1α,25-Dihydroxyvitamin-D3-3-bromoacetate regulates AKT/mTOR signaling cascades: a therapeutic agent for psoriasis

J Invest Dermatol. 2013 Jun;133(6):1556-64. doi: 10.1038/jid.2013.3. Epub 2013 Jan 11.

Abstract

The efficacy of 1α,25-dihydroxyvitamin D3 (Vit-D) limits its topical use despite its profound effects on cellular differentiation, proliferation, and immunomodulation. Therefore, in search for a more effective analog of Vit-D, in this study we have evaluated the antiproliferative and proapoptotic effects of 1α,25-dihydroxyvitamin D3-3-bromoacetate (BE). Proliferation and apoptosis studies in normal human epidermal keratinocytes (NHEKs) were conducted by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), CFSE (carboxy fluorescein succinimidyl ester) dilution, and Annexin V assays. Western blot analysis and real-time PCR were performed to determine its effect on signal transduction. A reconstructed human epidermis (RHE) model was used to further validate the therapeutic role of BE in psoriasis. BE was significantly more potent than an equivalent concentration of Vit-D in inhibiting growth and survival of human keratinocytes. The antimitotic effect was found to be due to the inhibition of phosphorylation of serine/threonine protein kinase (AKT) and its downstream target, mammalian target of rapamycin (mTOR). In the RHE model, BE reversed IL-22-induced psoriasiform changes more effectively than Vit-D. Interestingly, BE inhibited the IL-22-induced gene expression of AKT1, MTOR, chemokines [IL-8 and RANTES (regulated upon activation, normal T-cell expressed and secreted)], and psoriasin (S100A7) more significantly than Vit-D. These results suggest the potential of BE as a prospective therapeutic agent for psoriasis.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / drug effects
  • Calcitriol / analogs & derivatives*
  • Calcitriol / pharmacology
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Cells, Cultured
  • Chemokine CCL5 / genetics
  • Chemokine CCL5 / metabolism
  • Epidermal Cells
  • Gene Expression / drug effects
  • Gene Expression / physiology
  • Humans
  • Interleukin-22
  • Interleukin-8 / genetics
  • Interleukin-8 / metabolism
  • Interleukins / metabolism
  • Keratinocytes / cytology
  • Keratinocytes / drug effects*
  • Keratinocytes / metabolism
  • Phosphorylation / drug effects
  • Phosphorylation / physiology
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Psoriasis / drug therapy*
  • Psoriasis / metabolism
  • Psoriasis / pathology
  • S100 Calcium Binding Protein A7
  • S100 Proteins / genetics
  • S100 Proteins / metabolism
  • Signal Transduction / drug effects*
  • Signal Transduction / physiology
  • TOR Serine-Threonine Kinases / metabolism*
  • Vitamin D / pharmacology
  • Vitamins / pharmacology

Substances

  • 1,25-dihydroxyvitamin D3-3-bromoacetate
  • CXCL8 protein, human
  • Chemokine CCL5
  • Interleukin-8
  • Interleukins
  • S100 Calcium Binding Protein A7
  • S100 Proteins
  • S100A7 protein, human
  • Vitamins
  • Vitamin D
  • MTOR protein, human
  • AKT1 protein, human
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases
  • Calcitriol