Jul 2026· Biochimica et Biophysica Acta - General Subjects· pp.
130984
· 0 citations· 37 references
Medicine
TL;DR
Fosl2 or c-Jun knockdown reduced cerebral infarction volume, alleviated blood-brain barrier injury, and suppressed oxidative stress and ERS, thereby contributing to ICI.
Abstract
Objective
Ischemic cerebral infarction (ICI) results in high disability and mortality rates. This study aims to validate that the Fosl2/c-Jun dimer promotes ICI via the transcriptional activation of Lcn2.
Methods
Differentially expressed genes were identified and screened in the microvasculature of sham-operated and transient middle cerebral artery occlusion/reperfusion (tMCAO/R) mouse brains through bioinformatics analysis. Mouse models were established via tMCAO/R surgery, while mouse brain-derived Endothelial cells.3 (bEnd.3) were exposed to oxygen-glucose deprivation/reoxygenation (OGD/R). Fosl2 and c-Jun expression levels were detected, and their interaction was validated. Knockdown of Fosl2 or c-Jun was performed in tMCAO/R mice and bEnd.3 cells, followed by detection of AP-1 transcriptional activity, oxidative stress levels, infarct extent, blood-brain barrier integrity, and endoplasmic reticulum stress (ERS)-related proteins. The downstream target of Fosl2 was predicted using bioinformatics databases. Lcn2 expression was detected via RT-qPCR and Western blot. The transcriptional regulatory relationship was validated through dual-luciferase and ChIP assays.
Results
Fosl2, c-Jun, and Lcn2 were highly expressed in mouse and cell models of ICI. Fosl2 interacted with c-Jun, and the Fosl2/c-Jun dimer transcriptionally activated Lcn2 by binding to its promoter. Fosl2 or c-Jun knockdown reduced cerebral infarction volume, alleviated blood-brain barrier injury, and suppressed oxidative stress and ERS. Overexpression of Lcn2 partially attenuated the suppressive effects of Fosl2 or c-Jun knockdown.
Conclusion
Fosl2/c-Jun dimer induces Lcn2 transcription activation to promote oxidative stress and ERS, thereby contributing to ICI. This study reveals a potential mechanism for the clinical treatment of ICI.
The findings indicate that an increase in oxidative stress parameters arose at the earlier phase of ischemic neurodegenerative processes, while SREBP-1 expression increased in the mid-phase.
M. Dağdeviren, M. Işcan, P. Kelicen-Uğur· Turkish Journal of Biochemis...· 0 citations
Ischemic stroke is a prevalent cerebrovascular disease and remains a major cause of chronic disability and death worldwide. Runt-related transcription factor-1 (RUNX1) is a critical member of the core-binding factor family abnormally elevated in ischemic brain tissue. However, the exact roles of RUNX1 and its underlying cellular mechanisms in cerebral ischemia/reperfusion (I/R) injury have not been explored. Here we found that RUNX1 was highly expressed in brain tissues from middle cerebral artery occlusion (MCAO) mice and oxygen-glucose deprivation and reperfusion (OGD/R)-treated HT22 cells. In vivo experiments also showed that knockdown of RUNX1 significantly reduced the infarct volume and ameliorated neurological deficits in MCAO mice. Next, we investigated the exact mechanisms underlying the neuroprotective effect of si-RUNX1 against cerebral I/R injury. The results showed that knockdown of RUNX1 suppressed endoplasmic reticulum stress (ERS) and ERS-mediated neuroinflammation, as well as ferritinophagy and ferroptosis in both MCAO mice and OGD/R-treated HT22 cells. Mechanistically, RUNX1 directly targeted ELAV-like family protein 2 (CELF2) and regulated its transcription, therefore regulating the mTOR signaling. We also found that CELF2/mTOR mediated the inhibitory effects of si-RUNX1 on ERS-mediated inflammation and ferritinophagy-mediated ferroptosis both in vivo and in vitro. In summary, these data taken together revealed that si-RUNX1 suppressed ERS-mediated neuroinflammation and ferritinophagy-mediated ferroptosis through regulating the CELF2/mTOR signaling. These findings indicated that RUNX1/CELF2/mTOR might serve as therapeutic targets for cerebral I/R injury.
The activation of endoplasmic reticulum stress (ERS), specifically the PERK/eIF2α/CHOP signaling, is a recognized consequence of ischemic stroke. However, the roles and mechanisms of CRM‐1 regulating ERS in stroke are poorly elucidated. A murine model of stroke was generated via transient middle cerebral artery occlusion (MCAO). The endpoints included TTC‐derived infarct volume, H&E/TUNEL histopathology, p‐PERK immunohistochemistry, and Western blot. Oxygen–glucose deprivation/reoxygenation (OGD/R) was employed in HT22 neurons. The CRM1–ALKBH5 interaction and subcellular distribution were assessed by co‐immunoprecipitation (co‐IP), cytoplasm–nucleus fractionation, and confocal microscopy. m6A regulation of BANF1 was examined using MeRIP‐qPCR, RIP‐qPCR, and a dual‐luciferase reporter assay. Knockdown of CRM‐1 reduced the infarct size, decreased ER stress activation, decreased apoptosis in vivo, and improved cell viability after OGD/R. CRM‐1 was attached to ALKBH5 and promoted its export from the nucleus, which increased m6A modification and expression on BANF1. IGF2BP2 and YTHDF1, respectively, enhanced the stability and translation of BANF1 mRNA, thereby upregulating its expression. BANF1 overexpression restored PERK/eIF2α/CHOP activation and apoptosis in the CRM‐1 knockdown context. CRM‐1 exacerbated ischemic stroke injury by exporting ALKBH5 to upregulate BANF1 in an m6A‐IGF2BP2/YTHDF1‐dependent manner. This cascade subsequently activated the PERK/eIF2α/CHOP ERS pathway.
Chujuan Liu, Chen Li, Tingting Hu et al.· The FASEB Journal· 0 citations
Abstract Neonatal hypoxic-ischemic brain damage (HIBD) is a major cause of neurological disability. This study investigated the role of the transcription factor specificity protein 1 (SP1) and its target, Acyl-CoA Synthetase Long-Chain Family Member 4 (ACSL4), in regulating ferroptosis in neonatal HIBD. Using a neonatal mouse HIBD model and an in vitro neuronal oxygen-glucose deprivation/reperfusion (OGD/R) model, we applied gene knockdown/overexpression and pharmacological tools, analyzed via molecular and histological techniques. Ferroptosis was activated in HIBD. Hypoxic-ischaemic injury upregulated SP1, which transcriptionally activated ACSL4 by binding its promoter. SP1 knockdown attenuated neuronal and brain injury, reducing lipid peroxidation and iron accumulation while improving cell viability and cognitive function. These protections were abolished by ACSL4 overexpression or erastin co-treatment, and were associated with suppression of the ACSL4-dependent ferroptotic pathway. The SP1/ACSL4 axis critically aggravates neonatal hypoxic-ischaemic brain damage by promoting ferroptosis, representing a promising therapeutic target.
Shuting Chang, Weiqing Huang, Biao Yi et al.· ASN Neuro· 0 citations
Functional experiments revealed that silencing miR-9–5p protected against cerebral ischemia/reperfusion injury and suppressed NLRP3 inflammasome activation following IS, suggesting that its blockade could be a potential therapeutic strategy for ischemic brain injury.