👤 Shude Xu

Based on genetic studies, lysosome dysfunction is thought to play a pathogenetic role in Parkinson's disease. Here we show that VPS13C, a bridge-like lipid-transport protein and a Parkinson's disease gene, is a sensor of lysosome stress or damage. Following lysosome membrane perturbation, VPS13C rapidly relocates from the cytosol to the surface of lysosomes where it tethers their membranes to the ER. This recruitment depends on Rab7 and requires a signal at the damaged lysosome surface that releases an inhibited state of VPS13C, which hinders access of its VAB domain to lysosome-bound Rab7. Although another Parkinson's disease protein, LRRK2, is also recruited to stressed or damaged lysosomes, its recruitment occurs at much later stages and by different mechanisms. Given the role of VPS13 proteins in bulk lipid transport, these findings suggest that lipid delivery to lysosomes by VPS13C is part of an early protective response to lysosome damage. Show less

Based on genetic studies, lysosome dysfunction is thought to play a pathogenetic role in Parkinson's disease (PD). Here we show that VPS13C, a bridge-like lipid transport protein and a PD gene, is a sensor of lysosome stress/damage. Upon lysosome membrane perturbation, VPS13C rapidly relocates from the cytosol to the surface of lysosomes where it tethers their membranes to the ER. This recruitment depends on Rab7 and requires a signal at the damaged lysosome surface that releases an inhibited state of VPS13C which hinders access of its VAB domain to lysosome-bound Rab7. While another PD protein, LRRK2, is also recruited to stressed/damaged lysosomes, its recruitment occurs at much later stages and by different mechanisms. Given the role of VPS13 proteins in bulk lipid transport, these findings suggest that lipid delivery to lysosomes by VPS13C is part of an early protective response to lysosome damage. Show less

Diabetic retinopathy (DR) is the main cause of blindness worldwide, and its prevalence rate is constantly rising. More in-depth exploration of its risk factors and pathogenic mechanisms is needed. This study systematically identified potential therapeutic targets for DR by evaluating causal effects of 16,989 genes and 2,923 proteins on DR/subtypes via two-sample Mendelian randomization (MR), validated with colocalization/Summary-data-based Mendelian randomization (SMR). National Health and Nutrition Examination Survey (NHANES) 1999-2010 cross-sectional data (weighted logistic/Restricted cubic spline (RCS)) pinpointed key risk factors; MR explored their links to DR subtypes. Bioinformatics (bulk and single-cell transcriptomics) analyzed molecular mechanisms of shared targets (gene expression, immune infiltration, pathway enrichment). Machine learning selected key targets for models. Finally, two-step mediation MR examined how targets regulate DR via risk factors. This study identified 64 core targets with causal links to DR. Subtype analysis revealed 2,128 causal genes and subtype-specific targets (e.g. 52 for background DR, 66 for proliferative DR). SMR validated these findings. NHANES data highlighted body mass index (BMI), stroke, hypertension (HBP), and C-reactive protein (CRP) as key DR risk factors, confirmed by MR. Transcriptomics identified 29 differentially expressed genes associated with both risk factors and DR, linked to immune cell regulation. Machine learning selected core targets (LY9, WWP2, etc.) and built a nomogram for DR risk prediction. Functional enrichment showed these targets enriched in chemokine/cytokine and immune-inflammatory pathways. Two-step mediation MR further revealed LY9, ARHGAP1, and WWP2 influence DR subtypes via regulating BMI, CRP, and HBP. This study systematically elucidates the key risk factors, potential molecular mechanisms, and core regulatory targets of DR through multi-omics integration, causal inference, and bioinformatics approaches. The results indicate that inflammation, immune dysregulation, and metabolic disorders play crucial roles in the pathogenesis of DR. Key genes such as LY9, ARHGAP1, and WWP2 could serve as potential intervention targets, offering theoretical foundations and strategic support for early warning and precision treatment of DR. Show less

Genomic structural variants (SVs) are a major source of genetic diversity in humans. Here, through long-read sequencing of 945 Han Chinese genomes, we identify 111,288 SVs, including 24.56% unreported variants, many with predicted functional importance. By integrating human population-level phenotypic and multi-omics data as well as two humanized mouse models, we demonstrate the causal roles of two SVs: one SV that emerges at the common ancestor of modern humans, Neanderthals, and Denisovans in GSDMD for bone mineral density and one modern-human-specific SV in WWP2 impacting height, weight, fat, craniofacial phenotypes and immunity. Our results suggest that the GSDMD SV could serve as a rapid and cost-effective biomarker for assessing the risk of cisplatin-induced acute kidney injury. The functional conservation from human to mouse and widespread signals of positive natural selection suggest that both SVs likely influence local adaptation, phenotypic diversity, and disease susceptibility across diverse human populations. Show less

