Receptor Subunit Research Articles

Dietary supplementation with grape seed extract from Vitus vinifera prevents suppression of GABAergic protein expression in female Sprague Dawley trigeminal ganglion in a model of chronic temporomandibular joint disorder

ObjectiveTo investigate cellular changes in protein expression in the trigeminal ganglion in an established preclinical chronic model of temporomandibular joint disorder (TMD) in response to grape seed extract (GSE) supplementation based on its beneficial use in preclinical chronic orofacial pain models. DesignThree experimental conditions included female Sprague-Dawley rats as naïve controls, and animals subjected to neck muscle inflammation and prolonged jaw opening with and without daily supplementation of GSE in the drinking water prior to inflammation. Changes were evaluated in mechanical sensitivity to von Frey filaments and protein expression in the trigeminal ganglion of animals 14 days post jaw opening. ResultsCalcitonin-gene related peptide and protein kinase A, proteins positively associated with peripheral sensitization and enhanced nociception, did not show elevated expression at day 14 in the model compared to naïve or GSE supplemented animals. However, neuronal levels of glutamate decarboxylase (GAD) 65/67, which are enzymes responsible for the synthesis of the inhibitory neurotransmitter GABA that functions to suppress neuronal excitability, were significantly decreased on day 14 post jaw opening. Similarly, a significant decrease in neuronal expression of the GABA receptor subunits GABAB1 and GABAB2, but not GABAA, was observed in the TMD model. Importantly, GSE prevented suppression of GAD 65/67 and GABAB subunits, maintaining levels similar to naïve animals. ConclusionResults from our study provide evidence of the downregulation of inhibitory GABAergic proteins in trigeminal ganglion neurons in a preclinical chronic TMD model and the benefits of GSE supplementation in preventing their suppression and maintaining normal levels.

Induction of the antiviral factors APOBEC3A and RSAD2 upon CCL2 neutralization in primary human macrophages involves NF-κB, JAK/STAT, and gp130 signaling.

The CCL2/CC chemokine receptor 2 axis plays key roles in the pathogenesis of HIV-1 infection. We previously reported that exposure of monocyte-derived macrophages to CCL2 neutralizing antibody (αCCL2 Ab) restricted HIV-1 replication at postentry steps of the viral life cycle. This effect was associated with induction of transcripts coding for innate antiviral proteins, including APOBEC3A and RSAD2. This study aimed at identifying the signaling pathways involved in induction of these factors by CCL2 blocking in monocyte-derived macrophages. Through a combination of pharmacologic inhibition, quantitative reverse transcription polymerase chain reaction, Western blotting, and confocal laser-scanning microscopy, we demonstrated that CCL2 neutralization activates the canonical NF-κB and JAK/STAT pathways, as assessed by time-dependent phosphorylation of IκB, STAT1, and STAT3 and p65 nuclear translocation. Furthermore, pharmacologic inhibition of IκB kinase and JAKs strongly reduced APOBEC3A and RSAD2 transcript accumulation elicited by αCCL2 Ab treatment. Interestingly, exposure of monocyte-derived macrophages to αCCL2 Ab resulted in induction of IL-6 family cytokines, and interference with glycoprotein 130, the common signal-transducing receptor subunit shared by these cytokines, inhibited APOBEC3A and RSAD2 upregulation triggered by CCL2 neutralization. These results provide novel insights into the signal transduction pathways underlying the activation of innate responses triggered by CCL2 neutralization in macrophages. Since this response was found to be associated with protective antiviral effects, the new findings may help design innovative therapeutic approaches targeting CCL2 to strengthen host innate immunity.

Краткосрочная эффективность анифролумаба в лечении системной красной волчанки

Anifrolumab is a fully human monoclonal antibody that targets the type I IFN-α receptor subunit and blocks the action of the type I IFN.

