To explore the role of GFPT2 in the sensitivity of STK11/KRAS lung cancer cells to cisplatin chemotherapy, and its underlying mechanism.

A549 and H460 cells were used to analyze the effect of GFPT2 on cisplatin chemotherapy sensitivity, as both carry KRAS mutations and H460 has LKB1 inactivation mutations, meeting the requirements of a KRAS/LKB1 co mutant tumor model. The levels of UDP-GlcNAc, OGT, OGA, and O-GlcNAc in the HBP pathway were also determined. To verify the potential role of HBP, we added OGT inhibitors. In vivo, we constructed a nude mouse model bearing A549 tumor to further validate the results of in vitro cell experiments.

GFPT2 silencing can significantly inhibit cell proliferation, invasion, and migration, promote cell apoptosis, and enhance the effect of cisplatin (p < 0.05). After OSMI-1 processing, GFPT2 enhances O-GlcNAc modification levels via the OGT-mediated HBP, thereby decreasing the sensitivity of STK11/KRAS mutant cells to cisplatin chemotherapy. In addition, GFPT2 silencing enhances the chemotherapy sensitivity of cisplatin and inhibits tumor growth, while overexpression of GFPT2 weakens this effect (p < 0.05). The above results provide new targets and combination therapy options for the clinical treatment of KRAS/LKB1 mutant lung cancer.

Our study found that inhibiting GFPT2 can enhance the chemotherapy sensitivity of cisplatin to STK11/KRAS/LKB1 mutant NSCLCs cells through the OGT mediated HBP pathway, filling a key gap in the chemotherapy resistance mechanism of KRAS/LKB1 mutant lung cancer.

O-GlcNAcylation, a dynamic post-translational modification occurring on serine or threonine residues of numerous proteins, plays a pivotal role in various cellular processes, including gene regulation, metabolism, and stress response. Abundant in the brain, O-GlcNAcylation intricately governs neurodevelopment, synaptic assembly, and neuronal functions. Recent investigations have established a correlation between the dysregulation of brain O-GlcNAcylation and a broad spectrum of neurological disorders and injuries, spanning neurodevelopmental, neurodegenerative, and psychiatric conditions, as well as injuries to the central nervous system (CNS). Manipulating O-GlcNAcylation has demonstrated neuroprotective properties against these afflictions. This review delineates the roles and mechanisms of O-GlcNAcylation in the CNS under both physiological and pathological circumstances, with a focus on its neuroprotective effects in neurological disorders and injuries. We discuss the involvement of O-GlcNAcylation in key processes such as neurogenesis, synaptic plasticity, and energy metabolism, as well as its implications in conditions like Alzheimer's disease, Parkinson's disease, and ischemic stroke. Additionally, we explore prospective therapeutic approaches for CNS disorders and injuries by targeting O-GlcNAcylation, highlighting recent clinical developments and future research directions. This comprehensive overview aims to provide insights into the potential of O-GlcNAcylation as a therapeutic target and guide future investigations in this promising field.

Gastric cancer, a leading cause of cancer-related mortality, has a median survival of just 15 months in advanced stages and currently lacks effective treatment options. Neddylation blockade is a promising therapeutic strategy, yet its clinical application faces challenge with the emergence of drug resistance. Currently, the underlying mechanisms behind the drug resistance are not fully understood. Our study uncovers the link between MLN4924-induced metabolic reprogramming and its antitumor efficacy in gastric cancer cells. We first demonstrated that MLN4924, a neddylation blocker, has multiple effects on gastric cancer cell growth, notably inducing mitochondrial damage. Untargeted metabolomic analysis revealed that MLN4924 enhances glucose utilization in gastric cancer cells in a concentration-dependent manner. Mechanistically, MLN4924 reduces the neddylation of cullin2, thereby inhibiting the degradation of HIF-1α. This leads to the accumulation of HIF-1α, which upregulates GLUT1 levels and facilitates increased glucose uptake. This metabolic adaptation allows gastric cancer cells to maintain their energy supply despite mitochondrial impairment. Based on the increased glucose dependency following neddylation inhibition by MLN4924, we propose a co-targeting strategy with GLUT1 inhibition, which significantly improves therapeutic efficacy in vitro and in vivo models without safety risks. This dual-targeting approach represents a potent new strategy for gastric cancer treatment.

Glycosylation, a key post-translational modification, plays a pivotal role in cancer progression by influencing critical processes such as protein folding, immune modulation, and intercellular signaling. Altered glycosylation patterns are increasingly recognized as fundamental drivers of tumorigenesis, contributing to key cancer hallmarks like enhanced tumor migration, metastasis, and immune evasion. These aberrant glycosylation signatures not only offer insights into cancer biology but also serve as valuable diagnostic markers and potential therapeutic targets across a range of malignancies. This review explores the mechanisms underlying glycosylation alterations in cancer. We discuss the molecular basis of these changes, including genetic mutations, epigenetic regulation, and oncogene-driven shifts in glycosylation pathways. Additionally, we highlight recent advancements in glycomics research, with a focus on how these alterations influence tumor progression, angiogenesis, and the tumor microenvironment. Furthermore, the review considers the clinical implications of glycosylation changes, including their role in resistance to anti-cancer therapies and their potential as biomarkers for personalized treatment strategies. By bridging fundamental glycosylation research with clinical applications, this review underscores the promise of glycosylation as both a diagnostic tool and a therapeutic target in oncology, offering new avenues for improved patient stratification and precision medicine.

