ABSTRACT
Bone homeostasis is known as a dynamic balance, including bone formation through osteoblasts and bone resorption by osteoclasts. MicroRNAs (miRs) play a critical role in regulating bone formation and homeostasis. In the study, the effects of miR-451a on bone homeostasis were investigated. The results indicated that the primary osteoblasts and mesenchymal stem cells (MSCs), as the main source of osteoblasts, isolated from miR-451a-knockout (KO) mice showed promoted osteogenesis. in vivo, an ovariectomized (OVX) animal model was used to further explore the effect of miR-451a on osteoporosis. Micro-computed tomography (µCT) indicated a promoted bone volume in miR-451a-KO mice compared to wild-type (WT) mice after OVX operation, demonstrating a redundant bone formation after the knockout of miR-451a. Importantly, we for the first time found that bone morphogenetic protein 6 (Bmp6) was a direct target of miR-451a, elevating bone formation through regulating SMAD1/5/8 expression. In conclusion, reducing miR-451a expression levels could enhance bone formation during the progression of osteoporosis, which might be at least partly via the meditation of Bmp6 expression.
Subject(s)
Bone Morphogenetic Protein 6/metabolism , Bone Resorption/metabolism , Mesenchymal Stem Cells/metabolism , MicroRNAs/metabolism , Osteoblasts/metabolism , Osteogenesis , Osteoporosis, Postmenopausal/metabolism , Animals , Bone Morphogenetic Protein 6/genetics , Bone Resorption/genetics , Bone Resorption/pathology , Cells, Cultured , Disease Models, Animal , Down-Regulation , Female , Humans , Mesenchymal Stem Cells/pathology , Mice, Knockout , MicroRNAs/genetics , Osteoblasts/pathology , Osteoporosis, Postmenopausal/genetics , Osteoporosis, Postmenopausal/pathology , Ovariectomy , Signal Transduction , Smad1 Protein/metabolism , Smad5 Protein/metabolism , Smad8 Protein/metabolismABSTRACT
Over the last decade, the controllable reversible phase transition of functional materials has received growing interest as it shows unique suitability for various technological applications. Although many metal-organic frameworks (MOFs) possess a lamellar structure, the reversible structural transformation of MOFs between their three-dimensional (3D) phase and two-dimensional (2D) phase remains a largely unexplored area. Herein, we report for the first time a europium MOF with unprecedented reversible morphology in different solvents at room temperature. This europium MOF displayed a 3D nanorod morphology in organic solvent and a 2D nanobelt architecture in water. As a proof of concept for potential applications of this reversible-phase-transition MOF, we were able to use a delamination recovery method to load dye molecules that previously could not be loaded into europium MOFs.
ABSTRACT
This study aims to evaluate the effectiveness and safety of the application of a 3-dimensional (3D)-printed composite guide plate for atlantoaxial pedicle screw.This was a retrospective study. A total of 43 atlantoaxial dislocation patients admitted in our hospital between January 2014 and October 2016 were retrospectively analyzed. According to the different methods of operation, patients were divided into 2 groups: 3D-printed plate group (nâ=â19) and traditional fixation group (nâ=â24). Placement time, operation duration, fluoroscopy number, intraoperative bleeding volume, and the neck and shoulder pain visual analog scale and Japanese Orthopaedic Association cervical nerve function scores were compared between pre- and postoperation.Differences in general data between these 2 groups were not statistically significant (Pâ>â.05). For patients in the 3D-printed plate group, a total of 68 assisting screws were placed at the pedicle, the accuracy rate of screw placement was 94.1%, placement time was 2.2â±â0.4âminutes, fluoroscopy number was 4.6â±â1.1 times, operation duration was 197â±â41âminutes, and intraoperative bleeding volume was 395â±â64âmL. In the traditional fixation group, a total of 76 screws were placed at the pedicle of patients, the accuracy rate of screw placement was 76.3%, placement time was 3.4â±â0.7âminutes, fluoroscopy number was 9.4â±â2.7 times, operation duration was 245â±â67âminutes, and intraoperative bleeding volume was 552â±â79âmL. Differences in accuracy rate, placement time, fluoroscopy number, operation duration, and intraoperative bleeding volume between these 2 groups were statistically significant (Pâ<â.05).The effectiveness and safety of 3D-printed composite guide plate for atlantoaxial pedicle screw were better than traditional method.
