Receptor Function Research Articles

Peripubertal exposure to oxyfluorfen, a diphenyl herbicide, delays pubertal development in the male rat by antagonizing androgen receptor activity.

We recently identified the herbicide oxyfluorfen as an inhibitor of iodide uptake by the sodium iodide symporter (NIS), a key step in thyroid hormone synthesis, using in vitro assays. We also observed a suppression of serum T4 and T3 in juvenile rats exposed orally to oxyfluorfen for 4-8 days. The purpose of the present study was to further evaluate effects of an extended 31-day oral exposure using a male pubertal rat study (15 to 500 mg/kg). Oxyfluorfen delayed puberty at all doses (1.3 -3.5 days) suppressing ventral prostate at 62.5 mg/kg and above and seminal vesicle weights at 31.25 mg/kg and above with no effect on testosterone or luteinizing hormone. Serum T4 and T3 were suppressed by all doses up to 80%, with a linear increase in serum TSH. Based on delayed puberty without changes in testosterone, we hypothesized that oxyfluorfen interferes with androgen receptor (AR) function. Results from our Hershberger study, with oxyfluorfen (62.5 and 125 mg/kg) co-treated with testosterone proprionate (TP , 1 mg/kg) for 10 days showed 3 of 5 of the androgenic tissue weights were suppressed compared to TP alone indicating AR antagonism. We next confirmed this effect in an in vitro AR transcriptional activation reporter assay (0-20 μM) with 125 pM 5αDH-11-ketotestosterone and found concentration-dependent inhibition of AR luminescence activity (EC50 1.75 µM) without cytotoxicity. Here, we confirmed the endocrine disrupting effects of oxyfluorfen using both in vitro and in vivo evaluations of the thyroid hormone and AR pathways. This abstract doesn't necessarily reflect U.S. EPA policy.

Cannabinoid regulation of sex-dependent murine odorant-stimulated salivation

Salivation is easily taken for granted, but without normal salivation, simple essential tasks such as chewing and swallowing become difficult, with consequences for quality of life, nutrition and oral health. Many important drug classes cause dry mouth as a side effect, contributing substantially to patient non-compliance. Available treatments are mostly palliative. Cannabis user complaints of dry mouth prompted a study that showed that basal salivation is likely regulated by cannabinoid CB1 receptors on neurons that innervate the submandibular gland. But what about stimulated salivation? The adjoining parotid gland releases saliva in response to olfactory or other cues and contributes a large portion of the net salivation in humans. We investigated cannabinoid regulation of stimulated salivation using functional and protein-expression studies in mice. In developing a model of stimulated salivary responses to food-related odorants in mice, we noted sex-dependent responses to food-related cues. Only male mice learned to salivate in response to the odor of peanut butter while only female mice responded to a chocolate hazelnut spread. Both males and females responded to sugar or marmite. Testing peanut butter, we found that the cannabinoid receptor agonist CP55940 (0.5 mg/kg, IP) lowered baseline salivation, as shown previously, but also prevented the odorant-induced increase in salivation. CB1 receptors are expressed in axons innervating the parotid gland, paralleling our findings in the submandibular gland. Notably, we also found that CB1 deletion impaired some responses (those to peanut butter and chocolate hazelnut spread) but not others (sugar or marmite). In mice, the CB1 antagonist SR141716 (4 mg/kg, IP) prevented a previously learned salivary response to peanut butter. We find that CB1 receptors are expressed in a subset of glomeruli in coronal sections of olfactory bulb that may serve as a site of action for scent-specific effects of CB1 receptors. We additionally observe CB1 expression in accessory olfactory bulb. In summary, we find a novel sex-dependence in responses to a subset of food-related odorant cues and that cannabinoid receptors regulate some of these responses. We propose that CB1 receptors act at the parotid gland to inhibit stimulated salivation but also in the olfactory system, where functional CB1 receptors are required for salivary responses to specific appetitive odors.

