OBJECTIVE: To examine the mechanism of action of tanshinone II A (Tan II A) in promoting chemosensitization of osteosarcoma cells to cisplatin (DDP). METHODS: The effects of different concentrations of Tan II A (0-80 µ mol/L) and DDP (0-2 µ mol/L) on the proliferation of osteosarcoma cell lines (U2R, U2OS, 143B, and HOS) at different times were examined using the cell counting kit-8 and colony formation assays. Migration and invasion of U2R and U2OS cells were detected after 24 h treatment with 30 µ mol/L Tan II A, 0.5 µ mol/L DDP alone, and a combination of 10 µ mol/L Tan II A and 0.25 µ mol/L DDP using the transwell assay. After 48 h of treatment of U2R and U2OS cells with predetermined concentrations of each group of drugs, the cell cycle was analyzed using a cell cycle detection kit and flow cytometry. After 48 h treatment, apoptosis of U2R and U2OS cells was detected using annexin V-FITC apoptosis detection kit and flow cytometry. U2R cells were inoculated into the unilateral axilla of nude mice and then the mice were randomly divided into 4 groups of 6 nude mice each. The 4 groups were treated with equal volume of Tan II A (15 mg/kg), DDP (3 mg/kg), Tan II A (7.5 mg/kg) + DDP (1.5 mg/kg), and normal saline, respectively. The body weight of the nude mice was weighed, and the tumor volume and weight were measured. Cell-related gene and signaling pathway expression were detected by RNA sequencing and Kyoto Encyclopedia of Genes and Genomes pathway analysis. p38 MAPK signaling pathway proteins and apoptotic protein expressions were detected by Western blot. RESULTS: In vitro studies have shown that Tan II A, DDP and the combination of Tan II A and DDP inhibit the proliferation, migration and invasion of osteosarcoma cells. The inhibitory effect was more pronounced in the Tan II A and DDP combined treatment group (P<0.05 or P<0.01). Osteosarcoma cells underwent significantly cell-cycle arrest and cell apoptosis by Tan II A-DDP combination treatment (P<0.05 or P<0.01). In vivo studies demonstrated that the Tan II A-DD combination treatment group significantly inhibited tumor growth compared to the Tan II A and DDP single drug group (P<0.01). Additionally, we found that the combination of Tan II A and DDP treatment enhanced the p38 MAPK signaling pathway. Western blot assays showed higher p-p38, cleaved caspase-3, and Bax and lower caspase-3, and Bcl-2 expressions with the combination of Tan II A and DDP treatment compared to the single drug treatment (P<0.01). CONCLUSION Tan II A synergizes with DDP by activating the p38/MAPK pathway to upregulate cleaved caspase-3 and Bax pro-apoptotic gene expressions, and downregulate caspase-3 and Bcl-2 inhibitory apoptotic gene expressions, thereby enhancing the chemosensitivity of osteosarcoma cells to DDP.
