Biology subjects

Taylor, E. B.

Publications and source records attributed to Taylor, E. B..

18 recordsLinked to original sources

bioRxiv2026

Microglial and Neuronal Cross-talk in the Nucleus Accumbens

Microglia are the brain's resident immune cells and rapidly migrate toward sites of neuronal stress and neurotransmitter imbalance. The molecular cues directing microglia movement remain poorly understood, particularly in brain regions involved in reward processing, including the nucleus accumbens (NAc). Dopamine (DA) dysregulation and production of reactive oxygen species (ROS) are hallmarks of substance use disorders and neurodegenerative diseases. Dopamine and adenosine triphosphate (ATP) are co-released in the NAc, but the effects of ROS on ATP/DA co-transmission and microglia surveillance remain unknown. Using multiphoton imaging in brain slices with GFP-labeled microglia, we found that ATP consistently and non-selectively drives microglia chemoattraction, whereas DA chemoattraction only occurs in a subset of microglia through D1 but not D2 receptor activation. Microglia enter a reactive state via LPS, and LPS results in enhanced DA/ATP release measured via fast scan cyclic voltammetry. ROS production also transitions microglia to a reactive state, but inhibits DA release, with mixed effects on ATP release. These findings identify ATP- and DA-mediated mechanisms for NAc microglia chemoattraction and opposing immune dysregulation (via LPS or ROS) of DA terminal function.

neuroscience↗

bioRxiv2026

Metabolic Reprogramming Induced by Mitochondrial Citrate Carrier Deletion Mitigates Antibiotics-Induced Acute Tubular Injury

IntroductionThe mitochondrial citrate carrier (CiC), which mediates the transport of citrate across mitochondria, has been implicated in various diseases, but its role in kidney tubules is unclear. Here, we unraveled a novel role of CiC in tubular metabolism in the context of antibiotics-induced acute tubular injury (ATI). MethodsATI was induced by administration of vancomycin and gentamycin for 48 hours in mice (V+G-ATI). Tubular-specific CiC knockout (KO) was induced by adeno-associated virus (AAV) serotype 9 encoding Cre recombinase driven by KSP promoter (AAV9-Ksp-Cre) injection. Unbiased proteomic and metabolomic analyses were performed in CiC KO mouse kidneys. We performed in vivo 13C metabolic flux analysis to elucidate metabolic alterations in ATI and the effect of CiC KO. ResultsIn this study, V+G-induced ferroptosis, oxidative damage, and extensive ATI in mice were alleviated by CiC KO. Metabolic reprogramming induced by CiC KO increased mitochondrial TCA cycle intermediates, including alpha ketoglutarate (AKG), and elevated levels of the endogenous antioxidant glutathione (GSH). Supplementation with AKG or GSH attenuated V+G-ATI in mice. Tracking of the 13C pyruvate / lactate revealed an increased flux of glucose oxidation pathway in V+G-ATI. Interestingly, tubular-specific CiC KO expands the effective TCA cycle pool reserve space, which may contribute to mitigation of ROS. The beneficial metabolic alteration in CiC KO requires AKG and glutamate, as simultaneous inhibition of mitochondrial transporters of AKG and glutamate attenuated the cytoprotective effects of CiC KO against antibiotic-induced oxidative damage. ConclusionsThis is the first study to demonstrate the role of mitochondrial CiC in kidney tubular epithelial cells, showing that it induces metabolic alterations that protect against antibiotic-induced ATI.

pathology↗

bioRxiv2026

Metabolic Analysis of Human Retinal Pigment Epithelium and Choroid Tissue in Aging and Macular Degeneration

Age-related macular degeneration is a common ocular disease that causes vision loss in the elderly, with a complex set of risk factors and proposed mechanisms of pathogenesis. A powerful method for investigating changes in disease is metabolomics, by which small molecules can be identified and quantified simultaneously. We report here the metabolic analysis of human RPE-choroid tissue in aging and macular degeneration (AMD), as well as comparisons of human macular and extramacular RPE-choroid and neural retina. Levels of 215 metabolites were determined in young donors, AMD donors (early/intermediate, geographic atrophy, and neovascularization) and age-matched controls. The largest number of metabolite differences were observed between young and healthy aged controls, as opposed to between aged controls and any stage of AMD. Two notable metabolites found to be increased in aging choroids are trimethylamine N-oxide and uric acid, both of which were significant after Bonferroni correction. A mouse endothelial cell line treated with a high concentration of uric acid exhibited reduced migration in a wound closure assay. This study provides initial insights into the metabolome of human choroids in varying states of age and macular degeneration, as well as functional implications of these changes in the aging choroid.

