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Synaptic dysfunction caused by soluble β-amyloid peptide (Aβ) is a hallmark of early-stage Alzheimer's disease (AD), and is tightly linked to cognitive decline. By yet unknown mechanisms, Aβ suppresses the transcriptional activity of cAMP-responsive element-binding protein (CREB), a master regulator of cell survival and plasticity-related gene expression. Here, we report that Aβ elicits nucleocytoplasmic trafficking of Jacob, a protein that connects a NMDA-receptor-derived signalosome to CREB, in AD patient brains and mouse hippocampal neurons. Aβ-regulated trafficking of Jacob induces transcriptional inactivation of CREB leading to impairment and loss of synapses in mouse models of AD. The small chemical compound Nitarsone selectively hinders the assembly of a Jacob/LIM-only 4 (LMO4)/ Protein phosphatase 1 (PP1) signalosome and thereby restores CREB transcriptional activity. Nitarsone prevents impairment of synaptic plasticity as well as cognitive decline in mouse models of AD. Collectively, the data suggest targeting Jacob protein-induced CREB shutoff as a therapeutic avenue against early synaptic dysfunction in AD.

Libro que recoge en 16 capítulos temas como: Historia de la cirugía en Ecuador y en el mundo, Central de Esterilización, Valoración preoperatoria, Buenas prácticas quirúrgicas, Heridas y cicatrización, Infección quirúrgica y antibióticos en cirugía, Manejo de líquidos y electrolitos en pacientes quirúrgicos, Dolor agudo postoperatorio, Complicaciones postoperatorias, Equipo de anestesia, Historia de la anestesiología, Vigilancia del paciente anestesiado, Evaluación anestésica y premedicación e Interacciones farmacológicas en anestesia.

Following approval of antagonists in Parkinson's disease therapy, the AThis review focuses on the therapeutic potential of targeting AThere is a pending issue, namely, how to demonstrate the neuroprotective potential of A

Microdialysis assays demonstrated a possible role of orexin in the regulation of amyloid beta peptide (Aß) levels in the hippocampal interstitial fluid in the APP transgenic model. CB

The following article presents the process to obtain the kinematic and dynamic model of a Cartesian robot with 3 degrees of freedom. The robot that is used was designed for educational purposes, it allows two linear movements and one angular. The kinematic model has two forms, direct and inverse, the first provides the final position of the robot if desired values are given to each of the robot's joints, the second provides the values of the joints if there are desired values for the effector final. On the other hand, the obtaining of the dynamic model is presented in detail, which obtains the torques and forces necessary for the robot to be able to move to a specific point. The procedure includes kinematic analysis using Denavit-Hartenberg parameters and dynamic analysis using Jacobeans. As a result, responses obtained from a Simulink model are presented that show the behavior of the developed models.

We have here assessed, using Δ9 -tetrahydrocannabinol (Δ9 -THC) for comparison, the effect of Δ9 -tetrahydrocannabinolic acid (Δ9 -THCA) and of Δ9 -tetrahydrocannabivarin (Δ9-THCV) that is mediated by human versions of CB1, CB2, and CB1-CB2 receptor functional units, expressed in a heterologous system. Binding to the CB1 and CB2 receptors was addressed in living cells by means of a homogeneous assay. A biphasic competition curve for the binding to the CB2 receptor, was obtained for Δ9 -THCV in cells expressing the two receptors. Signaling studies included cAMP level determination, activation of the mitogen-activated protein kinase pathway and ß-arrestin recruitment were performed. The signaling triggered by Δ9 -THCA and Δ9 -THCV via individual receptors or receptor heteromers disclosed differential bias, i.e. the bias observed using a given phytocannabinoid depended on the receptor (CB1, CB2 or CB1-CB2) and on the compound used as reference to calculate the bias factor (Δ9 -THC, a selective agonist or a non-selective agonist). These results are consistent with different binding modes leading to differential functional selectivity depending on the agonist structure, and the state (monomeric or heteromeric) of the cannabinoid receptor. In addition, on studying Gi-coupling we showed that Δ9 -THCV and Δ9 -THCA and Δ9 -THCV were able to revert the effect of a selective CB2 receptor agonist, but only Δ9-THCV, and not Δ9-THCA, reverted the effect of arachidonyl-2′ -chloroethylamide (ACEA 100 nM) a selective agonist of the CB1 receptor. Overall, these results indicate that cannabinoids may have a variety of binding modes that results in qualitatively different effects depending on the signaling pathway that is engaged upon cannabinoid receptor activation

