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Reference 1 Li X-Q, Chen F-S, Tan W-F, Fang Bo, Zhang Z-L, Ma H. Elevated microRNA-129-5p level ameliorates neuroinflammation and blood-spinal cord barrier damage after ischemia-reperfusion by inhibiting HMGB1 and the TLR3-cytokine pathway. Correction to: Elevated microRNA-129-5p level ameliorates neuroinflammation and blood-spinal cord barrier damage after ischemia-reperfusion by inhibiting HMGB1 and the TLR3-cytokine pathway Scale bars = 50 m. b Quantification of HMGB1 signals was performed based on the average of three independent images. c Quantification of HMGB1-positive neurons and microglia in the spinal cords at 48 h after IR. [Extracted from the article]

Background: Ischaemia reperfusion (IR) induces multiple pathophysiological changes. In addition to its classical role in regulating tumourigenesis, the feedback loop formed by p53 and its driven target p53-upregulated modulator of apoptosis (PUMA) was recently demonstrated to be the common node tightly controlling various cellular responses during myocardial IR. However, the roles of the p53-PUMA feedback loop in the spinal cord remain unclear. This study aimed to elucidate the roles of p53-PUMA feedback interactions in the spinal cord after IR, specifically investigating their regulation of caspase 3-mediated apoptosis and nuclear factor (NF)-κB-mediated cytokine release.Methods: SD rats subjected to 12 min of aortic arch occlusion served as IR models. Neurological assessment as well as p53 and PUMA mRNA and protein expression analyses were performed at 12-h intervals during a 48-h reperfusion period. The cellular distributions of p53 and PUMA were determined via double immunofluorescence staining. The effects of the p53-PUMA feedback loop on modulating hind-limb function; the number of TUNEL-positive cells; and protein levels of caspase 3, NF-κB and cytokines interleukin (IL)-1β and tumour necrosis factor (TNF)-α, were evaluated by intrathecal treatment with PUMA-specific or scramble siRNA and pifithrin (PFT)-α. Blood-spinal cord barrier (BSCB) breakdown was examined by Evans blue (EB) extravasation and water content analyses.Results: IR induced significant behavioural deficits as demonstrated by deceased Tarlov scores, which displayed trends opposite those of PUMA and p53 protein and mRNA expression. Upregulated PUMA and p53 fluorescent labels were widely distributed in neurons, astrocytes and microglia. Injecting si-PUMA and PFT-α exerted significant anti-apoptosis effects as shown by the reduced number of TUNEL-positive cells, nuclear abnormalities and cleaved caspase 3 levels at 48 h post-IR. Additionally, p53 colocalized with NF-κB within the cell. Similarly, injecting si-PUMA and PFT-α exerted anti-inflammatory effects as shown by the decreased NF-κB translocation and release of IL-1β and TNF-α. Additionally, injecting si-PUMA and PFT-α preserved the BSCB integrity as determined by decreased EB extravasation and spinal water content. However, injecting si-Con did not induce any of the abovementioned effects.Conclusions: Inhibition of aberrant p53-PUMA feedback loop activation by intrathecal treatment with si-PUMA and PFT-α prevented IR-induced neuroapoptosis, inflammatory responses and BSCB breakdown by inactivating caspase 3-mediated apoptosis and NF-κB-mediated cytokine release. [ABSTRACT FROM AUTHOR]

Spinal cord ischemia/reperfusion injury (SCII) is a severe complication driven by apoptosis and neuroinflammation. An increase in the expression of c‐Fos, a member of the AP‐1 family, is known as a neuronal activation marker in SCII. The AP‐1 family is composed of Jun, Fos, and is associated with the regulation of cytokines expression and apoptosis. Fra‐1 is a member of the Fos family, however, the contribution of Fra‐1 to SCII is still unclear. In our study, Fra‐1 was highly upregulated especially in neurons and microglia and promoted apoptosis by changing the expression of Bax/Bcl‐2 after SCII. Furthermore, we found that Fra‐1 directly regulated the transcription expression of S100A8. We demonstrated that knockdown of Fra‐1 alleviated S100A8 mediated neuronal apoptosis and inflammatory factor release, thus improved motor function after SCII. Interestingly, we showed that administration of TAK‐242, the TLR4 inhibitor, to the ischemia/reperfusion (I/R) injury induced rats suppressed the activation of the ERK and NF‐κB pathways, and further reduced Fra‐1 expression. In conclusion, we found that Fra‐1‐targeted S100A8 was expressed the upstream of Fra‐1, and the Fra‐1/S100A8 interaction formed a feedback loop in the signaling pathways activated by SCII. [ABSTRACT FROM AUTHOR]

