Interleukin-10 provides direct trophic support to neurons

Area of Science:

• Neuroscience
• Immunology
• Cell Biology

Background:

• Interleukin-10 (IL-10) is an anti-inflammatory cytokine with known in vivo neuroprotective effects.
• The precise neuronal mechanisms of IL-10-mediated neuroprotection remain incompletely understood.

Purpose of the Study:

• To investigate the direct effects of IL-10 on primary neurons in culture.
• To elucidate the molecular pathways through which IL-10 confers neuroprotection.

Main Methods:

• Primary spinal cord neurons were cultured and treated with IL-10.
• Neuronal survival, signaling pathway activation (JAK/STAT, PI3K/AKT, NF-κB), and gene expression (Bcl-2, Bcl-xL) were assessed.
• Mechanisms of glutamate-induced neurotoxicity and IL-10's protective role were examined, including cytochrome c release and caspase activation.

Main Results:

• IL-10 demonstrated a direct trophic effect on spinal cord neurons, promoting survival.
• Activation of the neuronal IL-10 receptor provided trophic support and counteracted glutamate neurotoxicity.
• IL-10 activated JAK/STAT and PI3K/AKT pathways, upregulating Bcl-2 and Bcl-xL expression, and inhibiting cytochrome c release and caspase cleavage under stress.
• IL-10 activated the NF-κB pathway, enhancing p50/p65 translocation and DNA binding, with p50 being crucial for neuronal survival.

Conclusions:

• IL-10 exerts direct neurotrophic and neuroprotective effects on neurons, independent of its anti-inflammatory actions on other cells.
• The findings reveal novel intracellular signaling mechanisms, including JAK/STAT, PI3K/AKT, and NF-κB pathways, mediating IL-10's neuronal survival effects.
• IL-10 holds significant therapeutic potential for neurodevelopmental disorders and neuroprotection strategies.