European Journal of Pharmacology

AimsIn the present research, we assessed the therapeutic effects of Exendin-4 (Ex-4) on rat models with spinal cord injury (SCI). Materials and methods36 male Sprague-Dawley rats were randomly allocated into three groups, including sham operation group, SCI group and SCI+Ex-4 group (Ex-4 treatment (10 {micro}g/rat) after SCI, i.p.). In the SCI group, a laminectomy was performed at the T10 vertebrae, followed by weight-drop contusion of the spinal cord. In the sham group, a laminectomy was carried out without SCI contusion. Key findingsOur results showed that Basso-Beattie-Bresnahan scale scores were significantly decreased after SCI, and were obviously improved in SCI rats with Ex-4 administration. Additionally, the water content of spinal cord in SCI group was dramatically increased than that in sham group, and after Ex-4 treatment, degree of edema of spinal cord was remarkably reduced. And also, concentration levels of inflammatory cytokines (IL-1, IL-1{beta}, IL-6 and TNF-) in the spinal cord were significantly elevated after SCI, and were remarkably reduced in SCI rats with Ex-4 administration. Subsequently, cell apoptosis rate in the injured spinal cord was significantly increased, and after Ex-4 treatment, cell apoptosis rate was remarkably decreased. We also revealed that levels of PCBP2 mRNA and protein were significantly up-regulated after SCI, and were dramatically dropped in SCI rats with Ex-4 administration. SignificanceTake altogether, our findings disclosed that Ex-4 plays a role in promoting neurological function recovery and inhibiting neuronal apoptosis through effecting PCBP2 expression in SCI rat models.

This study investigates the therapeutic effectiveness of intranasal dantrolene nanoparticles pretreatment to inhibit lipopolysaccharide (LPS)-induced pathological inflammation and synapse destruction and depressive and anxiety behavior in mice. B6SJLF1/J adult mice were pretreated with intranasal dantrolene nanoparticles (dantrolene: 5mg/kg), daily, Monday to Friday, 5 days per week, for 4 weeks. Then, mice were treated with intraperitoneal injection of LPS (5mg/kg) for one time. Behavioral tests for depression and anxiety were performed 24 hours after a one-time LPS injection. Biomarkers for pyroptosis-related inflammation cytokines (IL-1{beta} and IL-18) in blood and brains were measured using enzyme-linked immunosorbent assay (ELISA) and immunoblotting, respectively. The changes of primary proteins activation inflammatory pyroptosis (NLRP3: NLR family pyrin domain containing 3, Caspase-1, N-GSDMD: N terminal protein gasdermin D) and synapse proteins (PSD-95 and synpatin-1) in brains were measured using immunoblotting. Intranasal dantrolene nanoparticles robustly inhibited LPS-induced depression and anxiety behavior. Intranasal dantrolene nanoparticles significantly inhibited LPS-induced pathological elevation of IL-1{beta} and IL-18 in the blood and brain and inhibited LPS induced activation of pyroptosis. Intranasal dantrolene nanoparticles significantly ameliorated decrease of PSD-95 and synpatin-1 proteins in brains. Thus, intranasal dantrolene nanoparticles has demonstrated neuroprotection against inflammation mediated depression and anxiety behaviors and should be studied furthermore as a future effective drug treatment of major depression disorder or anxiety psychiatric disorder.

