miR-136-5p Regulates the Inflammatory Response by Targeting the IKKβ/NF-κB/A20 Pathway After Spinal Cord Injury

Abstract

Background/Aims: miR-136-5p participates in recovery after spinal cord injury (SCI) via an unknown mechanism. We investigated the mechanism underlying the involvement of miR-136-5p in the inflammatory response in a rat model of SCI. Methods: Sprague-Dawley rat astrocytes were cultured in vitro to construct a reporter plasmid. Luciferase assays were used to detect the ability of miR-136-5p to target the IKKβ and A20 genes. Next, recombinant lentiviral vectors were constructed, which either overexpressed miR-136-5p or inhibited its expression. The influence of miR-136-5p overexpression and miR-136-5p silencing on inflammation was observed in vivo in an SCI rat model. The expression of IL-1β, IL-6, TNF-α, IFN-α, and related proteins (A20, IKKβ, and NF-κB) was detected. Results: In vitro studies showed that luciferase activity was significantly activated in the presence of the 3’ untranslated region (UTR) region of the IKKβ gene after stimulation of cells with miR-136-5p. However, luciferase activity was significantly inhibited in the presence of the 3’UTR region of the A20 gene. Thus, miR-136-5p may act directly on the 3’UTR regions of the IKKβ and A20 genes to regulate their expression. miR-136-5p overexpression promoted the production of related cytokines and NF-κB in SCI rats and inhibited the expression of A20 protein. Conclusion: Overexpression of miR-136-5p promotes the generation of IL-1β, IL-6, TNF-α, IFN-α, IKKβ, and NF-κB in SCI rats but inhibits the expression of A20. Under these conditions, inflammatory cell infiltration into the rat spinal cord increases and injury is significantly aggravated. Silencing of miR-136-5p significantly reduces the protein expression results described after miR-136-5p overexpression and ameliorates the inflammatory cell infiltration and damage to the spinal cord. Therefore, miR-136-5p might be a new target for the treatment of SCI.

Comprehensive analysis of the differential expression profile of microRNAs in rats with spinal cord injury treated by electroacupuncture

“…Silencing of mir-136-5p significantly reduces these changes in protein expression and ameliorates the inflammatory cell infiltration and spinal cord damage. Therefore, mir-136-5p might be a new target for the treatment of Sci (45). in the present study, mir-136-5p expression was decreased in ea-treated Sci rats, compared with the Sci group.…”

“…Furthermore, mirna-136-5p upregulates p-nuclear factor κB (p-nF-κB) expression by downregulating a20 expression, which causes astrocytes to produce inflammatory factors and chemokine factors, thus aggravating Sci (59). recently, deng et al (45) found that il-1β, il-6, TnF-α, interferon-α, inhibitor of nuclear factor kappa B kinase subunit β, and nF-κB in Sci rats were upregulated, while a20 was downregulated following miR-136-5p overexpression. Under these conditions, inflammatory cell infiltration into the rat spinal cord increases, significantly aggravating injury.…”

“…To confirm the nGS results, five mirnas, rno-mir-219a-5p, rno-mir-486, rno-mir-136-5p, rno-mir-128-3p and rno-mir-7b, with high fold change and high abundance were selected as candidate mirnas and were screened as they or their target mrnas were involved in Sci recovery (45)(46)(47). compared with the Sci group, r no-mir-219a-5p, rno-miR-128-3p, and rno-miR-136-5p were significantly downregulated (P<0.05) in the sham and SCI+EA groups.…”

Cytokine profile as a marker of cell damage and immune dysfunction after spinal cord injury

“…Activated astrocytes are the main source of all these factors: they account for about 30% of all cellular components; overexpression of the microRNA miR-136-5p in these cells during SCI is one of the inducers of proinflammatory factors and chemokines (primarily TNF-α and IL-1β) [ 26 , 27 , 28 ]. This process triggers an inflammatory immune response involving type 17 T-helpers [ 29 ].…”

Galuteolin suppresses proliferation and inflammation in TNF-α-induced RA-FLS cells by activating HMOX1 to regulate IKKβ/NF-κB pathway

“…XAN signi cantly inhibited the proliferation of RA-FLS cells by inhibiting IκκB/NF-κB and downstream target proteins [16]. Silencing miR-136-5p signi cantly reduced the levels of IL-1, IL-6, TNF-α, IFN-α, IκκB and NF-κB and ameliorates the in ammatory cell in ltration and damage to the spinal cord [17]. These ndings indicated that the IKKβ/NF-κB signal pathway participated in the proliferation and in ammation in RA-FLS cells.…”