CCL3 and MMP-9 are induced by TL1A during death receptor 3 (TNFRSF25)-dependent osteoclast function and systemic bone loss

Abstract

Reduced bone density and secondary osteoporosis, resulting in increased risk of fracture, is a significant complicating factor in the inflammatory arthritides. While the exact etiology of systemic bone loss is not fully elucidated, recent insights into the tumor necrosis factor super family (TNFSF) revealed a potential role for death receptor 3 (DR3/TNFRSF25) and one of its ligands, TNF-like protein 1A (TL1A/TNFSF15). The mechanisms by which DR3/TL1A signalling modulates bone loss are unclear. We investigated the effect of DR3/TL1A signalling upon osteoclast-dependent chemokine and MMP production to unravel novel mechanisms whereby this pathway regulates OC formation and OC-dependent bone resorption. Collagen induced arthritis (CIA) was established in DR3wt and DR3ko mice, joints were sectioned and analysed histologically for bone damage while systemic trabecular bone loss distal to the affected joints was compared by micro-CT. Ablation of DR3 protected DBA/1 mice against the development and progression of CIA. In DR3ko, joints of the ankle and mid-foot were almost free of bone erosions and long bones of mice with CIA were protected against systemic trabecular bone loss. In vitro, expression of DR3 was confirmed on primary human CD14+ osteoclast precursors by flow cytometry. These cells were treated with TL1A in osteoclast differentiation medium and TRAP+ osteoclasts, bone resorption, levels of osteoclast-associated chemokines (CCL3, CCL2 and CXCL8) and MMP-9 measured. TL1A intensified human osteoclast differentiation and bone resorption and increased osteoclast-associated production of CCL3 and MMP-9. Our data reveals the DR3 pathway as an attractive therapeutic target to combat adverse bone pathology associated with inflammatory arthritis. We demonstrate that DR3 is critical in the pathogenesis of murine CIA and associated secondary osteoporosis. Furthermore, we identify a novel mechanism by which the DR3/TL1A pathway directly enhances human OC formation and resorptive activity, controlling expression and activation of CCL3 and MMP-9.

Inhibition of CCL3 abrogated precursor cell fusion and bone erosions in human osteoclast cultures and murine collagen-induced arthritis

“…Flow cytometry confirmed ⩾95% cells were CD14 positive. Purified CD14-positive cells were re-suspended in complete medium (3.2 × 10 6 cells/ml) and seeded onto ivory disks to model cell/substrate interactions on bone matrix [ 26 ]. CD14-positive cells were adhered to the ivory disks, which were subsequently transferred into individual wells containing 500 μl of complete medium containing M-CSF (10 ng/ml).…”

RANKL from Bone Marrow Adipose Lineage Cells Promotes Osteoclast Formation and Bone Loss

“…And the tooth eruption was evaluated by the X ray.Histochemistry, immunohistochemistry, and immunofluorescent stainingFemurs were fixed in 4% paraformaldehyde for 24 h and decalcified in 10% EDTA (room temperature) for 2 weeks. After dehydration in an alcohol gradient (50%, 75%, 85%, 95%, or 100%), femurs were embedded in paraffin, cut into 4 µm thick sections using a Thermo Scientific Microm HM 325 Rotary Microtome, and processed for hematoxylin-eosin (H&E) staining and TRAP staining according the manufacturer's instructions(43). For immunohistochemistry staining, sections were incubated with primary antibodies against RANKL (Abcam; catalog no.…”

Doxercalciferol Alleviates Bone Deteriorations and Cartilage Degeneration in Aging Mice

“…Inhibition of Ctsk alleviates bone erosion and cartilage degradation in arthritic mice [26]. In addition, activation of MMP9 and CAII is associated with enhancing osteoclasts formation and resorptive activity [27,28]. Our findings suggested that DOX treatment led to down-regulation of Ctsk, MMP9 and CAII mRNA expression and restored cartilage damage in aging mice, indicating that inhibition of osteoclast activity by DOX might protect against age-related bone injury.…”