👤 Ding Yang

The STAT3 pathway promotes epithelial-mesenchymal transition, migration, invasion and metastasis in cancer. STAT3 upregulates the transcription of the key epithelial-mesenchymal transition transcription factor SNAIL in a DNA binding-independent manner. However, the mechanism by which STAT3 is recruited to the SNAIL promoter to upregulate its expression is still elusive. In our study, the lysine methylation binding protein L3MBTL3 is positively associated with metastasis and poor prognosis in female patients with breast cancer. L3MBTL3 also promotes epithelial-mesenchymal transition and metastasis in breast cancer. Mechanistic analysis reveals that L3MBTL3 interacts with STAT3 and recruits STAT3 to the SNAIL promoter to increase SNAIL transcription levels. The interaction between L3MBTL3 and STAT3 is required for SNAIL transcription upregulation and metastasis in breast cancer, while the methylated lysine binding activity of L3MBTL3 is not required for these functions. In conclusion, L3MBTL3 and STAT3 synergistically upregulate SNAIL expression to promote breast cancer metastasis. Show less

Computational modeling indicated that pathological high shear stress (HSS; 100 dyn/cm We used the Ibidi perfusion system to determine whether HSS applied to human PA endothelial cells (ECs) induces EndMT when compared with physiological laminar shear stress (15 dyn/cm EndMT, a feature of PAH not previously attributed to HSS, was observed. HSS did not alter the induction of transcription factors KLF (Krüppel-like factor) 2/4, but an ERG (ETS-family transcription factor) was reduced, as were histone H3 lysine 27 acetylation enhancer-promoter peaks containing ERG motifs. Consequently, there was reduced interaction between ERG and KLF2/4, a feature important in tethering KLF and the chromatin remodeling complex to DNA. In PA ECs under laminar shear stress, reducing ERG by siRNA caused EndMT associated with decreased BMPR2 (bone morphogenetic protein receptor 2), CDH5 (cadherin 5), and PECAM1 (platelet and EC adhesion molecule 1) and increased SNAI1/2 (Snail/Slug) and ACTA2 (smooth muscle α2 actin). In PA ECs under HSS, transfection of ERG prevented EndMT. HSS was then induced in mice by an aortocaval shunt, causing progressive PAH over 8 weeks. An adeno-associated viral vector (AAV2-ESGHGYF) was used to replenish ERG selectively in PA ECs. Elevated PA pressure, EndMT, and vascular remodeling (muscularization of peripheral arteries) in the aortocaval shunt mice were markedly reduced by ERG delivery. Pathological HSS reduced lung EC ERG, resulting in EndMT and PAH. Agents that upregulate ERG could reverse HSS-mediated PAH and occlusive vascular remodeling resulting from high flow or narrowed PAs. Show less

Ischemic stroke (IS) is a severe disease. The altered activation states of microglia play important roles in IS. In present study, a total of 125 C57BL/6 mice was used (N = 6 per group). Middle cerebral artery occlusion (MCAO) and oxygen-glucose deprivation (OGD) were performed for in vivo and in vitro model construction. The infarct size was detected using TTC staining. The nerve injury was evaluated by a neurological deficit score. OGD-treated brain microvascular endothelial cells (BMECs) were co-cultured with BV2 cells. Cell viability was determined by CCK-8 assay, and the apoptosis rate was identified by flow cytometry analysis. Transendothelial electronic resistance (TEER) of the cells was measured by TEER measurement. Molecular interactions were analyzed using dual-luciferase reporter gene, ChIP, and Co-IP assays. All in vitro experiments were conducted with three replicates, and each experiment was performed in triplicate. We found that Src Homology 2B Adaptor Protein 3 (SH2B3) was overexpressed in the cerebral cortex tissues of MCAO treated mice (P < 0.01), and BMECs co-cultured with BV-2 cells under OGD conditions (P < 0.01). SH2B3 knockdown or Myocyte Enhancer Factor 2 A (MEF2A) overexpression reduced infarct size and improved neurological function in MCAO mice. SH2B3 knockdown enhanced OGD-treated cell viability (P < 0.05), inhibited cell apoptosis (P < 0.05) in BMECs, and ameliorated BBB (P < 0.01). Moreover, SH2B3 knockdown changed the activation status of microglia. MEF2A promoted the transcriptional activation of WW Domain Containing E3 Ubiquitin Protein Ligase 2 (WWP2) and WWP2 promoted the ubiquitination and degradation of SH2B3. SH2B3 overexpression reversed the effects of MEF2A overexpression on microglia states, BMECs injury and BBB function. In summary, MEF2A promoted the ubiquitination-mediated degradation of SH2B3 via transcription up-regulating WWP2, then changed the activation status of microglia, thus ameliorating BMEC injury, and finally ameliorating IS injury. Show less

