Macrophage membrane-camouflaged pH-sensitive nanoparticles for targeted therapy of oral squamous cell carcinoma.

BACKGROUND: Oral cancer is the most common malignant tumor of the head and neck, and 90% of cases are oral squamous cell carcinoma (OSCC). Chemotherapy is an important component of comprehensive treatment for OSCC. However, the clinical treatment effect of chemotherapy drugs, such as doxorubicin (DOX), is limited due to the lack of tumor targeting and rapid clearance by the immune system. Thus, based on the tumor-targeting and immune evasion abilities of macrophages, macrophage membrane-encapsulated poly(methyl vinyl ether alt maleic anhydride)-phenylboronic acid-doxorubicin nanoparticles (MM@PMVEMA-PBA-DOX NPs), briefly as MM@DOX NPs, were designed to target OSCC. The boronate ester bonds between PBA and DOX responded to the low pH value in the tumor microenvironment, selectively releasing the loaded DOX. RESULTS: The results showed that MM@DOX NPs exhibited uniform particle size and typical core-shell structure. As the pH decreased from 7.4 to 5.5, drug release increased from 14 to 21%. The in vitro targeting ability, immune evasion ability, and cytotoxicity of MM@DOX NPs were verified in HN6 and SCC15 cell lines. Compared to free DOX, flow cytometry and fluorescence images demonstrated higher uptake of MM@DOX NPs by tumor cells and lower uptake by macrophages. Cell toxicity and live/dead staining experiments showed that MM@DOX NPs exhibited stronger in vitro antitumor effects than free DOX. The targeting and therapeutic effects were further confirmed in vivo. Based on in vivo biodistribution of the nanoparticles, the accumulation of MM@DOX NPs at the tumor site was increased. The pharmacokinetic results demonstrated a longer half-life of 9.26 h for MM@DOX NPs compared to 1.94 h for free DOX. Moreover, MM@DOX NPs exhibited stronger tumor suppression effects in HN6 tumor-bearing mice and good biocompatibility. CONCLUSIONS: Therefore, MM@DOX NPs is a safe and efficient therapeutic platform for OSCC.

The application of phenylboronic acid pinacol ester functionalized ROS-responsive multifunctional nanoparticles in the treatment of Periodontitis.

Periodontitis is an inflammatory disease induced by the complex interactions between the host immune system and the microbiota of dental plaque. Oxidative stress and the inflammatory microenvironment resulting from periodontitis are among the primary factors contributing to the progression of the disease. Additionally, the presence of dental plaque microbiota plays a significant role in affecting the condition. Consequently, treatment strategies for periodontitis should be multi-faceted. In this study, a reactive oxygen species (ROS)-responsive drug delivery system was developed by structurally modifying hyaluronic acid (HA) with phenylboronic acid pinacol ester (PBAP). Curcumin (CUR) was encapsulated in this drug delivery system to form curcumin-loaded nanoparticles (HA@CUR NPs). The release results indicate that CUR can be rapidly released in a ROS environment to reach the concentration required for treatment. In terms of uptake, HA can effectively enhance cellular uptake of NPs because it specifically recognizes CD44 expressed by normal cells. Moreover, HA@CUR NPs not only retained the antimicrobial efficacy of CUR, but also exhibited more pronounced anti-inflammatory and anti-oxidative stress functions both in vivo and in vitro. This provides a good potential drug delivery system for the treatment of periodontitis, and could offer valuable insights for dental therapeutics targeting periodontal diseases.

Expert consensus on difficulty assessment of endodontic therapy.

