The temporal protein signature analyses of developing human deciduous molar tooth germ.

The tooth serves as an exemplary model for developmental studies, encompassing epithelial-mesenchymal transition and cell differentiation. The essential factors and pathways identified in tooth development will help understand the natural development process and the malformations of mineralized tissues such as skeleton. The time-dependent proteomic changes were investigated through the proteomics of healthy human molars during embryonic stages, ranging from the cap-to-early bell stage. A comprehensive analysis revealed 713 differentially expressed proteins (DEPs) exhibiting five distinct temporal expression patterns. Through the application of weighted gene co-expression network analysis (WGCNA), 24 potential driver proteins of tooth development were screened, including CHID1, RAP1GDS1, HAPLN3, AKAP12, WLS, GSS, DDAH1, CLSTN1, AFM, RBP1, AGO1, SET, HMGB2, HMGB1, ANP32A, SPON1, FREM1, C8B, PRPS2, FCHO2, PPP1R12A, GPALPP1, U2AF2, and RCC2. Then, the proteomics and transcriptomics expression patterns of these proteins were further compared, complemented by single-cell RNA-sequencing (scRNA-seq). In summary, this study not only offers a wealth of information regarding the molecular intricacies of human embryonic epithelial and mesenchymal cell differentiation but also serves as an invaluable resource for future mechanistic inquiries into tooth development.

Osteopontin interacts with dendritic cells and macrophages in pulp inflammation: Comprehensive transcriptomic analysis and laboratory investigations.

AIM: To investigate novel diagnostic markers for pulpitis and validate by clinical samples from normal and inflamed pulp. To explore the relationship between diagnostic markers and immune cells or their phenotypes during pulp inflammation. METHODOLOGY: Two microarray datasets, GSE77459 and GSE92681, and identified differential expression genes were integrated. To understand immune features, gene functions, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Disease Ontology (DO) and ImmuneSigDB Gene Set Enrichment Analysis (GSEA) were analysed. For predictive purposes, machine learning techniques were applied to detect diagnostic markers. Immune infiltration in inflamed pulp was studied using CIBERSORT. The relationship between diagnostic markers and immune cells was investigated and validated their gene expression in clinical samples from the normal or inflamed pulp by qRT-PCR. Finally, the correlation between one marker, secreted phosphoprotein 1 (SPP1), encoding osteopontin (OPN), and dendritic cells (DCs)/macrophages was identified via HE staining and multiplex immunohistochemistry. An in vitro inflammatory dental pulp microenvironment model of THP-1 macrophages cocultured with dental pulp cells derived conditioned media (DPCs-CM) to investigate OPN production and macrophage phenotypes was established. RESULTS: Analysis revealed unique immunologic features in inflamed pulp. Three diagnostic markers for pulpitis: endothelin-1 (EDN1), SPP1, and purine nucleoside phosphorylase (PNP), and validated them using qRT-PCR were predicted. Multiplex immunohistochemistry demonstrated OPN co-localized with activated DCs and M2 macrophages during pulp inflammation. In vitro experiments showed that THP-1 macrophages produced the highest levels of OPN when stimulated with DPCs-CM derived from the 20 µg/mL LPS pre-conditioned group, suggesting an M2b-like phenotype by increasing surface marker CD86 and expression of IL6, TNFα, IL10, and CCL1 but not CCL17 and MerTK. Levels of CCL1 and IL10 elevated significantly in the macrophages' supernatant from the 20 µg/mL LPS pre-conditioned CM group. OPN was proven co-localizing with CD86 in the inflamed pulp by immunofluorescence. CONCLUSIONS: The current findings suggest that OPN can serve as a promising biomarker for pulpitis, correlated with DCs and macrophages. OPN+ macrophages in the inflamed pulp are associated with M2b-like phenotypes. These insights offer the potential for improved diagnosis and targeted therapy.

Genome-wide identification of potential odontogenic genes involved in the dental epithelium-mesenchymal interaction during early odontogenesis.

