Periodontitis is a common oral disease caused by bacteria coupled with an excessive host immune response. Stem cell therapy can be a promising treatment strategy for periodontitis, but the relevant mechanism is complicated. This study aimed to explore the therapeutic potential of mitochondria from human embryonic stem cell-derived mesenchymal stem cells (hESC-MSCs) for the treatment of periodontitis. The gingival tissues of periodontitis patients are characterized by abnormal mitochondrial structure. Human gingival fibroblasts (HGFs) were exposed to 5 μg/mL lipopolysaccharide (LPS) for 24 h to establish a cell injury model. When treated with hESC-MSCs or mitochondria derived from hESC-MSCs, HGFs showed reduced expression of inflammatory genes, increased adenosine triphosphate (ATP) level, decreased reactive oxygen species (ROS) production, and enhanced mitochondrial function compared to the control. The average efficiency of isolated mitochondrial transfer by hESC-MSCs was determined to be 8.93%. Besides, a therapy of local mitochondrial injection in mice with LPS-induced periodontitis showed a reduction in inflammatory gene expression, as well as an increase in both the mitochondrial number and the aspect ratio in gingival tissues. In conclusion, our results indicate that mitochondria derived from hESC-MSCs can reduce the inflammatory response and improve mitochondrial function in HGFs, suggesting that the transfer of mitochondria between hESC-MSCs and HGFs serves as a potential mechanism underlying the therapeutic effect of stem cells.
Humans ; Gingiva/cytology* ; Fibroblasts/metabolism* ; Mitochondria/physiology* ; Mesenchymal Stem Cells/cytology* ; Animals ; Periodontitis/therapy* ; Mice ; Reactive Oxygen Species/metabolism* ; Inflammation ; Lipopolysaccharides ; Human Embryonic Stem Cells/cytology* ; Cells, Cultured ; Adenosine Triphosphate/metabolism* ; Male

OBJECTIVES: To investigate the role of the BNIP3-PI3K/Akt signaling pathway in mediating the inhibitory effect of Buyang Huanwu Decoction (BYHWT) on mitochondrial autophagy in human synovial fibroblasts from rheumatoid arthritis patients (FLS-RA) cultured under a hypoxic condition. METHODS: Forty normal Wistar rats were randomized into two groups (n=20) for daily gavage of BYHWT or distilled water for 7 days to prepare BYHWT-medicated or control sera. FLS-RA were cultured in routine condition or exposed to hypoxia (10% O₂) for 24 h wigh subsequent treatment with IL-1β, followed by treatment with diluted BYHWT-medicated serum (5%, 10% and 20%) or control serum. AnnexinV-APC/7-AAD double staining and T-AOC kit were used for detecting apoptosis and total antioxidant capacity of the cells, and the changes in ROS, ATP level, mitochondrial membrane potential and Ca²⁺ homeostasis were analyzed. The changes in mRNA and protein expressions of BNIP3, PI3K and AKT and mRNA expressions of LC3, Beclin-1 and P62 were detected using RT-qPCR and Western blotting. RESULTS: Treatment with BYHWT-medicated serum dose-dependently lowered apoptosis rate of IL-1β-induced FLS-RA with hypoxic exposure. The treatment significantly decreased T-AOC concentration, increased ROS production, autophagosome formation and ATPase levels, and lowered mitochondrial membrane potential and Ca²⁺ level in the cells. In IL-1β-induced FLS-RA with hypoxic exposure, treatment with BYHWT-medicated serum significantly increased BNIP3 protein expression, decreased the protein expressions of PI3K and AKT, increased the mRNA expressions of BNIP3 and P62, and lowered the mRNA expressions of PI3K, AKT, LC3 and Beclin-1 without significantly affecting Beclin-1 protein expression. The cells treated with 5% and 10% BYHWT-medicated serum showed no significant changes in LC3 expression. CONCLUSIONS BYHWT inhibits mitochondrial autophagy in IL-1β-induced FLS-RA with hypoxic exposure possibly by inhibiting BNIP3-mediated PI3K/AKT signaling pathway.
Drugs, Chinese Herbal/pharmacology* ; Arthritis, Rheumatoid/pathology* ; Animals ; Signal Transduction/drug effects* ; Proto-Oncogene Proteins c-akt/metabolism* ; Autophagy/drug effects* ; Humans ; Fibroblasts/cytology* ; Rats, Wistar ; Membrane Proteins/metabolism* ; Rats ; Phosphatidylinositol 3-Kinases/metabolism* ; Mitochondria/metabolism* ; Cells, Cultured ; Proto-Oncogene Proteins/metabolism* ; Apoptosis/drug effects* ; Cell Hypoxia ; Synovial Membrane/cytology* ; Male ; Mitochondrial Proteins

