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1.
Int J Mol Sci ; 22(16)2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34445634

RESUMO

Cannabinoids have been reported as orexigenic, i.e., as promoting food intake that, among others, is controlled by the so-called "hunger" hormone, ghrelin. The aim of this paper was to look for functional and/or molecular interactions between ghrelin GHSR1a and cannabinoid CB2 receptors at the central nervous system (CNS) level. In a heterologous system we identified CB2-GHSR1a receptor complexes with a particular heteromer print consisting of impairment of CB2 receptor/Gi-mediated signaling. The blockade was due to allosteric interactions within the heteromeric complex as it was reverted by antagonists of the GHSR1a receptor. Cannabinoids acting on the CB2 receptor did not affect cytosolic increases of calcium ions induced by ghrelin acting on the GHSR1a receptor. In situ proximity ligation imaging assays confirmed the expression of CB2-GHSR1a receptor complexes in both heterologous cells and primary striatal neurons. We tested heteromer expression in neurons from offspring of high-fat-diet mouse mothers as they have more risk to be obese. Interestingly, there was a marked upregulation of those complexes in striatal neurons from siblings of pregnant female mice under a high-fat diet.


Assuntos
Corpo Estriado/patologia , Dieta Hiperlipídica/efeitos adversos , Grelina/metabolismo , Neurônios/patologia , Obesidade/patologia , Receptor CB2 de Canabinoide/metabolismo , Receptores de Grelina/metabolismo , Animais , Canabinoides/farmacologia , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/metabolismo , Feminino , Grelina/genética , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Obesidade/etiologia , Obesidade/metabolismo , Receptor CB2 de Canabinoide/genética , Receptores de Grelina/genética , Transdução de Sinais , Regulação para Cima
2.
Redox Biol ; 46: 102078, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34333284

RESUMO

ACE2 plays a pivotal role in the balance between the pro-oxidative pro-inflammatory and the anti-oxidative anti-inflammatory arms of the renin-angiotensin system. Furthermore, ACE2 is the entry receptor for SARS-CoV-2. Clarification of ACE2-related mechanisms is crucial for the understanding of COVID-19 and other oxidative stress and inflammation-related processes. In rat and monkey brain, we discovered that the intracellular ACE2 and its products Ang 1-7 and alamandine are highly concentrated in the mitochondria and bind to a new mitochondrial Mas-related receptor MrgE (MrgE) to produce nitric oxide. We found MrgE expressed in neurons and glia of rodents and primates in the substantia nigra and different brain regions. In the mitochondria, ACE2 and MrgE expressions decreased and NOX4 increased with aging. This new ACE2/MrgE/NO axis may play a major role in mitochondrial regulation of oxidative stress in neurons, and possibly other cells. Therefore, dysregulation of the mitochondrial ACE2/MrgE/NO axis may play a major role in neurodegenerative processes of dopaminergic neurons, where mitochondrial dysfunction and oxidative stress play a crucial role. Since ACE2 binds SARS-CoV-2 spike protein, the mitochondrial ACE2/MrgE/NO axis may also play a role in SARS-CoV-2 cellular effects.


Assuntos
Enzima de Conversão de Angiotensina 2/metabolismo , Neurônios Dopaminérgicos/metabolismo , Mitocôndrias/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Animais , COVID-19 , Humanos , Primatas , Ratos , Roedores , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus
3.
Enferm Infecc Microbiol Clin (Engl Ed) ; 39(8): 372-382, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34373227

