This study aimed to demonstrate the promoting effect of elastic fixation on fracture, and further explore its mechanism at the gene and protein expression levels. A closed tibial fracture model was established using 12 male Japanese white rabbits, and divided into elastic and stiff fixation groups based on different fixation methods. Two weeks after the operation, a radiograph and pathological examination of callus tissue were used to evaluate fracture healing. Then, the differentially expressed proteins (DEPs) were examined in the callus using proteomics. Finally, in vitro cell experiments were conducted to investigate hub proteins involved in this process.Aims
Methods
Platelet Rich Plasma (PRP), either rich (L-PRP) or poor (P-PRP) of leukocytes, is frequently used as an anti-inflammatory and regenerative tool in osteoarthritis (OA). PRP contains proteins but not genes as it is derived from megakaryocytes.
Differentiation of infected (INF) nonunion from aseptic (AS) nonunion is crucial for the choice of intra- and postoperative treatment. Preoperative diagnosis of infected nonunion is challenging, especially in case of low-grade infection lacking clinical signs of infection. Standard blood markers such as C-reactive protein or leucocyte count do not aid in preoperative diagnosis. Proteomic profiling has shown promising results for differentiation of numerous chronic disease states, and in this study was applied to preoperative blood samples of patients with nonunion in an attempt to identify potential biomarkers. This prospective multicenter study enrolled patients undergoing revision surgery of femur or tibia nonunion. Patients with implant removal after regular fracture healing (HEAL) were included as a control-group. Preoperative blood samples, intraoperative tissue samples, sonication of osteosynthesis material and 1-year-follow-up questionnaire were taken. Nonunion patients were grouped into INF or AS after assessing bacterial culture and histopathology of retrieved samples. Diagnosis of infection followed the fracture related infection consensus group criteria, with additional consideration of healing one year after revision surgery. Targeted proteomics was used to investigate a predefined panel of 45 cytokines in preoperative blood samples. Statistical differences were calculated with Kruskal Wallis and Dunn's post hoc test. Cytokines with less than 80% of samples being above the lower limit of detection range (LLDR) were excluded for this study.Aim
Method
A promising therapy for early osteoarthritis (OA) is the transplantation of human umbilical cord-derived mesenchymal stromal cells (hUC-MSCs). The synovial fluid (SF) from a pre-clinical ovine model treated with hUC-MSCs has been profiled using proteomics and bioinformatics to elucidate potential mechanisms of therapeutic effect. Four weeks after a medial meniscus transection surgery, sheep were injected with 107 hUC-MSCs in Phosphate Buffered Saline (PBS) or PBS only (n=7) and sacrificed at 12 weeks. SF was normalised for protein abundance (ProteoMinerTM) and analysed using label-free quantitation proteomics. Bioinformatics analyses (Ingenuity Pathway Analysis (IPA) and STRING) were used to assess differentially regulated functions from the proteomic data. Human orthologues were identified for the ovine proteins using UniProt and DAVID resources and proteins that were ≥±1.3 fold differentially abundant between treatment groups, were included in the bioinformatics analyses.Abstract
Objectives
Methods
The extracellular matrix (ECM) is the non-cellular structural support that provides cells with a network of biochemical and biomechanical factors for cellular processes. The ECM regulates cell function, differentiation and homeostasis. Here, we present a proteomics characterization of three commonly used additive manufactured polymers: polylactic acid (PLA), polyactive (PEOT/PBT) and polycaprolactone (PCL). We cultured human mesenchymal stromal cells (hMSCs) and make them undergo chondrogenic and osteogenic differentiation on 3D printed PCL, PEOT/PBT and PLA scaffolds. hMSCs were cultured in basal, chondrogenic and osteogenic media (200000 cells/scaffold) and analyzed after 35 days of culture. Differentiation was proved through biochemical assays, immunofluorescence and histology. The protein content was explored using label free liquid chromatography mass spectrometry (LC-MS), which revealed upregulated proteins and their related pathways. A higher difference was found among different media compared to the scaffold type through principal component analysis (PCA). Interestingly, in all three materials, chondrogenesis was characterized by a lower but more diverse amount of proteins. PCL induced ECM production in both differentiation media, but it led to more apoptosis and GAG degradation in the chondrogenic medium compared to the osteogenic one. During chondrogenesis in PEOT/PBT and PLA, cell differentiation resulted in the activation of stress response cascades, collagen formation and ECM remodelling. On the other hand, in osteogenesis, PCL enhanced insulin-like growth factor pathway and fibrin clot related pathways.
