Biology subjects

Kiefer, F.

Publications and source records attributed to Kiefer, F..

11 recordsLinked to original sources

bioRxiv2026

Multimodal longitudinal prediction of alcohol-use trajectories in adolescents and young adults: Social context, real-life social affective benefit, and fronto-striatal involvement

Escalating alcohol use during adolescence and young adulthood confers substantial risk for later substance misuse and adverse mental health outcomes, yet the factors that determine early drinking trajectories remain poorly understood. Here, we examined alcohol use across social, affective, and neural domains in a cohort of 378 community-based young drinkers using a combination of longitudinal phenotyping, ecological momentary assessment (EMA) and functional neuroimaging. Across different levels of analysis, higher baseline alcohol consumption (standard drinks per week) was associated with immediate substance-use social context, greater social-affective benefit in daily life, and heightened engagement of the fronto-striatal reward circuitry. In a one-year longitudinal follow-up, individual social-affective benefit and substance-related social environmental factors showed the strongest predictive value for drinking trajectories in a follow-up of 219 individuals after one year. Our findings identify key social and neural reward-related determinants of youth drinking behavior, informing the development of evidence-based risk detection and prevention measures.

neuroscience↗

bioRxiv2026

Predicting alcohol consumption from resting-state functional connectivity: Feature relevance and the potential of meta-matching.

Alcohol use disorder (AUD) is among the most prevalent mental disorders. Associations between resting-state fMRI functional connectivity (FC) and AUD have been reported but rarely replicated. In this preregistered study, we investigated the extent to which FC predicts alcohol consumption, as measured by the AUDIT-C score, in a large sample of non-treatment-seeking alcohol consumers (N = 739), including 528 participants with varying degrees of AUD severity. To optimize performance, we compared kernel ridge regression (KRR) trained directly on this sample with transfer-learning models based on multilayer meta-matching embeddings, from which we derived data-driven relevance maps at the connection, region, and network levels. We tested split-half reliability, reproducibility across cohorts, and outcome specificity of the relevance maps. Both models predicted AUDIT-C scores moderately but significantly (r {approx} 0.15). Meta-matching did not outperform KRR in prediction. Relevance maps showed limited split-half reliability, consistent with the modest predictive performance, but reproduced moderately well across two independent cohorts. These maps indicate reduced connectivity among limbic regions, the anterior middle temporal gyrus, the dorsomedial prefrontal cortex, and dorsal attention network regions. In contrast, hypothesized hyperconnectivity patterns involving the striatum, anterior cingulate cortex, and precuneus were less reliable and mostly non-significant. Overall, our findings suggest that resting-state FC contains reproducible but weak signals related to alcohol consumption. Transfer learning improved relevance-map reliability but not prediction performance and reduced outcome specificity. These results support the utility of interpretable machine learning for identifying connectivity patterns related to drinking behavior, while also highlighting current limitations in its predictive power.

neuroscience↗

bioRxiv2026

Neurostructural correlates of real-life social drinking risk in alcohol use disorder

The social context of alcohol consumption is increasingly recognized as an important factor in the development of alcohol use disorder (AUD). However, individuals with AUD may differ in how strongly alcohol use by people around them is associated with their own drinking, and the neurostructural basis of this variation remains unclear. Here we studied 83 individuals with AUD (53 men, 30 women; mean [SD] age, 37.20 [12.42] years; median DSM-5 AUD criteria, 4) using six weeks of ecological momentary assessment and structural magnetic resonance imaging (n = 80). Across 5,221 non-solitary observations, greater exposure to surrounding drinkers was associated with increased odds of momentary drinking (odds ratio, 4.23; 95% CI, 3.60-4.97), with significant between-person variation that we quantified as social drinking risk (SDR). Higher SDR was associated with lower gray matter volume in the pregenual anterior cingulate cortex (T = 5.40; P < .001) and weaker pregenual anterior cingulate cortex-ventral striatum structural covariance (T = 3.15; P = .032). These findings support SDR as an ecologically grounded phenotype linking daily-life social-context sensitivity to cingulostriatal structure, with potential relevance for mechanistic and interventional research in AUD.