cell biology↗

bioRxiv2026

Inhibition of NLRP3 Differentially Regulates Blood Pressure and Inflammation in Male versus Female DOCA-Salt Sprague Dawley Rats

BackgroundDeoxycorticosterone acetate (DOCA)-salt induces greater increases in blood pressure (BP) and a more pro-inflammatory T cell profile in males compared to females. T cells contribute to DOCA-salt hypertension, however, the mechanisms driving T cell activation remain unclear. The NLRP3 inflammasome has been implicated in DOCA hypertension in male mice. Little is known regarding NLRP3 in females. The goal of the current study was to test the hypothesis that NLRP3 contributes to greater increases in BP and renal inflammation with DOCA in males vs. females. MethodsRenal NLRP3 protein levels were measured in normotensive and hypertensive male and female subjects and in male and female Sprague Dawley uni-nephrectomized (UNX) control and DOCA-salt rats. Additional 11-wk-old Sprague Dawley rats were UNX and randomized to: 1) DOCA + vehicle or 2) DOCA + the NLRP3 inhibitor MCC950 (10 mg/kg/day in saline) from 11-14 wks of age. At 14-wks-of-age rats were euthanized, terminal plasma samples and remaining kidneys were collected for flow cytometric analysis of T cells. ResultsRenal NLRP3 levels were significantly greater in hypertensive males and females vs. normotensive controls. DOCA increased BP in both sexes, with greater elevations in males. MCC950 attenuated DOCA-induced increases in BP in male, but not female rats. MCC950 decreased circulating and renal CD4 and Th17 cells in both sexes, although the effect was greater in males. ConclusionDespite both males and females exhibiting an increase in NLRP3 in hypertension, NLRP3 contributes to BP elevations only in DOCA-salt males.

physiology↗

bioRxiv2026

IFN-driven lipid synthesis shutdown in CD4⁺ T cells during acute SIV infection and persistent OXPHOS with ART initiation

Cellular metabolism regulates HIV/SIV replication and reservoir establishment, yet how infection and antiretroviral therapy initiation (ARTi) shape CD4 T cell metabolism in vivo remains poorly defined. Using the SIVmac239 macaque model, we integrated single-cell metabolic profiling (MIST), transcriptomics, lipidomics and genome-scale metabolic modeling to characterize their metabolic remodeling. At peak viremia, CD4 T cells exhibited shutdown of de novo fatty-acid (FA) synthesis, reflected by acetyl-CoA carboxylase-1 (ACC1) downregulation, inhibition of lipid-anabolic reactions, and depletion of membrane phospholipids. This state was driven by type I interferon (IFN-I) responses, and IFN-I suppressed ACC1 in vitro. Pharmacologic inhibition of FA synthesis enhanced T cell activation and exerted direct antiviral effects. Following ARTi, most metabolic pathways in CD4+ T cells were suppressed, whereas oxidative phosphorylation (OXPHOS) remained elevated and its levels in effector memory cells correlated with cell-associated-vDNA These findings identify IFN-driven FA synthesis suppression as a novel effector mechanism during acute viral infection, and persistent OXPHOS in effector CD4 T cells as a metabolic correlate of early reservoir establishment.

immunology↗

bioRxiv2025

PANK2-mediated de novo CoA synthesis is required for metabolic switching to fatty acid oxidation

Humans have 3 different PANK enzymes (PANK1-3) that catalyze the first step in the de novo synthesis of Coenzyme A (CoA). All PANKs are feedback inhibited by acyl-CoAs but only PANK2 can overcome this inhibition by binding palmitoyl-carnitine. Previous studies, conducted under glucose-replete conditions, have failed to detect a PANK2-mediated contribution to CoA synthesis. We found that exposure to BSA-conjugated palmitate (PAL-BSA) led to activation of fatty acid oxidation (FAO) and the accumulation of both palmitoyl-carnitine and palmitoyl-CoA in HEK293T cells, suggesting that PANK2 is active under these conditions. Isotope tracing experiments with 13C15N-pantothenate showed that PANK2 uniquely sustains de novo CoA synthesis and high production of Acetyl-CoA in the presence of long-chain fatty acids, indicating that FAO is limited by CoA availability in these conditions. Consistent with this mechanism, fibroblasts from PKAN patients exhibited impaired oxidation of palmitoyl-carnitine, confirming the functional relevance of our results in a disease context.

biochemistry↗

bioRxiv2025

Brief Pulses of High-Level Fluid Shear Stress Enhance Metastatic Potential and Rapidly Alter the Metabolism of Cancer Cells.

