Time of exercise differentially impacts bone growth in mice.

Although physical training has been shown to improve bone mass, the time of day to exercise for optimal bone growth remains uncertain. Here we show that engaging in physical activity during the early active phase, as opposed to the subsequent active or rest phase, results in a more substantial increase in bone length of male and female mice. Transcriptomic and metabolomic methodologies identify that exercise during the early active phase significantly upregulates genes associated with bone development and metabolism. Notably, oxidative phosphorylation-related genes show a rhythmic expression in the chondrification centre, with a peak at the early active phase, when more rhythmic genes in bone metabolism are expressed and bone growth is synergistically promoted by affecting oxidative phosphorylation, which is confirmed by subsequent pharmacological investigations. Finally, we construct a signalling network to predict the impact of exercise on bone growth. Collectively, our research sheds light on the intricacies of human exercise physiology, offering valuable implications for interventions.

Matrix stiffness regulates macrophage polarisation via the Piezo1-YAP signalling axis.

Macrophages play a pivotal role in the immunological cascade activated in response to biomedical implants, which predetermine acceptance or rejection of implants by the host via pro- and anti-inflammatory polarisation states. The role of chemical signals in macrophage polarisation is well-established, but how physical cues regulate macrophage function that may play a fundamental role in implant-bone interface, remains poorly understood. Here we find that bone marrow-derived macrophages (BMDM) cultured on polyacrylamide gels of varying stiffness exhibit different polarisation states. BMDM are 'primed' to a pro-inflammatory M1 phenotype on stiff substrates, while to an anti-inflammatory M2 phenotype on soft and medium stiffness substrates. It is further observed that matrix stiffening increases Piezo1 expression, as well as leads to subsequent activation of the mechanotransduction signalling effector YAP, thus favouring M1 polarisation whilst suppressing M2 polarisation. Moreover, upon treatment with YAP inhibitor, we successfully induce macrophage re-polarisation to the M2 state within the implant site microenvironment, which in turn promotes implant osseointegration. Collectively, our present study thus characterises the critical role of the Piezo1-YAP signalling axis in macrophage mechanosensing and stiffness-mediated macrophage polarisation and provides cues for the design of immuno-modulatory biomaterials that can regulate the macrophage phenotype.

The osteoclastic activity in apical distal region of molar mesial roots affects orthodontic tooth movement and root resorption in rats.

The utilization of optimal orthodontic force is crucial to prevent undesirable side effects and ensure efficient tooth movement during orthodontic treatment. However, the sensitivity of existing detection techniques is not sufficient, and the criteria for evaluating optimal force have not been yet established. Here, by employing 3D finite element analysis methodology, we found that the apical distal region (A-D region) of mesial roots is particularly sensitive to orthodontic force in rats. Tartrate-resistant acidic phosphatase (TRAP)-positive osteoclasts began accumulating in the A-D region under the force of 40 grams (g), leading to alveolar bone resorption and tooth movement. When the force reached 80 g, TRAP-positive osteoclasts started appearing on the root surface in the A-D region. Additionally, micro-computed tomography revealed a significant root resorption at 80 g. Notably, the A-D region was identified as a major contributor to whole root resorption. It was determined that 40 g is the minimum effective force for tooth movement with minimal side effects according to the analysis of tooth movement, inclination, and hyalinization. These findings suggest that the A-D region with its changes on the root surface is an important consideration and sensitive indicator when evaluating orthodontic forces for a rat model. Collectively, our investigations into this region would aid in offering valuable implications for preventing and minimizing root resorption during patients' orthodontic treatment.

The Roles of Periodontal Bacteria in Atherosclerosis.

Atherosclerosis (AS) is an inflammatory vascular disease that constitutes a major underlying cause of cardiovascular diseases (CVD) and stroke. Infection is a contributing risk factor for AS. Epidemiological evidence has implicated individuals afflicted by periodontitis displaying an increased susceptibility to AS and CVD. This review concisely outlines several prevalent periodontal pathogens identified within atherosclerotic plaques, including Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum. We review the existing epidemiological evidence elucidating the association between these pathogens and AS-related diseases, and the diverse mechanisms for which these pathogens may engage in AS, such as endothelial barrier disruption, immune system activation, facilitation of monocyte adhesion and aggregation, and promotion of foam cell formation, all of which contribute to the progression and destabilization of atherosclerotic plaques. Notably, the intricate interplay among bacteria underscores the complex impact of periodontitis on AS. In conclusion, advancing our understanding of the relationship between periodontal pathogens and AS will undoubtedly offer invaluable insights and potential therapeutic avenues for the prevention and management of AS.

