Potential roles for tumour necrosis factorα during embryonic development

This paper reviews the evidence indicating possible roles for tumour necrosis factor-alpha (TNFα) in development. It is proposed that TNFα may have essentially three major roles during embryonic development, which may be analogous to its roles in the immune system and during inflammation: a role in programmed cell death; a role as a cellular growth and differentiation factor; and also a role in the remodelling of extracellular matrix, and the regulation of cell adhesion molecules and integrins. The concept of the existence of a cytokine array during embryogenesis, analogous to that occurring in inflammation, is discussed, as well as potential roles for TNFα in the induction of ubiquitin; protective mechanisms embryonic cells may employ against TNFα-mediated cytotoxicity; and a consideration of the role TNFα may play in a "free radical theory of development".