American journal of physiology. Gastrointestinal and liver physiology最新文献

{"title":"<i>Lacticaseibacillus rhamnosus GG</i>-driven remodeling of arginine metabolism mitigates gut barrier dysfunction.","authors":"Jayson M Antonio, Yue Liu, Panan Suntornsaratoon, Abigail Jones, Jayanth Ambat, Ajitha Bala, Joshua Joby Kanattu, Juan Flores, Sheila Bandyopadhyay, Ravij Upadhyay, Jagannatham Naidu Bhupana, Xiaoyang Su, Wei Vivian Li, Nan Gao, Ronaldo P Ferraris","doi":"10.1152/ajpgi.00366.2024","DOIUrl":"10.1152/ajpgi.00366.2024","url":null,"abstract":"<p><p>Inflammatory bowel diseases (IBDs) and gut barrier impairment are associated with changes in dietary tryptophan and arginine metabolism, but mechanisms of barrier perturbation and restoration are unclear. We show here that the widely consumed probiotic <i>Lacticaseibacillus rhamnosus</i> GG (LGG) enhances gut barrier functions in part through stimulating the intestinal arginine metabolic pathway, and this mechanism depends on the sufficiency of dietary tryptophan in the host. Specifically, LGG markedly upregulates argininosuccinate lyase (ASL), the enzyme that breaks down argininosuccinate into arginine. ASL expression is markedly reduced during experimental colitis with an accumulation of serum argininosuccinate. LGG colonization in mice reduces serum argininosuccinate, a metabolite that inversely correlates with tight junction gene expression, impairs barrier function, and exacerbates dextran sodium sulfate colitis. We show that LGG-derived indoles as well as arginine metabolites enhanced argininosuccinate lyase (ASL) and nitric oxide synthase (NOS2) expression, linking microbial metabolism to nitric oxide production and epithelial homeostasis. Patients with IBD have increased ASS1 and decreased ASL expression, suggesting a metabolic bottleneck driving ASA accumulation. We propose that signaling pathways underlying LGG and tryptophan-mediated ASL upregulation can be useful therapeutic targets to normalize arginine metabolism in select patients with IBD.<b>NEW & NOTEWORTHY</b> This study identifies a novel probiotic-driven mechanism linking dietary tryptophan and host arginine metabolism. <i>Lacticaseibacillus rhamnosus</i> GG, in synergy with tryptophan, enhances gut barrier integrity by upregulating argininosuccinate lyase (ASL), a critical enzyme in arginine biosynthesis. Furthermore, we uncover ASL downregulation and serum argininosuccinate elevation in experimental colitis in mice, suggesting a target to guide precision probiotics.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":"G162-G185"},"PeriodicalIF":3.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144148876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The multifaceted role of sirtuins in inflammatory bowel diseases.","authors":"Sadhana A Samant, Sanjiv K Hyoju, John C Alverdy, Mahesh P Gupta","doi":"10.1152/ajpgi.00311.2024","DOIUrl":"10.1152/ajpgi.00311.2024","url":null,"abstract":"<p><p>Inflammatory bowel diseases (IBDs), mainly involving the disease states of ulcerative colitis (UC) and Crohn's disease (CD), are characterized by chronic, relapsing inflammation of the gastrointestinal tract. IBD has an unclear etiology and likely develops from a complex interaction between the host's genetic predisposition, the gut microbiota, the immune system, and elements within the environment. In the United States alone, the estimated health care cost for IBD, according to a recent study, exceeds $25 billion. More than 200 genetic loci have been identified to be associated with IBD, highlighting its complex pathophysiology. Although existing treatments for IBD are generally supportive, they are not curative, underscoring the need to identify the causative agents that drive disease pathogenesis. Several studies have reported metabolic alterations in the pathogenesis of IBD. In all living cells, the central action of nicotinamide adenine dinucleotide (NAD⁺) plays a pivotal role in the regulation of energy metabolism and cell signaling. Dysregulated NAD⁺ metabolism is reported in patients with IBD. Sirtuins, a protein family of posttranslational modifiers, need NAD⁺ as a cofactor to perform enzymatic reactions such as deacylation and ADP-ribosylation of not only histones, but also of various other key cellular proteins. Therefore, sirtuins play a vital and central role as stress-responsive metabolic sensors in cells. In this review, we address novel mechanisms by which sirtuins play a role in IBD pathogenesis, thus exposing a potential therapeutic role of this group of enzymes that might be useful in curtailing IBD and several other debilitating gastrointestinal inflammatory disorders.