Abietanes/therapeutic use* ; Osteosarcoma/enzymology* ; Cisplatin/therapeutic use* ; Humans ; Cell Line, Tumor ; Animals ; Apoptosis/drug effects* ; Mice, Nude ; Cell Proliferation/drug effects* ; Cell Movement/drug effects* ; p38 Mitogen-Activated Protein Kinases/metabolism* ; MAP Kinase Signaling System/drug effects* ; Bone Neoplasms/enzymology* ; Cell Cycle/drug effects* ; Xenograft Model Antitumor Assays ; Mice ; Drug Resistance, Neoplasm/drug effects* ; Neoplasm Invasiveness ; Mice, Inbred BALB C

OBJECTIVE: To elucidate the effect of Huanglian-Renshen-Decoction (HRD) on ameliorating type 2 diabetes mellitus by maintaining islet β -cell identity through regulating paracrine and endocrine glucagon-like peptide-1 (GLP-1)/GLP-1 receptor (GLP-1R) in both islet and intestine. METHODS: The db/db mice were divided into the model (distilled water), low-dose HRD (LHRD, 3 g/kg), high-dose HRD (HHRD, 6 g/kg), and liraglutide (400 µ g/kg) groups using a random number table, 8 mice in each group. The db/m mice were used as the control group (n=8, distilled water). The entire treatment of mice lasted for 6 weeks. Blood insulin, glucose, and GLP-1 levels were quantified using enzyme-linked immunosorbent assay kits. The proliferation and apoptosis factors of islet cells were determined by immunohistochemistry (IHC) and immunofluorescence (IF) staining. Then, GLP-1, GLP-1R, prohormone convertase 1/3 (PC1/3), PC2, v-maf musculoaponeurotic fibrosarcoma oncogene homologue A (MafA), and pancreatic and duodenal homeobox 1 (PDX1) were detected by Western blot, IHC, IF, and real-time quantitative polymerase chain reaction, respectively. RESULTS: HRD reduced the weight and blood glucose of the db/db mice, and improved insulin sensitivity at the same time (P<0.05 or P<0.01). HRD also promoted mice to secrete more insulin and less glucagon (P<0.05 or P<0.01). Moreover, it also increased the number of islet β cell and decreased islet α cell mass (P<0.01). After HRD treatment, the levels of GLP-1, GLP-1R, PC1/3, PC2, MafA, and PDX1 in the pancreas and intestine significantly increased (P<0.05 or P<0.01). CONCLUSION HRD can maintain the normal function and identity of islet β cell, and the underlying mechanism is related to promoting the paracrine and endocrine activation of GLP-1 in pancreas and intestine.
Animals ; Glucagon-Like Peptide 1/metabolism* ; Diabetes Mellitus, Type 2/metabolism* ; Glucagon-Like Peptide-1 Receptor/metabolism* ; Insulin-Secreting Cells/pathology* ; Drugs, Chinese Herbal/pharmacology* ; Male ; Blood Glucose/metabolism* ; Insulin/blood* ; Mice ; Intestinal Mucosa/pathology* ; Apoptosis/drug effects* ; Cell Proliferation/drug effects* ; Islets of Langerhans/pathology*

OBJECTIVE: To explore the role of the natural compound hesperidin in glycolysis, the key ratelimiting enzyme, in colorectal cancer (CRC) cell lines. METHODS: In vitro, HCT116 and SW620 were treated with different doses of hesperidin (0-500 µmol/L), cell counting kit-8 and colone formation assays were utilized to detected inhibition effect of hesperidin on CRC cell lines. Transwell and wound healing assays were performed to detect the ability of hesperidin (0, 25, 50 and 75 µmol/L) to migrate CRC cells. To confirm the apoptotic-inducing effect of hesperidin, apoptosis and cycle assays were employed. Western blot, glucose uptake, and lactate production determination measurements were applied to determine inhibitory effects of hesperidin (0, 25 and 50 µmol/L) on glycolysis. In vivo, according to the random number table method, nude mice with successful tumor loading were randomly divided into vehicle, low-dose hesperidin (20 mg/kg) and high-dose hesperidin (60 mg/kg) groups, with 6 mice in each group. The body weights and tumor volumes of mice were recorded during 4-week treatment. The expression of key glycolysis rate-limiting enzymes was determined using Western blot, and glucose uptake and lactate production were assessed. Finally, protein interactions were probed with DirectDIA Quantitative Proteomics, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. RESULTS: Hesperidin could inhibit CRC cell line growth (P<0.05 or P<0.01). Moreover, hesperidin presented an inhibitory effect on the migrating abilities of CRC cells. Hesperidin also promoted apoptosis and cell cycle alterations (P<0.05). The immunoblotting results manifested that hesperidin decreased the levels of hexokinase 2, glucose transporter protein 1 (GLUT1), GLUT3, L-lactate dehydrogenase A, 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 2 (PFKFB2), PFKFB3, and pyruvate kinase isozymes M2 (P<0.01). It remarkably suppressed tumor xenograft growth in nude mice. GO and KEGG analyses showed that hesperidin treatment altered metabolic function. CONCLUSION Hesperidin inhibits glycolysis and is a potential therapeutic choice for CRC treatment.