Distribution of progesterone receptors and the membrane component of progesterone receptor in various organs and tissues of male and female rats

Progesterone regulates reproductive processes and affects many functions of various non-reproductive organs. Its effects in mammals and humans are mediated by nuclear (nPRs) and membrane progesterone receptors (mPRs). The action of progesterone through different types of receptors may differ significantly and has tissue specific features. The expression of known types and subtypes of progesterone receptors in the tissues of male and female rats has been studied fragmentarily. The purpose of our work was to study the expression of five mPRs genes, as well as the nPRs gene and the membrane component of the progesterone receptor PGRMC I in the reproductive organs and in 17 non-reproductive tissues of male and female rats using reverse transcription followed by real-time PCR. In this study, it was shown that a high level of nPRs gene expression in rats is found not only in reproductive organs of females (uterus, ovary, mammary glands), but also in seminal vesicles of males, in the brain and trachea of both sexes, in blood vessels, and in the pancreas of females. The highest level of expression of mPRs genes of all subtypes was found in the testes, while expression of the gene encoding nPRs was practically undetectable in them. Expression of genes encoding mPRs was also detected in the liver and spleen of male and female rats, while expression of the gene encoding nPRs was at background levels. Virtually no expression of nPRs, mPRs, and membrane component of progesterone receptor (PGRMC I) genes was detected in muscle, and its level was very low in the heart in animals of both sexes. We found sex-specific differentiation of nuclear and membrane receptor mRNA levels in rats in non-reproductive tissues, characterized by a predominance of nPRs transcripts and three subtypes of mPRs (α, β, δ) in females and two subtypes of mPRs (γ, ε) in males. Data on the presence of progesterone receptors in tissues not involved in reproduction confirm the effect of progesterone on these organs. High levels of mRNA for various progesterone receptors in the tissues of male rats, such as the pancreas, lungs, kidney, and trachea, indicate an important physiological role of progestins not only in females, but also in males, which is still poorly understood. The work also discusses the known functions of progesterone receptors in the tissues studied.

Effects of Bisphenol A on the Risk of Developing Obesity

Background: Every year the global incidence of obesity increases considerably and among the factors that favor it is bisphenol A (BPA), an endocrine disruptor widely used in plastics and omnipresent in many everyday objects. Methods: A total of 19 studies published between 2018 and 2023 that addressed the relationship between BPA exposure and obesity were included in this review in order to better understand its behavior and mechanisms of action. Results: The studies reviewed conclude that BPA is an obesogen that alters the function of hormonal receptors, promotes metabolic syndrome, affects certain genes, etc., leading to a greater risk of developing obesity. With important emphasis on the ability to cause epigenetic changes, thus transmitting the effects to offspring when exposure has occurred during critical stages of development such as during gestation or the perinatal period. Conclusions: There is sufficient evidence to show that BPA is a risk factor in the development of obesity. Even so, further research is necessary to exhaustively understand the causal relationship between the two in order to develop prevention measures and avoid possible future adverse effects.

Role of adenosine in the pathophysiology and treatment of attention deficit hyperactivity disorder.

Attention deficit hyperactivity disorder (ADHD) is a complex neurodevelopmental condition characterized by persistent inattention, hyperactivity, and impulsivity. Although its precise etiology remains unclear, current evidence suggests that dysregulation within the neurotransmitter system plays a key role in the pathogenesis of ADHD. Adenosine, an endogenous nucleoside widely distributed throughout the body, modulates various physiological processes, including neurotransmitter release, sleep regulation, and cognitive functions through its receptors. This review critically examines the role of the adenosine system in ADHD, focusing on the links between adenosine receptor function and ADHD-related symptoms. Additionally, it explores how adenosine interacts with dopamine and other neurotransmitter pathways, shedding light on its involvement in ADHD pathophysiology. This review aims to provide insights into the potential therapeutic implications of targeting the adenosine system for ADHD management.

Pan-ErbB inhibition impairs cognition via disrupting myelination and aerobic glycolysis in oligodendrocytes

