Annexins as Neuroprotective Agents in the Central Nervous System

In the past ten years, experimental observations have accumulated that annexins, forming a family of homologous Ca2+- and membrane-binding proteins and represented in mammalian tissues by 12 subfamilies, are expressed in the central nervous system (CNS). Here, they exhibit multiple functions, including the role of neuroprotective agents. It was found that annexins may be related to some CNS pathologies and disorders. In addition, in vitro, they were found to bind neurotransmitter precursors and nucleotides. The nucleotide-binding properties of annexins included GTP-induced calcium channel activity. These properties suggest that some annexin isoforms may play the role of a coupling factor between calcium homeostasis and cellular metabolism in neurons and neuroendocrine cells, especially in light of the observation that annexins participate in nucleotide-dependent processes, such as vesicular transport in neurotransmitter release, and they also interact with nucleotide-binding proteins in brain.