BACKGROUND: Epithelium-mesenchymal interactions are involved in odontogenic processes. Previous studies have focused on the intracellular signalling regulatory network in tooth development, but the functions of extracellular regulatory molecules have remained unclear. This study aims to explore the gene profile of extracellular proteoglycans and their glycosaminoglycan chains potentially involved in dental epithelium-mesenchymal interactions using high-throughput sequencing to provide new understanding of early odontogenesis. RESULTS: Whole transcriptome profiles of the mouse dental epithelium and mesenchyme were investigated by RNA sequencing (RNA-seq). A total of 1,281 and 1,582 differentially expressed genes were identified between the dental epithelium and mesenchyme at E11.5 and E13.5, respectively. Enrichment analysis showed that extracellular regions and ECM-receptor interactions were significantly enriched at both E11.5 and E13.5. Polymerase chain reaction analysis confirmed that the extracellular proteoglycan family exhibited distinct changes during epithelium-mesenchymal interactions. Most proteoglycans showed higher transcript levels in the dental mesenchyme, whereas only a few were upregulated in the epithelium at both stages. In addition, 9 proteoglycans showed dynamic expression changes between these two tissue compartments. Gpc4, Sdc2, Spock2, Dcn and Lum were expressed at higher levels in the dental epithelium at E11.5, whereas their expression was significantly higher in the dental mesenchyme at E13.5, which coincides with the odontogenic potential shift. Moreover, the glycosaminoglycan biosynthetic enzymes Ext1, Hs3st1/5, Hs6st2/3, Ndst3 and Sulf1 also exhibited early upregulation in the epithelium but showed markedly higher expression in the mesenchyme after the odontogenic potential shift. CONCLUSION: This study reveals the dynamic expression profile of extracellular proteoglycans and their biosynthetic enzymes during the dental epithelium-mesenchymal interaction. This study offers new insight into the roles of extracellular proteoglycans and their distinct sulfation underlying early odontogenesis.

Establishment and validation of the autophagy-related ceRNA network in irreversible pulpitis.

BACKGROUND: The molecular mechanisms underlying the onset and progression of irreversible pulpitis have been studied for decades. Many studies have indicated a potential correlation between autophagy and this disease. Against the background of the competing endogenous RNA (ceRNA) theory, protein-coding RNA functions are linked with long noncoding RNAs (lncRNAs) and microRNAs (miRNAs). This mechanism has been widely studied in various fields but has rarely been reported in the context of irreversible pulpitis. The hub genes selected under this theory may represent the key to the interaction between autophagy and irreversible pulpitis. RESULTS: Filtering and differential expression analyses of the GSE92681 dataset, which contains data from 7 inflamed and 5 healthy pulp tissue samples, were conducted. The results were intersected with autophagy-related genes (ARGs), and 36 differentially expressed ARGs (DE-ARGs) were identified. Functional enrichment analysis and construction of the protein‒protein interaction (PPI) network of DE-ARGs were performed. Coexpression analysis was conducted between differentially expressed lncRNAs (DElncRNAs) and DE-ARGs, and 151 downregulated and 59 upregulated autophagy-related DElncRNAs (AR-DElncRNAs) were identified. StarBase and multiMiR were then used to predict related microRNAs of AR-DElncRNAs and DE-ARGs, respectively. We established ceRNA networks including 9 hub lncRNAs (HCP5 and AC112496.1 ↑; FENDRR, AC099850.1, ZSWIM8-AS1, DLX6-AS1, LAMTOR5-AS1, TMEM161B-AS1 and AC145207.5 ↓), which were validated by a qRT‒PCR analysis of pulp tissue from patients with irreversible pulpitis. CONCLUSION: We constructed two networks consisting of 9 hub lncRNAs based on the comprehensive identification of autophagy-related ceRNAs. This study may provide novel insights into the interactive relationship between autophagy and irreversible pulpitis and identifies several lncRNAs that may serve as potential biological markers.

Inhibition of gingival fibroblast necroptosis mediated by RIPK3/MLKL attenuates periodontitis.

AIM: Necroptosis participates in the pathogenesis of many inflammatory diseases, including periodontitis. Here, we aimed to investigate the role and mechanism of necroptosis inhibitors in attenuating periodontitis. MATERIALS AND METHODS: The Gene Expression Omnibus (GEO) dataset GSE164241 was re-analysed to identify the role of necroptosis in periodontitis. Gingival specimens from healthy subjects or periodontitis patients were collected to evaluate the expression level of necroptosis-associated proteins. The therapeutic effect of necroptosis inhibitors on periodontitis was assessed in vivo and in vitro. Moreover, Transwell assays and Western blotting and siRNA transfection were used to identify the effects of necroptotic human gingival fibroblasts (hGFs) on THP-1 macrophages. RESULTS: Re-analysis revealed that gingival fibroblasts (GFs) in periodontitis gingiva showed the highest area under the curve score of necroptosis. Elevated levels of necroptosis-associated proteins were identified in GFs in periodontitis gingiva collected from patients and mice. In ligature-induced periodontitis mice, local administration of receptor interacting protein kinase 3(RIPK3) inhibitor GSK'872 or sh-mixed-lineage kinase domain-like pseudokinase (Mlkl) markedly abrogated necroptosis and rescued periodontitis. Analogously, necroptosis inhibitors alleviated the inflammatory response and release of damage-associated molecular patterns in lipopolysaccharide- or LAZ (LPS + AZD'5582 + z-VAD-fmk, necroptosis inducer)-induced GFs and then reduced THP-1 cell migration and M1 polarization. CONCLUSIONS: Necroptosis in GFs aggravated gingival inflammation and alveolar bone loss. Necroptosis inhibitors attenuate this process by modulating THP-1 macrophage migration and polarization. This study offers novel insights into the pathogenesis and potential therapeutic targets of periodontitis.

