aPKCζ-dependent Repression of Yap is Necessary for Functional Restoration of Irradiated Salivary Glands with IGF-1

Sci Rep. 2018 Apr 20;8(1):6347. doi: 10.1038/s41598-018-24678-4.

Abstract

Xerostomia and salivary hypofunction often result as a consequence of radiation therapy for head and neck cancers, which are diagnosed in roughly 60,000 individuals every year in the U.S. Due to the lack of effective treatments for radiation-induced salivary hypofunction, stem cell-based therapies have been suggested to regenerate the irradiated salivary glands. Pharmacologically, restoration of salivary gland function has been accomplished in mice by administering IGF-1 shortly after radiation treatment, but it is not known if salivary stem and progenitor cells play a role. We show that radiation inactivates aPKCζ and promotes nuclear redistribution of Yap in a population of label-retaining cells in the acinar compartment of the parotid gland (PG)- which comprises a heterogeneous pool of salivary progenitors. Administration of IGF-1 post-radiation maintains activation of aPKCζ and partially rescues Yap's cellular localization in label retaining cells, while restoring salivary function. Finally, IGF-1 fails to restore saliva production in mice lacking aPKCζ, demonstrating the importance of the kinase as a potential therapeutic target.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism*
  • Adaptor Proteins, Signal Transducing / physiology
  • Animals
  • Cell Cycle Proteins
  • Female
  • Head and Neck Neoplasms / radiotherapy
  • Insulin-Like Growth Factor I / pharmacology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Parotid Gland / radiation effects
  • Phosphoproteins / metabolism*
  • Phosphoproteins / physiology
  • Protein Kinase C / metabolism*
  • Protein Kinase C / physiology
  • Radiotherapy / adverse effects
  • Saliva / radiation effects
  • Salivary Glands / cytology
  • Salivary Glands / radiation effects*
  • Stem Cells / cytology
  • Xerostomia / therapy
  • YAP-Signaling Proteins

Substances

  • Adaptor Proteins, Signal Transducing
  • Cell Cycle Proteins
  • Phosphoproteins
  • YAP-Signaling Proteins
  • Yap1 protein, mouse
  • Insulin-Like Growth Factor I
  • protein kinase C zeta
  • Protein Kinase C