Circulating tumor cells (CTCs) face challenges to their survival including mechanical and oxidative stresses that are different from cancer cells in solid primary and metastatic tumors. The impact of adaptations to the fluid microenvironment of the circulation on the outcome of the metastatic cascade are not well understood. Here we find that cancer cells (PC-3, MDA-MB-231, Myc-CaP) exposed to brief pulses of high-level FSS exhibit enhanced invasiveness and anchorage-independent proliferation in vitro and enhanced metastatic colonization/tumor formation in vivo. Cancer cells exposed to FSS rapidly alter their metabolism in a manner that promotes survival by providing energy for cytoskeletal remodeling and contractility as well as reducing equivalents to counter oxidative stress associated with cell detachment. Thus, exposure to FSS may provide CTCs an unexpected survival benefit that promotes metastatic colonization.

cancer biology↗

bioRxiv2025

Histone Lysine Crotonylation Regulates Long-Term Memory Storage

Histone post-translational modifications (PTMs), particularly lysine acetylation (Kac), are critical epigenetic regulators of transcriptional programs underlying long-term memory consolidation. Beyond Kac, several other non-acetyl acylations have been identified with the ability to regulate transcription; however, their role in memory consolidation remains unknown. Here, we identify histone lysine crotonylation (Kcr) as a molecular switch for long-term memory and glutamatergic neurotransmission. We find that spatial learning induces distinct spatiotemporal patterns of Kcr across hippocampal subregions, and that Kcr stimulates learning-induced gene expression. Through genetic and pharmacological manipulations, we show that reducing hippocampal Kcr levels impairs memory, while increasing Kcr enhances long-term memory. Single-nuclei transcriptome and chromatin accessibility analyses reveals that Kcr facilitates activation of genes regulating glutamate signaling. Cell-cell communication analysis further infers that Kcr enhancement strengthens glutamatergic signaling within principal hippocampal neurons. Real-time fluorescence imaging with genetically encoded sensors functionally validates our multiomics and computational findings--demonstrating the role of Kcr in regulating presynaptic glutamate release and neuronal activity. In summary, our findings elucidate a novel mechanism underlying long-term memory consolidation and excitatory neurotransmission, linking epigenetic events to synaptic function and behavior.

neuroscience↗

bioRxiv2024

The mitochondrial dicarboxylate carrier mediates in vivo hepatic gluconeogenesis

Hepatic gluconeogenesis (GNG) is essential for maintaining euglycemia during prolonged fasting. However, GNG becomes pathologically elevated and drives chronic hyperglycemia in type 2 diabetes (T2D). Lactate/pyruvate is a major GNG substrate known to be imported into mitochondria for GNG. Yet, the subsequent mitochondrial carbon export mechanisms required to supply the extra-mitochondrial canonical GNG pathway have not been genetically delineated. Here, we evaluated the role of the mitochondrial dicarboxylate carrier (DiC) in mediating GNG from lactate/pyruvate. We generated liver-specific DiC knockout (DiC LivKO) mice. During lactate/pyruvate tolerance tests, DiC LivKO decreased plasma glucose excursion and 13C-lactate/-pyruvate flux into hepatic and plasma glucose. In a Western diet (WD) feeding model of T2D, acute DiC LivKO after induction of obesity decreased lactate/pyruvate-driven GNG, hyperglycemia, and hyperinsulinemia. Our results show that mitochondrial carbon export through the DiC mediates GNG and that the DiC contributes to impaired glucose homeostasis in a mouse model of T2D.

biochemistry↗

bioRxiv2023

3-hydroxykynurenine is a ROS-inducing cytotoxic tryptophan metabolite that disrupts the TCA cycle

