Transcriptome sequencing reveals core regulation modules and gene signatures of Zusanli acupoints in response to different moxibustion warm stimulation in adjuvant arthritis rat

Background: The efficacy of moxibustion in treating rheumatoid arthritis is recognized, but its molecular mechanism is still unclear. This study aimed to characterize the molecular map and potential key genes in the process of different moxibustion warm at Zusanli acupoint treatment of adjuvant arthritis (AA) model.

Methods: AA rat model was induced by complete Freund's adjuvant (CFA) and then accessed by foot swelling and thermal hyperalgesia test. Transcriptome sequencing, series test of cluster (STC) and weighted gene co-expression network analysis (WGCNA) were used in this study.

Results: CFA-induced inflammation, foot swelling, and pain in AA rats were significantly improved by moxibustion warm. Differentially expressed genes (DEGs) were screened in nine different comparison groups and a total of 4535 DEGs were identified, and these DEGs were preferentially clustered in inflammatory and immune-related pathways, such as MAPK signaling pathway. Only 1 DEG of heat shock protein 90, alpha (cytosolic), class A member 1 (Hsp90aa1) was shared in comparison groups of model with moxibustion treatment. STC analysis also revealed that Hsp90aa1 was increased in AA model, but decreased after 37 °C moxibustion intervention, and constantly decreased after 42 °C moxibustion treatment. GO and KEGG pathway analysis revealed that these genes enriched in inflammatory and immune-related pathways. Moreover, WGCNA identified that violet module was positively correlated with model temperature while negatively correlated with control, and the paleturquoise module was positively correlated with model. The violet and paleturquoise module gene were significantly enriched in MAPK signaling pathway. Importantly, Hsp90aa1 also played a central role in the violet module by interacting with multiple proteins.

Conclusions: Moxibustion warm improved AA in rat, and we obtained the transcriptome profile and excavate a critical gene of Hsp90aa1, and provided insight into gene signatures for moxibustion warm at Zusanli acupoint in AA rat.