Johann Steiner, Hans-Gert Bernstein, Bernhard Bogerts
Department of Psychiatry, University of Magdeburg, Magdeburg, Germany
Carlos-Alberto Gonçalves
Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil

Abstract:

Background: Scientific evidence for increased S100B concentrations in the peripheral blood of acutely ill schizophrenia patients is consistent. In the past, this finding was mainly considered to reflect astroglial or blood-brain barrier dysfunction. Methods: Using Entrez, PubMed was searched for articles published on or before June 15, 2011, including electronic early release publications, in order to determine other potential links between S100B and current hypotheses for schizophrenia. Results: S100B is potentially associated with the dopamine and glutamate hypotheses. Supporting the glial hypothesis, an increased expression of S100B has been detected in cortical astrocytes of paranoid schizophrenia cases, while decreased oligodendrocytic expression has been observed in residual schizophrenia. Recently, the neuroinflammation hypothesis of schizophrenia has gained attention. S100B may act as a cytokine after secretion from glial cells, CD8+ lymphocytes and NK cells, activating monocytes and microglial cells. Moreover, S100B exhibits adipokine-like properties and may be dysregulated in schizophrenia due to disturbances in insulin signaling, leading to the increased release of S100B and free fatty acids from adipose tissue. Discussion: Dysregulation of pathways related to S100B appears to play a role in schizophrenia. However, S100B is expressed in different cell types and is involved in many regulatory processes. Currently, “the most important” mechanism related to schizophrenia cannot be determined.

Keywords:Schizophrenia, astrocyte, oligodendrocyte, glia, neuropil, neurodegeneration, dopamine, glutamate, blood-brain barrier, lymphocyte, NK-cell, adipocyte, glucose, insulin.