We have here assessed, using Δ

Microdialysis assays demonstrated a possible role of orexin in the regulation of amyloid beta peptide (Aß) levels in the hippocampal interstitial fluid in the APP transgenic model. CB2R is overexpressed in activated microglia, showing a neuroprotective effect. These two receptors may interact, forming CB2-OX1-Hets and becoming a new target to combat Alzheimer’s disease. Aims: Demonstrate the potential role of CB2-OX1-Hets expression and function in microglia from animal models of Alzheimer’s disease. Receptor heteromer expression was detected by immunocytochemistry, bioluminescence resonance energy transfer (BRET) and proximity ligation assay (PLA) in transfected HEK-293T cells and microglia primary cultures. Quantitation of signal transduction events in a heterologous system and in microglia cells was performed using the AlphaScreen® SureFire® kit, western blot, the GCaMP6 calcium sensor and the Lance Ultra cAMP kit (PerkinElmer). The formation of CB2-OX1 receptor complexes in transfected HEK-293T cells has been demonstrated. The tetrameric complex is constituted by one CB2R homodimer, one OX1R homodimer and two G proteins, a Gi and a Gq. The use of TAT interfering peptides showed that the CB2-OX1 receptor complex interface is TM4-TM5. At the functional level it has been observed that the OX1R antagonist, SB334867, potentiates the action induced by CB2R agonist JWH133. This effect is observed in transfected HEK-293T cells and microglia, and it is stronger in the Alzheimer’s disease (AD) animal model APPSw/Ind where the expression of the complex assessed by the proximity ligation assay indicates an increase in the number of complexes compared to resting microglia. The CB2-OX1 receptor complex is overexpressed in microglia from AD animal models where OX1R antagonists potentiate the neuroprotective actions of CB2R activation. Taken together, these results point to OX1R antagonists as drugs with therapeutic potential to combat AD. Data access statement: Raw data will be provided by the corresponding author upon reasonable requirement.

Cookery is perceived today as an instructive methodology that involves at least two cooks working together to develop something that is consumable in the market. Moreover, cooking is depicted as an approach of the coordination of the various aspects making up an individual such as knowledge and skills (Wang, Moore, Roehrig, and Park, 2016). In addition, skills and knowledge in cooking, particularly in commercial cooking involves the utilization of instructional materials that gives a student a background on what should be done inside the kitchen specifically, in commercial cooking, and the skills that should be developed prior to employing the knowledge obtained from instructional materials to the field of practice (Corlu and Capraro, 2019). Hence, the researcher conducted this study to assess the perception of the respondents on the instructional materials in commercial cooking, the level of competency of the respondents in commercial cooking upon using the instructional material, the relationship between the significant relationship between the instructional materials used in commercial cooking and the level of competency of the respondents, and the prediction of instructional materials used in commercial cooking and the level of competency. In accordance to this the findings revealed that there is no significant relationship between the instructional materials used in commercial cooking and the level of competency of the respondents. Furthermore, it was predicted that the four phases in the instructional material significantly contributed to the level of competency of the respondents upon using the instructional materials.

Addiction and eating disorders involve brain reward circuits. Binge eating predisposes to addictive behavior, while the cessation of exposure to drugs of abuse leads to reward activities, including intake of tasty foods. Cocaine use is associated with a decrease in food intake, with reversal after drug use is discontinued. Exciting new findings show that receptors for the ‘hunger’ hormone, ghrelin, directly interact with the sigma-1 receptor (σ1R), which is a target of cocaine. σ1Rs are key players in regulating dopaminergic neurotransmission and ghrelin-mediated actions. This review focuses on the σ1 receptor as a general neuroendocrine regulator by directly interacting with neuronal G-protein-coupled receptors. This review also covers the early mechanisms by which cocaine binding to σ1 blocks the food-seeking behavior triggered by ghrelin. Those findings appear as fundamental to understand common mechanisms in drug addiction and eating disorders.

