Publications by authors named "Haopeng Xiao"

Zinc is an essential micronutrient that regulates a wide range of physiological processes, most often through zinc binding to protein cysteine residues. Despite being critical for modulation of protein function, the cysteine sites in the majority of the human proteome that are subject to zinc binding remain undefined. Here, we develop ZnCPT, a deep and quantitative mapping of the zinc-binding cysteine proteome.

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Neurodegenerative disorders alter mitochondrial functions, including the production of reactive oxygen species (ROS). Mitochondrial complex III (CIII) generates ROS implicated in redox signaling, but its triggers, targets, and disease relevance are not clear. Using site-selective suppressors and genetic manipulations together with mitochondrial ROS imaging and multiomic profiling, we found that CIII is the dominant source of ROS production in astrocytes exposed to neuropathology-related stimuli.

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Uptake of circulating succinate by brown adipose tissue (BAT) and beige fat elevates whole-body energy expenditure, counteracts obesity and antagonizes systemic tissue inflammation in mice. The plasma membrane transporters that facilitate succinate uptake in these adipocytes remain undefined. Here we elucidate a mechanism underlying succinate import into BAT via monocarboxylate transporters (MCTs).

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That uncoupling protein 1 (UCP1) is the sole mediator of adipocyte thermogenesis is a conventional viewpoint that has primarily been inferred from the attenuation of the thermogenic output of mice genetically lacking Ucp1 from birth (germline Ucp1). However, germline Ucp1 mice harbor secondary changes within brown adipose tissue. To mitigate these potentially confounding ancillary changes, we constructed mice with inducible adipocyte-selective Ucp1 disruption.

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Zinc is an essential micronutrient that regulates a wide range of physiological processes, principally through Zn binding to protein cysteine residues. Despite being critical for modulation of protein function, for the vast majority of the human proteome the cysteine sites subject to regulation by Zn binding remain undefined. Here we develop ZnCPT, a comprehensive and quantitative mapping of the zinc-regulated cysteine proteome.

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  • Lactate is found in high levels in rapidly dividing cells due to increased glucose breakdown needed for cell growth, but its impact on cell proliferation was unclear.
  • Research revealed that accumulated lactate alters the anaphase promoting complex (APC/C) by inhibiting the SUMO protease SENP1, which affects protein regulation during the cell cycle.
  • This mechanism allows lactate to signal the cell to proceed with division during nutrient-rich conditions, but excessive lactate can lead to faulty APC/C regulation and resistance to anti-mitotic treatments.
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Uptake of circulating succinate by brown adipose tissue (BAT) and beige fat elevates whole body energy expenditure, counteracts obesity, and antagonizes systemic tissue inflammation in mice. The plasma membrane transporters that facilitate succinate uptake in these adipocytes remain undefined. Here we elucidate a mechanism underlying succinate import into BAT via monocarboxylate transporters (MCTs).

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  • Creatine kinases (CKs) help make energy during times when our bodies need lots of it, like when we're growing or exercising a lot.
  • In some fast-growing cancers, problems with CKs can cause issues, but we don’t have effective medicines to target them yet.
  • Researchers created a new drug called CKi which specifically targets CKs, making it harmful to certain cancer cells, and found it also helps understand how CKs affect inflammation in immune cells.
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  • * Traditional proteomics faces challenges due to the presence of abundant proteins in serum, which makes it hard to detect those present in lower amounts, but extracellular fluid (EF) from muscle and fat shows distinct protein profiles.
  • * By analyzing EFs from mice under different conditions like exercise, researchers discovered new proteins (including prosaposin) that can stimulate key processes in fat cells, showcasing the potential of EF isolation for discovering new myokines and adipokines.
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Reactive oxygen species (ROS) regulate the activities of inflammasomes, which are innate immune signaling organelles that induce pyroptosis. The mechanisms by which ROS control inflammasome activities are unclear and may be multifaceted. Herein, we report that the protein gasdermin D (GSDMD), which forms membrane pores upon cleavage by inflammasome-associated caspases, is a direct target of ROS.

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  • Researchers studied brown fat tissue (BAT) in a diverse group of 163 mice to learn how it affects metabolism, unlike past studies which focused on just one type of mouse.
  • They found over 10,000 proteins in BAT and figured out how some work together, identifying 2,578 proteins that help regulate BAT.
  • The team also discovered specific proteins like SFXN5, LETMD1, and ATP1A2 that can help control fat burning and body fat, helping us understand more about how BAT works in metabolism.
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Glycoproteins with diverse glycans are essential to human cells, and subtle differences in glycan structures may result in entirely different functions. One typical example is proteins modified with O-linked β--acetylglucosamine (O-GlcNAc) and O-linked α--acetylgalactosamine (O-GalNAc) (the Tn antigen), in which the two glycans have very similar structures and identical chemical compositions, making them extraordinarily challenging to be distinguished. Here, we developed an effective method benefiting from selective enrichment and the enzymatic specificity to simultaneously identify and distinguish glycoproteins with O-GlcNAc and O-GalNAc.

