Mechanisms of Renal-Splenic Axis Involvement in Acute Kidney Injury Mediated by the α7nAChR-NF-κB Signaling Pathway

Inflammation. 2021 Apr;44(2):746-757. doi: 10.1007/s10753-020-01374-y. Epub 2020 Nov 3.

Abstract

This study aimed to investigate the effect of splenectomy on dexmedetomidine-activated cholinergic anti-inflammatory pathway-mediated alleviation of LPS-induced AKI. A mouse model of septic kidney injury was established in C57BL/6 mice. A total of 30 C57BL/6 mice were randomly divided into the control group, LPS group, dexmedetomidine + LPS group, splenectomy group, splenectomy + LPS group, and splenectomy + dexmedetomidine + LPS group. The pathological effects in kidney tissues in each group were analyzed by HE staining. Apoptosis in each group was examined by the TUNEL method. Cr and Cys-C levels in each group were measured by ELISA. The expression levels of IL-6, NF-κB p65, Caspase-3, the antiapoptotic protein Bcl-2, the proapoptotic protein Bax, and α7nAChR in each group were measured by qRT-PCR and Western blotting. Dexmedetomidine alone reduced apoptosis in kidney tissue; however, apoptosis was increased after splenectomy in mice treated with dexmedetomidine. Splenectomy reduced the production of proinflammatory cytokines in circulation and had a protective effect on the kidney. Splenectomy inhibited dexmedetomidine-mediated activation of the α7nAChR pathway. Dexmedetomidine effectively alleviated LPS-induced kidney injury, and splenectomy inhibited the anti-inflammatory, antiapoptotic, and renoprotective effects of dexmedetomidine. The kidney-spleen axis is mediated by the α7nAChR-NF-κB signaling pathway and is involved in the development of AKI.

Keywords: AKI; apoptosis; cholinergic anti-inflammatory pathway; dexmedetomidine; inflammatory reaction; splenectomy; α7nAChR.

MeSH terms

  • Acute Kidney Injury / drug therapy
  • Acute Kidney Injury / etiology
  • Acute Kidney Injury / immunology*
  • Acute Kidney Injury / metabolism
  • Animals
  • Anti-Inflammatory Agents / pharmacology
  • Anti-Inflammatory Agents / therapeutic use
  • Apoptosis / drug effects
  • Apoptosis / immunology
  • Biomarkers / metabolism
  • Blotting, Western
  • Dexmedetomidine / pharmacology
  • Dexmedetomidine / therapeutic use
  • Enzyme-Linked Immunosorbent Assay
  • In Situ Nick-End Labeling
  • Kidney / drug effects
  • Kidney / immunology*
  • Kidney / metabolism
  • Lipopolysaccharides
  • Male
  • Mice
  • Mice, Inbred C57BL
  • NF-kappa B / immunology*
  • NF-kappa B / metabolism
  • Random Allocation
  • Sepsis / complications
  • Sepsis / immunology
  • Sepsis / metabolism
  • Signal Transduction / drug effects
  • Signal Transduction / immunology
  • Spleen / drug effects
  • Spleen / immunology*
  • Spleen / metabolism
  • Spleen / surgery
  • Splenectomy
  • alpha7 Nicotinic Acetylcholine Receptor / immunology*
  • alpha7 Nicotinic Acetylcholine Receptor / metabolism

Substances

  • Anti-Inflammatory Agents
  • Biomarkers
  • Lipopolysaccharides
  • NF-kappa B
  • alpha7 Nicotinic Acetylcholine Receptor
  • Dexmedetomidine