Neuroprotective M2-skewed microglia appear as promising to alter the course of neurodegenerative diseases and G protein-coupled receptors (GPCRs) are potential targets to achieve such microglial polarization. A common feature of adenosine A2A (A2A R) and cannabinoid CB2 (CB2 R) GPCRs in microglia is that their expression is upregulated in Alzheimer's disease (AD). On the one hand, CB2 R seems a target for neuroprotection, delaying neurodegenerative processes like those associated to AD or Parkinson's diseases. A2A R antagonists reduce amyloid burden and improve cognitive performance and memory in AD animal models. We here show a close interrelationship between these two receptors in microglia; they are able to physically interact and affect the signaling of each other, likely due to conformational changes within the A2A -CB2 receptor heteromer (A2A -CB2 Het). Particularly relevant is the upregulation of A2A -CB2 Het expression in samples from the APPSw ,Ind AD transgenic mice model. The most relevant finding, confirmed in both heterologous cells and in primary cultures of microglia, was that blockade of A2A receptors results in increased CB2 R-mediated signaling. This heteromer-specific feature suggests that A2A R antagonists would potentiate, via microglia, the neuroprotective action of endocannabinoids with implications for AD therapy.

Using a previously unexplored, efficient, and versatile multicomponent method, we herein report the rapid generation of novel potent and subtype-selective DRD2 biased partial agonists. This strategy exemplifies the search for diverse and previously unexplored moieties for the secondary/allosteric pharmacophore of the common phenyl-piperazine scaffold. The pharmacological characterization of the new compound series led to the identification of several ligands with excellent DRD2 affinity and subtype selectivity and remarkable functional selectivity for either the cAMP (22a and 24d) or the β-arrestin (27a and 29c) signaling pathways. These results were further interpreted on the basis of molecular models of these ligands in complex with the recent DRD2 crystal structures, highlighting the critical role of the secondary/allosteric pharmacophore in modulating the functional selectivity profile.

Resumen La biblioclastia es la destrucción de libros y material bibliográfico. El objetivo de esta investigación fue identificar los métodos y los contextos históricos de la destrucción intencional de libros en los siglos XX y XXl a través de una revisión sistematizada de la literatura. La búsqueda bibliográfica se realizó en: Scopus, Core, Google Scholar, Repositorios Latinoamericanos, Web of Science, Springer, Oxford, Unesco, E-lis, La Referencia, Jstor y Dialnet. Se seleccionaron 27 documentos para su análisis, a partir del cual se establecieron dos contextos en los que se produce la biblioclastia: Conflicto y No conflicto. Además, se identificaron tres técnicas con las que se destruyen los libros: Quema, Destrucción manual y Trituración. Se concluye que en el contexto Conflicto la causa principal de la biblioclastia es la censura por lo que representa el libro como medio de libertad de expresión. En el contexto No conflicto la destrucción es por motivos artísticos, vandálicos o por seguridad sanitaria. El método más usado es la quema de libros, relacionado con los contextos de conflictos y de seguridad (pandemia). Otros métodos fueron usados en menor medida, como la trituración. Abstract Biblioclasty is the destruction of books and bibliographic material. The objective of this research was to identify the methods and historical contexts of the intentional destruction of books in the 20th and 21st centuries through a systematized literature review. A bibliographic search was conducted in the databases Scopus, Core, Google Scholar, Repositorios Latinoamericanos, Web of Science, Springer, Oxford, Unesco, E-lis, La Referencia, Jstor y Dialnet. 27 documents were selected for analysis, from which two contexts were established in which biblioclasty occurs: Conflict and Non-conflict. In addition, three techniques with which books are destroyed were identified: Burning, Manual Destruction, and Shredding. It is concluded that in the conflict context, the main cause of biblioclasty is censorship because of what the book represents as a means of freedom of expression. In the non-conflict context the destruction is for artistic reasons, vandalism or for health security. The most used method is book burning, related to conflict and security contexts (pandemic). Other methods were used to a lesser extent such as crushing.

