Evaluating tooth extraction as a stand-alone treatment for odontogenic sinusitis.

BACKGROUND: There are multiple treatment methods for odontogenic sinusitis (OS); however, the optimal treatment remains unclear. AIMS/OBJECTIVE: To determine the cure rate of OS after tooth extraction and the factors contributing to the cure. MATERIAL AND METHODS: We prospectively identified 37 patients diagnosed with OS with an indication for causative tooth extraction. Before and three months after tooth extraction, the patients were assessed using sinus computed tomography and classified as either cured or uncured based on the absence or presence of soft tissue shadow in the maxillary sinus. The prognostic factors were analysed by comparing the two groups. RESULTS: There were ten patients for whom all data could be obtained. The mean age of the patients at the time of tooth extraction was 53.8 ± 12.9 years (range, 34-75 years). In seven patients, the soft tissue shadow in the maxillary sinus disappeared; these patients were classified as cured. Uncured patients were significantly younger than cured patients (59.9 vs. 39.7 years). CONCLUSIONS AND SIGNIFICANCE: Tooth extraction effectively treated OS in 70% of patients. However, even after tooth extraction, OS may not improve, particularly in younger patients.

Induction of salivary gland-like cells from epithelial tissues transdifferentiated from mouse embryonic fibroblasts.

Salivary gland hypofunction due to radiation therapy for head and neck cancer or Sjögren syndrome may cause various oral diseases, which can lead to a decline in the quality of life. Cell therapy using salivary gland stem cells is a promising method for restoring hypofunction. Herein, we show that salivary gland-like cells can be induced from epithelial tissues that were transdifferentiated from mouse embryonic fibroblasts (MEFs). We introduced four genes, Dnp63a, Tfap2a, Grhl2, and Myc (PTMG) that are known to transdifferentiate fibroblasts into oral mucosa-like epithelium in vivo into MEFs. MEFs overexpressing these genes showed epithelial cell characteristics, such as cobblestone appearance and E-cadherin positivity, and formed oral epithelial-like tissue under air-liquid interface culture conditions. The epithelial sheet detached from the culture dish was infected with adenoviruses encoding Sox9 and Foxc1, which we previously identified as essential factors to induce salivary gland formation. The cells detached from the cell sheet formed spheres 10 days after infection and showed a branching morphology. The spheres expressed genes encoding basal/myoepithelial markers, cytokeratin 5, cytokeratin 14, acinar cell marker, aquaporin 5, and the myoepithelial marker α-smooth muscle actin. The dissociated cells of these primary spheres had the ability to form secondary spheres. Taken together, our results provide a new strategy for cell therapy of salivary glands and hold implications in treating patients with dry mouth.

Aging-associated stem/progenitor cell dysfunction in the salivary glands of mice.

Although stem cell aging leads to a decline in tissue homeostasis and regenerative capacity, it remains unclear whether salivary gland stem cell function changes during this process. However, the salivary glands are gradually replaced by connective tissue during aging. Here, we show a decline in the stem cell ability of CD133-positive stem/progenitor cells in the salivary glands of aged mice. The CD133-positive cells were isolated from young, adult, and aged mice. The number of CD133-positive cells was significantly decreased in aged mice. They also showed a lower sphere formation capacity compared to young and adult mice. RNA sequencing revealed that CD133-positive cells in aged mice exhibited lower gene expression of several aging-related genes, including FoxO3a, than those in young and adult mice. Salivary gland cells infected with a recombinant lentivirus encoding the FoxO3a gene showed a reduction in oxidative stress induced by hydrogen peroxide compared with those infected with a control virus. Thus, FoxO3a may inhibit stem cell aging via oxidative stress.

Sox9 function in salivary gland development.

BACKGROUND: Organogenesis is regulated by morphogen signaling and transcription networks. These networks differ between organs, and identifying the organ-specific network is important to clarify the molecular mechanisms of development and regeneration of organs. Several studies have been conducted to identify salivary gland-specific networks using a mouse submandibular gland model. The submandibular glands (SMGs) of mice manifest as a thickening of the oral epithelium at embryonic day 11.5 and invaginate into the underlying mesenchyme. The network between Fgf10 and Sox9 is involved in SMG development in mice. HIGHLIGHT: Sox9, a member of the Sox family, is expressed in the SMG in mice from the embryonic stage to the adult stage, although the distribution changes during development. A null mutation of mouse Sox9 is lethal during the neonatal period due to respiratory failure, whereas deletion of Sox9 in the oral epithelium using the Cre/lox P system, can lead to smaller initial buds of SMGs in conditional knockout (cKO) mice than in normal mice. In addition, we showed that adenoviral transduction of Sox9 and Foxc1 genes into mouse embryonic stem cell-derived oral ectoderm could induce salivary gland rudiment in an organoid culture system. ChIP-sequencing revealed that Sox9 possibly regulates several tube- and branching-formation-related genes. CONCLUSION: Sox9 may serve as an essential transcription factor for salivary gland development. The Sox9-mediated pathway can be a promising candidate for regenerating damaged salivary glands.

