PTHrP promotes subchondral bone formation in TMJ-OA / 国际口腔科学杂志·英文版

PTH-related peptide (PTHrP) improves the bone marrow micro-environment to activate the bone-remodelling, but the coordinated regulation of PTHrP and transforming growth factor-β (TGFβ) signalling in TMJ-OA remains incompletely understood. We used disordered occlusion to establish model animals that recapitulate the ordinary clinical aetiology of TMJ-OA. Immunohistochemical and histological analyses revealed condylar fibrocartilage degeneration in model animals following disordered occlusion. TMJ-OA model animals administered intermittent PTHrP (iPTH) exhibited significantly decreased condylar cartilage degeneration. Micro-CT, histomorphometry, and Western Blot analyses disclosed that iPTH promoted subchondral bone formation in the TMJ-OA model animals. In addition, iPTH increased the number of osterix (OSX)-positive cells and osteocalcin (OCN)-positive cells in the subchondral bone marrow cavity. However, the number of osteoclasts was also increased by iPTH, indicating that subchondral bone volume increase was mainly due to the iPTH-mediated increase in the bone-formation ability of condylar subchondral bone. In vitro, PTHrP treatment increased condylar subchondral bone marrow-derived mesenchymal stem cell (SMSC) osteoblastic differentiation potential and upregulated the gene and protein expression of key regulators of osteogenesis. Furthermore, we found that PTHrP-PTH1R signalling inhibits TGFβ signalling during osteoblastic differentiation. Collectively, these data suggested that iPTH improves OA lesions by enhancing osteoblastic differentiation in subchondral bone and suppressing aberrant active TGFβ signalling. These findings indicated that PTHrP, which targets the TGFβ signalling pathway, may be an effective biological reagent to prevent and treat TMJ-OA in the clinic.

Gap junction-mediated cell-to-cell communication in oral development and oral diseases: a concise review of research progress / 国际口腔科学杂志·英文版

Homoeostasis depends on the close connection and intimate molecular exchange between extracellular, intracellular and intercellular networks. Intercellular communication is largely mediated by gap junctions (GJs), a type of specialized membrane contact composed of variable number of channels that enable direct communication between cells by allowing small molecules to pass directly into the cytoplasm of neighbouring cells. Although considerable evidence indicates that gap junctions contribute to the functions of many organs, such as the bone, intestine, kidney, heart, brain and nerve, less is known about their role in oral development and disease. In this review, the current progress in understanding the background of connexins and the functions of gap junctions in oral development and diseases is discussed. The homoeostasis of tooth and periodontal tissues, normal tooth and maxillofacial development, saliva secretion and the integrity of the oral mucosa depend on the proper function of gap junctions. Knowledge of this pattern of cell-cell communication is required for a better understanding of oral diseases. With the ever-increasing understanding of connexins in oral diseases, therapeutic strategies could be developed to target these membrane channels in various oral diseases and maxillofacial dysplasia.

Berberine mediates root remodeling in an immature tooth with apical periodontitis by regulating stem cells from apical papilla differentiation / 国际口腔科学杂志·英文版

Once pulp necrosis or apical periodontitis occurs on immature teeth, the weak root and open root apex are challenging to clinicians. Berberine (BBR) is a potential medicine for bone disorders, therefore, we proposed to apply BBR in root canals to enhance root repair in immature teeth. An in vivo model of immature teeth with apical periodontitis was established in rats, and root canals were filled with BBR, calcium hydroxide or sterilized saline for 3 weeks. The shape of the roots was analyzed by micro-computed tomography and histological staining. In vitro, BBR was introduced into stem cells from apical papilla (SCAPs). Osteogenic differentiation of stem cells from apical papilla was investigated by alkaline phosphatase activity, mineralization ability, and gene expression of osteogenic makers. The signaling pathway, which regulated the osteogenesis of SCAPs was evaluated by quantitative real time PCR, Western blot analysis, and immunofluorescence. In rats treated with BBR, more tissue was formed, with longer roots, thicker root walls, and smaller apex diameters. In addition, we found that BBR promoted SCAPs osteogenesis in a time-dependent and concentration-dependent manner. BBR induced the expression of β-catenin and enhanced β-catenin entering into the nucleus, to up-regulate more runt-related nuclear factor 2 downstream. BBR enhanced root repair in immature teeth with apical periodontitis by activating the canonical Wnt/β-catenin pathway in SCAPs.

Effects of different application methods of Bacillus subtilis agent on soil microbial diversity and growth of muskmelon / 生物工程学报