White matter (WM) abnormalities are an emerging feature of schizophrenia, yet the underlying pathophysiological mechanisms are largely unknown. Disruption of ErbB signaling, which is essential for peripheral myelination, has been genetically associated with schizophrenia and WM lesions in schizophrenic patients. However, the roles of ErbB signaling in oligodendrocytes remain elusive. Here, we used an in vivo pan-ErbB inhibition strategy and demonstrated the functions of endogenous ErbB receptors in oligodendrocytes. Through analyses of the cellular, histological, biochemical, behavioral, and electrophysiological differences in mice with manipulated ErbB activities in oligodendrocytes at different differentiation stages, we found that ErbB signaling regulates myelination and aerobic glycolysis in oligodendrocytes, and both functions are required for working memory. ErbB inhibition in oligodendrocytes at early differentiation stages induces hypomyelination by suppressing the myelinating capacity of newly formed oligodendrocytes. In contrast, ErbB inhibition in mature oligodendrocytes alters neither myelination nor oligodendrocyte numbers, but accelerates axonal conduction decline under energy stress. Mechanistically, ErbB inhibition attenuates K-Ras activities, leading to the reduced expression of lactate dehydrogenase A that promotes aerobic glycolysis in mature oligodendrocytes. Supplementation of L-lactate restores axonal conduction and working memory capacity that are suppressed by ErbB inhibition in mature oligodendrocytes. These findings emphasize the indispensable roles of ErbB signaling in WM integrity and function and provide insights into the multifaceted contributions of WM abnormalities to cognitive impairment.

Design of customized coronavirus receptors.

Although coronaviruses use diverse receptors, the characterization of coronaviruses with unknown receptors has been impeded by a lack of infection models1,2. Here we introduce a strategy to engineer functional customized viral receptors (CVRs). The modular design relies on building artificial receptor scaffolds comprising various modules and generating specific virus-binding domains. We identify key factors for CVRs to functionally mimic native receptors by facilitating spike proteolytic cleavage, membrane fusion, pseudovirus entry and propagation for various coronaviruses. We delineate functional SARS-CoV-2 spike receptor-binding sites for CVR design and reveal the mechanism of cell entry promoted by the N-terminal domain-targeting S2L20-CVR. We generated CVR-expressing cells for 12 representative coronaviruses from 6 subgenera, most of which lack known receptors, and show that a pan-sarbecovirus CVR supports propagation of a propagation-competent HKU3 pseudovirus and of authentic RsHuB2019A3. Using an HKU5-specific CVR, we successfully rescued wild-type and ZsGreen-HiBiT-incorporated HKU5-1 (LMH03f) and isolated a HKU5 strain from bat samples. Our study demonstrates the potential of the CVR strategy for establishing native receptor-independent infection models, providing a tool for studying viruses that lack known susceptible target cells.

The Impact of Chemokine-Like Receptor 1 Gene Knockout on Lipopolysaccharide-Induced Epididymo-Orchitis in Mice.

This comprehensive study delved into the pivotal function of chemokine-like receptor 1 (CMKLR1) in lipopolysaccharide (LPS)-triggered epididymo-orchitis in mice. Upon LPS exposure, wild-type (WT) mice exhibited marked elevations in serum pro-inflammatory markers, including G-CSF, IL-6, and RANTES, along with heightened levels of TNF-α and IL-6 in testicular and epididymal tissues, which accompanied by pronounced structural damage within the testicular tissue and a concurrent decline in serum testosterone, estradiol (E2) levels, and testicular steroid synthetase expression. Remarkably, Cmklr1 gene ablation intensified the pro-inflammatory response in the serum (especially IFN-γ), testes, and epididymis of epididymo-orchitis models. Furthermore, Cmklr1 deficiency uniquely induced structural alterations within the epididymis, which is absent in the WT model. This genetic manipulation also exacerbated the decline in serum testosterone and E2 levels and testicular steroid synthase activity. While chemerin levels were significantly diminished in WT epididymo-orchitis models, Cmklr1 knockout had no discernible effect on chemerin expression in the model. In addition, a noteworthy observation was the elevation of the serum low density lipoprotein/high density lipoprotein (LDL/HDL) ratio in Cmklr1-deficient mice. Collectively, these findings underscore that the lack of chemerin/CMKLR1 signaling axis could potentially worsen the symptoms during LPS-induced epididymo-orchitis, highlighting its potential as a therapeutic target in related pathologies.

