Macrophage LMO7 deficiency facilitates inflammatory injury via metabolic-epigenetic reprogramming

Comprehensive analysis Neddylation-related genes identified UBB as a prognostic biomarker for clear cell renal cell carcinoma

Neddylation, as a type of post-translational modification, plays a key role in cancer development. However, the biological characteristics and clinical prognosis value of Neddylation-related genes (NRGs) signatures in clear cell renal cell carcinoma (ccRCC) remain undetermined. Here, we identified two subtypes of NRGs in ccRCC based on TCGA data and constructed a NRGs risk signature (NRGS). Survival analysis, ROC curves, and nomograms showed that NRGS was an important predictor of prognosis in patients with clear cell renal cell carcinoma. We further revealed important correlations between NRGS and clinicopathological features, gene mutations, drug sensitivity, and immune cell infiltration. High NRGS indicates a poorer prognosis for kidney cancer, but higher remission rates with immunotherapy. Drug sensitivity also varies across risk groups. UBB was identified as a hub gene for NRGS and was downregulated in ccRCC, which is associated with poor prognosis. In conclusion, this study provides strategies for predicting prognosis and individualizing treatment for ccRCC.

Identification of Key Mitochondrial Autophagy-Related Genes in Fetal Growth Restriction

Objective

To identify key mitochondrial autophagy-related genes (MARGs) in fetal growth restriction (FGR)and evaluate their diagnostic potential through bioinformatics and machine learning approaches.

Methods

The GSE24192 dataset were obtained from Gene Expression Omnibus data base (GEO). Differentially expressed genes (DEGs) were identified using differentially expressed analysis. Mitochondrial autophagy-related genes (MARGs) were identified using GeneCards. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed with the clusterProfiler package. Protein-protein interaction (PPI) network was constructed using STRING, and key genes were selected using machine learning. Receiver operating characteristic (ROC) curves assessed diagnostic performance of key genes. Immune infiltration analysis was used to evaluated immune microenvironment. The miRNAs were predicted in TargetScan website.

Results

A total of 42 MARGs were identified in FGR samples, and three key genes (THBS1, RAB15, LMO7) were selected through machine learning methods. These genes showed high diagnostic potential with area under the curve (AUC) values of 0.97, 0.95, and 0.92, respectively. Immune infiltration analysis revealed significant increase of CD8+ T cells, endothelial cells, and macrophages in FGR samples. Correlation analysis indicated THBS1 was positively related to several immune cells, while RAB15 and LMO7 were negatively related to several immune cells. The miRNA-mRNA regulatory network revealed four miRNAs potentially regulating these key genes.

Conclusion

In conclusion, our study identified THBS1, RAB15, and LMO7 as key mitochondrial autophagy-related genes in FGR, with potential as diagnostic biomarkers.

Metabolic reprogramming in astrocytes prevents neuronal death through a UCHL1/PFKFB3/H4K8la positive feedback loop

Astrocytic metabolic reprogramming is an adaptation of metabolic patterns to meet increased energy demands, although the role after spinal cord injury (SCI) remains unclear. Analysis of single-cell RNA sequencing (scRNA-seq) data identified an increase in astrocytic glycolysis, while PFKFB3, a key regulator of glycolytic flux, was significantly upregulated following SCI. Loss of PFKFB3 in astrocytes prohibited neuronal energy supply and enhanced neuronal ferroptosis in vitro and expanded infiltration of CD68+ macrophages/microglia, exacerbated neuronal loss, and hindered functional recovery in vivo after SCI. Mechanistically, deubiquitinase UCHL1 plays a crucial role in stabilizing and enhancing PFKFB3 expression by cleaving K48-linked ubiquitin chains. Genetic deletion of Uchl1 inhibited locomotor recovery after SCI by suppression of PFKFB3-induced glycolytic reprogramming in astrocytes. Furthermore, the UCHL1/PFKFB3 axis increased lactate production, leading to enhanced histone lactylation and subsequent transcription of Uchl1 and several genes related to glycolysis, suggesting a glycolysis/H4K8la/UCHL1 positive feedback loop. These findings help to clarify the role of the UCHL1/PFKFB3/H4K8la loop in modulation of astrocytic metabolic reprogramming and reveal a potential target for treatment of SCI.

