Object: The present study investigated the role of hypoxia-inducible factor-1α (HIF-1α), aquaporin-4 (AQP-4), and matrix metalloproteinase-9 (MMP-9) in blood-brain barrier (BBB) permeability alterations and brain edema formation in a rodent traumatic brain injury (TBI) model.
Methods: The brains of adult male Sprague-Dawley rats (400-425 g) were injured using the Marmarou closed-head force impact model. Anti-AQP-4 antibody, minocycline (an inhibitor of MMP-9), or 2-methoxyestradiol (2ME2, an inhibitor of HIF-1α), was administered intravenously 30 minutes after injury. The rats were killed 24 hours after injury and their brains were examined for protein expression, BBB permeability, and brain edema. Expression of HIF-1α, AQP-4, and MMP-9 as well as expression of the vascular basal lamina protein (laminin) and tight junction proteins (zona occludens-1 and occludin) was determined by Western blotting. Blood-brain barrier disruption was assessed by FITC-dextran extravasation, and brain edema was measured by the brain water content.
Results: Significant (p < 0.05) edema and BBB extravasations were observed following TBI induction. Compared with sham-operated controls, the injured animals were found to have significantly (p < 0.05) enhanced expression of HIF-1α, AQP-4, and MMP-9, in addition to reduced amounts (p < 0.05) of laminin and tight junction proteins. Edema was significantly (p < 0.01) decreased after inhibition of AQP-4, MMP-9, or HIF-1α. While BBB permeability was significantly (p < 0.01) ameliorated after inhibition of either HIF-1α or MMP-9, it was not affected following inhibition of AQP-4. Inhibition of MMP reversed the loss of laminin (p < 0.01). Finally, while inhibition of HIF-1α significantly (p < 0.05) suppressed the expression of AQP-4 and MMP-9, such inhibition significantly (p < 0.05) increased the expression of laminin and tight junction proteins.
Conclusions: The data support the notion that HIF-1α plays a role in brain edema formation and BBB disruption via a molecular pathway cascade involving AQP-4 and MMP-9. Pharmacological blockade of this pathway in patients with TBI may provide a novel therapeutic strategy.
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http://dx.doi.org/10.3171/2010.6.JNS10207 | DOI Listing |
Cureus
December 2024
Internal Medicine, Pedro Hispano Hospital, Matosinhos Local Health Unit, Matosinhos, PRT.
Intracranial complications of otitis media are rare but pose a significant risk of morbidity and mortality. We report a case of a 27-year-old man with cognitive impairment who presented with fever, right-sided otalgia, otorrhea, and vomiting for three days. His neurological examination was unremarkable, and a brain computed tomography (CT) revealed right-sided otomastoiditis without intraparenchymal lesions.
View Article and Find Full Text PDFNMR Biomed
March 2025
Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands.
Gliomas are highly heterogeneous and often include a nonenhancing component that is hyperintense on T weighted MRI. This can often not be distinguished from secondary gliosis and surrounding edema. We hypothesized that the extent of these T hyperintense areas can more accurately be determined on high-quality 7 T MRI scans.
View Article and Find Full Text PDFBMC Neurol
January 2025
Neurological Disorder Center, Department of Cerebrovascular Disease, Suining Central Hospital, Sichuan, 629000, China.
Background: Hyponatremia (< 135 mmol/L) is the most common electrolyte disturbance in patients with stroke. However, few studies have reported the relationship between hyponatremia at admission and outcomes in patients with acute ischemic stroke (AIS) treated with mechanical thrombectomy (MT). This study is aimed to explore the association between hyponatremia and clinical outcomes following MT.
View Article and Find Full Text PDFSci Rep
January 2025
Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai, China.
Prediction of isocitrate dehydrogenase (IDH) mutation status and epilepsy occurrence are important to glioma patients. Although machine learning models have been constructed for both issues, the correlation between them has not been explored. Our study aimed to exploit this correlation to improve the performance of both of the IDH mutation status identification and epilepsy diagnosis models in patients with glioma II-IV.
View Article and Find Full Text PDFNovel Insights In presence of cardiotocographic features suspected for hypoxic insult, intrapartum ultrasound in the hands of experienced operators can demonstrate cerebral edema as an indirect sign of fetal hypoxia affecting the fetal CNS and exclude non-hypoxic conditions potentially leading to abnormalities of the fetal heart rate. Introduction Hypoxic-ischemic encephalopathy is a syndrome involving the fetal central nervous system as the result of a perinatal hypoxic-ischemic injury. To date, transfontanellar ultrasound represents the first line exam in neonates with clinical suspicion of HIE as it allows to show features indicating acute hypoxic injury and exclude potential non-hypoxic determinants of HIE, however there is no report concerning the sonographic assessment of the brain during labor.
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