Cry1Ac toxin binding in the velvetbean caterpillar Anticarsia gemmatalis: study of midgut aminopeptidases N

The velvetbean caterpillar Anticarsia gemmatalis is one of the main soybean defoliators in Brazil. Currently, the main biopesticide used to control insect pests worldwide is the bacteria Bacillus thuringiensis (Bt), which produces entomopathogenic Crystal toxins (Cry) that act in the midgut of susceptible insects, leading them to death. The mode of action of Cry toxins in the midgut involves binding to specific receptors present on the brush border of epithelial cells such as aminopeptidase N (APN), alkaline phosphatase (ALP), cadherin, and others. Mutations in these receptors, among other factors, may be involved in the development of resistance; identification of functional Cry receptors in the midgut of A. gemmatalis is crucial to develop effective strategies to overcome this possible scenario. This study’s goal is to characterize APNs of A. gemmatalis and identify a receptor for Cry1Ac in the midgut. The interaction of Bt spores with the midgut epithelium was observed in situ by immunohistochemistry and total aminopeptidase activity was estimated in brush border membrane vesicle (BBMV) samples, presenting higher activity in challenged individuals than in control ones. Ten APN sequences were found in a A. gemmatalis’ transcriptome and subjected to different in silico analysis, such as phylogenetic tree, multiple sequence alignment and identification of signal peptide, activity domains and GPI-anchor signal. BBMV proteins from 5th instar larvae were submitted to a ligand blotting using activated Cry1Ac toxin and a commercial anti-Cry polyclonal antibody; corresponding bands of proteins that showed binding to Cry toxin were excised from the SDS-PAGE gel and subjected to mass spectrometry analysis, which resulted in the identification of seven of those APNs. Quantitative PCR was realized to compare expression levels between individuals subjected to sublethal infection with Bt spores and control ones, presenting up- and downregulations upon Bt infection. From these results, we can infer that aminopeptidases N in A. gemmatalis could be involved in the mode of action of Cry toxins in its larval stage.

Transmembrane Domains of Bitopic Proteins As a Key to Understand the Cellular Signaling

This work presents in a systematic manner key modeling results corroborated by experimental biophysical data and obtained by the authors during long-term research on bitopic (single-pass) membrane proteins (BMP), which are the crucial elements of cell signaling. The manuscript does not claim to be a comprehensive review on the topic, whereby the authors did not aim to describe accurately the current state of the art, given the numerous reliable publications. Rather, it is an essay illustrating the authors’ understanding of the basic principles in organization of transmembrane protein domains (TMD) and their contribution to the cell functioning. Among the key topics highlighted in the present work are the fine-tuned processes of TMD oligomerization and direct contribution of the dynamic membrane environment to this process, the key role of TMD in the functioning of cell receptors and mutual relations between all components of protein-membrane complexes during the signal transduction in normal and pathological conditions.

Dopamine internalization via Uptake2 and stimulation of intracellular D5-receptor-dependent calcium mobilization and CDP-diacylglycerol signaling

Dopamine stimulates CDP-diacylglycerol biosynthesis through D1-like receptors, particularly the D5 subtype most of which is intracellularly localized. CDP-diacylglycerol regulates phosphatidylinositol-4,5-bisphosphate-dependent signaling cascades by serving as obligatory substrate for phosphatidylinositol biosynthesis. Here, we used acute and organotypic brain tissues and cultured cells to explore the mechanism by which extracellular dopamine acts to modulate intracellular CDP-diacylglycerol. Dopamine stimulated CDP-diacylglycerol in organotypic and neural cells lacking the presynaptic dopamine transporter, and this action was selectively mimicked by D1-like receptor agonists SKF38393 and SKF83959. Dopaminergic CDP-diacylglycerol stimulation was blocked by decynium-22 which blocks Uptake2-like transporters and by anti-microtubule disrupters of cytoskeletal transport, suggesting transmembrane uptake and guided transport of the ligands to intracellular sites of CDP-diacylglycerol regulation. Fluorescent or radiolabeled dopamine was saturably transported into primary neurons or B35 neuroblastoma cells expressing the plasmamembrane monoamine transporter, PMAT. Microinjection of 10-nM final concentration of dopamine into human D5-receptor-transfected U2-OS cells rapidly and transiently increased cytosolic calcium concentrations by 316%, whereas non-D5-receptor-expressing U2-OS cells showed no response. Given that U2-OS cells natively express PMAT, bath application of 10 μM dopamine slowly increased cytosolic calcium in D5-expressing cells. These observations indicate that dopamine is actively transported by a PMAT-implicated Uptake2-like mechanism into postsynaptic-type dopaminoceptive cells where the monoamine stimulates its intracellular D5-type receptors to mobilize cytosolic calcium and promote CDP-diacylglycerol biosynthesis. This is probably the first demonstration of functional intracellular dopamine receptor coupling in neural tissue, thus challenging the conventional paradigm that postsynaptic dopamine uptake serves merely as a mechanism for deactivating spent or excessive synaptic transmitter.

