Akt-mediated anti-apoptotic effects of substance P in Anti-Fas-induced apoptosis of human tenocytes

J Cell Mol Med. 2013 Jun;17(6):723-33. doi: 10.1111/jcmm.12059. Epub 2013 Apr 11.


Substance P (SP) and its receptor, the neurokinin-1 receptor (NK-1 R), are expressed by human tenocytes, and they are both up-regulated in cases of tendinosis, a condition associated with excessive apoptosis. It is known that SP can phosphorylate/activate the protein kinase Akt, which has anti-apoptotic effects. This mechanism has not been studied for tenocytes. The aims of this study were to investigate if Anti-Fas treatment is a good apoptosis model for human tenocytes in vitro, if SP protects from Anti-Fas-induced apoptosis, and by which mechanisms SP mediates an anti-apoptotic response. Anti-Fas treatment resulted in a time- and dose-dependent release of lactate dehydrogenase (LDH), i.e. induction of cell death, and SP dose-dependently reduced the Anti-Fas-induced cell death through a NK-1 R specific pathway. The same trend was seen for the TUNEL assay, i.e. SP reduced Anti-Fas-induced apoptosis via NK-1 R. In addition, it was shown that SP reduces Anti-Fas-induced decrease in cell viability as shown with crystal violet assay. Protein analysis using Western blot confirmed that Anti-Fas induces cleavage/activation of caspase-3 and cleavage of PARP; both of which were inhibited by SP via NK-1 R. Finally, SP treatment resulted in phosphorylation/activation of Akt as shown with Western blot, and it was confirmed that the anti-apoptotic effect of SP was, at least partly, induced through the Akt-dependent pathway. In conclusion, we show that SP reduces Anti-Fas-induced apoptosis in human tenocytes and that this anti-apoptotic effect of SP is mediated through NK-1 R and Akt-specific pathways.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Achilles Tendon / cytology
  • Achilles Tendon / drug effects*
  • Achilles Tendon / metabolism
  • Antibodies / pharmacology
  • Apoptosis / drug effects*
  • Caspase 3 / genetics
  • Caspase 3 / metabolism
  • Gene Expression Regulation
  • Humans
  • L-Lactate Dehydrogenase / metabolism
  • Phosphorylation
  • Poly(ADP-ribose) Polymerases / genetics
  • Poly(ADP-ribose) Polymerases / metabolism
  • Primary Cell Culture
  • Proto-Oncogene Proteins c-akt / genetics*
  • Proto-Oncogene Proteins c-akt / metabolism
  • Receptors, Neurokinin-1 / genetics
  • Receptors, Neurokinin-1 / metabolism
  • Signal Transduction
  • Substance P / pharmacology
  • Substance P / physiology*
  • fas Receptor / antagonists & inhibitors
  • fas Receptor / genetics*
  • fas Receptor / metabolism


  • Antibodies
  • FAS protein, human
  • Receptors, Neurokinin-1
  • fas Receptor
  • Substance P
  • L-Lactate Dehydrogenase
  • Poly(ADP-ribose) Polymerases
  • Proto-Oncogene Proteins c-akt
  • Caspase 3