Glyoxalase 1 (Glo1) detoxifies reactive dicarbonyl compounds such as methylglyoxal, a precursor of advanced glycation end products (AGEs), which contribute to metabolic disorders. However, the contribution of AGE-independent mechanisms to Glo1-related metabolic dysfunction remains unclear. We conducted a longitudinal study in male and female Glo1 heterozygous knockdown (Glo1+/-) mice (∼50% Glo1 expression). Metabolic phenotypes, including body weight, adiposity, glycemic control, and plasma lipid levels, were assessed over time. Atherosclerotic burden, AGE levels, and gene expression profiles in liver, adipose, muscle, kidney, and aorta were examined to identify pathway alterations and regulatory genes affected by Glo1 reduction. Partial Glo1 loss resulted in obesity, hyperglycemia, dyslipidemia, and altered lipid metabolism in an age- and sex-dependent manner, with most phenotypes emerging after ∼14 wk. Glo1+/- females exhibited impaired glycemic control and elevated triglycerides, along with perturbations in adipogenesis, peroxisome proliferator-activated receptor-γ (PPARγ) signaling, insulin signaling, and fatty acid metabolism in liver and adipose tissue. Glo1+/- males displayed increased skeletal muscle mass and visceral adiposity with changes in lipid metabolic pathways. Methylglyoxal-derived AGE accumulation was altered only in male skeletal muscle and did not explain broader phenotypes. Transcriptomic analyses suggest that altered glucose and lipid metabolism may be partially driven by the alternative detoxification of methylglyoxal to metabolites such as pyruvate. Transcription factor analysis identified Hnf4a (across tissues) and Arntl (in aorta, liver, and kidney) as female-biased regulators altered by Glo1 deficiency. Glo1 reduction disrupts metabolic health through sex- and age-dependent pathways largely independent of AGE accumulation, involving tissue-specific metabolic reprogramming and transcriptional regulation.NEW & NOTEWORTHY This study reveals that partial deficiency of glyoxalase 1 (Glo1) leads to age- and sex-specific metabolic dysfunction in mice through transcriptional and regulatory changes independent of advanced glycation end products (AGEs). Transcriptomic profiling and integrative genomics identified female-biased transcription factors and genome-wide association study (GWAS)-linked metabolic genes as key mediators. These findings uncover novel, AGE-independent regulatory pathways linking Glo1 to metabolic disease risk and emphasize the importance of sex-specific analysis in metabolic genomics research.

New approach methods (NAMs), including in vitro paradigms, are needed to increase throughput, sustainability, and ethicality in toxicity research. However, selecting optimal cell culture models that mimic in vivo physiological conditions is challenging. To identify cell lines that best recapitulate physiological cells, we compared gene expression signatures of cell lines and in vivo tissues. We curated 214 transcriptomics datasets from 17 human and mouse hepatic cell lines representing hepatocytes, hepatic stellate cells, and cholangiocytes and determined basal gene expression profiles for each. We also collected 7 in vivo single-cell RNA sequencing (scRNAseq) datasets from human and mouse livers, which provide physiologically relevant transcriptome profiles for hepatic cell types. We compared cell line transcriptome profiles to liver scRNAseq data to determine which cell lines best represent in vivo physiology for each cell type and compared genes, regulatory networks, and biological pathways between cell lines and hepatic cell types. We further analyzed 15 cell lines, in vivo, and primary hepatocyte datasets from hepatotoxicity studies to relate baseline patterns to toxicological responses. We identified HepaRG as optimal to model hepatocytes both at baseline and in hepatotoxicity application studies of diverse toxicants, and further provided biological insights into the key differences of some of the widely used hepatic cell lines from in vivo biology. Overall, we present a new in silico approach that leverages existing big data to guide the selection of cell lines with better functional relevance, which can be applied to in vitro modeling of other tissues and broad biomedical applications.