Neuropathic pain, a debilitating condition with unmet medical needs, can be charactarised as hyperexcitability of nociceptive neurons caused by dysfunction of ion channels. Voltage-gated potassium channel type 7 (Kv7), responsible for maintaining neuronal resting membrane potential and thus neuronal exitability, resides under tight control of G protein-coupled receptors (GPCR). Calcium-sensing receptor (CaSR) is a GPCR that is known to regulate activity of numerous ion channels, but whether CaSR could control Kv7 channel function has been unexplored until now. Our results demonstrate that CaSR is expressed in recombinant cell models, human induced pluripotent stem cell (hiPSC)-derived nociceptive-like neurons and mouse dorsal root ganglia neurons, and its activation induced depolarisation via Kv7.2/7.3 channel inhibition. The CaSR-Kv7.2/7.3 channel crosslink was mediated via the Gi/o protein/adenylate cyclase/cyclic adenosine monophosphate/protein kinase A signalling cascade. Suppression of CaSR function rescued hiPSC-derived nociceptive-like neurons from algogenic cocktail-induced hyperexcitability. To conclude, this study demonstrates that CaSR-Kv7.2/7.3 channel crosslink via the Gi/o protein signalling pathway effectively regulates neuronal excitability, providing a feasible pharmacological target for neuronal hyperexcitability management in neuropathic pain.

Cancer pain is a global public health problem. The mechanism of cancer pain is complex, and opioid analgesics, which are widely used clinically, have obvious addiction and side effects, which seriously affect patientslife functions and may aggravate their anxiety, depression and other negative emotions. Acupuncture has a history of thousands of years in China, and acupuncture analgesia has been confirmed by many studies. This study investigated whether electroacupuncture can alleviate abnormal pain in bone cancer pain (BCP) mouse models and its possible central mechanism. A bone cancer pain model was established by injecting Lewis lung cancer cells into the left femoral cavity of adult male mice. Mechanical paw withdrawal threshold was tested baseline before surgery and 1, 4, 7, 10, 14 and 21 days after surgery. On day 21, behaviours related to depression emotions were tested. After the behaviours, the femurs were removed to observe pathological changes, the neck was broken and brain tissue was collected from the basal lateral amygdala (BLA) area for subsequent Western Blot and ELISA experiments were performed to verify the expression of (stimulator of interferon genes, STING) STING/NF-{kappa}B pathway proteins and the expression of inflammatory factors. Immunofluorescence of Ionized calcium-binding adapter molecule-1 (Iba-1) and STING in the basal lateral amygdala (BLA) brain region was also performed. The results show that electroacupuncture can increase the pain threshold of the bone cancer pain model and alleviate the depressive-like emotional phenotype. Electroacupuncture inhibited the expression of STING/NF-{kappa}B pathway proteins, activation of microglia and release of inflammatory factors in the basal lateral amygdala (BLA) area. Therefore, this study shows that electroacupuncture may relieve bone cancer pain by regulating microglial activation and inflammatory factor release through the STING/NF-{kappa}B pathway.

Recurrent hypoglycemia increases cognitive impairment in diabetes mellitus patients. Following cerebral neuron injury, endothelial cells provide morphological, metabolic and immune support to damaged neurons. We investigated the inflammatory mechanism involved in hippocampal neuron degeneration. Behavioral experiments, including the open field test (OFT) and the Morris water maze test, were performed to measure cognitive changes. Using a vascular ring experiment, we evaluated vasodilation of the carotid artery. ZBP1 expression was knocked down after transfection with small interfering RNA in a brain endothelial cell line (bEnd3). In this study, PANoptosis, a recently defined form of programmed cell death (PCD), was found to be increased by hypoglycemia in the hippocampus of type 2 diabetic mice in vivo and by low glucose in bEnd3 cells in vitro. ZBP1 knockdown decreased PANoptosis induced by low-glucose stimulation in high-glucose-cultivated bEnd3 cells. RNA transcriptomics sequencing revealed that AGE-RAGE signaling significantly changed after ZBP1 was knocked down in bEnd3 cells. Corresponding biochemical data confirmed that ZBP1 knockdown regulated the advanced glycation end products (AGEs)-Receptor for Advanced Glycation End Products (RAGE) axis in bEnd3 cells. We present the first evidence that hypoglycemia impaired cognition in mice with type 2 diabetes by activating brain endothelial ZBP1-mediated PANoptosis via the AGE-RAGE axis. ARTICLE HIGHLIGHTSO_LIPANoptosis, a newly defined form of programmed cell death, is induced in the hippocampus after recurrent hypoglycemia in male db/db mice. C_LIO_LIZBP1, a sensor of the PANoptosome, was activated in low glucose cultured brain endothelial cells. C_LIO_LIHypoglycemia impairs vasodilation and cognitive function in type 2 diabetic mice. C_LIO_LIOur study indicates that inhibiting ZBP1-PANoptosis and the AGE-RAGE axis may be a potential approach to prevent hypoglycemia-induced cognitive degeneration in individuals with type 2 diabetes. C_LI

