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JAK-2 as a novel mediator of the profibrotic effects of transforming growth factor β in systemic sclerosis

Clara Dees1, Michal Tomcik, Katrin Palumbo-Zerr

  • 1University of Erlangen-Nuremberg, Erlangen, Germany.

Arthritis and Rheumatism
|May 3, 2012
PubMed
Abstract

Insights

Janus kinase 2 (JAK-2) is activated in systemic sclerosis (SSc) skin fibroblasts. Inhibiting JAK-2 shows potent antifibrotic effects, suggesting its potential as a novel therapeutic target for SSc treatment.

Area of Science:

  • Dermatology
  • Immunology
  • Pharmacology

Background:

  • Systemic sclerosis (SSc) is characterized by pathologic fibroblast activation.
  • The role of Janus kinase 2 (JAK-2) in SSc pathogenesis is not fully understood.

Purpose of the Study:

  • To investigate JAK-2 activation in SSc fibroblasts.
  • To evaluate the antifibrotic potential of JAK-2 inhibition in SSc treatment.

Main Methods:

  • Immunohistochemical analysis of JAK-2 activation in human SSc skin and experimental fibrosis models.
  • Inhibition of JAK-2 signaling using TG101209 or small interfering RNA.
  • Evaluation of antifibrotic effects in bleomycin-induced and TSK-1 mouse models of fibrosis.

Main Results:

  • Increased JAK-2 activation was observed in SSc skin fibroblasts, dependent on transforming growth factor β (TGFβ).
  • JAK-2 inhibition selectively reduced collagen synthesis in SSc fibroblasts and blocked TGFβ-induced fibroblast activation.
  • TG101209 treatment prevented and reduced dermal fibrosis in mouse models.

Conclusions:

  • JAK-2 is activated in a TGFβ-dependent manner in SSc.
  • JAK-2 inhibition demonstrates significant antifibrotic effects.
  • JAK-2 inhibitors may offer a promising therapeutic strategy for SSc.

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