Hydroxysafflor Yellow A Reduced Neuroinflammation Induced by Astrocyte-Derived IL-17A by Inhibiting the IL-17RA/ACT1/NF-κB/IL-17A Loop After OGD/R

Lijuan Song,1,2,* Jianlin Hua,2,3,* Kexin Liu,2 Yanzhe Duan,2 Yukang Sun,2 Jiezhong Yu,1,4 Jinzhu Yin,2,3,5 Cungen Ma,1,2 Baoguo Xiao,2,6 Dong Ma,2,3,5 Jianjun Huang2– 4 1Shanxi Key Laboratory of Innovative Drug for the Treatment of Serious Diseases Basing on the Chronic Inflammation, Shanxi University of Chinese Medicine, Jinzhong, Shanxi, 030619, People’s Republic of China; 2Research Center of Neurobiology, Shanxi University of Chinese Medicine, Jinzhong, Shanxi, 030619, People’s Republic of China; 3Department of Neurosurgery, Sinopharm Tongmei General Hospital, Datong, Shanxi, 037003, People’s Republic of China; 4First Affiliated Hospital, Shanxi Datong University, Datong, Shanxi, 037009, People’s Republic of China; 5The Key Laboratory of Prevention and Treatment of Neurological Disease of Shanxi Provincial Health Commission, Sinopharm Tongmei General Hospital, Datong, Shanxi, 037003, People’s Republic of China; 6Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200433, People’s Republic of China*These authors contributed equally to this workCorrespondence: Dong Ma, Email [email protected] Jianjun Huang, Email [email protected]: Neuroinflammation induced by astrocytes has garnered significant attention recently. The IL-17A/IL-17RA signal pathway plays an important role in ischemic stroke (IS). Hydroxysafflor yellow A (HSYA) has been reported to have anti-apoptotic and anti-inflammatory properties that can protect neurons. In this study, we explore a novel mechanism that underlies the anti-apoptotic and anti-inflammatory effects of HSYA.Methods: In vitro experiments were carried out using primary astrocytes and HT22 neuronal cells in an oxygen–glucose deprivation/reoxygenation (OGD/R) model. Techniques such as Western blot, immunofluorescence staining, Enzyme-linked immunosorbent assay (ELISA), and quantitative real-time polymerase chain reaction (qRT-PCR) were utilized to detect relevant indicators. The purpose was to investigate the effect of HSYA on the influence of IL-17A secreted by primary astrocytes after OGD/R on HT22 neuronal cells.Results: The results indicated that the production of IL-17A by astrocytes increased following OGD/R, which was reduced due to HSYA treatment. In addition, astrocyte-derived IL-17A resulted in neuronal cell damage. Further studies showed that HSYA reduced IL-17A production by inhibiting activation of the IL-17RA/ACT1/NF-κB/IL-17A loop, which ultimately alleviated neuroinflammation and reduced neuronal apoptosis.Discussion: These findings suggest that an activated loop indeed exists between IL-17A and IL-17RA/ACT1/NF-κB after OGD/R, and HSYA treatment alleviated IL-17A release from astrocytes after OGD/R by inhibiting the IL-17RA/ACT1/NF-κB/IL-17A loop. These results further emphasize the anti-inflammatory and neuroprotective effects of HSYA and suggest that it may be a promising drug for treating IS.Keywords: hydroxysafflor yellow A, neuroinflammation, IL-17A, astrocytes, oxygen-glucose deprivation/reoxygenation, OGD/R