Publications by authors named "Travis Nemkov"

Caffeine is the most widely consumed psychoactive substance globally, yet its peripheral physiological effects remain incompletely understood. Leveraging comprehensive data from 13,091 blood donors in the REDS RBC-Omics study, we identify caffeine as a significant modulator of red blood cell (RBC) storage quality and transfusion outcomes. Elevated caffeine levels were reproducible across multiple donations from 643 recalled donors, selected based on their extremes in hemolytic propensity.

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Glucose-6-phosphate dehydrogenase (G6PD) deficiency, the most common enzymatic disorder, affects over 500 million people worldwide and is often linked to exercise intolerance due to oxidative stress, but its true impact on physical performance remains unclear. This study aimed to evaluate the physiological and metabolic effects of G6PD deficiency on endurance capacity. Using humanized mice carrying the African G6PD variant [V68M; N126D] (hG6PD), we show that despite reduced pentose phosphate pathway activity, these mice exhibit a 10.

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Background: Diabetic ketoacidosis is an acute, potentially life-threatening, metabolic complication and often first presentation of type 1 diabetes (T1D) mellitus. Here, we investigated the metabolic and lipid profiles from pediatric patients with T1D, at initial diagnosis and after two weeks of insulin treatment, employing findings from patients affected by maple syrup urine disease (MSUD) and the Recipient Epidemiology and Donor Evaluation Study (REDS) III RBC Omics.

Methods: 27 patients with newly onset T1D were assessed at the University of Campania "L.

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Unlabelled: Caffeine is the most widely consumed psychoactive substance globally, yet its peripheral physiological effects remain incompletely understood. Leveraging comprehensive data from 13,091 blood donors in the REDS RBC-Omics study, we identify caffeine as a significant modulator of red blood cell (RBC) storage quality and transfusion outcomes. Elevated caffeine levels were reproducible across multiple donations from 643 recalled donors, selected based on their extremes in hemolytic propensity.

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Platelets play a dual role in hemostasis and inflammation-associated thrombosis and hemorrhage. Although the mechanisms linking inflammation to platelet dysfunction remain poorly understood, our previous work demonstrated that TNF-α alters mitochondrial mass, platelet activation, and autophagy-related pathways in megakaryocytes. Here, we hypothesized that TNF-α impairs platelet function by disrupting autophagy, a process critical for mitochondrial health and cellular metabolism.

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Mitochondrial DNA (mtDNA) shares characteristics with bacterial DNA and activates immune cells via TLR9Extracellular vesicles (EVs) and mtDNA have been found in blood products and can activate immune cells; we sought to characterize their evolution in stored blood products. From a previous study of hemolysis in 13,403 blood donors, a second blood unit was drawn from 651 donors and sampled at days 10, 21, and 42. EV counts and RBC-EVs increased with storage time, and EV levels were higher in males and in RBC units processed in AS-1 compared with AS-3.

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D-2-hydroxyglutarate (D-2HG) is a potent oncometabolite capable of disrupting chromatin architecture, altering metabolism, and promoting cellular dedifferentiation. As a result, ectopic D-2HG accumulation induces neurometabolic disorders and promotes progression of multiple cancers. However, the disease-associated effects of ectopic D-2HG accumulation are dependent on genetic context.

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Background: Lung cancer is the leading cause of cancer death in the world. While cigarette smoking is the major preventable factor for cancers in general and lung cancer in particular, old age is also a major risk factor. Aging-related chronic, low-level inflammation, termed inflammaging, has been widely documented; however, it remains unclear how inflammaging contributes to increased lung cancer incidence.

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Drosophila larval growth requires efficient conversion of dietary nutrients into biomass. Lactate dehydrogenase (Ldh) and glycerol-3-phosphate dehydrogenase (Gpdh1) support this larval metabolic program by cooperatively promoting glycolytic flux. Consistent with their cooperative functions, the loss of both enzymes, but not either single enzyme alone, induces a developmental arrest.

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Unlabelled: Ultra-endurance exercise places extreme physiological demands on oxygen transport, yet its impact on red blood cells (RBCs) remains underexplored. We conducted a multi-omics analysis of plasma and RBCs from endurance athletes before and after a 40-km trail race (MCC) and a 171-km ultramarathon (UTMB ). Ultra-running led to oxidative stress, metabolic shifts, and inflammation-driven RBC damage, including increased acylcarnitines, kynurenine accumulation, oxidative lipid and protein modifications, reduced RBC deformability, enhanced microparticle release, and increased senescence markers such as externalized phosphatidylserine (PS).

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Short-lived effector cells are characterized metabolically by a highly glycolytic state, driving energy and biomass acquisition, whereas memory-fated T cells have historically been described as meeting these requirements through mitochondrial metabolism. Here, we show that the mitochondrial protein optic atrophy 1 (OPA1) is critical for rapidly dividing CD8 T cells in vivo, the requirement for which is most pronounced in effector CD8 T cells. More specifically, OPA1 supports proper cell cycle initiation and progression and the viability and survival of CD8 T cells during clonal expansion.