Although genome-wide association studies (GWAS) have identified loci associated with type 1 diabetes, the specific pathways and regulatory networks linking these loci to disease pathology remain largely unknown. We hypothesised that type 1 diabetes genetic risk factors disrupt tissue-specific biological pathways and gene networks that ultimately lead to beta cell loss. We conducted a multi-tissue multi-omics analysis that integrates human GWAS data for type 1 diabetes with tissue-specific regulatory data for gene expression and gene network models across relevant tissues to highlight key pathways and key driver (KD) genes contributing to type 1 diabetes pathogenesis. KD genes were validated using islet-specific gene expression and protein data from non-obese diabetic (NOD) mice compared with type 2 diabetic and non-diabetic mouse models. Drug repositioning predictions were generated using the INCS L1000 and PharmOmics platforms, and candidate drugs were tested using electronic medical records (EMRs) of individuals with type 1 diabetes from the OneFlorida+ Clinical Data Network. Our integrative genomics approach identified known immune pathways across multiple tissues, such as adaptive immune responses, cytokine-mediated inflammation, primary immunodeficiency, and interactions between lymphoid and non-lymphoid cells. Tissue-specific signals included genes related to type 2 diabetes in lymphocytes, viral response pathways in macrophages and monocytes, and Notch signalling in adipose tissue and immune cells. In pancreatic islet analysis, we observed significant enrichment for type 1 diabetes and type 2 diabetes gene sets alongside immune-related pathways, including antigen processing, systemic lupus erythematosus and IFN signalling. Removing HLA genes from the analysis revealed additional immune pathways, such as retinoic acid-inducible gene I (RIG-I)/melanoma differentiation-associated protein 5 (MDA5) induction of interferons, together with melanogenesis, steroid hormone synthesis and iron transport. Network modelling highlighted the autoimmune basis of disease, with KDs such as FYN, TAP1, WAS and HLA-B/C/G, as well as additional immunomodulatory proteins such as LCK, LCP2 and genes such as EMR1 and GC. These KDs were further supported by gene and protein expression data from NOD mice. We additionally highlight various drug classes that target the type 1 diabetes genetic networks and may be useful to delay type 1 diabetes development; some of these were supported by our EMR screen. Our multi-tissue multi-omics approach provides a detailed landscape of the tissue-specific genetic networks and regulators underlying type 1 diabetes. This analysis confirms the roles of known immune pathways while uncovering additional regulatory elements and disease-associated networks, thus expanding our understanding of type 1 diabetes pathogenesis. The identification of potential drug candidates through network analysis, with supporting evidence from EMRs, offers potential therapeutic strategies for targeting disease pathways and holds promise for delaying or preventing type 1 diabetes progression.

Background Obesity is driven by the pathological expansion and accumulation of adipose tissue and demonstrates sex differences. Estradiol (E2) is known to influence fat distribution and metabolism. However, a comprehensive understanding of the sex-specific effect of E2 on individual adipose cell types remains elusive. Methods We measured adiposity and utilized single-cell RNA sequencing to dissect how E2 affects the molecular processes within gonadal adipose tissue from diet-induced obese, gonadectomized mice of both sexes (XX and XY) through differential gene expression, pathway enrichment, transcription factor enrichment, intracellular and intercellular network modeling, and human disease relevance analysis. Results We found striking sex-and cell-type-specific responses to E2 treatment. Accompanying more significant fat reduction under diet-induced obesity in XX mice, adipose stem and progenitor cells (ASPCs) of XX mice exhibited a stronger transcriptomic shift in response to E2 than ASPCs in XY mice, with altered expression of genes related to stemness and lipid metabolism. E2 broadly suppressed extracellular matrix (ECM) genes in both sexes, with more pronounced downregulation of collagen, glycoprotein, and metalloproteinase-related genes in XY preadipocytes, and reduced proteoglycan genes in XX mice. Macrophages also demonstrated heightened sensitivity to E2, showing trends in decreased proportion of lipid-associated macrophages, increased perivascular-like macrophages, and downregulated inflammatory and metabolic pathways in both sexes as well as sex-specific changes in immune genes. Furthermore, we identified strengthened macrophage to ASPC communications in XX mice and differential enrichment patterns of sex-biased E2-altered genes with human metabolic diseases. Conclusions Our findings provide a cell-resolution, sex-specific understanding of E2's profound impact on gonadal adipose tissue remodeling to guide sex-specific therapeutic interventions in obesity.

