Therapeutic value of curcumin on the initiation and development of inflammation in Takayasu’s arteritis mediated by HSP65-induced CCL2 overexpression

Abstract Background Takayasu’s arteritis (TAK) is a chronic inflammatory disease characterized by macrophage infiltration. During the active stage, aorta adventitial fibroblasts (AAFs) proliferate excessively and produce numerous pro-inflammatory factors in the adventitia, the primary target of TAK therapy. Although the monocyte chemokine, CCL2, may contribute to macrophage infiltration in TAK arteries, whether there is an associated relationship with HSP65 remains unknown. Moreover, there are no reports of the activation of AAFs to produce inflammatory factors involvement in TAK pathogenesis. TAK treatment is associated with several challenges and contradictions. Curcumin is a traditional Chinese medicine with anti-inflammatory effects; however, its effectiveness for TAK and the underlying mechanism remains unclear. Methods We first verified high HSP65 expression in the aortic adventitia of TAK patients by IHC. mRNA-seq was used to profile differentially expressed genes (DEGs) between AAFs stimulated by HSP65 with or without pretreatment with curcumin, and untreated AAFs. The key chemokine, CCL2, screened by mRNA-seq was detected in the adventitia of the TAK aorta, and its correlation with HSP65 expression was analyzed by double-labelled immunofluorescence. We subsequently explored how HSP65 affected the production of inflammatory factors by AAFs at a cellular level and the related signaling pathway. We explored whether curcumin could hinder this process and verified the effect of curcumin on the level of serum CCL2 in patients with TAK. Results HSP65 was highly expressed in the adventitia of TAK arteries. The DEG analysis showed a key role of CCL2. The expression of CCL2 in the adventitia of TAK arteries was significantly higher than that of healthy subjects, and was correlated with HSP65. HSP65 facilitated the production of CCL2, IL-6, and IL-1β by AAFs via activation of the TLR4-JAK2/AKT/STAT3 pathway, among which the change in CCL2 was the greatest. Curcumin treatment reversed HSP65-induced CCL2 upregulation in vitro, which was more obvious than that of MTX and tofacitinib. Finally, curcumin significantly downregulated the level of serum CCL2 in TAK patients. Conclusion HSP65 initiates and promotes TAK inflammation by upregulating CCL2 in AAFs through the JAK2/AKT/STAT3 pathway, whereas curcumin could reverse this process and slow the initiation and development of TAK.