Cervical squamous cell carcinoma (CESC) is one of the most common cancers in women, and radiotherapy has been used as a primary treatment. However, its efficacy is limited by intrinsic and acquired radiation resistance. Our previous study demonstrated that Deoxycytidine kinase (dCK) inhibits ionizing radiation (IR)-induced cell death, including apoptosis and mitotic catastrophe, and dCK is a HSP90-interacting protein by mass spectrometry and co-immunoprecipitation assay. In the present study, we found that dCK inhibited IR-induced ferroptosis by increasing the activity and stability of SLC7A11. Using the E3 ubiquitin ligase database (UbiBrowser), we predicted NEDD4L as a potential ubiquitin ligase of dCK, and WWP1/2 as potential ubiquitin ligases of NEDD4L, respectively. These predictions were subsequently verified through a ubiquitination IP assay. Our findings indicate that HSP90 regulates dCK stability by inhibiting NEDD4L through the recruitment of ubiquitin ligases WWP1/2. In summary, our study reveals the HSP90-WWP1/WWP2-NEDD4L-dCK-SLC7A11 axis as a critical regulator of IR-induced ferroptosis in HeLa cells. These findings provide valuable insights into potential strategies for the radiosensitization of cervical cancer. Show less

Mitophagy plays a critical role in maintaining mitochondrial quality and cellular homeostasis. But the specific contribution of mitophagy-related E3 ubiquitin ligases to prognoses remains largely unexplored. In this study, we identified a novel mitophagy-related E3 ubiquitin ligase prognostic signature using least absolute shrinkage and selector operator (LASSO) and multivariate Cox regression analyses in breast cancer. Based on median risk scores, patients were divided into high-risk and low-risk groups. Functional enrichment analyses were conducted to explore the biological differences between the two groups. Immune infiltration, drug sensitivity, and mitochondrial-related phenotypes were also analyzed to evaluate the clinical implications of the model. A four-gene signature (ARIH1, SIAH2, UBR5, and WWP2) was identified, and Kaplan-Meier analysis demonstrated that the high-risk group had significantly worse overall survival (OS). The high-risk patients exhibited disrupted mitochondrial metabolism and immune dysregulation with upregulated immune checkpoint molecules. Additionally, the high-risk group exhibited higher sensitivity to several drugs targeting the Akt/PI3K/mTORC1 signaling axis. Accompanying mitochondrial metabolic dysregulation, mtDNA stress was elevated, contributing to activation of the senescence-associated secretory phenotype (SASP) in the high-risk group. In conclusion, the identified signature provides a robust tool for risk stratification and offers insights into the interplay between mitophagy, immune modulation, and therapeutic responses for breast cancer. Show less

