Therapeutic utility of glucocorticoids and antihistamines cotreatment. Rationale and perspectives

Antihistamines and glucocorticoids (GCs) are often used together in the clinic, in several inflammatory-related situations. Even though there is no clear rationale for this drug association, the clinical practice is based on the assumption that due to their concomitant antiinflammatory effects, there should be an intrinsic benefit in their coadministration. Our group has studied the molecular interaction between the histamine H1 receptor and the glucocorticoid receptor (GR) signaling pathways, showing an enhancing effect on GC-induced GR transcriptional activity induced by antihistamines. We hypothesize that the existence of this synergistic effect could contribute in reducing the GCs clinical doses, ineffective by itself but effective in combination with an antihistamine. This could result in a therapeutic advantage as the GC-desired effects may be reinforced by the addition of an antihistamine and, as a consequence of the dose reduction, GC-related adverse effects could be reduced or at least mitigated. Here we discuss the potential therapeutic applications of this cotreatment seeking to evaluate its usefulness, especially in inflammatory-related conditions.Fil: Zappia, Carlos Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Monczor, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; Argentin

Respuesta cruzada entre la actividad del receptor a glucocorticoides y la señalización del receptor H1 a histamina

Histamine H1 receptor (H1R) antagonists and glucocorticoid receptor (GR) agonists are used to treat inflammatory conditions and are the targets of the greatest number of approved drugs. In many situations their ligands are co-administered, although this drug association has no clear rationale and has arisen from clinical practice. We hypothesized that H1R signaling could affect GR-mediated activity, impacting on its transcriptional outcome. Indeed, our results show a dual regulation of GR activity by the H1R: a potentiation mediated by G-protein ?? subunits and a parallel inhibitory effect mediated by G?q-PLC pathway. Activation of the H1R by its full agonists resulted in a composite potentiating effect. Intriguingly, inactivation of the G?q-PLC pathway by H1R inverse agonists resulted also in a potentiation of GR activity. Moreover, histamine and clinically relevant antihistamines synergized with the GR agonist dexamethasone to induce gene transactivation and transrepression in a gene-specific manner. Furthermore, in a murine model of asthma, the cotreatment was effective to improve the disease. Our work provides a delineation of molecular mechanisms underlying the widespread clinical association of antihistamines and GR agonists, which may contribute to future dosage optimization and reduction of well-described side effects associated with glucocorticoid administration.Fil: Zappia, Carlos Daniel. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaEl receptor a glucocorticoides (GR) y el receptor H1 a histamina (H1R) son los blancos farmacológicos con mayor número de drogas aprobadas para uso clínico. Más aun, existen numerosos cuadros de tipo inflamatorio, en los que ambas drogas son coadministradas. Dada su relevancia clínica, nos propusimos estudiar la regulación de la actividad del GR por parte de la señalización del H1R ahondando en los mecanismos moleculares de dicha interacción. Nuestros resultados muestran que la activación del H1R incrementa la actividad del GR a través un mecanismo dual, inhibitorio mediado por G?q-PLC-Rac, y estimulatorio mediado por G?? y JNK, prevaleciendo este último. Curiosamente, los antihistamínicos al inactivar al H1R, también incrementan la actividad del GR disminuyendo la actividad de la vía inhibitoria. Estos resultados fueron obtenidos utilizando sistemas de gen-reportero y midiendo la expresión de genes endógenos relacionados con los procesos inflamatorios. Además, en un modelo de asma murino, resultados preliminares muestran que dicho cotratamiento resulta eficaz para mejorar el cuadro patológico. Nuestro trabajo delinea los mecanismos moleculares subyacentes al uso clínico de ambos ligandos, lo que puede contribuir, en un futuro, a la optimización de las dosis utilizadas reduciendo los efectos adversos producidos por la administración de corticoides

Effects of histamine H1 receptor signaling on glucocorticoid receptor activity. Role of canonical and non-canonical pathways

Histamine H1 receptor (H1R) antagonists and glucocorticoid receptor (GR) agonists are used to treat inflammatory conditions such as allergic rhinitis, atopic dermatitis and asthma. Consistent with the high morbidity levels of such inflammatory conditions, these receptors are the targets of a vast number of approved drugs, and in many situations their ligands are co-administered. However, this drug association has no clear rationale and has arisen from clinical practice. We hypothesized that H1R signaling could affect GR-mediated activity, impacting on its transcriptional outcome. Indeed, our results show a dual regulation of GR activity by the H1R: a potentiation mediated by G-protein βγ subunits and a parallel inhibitory effect mediated by Gαq-PLC pathway. Activation of the H1R by its full agonists resulted in a composite potentiating effect. Intriguingly, inactivation of the Gαq-PLC pathway by H1R inverse agonists resulted also in a potentiation of GR activity. Moreover, histamine and clinically relevant antihistamines synergized with the GR agonist dexamethasone to induce gene transactivation and transrepression in a gene-specific manner. Our work provides a delineation of molecular mechanisms underlying the widespread clinical association of antihistamines and GR agonists, which may contribute to future dosage optimization and reduction of well-described side effects associated with glucocorticoid administration.Fil: Zappia, Carlos Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas (i); Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Química Medicinal; ArgentinaFil: Granja Galeano, Gina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas (i); Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Química Medicinal; ArgentinaFil: Fernandez, Natalia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas (i); Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Química Medicinal; ArgentinaFil: Shayo, Carina Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Davio, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas (i); Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Química Medicinal; ArgentinaFil: Fitzsimons, Carlos P.. University Of Amsterdam; Países BajosFil: Monczor, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas (i); Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Química Medicinal; Argentin