Sox9 regulates the luminal stem/progenitor cell properties of salivary glands.

Exocrine glands share a common morphology consisting of ductal, acinar, and basal/myoepithelial cells, but their functions and mechanisms of homeostasis differ among tissues. Salivary glands are an example of exocrine glands, and they have been reported to contain multipotent stem cells that differentiate into other tissues. In this study, we purified the salivary gland stem/progenitor cells of adult mouse salivary glands using the cell surface marker CD133 by flow cytometry. CD133+ cells possessed stem cell capacity, and the transplantation of CD133+ cells into the submandibular gland reconstituted gland structures, including functional acinar. CD133+ cells were sparsely distributed in the intercalated and exocrine ducts and expressed Sox9 at higher levels than CD133- cells. Moreover, we demonstrated that Sox9 was required for the stem cell properties CD133+ cells, including colony and sphere formation. Thus, the Sox9-related signaling may control the regeneration salivary glands.

Inhibition of mitogen activated protein kinase activity induces parthenogenetic activation and increases cyclin B accumulation during porcine oocyte maturation.

The inhibition of mitogen activated protein kinase (MAPK) activation during porcine oocyte maturation leads to decreased maturation promoting factor (MPF) activity and to the induction of parthenogenetic activation. In the present study, in order to analyze the mechanism underlying the suppression of MPF activity in MAPK-inhibited porcine oocytes, we injected mRNA of SASA-MEK, a dominant negative MAPK kinase, or antisense RNA of c-mos, a MAPK kinase kinase, into immature porcine oocyte cytoplasm. The injection of SASA-MEK mRNA or c-mos antisense RNA inhibited the MAPK activity partially or completely, respectively, decreased the MPF activity slightly or significantly, respectively, and induced parthenogenetic activation in 17.1% or 96.6% of mature oocytes, respectively, although no parthenogenetic activation was observed in the control oocytes. Immunoblotting experiments revealed that cyclin B accumulation in these MAPK-suppressed porcine oocytes was increased significantly after 50 h of culture and that a considerable amount of MPF was converted into inactive pre-MPF by hyperphosphorylation. These results indicate that the inhibition of MAPK activity in porcine oocytes did not promote cyclin B degradation but rather suppressed it; also the decrease in MPF activity in MAPK-suppressed porcine oocytes correlated with the conversion of active MPF into inactive pre-MPF.

Analysis of the roles of cyclin B1 and cyclin B2 in porcine oocyte maturation by inhibiting synthesis with antisense RNA injection.

The function of cyclin B1 (CB1) and cyclin B2 (CB2) during porcine oocyte maturation was investigated by injecting oocytes with their antisense RNAs (asRNAs). At first, protein levels of both cyclin Bs were examined by immunoblotting, revealing that immature oocytes had only CB2, at a level comparable to 1/20 to 1/40 of that detected in first metaphase oocytes. Both cyclin B syntheses were started around germinal vesicle breakdown (GVBD); CB1 and CB2 peaked at the second metaphase and first metaphase, respectively. We obtained a porcine CB2 cDNA fragment, which was 88% homologous with human CB2, by reverse-transcriptase polymerase chain reaction (RT-PCR) using total RNAs of immature porcine oocytes and a primer set of human CB2. Specific asRNAs of CB1 and CB2 were prepared in vitro. Then one, the other, or both were injected into the cytoplasm of immature oocytes. CB1 asRNA inhibited CB1 synthesis specifically; the injected oocytes underwent first meiosis normally but could not arrest at the second meiotic metaphase. CB2 asRNA inhibited CB2 synthesis specifically, but had almost no effect on the maturation of injected oocytes. When both CB1 and CB2 asRNAs were injected, synthesis of both cyclin Bs was inhibited, and GVBD was significantly suppressed but occurred slowly. These results suggest that CB1 is the principal molecule for regulation in mammalian oocyte maturation, whereas CB2 has only an accessory role. They also show that in porcine oocytes, cyclin B synthesis is not necessary for GVBD induction itself, but synthesis of at least one cyclin B, CB1 or CB2, is necessary for GVBD induction in a normal time course.