Neuronal survival depends on the glia, that is, on the astroglial and microglial support. Neurons die and microglia are activated not only in neurodegenerative diseases but also in physiological aging. Activated microglia, once considered harmful, express two main phenotypes: the pro-inflammatory or M1, and the neuroprotective or M2. When neuroinflammation, i.e., microglial activation occurs, it is important to achieve a good M1/M2 balance, i.e., at some point M1 microglia must be skewed into M2 cells to impede chronic inflammation and to afford neuronal survival. G protein-coupled receptors in general and adenosine receptors in particular are potential targets for increasing the number of M2 cells. This article describes the mechanisms underlying microglial activation and analyzes whether these cells exposed to a first damaging event may be ready to be preconditioned to better react to exposure to more damaging events. Adenosine receptors are relevant due to their participation in preconditioning. They can also be overexpressed in activated microglial cells. The potential of adenosine receptors and complexes formed by adenosine receptors and cannabinoids as therapeutic targets to provide microglia-mediated neuroprotection is here discussed. Keywords: neurodegeneration; aging; Parkinson's disease; Alzheimer's disease; neuroprotection; neuronal survival; cannabinoids; receptor heteromers

The mechanism of nigral dopaminergic neuronal degeneration in Parkinson’s disease (PD) is unknown. One of the pathological characteristics of the disease is the deposition of α-synuclein (α-syn) that occurs in the brain from both familial and sporadic PD patients. This paper constitutes a narrative review that takes advantage of information related to genes (SNCA, LRRK2, GBA, UCHL1, VPS35, PRKN, PINK1, ATP13A2, PLA2G6, DNAJC6, SYNJ1, DJ-1/PARK7 and FBXO7) involved in familial cases of Parkinson’s disease (PD) to explore their usefulness in deciphering the origin of dopaminergic denervation in many types of PD. Direct or functional interactions between genes or gene products are evaluated using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database. The rationale is to propose a map of the interactions between SNCA, the gene encoding for α-syn that aggregates in PD, and other genes, the mutations of which lead to early-onset PD. The map contrasts with the findings obtained using animal models that are the knockout of one of those genes or that express the mutated human gene. From combining in silico data from STRING-based assays with in vitro and in vivo data in transgenic animals, two likely mechanisms appeared: (i) the processing of native α-syn is altered due to the mutation of genes involved in vesicular trafficking and protein processing, or (ii) α-syn mutants alter the mechanisms necessary for the correct vesicular trafficking and protein processing. Mitochondria are a common denominator since both mechanisms require extra energy production, and the energy for the survival of neurons is obtained mainly from the complete oxidation of glucose. Dopamine itself can result in an additional burden to the mitochondria of dopaminergic neurons because its handling produces free radicals. Drugs acting on G protein-coupled receptors (GPCRs) in the mitochondria of neurons may hopefully end up targeting those receptors to reduce oxidative burden and increase mitochondrial performance. In summary, the analysis of the data of genes related to familial PD provides relevant information on the etiology of sporadic cases and might suggest new therapeutic approaches.

Using a previously unexplored, efficient, and versatile multicomponent method, we herein report the rapid generation of novel potent and subtype-selective DRD2 biased partial agonists. This strategy exemplifies the search for diverse and previously unexplored moieties for the secondary/allosteric pharmacophore of the common phenyl-piperazine scaffold. The pharmacological characterization of the new compound series led to the identification of several ligands with excellent DRD2 affinity and subtype selectivity and remarkable functional selectivity for either the cAMP (22a and 24d) or the β-arrestin (27a and 29c) signaling pathways. These results were further interpreted on the basis of molecular models of these ligands in complex with the recent DRD2 crystal structures, highlighting the critical role of the secondary/allosteric pharmacophore in modulating the functional selectivity profile This work was financially supported by the Consellería de Cultura, Educación e Ordenación Universitaria of the Galician Government: (grant: ED431B 2020/43), Centro Singular de Investigación de Galicia accreditation 2019-2022 (ED431G 2019/03), the Spanish Ministerio de Economía y Competitividad (SAF2017-84117-R), the European Regional Development Fund (ERDF) and the Swedish Research Council. Additional support from the Swedish strategic research program eSSENCE and Deputación da Coruña (grant: 2019000011466) are acknowledged. The computations were performed on resources provided by the Swedish National Infrastructure for Computing (SNIC). This research program was developed within the framework of the European COST action ERNEST (CA 18133) SI

G protein-coupled receptors (GPCRs), which constitute the most populous family of the human proteome, are the target of 35–45% of approved therapeutic drugs. This review focuses on natural products (excluding peptides) that target GPCRs. Natural compounds identified so far as agonists, antagonists or allosteric modulators of GPCRs have been found in all groups of existing living beings according to Whittaker’s Five Kingdom Classification, i.e., bacteria (monera), fungi, protoctists, plants and animals. Terpenoids, alkaloids and flavonoids are the most common chemical structures that target GPCRs whose endogenous ligands range from lipids to epinephrine, from molecules that activate taste receptors to molecules that activate smell receptors. Virtually all of the compounds whose formula is displayed in this review are pharmacophores with potential for drug discovery; furthermore, they are expected to help expand the number of GPCRs that can be considered as therapeutic targets.