Endodontic diseases are a kind of chronic infectious oral disease. Common endodontic treatment concepts are based on the removal of inflamed or necrotic pulp tissue and the replacement by gutta-percha. However, it is very essential for endodontic treatment to debride the root canal system and prevent the root canal system from bacterial reinfection after root canal therapy (RCT). Recent research, encompassing bacterial etiology and advanced imaging techniques, contributes to our understanding of the root canal system's anatomy intricacies and the technique sensitivity of RCT. Success in RCT hinges on factors like patients, infection severity, root canal anatomy, and treatment techniques. Therefore, improving disease management is a key issue to combat endodontic diseases and cure periapical lesions. The clinical difficulty assessment system of RCT is established based on patient conditions, tooth conditions, root canal configuration, and root canal needing retreatment, and emphasizes pre-treatment risk assessment for optimal outcomes. The findings suggest that the presence of risk factors may correlate with the challenge of achieving the high standard required for RCT. These insights contribute not only to improve education but also aid practitioners in treatment planning and referral decision-making within the field of endodontics.

Biomimetic nanotherapeutics for homotypic-targeting photothermal/chemotherapy of oral cancer.

Given the inherent complexity of cancer treatment and the limitations of singular therapeutic modalities, the development of an optimal nanocarrier system capable of facilitating synergistic organic therapy remains a profound challenge. Herein, a synergetic chemo/photothermal therapy nanoplatform was exploited to specifically tailor for the augmented treatment of oral cancer. A cancer cell membrane-camouflaged nanocarrier was developed with a polymeric core encapsulating doxorubicin (DOX). The designed nanoparticles (CC@DOXNPs) inherited the functional membrane proteins from the source cancer cells, endowing their remarkable ability to selectively target cancer cells delivery both in vitro and in vivo. Moreover, indocyanine green (ICG), modified with the phospholipid polymer DSPE-PEG2000, was introduced into the cancer cell membrane to enable photothermal therapy. Remarkably, as evaluated in a preclinical subcutaneous and orthotopic mice model of oral cancer, biomimetic composite nanotherapeutics (lip-CC@DOXNPs) could significantly accumulate into tumor lesion and effectively suppress tumor growth under the near-infrared (NIR, 808 nm) irradiation, without causing the undesirable systematic toxicity. Moreover, RNA sequence analyses indicated that chemo/photothermal therapy triggers the intrinsic mitochondria-mediated apoptosis through the p53 signaling pathway. Combined with gene expression results, this intrinsic mitochondria-mediated apoptosis pathway was further demonstrated. Collectively, this multifaceted nanoplatforms possess a remarkable capability for tumor-targeting drug delivery, and the proficient photothermal conversion ability, rendering them an ideal therapeutic approach for oral cancer treatment.

Expert consensus on digital guided therapy for endodontic diseases.

Digital guided therapy (DGT) has been advocated as a contemporary computer-aided technique for treating endodontic diseases in recent decades. The concept of DGT for endodontic diseases is categorized into static guided endodontics (SGE), necessitating a meticulously designed template, and dynamic guided endodontics (DGE), which utilizes an optical triangulation tracking system. Based on cone-beam computed tomography (CBCT) images superimposed with or without oral scan (OS) data, a virtual template is crafted through software and subsequently translated into a 3-dimensional (3D) printing for SGE, while the system guides the drilling path with a real-time navigation in DGE. DGT was reported to resolve a series of challenging endodontic cases, including teeth with pulp obliteration, teeth with anatomical abnormalities, teeth requiring retreatment, posterior teeth needing endodontic microsurgery, and tooth autotransplantation. Case reports and basic researches all demonstrate that DGT stand as a precise, time-saving, and minimally invasive approach in contrast to conventional freehand method. This expert consensus mainly introduces the case selection, general workflow, evaluation, and impact factor of DGT, which could provide an alternative working strategy in endodontic treatment.

Let-7a promotes periodontal bone regeneration of bone marrow mesenchymal stem cell aggregates via the Fas/FasL-autophagy pathway.