Adriamycin (ADR) is a chemotherapy drug for breast cancer, and its resistance is a major obstacle in the clinical treatment of breast cancer. O-GlcNAcylation is a post-translational modification that impacts chemotherapy resistance in cancers. This present study aims to investigate the mechanism of O-GlcNAcylation-mediated ADR resistance in breast cancer. Cell viability, proliferation, and apoptosis were performed to evaluate ADR resistance in breast cancer cells. O-GlcNAcylation, OGA and OGT levels in patients, and breast cancer cells resistant to ADR or not were detected by western blot and quantitative real-time PCR. Glycolysis of ADR-resistant cells was evaluated by measurement of glucose and lactic acid levels, and extracellular acidification rate and oxygen consumption rate. The underlying mechanism was explored by western blot and pathway enrichment analysis. Effects of OGT in vivo were assessed by xenograft tumor model. Results showed that OGT protein and mRNA levels were increased in MCF-7R and BT-549R cells and tumors of ADR-resistant patients with breast cancer. Moreover, O-GlcNAcylation was increased in ADR-resistant breast cancer cells. OGT knockdown inhibited glycolysis and O-GlcNAcylation and protein level of MDM4 at S96 site. Notably, MDM4 overexpression restored glycolysis in MCF-7R and BT-549R cells inhibited by OGT knockdown. Additionally, OGT knockdown inhibited tumor growth in vivo. Collectively, this study demonstrated that OGT promote breast cancer resistant to ADR through facilitating glycolysis in breast cancer cells by O-GlcNAcylation on MDM4. This study may provide a target for overcoming ADR resistance in breast cancer.

Integrin glycosylation is one mechanism regulating the invasion and metastasis of malignant tumors. Little information exists about integrin glycosylation in head and neck squamous cell carcinoma (HNSCC). In this study, we evaluated the glycosylation of integrins in HNSCC tumor and serum samples.

Intraoperative fresh tumor and normal tissue samples and blood samples were collected from HNSCC patients (N = 24). Lectin-bioaffinity assays using six nanoparticle-bound lectins were used to evaluate the glycosylation of integrins ITGA2, ITGA3, ITGA5, ITGA6, ITGB1, and ITGB4. Associations with metastasis, therapy response, and clinical factors were analyzed.

Glycosylation profiles of the integrins were relatively similar. High intratumoral ITGB1-WFL results were associated with high T class, whereas none of the integrin glycovariant assays provided significant resolution in the detection of nodal metastasis. While the serum integrin glycovariant levels were low overall, serum ITGA2-UEA offered significant resolution in both radiotherapy response prediction and cancer recurrence prognostication.

We demonstrate that while integrin glycovariants are abundant in HNSCC tumors and ITGB1-WFL was associated with invasiveness, integrin glycovariants do not directly correlate with metastatic behavior. Further, serum ITGA2-UEA appeared as a potential radioresponse biomarker.

Glycosylation is a complex co-translational and post-translational modification (PTM) in eukaryotes that utilizes glycosyltransferases to generate a vast array of glycoconjugate structures. Recent studies have highlighted the role of glycans in regulating essential molecular, cellular, tissue, organ, and systemic biological processes with significant implications for human diseases, particularly cancer. The metabolic reliance of cancer, spanning tumor initiation, disease progression, and resistance to therapy, necessitates a range of uniquely altered cellular metabolic pathways. In addition, the intricate interplay between cell-intrinsic and -extrinsic mechanisms is exemplified by the communication between cancer cells, cancer stem cells (CSCs), cancer-associated fibroblasts (CAFs), and immune cells within the tumor microenvironment (TME). In this review article, we explore how differential glycosylation in cancer influences the metabolism and stemness features alongside new avenues in glycobiology.

Hypoxia-inducible factor 1-alpha (HIF-1α) is essential for glycolysis regulation. Its expression in the endometrium is significantly reduced in recurrent implantation failure (RIF), indicating that lower levels of HIF-1α may contribute to embryo implantation failure. O-GlcNAcylation is a dynamic posttranslational modification mediated by O-GlcNAc transferase (OGT), known to regulate HIF-1α in cancer cells. However, it remains unclear whether OGT affects glycolytic processes in uterine endometrial stromal cells (ESCs) and its potential role in embryo implantation. This study utilized In Vitro and In Vivo experiments to investigate the role of OGT in decidualization and embryo implantation, along with its underlying mechanisms. Our findings show that OGT expression is significantly reduced in the endometrium of patients with RIF. Additionally, OGT knockdown led to failed embryo implantation in mice. Further analysis revealed that OGT promotes decidualization by stabilizing HIF-1α, which enhances glycolytic activity. Inhibiting OGT resulted in insufficient decidualization among human ESCs. Moreover, our results indicate that OGT partially regulates CCL2 secretion by maintaining HIF-1α levels within human ESCs, which is essential for successful embryo implantation. Based on these findings, we propose that OGT represents a novel and promising therapeutic target for both the diagnosis and treatment of RIF.

Background/Objectives: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with poor early detection rates owing to the limited sensitivity and specificity of the current biomarker CA19-9. Gut microbiota dysbiosis plays a key role in PDAC pathogenesis. This study aimed to evaluate the noninvasive approach we developed, combining metagenome-derived microbial signatures with CA19-9, to improve PDAC detection. Methods: This study included 50 treatment-naïve patients with PDAC and their matched controls. Fecal samples were analyzed using shotgun metagenomic sequencing. Machine learning algorithms were used to develop and validate a diagnostic panel integrating microbial signatures and CA19-9 levels. Subgroup analyses were used to confirm the robustness of the microbial markers. Results: The combined models at both species and genus levels effectively distinguished patients with PDAC from healthy individuals, and their strong diagnostic efficacy and accuracy were demonstrated through rigorous validation. Conclusions: In conclusion, the combination of gut microbiome profiling and CA19-9 improves PDAC detection accuracy compared to the use of CA19-9 alone, showing promise for early and noninvasive diagnosis.