Biased agonism, the ability of agonists to differentially activate downstream signaling pathways by stabilizing specific receptor conformations, is a key issue for G protein-coupled receptor (GPCR) signaling. The C-terminal domain might influence this functional selectivity of GPCRs as it engages G proteins, GPCR kinases, β-arrestins, and several other proteins. Thus, the aim of this paper is to compare the agonist-dependent selectivity for intracellular pathways in a heterologous system expressing the full-length (A2AR) and a C-tail truncated (A2AΔ40R lacking the last 40 amino acids) adenosine A2A receptor, a GPCR that is already targeted in Parkinson’s disease using a first-in-class drug. Experimental data such as ligand binding, cAMP production, β-arrestin recruitment, ERK1/2 phosphorylation and dynamic mass redistribution assays, which correspond to different aspects of signal transduction, were measured upon the action of structurally diverse compounds (the agonists adenosine, NECA, CGS-21680, PSB-0777 and LUF-5834 and the SCH-58261 antagonist) in cells expressing A2AR and A2AΔ40R. The results show that taking cAMP levels and the endogenous adenosine agonist as references, the main difference in bias was obtained with PSB-0777 and LUF-5834. The C-terminus is dispensable for both G-protein and β-arrestin recruitment and also for MAPK activation. Unrestrained molecular dynamics simulations, at the μs timescale, were used to understand the structural arrangements of the binding cavity, triggered by these chemically different agonists, facilitating G protein binding with different efficacy.

The aim of this paper was to check the possible interaction of two of the four purinergic P1 receptors, the A2A and the A3. Discovery of the A2A–A3 receptor complex was achieved by means of immunocytochemistry and of bioluminescence resonance energy transfer. The functional properties and heteromer print identification were addressed by combining binding and signaling assays. The physiological role of the novel heteromer is to provide a differential signaling depending on the pre-coupling to signal transduction components and/or on the concentration of the endogenous agonist. The main feature was that the heteromeric context led to a marked decrease of the signaling originating at A3 receptors. Interestingly from a therapeutic point of view, A2A receptor antagonists overrode the blockade, thus allowing A3 receptor-mediated signaling. The A2A–A3 receptor heteromer print was detected in primary cortical neurons. These and previous results suggest that all four adenosine receptors may interact with each other. Therefore, each adenosine receptor could form heteromers with distinct properties, expanding the signaling outputs derived from the binding of adenosine to its cognate receptors.

Recent approved medicines whose active principles are ΔCannabinoid CBDetermination of the affinity of phytocannabinoids for cannabinoid receptors and functional assessment of effects promoted by these compounds when interacting with cannabinoid receptors.A heterologous system expressing the human versions of CBAffinity of cannabinoids depend on the ligand of reference and may be different in membranes and in living cells. All tested phytocannabinoids have agonist-like behavior but behaved as inverse-agonists in the presence of selective receptor agonists. CBGV displayed enhanced potency in many of the functional outputs. However, the most interesting result was a biased signaling that correlated with differential affinity, i.e. the overall results suggest that the binding mode of each ligand leads to specific receptor conformations underlying biased signaling outputs.Results here reported and the recent elucidation of the three-dimensional structure of CB