Autoantibodies hold promise for diagnosing lung cancer. However, their effectiveness in early-stage detection needs improvement. In this study, we investigated novel IgG and IgM autoantibodies for detecting early-stage lung adenocarcinoma (Early-LUAD) by employing a multi-step approach, including Human Proteome Microarray (HuProtTM) discovery, focused microarray verification, and ELISA validation, on 1246 individuals consisting of 634 patients with Early-LUAD (stage 0-I), 280 patients with benign lung disease (BLD), and 332 normal healthy controls (NHCs). HuProtTM selected 417 IgG/IgM candidates, and focused microarray further verified 55 significantly elevated IgG/IgM autoantibodies targeting 32 tumor-associated antigens in Early-LUAD compared to BLD/NHC/BLD+NHC. A novel panel of 10 autoantibodies (ELAVL4-IgM, GDA-IgM, GIMAP4-IgM, GIMAP4-IgG, MGMT-IgM, UCHL1-IgM, DCTPP1-IgM, KCMF1-IgM, UCHL1-IgG, and WWP2-IgM) demonstrated a sensitivity of 70.5% and a specificity of 77.0% or 80.0% for distinguishing Early-LUAD from BLD or NHC in ELISA validation. Positive predictive values for distinguishing Early-LUAD from BLD with nodules ≤ 8 mm, 9-20 mm, and > 20 mm significantly increased from 47.27%, 52.00%, and 62.90% [low-dose computed tomography (LDCT) alone] to 79.17%, 71.13%, and 87.88% (10-autoantibody panel combined with LDCT), respectively. The combined risk score (CRS), based on the 10-autoantibody panel, sex, and imaging maximum diameter, effectively stratified the risk for Early-LUAD. Individuals with 10 ≤ CRS ≤ 25 and CRS > 25 indicated a higher risk of Early-LUAD compared to the reference (CRS < 10), with adjusted odds ratios of 5.28 [95% confidence interval (CI): 3.18-8.76] and 9.05 (95% CI: 5.40-15.15), respectively. This novel panel of IgG and IgM autoantibodies offers a complementary approach to LDCT in distinguishing Early-LUAD from benign nodules. Show less

Acute kidney injury (AKI) is associated with high morbidity and mortality rates. The molecular mechanisms underlying AKI are currently being extensively investigated. WWP2 is an E3 ligase that regulates cell proliferation and differentiation. Whether WWP2 plays a regulatory role in AKI remains to be elucidated. We aimed to investigate the implication of WWP2 in AKI and its underlying mechanism in the present study. We utilized renal tissues from patients with AKI and established AKI models in global or tubule-specific knockout (cKO) mice strains to study WWP2's implication in AKI. We also systemically analyzed ubiquitylation omics and proteomics to decipher the underlying mechanism. In the present study, we found that WWP2 expression significantly increased in the tubules of kidneys with AKI. Global or tubule-specific knockout of WWP2 significantly aggravated renal dysfunction and tubular injury in AKI kidneys, whereas WWP2 overexpression significantly protected tubular epithelial cells against cisplatin. WWP2 deficiency profoundly affected autophagy in AKI kidneys. Further analysis with ubiquitylation omics, quantitative proteomics and experimental validation suggested that WWP2 mediated poly-ubiquitylation of CDC20, a negative regulator of autophagy. CDC20 was significantly decreased in AKI kidneys, and selective inhibiting CDC20 with apcin profoundly alleviated renal dysfunction and tubular injury in the cisplatin model with or without WWP2 cKO, indicating that CDC20 may serve as a downstream target of WWP2 in AKI. Inhibiting autophagy with 3-methyladenine blocked apcin's protection against cisplatin-induced renal tubular cell injury. Activating autophagy by rapamycin significantly protected against cisplatin-induced AKI in WWP2 cKO mice, whereas inhibiting autophagy by 3-methyladenine further aggravated apoptosis in cisplatin-exposed WWP2 KO cells. Taken together, our data indicated that the WWP2/CDC20/autophagy may be an essential intrinsic protective mechanism against AKI. Further activating WWP2 or inhibiting CDC20 may be novel therapeutic strategies for AKI. Show less

Sichuan donkeys are small-statured donkeys native to the plateau and mountainous regions of southwestern China. They are well-suited for transportation tasks in mountainous terrain and exhibit remarkable adaptability to the harsh environment, characterized by low temperatures and hypoxia. Adaptation to the local environment has shaped their unique genomic characteristics and is an important source of genetic variation. However, the genome-wide landscape of Sichuan donkeys remains undescribed. In this study, we obtained whole-genome sequencing data from 17 Sichuan donkeys and combined this data with published data of 99 donkeys from 9 other donkey breeds. We aimed to elucidate the population structure, genetic diversity, genetic differentiation, and selection pressure of Sichuan donkeys at the whole-genome level. Population structure and genetic diversity analysis showed that Sichuan donkeys were less influenced by the hybridization of foreign donkey breeds. They maintained a relatively pure lineage of Chinese native donkeys and exhibited higher genetic diversity. The study also found that Sichuan donkeys were genetically closest to Tibetan and Yunnan donkeys. Although their effective population size around 1000 years ago was smaller compared to Tibetan and Yunnan donkeys, it was still larger than that of other donkey breeds. Moreover, selective signature analysis (θπ, CLR, F This study clarified the genetic diversity, genetic differentiation, and effective population size of Sichuan donkeys by comparing them with other donkey breeds. Our findings contribute to deeper understanding of the high-altitude adaptability of Sichuan donkeys, and provide valuable information for the conservation and breeding of the breed. Show less

