Reactive oxygen species (ROS) have physiological roles as second messengers, but can also exert detrimental modifications on DNA, proteins and lipids if resulting from enhanced generation or reduced antioxidant defense (oxidative stress). Venous thrombus (DVT) formation and resolution are influenced by ROS through modulation of the coagulation, fibrinolysis, proteolysis and the complement system, as well as the regulation of effector cells such as platelets, endothelial cells, erythrocytes, neutrophils, mast cells, monocytes and fibroblasts. Many conditions that carry an elevated risk of venous thrombosis, such as the Antiphospholipid Syndrome, have alterations in their redox homeostasis. Dietary and pharmacological antioxidants can modulate several important processes involved in DVT formation, but their overall effect is unknown and there are no recommendations regarding their use. The development of novel antioxidant treatments that aim to abrogate the formation of DVT or promote its resolution will depend on the identification of targets that enable ROS modulation confined to their site of interest in order to prevent off-target effects on physiological redox mechanisms. Subgroups of patients with increased systemic oxidative stress might benefit from unspecific antioxidant treatment, but more clinical studies are needed to bring clarity to this issue.

Neurological disorders are the leading cause of disability and the second largest cause of death worldwide. Despite significant research efforts, neurology remains one of the most failure‐prone areas of drug development. The complexity of the human brain, boundaries to examining the brain directly in vivo, and the significant evolutionary gap between animal models and humans, all serve to hamper translational success. Recent advances in microfluidic in vitro models have provided new opportunities to study human cells with enhanced physiological relevance. The ability to precisely micro‐engineer cell‐scale architecture, tailoring form and function, has allowed for detailed dissection of cell biology using microphysiological systems (MPS) of varying complexities from single cell systems to “Organ‐on‐chip” models. Simplified neuronal networks have allowed for unique insights into neuronal transport and neurogenesis, while more complex 3D heterotypic cellular models such as neurovascular unit mimetics and “Organ‐on‐chip” systems have enabled new understanding of metabolic coupling and blood–brain barrier transport. These systems are now being developed beyond MPS toward disease specific micro‐pathophysiological systems, moving from “Organ‐on‐chip” to “Disease‐on‐chip.” This review gives an outline of current state of the art in microfluidic technologies for neurological disease research, discussing the challenges and limitations while highlighting the benefits and potential of integrating technologies. We provide examples of where such toolsets have enabled novel insights and how these technologies may empower future investigation into neurological diseases.

Vascular ageing in conditions such as atherosclerosis, diabetes and chronic kidney disease, is associated with the activation of the renin angiotensin system (RAS) and diminished expression of antioxidant defences mediated by the transcription factor nuclear factor erythroid 2‐related factor 2 (Nrf2). The anti‐ageing hormone klotho promotes longevity and protects against cardiovascular and renal diseases. Klotho has been shown to activate Nrf2 and attenuate oxidative damage in neuronal cells, however, the mechanisms by which it protects against vascular smooth muscle cell VSMC dysfunction elicited by Angiotensin II (AngII) remain to be elucidated. AngII contributes to vascular ageing and atherogenesis by enhancing VSMC oxidative stress, senescence and apoptosis. This study demonstrates that soluble klotho (1 nM, 24 hrs) significantly induces expression of Nrf2 and the antioxidant enzymes haeme oxygenase (HO‐1) and peroxiredoxin‐1 (Prx‐1) and enhances glutathione levels in human aortic smooth muscle cells (HASMC). Silencing of Nrf2 attenuated the induction of HO‐1 and Prx‐1 expression by soluble klotho. Furthermore, soluble klotho protected against AngII‐mediated HASMC apoptosis and senescence via activation of Nrf2. Thus, our findings highlight a novel Nrf2‐mediated mechanism underlying the protective actions of soluble klotho in HAMSC. Targeting klotho may thus represent a therapeutic strategy against VSMC dysfunction and cardiovascular ageing.

Migration of adventitial fibroblasts, in addition to smooth muscle cell proliferation, plays a role in neointima formation following vascular injury. Previous studies have not directly addressed whether endogenous adventitial cells migrate towards the intima following balloon injury in the absence of medial dissection. We have employed an in vivo gene transfer technique to the rat carotid artery to directly label adventitial fibroblasts prior to balloon injury. An adenoviral vector coordinating expression of nuclear targeted beta-galactosidase (AdLacZ) suspended in pluronic gel was applied to the perivascular surface of left carotid arteries of male Sprague-Dawley rats. Balloon catheter mediated vascular injury was performed on these arteries 4 days later and animals killed at 3, 7 and 14 days after injury. Expression of LacZ up to 14 days after application of the adenovirus was restricted only to the adventitia of uninjured arteries and absent from untransfected right carotid arteries. However, following balloon catheter injury, LacZ positive cells were observed within the medial layer of vessels by 3 days, and contributed to the population of cells within the neointima at 7-14 days. Adventitial cells in uninjured arteries did not express smooth muscle alpha-actin but after injury, LacZ positive cells migrating towards the lumen exhibited alpha-actin immunostaining, suggesting their change to a myofibroblastic phenotype. These findings provide direct evidence that adventitial fibroblasts migrate and contribute to neointima formation after balloon injury and show that in vivo gene transfer to the adventitia results in sustained transgene expression capable of labelling migrating adventitial cells within the media and neointima of injured vessels.

Cu^(II)ATSM was developed as a hypoxia sensitive positron emission tomography agent. Recent reports have highlighted the neuroprotective properties of Cu^(II)ATSM, yet there are no reports that it confers cardioprotection. We demonstrate that Cu^(II)ATSM activates the redox-sensitive transcription factor Nrf2 in human coronary artery smooth muscle cells (HCASMC) and cardiac myocytes (HCM), leading to upregulation of antioxidant defense enzymes. Oral delivery of Cu^(II)ATSM in mice induced expression of the Nrf2-regulated enzymes in the heart and aorta. In HCASMC, Cu^(II)ATSM increased expression of the Nrf2 stabilizer DJ-1, and knockdown of Nrf2 or DJ-1 attenuated Cu^(II)ATSM-mediated heme oxygenase-1 and NADPH quinone oxidoreductase-1 induction. Pre-treatment of HCASMC with Cu^(II)ATSM protected against the pro-oxidant effects of angiotensin II (Ang II) by attenuating superoxide generation, apoptosis, proliferation and increases in intracellular calcium. Notably, Cu^(II)ATSM-mediated protection against Ang II-induced HCASMC apoptosis was diminished by Nrf2 knockdown. Acute treatment with Cu^(II)ATSM enhanced the association of DJ-1 with superoxide dismutase-1 (SOD1), paralleled by significant increases in intracellular Cu^(II) levels and SOD1 activity. We describe a novel mechanism by which Cu^(II)ATSM induces Nrf2-regulated antioxidant enzymes and protects against Ang II-mediated HCASMC dysfunction via activation of the Nrf2/DJ-1 axis. Cu^(II)ATSM may provide a therapeutic strategy for cardioprotection via upregulation of antioxidant defenses.