Background/Aims : The renin-angiotensin system (RAS) is altered in Parkinson’s disease (PD), a disease due to substantia nigra neurodegeneration and whose dopamine-replacement therapy, using the precursor levodopa, leads to dyskinesias as the main side effect. Angiotensin AT 1 and AT 2 receptors, mainly known for their role in regulating water homeostasis and blood pressure and able to form heterodimers (AT 1/2 Hets), are present in the central nervous system. We assessed the functionality and expression of AT 1/2 Hets in Parkinson Disease (PD). Methods: Immunocytochemistry was used to analyze the colocalization between angiotensin receptors, bioluminescence resonance energy transfer was used to detect AT 1/2 Hets. Calcium and cAMP determination, MAPK activation and label-free assays were performed to characterize signaling. Proximity ligation assays was used to quantify receptor expression in microglial cells and brain striatal slices. Results: We confirmed that AT 1 and AT 2 receptors form AT 1/2 Hets that are expressed in cells of the central nervous system. AT 1/2 Hets are novel functional units with particular signaling properties. Importantly, the coactivation of the two receptors in the heteromer reduces the signaling output of angiotensin. Remarkably, AT 1/2 Hets that are expressed in both striatal neurons and microglia show a cross-potentiation, i.e. candesartan, the antagonist of AT 1 increases the effect of AT 2 receptor agonists. In addition, the level of expression in the unilateral 6-OH-dopamine lesion rat PD model increases upon disease progression and is maximal in dyskinetic animals. Conclusion: The results indicate that boosting the action of neuroprotective AT 2 receptors using an AT 1 receptor antagonist constitutes a promising therapeutic strategy in PD.

Background/aims The renin-angiotensin system (RAS) is altered in Parkinson’s disease (PD), a disease due to substantia nigra neurodegeneration and whose dopamine-replacement therapy, using the precursor levodopa, leads to dyskinesias as the main side effect. Angiotensin AT1 and AT2 receptors, mainly known for their role in regulating water homeostasis and blood pressure and able to form heterodimers (AT1/2Hets), are present in the central nervous system. We assessed the functionality and expression of AT1/2Hets in Parkinson disease (PD). Methods Immunocytochemistry was used to analyze the colocalization between angiotensin receptors; bioluminescence resonance energy transfer was used to detect AT1/2Hets. Calcium and cAMP determination, MAPK activation, and label-free assays were performed to characterize signaling in homologous and heterologous systems. Proximity ligation assays were used to quantify receptor expression in mouse primary cultures and in rat striatal sections. Results We confirmed that AT1 and AT2 receptors form AT1/2Hets that are expressed in cells of the central nervous system. AT1/2Hets are novel functional units with particular signaling properties. Importantly, the coactivation of the two receptors in the heteromer reduces the signaling output of angiotensin. Remarkably, AT1/2Hets that are expressed in both striatal neurons and microglia make possible that candesartan, the antagonist of AT1, increases the effect of AT2 receptor agonists. In addition, the level of striatal expression increased in the unilateral 6-OH-dopamine lesioned rat PD model and was markedly higher in parkinsonian-like animals that did not become dyskinetic upon levodopa chronic administration if compared with expression in those that became dyskinetic. Conclusion The results indicate that boosting the action of neuroprotective AT2 receptors using an AT1 receptor antagonist constitutes a promising therapeutic strategy in PD.

BACKGROUND AND PURPOSE: Often, glaucoma presents with elevated eye hydrostatic pressure, which is regulated by endogenous melatonin. Phenylephrine increases cytoplasmic [Ca(2+)], via α(1)‐adrenoceptor activation, that is detrimental in glaucoma. The aims of this study were (a) to elucidate the role of melatonin receptors in humour production and intraocular pressure (IOP) maintenance and (b) to identify glaucoma‐relevant melatonin–adrenoceptor interactions. EXPERIMENTAL APPROACH: Biophysical and proximity ligation assays were performed to identify interactions in heterologous expression systems, in cell lines and in human eyes. G(s)/G(i)/G(q) signalling was investigated in these systems and in cells producing aqueous humour. IOP was determined in a mice model of glaucoma. Retinography and topically pharmacological treatment were performed in control and in glaucomatous mice. KEY RESULTS: α(1)‐adreno‐ and melatonin receptors form functional complexes in which the C‐terminal tail of the adrenoceptor plays a role. Remarkably, activation of α(1)‐adrenoceptors in these complexes did not lead to cytosolic Ca(2+) increases, suggesting G(s) instead of G(q) coupling is involved. The number of these complexes significantly decreased in models of glaucoma and, importantly, in human samples from glaucoma patients. This has led to hypothesize that melatonin, a hypotensive agent, plus blockade of α(1)‐adrenoceptors could normalize pressure in glaucoma. Remarkably, co‐instillation of melatonin and prazosin, an α(1)‐adrenoceptor antagonist, resulted in long‐term decreases in IOP in a well‐established animal model of glaucoma. CONCLUSIONS AND IMPLICATIONS: The findings are instrumental to understand the physiological function of melatonin in the eye and its potential to address eye pathologies by targeting melatonin receptors and their complexes.