Periodontal bone regeneration using bone marrow mesenchymal stem cell (BMMSC) transplantation is a promising method; however, the method for osteogenic differentiation of BMMSCs needs to be improved. In this research, we sought to identify the roles of let-7a in the osteogenesis of BMMSCs and to provide a potential method for periodontal bone regeneration. Our previous study revealed that Fas/FasL is a target of let-7a. In this study, we demonstrated that let-7a overexpression significantly enhanced BMMSC-CAs osteogenesis both in vitro and in vivo. Mechanistically, upregulation of Fas/FasL using the rfas/rfaslg plasmid obstructed the osteogenesis of BMMSCs by inhibiting autophagy. Furthermore, we confirmed that overexpression of let-7a activated autophagy and alleviated the inhibited osteogenesis by the autophagy inhibitor 3-MA and the rfas/rfaslg plasmid of BMMSCs. In general, our findings showed that let-7a promoted the osteogenesis of BMMSCs through the Fas/FasL-autophagy pathway, suggesting that the application of let-7a in BMMSC-CAs based periodontal bone regeneration could be a promising strategy.

Bacterial growth stage determines the yields, protein composition, and periodontal pathogenicity of Porphyromonas gingivalis outer membrane vesicles.

Introduction: P. gingivalis (W83), as the keystone pathogen in chronic periodontitis, has been found to be tightly bound to systemic diseases. Outer membrane vesicles (OMVs) produced by P. gingivalis (W83) are thought to serve key functions in bacterial virulence and pathogenicity. This study aims to comprehend the biological functions of P. gingivalis OMVs isolated from different growth stages by comparing their physicochemical properties and pathogenicity. Methods: Protein composition was analyzed via isotope-labeled relative and absolute quantification (iTRAQ). Macrophage polarization and the expression of IL-6 and IL-1ß were detected. The proliferation, migration, osteogenic differentiation, and IL-1b/NLRP3 expression of periodontal ligament stem cells (PDLSCs) were evaluated. P. gingivalis/P. gingivalis OMVs-induced periodontal models were also constructed in Sprague Dawley rats. Results: The protein composition of P. gingivalis OMVs isolated from different growth stages demonstrated obvious differences ranging from 25 KDa to 75 KDa. In the results of flow cytometry, we found that in vitro experiments the M1 subtype of macrophages was more abundant in the late-log OMVs and stationary OMVs groups which boosted the production of inflammatory cytokines more than pre-log OMVs. Compared to pre-log OMVs, late-log OMVs and stationary OMVs had more pronounced inhibitory effects on proliferation, migration, and early osteogenesis of PDLSCs. The NLRP3 inflammasome was activated to a larger extent in the stationary OMVs group. Micro-computed tomography (Micro CT), hematoxylin-eosin staining (HE), and tartrate acid phosphatase (TRAP) results showed that the periodontal damage in the stationary OMVs group was worse than that in the pre-log OMVs and late-log OMVs group, but almost equal to that in the positive control group (P. gingivalis). Discussion: In general, both in vivo and in vitro experiments showed that late-log OMVs and stationary OMVs have more significant pathogenicity in periodontal disease.

Experts consensus on the procedure of dental operative microscope in endodontics and operative dentistry.

The dental operative microscope has been widely employed in the field of dentistry, particularly in endodontics and operative dentistry, resulting in significant advancements in the effectiveness of root canal therapy, endodontic surgery, and dental restoration. However, the improper use of this microscope continues to be common in clinical settings, primarily due to operators' insufficient understanding and proficiency in both the features and established operating procedures of this equipment. In October 2019, Professor Jingping Liang, Vice Chairman of the Society of Cariology and Endodontology, Chinese Stomatological Association, organized a consensus meeting with Chinese experts in endodontics and operative dentistry. The objective of this meeting was to establish a standard operation procedure for the dental operative microscope. Subsequently, a consensus was reached and officially issued. Over the span of about four years, the content of this consensus has been further developed and improved through practical experience.

Biomimetic nanoparticles to enhance the reverse cholesterol transport for selectively inhibiting development into foam cell in atherosclerosis.

