Tau in Tauopathies That Leads to Cognitive Disorders and in Cancer

Tau is a copious microtubule-associated protein mainly expressed in neurons; it is also expressed in non-neuronal cells. Tauopathies are neurodegenerative diseases occurring mostly within the neuronal and glial cells of the central nervous system with a conspicuous tau pathology. In tauopathies, soluble tau disconnects from microtubules and forms abnormal, aggregated filamentous assemblies of hyperphosphorylated tau. Genetic, pathological and biochemical analyses have also proved that tau protein plays a major role in the pathogenesis of several tauopathies. Cognitive disorders are a type of psychological disorders that mainly distress observation, learning, memory, and problem elucidating. Among different cognitive disorders like amnesia, dementia, and delirium tauopathies mainly involve in dementia. Though tau is a neuronal protein, it is also expressed in various non-neuronal cells, like those of the liver, kidney and muscle. The activity of non-neuronal tau, especially in cancer cells, still needs to be elucidated; tau might have significant functions in non-neuronal cells. This chapter describes the associations between tauopathies and cancer