Structural basis for hepatitis B virus restriction by a viral receptor homologue

Macaque restricts hepatitis B virus (HBV) infection because its receptor homologue, NTCP (mNTCP), cannot bind preS1 on viral surface. To reveal how mNTCP loses the viral receptor function, we here solve the cryo-electron microscopy structure of mNTCP. Superposing on the human NTCP (hNTCP)-preS1 complex structure shows that Arg158 of mNTCP causes steric clash to prevent preS1 from embedding onto the bile acid tunnel of NTCP. Cell-based mutation analysis confirms that only Gly158 permitted preS1 binding, in contrast to robust bile acid transport among mutations. As the second determinant, Asn86 on the extracellular surface of mNTCP shows less capacity to restrain preS1 from dynamic fluctuation than Lys86 of hNTCP, resulting in unstable preS1 binding. Additionally, presence of long-chain conjugated-bile acids in the tunnel induces steric hindrance with preS1 through their tailed-chain. This study presents structural basis in which multiple sites in mNTCP constitute a molecular barrier to strictly restrict HBV.

Agonists of the nuclear receptor PPARγ can produce biased signaling.

Biased signaling and ligand bias, often termed functional selectivity or selective nuclear receptor modulation, have been reported for nuclear receptor partial agonists over the past 20 years. Whether signaling differences produced by partial agonists result from less intense modulation, off-target effects, or biased signaling remains unclear. A commonly postulated mechanism for biased signaling is coactivator favoritism, where agonists induce different coactivator recruitment profiles. We find that both GW1929 (full agonist) and MRL24 (partial agonist) favor recruitment of 100-300 residue regions from S-motif coactivators compared to a reference full agonist (rosiglitazone), yielding 95% bias value confidence intervals of 0.05-0.17 and 0.29-0.38 respectively. Calculations based on these data indicate that GW1929 and MRL24 would induce 30-60% higher S-motif coactivator occupancy at the receptor compared to rosiglitazone. We compare the transcriptional effects of these same three ligands on human adipocytes using RNA sequencing and exploratory KEGG pathway analysis. Only 50% (rosiglitazone) and 77% (GW1929) of all gene expression changes are shared between these full agonists after 3 hours of exposure. After 24 hours of exposure, 13/98 KEGG pathways appear more intensely modulated by rosiglitazone than GW1929 (e.g., 95% CI of bias in the regulation of lipolysis in adipocytes pathway is 0.03-0.09), despite similar signaling for the remaining 85 affected pathways. Similarly, rosiglitazone has an unusually large effect on several lipid metabolism-related pathways compared to the partial agonist MRL24. These data indicate that nuclear receptor full and partial agonists can induce biased signaling, likely through differences in coactivator recruitment. Significance Statement Many nuclear receptor partial agonists cause fewer adverse effects and similar efficacy compared to full agonists, potentially by inducing biased agonism. Our data support the idea that partial agonists, and a full agonist, of the nuclear receptor Peroxisome proliferator-activated receptor gamma (PPARγ) are biased agonists, causing different signaling by inducing PPARγ to favor different coactivators. These data indicate that biased agonism can occur in nuclear receptors and should be considered in efforts to develop improved nuclear receptor-targeted drugs.

The beta 2 adrenergic receptor cross-linked interactome identifies 14-3-3 proteins as regulating the availability of signaling-competent receptors.

The emerging picture of G protein-coupled receptor function suggests that the global signaling response is an integrated sum of a multitude of individual receptor responses, each regulated by their local protein environment. The beta 2 adrenergic receptor (B2AR) has long served as an example receptor in the development of this model. But the mechanism and the identity of the protein-protein interactions that govern the availability of receptors competent for signaling remains incompletely characterized. To address this question, we characterized the interactome of agonist-stimulated B2AR in HEK293 cells using FLAG co-immunoprecipitation coupled to SILAC labeling and mass spectrometry. Our B2AR cross-linked interactome identified 190 high-confidence proteins, including almost all known interacting proteins and six out of seven isoforms of the 14-3-3 family of scaffolding proteins. Inhibiting 14-3-3 proteins with the peptide difopein enhanced isoproterenol-stimulated adrenergic signaling via cAMP approximately three-fold, and increased both miniGs and arrestin recruitment to B2AR more than two fold each, without noticeably changing EC50 with respect to cAMP signaling or effector recruitment upon stimulation. Our results show that 14-3-3 proteins negatively regulate downstream signaling by inhibiting access of B2AR to effector proteins. We propose that 14-3-3 proteins maintain a dynamic pool of B2AR that has reduced signaling efficacy in response to acute agonist stimulation, limiting the amount of signaling-competent receptors at the plasma membrane. Significance Statement This study presents a new interactome of the agonist-stimulated beta 2 adrenergic receptor (B2AR), a paradigmatic GPCR that is both a model system for members of this class and an important signaling protein in respiratory, cardiovascular, and metabolic regulation. We identify 14-3-3 proteins as responsible for restricting B2AR access to signaling effectors and maintaining a receptor population that is insensitive to acute stimulation by agonists.

