BACKGROUND: P16 inactivation is frequently accompanied by telomerase reverse transcriptase ( TERT ) amplification in human cancer genomes. P16 inactivation by DNA methylation often occurs automatically during immortalization of normal cells by TERT . However, direct evidence remains to be obtained to support the causal effect of epigenetic changes, such as P16 methylation, on cancer development. This study aimed to provide experimental evidence that P16 methylation directly drives cancer development. METHODS: A zinc finger protein-based P16 -specific DNA methyltransferase (P16-Dnmt) vector containing a "Tet-On" switch was used to induce extensive methylation of P16 CpG islands in normal human fibroblast CCD-18Co cells. Battery assays were used to evaluate cell immortalization and transformation throughout their lifespan. Cell subcloning and DNA barcoding were used to track the diversity of cell evolution. RESULTS: Leaking P16-Dnmt expression (without doxycycline-induction) could specifically inactivate P16 expression by DNA methylation. P16 methylation only promoted proliferation and prolonged lifespan but did not induce immortalization of CCD-18Co cells. Notably, cell immortalization, loss of contact inhibition, and anchorage-independent growth were always prevalent in P16-Dnmt&TERT cells, indicating cell transformation. In contrast, almost all TERT cells died in the replicative crisis. Only a few TERT cells recovered from the crisis, in which spontaneous P16 inactivation by DNA methylation occurred. Furthermore, the subclone formation capacity of P16-Dnmt&TERT cells was two-fold that of TERT cells. DNA barcoding analysis showed that the diversity of the P16-Dnmt&TERT cell population was much greater than that of the TERT cell population. CONCLUSION P16 methylation drives TERT -mediated immortalization and transformation of normal human cells that may contribute to cancer development.
Humans ; Telomerase/genetics* ; DNA Methylation/physiology* ; Fibroblasts/cytology* ; Cyclin-Dependent Kinase Inhibitor p16/metabolism* ; Cell Line ; Cell Transformation, Neoplastic/genetics*

BACKGROUND: Senescent human skin primary fibroblast (FB) models have been established for studying aging-related, proliferative, and inflammatory skin diseases. The aim of this study was to compare the transcriptome characteristics of human primary dermal FBs from children and the elderly with four senescence models. METHODS: Human skin primary FBs were obtained from healthy children (FB-C) and elderly donors (FB-E). Senescence models were generated by ultraviolet B irradiation (FB-UVB), D-galactose stimulation (FB-D-gal), atazanavir treatment (FB-ATV), and replication exhaustion induction (FB-P30). Flow cytometry, immunofluorescence staining, real-time quantitative polymerase chain reaction, co-culturing with immune cells, and bulk RNA sequencing were used for systematic comparisons of the models. RESULTS: In comparison with FB-C, FB-E showed elevated expression of senescence-related genes related to the skin barrier and extracellular matrix, proinflammatory factors, chemokines, oxidative stress, and complement factors. In comparison with FB-E, FB-UVB and FB-ATV showed higher levels of senescence and expression of the genes related to the senescence-associated secretory phenotype (SASP), and their shaped immune microenvironment highly facilitated the activation of downstream immune cells, including T cells, macrophages, and natural killer cells. FB-P30 was most similar to FB-E in terms of general transcriptome features, such as FB migration and proliferation, and aging-related characteristics. FB-D-gal showed the lowest expression levels of senescence-related genes. In comparisons with the single-cell RNA sequencing results, FB-E showed almost complete simulation of the transcriptional spectrum of FBs in elderly patients with atopic dermatitis, followed by FB-P30 and FB-UVB. FB-E and FB-P30 showed higher similarity with the FBs in keloids. CONCLUSIONS Each senescent FB model exhibited different characteristics. In addition to showing upregulated expression of natural senescence features, FB-UVB and FB-ATV showed high expression levels of senescence-related genes, including those involved in the SASP, and FB-P30 showed the greatest similarity with FB-E. However, D-galactose-stimulated FBs did not clearly present aging characteristics.
Humans ; Fibroblasts/drug effects* ; Cellular Senescence/physiology* ; Skin/metabolism* ; Child ; Transcriptome/genetics* ; Aged ; Ultraviolet Rays ; Cells, Cultured ; Galactose/pharmacology*

