Figure 1. Multifaceted roles of IL-32γ in bone metabolism in RA and AS. RA is characterized by bone destruction, whereas AS is characterized by bone formation. In RA, IL-32γ and TNF-α promote OC formation by increasing RANKL production from RA-FLSs and OBs, thereby contributing to inflammatory bone loss in RA. However, in AS, highly elevated IL-32γ in the joint plays a key role in excessive bone formation by enhancing OB differentiation via inhibition of DKK-1.
