MANF in the lateral septum dynamically regulates endoplasmic reticulum function in chronic stress response

Area of Science:

• Neuroscience
• Molecular Biology
• Psychiatry

Background:

• Major depressive disorder (MDD) is linked to chronic stress, but the underlying temporal molecular mechanisms are unclear.
• The lateral septum (LS) is a key brain region for processing stress responses.

Purpose of the Study:

• To investigate the dynamic molecular changes in the LS during the transition from acute to chronic stress.
• To identify key molecular players and pathways involved in stress-induced depressive phenotypes.

Main Methods:

• Longitudinal transcriptomic analysis of the LS in response to varying stress durations.
• Functional studies involving knockdown and overexpression of mesencephalic astrocyte-derived neurotrophic factor (MANF) in the LS.
• Assessment of endoplasmic reticulum (ER) stress, synaptic plasticity, and depressive-like behaviors.

Main Results:

• A biphasic transcriptomic response in the LS was observed: initial gene upregulation followed by downregulation under chronic stress.
• Persistent endoplasmic reticulum (ER) stress pathway activation, particularly the unfolded protein response, was identified.
• Mesencephalic astrocyte-derived neurotrophic factor (MANF) showed rapid acute upregulation and sustained chronic suppression, directly linking to ER dysfunction, impaired synaptic plasticity, and depressive behaviors.

Conclusions:

• The temporal dynamics of LS molecular reorganization are critical in MDD pathogenesis.
• MANF is a pivotal regulator connecting ER stress adaptation to neural circuit dysfunction in depression.
• Findings provide a mechanistic basis for developing early intervention strategies and biomarkers for MDD.