LMO7 drives profibrotic fibroblast polarization and pulmonary fibrosis in mice through TGF-β signalling

Idiopathic pulmonary fibrosis (IPF) is a progressive lethal disease. Profibrotic fibroblast polarization during wound healing is one of the main causes of IPF, and the molecular mechanisms involved have yet to be fully determined. LIM domain-only protein 7 (LMO7), which acts as an E3 ubiquitin ligase, is highly expressed in the lung, brain and heart and plays important roles in embryonic development, cancer progression, inflammatory bowel disease and Dreifuss muscular dystrophy (EDMD). In this study, we investigated the role of LMO7 in pulmonary fibrosis. Bleomycin (BLM)-induced lung fibrosis was established in mice. For AAV-mediated gene therapy, AAV-Lmo7 shRNA (AAV-Lmo7 shRNA) was intratracheally administered 6 days before BLM injection. Through transcriptome analysis, we found that the expression of LMO7 was significantly upregulated in the fibroblasts of IPF patients and BLM-induced mice. Knockdown of LMO7 impaired the profibrotic phenotype of fibroblasts in BLM-treated mice and in primary lung fibroblasts stimulated with TGF-β in vitro. We observed that LMO7 binds to SMAD7, mediating its degradation by polyubiquitination of lysine 70 and increasing the stability of TGF-β receptor 1 (TGFβR1). Finally, intratracheal administration of adeno-associated virus (AAV)-mediated Lmo7 shRNA significantly ameliorated the progression of BLM-induced lung fibrosis. Our results suggest that LMO7 is a promising target for blocking profibrotic fibroblast polarization for the treatment of fibrotic lung disease. A model for the role of LMO7 in TGF-β/SMAD signaling during pulmonary fibrosis. During pulmonary fibrosis, ubiquitin E3 ligase LMO7 is up-regulated, and binds with. SMAD7. LMO7 mediates the ubiquitination of SMAD7 on Lysine 70, leading to its degradation, and further enhances the stability of transforming growth factor-beta receptor 1 (TGFβR1).

Micheliolide attenuates sepsis-induced acute lung injury by suppressing mitochondrial oxidative stress and PFKFB3-driven glycolysis

BACKGROUND

Sepsis is a potentially fatal condition with a significant risk of death. Acute lung injury (ALI) is a life-threatening complication of sepsis, and the inflammatory response plays a critical role in sepsis-induced ALI. The protective effects of micheliolide (MCL) against renal fibrosis and leukemia have been demonstrated, but the precise underlying mechanisms remain unclear.

METHODS

In vitro, lipopolysaccharides (LPS) and interferon-gamma (IFN-γ) were used to stimulate RAW264.7 cells and bone marrow-derived macrophages (BMDMs) to investigate the protective effect of MCL on sepsis-induced ALI. Cecal ligation and puncture (CLP) models were constructed in mice to induce ALI in vivo. The expression of inflammatory factors, macrophage polarization markers, and the glycolysis-related enzyme 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) were measured in vivo. Mitochondrial function, oxidative stress, and mitochondrial-related proteins were evaluated in vitro.

RESULTS

MCL inhibited CLP-induced ALI, as evidenced by improvements in proinflammatory factor levels, lung wet/dry ratios, and histopathological findings. In vitro, MCL treatment significantly suppressed LPS + IFN-γ-induced M1-type polarization of RAW264.7 cells and BMDMs, as well as the production of inflammatory factors and oxidative stress. Mechanistic experiments revealed that MCL suppresses PFKFB3-driven glycolysis to reduce inflammation and activates the mitochondrial unfolded protein response (UPRmt) to alleviate mitochondrial stress. However, the therapeutic effect of MCL was diminished when PFKFB3 was overexpressed in cells.