Elevated circulating lactate serves as a critical biomarker in sepsis, yet the epigenetic mechanisms by which lactate influences disease progression remain unclear. This study aims to identify lactate-associated genes in sepsis, decode their regulatory roles, and assess their potential as therapeutic targets. We performed transcriptome-wide bioinformatic analyses to identify lactylation-related differentially expressed genes (DEGs) between sepsis patients and healthy controls. Pathway enrichment highlighted immune signaling circuits. Five DEGs (ZC3H4, RBM10, PCBP2, RBM25, HNRNPM) were prioritized via ROC analysis, and their combined expression formed a prognostic signature with strong predictive power (AUC > 0.85). Validation in murine sepsis-induced acute lung injury (ALI) models (cecal ligation-puncture and LPS challenge) confirmed significant upregulation of these five genes by qRT-PCR. RBM25 was selected for deeper functional study. Mechanistic assays implicate an RBM25-Acly axis that couples altered metabolism to histone lactylation and transcriptional reprogramming. Notably, we propose the RBM25-Acly axis that couples altered metabolism to histone lactylation and transcriptional reprogramming. Our work uncovers a novel metabolic-epigenetic circuit in sepsis driven by lactylation, with RBM25 and its regulation of ACLY as a key node. The lactylation-based gene signature offers a high-fidelity prognostic tool, and targeting the RBM25-Acly pathway may open new therapeutic avenues. These findings lay a foundation for precision interventions that integrate metabolic and epigenetic strategies in sepsis care. Show less

Inorganic phosphorus (Pi) deficiency significantly impacts plant growth, development, and photosynthetic efficiency. This study evaluated 206 rice accessions from a MiniCore population under both Pi-sufficient (Pi Show less

Activation of mitochondrial function and heat production in adipose tissue by the modification of dietary fat is a promising strategy against obesity. However, as an important source of lipids for ketogenic and daily diets, the function of fats extracted from different adipose tissue sites was largely unknown. In this study, we illustrated the function of fats extracted from adipose tissues with different "beigeing" properties in the ketogenic diet and identified lipid profiles of fats that facilitate energy expenditure. We found that the anti-obesity effect of ketogenic diets was potentiated by using "beigeing" fat [porcine subcutaneous adipose tissue (SAT)] as a major energy-providing ingredient. Through lipidomic analyses, phosphatidylserine (PS) was identified as a functional lipid activating thermogenesis in adipose tissue. Moreover, in vivo studies showed that PS induces adipose tissue thermogenesis and alleviates diet-induced obesity in mice. In vitro studies showed that PS promotes UCP1 expression and lipolysis of adipocytes. Mechanistically, PS promoted mitochondrial function in adipocytes via the ADCY3-cAMP-PKA-PGC1α pathway. In addition, PS-PGC1a binding may affect the stability of the PGC1α protein, which further augments PS-induced thermogenesis. These results demonstrated the efficacy of dietary SAT fats in diminishing lipid accumulation and the underlying molecular mechanism of PS in enhancing UCP1 expression and mitochondrial function. Thus, our findings suggest that as dietary fat, "beigeing" fat provides more beneficial lipids that contribute to the improvement of mitochondrial function, including PS, which may become a novel, nonpharmacological therapy to increase energy expenditure and counteract obesity and its related diseases. Show less

Glucose-dependent insulinotropic polypeptide (GIP) is a ligand of glucose-dependent insulinotropic polypeptide receptor (GIPR) that plays an important role in the digestive system. In recent years, GIP has been regarded as a hormone-like peptide to regulate the local metabolic environment. In this study, we investigated the antioxidant role of GIP on the neuron and explored the possible mechanism. Cell counting Kit-8 (CCK-8) was used to measure cell survival. TdT-mediated dUTP Nick-End Labeling (TUNEL) was used to detect apoptosis in vitro and in vivo. Reactive oxygen species (ROS) levels were probed with 2', 7'-Dichloro dihydrofluorescein diacetate (DCFH-DA), and glucose intake was detected with 2-NBDG. Immunofluorescence staining and western blot were used to evaluate the protein level in cells and tissues. Hematoxylin-eosin (HE) staining, immunofluorescence staining and tract-tracing were used to observe the morphology of the injured spinal cord. Basso-Beattie-Bresnahan (BBB) assay was used to evaluate functional recovery after spinal cord injury. GIP reduced the ROS level and protected cells from apoptosis in cultured neurons and injured spinal cord. GIP facilitated wound healing and functional recovery of the injured spinal cord. GIP significantly improved the glucose uptake of cultured neurons. Meanwhile, inhibition of glucose uptake significantly attenuated the antioxidant effect of GIP. GIP increased glucose transporter 3 (GLUT3) expression via up-regulating the level of hypoxia-inducible factor 1α (HIF-1α) in an Akt-dependent manner. GIP increases GLUT3 expression and promotes glucose intake in neurons, which exerts an antioxidant effect and protects neuronal cells from oxidative stress both in vitro and in vivo. Show less