A novel single-base deletion of the RUNX Family Transcription Factor 2 gene associated with cleidocranial dysplasia.

Cleidocranial dysplasia (CCD) is a rare, autosomal dominant hereditary disorder characterized by skeletal malformations and dental abnormalities. The purpose of this study was to explore the functional role of a novel mutation in the pathogenesis of CCD. Genomic DNA was extracted from peripheral blood mononuclear cells collected from family members of a Chinese patient with CCD. An analysis of their RUNX Family Transcription Factor 2 (RUNX2) gene sequences was performed by PCR amplification and Sanger sequencing. The function of the mutant RUNX2 was studied by bioinformatics, real-time PCR, western blotting, and subcellular localization analysis. Sanger sequencing identified a novel single-base deletion (NM_001024630.4:c.132delG;NP_001019801.3: Val45Trpfs* 99) in the RUNX2 gene present in the Chinese patient with CCD. In vitro, functional studies showed altered protein localization and increased expression of mutant RUNX2 mRNA and mutant Runt-related transcription factor 2 (RUNX2). Luciferase reporter assay demonstrated that the novel RUNX2 mutations significantly increased the transactivation activity of RUNX2 on the osteocalcin gene promoter. In conclusion, we identified a patient with sporadic CCD carrying a novel deletion/frameshift mutation of the RUNX2 gene and performed screening and functional analyses to determine the cause of the CCD phenotype. This study provides new insights into the pathogenesis of CCD.3.

Photobiomodulation activates undifferentiated macrophages and promotes M1/M2 macrophage polarization via PI3K/AKT/mTOR signaling pathway.

Macrophages are the main mediators of the inflammatory response and play a major role in the onset and maintenance of periodontitis. Studies revealed that photobiomodulation (PBM) can change the polarization state of macrophages and inflammation reduction, although the cellular mechanisms are not fully elucidated. Here, the present study explored the effect of PBM (980 nm) on undifferentiated and M1-type macrophages and the underlying mechanism. RAW264.7 cells were exposed to laser irradiation under different laser parameters (0.5, 5.0, and 10.0 J/cm2) with or without LY294002 (an inhibitor of PI3K pathway). Then, confocal laser microscopy was used to observe cell differentiation; qPCR was performed to examine the gene expression and western blotting was used to detect the protein in the PI3K/AKT/mTOR pathway and activated macrophage markers. The obtained results revealed that 980 nm PBM increased the mRNA expression of iNOS, Il-10, Arg1, and Il-12 along with the inflammatory cytokines Tnfα, IL-1ß, and Il-6 in M0-type macrophages in dose-dependent manner. More interestingly, PBM at 5 J/cm2 decreased the mRNA expression of iNOS, Il-12, Tnfα, IL-1ß, and Il-6 and increased the expression of Arg1 and Il-10 by M1-type macrophages, along with the elevated expression of phosphorylation of AKT and mTOR. Moreover, PBM-induced M1-type macrophage polarization was significantly attenuated via LY294002 treatment. These suggest that 980 nm PBM could activate M0-type macrophages and increase M2/M1 ratio via the PI3K/AKT/mTOR pathway.

Caesarean-section delivery and caries risk of 3-year-old Chinese children: a retrospective cohort study.

