Fractalkine and its receptor, CX3CR1, promote hypertensive interstitial fibrosis in the kidney

Hypertens Res. 2011 Jun;34(6):747-52. doi: 10.1038/hr.2011.23. Epub 2011 Mar 31.

Abstract

Hypertension promotes and escalates kidney injury, including kidney fibrosis. Fractalkine/CX3CL1 is a unique chemokine that works as a leukocyte chemoattractant and an adhesion molecule. Recently, fractalkine/CX3CL1 has been reported to promote tissue fibrosis via its cognate receptor, CX3CR1. However, the involvement of the fractalkine-CX3CR1 axis in the pathogenesis of hypertensive kidney fibrosis remains unclear. The impacts of the fractalkine-CX3CR1 axis on hypertensive kidney fibrosis were investigated in a deoxycorticosterone acetate (DOCA)-salt hypertensive model in CX3CR1-deficient mice, which were sacrificed on day 28. The blood pressure levels were similarly elevated in both CX3CR1-/- C57BL/6 and wild-type C57BL/6 mice. Fractalkine and CX3CR1 were upregulated in kidneys that were damaged by hypertension. Deficiency in CX3CR1 inhibited kidney fibrosis, as evidenced by a decrease in the presence of interstitial fibrotic area detected by type I collagen in Mallory-Azan staining, concomitant with the downregulation of transforming growth factor (TGF)-β(1) and type I procollagen mRNA expression in damaged kidneys. The CX3CR1 blockade also decreased the number of infiltrating F4/80-positive macrophages in damaged kidneys. These results suggest that the fractalkine-CX3CR1 axis contributes to kidney fibrosis in a hypertensive mouse model, possibly by the upregulation of macrophage infiltration and the expression of TGF-β(1) and type I collagen.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Differentiation / analysis
  • CX3C Chemokine Receptor 1
  • Chemokine CX3CL1 / physiology*
  • Desoxycorticosterone
  • Fibrosis
  • Hypertension / pathology*
  • Kidney / pathology*
  • Macrophages / immunology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Receptors, Chemokine / physiology*
  • Signal Transduction
  • Transforming Growth Factor beta1 / analysis

Substances

  • Antigens, Differentiation
  • CX3C Chemokine Receptor 1
  • Chemokine CX3CL1
  • Cx3cl1 protein, mouse
  • Cx3cr1 protein, mouse
  • Receptors, Chemokine
  • Transforming Growth Factor beta1
  • monocyte-macrophage differentiation antigen
  • Desoxycorticosterone