The atypical ubiquitin ligase RNF31 stabilizes c-Myc via epigenetic inactivation of FBXO32 and promotes cancer development.

RNF31, an atypical E3 ubiquitin ligase of the RING-between-RING protein family, is one of the important components of the linear ubiquitin chain complex LUBAC. It plays a carcinogenic role in a variety of cancers by promoting cell proliferation, invasion and inhibiting apoptosis. However, the specific molecular mechanism by which RNF31 exerts its cancer-promoting effects is still unclear. By analyzing the expression profile of RNF31-depleted cancer cells, we found that loss of RNF31 significantly resulted in the inactivation of the c-Myc pathway. We further showed that RNF31 played an important role in the maintenance of c-Myc protein levels in cancer cells by extending the half-life of c-Myc protein and reducing its ubiquitination. c-Myc protein levels are tightly regulated by the ubiquitin proteasome, in which the E3 ligase FBXO32 is required to mediate its ubiquitin-dependent degradation. We found that RNF31 inhibited the transcription of FBXO32 through EZH2-mediated trimethylation of histone H3K27 in the FBXO32 promoter region, leading to the stabilization and activation of c-Myc protein. Under this circumstance, the expression of FBXO32 was significantly increased in RNF31-deficient cells, promoting the degradation of c-Myc protein, inhibiting cell proliferation and invasion, increasing cell apoptosis, and ultimately blocking the progression of tumors. Consistent with these results, the reduced malignancy phenotype caused by RNF31 deficiency could be partially reversed by overexpression of c-Myc or further knockdown of FBXO32. Together, our results reveal a key association between RNF31 and epigenetic inactivation of FBXO32 in cancer cells, and suggest that RNF31 may be a promising target for cancer therapy.

Epigenetic reactivation of PEG3 by EZH2 inhibitors suppresses renal clear cell carcinoma progress.

PEG3 is a paternally imprinted gene located on chromosome 19q13.4 and one of the most common low-expression genes in human ovarian cancer. PEG3 plays an important role in p53-related cell death. However, whether PEG3 plays a role in renal clear cell carcinoma (ccRCC) remains unclear. Here, we found that PEG3 was epigenetic inactivated and played a tumor suppressor role in ccRCC. Overexpression of PEG3 inhibited ccRCC cell proliferation and colony formation, while removal of PEG3 significantly promoted cell proliferation in vitro and tumor formation in nude mice in vivo. EZH2-mediated H3K27me3 at the PEG3 promoter suppressed PEG3 expression. EZH2 specific inhibitors promote PEG3 transcriptional expression through the transition from H3K27me3 to H3K27ac at the PEG3 promoter region. Depletion of PEG3 inhibited the activation of the p53 signaling pathway, resulting in the resistance of ccRCC to EZH2 inhibitors treatment. Thus, our data show that EZH2-mediated epigenetic inactivation of PEG3 promotes the progress of ccRCC, and reactivation of PEG3 may be a promising strategy for ccRCC.

A novel ribociclib derivative WXJ-103 exerts anti-breast cancer effect through CDK4/6.

The triple-negative breast cancer (TNBC) subtype is the most aggressive type of breast cancer with a low survival prognosis and high recurrence rate. There is currently no effective treatment to improve it. In this work, we explored the effect of a synthetic compound named WXJ-103 on several aspects of TNBC biology. The human breast cancer cell lines MDA-MB-231 and MCF-7 were used in the experiments, and the cell viability was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method, and the cell migration and invasion abilities were detected by wound healing assay and Transwell invasion assay. Cell cycle and apoptosis experiments were analyzed by flow cytometry, and protein levels related to cyclin-dependent kinase (CDK) 4/6-cyclin D-Rb-E2F pathway were analyzed by western blotting. Then, in-vivo experiments were performed to determine the clinical significance and functional role of WXJ-103. The results show that WXJ-103 can inhibit the adhesion, proliferation, migration, and invasion of TNBC cells, and can arrest the cell cycle in G1 phase. The levels of CDK4/6-cyclin D-Rb-E2F pathway-related proteins such as CDK6 and pRb decreased in a dose-dependent manner. Therefore, the antitumor activity of WXJ-103 may depend on the inhibition of CDK4/6-cyclin D1-Rb-E2F pathway. This research shows that WXJ-103 may be a new promising antitumor drug, which can play an antitumor effect on TNBC and provide new ideas for the treatment of TNBC.

