Electroacupuncture on ST36 and GB39 Acupoints Inhibits Synovial Angiogenesis via Downregulating HIF-1α/VEGF Expression in a Rat Model of Adjuvant Arthritis.

Jun Zhu,Yuzhou Chen,Chengguo Su,Xinyu Hao,Jianzhen Jiang

doi:10.1155/2019/5741931

Abstract

Introduction. The hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) play a key role in synovial angiogenesis in rheumatoid arthritis (RA). Therefore, this study aimed to test the hypothesis that electroacupuncture (EA) may inhibit RA synovial angiogenesis via HIF-1α/VEGF expression. Methods. Sprague-Dawley rats were randomly distributed to 4 groups: control, adjuvant arthritis (AA), AA+electroacupuncture (AA+EA), and AA+sham EA groups. AA model was induced by injection of Freund's complete adjuvant in bilateral hind footpad. 3 days after injection, EA was delivered to the acupoints Zusanli (ST 36) and Xuanzhong (GB 39) once every two days for a total of 8 times in the AA+EA group, while sham EA treatment was applied in the AA+sham EA group. The arthritis score, paw volume, and H&E staining for each animal were measured. CD34 expression in synovial tissue of ankle joint was observed by immunohistochemistry. HIF-1α and VEGF mRNA and protein levels in synovial tissue were determined by real-time quantitative PCR and Western blot, respectively. Results. Compared with rats in AA group, EA stimulation significantly decreased arthritis scores, paw volume, and pathological damage of synovial tissues. Moreover, EA markedly suppressed the synovial angiogenesis of AA rats, as evidenced by reduced CD34 positive expression. Furthermore, EA significantly reduced HIF-1α and VEGF mRNA and protein levels in synovial of AA rats. Finally, the CD34 expression in synovial tissue was positively correlated with HIF-1α and VEGF protein levels. Conclusion. EA on ST36 and GB39 acupoints can effectively inhibit synovial angiogenesis in the AA rat model via downregulating HIF-1α/VEGF expression.

Highlights

The hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) play a key role in synovial angiogenesis in rheumatoid arthritis (RA)
We aimed to evaluate the effects of stimulating GB39 and ST36 acupoints on HIF-1α/VEGF expression by a adjuvant arthritis (AA) rat model
In the theory of meridians and collaterals of traditional Chinese medicine, it has a significant beneficial effect and can markedly inhibit the progress of RA [28]. The combination of these two acupoints has a more significant effect on inhibiting arthritis, and it is a classical acupoint pairing commonly used in clinical electroacupuncture treatment of RA patients [12, 14, 28]. Synchronously stimulated both ST36 and GB39 acupoints to observe its therapeutic effect on AA rat model

Summary

Introduction

The hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) play a key role in synovial angiogenesis in rheumatoid arthritis (RA). Compared with rats in AA group, EA stimulation significantly decreased arthritis scores, paw volume, and pathological damage of synovial tissues. EA significantly reduced HIF-1α and VEGF mRNA and protein levels in synovial of AA rats. The CD34 expression in synovial tissue was positively correlated with HIF-1α and VEGF protein levels. EA on ST36 and GB39 acupoints can effectively inhibit synovial angiogenesis in the AA rat model via downregulating HIF-1α/VEGF expression. Evidence indicates that hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) may play a key signaling-mediated role in this process [5]. Synovial angiogenesis feeds the expression of HIF-1α and VEGF in synovial tissue [7]

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