Lesion-associated expression of transforming growth factor-beta-2 in the rat nervous system: evidence for down-regulating the phagocytic activity of microglia and macrophages.

The mechanisms that control the phagocytic activities of microglia and macrophages during disorders of the nervous system are largely unknown. In the present investigation, we assessed the functional role of transforming growth factor (TGF)beta2 in vitro and studied TGFbeta-2mRNA and protein expression in two CNS lesion paradigms in vivo characterized by fundamental differences in microglia/macrophage behaviour: optic nerve crush exhibiting slow, and focal cerebral ischemia exhibiting rapid phagocytic transformation. Furthermore, we used sciatic nerve crush injury as a PNS lesion paradigm comparable to brain ischemia in its rapid phagocyte response.