Shuke Xiao

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

• PTER is a N-acetyltaurine hydrolase that regulates feeding and obesity. Nature Wei, W., Lyu, X., Markhard, A. L., Fu, S., Mardjuki, R. E., Cavanagh, P. E., Zeng, X., Rajniak, J., Lu, N., Xiao, S., Zhao, M., Moya-Garzon, M. D., Truong, S. D., Chou, J. C., Wat, L. W., Chidambaranathan-Reghupaty, S., Coassolo, L., Xu, D., Shen, F., Huang, W., Ramirez, C. B., Jang, C., Li, L., Svensson, K. J., Fischbach, M. A., Long, J. Z. 2024

  Abstract

  Taurine is a conditionally essential micronutrient and one of the most abundant amino acids in humans1-3. In endogenous taurine metabolism, dedicated enzymes are involved in the biosynthesis of taurine from cysteine and in the downstream metabolism of secondary taurine metabolites4,5. One taurine metabolite is N-acetyltaurine6. Levels of N-acetyltaurine are dynamically regulated by stimuli that alter taurine or acetate flux, including endurance exercise7, dietary taurine supplementation8 and alcohol consumption6,9. So far, the identities of the enzymes involved in N-acetyltaurine metabolism, and the potential functions of N-acetyltaurine itself, have remained unknown. Here we show that the body mass index associated orphan enzyme phosphotriesterase-related (PTER)10 is a physiological N-acetyltaurine hydrolase. In vitro, PTER catalyses the hydrolysis of N-acetyltaurine to taurine and acetate. In mice, PTER is expressed in the kidney, liver and brainstem. Genetic ablation of Pter in mice results in complete loss of tissue N-acetyltaurine hydrolysis activity and a systemic increase in N-acetyltaurine levels. After stimuli that increase taurine levels, Pter knockout mice exhibit reduced food intake, resistance to diet-induced obesity and improved glucose homeostasis. Administration of N-acetyltaurine to obese wild-type mice also reduces food intake and body weight in a GFRAL-dependent manner. These data place PTER into a central enzymatic node of secondary taurine metabolism and uncover a role for PTER and N-acetyltaurine in body weight control and energy balance.

  View details for DOI 10.1038/s41586-024-07801-6

  View details for PubMedID 39112712

  View details for PubMedCentralID 3501277

• Lac-Phe (N-lactoyl-phenylalanine). Trends in endocrinology and metabolism: TEM Xiao, S., Li, V. L., Long, J. Z. 2024; 35 (8): 758-759

  View details for DOI 10.1016/j.tem.2024.05.007

  View details for PubMedID 39137723

• A PTER-dependent pathway of taurine metabolism linked to energy balance. bioRxiv : the preprint server for biology Wei, W., Lyu, X., Markhard, A. L., Fu, S., Mardjuki, R. E., Cavanagh, P. E., Zeng, X., Rajniak, J., Lu, N., Xiao, S., Zhao, M., Moya-Garzon, M. D., Truong, S. D., Chou, J. C., Wat, L. W., Chidambaranathan-Reghupaty, S., Coassolo, L., Xu, D., Shen, F., Huang, W., Ramirez, C. B., Jang, C., Svensson, K. J., Fischbach, M. A., Long, J. Z. 2024

  Abstract

  Taurine is a conditionally essential micronutrient and one of the most abundant amino acids in humans1-3. In endogenous taurine metabolism, dedicated enzymes are involved in biosynthesis of taurine from cysteine as well as the downstream derivatization of taurine into secondary taurine metabolites4,5. One such taurine metabolite is N-acetyltaurine6. Levels of N-acetyltaurine are dynamically regulated by diverse physiologic perturbations that alter taurine and/or acetate flux, including endurance exercise7, nutritional taurine supplementation8, and alcohol consumption6,9. While taurine N-acetyltransferase activity has been previously detected in mammalian cells6,7, the molecular identity of this enzyme, and the physiologic relevance of N-acetyltaurine, have remained unknown. Here we show that the orphan body mass index-associated enzyme PTER (phosphotriesterase-related)10 is the principal mammalian taurine N-acetyltransferase/hydrolase. In vitro, recombinant PTER catalyzes bidirectional taurine N-acetylation with free acetate as well as the reverse N-acetyltaurine hydrolysis reaction. Genetic ablation of PTER in mice results in complete loss of tissue taurine N-acetyltransferase/hydrolysis activities and systemic elevation of N-acetyltaurine levels. Upon stimuli that increase taurine levels, PTER-KO mice exhibit lower body weight, reduced adiposity, and improved glucose homeostasis. These phenotypes are recapitulated by administration of N-acetyltaurine to wild-type mice. Lastly, the anorexigenic and anti-obesity effects of N-acetyltaurine require functional GFRAL receptors. Together, these data uncover enzymatic control of a previously enigmatic pathway of secondary taurine metabolism linked to energy balance.