Tryptophan is an essential amino acid that is extensively characterized as a regulator of cellular function through its metabolism by indoleamine 2,3-deoxygenase (IDO) into the kynurenine pathway. However, despite decades of research on tryptophan metabolism, the metabolic regulatory roles of it and its metabolites are not well understood. To address this, we performed an activity metabolomics screen of tryptophan and most of its known metabolites in cell culture. We discovered that treatment of human colon cancer cells (HCT116) with 3-hydroxykynurenine (3-HK), a metabolite of kynurenine, potently disrupted TCA cycle function. Citrate and aconitate levels were increased, while isocitrate and all downstream TCA metabolites were decreased, suggesting decreased aconitase function. We hypothesized that 3HK or one of its metabolites increased reactive oxygen species (ROS) and inhibited aconitase activity. Accordingly, we observed almost complete depletion of reduced glutathione and a decrease in total glutathione levels. We observed a dose-dependent decrease in cell viability after 48 hours of 3HK treatment. These data suggest that raising the intracellular levels of 3HK could be sufficient to induce ROS-mediated apoptosis. We modulated the intracellular levels of 3HK by combined induction of IDO and knockdown of kynureninase (KYNU) in HCT116 cells. Cell viability decreased significantly after 48 hours of KYNU knockdown compared to controls, which was accompanied by increased ROS production and Annexin V staining revealing apoptosis. Finally, we identify xanthommatin production from 3-HK as a candidate radical-producing, cytotoxic mechanism. Our work indicates that KYNU may be a target for disrupting tryptophan metabolism. Interestingly, many cancers exhibit overexpression of IDO, providing a cancer-specific metabolic vulnerability that could be exploited by KYNU inhibition.

biochemistry↗

bioRxiv2023

Hepatic IRE1 Protects Against Septic Cardiac Failure

SUMMARYMetabolic reprogramming in response to infection plays a critical role for septic survival. During a septic episode, the heart heavily relies on hepatic lipid particles to prevent heart damage and failure. Inositol- Requiring Enzyme 1 (IRE1) is the most conserved unfolded protein response (UPR) regulator that governs homeostasis of the endoplasmic reticulum (ER), the major site for lipid synthesis and processing. Here we show that hepatocyte IRE1 is indispensable for protecting against septic mortality in two different rodent models of experimental sepsis. The protective effect of hepatic IRE1 was not attributed to the inflammatory response since hepatic IRE1 deletion did not alter hepatic or systemic cytokine response. However, loss of IRE1 in the liver significantly augmented septic cardiac dysfunction in part due to a skewed immune-metabolic balance. Lipidomic and metabolomic analyses further revealed that loss of IRE1 in the liver compromised adaptive intrahepatic and circulating lipid reprogramming, including VLDL, in response to septic challenge. Furthermore, we identified that the protective effects against septic mortality are mediated by a non-canonical IRE1-dependent mechanism. Together, our study provides the first insight into how a disruption of hepatic ER-mediated lipid metabolic regulation promotes sepsis-associated cardiac immuno-metabolic imbalance.

pathology↗

bioRxiv2023

Tubular Mitochondrial Pyruvate Carrier Disruption Elicits Redox Adaptations that Protect from Acute Kidney Injury

Energy-intensive kidney reabsorption processes essential for normal whole-body function are maintained by tubular epithelial cell metabolism. Tubular metabolism changes markedly following acute kidney injury (AKI), but which changes are adaptive versus maladaptive remain poorly understood. In publicly available data sets, we noticed a consistent downregulation of the mitochondrial pyruvate carrier (MPC) after AKI, which we experimentally confirmed. To test the functional consequences of MPC downregulation, we generated novel tubular epithelial cell-specific Mpc1 knockout (MPC TubKO) mice. 13C-glucose tracing, steady-state metabolomic profiling, and enzymatic activity assays revealed that MPC TubKO coordinately increased activities of the pentose phosphate pathway and the glutathione and thioredoxin oxidant defense systems. Following rhabdomyolysis-induced AKI, MPC TubKO decreased markers of kidney injury and oxidative damage and strikingly increased survival. Our findings suggest that decreased mitochondrial pyruvate uptake is a central adaptive response following AKI and raise the possibility of therapeutically modulating the MPC to attenuate AKI severity.