RESUMO

INTRODUCTION: This study sought to analyse differences in epidemiology and survival between women and men living with HIV (WLHIV and MLHIV) in the CoRIS cohort and the course of their disease over a 10-year period. METHODS: Variables of interest between WLHIV and MLHIV were compared. A trend analysis was performed using the Mantel-Haenszel test. Kaplan-Meier survival curves and a Cox regression analysis were used to study survival. RESULTS: A total of 10,469 people were enrolled; of them, 1,742 (16.6%) were women. At the time of enrolment in the cohort, WLHIV, compared to MLHIV, had higher rates of transmission due to intravenous drug use (IDU), hepatitis C virus (HCV) coinfection, AIDS-stage disease and foreign origin. They also had a worse immunovirological status and a lower educational level. These differences were maintained in the trend study. Regarding age, the women included in the cohort were older whereas the men were younger. In the comparative analysis between women according to place of origin, we found that the group of Spanish WLHIV featured older women with higher rates of IDU transmission and HCV coinfection, whereas the group of WLHIV born outside of Spain featured women with higher rates of syphilis infection. There were no major differences in relation to other characteristics such as educational level or disease status. Although sex was not a determinant of survival, conditions more prevalent in women were determinants of survival. CONCLUSIONS: HIV-infected women presented at diagnosis with certain epidemiological and HIV-associated characteristics that made them more vulnerable. These trends became more marked or did not improve during the years of observation.

4.
Curr Issues Mol Biol ; 43(2): 650-664, 2021 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-34287292

RESUMO

Although antioxidants can act locally to react with an oxidant, oral administration of "antioxidants" is quite useless in treating oxidative stress in tissues. Furthermore, it does not make sense to consider a vitamin as an antioxidant, but vitamin B3 leads to the in vivo formation of compounds that are essential for reducing this stress. A rigorous treatment of the subject indicates that to deal with oxidative stress, the most direct approach is to enhance the innate antioxidant mechanisms. The question is whether this is possible through daily activities. Diets can contain the necessary components for these mechanisms or may induce the expression of the genes involved in them. Another possibility is that pro-oxidant molecules in food increase the sensitivity and power of the detoxification pathways. This option is based on well-known DNA repair mechanisms after exposure to radiation (even from the Sun), or strong evidence of induction of antioxidant capacity after exposure to powerful pro-oxidants such as H2O2. More experimental work is required to test whether some molecules in food can increase the expression of antioxidant enzymes and/or improve antioxidant mechanisms. Identifying effective molecules to achieve such antioxidant power is critical to the food and nutraceutical industries. The potential of diet-based interventions to combat oxidative stress must be viewed from a new perspective.

5.
Cells ; 10(5)2021 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-34066933

RESUMO

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.

6.
J Med Chem ; 64(13): 9354-9364, 2021 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-34161090

RESUMO

Cannabidiol (CBD), the second most abundant of the active compounds found in the Cannabis sativa plant, is of increasing interest because it is approved for human use and is neither euphorizing nor addictive. Here, we design and synthesize novel compounds taking into account that CBD is both a partial agonist, when it binds to the orthosteric site, and a negative allosteric modulator, when it binds to the allosteric site of the cannabinoid CB2 receptor. Molecular dynamic simulations and site-directed mutagenesis studies have identified the allosteric site near the receptor entrance. This knowledge has permitted to perform structure-guided design of negative and positive allosteric modulators of the CB2 receptor with potential therapeutic utility.


Assuntos
Produtos Biológicos/farmacologia , Canabidiol/farmacologia , Agonistas de Receptores de Canabinoides/farmacologia , Desenho de Fármacos , Receptor CB2 de Canabinoide/agonistas , Sítio Alostérico/efeitos dos fármacos , Produtos Biológicos/síntese química , Produtos Biológicos/química , Canabidiol/síntese química , Canabidiol/química , Agonistas de Receptores de Canabinoides/síntese química , Agonistas de Receptores de Canabinoides/química , Cannabis/química , Relação Dose-Resposta a Droga , Humanos , Simulação de Dinâmica Molecular , Estrutura Molecular , Relação Estrutura-Atividade
7.
J Med Chem ; 64(12): 8710-8726, 2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-34110150

RESUMO

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 ß-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.