Biased agonism at histamine H1 receptors

GPCRs (G-protein coupled receptors) exist as conformational collectionsin which different conformations lead to differential downstream behaviors suchas G-protein activation, receptor phosphorylation or internalization. In thiscontext, a ligand may cause differential activation of some, but not all, ofthe signaling events associated to a particular receptor and would lead tobiased agonism. On the other hand, antihistamines used clinically asantiallergics rank among the most widely prescribed and over-the-counter drugsin the world. The aim of the present study was to investigate whether widelyused histamine H1 receptor (H1R) ligands that exert therapeutic actions byblocking the effects of histamine, due to null or negative efficacy towards Gαq-phospholipaseC (PLC)-inositol triphosphates (IP3) and Nuclear Factor-kB cascades, coulddisplay positive efficacy concerning receptor desensitizationor internalization. We used A549 cells, derivedfrom human lung epithelium, endogenously expressing the H1R. Pretreatment of A549 cells during 10 minutes with 1, 3, 10 and 33 μM ofchlorpheniramine and triprolidine prevented the increase of cytosolic Ca2+levels evoked by 100 μM of histamine suggesting that both ligands maypromote H1R desensitization. On the contrary, pretreatment with diphenhydraminedid not modify the H1R response to the agonist. To examine the mechanismsinvolved in these desensitizations we transfected A549 cells with GRK2 anddynamin dominant-negative mutants. Our results indicate that although thesemutants potentiate calcium response to histamine and partially impairedhistamine induced H1R desensitization they did not revert chlorpheniramine nortriprolidine induced desensitization. Finally, preliminary results of saturation-binding assays suggest that some ofthese ligands may also lead to receptor internalization. In conclusion, H1Rdesensitization and/or internalization promoted by these ligands demonstratetheir biased nature and could explain their undesired effects. Accordingly, thisstudy contributes to a correct classification, providing evidence for a morerational and safe use of antihistamines.Fil: Burghi, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Echeverría, Emiliana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Díaz Nebreda, Antonela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Zappia, Carlos Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Shayo, Carina Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Davio, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Monczor, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Fernandez, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaLXIII Reunión anual de la Sociedad Argentina de Investigación Clínica; LXVI Reunión anual de la Sociedad Argentina de Inmunología y Reunión Anual de la Asociación Argentina de FisiologíaMar del PlataArgentinaSociedad Argentina de Investigación ClínicaSociedad Argentina de InmunologíaAsociación Argentina de VirologíaAsociación Argentina de Nanomedicina

The cross-regulation between h1 and h2 histamine receptors modulates the behavior of h2 receptor blockers

Histamine modulates severalbiological processes, including allergy and gastric acid secretion, through H1and H2 receptors (H1R, H2R). H2R blockers are mainlyused to treat gastrointestinaldisorders, such as gastric acid secretion and there is much interest on theirrepositioning for other pathologies. Thus, deepunderstanding of theirmechanisms of action is needed. We have previously described that H1R and H2Ragonists induce the receptor?s co-internalization andcross-desensitization. We havealso reported that H2R blockers lead to desensitization and internalization ofH2 receptor.The aim of this work was tostudy the capacity of H2R blockers (cimetidine, ranitidine and famotidine) toinduce the H1R cross-desensitization and how thismechanism affects the behaviorof H2R blockers. In this way, we used promonocytic U937 cells (endogenouslyexpressing H1R and H2R), PMA-differentiated U937cells and HEK293 cellstransiently transfected with one or both receptors.Fil: Díaz Nebreda, Antonela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Sahores, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Zappia, Carlos Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Rodriguez Gonzalez, Angela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Burghi, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Monczor, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Davio, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Fernandez, Natalia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Shayo, Carina Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaLXIII Reunión Anual de la Sociedad Argentina de Investigación Clínica; LXVI Reunión Anual de la Sociedad Argentina de Inmunología y Reunión Anual de la Sociedad Argentina de Fisiología.Mar del PlataArgentinaSociedad Argentina de Investigación ClínicaSociedad Argentina de InmunologíaSociedad Argentina de Fisiologí

