No abstract

No abstract

Classic embryological studies have documented the inductive role of root dentin on adjacent periodontal ligament differentiation.  The biochemical composition of root dentin includes collagens and cleavage products of dentin sialophosphoprotein (DSPP), such as dentin sialoprotein (DSP).  The high abundance of DSP in root dentin prompted us to ask the question whether DSP or peptides derived thereof would serve as potent biological matrix components to induce periodontal progenitors to further differentiate into periodontal ligament cells. Here, we test the hypothesis that domain of DSP influences cell fate. In situ hybridization and immunohistochemical analyses showed that the COOH-terminal DSP domain is expressed in mouse periodontium at various stages of root development. The recombinant COOH-terminal DSP fragment (rC-DSP) enhanced attachment and migration of human periodontal ligament stem cells (PDLSC), human primary PDL cells without cell toxicity. rC-DSP induced PDLSC cell proliferation as well as differentiation and mineralization of PDLSC and PDL cells by formation of mineralized tissue and ALPase activity. Effect of rC-DSP on cell proliferation and differentiation was to promote gene expression of tooth/bone-relate markers, transcription factors and growth factors. The results for the first time showed that rC-DSP may be one of the components of cell niche for stimulating stem/progenitor cell proliferation and differentiation and a natural scaffold for periodontal regeneration application.

Although Bmp2 is essential for tooth formation, the role of Bmp2 during enamel formation remains unknown in vivo. In this study, the role of Bmp2 in regulation of enamel formation was investigated by the Bmp2 conditional knock out (Bmp2 cKO) mice. Teeth of Bmp2 cKO mice displayed severe and profound phenotypes with asymmetric and misshaped incisors as well as abrasion of incisors and molars. Scanning electron microscopy analysis showed that the enamel layer was hypoplastic and enamel lacked a typical prismatic pattern. Teeth from null mice were much more brittle as tested by shear and compressive moduli. Expression of enamel matrix protein genes, amelogenin, enamelin, and enamel-processing proteases, Mmp-20 and Klk4 was reduced in the Bmp2 cKO teeth as reflected in a reduced enamel formation. Exogenous Bmp2 up-regulated those gene expressions in mouse enamel organ epithelial cells. This result for the first time indicates Bmp2 signaling is essential for proper enamel development and mineralization in vivo.

Oral submucous fibrosis (OSF) is a potentially malignant disease predominantly found in Asian people. The areca nut has been implicated in this disease. Arecoline, one of the areca alkaloids, induces epithelial-mesenchymal transition (EMT)-related factors in primary human buccal mucosal fibroblasts. Yet, the mechanisms of the underlying arecoline-induced EMT in OSF remain unknown. In the present study, we aimed to investigate the role of microRNAs (miRNAs) in arecoline-induced EMT in HaCaT cells. We found that miR-203 was significantly downregulated in OSF tissues compared to that in normal buccal mucosa tissues, and that miR-203 negatively regulated secreted frizzled-related protein 4 (SFRP4) and positively regulated transmembrane-4 L six family member 1 (TM4SF1). We observed that upregulation of miR-203 significantly decreased the cell proliferation of HaCaT cells, and significantly upregulated the expression of cytokeratin 19 (CK19) and E-cadherin proteins, whereas it significantly downregulated the expression of N-cadherin and vimentin compared to these levels in the vehicle control cells. Thus, we provide evidence to illustrate that miR-203 plays a role in the pathogenesis of OSF, which may be a target for OSF management.

Lymphocyte infiltrates have been observed in the microenvironment of oral cancer; however, little is known about whether the immune response of the lymphocyte infiltrate affects tumor biology. For a deeper understanding of the role of the infiltratinglymphocytes in oral squamous cell carcinoma (OSCC), we characterized the lymphocyte infiltrate repertoires and defined their features. Immunohistochemistry revealed considerable T and B cell infiltrates and lymphoid follicles with germinal center-like structures within the tumor microenvironment. Flow cytometry demonstrated that populations of antigen-experienced CD41 and CD81 cells were present, as well as an enrichment of regulatory T cells; and T cells expressing programmed death-1 (PD-1) and T cell Ig and mucin protein-3 (Tim-3), indicative of exhaustion, within the tumor microenvironment. Characterization of tumorinfiltrating B cells revealed clear evidence of antigen exposure, in that the cardinal features of an antigen-driven B cell response were present, including somatic mutation, clonal expansion, intraclonal variation and isotype switching. Collectively, our results point to an adaptive immune response occurring within the OSCC microenvironment, which may be sustained by the expression of specific antigens in the tumor.Oral cancer is the sixth most common cancer in the world, most of which is oral squamous cell carcinoma (OSCC), accounting for 3% of all malignancies and increasing by 275,000 new cases per year.1,2 Oral cancer is life-threatening because of its invasion of critical structures responsible for speaking, swallowing, and respiration. 3 The treatment of oral cancer has advanced considerably from surgery to a comprehensive sequential treatment that include surgery in combination with chemoradiotherapy; however, the 5-year survival rate has not significantly improved in recent decades, primarily because of its extreme malignancy, including local metastasis, and high recurrence potential. 3,4 Thus, more substantial efforts have stimulated in developing more effective treatments in order to improve the survival rate. Due to the progress in the field of tumor immunology, immunotherapy emerges as a promising option. 5,6The immune response between host and tumor is extremely complex. The function of immune system is to eliminate alien cells; however within the tumor microenvironment, tumor cells escape the immune surveillance and

Introduction Eating breakfast has been proved to positively influence human health. However, evidence for the association between breakfast consumption and depressive symptoms is lacking, especially among young adults. The aim of this study was to determine whether breakfast consumption is associated with depressive symptoms among Chinese university students. Methods A cross-sectional study involving 10,174 undergraduate students (6,287 males and 3,887 females) was conducted in 2015. Breakfast consumption was assessed using a self-reported questionnaire. Depressive symptoms were assessed using the Zung self-rating depression scale (SDS) score. Three cut-off values of the SDS score (40, 45, and 50) were used to assess the severity of the depressive symptoms. Logistic regression models were used to analyze the association between the frequency of breakfast consumption and depressive symptoms. Results The mean SDS score was 37.1±8.0 in present study. In crude model, a higher frequency of breakfast consumption was primarily associated with a lower prevalence of depressive symptoms in all three SDS groups (p = 0.001, < 0.001, = 0.009 for SDS cut-off value 40, 45, and 50 points, respectively). These associations remained significant after adjustment for confounding factors. Conclusions A higher frequency of breakfast consumption was strongly associated with a lower prevalence of depressive symptoms among Chinese university students. These results corroborate the evidence that the habit of eating breakfast may be beneficial to mental health.

No abstract