Assuntos
Piperazinas/farmacologia , Receptores de Dopamina D2/agonistas , AMP Cíclico/metabolismo , Desenho de Fármacos , Agonismo Parcial de Drogas , Células HEK293 , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Piperazinas/síntese química , Piperazinas/metabolismo , Receptores de Dopamina D2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade , beta-Arrestinas/metabolismo
9.
Int J Mol Sci ; 22(9)2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33924963

RESUMO

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.


Assuntos
Doença de Parkinson/genética , Animais , Animais Geneticamente Modificados , Neurônios Dopaminérgicos/metabolismo , Humanos , Doença de Parkinson/metabolismo , Substância Negra/metabolismo , alfa-Sinucleína/metabolismo
10.
Cell Mol Gastroenterol Hepatol ; 12(2): 489-506, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33864900

RESUMO

BACKGROUND AND AIMS: CD4+ T cells constitute central players in inflammatory bowel diseases (IBDs), driving inflammation in the gut mucosa. Current evidence indicates that CCR9 and the integrin α4ß7 are necessary and sufficient to imprint colonic homing on CD4+ T cells upon inflammation. Interestingly, dopaminergic signaling has been previously involved in leukocyte homing. Despite dopamine levels are strongly reduced in the inflamed gut mucosa, the role of dopamine in the gut homing of T cells remains unknown. Here, we study how dopaminergic signaling affects T cells upon gut inflammation. METHODS: Gut inflammation was induced by transfer of naïve T cells into Rag1-/- mice or by administration of dextran sodium sulfate. T cell migration and differentiation were evaluated by adoptive transfer of congenic lymphocytes followed by flow cytometry analysis. Protein interaction was studied by bioluminescence resonance energy transfer analysis, bimolecular fluorescence complementation, and in situ proximity ligation assays. RESULTS: We show the surface receptor providing colonic tropism to effector CD4+ T cells upon inflammation is not CCR9 but the complex formed by CCR9 and the dopamine receptor D5 (DRD5). Assembly of the heteromeric complex was demonstrated in vitro and in vivo using samples from mouse and human origin. The CCR9:DRD5 heteroreceptor was upregulated in the intestinal mucosa of IBD patients. Signaling assays confirmed that complexes behave differently than individual receptors. Remarkably, the disruption of CCR9:DRD5 assembly attenuated the recruitment of CD4+ T cells into the colonic mucosa. CONCLUSIONS: Our findings describe a key homing receptor involved in gut inflammation and introduce a new cell surface module in immune cells: macromolecular complexes formed by G protein-coupled receptors integrating the sensing of multiple molecular cues.

11.
Int J Mol Sci ; 22(5)2021 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-33803075

RESUMO

Methamphetamine is, worldwide, one of the most consumed drugs of abuse. One important side effect is neurodegeneration leading to a decrease in life expectancy. The aim of this paper was to check whether the drug affects one of the receptors involved in neurodegeneration/neuroprotection events, namely the adenosine A2A receptor (A2AR). First, we noticed that methamphetamine does not affect A2A functionality if the receptor is expressed in a heterologous system. However, A2AR becomes sensitive to the drug upon complexes formation with the cannabinoid CB1 receptor (CB1R) and the sigma 1 receptor (σ1R). Signaling via both adenosine A2AR and cannabinoid CB1R was affected by methamphetamine in cells co-expressing the two receptors. In striatal primary cultures, the A2AR-CB1R heteromer complex was detected and methamphetamine not only altered its expression but completely blocked the A2AR- and the CB1R-mediated activation of the mitogen activated protein kinase (MAPK) pathway. In conclusion, methamphetamine, with the participation of σ1R, alters the expression and function of two interacting receptors, A2AR, which is a therapeutic target for neuroprotection, and CB1R, which is the most abundant G protein-coupled receptor (GPCR) in the brain.