Lipid remodeling is crucial for cold tolerance in plants. However, the precise alternations of lipidomics during cold responses remain elusive, especially in maize (Zea mays L.). In addition, the key genes responsible for cold tolerance in maize lipid metabolism have not been identified. Here, we integrate lipidomic, transcriptomic, and genetic analysis to determine the profile of lipid remodeling caused by cold stress. We find that the homeostasis of cellular lipid metabolism is essential for maintaining cold tolerance of maize. Also, we detect 210 lipid species belonging to 13 major classes, covering phospholipids, glycerides, glycolipids, and free fatty acids. Various lipid metabolites undergo specific and selective alterations in response to cold stress, especially mono-/di-unsaturated lysophosphatidic acid, lysophosphatidylcholine, phosphatidylcholine, and phosphatidylinositol, as well as polyunsaturated phosphatidic acid, monogalactosyldiacylglycerol, diacylglycerol, and triacylglycerol. In addition, we identify a subset of key enzymes, including ketoacyl-acyl-carrier protein synthase II (KAS II), acyl-carrier protein 2 (ACP2), male sterility33 (Ms33), and stearoyl-acyl-carrier protein desaturase 2 (SAD2) involved in glycerolipid biosynthetic pathways are positive regulators of maize cold tolerance. These results reveal a comprehensive lipidomic profile during the cold response of maize and provide genetic resources for enhancing cold tolerance in crops. Show less

Ulcerative colitis (UC) is an increasing incidence of inflammatory disorder in the colon mucosa. One of the current research focuses is the alteration of metabolic networks in UC. One of the important aspects of this metabolic shift is the expression of purine metabolism genes (PMGs) vital for nucleic acid synthesis. Nevertheless, the precise function of PMGs in the pathophysiology of UC is not yet fully known. To this end, this study used state-of-the-art bioinformatics tools and approaches to discover and confirm the PMGs involved in UC. All the 114 candidate PMGs were compared for their expression levels. GSEA and GSVA were applied to define the functional and pathway implications of these PMGs. Lasso regression and SVM-RFE approaches were used for the identification of hub genes and to assess the diagnostic potential of eight PMGs in UC classification. The relationship between these critical PMGs and clinical features was also systematically evaluated as well. The expression levels of these eight PMGs were validated using datasets GSE206285 and GSE179285. Using bioinformatics and machine learning, this work seeks to establish the involvement of PMGs in UC. From the LASSO and SVM models, 114 DE PMGs were selected and investigated to build a stable predictive model. Based on these studies, the following genes: IMPDH1, GUK1, POLE3, ADCY3, ADCY4, PDE6B, PNPT1 and PDE4D were suggested as potential biomarkers of UC. Gene ontology enrichment analysis revealed that these genes are implicated in the biological processes of particular relevance to immune and inflammatory responses. The study also provided a lot of information on the interaction between immune cells and PMGs indicating that these genes may control some immune-related pathways in UC. Moreover, drug-gene interaction analysis presents potential therapeutic opportunities for potential drug targets which were further confirmed through molecular docking. Mendelian randomization analysis revealed that ADCY4 and PDAZN are involved in PMG-related processes, thus opening new possibilities for treatment. This work reveals eight PMGs closely related to UC and provides new perspectives on possible markers of this inflammatory disease. These findings not only increase the understanding of the pathogenesis of UC but also offer potential for improving the surveillance of disease and its progression. Show less

Class B1 G protein-coupled receptors (GPCRs) are important regulators of many physiological functions such as glucose homeostasis, which is mainly mediated by three peptide hormones, i.e., glucagon-like peptide-1 (GLP-1), glucagon (GCG), and glucose-dependent insulinotropic polypeptide (GIP). They trigger a cascade of signaling events leading to the formation of an active agonist-receptor-G protein complex. However, intracellular signal transducers can also activate the receptor independent of extracellular stimuli, suggesting an intrinsic role of G proteins in this process. Here, we report cryo-electron microscopy structures of the human GLP-1 receptor (GLP-1R), GCG receptor (GCGR), and GIP receptor (GIPR) in complex with G 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

