Journal: Arthritis research & therapy

Article Title: Targeting osteoclast-derived DPP4 alleviates inflammation-mediated ectopic bone formation in ankylosing spondylitis.

doi: 10.1186/s13075-025-03474-2

Figure Lengend Snippet: Fig. 1 Expression of DPP4 is significantly elevated in AS. We measured soluble DPP4 level in serum and synovial fluid. Soluble DPP4 level was assessed by ELISA in (A) the serum of healthy control participants (HC; n = 26) and patients with AS (n = 30) and in (B) synovial fluid samples from patients with osteoarthritis (OA; n = 7) and AS (n = 24). Immunohistochemical staining (C) and immunofluorescence staining (E) for DPP4 was performed on facet joint tissues from control (n = 5) and AS (n = 5) patients. Representative images are shown. D and F DPP4-positive cells were counted and quantified by two independent researchers. Statistical significance is shown by **p < 0.01, ***p < 0.001 based on the Mann–Whitney U test

Article Snippet: DPP4 levels in serum and synovial fluid were determined using a commercial ELISA kit (RK02755; ABclonal) according to the manufacturer’s protocol.

Techniques: Expressing, Enzyme-linked Immunosorbent Assay, Control, Immunohistochemical staining, Staining, Immunofluorescence, MANN-WHITNEY

Journal: Arthritis research & therapy

Article Title: Targeting osteoclast-derived DPP4 alleviates inflammation-mediated ectopic bone formation in ankylosing spondylitis.

doi: 10.1186/s13075-025-03474-2

Figure Lengend Snippet: Fig. 2 DPP4 expression is highly expressed in human mature osteoclasts. A Osteoclast-related genes were analyzed by RNA-sequencing (GSE225974), and a heatmap was generated to compare the expression of osteoclast-related genes and DPP4 between peripheral blood mononuclear cell (PBMC) (n = 4) and osteoclast (n = 4) groups. B Schematic graphic illustrating the isolation of CD14 + cells from human PBMCs and their differentiation into mature osteoclasts in the presence of M-CSF (20 ng/mL) for 2 days followed by co-stimulation with M-CSF (20 ng/ mL) and RANKL (40 ng/mL) for an additional 6–7 days. Figure was created using BioRender.com. Mature osteoclasts were subjected to (C) staining with TRAP and F-actin ring on day 8, (D) immunoblotting for NFATc1, DPP4, and β-actin as loading control, (E) RT-qPCR for osteoclast markers including TRAP, CTSK, ITGB3, DC-STAMP, and DPP4 (normalized to expression of GAPDH). F DPP4 localization in mature osteoclasts was observed by immunofluorescence, with DPP4 shown in red and F-actin in green. Statistical significance is shown by *p < 0.05, ***p < 0.001 based on the Mann–Whitney U test

Article Snippet: DPP4 levels in serum and synovial fluid were determined using a commercial ELISA kit (RK02755; ABclonal) according to the manufacturer’s protocol.

Techniques: Expressing, RNA Sequencing, Generated, Isolation, Staining, Western Blot, Control, Quantitative RT-PCR, Immunofluorescence, MANN-WHITNEY

Journal: Arthritis research & therapy

Article Title: Targeting osteoclast-derived DPP4 alleviates inflammation-mediated ectopic bone formation in ankylosing spondylitis.

doi: 10.1186/s13075-025-03474-2

Figure Lengend Snippet: Fig. 3 Oral administration of DPP4 inhibitor attenuates arthritis, enthesitis, and inflammation in the peripheral joints of curdlan-injected SKG mice. Eight-week-old male SKG mice (total n = 20) were intraperitoneally injected with 3 mg of curdlan. After 1 week, SKG mice were randomly divided into two groups (n = 8 mice per group) and received oral administration of either PBS or of DPP4 inhibitor three times per week for 5 weeks. At the end of the 5 weeks, mice were sacrificed for further experiments. Experimental design is shown in (A). B Clinical arthritis scores and hind paw thickness were quantified. C Representative gross images of ankles and hind paws are displayed; blocked arrows indicate ectopic bone. D Histological images of ankle tissues stained with H&E that received histological scores (n = 8 mice per group). E Histological score at ankle were quantified as shown in (D). F Representative Micro-CT images of hind paws are shown, with orange and red arrows indicating low density bone and ectopic bone formation at peripheral joints, respectively. G Micro-CT image data were quantified as shown in (F). Statistical significance is shown by *p < 0.05, **p < 0.01, ***p < 0.001 based on two-way ANOVA and the Mann–Whitney U test

Article Snippet: DPP4 levels in serum and synovial fluid were determined using a commercial ELISA kit (RK02755; ABclonal) according to the manufacturer’s protocol.

Techniques: Injection, Staining, Micro-CT, MANN-WHITNEY