title: Endoplasmic Reticulum Stress and Bipolar Disorder - Almost Forgotten Therapeutic Drug Targets in the Unfolded Protein Response Pathway Revisited.
abstract: Bipolar Disorder (BD) is characterized by recurring mood swings, which are not completely understood yet. So far, it is an accepted theory that multiple factors contribute to pathogenesis of BD according to the vulnerability-stressmodel. This model combines on the one hand biological predisposing vulnerability, and on the other hand several chronic and acute stressful negative events as underlying mechanisms of BD. Recently, ER (Endoplasmic Reticulum) stress reached the spotlight of BD research again. The expression of the chaperone BiP (syn. GRP78/glucose-regulated protein, 78kDa), which is highly expressed in the Endoplasmic Reticulum (ER), is upregulated by different kinds of mood stabilizers. These results implied that the ER, an organelle which is prone towards different kinds of cellular stress, might be involved in the pathophysiology of BD. This hypothesis was further strengthened by hypothesis driven genetic association studies, which showed significant association of BiP promotor polymorphisms with BD. Also other ER-stress associated genes like XBP1 (X-box binding protein 1) or GRP94 (glucose-regulated protein, 94kDa, synonym for heat shock protein HSP90B1) were recently linked to BD in hypothesis driven gene association studies. In addition to the proteins mentioned before, our review focuses on further UPR (Unfolded Protein Response) related proteins associated with BD and raises the hypothesis that ER-stress may represent a common interface between BD and obesity which is overrepresented in BD patients. Finally, members of the UPR pathway are discussed as putative targets for mood stabilizers.
authors.forename: Susanne A
authors.initials: SA
authors.lastname: Bengesser
authors.forename: Robert
authors.initials: R
authors.lastname: Fuchs
authors.forename: Nina
authors.initials: N
authors.lastname: Lackner
authors.forename: Armin
authors.initials: A
authors.lastname: Birner
authors.forename: Bernd
authors.initials: B
authors.lastname: Reininghaus
authors.forename: Nathalie
authors.initials: N
authors.lastname: Meier-Allard
authors.forename: Anika
authors.initials: A
authors.lastname: Stracke
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Kapfhammer
authors.affiliation: Department of Psychiatry, Medical University of Graz, Auenbruggerplatz 31, A-8036 Graz, Austria. eva.reininghaus@medunigraz.at.
authors.forename: Eva Z
authors.initials: EZ
authors.lastname: Reininghaus
authors.forename: Sandra
authors.initials: S
authors.lastname: Wallner-Liebmann
mesh_terms: D018692:Antimanic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy / Q000503:physiopathology*; D000091342:Endoplasmic Reticulum Chaperone BiP; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D058767:Protein Unfolding / Q000187:drug effects*; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D018692:Antimanic Agents; D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human