BackgroundEpidemiologic study suggests nicotine reduces risk of PD, could be potential treatment for Parkinsons disease. ObjectiveTo study the effect of nicotine on behavioral phenotypes and pathological characteristics of mice induced by human alpha-synuclein preformed fibers (-syn-PFF). MethodsMice were injected with 5 g of human -syn-PFF in the hippocampus while administering nicotine-containing drinking water (200g/mL). After 1 month, the motor ability, mood, spatial learning, and memory ability of the Parkinsons disease(PD)phenotype-like model were detected using open field, rotarod, Y maze, and O maze tests. The expression of pathological -syn, apoptotic proteins and the numbers of glial cells and neural stem cells in the hippocampus of mice were detected using western blotting and immunofluorescence. ResultsNicotine significantly reduced pathological -syn accumulation, -syn serine 129 phosphorylation and cell death caused by PFF injection in the hippocampus of mice, inhibited the increase of glial, microglia and apoptotic cells, decreased the expression levels of PI3K and Akt. ConclusionsNicotine may have inhibitory effects on human -syn-PFF-induced neuroinflammation and apoptosis. Thus, it reduces human -syn-PFF-induced behavioral deficits and pathological changes in mice.

ObjectiveElectroacupuncture has demonstrated beneficial effects in post-stroke motor dysfunction, yet the molecular mechanisms underlying its therapeutic efficacy remain incompletely understood. This study aims to investigate whether electroacupuncture promotes post-stroke motor function recovery by modulating the interaction between miR-124-3p and the NRG1/ErbB4 signaling pathway, specifically exploring whether miR-124-3p directly targets NRG1 to regulate neural plasticity in a focal cerebral ischemia rat model. MethodsThe ischemic stroke model was established by middle cerebral artery occlusion/reperfusion (MCAO/R) in adult rats. These rats were randomly divided into sham, model, electroacupuncture and model plus miR-124-3p inhibitor groups. The model group, electroacupuncture group and model plus miR-124-3p inhibitor group received EA intervention 24 h after modelling for 7 consecutive days. Behavioural function was assessed by Zea Longa score and mechanical pain rating. Hippocampal damage was detected by HE staining and neuronal apoptosis was observed by TUNEL staining. IL-1{beta} and IL-18 levels were measured by ELISA. PCR and Western blotting were used to detect the expression of miR-124-3p and inflammatory pathway proteins. The interaction between miR-124-3p and TLR4 was verified by dual-luciferase reporter assay. ResultsElectroacupuncture improved motor function in rat model of MCAO/R, as evidenced by improved Zea Longa scores and decreased mechanical withdrawal thresholds. Electroacupuncture significantly attenuated neuronal damage and also inhibited the inflammatory response by decreasing IL-18 and IL-1{beta} levels (P < 0.001). Notably, electroacupuncture upregulated miR-124-3p expression (P < 0.0001) and activated the NRG1/ErbB4 signaling pathway in the hippocampus. When miR-124-3p was inhibited, NRG1 protein expression decreased while GABA expression tended to increase. Dual-luciferase reporter assays confirmed that miR-124-3p directly targets the 3UTR of NRG1 mRNA and regulates its expression at the translational level. These findings suggest that electroacupuncture may alleviate neuronal and axonal damage by modulating miR-124-3p/NRG1/ErbB4 signalling and regulating GABA release. ConclusionElectroacupuncture can ameliorate motor dysfunction induced after brain I/R injury by targeting and modulating the NRG1-ErbB4 signaling pathway via miR-124-3p. These data are expected to provide new insights into the mechanisms of electroacupuncture for the prevention of potential targets for the recovery of motor dysfunction after stroke.