CONCLUSION

This study is the first to demonstrate that MCL attenuates sepsis-induced ALI by reducing M1-type macrophage polarization. Its therapeutic effect is closely related to the suppression of oxidative stress and PFKFB3-driven glycolysis.

LIM domain only 7: a novel driver of immune evasion through regulatory T cell differentiation and chemotaxis in pancreatic ductal adenocarcinoma

With advancements in genomics and immunology, immunotherapy has emerged as a revolutionary strategy for tumor treatment. However, pancreatic ductal adenocarcinoma (PDAC), an immunologically "cold" tumor, exhibits limited responsiveness to immunotherapy. This study aimed to address the urgent need to uncover PDAC's immune microenvironment heterogeneity and identify the molecular mechanisms driving immune evasion. Using single-cell RNA sequencing datasets and spatial proteomics, we discovered LIM domain only 7 (LMO7) in PDAC cells as a previously unrecognized driver of immune evasion through Treg cell enrichment. LMO7 was positively correlated with infiltrating regulatory T cells (Tregs) and dysfunctional CD8+ T cells. A series of in vitro and in vivo experiments demonstrated LMO7's significant role in promoting Treg cell differentiation and chemotaxis while inhibiting CD8+ T cells and natural killer cell cytotoxicity. Mechanistically, LMO7, through its LIM domain, directly bound and promoted the ubiquitination and degradation of Foxp1. Foxp1 negatively regulated transforming growth factor-beta (TGF-β) and C-C motif chemokine ligand 5 (CCL5) expression by binding to sites 2 and I/III, respectively. Elevated TGF-β and CCL5 levels contribute to Treg cell enrichment, inducing immune evasion in PDAC. Combined treatment with TGF-β/CCL5 antibodies, along with LMO7 inhibition, effectively reversed immune evasion in PDAC, activated the immune response, and prolonged mouse survival. Therefore, this study identified LMO7 as a novel facilitator in driving immune evasion by promoting Treg cell enrichment and inhibiting cytotoxic effector functions. Targeting the LMO7-Foxp1-TGF-β/CCL5 axis holds promise as a therapeutic strategy for PDAC. Graphical abstract revealing LMO7 as a novel facilitator in driving immune evasion by promoting Tregs differentiation and chemotaxis, inducing CD8+ T/natural killer cells inhibition.

Activation of sphingosine-1-phosphate receptor 2 (S1PR2) upregulates dihydropyrimidine dehydrogenase (DPD) expression in colon cancer cells

INTRODUCTION

Dihydropyrimidine dehydrogenase (DPD) is a major determinant of cancer 5-fluorouracyl (5-FU) resistance via its direct degradation. However, the mechanisms of tumoral DPD upregulation have not been fully understood.

OBJECTIVES

This study aimed to explore the role of S1PR2 in the regulation of tumoral DPD expression, identifying S1PR2 as the potential target for reversing 5-FU resistance.

METHODS

Western blot was used to analyze S1PR2 expression in cultured cancer cells and human colorectal cancer (CRC) tissues. 5-FU resistance was estimated in mouse xenografts of HT-29sh-S1PR2 and SW480S1PR2 cells. HPLC-UV was used to measure 5-FU levels in the xenografts. Chromatin immunoprecipitation (ChIP) was used to analyze the binding of YAP1/TEAD1 to the TWIST1 promoter. A luciferase reporter was used to analyze the binding of TWIST1 to the DPYD promoter.