A disorder of cholesterol homeostasis is one of the main initiating factors in the progression of atherosclerosis (AS). Metabolism and removal of excess cholesterol facilitates the prevention of foam cell formation. However, the failure of treatment with drugs (e.g. methotrexate, MTX) to effectively regulate progression of disease may be related to the limited drug bioavailability and rapid clearance by immune system. Thus, based on the inflammatory lesion "recruitment" properties of macrophages, MTX nanoparticles (MTX NPs) camouflaged with macrophage membranes (MM@MTX NPs) were constructed for the target to AS plaques. MM@MTX NPs exhibited a uniform hydrodynamic size around ~ 360 nm and controlled drug release properties (~ 72% at 12 h). After the macrophage membranes (MM) functionalized "homing" target delivery to AS plaques, MM@MTX NPs improved the solubility of cholesterol by the functionalized ß-cyclodextrin (ß-CD) component and significantly elevate cholesterol efflux by the loaded MTX mediated the increased expression levels of ABCA1, SR-B1, CYP27A1, resulting in efficiently inhibiting the formation of foam cells. Furthermore, MM@MTX NPs could significantly reduce the area of plaque, aortic plaque and cholesterol crystals deposition in ApoE-/- mice and exhibited biocompatibility. It is suggested that MM@MTX NPs were a safe and efficient therapeutic platform for AS.

Dental Pulp Stem Cell-Derived Exosomes Regulate Anti-Inflammatory and Osteogenesis in Periodontal Ligament Stem Cells and Promote the Repair of Experimental Periodontitis in Rats.

Purpose: Dental pulp stem cell-derived exosomes (DPSC-EXO), which have biological characteristics similar to those of metrocytes, have been found to be closely associated with tissue regeneration. Periodontitis is an immune inflammation and tissue destructive disease caused by plaque, resulting in alveolar bone loss and periodontal epithelial destruction. It is not clear whether DPSC-EXO can be used as an effective therapy for periodontal regeneration. The purpose of this study was not only to verify the effect of DPSC-EXO on reducing periodontitis and promoting periodontal tissue regeneration, but also to reveal the possible mechanism. Methods: DPSC-EXO was isolated by ultracentrifugation. Then it characterized by transmission electron microscope (TEM), nanoparticle tracking analysis (NTA) and Western Blot. In vitro, periodontal ligament stem cells (PDLSCs) were treated with DPSC-EXO, the abilities of cell proliferation, migration and osteogenic potential were evaluated. Furthermore, we detected the expression of IL-1ß, TNF-αand key proteins in the IL-6/JAK2/STAT3 signaling pathway after simulating the inflammatory environment by LPS. In addition, the effect of DPSC-EXO on the polarization phenotype of macrophages was detected. In vivo, the experimental periodontitis in rats was established and treated with DPSC-EXO or PBS. After 4 weeks, the maxillae were collected and detected by micro-CT and histological staining. Results: DPSC-EXO promoted the proliferation, migration and osteogenesis of PDLSCs in vitro. DPSC-EXO also regulated inflammation by inhibiting the IL-6/JAK2/STAT3 signaling pathway during acute inflammatory stress. In addition, the results showed that DPSC-EXO could polarize macrophages from the M1 phenotype to the M2 phenotype. In vivo, we found that DPSC-EXO could effectively reduce alveolar bone loss and promote the healing of the periodontal epithelium in rats with experimental periodontitis. Conclusion: DPSC-EXO plays an important role in inhibiting periodontitis and promoting tissue regeneration. This study provides a promising acellular therapy for periodontitis.

A novel LncRNA SPIRE1/miR-181a-5p/PRLR axis in mandibular bone marrow-derived mesenchymal stem cells regulates the Th17/Treg immune balance through the JAK/STAT3 pathway in periodontitis.