BACKGROUND: Caesarean-section (C-section) may influence children's long-term health by affecting bacterial colonization. However, few studies have focused on the association between C-section delivery (CSD) and dental caries, and previous conclusions have been conflicting. This study aimed to explore whether CSD would increase the risk of early childhood caries (ECC) in preschool children in China. METHODS: This study was a retrospective cohort study. Three-year-old children with full primary dentition were included through the medical records system. Children in the nonexposure group were vaginally delivered (VD), while children in the exposure group were delivered through C-section. The outcome was the occurrence of ECC. After agreeing to participate in this study, guardians of included children completed a structured questionnaire on maternal sociodemographic factors, children's oral hygiene and feeding habits. The chi-square test was used to determine differences in the prevalence and severity of ECC between the CSD and VD groups and to analyse the prevalence of ECC according to sample characteristics. Subsequently, potential risk factors for ECC were preliminarily identified through univariate analysis, and the adjusted odds ratios (ORs) were further calculated through multiple logistic regression analysis after controlling for confounding factors. RESULTS: The VD group included 2115 participants while CSD group included 2996 participants. The prevalence of ECC was higher in CSD children than in VD children (27.6% vs. 20.9%, P < 0.05), and the severity of ECC in CSD children was higher (mean number of decayed, missing, and filled teeth, dmft: 2.1 vs. 1.7, P < 0.05). CSD was a risk factor for ECC in 3-year-old children (OR = 1.43, 95% CI = 1.10-2.83). In addition, irregular tooth brushing and always prechewing children's food were risk factors for ECC (P < 0.05). Low maternal educational attainment (high school or below) or socioeconomic status (SES-5) may also increase the prevalence of ECC in preschool children and CSD children (P < 0.05). CONCLUSIONS: CSD would increase the risk of ECC in 3-year-old Chinese children. Paediatric dentists should devote more attention to the development of caries in CSD children. Obstetricians should also prevent excessive and unnecessary CSD.

Comprehensive analysis of the long noncoding RNA-associated competitive endogenous RNA network in the osteogenic differentiation of periodontal ligament stem cells.

BACKGROUD: The mechanism implicated in the osteogenesis of human periodontal ligament stem cells (PDLSCs) has been investigated for years. Previous genomics data analyses showed that long noncoding RNA (lncRNA), microRNA (miRNA) and messenger RNA (mRNA) have significant expression differences between induced and control human PDLSCs. Competing for endogenous RNAs (ceRNA), as a widely studied mechanism in regenerative medicine, while rarely reported in periodontal regeneration. The key lncRNAs and their ceRNA network might provide new insights into molecular therapies of periodontal regeneration based on PDLSCs. RESULTS: Two networks reflecting the relationships among differentially expressed RNAs were constructed. One ceRNA network was composed of 6 upregulated lncRNAs, 280 upregulated mRNAs, and 18 downregulated miRNAs. The other network contained 33 downregulated lncRNAs, 73 downregulated mRNAs, and 5 upregulated miRNAs. Functional analysis revealed that 38 GO terms and 8 pathways related with osteogenesis were enriched. Twenty-four osteogenesis-related gene-centred lncRNA-associated ceRNA networks were successfully constructed. Among these pathways, we highlighted MAPK and TGF-beta pathways that are closely related to osteogenesis. Subsequently, subnetworks potentially linking the GO:0001649 (osteoblast differentiation), MAPK and TGF-beta pathways were constructed. The qRT-PCR validation results were consistent with the microarray analysis. CONCLUSION: We construct a comprehensively identified lncRNA-associated ceRNA network might be involved in the osteogenesis of PDLSCs, which could provide insights into the regulatory mechanisms and treatment targets of periodontal regeneration.

Development and validation of a new multiplex Y-STR panel designed to increase the power of discrimination.

In an attempt to increase the discrimination capacity (DC) and reduce the adventitious match probability, a 6-dye multiplex Y-chromosomal short tandem repeat (Y-STR) panel named Y34plex was constructed that combined 25 Y-chromosomal markers (DYS456, DYS627, DYS390, DYS570, DYS635, DYS385a/b, DYS448, DYS437, DYS533, DYS449, DYS481, DYS392, DYS391, DYS389I, DYS460, YGATAH4, DYS438, DYS389II, DYS19, DYS458, DYF387S1a/b, DYS439, DYS393, DYS576, and DYS518) in widely used commercial kits, with nine highly polymorphic Y-STR loci (DYS557, DYS527a/b, DYS593, DYS444, DYS596, DYS643, DYS447, DYS549, and DYS645). The Y34plex is a promising type system to distinguish both unrelated and related male individuals due to the incorporation of rapidly mutated Y-STR loci. A validation study of the Y34plex was performed and followed the guidelines of the Scientific Working Group on DNA analysis methods. Results show that full Y-STR profiles were obtained from male/female DNA mixtures with 125 pg of male DNA in the presence of 50 ng of female DNA. The ability to tolerate polymerase chain reaction inhibitors commonly contained in forensic casework samples demonstrated the applicability and robustness of the Y34plex. Compared with the Yfiler Plus kit, the novel panel showed an increased power of discrimination in Chinese Wuxi Han population (n = 434). The overall haplotype diversity of the Y34plex was 0.999606, whereas DC value was 0.956221, which is suitable for use on forensic paternal investigation.

mTORC1 promotes mineralization via p53 pathway.