OBJECTIVES: To investigate the regulatory effect of LINC00837/miR-671-5p/SERPINE2 functional axis on pathological processes of fibroblast-like synovial cells (FLS) in rheumatoid arthritis (RA). METHODS: RA-FLS were transfected with a LINC00837 overexpression plasmid (pcDNA3.1-LINC00837), a LINC00837 interference plasmid (siRNA-LINC00837), or their respective negative control plasmids (pcDNA3.1-NC and siRNA-NC). Dual luciferase was used to verify the targeting relationship between LINC00837 and miR-671-5p and between miR-671-5p and SERPINE2. RT-qPCR was used to detect the expression levels of LINC00837, miR-671-5p and SERPINE2 in normal FLS or the transfected cells, whose proliferation and migration abilities were assessed using Edu assay and scratch healing assay and by detecting the expression levels of Ki-67, PCNA, E-cadherin and N-cadherin with Western blotting. The changes in cellular secretion of the inflammatory cytokines (TNF‑α, IL-17, IL-4 and IL-10) were examined using ELISA. RESULTS: Dual luciferase reporter gene assay showed that LINC00837 was capable of binding to the 3'-UTR of miR-671-5p, and the latter bound to the 3-UTR of SERPINE2 at specific binding sites between them. Compared with normal FLS, RA-FLS showed significantly increased expressions of LINC00837 and SERPINE2, lowered miR-671-5p expression and enhanced proliferation and migration abilities with increased expressions of pro-inflammatory cytokines and reduced expressions of anti-inflammatory cytokines. Transfection of RA-FLS with pcDNA-LINC00837 further enhanced cell proliferation and migration and the changes in the inflammatory cytokines, while transfection with si-LINC00837 produced the opposite changes. CONCLUSIONS RA-FLS have a LINC00837/miR-671-5p/SERPINE2 functional axis, which regulates cell proliferation, migration and secretion of inflammatory factors, and interventions targeting LINC00837 may provide a potential strategy to regulate the pathological processes in RA-FLS.
Arthritis, Rheumatoid/metabolism* ; MicroRNAs/metabolism* ; Humans ; Cell Proliferation ; Cell Movement ; Synovial Membrane/pathology* ; RNA, Long Noncoding/genetics* ; Fibroblasts/metabolism* ; Synoviocytes/metabolism* ; Cells, Cultured ; Transfection