Pediatric mild traumatic brain injury (mTBI) is common and can potentially lead to novel psychiatric disorders (NPDs). However, the psychiatric sequelae of mTBI in community-dwelling children require further study. NPDs were characterized during the first 2 years following injury in children with a first lifetime mTBI between 9 and 11 years of age in the Adolescent Brain Cognitive Development study (n = 99), compared with orthopedically injured (n = 380) and noninjured (n = 374) controls. Outcomes were defined as NPD-Any (NPD-A), which included all NPDs with onset during the study period, and NPD-Current (NPD-C), which included only those NPDs that were still active at the follow-up study visit. Possible confounders, including injury and non-injury-related factors, were also considered. NPDs were common at the year 2 study visit, particularly anxiety disorders, but rates were similar across injury groups. Mild TBI was not associated with differential odds of NPD. However, family psychiatric history predicted greater odds of NPD (for NPD-C, odds ratio [OR] = 1.345; 95% confidence interval [CI] = 1.124-1.615; p < 0.001; for NPD-A, OR = 1.217; 95% CI = 1.078-1.375; p = 0.002), and pre-injury psychiatric disorder was associated with increased risk of NPD at year 2 (for NPD-C, OR = 1.557; 95% CI = 1.022-2.346; p = 0.037; for NPD-A, OR = 1.568; 95% CI = 1.198-2.055, p = 0.001). In this representative community-dwelling sample of children in the United States who experienced a first lifetime mTBI between 9 and 11 years of age, mTBI was not associated with risk for NPDs in the first 2 years following injury. However, non-injury-related factors, including family psychiatric history and pre-injury psychiatric disorders, were associated with NPDs.

Sex differences in brain development may contribute to well-known sex differences in behavior and neuropsychiatric risk - making it important to comprehensively map and mechanistically annotate normative sex differences in brain organization. Most sex differences in mammalian brain organization have previously been attributed to differential effects of gonadal hormones based on outcomes from rodent endocrine manipulations at canonical subcortical foci of male-biased brain volume. However, a systematic quantification of both gonadal and sex chromosome dosage (SCD) contributions across all regions of sex-biased brain volume has been lacking. Here, using structural neuroimaging scans from wild-type (n=670) and transgenic mice that dissociate gonadal, X-, and Y-chromosome effects (n=181), we show that: many more brain regions are volumetrically sex-biased than previously recognized; gonadal effects dominate throughout this expanded map of sex differences; several regions also show prominent SCD contributions to anatomical sex differences, which can both reinforce or counteract gonadal effects in a regionally specific manner. Targeted single nucleus RNA sequencing at a region of female-biased cerebellar volume reveals that combined gonadal and SCD effects also drive sex-biased cellular gene expression. These findings revise our understanding of the spatial distribution and causal basis of sex-differences in the mammalian brain, illuminating a key axis of biological variation in health and disease.

The genetic heterogeneity of autism spectrum disorder (ASD) presents significant challenges in understanding its pathogenic mechanisms, as the genetic risk involves numerous common variants and rare de novo or inherited variants. Prior research has mainly focused on identifying rare variants and their impact on neurodevelopment and neuronal functions in cortical brain regions. By contrast, common variants, which contribute substantially to ASD heritability, remain understudied, suggesting a need to consider both variant types to understand ASD's genetic mechanisms. Previous studies have also implicated subcortical brain regions and peripheral digestive and immune systems, but tissue-specific mechanisms remain unclear. We address these knowledge gaps by identifying gene networks, pathways, and key regulators informed by ASD common variants in brain and peripheral tissues, further examining whether these networks also capture genes informed by rare variants. Our approach integrates genome wide association study (GWAS) summary statistics, tissue-level genetics of gene expression, and gene coexpression and transcriptional regulatory networks across ~50 tissues. Our multitissue, multiomics analysis reveals that key brain regions and networks crucial for synaptic signaling and neurodevelopment are enriched for both rare and common variants, whereas peripheral tissues, such as the digestive and immune systems, are primarily informed by common variants. This partitioning of key tissues and biological pathways into core (targeted by both variant types) and modifying components provide insight into ASD heterogeneity. We also identified central gene network regulators, such as SYT1 and ADD2, which may orchestrate the effects of both common and rare ASD genetic risk factors on ASD pathogenesis.

Abstract The gut microbiome is emerging as a modifier of risk for neurodegenerative diseases, but underlying mechanisms remain poorly understood. Here, we show that the hTau.P301S mouse model for progressive tauopathy develops alterations in the composition and function of the gut microbiome that are not recapitulated in amyloid-based 5xFAD or 3xTg models for Alzheimer’s disease. Disrupting the gut microbiome via chronic antibiotic treatment exacerbates cognitive deficits and tau pathology in hTau.P301S mice, demonstrating a causal influence of the microbiome on tau-driven disease progression. This corresponds with widespread alterations in microbiome-dependent metabolites in the sera and brains of hTau.P301S mice, including subsets that correlate with the severity of tau pathology. By screening against tau biosensor cells, we identify select microbial metabolites—trimethylamine-N-oxide, 3-indoxyl sulfate, phenol sulfate, thymidine, and 2’deoxyuridine—that promote tau seeding and aggregation. Systemic administration of these metabolites worsens cognitive impairment and tau pathology in hTau.P301S mice. These findings establish a mechanistic link between the gut microbiome, serum and brain metabolites, as well as tau aggregation, suggesting that select microbial metabolites could potentially serve as therapeutic targets for tau-driven diseases.

