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  • Academic
    alantung@stanford.edu
    University - Student Department: School of Medicine - IDP's - Cancer Biology Position: Graduate

All Publications

  • SLC17A1/3 transporters mediate renal excretion of Lac-Phe in mice and humans. Nature communications Li, V. L., Xiao, S., Schlosser, P., Scherer, N., Wiggenhorn, A. L., Spaas, J., Tung, A. S., Karoly, E. D., Köttgen, A., Long, J. Z. 2024; 15 (1): 6895

    Abstract

    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. In cell culture, SLC17A1/3 exhibit high Lac-Phe efflux activity. In humans, levels of Lac-Phe in urine exhibit a strong genetic association with the SLC17A1-4 locus. Urine Lac-Phe levels are increased following a Wingate sprint test. In mice, genetic ablation of either SLC17A1 or SLC17A3 reduces urine Lac-Phe levels. Despite these differences, both knockout strains have normal blood Lac-Phe and body weights, demonstrating SLC17A1/3-dependent de-coupling of urine and plasma Lac-Phe pools. Together, these data establish SLC17A1/3 family members as the physiologic urine Lac-Phe transporters and uncover a biochemical pathway for the renal excretion of this signaling metabolite.

    View details for DOI 10.1038/s41467-024-51174-3

    View details for PubMedID 39134528

    View details for PubMedCentralID 7983055

  • Lac-Phe mediates the effects of metformin on food intake and body weight. Nature metabolism Xiao, S., Li, V. L., Lyu, X., Chen, X., Wei, W., Abbasi, F., Knowles, J. W., Tung, A. S., Deng, S., Tiwari, G., Shi, X., Zheng, S., Farrell, L., Chen, Z. Z., Taylor, K. D., Guo, X., Goodarzi, M. O., Wood, A. C., Chen, Y. I., Lange, L. A., Rich, S. S., Rotter, J. I., Clish, C. B., Tahir, U. A., Gerszten, R. E., Benson, M. D., Long, J. Z. 2024

    Abstract

    Metformin is a widely prescribed anti-diabetic medicine that also reduces body weight. There is ongoing debate about the mechanisms that mediate metformin's effects on energy balance. Here, we show that metformin is a powerful pharmacological inducer of the anorexigenic metabolite N-lactoyl-phenylalanine (Lac-Phe) in cells, in mice and two independent human cohorts. Metformin drives Lac-Phe biosynthesis through the inhibition of complex I, increased glycolytic flux and intracellular lactate mass action. Intestinal epithelial CNDP2+ cells, not macrophages, are the principal in vivo source of basal and metformin-inducible Lac-Phe. Genetic ablation of Lac-Phe biosynthesis in male mice renders animals resistant to the effects of metformin on food intake and body weight. Lastly, mediation analyses support a role for Lac-Phe as a downstream effector of metformin's effects on body mass index in participants of a large population-based observational cohort, the Multi-Ethnic Study of Atherosclerosis. Together, these data establish Lac-Phe as a critical mediator of the body weight-lowering effects of metformin.

    View details for DOI 10.1038/s42255-024-00999-9

    View details for PubMedID 38499766

    View details for PubMedCentralID 6829283

  • Organism-wide, cell-type-specific secretome mapping of exercise training in mice. Cell metabolism Wei, W., Riley, N. M., Lyu, X., Shen, X., Guo, J., Raun, S. H., Zhao, M., Moya-Garzon, M. D., Basu, H., Sheng-Hwa Tung, A., Li, V. L., Huang, W., Wiggenhorn, A. L., Svensson, K. J., Snyder, M. P., Bertozzi, C. R., Long, J. Z. 2023

    Abstract

    There is a significant interest in identifying blood-borne factors that mediate tissue crosstalk and function as molecular effectors of physical activity. Although past studies have focused on an individual molecule or cell type, the organism-wide secretome response to physical activity has not been evaluated. Here, we use a cell-type-specific proteomic approach to generate a 21-cell-type, 10-tissue map of exercise training-regulated secretomes in mice. Our dataset identifies >200 exercise training-regulated cell-type-secreted protein pairs, the majority of which have not been previously reported. Pdgfra-cre-labeled secretomes were the most responsive to exercise training. Finally, we show anti-obesity, anti-diabetic, and exercise performance-enhancing activities for proteoforms of intracellular carboxylesterases whose secretion from the liver is induced by exercise training.

    View details for DOI 10.1016/j.cmet.2023.04.011

    View details for PubMedID 37141889

  • An exercise-inducible metabolite that suppresses feeding and obesity. Nature Li, V. L., He, Y., Contrepois, K., Liu, H., Kim, J. T., Wiggenhorn, A. L., Tanzo, J. T., Tung, A. S., Lyu, X., Zushin, P. H., Jansen, R. S., Michael, B., Loh, K. Y., Yang, A. C., Carl, C. S., Voldstedlund, C. T., Wei, W., Terrell, S. M., Moeller, B. C., Arthur, R. M., Wallis, G. A., van de Wetering, K., Stahl, A., Kiens, B., Richter, E. A., Banik, S. M., Snyder, M. P., Xu, Y., Long, J. Z. 2022

    Abstract

    Exercise confers protection against obesity, type 2 diabetes and other cardiometabolic diseases1-5. However, the molecular and cellular mechanisms that mediate the metabolic benefits of physical activity remain unclear6. Here we show that exercise stimulates the production of N-lactoyl-phenylalanine (Lac-Phe), a blood-borne signalling metabolite that suppresses feeding and obesity. The biosynthesis of Lac-Phe from lactate and phenylalanine occurs in CNDP2+ cells, including macrophages, monocytes and other immune and epithelial cells localized to diverse organs. In diet-induced obese mice, pharmacological-mediated increases in Lac-Phe reduces food intake without affecting movement or energy expenditure. Chronic administration of Lac-Phe decreases adiposity and body weight and improves glucose homeostasis. Conversely, genetic ablation of Lac-Phe biosynthesis in mice increases food intake and obesity following exercise training. Last, large activity-inducible increases in circulating Lac-Phe are also observed in humans and racehorses, establishing this metabolite as a molecular effector associated with physical activity across multiple activity modalities and mammalian species. These data define a conserved exercise-inducible metabolite that controls food intake and influences systemic energy balance.

    View details for DOI 10.1038/s41586-022-04828-5

    View details for PubMedID 35705806