Hesperidin/therapeutic use* ; Colorectal Neoplasms/metabolism* ; Glycolysis/drug effects* ; Animals ; Humans ; Apoptosis/drug effects* ; Mice, Nude ; Cell Movement/drug effects* ; Cell Line, Tumor ; Cell Proliferation/drug effects* ; Glucose/metabolism* ; Cell Cycle/drug effects* ; Mice, Inbred BALB C ; Mice ; HCT116 Cells ; Lactic Acid

OBJECTIVE: To entrap carvacrol (CAR) in bovine serum albumin nanoparticles (BSANPs) to form CAR-loaded BSANPs (CAR@BSANPs) and to explore the anti-cancer effects in breast adenocarcinoma cells (MCF-7 cells) treated with CAR and CAR@BSANPs. METHODS: A desolvation method was used to synthesize BSANPs and CAR@BSANPs. The BSANPs and CAR@BSANPs were characterized by several physicochemical methods, including visual observation, high-resolution field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and high-performance liquid chromatography. MCF-7 cells were used and analyzed after 24 h of exposure to CAR and CAR@BSANPs at half-maximal inhibitory concentration. The anti-proliferative, apoptotic, reactive oxygen species (ROS), and nitric oxide (NO) scavenging activity as well as gene expression analysis were investigated by the cell viability assay, phase-contrast microscopy, 2',7'-dichlorofluorescein-diacetate assay, Griess-Illosvoy colorimetric assay, and quantitative real-time polymerase chain reaction, respectively. RESULTS: CAR and CAR@BSANPs showed anti-proliferative, apoptotic, ROS generation, and NO scavenging effects on MCF-7 cells. Expression profile of B-cell lymphoma 2-like 11 (BCL2L11), vascular endothelial growth factor A (VEGFA), hypoxia inducible factor factor-1α (HIF1A), BCL2L11/apoptosis regulator (BAX), and BCL2L11/Bcl2 homologous antagonist/killer 1 (BAK1) ratios revealed downregulated genes; and BAX, BAK1, and CASP8 were upregulated by CAR and CAR@BSANPs treatment. In vitro anticancer assays of the CAR and CAR@BSANPs showed that CAR@BSANPs demonstrated higher therapeutic efficacy in the MCF-7 cells than CAR. CONCLUSIONS CAR and CAR@BSANPs affect gene expression and may subsequently reduce the growth and proliferation of the MCF-7 cells. Molecular targeting of regulatory genes of the MCF-7 cells with CAR and CAR@BSANPs may be an effective therapeutic strategy against breast cancer.
Humans ; Cymenes ; Nanoparticles/ultrastructure* ; MCF-7 Cells ; Breast Neoplasms/genetics* ; Apoptosis/drug effects* ; Serum Albumin, Bovine/chemistry* ; Monoterpenes/therapeutic use* ; Adenocarcinoma/genetics* ; Cell Proliferation/drug effects* ; Reactive Oxygen Species/metabolism* ; Female ; Cell Survival/drug effects* ; Animals ; Gene Expression Regulation, Neoplastic/drug effects* ; Nitric Oxide/metabolism* ; Cattle

OBJECTIVE: To evaluate the anti-hepatocellular carcinoma (HCC) activity of total alkaloids from Gelsemium elegans Benth. (TAG) in vivo and in vitro and to elucidate their potential mechanisms of action through transcriptomic analysis. METHODS: TAG extraction was conducted, and the primary components were quantified using high-performance liquid chromatography (HPLC). The effects of TAG (100, 150, and 200 µg/mL) on various tumor cells, including SMMC-7721, HepG2, H22, CAL27, MCF7, HT29, and HCT116, were assessed. Effects of TAG on HCC proliferation and apoptosis were detected by colony formation assays and cell stainings. Caspase-3, Bcl-2, and Bax protein levels were detected by Western blotting. In vivo, a tumor xenograft model was developed using H22 cells. Totally 40 Kunming mice were randomly assigned to model, cyclophosphamide (20 mg/kg), TAG low-dose (TAG-L, 0.5 mg/kg), and TAG high-dose (TAG-H, 1 mg/kg) groups, with 10 mice in each group. Tumor volume, body weight, and tumor weight were recorded and compared during 14-day treatment. Immune organ index were calculated. Tissue changes were oberseved