Botfield, H. | Search bioRxiv

bioRxiv2025

Adult organotypic brain slice cultures recapitulate extracellular matrix remodelling in haemorrhagic stroke

1.Haemorrhagic stroke is a devastating condition characterised by vessel rupture and free blood within the brain parenchyma or cerebrospinal fluid (CSF) filled spaces. Across the major subtypes of haemorrhagic stroke (subarachnoid, intracerebral, and intraventricular haemorrhages), the presence of blood in the CSF generates significant tissue damage in the first 72 hours after the event, known as early brain injury (EBI). EBI includes neuroinflammation, blood-brain barrier breakdown and dysregulation of extracellular matrix (ECM) dynamics. ECM dysfunction has been shown to trigger fibrosis of the cortical blood vessels, limiting normal CSF circulation and resulting in the buildup of metabolic waste or the development of post-haemorrhagic hydrocephalus. Limiting or preventing this fibrosis may therefore reduce the rate of morbidity experienced by survivors, providing a potential avenue for non-surgical treatment to reduce secondary brain injury post-stroke. Despite this, current in vivo approaches fail to differentiate between the effect of blood products and secondary consequences including intracranial pressure (ICP) elevation and mass effect. Here, we describe an adult rat organotypic brain slice culture (OBSC) model of haemorrhagic stroke which enables the identification of the effect of blood products on ECM dysregulation. We demonstrate the distribution of key cell types across a time course of 0, 3 and 7 days in culture, indicating that such cultures are viable for a minimum of 7 days. Using immunofluorescence staining, Western blotting and RNA sequencing, we show that exposure of OBSCs to lysed blood markedly increases ECM deposition around cortical blood vessels. This is accompanied by dysregulation of ECM regulatory genes and upregulation of inflammation and oxidative stress-related genes, successfully recapitulating the changes seen in human stroke survivors. This versatile ex vivo model provides a translational platform to further understanding of haemorrhagic stroke pathophysiology and develop or trial novel therapeutics prior to progression to in vivo stroke studies.

neuroscience↗

bioRxiv2019

11β-Hydroxysteroid Dehydrogenase Type 1 inhibition in Idiopathic Intracranial Hypertension: a double-blind randomized controlled trial.

Treatment options for idiopathic intracranial hypertension are limited. The enzyme 11{beta}-hydroxysteroid dehydrogenase type 1 has been implicated in regulating cerebrospinal fluid secretion, and its activity is associated with alterations in intracranial pressure in idiopathic intracranial hypertension. We assessed therapeutic efficacy, safety and tolerability, and investigate indicators of in vivo efficacy of the 11{beta}-hydroxysteroid dehydrogenase type 1 inhibitor AZD4017 compared to placebo in idiopathic intracranial hypertension. A multicenter, UK, 16-week phase II randomized, double-blind, placebo-controlled trial of 12-weeks treatment with AZD4017 or placebo was conducted. Women aged 18 to 55 years with active idiopathic intracranial hypertension (>25cmH2O lumbar puncture opening pressure and active papilledema) were included. Participants received 400mg twice daily of oral AZD4017 compared to matching placebo over 12-weeks. The outcome measures were initial efficacy, safety and tolerability. The primary clinical outcome was lumbar puncture opening pressure at 12 weeks analysed by intention-to-treat. Secondary clinical outcomes were symptoms, visual function, papilledema, headache and anthropological measures. In vivo efficacy was evaluated in the central nervous system and systemically. 31 subjects (mean age 31.2 (SD=6.9) years and BMI 39.2 (SD=12.6) kg/m2) were randomized to AZD4017 (n=17) or placebo (n=14). At 12 weeks, lumbar puncture pressure was lower in the AZD4017 group (29.7 cmH2O) compared with placebo (31.3 cmH2O), but the difference between groups was not statistically significant (mean difference: -2.8, 95% confidence interval: -7.1-1.5; p=0.2). An exploratory analysis assessing mean change in lumbar puncture pressure within each group found a significant decrease in the AZD4017 group (mean change: -4.3 cmH2O (SD=5.7); p=0.009) but not in the placebo group (mean change: -0.3 cmH2O (SD=5.9); p=0.8). AZD4017 was safe, with no withdrawals related to adverse effects. Nine transient drug-related adverse events were reported. One serious adverse event occurred in the placebo group (deterioration requiring shunt surgery). In vivo biomarkers of 11{beta}-hydroxysteroid dehydrogenase type 1 activity (urinary glucocorticoid metabolites, hepatic prednisolone generation and CSF cortisone to cortisol ratios) demonstrated significant enzyme inhibition. This is the first phase 2 randomized controlled trial in idiopathic intracranial hypertension evaluating a novel therapeutic target. AZD4017 was safe, well-tolerated and inhibited 11{beta}-hydroxysteroid dehydrogenase type 1 activity in vivo. Possible clinical benefits were noted in this small cohort. A longer, larger study would now be of interest.

clinical trials↗