Refinement of TSLP expression mediates chronic allodynia associated with IL22/STAT3 axis

Area of Science:

• Neuroscience
• Immunology
• Pharmacology

Background:

• Chronic allodynia results from maladaptive neuroplasticity in the central nervous system.
• Interleukin-22 (IL22) is a key mediator with both pro-inflammatory and immunosuppressive roles.
• Thymic stromal lymphopoietin (TSLP) is implicated in inflammatory and immune responses.

Purpose of the Study:

• To investigate the therapeutic potential of modulating TSLP expression for chronic allodynia.
• To elucidate the mechanisms underlying TSLP's role in allodynia, particularly its interaction with the IL22 pathway.
• To assess the neuroprotective effects of TSLP modulation in vitro.

Main Methods:

• Generated TSLP knockout (KO) mice and compared them with wild-type (WT) mice under bleomycin-induced allodynia conditions.
• Administered bleomycin to induce chronic allodynia and assessed gliosis, neuron loss, and mechanical withdrawal thresholds.
• Utilized differentiated human SH-SY5Y cells to evaluate TSLP's neuroprotective effects against hydrogen peroxide-induced neurotoxicity.

Main Results:

• Bleomycin-induced chronic allodynia in WT mice was associated with reduced IL22/STAT3 pathway activity, increased gliosis, and neuron loss.
• TSLP-deficient mice exhibited significantly reduced gliosis, neuron loss, and altered mechanical withdrawal thresholds compared to WT mice.
• TSLP deficiency protected SH-SY5Y cells from hydrogen peroxide-induced neurotoxicity, and IL22 stimulation further enhanced this protection.

Conclusions:

• A lack of TSLP decreases neuroinflammation, neurotoxicity, and chronic allodynia by downregulating TSLP receptor (TSLPR)/STAT5 and the IL22/STAT3 axis.
• Inhibiting TSLP can rescue the IL22/STAT3-mediated effects, regulating neuroglial interactions to alleviate chronic allodynia.
• Targeting the TSLP/TSLPR pathway presents a promising therapeutic strategy for chronic allodynia by mitigating gliosis, neuron loss, and neuroinflammation.