by hematoxylin and eosin staining and immunohistochemistry. Additionally, transcriptomic and metabolomic analyses, as well as quatitative real-time polymerase chain reaction (RT-qPCR), were performed to detect mRNA and metabolite expressions. RESULTS: HPLC successfully identified the components of TAG extraction. Live cell imaging and analysis, along with cell viability assays, demonstrated that TAG inhibited the proliferation of SMMC-7721, HepG2, H22, CAL27, MCF7, HT29, and HCT116 cells. Colony formation assays, Hoechst 33258 staining, Rhodamine 123 staining, and Western blotting revealed that TAG not only inhibited HCC proliferation but also promoted apoptosis (P<0.05). In vivo experiments showed that TAG inhibited the growth of solid tumors in HCC in mice (P<0.05). Transcriptomic analysis and RT-qPCR indicated that the inhibition of HCC by TAG was associated with the regulation of the key gene CXCL13. CONCLUSION TAG inhibits HCC both in vivo and in vitro, with its inhibitory effect linked to the regulation of the key gene CXCL13.
Animals ; Apoptosis/drug effects* ; Liver Neoplasms/genetics* ; Carcinoma, Hepatocellular/genetics* ; Humans ; Alkaloids/therapeutic use* ; Gelsemium/chemistry* ; Cell Line, Tumor ; Cell Proliferation/drug effects* ; Mice ; Xenograft Model Antitumor Assays

OBJECTIVE: To investigate the effect and mechanism of Shuangshi Tonglin Capsules (SSTL) in the treatment of prostate fibrosis (PF). METHODS: Human prostate stromal cells (WPMY-1) were used for in vitro experiments to establish PF cell models induced with estradiol (E₂). The cell proliferation, migration and clonogenic capacity were determined by cell counting kit-8, scratch assay, and crystal violet staining, respectively. Sprague-Dawley rats were used for in vivo experiments. The changes in histomorphology and organ index of rat prostate by SSTL were determined. Pathologic changes and collagen deposition changes in rat prostate were observed by haematoxylin and eosin (HE) and Masson staining. Enzyme-linked immunosorbent assay kits were used to determine changes in rat PF markers fibroblast growth factor-23 (FGF-23), E₂ and prostate specific antigen (PSA). Mechanistically, changes in oxidative stress indicators by SSTL were determined in WPMY-1 cells and PF rats. Then the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) and transforming growth factor-β1 (TGF-β1)/Smad pathway-related proteins as well as Nrf2 and TGF-β1 mRNA were further detected by Western blot or quantitative real-time polymerase chain reaction both in vivo and in vitro. RESULTS: In the efficacy study, SSTL significantly reduced the proliferation, migration, and clonogenic ability of cells, improved the morphology of the glandular tissue, significantly reduced the prostate index, reduced glandular fibrous tissue and collagen deposition, and resulted in a significant decrease in the levels of FGF-23, E₂ and PSA (P<0.01 or P<0.05). In the mechanistic study, SSTL ameliorated oxidative stress by significantly increasing superoxide dismutase and glutathione peroxidase levels and decreasing malondialdehyde level in WPMY-1 cells and rats (P<0.01 or P<0.05). SSTL significantly elevated the expressions of Nrf2, HO-1, NAD(P)H quinone oxidoreductase 1 (NQO-1), and Smad7 proteins in both cells and rats, and significantly decreased the expressions of TGF-β1, collagen I, α-smooth muscle actin and Smad4 proteins (P<0.01 or P<0.05). SSTL also elevated the content of Nrf2 mRNA and decreased the content of TGF-β1 mRNA in cells and rats (P<0.01 or P<0.05). The Nrf2 inhibitor ML385 was added in in vitro experiments to further validate the pathway relevance. CONCLUSION SSTL was effective in improving PF in vivo and in vitro, and its mechanism of action may function through the Nrf2/TGF-β1 signaling pathway.