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":"G58-G68"},"PeriodicalIF":3.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12199837/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143956300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biomarkers of intestinal permeability are linked to incident cardiovascular diseases and cardiovascular events: a review of prospective studies.","authors":"Alexis R Quirk, Jenna K Schifferer, Katherine A Maki, Austin T Robinson, Bryant H Keirns","doi":"10.1152/ajpgi.00120.2025","DOIUrl":"10.1152/ajpgi.00120.2025","url":null,"abstract":"<p><p>Intestinal hyperpermeability, which refers to translocation of microbial factors into the bloodstream, is associated with many chronic diseases. Increased intestinal permeability may contribute to the pathophysiology of these diseases by promoting systemic inflammation. Although early work on the health implications of increased intestinal permeability focused on diseases of the gastrointestinal tract, subsequent preclinical and cross-sectional data identified that various types of cardiometabolic and cardiovascular diseases (CVDs) are linked to gut barrier dysfunction. More recently, a body of epidemiological studies has emerged, indicating that elevated biomarkers of intestinal permeability are prospectively linked to incident CVD and CVD events, such as myocardial infarction and stroke, even after controlling for traditional CVD risk factors. In this brief review, we discuss gut barrier function in health and disease, highlight methodologies used to assess intestinal permeability, and review the emerging literature demonstrating that measures of intestinal permeability predict future CVD across several populations.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":"G79-G87"},"PeriodicalIF":3.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144092414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polyamines regulate mitochondrial metabolism essential for intestinal epithelial renewal and wound healing.","authors":"Cassandra A Cairns, Ting Chen, Naomi Han, Hongxia Chen, Hee K Chung, Lan Xiao, Jian-Ying Wang","doi":"10.1152/ajpgi.00023.2025","DOIUrl":"10.1152/ajpgi.00023.2025","url":null,"abstract":"<p><p>Homeostasis of the mammalian intestinal epithelium is tightly regulated by multiple factors, including cellular polyamines, but the exact mechanism underlying polyamines in this process remains largely unknown. Mitochondria are the powerhouse of cells and can also function as signaling organelles by releasing metabolic by-products. Here, we determined whether polyamines regulate intestinal epithelial renewal and wound healing by altering mitochondrial activity. Depletion of cellular polyamines by inhibiting ornithine decarboxylase with α-difluoromethylornithine (DFMO) resulted in mitochondrial dysfunction as evidenced by decreases in basal and maximal respiration levels, ATP production, and spare respiration capacity. Polyamine depletion by DFMO also decreased the levels of mitochondria-associated proteins prohibitin 1 and COX-IV. Mitochondrial dysfunction induced by DFMO was associated with an inhibition of intestinal organoid growth and epithelial repair after wounding, and this inhibition was ameliorated by administration of the mitochondrial activator Mito-Tempo or exogenous polyamine putrescine. These results indicate that polyamines are necessary for mitochondrial metabolism, in turn, controlling constant intestinal mucosal growth and epithelial repair after acute injury. <b>NEW & NOTEWORTHY</b> Our results indicate that polyamines are required for maintaining mitochondrial integrity in intestinal epithelial cells. Polyamine depletion led to mitochondrial dysfunction, along with an inhibition of intestinal epithelial renewal and delayed wound healing. Reinforcing mitochondrial activity by Mito-Tempo ameliorated reduced epithelial renewal and delayed healing in polyamine-deficient cells, demonstrating the importance of mitochondrial metabolism in polyamine-regulated mucosal growth and repair after injury.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":"G191-G200"},"PeriodicalIF":3.