F.5 A neurotransmitter-dependent mechanism of ependymal cell activation: Insights into a novel therapeutic target for spinal cord injury

Background: The drivers that activate endogenous ependymal-derived neural stem/progenitor cells (epNSPCs) remain unknown. Understanding the mechanisms that govern the biology of these cells is critical in developing a therapeutic strategy to harness their regenerative potential after injury. Methods: FoxJ1-CreER-tdTomato reporter mice were used for epNSPC lineage tracing. A conditional genetic knock-out mouse line of glutamate-subtype AMPA receptor (AMPAR) subunits in epNSPCs was generated. Electrophysiological properties were assessed using single cell patch clamp and slice culture recordings. For in vivo studies, mice underwent cervical SCI. To examine the effect of positive modulation of AMPARs, mice received the ampakine CX546 or vehicle and underwent electrophysiological testing, behavioural assessment and spinal cord extraction. Results: Glutamate excitotoxicity, a hallmark in the pathogenesis of acute SCI, drives epNSPCs activation via AMPARs. Genetic knock-out of AMPARs in epNSPCs inhibits their activation following SCI. Positive pharmacological modulation of AMPARs after SCI enhances the migration and differentiation of epNSPCs, increases neuronal sparing and improves long-term locomotor/forelimb function. SCI decreases the excitability of corticospinal tract projections, which is improved with positive AMPAR modulation. Conclusions: Glutamatergic signaling via AMPARs is an important mediator of epNSPC activation after injury. Pharmacological targeting of this mechanism can be used to enhance endogenous regeneration and improve recovery post-SCI.

Unveiling promising drug targets for autism spectrum disorder: insights from genetics, transcriptomics, and proteomics.

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder for which current treatments are limited and drug development costs are prohibitive. Identifying drug targets for ASD is crucial for the development of targeted therapies. Summary-level data of expression quantitative trait loci obtained from GTEx, protein quantitative trait loci data from the ROSMAP project, and two ASD genome-wide association studies datasets were utilized for discovery and replication. We conducted a combined analysis using Mendelian randomization (MR), transcriptome-wide association studies, Bayesian colocalization, and summary-data-based MR to identify potential therapeutic targets associated with ASD and examine whether there are shared causal variants among them. Furthermore, pathway and drug enrichment analyses were performed to further explore the underlying mechanisms and summarize the current status of pharmacological targets for developing drugs to treat ASD. The protein-protein interaction (PPI) network and mouse knockout models were performed to estimate the effect of therapeutic targets. A total of 17 genes revealed causal associations with ASD and were identified as potential targets for ASD patients. Cathepsin B (CTSB) [odd ratio (OR) = 2.66 95, confidence interval (CI): 1.28-5.52, P = 8.84 × 10-3], gamma-aminobutyric acid type B receptor subunit 1 (GABBR1) (OR = 1.99, 95CI: 1.06-3.75, P = 3.24 × 10-2), and formin like 1 (FMNL1) (OR = 0.15, 95CI: 0.04-0.58, P = 5.59 × 10-3) were replicated in the proteome-wide MR analyses. In Drugbank, two potential therapeutic drugs, Acamprosate (GABBR1 inhibitor) and Bryostatin 1 (CASP8 inhibitor), were inferred as potential influencers of autism. Knockout mouse models suggested the involvement of the CASP8, GABBR1, and PLEKHM1 genes in neurological processes. Our findings suggest 17 candidate therapeutic targets for ASD and provide novel drug targets for therapy development and critical drug repurposing opportunities.

AMPA and NMDA receptors in dentate gyrus mediate memory for sucrose in two port discrimination task.