VHL-HIF-2α axis-induced SEMA6A upregulation stabilized ß-catenin to drive clear cell renal cell carcinoma progression.

SEMA6A is a multifunctional transmembrane semaphorin protein that participates in various cellular processes, including axon guidance, cell migration, and cancer progression. However, the role of SEMA6A in clear cell renal cell carcinoma (ccRCC) is unclear. Based on high-throughput sequencing data, here we report that SEMA6A is a novel target gene of the VHL-HIF-2α axis and overexpressed in ccRCC. Chromatin immunoprecipitation and reporter assays revealed that HIF-2α directly activated SEMA6A transcription in hypoxic ccRCC cells. Wnt/ß-catenin pathway activation is correlated with the expression of SEMA6A in ccRCC; the latter physically interacted with SEC62 and promoted ccRCC progression through SEC62-dependent ß-catenin stabilization and activation. Depletion of SEMA6A impaired HIF-2α-induced Wnt/ß-catenin pathway activation and led to defective ccRCC cell proliferation both in vitro and in vivo. SEMA6A overexpression promoted the malignant phenotypes of ccRCC, which was reversed by SEC62 depletion. Collectively, this study revealed a potential role for VHL-HIF-2α-SEMA6A-SEC62 axis in the activation of Wnt/ß-catenin pathway. Thus, SEMA6A may act as a potential therapeutic target, especially in VHL-deficient ccRCC.

F. nucleatum facilitates oral squamous cell carcinoma progression via GLUT1-driven lactate production.

BACKGROUND: Tumor-resident microbiota has been documented for various cancer types. Oral squamous cell carcinoma (OSCC) is also enriched with microbiota, while the significance of microbiota in shaping the OSCC microenvironment remains elusive. METHODS: We used bioinformatics and clinical sample analysis to explore relationship between F. nucleatum and OSCC progression. Xenograft tumor model, metabolic screening and RNA sequencing were performed to elucidate mechanisms of pro-tumor role of F. nucleatum. FINDINGS: We show that a major protumorigenic bacterium, F. nucleatum, accumulates in invasive margins of OSCC tissues and drives tumor-associated macrophages (TAMs) formation. The mechanistic dissection shows that OSCC-resident F. nucleatum triggers the GalNAc-Autophagy-TBC1D5 signaling, leading to GLUT1 aggregation in the plasma membrane and the deposition of extracellular lactate. Simultaneous functional inhibition of GalNAc and GLUT1 efficiently reduces TAMs formation and restrains OSCC progression. INTERPRETATION: These findings suggest that tumor-resident microbiota affects the immunomodulatory and protumorigenic microenvironment via modulating glycolysis and extracellular lactate deposition. The targeted intervention of this process could provide a distinct clinical strategy for patients with advanced OSCC. FUNDING: This work was supported by the National Natural Science Foundation of China for Key Program Projects (82030070, to LC) and Distinguished Young Scholars (31725011, to LC), as well as Innovation Team Project of Hubei Province (2020CFA014, to LC).

Identification of the deubiquitinase USP28 as a novel molecular therapeutic target of ovarian cancer.

Ubiquitin specific proteinase 28 (USP28) is a member of the deubiquitylating enzymes, which are mainly involved in cell cycle, apoptosis and DNA damage repair. Although USP28 has been found to be upregulated in some tumors, its role in ovarian cancer (OV) remains unclear. Here we show that USP28 was highly expressed in OV samples compared with normal ovarian tissue, and OV patients with higher USP28 levels had a worse prognosis. We found that the abnormal expression of USP28 mRNA in OV was related to the activation of ß-catenin signaling pathway, and USP28 was a transcriptional target gene of the ß-catenin/YAP1/TBX5 complex. In addition, genetic ablation or pharmacological inhibition of USP28 impaired the proliferation ability of OV cells in vitro and in vivo. In conclusion, our findings show that ß-catenin/YAP1/TBX5-mediated aberrant expression of USP28 promotes the malignant phenotype of OV, suggesting that USP28 may be a therapeutic target for OV.

FBXO2 targets glycosylated SUN2 for ubiquitination and degradation to promote ovarian cancer development.