While natural Δ9-tetrahidrocannabinol (Δ9THC), cannabidiol (CBD), and their therapeutic potential have been extensively researched, some cannabinoids have been less extensively investigated. The present article compiles data from the literature that highlight the health benefits and therapeutic potential of lesser known phytocannabinoids, which we have divided into varinic, acidic, and "minor" (i.e., cannabinoids that are not present in high quantities in common varieties of Cannabis sativa L). A growing interest in these compounds, which are enriched in some cannabis varieties, has already resulted in enough preclinical information to show that they are promising therapeutic agents for a variety of diseases. Every phytocannabinoid has a "preferential" mechanism of action, and often targets the cannabinoid receptors, CB1 and/or CB2. The recent resolution of the structure of cannabinoid receptors demonstrates the atypical nature of cannabinoid binding, and that different binding modes depend on the agonist or partial agonist/inverse agonist, which allows for differential signaling, even acting on the same cannabinoid receptor. In addition, other players and multiple signaling pathways may be targeted/engaged by phytocannabinoids, thereby expanding the mechanistic possibilities for therapeutic use.

Background: Experiments in the late nineties showed an inverse relationship in the eye levels of melatonin and dopamine, thereby constituting an example of eye parameters that are prone to circadian variations. The underlying mechanisms are not known but these relevant molecules act via specific cell surface dopamine and melatonin receptors. This study investigated whether these receptors formed heteromers whose function impact on eye physiology. We performed biophysical assays to identify interactions in heterologous systems. Particular heteromer functionality was detected using Gi coupling, MAPK activation, and label-free assays. The expression of the heteroreceptor complexes was assessed using proximity ligation assays in cells producing the aqueous humor and human eye samples. Dopamine D3 receptors (D3Rs) were identified in eye ciliary body epithelial cells. We discovered heteromers formed by D3R and either MT1 (MT1R) or MT2 (MT2R) melatonin receptors. Heteromerization led to the blockade of D3R-Gi coupling and regulation of signaling to the MAPK pathway. Heteromer expression was negatively correlated with intraocular hypertension. Conclusions: Heteromers likely mediate melatonin and dopamine actions in structures regulating intraocular pressure. Significant expression of D3R&ndash, MT1R and D3R&ndash, MT1R was associated with normotensive conditions, whereas expression diminished in a cell model of hypertension. A clear trend of expression reduction was observed in samples from glaucoma cases. The trend was marked but no statistical analysis was possible as the number of available eyes was 2.

Angiotensin-converting enzyme 2 (ACE2) is a membrane peptidase and a component of the renin-angiotensin system (RAS) that has been found in cells of all organs, including the lungs. While ACE2 has been identified as the receptor for severe acute respiratory syndrome (SARS) coronaviruses, the mechanism underlying cell entry remains unknown. Human immunodeficiency virus infects target cells via CXC chemokine receptor 4 (CXCR4)-mediated endocytosis. Furthermore, CXCR4 interacts with dipeptidyl peptidase-4 (CD26/DPPIV), an enzyme that cleaves CXCL12/SDF-1, which is the chemokine that activates this receptor. By analogy, we hypothesized that ACE2 might also be capable of interactions with RAS-associated G-protein coupled receptors. Using resonance energy transfer and cAMP and mitogen-activated protein kinase signaling assays, we found that human ACE2 interacts with RAS-related receptors, namely the angiotensin II type 1 receptor (AT1R), the angiotensin II type 2 receptor (AT2R), and the MAS1 oncogene receptor (MasR). Although these interactions led to various alterations of signal transduction, but, more importantly, ligand binding to AT1R resulted in the downregulation of ACE2 cell surface expression, while ligand binding to AT2R, but not to MasR, resulted in upregulation of ACE2 cell surface expression. Proximity ligation assays performed in situ revealed macromolecular complexes containing ACE2 and AT1R, AT2R or MasR in adult but not fetal mouse lung tissue. These findings highlight the relevance of RAS in SARS-CoV-2 infection and the role of ACE2-containing complexes as potential therapeutic targets The Molecular Neurobiology Laboratory of the University of Barcelona is considered a research group of excellence by the Regional Catalonian Government (grup consolidat #2017 SGR 1497) SI