BACKGROUND: Fibrosis of the connective tissue in the vaginal wall predominates in pelvic organ prolapse (POP), which is characterized by excessive fibroblast-to-myofibroblast differentiation and abnormal deposition of the extracellular matrix (ECM). Our study aimed to investigate the effect of ECM stiffness on vaginal fibroblasts and to explore the role of methyltransferase 3 (METTL3) in the development of POP. METHODS: Polyacrylamide hydrogels were applied to create an ECM microenvironment with variable stiffness to evaluate the effects of ECM stiffness on the proliferation, differentiation, and expression of ECM components in vaginal fibroblasts. METTL3 small interfering RNA and an overexpression vector were transfected into vaginal fibroblasts to evaluate the effects of METTL3 silencing and overexpression on matrix stiffness-induced vaginal fibroblast-to-myofibroblast differentiation and abnormal modulation of the ECM. Both procedures were detected by 5-ethynyl-2'-deoxyuridine (EdU) staining, Western blotting (WB), quantitative real-time polymerase chain reaction (RT-qPCR), and immunofluorescence (IF). RESULTS: Vaginal fibroblasts from POP patients exhibited increased proliferation ability, increased expression of α-smooth muscle actin (α-SMA), decreased expression of collagen I/III, and significantly decreased expression of tissue inhibitors of matrix metalloproteinases (TIMPs) in the stiff matrix ( P <0.05). Compared with those from non-POP patients, vaginal wall tissues from POP patients demonstrated a significant increase in METTL3 content ( P <0.05). However, silencing METTL3 expression in vaginal fibroblasts with high ECM stiffness resulted in decreased proliferation ability, decreased α-SMA expression, an increased ratio of collagen I/III, and increased TIMP1 and TIMP2 expression. Conversely, METTL3 overexpression significantly promoted the process of increased proliferation ability, increased α-SMA expression, decreased ratio of collagen I/III and decreased TIMP1 and TIMP2 expression in the soft matrix ( P <0.05). CONCLUSIONS Elevated ECM stiffness can promote excessive proliferation, differentiation, and abnormal ECM modulation, and the expression of METTL3 plays an important role in alleviating or aggravating matrix stiffness-induced vaginal fibroblast-to-myofibroblast differentiation and abnormal ECM modulation.
Humans ; Female ; Extracellular Matrix/metabolism* ; Cell Differentiation/genetics* ; Methyltransferases/metabolism* ; Pelvic Organ Prolapse/pathology* ; Fibroblasts/metabolism* ; Myofibroblasts/metabolism* ; Vagina/metabolism* ; Cell Proliferation/physiology* ; Cells, Cultured ; Middle Aged

Obesity and metabolic dysfunction-associated steatotic liver disease (MASLD) are linked to numerous chronic conditions, including cardiovascular disease, atherosclerosis, chronic kidney disease, and type II diabetes. Previous research identified the natural flavonoid diosmin, derived from Chrysanthemum morifolium, as a regulator of glucose metabolism. However, its effects on lipid metabolism and underlying mechanisms remained unexplored. The AMP-activated protein kinase (AMPK) pathway serves a critical function in glucose and lipid metabolism. The relationship between diosmin and the AMPK pathway has not been previously documented. This investigation examined diosmin's capacity to reduce lipid content through AMPK pathway activation in hepatoblastoma cell line G2 (HepG2) and 3T3-L1 cells. The study revealed that diosmin inhibits lipogenesis, indicating its potential as an anti-obesity agent in obese mice. Moreover, diosmin demonstrated effective MASLD alleviation in vivo. These findings suggest that diosmin may represent a promising therapeutic candidate for treating obesity and MASLD.
Diosmin/administration & dosage* ; Animals ; AMP-Activated Protein Kinases/genetics* ; Humans ; Non-alcoholic Fatty Liver Disease/enzymology* ; Mice ; Obesity/enzymology* ; Hep G2 Cells ; Male ; 3T3-L1 Cells ; Mice, Inbred C57BL ; Signal Transduction/drug effects* ; Lipid Metabolism/drug effects* ; Chrysanthemum/chemistry* ; Lipogenesis/drug effects*