Continuous planting of muskmelon and excessive application of chemical fertilizers have caused a series of problems, such as imbalance of the soil micro-ecological environment, serious soil-borne diseases and yield loss. Application of Bacillus subtilis agent is an important way to improve soil micro-ecological environment, prevent soil-borne diseases, and promote plant growth. In this study, B. subtilis was used as experimental agent to analyze the effects of different application methods on the soil microbial diversity and growth of muskmelon in greenhouse. The number of culturable microorganisms in soil was measured by dilution-plate method. The diversity of soil uncultivated microorganisms was determined by Illumina Miseq sequencing technology. The yield of muskmelon was measured by weighing method. The number of culturable bacteria in the root irrigation, hole application and dipping root application groups was higher than that of the control in different muskmelon growth stages, but there was no significant difference among the three different application methods. The number of soil fungi from B. subtilis agent treatment groups in flowering stage was significantly lower in comparison to the control group. However, B. subtilis agent treatment did not cause significant difference on soil fungi number at the fruiting and pulling stage. Diversity analysis of uncultured microorganisms showed that the Shannon index values of bacteria were higher and Simpson index values were lower respectively in the three B. subtilis treatment groups than that in the control. Moreover, the dipping root treatment produced the lowest Shannon index value and the highest Simpson index value of fungi. NMDS and cluster analysis showed that B. subtilis agents dipping root treatment significantly affected the bacterial and fungal flora, both of which were clustered into one independent branch. The application of B. subtilis agents, especially dipping root treatment, significantly decreased the abundance of Bacteroidetes, increased the abundance of Actinobacteria and Acidobacteria. The B. subtilis agent treatment didn't produce significant effect on the diversity of fungal flora except Chytridiomycota. The height, stem diameter and leaf area of muskmelon increased by applying B. subtilis agents, and dipping root treatment produced the most significant effect. As a new type of environmental protection fertilizer, B. subtilis agent can increase the number of soil culturable microorganisms, improve soil microbial diversity, and promote growth and yield. This study would provide a scientific basis for the rational application of B. subtilis.

Disturbed bone remodelling activity varies in different stages of experimental, gradually progressive apical periodontitis in rats / 国际口腔科学杂志·英文版

Bone remodelling keeps going through the lifespan of human by bone formation and bone resorption. In the craniofacial region, mandibles act as the main force for biting and chewing, and also become susceptible to a common bone-loss disease, namely, apical periodontitis, once infected dental pulp is not treated timely, during which bone resorption occurs from the apical foramen to the apical bone area. Although conventional root canal treatment (RCT) can remove the most of the infection, chronical apical periodontitis due to incomplete removal of dental pulp and subsequent microleakage will become refractory and more challenging, and this process has scarcely been specifically studied as a bone remodelling issue in rat models. Therefore, to study chronical and refractory apical periodontitis owing to incomplete cleaning of infected dental pulp and microleackage in vivo, we establish a modified rat model of gradually progressive apical periodontitis by sealing residual necrotic dental pulp and introducing limited saliva, which simulates gradually progressive apical periodontitis, as observed in the clinical treatment of chronical and refractory apical periodontitis. We show that bone-loss is inevitable and progressive in this case of apical periodontitis, which confirms again that complete and sound root canal treatment is crucial to halt the progression of chronical and refractory apical periodontitis and promote bone formation. Interestingly, bone remodelling was enhanced at the initial stage of apical periodontitis in this model while reduced with a high osteoblast number afterwards, as shown by the time course study of the modified model. Suggesting that the pathological apical microenvironment reserve its hard tissue formation ability to some degree but in a disturbed manner. Hopefully, our findings can provide insights for future bone regenerative treatment for apical periodontitis-associated bone loss.

Strategies of caries management in whole life cycle / 中华口腔医学杂志

Dental caries is one of the most important chronic oral diseases that seriously threaten human health. Because of the characteristics of high incidence, low rate of treatment and high rate of retreatment, conventional prevention and treatment strategies cannot effectively control the occurrence of caries. This article proposes the concept of whole life cycle management of dental caries, focusing on group management of dental caries according to different ages and physiological characteristics on one hand, and personal management of dental caries according to various risk factors and risk levels of individual patient on the other hand, to achieve the goals of controlling the multiple factors that affect the development of dental caries, restoring the oral microecological balance, and further controlling the progress of caries and reconstructing the structure and function of carious teeth.

Management of oral diseases during pregnancy / 华西口腔医学杂志

Management of oral diseases during pregnancy prefers to be a comprehensive oral health care strategy throughout pre-pregnant, pregnant and prenatal stages. It provides guidance not only to promote the overall health in pregnant women, but also concern fetus development and children's oral health. Pregnancy is a time of particular vulnerability in terms of oral health due to complex physical and physiological changes. Physicians and dentists are responsible for providing professional medical care and treatment following clinical guidelines especially for pregnancy. It is also an opportune time in pregnancy to educate women about oral health care and preventing oral problems in young children. This article reviews the commonly occurring oral problems and their pathogenesis during pregnancy, dental procedures that can be carried out by physicians and preventive strategies that could be helpful in promoting oral health in both pregnant women and young children.

Comparison of oral and gastrointestinal opportunistic pathogen contamination between tooth mugs placed up-ward and downward / 实用口腔医学杂志

The oral and gastrointestinal opportunistic pathogen contamination was compared between tooth mugs placed upward and down-ward(n=9)for 1 4 days.Selective cultivation of the pathogens was uesd to measure the extent of contamination.The colony forming units (CFU)of colibacillus in group up and group down were 4.25 ±0.71 and 2.84 ±1 .40(P=0.046),S.mutans 89 ±0.31 and 2.84 ±1 .40 (P<0.001 ),Candida 2.28 ±1 .36 and 2.53 ±1 .92(P=0.002),fungus 2.44 ±0.99 and 0,respecitvely.Thus,tooth mug placed open-ing down is superior for health.

Precision stomatology: current status and challenges / 华西口腔医学杂志

The completion of human genome project and the progress in medical practice have inevitably lead to the development of precision medicine, which is a medical model that proposes the customization of medical care including medical decisions, practices, and/or medical products with patient's genetic background, environmental factors and life behavior being taken into account. The current work proposed precision stomatology for the first time, and by integrating data reported in recent literature, we described the current practice of precision stomatology in multiple disciplines in modem dentistry. The clinical significance of precision stomatology and its future challenges have also been discussed.