Non-alcoholic fatty liver disease (NAFLD) is becoming the most common chronic liver disease worldwide while still lacks drugs for treatment or prevention. We aimed to investigate the causal role of glucose-dependent insulinotropic polypeptide receptor agonists (GIPRAs) on NAFLD and identify the mediated risk factors by which GIPRAs exert their therapeutic effects. Genetic proxies of GIPRAs were identified as cis-SNPs of GIPR associated with both the gene expression level and HbA1c and analyses including colocalization and linkage disequilibrium (LD) were performed for validation. We then performed two-sample two-step mendelian randomization to determine the causal effect of GIPRAs on NAFLD. The MR analysis suggested genetic proxies of GIPRAs were causally associated with reduced risk of NAFLD (Odds ratio (OR): 0.46, 95 % confidence interval (95 % CI): 0.24-0.88, P = 0.02) and T2DM (OR: 0.10, 95 % CI: 0.07-0.13, P < 0.01). In addition, Mediation analysis showed evidence of indirect effect of GIPRAs on NAFLD via TRIG (0.88, [0.85-0.92], P < 0.01) and HDL-C (0.85, [0.80-0.90], P < 0.01). Our study provided strong evidence to support the causal role of GIPRAs on reducing the risk of NAFLD probably through improving lipid metabolism, especially TG and HDL-C, providing guidance for future clinical trials. Show less

Bone is a highly dynamic organ that changes with the daily circadian rhythm. During the day, bone resorption is suppressed due to eating, while it increases at night. This circadian rhythm of the skeleton is regulated by gut hormones. Until now, gut hormones that have been found to affect skeletal homeostasis include glucagon-like peptide-1 (GLP-1), glucagon-like peptide-2 (GLP-2), glucose-dependent insulinotropic polypeptide (GIP), and peptide YY (PYY), which exerts its effects by binding to its cognate receptors (GLP-1R, GLP-2R, GIPR, and Y1R). Several studies have shown that GLP-1, GLP-2, and GIP all inhibit bone resorption, while GIP also promotes bone formation. Notably, PYY has a strong bone resorption-promoting effect. In addition, gut microbiota (GM) plays an important role in maintaining bone homeostasis. This review outlines the roles of GLP-1, GLP-2, GIP, and PYY in bone metabolism and discusses the roles of gut hormones and the GM in regulating bone homeostasis and their potential mechanisms. Show less

Glucose-dependent insulinotropic polypeptide (GIP) is a gastrointestinal hormone secreted by K cells in the small intestine and is considered an obesity-promoting factor. In this study, we systematically investigated the anti-obesity effects of intragastric safflower yellow (SY)/hydroxysafflor yellow A (HSYA) and the underlying mechanism for the first time. Our results showed that intragastric SY/HSYA, rather than an intraperitoneal injection, notably decreased serum GIP levels and GIP staining in the small intestine in diet-induced obese (DIO) mice. Moreover, intragastric SY/HSYA was also first found to significantly suppress GIP receptor (GIPR) signaling in both the hypothalamus and subcutaneous White adipose tissue. Our study is the first to show that intragastric SY/HSYA obviously reduced food intake and body weight gain in leptin sensitivity experiments and decreased serum leptin levels in DIO mice. Further experiments demonstrated that SY treatment also significantly reduced leptin levels, whereas the inhibitory effect of SY on leptin levels was reversed by activating GIPR in 3 T3-L1 adipocytes. In addition, intragastric SY/HSYA had already significantly reduced serum GIP levels and GIPR expression before the serum leptin levels were notably changed in high-fat-diet-fed mice. These findings suggested that intragastric SY/HSYA may alleviate diet-induced obesity in mice by ameliorating hyperleptinemia via dual inhibition of the GIP-GIPR axis. Show less