Osteosarcoma (OS) remains a challenging malignancy with poor prognosis, especially in metastatic or recurrent cases. Despite progress, the molecular mechanisms driving OS, particularly the regulation of autophagy, are not fully understood. Here, through integrated analysis of single-cell and transcriptomic data, we identify a novel long non-coding RNA (lncRNA), OLMALINC, as a critical autophagy regulator in OS. OLMALINC is significantly upregulated in OS tissues, with its expression correlating to poor clinical outcomes. Functional studies show that altering OLMALINC expression impacts OS cell progression and autophagy. Mechanistically, transcriptome analysis and RNA immunoprecipitation reveal Ubiquitin-Specific Peptidase 1 (USP1) as a direct downstream target of OLMALINC. The OLMALINC-USP1 axis inhibits autophagy and activates the hypoxia-inducible factor 1 (HIF-1α) pathway, promoting OS progression. Therapeutically, combining the USP1 inhibitor ML-323 with doxorubicin demonstrated synergistic anti-tumor effects in vitro and in vivo, enhancing autophagy and apoptosis while inhibiting tumor growth. These findings uncover a novel OLMALINC-USP1-HIF-1α axis in OS progression and highlight the potential of combining autophagy modulation with chemotherapy for improved therapeutic outcomes.

The endoplasmic reticulum (ER) serves as a crucial hub for protein synthesis and processing, playing an essential role in maintaining protein homeostasis. Perturbations, such as hypoxia, oxidative stress, inadequate amino acid supply, Ca2+ imbalance, and acidosis, can disrupt cellular equilibrium and result in the accumulation of misfolded/unfolded proteins within the ER lumen. This triggers ER stress. In response to this stress, an unfolded protein response (UPR) is activated as a mechanism to cope with the stress and restore internal balance. The UPR is regulated by three sensors located in the ER: inositol-requiring enzyme 1 (IRE1), protein kinase RNA-like endoplasmic reticulum kinase (PERK), and activating transcription factor 6 (ATF6). However, the UPR can promote tumor growth in vivo by affecting tumor angiogenesis, cell migration, cell metabolism, and treatment resistance, and has a huge impact on the tumor microenvironment.

We conducted a literature review of scientific papers on the topic of ER stress in the tumor microenvironment.

This review focuses on the inducing factors of ER stress, the mechanism of the UPR signaling pathway induced by ER stress, and the effect of ER stress on the tumor microenvironment and immune-infiltrating cells. Tumors can regulate their evolution by affecting themselves and the tumor microenvironment through endoplasmic reticulum stress. This study reveals the important role of endoplasmic reticulum stress in the occurrence and development of tumors, and provides new ideas and potential therapeutic targets for the precision treatment of tumors. Future studies can further explore the molecular mechanism of ER stress regulating tumor microenvironment and explore its application potential in clinical diagnosis and treatment.

O-linked-N-acetylglucosaminylation (O-GlcNAcylation), one of the protein post-translational modifications, is the process of adding O-linked-β-D-N-acetylglucosaminylation (O-GlcNAc) to serine and threonine residues of proteins. O-GlcNAcylation regulates various fundamental cell biological processes, including gene transcription, signal transduction, and cellular metabolism. The role of dysregulated O-GlcNAcylation in tumorigenesis has been recognized, but its role in cancer therapy tolerance has not been elucidated. Therefore, this paper provides the latest evidence on the role of O-GlcNAcylation in cancer therapy responsiveness to understand the impact of O-GlcNAcylation on cancer therapy outcomes, as well as analyzing several possible mechanisms by which O-GlcNAcylation dysregulation affects cancer therapy efficacy, and discusses the possibility of O-GlcNAcylation as a cancer therapy sensitizer.

Astrocyte activation plays a pivotal role in accelerating the cascade of neuroinflammation associated with the development of hypoxic-ischemic brain injury. This study aimed to investigate the mechanism by which sevoflurane postconditioning mitigates neuronal damage through astrocytes by regulating reactive astrocytic Signal Transducer and Activator of Transcription 3 (STAT3) modifications. A modified Rice‒Vannucci model in rats and a conditioned culture system established by subjecting primary astrocytes to oxygen glucose deprivation, followed by using the conditioned medium to culture the neuron cell line SH-SY5Y were used to simulate HI insult in vivo and in vitro, respectively. These models were followed by 30 min of 2.5 % sevoflurane treatment. Stattic was used to inhibit STAT3 phosphorylation, and (Z)-PUGNAc or OSMI-1 was added to regulate O-linked-β-N-acetylglucosamine modification (O-GlcNAcylation) in primary astrocytes in vitro. Neurobehavioral tests, Nissl staining, CCK8 assay, and flow cytometry for apoptosis were used to assess neuronal function. Immunofluorescence staining was used to detect astrocyte reactivity and the intracellular distribution of STAT3. Immunoprecipitation combined with Western blotting was used to evaluate the O-GlcNAcylation of STAT3. Protein expression and phosphorylation levels were detected by Western blotting. ELISA was conducted to detect the detrimental cytokines IL-6 and IL-1β in astrocyte-conditioned medium. Sevoflurane postconditioning enhanced the O-GlcNAcylation of astrocytic STAT3 following HI insult via the manner of OGT. Crosstalk between O-GlcNAcylation and phosphorylation of STAT3 showed that O-GlcNAcylation inhibited STAT3 phosphorylation. The inhibitory effect on astrocytes suppressed STAT3 nuclear translocation, reduced astrocyte reactivity, decreased the release of the inflammatory cytokines IL6 and IL-1β, attenuated neuronal apoptosis following HI insult, and improved neuron viability. Sevoflurane postconditioning increased astrocytic STAT3 O-GlcNAcylation level to competitively inhibit STAT3 phosphorylation. This deactivated downstream inflammation pathways and reduced astrocyte reactivity, thereby mitigating HI insult in neurons both in vivo and in vitro.