Diabetes Mellitus (DM) is a rapidly increasing disease around the world. It is known that DM is associated with numerous complications which affect life quality by its debilitating nature. DM is associated with cognitive impairment and neurodegeneration, partly driven by neuroinflammation and disrupted neuronal signalling. Incretin-based treatments have recently been suggested to exert potential effects on the central nervous system in diabetic patients. However, the triple agonist of GIP/GLP-1/GCG Retatrutides effects on cognition under diabetic conditions remain unexplored. This study aims to reveal whether impaired cognitive performance, such as learning and memory, is ameliorated by Retatrutide treatment in diabetic rats, together with associated metabolic, inflammatory and histological changes. Male Sprague-Dawley rats were allocated to four groups: control (C), streptozotocin-induced diabetic (STZ), streptozotocin-induced diabetic rats treated with Retatrutide (STZR), and sham rats treated with Retatrutide alone (R). DM was induced by streptozotocin injections. Spatial learning and memory were assessed using the Morris Water Maze and Passive Avoidance tests. Metabolic parameters were monitored, while neuroinflammatory markers (IL-1{beta}, TNF-), neurotrophic-related gene expression (BDNF, CREB, AKT), Tau protein levels, and histopathological changes in the cortex and hippocampus were evaluated using molecular, biochemical, and histological analyses. Streptozotocin-induced diabetes resulted in persistent hyperglycaemia, total body weight loss, impaired learning and memory. Retatrutide treatment reduced blood glucose levels without achieving a full euglycaemia or preventing weight loss. Behavioural tests showed that Retatrutide treatment preserved spatial learning and short-term memory compared to untreated animals. These effects were accompanied by attenuation of neuroinflammatory responses, particularly reduced TNF- levels, trends toward preserved neurotrophic-related transcriptional profiles, and partial maintenance of cortical and hippocampal structural integrity. Retatrutide alone did not enhance cognitive performance beyond control levels. These findings support the hypothesis that triple agonists may exert beneficial effects on cognitive performance under diabetic conditions. Retatrutide alleviates DM-associated cognitive impairment in streptozotocin-induced diabetic rats and is associated with reduced neural inflammatory burden and protected neuroanatomical structure. The observed cognitive benefits appear to extend beyond metabolic regulation alone. Further studies in models more closely reflecting type 2 diabetes are warranted to clarify the underlying mechanisms and translational relevance.

Alzheimers disease (AD) is the most common form of dementia. AD has a physical, emotional, and economic impact on the patients and their families and society at large. More than a decade since its discovery, there is still no available treatment. {Delta}9-tetrahydrocannabinol (THC) is emerging as a promising therapeutic agent. Using THC in conventional-high doses may have deleterious effects. Therefore, we propose to use an ultra-low dose of THC (ULD-THC). We previously published that a single injection of ULD-THC elevated Sirtuin-1 (Sirt-1) levels in the brain and ameliorated cognitive functioning in several models of brain injuries as well as in naturally aging mice. Our working hypothesis suggests that ULD-THC can prevent and even reverse AD pathology. In this preliminary study, we saw that a single injection of ULD-THC alleviated cognitive impairments of a mice model for AD, 5xFAD mice. Our work may establish the foundations for the development of a pharmaceutical preparation for the treatment of AD patients, thus, bringing the ULD-THC treatment closer to clinical application.