Cyclic dipeptides (CDPs), known for their diverse biological activities, have potential therapeutic applications in mental and behavioral disorders (MBDs), particularly schizophrenia. This study explores the CDPs' therapeutic potential using bibliometric analysis, network pharmacology, molecular docking, and experimental verification, focusing on the interactions with the SIGMA1 receptor. A literature review over three decades utilizing the Web of Science Core Collection (WOSCC) was conducted to identify the emerging trends in CDPs research. A compound library was constructed from the PubChem database, and target prediction using SwissTargetPrediction revealed 800 potential protein targets. A compound-target network highlighted the key interactions with kinases, G protein-coupled receptors, and chromatin-modifying enzymes. Enrichment analysis revealed significant associations with schizophrenia and other MBDs. Schizophrenia-related targets among the potential protein targets were identified using the GEO database. Molecular docking results showed interactions of MC4R, OPRK1, SIGMA1, and CDK5R1 with various CDPs compounds, with SIGMA1 being especially noteworthy. Most CDPs exhibited lower binding energies than the control compounds NE-100 and duloxetine. Experimental validation demonstrated that CDPs such as Cyclo(Ala-Gln), Cyclo(Ala-His), and Cyclo(Val-Gly) exhibited IC Show less

Most antipsychotic drugs (APDs) induce hyperphagia and weight gain. However, the neural mechanisms are poorly understood, partly due to challenges replicating their metabolic effects in rodents. Here, we report a new mouse model that recapitulates overeating induced by clozapine, a widely prescribed APD. Our study shows that clozapine boosts food intake by inhibiting melanocortin 4 receptor (MC4R) expressing neurons in the paraventricular nucleus of the hypothalamus. Interestingly, neither clozapine nor risperidone, another commonly used APD, affects receptor-ligand binding or the canonical Gαs signaling of MC4R. Instead, they inhibit neuronal activity by enhancing the coupling between MC4R and Kir7.1, leading to the open state of the inwardly rectifying potassium channel. Deletion of Show less

The serotonin 2C receptor (5-HT2CR)-melanocortin pathway plays well-established roles in the regulation of feeding behavior and body weight homeostasis. Dysfunctions in this system, such as loss-of-function mutations in the Htr2c gene, can lead to hyperphagia and obesity. In this study, we aimed to investigate the potential therapeutic strategies for ameliorating hyperphagia, hyperglycemia, and obesity associated with a loss-of-function mutation in the Htr2c gene (Htr2cF327L/Y). We demonstrated that reexpressing functional 5-HT2CR solely in hypothalamic pro-opiomelanocortin (POMC) neurons is sufficient to reduce food intake and body weight in Htr2cF327L/Y mice subjected to a high-fat diet (HFD). In addition, 5-HT2CR expression restores the responsiveness of POMC neurons to lorcaserin, a selective agonist for 5-HT2CR. Similarly, administration of melanotan II, an agonist of the melanocortin receptor 4 (MC4R), effectively suppresses feeding and weight gain in Htr2cF327L/Y mice. Strikingly, promoting wheel-running activity in Htr2cF327L/Y mice results in a decrease in HFD consumption and improved glucose homeostasis. Together, our findings underscore the crucial role of the melanocortin system in alleviating hyperphagia and obesity related to dysfunctions of the 5-HT2CR, and further suggest that MC4R agonists and lifestyle interventions might hold promise in counteracting hyperphagia, hyperglycemia, and obesity in individuals carrying rare variants of the Htr2c gene. Show less

Melanocortin-4 receptor (MC4R) functions as a crucial neuroendocrine G protein-coupled receptor (GPCR) in the central nervous system of mammals, displaying agonist-independent constitutive activity that is mainly determined by its N-terminal domain. We previously reported that zebrafish MC4R exhibited a much higher basal cAMP level in comparison to mammalian MC4Rs. However, the functional evolution of constitutive activities in chordate MC4Rs remains to be elucidated. Here we cloned and compared the constitutive activities of MC4Rs from nine vertebrate species and showed that the additive action of the N-terminus with the extracellular region or transmembrane domain exhibited a combined pharmacological effect on the MC4R constitutive activity. In addition, we demonstrated that four residues of F149, Q156, V163, and K164 of the second intracellular loop played a vital role in determining MC4R constitutive activity. This study provided novel insights into functional evolution and identified a key motif essential for constitutive modulation of MC4R signaling. Show less