biochemistry↗

bioRxiv2023

Mitochondrial citrate metabolism and efflux regulates trophoblast differentiation

Cytotrophoblasts fuse to form and renew syncytiotrophoblasts necessary to maintain placental health throughout gestation. During cytotrophoblast to syncytiotrophoblast differentiation, cells undergo regulated metabolic and transcriptional reprogramming. Mitochondria play a critical role in differentiation events in cellular systems, thus we hypothesized that mitochondrial metabolism played a central role in trophoblast differentiation. In this work, we employed static and stable isotope tracing untargeted metabolomics methods along with gene expression and histone acetylation studies in an established cell culture model of trophoblast differentiation. Trophoblast differentiation was associated with increased abundance of the TCA cycle intermediates citrate and -ketoglutarate. Citrate was preferentially exported from mitochondria in the undifferentiated state but was retained to a larger extent within mitochondria upon differentiation. Correspondingly, differentiation was associated with decreased expression of the mitochondrial citrate transporter (CIC). CRISPR/Cas9 disruption of the mitochondrial citrate carrier showed that CIC is required for biochemical differentiation of trophoblasts. Loss of CIC resulted in broad alterations in gene expression and histone acetylation. These gene expression changes were partially rescued through acetate supplementation. Taken together, these results highlight a central role for mitochondrial citrate metabolism in orchestrating histone acetylation and gene expression during trophoblast differentiation.

developmental biology↗

bioRxiv2022

Phosphatidylethanolamine facilitates mitochondrial pyruvate entry to regulate metabolic flexibility

Carbohydrates and lipids provide the majority of substrates to fuel mitochondrial oxidative phosphorylation (OXPHOS). Metabolic inflexibility, defined as an impaired ability to switch between these fuels, is implicated in a number of metabolic diseases. Here we explore the mechanism by which physical inactivity promotes metabolic inflexibility in skeletal muscle. We developed a mouse model of sedentariness by small mouse cage (SMC) that, unlike other classic models of disuse in mice, faithfully recapitulates metabolic responses that occur in humans. Bioenergetic phenotyping of mitochondria displayed metabolic inflexibility induced by physical inactivity, demonstrated by a reduction in pyruvate-stimulated respiration (JO2) in absence of a change in palmitate-stimulated JO2. Pyruvate resistance in these mitochondria was likely driven by a decrease in phosphatidylethanolamine (PE) abundance in the mitochondrial membrane. Reduction in mitochondrial PE by deletion of phosphatidylserine decarboxylase (PSD) was sufficient to induce metabolic inflexibility measured at the whole-body level, as well as at the level of skeletal muscle mitochondria. Low mitochondrial PE was sufficient to increase glucose flux towards lactate. We further implicate that resistance to pyruvate metabolism is due to attenuated mitochondrial entry via mitochondrial pyruvate carrier (MPC). These findings suggest a novel mechanism by which mitochondrial PE directly regulates MPC activity to modulate metabolic flexibility.

physiology↗

bioRxiv2022

Mouse tissue harvest-induced hypoxia rapidly alters the in vivo metabolome, between-genotype metabolite level differences, and 13C-tracing enrichments

Metabolism is potently regulated by oxygen as the terminal acceptor of the electron transport chain. Thus, a challenge for capturing the in vivo metabolome of animal tissues is to achieve rapid freezing after dissection-induced loss of perfusion before the onset of hypoxia-driven metabolomic remodeling. However, the timing of the metabolomic changes elicited by post-dissection freezing delays are not well described. We addressed this problem by carefully and systematically assessing broad, genotype-specific, and 13C isotopologue metabolomic change resulting from post-dissection, ex vivo mouse tissue metabolism. Based on experiments with mouse liver, heart muscle, and skeletal muscle, we show that broad metabolomic change is rapid, that both false negative and false positive between genotype differences are induced, and that 13C-isotopologue abundances and enrichment percentages change with post-dissection hypoxia. These findings provide a previously absent, systematic illustration of the extensive and confounding metabolomic changes occurring within the early minutes of delayed tissue freezing.

biochemistry↗

bioRxiv2021

Large1 Gene Transfer in Older myd Mice with Severe Muscular Dystrophy Restores Muscle Function and Greatly Improves Survival