The medial prefrontal cortex (mPFC) belong to the neural circuitry responsible for the behavioral responses to antidepressants in humans or animals. In the forced swimming (FST), a predictive test for antidepressants in laboratory rodents, inhibition, or stimulation of mPFC may produce antidepressant-like, unlike or no behavioral effect at all. Controversial findings may result from the variety of subregions of mPFC controlling behaviour of rats in the FST. The aim in the present study was to estimate the contribution of subregions of the mPFC to the control of rat behavior in the FST. For an unbiased view and well-powered analysis of the mentioned effects, a systematic review at Medline (Pubmed) followed by a meta-analysis was performed. Compared to other subdivisions, inhibition of prelimbic or infralimbic mPFC caused a significant drop of immobility time in the FST, which is an antidepressant-like effect. Summarizing, prelimbic or infralimbic cortices seem more relevant than other subregions to the control of immobility in the FST underlying the effects of antidepressants on mood and behaviour.

Post-traumatic stress disorder (PTSD) is a mental health disorder triggered by the exposure to a traumatic event that manifests with anguish, intrusive memories and negative mood changes. So far, there is no efficient treatment for PTSD other than symptomatic palliative care. Based on the implication of the functional amyloid cytoplasmic polyadenylation element binding protein-3 (CPEB3) in the consolidation of memory, we propose its active amyloid state as a possible therapeutic target by blocking the consolidation of traumatic memories through polyglutamine binding peptide 1 (QBP1), an inhibitor of the amyloid oligomerization previously investigated in Drosophila. To test this idea in mammals, here we have developed a transgenic mouse that constitutively expresses QBP1 peptide. We first assessed the innocuousness of this peptide for the normal development of the animal, which also showed normal locomotor activity and anxiety. By performing a battery of standard memory paradigms, we then showed that hippocampal-dependent and aversive memories were impaired in the QBP1 mice. Furthermore, protein expression in the hippocampi of experienced mice showed that QBP1 mice do not increase their levels of amyloid oligomerization, evincing the blockade of the CPEB3 protein in its inactive state. The ability of QBP1 to block aversive memories in mice represents the proof of concept of a novel pharmacological approach for prophylaxis and therapy of acute stress and post-traumatic stress disorders.

Williams-Beuren syndrome (WBS) is a rare genetic multisystemic disorder characterized by mild to moderate intellectual disability and hypersocial phenotype, while the most life-threatening features are cardiovascular abnormalities. Nowadays, there are no available treatments to ameliorate the main traits of WBS. The endocannabinoid system (ECS), given its relevance for both cognitive and cardiovascular function, could be a potential druggable target in this syndrome. We analyzed the components of the ECS in the complete deletion (CD) mouse model of WBS and assessed the impact of its pharmacological modulation in key phenotypes relevant for WBS. CD mice showed the characteristic hypersociable phenotype with no preference for social novelty and poor object-recognition performance. Brain cannabinoid type-1 receptor (CB1R) in CD male mice showed alterations in density and coupling with no detectable change in main endocannabinoids. Endocannabinoid signaling modulation with sub-chronic (10 d) JZL184, a selective inhibitor of monoacylglycerol lipase (MAGL), specifically normalized the social and cognitive phenotype of CD mice. Notably, JZL184 treatment improved cardiac function and restored gene expression patterns in cardiac tissue. These results reveal the modulation of the ECS as a promising novel therapeutic approach to improve key phenotypic alterations in WBS.

Chronic pain is a debilitative disease affecting 1 in 5 adults globally1. The current understanding of chronic pain remains inadequate, coupled with few available therapeutics for the treatment of associated mental health disorders. Cellular homeostasis is crucial for normal bodily functions and investigation at the cellular levels may reveal a better understanding of the processes that occur leading to the development of chronic pain. Using the spared nerve injury (SNI) model of neuropathic pain, we found that adult male mice with impaired BECLIN-1 function show enhanced mechanical and thermal hypersensitivity compared to wildtype controls. Remarkably, we found that while SNI induced increases in anxiety-like behaviours in wildtype mice, this was not observed in mice with impaired BECLIN-1 protein function. Our data thus indicates that BECLIN-1 is differentially involved in the nociceptive and emotion related effects of chronic neuropathic pain.