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  • Uncoupling protein 1 (UCP1) is crucial for regulating energy expenditure in brown and beige fat, but previous loss-of-function models showed issues with the entire energy pathway, making UCP1's role unclear.
  • Researchers identified a specific site (cysteine-253) on UCP1 that, when modified, boosts its activity and created a genetic mouse model lacking this site (UCP1 C253A) to study its effects.
  • UCP1 C253A mice had reduced thermogenesis but did not gain extra fat; instead, they experienced tissue stress and inflammation in males, which was mitigated in females due to higher systemic estrogen levels.
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Adipocytes increase energy expenditure in response to prolonged sympathetic activation via persistent expression of uncoupling protein 1 (UCP1). Here we report that the regulation of glycogen metabolism by catecholamines is critical for UCP1 expression. Chronic β-adrenergic activation leads to increased glycogen accumulation in adipocytes expressing UCP1.

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  • Non-alcoholic fatty liver disease (NAFLD) is a common liver condition linked to obesity and type 2 diabetes, characterized by liver inflammation that contributes to disease progression.
  • The study identifies a pathway regulated by uncoupling protein 1 (UCP1) in brown and beige fat that helps combat liver inflammation, operating independently of any impact on obesity itself.
  • Findings suggest that enhancing UCP1 activity could help reduce liver inflammation and improve overall liver health, providing a potential therapeutic approach for managing NAFLD.
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Adipose thermogenesis is repressed in obesity, reducing the homeostatic capacity to compensate for chronic overnutrition. Inflammation inhibits adipose thermogenesis, but little is known about how this occurs. Here we showed that the innate immune transcription factor IRF3 is a strong repressor of thermogenic gene expression and oxygen consumption in adipocytes.

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In response to skeletal muscle contraction during exercise, paracrine factors coordinate tissue remodeling, which underlies this healthy adaptation. Here we describe a pH-sensing metabolite signal that initiates muscle remodeling upon exercise. In mice and humans, exercising skeletal muscle releases the mitochondrial metabolite succinate into the local interstitium and circulation.

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  • Pathway proteomics measures changes in protein expression linked to specific cellular functions, allowing the quantification of hundreds of proteins across multiple samples using a targeted tandem mass tags approach.* -
  • The new software Tomahto offers enhanced control over sample multiplexing experiments on the Orbitrap Tribrid mass spectrometer by optimizing data scans in real time, enabling efficient and sensitive protein quantification.* -
  • A demonstration using metabolic and inflammatory pathways in tissue samples from old and young mice revealed insights into aging effects, particularly in white adipose tissue, and validated the method against broader proteome analyses.*
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Proteins are continuously synthesized during cell growth and proliferation. At the same time, excessive and misfolded proteins have to be degraded, otherwise they are a burden to cells. Protein degradation is essential to maintain proteostasis in cells, and dysfunction of protein degradation systems results in numerous diseases such as cancer and neurodegenerative diseases.

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Mammalian tissues engage in specialized physiology that is regulated through reversible modification of protein cysteine residues by reactive oxygen species (ROS). ROS regulate a myriad of biological processes, but the protein targets of ROS modification that drive tissue-specific physiology in vivo are largely unknown. Here, we develop Oximouse, a comprehensive and quantitative mapping of the mouse cysteine redox proteome in vivo.

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Glycation as a type of non-enzymatic protein modification is related to aging and chronic diseases, especially diabetes. Global analysis of protein glycation will aid in a better understanding of its formation mechanism and biological significance. In this work, we comprehensively investigated protein glycation in human cells (HEK293T, Jurkat, and MCF7 cells).

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The original version of this Article omitted a declaration from the Competing Interests statement, which should have included the following: 'A patent has been applied for by Emory University with F.E.L, I.

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Protein glycosylation is ubiquitous in biological systems and plays essential roles in many cellular events. Global and site-specific analysis of glycoproteins in complex biological samples can advance our understanding of glycoprotein functions and cellular activities. However, it is extraordinarily challenging because of the low abundance of many glycoproteins and the heterogeneity of glycan structures.

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Human antibody-secreting cells (ASC) in peripheral blood are found after vaccination or infection but rapidly apoptose unless they migrate to the bone marrow (BM). Yet, elements of the BM microenvironment required to sustain long-lived plasma cells (LLPC) remain elusive. Here, we identify BM factors that maintain human ASC > 50 days in vitro.

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