Aug 2026· Turkish Journal of Biochemistry· 0 citations· 59 references
TL;DR
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.
Abstract
Abstract Objectives Ischemic brain injury causes neurodegeneration. This study investigated the mechanism of neurodegeneration by examining the expression of transcription factors, sterol regulatory element-binding protein-1 (SREBP-1) and CCAAT enhancer-binding protein β (C/EBPβ), in a time course. Besides oxidative stress markers such as thiobarbituric acid-reactive substances (TBARS), total thiol molecule (TTM) levels, and superoxide dismutase (SOD), glutathione-S-transferase (GST) activities were also detected. Methods In adult male rats, carotid artery occlusion and hypotension were produced for 10 min. Control groups were sham-operated. Animals were sacrificed after 24 h, 1, 2, and 4 weeks of reperfusion periods. The expression of SREBP-1 and C/EBPβ in the rat brain cortex and cerebellum was examined by Western blotting. Results C/EBPβ expression significantly increased in both cytosolic (1.19-, 1.58-fold) and nuclear (1.73-, 1.81-fold) extracts of the brain cortex after 24 h and 1 week of reperfusion. In the cerebellum, C/EBPβ expression significantly increased in 1 week, cytosolic (1.63-fold), and nuclear (1.35-fold) extracts. SREBP-1 expression significantly increased in both cytosolic (2.07-fold) and nuclear (1.41-fold) extracts of the brain cortex after 1 week of reperfusion. SREBP-1 expression significantly increased in cytosolic (2.15-fold) and nuclear (1.79-fold) extracts of cerebellum after 1 week of reperfusion. In addition, TBARS levels and SOD activities significantly increased by 43.16 % and 47.30 %, respectively, after 24 h of reperfusion. Conclusions Our 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. C/EBPβ expressions were increased at early to mid-phases of reperfusion injury.
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.
Objective To investigate the neuroprotective effects of β-hydroxybutyrate (BHB) on cerebral ischemia–reperfusion injury (CIRI) and its underlying molecular mechanisms; to clarify the association between ketone bodies and the severity of CIRI under obese conditions. Methods CIRI rat model was established using modified middle cerebral artery occlusion/reperfusion (MCAO/R), while obesity was induced using high fat diet. BHB was administered via subcutaneous osmotic pumps. Lipopolysaccharide (LPS) was intraperitoneally injected to forcibly activate the nuclear factor-κB (NF-κB)/NOD-like receptor protein 3 (NLRP3) pathway. Neurological deficits were evaluated using the Zea–Longa 5-point scoring system. Serum BHB levels were measured by colorimetric assay. Immunofluorescence was performed to detect CD86 (M1 phenotype) and CD206 (M2 phenotype) levels. Inflammatory cytokines in brain tissues were measured. Levels of phosphorylated p65 (p-p65), cleaved caspase-1, and ionized calcium-binding adapter molecule 1 (Iba1) were analyzed by Western blotting. Results CIRI rats with obesity exhibited increased serum BHB levels, reduced neurological deficit scores, and markedly decreased infarct volumes. Moreover, levels of p-p65, cleaved caspase-1, Iba1, and pro-inflammatory cytokines, were decreased, while Iba1+CD206+ co-localization was increased. BHB treatment for CIRI rats with normal weight reduced neurological deficit scores, increased serum BHB, and decreased infarct volume. Following further LPS administration, neurological deficit scores and infarct volume were enhanced, with no difference in serum BHB levels. Conclusion Elevated endogenous BHB under obese conditions exerts neuroprotective effects against CIRI, and exogenous BHB can mimic this effect. Mechanistically, BHB inhibits activation of the NF-κB/NLRP3 pathway and promotes microglial polarization toward the anti-inflammatory M2 phenotype, thereby alleviating CIRI.
Qiong Chen, Shui Cheng, Chang Huang et al.· Frontiers in Neurology· 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.