The liver and heart are tightly interconnected organs, and liver disease is frequently accompanied by cardiovascular dysfunction, including heart failure1-5. Despite this clinical association, the mechanisms by which liver-derived endocrine signals influence cardiac gene programs and disease susceptibility remain poorly defined. Inter-organ endocrine communication is increasingly recognized as a key regulator of systemic physiology, including cardiac function6-8, but a comprehensive understanding of liver-heart communication is lacking. Here we use an unbiased, population-based systems genetics approach in a genetically diverse mouse cohort to identify liver-derived secreted factors associated with cardiac transcriptomic variation. This analysis reveals hepatocyte growth factor activator (HGFAC) as a candidate mediator of inter-organ communication. Cross-tissue analysis of human genetic and transcriptomic datasets further suggests a conserved relationship between hepatic HGFAC expression and cardiac gene programs. These observations implicate a previously unrecognized liver-heart axis that appears to contribute to heart failure pathophysiology across species.

Background: Alzheimer’s disease (AD) is a pervasive neurodegenerative disorder with hallmarks of beta-amyloid (Aβ) plaques and neurofibrillary tangles. Considering the suboptimal benefit of Aβ clearing drugs, the association between metabolic disorders and AD provides an alternative angle to understand the role of metabolic dysfunction in AD pathogenesis and the potential of modulating metabolism for therapeutic development. Methods: We investigated the effects of metabolic modulators, namely, high fructose consumption as a potential risk, and docosahexaenoic acid (DHA) and nicotinamide riboside (NR) as potentially beneficial, on cell type specific transcriptomic responses in the hippocampus and hypothalamus of the 5xFAD mouse model featuring advanced Aβ plaques. Findings: Fructose-induced metabolic syndrome increased expression of complement component 3 in ependymal cells and inflammatory genes in microglia, which were normalized by DHA and NR. NR and DHA led to reversals of Aβ-associated transcriptional signatures across cell types, but the effects were modified by fructose. DHA and NR also both reversed the loss of hippocampal oligodendrocytes in AD, with DHA further reducing hippocampal microglia and increasing hypothalamic astrocytes and NR further increasing hippocampal neuronal proportions. Interpretation: Our study supports the impact of metabolic regulation on AD-associated cell types and pathways and provides molecular support for utilizing nutritional modulators for AD intervention.

Youth sports are popular in the United States and provide many physical and social benefits for children. However, sports participation is also a major source of pediatric traumatic injuries, including mild traumatic brain injury (mTBI) and orthopedic injury (OI). Previous studies have identified certain sports associated with higher risks of mTBI and/or OI, but are limited to retrospective data. The aim of this study is to prospectively examine the association between individual sports and the risk of mTBI and OI using longitudinal data from the Adolescent Brain Cognitive Development (ABCD) study. We analyzed longitudinal data from 11,332 children at the 1-, 2-, and 3-year follow-ups (ages 10-13 years) from the ABCD study. Participation in 23 sports and the incidence of mTBI and OI were reported by parents at each visit. Generalized linear mixed-effects models with subject-level random intercepts were used to fit the longitudinal data, adjusting for age, sex, race/ethnicity, parental income, parental education, and children's behavior problems. The results indicated that most sports showed a decline in participation rate over time. Children who played soccer had higher risks of mTBI, odds ratio (OR) = 1.320 (1.075, 1.621), p = 0.008, and OI, OR = 1.208 (1.057, 1.379), p = 0.005, compared with those who did not (95% confidence interval in parentheses). Children who played American football also had higher risks of mTBI, OR = 1.639 (1.238, 2.171), p < 0.001, and OI, OR = 1.405 (1.159, 1.704), p ≤ 0.001, compared with those who had not. Children who played ice hockey had a significantly higher risk of mTBI than OI, ratio of odds ratio = 2.700 (1.445, 5.043), p = 0.002. Finally, children who played volleyball exhibited lower risks of mTBI, OR = 0.442 (0.234, 0.835), p = 0.012, than those who did not. Sensitivity analyses adjusting for additional behavioral and neurocognitive variables and restricting the analysis sample to children who played at least one sport in the 3-year interval showed consistent findings. The findings suggested that sports-specific differences exist in injury risks, and sport-specific and injury-specific prevention strategies are needed in youth sports.