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D-2-hydroxyglutarate (D-2HG) is a potent oncometabolite capable of disrupting chromatin architecture, altering metabolism, and promoting cellular dedifferentiation. As a result, ectopic D-2HG accumulation induces neurometabolic disorders and promotes progression of multiple cancers. However, the disease-associated effects of ectopic D-2HG accumulation are dependent on genetic context.

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Red blood cells (RBCs) transport oxygen but accumulate oxidative damage over time, reducing function in vivo and during storage-critical for transfusions. To explore genetic influences on RBC resilience, we profiled proteins, metabolites, and lipids from fresh and stored RBCs obtained from 350 genetically diverse mice. Our analysis identified over 6,000 quantitative trait loci (QTL).

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Red blood cell (RBC) transfusion, a life-saving intervention, is limited by reduced RBC potency over time. Cold storage at +4 °C for up to 42 days can reduce transfusion efficacy due to alterations termed the "storage lesion." Strategies to mitigate the storage lesion include alkaline additive solutions and supercooled storage to extend storage by reducing metabolic stresses.

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Background: Previous studies have primarily focused on nucleos(t)ide reverse transcriptase inhibitor pharmacology in peripheral blood mononuclear cells (PBMCs) and erythrocytes via dried blood spots (DBS), but not other major blood cells.

Objectives: Our objectives were to describe and compare the concentrations of tenofovir-diphosphate (TFV-DP) and emtricitabine-triphosphate (FTC-TP) in DBS, PBMCs, neutrophils, and platelets in people with HIV (PWH) and people without HIV (PWOH).

Methods: DBS, PBMCs, neutrophils, and platelets were isolated from whole blood drawn from PWH and PWOH receiving tenofovir alafenamide and emtricitabine.

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Objectives: The rapid growth that occurs during Drosophila larval development requires a dramatic rewiring of central carbon metabolism to support biosynthesis. Larvae achieve this metabolic state, in part, by coordinately up-regulating the expression of genes involved in carbohydrate metabolism. The resulting metabolic program exhibits hallmark characteristics of aerobic glycolysis and establishes a physiological state that supports growth.

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The rapid growth that occurs during larval development requires a dramatic rewiring of central carbon metabolism to support biosynthesis. Larvae achieve this metabolic state, in part, by coordinately up-regulating the expression of genes involved in carbohydrate metabolism. The resulting metabolic program exhibits hallmark characteristics of aerobic glycolysis and establishes a physiological state that supports growth.

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Background: Storage of packed red blood cells (RBCs) for transfusion leads to biochemical and morphological changes, increasing hemolysis risk. Urate levels in blood bags at donation contribute to the molecular heterogeneity and hemolytic propensity of stored RBCs. However, studies to date have been underpowered to investigate at scale the contribution of donor demographics and genetics to the heterogeneity in urate levels across donations.

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Purpose: The development of endocrine resistance remains a significant challenge in the clinical management of estrogen receptor-positive () breast cancer. Metabolic reprogramming is a prominent component of endocrine resistance and a potential therapeutic intervention point. However, a limited understanding of which metabolic changes are conserved across the heterogeneous landscape of ER+ breast cancer or how metabolic changes factor into ER DNA binding patterns hinder our ability to target metabolic adaptation as a treatment strategy.

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Background: Pulmonary arterial hypertension (PAH) is a rare but severe and life-threatening condition that primarily affects the pulmonary blood vessels and the right ventricle of the heart. The limited availability of human tissue for research ~most of which represents only end-stage disease~ has led to a reliance on preclinical animal models. However, these models often fail to capture the heterogeneity and complexity of the human condition.

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Streptococcus pneumoniae (S. pneumoniae) employs various metabolic pathways to generate nicotinamide adenine dinucleotide phosphate (NADPH), which is essential for redox balance, fatty acid synthesis, and energy production. GAPN, a non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase, plays a role in this process by directly reducing NADP to NADPH, effectively contributing to glucose metabolism.

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Background: Pathogen reduction technology (PRT)-treated apheresis platelets (APs) were returned without platelet swirl and with pH < 6.2. The platelet donor was taking prescription levothyroxine and metformin plus over-the-counter medications and supplements.

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Red blood cell (RBC) metabolism regulates hemolysis during aging in vivo and in the blood bank. However, the genetic underpinnings of RBC metabolic heterogeneity and extravascular hemolysis at population scale are incompletely understood. On the basis of the breeding of 8 founder strains with extreme genetic diversity, the Jackson Laboratory diversity outbred population can capture the impact of genetic heterogeneity in like manner to population-based studies.

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Article Synopsis
  • - Glucose-6-phosphate dehydrogenase (G6PD) deficiency, affecting 500 million people, impairs red blood cell antioxidant functions, raising the risk of hemolysis during oxidative stress, particularly during exercise.
  • - A study using mice with a specific G6PD variant showed that, despite lower enzyme activity, these mice had better exercise performance and improved heart function post-exercise compared to normal mice.
  • - Analysis revealed enhanced mitochondrial function and changes in energy metabolism and protein turnover, indicating that G6PD-deficient individuals might have a metabolic advantage during exercise, challenging existing beliefs about hemolytic risks.
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