To explore the potential mechanisms which O-linked-N-acetylglucosaminylation (O-GlcNAcylation) regulates osteogenesis, a publicly RNA-seq dataset was re-analyzed with literature-mining and showed the primary targets of O-GlcNAcylation in osteoblasts are mitochondria/cytoskeleton. Although the O-GlcNAcylation-regulated mitochondria/cytoskeleton has been extensively studied, its specific role during osteogenesis remains unclear. To address this, we knocked out Ogt (Ogt-KO) in MC3T3-E1 osteoblastic cells. Then, significantly reduced osteoblast differentiation, motility, proliferation, mitochondria-endoplasmic reticulum (Mito-ER) coupling, volume of ER, nuclear tubulins, and oxygen metabolism were observed in Ogt-KO cells. Through artificial intelligence (AI)-predicted cellular structures, the time-lapse live cells imaging with reactive-oxygen-species/hypoxia staining showed that lower cell proliferation and altered oxygen metabolism in the Ogt-KO cells were correlated with the Mito-ER coupling. Bioinformatics analysis, combined with correlated mRNA and protein expression, suggested that Ezh2 and its downstream targets (Opa1, Gsk3a, Wnt3a, Hif1a, and Hspa9) may be involved in O-GlcNAcylation-regulated Mito-ER coupling, ultimately impacting osteoblast differentiation. In conclusion, our findings indicate that O-GlcNAcylation-regulated osteoblast differentiation is linked to morphological changes in mitochondria, cytoskeleton, and ER, with Ezh2 potentially playing a crucial role.

Understanding the fundamental biochemical and metabolic requirements for the replication of coronaviruses within infected cells is of notable interest for the development of broad-based therapeutic strategies, given the likelihood of the emergence of new pandemic-potential virus species, as well as future variants of SARS-CoV-2. Here we demonstrate members of the glutaminase family of enzymes (GLS and GLS2), which catalyze the hydrolysis of glutamine to glutamate (i.e., the first step in glutamine metabolism), play key roles in coronavirus replication in host cells. Using a range of human seasonal and zoonotic coronaviruses, we show three examples where GLS expression increases during coronavirus infection of host cells, and another where GLS2 is upregulated. The viruses hijack the metabolic machinery responsible for glutamine metabolism to generate the building blocks for biosynthetic processes and satisfy the bioenergetic requirements demanded by the "glutamine addiction" of virus-infected cells. We demonstrate that genetic silencing of glutaminase enzymes reduces coronavirus infection and that newer members of two classes of allosteric inhibitors targeting these enzymes, designated as SU1, a pan-GLS/GLS2 inhibitor, and UP4, a specific GLS inhibitor, block viral replication in epithelial cells. Moreover, treatment of SARS-CoV-2 infected K18-human ACE2 transgenic mice with SU1 resulted in their complete survival compared to untreated control animals, which succumbed within 10 days post-infection. Overall, these findings highlight the importance of glutamine metabolism for coronavirus replication in human cells and mice and show that glutaminase inhibitors can block coronavirus infection and thereby may represent a novel class of broad-based anti-viral drug candidates.

We aim to identify molecular clusters related to O-GlcNAcylation and establish a novel scoring system for predicting prognosis and immunotherapy efficacy in patients with gastric cancer (GC). The transcriptomic and clinical data are obtained from XENA-UCSC and GEO databases. The O-GlcNAcylation-related genes are obtained from the GSEA database. Consensus clustering analysis is employed to identify O-GlcNAcylation-related molecular clusters, and principal component analysis (PCA) is utilized to develop a novel prognostic scoring system for predicting GC outcomes and immunotherapy efficacy. The prognostic accuracy of the scoring system is assessed across five real-world cohorts. The biological function of actin alpha 2, smooth muscle (ACTA2) in GC is determined through experimental verification. Using 34 O-GlcNAcylation-related genes associated with prognosis in GC patients, these individuals are divided into two distinct subgroups characterized by different outcomes, tumor microenvironment profiles, and clinical case characteristics. The DEGs between the two subgroups are subsequently used to further divide the GC patients into two subgroups by consensus cluster analysis. PCA is used to construct a prognostic scoring system, which reveal that patients in the low-score subgroup have a better prognosis and greater benefit from immunotherapy. The accuracy of the scoring system is confirmed through validation in a cohort of patients receiving immunotherapy in the real world. ACTA2 promotes proliferation and inhibits apoptosis in GC cells. These findings suggest that we successfully establish molecular clusters associated with O-GlcNAcylation and develop a scoring system that demonstrates strong performance in predicting the prognosis of patients with GC and the effect of immunotherapy interventions.

The level and breadth of deoxynivalenol (DON) contamination in foods made with cereals have increased due to global warming. Consumption of DON-contaminated food and feed poses significant risks to human health and animal production. However, the mechanism by which prolonged exposure to low-dose DON leads to liver damage in animals and effective treatments remain unclear. Our investigation focused on the impact of varying DON exposure times on AML12 cells as well as the long-term liver damage caused by low-dose DON exposure in mice. In addition, this article investigated the unique role of hesperidin in mitigating hepatic ferroptosis induced by low-dose DON exposure. Our results imply that DON's suppression of O-GlcNAcylation exacerbated mitophagy by encouraging ferritinophagy and causing labile iron to aggregate within mitochondria. Furthermore, DON could increase NCOA4-mediated ferritinophagy by De-O-GlcNAcylation FTH to trigger ferroptosis-associated liver injury in mice. Notably, hesperidin alleviated the susceptibility to ferroptosis by increasing O-GlcNAcylation levels and effectively attenuated the liver injury induced by low-dose DON exposure. This finding provides a new strategy for dealing with liver injury caused by low-dose DON exposure.

