Functional study of novel PAX9 variants: The paired domain and non-syndromic oligodontia.

OBJECTIVES: To investigate pathogenic variants of the paired box 9 (PAX9) gene in patients with non-syndromic oligodontia, and the functional impact of these variants. SUBJECTS AND METHODS: Whole exome sequencing and Sanger sequencing were utilized to detect gene variants in a cohort of 80 patients diagnosed with non-syndromic oligodontia. Bioinformatic and conformational analyses, fluorescence microscopy and luciferase reporter assay were employed to explore the functional impact. RESULTS: We identified three novel variants in the PAX9, including two frameshift variants (c.211_212insA; p.I71Nfs*246 and c.236_237insAC; p.T80Lfs*6), and one missense variant (c.229C > G; p.R77G). Familial co-segregation verified an autosomal-dominant inheritance pattern. Conformational analyses revealed that the variants resided in the paired domain, and could cause corresponding structural impairment of the PAX9 protein. Fluorescence microscopy showed abnormal subcellular localizations of frameshift variants, and luciferase assay showed impaired downstream transactivation activities of the bone morphogenetic protein 4 (BMP4) gene in all variants. CONCLUSIONS: Our findings broaden the spectrum of PAX9 variants in patients with non-syndromic oligodontia and support that paired domain structural impairment and the dominant-negative effect are likely the underlying mechanisms of PAX9-related non-syndromic oligodontia. Our findings will facilitate genetic diagnosis and counselling, and help lay the foundation for precise oral health therapies.

DLX3 regulates osteogenic differentiation of bone marrow mesenchymal stem cells via Wnt/ß-catenin pathway mediated histone methylation of DKK4.

OBJECTIVE: Distal-less homeobox 3 (DLX3) is an important transcription factor involved in the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). However, the underlying mechanism is not clear. This study investigated the underlying mechanism of DLX3 in osteogenic differentiation. METHODS: DLX3 overexpression and knockdown in cells were achieved using lentiviruses. The osteogenic differentiation of BMSCs was detected using alkaline phosphatase expression, alizarin red staining, real-time quantitative polymerase chain reaction (RT-qPCR), Western blotting, and chromatin immunoprecipitation (ChIP) assays. RESULTS: DLX3 overexpression promoted the osteogenic differentiation of BMSCs, whereas DLX3 knockdown reduced the osteogenic differentiation of BMSCs. RT-qPCR and Western blotting assays showed that DLX3 modulated osteogenic differentiation via the Wnt/ß-catenin pathway. ChIP-qPCR showed that DLX3 knockdown promoted DKK4 expression by decreasing the enrichment of histone H3 lysine 27 trimethylation (H3K27me3) in the promotor region of DKK4. CONCLUSION: Our data implied that DLX3 regulated Wnt/ß-catenin pathway through histone modification of DKK4 during the osteogenic differentiation of BMSCs.

Development and Evaluation of Multistructured and Hierarchical Epidermal Growth Factor-Poly ( ε -Caprolactone) Scaffolds.

In this paper, we separately fabricated the poly ( ε -caprolactone) (PCL) scaffolds containing epidermal growth factor (EGF) by using our-self fabricated electrospinning machine for tissue regeneration application. Several fundamental properties, including the dimensions, wettability, and EGF release profiles, of the fabricated EGF-PCL bead, fibrous, and multistructured scaffolds were characterized by using the scanning electron microscopy (SEM), contact angle goniometer, and vertical diffusion system. The EGF release profiles of three scaffolds were measured for 200 h, and the multistructured scaffold performed stable and long EGF release properties. Furthermore, the in vitro and in vivo experiments were conducted to evaluate the performance of three types of EGF-PCL scaffolds. The NIH-3T3 fibroblast cells were cultured on the scaffolds to study the effects of the released EGF by using the Alamar Blue Cell Viability Assays, fluorescence image analysis, and SEM. The animal experiment demonstrated that the multistructured EGF-PCL scaffold achieved 95% of the wound healing rate to the cut-damaged wounds after 16 days. Moreover, the histopathological skin tissue showed that the wound regenerated well after the treatment of the multistructured EGF-PCL scaffold. The developed multistructured EGF-PCL scaffold has a high potential for the wound healing applications.

Occlusal Rehabilitation in a Patient with Oligodontia and Microdontia using Implants and Full-Ceramic Restorations: A Clinical Report.

Oligodontia is the agenesis of six or more permanent teeth, excluding the third molars. Multidisciplinary dental treatments should be performed sequentially due to the restoration requirements for good oral function, aesthetics and self-confidence of patients. In this study, we report a case using dental implants and full-ceramic prostheses to restore the absent and malformed teeth in a patient with agenesis of 18 permanent teeth and with some primary teeth retained. The dental sequential treatments began when she was 16 years old, and she wore removable partial dentures for 4 years with unsatisfying restoration outcome. When she became an adult, dental implants and full-ceramic prostheses were used to restore the absent and malformed teeth. Finally, the patient was very satisfied with the functional and aesthetic outcomes of the prosthetic treatment.

Electrospun Poly(ε-caprolactone) Nanofibrous Mesh for Imiquimod Delivery in Melanoma Therapy.

Drug delivery systems (DDS) are commonly employed to administer drug-loaded composites to their therapeutic targets both in vitro and in vivo. Thus, we herein report the study of imiquimod-poly(ε-caprolactone) (IMQ-PCL) nanofibrous meshes for application in melanoma therapy. The preparation route employed was based on the electrospinning technique, with the melanoma cells being cultured on electrospun nanofibrous meshes to study their biocompatibility. All parameters employed, including the flow rate and polymer solution concentration, were examined to gain an improved understanding of the factors influencing the diameter and morphology of the electrospun fibre. The optimised parameters were employed to produce 12 IMQ-PCL nanofibrous meshes with diameters ranging from 100 to 900 nm to the melanoma cell viability. The relationship between the fibrous diameter and the imiquimod release profile was also determined using UV-Vis spectroscopy. In addition, similar results were obtained for the simulated imiquimod release profile obtained by COMSOL Multiphysics®. The IMQ-PCL nanofibrous meshes were found to decrease cell viability by ≥50%, with the number of cells dropping by ~10% over 48 h. As the cell viability was affected by the release of imiquimod, we believe that IMQ-PCL nanofibrous meshes are a promising drug delivery system for application in melanoma therapy.