Making the patient voice heard in a research consortium: experiences from an EU project (IMI-APPROACH)

Abstract: APPROACH is an EU-wide research consortium with the goal to identify different subgroups of knee osteoarthritis to enable future differential diagnosis and treatment. During a 2-year clinical study images, biomarkers and clinical data are collected from people living with knee osteoarthritis and data are analyzed to confirm patterns that can indicate such different subgroups. A Patient Council (PC) has been set up at project initiation and consists of five people from Norway, The Netherlands and UK. Initially, this group of individuals had to learn how to effectively work with each other and with the researchers. Today, the PC is a strong team that is fully integrated in the consortium and acknowledged by researchers as an important sounding board. The article describes this journey looking at formal processes of involvement – organizational structure, budget, meetings – and more informal processes such as building relationships and changing researcher perceptions. It describes how the PC helped improve the experience and engagement of study participants by providing input to the clinical protocol and ensuring effective communication (e.g. through direct interactions with participants and newsletters). Furthermore, the PC is helping with dissemination of results and project advocacy, and overall provides the patient perspective to researchers. Additionally, the authors experienced and describe the intangible benefits such as a shift in researcher attitudes and a sense of community and purpose for PC members. Importantly, learnings reported in this article also include the challenges, such as effective integration of the PC with researchers’ work in the early phase of the project. Trial registration: US National Library of Medicine, NCT03883568, retrospectively registered 21 March 2019

Gene therapy in epilepsy: neuropeptides and neurotrophic factors

Temporal lobe epilepsy (TLE) is the most common form of epilepsy among adult patients, and the most problematic one as seizures cannot be controlled by currently available drugs in 30 % of patients. Gene therapy based on overexpression of endogenous anti-epileptic agents such as the neuropeptide galanin and the glial cell line-derived neurotrophic factor (GDNF) represents a promising new approach for treatment of TLE. Using this strategy, supply of the respective therapeutic agent is restricted to the brain structure where seizure suppression is both necessary and sufficient, without disturbing normal function in other brain areas. In the present thesis, the anti-epileptic potential of local gene therapy-based increase of galanin and GDNF was determined in different animal models for TLE, i.e., kindling and status epilepticus. Target areas for localised overexpression were the hippocampus, a common structure of seizure origin, and the piriform cortex (PC), an area important in seizure generalisation. Galanin was overexpressed either in transgenic mice (paper I), or in rats using a viral vector (paper II). GDNF gene therapy was based on in vivo transduction of endogenous cells by viral vector (papers III and IV) or on transplantation of in vitro-manipulated, encapsulated cells (paper V). The data collected in this thesis show that increased supply of galanin and GDNF in the PC and/or the hippocampus influenced in particular generalised seizure activity in different models for TLE. These findings demonstrate that gene therapy based on overexpression of galanin and GDNF represents a promising approach for control of epileptic seizures. However, in order to also achieve modulation of initial seizure threshold and overall epileptogenesis, the pathways of galanin and GDNF anti-epileptic effects have to be understood in more detail and gene transfer methods have to be modified accordingly to reach optimal temporal and spatial overexpression and release

VEGF receptor-2 (flk-1) overexpression in mice counteracts focal epileptic seizures.

Vascular endothelial growth factor (VEGF) was first described as an angiogenic agent, but has recently also been shown to exert various neurotrophic and neuroprotective effects in the nervous system. These effects of VEGF are mainly mediated by its receptor, VEGFR-2, which is also referred to as the fetal liver kinase receptor 1 (Flk-1). VEGF is up-regulated in neurons and glial cells after epileptic seizures and counteracts seizure-induced neurodegeneration. In vitro, VEGF administration suppresses ictal and interictal epileptiform activity caused by AP4 and 0 Mg(2+) via Flk-1 receptor. We therefore explored whether increased VEGF signaling through Flk-1 overexpression may regulate epileptogenesis and ictogenesis in vivo. To this extent, we used transgenic mice overexpressing Flk-1 postnatally in neurons. Intriguingly, Flk-1 overexpressing mice were characterized by an elevated threshold for seizure induction and a decreased duration of focal afterdischarges, indicating anti-ictal action. On the other hand, the kindling progression in these mice was similar to wild-type controls. No significant effects on blood vessels or glia cells, as assessed by Glut1 and GFAP immunohistochemistry, were detected. These results suggest that increased VEGF signaling via overexpression of Flk-1 receptors may directly affect seizure activity even without altering angiogenesis. Thus, Flk-1 could be considered as a novel target for developing future gene therapy strategies against ictal epileptic activity

Activity-dependent volume transmission by transgene NPY attenuates glutamate release and LTP in subiculum

Neuropeptide Y (NPY) gene transduction of the brain using viral vectors in epileptogenic regions can effectively suppress seizures in animals, and is being considered as a promising alternative treatment strategy for epilepsy. Therefore, it is fundamental to understand the detailed mechanisms governing the release and action of transgene NPY in neuronal circuitries. Using whole-cell recordings from subicular neurons, we show that in animals transduced by recombinant adeno-associated viral (rAAV) vector carrying the NPY gene, transgene NPY is released during high-frequency activation of CA1-subicular synapses. Released transgene NPY attenuates excitatory synaptic transmission not only in activated, but also in neighboring, non-activated synapses. Such broad action of transgene NPY may prevent recruitment of excitatory synapses in epileptic activity and could play a key role in limiting the spread and generalization of seizures