Although the phenomenon of memory formation and recall associated with the use of psychotropic drugs has been extensively studied, mechanisms underlying memories for natural reward have not been clarified. Herein, we test the hypothesis that glutamatergic receptors in the dentate gyrus play a role in memories associated with sucrose. We used pellet self-administration protocol to generate memories in two-port nose-poke discrimination task using male Wistar rats. During non-rewarded probe trial, the conditioned animals readily discriminated the active port versus inactive port and showed massive increase in mRNA expression of AMPA receptor subunit genes (gria2, gria3) as well as c-Fos protein in the DG. Access to sweet pellet further enhanced c-Fos expression in the DG. However, animals pre-treated with AMPA receptor antagonist CNQX (intra-DG), on exposure to operant chamber (no pellet), showed decreased discrimination as well as c-Fos expression. We suggest that AMPA receptors in DG mediate recall and consolidation of memories associated with sucrose consumption. CNQX pre-treated animals, if presented with sweet pellet on nose poke, exhibited high discrimination index coupled with increased c-Fos expression. In these CNQX treated rats, the DI was again decreased following administration of NMDA receptor antagonist AP5. We suggest that, although AMPA receptors are blocked, the access to sweet pellet may induce surge of glutamate in the DG, which in turn may reinstate memories via activation of erstwhile silent synapses in NMDA dependant manner.

Kainate receptor channel opening and gating mechanism

Kainate receptors, a subclass of ionotropic glutamate receptors, are tetrameric ligand-gated ion channels that mediate excitatory neurotransmission1–4. Kainate receptors modulate neuronal circuits and synaptic plasticity during the development and function of the central nervous system and are implicated in various neurological and psychiatric diseases, including epilepsy, depression, schizophrenia, anxiety and autism5–11. Although structures of kainate receptor domains and subunit assemblies are available12–18, the mechanism of kainate receptor gating remains poorly understood. Here we present cryo-electron microscopy structures of the kainate receptor GluK2 in the presence of the agonist glutamate and the positive allosteric modulators lectin concanavalin A and BPAM344. Concanavalin A and BPAM344 inhibit kainate receptor desensitization and prolong activation by acting as a spacer between the amino-terminal and ligand-binding domains and a stabilizer of the ligand-binding domain dimer interface, respectively. Channel opening involves the kinking of all four pore-forming M3 helices. Our structures reveal the molecular basis of kainate receptor gating, which could guide the development of drugs for treatment of neurological disorders.

Anxiolytic effects of Enterococcus faecalis 2001 on a mouse model of colitis

Ulcerative colitis (UC) is a refractory inflammatory bowel disease, which is known to cause psychiatric disorders such as anxiety and depression at a high rate in addition to peripheral inflammatory symptoms. However, the pathogenesis of these psychiatric disorders remains mostly unknown. While prior research revealed that the Enterococcus faecalis 2001 (EF-2001) suppressed UC-like symptoms and accompanying depressive-like behaviors, observed in a UC model using dextran sulfate sodium (DSS), whether it has an anxiolytic effect remains unclear. Therefore, we examined whether EF-2001 attenuates DSS-induced anxiety-like behaviors. Treatment with 2% DSS for seven days induced UC-like symptoms and anxiety-like behavior through the hole-board test, increased serum lipopolysaccharide (LPS) and corticosterone concentration, and p-glucocorticoid receptor (GR) in the prefrontal cortex (PFC), and decreased N-methyl-d-aspartate receptor subunit (NR) 2A and NR2B expression levels in the PFC. Interestingly, these changes were reversed by EF-2001 administration. Further, EF-2001 administration enhanced CAMKII/CREB/BDNF-Drebrin pathways in the PFC of DSS-treated mice, and labeling of p-GR, p-CAMKII, and p-CREB showed colocalization with neurons. EF-2001 attenuated anxiety-like behavior by reducing serum LPS and corticosterone levels linked to the improvement of UC symptoms and by facilitating the CAMKII/CREB/BDNF-Drebrin pathways in the PFC. Our findings suggest a close relationship between UC and anxiety.