Patients with traumatic brain injury (TBI) frequently exhibit heightened pain and associated complications such as cognitive decline, depression, and anxiety. GPR37 is widely expressed in various brain regions, but its function remains largely unclear. We recently discovered neuroprotectin D1 (NPD1) as a novel GPR37 ligand. In this study, we examined the protective role of the NPD1/GPR37 signaling pathway in TBI-induced neuropathic pain and its complications. TBI was induced by closed-head impact and resulted in transient neuropathic pain for less than two weeks, showing periorbital and cutaneous mechanical allodynia/hyperalgesia, as well as motor deficiency and cognitive impairment. We found that peri-surgical treatment with NPD1, effectively prevented TBI-induced mechanical hypersensitivity, motor deficiency, and cognitive impairment. NPD1 treatment also substantially inhibited TBI-induced microgliosis, astrogliosis (including A1 astrocyte markers), and neuroinflammation in the sensory cortex and hippocampus. RNA sequencing and GO enrichment analysis revealed downregulations of genes related to "calcium ion homeostasis," and "GPCR signaling pathway" in the TBI-affected brain. These downregulations were restored by NPD1 treatment. RNAscope in situ hybridization revealed predominant Gpr37 mRNA expression in oligodendrocytes. TBI resulted in rapid and remarkable demyelination and downregulation of Gpr37 mRNA expression in oligodendrocytes, and both were protected by NPD1 treatment. NPD1s inhibition of periorbital and cutaneous mechanical pain was abolished in Gpr37-/- mice. Moreover, TBI-induced neuropathic pain was prolonged by swimming stress, and NPD1 treatment prevented the stress-induced transition from acute to chronic pain in wild-type mice but not Gpr37-/- mice. Finally, chronic pain was associated with depression and anxiety, and NPD1 treatment mitigated these chronic pain complications through GPR37. Thus, through modulation of demyelination, diverse responses of glial cells, and neuroinflammation, the NPD1/GPR37 axis serves as a protective mechanism and a therapeutic target against painful traumatic brain injury and its complications.

Achieving an improved understanding of the temporal sequence of factors involved in Parkinsons disease (PD) pathogenesis may accelerate drug discovery. In this study, we performed a longitudinal transcriptome analysis to identify associated genes underlying the pathogenesis of PD at three temporal phases. We firstly found that multiple initiator genes, which are related to processes of olfactory transduction and stem cell pluripotency, indicate PD risk to those subjects at the prodromal phase. And many facilitator genes involved in calcium signaling and stem cell pluripotency contribute to PD onset. We next identified 325 aggravator genes whose expression could lead to disease progression through damage to dopaminergic synapses and ferroptosis via an integrative analysis with DNA methylation. Last, we made a systematic comparison of gene expression patterns across PD development and accordingly provided candidate drugs at different phases in an attempt to prevent the neurodegeneration process.