Male ; NF-E2-Related Factor 2/metabolism* ; Animals ; Drugs, Chinese Herbal/therapeutic use* ; Signal Transduction/drug effects* ; Transforming Growth Factor beta1/metabolism* ; Rats, Sprague-Dawley ; Humans ; Fibrosis ; Prostate/drug effects* ; Cell Proliferation/drug effects* ; Capsules ; Cell Movement/drug effects* ; Oxidative Stress/drug effects* ; Rats

OBJECTIVES: To explore the underlying pharmacological mechanisms and its potential effects of Chinese medicine herbal formula Sini Powder (SNP) on hepatocellular carcinoma (HCC). METHODS: The active components of SNP and their in vivo distribution were identified using ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. Construction of component-target-disease networks, protein-protein interaction network, Gene Ontology function and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis, and molecular docking were employed to analyze the active components and anti-HCC mechanisms of SNP. Cell viability assay and wound healing assay were utilized to confirm the effect of SNP-containing serum (2.5%, 5.0%, 10%, 20%, and 40%), isoprenaline or propranolol (both 10, 100, and 1,000 µ mol/L) on proliferation and migration of HepG 2 or Huh7 cells. Meanwhile, the effect of isoprenaline or propranolol on the β 2 adrenergic receptor (ADRB2) mRNA expression on HepG2 cells were measured by real-time quantitative reverse transcription (RT-qPCR). Mice with subcutaneous tumors were either subjected to chronic restraint stress (CRS) followed by SNP administration (364 mg/mL) or directly treated with SNP (364 mg/mL). These two parallel experiments were performed to validate the effects of SNP on stress responses. Stress-related proteins and hormones were quantified using RT-qPCR, enzyme-linked immunosorbent assay, and immunohistochemistry. Metagenomic sequencing was performed to confirm the influence of SNP on the gut microbiota in the tumor-bearing CRS mice. RESULTS: The distribution of the 12 active components of SNP was confirmed in various tissues and feces. Network pharmacology analysis confirmed the anti-HCC effects of the 5 active components. The potential anti-HCC mechanisms of SNP may involve the epidermal growth factor receptor (EGFR), proto-oncogene tyrosine-protein kinase Src (SRC) and signal transducer and activator of transcription 3 (STAT3) pathways. SNP-containing serum inhibited the proliferation of HepG2 and Huh7 cells at concentrations of 2.5% and 5.0%, respectively, after 24 h of treatment. Furthermore, SNP suppressed tumor progression in tumor-bearing mice exposed to CRS. SNP treatment also downregulated the expressions of stress-related proteins and pro-inflammatory cytokines, primarily by modulating the gut microbiota. Specifically, the abundance of Alistipes and Prevotella, which belong to the phylum Bacteroidetes, increased in the SNP-treated group, whereas Lachnospira, in the phylum Firmicutes, decreased. CONCLUSION SNP can combat HCC by alleviating stress responses through the regulation of gut microbiota.