Periodontitis is a microbial-related chronic inflammatory disease associated with imbalanced differentiation of Th17 cells and Treg cells. Bone marrow-derived mesenchymal stem cells (BM-MSCs) possess wide immunoregulatory properties. Long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) contribute to the immunomodulation in the pathological mechanisms of inflammatory diseases. However, critical lncRNAs/miRNAs involved in immunomodulation of mandibular BM-MSCs largely remain to be identified. Here, we explored the molecular mechanisms behind the defective immunomodulatory ability of mandibular BM-MSCs under the periodontitis settings. We found that mandibular BM-MSCs from P. gingivalis-induced periodontitis mice had significantly reduced expression of LncRNA SPIRE1 than that from normal control mice. LncRNA SPIRE1 knockdown in normal BM-MSCs caused Th17/Treg cell differentiation imbalance during the coculturing of BM-MSCs and CD4 T cells. In addition, LncRNA SPIRE1 was identified as a competitive endogenous RNA that sponges miR-181a-5p in BM-MSCs. Moreover, miR-181a-5p inhibition attenuated the impact of LncRNA SPIRE1 knockdown on the ability of BM-MSCs in modulating Th17/Treg balance. Prolactin receptor (PRLR) was validated as a downstream target of miR-181a-5p. Notably, targeted knockdown of LncRNA SPIRE1 or PRLR or transfection of miR-181a-5p mimics activated the JAK/STAT3 signaling in normal BM-MSCs, while treatment with STAT3 inhibitor C188-9 restored the immunomodulatory properties of periodontitis-associated BM-MSCs. Furthermore, BM-MSCs with miR-181a-5p inhibition or PRLR-overexpression showed enhanced in vivo immunosuppressive properties in the periodontitis mouse model. Our results indicate that the JAK/STAT3 pathway is involved in the immunoregulation of BM-MSCs, and provide critical insights into the development of novel targeted therapies against periodontitis.

CD93 Ameliorates Diabetic Wounds by Promoting Angiogenesis via the p38MAPK/MK2/HSP27 Axis.

OBJECTIVE: Diabetic wounds are a complication of diabetes mellitus, which is characterised by microcirculation dysfunction caused by decreased local blood supply and insufficient metabolic exchange. Clinically, in addition to glycaemic control, the most important treatment for diabetic wounds is to promote local angiogenesis, which accelerates wound healing. The authors previous study demonstrated that CD93, which is specifically expressed on vascular endothelial cells (ECs), redundantly regulates angiogenesis in zebrafish, suggesting that CD93 is a potential angiogenic molecule. However, the role of CD93 in diabetic wounds has not yet been elucidated. METHODS: The angiogenic effects of CD93 were studied from four aspects: exogenous, endogenous, in vitro, and in vivo. CD93 recombinant protein was used in microvascular ECs and in mice to observe angiogenesis in vitro and in vivo. The wound model was established in CD93-/- and wild type diabetic mice, and the degree of wound healing as well as the amount and maturity of neovascularisation were investigated. The possible mechanism of CD93 in angiogenesis was determined by CD93 overexpression in cultured ECs. RESULTS: CD93 recombinant protein was found to exogenously promote tube formation and sprouting of ECs. It also recruited cells to promote the formation of vascular like structures in subcutaneous tissue and accelerated wound healing by optimising angiogenesis and re-epithelisation. Furthermore, CD93 deficiency was observed to delay wound repair, characterised by reduced neovascularisation, vascular maturity, and re-epithelisation level. Mechanically, CD93 activated the p38MAPK/MK2/HSP27 signalling pathway, positively affecting the angiogenic functions of ECs. CONCLUSION: This study demonstrated that CD93 promotes angiogenesis both in vitro and in vivo and that its angiogenic role in vitro is mediated by the p38MAPK/MK2/HSP27 signalling pathway. It was also found that CD93 exerts beneficial effects on wound healing in diabetic mice by promoting angiogenesis and re-epithelisation.

Establishing and characterizing human stem cells from the apical papilla immortalized by hTERT gene transfer.

Stem cells from the apical papilla (SCAPs) are promising candidates for regenerative endodontic treatment and tissue regeneration in general. However, harvesting enough cells from the limited apical papilla tissue is difficult, and the cells lose their primary phenotype over many passages. To get over these challenges, we immortalized human SCAPs with lentiviruses overexpressing human telomerase reverse transcriptase (hTERT). Human immortalized SCAPs (hiSCAPs) exhibited long-term proliferative activity without tumorigenic potential. Cells also expressed mesenchymal and progenitor biomarkers and exhibited multiple differentiation potentials. Interestingly, hiSCAPs gained a stronger potential for osteogenic differentiation than the primary cells. To further investigate whether hiSCAPs could become prospective seed cells in bone tissue engineering, in vitro and in vivo studies were performed, and the results indicated that hiSCAPs exhibited strong osteogenic differentiation ability after infection with recombinant adenoviruses expressing BMP9 (AdBMP9). In addition, we revealed that BMP9 could upregulate ALK1 and BMPRII, leading to an increase in phosphorylated Smad1 to induce the osteogenic differentiation of hiSCAPs. These results support the application of hiSCAPs in tissue engineering/regeneration schemes as a stable stem cell source for osteogenic differentiation and biomineralization, which could be further used in stem cell-based clinical therapies.