Assuntos
Antagonistas do Receptor A2 de Adenosina/farmacologia , Corpo Estriado/metabolismo , Metanfetamina/farmacologia , Neurônios/metabolismo , Receptor A2A de Adenosina/metabolismo , Receptor CB1 de Canabinoide/metabolismo , Receptores sigma/metabolismo , Animais , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Células HEK293 , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos
12.
Brain Sci ; 11(2)2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33671675

RESUMO

Suitable in vivo and in vitro models are instrumental for the development of new drugs aimed at improving symptoms or progression of multiple sclerosis (MS). The cuprizone (CPZ)-induced murine model has gained momentum in recent decades, aiming to address the demyelination component of the disease. This work aims at assessing the differential cytotoxicity of CPZ in cells of different types and from different species: human oligodendroglial (HOG), human neuroblastoma (SH-SY5Y), human glioblastoma (T-98), and mouse microglial (N-9) cell lines. Moreover, the effect of CPZ was investigated in primary rat brain cells. Cell viability was assayed by oxygen rate consumption and by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide-based (MTT) method. Our results demonstrated that CPZ did not cause death in any of the assayed cell models but affected mitochondrial function and aerobic cell respiration, thus compromising cell metabolism in neural cells and neuron-glia co-cultures. In this sense, we found differential vulnerability between glial cells and neurons as is the case of the CPZ-induced mouse model of MS. In addition, our findings demonstrated that reduced viability was spontaneous reverted in a time-dependent manner by treatment discontinuation. This reversible cell-based model may help to further investigate the role of mitochondria in the disease, and study the molecular intricacies underlying the pathophysiology of the MS and other demyelinating diseases.

13.
Addict Biol ; 26(5): e13017, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33559278

RESUMO

Cocaine not only increases brain dopamine levels but also activates the sigma1 receptor (σ1 R) that in turn regulates orexigenic receptor function. Identification of interactions involving dopamine D1 (D1 R), ghrelin (GHS-R1a ), and σ1 receptors have been addressed by biophysical techniques and a complementation approach using interfering peptides. The effect of cocaine on receptor functionality was assayed by measuring second messenger, cAMP and Ca2+ , levels. The effect of acute or chronic cocaine administration on receptor complex expression was assayed by in situ proximity ligation assay. In silico procedures were used for molecular model building. σ1 R KO mice were used for confirming involvement of this receptor. Upon identification of protomer interaction and receptor functionality, a unique structural model for the macromolecular complex formed by σ1 R, D1 R, and GHS-R1a is proposed. The functionality of the complex, able to couple to both Gs and Gq proteins, is affected by cocaine binding to the σ1 R, as confirmed using samples from σ1 R-/- mice. The expression of the macromolecular complex was differentially affected upon acute and chronic cocaine administration to rats. The constructed 3D model is consistent with biochemical, biophysical, and available structural data. The σ1 R, D1 R, and GHS-R1a complex constitutes a functional unit that is altered upon cocaine binding to the σ1 R. Remarkably, the heteromer can simultaneously couple to two G proteins, thus allowing dopamine to signal via Ca2+ and ghrelin via cAMP. The anorexic action of cocaine is mediated by such complex whose expression is higher after acute than after chronic administration regimens.

14.
Cell Mol Life Sci ; 78(8): 3957-3968, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33580270

RESUMO

Adenosine is one of the most ancient signaling molecules and has receptors in both animals and plants. In mammals there are four specific receptors, A1, A2A, A2B, and A3, which belong to the superfamily of G-protein-coupled receptors (GPCRs). Evidence accumulated in the last 20 years indicates that GPCRs are often expressed as oligomeric complexes formed by a number of equal (homomers) or different (heteromers) receptors. This review presents the data showing the occurrence of heteromers formed by A1 and A2A, A2A and A2B, and A2A and A3 receptors highlighting (i) their tetrameric structural arrangements, and (ii) the functional diversity that those heteromers provide to adenosinergic signaling.