Mild traumatic brain injury (mTBI) disproportionately affects children and adolescents and has been associated with poorer neurocognitive performance, but the biological mechanisms driving symptom variability and severity remain understudied. In accordance with the omnigenic disease model, we integrated gene-by-mTBI interaction genome-wide association studies on neurocognition from the Adolescent Brain Cognitive Development (ABCD) cohort with single-cell RNA sequencing gene regulatory networks to elucidate the cell type-specific key regulators and molecular mechanisms governing neurocognitive outcome of mTBI, specifically learning and memory performance. Our analysis revealed distinct network regulators in neuronal and glial cell types across hippocampal and cortical brain regions to orchestrate key neurodevelopmental pathways. Examples include APP for synaptic signaling in excitatory neurons, COX5A for mitochondrial function in inhibitory neurons, MOG for myelination in oligodendrocytes in the hippocampus; GRM7 for synaptic signaling in excitatory neurons, SV2A for synaptic signaling in inhibitory neurons, and MOG for myelination in oligodendrocytes in the cortex. These mechanisms also associate with learning and memory through pathway-based polygenic risk score modeling in ABCD. Our findings provide brain region- and cell type-specific insights into the complex regulatory network landscape of mTBI pathology and potential therapeutic candidates at the pathway and network levels.

ABSTRACT Background The epicardium is reactivated after myocardial infarction (MI); however, the gene expression profiles of post-MI adult epicardial subpopulations remain incompletely defined. Methods Single-cell RNA sequencing was performed on lineage-traced Wt1 + epicardial cells from Wt1 CreERT 2 /+ ; R26 tdT/+ ; Pdgfra nGFP/+ adult mice after sham surgery or at 7 and 14 days after permanent artery ligation to induce MI. Immunostaining was performed on Wt1 -lineage-traced cardiac tissue to validate spatial expression after ischemic injury. Results Unbiased clustering identified nine transcriptionally distinct epicardial populations, encompassing mesothelial, fibroblast/mesenchymal, transitional, and proliferative phenotypes. Fibroblast-like epicardial cells (Wt1 + /Pdgfra + ) showed time-dependent expression profiles associated with upregulation of epithelial-to-mesenchymal transition (EMT) and extracellular matrix (ECM) gene programs. At 7 days post-MI, there was notable enrichment of genes related to chemokines and Wnt components. By 14 days post-MI, the expression profile shifted toward immune regulation. In contrast, a Wt1 high /Msln + population showed minimal upregulation of EMT gene programs but enhanced paracrine signaling related to wound healing and semaphorins, suggesting reactivation of reparative and angiogenic functions akin to those of the epicardium during embryonic development. Immunostaining and in situ hybridization fluorescence analyses validated laminar epicardial cell placement after MI, comprising a surface Msln + sheet, an overlapping Wt1 -lineage band, and a subadjacent PDGFRα + and Periostin + compartment that expands 7-14 days after MI and regresses by day 28 post-ischemia. Conclusions Our data define epicardial gene programs in which a signaling epithelial cell surface overlays an effector mesenchymal cell stroma to coordinate angiogenesis, leukocyte recruitment, and ECM remodeling. This study presents the first integrated single-cell atlas of epicardial-derived cells across multiple post-ischemic timepoints, offering new insights into their reparative potential and dynamic signaling diversity in the injured adult heart.