To explore the prevalence and associated factors of obesity in Tibetan adults in Qinghai, China, and to determine the association between the FTO (rs1121980 and rs17817449) and MC4R gene (rs17782313 and rs12970134) polymorphisms with obesity. A cross-sectional survey was conducted in 2015 in Qinghai to selected Tibetan adults aged 20 to 80 years. Prevalence of obesity (BMI ≥ 28 kg/m A total of 1741 Tibetan adults were enrolled. The age- and sex- standardized prevalence of obesity and overweight was 18.09% and 31.71%, respectively. Male sex, older age, heavy level of leisure-time exercise, current smoke, and heavy level of occupational physical activity were associated with both obesity and overweight. MC4R gene polymorphisms were associated with obesity in Tibetan adults. No significant gene-environment interaction was detected. The prevalence of obesity and overweight in Tibetan adults was high. Both environmental and genetic factors contributed to the obesity prevalent. Show less

The skeleton is traditionally known for its structural support, organ protection, movement, and maintenance of mineral homeostasis. Over the last 10 years, bone has emerged as an endocrine organ with diverse physiological functions. The two key molecules in this context are fibroblast growth factor 23 (FGF23), secreted by osteocytes, and osteocalcin, a hormone produced by osteoblasts. FGF23 affects mineral homeostasis through its actions on the kidneys, and osteocalcin has beneficial effects in improving glucose homeostasis, muscle function, brain development, cognition, and male fertility. In addition, another osteoblast-derived hormone, lipocalin 2 (LCN2) has emerged into the researchers' field of vision. In this review, we mainly focus on LCN2's role in appetite regulation and glucose metabolism and also briefly introduce its effects in other pathophysiological conditions, such as nonalcoholic fatty liver disease, sarcopenic obesity, and cancer-induced cachexia. Show less

Anorectal malformations (ARMs) are congenital diseases that lead to postoperative fecal incontinence, constipation, and soiling, despite improvements in surgery; however, their pathological mechanisms remain unclear. Here, we report the role of microRNA-141-3p in maintaining homeostasis between apoptosis and autophagy in the lumbosacral defecation center of fetal rats with ARMs. Elevated microRNA-141-3p expression inhibited YIN-YANG-1 expression by binding its 3' UTR, and repressed autophagy and triggered apoptosis simultaneously. Then, adenylate cyclase 3 was screened to be the downstream target gene of YIN-YANG-1 by chromatin immunoprecipitation sequencing experiments, and Yin Yang 1 could positively activate the transcription of adenylate cyclase 3 by directly interacting with the motif GAGATGG and ATGG in its promoter. Intraamniotic microinjection of adeno-rno-microRNA-141-3p-sponge-GFP in fetal rats with ARMs on embryonic day 15 restored apoptosis-autophagy homeostasis. These findings reveal that microRNA-141-3p upregulation impaired homeostasis between apoptosis and autophagy by inhibiting the YIN-YANG-1/adenylate cyclase 3 axis, and that intraamniotic injection of anti-microRNA-141-3p helped maintain homeostasis in the lumbosacral defecation center of ARMs during embryogenesis. Show less

Brown adipose tissue (BAT) is the main site of nonshivering thermogenesis which plays an important role in thermogenesis and energy metabolism. However, the regulatory factors that inhibit BAT activity remain largely unknown. Here, cardiotrophin-like cytokine factor 1 (CLCF1) is identified as a negative regulator of thermogenesis in BAT. Adenovirus-mediated overexpression of CLCF1 in BAT greatly impairs the thermogenic capacity of BAT and reduces the metabolic rate. Consistently, BAT-specific ablation of CLCF1 enhances the BAT function and energy expenditure under both thermoneutral and cold conditions. Mechanistically, adenylate cyclase 3 (ADCY3) is identified as a downstream target of CLCF1 to mediate its role in regulating thermogenesis. Furthermore, CLCF1 is identified to negatively regulate the PERK-ATF4 signaling axis to modulate the transcriptional activity of ADCY3, which activates the PKA substrate phosphorylation. Moreover, CLCF1 deletion in BAT protects the mice against diet-induced obesity by promoting BAT activation and further attenuating impaired glucose and lipid metabolism. Therefore, our results reveal the essential role of CLCF1 in regulating BAT thermogenesis and suggest that inhibiting CLCF1 signaling might be a potential therapeutic strategy for improving obesity-related metabolic disorders. 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

