Publications by authors named "Edward D Karoly"

Article Synopsis
  • N-lactoyl-phenylalanine (Lac-Phe) is a substance that helps control how much food we eat and can lower body weight.
  • Scientists found two specific proteins, SLC17A1 and SLC17A3, in the kidneys that help move Lac-Phe out of the body through urine.
  • Research in both humans and mice shows that these proteins are important for getting rid of Lac-Phe in urine, but they don't affect the amount of Lac-Phe in the blood or body weight.
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N-lactoyl-phenylalanine (Lac-Phe) is a lactate-derived metabolite that suppresses food intake and body weight. Little is known about the mechanisms that mediate Lac-Phe transport across cell membranes. Here we identify SLC17A1 and SLC17A3, two kidney-restricted plasma membrane-localized solute carriers, as physiologic urine Lac-Phe transporters.

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Article Synopsis
  • * In a study of nearly 2,000 metabolites, researchers found significant associations that would have been missed if only plasma was analyzed, highlighting urine's unique contributions.
  • * Key findings include urine-specific mechanisms like glycerol transport and genetic links to metabolic diseases, emphasizing that examining metabolites in both plasma and urine offers deeper insights into kidney function and related health issues.
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Metabolites are small products of metabolism that provide a snapshot of the wellbeing of an organism and the mechanisms that control key physiological processes involved in health and disease. Here we report the results of a genome-wide association study of 722 circulating metabolite levels in 8809 subjects of European origin, providing both breadth and depth. These analyses identified 202 unique genomic regions whose variations are associated with the circulating levels of 478 different metabolites.

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Background: Polypharmacy is common among patients with CKD, but little is known about the urinary excretion of many drugs and their metabolites among patients with CKD.

Methods: To evaluate self-reported medication use in relation to urine drug metabolite levels in a large cohort of patients with CKD, the German Chronic Kidney Disease study, we ascertained self-reported use of 158 substances and 41 medication groups, and coded active ingredients according to the Anatomical Therapeutic Chemical Classification System. We used a nontargeted mass spectrometry-based approach to quantify metabolites in urine; calculated specificity, sensitivity, and accuracy of medication use and corresponding metabolite measurements; and used multivariable regression models to evaluate associations and prescription patterns.

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Understanding the mechanisms for cellular aging is a fundamental question in biology. Normal red blood cells (RBCs) survive for approximately 100 days, and their survival is likely limited by functional decline secondary to cumulative damage to cell constituents, which may be reflected in altered metabolic capabilities. To investigate metabolic changes during RBC aging, labeled cell populations were purified at intervals and assessed for abundance of metabolic intermediates using mass spectrometry.

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The influence of maternal high-fat diet (HFD) on metabolic response to ozone was examined in Long-Evans rat offspring. F0 females were fed control diet (CD; 10%kcal from fat) or HFD (60%kcal from fat) starting at post-natal day (PND) 30. Rats were bred on PND 72.

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Article Synopsis
  • Increased consumption of saturated fat and obesity are linked to a higher risk of prostate cancer progression and mortality, but the reasons behind this connection are not well understood.* -
  • Research using a mouse model shows that a high-fat diet enhances the MYC gene's activity, promoting tumor growth by altering metabolism and reducing certain histone modifications.* -
  • A shift from a high-fat diet to a low-fat one can reduce the aggressive MYC signature in tumors, suggesting dietary changes could be a potential treatment strategy for prostate cancer.*
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Ozone is an asthma trigger. In mice, the gut microbiome contributes to ozone-induced airway hyperresponsiveness, a defining feature of asthma, but the mechanistic basis for the role of the gut microbiome has not been established. Gut bacteria can affect the function of distal organs by generating metabolites that enter the blood and circulate systemically.

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Article Synopsis
  • Ozone exposure leads to decreased lung function and inflammation, with increased neutrophils and proinflammatory cytokines indicating a negative impact on the lungs.
  • A study was conducted with healthy volunteers exposed to ozone and filtered air, revealing significant changes in metabolites in bronchoalveolar lavage fluid (BALF) collected at 1 and 24 hours post-exposure.
  • At 1 hour, metabolic changes suggested immediate responses to oxidative stress, while at 24 hours, increased metabolites indicated processes related to tissue repair, highlighting the utility of metabolomic analysis in understanding ozone's pulmonary effects.
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Hotspot mutations in the isocitrate dehydrogenase 1 () gene occur in a number of human cancers and confer a neomorphic enzyme activity that catalyzes the conversion of α-ketoglutarate (αKG) to the oncometabolite D-(2)-hydroxyglutarate (D2HG). In malignant gliomas, IDH1 expression induces widespread metabolic reprogramming, possibly requiring compensatory mechanisms to sustain the normal biosynthetic requirements of actively proliferating tumor cells. We used genetically engineered mouse models of glioma and quantitative metabolomics to investigate IDH1-dependent metabolic reprogramming and its potential to induce biosynthetic liabilities that can be exploited for glioma therapy.