The objectives of our study were to investigate the roles of mTORC1 in odontoblast proliferation and mineralization and to determine the mechanism by which mTORC1 regulates odontoblast mineralization. In vitro, MDPC23 cells were treated with rapamycin (10 nmol/L) and transfected with a lentivirus for short hairpin (shRNA)-mediated silencing of the tuberous sclerosis complex (shTSC1) to inhibit and activate mTORC1, respectively. CCK8 assays, flow cytometry, Alizarin red S staining, ALP staining, qRT-PCR, and western blot analysis were performed. TSC1-conditional knockout (DMP1-Cre+ ; TSC1f/f , hereafter CKO) mice and littermate control (DMP1-Cre- ; TSC1f/f , hereafter WT) mice were generated. H&E staining, immunofluorescence, and micro-CT analysis were performed. Transcriptome sequencing analysis was used to screen the mechanism of this process. mTORC1 inactivation decreased the cell proliferation. The qRT-PCR and western blot results showed that mineralization-related genes and proteins were downregulated in mTORC1-inactivated cells. Moreover, mTORC1 overactivation promoted cell proliferation and mineralization-related gene and protein expression. In vivo, the micro-CT results showed that DV/TV and dentin thickness were higher in CKO mice than in controls and H&E staining showed the same results. Mineralization-related proteins expression was upregulated. Transcriptome sequencing analysis revealed that p53 pathway-associated genes were differentially expressed in TSC1-deficient cells. By inhibiting p53 alone or both mTORC1 and p53 with rapamycin and a p53 inhibitor, we elucidated that p53 acts downstream of mTORC1 and that mTORC1 thereby promotes odontoblast mineralization. Taken together, our findings demonstrate that the role of mTORC1 in odontoblast proliferation and mineralization, and confirm that mTORC1 upregulates odontoblast mineralization via the p53 pathway.

Study of the Osteoimmunomodulatory Properties of Curcumin-Modified Copper-Bearing Titanium.

Peri-implantitis can lead to implant failure. In this study, curcumin (CUR) was modified onto the copper-bearing titanium alloy (Cu-Ti) with the assistance of polydopamine (PDA) in order to study the bone immune response and subsequent osteogenesis. FE-SEM, XPS and water contact angle were utilized to characterize the coating surface. Bone marrow mesenchymal stem cells (BMSCs) and macrophages were cultured separately and together onto the CUR modified Cu-Ti. Cell activity, expression of relative genes and proteins, cell migration ability, and fluorescence staining of cells were performed. CUR modification slightly increased the activation of M1-type and M2-type cells under physiological conditions. In the inflammation state, CUR inhibited the overexpression of M1 macrophages and induced M2-type differentiation. In addition, the modification itself could provoke the expression of osteoblastic-related genes of BMSCs, while promoting the osteogenic differentiation of BMSCs through the activation of macrophages in both physiological and inflammatory states. The BMSCs migration was increased, the expression of osteogenic-related genes and proteins was up-regulated, and alkaline phosphatase activity (ALP) was increased. Thus, the modification of CUR can promote the osteointegration effect of Cu-Ti by bone immunomodulation and may, in addition, improve the success rate of implants.

Vertucci's root canal configuration of 11,376 mandibular anteriors and its relationship with distolingual roots in mandibular first molars in a Cantonese population: a cone-beam computed tomography study.

