Intrathecal Lentivirus-mediated Transfer of
Interleukin-10 Attenuates Chronic Constriction
Injury-induced Neuropathic Pain through Modulation
of Spinal High-mobility Group Box 1 in Rats
Authors: Zou Wangyuan 
Published: March 2021

Background: Neuropathic pain is a complex state of chronic pain that is usually accompanied by
peripheral and central nervous system damage or dysfunction. Previous studies have indicated that
neuroinflammation in the spinal cord is an important contributor to neuropathological and behavioral
abnormalities. A series of early inflammatory markers, such as IL-1, TNF-α, and IFN-γ, and advanced
inflammatory markers, such as high-mobility group box 1 (HMGB1), are involved in neuroinflammation.
Study Design: A randomized, double blind, controlled animal trial.
Objective: In this study, a lentivirus delivering human IL-10 (LV/hIL-10) was administered
intrathecally to determine the effects of IL-10 on allodynia and hyperalgesia in a chronic constriction
injury-induced (CCI) rat model of neuropathic pain.
Methods: Sprague-Dawley rats weighting 260 - 320 g were randomly divided into 4 groups.
Group Sham (Sham), Group CCI±Normal Saline (NS), Group CCI±LV/hIL-10 (LV/hIL-10), and Group
CCI±LV/control (vector). Rats in each group were intrathecally administered NS, LV/control, or
recombinant vector LV/hIL-10 in a total volume of 10 μl. Paw withdrawal mechanical thresholds
(PWMT) and paw withdrawal thermal latency PWTL were measured one day before CCI (baseline)
and 0, 3, 7, 14, and 28 days after intrathecal administration. Cerebrospinal fluid (CSF) samples
were collected during surgical plane anesthesia and the collected CSF samples were used to
assay for human IL-10, rat IL-1β, rat IL-6, and rat TNF-α by enzyme-linked immunosorbent assay
(ELISA). Animals were sacrificed and the L4-5 lumbar segment of the spinal cord was removed for
determination of green fluorescent protein (GFP) expression. Immunohistochemical analysis was
performed using anti HMGB1 antibodies and the expression of HMGB1 protein in the spinal cord
was determined by Western blot analysis after intrathecal delivery (n = 8 each).
Results: The results show that intrathecal LV/hIL-10 reverses enhanced pain states. Moreover,
the increased level of HMGB1 exhibited in a late stage of CCI was inhibited by exogenous
overexpression of hIL-10 in the CCI model. Expression of HMGB1, RAGE, and pAkt were lower
in CCI-induced rats treated with LV/hIL-10 than in those treated with LV/control (vector) or saline
(NS). Our results showed that IL-10 inhibits activation of the inflammatory HMGB1-RAGE pathway
in the CCI rat model.
Limitations: Further experimental investigations are needed to clarify the specific biological roles
played by HMGB1 in IL-10-mediated regulation of neuropathic pain.
Conclusion: Our results indicate that intrathecal lentiviral-mediated transfer of IL-10 attenuates
CCI-induced neuropathic pain in rats. The anti-thermal hyperalgesia and anti-mechanical allodynia
may be partly attributable to the decreased expression of HMGB1 and inhibition of HMGB1-RAGE
pathway.
Key words: Analgesia, interleukin-10, lentiviral, HMGB1, intrathecal, randomized, controlled trial