BackgroundCompound mutations of TNNT2R141W/+ (encoding troponin T) and MYPNS1296T/+ (encoding myopalladin) are associated with familial left ventricle non-compaction cardiomyopathy (LVNC). However, it remains unclear in which would be the pathogenic mutation, the underlying mechanism, and the target therapy for LVNC. MethodsKnock-in C57BL/6J mice harboring mutations in orthologous genes in Tnnt2R154W or/and MypnS1291T and human cardiomyocytes derived from iPSC of healthy donors and LVNC patients (LVNC-hCM) were employed for disease modeling, omics analysis, mechanistic study, and drug development. ResultsUsing knock-in mice for disease modeling, it was clarified that the orthologous mutation in Tnnt2, but not in Mypn, led to cardiac hypertrabeculation, noncompaction, and heart failure. 3D protein structure modeling by Swiss-model found a loss of slat bridge between TNNT2(R141W) and E-257 in tropomyosin, contributing to the decreased cardiac contraction. Further mechanistic study discovered that troponin T (TNNT2) appears to function as an HDAC1 sponge in cardiomyocyte nuclei. The compromised association between nuclear TNNT2(R141W) and HDAC1 causes cardiac epigenetic perturbation and subsequentially leads to transcriptional dysregulation. The downregulation of cardiac muscular genes was concomitant with the impairment of cardiac contraction, which would be partially rescued by pan HDAC inhibitor. Besides, the upregulation of TGF{beta}-signaling molecules and EZH2 did contribute to cardiac growth defects, which were mitigated by TGF{beta}R1 inhibitor (A83-01) and EZH2 inhibitor (GSK503), respectively. Simvastatin, a hit drug identified from the repurposed drug screening, can restore nuclear TNNT2(R141W)-HDAC1 association, thereby recovering cardiac epigenetic, translational profiles, growth and function in LVNC-hCM in vitro and cardiac function in LVNC mice harboring Tnnt2R154W in vivo. The cardiac function was significantly improved in the proband receiving 5 mg once daily for consecutive two years. ConclusionMutant TNNT2(R141W) diminished its nuclear HDAC1 sponge function in cardiomyocyte to induce LVNC pathogenesis through perturbating cardiac epigenetic and the gene expressions. Targeting to HDAC, TGF{beta}, EZH2 may rescue part of cardiac pathological signaling. Simvastatin can act as a chemical chaperone to comprehensively recover cardiac epigenetic via restoring nuclear TNNT2(R141W)-HDAC1 association.

The endocannabinoid system interacts with the reward system to modulate responsiveness to natural reinforcers, as well as drugs of abuse. Previous preclinical studies suggested that direct blockade of CB1 cannabinoid receptors (CB1R) could be leveraged as a potential pharmacological approach to treat substance use disorder, but this strategy failed during clinical trials due to severe psychiatric side effects. Alternative strategies have emerged to circumvent the side effects of direct CB1 binding through the development of allosteric modulators. We hypothesized that pharmacological inhibition of CB1R signaling through negative allosteric modulation (NAM) would reduce the reinforcing properties of morphine and decrease opioid addictive behaviors. By employing i.v. self-administration in mice, we studied the effects of the CB1-biased NAM GAT358 on morphine intake, relapse-like behavior, and motivation to work for morphine infusions. Our data revealed that GAT358 reduced morphine infusion intake during the maintenance phase of morphine self-administration under fixed ratio 1 schedule of reinforcement. GAT358 decreased morphine-seeking behavior after forced abstinence. Moreover, GAT358 dose-dependently decreased the motivation to obtain morphine infusions in a progressive ratio schedule of reinforcement. Strikingly, GAT358 did not affect the motivation to work for food rewards in an identical progressive ratio task, suggesting that the effect of GAT358 in decreasing opioid self-administration is reward specific. Furthermore, GAT58 did not produce motor ataxia in the rota-rod test. Our results suggest that CB1R NAMs reduced the reinforcing properties of morphine and could represent a viable therapeutic route to safely decrease opioid-addicted behaviors.

Pharmacological targeting of ion channels represents a crucial avenue for pain management. Among these, the Kv7 family of ion channels plays a significant role controlling neuronal excitability and the generation and propagation of pain-related nerve impulses, thus mitigating excessive electrical signaling and curtailing the exaggerated transmission of pain signals. Pain management strategies often involve a multimodal approach, combining various medications with distinct mechanisms of action to achieve optimal outcomes. Eugenol possesses a spectrum of biological activities, including analgesic and anti-inflammatory properties. When used in conjunction with the anti-inflammatory drug diclofenac, eugenol demonstrates enhanced analgesic efficacy in animal models. We investigated the effects of diclofenac and eugenol on Kv7 and TRPV1 ion channels, both agents act as Kv7 activators, whereas diclofenac inhibits the TRPV1 current, and eugenol reduce the capsaicin-activated current presumably competing for the same binding site. Eugenol shows a time dependent biphasic effect on acid-activated TRPV1 current, first activating and then a slow decay of the current. When eugenol and diclofenac are used together, they limit the extent of depolarization of cells expressing Kv7 and TRPV1. Our results shed light on the combined effectiveness of eugenol and diclofenac in the treatment of acute pain.