Senescence is recognized as a principal risk factor for cardiovascular diseases, with a significant association between the senescence of cardiomyocytes and inferior cardiac function. Furthermore, type 2 diabetes exacerbates this aging process. Sodium-glucose co-transporter 2 inhibitor (SGLT2i) has well-established cardiovascular benefits and, in recent years, has been posited to possess anti-aging properties. However, there are no reported data on their improvement of cardiomyocytes function through the alleviation of aging. Consequently, our study aims to investigate the mechanism by which SGLT2i exerts anti-aging and protective effects at the cardiac level through its action on the FOXO1-ANGPTL4 pathway. To elucidate the underlying functions and mechanisms, we established both in vivo and in vitro disease models, utilizing mice with diabetic cardiomyopathy (DCM) induced by type 2 diabetes mellitus (T2DM) through high-fat diet combined with streptozotocin (STZ) administration, and AC16 human cardiomyocyte cell subjected to stimulation with high glucose (HG) and palmitic acid (PA). These models were employed to assess the changes in the senescence phenotype of cardiomyocytes and cardiac function following treatment with SGLT2i. Concurrently, we identified ANGPTL4, a key factor contributing to senescence in DCM, using RNA sequencing (RNA-seq) technology and bioinformatics methods. We further clarified ANGPTL4 role in promoting pathological aging of cardiomyocytes induced by hyperglycemia and hyperlipidemia through knockdown and overexpression of the factor, as well as analyzed the impact of SGLT2i intervention on ANGPTL4 expression. Additionally, we utilized chromatin immunoprecipitation followed by quantitative real-time PCR (ChIP-qPCR) to confirm that FOXO1 is essential for the transcriptional activation of ANGPTL4. The therapeutic intervention with SGLT2i alleviated the senescence phenotype in cardiomyocytes of the DCM mouse model constructed by high-fat feeding combined with STZ, as well as in the AC16 model stimulated by HG and PA, while also improving cardiac function in DCM mice. We observed that the knockdown of ANGPTL4, a key senescence-promoting factor in DCM identified through RNA-seq technology and bioinformatics, mitigated the senescence of cardiomyocytes, whereas overexpression of ANGPTL4 exacerbated it. Moreover, SGLT2i improved the senescence phenotype by suppressing the overexpression of ANGPTL4. In fact, we discovered that SGLT2i exert their effects by regulating the upstream transcription factor FOXO1 of ANGPTL4. Under conditions of hyperglycemia and hyperlipidemia, compared to the control group without FOXO1, the overexpression of FOXO1 in conjunction with SGLT2i intervention significantly reduced both ANGPTL4 mRNA and protein levels. This suggests that the FOXO1-ANGPTL4 axis may be a potential target for the cardioprotective effects of SGLT2i. Collectively, our study demonstrates that SGLT2i ameliorate the pathological aging of cardiomyocytes induced by a high glucose and high fat metabolic milieu by regulating the interaction between FOXO1 and ANGPTL4, thereby suppressing the transcriptional synthesis of the latter, and consequently restoring cardiac function. Show less

This study aimed to investigate the possible mechanisms by which ANGPTL4 is involved in the pathogenesis of choroidal neovascularization (CNV) and subretinal fibrosis. Differentially expressed genes in retinal pigmented epithelium (RPE)-choroid-sclera complex tissues from nAMD patients and control individuals were identified via the GEO database, followed by GO and KEGG analyses. A Venn diagram was used to identify EndMT-related DEGs. A logistic regression model was constructed to screen for prognostic genes. Laser-induced CNV mouse models were established and validated with FFA and OCTA. The expression of ANGPTL4 and EndMT-related markers in the RPE-choroid-sclera complex was measured via RT‒qPCR and Western blotting. TGF-β2-induced HUVECs were used as EndMT cell models, and specific siRNAs targeting ANGPTL4 (si-ANGPTL4) were designed and screened. The effects of ANGPTL4 knockdown on the migration and invasion of HUVECs were also examined. Laser-induced CNV mouse models were constructed, and an intravitreal injection of cholesterol-modified si-ANGPTL4 was used to knock down ANGPTL4. FFA, OCTA and immunofluorescence staining were used to observe CNV formation and subretinal fibrosis, and the expression of ANGPTL4 and EndMT-related markers was determined. ANGPTL4 expression was significantly increased in mice with CNV and colocalized with IB4. In TGF-β2-induced EndMT, ANGPTL4 was also upregulated, and its knockdown led to the inhibition of EndMT and cell migration and invasion, while its overexpression promoted the EndMT process. ANGPTL4 knockdown reduced the formation of CNV and subretinal fibrosis in mice with CNV by suppressing EndMT. ANGPTL4 may promote CNV and subretinal fibrosis through EndMT, suggesting that ANGPTL4 may be a novel potential target for nAMD therapy. Show less

