Dkk-1 levels were significantly (P<0.05) higher in AS patients with elevated ESR and CRP and no syndesmophytes, and were significantly (P<0.001) correlated with sclerostin levels (r=0.592).
Although serum DKK-1 concentration was not significantly different in AS vs. healthy controls, it may be used as a biomarker of inflammation and radiographic damage in AS.
At the baseline and 2-year follow-up, serum adiponectin, leptin, resistin, tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, and Dickkopf-1(DKK-1) levels were measured in AS patients using enzyme-linked immunosorbent assays; these measurements were only performed at the baseline for healthy controls.
Furthermore, Dkk-1 concentrations were significantly higher along a spectrum of increasing axial arthritis; Dkk-1 concentrations were higher in AS compared with PsSpA (OR<sub>adj</sub> 1.18 per ng/mL increase; p = 0.02).
Mechanism studies further revealed that loss of DKK1 partly reversed the effect of miR-146a inhibitor on cell proliferation, apoptosis and osteogenic potential in AS fibroblasts.
Recent evidence suggests that new bone formation in AS may be due to upregulation of Wnt signaling in the osteoblastic pathway secondary to low serum Dickkopf homolog 1 (Dkk-1) levels.
Significant additive interactions were observed between DKK1: rs1896368 and LRP5: rs3736228, relative excess risk due to interaction (RERI) = 0.40, 95% CI = 0.08 - 0.71; attributable proportion due to interaction (AP) = 51%, 95% CI = 0.07 - 0.94, DKK1: rs1569198 and LRP5: rs3736228 (RERI = 0.49, 95% CI = 0.12 - 0.86; AP = 49%, 95% CI = 0.17 - 0.82), LRP5: rs3736228 and SOST: rs4792909 (RERI = 0.33, 95% CI = 0.002 - 0.65; AP = 41%, 95% CI = 0.01 - 0.81) in the dominant model.<b>Conclusions:</b> Our research implies a potential gene-gene interaction, thus revealing the importance of the Wnt/β-catenin signalling pathway for understanding the genetic architecture of AS.
The expression of miR-29a, DKK-1 and β-catenin in normal and AS tissues were detected with real-time polymerase chain reaction (RT-PCR) and western blotting.
Therefore, we concluded that the beneficial role of <i>Chrysanthemum indicum</i> in AS is manifested through downregulating oxidative stress, inhibiting inflammatory mediators and NF-<i>κ</i>B, and increasing DKK-1 and SOST levels.