Evaluation of apical extrusion of debris and centering ability in different nickel-titanium files during curved root canal preparation.

BACKGROUND: Curved root canals lead to difficulties in cleaning, shaping and filling the root canal system. Apical extrusion of debris and root canal transportation are important factors causing postoperative complications. In clinical practice, commonly selected instruments include multifile NiTi systems, such as M3-Pro PLUS (M3-PRO), Orodeka Plex 2.0 (ODP), Rotate (ROT), and Protaper Gold (PTG), as well as single-file NiTi systems, such as M3-L Platinum 2019 (M3L), Waveone Gold (WOG), and Reciproc Blue (RCB). This study aimed to comprehensively evaluate the differences in the apical extrusion of debris and centering ability of the above NiTi files. METHODS: Seventy 3D-printed resin teeth were used (n = 10). The apically extruded debris was collected in a preweighed centrifuge tube. The resin teeth with or without root canal preparation were cut into separate cross sections at 1 mm, 3 mm, 5 mm, and 7 mm away from the root apex, and then the root canal transportation and centering ratio of each cross section were calculated. RESULTS: Apical extrusion of debris was highest in RCB but lowest in OD-P (P < 0.05). Root call deviation was lowest in ROT at the 3 mm level, in PTG at the 5 mm level, and in PTG and ROT at the 7 mm level (P < 0.05). The centering ratio of NiTi files was highest in the RCB group at the 3 mm level, in the PTG group at the 5 mm level, in the ROT group at the 7 mm level (P < 0.05). CONCLUSIONS: For NiTi files with the same system, the cross-sectional design is the greatest factor affecting the extrusion of debris, and motion mode is the second. In addition, the multifile system could reduce the degree of root canal transportation.

Heavy Ion Radiation Directly Induced the Shift of Oral Microbiota and Increased the Cariogenicity of Streptococcus mutans.

Radiation caries is one of the most common complications of head and neck radiotherapy. A shift in the oral microbiota is the main factor of radiation caries. A new form of biosafe radiation, heavy ion radiation, is increasingly being applied in clinical treatment due to its superior depth-dose distribution and biological effects. However, how heavy ion radiation directly impacts the oral microbiota and the progress of radiation caries are unknown. Here, unstimulated saliva samples from both healthy and caries volunteers and caries-related bacteria were directly exposed to therapeutic doses of heavy ion radiation to determine the effects of radiation on oral microbiota composition and bacterial cariogenicity. Heavy ion radiation significantly decreased the richness and diversity of oral microbiota from both healthy and caries volunteers, and a higher percentage of Streptococcus was detected in radiation groups. In addition, heavy ion radiation significantly enhanced the cariogenicity of saliva-derived biofilms, including the ratios of the genus Streptococcus and biofilm formation. In the Streptococcus mutans-Streptococcus sanguinis dual-species biofilms, heavy ion radiation increased the ratio of S. mutans. Next, S. mutans was directly exposed to heavy ions, and the radiation significantly upregulated the gtfC and gtfD cariogenic virulence genes to enhance the biofilm formation and exopolysaccharides synthesis of S. mutans. Our study demonstrated, for the first time, that direct exposure to heavy ion radiation can disrupt the oral microbial diversity and balance of dual-species biofilms by increasing the virulence of S. mutans, increasing its cariogenicity, indicating a potential correlation between heavy ions and radiation caries. IMPORTANCE The oral microbiome is crucial to understanding the pathogenesis of radiation caries. Although heavy ion radiation has been used to treat head and neck cancers in some proton therapy centers, its correlation with dental caries, especially its direct effects on the oral microbiome and cariogenic pathogens, has not been reported previously. Here, we showed that the heavy ion radiation directly shifted the oral microbiota from a balanced state to a caries-associated state by increasing the cariogenic virulence of S. mutans. Our study highlighted the direct effect of heavy ion radiation on oral microbiota and the cariogenicity of oral microbes for the first time.