Obesity is a prevalent, systemic metabolic disease affecting not only various adipose depots but also the liver, where lipid accumulation results in metabolic dysfunction-associated fatty liver disease, dyslipidemia, and insulin resistance. While estradiol (E2) has been known to be hepatoprotective for glucose and lipid metabolism in females, whether E2’s effects on individual liver cell types are shared between sexes or are sex-specific with obesity remains poorly defined. We performed single-nucleus RNA sequencing on liver tissue of E2-treated obese, gonadectomized male (XY) and female (XX) mice with diet-induced obesity to evaluate the sex-concordant and discordant effects of chronic E2 treatment. Differential gene expression, pathway analysis, intracellular and intercellular regulatory network modeling, and human metabolic disease/trait association analysis were conducted. E2-induced transcriptional effects among hepatocyte subtypes were largely sex-concordant in both males and females, along with sex-specific E2 changes. In pericentral hepatocytes, E2 concordantly reduced the expression of genes involved in insulin resistance, FOXO signaling, and lipid biosynthesis; in periportal hepatocytes, E2 treatment enhanced cholesterol efflux genes and suppressed oxidative stress response genes. XY-specific effects of E2 included additional suppression of lipid and energy metabolic pathways in pericentral hepatocytes and oxidative phosphorylation in periportal hepatocytes, while in XX mice E2 showed unique regulation of glucose and lipid utilization programs. Network analysis revealed that E2-responsive genes in hepatocyte subtypes in both sexes showed enriched transcription factors associated with estrogen receptor signaling and lipid sensing and metabolism, alongside sex-specific regulators. Intercellular signaling affected by E2 showed more changes in XY mice than in XX mice across hepatocyte subtypes. Lastly, while E2-responsive genes in hepatocyte subtypes of both sexes were enriched for human genetic signals associated with lipid profiles and coronary artery disease, we also identified sex-specific associations, such as the link of E2-downregulated genes in XY hepatocytes to body mass index in men. Our findings revealed that chronic E2 administration remodels gene regulatory programs in individual liver cell types through both shared and sex-specific mechanisms, highlighting the importance of considering sex chromosome-dependent E2 responses when developing therapeutic strategies for obesity and associated hepatic metabolic dysfunction. Obesity is a growing global health concern that has negative impacts on a broad spectrum of organs, including the liver. Estradiol (E2) is a sex hormone that generally plays a protective role in both sexes against liver dysfunctions. However, whether and how E2 effects differ between sexes and across various liver cell types remains understudied. Here, we compared and contrasted how liver cells responded to chronic E2 treatment between obese female and male mice. We found that hepatocytes, the major liver cell type, generally responded to E2 in similar ways in both sexes. In hepatocytes located near the liver’s central vein, E2 dampened shared pathways related to insulin resistance and lipid synthesis in both sexes, while additionally suppressing lipid and energy metabolic processes in males only. In hepatocytes near the portal triad, where oxygenated and nutrient-rich blood arrives, E2 enhanced cholesterol processing and reduced oxidative stress response in both sexes. E2 also induced more cell–cell communication changes in male mice than in female mice across hepatocyte subtypes. Lastly, E2-responsive genes in hepatocyte subtypes of both sexes were largely associated with lipid profiles and heart disease, with additional sex-specific obesity and diabetes associations also observed. Single-nucleus RNA sequencing revealed sex-concordant and discordant genes and pathways in hepatic cell types of obese gonadectomized mice, with hepatocyte subtypes showing greater concordance between sexes. Shared E2 effects include dampened insulin resistance, FOXO signaling, and lipid biosynthesis in pericentral hepatocytes, along with enhanced cholesterol efflux and suppressed oxidative stress response in periportal hepatocytes. Sex-discordant effects were also observed: in XY mice, lipid and energy metabolic pathways were additionally suppressed in pericentral and periportal hepatocytes, while in XX mice, unique regulation of glucose and lipid utilization programs was observed. Cell–cell communication analysis revealed more E2-induced signaling changes in XY mice than in XX mice across hepatocyte subtypes. E2-responsive genes in hepatocytes of both sexes were enriched for human genetic signals associated with lipid profiles and heart diseases, while cell type- and sex-specific associations with obesity and diabetes were also observed.