O-Linked β-N-acetylglucosamine (O-GlcNAc) is an essential, dynamic monosaccharide post-translational modification (PTM) found on serine and threonine residues of thousands of nucleocytoplasmic proteins. The installation and removal of O-GlcNAc is controlled by a single pair of enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), respectively. Since its discovery four decades ago, O-GlcNAc has been found on diverse classes of proteins, playing important functional roles in many cellular processes. Dysregulation of O-GlcNAc homeostasis has been implicated in the pathogenesis of disease, including neurodegeneration, X-linked intellectual disability (XLID), cancer, diabetes, and immunological disorders. These foundational studies of O-GlcNAc in disease biology have motivated efforts to target O-GlcNAc therapeutically, with multiple clinical candidates under evaluation. In this review, we describe the characterization and biochemistry of OGT and OGA, cellular O-GlcNAc regulation, development of OGT and OGA inhibitors, O-GlcNAc in pathophysiology, clinical progress of O-GlcNAc modulators, and emerging opportunities for targeting O-GlcNAc. This comprehensive resource should motivate further study into O-GlcNAc function and inspire strategies for therapeutic modulation of O-GlcNAc.

Sleep deprivation (SD) has been reported to induce intestinal damage by several mechanisms, yet its role in modulating epithelial repair remains unclear. In this study, we find that chronic SD leads to colonic damage through continuous hypoxia. However, HIF1α, which generally responds to hypoxia to modulate barrier integrity, was paradoxically dysregulated in the colon. Further investigation revealed that a metabolic disruption during SD causes accumulation of α-ketoglutarate in the colon. The excessive α-ketoglutarate degrades HIF1α protein through PHD2 (prolyl hydroxylase 2) to abolish the intestinal repair functions of HIF1α. Collectively, these findings provide insights into how SD can exacerbate intestinal damage by fine-tuning metabolism to abolish HIF1α-mediated repair.

Cerebral ischemia‒reperfusion (I/R) injury seriously threatens the lives of patients. Astragalus polysaccharide (APS) is the main active ingredient of Astragalus membranaceus and has a wide range of pharmacological activities. Here, we aimed to explore the impacts of APS on cerebral I/R injury and its specific mechanisms. We established a cerebral I/R injury model using middle cerebral artery occlusion (MCAO)-treated rats and oxygen glucose deprivation/reoxygenation (OGD/R)-treated BV2 cells. The interleukin 1β (IL-1β), interleukin 6 (IL-6) and interleukin (IL-10) levels were determined using corresponding ELISA kits and RT‒qPCR. The levels of M1 microglial markers (INOS and CD16) and M2 microglial markers (Arg-1 and CD206) were measured by RT‒qPCR. The O-linked N-acetylglucosamine modification (O-GlcNAcylation), O-GlcNAc transfer (OGT) and O-GlcNAc glycosidase (OGA) protein levels were measured by Western blot. Our results showed that APS treatment decreased IL-1β (179.72 ± 9.08 vs. 81.33 ± 6.30) and IL-6 (445.56 ± 33.09 vs. 234.75 ± 27.62) levels and increased IL-10 (41.95 ± 4.18 vs. 86.40 ± 7.16) levels in OGD/R-treated BV2 cells (p < 0.001). In addition, APS promoted the M2 polarization of OGD/R-treated BV2 cells, manifested by an increase in Arg-1 (0.43 ± 0.04 vs. 0.76 ± 0.03) and CD206 (0.36 ± 0.03 vs. 0.65 ± 0.06) and a decrease in INOS (2.84 ± 0.39 vs. 1.56 ± 0.19) and CD16 (4.04 ± 0.36 vs. 1.88 ± 0.09) in OGD/R-treated BV2 cells (p < 0.001). Additionally, APS treatment increased the O-GlcNAcylation and OGT levels in OGD/R-treated BV2 cells, while OGT knockdown reversed the effect of APS in OGD/R-treated BV2 cells and MCAO-treated rats (p < 0.05). Our study demonstrated that APS alleviated cerebral I/R injury by promoting the M2 polarization of microglia by enhancing OGT-mediated O-GlcNAcylation.

Hypoxia-inducible factor-1 (HIF-1) regulates cell growth, protein translation, metabolic pathways and therefore, has been advocated as a promising biological target for the therapeutic interventions against cancer. In general, hyperactivation of HIF-1 in cancer has been associated with increases in the expression of glucose transporter type-1 (GLUT-1) thus, enhancing glucose consumption and hyperactivating metabolic pathways. The collective behavior of GLUT-1 along with previously known key players AKT, OGT, and VEGF is not fully characterized and lacks clarity of how glucose uptake through this pathway (HIF-1) probes the cancer progression. This study uses a Rene Thomas qualitative modeling framework to comprehend the signaling dynamics of HIF-1 and its interlinked proteins, including VEGF, ERK, AKT, GLUT-1, β-catenin, C-MYC, OGT, and p53 to elucidate the regulatory mechanistic of HIF-1 in cancer. Our dynamic model reveals that continuous activation of p53, β-catenin, and AKT in cyclic conditions, leads to oscillations representing homeostasis or a stable recovery state. Any deviation from this cycle results in a cancerous or pathogenic state. The model shows that overexpression of VEGF activates ERK and GLUT-1, leads to more aggressive tumor growth in a cancerous state. Moreover, it is observed that collective modulation of VEGF, ERK, and β-catenin is required for therapeutic intervention because these genes enhance the expression of GLUT-1 and play a significant role in cancer progression and angiogenesis. Additionally, SimBiology simulation unveils dynamic molecular interactions, emphasizing the need for targeted therapeutics to effectively regulate VEGF and ERK concentrations to modulate cancer cell proliferation.