Imbalance in energy regulation is a major cause of insulin resistance and diabetes. Melanocortin-4 receptor (MC4R) signaling at specific sites in the central nervous system has synergistic but non-overlapping functions. However, the mechanism by which MC4R in the arcuate nucleus (ARC) region regulates energy balance and insulin resistance remains unclear. The MC4R POMC neuron-specific ablation of MC4R in the ARC region promoted food intake, impaired energy expenditure, leading to increased weight gain and impaired systemic glucose homeostasis. Additionally, MC4R ablation reduced the activation of POMC neuron, and is not tissue-specific for peripheral regulation, suggesting the importance of its central regulation. Mechanistically, sequencing analysis and Co-IP assay demonstrated a direct interaction of MC4R with Kir2.1. Knockdown of Kir2.1 in POMC neuron-specific ablation of MC4R restored the effect of MC4R ablation on energy expenditure and systemic glucose homeostasis, indicating by reduced body weight and ameliorated insulin resistance. Hypothalamic POMC neuron-specific knockout of MC4R affects energy balance and insulin sensitivity by regulating Kir2.1. Kir2.1 represents a new target and pathway that could be targeted in obesity. Show less

The prevalence of childhood obesity is increasing worldwide, along with the associated common comorbidities of type 2 diabetes and cardiovascular disease in later life. Motivated by evidence for a strong genetic component, our prior genome-wide association study (GWAS) efforts for childhood obesity revealed 19 independent signals for the trait; however, the mechanism of action of these loci remains to be elucidated. To molecularly characterize these childhood obesity loci we sought to determine the underlying causal variants and the corresponding effector genes within diverse cellular contexts. Integrating childhood obesity GWAS summary statistics with our existing 3D genomic datasets for 57 human cell types, consisting of high-resolution promoter-focused Capture-C/Hi-C, ATAC-seq, and RNA-seq, we applied stratified LD score regression and calculated the proportion of genome-wide SNP heritability attributable to cell type-specific features, revealing pancreatic alpha cell enrichment as the most statistically significant. Subsequent chromatin contact-based fine-mapping was carried out for genome-wide significant childhood obesity loci and their linkage disequilibrium proxies to implicate effector genes, yielded the most abundant number of candidate variants and target genes at the Show less

Since ANGPTL4 was discovered to be involved in lipid metabolism in 2000 for the first time, Angptl4 has attracted the attention of researchers. With the further research, it was found that angptl4 was also involved in many biological activities (glucose metabolism, angiogenesis, wound healing, tumor growth, etc.) in vivo. In this review, we provide an overview of the fundamental role of ANGPTL4 in metabolic regulation and its impact on tumor growth. These insights may provide a way for exploring ANGPTL4 as a potential therapeutic target for future disease treatments. Show less

Despite recent advances, rheumatoid arthritis (RA) patients remain refractory to therapy. Dysregulated overproduction of angiopoietin-like protein 4 (ANGPTL4) is thought to contribute to the disease development. ANGPTL4 was initially identified as a regulator of lipid metabolism, which is hydrolyzed to N-terminal and C-terminal (cANGPTL4) fragments in vivo. cANGPTL4 is involved in several non-lipid-related processes, including angiogenesis and inflammation. This study revealed that the level of ANGPTL4 was markedly elevated in the sera and synovial tissues from patients with RA versus controls. The administration of a neutralizing antibody against cANGPTL4 (anti-cANGPTL4 Ab) resulted in the inhibition of inflammatory processes and bone loss in animal models of collagen-induced arthritis and adjuvant-induced arthritis (AIA). Transcriptomic and proteomic profiling of synovial tissues from an AIA model indicated that the anti-cANGPTL4 Ab inhibited fibroblast-like synoviocyte (FLS) immigration and inflammatory-induced osteoclastogenesis. Mechanistically, the anti-cANGPTL4 Ab has been shown to inhibit TNF-α-induced inflammatory cascades in RA-FLS through the sirtuin 1/nuclear factor-κB signaling pathway. Moreover, the anti-cANGPTL4 Ab was found to block FLS invasion- and immigration-induced osteoclast activation. Collectively, these findings identify ANGPTL4 as a prospective biomarker for the diagnosis of RA, and targeting cANGPTL4 should represent a potential therapeutic strategy. Show less

