Methods

In a series of in vitro experiments, we used tert-Butyl hydroperoxide (TBHP) to induce senescence of MLO-Y4 cells successfully, and collected conditioned medium (CM) and senescent MLO-Y4 cell-derived exosomes, which were then applied to MC3T3-E1 cells, separately, to evaluate their effects on osteogenic differentiation. Furthermore, we identified differentially expressed microRNAs (miRNAs) between exosomes from senescent and normal MLO-Y4 cells by high-throughput RNA sequencing. Based on the key miRNAs that were discovered, the underlying mechanism by which senescent osteocytes regulate osteogenic differentiation was explored. Lastly, in the in vivo experiments, the effects of senescent MLO-Y4 cell-derived exosomes on age-related bone loss were evaluated in male SAMP6 mice, which excluded the effects of oestrogen, and the underlying mechanism was confirmed.

Methods

CREB1 activity and expression of a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS4) in cells and tissues were measured by immunoblotting and immunohistochemical (IHC) staining. The effect of 666-15 on chondrocyte viability and apoptosis was examined by cell counting kit-8 (CCK-8) assay, JC-10, and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling (TUNEL) staining. The effect of 666-15 on the microstructure of subchondral bone, and the synthesis and catabolism of cartilage, in anterior cruciate ligament transection mice were detected by micro-CT, safranin O and fast green (S/F), immunohistochemical staining, and enzyme-linked immunosorbent assay (ELISA).

Methods

Empty adenovirus (EP) and a HDAC4 overexpression adenovirus were transfected into cultured human chondrocytes. The cell survival rate was examined by real-time cell analysis (RTCA) and EdU and flow cytometry assays. Cell biofunction was detected by Western blotting. The expression profiles of messenger RNAs (mRNAs) in the EP and HDAC4 transfection groups were assessed using whole-transcriptome sequencing (RNA-seq). Volcano plot, Gene Ontology, and pathway analyses were performed to identify differentially expressed genes (DEGs). For verification of the results, the A289E/S246/467/632 A sites of HDAC4 were mutated to enhance the function of HDAC4 by increasing HDAC4 expression in the nucleus. RNA-seq was performed to identify the molecular mechanism of HDAC4 in chondrocytes. Finally, the top ten DEGs associated with ribosomes were verified by quantitative polymerase chain reaction (QPCR) in chondrocytes, and the top gene was verified both in vitro and in vivo.

Methods

We examine the inhibitory effect of a high affinity, glycosyl-phosphatidylinositol-anchored TIMP variant named ‘T1^PrαTACE’ on receptor activator of nuclear factor kappa-Β ligand (RANKL)-induced osteoclast differentiation.

Methods

This was a retrospective analysis of 20 patients. All cases were delayed presentations (n = 15) or failed nonoperatively managed scaphoid fractures (n = 5). Surgery was performed at a mean duration of 27 months (7 to 120) following injury with arthroscopic debridement and arthroscopic iliac crest autograft. Fracture fixation was performed percutaneously with Kirschner (K)-wires in 12 wrists, a headless screw in six, and a combination of a headless screw and single K-wire in two. Clinical outcomes were assessed using grip strength, patient-reported outcome measures, and wrist range of motion (ROM) measurements.

Methods

The function of LY3023414 was explored in the context of osteogenesis (bone formation by osteoblasts) and osteoclastogenesis (osteoclast formation and bone resorption). Murine preosteoblast MC3T3-E1 cell line and murine bone marrow-derived macrophage cells (BMMs) were subjected to different treatments. An MTS cell proliferation assay was used to examine the cytotoxicity. Thereafter, different induction conditions were applied, such as MCSF and RANKL for osteoclastogenesis and osteogenic media for osteogenesis. Specific staining, a bone resorption assay, and quantitative real-time polymerase chain reaction (qRT-PCR) were subsequently used to evaluate the effect of LY3023414. Moreover, small interfering RNA (siRNA) was applied to knockdown Akt1 or Akt2 for further validation. Lastly, western blot was used to examine the exact mechanism of action.

Methods

Collagenase-induced OA was established in C57Bl/6 mice. Therapy with PTH (1-34) (10 μg/kg/day or 40 μg/kg/day) was initiated immediately after surgery and continued for six weeks. Cartilage pathology was evaluated by gross visual, histology, and immunohistochemical assessments. Cell apoptosis was analyzed by TUNEL staining. Microcomputed tomography (micro-CT) was used to evaluate the bone mass and the microarchitecture in subchondral bone.

Methods

We searched PubMed, Embase, and the Cochrane Library, with keywords including “knee osteoarthritis” and “mesenchymal stem cells”, up to June 2019. We selected randomized controlled trials (RCTs) that explored the use of MSCs to treat knee OA. The visual analogue scale (VAS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), adverse events, and the whole-organ MRI score (WORMS) were used as the primary evaluation tools in the studies. Our meta-analysis included a subgroup analysis of cell dose and cell source.

Methods

In total, 759 adult patients with 766 affected knees were retrospectively reviewed. The TPF fragments on CT were multiplanar reconstructed, and virtually reduced to match a 3D model of the proximal tibia. 3D heat mapping was subsequently created by graphically superimposing all fracture lines onto a tibia template.

Patients and Methods

We included 210 450 patients undergoing primary hip arthroplasty registered in the Hospital Quality Monitoring System in China between 2013 and 2016. In-hospital mortality after hip arthroplasty and its relation to potential risk factors were assessed using multivariable Poisson regression.

Patients and Methods

We reviewed 141 patients who, between 2005 and 2014, had undergone surgical excision of a pelvic tumour with invasion of the sacrum.

In a new classification, pelvisacral (Ps) I, II, and III resections refer to a sagittal osteotomy through the ipsilateral wing of the sacrum, through the sacral midline, or lateral to the contralateral sacral foramina, respectively. A Ps a resection describes a pelvic osteotomy through the ilium and a Ps b resection describes a concurrent resection of the acetabulum with osteotomies performed through the pubis and ischium or the pubic symphysis. Within each type, surgical approaches were standardized to guide resection of the tumour.

Patients and Methods

A total of 35 patients underwent resection of a pelvic tumour and reconstruction using 3D-printed endoprostheses between September 2013 and December 2015. According to Enneking’s classification of bone defects, there were three Type I lesions, 12 Type II+III lesions, five Type I+II lesions, two Type I+II+III lesions, ten type I+II+IV lesions and three type I+II+III+IV lesions. A total of three patients underwent reconstruction using an iliac prosthesis, 12 using a standard hemipelvic prosthesis and 20 using a screw-rod connected hemipelvic prosthesis.

Materials and Methods

The influence of the viewing perspective on the GPA was assessed, as were the differences in the measurements of the GPA between 3D CT reconstructions and AP scapular view radiographs in 68 cadaveric scapulae.

Methods

CT scans of 15 healthy feet and 15 feet with stage II PTTD flatfoot were taken first in a non-weight-bearing condition, followed by a simulated full-body weight-bearing condition. The images of the hindfoot bones were reconstructed into 3D models. The ‘twice registration’ method in three planes was used to calculate the position of the talus relative to the calcaneus in the talocalcaneal joint, the navicular relative to the talus in talonavicular joint, and the cuboid relative to the calcaneus in the calcaneocuboid joint.