Augmenting endogenous Wnt signaling improves skin wound healing.

Wnt signaling is required for both the development and homeostasis of the skin, yet its contribution to skin wound repair remains controversial. By employing Axin2(LacZ/+) reporter mice we evaluated the spatial and temporal distribution patterns of Wnt responsive cells, and found that the pattern of Wnt responsiveness varies with the hair cycle, and correlates with wound healing potential. Using Axin2(LacZ/LacZ) mice and an ear wound model, we demonstrate that amplified Wnt signaling leads to improved healing.

Wnt signaling and injury repair.

Wnt signaling is activated by wounding and participates in every subsequent stage of the healing process from the control of inflammation and programmed cell death, to the mobilization of stem cell reservoirs within the wound site. In this review we summarize recent data elucidating the roles that the Wnt pathway plays in the injury repair process. These data provide a foundation for potential Wnt-based therapeutic strategies aimed at stimulating tissue regeneration.

Density of human bone marrow stromal cells regulates commitment to vascular lineages.

Mechanisms underlying the vascular differentiation of human bone marrow stromal cells (HBMSCs) and their contribution to neovascularisation are poorly understood. We report the essential role of cell density-induced signals in directing HBMSCs along endothelial or smooth muscle lineages. Plating HBMSCs at high density rapidly induced Notch signaling, which initiated HBMSC commitment to a vascular progenitor cell population expressing markers for both vascular lineages.