p-cresol but not p-cresyl sulfate stimulate MCP-1 production via NF-κB p65 in human vascular smooth muscle cells

J Bras Nefrol. 2016 Jun;38(2):153-60. doi: 10.5935/0101-2800.20160024.
[Article in English, Portuguese]

Abstract

Introduction: p-cresol (PC) and p-cresyl sulfate (PCS) are responsible for many of the uremia clinical consequences, such as atherosclerosis in Chronic Kidney Disease (CKD) patients.

Objectives: We investigate the in vitro impact of PC and PCS on monocyte chemoattractant protein-1 (MCP-1) expression via NF-kappa B (NF-κB) p65 in VSMC.

Methods: PCS was synthesized by PC sulfatation. VSMC were extracted by enzymatic digestion of umbilical cord vein and characterized by immunofluorescence against α-actin antibody. The cells were treated with PC and PCS at their normal (n), uremic (u) and maximum uremic concentrations (m). Cell viability was assessed by MTT. MCP-1 expression was investigated by ELISA in cells supernatants after toxins treatment with or without the NF-κB p65 inhibitor.

Results: There was no significant difference in cell viability after toxins treatment for all concentrations tested. There was a significant increase in MCP-1 expression in cells treated with PCu and PCm (p < 0.001) and PCSn, PCSu and PCSm (p < 0.001), compared with the control. When VSMC were treated with the NF-κB p65 inhibitor plus PCu and PCm, there was a significant decrease in MCP-1 production (p < 0.005). This effect was not observed with PCS.

Conclusions: VSMC are involved in atherosclerosis lesion formation and production of MCP-1, which contributes to the inflammatory response initiation. Our results suggest that PC mediates MCP-1 production in VSMC, probably through NF-κB p65 pathway, although we hypothesize that PCS acts through a different subunit pathway since NF-κB p65 inhibitor was not able to inhibit MCP-1 production.

MeSH terms

  • Cells, Cultured
  • Chemokine CCL2 / biosynthesis*
  • Chemokine CCL2 / drug effects*
  • Cresols / pharmacology*
  • Humans
  • Muscle, Smooth, Vascular / cytology*
  • Muscle, Smooth, Vascular / metabolism*
  • Sulfuric Acid Esters / pharmacology*
  • Transcription Factor RelA / physiology*

Substances

  • CCL2 protein, human
  • Chemokine CCL2
  • Cresols
  • Sulfuric Acid Esters
  • Transcription Factor RelA
  • 4-cresol
  • 4-cresol sulfate