Aims. Osteoarthritis (OA) is a common degenerative joint disease worldwide, which is characterized by articular cartilage lesions. With more understanding of the disease, OA is considered to be a disorder of the whole joint. However, molecular communication within and between tissues during the disease process is still unclear. In this study, we used transcriptome data to reveal crosstalk between different tissues in OA. Methods. We used four groups of transcription profiles acquired from the Gene Expression Omnibus database, including articular cartilage, meniscus, synovium, and subchondral bone, to screen differentially expressed genes during OA. Potential crosstalk between tissues was depicted by ligand-receptor pairs. Results. During OA, there were 626, 97, 1,060, and 2,330 differentially expressed genes in articular cartilage, meniscus, synovium, and subchondral bone, respectively. Gene Ontology enrichment revealed that these genes were enriched in extracellular matrix and structure organization, ossification, neutrophil degranulation, and activation at different degrees. Through ligand-receptor pairing and proteome of OA synovial fluid, we predicted ligand-receptor interactions and constructed a crosstalk atlas of the whole joint. Several interactions were reproduced by transwell experiment in chondrocytes and synovial cells, including TNC-NT5E, TNC-SDC4, FN1-ITGA5, and FN1-NT5E. After lipopolysaccharide (LPS) or interleukin (IL)-1β stimulation, the ligand expression of chondrocytes and synovial cells was upregulated, and corresponding receptors of co-culture cells were also upregulated. Conclusion. Each tissue displayed a different expression pattern in transcriptome, demonstrating their specific roles in OA. We highlighted tissue molecular crosstalk through ligand-receptor pairs in OA pathophysiology, and generated a crosstalk atlas. Strategies to interfere with these candidate ligands and receptors may help to discover molecular targets for future OA therapy. Cite this article: Bone Joint Res 2022;11(12):862–872

Summary. Wear particles from joint replacements may result in loosening and periprosthetic osteolysis. Interference with systemic macrophage trafficking to the implant, modulation of macrophage phenotype from M1 to M2, and inhibition of NFκB may mitigate these adverse effects. Introduction. Joint replacement of the lower extremity is highly successful in alleviating pain, and improving ambulation and function. However, prosthetic byproducts of different materials, in sufficient amounts, may lead to loosening and periprosthetic osteolysis. Debris from polymers (such as polyethylene and PMMA), metals and ceramics are capable of inciting an adverse tissue reaction, which is orchestrated by cells of the monocyte/macrophage lineage. Three experimental approaches have been taken by our group to potentially mitigate the adverse biological sequela of particle disease. These include: 1) interfering with ongoing migration of monocyte/macrophages to the implant site by inhibiting the chemokine system 2) altering the functional activities of local macrophages by converting pro-inflammatory M1 macrophages to an anti-inflammatory pro-tissue healing M2 phenotype and 3) modulating the production and release of pro-inflammatory cytokines, chemokines and other potentially harmful factors by inhibiting the key transcription factor NFκB. Methods. First, a murine model of systemic trafficking of remotely infused macrophages to locally infused clinically relevant wear particles was established. After preliminary in vitro studies in which a key macrophage chemokine, MCP-1 was identified, blocking of this chemokine ligand-receptor axis using antagonists and knockouts was undertaken. Second, in vitro and in vivo studies were performed to convert M1 pro-inflammatory macrophages (associated with wear particles ± endotoxin) to an M2 alternative phenotype by the infusion of the anti-inflammatory cytokine Interleukin-4 (IL-4). Third, in vitro studies were undertaken in which activated macrophages were exposed to an NFκB decoy oligodeoxynucleotide (ODN), which interferes with the production of pro-inflammatory mediators. The analytical techniques used included bioluminescence, microCT, immunohistochemical and immunofluorescent microscopy, histomorphometry, ELISA, rT-PCR and cell sorting. Results. Interference of the MCP-1-CCR2 ligand-receptor axis decreased systemic macrophage migration to the area of particle infusion, and subsequent osteolysis at the implant site. Local delivery of IL-4 promoted an alternative anti-inflammatory M2 macrophage phenotype (rather than a pro-inflammatory M1 phenotype), mitigating inflammation and osteolysis. Preliminary studies exposing activated macrophages to NFκB ODN decreased pro-inflammatory cytokine production. Discussion/Conclusion. Macrophage-induced inflammation and osteolysis due to wear byproducts limit the longevity of joint replacements. The interventions outlined above may be useful in preventing these events. For example, coatings that limit macrophage migration to the implant site or local delivery of biologics that alter macrophage phenotype might facilitate osseointegration and provide a more robust bone-implant interface initially. Early osteolysis with a salvageable joint replacement might be mitigated by local infusion of IL-4 or an NFκB ODN. These treatments are less invasive compared to surgical revision, and might prolong the lifetime of a joint replacement in humans

Aims

We aimed to develop a gene signature that predicts the occurrence of postmenopausal osteoporosis (PMOP) by studying its genetic mechanism.

Aims

Therapeutic agents that prevent chondrocyte loss, extracellular matrix (ECM) degradation, and osteoarthritis (OA) progression are required. The expression level of epidermal growth factor (EGF)-like repeats and discoidin I-like domains-containing protein 3 (EDIL3) in damaged human cartilage is significantly higher than in undamaged cartilage. However, the effect of EDIL3 on cartilage is still unknown.

During the last decades, several research groups have used bisphosphonates for local application to counteract secondary bone resorption after bone grafting, to improve implant fixation or to control bone resorption caused by bone morphogenetic proteins (BMPs). We focused on zoledronate (a bisphosphonate) due to its greater antiresorptive potential over other bisphosphonates. Recently, it has become obvious that the carrier is of importance to modulate the concentration and elution profile of the zoledronic acid locally. Incorporating one fifth of the recommended systemic dose of zoledronate with different apatite matrices and types of bone defects has been shown to enhance bone regeneration significantly in vivo. We expect the local delivery of zoledronate to overcome the limitations and side effects associated with systemic usage; however, we need to know more about the bioavailability and the biological effects. The local use of BMP-2 and zoledronate as a combination has a proven additional effect on bone regeneration. This review focuses primarily on the local use of zoledronate alone, or in combination with bone anabolic factors, in various preclinical models mimicking different orthopaedic conditions.

Cite this article: I. Qayoom, D. B. Raina, A. Širka, Š. Tarasevičius, M. Tägil, A. Kumar, L. Lidgren. Anabolic and antiresorptive actions of locally delivered bisphosphonates for bone repair: A review. Bone Joint Res 2018;7:548–560. DOI: 10.1302/2046-3758.710.BJR-2018-0015.R2.

Objectives

In order to screen the altered gene expression profile in peripheral blood mononuclear cells of patients with osteoporosis, we performed an integrated analysis of the online microarray studies of osteoporosis.