Validation of TREK1 ion channel activators as an immunomodulatory and neuroprotective strategy in neuroinflammation.

Modulation of two-pore domain potassium (K2P) channels has emerged as a novel field of therapeutic strategies as they may regulate immune cell activation and metabolism, inflammatory signals, or barrier integrity. One of these ion channels is the TWIK-related potassium channel 1 (TREK1). In the current study, we report the identification and validation of new TREK1 activators. Firstly, we used a modified potassium ion channel assay to perform high-throughput-screening of new TREK1 activators. Dose-response studies helped to identify compounds with a high separation between effectiveness and toxicity. Inside-out patch-clamp measurements of Xenopus laevis oocytes expressing TREK1 were used for further validation of these activators regarding specificity and activity. These approaches yielded three substances, E1, B3 and A2 that robustly activate TREK1. Functionally, we demonstrated that these compounds reduce levels of adhesion molecules on primary human brain and muscle endothelial cells without affecting cell viability. Finally, we studied compound A2 via voltage-clamp recordings as this activator displayed the strongest effect on adhesion molecules. Interestingly, A2 lacked TREK1 activation in the tested neuronal cell type. Taken together, this study provides data on novel TREK1 activators that might be employed to pharmacologically modulate TREK1 activity.

Shining the Light on You:: An Evidence-Based Program Designed to Improve the Health and Wellbeing of Family Child Care Professionals.

Objective: To design and assess the effectiveness of an evidence-based intervention to improve the health and wellbeing of family child care professionals. Methods: The early care and education (ECE) workforce, and family child care (FCC) educators in particular, face challenges to their wellbeing, mental and physical health. In addition, the demographics of the FCC workforce - disproportionately composed of low-income women of color - are associated with higher risk for chronic diseases. The Shining the Light on You program is designed to address FCC professional wellbeing in a feasible, evidence-based manner. The program includes weekly virtual sessions co-facilitated by a Board-Certified Health and Wellness Coach (HWC) and a Technical Assistance Coach (Early Childhood Specialist) and three individual coaching sessions with the HWC. HWC is built upon a foundation of behavior change theories, motivational strategies and effective communication approaches from psychology, medicine, public health and related fields. Using a mixed methods approach to gather data, participants from three initial cohorts of the program (n=33) implemented in Delaware reported improvement in health and wellbeing indicators. Results: Participants reported improvements in social support, physical activity and water consumption from pre- to post-program surveys. In interviews conducted with the participants following the program, participants consistently commented on the connections between all components of wellbeing and the importance of self-care. Conclusions: This model demonstrates the potential of integrating best practices from HWC and the ECE system.

Vasodilation of rat skeletal muscle arteries by the novel BK channel opener GoSlo is mediated by the simultaneous activation of BK and Kv 7 channels.

BACKGROUND AND PURPOSE: BK channels play important roles in various physiological and pathophysiological processes and thus have been the target of several drug development programmes focused on creating new efficacious BK channel openers, such as the GoSlo-SR compounds. However, the effect of GoSlo-SR compounds on vascular smooth muscle has not been studied. Therefore, we tested the hypothesis that GoSlo-SR compounds dilate arteries exclusively by activating BK channels. EXPERIMENTAL APPROACH: Experiments were performed on rat Gracilis muscle, saphenous, mesenteric and tail arteries using isobaric and isometric myography, sharp microelectrodes, digital droplet PCR and the patch-clamp technique. KEY RESULTS: GoSlo-SR compounds dilated isobaric and relaxed and hyperpolarised isometric vessel preparations and their effects were abolished after (a) functionally eliminating K+ channels by pre-constriction with 50 mM KCl or (b) blocking all K+ channels known to be expressed in vascular smooth muscle. However, these effects were not blocked when BK channels were inhibited. Surprisingly, the Kv 7 channel inhibitor XE991 reduced their effects considerably, but neither Kv 1 nor Kv 2 channel blockers altered the inhibitory effects of GoSlo-SR. However, the combined blockade of BK and Kv 7 channels abolished the GoSlo-SR-induced relaxation. GoSlo-SR compounds also activated Kv 7.4 and Kv 7.5 channels expressed in HEK 293 cells. CONCLUSION AND IMPLICATIONS: This study shows that GoSlo-SR compounds are effective relaxants in vascular smooth muscle and mediate their effects by a combined activation of BK and Kv 7.4/Kv 7.5 channels. Activation of Kv 1, Kv 2 or Kv 7.1 channels or other vasodilator pathways seems not to be involved.