BACKGROUND: Cone-beam computed tomography (CBCT) was used to study the root canal system of mandibular anteriors (MAs) in a Cantonese population and to evaluate the correlation between the complicated root canal configurations of mandibular lateral incisors (MLIs) and the presence of distolingual roots (DLRs) in mandibular first molars (MFMs). METHODS: A total of 11,376 mandibular anterior teeth were scanned by CBCT. Those whose images met the inclusion criteria were first analysed according to Vertucci's root canal configuration and then grouped based on gender, age, and side, and their effects on root canal morphology were analysed. Finally, statistical analysis was used to evaluate the correlation between the complicated root canal configurations of MLIs and the existence of DLRs in MFMs. All statistical analyses were performed by using SPSS 25.0 software. Quantitative data are presented as the mean ± standard deviation. Student's t tests were used to calculate statistical significance. P < 0.05 was considered statistically significant. RESULTS: In MAs in the Cantonese population, all mandibular central incisors (MCIs) and MLIs had one root, and 0.37% of mandibular canines (MCs) had two roots. The most common Vertucci's root canal configuration was Vertucci I followed by Vertucci III. A total of 30.91% of MLIs and approximately 8% of MCIs and MCs have complicated root canal configurations. There were no significant differences in the prevalence of DLRs in MFMs and the incidence of complicated root canal configurations of MLIs between males and females or between the right and left teeth. However, a significant difference was found in different age groups of root canal configurations in MLIs. Moreover, significant ipsilateral and contralateral correlations between MFMs with DLRs and MLIs with complicated root canal configurations were observed on both sides. CONCLUSION: In Cantonese population, the possibility of complicated root canal configuration in MLIs was higher, when DLR appeared in MFMs.

Relationship between Chinese Baijiu consumption and dental caries among 55- to 74-year-old adults in Guangdong, southern China: a cross-sectional survey.

BACKGROUND: Whether an association between alcohol consumption and dental caries exists is still unclear. Chinese Baijiu is the most common alcohol consumed by middle-aged and elderly Chinese individuals. This study aimed to assess the relationship between alcohol consumption (Chinese Baijiu) and dental caries in Guangdong Province, southern China. METHODS: A cross-sectional study was conducted in Guangdong Province using a multistage, stratified, equal-sized, random sampling strategy. In total, 576 individuals aged 55-74 were recruited to fill out a questionnaire through face-to-face and one-on-one interviews and to undergo a series of dental examinations with a Community Periodontal Index (CPI) probe. According to the standard for clinical dentition examination of the WHO 2013 criteria, the presence of dental caries was determined by the DFT/DFRoot (decayed-filled tooth/root) index. The ratios of males to females and urban people to countrymen were both 1:1. Then, the chi-square test and rank-sum tests were used to compare the differences in caries between subgroups, and multivariate logistic regression analyses, as well as negative binomial regression analyses, were executed to identify the potential relationship between alcohol consumption and caries. RESULTS: The prevalence of crown caries was 79.17% with a DFT index of 3.19, while that of root caries was 61.28% with a DFRoot index of 2.08. The prevalence and mean tooth of crown caries of females were higher than those of males. The prevalence and mean DFRoot of root caries in rural areas were higher than those in urban areas. The results of the multivariate logistic regression analysis and negative binomial regression analysis showed that there was a statistically significant negative correlation between the consumption frequency of Chinese Baijiu and caries (often vs. never/rarely, crown caries: odds ratio (OR) = 0.54, 95% confidence interval (CI): 0.26-1.13, P = 0.103, incidence rate ratio (IRR) = 0.63, 95% CI: 0.44-0.92, P = 0.015; root caries: OR = 0.47, 95% CI: 0.24-0.93, P = 0.030, IRR = 0.52, 95% CI: 0.32-0.54, P = 0.008). CONCLUSIONS: Within the limitations of this study, frequent consumption of Chinese Baijiu was a protective factor for caries in middle-aged and elderly people in Guangdong Province. However, considering the harm of alcohol to one's general health, it is recommended to drink moderately and avoid alcohol abuse.

Studies on antimicrobial peptide-loaded nanomaterial for root caries restorations to inhibit periodontitis related pathogens in periodontitis care.

AIMS: To prepare a novel antimicrobial peptide Nal-P-113 loaded poly (ethylene glycol) combined chitosan nanoparticles (Nal-P-113-PEG-CSNPs) for root caries restorations to control the periodontitis related pathogens in periodontitis care. METHODS: Nanoparticles were prepared by simple polymerisation method and characterised using effective analytical methods (TEM, UV, etc.). The antimicrobial activity and biofilm formation of Nal-P-113-PEG-CSNPs was tested against periodontal bacterial pathogens by different in vitro methods. RESULTS: The size of Nal-P-113 loaded PEG-Chitosn nanoparticles was 216.2 ± 1.6 nm. The drug encapsulation efficiency (%EE (w/w) of Nal-P-113-PEG-CSNPs was found to be 89.33 ± 1.67% (w/w). The antimicrobial examination showed that prepared NPs have effectively inhibited the growth of Fusobacterium nucleatum, Streptococcus gordonii, and Porphyromonas gingivalis with the MIC of 23 µg/mL, 6 µg/mL and 31 µg/mL, respectively. CONCLUSIONS: The prepared antimicrobial peptide-loaded PEG-CSNPs provide excellent in vitro efficiency but, further studies are necessary to confirm its therapeutic efficacy on periodontitis care.