SAD1/UNC84 domain protein-2 (SUN2) plays a tumor suppressor role in various types of cancer by inhibiting cancer cell proliferation, migration and promoting apoptosis. However, the post-translational regulation of SUN2 and the cellular mechanism responsible for its proteasomal degradation remains largely unknown. Here, we show that FBXO2, an E3 ubiquitin ligase of the F-box proteins (FBPs) family targets glycosylated SUN2 for ubiquitination and degradation via the ubiquitin-proteasome system (UPS). By integrating the Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and the Encyclopedia of Cancer Cell Lines (CCLE) databases, we revealed that FBXO2 was selectively highly expressed in ovarian cancer (OV) tissues and cells. Patients with relatively high FBXO2 expression levels were associated with worse prognosis. Manipulation of the expression of FBXO2 affecting ovarian cancer cell proliferation, migration/invasion in vitro, and tumor growth in mice in vivo. The transcription factor SOX6 promoted FBXO2 expression by recognizing a putative response element localized on the promoter region of FBXO2. Abnormally highly expressed FBXO2 recognized and targeted glycosylated SUN2 protein for ubiquitination-depended degradation to prevent cell apoptosis, promote cell proliferation, and ultimately promote the progression of OV. Thus, we revealed a new SOX6-FBXO2-SUN2 axis that contributed to the development of OV, and targeting this axis may represent an effective OV treatment strategy.

Circadian rhythm modulates endochondral bone formation via MTR1/AMPKß1/BMAL1 signaling axis.

The circadian clock is a master regulator in coordinating daily oscillations of physiology and behaviors. Nevertheless, how the circadian rhythm affects endochondral ossification is poorly understood. Here we showed that endochondral bone formation exhibits circadian rhythms, manifested as fast DNA replication in the daytime, active cell mitosis, and matrix synthesis at night. Circadian rhythm disruption led to endochondral ossification deformities. The mechanistic dissection revealed that melatonin receptor 1 (MTR1) periodically activates the AMPKß1 phosphorylation, which then orchestrates the rhythms of cell proliferation and matrix synthesis via destabilizing the clock component CRY1 and triggering BMAL1 expression. Accordingly, the AMPKß1 agonist is capable of alleviating the abnormity of endochondral ossification caused by circadian dysrhythmias. Taken together, these findings indicated that the central circadian clock could control endochondral bone formation via the MTR1/AMPKß1/BMAL1 signaling axis in chondrocytes. Also, our results suggested that the AMPKß1 signaling activators are promising medications toward endochondral ossification deformities.

SOX9-mediated UGT8 expression promotes glycolysis and maintains the malignancy of non-small cell lung cancer.

UDP-glycosyltransferases (UGTs) catalyze the covalent addition of sugars to small lipophilic chemicals and are associated with a wide range of diseases including cancer. The human genome contains 22 UGT genes which could be classified into four families: UGT1, UGT2, UGT3, and UGT8. The UGT8 family contains only one member which utilizes UDP galactose to galactosidate ceramide. Although higher UGT8 mRNA was observed in some types of cancer, its pathological significances remain elusive. Here, by integrating the Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and the Genotype-Tissue Expression (GTEx) databases, we showed that UGT8 was selectively highly expressed in non-small cell lung cancer (NSCLC) and associated with worse prognosis. The transcription factor SOX9 promoted UGT8 expression in NSCLC by recognizing two putative response elements localized on the promoter region of UGT8. Silencing UGT8 impaired glycolysis and reduced the malignancy of NSCLC cells both in vitro and in vivo. On the contrary, inhibition of glycolysis by 2-deoxy-d-glucose (2-DG) significantly impaired the pro-proliferation function of UGT8 in NSCLC cells. In conclusion, our results suggest that UGT8 maintains the malignancy of NSCLC mainly via enhanced glycolysis and provides a promising therapeutic target for NSCLC.

WXJ-202, a novel Ribociclib derivative, exerts antitumor effects against breast cancer through CDK4/6.