Receptor usage of Syncytin-1: ASCT2, but not ASCT1, is a functional receptor and effector of cell fusion in the human placenta

Syncytin-1, a human fusogenic protein of retroviral origin, is crucial for placental syncytiotrophoblast formation. To mediate cell-to-cell fusion, Syncytin-1 requires specific interaction with its cognate receptor. Two trimeric transmembrane proteins, Alanine, Serine, Cysteine Transporters 1 and 2 (ASCT1 and ASCT2), were suggested and widely accepted as Syncytin-1 cellular receptors. To quantitatively assess the individual contributions of human ASCT1 and ASCT2 to the fusogenic activity of Syncytin-1, we developed a model system where the ASCT1 and ASCT2 double knockout was rescued by ectopic expression of either ASCT1 or ASCT2. We demonstrated that ASCT2 was required for Syncytin-1 binding, cellular entry, and cell-to-cell fusion, while ASCT1 was not involved in this receptor interaction. We experimentally validated the ASCT1-ASCT2 heterotrimers as a possible explanation for the previous misidentification of ASCT1 as a receptor for Syncytin-1. This redefinition of receptor specificity is important for proper understanding of Syncytin-1 function in normal and pathological pregnancy.

In vivo functional profiling and structural characterisation of the human Glp1r A316T variant.

Glucagon-like peptide-1 receptor (GLP-1R) agonists are a highly effective therapy class for type 2 diabetes (T2D) and obesity, yet there are variable patient responses. Variation in the human Glp1r gene leading to altered receptor structure, signal transduction, and function might be directly linked to therapeutic responses in patients. A naturally occurring, low-frequency, gain-of-function missense variant, rs10305492 G>A (A316T), protects against T2D and cardiovascular disease. Here we employ CRISPR/Cas9 technology to generate a humanised knock-in mouse model bearing the homozygous Glp1r A316T substitution. Human Glp1r A316T/A316T mice displayed lower fasting blood glucose levels and improved glucose tolerance, as well as increased plasma insulin levels and insulin secretion responses, even under metabolic stress. They also exhibited alterations in islet cytoarchitecture and β-cell identity indicative of compensatory mechanisms under a high-fat, high-sucrose (HFHS) diet challenge. Across all models investigated, the human Glp1r A316T variant exhibited characteristics of constitutive activation but blunted incretin-induced responses. Our results are further supported by cryo-EM analysis and molecular dynamics (MD) simulations of the GLP-1R A316T structure, demonstrating that the A316T Glp1r variant governs basal receptor activity and pharmacological responses to GLP-1R-targeting anti-diabetic therapies, highlighting the importance of the precise molecular characterisation of human Glp1r variants to predict individual therapy responses.

Spatial mRNA expression patterns of orexin receptors in the dorsal hippocampus.

Orexins are wake-promoting neuropeptides that originate from hypothalamic neurons projecting to widespread brain areas throughout the central nervous system. They modulate various physiological functions via their orexin 1 (OXR1) and 2 (OXR2) receptors, including sleep-wake rhythm but also cognitive functions such as memory formation. Here, we provide a detailed analysis of OXR1 and OXR2 mRNA expression profiles in the dorsal hippocampus as a key region for memory formation, using RNAscope multiplex in situ hybridization. Interconnected subareas relevant for cognition and memory such as the medial prefrontal cortex and the nucleus reuniens of the thalamus were assessed as well. Both receptor types display distinct profiles, with the highest percentage of OXR1 mRNA-positive cells in the hilus of the dentate gyrus. Here, the content of OXR1 mRNA per cell was slightly modulated at selected time points over a 12h light/ 12 dark light phase. Using RNAScope and quantitative polymerase chain reaction approaches, we began to address a cell-type specific expression of OXR1 in hilar GABAergic interneurons. The distinct expression profiles of both receptor subtypes within hippocampal subareas and circuits provide an interesting basis for future interventional studies on orexin receptor function in spatial and contextual memory.