Galanin gene transfer curtails generalized seizures in kindled rats without altering hippocampal synaptic plasticity

Gene therapy-based overexpression of endogenous seizure-suppressing molecules represents a promising treatment strategy for epilepsy. Viral vector-based overexpression of the neuropeptide galanin has been shown to effectively suppress generalized seizures in various animal models of epilepsy. However, it has not been explored whether such treatment can also prevent the epileptogenesis. Using a recombinant adeno-associated viral (rAAV) vector, we induced hippocampal galanin overexpression under the neuron specific enolase promoter in rats. Here we report that in animals with galanin overexpression, the duration of electrographic afterdischarges was shortened and initiation of convulsions was delayed at generalized seizure stages. However, the hippocampal kindling development was unchanged. Short-term plasticity of mossy fiber-cornu ammonis (CA) 3 synapses was unaltered, as assessed by paired-pulse and frequency facilitation of field excitatory postsynaptic potentials (fEPSPs) in hippocampal slices, suggesting that despite high transgene galanin expression, overall release probability of glutamate in these synapses was unaffected. These data indicate that hippocampal rAAV-based galanin overexpression is capable of mediating anticonvulsant effects by lowering the seizure susceptibility once generalized seizures are induced, but does not seem to affect kindling development or presynaptic short-term plasticity in mossy fibers

GDNF released from encapsulated cells suppresses seizure activity in the epileptic hippocampus.

To date, a variety of pharmacological treatments exists for patients suffering epilepsy, but systemically administered drugs offer only symptomatic relief and often cause unwanted side effects. Moreover, available drugs are not effective in one third of the patients. Thus, more local and more effective treatment strategies need to be developed. Gene therapy-based expression of endogenous anti-epileptic agents represents a novel approach that could interfere with the disease process and result in stable and long-term suppression of seizures in epilepsy patients. We have reported earlier that direct in vivo viral vector-mediated overexpression of the glial cell line-derived neurotrophic factor (GDNF) in the rat hippocampus suppressed seizures in different animal models of epilepsy. Here we explored whether transplantation of encapsulated cells that release GDNF in the hippocampus could also exert a seizure-suppressant effect. Such ex vivo gene therapy approach represents a novel, more clinically safe approach, since the treatment could be terminated by retrieving the transplants from the brain. We demonstrate here that encapsulated cells, which are genetically modified to produce and release GDNF, can suppress recurrent generalized seizures when implanted into the hippocampus of kindled rats

NPY gene transfer in the hippocampus attenuates synaptic plasticity and learning.

Recombinant adeno-associated viral (rAAV) vector-induced neuropeptide Y (NPY) overexpression in the hippocampus exerts powerful antiepileptic and antiepileptogenic effects in rats. Such gene therapy approach could be a valuable alternative for developing new antiepileptic treatment strategies. Future clinical progress, however, requires more detailed evaluation of possible side effects of this treatment. Until now it has been unknown whether rAAV vector-based NPY overexpression in the hippocampus alters normal synaptic transmission and plasticity, which could disturb learning and memory processing. Here we show, by electrophysiological recordings in CA1 of the hippocampal formation of rats, that hippocampal NPY gene transfer into the intact brain does not affect basal synaptic transmission, but slightly alters short-term synaptic plasticity, most likely via NPY Y2 receptor-mediated mechanisms. In addition, transgene NPY seems to be released during high frequency neuronal activity, leading to decreased glutamate release in excitatory synapses. Importantly, memory consolidation appears to be affected by the treatment. We found that long-term potentiation (LTP) in the CA1 area is partially impaired and animals have a slower rate of hippocampal-based spatial discrimination learning. These data provide the first evidence that rAAV-based gene therapy using NPY exerts relative limited effect on synaptic plasticity and learning in the hippocampus, and therefore this approach could be considered as a viable alternative for epilepsy treatment. (c) 2008 Wiley-Liss, Inc

Hippocampal NPY gene transfer attenuates seizures without affecting epilepsy-induced impairment of LTP.

Recently, hippocampal neuropeptide Y (NPY) gene therapy has been shown to effectively suppress both acute and chronic seizures in animal model of epilepsy, thus representing a promising novel antiepileptic treatment strategy, particularly for patients with intractable mesial temporal lobe epilepsy (TLE). However, our previous studies show that recombinant adeno-associated viral (rAAV)-NPY treatment in naive rats attenuates long-term potentiation (LTP) and transiently impairs hippocampal learning process, indicating that negative effect on memory function could be a potential side effect of NPY gene therapy. Here we report how rAAV vector-mediated overexpression of NPY in the hippocampus affects rapid kindling, and subsequently explore how synaptic plasticity and transmission is affected by kindling and NPY overexpression by field recordings in CA1 stratum radiatum of brain slices. In animals injected with rAAV-NPY, we show that rapid kindling-induced hippocampal seizures in vivo are effectively suppressed as compared to rAAV-empty injected (control) rats. Six to nine weeks later, basal synaptic transmission and short-term synaptic plasticity are unchanged after rapid kindling, while LTP is significantly attenuated in vitro. Importantly, transgene NPY overexpression has no effect on short-term synaptic plasticity, and does not further compromise LTP in kindled animals. These data suggest that epileptic seizure-induced impairment of memory function in the hippocampus may not be further affected by rAAV-NPY treatment, and may be considered less critical for clinical application in epilepsy patients already experiencing memory disturbances