Cyclin-dependent kinases 4 and 6 (CDK4/6) are key regulatory proteins in the cell division and proliferative cycle in humans. They are overactive in many malignant tumors, particularly in triple-negative breast cancer (TNBC). Inhibition of CDK4/6 targets can have anti-tumor effects. Here, we designed and synthesized a novel derivative of Ribociclib that could affect CDK4/6, named WXJ-202. This study aimed to investigate the effects of compound WXJ-202 on proliferation, apoptosis, and cell cycle arrest in human breast cancer cell lines and their molecular mechanisms. We assayed cell viability with methyl thiazolyl tetrazolium (MTT) assay. Clone formation, migration, and invasion ability were assayed by clone formation assay, wound healing assay, and transwell invasion assay. The effect of compound WXJ-202 on apoptosis and cell cycle was detected by flow cytometry analysis. Western blotting was performed to detect the expression of proteins related to the CDK4/6-Rb-E2F pathway. The anti-cancer effects were studied in vivo transplantation tumor models. WXJ-202 was shown to inhibit cell proliferation, colony formation, migration, and invasion, as well as induce apoptosis and cycle arrest in breast cancer cells. The levels of proteins related to the CDK4/6-Rb-E2F pathway, such as CDK4, CDK6, and p-Rb, were decreased. Finally, studies had shown that compound WXJ-202 exhibited significant anti-tumor activity in transplantation tumor models. In this research, the compound WXJ-202 was shown to have better anti-tumor cell proliferative effects and could be used as a potential candidate against TNBC tumors.

PLAU Promotes Cell Proliferation and Epithelial-Mesenchymal Transition in Head and Neck Squamous Cell Carcinoma.

Plasminogen activator, urokinase (uPA) is a secreted serine protease whose Dysregulation is often accompanied by various cancers. However, the biological functions and potential mechanisms of PLAU in head and neck squamous cell carcinoma (HNSCC) remain undetermined. Here, the expression, prognosis, function, and coexpression genetic networks of PLAU in HNSCC were investigated by a series of public bioinformatics tools. A Higher PLAU level predicted a poorer clinical outcome. Meanwhile, functional network analysis implied that PLAU and associated genes mainly regulated cell-substrate adhesion, tissue migration, and extracellular matrix binding. The top 4 significantly associated genes are C10orf55, ITGA5, SERPINE1, and TNFRSF12A. Pathway enrichment analysis indicated that PLAU might activate the epithelial-to-mesenchymal transition (EMT) process, which could explain the poor prognosis in HNSCC. Besides, genes associated with PLAU were also enriched in EMT pathways. We further validated the bioinformatics analysis results by in vivo and in vitro experiments. Then, we found that much more PLAU was detected in HNSCC tissues, and the silencing of PLAU inhibit the proliferation, migration, and EMT process of CAL27 cell lines. Notably, the downregulation of PLAU decreased the expression of TNFRSF12A. Moreover, knockdown TNFRSF12A also inhibits cell proliferation and migration. In vivo experiment results indicated that PLAU inhibition could suppress tumor growth. Collectively, PLAU is necessary for tumor progression and can be a diagnostic and prognostic biomarker in HNSCC.

Insights into the mechanism of vascular endothelial cells on bone biology.

In the skeletal system, blood vessels not only function as a conduit system for transporting gases, nutrients, metabolic waste, or cells but also provide multifunctional signal molecules regulating bone development, regeneration, and remodeling. Endothelial cells (ECs) in bone tissues, unlike in other organ tissues, are in direct contact with the pericytes of blood vessels, resulting in a closer connection with peripheral connective tissues. Close-contact ECs contribute to osteogenesis and osteoclastogenesis by secreting various cytokines in the paracrine or juxtacrine pathways. An increasing number of studies have revealed that extracellular vesicles (EVs) derived from ECs can directly regulate maturation process of osteoblasts and osteoclasts. The different pathways focus on targets at different distances, forming the basis of the intimate spatial and temporal link between bone tissue and blood vessels. Here, we provide a systematic review to elaborate on the function of ECs in bone biology and its underlying mechanisms based on three aspects: paracrine, EVs, and juxtacrine. This review proposes the possibility of a therapeutic strategy targeting blood vessels, as an adjuvant treatment for bone disorders.

The Effects of Porphyromonas gingivalis on Atherosclerosis-Related Cells.

Atherosclerosis (AS), one of the most common types of cardiovascular disease, has initially been attributed to the accumulation of fats and fibrous materials. However, more and more researchers regarded it as a chronic inflammatory disease nowadays. Infective disease, such as periodontitis, is related to the risk of atherosclerosis. Porphyromonas gingivalis (P. gingivalis), one of the most common bacteria in stomatology, is usually discovered in atherosclerotic plaque in patients. Furthermore, it was reported that P. gingivalis can promote the progression of atherosclerosis. Elucidating the underlying mechanisms of P. gingivalis in atherosclerosis attracted attention, which is thought to be crucial to the therapy of atherosclerosis. Nevertheless, the pathogenesis of atherosclerosis is much complicated, and many kinds of cells participate in it. By summarizing existing studies, we find that P. gingivalis can influence the function of many cells in atherosclerosis. It can induce the dysfunction of endothelium, promote the formation of foam cells as well as the proliferation and calcification of vascular smooth muscle cells, and lead to the imbalance of regulatory T cells (Tregs) and T helper (Th) cells, ultimately promoting the occurrence and development of atherosclerosis. This article summarizes the specific mechanism of atherosclerosis caused by P. gingivalis. It sorts out the interaction between P. gingivalis and AS-related cells, which provides a new perspective for us to prevent or slow down the occurrence and development of AS by inhibiting periodontal pathogens.

