Sublytic C5b-9 Induces CCL3/4 Production and Macrophage Accumulation in Thy-1N Rats via PKC-α/p65/IRF-8 Axis

  • Int J Biol Sci. 2022 May 1;18(8):3178-3193. doi: 10.7150/ijbs.69652.
Wenbo Wang  1 ,  Baomei Qian  1 ,  Chenhui Zhao  2 ,  Mingyu Peng  1 ,  Longfei Liu  1 ,  Mengxiao Xie  1 ,  Na Peng  3 ,  Qingling He  1 ,  Shuai Ying  1 ,  Yufeng Zhu  4 ,  Tao Wang  5 ,  Dajun Hu  3 ,  Dan Zhao  1 ,  Jing Zhang  1 ,  Yingwei Wang  1  6 ,  Wen Qiu  1  6
Affiliations
  • 1. Department of Immunology, and Key Laboratory of Immunological Environment and Disease, Nanjing Medical University, Nanjing, Jiangsu 211166, China.
  • 2. Department of Medicine, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China.
  • 3. Department of Rheumatology and Nephrology, The Second People's Hospital of China Three Gorges University, Yichang, China.
  • 4. Clinical Medical Science of the First Clinical Medical College, Nanjing Medical University, Nanjing, Jiangsu 211166, China.
  • 5. Department of Nephrology, The Affiliated Jiangning Hospital of Nanjing Medical University, Nanjing, Jiangsu 211100, China.
  • 6. Key Laboratory of Antibody Technology of Ministry of Health, Nanjing Medical University, Nanjing, Jiangsu 211166, China.
PMID: 35637950 DOI: 10.7150/ijbs.69652
Abstract

Mesangioproliferative glomerulonephritis (MsPGN) is a common human kidney disease. Rat Thy-1 nephritis (Thy-1N) is an animal model widely used for the study of MsPGN. Thy-1N is not only sublytic C5b-9-dependent, but also related to pro-inflammatory cytokine production and macrophage (Mφ) accumulation in rat renal tissues. In this study, we found that the expression or phosphorylation of chemokine CCL3/4, CD68 (Mφ marker), IRF-8, PKC-α and NF-κB-p65 (p65) were all up-regulated both in the renal tissues of Thy-1N rats (in vivo) and in the glomerular mesangial cells (GMCs) upon sublytic C5b-9 stimulation (in vitro). Further experiments in vitro revealed that the phosphorylated PKC-α (p-PKC-α) could promote p65 phosphorylation, and then p-p65 enhanced IRF-8 expression through binding to IRF-8 promotor (-591 ~ -582 nt and -299 ~ -290 nt). Additionally, up-regulation or silencing of IRF-8 gene promoted or reduced CCL3/4 production, and then regulated Mφ chemotaxis. The underlying mechanism involved in IRF-8 binding to CCL3 promoter (-249 ~ -236 nt), which resulted in CCL3 gene transcription. The experiments in vivo showed that knockdown of renal PKC-α, p65, IRF-8 and CCL3/4 genes could inhibit CCL3/4 production, Mφ accumulation, GMC proliferation and proteinuria of Thy-1N rats. Furthermore, p-PKC-α, p-p65, IRF-8, CCL3/4 expression and Mφ accumulation were also increased in the renal tissues of MsPGN patients. Collectively, these findings indicate that sublytic C5b-9 induces CCL3/4 production and Mφ accumulation via PKC-α/p65/IRF-8 axis, and finally aggravates the pathological changes of MsPGN.

Keywords
CCL3/4; IRF-8; Thy-1 nephritis; macrophage; mesangioproliferative glomerulonephritis; sublytic C5b-9.
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