The antidiabetic agent metformin inhibits fibrosis in various organs. This study aims to elucidate the effects of hyperglycaemia and metformin on knee joint capsule fibrosis in mice. Eight-week-old wild-type (WT) and type 2 diabetic (db/db) mice were divided into four groups without or with metformin treatment (WT met(-/+), Db met(-/+)). Mice received daily intraperitoneal administration of metformin and were killed at 12 and 14 weeks of age. Fibrosis morphology and its related genes and proteins were evaluated. Fibroblasts were extracted from the capsules of 14-week-old mice, and the expression of fibrosis-related genes in response to glucose and metformin was evaluated in vitro.Aims
Methods
The anterior cruciate ligament (ACL) is known to have a poor wound healing capacity, whereas other ligaments outside of the knee joint capsule such as the medial collateral ligament (MCL) apparently heal more easily. Plasmin has been identified as a major component in the synovial fluid that varies among patients. The aim of this study was to test whether plasmin, a component of synovial fluid, could be a main factor responsible for the poor wound healing capacity of the ACL. The effects of increasing concentrations of plasmin (0, 0.1, 1, 10, and 50 µg/ml) onto the wound closing speed (WCS) of primary ACL-derived ligamentocytes (ACL-LCs) were tested using wound scratch assay and time-lapse phase-contrast microscopy. Additionally, relative expression changes (quantitative PCR (qPCR)) of major LC-relevant genes and catabolic genes were investigated. The positive controls were 10% fetal calf serum (FCS) and platelet-derived growth factor (PDGF).Aims
Methods
Proliferation, migration, and differentiation of anterior cruciate ligament (ACL) remnant and surrounding cells are fundamental processes for ACL reconstruction; however, the interaction between ACL remnant and surrounding cells is unclear. We hypothesized that ACL remnant cells preserve the capability to regulate the surrounding cells’ activity, collagen gene expression, and tenogenic differentiation. Moreover, extracorporeal shock wave (ESW) would not only promote activity of ACL remnant cells, but also enhance their paracrine regulation of surrounding cells. Cell viability, proliferation, migration, and expression levels of Collagen-I (COL-I) A1, transforming growth factor beta (TGF-β), and vascular endothelial growth factor (VEGF) were compared between ACL remnant cells untreated and treated with ESW (0.15 mJ/mm2, 1,000 impulses, 4 Hz). To evaluate the subsequent effects on the surrounding cells, bone marrow stromal cells (BMSCs)’ viability, proliferation, migration, and levels of Type I Collagen, Type III Collagen, and tenogenic gene (Aims
Methods
It is increasingly appreciated that coordinated regulation of angiogenesis and osteogenesis is needed for bone formation. How this regulation is achieved during peri-implant bone healing, such as osseointegration, is largely unclear. This study examined the relationship between angiogenesis and osteogenesis in a unique model of osseointegration of a mouse tibial implant by pharmacologically blocking the vascular endothelial growth factor (VEGF) pathway. An implant was inserted into the right tibia of 16-week-old female C57BL/6 mice (n = 38). Mice received anti-VEGF receptor-1 (VEGFR-1) antibody (25 mg/kg) and VEGF receptor-2 (VEGFR-2) antibody (25 mg/kg; n = 19) or an isotype control antibody (n = 19). Flow cytometric (n = 4/group) and immunofluorescent (n = 3/group) analyses were performed at two weeks post-implantation to detect the distribution and density of CD31hiEMCNhi endothelium. RNA sequencing analysis was performed using sorted CD31hiEMCNhi endothelial cells (n = 2/group). Osteoblast lineage cells expressing osterix (OSX) and osteopontin (OPN) were also detected with immunofluorescence. Mechanical pull-out testing (n = 12/group) was used at four weeks post-implantation to determine the strength of the bone-implant interface. After pull-out testing, the tissue attached to the implant surface was harvested. Whole mount immunofluorescent staining of OSX and OPN was performed to determine the amount of osteoblast lineage cells.Aims
Materials and Methods
The lack of effective treatment for cartilage defects has prompted investigations using tissue engineering techniques for their regeneration and repair. The success of tissue-engineered repair of cartilage may depend on the rapid and efficient adhesion of transplanted cells to a scaffold. Our aim in this study was to repair full-thickness defects in articular cartilage in the weight-bearing area of a porcine model, and to investigate whether the CD44 monoclonal antibody biotin-avidin (CBA) binding technique could provide satisfactory tissue-engineered cartilage. Cartilage defects were created in the load-bearing region of the lateral femoral condyle of mini-type pigs. The defects were repaired with traditional tissue-engineered cartilage, tissue-engineered cartilage constructed with the biotin-avidin (BA) technique, tissue-engineered cartilage constructed with the CBA technique and with autologous cartilage. The biomechanical properties, Western blot assay, histological findings and immunohistochemical staining were explored.Objectives
Methods
Previous studies support the important role of
vascular endothelial growth factor (VEGF) and syndecan-4 in the pathogenesis
of osteoarthritis (OA). Both VEGF and syndecan-4 are expressed by
chondrocytes and both are involved in the regulation of matrix metalloproteinase-3,
resulting in the activation of aggrecanase II (ADAMTS-5), which
is essential in the pathogenesis of OA. However, the relationship
between VEGF and syndecan-4 has not been established. As a pilot
study, we assayed the expression of VEGF and syndecan-4 in cartilage
samples and cultured chondrocytes from osteoarthritic knee joints
and analysed the relationship between these two factors. Specimens were collected from 21 female patients (29 knees) who
underwent total knee replacement due to severe medial OA of the
knee (Kellgren–Lawrence grade 4). Articular cartilage samples, obtained
from bone and cartilage excised during surgery, were analysed and
used for chondrocyte culture. We found that the levels of expression
of VEGF and syndecan-4 mRNA did not differ significantly between
medial femoral cartilage with severe degenerative changes and lateral
femoral cartilage that appeared grossly normal (p = 0.443 and 0.622,
respectively). Likewise, the levels of expression of VEGF and syndecan-4
mRNA were similar in cultured chondrocytes from medial and lateral
femoral cartilage. The levels of expression of VEGF and syndecan-4
mRNAs were significantly and positively correlated in cartilage
explant (r = 0.601, p = 0.003) but not in cultured chondrocytes.
These results suggest that there is a close relationship between
VEGF and syndecan-4 in the cartilage of patients with OA. Further
studies are needed to determine the exact pathway by which these
two factors interact in the pathogenesis of OA. Cite this article:
Our objective in this article is to test the hypothesis that
type 2 diabetes mellitus (T2DM) is a factor in the onset and progression
of osteoarthritis, and to characterise the quality of the articular
cartilage in an appropriate rat model. T2DM rats were obtained from the UC Davis group and compared
with control Lewis rats. The diabetic rats were sacrificed at ages
from six to 12 months, while control rats were sacrificed at six
months only. Osteoarthritis severity was determined via histology
in four knee quadrants using the OARSI scoring guide. Immunohistochemical
staining was also performed as a secondary form of osteoarthritic
analysis.Objectives
Methods