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12229264/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144232914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mouse models of eosinophilic esophagitis: molecular and translational insights.","authors":"Jazmyne L Jackson, Abigail J Staub, Annie D Fuller, John M Crespo, Travis H Bordner, Courtney Worrell, No'ad Shanas, Danielle Waheed, Tatiana A Karakasheva, Melanie Ruffner, Amanda B Muir, Kelly A Whelan","doi":"10.1152/ajpgi.00396.2024","DOIUrl":"10.1152/ajpgi.00396.2024","url":null,"abstract":"<p><p>Eosinophilic esophagitis (EoE) is a chronic allergic inflammatory disease of the esophagus that exerts a significant clinical and financial burden in developed countries. Despite an emerging interest in this disease, the cellular and molecular mechanisms driving EoE pathogenesis remain elusive. Addressing this knowledge gap is critical to guide the development of novel approaches for diagnosis, monitoring, and therapy in patients with EoE. As EoE is an allergic inflammatory disorder that results in esophageal inflammation and tissue remodeling, in vivo studies are critical to develop a better understanding of this disease. Here, we provide a review of murine models of EoE, highlighting the mechanistic and translational insights into EoE pathogenesis and therapeutic approaches that studies using these models have uncovered. We further discuss the strengths and limitations of EoE mouse models, as well as opportunities for future in vivo approaches to study EoE. Overall, this article reviews the progress, challenges, unmet needs, and opportunities in murine modeling of EoE.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":"G215-G231"},"PeriodicalIF":3.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144214686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lymphatic alterations in Crohn's disease: the villain or victim.","authors":"Geoffrey E Hespe, Raghu P Kataru","doi":"10.1152/ajpgi.00134.2025","DOIUrl":"10.1152/ajpgi.00134.2025","url":null,"abstract":"","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":"G186-G188"},"PeriodicalIF":3.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12181045/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143958118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Generation of gastric proton pump <i>atp4a</i> knockouts in <i>Astyanax mexicanus</i>: a fish model for insights into the mechanisms of acidification by oxynticopeptic cells.","authors":"Patrícia G Ferreira, A Wayne Vogl, L Filipe C Castro, Jonathan M Wilson","doi":"10.1152/ajpgi.00382.2024","DOIUrl":"10.1152/ajpgi.00382.2024","url":null,"abstract":"<p><p>The gastric proton pump H⁺/K⁺-ATPase (HKA) is the highly conserved acid secretory mechanism of the gnathostome stomach. HKA is a heterodimeric pump composed of α and β-subunits. In this study, we have explored the involvement of this enzyme in the transcriptional regulation of pathways linked to acid secretion (Cl^- and K⁺ movement across the cell membrane) and peptic digestion (pepsinogens) in the stomach of the teleost <i>Astyanax mexicanus</i>. To this end, we generated the first nonmammalian knockout line for the gastric proton pump, <i>atp4a</i> (HKA-α-subunit), in <i>A. mexicanus</i> using CRISPR-Cas9 gene editing. Homozygous mutant <i>atp4a</i>^-/- fish appeared healthy but were achlorhydric. The transcript and protein levels of the HKA-β-subunit remained unaltered despite the absence of α-subunit protein. Pepsinogen (<i>pga</i> and <i>pgc</i>) transcript levels were reduced, together with <i>kcne2</i>, <i>kcc4</i> (involved in apical K⁺ recycling), and <i>clcn2</i> (involved in the acid-coupled Cl^- secretion mechanism) mRNA levels. The <i>cftr</i> and <i>slc4a2b</i> transcript levels were significantly increased in knockout stomachs. The gastric morphology and cytology of <i>atp4a</i>^-/- characterized through bright-field and electron microscopy show that the lumen of the gastric glands of <i>atp4a</i>^-/- fish was dilated and the oxynticopeptic cells had large cytoplasmic inclusions that were absent in wild-type animals. The tubulovesicular system of knockouts was less developed relative to wild-type animals. Our findings provide novel evidence of the highly conservative nature of the gastric acid-peptic pathways across diverse vertebrates. Furthermore, this work highlights the potential for the use of nontraditional models in biomedical research.