Preventing neuronal death after ischemic stroke (IS) is crucial for neuroprotective treatment, yet current management options are limited. Enriched environment (EE) is an effective intervention strategy that promotes the recovery of neurological function after cerebral ischemia/reperfusion (I/R) injury. Ferroptosis has been identified as one of the mechanisms of neuronal death during IS, and inhibiting ferroptosis can reduce cerebral I/R injury. Our previous research has demonstrated that EE reduced ferroptosis by inhibiting lipid peroxidation, but the underlying mechanism still needs to be investigated. This study aims to explore the potential molecular mechanisms by which EE modulates iron metabolism to reduce ferroptosis. The experimental animals were randomly divided into four groups based on the housing environment and the procedure the animals received: the sham-operated + standard environment (SSE) group, the sham-operated + enriched environment (SEE) group, the ischemia/reperfusion + standard environment (ISE) group, and the ischemia/reperfusion + enriched environment (IEE) group. The results showed that EE reduced IL-6 expression during cerebral I/R injury, hence reducing JAK2-STAT3 pathway activation and hepcidin expression. Reduced hepcidin expression led to decreased DMT1 expression and increased FPN1 expression in neurons, resulting in lower neuronal iron levels and alleviated ferroptosis. In addition, EE also reduced the expression of TfR1 in neurons. Our research suggested that EE played a neuroprotective role by modulating iron metabolism and reducing neuronal ferroptosis after cerebral I/R injury, which might be achieved by inhibiting inflammatory response and down-regulating hepcidin expression.

Enriched environment (EE) has been proven to be an effective intervention strategy which can improve neurofunctional recovery following cerebral ischemia/reperfusion (I/R) injury. However, it still needs further investigation for the underlying mechanisms. Recently, it has been shown that ferroptosis played an essential role in the pathophysiological development of ischemic stroke (IS). This study is aimed at investigating whether EE plays a neuroprotective role by attenuating ferroptosis after cerebral I/R injury. We used middle cerebral artery occlusion/reperfusion (MCAO/R) to build a model of cerebral I/R injury. To evaluate the effect of EE on neurological recovery, we used the modified neurological severity score (mNSS) and the Morris water maze (MWM). We used the western blot to detect the protein levels of glutathione peroxidase 4 (GPX4), hypoxia-inducible factor-1α (HIF-1α), and acyl-CoA synthetase long-chain family member 4 (ACSL4). We used the quantitative real-time PCR (qRT-PCR) to measure the mRNA levels of ACSL4 and inflammatory cytokines including tumor necrosis factor alpha (TNFα), interleukin-6 (IL-6), and interleukin 1 beta (IL-1β). The occurrence of ferroptosis was detected by TdT-mediated dUTP nick-end labeling (TUNEL) assay, diaminobenzidine- (DAB-) enhanced Perls staining, iron level assays, and malondialdehyde (MDA) level assays. The results verified that EE enhanced functional recovery and attenuated ferroptosis and neuroinflammation after cerebral I/R injury. EE increased the expression of HIF-1α while inhibited the expression of ACSL4. Our research indicated that EE improved functional recovery after cerebral I/R injury through attenuating ferroptosis, and this might be related to its regulation of the neuroinflammation and HIF-1α-ACSL4 pathway.

Background: Long non-coding RNA taurine-upregulated gene 1 (TUG1) is involved in various cellular processes, but its role in cerebral ischemia–reperfusion injury remains unclear. This study investigated TUG1’s role in regulating the nucleocytoplasmic shuttling of human antigen R (HuR), a key apoptosis regulator under ischemic conditions. Methods: CRISPR-Cas9 technology was used to generate TUG1 knockout Sprague Dawley rats to assess TUG1’s impact on ischemic injury. The infarct area and neuronal apoptosis were evaluated using TUNEL, hematoxylin and eosin (HE), and TTC staining, while behavioral functions were assessed. Immunofluorescence staining with confocal microscopy was employed to examine TUG1-mediated HuR translocation and expression changes in the apoptosis-related proteins COX-2 and Bax. Results: TUG1 knockout rats showed significantly reduced cerebral infarct areas, decreased neuronal apoptosis, and improved neurological functions compared to controls. Immunofluorescence staining revealed that HuR translocation from the nucleus to the cytoplasm was inhibited, leading to decreased COX-2 and Bax expression levels. Conclusions: TUG1 knockout reduces ischemic damage and neuronal apoptosis by inhibiting HuR nucleocytoplasmic shuttling, making TUG1 a potential therapeutic target for ischemic stroke.

Neuroplasticity plays a pivotal role in post‐stroke recovery, and Angelica sinensis polysaccharide has demonstrated neuroprotective properties. This study investigated the neuroprotective effects of low‐molecular‐weight Angelica sinensis polysaccharide (LMW‐ASP) in a rat middle cerebral artery occlusion/reperfusion (MCAO/R) model. Structural characterization revealed that LMW‐ASP (3.9 kDa), containing a pyranose ring and uronic acid, was a heteropolysaccharide that comprised fucose, galactosamine hydrochloride, rhamnose, arabinose, glucosamine hydrochloride, galactose, glucose, xylose, mannose, galacturonic acid, and glucuronic acid (0.007:0.003:0.057:0.209:0.009:0.284:0.303:0.006:0.032:0.083:0.007). Post‐stroke administration of LMW‐ASP (50 mg/kg) significantly improved body weight and neurological functions after MCAO/R. Moreover, microtubule‐associated protein‐2 expression was notably higher in the LMW‐ASP group than in the model group ( p < 0.01). Furthermore, Golgi‐Cox staining confirmed that LMW‐ASP increased the number of dendritic intersections ( p < 0.05 for 90–120, 180, and 200 μm; p < 0.001 for 70 and 80 μm), the number of terminal branches ( p < 0.01), the number of branch points ( p < 0.01), and the density of basal dendritic spines ( p < 0.05). Finally, transmission electron microscopy revealed an increase in the number of synapses ( p < 0.001) and presynaptic vesicles ( p < 0.001) in the LMW‐ASP group. These results suggest that LMW‐ASP is a potential pharmaceutical therapeutic approach for stroke recovery that enhances neuroplasticity.