CTGF/CCN2 activates canonical Wnt signalling in mesangial cells through LRP6: implications for the pathogenesis of diabetic nephropathy

FEBS Lett. 2011 Feb 4;585(3):531-8. doi: 10.1016/j.febslet.2011.01.004. Epub 2011 Jan 14.

Abstract

We describe the activation of Wnt signalling in mesangial cells by CCN2. CCN2 stimulates phosphorylation of LRP6 and GSK-3β resulting in accumulation and nuclear localisation of β-catenin, TCF/LEF activity and expression of Wnt targets. This is coincident with decreased phosphorylation of β-catenin on Ser 33/37 and increased phosphorylation on Tyr142. DKK-1 and LRP6 siRNA reversed CCN2's effects. Microarray analyses of diabetic patients identified differentially expressed Wnt components. β-Catenin is increased in type 1 diabetic and UUO mice and in in vitro models of hyperglycaemia and hypertension. These findings suggest that Wnt/CCN2 signalling plays a role in the pathogenesis of diabetic nephropathy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Connective Tissue Growth Factor / genetics
  • Connective Tissue Growth Factor / metabolism*
  • Diabetes Mellitus, Type 1 / chemically induced
  • Diabetes Mellitus, Type 1 / metabolism
  • Diabetes Mellitus, Type 1 / pathology
  • Diabetic Nephropathies / metabolism*
  • Diabetic Nephropathies / pathology
  • Diabetic Nephropathies / physiopathology
  • Glycogen Synthase Kinase 3 / metabolism
  • Glycogen Synthase Kinase 3 beta
  • Humans
  • Hyperglycemia / metabolism
  • Hypertension / metabolism
  • Kidney Cortex / metabolism
  • Kidney Cortex / pathology
  • LDL-Receptor Related Proteins / genetics
  • LDL-Receptor Related Proteins / metabolism*
  • Low Density Lipoprotein Receptor-Related Protein-6
  • Male
  • Mesangial Cells / cytology
  • Mesangial Cells / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Phosphorylation
  • Protein Transport
  • RNA, Small Interfering
  • Signal Transduction*
  • Ureteral Obstruction / metabolism
  • Ureteral Obstruction / pathology
  • Wnt Proteins / metabolism*
  • beta Catenin / metabolism

Substances

  • CCN2 protein, mouse
  • CTNNB1 protein, mouse
  • LDL-Receptor Related Proteins
  • LRP6 protein, human
  • Low Density Lipoprotein Receptor-Related Protein-6
  • Lrp6 protein, mouse
  • RNA, Small Interfering
  • Wnt Proteins
  • beta Catenin
  • Connective Tissue Growth Factor
  • GSK3B protein, human
  • Glycogen Synthase Kinase 3 beta
  • Gsk3b protein, mouse
  • Glycogen Synthase Kinase 3