<b>NEW & NOTEWORTHY</b> We have knocked out stomach acidification in a nonmammalian gnathostome for the first time using CRISPR-Cas9 gene editing in the teleost fish <i>Astyanax mexicanus</i> targeting the gastric proton pump. This offers a novel and insightful alternative to murine models, having larger offspring numbers, rapid development, and ease of maintenance. In accordance, we present the first demonstration in a knockout animal of how diverse chloride and potassium transporters dynamically respond to-and are directly altered by-acidification.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":"G88-G101"},"PeriodicalIF":3.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144075441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gly-βMCA modulates bile acid metabolism to reduce hepatobiliary injury in <i>Mdr2</i> KO mice.","authors":"Mohammad Nazmul Hasan, Huaiwen Wang, Wenyi Luo, Yanhong Du, Tiangang Li","doi":"10.1152/ajpgi.00044.2025","DOIUrl":"10.1152/ajpgi.00044.2025","url":null,"abstract":"<p><p>Cholestasis results from impaired bile flow that causes accumulation of hepatic bile acid and injury. Alleviating bile acid hepatobiliary toxicity is a major therapeutic goal in cholestasis. Our recent study revealed a potent anticholestasis effect of glycine-conjugated β-muricholic acid (Gly-βMCA) in <i>Cyp2c70</i> knockout (KO) mice with humanized hydrophobic bile acid composition. To better understand the mechanisms and human relevance of the therapeutic benefits of Gly-βMCA, we investigated the effects of Gly-βMCA on bile acid metabolism and biliary injury in <i>Mdr2</i> KO mice, a cholestasis model with a hydrophilic murine bile acid composition. Gly-βMCA significantly reduced serum alkaline phosphatase (ALP), ductular reaction, and liver cytokine expression in female mice but offered little benefits in male mice. Consistently, Gly-βMCA reduced hepatic bile acids and total bile acid pool size in female but not male mice, due to its ability to promote fecal bile acid excretion. However, the endogenous taurine-conjugated muricholic acid (T-MCA) limited the ability of Gly-βMCA to further enrich the bile acid pool with Gly-βMCA-derived T-βMCA to reduce bile acid hydrophobicity. Overall, Gly-βMCA showed diminished therapeutic efficacy in <i>Mdr2</i> KO mice than <i>Cyp2c70</i> KO mice, which may be due to differences in bile acid hydrophobicity and disease etiology in the two cholestasis models. These findings suggest that the benefits of Gly-βMCA are mediated by its unique pharmacokinetics, which allows for simultaneous reduction of bile acid pool size and hydrophobicity. Gly-βMCA may be a promising therapy for treating human cholestasis, despite its reduced efficacy in improving the toxicity profile of murine bile acid pool.<b>NEW & NOTEWORTHY</b> Gly-βMCA decreases liver injury in female but not male <i>Mdr2</i> KO mice. Gly-βMCA blocks bile acid absorption to reduce bile acid pool in female <i>Mdr2</i> KO mice. Gly-βMCA reduces bile acid hydrophobicity by causing T-βMCA enrichment in bile, but this therapeutic benefit was partially masked by a murine bile acid composition due to abundantly synthesized T-MCA in <i>Mdr2</i> KO mice. Gly-βMCA alleviates bile acid hepatobiliary toxicity by reducing both bile acid pool size and hydrophobicity.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":"G45-G57"},"PeriodicalIF":3.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12178242/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144148879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Contribution of neuroligin and neurexin alternative splicing to the establishment of enteric neuronal synaptic specificity.","authors":"Fabien D'Autréaux, Alcmène Chalazonitis, Dena Arumugam, Timothy Gershon, Michael D Gershon","doi":"10.1152/ajpgi.00408.2024","DOIUrl":"10.1152/ajpgi.00408.2024","url":null,"abstract":"<p><p>The enteric nervous system (ENS) is unique among components of the peripheral nervous system due to its complexity in structure and neurotransmitter phenotype diversity. In this complexity, the ENS resembles the central nervous system (CNS). Although the ENS is derived from the neural crest rather than the neural tube, similar mechanisms may generate complex connectivity in both the ENS and the CNS. Neuroligins and neurexins are cell adhesion molecules that participate in regulating CNS synaptogenesis. We investigated whether these molecules also play a role in establishing enteric synapses. We found that neuroligins and neurexins were expressed in mouse, rat, and human gut. Transcripts of both types of molecule were extensively spliced in the bowel during fetal and adult life. When transfected into non-neuronal cells, neuroligins and neurexins were sufficient to recruit, respectively, presynaptic and postsynaptic elements. Engineered soluble neurexin, which interferes with endogenous neurexin-neuroligin binding, inhibited enteric synapse formation/stabilization and recruitment of neurotransmitter receptors. Finally, we demonstrated that alternative splicing of neuroligin and neurexin contributes to ENS synaptic specificity. Some isoforms preferentially induced cholinergic synapses, whereas others promoted serotonergic synaptogenesis.