The neuropathologic hallmarks of Parkinsons disease (PD) are associated with mitochondrial dysfunction and metabolic abnormalities. We have reported that the Combined Metabolic Activators (CMA), consisting of L-serine, nicotinamide riboside, N-acetyl-L-cysteine, and L-carnitine tartrate can be used in treating metabolic abnormalities. These metabolic activators are the precursors of nicotinamide adenine dinucleotide (NAD+) and glutathione (GSH) and used in activation of mitochondrial and global metabolism. We have performed a placebo-controlled, phase-2 study in Alzheimers disease (AD) patients and reported that the cognitive functions in AD patients is significantly improved 29% in the CMA group whereas it is improved only 14% in the placebo group after 84 days of CMA administration. Here, we designed a randomized, double-blinded, placebo-controlled, phase-2 study in PD patients with CMA administration. We found that the cognitive functions in PD patients is significantly improved 21% in the CMA group, whereas it is improved only 11% in the placebo group after 84 days of CMA administration. We also found that the administration of CMA did not affect motor functions in PD patients. We performed a comprehensive multi-omics analysis of plasma proteins and metabolites, and revealed the molecular mechanism associated with the treatment of the patients. In conclusion, our results show that treating PD patients with CMAs leads to enhanced cognitive function, as recently reported in AD patients.

Solriamfetol [(R)-2-amino-3-phenylpropylcarbamate hydrochloride], a phenylalanine derivative initially developed as potential antidepressant, was shown by our group in 2009 to have potent, dose-dependent wake-promoting activity in mice. Solriamfetol (Sunosi(R)) is used since 2019 to counteract excessive daytime sleepiness (EDS) in patients with narcolepsy and obstructive sleep apnea (OSA). It has several advantages over other stimulants, notably that it is not associated with strong psychomotor activity, does not induce behavioral stereotypies and anxiety-related behaviors, in contrast to amphetamines and modafinil. Its mode-of-action remains incompletely solved. It was reported to act as dual dopamine-and-noradrenaline-reuptake-inhibitor (DNRI), and more recently, to have TAAR1 agonist activity. In our early mouse study, we showed that, at 150 mg/kg, Solriamfetol induces a state of wakefulness featuring a dramatic upregulation of EEG gamma activity, a cognitive biomarker, and the expression of genes implicated in neural plasticity, learning and memory. Besides being prescribed to treat EDS, central nervous system stimulants are commonly used as smart drugs to enhance cognition in normal individuals. Therefore, based on Solriamfetols ability to potently induce wakefulness, EEG and molecular markers of learning and memory, we aimed to determine whether it could improve the cognitive performance of wild-type mice. Because at doses of 50-150 mg/kg, Solriamfetol induced an alert waking state associated with low mobility, thus precluding behavioral testing, we used lower doses (1-3 mg/kg) to assess cognition in a battery of tests evaluating short- or long-term memory and spatial navigation. We found that compared to saline, Solriamfetol 3 mg/kg consistently improves sustained attention for a novel object, as well as spatial memory. Next, to determine the brain activity correlates of enhanced cognition, we performed EEG/EMG recording while the mice performed the novel object recognition (NOR) task. Power spectral density (PSD) analysis revealed that 3 mg/kg Solriamfetol reduced EEG delta (an index of sleepiness) during exposure to a novel context, and enhanced EEG fast-gamma (an index of mental concentration) during execution of the NOR task. Taken together, our data demonstrate that low-dose Solriamfetol improves memory and attentional performance in wild-type mice.