Abstract Obesity increases risk and worsens treatment outcome of acute lymphoblastic leukemia (ALL). To explore how adipose tissue may contribute to these effects, we previously performed single cell RNA sequencing in obese mice to compare gene expression in ALL from adipose tissue to ALL from marrow. We identified 577 differentially expressed genes (DEGs) with a log2-fold threshold of ±0.25 and Bonferroni corrected p-values <0.05. Using ex-vivo coculture of ALL and human adipose explants, we confirmed that adipose tissue upregulates a top DEG, TNFSF11, in ALL cells via secretion of prostaglandin E2 (PGE2). Additionally, we observed that PGE2 conferred modest resistance in vitro to vincristine and daunorubicin chemotherapies. In the present study, we explored whether adipose tissue PGE2 might contribute to poor ALL treatment outcome. We identified six additional genes in the top 50 DEGs that may be induced by PGE2-cAMP signaling and confirmed that these genes were upregulated in vitro by 200 ng/mL PGE2 in BV173 and RS4;11 ALL cell lines (Table)(N=6). To investigate the relevance of these genes to ALL survival, we analyzed data from the TARGET-ALL P2 clinical trial using the NCI GDC Data Portal. TARGET-ALL P2 included pediatric and young adult B-precursor ALL patients treated on Children’s Oncology Group protocols, enriched for patients who experienced relapse within 4 years of diagnosis. Survival and RNAseq expression on diagnostic specimens were available for 466 subjects. Expression of these six genes, as well as TNFSF11, was associated with significantly worse survival, with hazard ratios ranging from 1.7 to 3.7 (Table). Overall, our data shows that adipose tissue PGE2 can upregulate genes that are associated with a worse prognosis in ALL patients. Further work is needed to test whether adipose tissue PGE2 is a contributing factor for worse ALL outcomes in obese patients. Citation Format: Michael Cohen, Nayaonika Vasishtha, Byourak Shabane, Jia Tan, Tyler Kuk, Neha Chandra, In Sook Ahn, Xia Yang, Etan Orgel, Steven D. Mittelman. Prostaglandin E2 signaling promotes adverse survival outcome in B-cell acute lymphoblastic leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 2088.

Proper adipose tissue homeostasis is essential for systemic metabolic health, and its disruption promotes insulin resistance, inflammation, and cardiometabolic risk. Using unbiased systems genetics analyses in mice and humans identified ITIH5 as a central regulator of adipose homeostasis and whole-body metabolism. Acute administration of recombinant ITIH5 with pan-organ sequencing revealed a local adipose function, suppressing recruitment of circulating immune cells. Consistently, ITIH5 treatment in human endothelial cells reduced leukocyte recruitment. We generated temporally controlled, adipocyte-specific ITIH5 overexpression models in mice, which improved adipose architecture, glucose metabolism under high-fat diet conditions, while consistently reducing left ventricular mass and cardiac output regardless of dietary group.. Spatial transcriptomics of adipose tissue showed that elevated ITIH5 signaling to endothelia selectively impairs dendritic cell (DC) and B cell activation pathways. Collectively, these findings identify a mechanism whereby natural genetic variation in an adipocyte-secreted protein modulates endothelial–immune interactions in fat, influencing cardiometabolic homeostasis in a diet-dependent manner.

Understanding complex disease and identifying therapeutic strategies requires a deep understanding of gene interactions in healthy and disease conditions. Gene regulatory networks (GRNs) are graphical representations of regulatory interactions in a tissue or cell type, providing powerful models for inferring disease-associated regulatory mechanisms across cell and tissue types. Despite the rise of single cell reference atlases, there remains a paucity of comprehensive cell type GRN databases. Existing cell type GRN databases have GRNs derived from methods that focus on known transcription factors and binding sites, leaving other forms of regulation and novel regulators unexplored. To address this, we created scGRNdb, a cell type GRN database of over 1300 cell type GRNs spanning 88 human and mouse tissues from 8 single cell atlases, using a gradient-boosting based GRN construction method SCING to construct unbiased global gene regulatory networks that do not rely on known transcription factors and binding sites. We implemented analytical pipelines to partition and interpret GRN subnetworks in terms of functional pathway enrichment, compare networks across tissues and cell types, prioritize cell type GRNs that best model a user’s input gene sets, and identify cell type-specific key regulatory genes. Using test cases of cardiovascular disease and Alzheimer’s disease, we demonstrate the utility of scGRNdb in retrieving the relevant tissues, cell types, pathways, and regulators of disease and physiology. scGRNdb serves as a framework for accelerated hypothesis generation and disease target discovery beyond transcription factor regulation, enabling an unbiased means to characterize gene regulatory mechanisms underlying disease and physiological traits.