Assuntos
Adenosina/metabolismo , Receptores Purinérgicos P1/metabolismo , Animais , Humanos , Modelos Moleculares , Conformação Proteica , Multimerização Proteica , Receptores Purinérgicos P1/química , Transdução de Sinais
15.
Clin Transl Gastroenterol ; 12(2): e00304, 2021 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-33605613

RESUMO

INTRODUCTION: Guidelines for surveillance after polypectomy are lacking in strong evidence. Our aim was to identify some precursors of colorectal cancer lesions at 3 years after polypectomy to improve stratification and surveillance programs. METHODS: We included patients with high-risk lesions (HRLs), defined as advanced adenoma (AA), large serrated polyps (SPs), and multiplicity (≥3 of any adenomas/SPs). Data on age, sex, cardiovascular risk factors, pharmacological treatment, and the histological characteristics in each individual, and mutations in genes involved in the most advanced index polyp, were collected. Parameters independently associated with a metachronous HRL diagnosis were evaluated through univariate and multivariate analyses. The results are reported as odds ratios and 95% confidence intervals along with P values. RESULTS: A total of 537 cases (median age: 60.7 years; 66% male) were included. Dyslipidemia and smoking correlated with metachronous HRLs. Multivariate logistic regression analysis showed that the presence of multiplicity with ≥3 polyps on the index colonoscopy was significantly associated with metachronous HRL, AA, proximal AA, and ≥3 polyps at 3 years. In addition, independent predictors of metachronous proximal AA were increasing age, female sex, and the loss of expression of the MLH1 protein. DISCUSSION: Multiplicity was a strong predictor of HRLs at 3 years, although the inclusion of other clinical variables (age, sex, smoking status, and dyslipidemia) improves surveillance recommendations. Without these risk factors, the surveillance could be extended to 5 years; we propose examining the somatic expression of MHL1 in all patients.


Assuntos
Adenoma/diagnóstico , Pólipos do Colo/complicações , Pólipos do Colo/cirurgia , Colonoscopia , Neoplasias Colorretais/diagnóstico , Segunda Neoplasia Primária/diagnóstico , Fatores Etários , Idoso , Pólipos do Colo/genética , Pólipos do Colo/patologia , Dislipidemias/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Fumar/efeitos adversos
16.
Neurotherapeutics ; 18(2): 998-1016, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33474655

RESUMO

The renin-angiotensin system (RAS) not only plays an important role in controlling blood pressure but also participates in almost every process to maintain homeostasis in mammals. Interest has recently increased because SARS viruses use one RAS component (ACE2) as a target-cell receptor. The occurrence of RAS in the basal ganglia suggests that the system may be targeted to improve the therapy of neurodegenerative diseases. RAS-related data led to the hypothesis that RAS receptors may interact with each other. The aim of this paper was to find heteromers formed by Mas and angiotensin receptors and to address their functionality in neurons and microglia. Novel interactions were discovered by using resonance energy transfer techniques. The functionality of individual and interacting receptors was assayed by measuring levels of the second messengers cAMP and Ca2+ in transfected human embryonic kidney cells (HEK-293T) and primary cultures of striatal cells. Receptor complex expression was assayed by in situ proximity ligation assay. Functionality and expression were assayed in parallel in primary cultures of microglia treated or not with lipopolysaccharide and interferon-γ (IFN-γ). The proximity ligation assay was used to assess heteromer expression in parkinsonian and dyskinetic conditions. Complexes formed by Mas and the angiotensin AT1 or AT2 receptors were identified in both a heterologous expression system and in neural primary cultures. In the heterologous system, we showed that the three receptors-MasR, AT1R, and AT2R-can interact to form heterotrimers. The expression of receptor dimers (AT1R-MasR or AT2R-MasR) was higher in microglia than in neurons and was differentially affected upon microglial activation with lipopolysaccharide and IFN-γ. In all cases, agonist-induced signaling was reduced upon coactivation, and in some cases just by coexpression. Also, the blockade of signaling of two receptors in a complex by the action of a given (selective) receptor antagonist (cross-antagonism) was often observed. Differential expression of the complexes was observed in the striatum under parkinsonian conditions and especially in animals rendered dyskinetic by levodopa treatment. The negative modulation of calcium mobilization (mediated by AT1R activation), the multiplicity of possibilities on RAS affecting the MAPK pathway, and the disbalanced expression of heteromers in dyskinesia yield new insight into the operation of the RAS system, how it becomes unbalanced, and how a disbalanced RAS can be rebalanced. Furthermore, RAS components in activated microglia warrant attention in drug-development approaches to address neurodegeneration.