Perineural invasion (PNI) by tumor cells is a key phenotype of highly-invasive oral squamous cell carcinoma (OSCC). Since Schwann cells (SCs) and fibroblasts maintain the physiological homeostasis of the peripheral nervous system, and we have focused on cancer-associated fibroblasts (CAFs) for decades, it's imperative to elucidate the impact of CAFs on SCs in PNI⁺ OSCCs. We describe a disease progression-driven shift of PNI^- towards PNI⁺ during the progression of early-stage OSCC (31%, n = 125) to late-stage OSCC (53%, n = 97), characterized by abundant CAFs and nerve demyelination. CAFs inhibited SC proliferation/migration and reduced neurotrophic factors and myelin in vitro, and this involved up-regulated ER stress and decreased MAPK signals. Moreover, CAFs also aggravated the paralysis of the hind limb and PNI in vivo. Unexpectedly, leukemia inhibitory factor (LIF) was exclusively expressed on CAFs and up-regulated in metastatic OSCC. The LIF inhibitor EC330 restored CAF-induced SC inactivation. Thus, OSCC-derived CAFs inactivate SCs to aggravate nerve injury and PNI development.
Schwann Cells/metabolism* ; Mouth Neoplasms/metabolism* ; Humans ; Cancer-Associated Fibroblasts/metabolism* ; Animals ; Carcinoma, Squamous Cell/metabolism* ; Neoplasm Invasiveness/pathology* ; Male ; Female ; Mice ; Cell Movement/physiology* ; Cell Proliferation/physiology* ; Cell Line, Tumor ; Leukemia Inhibitory Factor/metabolism* ; Middle Aged

Abnormal accumulation of collagen fibrils is a hallmark feature of oral submucous fibrosis (OSF). However, the precise characteristics and underlying mechanisms remain unclear, impeding the advancement of potential therapeutic approaches. Here, we observed that collagen I, the main component of the extracellular matrix, first accumulated in the lamina propria and subsequently in the submucosa of OSF specimens as the disease progressed. Using RNA-seq and Immunofluorescence in OSF specimens, we screened the cartilage oligomeric matrix protein (COMP) responsible for the abnormal collagen accumulation. Genetic COMP deficiency reduced arecoline-stimulated collagen I deposition significantly in vivo. In comparison, both COMP and collagen I were upregulated under arecoline stimulation in wild-type mice. Human oral buccal mucosal fibroblasts (hBMFs) also exhibited increased secretion of COMP and collagen I after stimulation in vitro. COMP knockdown in hBMFs downregulates arecoline-stimulated collagen I secretion. We further demonstrated that hBMFs present heterogeneous responses to arecoline stimulation, of which COMP-positive fibroblasts secrete more collagen I. Since COMP is a molecular bridge with Fibril-associated collagens with Interrupted Triple helices (FACIT) in the collagen network, we further screened and identified collagen XIV, a FACIT member, co-localizing with both COMP and collagen I. Collagen XIV expression increased under arecoline stimulation in wild-type mice, whereas it was hardly expressed in the Comp^-/- mice, even with under stimulation. In summary, we found that COMP may mediates abnormal collagen I deposition by functions with collagen XIV during the progression of OSF, suggesting its potential to be targeted in treating OSF.
Oral Submucous Fibrosis/pathology* ; Cartilage Oligomeric Matrix Protein/genetics* ; Animals ; Mice ; Humans ; Fibroblasts/metabolism* ; Collagen Type I/metabolism* ; Arecoline/pharmacology* ; Mouth Mucosa/metabolism* ; Cells, Cultured ; Fluorescent Antibody Technique

Complement C3 plays a critical role in periodontitis. However, its source, role and underlying mechanisms remain unclear. In our study, by analyzing single-cell sequencing data from mouse model of periodontitis, we identified that C3 is primarily derived from periodontal fibroblasts. Subsequently, we demonstrated that C3a has a detrimental effect in ligature-induced periodontitis. C3ar^-/- mice exhibited significantly less destruction of periodontal support tissues compared to wild-type mice, characterized by mild gingival tissue damage and reduced alveolar bone loss. This reduction was associated with decreased production of pro-inflammatory mediators and reduced osteoclast infiltration in the periodontal tissues. Mechanistic studies suggested that C3a could promote macrophage polarization and osteoclast differentiation. Finally, by analyzing single-cell sequencing data from the periodontal tissues of patients with periodontitis, we found that the results observed in mice were consistent with human data. Therefore, our findings clearly demonstrate the destructive role of fibroblast-derived C3 in ligature-induced periodontitis, driven by macrophage M1 polarization and osteoclast differentiation. These data strongly support the feasibility of C3a-targeted interventions for the treatment of human periodontitis.
Animals ; Osteoclasts/cytology* ; Periodontitis/metabolism* ; Cell Differentiation ; Mice ; Fibroblasts/metabolism* ; Macrophages ; Disease Models, Animal ; Complement C3/metabolism* ; Humans ; Disease Progression ; Mice, Inbred C57BL ; Male ; Mice, Knockout