Correction to: Inhibiting aberrant p53-PUMA feedback loop activation attenuates ischaemia reperfusion-induced neuroapoptosis and neuroinflammation in rats by downregulating caspase 3 and the NF- B cytokine pathway Reference 1 Li X-Q, Yu Q, Chen F-S, Tan W-F, Zhang Z-L, Ma H. Inhibiting aberrant p53-PUMA feedback loop activation attenuates ischaemia reperfusion-induced neuroapoptosis and neuroinflammation in rats by downregulating caspase 3 and the NF- B cytokine pathway. Scale bars = 50 m. d Quantification of PUMA-positive neurons, astrocytes and microglia was performed and presented as the average of three independent images. [Extracted from the article]

Background: Ischemia-reperfusion (IR) affects microRNA (miR) expression and causes substantial inflammation. Multiple roles of the tumor suppressor miR-129-5p in cerebral IR have recently been reported, but its functions in the spinal cord are unclear. Here, we investigated the role of miR-129-5p after spinal cord IR, particularly in regulating high-mobility group box-1 (HMGB1) and the Toll-like receptor (TLR)-3 pathway.Methods: Ischemia was induced via 5-min occlusion of the aortic arch. The relationship between miR-129-5p and HMGB1 was elucidated via RT-PCR, western blotting, and luciferase assays. The cellular distribution of HMGB1 was determined via double immunofluorescence. The effect of miR-129-5p on the expression of HMGB1, TLR3, and downstream cytokines was evaluated using synthetic miRs, rHMGB1, and the TLR3 agonist Poly(I:C). Blood-spinal cord barrier (BSCB) permeability was examined by measuring Evans blue (EB) dye extravasation and the water content.Results: The temporal miR-129-5p and HMGB1 expression profiles and luciferase assay results indicated that miR-129-5p targeted HMGB1. Compared with the Sham group, the IR group had higher HMGB1 immunoreactivity, which was primarily distributed in neurons and microglia. Intrathecal injection of the miR-129-5p mimic significantly decreased the HMGB1, TLR3, interleukin (IL)-1β and tumor necrosis factor (TNF)-α levels and the double-labeled cell count 48 h post-surgery, whereas rHMGB1 and Poly(I:C) reversed these effects. Injection of miR-129-5p mimic preserved motor function and prevented BSCB leakage based on increased Basso Mouse Scale scores and decreased EB extravasation and water content, whereas injection rHMGB1 and Poly(I:C) aggravated these injuries.Conclusions: Increasing miR-129-5p levels protect against IR by ameliorating inflammation-induced neuronal and BCSB damage by inhibiting HMGB1 and TLR3-associated cytokines. [ABSTRACT FROM AUTHOR]

Autophagy plays an important role in spinal cord ischemia reperfusion (I/R) injury, but its neuroprotective or neurodegenerative role remains controversial. The extent and persistence of autophagy activation may be the critical factor to explain the opposing effects. In this study, the different roles and action mechanisms of autophagy in the early and later stages after I/R injury were investigated in rats. The spinal cord I/R injury was induced by 14-min occlusion of the aortic arch, after which rats were treated with autophagic inhibitor (3-methyladenine, 3-MA) or agonist (rapamycin) immediately or 48 h following the injury. Autophagy markers, microtubule-associated protein light chain 3-II (LC3-II) and Beclin 1 increased and peaked at the early stage (8 h) and the later stage (72 h) after spinal cord I/R injury. Beclin 1 was mostly expressed in neurons, but was also expressed to an extent in astrocytes, microglia and vascular endothelial cells. 8 h after injury, rats treated with 3-MA showed a decrease in the hind-limb Basso–Beattie–Bresnahan (BBB) motor function scores, surviving motor neurons, and B-cell lymphoma-2 (Bcl-2) expression, and increase in the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL)-positive cells, Bcl-2-associated X protein (Bax), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) expression, and activation of microglia, while those treated with rapamycin showed opposing effects. However, 72 h after injury, rats treated with 3-MA improved the BBB scores, and the surviving motor neurons, and reduced the autophagic cell death, while those treated with rapamycin had adverse effects. These findings provide the first evidence that early activated autophagy alleviates spinal cord I/R injury via inhibiting apoptosis and inflammation; however later excessively elevated autophagy aggravates I/R injury through inducing autophagic cell death. [ABSTRACT FROM AUTHOR]