Cellular Model for the Analysis of IRBIT-Dependent Regulation of the Type 1 IP<sub>3</sub> Receptor

In vertebrate genomes, three genes encode subunits of IP3 receptors, including IP3R1, IP3R2, and IP3R3. Despite high homology between different subunits, homotetrameric IP3 receptors formed by IP3R1, IP3R2, and IP₃R3 in the endoplasmic reticulum membrane are markedly distinct by their functional features and regulatory mechanisms. It was particularly reported that IP3R1 is specifically regulated by the IP3R binding protein released with IP₃ (IRBIT), which competes with IP3 for binding to IP3R1. In turn, affinity of IRBIT/IP₃R1 binding is regulated by phosphorylation of IRBIT. By using the CRISPR/Cas9 approach to edit the genome of HEK-293 cells, two monoclonal cell lines were generated as a platform for uncovering a role of IRBIT and associated regulatory circuits in control of the IP₃R1 activity. In one line, HEK-IP3R1, IP₃R2, and IP3R3 genes were disrupted, while IP₃R1 was remained functional. Based on this line, the HEK-IP3R1/DIRBIT line was generated, wherein IRBIT (AHCYL1) gene was inactivated. The comparative analysis of ACh-induced Ca2+ signaling in cells of both lines was performed by employing the Ca2+ dye Fluo-4 and Ca2+ imaging. It was particularly shown that ACh mobilized Ca2+ in cells of both lines, which responded to the agonist at widely varied doses in an “all-or-nothing” manner. Yet, HEK-IP₃R1/DIRBIT cells turned out to be less sensitive to ACh compared to HEK-IP₃R1 cells.

The predictive value of TNF family for pulmonary tuberculosis: a pooled causal effect analysis of multiple datasets.

Despite extensive research on the relationship between pulmonary tuberculosis (PTB) and inflammatory factors, more robust causal evidence has yet to emerge. Therefore, this study aims to screen for inflammatory proteins that may contribute to the susceptibility to PTB in different populations and to explain the diversity of inflammatory and immune mechanisms of PTB in different ethnicity. The inverse variance weighted (IVW) model of a two-sample Mendelian Randomization (MR) study was employed to conduct causal analysis on data from a genome-wide association study (GWAS). This cohort consisting PTB GWAS datasets from two European and two East Asian populations, as well as 91 human inflammatory proteins collected from 14,824 participants. Colocalization analysis aimed to determine whether the input inflammatory protein and PTB shared the same causal single nucleotide polymorphisms (SNPs) variation within the fixed region, thereby enhancing the robustness of the MR Analysis. Meta-analyses were utilized to evaluate the combined causal effects among different datasets. In this study, we observed a significant negative correlation between tumor necrosis factor-beta levels (The alternative we employ is Lymphotoxin-alpha, commonly referred to as LT) (P < 0.05) and tumor necrosis factor receptor superfamily member 9 levels (TNFRSF9) (P < 0.05). These two inflammatory proteins were crucial protective factors against PTB. Additionally, there was a significant positive correlation found between interleukin-20 receptor subunit alpha levels (IL20Ra) (P < 0.05), which may elevate the risk of PTB. Colocalization analysis revealed that there was no overlap in the causal variation between LT and PTB SNPs. A meta-analysis further confirmed the significant combined effect of LT, TNFRSF9, and IL20Ra in East Asian populations (P < 0.05). Levels of specific inflammatory proteins may play a crucial role in triggering an immune response to PTB. Altered levels of LT and TNFRSF9 have the potential to serve as predictive markers for PTB development, necessitating further clinical validation in real-world settings to ascertain the impact of these inflammatory proteins on PTB.

Communal nesting shapes the sex-dependent glutamatergic response to early life stress in the rat prefrontal cortex.