Classification and morphology of middle mesial canals of mandibular first molars in a southern Chinese subpopulation: a cone-beam computed tomographic study.

BACKGROUND: Cone-beam computed tomography (CBCT) was employed to study the morphology and curvature of middle mesial canals (MMCs) of mandibular first molars (MFMs). METHODS: CBCT scanning was performed on MFMs of 1100 patients. Patients' images that met the inclusion criteria were divided into group A (< 40 years old) and group B (≥ 40 years old) for further study. The images were used to study the incidence of MMCs at different ages, measure the curvature of MMCs in the mesiodistal and buccolingual directions using the Schneider method, and observe the anatomical morphology of the mesial root canal system. All statistical analyses were performed by using SPSS 21.0 software. Quantitative data were presented as mean ± standard deviation. Student's t-test was used to calculate the statistical significance. P < 0.05 was considered statistically significant. RESULTS: In 875 patients, 1750 MFM images met the inclusion criteria. Among these cases, 158 MFMs contained an MMC, yielding an incidence rate of 9.03%. The incidence rate of MMCs was 11.22% in group A and 6.61% in group B, and this difference was statistically significant (P < 0.05). The curvature in the mesiodistal direction was 29.39 ± 8.53° in group A and 26.06 ± 8.50° in group B, and this difference was also significant (P < 0.05). The curved regions in groups A and B were often located in the middle 1/3 of canal. No significant difference in the distance between MMC orifices and mesiobuccal canal orifices or mesiolingual canal orifices was noted (P > 0.05). The most common mesial root canal morphological type was type II (3-2) (53.80%). CONCLUSION: The incidence of MMCs in MFMs declined as age increased. The canal systems of MMCs were varied and complex, mainly exhibiting an obvious mesiodistal curve. CBCT is an outstanding method to help guide root canal therapy. *Yeqing Yang and Buling Wu have contribute equally to this article.

Diagnostic biomarker candidates for pulpitis revealed by bioinformatics analysis of merged microarray gene expression datasets.

BACKGROUND: Pulpitis is an inflammatory disease, the grade of which is classified according to the level of inflammation. Traditional methods of evaluating the status of dental pulp tissue in clinical practice have limitations. The rapid and accurate diagnosis of pulpitis is essential for determining the appropriate treatment. By integrating different datasets from the Gene Expression Omnibus (GEO) database, we analysed a merged expression matrix of pulpitis, aiming to identify biological pathways and diagnostic biomarkers of pulpitis. METHODS: By integrating two datasets (GSE77459 and GSE92681) in the GEO database using the sva and limma packages of R, differentially expressed genes (DEGs) of pulpitis were identified. Then, the DEGs were analysed to identify biological pathways of dental pulp inflammation with Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis and Gene Set Enrichment Analysis (GSEA). Protein-protein interaction (PPI) networks and modules were constructed to identify hub genes with the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) and Cytoscape. RESULTS: A total of 470 DEGs comprising 394 upregulated and 76 downregulated genes were found in pulpitis tissue. GO analysis revealed that the DEGs were enriched in biological processes related to inflammation, and the enriched pathways in the KEGG pathway analysis were cytokine-cytokine receptor interaction, chemokine signalling pathway and NF-κB signalling pathway. The GSEA results provided further functional annotations, including complement system, IL6/JAK/STAT3 signalling pathway and inflammatory response pathways. According to the degrees of nodes in the PPI network, 10 hub genes were identified, and 8 diagnostic biomarker candidates were screened: PTPRC, CD86, CCL2, IL6, TLR8, MMP9, CXCL8 and ICAM1. CONCLUSIONS: With bioinformatics analysis of merged datasets, biomarker candidates of pulpitis were screened and the findings may be as reference to develop a new method of pulpitis diagnosis.

Priming integrin α5 promotes human dental pulp stem cells odontogenic differentiation due to extracellular matrix deposition and amplified extracellular matrix-receptor activity.