The association between serum angiopoietin-like 4 (ANGPTL4) levels and the severity of diabetic kidney disease (DKD) in patients with type 2 diabetes mellitus remains unclear. A total of 1,115 type 2 diabetes mellitus patients were analyzed in this cross-sectional study. DKD index included DKD stages defined by estimated glomerular filtration rate, the albuminuria grades and DKD risk management grades. Serum levels of ANGPTL4 and other biomarkers were detected. Multivariable-adjusted linear and logistic analyses were used to study the association between ANGPTL4 and DKD. The protein levels of ANGPTL4 were assessed in the kidney. Renal tubular cells were stimulated with glucose to study ANGPTL4 expression. Compared with the participants in the third or fourth quantile of ANGPTL4, those in the first or second quantile of ANGPTL4 were younger, with lower glycated hemoglobin, triglycerides and urinary albumin creatinine ratio (all P < 0.05). There was a negative nonlinear relationship between ANGPTL4 and estimated glomerular filtration rate in type 2 diabetes mellitus patients. One standard deviation increased serum ANGPTL4 levels, the odds ratio of having DKD was 1.40 (95% confidence interval 1.08-1.80). The mediation analysis showed that triglycerides did not mediate the association between ANGPTL4 and DKD. Furthermore, ANGPTL4 could be the strongest among multiple panels of biomarkers in its association of DKD. Compared with mice at 8 weeks-of-age, db/db mice at 18 weeks-of-age had increased ANGPTL4 expression in glomeruli and tubular segments. In vitro, glucose could stimulate ANGPTL4 expression in tubular cells in a dose-dependent manner. ANGPTL4 could be a potential marker and therapeutic target for DKD treatment. Show less

Type 2 Diabetes Mellitus (T2D) and Osteoarthritis (OA) are both prevalent diseases that significantly impact the health of patients. Increasing evidence suggests that there is a big correlation between T2D and OA, but the molecular mechanisms remain elusive. The aims of this study are to investigate the shared biomarkers and potential molecular mechanisms in T2D combined with OA. T2D and OA-related differentially expressed genes (DEGs) were identified via bioinformatic analysis on Gene Expression Omnibus (GEO) datasets GSE26168 and GSE114007 respectively. Subsequently, extensive target prediction and network analysis were finished with Gene Ontology (GO), protein-protein interaction (PPI), and pathway enrichment with DEGs. The transcription factors (TFs) and miRNAs coupled in co-expressed DEGs involved in T2D and OA were predicted as well. The key genes expressed both in the clinical tissues of T2D and OA were detected with western blot and qRT-PCR assay. Finally, the most promising candidate compounds were predicted with the Drug-Gene Interaction Database (DGIdb) and molecular docking. In this study, 209 shared DEGs between T2D and OA were identified. Functional analysis disclosed that these DEGs are predominantly related to ossification, regulation of leukocyte migration, extracellular matrix (ECM) structural constituents, PI3K/AKT, and Wnt signaling pathways. Further analysis via Protein-Protein Interaction (PPI) analysis and validation with external datasets emphasized MMP9 and ANGPTL4 as crucial genes in both T2D and OA. Our findings were validated through qRT-PCR and Western blot analyses, which indicated high expression levels of these pivotal genes in T2D, OA, and T2D combined with OA cases. Additionally, the analysis of Transcription Factors (TFs)-miRNA interactions identified 7 TFs and one miRNA that jointly regulate these important genes. The Receiver Operating characteristic (ROC) analysis demonstrated the significant diagnostic potential of MMP9 and ANGPTL4.Moreover, we identified raloxifene, ezetimibe, and S-3304 as promising agents for patients with both T2D and OA. This study uncovers the shared signaling pathways, biomarkers, potential therapeutics, and diagnostic models for individuals suffering from both T2D and OA. These findings not only present novel perspectives on the complex interplay between T2D and OA but also hold significant promise for improving the clinical management and prognosis of patients with this concurrent condition. Show less