17.
Clin Sci (Lond) ; 135(3): 465-481, 2021 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-33479758

RESUMO

The key link between renin-angiotensin system (RAS) and COVID-19 is ACE2 (angiotensin-converting enzyme 2), which acts as a double-edged sword, because ACE2 increases the tissue anti-inflammatory response but it is also the entry receptor for the virus. There is an important controversy on several drugs that regulate RAS activity and possibly ACE2, and are widely used, particularly by patients most vulnerable to severe COVID-19. In the lung of healthy rats, we observed that candesartan (an angiotensin type-1, AT1, receptor blocker; ARB) and captopril (an ACE inhibitor; ACEI) up-regulated expression of tissue ACE2 and RAS anti-inflammatory axis receptors (AT2 and Mas receptors). This effect was particularly pronounced in rats with metabolic syndrome (obesity, increased blood pressure and hyperglycemia) and aged rats. Treatment of cultures of human type-II pneumocytes with candesartan or captopril induced up-regulation of ACE2 expression in cells. Treatment with viral spike protein induced a decrease in full-length (i.e. transmembrane) ACE2, an increase in levels of a short intracellular ACE2 polypeptide and an increase in ADAM17 activity in cells, together with an increase in levels of soluble ACE2 and major proinflammatory cytokines in the culture medium. Spike protein-induced changes and levels of spike protein internalization in cells were inhibited by pretreatment with the above-mentioned drugs. The results suggest that these drugs increase ACE2 levels and promote the anti-inflammatory RAS axis in the lung. Furthermore, possible up-regulation of viral entry by the drug-induced increase in expression of transmembrane ACE2 is counteracted by additional mechanisms, particularly by drug-induced inhibition of ADAM17 activity.


Assuntos
Benzimidazóis/administração & dosagem , Compostos de Bifenilo/administração & dosagem , COVID-19/tratamento farmacológico , Captopril/administração & dosagem , Tetrazóis/administração & dosagem , Proteína ADAM17/genética , Proteína ADAM17/metabolismo , Bloqueadores do Receptor Tipo 1 de Angiotensina II/administração & dosagem , Enzima de Conversão de Angiotensina 2/antagonistas & inibidores , Enzima de Conversão de Angiotensina 2/genética , Enzima de Conversão de Angiotensina 2/metabolismo , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Animais , COVID-19/genética , COVID-19/metabolismo , COVID-19/virologia , Feminino , Humanos , Pulmão/metabolismo , Pulmão/virologia , Masculino , Ratos , Sistema Renina-Angiotensina/efeitos dos fármacos , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/fisiologia
18.
Br J Pharmacol ; 178(7): 1507-1523, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33444462

