Akt3-Mediated Protection Against Inflammatory Demyelinating Disease

Area of Science:

• Neuroimmunology
• Cellular signaling
• Protein kinases

Background:

• Akt is a serine/threonine protein kinase regulating cellular processes; Akt3's role is less understood.
• Akt3 is primarily in the brain and influences brain size and response to injury.
• Akt3 deficiency exacerbates experimental autoimmune encephalomyelitis (EAE), suggesting a neuroprotective function.

Purpose of the Study:

• To investigate the specific role of Akt3 in neuroinflammation and neuronal integrity during EAE.
• To determine whether Akt3 signaling in different cell types (T-cells, neurons) affects EAE pathogenesis.

Main Methods:

• Utilized various mouse strains with manipulated Akt3 expression (knockout, enhanced activity, conditional deletion).
• Induced MOG-induced EAE to model inflammatory demyelinating disease.
• Assessed clinical scores, CNS inflammation, demyelination, axonal injury, and T-cell differentiation (iTregs).

Main Results:

• Enhanced Akt3 activity reduced EAE severity, delayed onset, and decreased CNS inflammation and axonal damage.
• Akt3 deficiency in CD4+ T-cells worsened EAE, increasing inflammation and reducing regulatory T-cells (FOXP3+).
• Akt3 deletion in neurons did not alter EAE outcomes, indicating Akt3's critical role in T-cells.

Conclusions:

• Akt3 signaling in T-cells is essential for maintaining central nervous system integrity during inflammatory demyelinating diseases.
• Akt3 plays a neuroprotective role in EAE by modulating T-cell responses and Treg differentiation.
• Targeting Akt3 in T-cells may offer therapeutic potential for neuroinflammatory conditions.