  View details for DOI 10.1101/2024.03.21.586194

  View details for PubMedID 38562797

  View details for PubMedCentralID PMC10983888

• 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

• Lac-Phe mediates the anti-obesity effect of metformin. bioRxiv : the preprint server for biology Xiao, S., Li, V. L., Lyu, X., Chen, X., Wei, W., Abbasi, F., Knowles, J. W., Deng, S., Tiwari, G., Shi, X., Zheng, S., Farrell, L., Chen, Z. Z., Taylor, K. D., Guo, X., Goodarzi, M. O., Wood, A. C., Ida Chen, Y. D., Lange, L. A., Rich, S. S., Rotter, J. I., Clish, C. B., Tahir, U. A., Gerszten, R. E., Benson, M. D., Long, J. Z. 2023

  Abstract

  Metformin is a widely prescribed anti-diabetic medicine that also reduces body weight. The mechanisms that mediate metformin's effects on energy balance remain incompletely defined. Here we show that metformin is a powerful pharmacological inducer of the anorexigenic metabolite Lac-Phe in mice as well as in two independent human cohorts. In cell culture, metformin drives Lac-Phe biosynthesis via inhibition of complex I, increased glycolytic flux, and intracellular lactate mass action. Other biguanides and structurally distinct inhibitors of oxidative phosphorylation also increase Lac-Phe levels in vitro. Genetic ablation of CNDP2, the principal biosynthetic enzyme for Lac-Phe, in mice renders animals resistant to metformin's anorexigenic and anti-obesity effects. Mediation analyses also support a role for Lac-Phe in metformin's effect on body mass index in humans. These data establish the CNDP2/Lac-Phe pathway as a critical mediator of the effects of metformin on energy balance.

  View details for DOI 10.1101/2023.11.02.565321

  View details for PubMedID 37961394

  View details for PubMedCentralID PMC10635077

• Meeting a threat of the Anthropocene: Taste avoidance of metal ions by Drosophila. Proceedings of the National Academy of Sciences of the United States of America Xiao, S., Baik, L. S., Shang, X., Carlson, J. R. 2022; 119 (25): e2204238119

  Abstract

  The Anthropocene Epoch poses a critical challenge for organisms: they must cope with new threats at a rapid rate. These threats include toxic chemical compounds released into the environment by human activities. Here, we examine elevated concentrations of heavy metal ions as an example of anthropogenic stressors. We find that the fruit fly Drosophila avoids nine metal ions when present at elevated concentrations that the flies experienced rarely, if ever, until the Anthropocene. We characterize the avoidance of feeding and egg laying on metal ions, and we identify receptors, neurons, and taste organs that contribute to this avoidance. Different subsets of taste receptors, including members of both Ir (Ionotropic receptor) and Gr (Gustatory receptor) families contribute to the avoidance of different metal ions. We find that metal ions activate certain bitter-sensing neurons and inhibit sugar-sensing neurons. Some behavioral responses are mediated largely through neurons of the pharynx. Feeding avoidance remains stable over 10 generations of exposure to copper and zinc ions. Some responses to metal ions are conserved across diverse dipteran species, including the mosquito Aedes albopictus. Our results suggest mechanisms that may be essential to insects as they face challenges from environmental changes in the Anthropocene.

  View details for DOI 10.1073/pnas.2204238119

  View details for PubMedID 35700364

  View details for PubMedCentralID PMC9231609

• Robust olfactory responses in the absence of odorant binding proteins. eLife Xiao, S., Sun, J. S., Carlson, J. R. 2019; 8

  Abstract

  Odorant binding proteins (Obps) are expressed at extremely high levels in the antennae of insects, and have long been believed essential for carrying hydrophobic odorants to odor receptors. Previously we found that when one functional type of olfactory sensillum in Drosophila was depleted of its sole abundant Obp, it retained a robust olfactory response (Larter et al., 2016). Here we have deleted all the Obp genes that are abundantly expressed in the antennal basiconic sensilla. All of six tested sensillum types responded robustly to odors of widely diverse chemical or temporal structure. One mutant gave a greater physiological and behavioral response to an odorant that affects oviposition. Our results support a model in which many sensilla can respond to odorants in the absence of Obps, and many Obps are not essential for olfactory response, but that some Obps can modulate olfactory physiology and the behavior that it drives.

  View details for DOI 10.7554/eLife.51040

  View details for PubMedID 31651397

  View details for PubMedCentralID PMC6814364