MiR-128-3p Alleviates Spinal Cord Ischemia/Reperfusion Injury Associated Neuroinflammation and Cellular Apoptosis via SP1 Suppression in Rat

Abstract

BackgroundNeuroinflammation and cellular apoptosis caused by spinal cord ischemia/reperfusion (I/R) injury result in neurological dysfunction. MicroRNAs (miRs) have crucial functions in spinal cord I/R injury pathogenesis according to previous evidences. Herein, whether miR-128-3p contributes to spinal cord I/R injury by regulating specificity protein 1 (SP1) was assessed.MethodsA rat model of spinal cord I/R injury was established by occluding the aortic arch for 14 min. Then, miR-128-3p’s interaction with SP1 was detected by dual-luciferase reporter assays. Next, miR-128-3p mimic and inhibitor, as well as adenovirus-delivered shRNA specific for SP1 were injected intrathecally for assessing the effects of miR-128-3p and SP1 on rats with spinal cord I/R injury. SP1, Bax and Bcl-2 expression levels in I/R injured spinal cord tissues were evaluated by Western blotting, while IL-1β, TNF-α, and IL-6 were quantitated by ELISA. Tarlov scores were obtained to detect hind-limb motor function. Evans blue (EB) dye extravasation was utilized to examine blood–spinal cord barrier (BSCB) permeability. Terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) staining was performed for neuronal apoptosis assessment.ResultsMiR-128-3p expression was decreased, while SP1 amounts were increased in rat spinal cord tissue specimens following I/R. SP1 was identified as a miR-128-3p target and downregulated by miR-128-3p. MiR-128-3p overexpression or SP1 silencing alleviated I/R-induced neuroinflammation and cell apoptosis, and improved Tarlov scores, whereas pretreatment with miR-128-3p inhibitor aggravated the above injuries.ConclusionOverexpression of miR-128-3p protects neurons from neuroinflammation and apoptosis during spinal cord I/R injury partially by downregulating SP1.

Inhibition of MALT1 Alleviates Spinal Ischemia/Reperfusion Injury-Induced Neuroinflammation by Modulating Glial Endoplasmic Reticulum Stress in Rats

“…Growing evidences have highlighted that the pathophysiology of SCI/R injury is linked to cerebrovascular dysfunction. [32][33][34] During SCI/R injury, disruption of the integrity of BSCB triggers infiltration of inflammatory cell at the injured area. Various pro-inflammatory cytokines are also produced by the neurovascular unit (for example: neurons, microglia and perivascular astrocyte) which further exacerbates neuroinflammation and BSCB damage.…”

Identification of the biological function of miR-9 in spinal cord ischemia-reperfusion injury in rats

“…Pretreatment with a synthesized miR-9 mimic (5′-UCUUUGGUUAUCUAGCUGUAUGA-3′), inhibitor (5′-TCATACAGCTAGATAACCAAAGA-3′) and negative control (NC) was previously described ( Li et al, 2015b ). Rats were intrathecally injected with 10 μl of the oligonucleotides (500 pmol/10 μl) and EntransterTM-in vivo transfection regent (Engreen, Beijing, China) ( Wang et al, 2020 ). Intrathecal injection was applied in vivo prior to ischemia induction once a day for three consecutive days according to the results of our preliminary experiment( Li et al, 2016b ; Li et al, 2015b ).…”

“…Notch2 siRNA or NC RNA were provided by Jima Inc. (Shanghai, China). For suppressing the expression of Notch2, two days before ischemia, intrathecal infusion of 5 μg of siRNA(5′- CCTCCCATCGTGACTTTCCAGCTTA-3′)or control RNA at a concentration of 1 μg/μl once a day was carried out, as directed by the manufacturer ( Chen et al, 2020b ; Meng et al, 2015 ; Wang et al, 2020 ).…”

“…Rats were assigned to four groups ( n = 8): (1) Sham group; (2) SCII group; (3) SCII+NC group; (4) miR-9 mimic group. miR-9 NC or miR-9 mimics was injected intrathecally prior to SCII induction once a day for three consecutive days in the SCII+NC group or miR-9 mimic group, respectively ( Li et al, 2015b ; Wang et al, 2020 ).…”

“…Rats were assigned to eight groups ( n = 8): (1)–(5) The first five groups are the same as those in Protocol II; (6) si-Notch2 + miR-9 inhibitor group; (7) si-Notch2 group; (8) siRNA NC group. In the si-Notch2 + miR-9 inhibitor group, except for miR-9 inhibitor pretreatment, si-Notch2 5 μg at a concentration of 1 μg/μl was injected intrathecally once a day for two consecutive days before SCII except for miR-9 inhibitor pretreatment ( Chen et al, 2020b ; Meng et al, 2015 ; Wang et al, 2020 ). si-Notch2 or siRNA NC was injected intrathecally prior to SCII induction once a day for two consecutive days in the si-Notch2 group or siRNA NC group, respectively.…”