Animals ; Gastrointestinal Microbiome/drug effects* ; Liver Neoplasms/microbiology* ; Carcinoma, Hepatocellular/microbiology* ; Humans ; Drugs, Chinese Herbal/therapeutic use* ; Powders ; Cell Proliferation/drug effects* ; Mice ; Molecular Docking Simulation ; Cell Line, Tumor ; Hep G2 Cells ; Receptors, Adrenergic, beta-2/genetics* ; Stress, Physiological/drug effects* ; Cell Movement/drug effects* ; Male ; Protein Interaction Maps/drug effects* ; Cell Survival/drug effects* ; Proto-Oncogene Mas

OBJECTIVE: To investigate the effect of miR-483-5p on hepatocellular carcinoma (HCC) cells proliferation and stemness, as well as the attenuating effect of Pien Tze Huang (PZH). METHODS: Differentially expressed miRNA between HepG2 cells and hepatic cancer stem-like cells (HCSCs) were identified by a miRNA microarray assay. miR-483-5p mimics were transfected into HepG2 cells to explore the effects of miR-483-5p on cell proliferation and stemness. HepG2 cells and HCSCs were treated with PZH (0, 0.25, 0.50 and 0.75 mg/mL) to explore the effects of PZH on the proliferation and stemness, both in non-induced state and the state induced by miR-483-5p mimics. RESULTS: miR-483-5p was significantly up-regulated in HCSCs and its overexpression increased cell proliferation and stemness in HepG2 cells (P<0.05). PZH not only significantly inhibited proliferation in HepG2 cells, but also significantly suppressed the cell proliferation and self-renewal of HCSCs (P<0.05). The effects of miR-483-5p mimics on proliferation and stemness of HepG2 cells were partially abolished by PZH. CONCLUSIONS miR-483-5p promotes proliferation and enhances stemness of HepG2 cells, which were attenuated by PZH, demonstrating that miR-483-5p is a potential molecular target for the treatment of HCC and provide experimental evidence to support clinical use of PZH for patients with HCC.
Humans ; MicroRNAs/metabolism* ; Cell Proliferation/drug effects* ; Liver Neoplasms/drug therapy* ; Carcinoma, Hepatocellular/drug therapy* ; Hep G2 Cells ; Neoplastic Stem Cells/metabolism* ; Drugs, Chinese Herbal/therapeutic use* ; Gene Expression Regulation, Neoplastic/drug effects*

OBJECTIVES: Metastasis is the primary cause of death in osteosarcoma, and current clinical treatments remain limited. BRD4, a key epigenetic regulator, has shown therapeutic promise in various cancers through its inhibition. However, the mechanistic role of BRD4 in osteosarcoma remains poorly understood. This study aims to elucidate the molecular mechanisms by which BRD4 regulate osteosarcoma progression and to explore novel therapeutic strategies. METHODS: Immunofluorescence was used to assess BRD4 expression levels in a tissue microarray containing 80 osteosarcoma samples from different patients. The Gene Expression Omnibus (GEO) dataset (GSE42352, containing survival data from 88 osteosarcoma patients) was downloaded to perform Kaplan-Meier survival analysis based on BRD4 gene expression levels. In vivo, an orthotopic intramedullary osteosarcoma model was established using HOS cells in C57 mice, followed by treatment with varying doses of the BRD4 inhibitor (+)-JQ1. Micro-CT, 3D reconstruction of bone tissue, and HE staining were employed to evaluate pathological changes in bone and intestinal lymph nodes. In vitro, cell viability was measured using the methyl thiazolyl tetrazolium (MTT) assay, while colony formation and Transwell assays assessed proliferative and invasive capacities. Chromatin-bound BRD4 was analyzed via co-immunoprecipitation combined with mass spectrometry (Co-IP/MS), and O-GlcNAc glycosylation sites and glycan chains of BRD4 were identified using Co-IP with Nano-LC MS/MS. Real-time PCR and Western blotting were used to analyze the relative mRNA and protein expression levels of target genes, respectively. RESULTS: BRD4 was positively expressed in 61.25% (49/80) of osteosarcoma tissues. Patients with high BRD4 expression exhibited significantly shorter survival times (P<0.05). In the orthotopic mouse model, intervention with (+)-JQ1, a potent and commonly used BETi, significantly inhibited tumor growth in vivo and reduced bone destruction (P<0.05). (+)-JQ1 treatment significantly suppressed the proliferation (P<0.001), invasion (P<0.001), and migration (P<0.05) of HOS cells. In osteosarcoma cells, BRD4 exhibited O-GlcNAc modifications at both N- and C- C-termini, particularly at Thr73, which is essential for protein stability. This modification also contributed to the activation of the EGFR tyrosine kinase inhibitor resistance pathway (KEGG Pathway: hsa01521). (+)-JQ1 treatment displaced BRD4 from enhancers and downregulated the transcription of pathway-related genes, such as EGFR and PDGFC, thereby suppressing the malignant behavior of osteosarcoma cells. CONCLUSIONS BRD4 promotes osteosarcoma progression via O-GlcNAc modification at Thr73 and plays a crucial role in tumor growth and metastasis.