Involvement of histamine H1 and H2 receptor inverse agonists in receptor's crossregulation

Histamine [2-(4-Imidazolyl)-ethylamine] modulates different biological processes, through histamine H1 and H2 receptors, and their respective blockers are widely used in treating allergic and gastric acid-related disorders. Histamine H1 and H2 receptor crossdesensitization and cointernalization induced by its agonists have been previously described. In this study, we show how this crosstalk determines the response to histamine H1 and H2 receptor inverse agonists and how histamine H1 and H2 receptor inverse agonists interfere with the other receptor's response to agonists. By desensitization assays we demonstrate that histamine H1 and H2 receptor inverse agonists induce a crossregulation between both receptors. In this sense, the histamine H1 receptor inverse agonists desensitize the cAMP response to amthamine, a histamine H2 receptor agonist. In turn, histamine H2 receptor inverse agonists interfere with histamine H1 receptor signaling. We also determine that the crossdesensitization induced by histamine H1 or H2 receptor agonists alters the histamine inverse agonists receptor response: activation of histamine H1 receptor affects cAMP response induced by histamine H2 receptor inverse agonists, whereas histamine H2 receptor agonist induces a negative regulation on the anti-inflammatory response of histamine H1 receptor inverse agonists. Binding studies revealed that histamine H1 and H2 receptors cointernalize after stimulus with histamine receptor inverse agonists. In addition, the inhibition of the internalization process prevents receptor crossregulation. Our study provides new insights in the mechanisms of action of histamine H1 and H2 receptors that explain the effect of histamine H1 and H2 receptor inverse agonists and opens up new venues for novel therapeutic applications.Fil: Díaz, Antonela Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Zappia, Carlos Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Rodriguez Gonzalez, Angela Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Sahores, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Sosa, Máximo Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Burghi, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Monczor, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Davio, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Fernandez, Natalia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Shayo, Carina Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

Epigenetic changes induced by pesticide exposure reactivate LINE-1 retrotransposon in breast cancer and mammary epithelial cells

Expression of long interspersed nuclear element-1 (LINE-1) is reactivated during breast cancer initiation and progression. Strong ligands of aryl hydrocarbon receptor (AhR) activate LINE-1 through the transforming growth factor-β1 (TGF-β1)/Smad pathway. Studies have linked breast cancer risk with pesticide exposure, including hexachlorobenzene (HCB) and chlorpyrifos (CPF), both weak AhR ligands which promote alterations in mammary gland and tumor growth in animal models. We examined the pesticides action on LINE-1 reactivation in MDA-MB-231 breast cancer cells and NMuMG epithelial breast cells, and we evaluated the role of TGF-β1 and AhR. Results show that 0.5 μM CPF and 0.005 μM HCB reduced the methylation of the 5´-UTR of LINE-1 and increased LINE-1 mRNA expression via Smad and AhR signaling in MDA-MB-231. Besides, 5 μM CPF and 0.005 μM HCB heighten ORF1p nuclear import, the protein encoded by LINE-1, through TGF-β1/Smad and stimulate DNA double-strand breaks. Disturbingly, 5 μM CPF and 0.005 μM HCB also enhanced LINE-1 mRNA levels in NMuMG cells. CPF effect was through AhR and TGF-β1, while HCB action depends only of AhR. In addition, both pesticides increased ORF1p expression and nuclear localization. In conclusion, HCB and CPF induce LINE-1 reactivation, not only in breast cancer cells but also in epithelial mammary cells, supporting the idea that pesticide exposure could promote epigenetic changes, contributing to cell transformation and tumorigenesis in breast cancer.Fil: Miret, Noelia Victoria. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Zappia, Carlos Daniel. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Altamirano, Gabriela Anahí. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pontillo, Carolina Andrea. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Zárate, Lorena Vanesa. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gomez, Ayelen Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Lasagna, Marianela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Físico Matemática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cocca, Claudia Marcela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Físico Matemática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Kass, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Salud y Ambiente del Litoral. Universidad Nacional del Litoral. Instituto de Salud y Ambiente del Litoral; ArgentinaFil: Monczor, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Randi, Andrea Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; ArgentinaBuenos Aires Breast Cancer SymposiumBuenos AiresArgentinaAsocacion Argentina de Oncología ClinicaSociedad Argentina de Investigación ClinicaInstituto Nacional del Cance