Muscular dystrophy is a progressive and ultimately lethal neuromuscular disease due to lack of therapeutic options that restore muscle function. Gene editing and gene transfer hold great promise as therapies for various neuromuscular diseases when administered prior to the onset of severe clinical symptoms. However, the efficacy of these strategies for restoring neuromuscular function and improving survival in the late stages of muscular dystrophy with severe muscle pathophysiology is unknown. Dystroglycanopathies are muscular dystrophies characterized by extensive skeletal muscle degeneration and, in many cases, are accompanied by eye and brain abnormalities. Thus far, mutations in at least eighteen human genes are known to cause dystroglycanopathies, including those in the like-acetylglucosaminyltransferase-1 (LARGE1) gene. LARGE1 encodes a xylosyl- and glucuronosyltransferase that modifies -dystroglycan (-DG) with matriglycan, a linear repeating disaccharide of alternating xylose and glucuronic acid that binds to the laminin G-like domains of extracellular matrix proteins with high affinity. Largemyd/Largemyd (myd) mice lack expression of Large1, and exhibit severe skeletal muscle pathophysiology, impaired mobility, and a drastically reduced lifespan (50% survivorship at 35 weeks of age). Here, we show that systemic delivery of AAV2/9 CMV Large1 (AAVLarge1) in >34-week-old myd mice with advanced disease restores matriglycan expression, attenuates skeletal muscle pathophysiology, improves motor and respiratory function, and normalizes systemic metabolism, which collectively and dramatically extends survival. Our results demonstrate that in a mouse model of muscular dystrophy, skeletal muscle function can be restored, illustrating its remarkable plasticity, and that survival can be greatly improved even after the onset of severe skeletal muscle pathophysiology.

physiology↗

bioRxiv2021

Small molecule SWELL1-LRRC8 complex induction improves glycemic control and nonalcoholic fatty liver disease in murine Type 2 diabetes

Type 2 diabetes (T2D) is associated with insulin resistance, impaired insulin secretion from the pancreatic {beta}-cell, and nonalcoholic fatty liver disease (NAFLD). SWELL1 (LRRC8a) ablation impairs adipose and skeletal muscle insulin-pAKT2 signaling, {beta}-cell insulin secretion and glycemic control - suggesting that SWELL1-LRRC8 complex dysfunction contributes to T2D pathogenesis. Here, we show that ICl,SWELL and SWELL1 protein are reduced in adipose and {beta}-cells in murine and human T2D. Combining cryo-electron microscopy, molecular docking, medicinal chemistry, and functional studies, we define a structure activity relationship to rationally-designed active derivatives (SN-40X) of a SWELL1 channel inhibitor (DCPIB/SN-401), that bind the SWELL1-LRRC8 hexameric complex, restore SWELL1-LRRC8 protein, plasma membrane trafficking, signaling and islet insulin secretion via SWELL1-dependent mechanisms. In vivo, SN-401 and active SN-40X compounds restore glycemic control and prevents NAFLD by improving insulin-sensitivity and insulin secretion in murine T2D. These findings demonstrate that small molecule SWELL1 modulators restore SWELL1-dependent insulin-sensitivity and insulin secretion in T2D and may represent a first-in-class therapeutic approach for T2D and NAFLD.

physiology↗

bioRxiv2019

NADPH and glutathione redox link TCA cycle activity to endoplasmic reticulum stress

Endoplasmic reticulum (ER) stress is associated with dysregulated metabolism, but little is known about how the ER responds to metabolic activity. Here, working primarily in mouse hepatocytes, we show that decreasing the availability of substrate for the TCA cycle diminished NADPH production and attenuated ER stress in a manner that depended on glutathione oxidation. ER stress was also alleviated by impairing either TCA-dependent NADPH production or Glutathione Reductase. Conversely, stimulating TCA activity favored NADPH production, glutathione reduction, and ER stress. Validating these findings, we show that deletion of the mitochondrial pyruvate carrier, which is known to decrease TCA cycle activity and protect the liver from diet-induced injury, also diminished NADPH, elevated glutathione oxidation, and alleviated ER stress. These results provide independent genetic evidence that mitochondrial oxidative metabolism is linked to ER homeostasis. Our results demonstrate a novel pathway of communication between mitochondria and the ER, through relay of redox metabolites.

cell biology↗