Osteosarcoma/drug therapy* ; Humans ; Transcription Factors/metabolism* ; Animals ; Cell Cycle Proteins ; Mice ; Bone Neoplasms/drug therapy* ; Azepines/pharmacology* ; Cell Line, Tumor ; Cell Proliferation/drug effects* ; Triazoles/pharmacology* ; Mice, Inbred C57BL ; Nuclear Proteins/metabolism* ; Gene Expression Regulation, Neoplastic ; Male ; Bromodomain Containing Proteins

OBJECTIVES: Pyroptosis plays a critical role in tubulointerstitial lesions of diabetic kidney disease (DKD). Annexin A2 (ANXA2) is involved in cell proliferation, apoptosis, and adhesion and may be closely related to DKD, but its specific mechanism remains unclear. This study aims to investigate the role and molecular mechanism of ANXA2 in high glucose-induced pyroptosis of renal tubular epithelial cells, providing new targets for DKD prevention and treatment. METHODS: Human renal tubular epithelial HK-2 cells were divided into a normal glucose group (5.5 mmol/L), a high glucose group (30.0 mmol/L), and a osmotic control group (24.5 mmol/L mannitol+5.5 mmol/L glucose). ANXA2 expression was modulated by overexpression of plasmids and small interfering RNA (siRNA). Cell proliferation was measured by 5-ethynyl-2'-deoxyuridine (EdU) assay, apoptosis by flow cytometry, and ANXA2, p50, and p65 subcellular localization by immunofluorescence. Western blotting was employed to detect α-smooth muscle actin (α-SMA), fibronectin (FN), and collagen type IV (Col-IV). Real-time fluorescence quantitative PCR (RT-qPCR) and Western blotting were used to analyze nuclear factor-κB (NF-κB) subunits p50/p65 and the pyroptosis pathway factors NLR family Pyrin domain containing 3 (NLRP3), caspase-1, inferleukin (IL)-1β, and IL-18. Protein interactions between ANXA2 and p50/p65 were examined by co-immunoprecipitation, while chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays were used to examine NF-κB binding to the ANXA2 promoter. RESULTS: High glucose upregulated ANXA2 expression and promoted its nuclear translocation (P<0.01). High glucose reduced cell proliferation, increased apoptosis, and elevated α-SMA, FN, and Col-IV expression (all P<0.05); ANXA2 overexpression aggravated these effects (all P<0.05), while ANXA2 knockdown reversed them (all P<0.05). High glucose activated NF-κB and increased NLRP3, caspase-1, L-1β, and IL-18 mRNA and protein expression (all P<0.05); ANXA2 overexpression further enhanced this, whereas knockdown suppressed NF-κB activation and downstream factors (all P<0.05). Co-immunoprecipitation confirmed ANXA2 directly binds the NF-κB subunit p65. ChIP assays revealed p65 binds specifically to ANXA2 promoter regions (ChIP-2, ChIP-4, and ChIP-6), and luciferase activity in corresponding mutant constructs (M2, M4, and M6) was significantly increased versus controls (all P<0.05), confirming positive transcriptional regulation of ANXA2 by p65. CONCLUSIONS ANXA2 and NF-κB form a positive feedback loop that sustains NLRP3 inflammasome activation, promotes pyroptosis pathway activation, and aggravates high glucose-induced renal tubular epithelial cell injury. Targeting ANXA2 or blocking its interaction with p65 may be a novel strategy to slow DKD progression.
Humans ; Pyroptosis/drug effects* ; Annexin A2/physiology* ; Epithelial Cells/cytology* ; Kidney Tubules/cytology* ; Glucose/pharmacology* ; Diabetic Nephropathies/metabolism* ; NF-kappa B/metabolism* ; Cell Line ; Cell Proliferation ; Transcription Factor RelA/metabolism* ; Feedback, Physiological