Peripheral S100B Protein Levels in Five Major Psychiatric Disorders: A Systematic Review

Abstract

Five major psychiatric disorders: schizophrenia, major depressive disorder, bipolar disorder, autistic spectrum disorder, and attention-deficit/hyperactivity disorder, show a shared genetic background and probably share common pathobiological mechanisms. S100B is a calcium-binding protein widely studied in psychiatric disorders as a potential biomarker. Our systematic review aimed to compare studies on peripheral S100B levels in five major psychiatric disorders with shared genetic backgrounds to reveal whether S100B alterations are disease-specific. EMBASE, Web of Science, and PubMed databases were searched for relevant studies published until the end of July 2023. This study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis Protocols (PRISMA) guidelines. Overall, 1215 publications were identified, of which 111 full-text articles were included in the systematic review. Study designs are very heterogeneous, performed mostly on small groups of participants at different stages of the disease (first-episode or chronic, drug-free or medicated, in the exacerbation of symptoms or in remission), and various clinical variables are analyzed. Published results are inconsistent; most reported elevated S100B levels across disorders included in the review. Alterations in S100B peripheral levels do not seem to be disease-specific.

Astroglial Dysfunctions in Mood Disorders and Rodent Stress Models: Consequences on Behavior and Potential as Treatment Target

“…Indeed, post-mortem studies showed a reduced transcription of S100B in the PFC of MDD suicide completers [ 46 , 64 ] and a reduction in S100B+ cell density in the CA1 region of the hippocampus of MDD brains [ 65 ]. Although some studies described peripheral changes in serum S100B in MDD patients, this was not systematically found in MDD or across psychiatric disorders [ 65 , 66 , 67 , 68 ]. Although controversial results were reported between MDD severity and plasma/CSF S100B levels in different clinical studies [ 69 , 70 , 71 ], a meta-analysis showed significantly positive correlations between MDD severity and plasma/CSF S100B levels [ 67 ].…”

“…Moreover, high baseline S100B in serum was associated with a greater response to antidepressant treatment [ 72 ]. These findings suggest that S100B could also be a potential peripheral biomarker for stress-related mood disorders or treatment response [ 68 , 73 ]. However, this statement has to be taken with caution, as both increased and decreased levels were reported in MDD.…”

S100B actions on glial and neuronal cells in the developing brain: an overview

“…Moreover, the S100B protein is at the crossroads of several chronic pathological conditions of the nervous system; regardless of their origin, these disorders share aspects attributable to inflammation, including Alzheimer’s and Parkinson’s diseases, amyotrophic lateral sclerosis, multiple sclerosis, acute traumatic and vascular neural injury, and epilepsy. In experimental models of these diseases in general, overexpression/administration of S100B worsens the clinical presentation, while deletion/inactivation of the protein contributes to the improvement of symptoms of these diseases ( Kozlowski et al, 2023 ; Michetti et al, 2023 ).…”