Dietary salt promotes ischemic brain injury and is associated with parenchymal migrasome formation.

Sodium chloride promotes vascular fibrosis, arterial hypertension, pro-inflammatory immune cell polarization and endothelial dysfunction, all of which might influence outcomes following stroke. But despite enormous translational relevance, the functional importance of sodium chloride in the pathophysiology of acute ischemic stroke is still unclear. In the current study, we show that high-salt diet leads to significantly worse functional outcomes, increased infarct volumes, and a loss of astrocytes and cortical neurons in acute ischemic stroke. While analyzing the underlying pathologic processes, we identified the migrasome as a novel, sodium chloride-driven pathomechanism in acute ischemic stroke. The migrasome was previously described in vitro as a migrating organelle, which incorporates and dispatches cytosol of surrounding cells and plays a role in intercellular signaling, whereas a pathophysiological meaning has not been elaborated. We here confirm previously reported characteristics of the migrasome in vivo. Immunohistochemistry, electron microscopy and proteomic analyses further demonstrate that the migrasome incorporates and dispatches cytosol of surrounding neurons following stroke. The clinical relevance of these findings is emphasized by neuropathological examinations, which detected migrasome formation in infarcted brain parenchyma of human stroke patients. In summary, we demonstrate that high-salt diet aggravates stroke outcomes, and we characterize the migrasome as a novel mechanism in acute stroke pathophysiology.

Targeting Voltage-Dependent Calcium Channels with Pregabalin Exerts a Direct Neuroprotective Effect in an Animal Model of Multiple Sclerosis.

BACKGROUND/AIMS: Multiple sclerosis (MS) is a prototypical autoimmune central nervous system (CNS) disease. Particularly progressive forms of MS (PMS) show significant neuroaxonal damage as consequence of demyelination and neuronal hyperexcitation. Immuno-modulatory treatment strategies are beneficial in relapsing MS (RMS), but mostly fail in PMS. Pregabalin (Lyrica®) is prescribed to MS patients to treat neuropathic pain. Mechanistically, it targets voltage-dependent Ca2+ channels and reduces harmful neuronal hyperexcitation in mouse epilepsy models. Studies suggest that GABA analogues like pregabalin exert neuroprotective effects in animal models of ischemia and trauma. METHODS: We tested the impact of pregabalin in a mouse model of MS (experimental autoimmune encephalomyelitis, EAE) and performed histological and immunological evaluations as well as intravital two-photon-microscopy of brainstem EAE lesions. RESULTS: Both prophylactic and therapeutic treatments ameliorated the clinical symptoms of EAE and reduced immune cell infiltration into the CNS. On neuronal level, pregabalin reduced long-term potentiation in hippocampal brain slices indicating an impact on mechanisms of learning and memory. In contrast, T cells, microglia and brain endothelial cells were unaffected by pregabalin. However, we found a direct impact of pregabalin on neurons during CNS inflammation as it reversed the pathological elevation of neuronal intracellular Ca2+ levels in EAE lesions. CONCLUSION: The presented data suggest that pregabalin primarily acts on neuronal Ca2+ channel trafficking thereby reducing Ca2+-mediated cytotoxicity and neuronal damage in an animal model of MS. Future clinical trials need to assess the benefit for neuronal survival by expanding the indication for pregabalin administration to MS patients in further disease phases.