Development of severe skeletal defects in induced SHP-2-deficient adult mice: a model of skeletal malformation in humans with SHP-2 mutations

Dis Model Mech. 2011 Mar;4(2):228-39. doi: 10.1242/dmm.006130. Epub 2010 Nov 10.

Abstract

SHP-2 (encoded by PTPN11) is a ubiquitously expressed protein tyrosine phosphatase required for signal transduction by multiple different cell surface receptors. Humans with germline SHP-2 mutations develop Noonan syndrome or LEOPARD syndrome, which are characterized by cardiovascular, neurological and skeletal abnormalities. To study how SHP-2 regulates tissue homeostasis in normal adults, we used a conditional SHP-2 mouse mutant in which loss of expression of SHP-2 was induced in multiple tissues in response to drug administration. Induced deletion of SHP-2 resulted in impaired hematopoiesis, weight loss and lethality. Most strikingly, induced SHP-2-deficient mice developed severe skeletal abnormalities, including kyphoses and scolioses of the spine. Skeletal malformations were associated with alterations in cartilage and a marked increase in trabecular bone mass. Osteoclasts were essentially absent from the bones of SHP-2-deficient mice, thus accounting for the osteopetrotic phenotype. Studies in vitro revealed that osteoclastogenesis that was stimulated by macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor kappa B ligand (RANKL) was defective in SHP-2-deficient mice. At least in part, this was explained by a requirement for SHP-2 in M-CSF-induced activation of the pro-survival protein kinase AKT in hematopoietic precursor cells. These findings illustrate an essential role for SHP-2 in skeletal growth and remodeling in adults, and reveal some of the cellular and molecular mechanisms involved. The model is predicted to be of further use in understanding how SHP-2 regulates skeletal morphogenesis, which could lead to the development of novel therapies for the treatment of skeletal malformations in human patients with SHP-2 mutations.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aging / pathology*
  • Animals
  • Biomarkers / blood
  • Bone and Bones / abnormalities*
  • Bone and Bones / enzymology
  • Bone and Bones / pathology*
  • Bone and Bones / physiopathology
  • Calcification, Physiologic / physiology
  • Cartilage / metabolism
  • Cartilage / pathology
  • Disease Models, Animal
  • Gene Deletion
  • Hematopoiesis / physiology
  • Humans
  • Macrophage Colony-Stimulating Factor / metabolism
  • Mice
  • Mutation / genetics*
  • Osteoclasts / metabolism
  • Osteoclasts / pathology
  • Osteogenesis / physiology
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11 / deficiency*
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11 / metabolism
  • Signal Transduction
  • Spinal Curvatures / blood
  • Spinal Curvatures / complications
  • Spinal Curvatures / pathology
  • Spinal Curvatures / physiopathology
  • Survival Analysis
  • Weight Loss

Substances

  • Biomarkers
  • Macrophage Colony-Stimulating Factor
  • PTPN11 protein, human
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11
  • Ptpn11 protein, mouse