Human foot cutaneous receptors function: clinical findings and prospects of using medical devices to stimulate mechanoreceptors in neurorehabilitation.

The effectiveness of the support stimulation of the mechanoreceptors of the feet has been first shown in space medicine. In space flight during support withdrawal with non-use of postural muscle, this method is a countermeasure against sensorimotor disorders. Later, it was applied in clinical practice as treatment of motor disorders after stroke, in Parkinson's disease, infantile cerebral palsy, neuropathies, and many others. The impact of such stimulation on motor control is due to spinal and supraspinal mechanisms, which are activated by creating an additional support afferent input through the plantar surface. Many studies confirmed the positive effect of support stimulation on motor control, but the protocols of such stimulation remain the subject of active discussion. This review includes (1) the features of sensitivity of the foot sole cutaneous afferents to the support mechanical stimuli, (2) data on spinal and supraspinal responses of the nervous system to support stimulation, and (3) the results of applying this approach in neurological practice via various techniques. Summarizing this information, the authors highlight the most promising ways and types of medical devices for foot support stimulation in neurology.

P2X7 receptor in macrophage polarization and its implications in neuroblastoma tumor behavior.

Tumor-associated macrophages (TAMs) exhibit antitumor or protumor responses related to inflammatory (or M1) and alternative (or M2) phenotypes, respectively. The P2X7 receptor plays a key role in macrophage polarization, influencing inflammation and immunosuppression. In this study, we investigated the role of the P2X7 receptor in TAMs. Using P2X7 receptor-deficient macrophages, we analyzed gene expression profiles and their implications for neuroblastoma invasion and chemoresistance. Our results showed that P2X7 receptor deficiency altered the expression of classical polarization markers, such as nitric oxide synthase 2 (Nos2) and tumor necrosis factor-α (Tnf), as well as alternative phenotype markers, including mannosereceptor C-type 1 (Mrc1) and arginase 1 (Arg1). P2X7 deficiency also influenced the expression of the ectonucleotidases Entpd1 and Nt5e and other purinergic receptors, especially P2ry2, suggesting compensatory mechanisms involved in macrophage polarization. In particular, TAMs deficient in P2X7 showed a phenotype with characteristicsintermideiate between resting macrophages (M0) and M1 polarization rather than the M2-type phenotype like and wild-type TAM macrophages. In addition, P2rx7-/- TAMs regulated the expression of P2X7 receptor isoforms in neuroblastoma cells, with downregulation of the P2X7A and B isoforms leading to a decrease in chemotherapy-induced cell death. However, TAMs expressing P2X7 downregulated only the B isoform, suggesting that TAMs play a role in modulating tumor behavior through P2X7 receptor isoform regulation. Taken together, our data underscore the regulatory function of the P2X7 receptor in orchestrating alternative macrophage polarization and in the interplay between tumor cells and TAMs. These findings help to clarify the complex interplay of purinergic signaling in cancer progression and open up avenues for future research and therapeutic interventions.

Histone Deacetylases (HDACs) Roles in Inflammation-mediated Diseases; Current Knowledge.

The histone acetyl transferases (HATs) and histone deacetylases (HDACs), which are mostly recognized for their involvement in regulating chromatin remodeling via histone acetylation/deacetylation, have been shown to also change several non-histone proteins to regulate other cellular processes. Acetylation affects the activity or function of cytokine receptors, nuclear hormone receptors, intracellular signaling molecules, and transcription factors in connection to inflammation. Some small-molecule HDAC inhibitors are utilized as anticancer medications in clinical settings due to their capability to regulate cellular growth arrest, differentiation, and death. Here, we summarize our present knowledge of the innate and adaptive immunological pathways that classical HDAC enzymes control. The aim is to justify the targeted (or non-targeted) use of inhibitors against certain HDAC enzymes in inflammatory diseases such as arthritis, inflammatory bowel diseases (IBD), airways inflammation and neurological diseases.