<b>NEW & NOTEWORTHY</b> We found that neuroligins and neurexins play roles in establishing ENS synapses. Both are extensively spliced in the fetal and adult gut. When expressed in non-neuronal cells, both neuroligins and neurexins are sufficient to recruit, respectively, presynaptic and postsynaptic elements. Soluble neurexin inhibits enteric synapse formation and recruitment of neurotransmitter receptors by interfering with endogenous neurexin/neuroligin binding. The neurexin/neuroligin splice code contributes physiologically to ENS synaptic specificity, promoting for example, cholinergic or serotonergic synaptogenesis.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":"G140-G158"},"PeriodicalIF":3.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12224031/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143956343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Glucose metabolism through the hexosamine biosynthetic pathway drives hepatic de novo lipogenesis via promoting <i>N</i>-linked protein glycosylation.","authors":"Yanhui Li, Qing Song, Rui Guo, Yanyu Qian, Yuwei Jiang, Zhenyuan Song","doi":"10.1152/ajpgi.00056.2025","DOIUrl":"10.1152/ajpgi.00056.2025","url":null,"abstract":"<p><p>De novo lipogenesis (DNL) converts excess glucose into lipids, whereas the hexosamine biosynthetic pathway (HBP), a glycolytic branch, generates UDP-<i>N</i>-acetylglucosamine for protein glycosylation, including <i>O</i>-GlcNAcylation and <i>N</i>-linked glycosylation. Both pathways are active in hepatocytes and integral to glucose metabolism; however, their functional interplay remains unclear. Here, we investigated the role of HBP in hepatic DNL activation using both in vitro and in vivo models. AML12 hepatocytes were cultured in low- and high-glucose media with or without HBP blockade, both pharmacologically and genetically. For in vivo studies, male C57BL/6J mice were subjected to a fasting-refeeding regimen with or without intraperitoneal administration of azaserine, a competitive inhibitor of glutamine-fructose-6-phosphate transaminase 1 (GFPT1), the rate-limiting enzyme of the HBP. Our results demonstrated that, in AML12 cells, glucose exposure activated both DNL and HBP, leading to triacylglycerol (TAG) accumulation, whereas HBP inhibition ameliorated DNL and TAG accumulation. In mice, refeeding after a 24-h fasting induced hepatic DNL, which was abolished by HBP inhibition, indicating its mechanistic involvement in glucose-driven lipogenesis. Mechanistically, we identified ATF4 as a key regulator of GFPT1 upregulation under high-glucose conditions. As expected, both glucose-treated hepatocytes and livers from fasting-refed mice exhibited increased protein glycosylation. Notably, blocking <i>N</i>-linked glycosylation, but not <i>O</i>-GlcNAcylation, abolished glucose-induced DNL activation, indicating that HBP is essential for glucose-induced DNL pathway activation via promoting <i>N</i>-linked glycosylation, independent of <i>O</i>-GlcNAcylation. In conclusion, our findings establish that an intact HBP is required for glucose-induced hepatic DNL activation, primarily through promoting protein <i>N</i>-linked glycosylation.<b>NEW & NOTEWORTHY</b> High-glucose exposure activates both hepatic HBP and DNL pathways. The glucose metabolism into HBP is essential for the activation of the DNL pathway. ATF4 activation plays a mechanistic role in high glucose-induced HBP activation. HBP drives high glucose-induced hepatic DNL activation via promoting <i>N</i>-linked protein glycosylation.</p>","PeriodicalId":7725,"journal":{"name":"American journal of physiology. Gastrointestinal and liver physiology","volume":" ","pages":"G746-G759"},"PeriodicalIF":3.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143962803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}