An integrated cell atlas of the lung in health and disease

Single-cell technologies have transformed our understanding of human tissues. Yet, studies typically capture only a limited number of donors and disagree on cell type definitions. Integrating many single-cell datasets can address these limitations of individual studies and capture the variability present in the population. Here we present the integrated Human Lung Cell Atlas (HLCA), combining 49 datasets of the human respiratory system into a single atlas spanning over 2.4 million cells from 486 individuals. The HLCA presents a consensus cell type re-annotation with matching marker genes, including annotations of rare and previously undescribed cell types. Leveraging the number and diversity of individuals in the HLCA, we identify gene modules that are associated with demographic covariates such as age, sex and body mass index, as well as gene modules changing expression along the proximal-to-distal axis of the bronchial tree. Mapping new data to the HLCA enables rapid data annotation and interpretation. Using the HLCA as a reference for the study of disease, we identify shared cell states across multiple lung diseases, including SPP1+ profibrotic monocyte-derived macrophages in COVID-19, pulmonary fibrosis and lung carcinoma. Overall, the HLCA serves as an example for the development and use of large-scale, cross-dataset organ atlases within the Human Cell Atlas

Assessment of the influence of the antihistamine azelastine on the onset of glucocorticoid-induced adverse effects. consequences on bone metabolism

We have previously described in vitro that histamine H1 receptor ligands potentiate the anti-inflammatory effects of glucocorticoids (GCs) and established its therapeutic potential in a murine asthma model. Though, it is crucial to evaluate how this crosstalk alters the onset of GC-induced adverse effects to assess cotreatment safety. Considering that the therapeutic use of GCs is often limited by bone loss, we used the MC3T3-E1 osteoblastic cells differentiated with ascorbic acid and β-glycerophosphate as an in-vitro model to study the joint effect of dexamethasone (DEX) and the antihistamine azelastine (AZE) on the expression of bone biomarkers OPG, RANKL and OC, determinants of the balance between bone formation and resorption. Treatment of the cells with 0.1 nM DEX reduced osteoprotegerin (OPG) and increased receptor activator of NF-kB ligand (RANKL) expression in a 17% and 100% respectively, while pre-treatment with 10 µM of AZE reversed both effects by increasing OPG and decreasing RANKL expression in a 92% and 66% respectively. Additionally, treatment with 1 nM DEX reduced osteocalcin (OC) gene expression in 48%, while in cells pre-treated with 10 µM AZE this reduction was 16%. These findings suggest that co-treatment might represent an advantage in terms of bone impairment. We also performed the MTS metabolic assay to assess the effect of AZE on cell proliferation. Treatment with DEX inhibited cell proliferation in a concentration-dependent manner, reaching the maximal effect at 1 µM while pretreatment of cells with 1 µM AZE potentiated DEX inhibition evidenced by a reduction of its pEC50 in one order of magnitude (8.28 ± 0.44 to 9.38 ± 0.2). In contrast with our previous results, this suggests that cotreatment might be unsafe in terms of bone impairment. Overall, these discrepancies grant further research to elucidate the composite effect and the molecular mechanisms by which antihistamines modulate the appearance of GC-induced adverse effects.Fil: Kelly, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Torralba Agu, Valeria Nora. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Zappia, Carlos Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Monczor, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaLXV Reunión Anual de la Sociedad Argentina de Investigación Clínica, LXVIII Reunión Anual de la Sociedad Argentina de Inmunología y Reunión anual de la Sociedad Argentina de FisiologíaArgentinaSociedad Argentina de Investigación ClínicaSociedad Argentina de InmunologíaSociedad Argentina de Fisiologí

Physiological implications of biased signaling at histamine H2 receptors.

Histamine mediates numerous functions acting through its four receptor subtypes all belonging to the large family of seven transmembrane G-protein coupled receptors (GPCRs). In particular, histamine H2 receptor (H2R) is mainly involved in gastric acid production, becoming a classic pharmacological target to treat Zollinger-Ellison disease and gastric and duodenal ulcers. H2 ligands rank among the most widely prescribed and over the counter-sold drugs in the world. Recent evidence indicate that some H2R ligands display biased agonism, selecting and triggering some, but not all, of the signaling pathways associated to the H2R. The aim of the present work is to study whether famotidine, clinically widespread used ligand acting at H2R, exerts biased signaling. Our findings indicate that while famotidine acts as inverse agonist diminishing cAMP basal levels, it mimics the effects of histamine and the agonist amthamine concerning receptor desensitization and internalization. Moreover, the treatment of HEK293T transfected cells with any of the three ligands lead to a concentration dependent pERK increment. Similarly in AGS gastric epithelial cells, famotidine treatment led to both, the reduction in cAMP levels as well as the increment in ERK phosphorylation, suggesting that this behavior could have pharmacological relevant implications. Based on that, histidine decarboxilase expression was studied by quantitative PCR in AGS cells and its levels were increased by famotidine as well as by histamine and amthamine. In all cases, the positive regulation was impeded by the MEK inhibitor PD98059, indicating that biased signaling towards ERK1/2 pathway is the responsible of such enzyme regulation. These results support that ligand bias is not only a pharmacological curiosity but has physiological and pharmacological implications on cell metabolism