The roles of osteocytes in alveolar bone destruction in periodontitis.

Periodontitis, a bacterium-induced inflammatory disease that is characterized by alveolar bone loss, is highly prevalent worldwide. Elucidating the underlying mechanisms of alveolar bone loss in periodontitis is crucial for understanding its pathogenesis. Classically, bone cells, such as osteoclasts, osteoblasts and bone marrow stromal cells, are thought to dominate the development of bone destruction in periodontitis. Recently, osteocytes, the cells embedded in the mineral matrix, have gained attention. This review demonstrates the key contributing role of osteocytes in periodontitis, especially in alveolar bone loss. Osteocytes not only initiate physiological bone remodeling but also assist in inflammation-related changes in bone remodeling. The latest evidence suggests that osteocytes are involved in regulating bone anabolism and catabolism in the progression of periodontitis. The altered secretion of receptor activator of NF-κB ligand (RANKL), sclerostin and Dickkopf-related protein 1 (DKK1) by osteocytes affects the balance of bone resorption and formation and promotes bone loss. In addition, the accumulation of prematurely senescent and apoptotic osteocytes observed in alveolar bone may exacerbate local destruction. Based on their communication with the bloodstream, it is noteworthy that osteocytes may participate in the interaction between local periodontitis lesions and systemic diseases. Overall, further investigations of osteocytes may provide vital insights that improve our understanding of the pathophysiology of periodontitis.

Porphyromonas gingivalis and Its Systemic Impact: Current Status.

The relationship between periodontitis and systemic diseases, notably including atherosclerosis and diabetes, has been studied for several years. Porphyromonas gingivalis, a prominent component of oral microorganism communities, is the main pathogen that causes periodontitis. As a result of the extensive analysis of this organism, the evidence of its connection to systemic diseases has become more apparent over the last decade. A significant amount of research has explored the role of Porphyromonas gingivalis in atherosclerosis, Alzheimer's disease, rheumatoid arthritis, diabetes, and adverse pregnancy outcomes, while relatively few studies have examined its contribution to respiratory diseases, nonalcoholic fatty liver disease, and depression. Here, we provide an overview of the current state of knowledge about Porphyromonas gingivalis and its systemic impact in an aim to inform readers of the existing epidemiological evidence and the most recent preclinical studies. Additionally, the possible mechanisms by which Porphyromonas gingivalis is involved in the onset or exacerbation of diseases, together with its effects on systemic health, are covered. Although a few results remain controversial, it is now evident that Porphyromonas gingivalis should be regarded as a modifiable factor for several diseases.

Porphyromonas gingivalis disrupts vascular endothelial homeostasis in a TLR-NF-κB axis dependent manner.

Cardiovascular disease is still the leading cause of mortality worldwide. Vascular endothelial dysfunction is viewed as the initial step of most cardiovascular diseases. Many studies have indicated that periodontal pathogens, especially Porphyromonas gingivalis, are closely correlated with vascular endothelial homeostasis, but the function of P. gingivalis and the underlying mechanisms are still elusive. To illuminate the effects and elucidate the mechanisms of P. gingivalis on endothelial structural integrity, we developed P. gingivalis infection models in vivo and in vitro. Endothelial cell proliferation, differentiation and apoptosis were detected. Here, we showed that P. gingivalis can impair endothelial integrity by inhibiting cell proliferation and inducing endothelial mesenchymal transformation and apoptosis of endothelial cells, which reduce the cell levels and cause the endothelium to lose its ability to repair itself. A mechanistic analysis showed that TLR antagonist or NF-κB signalling inhibitor can largely rescue the damaged integrity of the endothelium caused by P. gingivalis, suggesting that TLR-NF-κB signalling plays a vital role in vascular endothelial homeostasis destroyed by P. gingivalis. These results suggest a potential intervention method for the prevention and treatment of cardiovascular disease.