) have identified Bridging Integrator 1 (BIN1) as the second-most significant genetic risk factor for Alzheimers disease (AD). We performed GWAS by proxy (GWAX) using UKBiobank and replicated this finding. However, the mechanism by which BIN1 impacts AD risk is largely unknown. METHODSTo address this, we first measured the expression of BIN1 isoforms in a human induced pluripotent stem cells (hiPSC) model and further evaluated whether the BIN1 risk loci associated with the expression of BIN1 isoforms in a Phase 2 AD clinical trial. RESULTSOur data indicated BIN1 isoform expression patterns associated with the differentiation of hiPSC into neurons or microglia and found the variant rs35103166 impacts the expression of the BIN1 microglia-specific isoforms. DISCUSSIONGiven the strong association with susceptibility to AD, exploring the mechanisms of BIN1 genetic variants and their impacts on cell-type specific expression could serve as a valuable resource for novel drug discovery. HighlightsO_LIBIN1 variants are significantly associated with AD risk in GWAX analysis from UKBB. C_LIO_LIBIN1 isoforms show a cell-type-specific expression pattern during hiPSC differentiation into neurons or microglia. C_LIO_LIBIN1 risk alleles associate with BIN1 isoform expression in a Phase 2 AD trial (NCT02880956). C_LI

neuroscience↗

A Novel C. elegans Model for Tau spreading Reveals Genes Critical for Endolysosomal Integrity and Seeded Tau Aggregation

The spreading of Tau pathology is closely associated with the progression of neurodegeneration and cognitive decline in Alzheimers disease and other tauopathies. A key event in this process is the rupture of endolysosomal vesicles following the intercellular transfer of Tau aggregates, releasing the transferred Tau species into the cytosol where they can promote the aggregation of endogenous Tau. However, understanding of the cellular pathways involved in this process remains limited. In this study, we investigated cellular pathways that prevent endolysosomal vesicle rupture. We established a new C. elegans model of Tau spreading by introducing an mCherry-labelled, disease-associated aggregation-prone fragment of human Tau (F3{Delta}K281::mCh) into the six touch receptor neurons. F3{Delta}K281::mCh transgenic animals exhibited significant neurotoxicity and mechanosensory deficits due to the accumulation of this Tau fragment. In addition, its intercellular transmission compromised the endolysosomal system in receiving hypodermal cells. Using this model, we conducted an unbiased genome-wide RNAi screen and identified 59 genes critical for maintaining endolysosomal integrity. GO-term analysis revealed an enrichment of genes related to the ESCRT complex, the ubiquitin-proteasome system, mRNA splicing, and fatty acid metabolism. Silencing of selected conserved genes exacerbated seeded Tau aggregation in a human induced pluripotent stem cell (hiPSC)-derived cortical neuron model and triggered endolysosomal rupture in HEK293T cells, confirming the crucial role of endolysosomal damage in seeded Tau aggregation. Overall, this study discovered novel cellular pathways that safeguard endolysosomal integrity. These findings may guide the development of therapeutics that improve endolysosomal integrity to halt the progression of Tau pathology.

cell biology↗

Aberrant functional brain network organization is associated with relapse during 1-year follow-up in alcohol-dependent patients

Alcohol dependence (AD) is a debilitating disease associated with high relapse rates even after long periods of abstinence. Thus, elucidating neurobiological substrates of relapse risk is fundamental for the development of novel targeted interventions that could promote long-lasting abstinence. In the present study, we analyzed resting-state functional magnetic resonance imaging (rsfMRI) data from a sample of recently detoxified AD patients (n = 93) who were followed-up for 12 months after rsfMRI assessment. Specifically, we employed graph theoretic analyses to compare functional brain network topology and functional connectivity between future relapsers (REL, n = 59), future abstainers (ABS, n = 28) and age and gender matched controls (CON, n = 83). Our results suggest increased whole-brain network segregation, decreased global network integration and overall blunted connectivity strength in REL compared to CON. Conversely, we found evidence for a comparable network architecture in ABS relative to CON. At the nodal level, REL exhibited decreased integration and decoupling between multiple brain systems compared to CON, encompassing regions associated with higher-order executive functions, sensory and reward processing. Among AD patients, increased coupling between nodes implicated in reward valuation and salience attribution constitutes a particular risk factor for future relapse. Importantly, aberrant network organization in REL was consistently associated with shorter abstinence duration during follow-up, portending to a putative neural signature of relapse risk in AD. Future research should further evaluate the potential diagnostic value of the identified changes in network topology and functional connectivity for relapse prediction at the individual subject level.

neuroscience↗

A Fast And Intuitive Method For Calculating Dynamic Network Reconfiguration And Node Flexibility

AO_SCPLOWBSTRACTC_SCPLOWDynamic interactions between brain regions, either during rest or performance of cognitive tasks, have been studied extensively using a wide variance of methods. Although some of these methods allow elegant mathematical interpretations of the data, they can easily become computationally expensive or difficult to interpret and compare between subjects or groups. Here, we propose an intuitive and computationally efficient method to measure dynamic reconfiguration of brain regions, also termed flexibility. Our flexibility measure is defined in relation to an a-priori set of biologically plausible brain modules (or networks) and does not rely on a stochastic data-driven module estimation, which, in turn, minimizes computational burden. The change of affiliation of brain regions over time with respect to these a-priori template modules is used as an indicator of brain network flexibility. We demonstrate that our proposed method yields highly similar patterns of whole-brain network reconfiguration (i.e., flexibility) during a working memory task as compared to a previous study that uses a data-driven, but computationally more expensive method. This result illustrates that the use of a fixed modular framework allows for valid, yet more efficient estimation of whole-brain flexibility, while the method additionally supports more fine-grained flexibility analyses restricted to biologically plausible brain networks.

neuroscience↗

Age-dependent neurodegeneration and organelle transport deficiencies in mutant TDP43 patient-derived neurons are independent of TDP43 aggregation

TAR DNA-binding protein 43 (TDP43) is a cause of familiar and sporadic amyotrophic lateral sclerosis (ALS). The diverse postulated mechanisms by which TDP43 mutations cause the disease are not fully understood. Human wildtype and TDP43 S393L and G294V mutant spinal motor neuron cultures were differentiated from patient-derived iPSCs. Mutant hTDP43 and wildtype motor neuron cultures did not differ in neuron differentiation capacity during early maturation stage. During aging we detected a dramatic neurodegeneration including neuron loss and pathological neurofilament abnormalities in TDP43 mutant cultures only. Additionally mitochondria and lysosomes of aging spinal motor neurons revealed robust TDP43 mutation dependent abnormal phenotypes in size, shape, speed and motility which all appeared without TDP43 mislocalization or aggregation formation. Furthermore, D-sorbitol - known to induce stress granules and cytoplasmic mislocalization of TDP43 - rescued axonal trafficking phenotypes without any signs of TDP43 mislocalization or aggregation formation. Our data indicate TDP43 mutation-dependent but cytosolic aggregation-independent mechanisms of motor neuron degeneration in TDP43 ALS.

neuroscience↗