neuroscience↗

bioRxiv2026

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↗

bioRxiv2026

Super-Resolution Optical Sectioning Microscopy Visualizes Nanopores in the Plasma Membrane of Endothelial Cells in situ

The ultrastructure of endothelial cells (ECs) "in situ" is of great interest due to their involvement in many physiological processes. In some organs, these cells form transcellular pores or fenestrae, allowing for the rapid exchange of molecules between blood and interstitium. Despite their importance, no optical images of these dynamic morphological structures have yet been acquired in situ. Major obstacles to their in-situ imaging are the lack of specifical labels for fenestrae and their size well below the optical diffraction limit. Here, we report how we have overcome these challenges and managed to visualize the EC ultrastructure in situ in 25 {micro}m thick liver sections. To enable this, a lipophilic, fluorescent membrane dye was infused into the portal vein of murine livers to stain the sinusoidal ECs before the organ was harvested. Tissue sections were subsequently imaged using a novel, super-resolution optical-sectioning structured illumination microscope (OS-SIM), providing approx. 170 nm spatial resolution with significantly faster image acquisition compared to confocal microscopy.

biophysics↗

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↗

bioRxiv2023

Specialized mesenteric lymphatic capillaries by-pass the mesenteric lymph node chain to transport peritoneal antigens directly into mediastinal lymph nodes.

Lymphatic vessels (LVs) are indispensable for tissue fluid homeostasis and immune cell trafficking. The network of LVs that channel fluids from the gut into mesenteric lymph nodes (MLN) has been recognized as the sole lymphatic system in the mesentery. Here we describe an alternative, functionally autonomous set of capillary mesenteric LVs (capMLVs) that by-pass the MLNs and drain directly into mediastinal LNs. CapMLVs develop perinatally from valves of collective mesenteric lymphatic vessels (colMLVs) in response to arterial endothelial cell-derived VEGF-C. Once extended, capMLVs detach from colMLVs to form an independent elongated network comprised of LYVE1+, CCL21+ endothelial cells. Avascular areas of the mesentery juxtaposed to capMLVs contain cell islets that express ACKR4. This CCL21-scavenging atypical receptor facilitates the migration of mesenteric phagocytes into capMLVs to be channeled directly into mediastinal LNs. This allows peritoneum-derived ominous antigens to be processed separately from alimentary antigens.

developmental biology↗

bioRxiv2022

Lymphatic endothelium arises directly from specialized angioblasts

The lymphatic vasculature is essential for tissue fluid homeostasis, immune cell surveillance and dietary lipid absorption, and has emerged as a key regulator of organ growth and repair1. Despite significant advances in our understanding of lymphatic function, the precise developmental origin of lymphatic endothelial cells (LECs) has remained a point of debate for over a century2-5. It is currently widely accepted that most LECs are derived from venous endothelium4,6, although other sources have been described, including mesenchymal cells3, hemogenic endothelium7 and musculoendothelial progenitors8,9. Here we show that the initial expansion of mammalian LECs is driven primarily by the in situ differentiation of specialized angioblasts and not migration from venous endothelium. Single-cell RNA sequencing and genetic lineage tracing experiments in mouse revealed a population of Etv2+Prox1+ lymphangioblasts that arise directly from paraxial mesoderm-derived progenitors. Conditional lineage labelling and morphological analyses showed that these specialized angioblasts emerge within a tight spatiotemporal window, and give rise to LECs in numerous tissues. Analysis of early LEC proliferation and migration supported these findings, suggesting that emergence of LECs from venous endothelium is limited. Collectively, our data reconcile discrepancies between previous studies and indicate that LECs form through both de novo specification from lymphangioblasts and transdifferentiation from venous endothelium.

