Resumen:
Astrocytes are glial cells in the central nervous system (CNS) that play key roles in brain physiology, controlling processes, such as neurogenesis, brain energy metabolism and synaptic transmission. Recently, immune functions have also been demonstrated in astrocytes, influencing neuronal survival in the course of neuroinflammatory pathologies. In this regard, PKCepsilon (PKC¿) is a protein kinase with an outstanding role in inflammation. Our previous findings indicating that PKC¿ regulates voltage-dependent calcium channels as well as morphological stellation imply that this kinase controls multiple signalling pathways within astrocytes, including those implicated in activation of immune functions. The present study applies proteomics to investigate new protein targets of PKC¿ in astrocytes. Primary astrocyte cultures infected with an adenovirus that expresses constitutively active PKC¿ were compared with infection controls. Two-dimensional gel electrophoresis clearly detected 549 spots in cultured astrocytes, and analysis of differential protein expression revealed 18 spots regulated by PKC¿. Protein identification by mass spectrometry (nano-LC-ESI-MS/MS) showed that PKC¿ targets molecules with heterogeneous functions, including chaperones, cytoskeletal components and proteins implicated in metabolism and signalling. These results support the notion that PKC¿ is involved in astrocyte activation; also suggesting that multiple astrocyte-dependent processes are regulated by PKC¿, including those associated to neuroinflammation.
