The complement C3a-C3aR and C5a-C5aR pathways promote viability and inflammation of human retinal pigment epithelium cells by targeting NF-κB signaling

Shasha Luo; Huiyan Xu; Xuechun Gong; Jinyan Shen; Xuan Chen; Zhifeng Wu

doi:10.3892/etm.2022.11420

The complement C3a-C3aR and C5a-C5aR pathways promote viability and inflammation of human retinal pigment epithelium cells by targeting NF-κB signaling

Exp Ther Med. 2022 Jun 7;24(2):493. doi: 10.3892/etm.2022.11420. eCollection 2022 Aug.

Authors

Shasha Luo^{1

2}, Huiyan Xu^{1

2}, Xuechun Gong¹, Jinyan Shen¹, Xuan Chen¹, Zhifeng Wu^{1

2}

Affiliations

¹ Department of Ophthalmology, Nanjing Medical University Affiliated Wuxi Second Hospital, Wuxi, Jiangsu 214002, P.R. China.
² Department of Ophthalmology, Affiliated Wuxi Clinical College of Nantong University, Wuxi, Jiangsu 214002, P.R. China.

Abstract

Retinal detachment (RD) and its special form of rhegmatogenous RD associated with choroidal detachment (RRDCD) feature similar pathological alterations, including enhanced retinal cell inflammation. Although the importance of the complement components C3a and C5a and their corresponding receptors in retinal maintenance has been demonstrated, the relevance of these molecules to the pathogenesis of RD or RRDCD remains to be investigated. The contents of C3a, C5a and inflammatory factors, such as TNF-α, IL-1β, IL-6 and prostaglandin (PG)E2, in related clinical samples were examined by ELISA. Subsequently, human retinal pigment epithelial (HRPE) cells were subjected to challenge with the C3a and C5a recombinant proteins with or without C3a and C5a antagonists and NF-κB inhibitor, and the cell viability and inflammatory cytokines were then determined by a Cell Counting Kit-8 assay and ELISA, respectively. In addition, reverse transcription-quantitative PCR and western blot analyses were utilized to examine the mRNA or/and protein levels of C3a and its receptor C3aR, as well as C5a and its receptor C5aR, and NF-κB. In addition, the correlation of C3a and C5a with the aforementioned inflammatory factors was analyzed. The inflammatory factor levels of C3a and C5a were considerably elevated in patients with RRDCD compared to those in the controls. Consistently, C3a and C5a treatment led to increased cell viability and aggravated inflammation in HRPE cells. Accordingly, C3a and C5a induced upregulation of their corresponding receptors C3aR and C5aR, which was in turn observed to be linked to the activation of the NF-κB signaling pathway. Furthermore, there was a positive correlation of the complements C3a and C5a with individual TNF-α, IL-1β, IL-6 and PGE2. Taken together, the C3a-C3aR and C5a-C5aR pathways were indicated to promote cell viability and inflammation of HRPE cells by targeting the NF-κB signaling pathway.

Keywords: C3a-C3aR; C5a-C5aR; NF-κB signaling; cell viability; human retinal pigment epithelial cells; inflammation.

Grants and funding

Funding: This study was supported by the Social Development Project of Jiangsu Provincial Science and Technology Department (grant no. BE2017627), the youth project of Wuxi Health Committee (grant no. Q202038) and the reserve top talent project of Wuxi Municipal Health Commission (grant no. HB2020032).