Cocaine abuse has been strongly linked to blood-brain barrier (BBB) dysfunction, though the exact mechanism by which cocaine disrupts the BBB remains unclear. In this study, we found that cocaine treatment reduces the expression of glucose transporter 1 (GLUT1) in brain microvascular endothelial cells, a key factor in cocaine-induced brain glucose uptake, BBB leakage, and cognitive impairment. Mechanistically, our results show that cocaine upregulates miR-320a, which in turn suppresses GLUT1 expression via the beta 2-adrenergic receptor (ADRB2). Notably, the administration of adeno-associated viruses encoding full-length GLUT1 or miR-320a inhibitors to the brain microvascular endothelium significantly mitigated cocaine-induced BBB leakage and cognitive deficits. Additionally, we discovered that melatonin, a well-known neuroprotective hormone, alleviates cocaine-induced BBB disruption and cognitive impairment. This protective effect of melatonin was mediated through the upregulation of miR-320a-dependent GLUT1 expression in brain endothelial cells via MT1 receptor-mediated inhibition of the cAMP/PKA/CREB signaling pathway. In conclusion, our findings demonstrate that cocaine downregulates brain microvascular GLUT1, leading to BBB dysfunction, and highlight melatonin as a potential therapeutic agent for treating cocaine-related complications.

Mesothelioma (MESO) is an insidious malignancy with a complex diagnosis and a poor prognosis. Our study unveils Glutamine-Fructose-6-Phosphate Transaminase 2 (GFPT2) as a valuable diagnostic and prognostic marker for MESO, exploring its role in MESO pathogenesis.

We utilised tissue samples and clinicopathologic data to evaluate the diagnostic and prognostic significance of GFPT2 as a biomarker for MESO. The role of GFPT2 in the malignant progression of MESO was investigated through in vitro and in vivo experiments. The activation of NF-κB-p65 through O-GlcNAcylation at Ser75 was elucidated using experiments like HPLC-QTRAP-MS/MS and mass spectrometry analysis.

The study demonstrates that GFPT2 exhibits a sensitivity of 92.60% in diagnosing MESO. Overexpression of it has been linked to an unfavourable prognosis. Through rigorous verification, we have confirmed that elevated GFPT2 levels drive malignant proliferation, invasiveness, and metastasis in MESO. At the molecular level, GFPT2 augments p65 O-GlcNAcylation, orchestrating its nuclear translocation and activating the NF-κB signalling pathway.

Our insights suggest GFPT2's potential as a distinctive biomarker for MESO diagnosis and prognosis, and as an innovative therapeutic target, offering a new horizon for identification and treatment strategies in MESO management.

Metabolic disorder significantly contributes to diabetic vascular complications, including diabetic retinopathy, the leading cause of blindness in the working-age population. However, the molecular mechanisms by which disturbed metabolic homeostasis causes vascular dysfunction in diabetic retinopathy remain unclear. O-GlcNAcylation modification acts as a nutrient sensor particularly sensitive to ambient glucose. Here, we observe pronounced O-GlcNAc elevation in retina endothelial cells of diabetic retinopathy patients and mouse models. Endothelial-specific depletion or pharmacological inhibition of O-GlcNAc transferase effectively mitigates vascular dysfunction. Mechanistically, we find that Yes-associated protein (YAP) and Transcriptional co-activator with PDZ-binding motif (TAZ), key effectors of the Hippo pathway, are O-GlcNAcylated in diabetic retinopathy. We identify threonine 383 as an O-GlcNAc site on YAP, which inhibits its phosphorylation at serine 397, leading to its stabilization and activation, thereby promoting vascular dysfunction by inducing a pro-angiogenic and glucose metabolic transcriptional program. This work emphasizes the critical role of the O-GlcNAc-Hippo axis in the pathogenesis of diabetic retinopathy and suggests its potential as a therapeutic target.

The upregulation of O-GlcNAc signaling has long been implicated in the development and progression of numerous human malignancies, including colorectal cancer. In this study, we characterized eight colorectal cancer cell lines and one non-cancerous cell line for O-GlcNAc-related profiles such as the expression of OGT, OGA, and total protein O-GlcNAcylation, along with their sensitivity toward OSMI-1 (Os), an OGT inhibitor (OGTi). Indeed, Os dose-dependently suppressed the viability of all colorectal cancer cell lines tested. Among the three O-GlcNAc profiles, our results revealed that Os IC50 exhibited the strongest correlation with total protein O-GlcNAcylation (Pearson Correlation Coefficient r = -0.73), suggesting that total O-GlcNAcylation likely serves as a better predictive marker for OGTi sensitivity than OGT expression levels. Furthermore, we demonstrated that Os exhibited a synergistic relationship with regorafenib (Re). We believed that this synergism could be explained, at least in part, by the observed Re-mediated increase of cellular O-GlcNAcylation, which was counteracted by Os. Finally, we showed that the Os:Re combination suppressed the growth of NCI-H508 tumor spheroids. Overall, our findings highlighted OGTi as a potential anticancer agent that could be used in combination with other molecules to enhance the efficacy while minimizing adverse effects, and identified total cellular O-GlcNAcylation as a potential predictive marker for OGTi sensitivity.

