Reciprocal Regulation of Shh Trafficking and H₂O₂ Levels via a Noncanonical BOC-Rac1 Pathway

• Main Authors: Marion Thauvin (Author), Irène Amblard (Author), Christine Rampon (Author), Aurélien Mourton (Author), Isabelle Queguiner (Author), Chenge Li (Author), Arnaud Gautier (Author), Alain Joliot (Author), Michel Volovitch (Author), Sophie Vriz (Author)
• Format: Book
• Published: MDPI AG, 2022-04-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

Among molecules that bridge environment, cell metabolism, and cell signaling, hydrogen peroxide (H₂O₂) recently appeared as an emerging but central player. Its level depends on cell metabolism and environment and was recently shown to play key roles during embryogenesis, contrasting with its long-established role in disease progression. We decided to explore whether the secreted morphogen Sonic hedgehog (Shh), known to be essential in a variety of biological processes ranging from embryonic development to adult tissue homeostasis and cancers, was part of these interactions. Here, we report that H₂O₂ levels control key steps of Shh delivery in cell culture: increased levels reduce primary secretion, stimulate endocytosis and accelerate delivery to recipient cells; in addition, physiological in vivo modulation of H₂O₂ levels changes Shh distribution and tissue patterning. Moreover, a feedback loop exists in which Shh trafficking controls H₂O₂ synthesis via a non-canonical BOC-Rac1 pathway, leading to cytoneme growth. Our findings reveal that Shh directly impacts its own distribution, thus providing a molecular explanation for the robustness of morphogenesis to both environmental insults and individual variability.

Item Description

10.3390/antiox11040718
2076-3921