Early social environment, either positive or negative, shapes the adult brain. Communal nesting (CN), a naturalistic setting in which 2-3 females keep their pups in a single nest sharing care-giving behavior, provides high level of peer interaction for pups. Early social isolation (ESI) from dam and siblings represents, instead, an adverse condition providing no peer interaction. We investigated whether CN (enrichment setting) might influence the response to ESI (impoverishment setting) in terms of social behavior and glutamate system in the medial prefrontal cortex (mPFC) of adult and adolescent male and female rats. Pinning (a rewarding component of social play behavior) was significantly more pronounced in males than in females exposed to the combination of CN and ESI. CN sensitized the glutamate synapse in the mPFC of ESI-exposed male, but not female, rats. Accordingly, we observed (i) a potentiation of the glutamatergic neurotransmission in the mPFC of both adolescent and adult males, as shown by the recruitment of NMDA receptor subunits together with increased expression/activation of PSD95, SynCAM 1, Synapsin I and αCaMKII; (ii) a de-recruiting of NMDA receptors from active synaptic zones of same-age females, together with reduced expression/activation of the above-mentioned proteins, which might reduce the glutamate transmission. Whether similar sex-dependent glutamate homeostasis modulation occurs in other brain areas remains to be elucidated. CN and ESI interact to shape social behavior and mPFC glutamate synapse homeostasis in an age- and sex-dependent fashion, suggesting that early-life social environment may play a crucial role in regulating the risk to develop psychopathology.

GluN2A or GluN2B subunits of the NMDA receptor contribute to changes in neuronal excitability and impairments in LTP in the hippocampus of aging mice but do not mediate detrimental effects of oligomeric Aβ (1-42).

Studies in rodent models have revealed that oligomeric beta-amyloid protein [Aβ (1-42)] plays an important role in the pathogenesis of Alzheimer's disease. Early elevations in hippocampal neuronal excitability caused by Aβ (1-42) have been proposed to be mediated via enhanced activation of GluN2B-containing N-methyl-D-aspartate receptors (NMDAR). To what extent GluN2A or GluN2B-containing NMDAR contribute to Aβ (1-42)-mediated impairments of hippocampal function in advanced rodent age is unclear. Here, we assessed hippocampal long-term potentiation (LTP) and neuronal responses 4-5 weeks after bilateral intracerebral inoculation of 8-15 month old GluN2A+/- or GluN2B+/- transgenic mice with oligomeric Aβ (1-42), or control peptide. Whole-cell patch-clamp recordings in CA1 pyramidal neurons revealed a more positive resting membrane potential and increased total spike time in GluN2A+/-, but not GluN2B+/--hippocampi following treatment with Aβ (1-42) compared to controls. Action potential 20%-width was increased, and the descending slope was reduced, in Aβ-treated GluN2A+/-, but not GluN2B+/- hippocampi. Sag ratio was increased in Aβ-treated GluN2B+/--mice. Firing frequency was unchanged in wt, GluN2A+/-, and GluN2B+/-hippocampi after Aβ-treatment. Effects were not significantly different from responses detected under the same conditions in wt littermates, however. LTP that lasted for over 2 h in wt hippocampal slices was significantly reduced in GluN2A+/- and was impaired for 15 min in GluN2B+/--hippocampi compared to wt littermates. Furthermore, LTP (>2 h) was significantly impaired in Aβ-treated hippocampi of wt littermates compared to wt treated with control peptide. LTP induced in Aβ-treated GluN2A+/- and GluN2B+/--hippocampi was equivalent to LTP in control peptide-treated transgenic and Aβ-treated wt animals. Taken together, our data indicate that knockdown of GluN2A subunits subtly alters membrane properties of hippocampal neurons and reduces the magnitude of LTP. GluN2B knockdown reduces the early phase of LTP but leaves later phases intact. Aβ (1-42)-treatment slightly exacerbates changes in action potential properties in GluN2A+/--mice. However, the vulnerability of the aging hippocampus to Aβ-mediated impairments of LTP is not mediated by GluN2A or GluN2B-containing NMDAR.

ALKBH5 modulates bone cancer pain in a rat model by suppressing NR2B expression.