Saponins associated with Panax notoginseng (P. notoginseng) demonstrate significant therapeutic efficacy across multiple diseases. However, certain high-yield saponins face limited clinical applications due to their reduced pharmacological efficacy. This study synthesized and evaluated 36 saponin-1,2,3-triazole derivatives of ginsenosides Rg1/Rb1 and notoginsenoside R1 for anti-adipogenesis activity in vitro. The research revealed that the ginsenosides Rg1-1,2,3-triazole derivative a17 demonstrates superior adipogenesis inhibitory effects. Structure-activity relationships (SARs) analysis indicates that incorporating an amidyl-substituted 1,2,3-triazole into the saponin side chain via Click reaction enhances anti-adipogenesis activity. Additionally, several other derivatives exhibit general adipogenesis inhibition. Compound a17 demonstrated enhanced potency compared to the parent ginsenoside Rg1. Mechanistic investigations revealed that a17 exhibits dose-dependent inhibition of adipogenesis in vitro, accompanied by decreased expression of preadipocytes. Peroxisome proliferator-activated receptor γ (PPARγ), fatty acid synthase (FAS), and fatty acid binding protein 4 (FABP4) adipogenesis regulators. These findings establish the ginsenoside Rg1-1,2,3-triazole derivative a17 as a promising adipocyte differentiation inhibitor and potential therapeutic agent for obesity and associated metabolic disorders. This research provides a foundation for developing effective therapeutic approaches for various metabolic syndromes.
Adipogenesis/drug effects* ; Triazoles/chemical synthesis* ; Ginsenosides/chemical synthesis* ; Saponins/chemical synthesis* ; Animals ; Mice ; Structure-Activity Relationship ; PPAR gamma/genetics* ; 3T3-L1 Cells ; Adipocytes/metabolism* ; Panax notoginseng/chemistry* ; Drug Design ; Molecular Structure ; Humans ; Cell Differentiation/drug effects* ; Fatty Acid-Binding Proteins/genetics*

OBJECTIVES: To propose a hypothesis that aloe-emodin may inhibit scar tissue fibrosis through thrombospondin-1(THBS1)-PI3K-Akt pathway. METHODS: By cultivating fibroblasts derived from scar tissue after cleft palate surgery in humans, aloe emodin of different concentrations (10, 20, 30, 40 and 50 μmol/L) was added to the cells which activity was detected. At the same time, transcriptome sequencing was performed on scar tissue and cells, and bioinformatics methods were used to explore potential targets and signaling pathways of scar tissue fibrosis. RESULTS: Aloe-emodin had a concentration dependent inhibitory effect on fibroblast proliferation,with the 40 μmol/L concentration group showing the most significant effect. The results of tissue and cell sequencing indicated that differentially expressed genes were significantly enriched in extracellular matrix-receptor interaction pathway, and shared a common differential gene which was THBS1. The ORA analysis results indicated that differentially expressed genes, including THBS1, were significantly enriched in the PI3K-Akt signaling pathway. CONCLUSIONS Aloe emodin may inhibit the PI3K-Akt pathway by downregulating THBS1, thereby reducing the proliferation activity of fibroblasts derived from postoperative palatal scar tissue.
Thrombospondin 1/genetics* ; Humans ; Signal Transduction/drug effects* ; Fibroblasts/cytology* ; Proto-Oncogene Proteins c-akt/metabolism* ; Fibrosis ; Phosphatidylinositol 3-Kinases/metabolism* ; Cicatrix/metabolism* ; Cell Proliferation/drug effects* ; Anthraquinones/pharmacology* ; Cells, Cultured