Exopolysaccharides metabolism and cariogenesis of Streptococcus mutans biofilm regulated by antisense vicK RNA.

Background: Streptococcus mutans (S. mutans) is a pivotal cariogenic pathogen contributing to its multiple virulence factors, one of which is synthesizing exopolysaccharides (EPS). VicK, a sensor histidine kinase, plays a major role in regulating genes associated with EPS synthesis and adhesion. Here we first identified an antisense vicK RNA (ASvicK) bound with vicK into double-stranded RNA (dsRNA). Objective: This study aims to investigate the effect and mechanism of ASvicK in the EPS metabolism and cariogenesis of S. mutans. Methods: The phenotypes of biofilm were detected by scanning electron microscopy (SEM), gas chromatography-mass spectrometery (GC-MS) , gel permeation chromatography (GPC) , transcriptome analysis and Western blot. Co-immunoprecipitation (Co-ip) assay and enzyme activity experiment were adopted to investigate the mechanism of ASvicK regulation. Caries animal models were developed to study the relationship between ASvicK and cariogenicity of S. mutans. Results: Overexpression of ASvicK can inhibit the growth of biofilm, reduce the production of EPS and alter genes and protein related to EPS metabolism. ASvicK can adsorb RNase III to regulate vicK and affect the cariogenicity of S. mutans. Conclusions: ASvicK regulates vicK at the transcriptional and post-transcriptional levels, effectively inhibits EPS synthesis and biofilm formation and reduces its cariogenicity in vivo.

mTORC1 signaling pathway regulates tooth repair.

Tooth germ injury can lead to abnormal tooth development and even tooth loss, affecting various aspects of the stomatognathic system including form, function, and appearance. However, the research about tooth germ injury model on cellular and molecule mechanism of tooth germ repair is still very limited. Therefore, it is of great importance for the prevention and treatment of tooth germ injury to study the important mechanism of tooth germ repair by a tooth germ injury model. Here, we constructed a Tg(dlx2b:Dendra2-NTR) transgenic line that labeled tooth germ specifically. Taking advantage of the NTR/Mtz system, the dlx2b+ tooth germ cells were depleted by Mtz effectively. The process of tooth germ repair was evaluated by antibody staining, in situ hybridization, EdU staining and alizarin red staining. The severely injured tooth germ was repaired in several days after Mtz treatment was stopped. In the early stage of tooth germ repair, the expression of phosphorylated 4E-BP1 was increased, indicating that mTORC1 is activated. Inhibition of mTORC1 signaling in vitro or knockdown of mTORC1 signaling in vivo could inhibit the repair of injured tooth germ. Normally, mouse incisors were repaired after damage, but inhibition/promotion of mTORC1 signaling inhibited/promoted this repair progress. Overall, we are the first to construct a stable and repeatable repair model of severe tooth germ injury, and our results reveal that mTORC1 signaling plays a crucial role during tooth germ repair, providing a potential target for clinical treatment of tooth germ injury.