RESULTS

S1PR2 was highly expressed in cancer cell lines and human CRC tissues. Activation of S1PR2 upregulated DPD expression, leading to 5-FU resistance. Mechanistically, activated S1PR2 upregulated nuclear TWIST1 by activating the Hippo/TEAD1-TWIST1 pathway. Nuclear TWIST1 interacted with the JMJD3-RNA Pol II complex, resulting in the interaction of TWIST1 with the DPYD promoter, thus increasing H3K27me3-enriched DPYD transcription. These findings were confirmed in xenografted human colon cancer cells in nude mice. Transfection with an S1PR2 expression vector led to the upregulation of DPD, blunting the sensitivity of SW480S1PR2 cells to 5-FU by 45.14 %. Conversely, knockdown of S1PR2 resulted in a decrease of DPD, thus increasing the sensitivity of HT-29sh-S1PR2 cells to 5-FU by 62.12 %. Molecular analysis of these xenografts confirmed the role of S1PR2 in upregulating DPD expression by activating the Hippo/TEAD1-JMJD3 pathway.

CONCLUSIONS

Activation of S1PR2 upregulated DPD expression by activating the Hippo/TWIST1-JMJD3 pathway. S1PR2 is therefore a potential target for novel inhibitors that may reverse 5-FU resistance in cancer therapy.

Advances in the understanding of the role and mechanism of action of PFKFB3‑mediated glycolysis in liver fibrosis (Review)

Liver fibrosis is a pathophysiologic manifestation of chronic liver disease and a precursor to cirrhosis and hepatocellular carcinoma. Glycolysis provides intermediate metabolites as well as energy support for cell proliferation and phenotypic transformation in liver fibers. 6‑Phosphofructo‑2‑kinase/fructose‑2,6‑bisphosphatase 3 (PFKFB3) is a key activator of glycolysis and plays an important role in the process of glycolysis. The role of PFKFB3‑mediated glycolysis in myocardial fibrosis, renal fibrosis and pulmonary fibrosis has been demonstrated, and the role of PFKFB3 in the activation of hepatic stellate cells by aerobic glycolysis has been proven by relevant experiments. The present study reviews the research progress on the role and mechanism of action of PFKFB3‑mediated glycolysis in the progression of hepatic fibrosis to discuss the role of PFKFB3‑mediated glycolysis in hepatic fibrosis and to provide new ideas for research on PFKFB3 as a target for the treatment of hepatic fibrosis.

Immunometabolic rewiring in macrophages for periodontitis treatment via nanoquercetin-mediated leverage of glycolysis and OXPHOS

Periodontitis is a chronic inflammatory disease marked by a dysregulated immune microenvironment, posing formidable challenges for effective treatment. The disease is characterized by an altered glucose metabolism in macrophages, specifically an increase in aerobic glycolysis, which is linked to heightened inflammatory responses. This suggests that targeting macrophage metabolism could offer a new therapeutic avenue. In this study, we developed an immunometabolic intervention using quercetin (Q) encapsulated in bioadhesive mesoporous polydopamine (Q@MPDA) to treat periodontitis. Our results demonstrated that Q@MPDA could reprogram inflammatory macrophages to an anti-inflammatory phenotype (i.e., from-M1-to-M2 repolarization). In a murine periodontitis model, locally administered Q@MPDA reduced the presence of inflammatory macrophages, and decreased the levels of inflammatory cytokines (IL-1β and TNF-α) and reactive oxygen species (ROS) in the periodontium. Consequently, it alleviated periodontitis symptoms, reduced alveolar bone loss, and promoted tissue repair. Furthermore, our study revealed that Q@MPDA could inhibit the glycolysis of inflammatory macrophages while enhancing oxidative phosphorylation (OXPHOS), facilitating the shift from M1 to M2 macrophage subtype. Our findings suggest that Q@MPDA is a promising treatment for periodontitis via immunometabolic rewiring.

