Neuroinflammatory status produced via activation of toll like receptor-4 (TLR-4) and
interleukin-17 receptor (IL-17R) is one of the principal mechanisms involved in dopaminergic neuronal loss in
Parkinson's disease (PD). Activation of TLR-4 and IL-17R stimulates
reactive oxygen species (ROS) and proinflammatory
cytokines (IL-17, IL-1β, TNFα, IL-6) production that augments neurodegeneration and reduces neuro-survival axis (TrKB/Akt/CREB/
BDNF). So, reducing IL-17-driven
neuroinflammation via
secukinumab,
monoclonal antibody against
IL-17A, may be one of therapeutic approach for PD. Moreover, the aim was extended to delineate the possible neuroprotective mechanism involved against neuronal loss in
rotenone induced PD in rats. Rats received 11
subcutaneous injection of
rotenone (1.5 mg/kg) every other day for 21 consecutive days and treated with 2
subcutaneous injections of
secukinumab (15 mg/kg) on day 9 and 15, one hour after
rotenone administration. Treatment with
secukinumab improved motor impairment and muscle
incoordination induced by
rotenone, as verified by open field and rotarod tests. Moreover,
secukinumab attenuated neuronal loss and improve histopathological profile. Noteworthy,
secukinumab reduces neuro-inflammatory status by hindering the interaction between IL and 17A and IL-17RA together with inhibiting the activation of TLR-4 and its downstream cascade including pS536-NFκB p65, IL-1β and HMGB-1. Additionally,
secukinumab stimulated neuro-survival signalling cascade via activation pY515-TrKB receptor and triggered upsurge in its downstream targets (pS473-Akt/pS133-CREB/
BDNF). Furthermore,
secukinumab increased striatal
tyrosine hydroxylase immunoexpression, the rate limiting step in
dopamine biosynthesis, to guard against dopaminergic neuronal loss. In conclusion,
secukinumab exerts a
neuroprotective effect against
rotenone induced neuronal loss via inhibition IL17A/IL17RA interaction and
HMGB-1/TLR-4/NF-κBp65/IL1β signalling cascade, together with activation of TrKB/ Akt/CREB/
BDNF axis.