Cells must rapidly adapt to changes in nutrient conditions through responsive signalling cascades to maintain homeostasis. One of these adaptive pathways results in the post-translational modification of proteins by O-GlcNAc. O-GlcNAc modifies thousands of nuclear and cytoplasmic proteins in response to nutrient availability through the hexosamine biosynthetic pathway. O-GlcNAc is highly dynamic and can be added and removed from proteins multiple times throughout their life cycle, setting it up to be an ideal regulator of cellular processes in response to metabolic changes. Here, we describe the link between cellular metabolism and O-GlcNAc, and we explore O-GlcNAc's role in regulating cellular processes in response to nutrient levels. Specifically, we discuss the mechanisms of elevated O-GlcNAc levels in contributing to diabetes and cancer, as well as the role of decreased O-GlcNAc levels in neurodegeneration. These studies form a foundational understanding of aberrant O-GlcNAc in human disease and provide an opportunity to further improve disease identification and treatment.

Exosomes are mediators of intercellular communication. Cancer cell-secreted exosomes allow exosome donor cells to promote cancer growth, as well as metastasis.

Here, exosomes were isolated from the serum of non-small cell lung cancer (NSCLC) patients and characterized by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) and western blot analysis. NSCLC cell proliferation and migration were assessed using CCK-8, 5-ethynyl-2'-deoxyuridine (EdU) and Transwell assays. H1299 tumor formation and pulmonary metastasis were examined in a xenograft model in nude mice.

We found that exosomes derived from NSCLC (NSCLC-Exos) promoted NSCLC cell migration and proliferation, and that NSCLC-Exo-mediated malignant progression of NSCLC was mediated by miR-199b-5p. Inhibition of miR-199b-5p decreased the effects of NSCLC-Exos on NSCLC malignant progression. HIF1AN was identified as a downstream target of miR-199b-5p. Furthermore, overexpression of HIF1AN reversed the effects of miR-199b-5p on NSCLC malignant progression.

In summary, our findings demonstrated that exosomal-specific miR-199b-5p promoted proliferation in distant or neighboring cells via the miR-199b-5p/HIF1AN axis, resulting in enhanced tumor growth.

Tinnitus treatment remains a global challenge, and current therapeutic approaches are still controversial. This study aims to elucidate the potential mechanisms of Xiao-Chai-Hu-Tang (XCHT) in treating tinnitus through the analysis of network pharmacology, mendelian randomization and molecular docking, and molecular dynamics simulation analysis. We hope to contribute to the research on the target of action of traditional Chinese medicine and exploration of the mechanism of tinnitus.

We utilized network pharmacology to screen potential targets of action of XCHT on tinnitus. Mendelian randomization was employed to determine the causal relationship between potential targets of action and tinnitus. Finally, molecular docking and molecular dynamics simulation with clear targets and the combination of the active ingredient in effectiveness.

Through network pharmacology, we identified 38 potential targets of action. Mendelian randomization analysis revealed that HIF1A (OR [95 % CI] = 0.78 [0.65, 0.94], P = 0.008) and CCND1 (OR [95 % CI] = 1.22 [1.00, 1.49], P = 0.04) exhibited significant results with tinnitus. Molecular docking and molecular dynamics simulation of HIF1A and active ingredients demonstrated good binding efficacy.

HIF1A may play a key role in the treatment of tinnitus by XCHT, which may play a certain protective role in tinnitus patients and may inhibit the occurrence and development of tinnitus. However, the specific mechanism and effect need to be further studied and verified.

O-linked-N-acetylglucosaminylation (O-GlcNAcylation) is a common and important post-translational modification (PTM) linking O-linked β-N-acetylglucosamine (O-GlcNAc) to serine and threonine residues in proteins. Extensive research indicates its impact on target protein stability, activity, and interactions. O-linked N-acetylglucosamine transferase (OGT) is a critical enzyme that catalyzes O-GlcNAc modification, responsible for adding O-GlcNAc to proteins. OGT and O-GlcNAcylation are overexpressed in many tumors and closely associated with tumor growth, invasion, metabolism, drug resistance, and immune evasion. This review delineates the biochemical functions of OGT and summarizes its effects and mechanisms in tumors. Targeting OGT presents a promising novel approach for treating human malignancies.

Citrullination plays an essential role in various physiological or pathological processes, however, whether citrullination is involved in regulating tumour progression and the potential therapeutic significance have not been well explored. Here, we find that peptidyl arginine deiminase 4 (PADI4) directly interacts with and citrullinates hypoxia-inducible factor 1α (HIF-1α) at R698, promoting HIF-1α stabilization. Mechanistically, PADI4-mediated HIF-1αR698 citrullination blocks von Hippel-Lindau (VHL) binding, thereby antagonizing HIF-1α ubiquitination and subsequent proteasome degradation. We also show that citrullinated HIF-1αR698, HIF-1α and PADI4 are highly expressed in hepatocellular carcinoma (HCC) tumour tissues, suggesting a potential correlation between PADI4-mediated HIF-1αR698 citrullination and cancer development. Furthermore, we identify that dihydroergotamine mesylate (DHE) acts as an antagonist of PADI4, which ultimately suppresses tumour progression. Collectively, our results reveal citrullination as a posttranslational modification related to HIF-1α stability, and suggest that targeting PADI4-mediated HIF-1α citrullination is a promising therapeutic strategy for cancers with aberrant HIF-1α expression.

O-linked N-acetylglucosaminylation (O-GlcNAcylation) is a dynamic and reversible posttranslational modification that targets serine and threonine residues in a variety of proteins. Uridine diphospho-N-acetylglucosamine, which is synthesized from glucose via the hexosamine biosynthesis pathway, is the major donor of this modification. O-GlcNAc transferase is the sole enzyme that transfers GlcNAc onto protein substrates, while O-GlcNAcase is responsible for removing this modification. O-GlcNAcylation plays an important role in tumorigenesis and progression through the modification of specific protein substrates. In this review, we discuss the tumor-related biological functions of O-GlcNAcylation and summarize the recent progress in the development of pharmaceutical options to manipulate the O-GlcNAcylation of specific proteins as potential anticancer therapies.