Estrogen therapy and androgen‑deprivation were once combined to treat prostate cancer (PrCa). Clinical studies later showed that prolonged estrogen exposure in androgen‑deprived men raises cardiovascular disease (CVD) risk, yet the metabolic pathways responsible remain unclear. We generated an androgen‑deprived, 17β‑estradiol (E2)–treated mouse model by gonadectomizing male C57BL/6 J mice and implanting sub‑cutaneous delayed‑release E2 or vehicle pellets. Mice received a Western‑style diet and were housed at thermoneutrality to accelerate CVD‑risk phenotypes. Metabolic profiling included hyperinsulinemic‑euglycemic clamps, oral lipid and pyruvate tolerance tests, flow cytometry of immune cells, and single‑nucleus RNA sequencing of liver tissue. In hypogonadal males, E2 treatment induced several metabolic disturbances. During clamps, E2‑treated mice showed markedly elevated gluconeogenesis, corroborated by higher glucose peaks and AUC during pyruvate tolerance testing and by up‑regulation of hepatic Pck1 mRNA. Triglyceride (TG) clearance, which improves with E2 in females, was impaired in E2‑treated males: oral lipid‑tolerance testing revealed prolonged TG excursions, reduced maximal lipase activity, lower non‑lipase clearance at 6 h post-OLTT, and decreased free‑fatty‑acid peak levels. Hepatic lipase, VLDL clearance receptors Ldlr and Lrp1, and microsomal triglyceride transfer protein (MTP) transcripts were down‑regulated. SnRNA‑seq showed suppression of lipid‑clearance genes with E2 treatment in males. Subcutaneous adipocytes were hypertrophic, and flow cytometry identified increased TNFα‑positive macrophages, an inflammatory milieu that could promote insulin resistance. Cardiac morphology was modestly altered; E2‑treated males exhibited a larger left‑ventricular end‑diastolic diameter, while ejection fraction and arterial pressure remained unchanged. Estradiol administration in androgen‑deprived male mice produces a constellation of metabolic derangements—including enhanced hepatic gluconeogenesis, impaired TG clearance, and inflammatory adipocyte hypertrophy—that likely underlie the increased CVD risk observed clinically. The identified molecular nodes (PEPCK, hepatic lipase, LRP1, LDLR, MTP, and adipose‑macrophage TNFα) provide potential targets for mitigating estrogen‑induced CVD risk while preserving its therapeutic benefit for PrCa.

In the adult heart, the epicardium is activated following myocardial infarction (MI), contributing to cardiac repair primarily through the secretion of paracrine factors. However, the specific cellular subtypes and molecular signaling pathways that govern epicardial function during injury remain poorly understood. This study investigates the dynamic role of the epicardium in modulating the cardiac response to MI. Using the Wt1 (Wilms Tumor 1) CreERT2 ; R26 tdTomato tamoxifen-inducible epicardial-specific lineage tracing mouse model in combination with a Pdgfra nGFP fibroblast reporter, we performed single-cell RNA sequencing on epicardial-derived cells (tdTomato + ) isolated from sham, 7-, and 14-day post-MI hearts. We identified 9 transcriptionally distinct epicardial subpopulations, which clustered into three major functional groups with distinct roles in cardiac remodeling. Wt1 + Pdgfra + epicardial fibroblast-like cells were enriched for chemokines and semaphorins, suggesting a role in immune cell recruitment and vascular remodeling. In contrast, Wt1 + , Upk3b + , Msln + epicardial mesothelial-like cells showed enrichment in Wnt signaling and semaphorins. Temporal analysis revealed that epicardial cells actively regulate low-grade inflammation and leukocyte recruitment throughout the 7- to 14-day post-MI period. Altogether, our study highlights the heterogeneous and dynamic nature of epicardial cell function during cardiac repair and underscore the epicardium's critical role in orchestrating myocardial remodeling following injury.

Background:While sex differences in the brain have traditionally been attributed to gonadal hormones, emerging evidence points to regulation by sex chromosomes. This study aims to differentiate the influence of gonads versus sex chromosomes on cellular gene expression in the mouse medial septum (MS), a critically understudied brain region. Methods:Using single nucleus RNA-sequencing and the Sex Chromosome Trisomy mouse model, we (1) quantified sex differences in cellular gene expression and (2) isolated sex-biasing effects by identifying perturbed cell types, differentially expressed genes, biological pathways, and gene networks, which were integrated with GWAS data to explore links with sex-biased human phenotypes. Results:Our analysis revealed that volumetric sex differences in the MS are mirrored by widespread transcriptomic changes across cell types. Critically, genetic effects displayed elevated relevance compared to sex hormones in driving sex-biased gene expression. These effects converge to regulate synaptic/neuronal development, transcriptional regulation, and cellular metabolism. Sex chromosome-associated DEGs were enriched for various human disorders, suggesting a cellular and mechanistic basis for their sex-biased patterns. Conclusions:Our findings challenge the classical gonad-centric views of sexual differentiation, as the MS displays sex-biased transcriptional regulation driven by sex chromosome-associated effects that are highly relevant for human health.