developmental biology↗

bioRxiv2021

The blood vasculature instructs lymphatics patterning in a SOX7-dependent manner

Despite a growing catalogue of secreted factors critical for lymphatic network assembly, little is known about the mechanisms that modulate the expression level of these molecular cues in blood vascular endothelial cells (BECs). Here, we show that a BEC-specific transcription factor, SOX7, plays a crucial role in lymphatic vessel patterning by modulating the transcription of lymphangiocrine signals. While SOX7 is not expressed in lymphatic endothelial cells (LECs), loss of SOX7 function in mouse embryos causes a dysmorphic dermal lymphatic phenotype. We identify novel distant regulatory regions in mice and humans that contribute to directly repressing the transcription of a major lymphangiogenic growth factor (Vegfc) in a SOX7-dependent manner. Further, we show that SOX7 directly binds HEY1, a canonical repressor of the Notch pathway, suggesting that transcriptional repression may also be modulated by the recruitment of this protein partner at Vegfc genomic regulatory regions. Our work unveils a role for SOX7 in modulating downstream signalling events crucial for lymphatic patterning, at least in part via the transcriptional repression of VEGFC levels in the blood vascular endothelium.

developmental biology↗

bioRxiv2021

Vegfr3-tdTomato, a reporter mouse for microscopic visualization of lymphatic vessel by multiple modalities

Lymphatic vessels are indispensable for tissue fluid homeostasis, transport of solutes and dietary lipids and immune cell trafficking. In contrast to blood vessels, which are easily visible by their erythrocyte cargo, lymphatic vessels are not readily detected in the tissue context. Their invisibility interferes with the analysis of the three-dimensional lymph vessel structure in large tissue volumes and hampers dynamic intravital studies on lymphatic function and pathofunction. An approach to overcome these limitations are mouse models, which express transgenic fluorescent proteins under the control of tissue-specific promotor elements. We introduce here the BAC-transgenic mouse reporter strain Vegfr3-tdTomato that expresses a membrane-tagged version of tdTomato under control of Flt4 regulatory elements. Vegfr3-tdTomato mice inherited the reporter in a mendelian fashion and showed selective and stable fluorescence in the lymphatic vessels of multiple organs tested, including lung, kidney, heart, diaphragm, intestine, mesentery and dermis. In this model, tdTomato expression was sufficient for direct visualisation of lymphatic vessels by epifluorescence microscopy. Furthermore, lymph vessels were readily visualized using a number of microscopic modalities including confocal laser scanning, light sheet fluorescence and two-photon microscopy. Due to the early onset of VEGFR-3 expression in venous embryonic vessels and the short maturation time of tdTomato, this reporter offers an interesting alternative to Prox1-promoter driven lymphatic reporter mice for instance to study the developmental differentiation of venous to lymphatic endothelial cells.

cell biology↗

bioRxiv2020

p53 plays a central role in lymphatic anomalies

Activation of the transcription factor p53 has been associated with several developmental syndromes. In normal tissues, p53 is kept at very low undetectable physiological levels. When triggered by cellular stressors, p53 prompts important anti-proliferative and apoptotic programs part of its tumor suppressor activity or as the guardian of tissue homeostasis. We generated two murine models that display cutaneous hemorrhaging, severe edema, and distended blood-filled lymphatic vessels at late-gestation due to overactive p53 uniquely affecting lymphatic endothelial cells during development. Overactive p53 operated distinctively through anti-proliferative route in this tissue resulting in a decrease in initial lymphatics that normally absorb interstitial fluid. Remarkably, genetic or pharmacologic normalization of p53 restored lymphatic homeostasis and reversed lymphatic phenotypes. In parallel, several human lymphatic disease tissues exhibited high p53 levels exclusively in the lymphatic endothelium while p53 remained undetectable in surrounding arterial or venous vessels. We report here, for the first time, an extended role that the p53 pathway plays in the genesis of lymphatic homeostasis deficiencies opening the way for new therapeutic avenues for these rare, poorly understood, and incurable lymphatic maladies.

developmental biology↗