Retinopathy is a common complication of diabetes mellitus and the leading cause of visual impairment. Danggui Buxue decoction (RRP) has been used as a traditional drug for the treatment of diabetic nephropathy for many years. The aim of this study was to investigate the effects of RRP on hypoxia-induced retinal Müller cell injury. A model of retinal Müller cell damage was created using high glucose levels (25 mmol/L) and/or exposure to low oxygen conditions (1% O2). RRP was given to rats by continuous gavage for 7 days to obtain drug-containing serum. After sterilization, the serum was added to the culture medium at a ratio of 10%. Cell viability, apoptosis, and cell proliferation were assessed using the CCK-8 kit, Annexin V-FITC/propidium iodide apoptosis kit, and EdU kit. The mRNA levels of angiogenesis factors (ANGPTL4, VEGF) and inflammatory factors (IL-1B, ICAM-1) were detected by RT-qPCR. Western blot analysis was employed to assess the levels of proteins related to the ATF4/CHOP pathway. Following hypoxia for 48 h and 72 h, there was a significant decrease in cell viability and proliferation, as well as a notable increase in apoptosis compared to the control group (21% O2). However, high glucose stimulation had no significant effect, and high glucose combined with hypoxia had no further damage to cells. After 48 h of exposure to low oxygen levels, the mRNA expression levels of ANGPTL4, VEGF, IL-1B, and ICAM-1 in retinal Müller cells were significantly higher than in the control group (21% O2). RRP treatment significantly alleviated the increase of cell apoptosis and the upregulation of IL-1B and-1 in retinal Müller cells induced by hypoxia. RRP has the potential to reduce the suppression of the ATF4/CHOP pathway in hypoxia-induced retinal Müller cells, and it significantly alleviates cell apoptosis through regulating inflammatory factors and the ATF4/CHOP pathway. Show less

Increasing evidence suggests that metabolic disorders such as obesity are implicated in the development of Alzheimer's disease (AD). The pathological buildup of lipids in microglia is regarded as a key indicator in brain aging and the progression of AD, yet the mechanisms behind this process remain uncertain. The adipokine ANGPTL4 is strongly associated with obesity and is thought to play a role in the advancement of neurodegenerative diseases. This study utilized RNA sequencing to identify differential expression in lipid-accumulating BV2 microglia and investigated the potential mechanism through ANGPTL4 overexpression in BV2. Subsequently, animal models and clinical data were employed to further explore alterations in circulating ANGPTL4 levels in AD. RNA sequencing results indicated a correlation between ANGPTL4 and microglial lipid accumulation. The overexpression of ANGPTL4 in microglia resulted in increased secretion of inflammatory factors, elevated oxidative stress levels, and diminished antiviral capacity. Furthermore, when simulating the coexistence of AD and obesity through combined treatment with Amyloid-Beta 1-42 peptide (Aβ) and Free Fatty Acids (FFA) in vitro, we observed a notable upregulation of ANGPTL4 expression, highlighting its potential role in the interplay between AD and obesity. In vivo experiments, we also observed a significant increase in ANGPTL4 expression in the hippocampus and plasma of APP/PS1 mice compared to wild-type controls. This was accompanied by heightened microglial activation and reduced expression of longevity-related genes in the hippocampus. Clinical data from the UK Biobank indicated that plasma ANGPTL4 levels are elevated in patients with AD when compared to healthy controls. Moreover, significantly higher ANGPTL4 levels were observed in obese AD patients relative to their non-obese counterparts. Our findings suggest that ANGPTL4-mediated microglial aging may serve as a crucial link between AD and obesity, proposing ANGPTL4 as a potential biomarker for AD. Show less

