Suppression of the lncRNA TUG1 alleviates neuropathic pain in rats with chronic contractile injury via the miR-29b-3p/HMGB1 axis.

Introduction: The present research focused on the function of lncRNA taurine upregulated 1 (TUG1) in a rat neuropathic pain (NP) model constructed by chronic contractile injury (CCI).

Material and methods: Construction of the NP rat model was performed by CCI surgery. Paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) were applied to examine the NP behavior. RT-qPCR was established to explore the levels of TUG1, microRNA (miR)-29b-3p, and HMGB1. ELISA was carried out to evaluate the concentrations of interleukin (IL)-6, IL-1β, tumor necrosis factor α (TNF-α), IL-4, and IL-6. The underlying mechanisms of TUG1 were explored by RNA-binding protein immunoprecipitation (RIP) and dual-luciferase reporter (DLR) assay.

Results: TUG1 and HMGB1 were statistically elevated in the tissue of CCI rats, while miR-29b-3p was reduced. TUG1 competitively binds to miR-29b-3p to upregulate HMGB1 levels. Suppression of TUG1 persistently decreased PWL and PWT along with increased frequency of paw-lifting, whereas this alleviation was typically rescued by the abrogated miR-29b-3p. Analogously, knockdown of TUG1 inhibited CCI-induced overproduction of IL-6, IL-1β, and TNF-α, and reduction of IL-4 and IL-6, but this inhibition was partially abrogated by the reduction of miR-29b-3p.

Conclusions: Suppression TUG1 can alleviate NP hypersensitivity and neuroinflammation in CCI rats by competitively binding miR-29b-3p to weaken HMGB1.