RESUMO

BACKGROUND AND PURPOSE: The enzyme α/ß-hydrolase domain containing 6 (ABHD6), a new member of the endocannabinoid system, is a promising therapeutic target against neuronal-related diseases. However, how ABHD6 activity is regulated is not known. ABHD6 coexists in protein complexes with the brain-specific carnitine palmitoyltransferase 1C (CPT1C). CPT1C is involved in neuro-metabolic functions, depending on brain malonyl-CoA levels. Our aim was to study CPT1C-ABHD6 interaction and determine whether CPT1C is a key regulator of ABHD6 activity depending on nutritional status. EXPERIMENTAL APPROACH: Co-immunoprecipitation and FRET assays were used to explore ABHD6 interaction with CPT1C or modified malonyl-CoA-insensitive or C-terminal truncated CPT1C forms. Cannabinoid CB1 receptor-mediated signalling was investigated by determining cAMP levels. A novel highly sensitive fluorescent method was optimized to measure ABHD6 activity in non-neuronal and neuronal cells and in brain tissues from wild-type (WT) and CPT1C-KO mice. KEY RESULTS: CPT1C interacted with ABHD6 and negatively regulated its hydrolase activity, thereby regulating 2-AG downstream signalling. Accordingly, brain tissues of CPT1C-KO mice showed increased ABHD6 activity. CPT1C malonyl-CoA sensing was key to the regulatory role on ABHD6 activity and CB1 receptor signalling. Fasting, which attenuates brain malonyl-CoA, significantly increased ABHD6 activity in hypothalamus from WT, but not CPT1C-KO, mice. CONCLUSIONS AND IMPLICATIONS: Our finding that negative regulation of ABHD6 activity, particularly in the hypothalamus, is sensitive to nutritional status throws new light on the characterization and the importance of the proteins involved as potential targets against diseases affecting the CNS.


Assuntos
Carnitina O-Palmitoiltransferase , Monoacilglicerol Lipases/metabolismo , Estado Nutricional , Animais , Carnitina O-Palmitoiltransferase/genética , Hidrolases , Malonil Coenzima A , Camundongos
19.
Adv Exp Med Biol ; 1264: 81-92, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33332005

RESUMO

Three prevalent neurodegenerative diseases, Parkinson's, Alzheimer's, and Huntington's are in need of symptomatic relief of slowing disease progression or both. This chapter focuses on the potential of cannabinoids to afford neuroprotection, i.e. avoid or retard neuronal death. The neuroprotective potential of cannabinoids is known from the work in animal models and is mediated by the two cannabinoid receptors (CB1/CB2) and eventually, by their heteromers, GPR55, orphan receptors (GPR3/GPR6/GPR12/GPR18), or PPARγ. Now, there is the time to translate the findings into patients. The chapter takes primarily into account advances since 2016 and addresses the issue of proving neuroprotection in humans. One recent discovery is the existence of activated microglia with neuroprotective phenotype; cannabinoids are good candidates to skew phenotype, especially via glial CB2 receptors (CB2R), whose targeting has, a priori, less side effects those targeting the CBs1 receptor (CB1R), which are expressed in both neurons and glia. The fact that a cannabis extract (SativexTM) is approved for human therapy, such that cannabis use will likely be legalized in many countries and different possibilities that cannabinoid pharmacology suggests a successful route of cannabinoids (natural or synthetic) all the way to be approved and used in the treatment of neurodegeneration.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Canabinoides/farmacologia , Canabinoides/uso terapêutico , Doença de Huntington/tratamento farmacológico , Neuroproteção/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Doença de Parkinson/tratamento farmacológico , Animais , Humanos
20.
Int J Mol Sci ; 21(24)2020 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-33339432

RESUMO

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 lead to minor alterations of signal transduction, ligand binding to AT1R and AT2R, but not to MasR, resulted in the 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.


Assuntos
Enzima de Conversão de Angiotensina 2/metabolismo , COVID-19/patologia , Receptores CXCR4/metabolismo , Receptores Virais/metabolismo , SARS-CoV-2/metabolismo , Adulto , Linhagem Celular , Quimiocina CXCL12/metabolismo , Células HEK293 , Humanos , Peptidil Dipeptidase A/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptor Tipo 1 de Angiotensina/metabolismo , Receptor Tipo 2 de Angiotensina/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Sistema Renina-Angiotensina/fisiologia , Transdução de Sinais/fisiologia
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