To elucidate the mechanisms of angiopoietin-like 4 (ANGTPL4) in neovascularization (NV) in retinopathy of prematurity (ROP). We compared ANGPTL4 expression levels of aqueous humour and vitreous fluid samples in infants with acute-phase ROP and control group. ANGPTL4 Show less

Lipoprotein lipase (LPL) and multiple regulators of LPL activity (e.g., APOC2 and ANGPTL4) are present in all vertebrates, but GPIHBP1-the endothelial cell (EC) protein that captures LPL within the subendothelial spaces and transports it to its site of action in the capillary lumen-is present in mammals but in not chickens or other lower vertebrates. In mammals, GPIHBP1 deficiency causes severe hypertriglyceridemia, but chickens maintain low triglyceride levels despite the absence of GPIHBP1. To understand intravascular lipolysis in lower vertebrates, we examined LPL expression in mouse and chicken hearts. In both species, LPL was abundant on capillaries, but the distribution of Lpl transcripts was strikingly different. In mouse hearts, Lpl transcripts were extremely abundant in cardiomyocytes but were barely detectable in capillary ECs. In chicken hearts, Lpl transcripts were absent in cardiomyocytes but abundant in capillary ECs. In zebrafish hearts, lpl transcripts were also in capillary ECs but not cardiomyocytes. In both mouse and chicken hearts, LPL was present, as judged by immunogold electron microscopy, in the glycocalyx of capillary ECs. Thus, mammals produce LPL in cardiomyocytes and rely on GPIHBP1 to transport the LPL into capillaries, whereas lower vertebrates produce LPL directly in capillary ECs, rendering an LPL transporter unnecessary. Show less

High altitude pulmonary edema (HAPE) is an idiopathic, noncardiogenic form of pulmonary edema that occurs at high altitudes. It is characterized by a severe clinical course and carries a significant mortality risk. Despite its clinical relevance, the molecular mechanisms underlying HAPE are not well understood. We conducted whole-transcriptome RNA sequencing on blood samples from 6 pairs of HAPE patients and healthy controls to identify differentially expressed (DE) mRNAs, miRNAs, circRNAs, lncRNAs, along with alternative splicing (AS) events, gene fusions, and novel transcripts. To explore the regulatory dynamics, we constructed ceRNA networks and analyzed immune cell infiltration patterns, further annotating the biological functions of these transcripts. For empirical validation, we selected five circRNAs from the ceRNA network and conducted RT-qPCR on 50 paired samples. Additionally, we assessed the correlations between circRNA expression levels and clinical data to evaluate their diagnostic potential. We observed 2,023 differentially expressed mRNAs (DEmRNAs), 84 DEmiRNAs, 200 DEcircRNAs, and 3,573 DElncRNAs. A total of 139 'A3SS' events, 103 'A5SS' events, 545 'MXE' events, 14 'RI' events, and 1,482 'SE' events were identified in the AS events analysis between the two groups. Two ceRNA networks were constructed. T cells, follicular helper, and Macrophages M1 cells exhibited the strongest positive correlation (R=0.82), while naive B cells and memory B cells demonstrated the strongest negative correlation (R=-0.62). In total, the expression of three circRNAs was significantly different in a larger cohort. Hsa_circ₀₀₅₈₄₉₇, hsa_circ₀₀₈₁₀₀₆, and hsa_circ₀₀₈₃₂₂₀ demonstrated consistent with the RNA sequencing results. These three circRNAs strongly correlate with clinical indicators and exhibit potential as diagnostic biomarkers. Finally, we verified five genes (CXCR4, HSD17B2, ANGPTL4, TIMP3, N4BP3) that were differentially expressed in endothelial cells under normoxia and hypoxia through bioinformatics and RT-qPCR analyses. This study elucidates the differential expression of coding and non-coding RNAs (ncRNAs) in HAPE, identifies new transcripts and genes, and enhances our understanding of the transcriptional characteristics of HAPE. Moreover, it highlights the potential role of circRNAs in advancing the diagnosis and treatment of HAPE. 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