Currently, the clinical treatment of bone cancer pain (BCP) is mainly related to its pathogenesis. The aim of the present study was to elucidate the potential role of N6-methyladenosine (m6A) in BCP in the spinal cord dorsal root ganglia (DRG) of BCP rats and its specific regulatory mechanism in N-methyl-d-aspartate receptor subunit 2B (NR2B). A rat model of BCP was constructed by tibial injection of Walker256 cells, and ALKBH5 and NR2B expression in the spinal cord DRG was detected. ALKBH5 was silenced or overexpressed in PC12 cells to verify the regulatory effect of ALKBH5 on NR2B. The specific mechanism underlying the interaction between ALKBH5 and NR2B was investigated using methylated RNA immunoprecipitation and dual-luciferase reporter gene assays. The results showed increased expression of m6A, decreased expression of ALKBH5, and increased expression of NR2B in the DRG of the BCP rat model. Overexpression of ALKBH5 inhibited NR2B expression, whereas interference with ALKBH5 caused an increase in NR2B expression. In NR2B, interference with ALKBH5 caused an increase in m6A modification, which caused an increase in NR2B. Taken together, ALKBH5 affected the expression of NR2B by influencing the stability of the m6A modification site of central NR2B, revealing that ALKBH5 is a therapeutic target for BCP.

Identification of cytokines in benign and malignant thymus tumors: based on Mendelian randomization and proteomics.

The aim of this study was to identify potential causal cytokines in thymic malignancies and benign tumors from the FinnGen database using Mendelian randomization (MR). In this study, data from genome-wide association studies (GWAS) of 91 cytokines were used as exposure factors, and those of thymic malignant tumors and thymic benign tumors were the outcome variables. Two methods were used to determine the causal relationship between exposure factors and outcome variables: inverse variance weighting (IVW) and MR-Egger regression. Sensitivity analysis was performed using three methods, namely, the heterogeneity test, the pleiotropy test, and the leave-one-out test. There was a causal relationship between the expression of fibroblast growth factor 5, which is a risk factor for thymic malignant tumors, and thymic malignant tumors. C-C motif chemokine 19 expression, T-cell surface glycoprotein CD5 levels, and interleukin-12 subunit beta levels were causally related to thymic malignant tumors and were protective. Adenosine deaminase levels, interleukin-10 receptor subunit beta expression, tumor necrosis factor (TNF)-related apoptosis-inducing ligand levels, and TNF-related activation-induced cytokine levels showed a causal relationship with thymic benign tumors, which are its risk factors. Caspase 8 levels, C-C motif chemokine 28 levels, interleukin-12 subunit beta levels, latency-associated peptide transforming growth factor beta 1 levels, and programmed cell death 1 ligand 1 expression showed a causal relationship with thymic benign tumors, which are protective factors. Sensitivity analysis showed no heterogeneity. Cytokines showed a causal relationship with benign and malignant thymic tumors. Interleukin-12 subunit beta is a common cytokine that affects malignant and benign thymic tumors.

Gypenoside XVII Reduces Synaptic Glutamate Release and Protects against Excitotoxic Injury in Rats.

Excitotoxicity is a common pathological process in neurological diseases caused by excess glutamate. The purpose of this study was to evaluate the effect of gypenoside XVII (GP-17), a gypenoside monomer, on the glutamatergic system. In vitro, in rat cortical nerve terminals (synaptosomes), GP-17 dose-dependently decreased glutamate release with an IC50 value of 16 μM. The removal of extracellular Ca2+ or blockade of N-and P/Q-type Ca2+ channels and protein kinase A (PKA) abolished the inhibitory effect of GP-17 on glutamate release from cortical synaptosomes. GP-17 also significantly reduced the phosphorylation of PKA, SNAP-25, and synapsin I in cortical synaptosomes. In an in vivo rat model of glutamate excitotoxicity induced by kainic acid (KA), GP-17 pretreatment significantly prevented seizures and rescued neuronal cell injury and glutamate elevation in the cortex. GP-17 pretreatment decreased the expression levels of sodium-coupled neutral amino acid transporter 1, glutamate synthesis enzyme glutaminase and vesicular glutamate transporter 1 but increased the expression level of glutamate metabolism enzyme glutamate dehydrogenase in the cortex of KA-treated rats. In addition, the KA-induced alterations in the N-methyl-D-aspartate receptor subunits GluN2A and GluN2B in the cortex were prevented by GP-17 pretreatment. GP-17 also prevented the KA-induced decrease in cerebral blood flow and arginase II expression. These results suggest that (i) GP-17, through the suppression of N- and P/Q-type Ca2+ channels and consequent PKA-mediated SNAP-25 and synapsin I phosphorylation, reduces glutamate exocytosis from cortical synaptosomes; and (ii) GP-17 has a neuroprotective effect on KA-induced glutamate excitotoxicity in rats through regulating synaptic glutamate release and cerebral blood flow.