OBJECTIVES: This study aims to explore the potential relationships of cell-free DNA (cfDNA) in gingival crevicular fluid (GCF) with periodontal clinical indicators and the expression of DNA receptor pathway cyclic guanosine phosphate-adenosine phosphate synthase (cGAS)-stimulator of interferon genes (STING) in gingival tissues and human gingival fibroblasts (HGFs). METHODS: GCF and gingival tissue samples were collected from periodontally healthy individuals and patients diagnosed with periodontitis. Periodontal clinical indicators were recorded, including plaque index (PLT), bleeding index (BI), probing depth (PD), and clinical attachment level (CAL). The concentration of cfDNA in GCF was quantified, and the correlation between GCF and periodontal clinical indicators was analyzed. Immunofluorescence and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were used to assess the distribution of cGAS, STING, and p-STING in gingival tissues. Additionally, the mRNA expression levels of the key components of the cGAS-STING signaling pathway, namely, cGAS, STING, inhibitory of kappa-B kinase (IKK), nuclear factor kappa-B p65 (NF-κB p65), interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α), were measured. Furthermore, cfDNA extracted from GCF was employed to stimulate HGFs in the healthy control and periodontitis groups, and the mRNA expression levels of the key molecules of cGAS-STING signaling pathway were detected through Western blot and RT-qPCR. RESULTS: The concentration of cfDNA in GCF was found to be significantly elevated in the periodontitis group compared with the control group. Moreover, cfDNA concentration demonstrated a strong positive correlation with the periodontal clinical indicators. Immunofluorescence analysis revealed considerably increased percentage of fluorescence co-localization of cGAS, STING, and p-STING with the gingival fibroblast FSP-1 marker in the gingival tissues of the periodontitis group. The mRNA expression levels of cGAS, STING, IKK, NF-κB p65, IL-1β, IL-6,and TNF-α were significantly higher in the periodontitis group. In vitro stimulation of HGFs with GCF-derived cfDNA resulted in increased protein expression of cGAS and p-STING and considerably upregulated the mRNA expression levels of cGAS, STING, IKK, NF-κB p65, IL-1β, IL-6, and TNF-α in the healthy and periodontitis groups compared with the blank group. Correlation analysis showed that the concentration of cfDNA at the sampling site was positively correlated with the mRNA expression levels of cGAS, STING, NF-κB p65, and IL-6 in gingival tissues. CONCLUSIONS cfDNA concentrations in the GCF of patients with periodontitis are considerably elevated, and are associated with the activation of the cGAS-STING signaling pathway in HGFs. These findings suggest that cfDNA contributes to the progression of periodontitis.
Humans ; Gingival Crevicular Fluid/metabolism* ; Signal Transduction ; Gingiva/cytology* ; Nucleotidyltransferases/genetics* ; Membrane Proteins/genetics* ; Cell-Free Nucleic Acids/analysis* ; Fibroblasts/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Periodontitis/metabolism* ; Interleukin-1beta/metabolism* ; Interleukin-6/metabolism* ; Adult ; RNA, Messenger/metabolism* ; Male ; Female

Chronic non-healing wounds significantly impair patient rehabilitation and remain a critical clinical challenge. Stem cell-derived exosomes, owing to their biocompatibility and physiological activity, have emerged as a promising therapeutic approach in regenerative medicine. Beyond their intrinsic wound-healing properties, exosomes are increasingly explored as carriers for small-molecule drugs to enhance synergistic treatment effects. Although microRNAs (miRNAs) exhibit potential in promoting cell proliferation and re-epithelialization, their clinical application is hindered by poor stability. In this study, we investigated the therapeutic effects of miR-132-3p-loaded human umbilical mesenchymal stem cell-derived exosomes (miR-132-3p@UMSC-EXOs) on human foreskin fibroblast-1 (HFF-1). Our findings demonstrated that miR-132-3p@UMSC-EXOs significantly enhanced proliferation and migration of HFF-1, while reducing intracellular reactive oxygen species (ROS) levels compared with unloaded exosomes. Furthermore, qRT-PCR and Western blotting analyses revealed that miR-132-3p@UMSC-EXOs modulated the expression of genes associated with extracellular matrix (ECM) remodeling and inflammation, suggesting their potential to upregulate collagen synthesis and improve ECM metabolism. These results highlight the therapeutic promise of miR-132-3p@UMSC-EXOs in accelerating wound healing.
Humans ; MicroRNAs/pharmacology* ; Exosomes/metabolism* ; Mesenchymal Stem Cells/cytology* ; Wound Healing ; Umbilical Cord/cytology* ; Cell Proliferation ; Fibroblasts/cytology* ; Skin/injuries* ; Cell Movement ; Reactive Oxygen Species/metabolism* ; Cells, Cultured