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Malignant glioma is one of the most lethal adult cancers, yet its etiology remains largely unknown. We conducted a prospective serum metabolomic analysis of glioma based on 64 cases and 64 matched controls selected from Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study. Median time from collection of baseline fasting serum to diagnosis was nine years (inter-decile range 3-20 years).

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Pulmonary responses to the air pollutant, ozone, are increased in obesity. Both obesity and ozone cause changes in systemic metabolism. Consequently, we examined the impact of ozone on the lung metabolomes of obese and lean mice.

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Two recent investigations found serum lipid and energy metabolites related to aggressive prostate cancer up to 20 years prior to diagnosis. To elucidate whether those metabolomic profiles represent etiologic or tumor biomarker signals, we prospectively examined serum metabolites of prostate cancer cases by size and extent of primary tumors in a nested case-control analysis in the ATBC Study cohort that compared cases diagnosed with T2 (n = 71), T3 (n = 51), or T4 (n = 15) disease to controls (n = 200). Time from fasting serum collection to diagnosis averaged 10 years (range 1-20).

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Cellular senescence occurs by proliferative exhaustion (PEsen) or following multiple cellular stresses but had not previously been subject to detailed metabolomic analysis. Therefore, we compared PEsen fibroblasts with proliferating and transiently growth arrested controls using a combination of different mass spectroscopy techniques. PEsen cells showed many specific alterations in both the NAD+ de novo and salvage pathways including striking accumulations of nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR) in the amidated salvage pathway despite no increase in nicotinamide phosphoribosyl transferase or in the NR transport protein, CD73.

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Article Synopsis
  • Higher levels of branched-chain amino acids (BCAAs) like isoleucine, leucine, and valine are linked to an increased risk of type 2 diabetes, suggesting a need to explore if this relationship is causal.
  • A comprehensive genetic analysis of nearly 17,000 individuals identified key genomic regions associated with BCAA levels, particularly a strong association near the PPM1K gene, which plays a role in BCAA metabolism.
  • In a larger analysis involving nearly 48,000 diabetes cases and 267,000 controls, genetically predicted higher BCAA levels correlated with significantly increased odds of developing type 2 diabetes, supporting the premise that higher BCAAs may contribute to diabetes risk, though limitations in
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. The Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, a randomized controlled cancer prevention trial, showed a 32% reduction in prostate cancer incidence in response to vitamin E supplementation. Two other trials were not confirmatory, however.

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Treatment with celecoxib, a selective COX-2 inhibitor, reduces formation of premalignant adenomatous polyps in the gastrointestinal tracts of humans and mice. In addition to its chemopreventive activity, celecoxib can exhibit antimicrobial activity. Differing bacterial profiles have been found in feces from colon cancer patients compared with those of normal subjects.

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Rationale: Air pollution has been associated with increased prevalence of type 2 diabetes; however, the mechanisms remain unknown. We have shown that acute ozone exposure in rats induces release of stress hormones, hyperglycemia, leptinemia, and glucose intolerance that are associated with global changes in peripheral glucose, lipid, and amino acid metabolism.

Objectives: To examine ozone-induced metabolic derangement in humans using serum metabolomic assessment, establish human-to-rodent coherence, and identify novel nonprotein biomarkers.

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Background: Dates are tropical fruits with appreciable nutritional value. Previous attempts at global metabolic characterization of the date metabolome were constrained by small sample size and limited geographical sampling. In this study, two independent large cohorts of mature dates exhibiting substantial diversity in origin, varieties and fruit processing conditions were measured by metabolomics techniques in order to identify major determinants of the fruit metabolome.

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Background: In this era of precision medicine, the deep and comprehensive characterization of tumor phenotypes will lead to therapeutic strategies beyond classical factors such as primary sites or anatomical staging. Recently, "-omics" approached have enlightened our knowledge of tumor biology. Such approaches have been extensively implemented in order to provide biomarkers for monitoring of the disease as well as to improve readouts of therapeutic impact.

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Aims/hypothesis: Metabolomics has opened new avenues for studying metabolic alterations in type 2 diabetes. While many urine and blood metabolites have been associated individually with diabetes, a complete systems view analysis of metabolic dysregulations across multiple biofluids and over varying timescales of glycaemic control is still lacking.

Methods: Here we report a broad metabolomics study in a clinical setting, covering 2,178 metabolite measures in saliva, blood plasma and urine from 188 individuals with diabetes and 181 controls of Arab and Asian descent.

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Noninvasive diagnosis and prognostication of acute cellular rejection in the kidney allograft may help realize the full benefits of kidney transplantation. To investigate whether urine metabolites predict kidney allograft status, we determined levels of 749 metabolites in 1516 urine samples from 241 kidney graft recipients enrolled in the prospective multicenter Clinical Trials in Organ Transplantation-04 study. A metabolite signature of the ratio of 3-sialyllactose to xanthosine in biopsy specimen-matched urine supernatants best discriminated acute cellular rejection biopsy specimens from specimens without rejection.

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