Our previous study showed that knocking down integrin α5 (ITGA5) expression by using a lentiviral vector in human dental pulp stem cells (DPSCs) led to weakening proliferation and migration capacity while enhanced odontogenic differentiation. To seek for possible clinical application, we investigated the effect of the ITGA5 priming synthetic cyclic peptide (SCP; GA-CRRETAWAC-GA) on proliferation, migration, and the odontogenic differentiation of DPSCs. Remarkably, the involved mechanism was explored by isobaric tag for relative and absolute quantitation proteomic technique, and the in vivo effect of ITGA5 was investigated by nude mice subcutaneous transplantation of cell and hydroxyapatite/ß-tricalcium phosphate complex. Results showed that SCP weakened the proliferation and migration capacity while enhanced odontogenic differentiation of DPSCs as lentivirus. The phosphorylation of FAK, PI3K/AKT, and MEK1/2/ERK1/2, along with IGF2/IGFBP2 and Wnt/ß-catenin signaling pathway play an important role in this process. Proteomic Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed the key role of extracellular matrix (ECM) and ECM-receptor activity pathway were involved. ECM constituents, secreted protein acidic and cysteine-rich (SPARC), lumican, vitronectin, prolargin, decorin, collagen type VI α1 chain (COL6A1), COL6A2, COL14A1, and COL5A1 were upregulated in the ITGA5-silenced group. Inhibited expression of ITGA5 in DPSCs increased osteoid tissue formation and stronger related genes expression in vivo. In conclusion, the ITGA5 priming peptide could promote DPSCs odontogenic differentiation as lentivirus. Proteomics and bioinformatic analysis revealed that this may be due to the deposition of ECM and amplified ECM-receptor activity, which could fuel the application process of utilizing priming ITGA5 on dental clinical practice.

Plantamajoside attenuates inflammatory response in LPS-stimulated human gingival fibroblasts by inhibiting PI3K/AKT signaling pathway.

Periodontitis is an important inflammatory disease that often causes by periodontopathic bacteria. The present study, we tested the anti-inflammatory effects of plantamajoside on LPS-stimulated human gingival fibroblasts. Human gingival fibroblasts (HGFs) were stimulated with LPS from Porphyromonas gingivalis. Plantamajoside was administrated 1 h before LPS treatment. The results demonstrated that plantamajoside decreased the production of PGE2, NO, IL-6, and IL-8 in LPS-stimulated HGFs. LPS-induced NF-κB p65 and IκB phosphorylation were also suppressed by plantamajoside. Furthermore, plantamajoside inhibited LPS-induced PI3K and AKT phosphorylation. In conclusion, these results suggested that the mechanism of plantamajoside was through inhibiting PI3K/AKT signaling pathway, which lead to the inhibition of NF-κB activation and inflammatory response.

Assessment of microRNA-144-5p and its putative targets in inflamed gingiva from chronic periodontitis patients.

BACKGROUND AND OBJECTIVE: This study aimed to discover the distinctive MicroRNAs (miRNA) functioning in the pathogenesis of periodontal inflammation, which might be potential therapy targets of chronic periodontitis. MATERIAL AND METHODS: miRNA profiles of human inflamed gingival tissue from three previous microarrays were re-analysed. Gingival tissues were collected for the validation of overlapping miRNAs, and a network was constructed to show regulatory connection between overlapping miRNAs and periodontitis-associated target genes. Potential miRNAs were screened based on their expression levels and predicted target genes. Correlation analysis and binding site prediction were conducted to reveal the relationship between the potential miRNAs and their target genes. RESULTS: miR-144-5p, found to be upregulated in all three studies, showed the greatest upregulation (P < 0.0001). Another 16 miRNAs (10 upregulated and six downregulated) overlapped between any two of the three studies. All overlapping miRNAs had expected expression levels except for miR-203 during validation. Ten miRNAs (six upregulated and four downregulated) were found to have periodontal inflammation-associated targets. Cyclooxygenase 2 (COX2) and interleukin-17F (IL17F), predicted target genes of upregulated miR-144-5p, showed significant decreases and were negatively correlated with miR-144-5p in the periodontitis group (r = -0.742 for COX2, r = -0.615 for IL17F). CONCLUSION: This re-analysis of miRNA signatures has implied the potential regulatory mechanism of miR-144-5p and its potential for exploring alternative therapeutic approaches, especially those that use miRNA delivery systems to treat chronic periodontitis. Nevertheless, further study based on larger sample size and homogenous cells is needed to reveal the exact roles of miRNAs in chronic periodontitis.