Aerobic glycolysis has been recognized as a hallmark of human cancer. G protein pathway suppressor 2 (GPS2) is a negative regulator of the G protein-MAPK pathway and a core subunit of the NCoR/SMRT transcriptional co-repressor complex. However, how its biological properties intersect with cellular metabolism in breast cancer (BC) development remains poorly elucidated. Here, we report that GPS2 is low expressed in BC tissues and negatively correlated with poor prognosis. Both in vitro and in vivo studies demonstrate that GPS2 suppresses malignant progression of BC. Moreover, GPS2 suppresses aerobic glycolysis in BC cells. Mechanistically, GPS2 destabilizes HIF-1α to reduce the transcription of its downstream glycolytic regulators (PGK1, PGAM1, ENO1, PKM2, LDHA, PDK1, PDK2, and PDK4), and then suppresses cellular aerobic glycolysis. Notably, receptor for activated C kinase 1 (RACK1) is identified as a key ubiquitin ligase for GPS2 to promote HIF-1α degradation. GPS2 stabilizes the binding of HIF-1α to RACK1 by directly binding to RACK1, resulting in polyubiquitination and instability of HIF-1α. Amino acid residues 70-92 aa of the GPS2 N-terminus bind RACK1. A 23-amino-acid-long GPS2-derived peptide was developed based on this N-terminal region, which promotes the interaction of RACK1 with HIF-1α, downregulates HIF-1α expression and significantly suppresses BC tumorigenesis in vitro and in vivo. In conclusion, our findings indicate that GPS2 decreases the stability of HIF-1α, which in turn suppresses aerobic glycolysis and tumorigenesis in BC, suggesting that targeting HIF-1α degradation and treating with peptides may be a promising approach to treat BC.

The dysregulation of circadian rhythm oscillation is a prominent feature of various solid tumors. Thus, clarifying the molecular mechanisms that maintain the circadian clock is important. In the present study, we revealed that the transcription factor forkhead box FOXK1 functions as an oncogene in breast cancer. We showed that FOXK1 recruits multiple transcription corepressor complexes, including NCoR/SMRT, SIN3A, NuRD, and REST/CoREST. Among them, the FOXK1/NCoR/SIN3A complex transcriptionally regulates a cohort of genes, including CLOCK, PER2, and CRY2, that are critically involved in the circadian rhythm. The complex promoted the proliferation of breast cancer cells by disturbing the circadian rhythm oscillation. Notably, the nuclear expression of FOXK1 was positively correlated with tumor grade. Insulin resistance gradually became more severe with tumor progression and was accompanied by the increased expression of OGT, which caused the nuclear translocation and increased expression of FOXK1. Additionally, we found that metformin downregulates FOXK1 and exports it from the nucleus, while HDAC inhibitors (HDACi) inhibit the FOXK1-related enzymatic activity. Combined treatment enhanced the expression of circadian clock genes through the regulation of FOXK1, thereby exerting an antitumor effect, indicating that highly nuclear FOXK1-expressing breast cancers are potential candidates for the combined application of metformin and HDACi.

The tumor microenvironment (TME) consists of tumor cells, non-tumor cells, extracellular matrix, and signaling molecules, which can contribute to tumor initiation, progression, and therapy resistance. In response to starvation, hypoxia, and drug treatments, tumor cells undergo a variety of deleterious endogenous stresses, such as hypoxia, DNA damage, and oxidative stress. In this context, to survive the difficult situation, tumor cells evolve multiple conserved adaptive responses, including metabolic reprogramming, DNA damage checkpoints, homologous recombination, up-regulated antioxidant pathways, and activated unfolded protein responses. In the last decades, the protein O-GlcNAcylation has emerged as a crucial causative link between glucose metabolism and tumor progression. Here, we discuss the relevant pathways that regulate the above responses. These pathways are adaptive adjustments induced by endogenous stresses in cells. In addition, we systematically discuss the role of O-GlcNAcylation-regulated stress-induced adaptive response pathways (SARPs) in TME remodeling, tumor progression, and treatment resistance. We also emphasize targeting O-GlcNAcylation through compounds that modulate OGT or OGA activity to inhibit tumor progression. It seems that targeting O-GlcNAcylated proteins to intervene in TME may be a novel approach to improve tumor prognosis.

Clear cell renal cell carcinoma (ccRCC) demonstrates enhanced glycolysis, critically contributing to tumor development. Programmed death-ligand 1 (PD-L1) aids tumor cells in evading T-cell-mediated immune surveillance. Yet, the specific mechanism by which glycolysis influences PD-L1 expression in ccRCC is not fully understood. Our research identified that the glycolysis-related gene (GRG) HK3 has a unique correlation with PD-L1 expression. HK3 has been identified as a key regulator of O-GlcNAcylation in ccRCC. O-GlcNAcylation exists on the serine 900 (Ser900) site of EP300 and can enhance its stability and oncogenic activity by preventing ubiquitination. Stably expressed EP300 works together with TFAP2A as a co-transcription factor to promote PD-L1 transcription and as an acetyltransferase to stabilize PD-L1 protein. Furthermore, ccRCC exhibits interactive dynamics with tumor-associated macrophages (TAMs). The uridine 5'-diphospho-N-acetylglucosamine (UDP-GlcNAc), which serves as a critical substrate for the O-GlcNAcylation process, facilitates TAMs polarization. In ccRCC cells, HK3 expression is influenced by IL-10 secreted by M2 TAMs. Our study elucidates that HK3-mediated O-GlcNAcylation of EP300 is involved in tumor immune evasion. This finding suggests potential strategies to enhance the efficacy of immune checkpoint blockade therapy.