Objective This study aimed to investigate the association between the HOTAIR-miR-9–5p axis and the inflammatory response in ischemic stroke (IS) and elucidate the underlying molecular mechanisms. Methods Middle cerebral artery occlusion/reperfusion (MCAO/R) and oxygen-glucose deprivation/reoxygenation (OGD/R) were applied to simulate ischemic/reperfusion conditions in vivo and in vitro. The expression levels of HOTAIR and miR-9–5p in the serum of patients or in the brain tissue of MCAO/R mice were assessed by qRT-PCR, and the secretion levels of IL-1β and IL-18 were analyzed by ELISA. Dual-luciferase reporter assays, RNA-binding protein immunoprecipitation (RIP), and RNA pull-down assays were performed to validate the target relationship. Western blotting was applied to assess the expression of NLRP3, CASP1, and FOXP1. Moreover, MCAO/R mice with intracerebroventricular injection of antagomir-9–5p were used to evaluate the effect of antagomir-9–5p on cerebral ischemia-reperfusion injury (CIRI). Results A significant association was observed between the HOTAIR-miR-9–5p axis and inflammation in both IS patients and MCAO/R mice. HOTAIR was abnormally expressed at a low level, whereas miR-9–5p and the associated protein NLRP3 inflammatory response were increased in the serum of IS patients, as well as in the brain tissue of MCAO/R mice and in SH-SY5Y cells. Mechanistically, miR-9–5p negatively regulated the expression of HOTAIR and FOXP1. Furthermore, HOTAIR was found to regulate NLRP3 expression via the miR-9–5p/FOXP1 pathway. Functional experiments revealed that silencing miR-9–5p protected against cerebral ischemia/reperfusion injury and suppressed NLRP3 inflammasome activation. Conclusion These findings collectively demonstrate that the HOTAIR/miR-9–5p/FOXP1 axis plays a critical role in NLRP3 inflammasome activation following IS, suggesting that its blockade could be a potential therapeutic strategy for ischemic brain injury.
Abstract Objective Astragalus polysaccharide (APS) has therapeutic potential for neurodegenerative diseases; however, its specific mechanism of action against ischemic stroke (IS) requires further elucidation. This study aimed to elucidate the protective effects of APS on neural tissue and to explore the underlying molecular pathways in a rat population subjected to middle cerebral artery occlusion (MCAO) Methods The animals received intraperitoneal (IP) injections of APS. Neurological recovery was assessed using neurobehavioral tests, and neuronal morphology was examined using Nissl staining. Then, we assessed the mRNA levels of IL-1β, IL-6, and TNF-α as well as the concentrations of oxidative stress-related substances. Finally, we evaluated the expression levels of Nrf2, Keap1, HO-1, and GPX4 through Western blotting and immunofluorescence. Results APS improved neurological function and ameliorated neuronal damage. It concurrently inhibited IL-1β, IL-6, and TNF-α expression while enhancing antioxidative potential. Mechanistically, APS induced an elevation in the levels of Nrf2, HO-1, and GPX4 proteins while concurrently causing a reduction in the protein levels of Keap1 in the striatum. Conclusions APS effectively mitigated neuronal damage and motor dysfunction after cerebral ischemia. The protective mechanism involves the activation of the Nrf2/HO-1 axis and subsequent suppression of oxidative stress and neuroinflammation.
Qi Wu, Jinzhong Ni, Hui Teng et al.· Drug Research· 0 citations
Intestinal ischemia/reperfusion (I/R) injury is a critical condition characterized by oxidative stress, inflammation, and apoptosis, leading to significant tissue damage. Imeglimin (IMEG), a novel antidiabetic agent, has recently shown cytoprotective effects through modulation of mitochondrial function, oxidative stress, and inflammatory pathways. We aimed to investigate the potential protective effects of IMEG against II/R injury and to explore the underlying mechanisms involved. Thirty-two adult male Wistar albino rats were divided into four groups; sham group, IMEG group, intestinal I/R group, IMEG + Intestinal I/R group. Oxidative stress markers [malondialdehyde (MDA), reduced glutathione (GSH)], and histopathological changes were assessed. Biochemical analyses included measurement of phosphorylated AMP-activated protein kinase (p-AMPK), NOD-like receptor protein 3 (NLRP3) and caspase-3. Also, gene expression of interleukin (IL)-1β, caspase-1, apoptotic Bcl-2-associated protein x (BAX) and anti-apoptotic B-cell leukemia/lymphoma 2 protein (Bcl-2) were measured. Nuclear factor-κB (NF-κB) immuno expression was estimated. MDA, NLRP3, caspase-3 levels, IL-1β, caspase-1, Bax gene expression, and NF-κB immunohistochemical expression were all significantly elevated in the intestinal I/R group while GSH, p-AMPK levels and Bcl-2 gene expression were significantly decreased. Every metric indicated a notable improvement with IMEG. IMEG exerts a protective effect against intestinal I/R injury through its antioxidant, anti-inflammatory, and anti-apoptotic properties (Fig. 1).
WY Abdelzaher, H. Khalaf, R. K. Saleh et al.· InflammoPharmacology· 0 citations