CircTMEM30A/hsa-miR-130a-3p regulates TNFα and promotes the malignant progression of COPD with primary lung cancer.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) and lung cancer is the most common respiratory diseases among smokers. Lung cancer is one of the most common malignancy. COPD patients are at high risk of lung cancer, but the specific pathogenesis is still unclear. In recent years, circRNAs have become the focus of lung cancer research. This study investigated the effect of CircTMEM30A on COPD and lung cancer and its possible molecular mechanisms. METHODS: QPCR was used to detect the expression of CircTMEM30A in COPD patients, lung cancer patients, and COPD patients with lung cancer. CircTMEM30A was transfected with PPF, HFL1, A549 and NCI-H446 cells, and the transfection efficiency was verified by real-time quantitative PCR. The effects of CircTMEM30A on the proliferation, migration and invasion of fibroblasts and lung cancer cells were detected by MTT, Transwell and scratch tests. The target gene of CircTMEM30A was verified by luciferase reporter assay. Real-time quantitative PCR was used to detect the expression level of CircTMEM30A target gene. RESULTS: CircTMEM30A was the most highly expressed in COPD patients with lung cancer. Overexpression of CircTMEM30A enhanced the effects of proliferation, migration and invasion of fibroblasts and lung cancer cells, down-regulated the expression of E-cadherin, up-regulated the expression of Vimentin, and promoted EMT. After knocking down CircTMEM30A, the migration and invasion ability of lung cancer cells was significantly reduced. Bioinformatics retrieval and luciferase reporter gene confirmed that CircTMEM30A could be bind to miR-130a, while TNFα gene was the target gene of miR-130a. Further studies showed that overexpression of miR-130a and knockdown of TNFα reversed the promoting effect of CircTMEM30A on lung cancer cells. CONCLUSIONS: CircTMEM30A was highly expressed in COPD patients with lung cancer, and miR-130a was low expressed in lung cancer cells. CircTMEM30A regulated the expression of TNFα through miR-130a, thereby affecting the progression of COPD and lung cancer. CircTMEM30A may be a therapeutic target for COPD patients with lung cancer.

Sub-lethal concentrations of chlorhexidine inhibit Candida albicans growth by disrupting ROS and metal ion homeostasis.

Candida albicans is a normal resident of the human oral cavity. It is also the most common fungal pathogen, causing various oral diseases, particularly in immunocompromised individuals. Chlorhexidine digluconate (CHG) is a broad-spectrum antimicrobial agent widely used in dental practice and has been recommended to treat oral candidiasis. However, its action mechanism against the fungal pathogen C. albicans remains poorly understood. The aim of the present study was to investigate the effect of CHG at sub-lethal concentrations against C. albicans. CHG inhibited the growth of C. albicans in a dose- and time-dependent manner. Cells treated with CHG exhibited altered membrane permeability, reduced metabolic activity, and enhanced metal ion and reactive oxygen species (ROS) accumulation. Copper-sensing transcription factor Mac1, iron-sensing transcription factors Sfu1 and Sef2, and copper transporter Ctr1 regulated intracellular metal ion and ROS homeostasis in response to CHG. Deletion of MAC1, SFU1, or SEF2 increased intracellular ROS production and cell susceptibility to CHG. This study revealed a novel mechanism by which CHG induced apoptosis of C. albicans cells through the disruption of metal ion and ROS homeostasis, which may help to identify new targets for fungal infections.

[Materials for Selective Inhibition of Streptococcus mutans and Progress in Relevant Research].

Dental caries is a disease in which chronic progressive destruction of the hard dental tissues occurs under the influence of multiple factors, among which, bacterial infection being the most important one. Dental plaque biofilm is a key factor in the pathogenesis of dental caries. Under normal circumstances, microorganisms within the biofilm maintain a dynamic balance through coordination, competition, and antagonism. However, when the environment changes, the balance in the biofilm will be disrupted, and the number of cariogenic bacteria, especially Streptococcus mutans ( S. mutans), will increase significantly, thereby causing the production of large amounts of organic acids on the tooth surface, tooth demineralization, and the formation of dental caries. Therefore, finding ways to restore the dynamic balance of oral microorganisms through selective inhibition of S. mutans is key to the prevention and treatment of dental caries. Herein, we reviewed the research progress of recent years in the development of materials with selective antibacterial effect, intending to provide references for the further development of drugs for the prevention and treatment of dental caries. Future studies should focus on the following aspects, mechanism, clinical efficacy, chemical modification, and safety, to supplement and make improvements on the existing relevant research, and to promote progress in research and development of drugs for the prevention and treatment of dental caries.