Smoking is a well-established risk factor for periodontitis, yet the precise mechanisms by which smoking contributes to periodontal disease remain poorly understood. Recent advances in spatial transcriptomics have enabled a deeper exploration of the periodontal tissue microenvironment at single-cell resolution, offering new opportunities to investigate these mechanisms. In this study, we utilized Visium HD single-cell spatial transcriptomics to profile gingival tissues from 12 individuals, including those with periodontitis, those with smoking-associated periodontitis, and healthy controls. Our analysis revealed that smoking disrupts the epithelial barrier integrity, induces fibroblast alterations, and dysregulates fibroblast-epithelial cell communication, thereby exacerbating periodontitis. The spatial analysis showed that endothelial cells and macrophages are in close proximity and interact, which further promotes the progression of smoking-induced periodontal disease. Importantly, we found that targeting the endothelial CXCL12 signalling pathway in smoking-associated periodontitis reduced the proinflammatory macrophage phenotype, alleviated epithelial inflammation, and reduced alveolar bone resorption. These findings provide novel insights into the pathogenesis of smoking-associated periodontitis and highlight the potential of targeting the endothelial-macrophage interaction as a therapeutic strategy. Furthermore, this study establishes an essential information resource for investigating the effects of smoking on periodontitis, providing a foundation for future research and therapeutic development for this prevalent and debilitating disease.
Humans ; Gingiva/cytology* ; Smoking/adverse effects* ; Male ; Periodontitis/pathology* ; Single-Cell Analysis ; Female ; Adult ; Middle Aged ; Macrophages ; Fibroblasts ; Endothelial Cells ; Case-Control Studies ; Chemokine CXCL12/metabolism*

Frostbite is the most common cold injury and is caused by both immediate cold-induced cell death and the gradual development of localized inflammation and tissue ischemia. Delayed healing of frostbite often leads to scar formation, which not only causes psychological distress but also tends to result in the development of secondary malignant tumors. Therefore, a rapid healing method for frostbite wounds is urgently needed. Herein, we used a mouse skin model of frostbite injury to evaluate the recovery process after frostbite. Moreover, single-cell transcriptomics was used to determine the patterns of changes in monocytes, macrophages, epidermal cells, and fibroblasts during frostbite. Most importantly, human-induced pluripotent stem cell (hiPSC)-derived skin organoids combined with gelatin-hydrogel were constructed for the treatment of frostbite. The results showed that skin organoid treatment significantly accelerated wound healing by reducing early inflammation after frostbite and increasing the proportions of epidermal stem cells. Moreover, in the later stage of wound healing, skin organoids reduced the overall proportions of fibroblasts, significantly reduced fibroblast-to-myofibroblast transition by regulating the integrin α5β1-FAK pathway, and remodeled the extracellular matrix (ECM) through degradation and reassembly mechanisms, facilitating the restoration of physiological ECM and reducing the abundance of ECM associated with abnormal scar formation. These results highlight the potential application of organoids for promoting the reversal of frostbite-related injury and the recovery of skin functions. This study provides a new therapeutic alternative for patients suffering from disfigurement and skin dysfunction caused by frostbite.
Animals ; Organoids/metabolism* ; Mice ; Humans ; Wound Healing ; Frostbite/metabolism* ; Skin/pathology* ; Induced Pluripotent Stem Cells/cytology* ; Cicatrix/pathology* ; Fibroblasts/metabolism* ; Disease Models, Animal ; Mice, Inbred C57BL ; Extracellular Matrix/metabolism* ; Male

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*