Page 94 - JCTR-11-4

Journal of Clinical and
Translational Research NADPH oxidase inhibition in a rodent stroke model

Moreover, when extrapolating these findings clinically, and tissue-level OS markers are a technical limitation,
the prevalence of comorbidities, particularly diabetes restricting exploration of specific localised functional
and hyperglycaemia, in patients must be considered. outcomes and cellular effects. Furthermore, using VAS2870
Approximately 30% of ischaemic stroke patients have to modulate both NOX2 and NOX4 prevented assessment
diabetes, and an additional 40% of stroke patients of isoform-specific contributions. In addition, despite in
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develop stress hyperglycaemia during hospitalization. 93,94 vitro evidence supporting NADPH oxidase inhibition, 45-47
These conditions profoundly affect vascular function and in vivo pharmacokinetics remain unconfirmed. Specifically,
are known to modulate NADPH oxidase activity and cerebrovascular and brain tissue concentrations are
OS burden. 95,96 This may likely impact responsiveness not well-established, considering BBB impermeability
to NADPH oxidase-targeted therapies and highlight and post-ischaemic BBB biphasic opening. 98-100 We
the importance of including comorbid groups in assumed VAS2870 reached the cerebrovasculature, and
preclinical studies. Thus, a key limitation of the present therefore vascular NADPH oxidase, through intravenous
study is our use of healthy, normoglycaemic animals, administration due to high bioavailability; however, this
restricting direct translatability. The multifaceted nature was not verified, nor was brain tissue penetration tested.
of stroke and heterogeneity in patient populations, These unconfirmed aspects highlight a need for future
including comorbidities, is a recognised challenge in the research to quantify VAS2870’s brain penetration and local
development of effective, clinically translatable stroke concentration. Furthermore, MRI technical difficulties
therapeutics, highlighted by the Stroke Therapy Academic limited accurate 48-h infarct localisation across the groups,
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Industry Roundtable criteria. Future preclinical studies preventing direct correlation with delayed tissue analysis
incorporating comorbid models are crucial to better and hindering assessment of within-infarct post-ischaemia
understand NADPH oxidase’s role in clinically relevant changes. Consequently, our analysis focused on established
contexts. Reinforcing the idea that combination therapies functional regions, the SC, 101,102 and areas highly susceptible
targeting multiple pathways, including anti-diabetic to ischaemic injury after MCAO, including the STR and
and anti-inflammatory treatments, may be essential for hippocampus CA1 region. 103,104 Neurogenesis was assessed
effective clinical translation. solely in the DG due to its inherent lifelong neurogenic
Several limitations, beyond those highlighted above, capacity. 105,106 This is a significant limitation, and future
should be acknowledged. This study utilised a single analysis within the damaged brain region is needed for a
VAS2870 dose, administration route and time point, more precise assessment of therapeutic VAS2870 efficacy
restricting dynamic understanding of VAS2870 action, by determining neurogenic and inflammatory biomarkers.
necessitating explorations of a variety of doses, time A further study limitation is that cognitive assessment
points, and routes, alongside pharmacokinetics, for a was restricted to only spatial working memory at a sub-
full understanding of its effectiveness and applicability acute time point using the Y-maze. The Y-maze tests
for ischaemic stroke. Considering the role vascular short-term spatial memory and relies on the natural
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NADPH oxidase isoforms contribute to vascular tone exploratory drive; animals can rapidly habituate, making
through ROS production, 24,25 understanding VAS2870’s it unsuitable for repeated longitudinal testing. It can also
effect on vascular tone through focal CBF analysis be influenced by environmental sensitivity, affecting the
would be beneficial to understanding its mechanism of reliability and reproducibility of outcome measures. Given
action at endothelial NADPH oxidase; however, only the Y-maze’s reliance on varied intrinsic curiosity, with no
confirmatory filament placement CBF readings were use of positive or negative stimuli, training, or visual cues,
taken. Consequently, a more comprehensive exploration and the limitations of the mNSS functional deficit score
of post-reperfusion cerebrovascular dynamics, through discussed earlier, future studies evaluating post-stroke
laser Doppler flowmetry or laser speckle contrast imaging, VAS2870 treatment should more thoroughly assess its
would provide valuable insights into VAS2870’s impact on impact on cognitive and functional deficits. This necessitates
vascular reactivity and overall reperfusion. Furthermore, incorporating a wider array of sensitive tests performed
within this study, direct measurements of tissue-level at varied and longer-term time points. For instance, the
OS, including ROS levels, BBB permeability and oedema radial arm maze has reported deficits up to 65 days post-
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measures, were not performed. Addressing these would MCAO. The adhesive removal test 80,110 more sensitively
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provide valuable mechanistic insights. Confirmatory assesses long-term sensorimotor deficits following mild
analysis of acute ROS levels and acute oxidative damage injury, and the foot fault test, together, could provide
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markers, such as lipid peroxidation, would validate a deeper understanding of cognitive, sensory, and motor
VAS2870’s action against NADPH oxidase. In addition, impairments. As highlighted, the study was conducted
the lack of region-specific analysis for infarct damage in healthy young adult male rats, lacking clinically

Volume 11 Issue 4 (2025) 88 doi: 10.36922/jctr.25.00018