Evaluating the Neuroprotective Potential of Novel Benzodioxole Derivatives in Parkinson's Disease via AMPA Receptor Modulation.

Parkinson's disease (PD) is a significant health issue because it gradually damages the nervous system. α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors play a significant role in the development of PD. The current investigation employed hybrid benzodioxole-propanamide (BDZ-P) compounds to get information on AMPA receptors, analyze their biochemical and biophysical properties, and assess their neuroprotective effects. Examining the biophysical characteristics of all the subunits of the AMPA receptor offers insights into the impact of BDZ-P on the desensitization and deactivation rate. It demonstrates a partial improvement in the locomotor capacities in a mouse model of Parkinson's disease. In addition, the in vivo experiment assessed the locomotor activity by utilizing the open-field test. Our findings demonstrated that BDZ-P7 stands out with its remarkable potency, inhibiting the GluA2 subunit nearly 8-fold with an IC50 of 3.03 μM, GluA1/2 by 7.5-fold with an IC50 of 3.14 μM, GluA2/3 by nearly 7-fold with an IC50 of 3.19 μM, and GluA1 by 6.5-fold with an IC50 of 3.2 μM, significantly impacting the desensitization and deactivation rate of the AMPA receptor. BDZ-P7 showed an in vivo impact of partially reinstating locomotor abilities in a mouse model of PD. The results above suggest that the BDZ-P7 compounds show great promise as top contenders for the development of novel neuroprotective therapies.

Artificial fluorescent sensor reveals pre-synaptic NMDA receptors switch cholecystokinin release and LTP in the hippocampus.

Cholecystokinin (CCK) has been confirmed to be essential in NMDA-dependent long-term potentiation (LTP) at mouse cortical synapses. This paper has proven that CCK is necessary for LTP induced by high-frequency stimulation of mouse hippocampal synapses projected from the entorhinal cortex. We show that the subunit of the axonal NMDA receptor dominant modulates the activity-induced LTP by triggering pre-synaptic CCK release. A functional pre-synaptic NMDA receptor is required to induce LTP mediated by the axonal Ca2+ elevation and CCK exocytosis at CCK-specific neurons. Genetic depletion of the GluN1 subunit of NMDA receptors on CCK neurons, which projected from the entorhinal cortex largely abolished the axonal Ca2+ elevation and disturbed the secretion of CCK in hippocampus. These results demonstrate that activity-induced LTP at the hippocampal synapse is CCK-dependent, and CCK secretion from the axonal terminal is modulated by pre-synaptic NMDA receptors.

Explorations of Agonist Selectivity for the α9* nAChR with Novel Substituted Carbamoyl/Amido/Heteroaryl Dialkylpiperazinium Salts and Their Therapeutic Implications in Pain and Inflammation.