The role of mesenchymal stem cells in attenuating inflammatory bowel disease through ubiquitination

Inflammatory bowel disease (IBD), a condition of the digestive tract and one of the autoimmune diseases, is becoming a disease of significant global public health concern and substantial clinical burden. Various signaling pathways have been documented to modulate IBD, but the exact activation and regulatory mechanisms have not been fully clarified; thus, a need for constant exploration of the molecules and pathways that play key roles in the development of IBD. In recent years, several protein post-translational modification pathways, such as ubiquitination, phosphorylation, methylation, acetylation, and glycolysis, have been implicated in IBD. An aberrant ubiquitination in IBD is often associated with dysregulated immune responses and inflammation. Mesenchymal stem cells (MSCs) play a crucial role in regulating ubiquitination modifications through the ubiquitin-proteasome system, a cellular machinery responsible for protein degradation. Specifically, MSCs have been shown to influence the ubiquitination of key signaling molecules involved in inflammatory pathways. This paper reviews the recent research progress in MSC-regulated ubiquitination in IBD, highlighting their therapeutic potential in treating IBD and offering a promising avenue for developing targeted interventions to modulate the immune system and alleviate inflammatory conditions.

ASF1A-dependent P300-mediated histone H3 lysine 18 lactylation promotes atherosclerosis by regulating EndMT

Endothelial-to-mesenchymal transition (EndMT) is a key driver of atherosclerosis. Aerobic glycolysis is increased in the endothelium of atheroprone areas, accompanied by elevated lactate levels. Histone lactylation, mediated by lactate, can regulate gene expression and participate in disease regulation. However, whether histone lactylation is involved in atherosclerosis remains unknown. Here, we report that lipid peroxidation could lead to EndMT-induced atherosclerosis by increasing lactate-dependent histone H3 lysine 18 lactylation (H3K18la) in vitro and in vivo, as well as in atherosclerotic patients' arteries. Mechanistically, the histone chaperone ASF1A was first identified as a cofactor of P300, which precisely regulated the enrichment of H3K18la at the promoter of SNAI1, thereby activating SNAI1 transcription and promoting EndMT. We found that deletion of ASF1A inhibited EndMT and improved endothelial dysfunction. Functional analysis based on Apoe KO Asf1a ECKO mice in the atherosclerosis model confirmed the involvement of H3K18la in atherosclerosis and found that endothelium-specific ASF1A deficiency inhibited EndMT and alleviated atherosclerosis development. Inhibition of glycolysis by pharmacologic inhibition and advanced PROTAC attenuated H3K18la, SNAI1 transcription, and EndMT-induced atherosclerosis. This study illustrates precise crosstalk between metabolism and epigenetics via H3K18la by the P300/ASF1A molecular complex during EndMT-induced atherogenesis, which provides emerging therapies for atherosclerosis.

In situ profiling reveals spatially metabolic injury in the initiation of polystyrene nanoplastic-derived intestinal epithelial injury in mice

Despite increasing concerns regarding the harmful effects of plastic-induced gut injury, mechanisms underlying the initiation of plastic-derived intestinal toxicity remain unelucidated. Here, mice were subjected to long-term exposure to polystyrene nanoplastics (PS-NPs) of varying sizes (80, 200, and 1000 nm) at doses relevant to human dietary exposure. PS-NPs exposure did not induce a significant inflammatory response, histopathological damage, or intestinal epithelial dysfunction in mice at a dosage of 0.5 mg/kg/day for 28 days. However, PS-NPs were detected in the mouse intestine, coupled with observed microstructural changes in enterocytes, including mild villous lodging, mitochondrial membrane rupture, and endoplasmic reticulum (ER) dysfunction, suggesting that intestinal-accumulating PS-NPs resulted in the onset of intestinal epithelial injury in mice. Mechanistically, intragastric PS-NPs induced gut microbiota dysbiosis and specific bacteria alterations, accompanied by abnormal metabolic fingerprinting in the plasma. Furthermore, integrated data from mass spectrometry imaging-based spatial metabolomics and metallomics revealed that PS-NPs exposure led to gut dysbiosis-associated host metabolic reprogramming and initiated intestinal injury. These findings provide novel insights into the critical gut microbial-host metabolic remodeling events vital to nanoplastic-derived-initiated intestinal injury.