MicroRNA-7/Shank3 axis involved in schizophrenia pathogenesis

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Schizophrenia is a complex psychiatric disorder with poorly understood molecular mechanisms.
• MicroRNAs (miRNAs) are emerging as key regulators in neurological diseases.
• SHANK3 gene mutations are linked to neurodevelopmental disorders, suggesting its role in schizophrenia.

Purpose of the Study:

• To determine microRNA-7 (miR-7) expression differences between schizophrenia patients and healthy controls.
• To investigate the regulatory relationship between miR-7 and the SHANK3 gene in the context of schizophrenia.
• To explore the functional impact of miR-7 on neuronal morphology and function.

Main Methods:

• Quantitative polymerase chain reactions (qPCR) to measure miR-7 levels in plasma from 50 schizophrenia patients and 50 healthy controls.
• In vitro experiments using HT22 hippocampal neuron cell line with lentiviral vectors for miR-7 overexpression or knockdown.
• Measurement of SHANK3 mRNA and protein expression via qPCR and immunofluorescence.
• Luciferase reporter assay to confirm direct interaction between miR-7 and SHANK3.

Main Results:

• Circulating miR-7 levels were significantly higher in schizophrenia patients compared to healthy controls (p = 0.022).
• Overexpression of miR-7 led to suppressed SHANK3 expression (mRNA and protein).
• Knockdown of miR-7 resulted in significantly increased SHANK3 mRNA and protein levels.
• miR-7 directly binds to the 3-prime untranslated region of SHANK3 mRNA.

Conclusions:

• miR-7 directly targets and regulates SHANK3 gene expression.
• Altered miR-7 and SHANK3 interaction may contribute to neuronal morphology and function changes observed in schizophrenia.
• miR-7 represents a potential biomarker and therapeutic target for schizophrenia.