Skin and brain: common origins and common cures after trauma. In vivo experiment in mammals

Abstract

The skin and the CNS are both derived from ectoderm. Many factors used in skin healing should work for CNS injury. Factors including pH, collagen deposition rates, blood-clotting factors, immune response, formation of a basement membrane, basal lamina location and proximity to the lesion affect the ability of the skin to heal in the same way as in the CNS. Suramin has been shown to antagonize tenascin and GFAP production in astrocytes in the first three days after CNS injury in rats. This early intervention is something that we find extremely important in the success we have had in creating a permissive growth environment in the CNS. When studying skin scars and scarring (cicatrices), we look for models that can be used to draw parallels with scars in the CNS and other areas. As the body of evidence grows, similarities can be seen between the CNS and skin. In the CNS scarring produces a similar inflammatory response and migration of cells into the area as well as the walling off of the damaged area. The immune system then cleans up. Many of the components of the CNS scar are the same as the skin scar. However, the skin heals in a way that restores the original structure in many cases. In addition, the point of walling off and the disruption of the original tissue after the healing of a wound are very different in people who produce keloids when they heal. A keloid is a red, raised formation of fibrous scar tissue caused by excessive tissue repair in response to trauma or surgical incision. When keloids form the original structure is usually not regained and the area is numb due to the lack of reinnervation by sensory neurons. There is also great variation in the healing properties of the CNS. In some cases the scar is robust and a cyst forms, and in other cases the scar may be less and does not form a cyst. We report that we find similarities in the healing and scar disruption in the skin of nude mice and in the brains of hamsters using iron chelators and various healing materials.