Lymph node metastasis (LNM) is the primary mode of metastasis in gastric cancer (GC). However, the precise mechanisms underlying this process remain elusive. Tumor cells necessitate lipid metabolic reprogramming to facilitate metastasis, yet the role of lipoprotein lipase (LPL), a pivotal enzyme involved in exogenous lipid uptake, remains uncertain in tumor metastasis. Therefore, the aim of this study was to investigate the presence of lipid metabolic reprogramming during LNM of GC as well as the role of LPL in this process. Intracellular lipid levels were quantified using oil red O staining, BODIPY 493/503 staining, and flow cytometry. Lipidomics analysis was employed to identify alterations in intracellular lipid composition following LPL knockdown. Protein expression levels were assessed through immunohistochemistry, Western blotting, and enzyme-linked immunosorbent assays. The mouse popliteal LNM model was utilized to investigate differences in LNM. Immunoprecipitation and mass spectrometry were employed to examine protein associations. In vitro phosphorylation assays and Phos-tag sodium dodecyl-sulfate polyacrylamide gel electrophoresis assays were conducted to detect angiopoietin-like protein 4 (ANGPTL4) phosphorylation. We identified that an elevated intracellular lipid level represents a crucial characteristic of node-positive (N+) GC and further demonstrated that a high-fat diet can expedite LNM. LPL was found to be significantly overexpressed in N+ GC tissues and shown to facilitate LNM by mediating dietary lipid uptake within GC cells. Leptin, an obesity-related hormone, intercepted the effect exerted by ANGPTL4/Furin on LPL cleavage. Circulating leptin binding to the leptin receptor could induce the activation of inositol-requiring enzyme-1 (IRE1) kinase, leading to the phosphorylation of ANGPTL4 at the serine 30 residue and subsequently reducing its binding affinity with LPL. Moreover, our research revealed that LPL disrupted lipid homeostasis by elevating intracellular levels of arachidonic acid, which then triggered the cyclooxygenase-2/prostaglandin E2 (PGE2) pathway, thereby promoting tumor lymphangiogenesis. Leptin-induced phosphorylation of ANGPTL4 facilitates LPL-mediated lipid uptake and consequently stimulates the production of PGE2, ultimately facilitating LNM in GC. Show less

The quality and flavor of chicken are affected by muscle metabolites and related regulatory genes, and the molecular regulation mechanism of meat quality is different among different breeds of chicken. In this study, 40 one-day-old Daweishan mini chicken (DM) and Cobb broiler (CB) were selected from each group, with 4 replicates and 10 chickens in each replicate. The chickens were reared until 90 d of age under the same management conditions. Then, metabolomics and transcriptomics data of 90-day-old DM (n = 4) and CB (n = 4) were integrated to analyze metabolites affecting breast muscle quality and flavor, and to explore the important genes regulating meat quality and flavor related metabolites. The results showed that a total of 38 significantly different metabolites (SDMs) and 420 differentially expressed genes (DEGs) were detected in the breast muscle of the 2 breeds. Amino acid and lipid metabolism may be the cause of meat quality and flavor difference between DM and CB chickens, involving metabolites such as L-methionine, betaine, N6, N6, N6-Trimethyl-L-lysine, L-anserine, glutathione, glutathione disulfide, L-threonine, N-Acetyl-L-aspartic acid, succinate, choline, DOPC, SOPC, alpha-linolenic acid, L-palmitoylcarnitine, etc. Important regulatory genes with high correlation with flavor amino acids (GATM, GSTO1) and lipids (PPARG, LPL, PLIN1, SCD, ANGPTL4, FABP7, GK, B4GALT6, UGT8, PLPP4) were identified by correlation analysis, and the gene-metabolite interaction network of breast muscle mass and flavor formation in DM chicken was constructed. This study showed that there were significant differences in breast metabolites between DM and CB chickens, mainly in amino acid and lipid metabolites. These 2 kinds of substances may be the main reasons for the difference in breast muscle quality and flavor between the 2 breeds. In general, this study could provide a theoretical basis for further research on the molecular regulatory mechanism of the formation of breast muscle quality and flavor differences between DM and CB chickens, and provide a reference for the development, utilization and genetic breeding of high-quality meat chicken breeds. Show less

Angiopoietin-like protein 4 (ANGPTL4) is recognized as a crucial regulator in lipid metabolism. Acetyl-CoA carboxylases (ACACAs) play a role in the β-oxidation of fatty acids. Yet, the functions of ANGPTL4 and ACACA in dyslipidemia of obstructive sleep apnea (OSA) remain unclear. This study included 125 male OSA subjects from the Shanghai Sleep Health Study (SSHS) who were matched for age, body mass index (BMI), and lipid profile. Serum ANGPTL4 levels were measured Serum ANGPTL4 levels significantly decreased with increasing OSA severity (non-OSA: 59.6 ± 17.4 ng/mL, mild OSA: 50.0 ± 17.5 ng/mL, moderate OSA: 46.3 ± 15.5 ng/mL, severe OSA: 19.9 ± 14.3 ng/mL, respectively, Serum ANGTPL4 levels were significantly decreased in OSA patients, particularly among individuals with severe OSA. Although functional ANGTPL4 T266M variants were not associated with lipid levels in OSA, ANGTPL4 T266M could enhance binding affinity for the ACACA protein, potentially regulating lipid metabolism. Show less