OBJECTIVE: To investigate the effects of 4-methylcatechol (4MC) on the migration and inflammatory response in rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS), as well as its underlying mechanisms of action. METHODS: RA-FLS was isolated from synovial tissue donated by RA patients, and the optimal concentration of 4MC was determined by cell counting kit 8 method for subsequent experiments, and the effect of 4MC on the migratory ability of RA-FLS was evaluated via a cell scratch assay. An inflammation model of RA-FLS was induced by tumor necrosis factor α (TNF-α). Real-time fluorescence quantitative PCR and ELISA were employed to detect the gene and protein expression levels of interleukin-1β (IL-1β) and IL-6 in RA-FLS and their culture supernatants, respectively, thereby investigating the anti-inflammatory effects of 4MC. Western blot was used to examine the expressions of nuclear factor κB (NF-κB) signaling pathway-related proteins, including inhibitor of NF-κB-α (IKBα), phosphorylated (P)-IκBα, NF-κB-inducing kinase α (IKKα), P-IKKαβ, P-p65, and p65. Cellular immunofluorescence was utilized to detect the expression and localization of p65 in RA-FLS, exploring whether 4MC exerts its anti-inflammatory effects by regulating the NF-κB signaling pathway. Finally, a collagen-induced arthritis (CIA) mouse model was established. The anti-RA effect of 4MC in vivo was evaluated by gross observation and histological examination. RESULTS: 4MC inhibited RA-FLS migration in a concentration-dependent manner. In the TNF-α-induced RA-FLS inflammation model, 4MC significantly decreased the gene and protein expression levels of IL-1β and IL-6. Furthermore, 4MC markedly reduced the ratios of P-IΚBα/IΚBα, P-IKKαβ/IKKα, and P-p65/p65, thereby blocking the transcriptional activity of p65 by inhibiting its nuclear translocation. This mechanism effectively suppressed the activation of the TNF-α-mediated NF-κB signaling pathway. Animal studies demonstrated that 4MC [10 mg/(kg·day)] significantly lowered serum levels of IL-1β, IL-6, and TNF-α, and alleviated arthritis severity and bone destruction in CIA mice. CONCLUSION 4MC not only inhibits the migration of RA-FLS but also mitigates their inflammatory response by suppressing the NF-κB signaling pathway, thereby effectively exerting its anti-RA effects.
Synoviocytes/metabolism* ; Arthritis, Rheumatoid/metabolism* ; Animals ; Cell Movement/drug effects* ; Humans ; Catechols/therapeutic use* ; Fibroblasts/drug effects* ; Mice ; Tumor Necrosis Factor-alpha/pharmacology* ; Interleukin-1beta/metabolism* ; Interleukin-6/metabolism* ; Signal Transduction/drug effects* ; NF-kappa B/metabolism* ; Transcription Factor RelA/metabolism* ; Synovial Membrane/cytology* ; Cells, Cultured ; Male ; Arthritis, Experimental ; Anti-Inflammatory Agents/pharmacology* ; NF-KappaB Inhibitor alpha ; Inflammation

Objective To elucidate the molecular mechanism by which exosomes (Exo) derived from cancer-associated fibroblasts (CAF) carrying HOX transcript antisense intergenic RNA (lncRNA HOTAIR) promote the metastasis of esophageal squamous cell carcinoma (ESCC). Methods CAFs were collected from tumor tissues, and non-cancer associated fibroblasts (NFs) were obtained from adjacent normal tissues at least 5 cm away from the tumor. Exosomes (CAFs-Exo and NFs-Exo) were isolated from conditioned media collected from CAFs or NFs. CAFs-Exo and NFs-Exo were incubated with human ESCC cell line TE-1 for 24 hours, and CCK-8 was used to determine the cell proliferation ability. Scratch test and Transwell test were performed to determine the cell migration and invasion ability. TE-1 cells were divided into the following two groups: NC group and KD group. The NC group and KD group were transfected with control siRNAs or siRNAs targeting HOTAIR respectively. The effects of HOTAIR knock-down on cell proliferation, migration, invasion and glycolysis were determined. Results CAFs-Exo promoted the proliferation of TE-1 cells more significantly than NFs-Exo. Compared with NFs-Exo group, the migration and invasion ability of TE-1 cells treated with CAFs-Exo were improved significantly. In addition, CAFs-Exo treatment inhibited the expression of E-cadherin and enhanced the expression of N-cadherin. The expression of HOTAIR in CAFs was significantly higher than that in NFs. Compared with NFs-Exo, the expression level of HOTAIR in CAFs-Exo increased significantly. Compared with NC group, the proliferation, migration and invasion of TE-1 cells in KD group decreased significantly. Compared with NC group, hexokinase 2 (HK2), extracellular acidification rate (ECAR) and ATP/ADP ratio of TE-1 cells in KD group decreased significantly. Conclusion HOTAIR, an exosome derived from CAFs, may be involved in metastasis and EMT by regulating glycolysis in ESCC cells.
Humans ; RNA, Long Noncoding/metabolism* ; Esophageal Neoplasms/metabolism* ; Cell Movement/genetics* ; Cell Proliferation/genetics* ; Cell Line, Tumor ; Esophageal Squamous Cell Carcinoma ; Exosomes/genetics* ; Neoplasm Metastasis ; Neoplasm Invasiveness ; Gene Expression Regulation, Neoplastic ; Glycolysis/genetics* ; Cancer-Associated Fibroblasts/metabolism* ; Carcinoma, Squamous Cell/metabolism* ; Cadherins/genetics*