There is an urgent need for nonopioid treatments for chronic and neuropathic pain to provide effective alternatives amid the escalating opioid crisis. This study introduces novel compounds targeting the α9 nicotinic acetylcholine receptor (nAChR) subunit, which is crucial for pain regulation, inflammation, and inner ear functions. Specifically, it identifies novel substituted carbamoyl/amido/heteroaryl dialkylpiperazinium iodides as potent agonists selective for human α9 and α9α10 over α7 nAChRs, particularly compounds 3f, 3h, and 3j. Compound 3h (GAT2711) demonstrated a 230 nM potency as a full agonist at α9 nAChRs, being 340-fold selective over α7. Compound 3c was 10-fold selective for α9α10 over α9 nAChR. Compounds 2, 3f, and 3h inhibited ATP-induced interleukin-1β release in THP-1 cells. The analgesic activity of 3h was fully retained in α7 knockout mice, suggesting that analgesic effects were potentially mediated through α9* nAChRs. Our findings provide a blueprint for developing α9*-specific therapeutics for pain.

Promising Effects of Casearins in Tumor-Bearing Mice and Antinociceptive Action against Oncologic Pain: Molecular Docking and In Vivo Findings.

Safer analgesic drugs remain a hard challenge because of cardiovascular and/or gastrointestinal toxicity, mainly. So, this study evaluated in vivo the antiproliferative actions of a fraction with casearins (FC) from Casearia sylvestris leaves against human colorectal carcinomas and antihyperalgesic effects on inflammatory- or opiate-based pain relief and oncologic pain in Sarcoma 180 (S180)-bearing mice. Moreover, docking investigations evaluated the binding among Casearin X and NMDA(N-methyl-D-aspartate)-type glutamate receptors. HCT-116 colorectal carcinoma-xenografted mice were treated with FC for 15 days. Antinociceptive assays included chemically induced algesia and investigated mechanisms by pharmacological blockade. Intraplantar region S180-bearing animals received a single dose of FC and were examined for mechanical allodynia and behavior alterations. AutoDock Vina determined molecular interactions among Cas X and NMDA receptor subunits. FC reduced tumor growth at i.p. (5 and 10 mg/kg) and oral (25 mg/kg/day) doses (31.12-39.27%). FC reduced abdominal pain, as confirmed by formalin and glutamate protocols, whose antinociception activity was blocked by naloxone and L-NAME (neurogenic phase) and naloxone, atropine, and flumazenil (inflammatory phase). Meanwhile, glibenclamide potentiated the FC analgesic effects. FC increased the paw withdrawal threshold without producing changes in exploratory parameters or motor coordination. Cas X generated a more stable complex with active sites of the NMDA receptor GluN2B subunits. FC is a promising antitumor agent against colorectal carcinomas, has peripheral analgesic effects by desensitizing secondary afferent neurons, and inhibits glutamate release from presynaptic neurons and/or their action on cognate receptors. These findings emphasize the use of clerodane diterpenes against cancer-related pain conditions.

No Association of Polymorphisms in the Genes Encoding Interleukin-6 and Interleukin-6 Receptor Subunit Alpha with the Risk of Keloids in Polish Patients.

A keloid is a benign fibroproliferative hypertrophy of scar tissue that extends outside the original wound and invades adjacent healthy skin. Keloid formation is thought to be a complex process including overactivity of the interleukin-6 signaling pathway and genetic susceptibility. The aim of the study was to investigate possible associations between rs1800797, rs1800796, and rs1800795 polymorphisms in the promoter of the IL6 gene encoding interleukin-6 and the rs2228145 polymorphism in the IL6R gene encoding the interleukin-6 receptor subunit alpha with the predisposition to keloids in Polish patients. The genetic polymorphisms were identified either using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) or sequencing of samples of genomic DNA extracted from blood leukocytes of 86 adult patients with keloids and 100 newborns comprising a control group. No significant differences in the distributions of IL6 or IL6R alleles or genotypes were found between keloid patients and newborn controls. There were also no significant differences between both groups in the distribution of IL6 haplotypes. The IL6 rs1800797, rs1800796 and rs1800795 and IL6R rs2228145 polymorphisms were not found to predispose individuals in the study group to keloids. IL6 promoter haplotypes were not found to be associated with a higher risk of keloids in the studied group.