Coronary artery disease (CAD) is a complex disease that is influenced by environmental and genetic factors. In this study, we aimed to investigate the relationship between coding variants in lipid metabolism-related genes and CAD in a Chinese Han population. A total of 252 individuals were recruited for this study, including 120 CAD patients and 132 healthy control individuals. Rare and common coding variants in 12 lipid metabolism-related genes (ANGPTL3, ANGPTL4, APOA1, APOA5, APOC1, APOC3, CETP, LDLR, LIPC, LPL, PCSK9 and SCARB1) were detected via next-generation sequencing (NGS)-based targeted sequencing. Associations between common variants and CAD were evaluated by Fisher's exact test. A gene-based association test of rare variants was performed by the sequence kernel association test-optimal (SKAT-O test). We found 51 rare variants and 17 common variants in this study. One common missense variant, LIPC rs6083, was significantly associated with CAD after Bonferroni correction (OR = 0.47, 95% CI = 0.29-0.76, p = 1.9 × 10 Targeted sequencing is a powerful tool for identifying rare and common variants in CAD. The common missense variant LIPC rs6083 confers protection against CAD. The clinical relevance of rare variants in CAD aetiology needs to be investigated in larger sample sizes in the future. Show less

Ovarian cancer (OC) has the highest mortality rate among all gynecological malignancies. A hypoxic microenvironment is a common feature of solid tumors, including ovarian cancer, and an important driving factor of tumor cell survival and chemo- and radiotherapy resistance. Previous research identified the hypoxia-associated gene angiopoietin-like 4 (ANGPTL4) as both a pro-angiogenic and pro-metastatic factor in tumors. Hence, this work aimed to further elucidate the contribution of ANGPTL4 to OC progression. The expression of hypoxia-associated ANGPTL4 in human ovarian cancer was examined by bioinformatics analysis of TCGA and GEO datasets. The CIBERSORT tool was used to analyze the distribution of tumor-infiltrating immune cells in ovarian cancer cases in TCGA. The effect of ANGPTL4 silencing and overexpression on the proliferation and migration of OVCAR3 and A2780 OC cells was studied in vitro, using CCK-8, colony formation, and Transwell assays, and in vivo, through subcutaneous tumorigenesis assays in nude mice. GO enrichment analysis and WGCNA were performed to explore biological processes and genetic networks associated with ANGPTL4. The results obtained were corroborated in OC cells in vitro by western blotting. Screening of hypoxia-associated genes in OC-related TCGA and GEO datasets revealed a significant negative association between ANGPTL4 expression and patient survival. Based on CIBERSORT analysis, differential representation of 14 distinct tumor-infiltrating immune cell types was detected between low- and high-risk patient groups. Silencing of ANGPTL4 inhibited OVCAR3 and A2780 cell proliferation and migration in vitro and reduced the growth rate of xenografted OVCAR3 cells in vivo. Based on results from WGCNA and previous studies, western blot assays in cultured OC cells demonstrated that ANGPTL4 activates the Extracellular signal-related kinases 1 and 2 (ERK1/2) pathway and this results in upregulation of c-Myc, Cyclin D1, and MMP2 expression. Suggesting that the above mechanism mediates the pro-oncogenic actions of ANGPTL4T in OC, the pro-survival effects of ANGPTL4 were largely abolished upon inhibition of ERK1/2 signaling with PD98059. Our work suggests that the hypoxia-associated gene ANGPTL4 stimulates OC progression through activation of the ERK1/2 pathway. These findings may offer a new prospect for targeted therapies for the treatment of OC. Show less

In vitro cell culturing witnessed its applications in scientific research and industrial activities. Attempts to shorten the doubling time of cultured cells have never ceased. In plants, auxin is applied to promote plant growth, the synthetic derivative 1-Naphthaleneacetic acid (NAA) is a good example. Despite the auxin's naturally occurring receptors are not present in mammalian cells, studies suggested they may affect cell culturing. Yet the effects and mechanisms are still unclear. Here, an up to 2-fold increase in the yield of in vitro cultured human cells is observed. Different types of human cell lines and primary cells are tested and found that NAA is effective in all the cells tested. The PI staining followed by FACS suggested that NAA do not affect the cell cycling. Apoptosis-specific dye staining analysis implicated that NAA rescued cell death. Further bulk RNA sequencing is done and it is identified that the lipid metabolism-engaging and anti-apoptosis gene, ANGPTL4, is enhanced in expression upon NAA treatment. Studies on ANGPTL4 knockout cells indicated that ANGPTL4 is required for NAA-mediated response. Thus, the data identified a beneficial role of NAA in human cell culturing and highlighted its potency in in vitro cell culturing. Show less