Autoantibodies against Muscarinic Acetylcholine Receptor on Exocrine Glands in Sjögren Syndrome

These investigations demonstrate that serum antibodies against muscarinic acetylcholine receptors (mAChR) in primary Sjögren syndrome (pSS) and associated Sjögren syndrome (aSS) bind and activate both cholinergic receptors of M3 in salivary gland and M1 in neonatal myocardium and in the cerebral frontal cortex area subtypes; triggering the production of the second messengers and proinflammatory mediators related to mAChR activation. In this way the cholinergic autoantibodies damages these receptors, which thus starts acting as an antigen. On this basis M3 and M1 mAChR IgG can be considered new markers of pSS/aSS allowing the differentiation between dry eye and mouth of autoimmune and non-autoimmune nature. Given that cholinergic autoantibodies also deregulate the parasympathetic system of the target organs, they can also be seen as a new factor contributing to the etiopathology of the syndrome.Fil: Reina, Silvia Lorena. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Borda, Enri Santiago. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Role of M3 Muscarinic Acethylcholine Receptor Antibodies as a New Marker in Primary Sjögren Syndrome

Aims: This paper investigates the presence of M3 muscarinic acetylcholine receptor autoantibody present in the serum of patients with primary Sjögren syndrome (pSS). Main methods: We detected the levels of M3mAChR peptide IgG, PGE2, IL-1β in serum of SS patients using the enzyme-linked immune sorbent assay (ELISA). To measure the quantity of nitrite/nitrate, we used Griess reagent system. Key findings: Titres of M3mAChR antibody in sera from SS patients are significantly enhanced compared to healthy subjects (control). The enhancement of these autoantibodies is accompanied by the increase of the levels of PGE2, IL-1β and nitrite/nitrate in serum. Under in vitro conditions, the synthetic human M3 peptide impaires the increment of M3mAChR antibody but not that of nati-Ro/SSA antibody. In positive anti-Ro/SSA antibody patients, the increment of M3mAChR peptide IgG and the measured pro-inflammatory substances is related. Significance: On this basis, anti M3mAChR peptide IgG can be said to act as a modulator of the immune system and to play a role in the host-chronic increment of proinflammatory substances in SS patients with positive Ro/SSA antibody. This association between the antibody and the pathogenesis of SS disease may result in useful predicting SS.Fil: Reina, Silvia Lorena. Universidad Catolica de Las Misiones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pisoni, Cecilia. Centro de Educaciones Médicas e Investigación Clínica ; ArgentinaFil: González Arana, Roberto. Centro de Educaciones Médicas e Investigación Clínica ; ArgentinaFil: Ganzinelli, Sabrina Belen. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; ArgentinaFil: Borda, Enri Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; Argentin

Autoantibodies to the β1-Adrenoceptor from Patients with Periodontitis as a Risk Factor for Cardiac Dysfunction

The presence of serum autoantibodies in periodontitis (P) patients against β1-adrenoceptor (β1-AR), using cardiac membranes or a synthetic β1-AR peptide corresponding to the second extracellular loop of human β1-AR as antigens, permit us to detect circulating antibody from 40 P patients but not in 20 normal individuals (control). Simultaneously, the P patients exhibited a decrease in HRV. Anti-β1-AR IgG titters correlated with the decrease in HRV of the same patients and the anti-β1-AR peptide IgG displayed partial agonist-like activity and modified the contractility of isolated atria, produced cyclic nucleotides, and inhibited the β1-AR agonistic activity of isoproterenol. We demonstrated in this study an association between periodontitis infection and an increased risk of cardiac disease, thereby highlighting the role of anti-β1-AR autoantibodies in alteration of myocardial contractility

Anti-M 3 peptide IgG from Sjögren's syndrome triggers apoptosis in A253 cells

Primary Sjögren´s syndrome (pSS) is an autoimmune disease that targets salivary and lachrymal glands, characterized by anti-cholinergic autoantibodies directed against the M3 muscarinic acetylcholine receptor (mAChR). The aim of this work was to evaluate if cholinergic autoantibodies contained in IgG purified from Sjögren sera could trigger apoptosis of A253 cell line. We also determined if caspase-3 and matrix metalloproteinase 3 (MMP-3) are involved in the induction of A253 cell death. Our results demonstrated that anti-cholinergic autoantibodies stimulate apoptosis and inositol phosphate (InsP) accumulation accompanied by caspase-3 activation and MMP-3 production. All of these effects were blunted by atropine and J104794, indicating that M3 mAChRs are impacted by the anti-cholinergic autoantibodies. The intracellular pathway leading to autoantibody-induced biological effects involves phospholipase C (PLC), calcium/calmodulin (CaM) and extracellular calcium as demonstrated by treatment with U-73122, W-7, verapamil, BAPTA and BAPTA-AM, all of which blocked the effects of the anti-cholinergic autoantibodies. In conclusion, anti-cholinergic autoantibodies in IgG purified from pSS patient´s sera mediates apoptosis of the A253 cell line in an InsP, caspase-3 and MMP-3 dependent manner.Fil: Reina, Silvia Lorena. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Sterin Borda, Leonor. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; ArgentinaFil: Borda, Enri Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; Argentin

Role of Anti Muscarinic Acetylcholine IgA and anti autoantibodies in whole saliva from Primary Sjögren’s syndrome patients

Aims: The purpose of this report is to describe saliva IgA antibody against M3 muscarinic acetylcholine receptors (mAChRs) and anti-Ro autoantibodies in patients with primary Sjögren’s syndrome (pSS). In addition we want to clarify if this antibody anti-Ro is or not related to the presence of anti-IgA M3 mAChRs autoantibodies in whole saliva of pSS patients. Methods: Whole saliva samples were collected from healthy volunteers (n=30), patients with pSS anti-Ro positive (n=60) and patients with pSS anti-Ro negative (n=30). Saliva IgA patients and healthy subjects were tested by ELISA recognized the synthetic 25-mer peptide corresponding to the extracellular loop of the human M3 mAChRs. Also, concentration of nitrite/nitrate was determined by ELISA. Results: Optical density values for saliva IgA from pSS anti-Ro positive are significantly higher than those from IgA anti-Ro negative patients and IgA from normal subjects. These molecular interactions between IgA and human M3 mAChR synthetic peptide increased in optical density values compared with IgA from pSS anti-Ro negative and healthy subjects when M3 mAChR synthetic peptide was used as coating antigen. The specificity of this reaction was assessed by the ability of the M3 synthetic peptide (1x10-5 M) to inhibit the action when whole saliva was incubated previously with the M3 synthetic peptide for 40 min at 37ºC and then added together in the microtiter plates. On the other hand, the concentration of nitrate/nitrite in whole saliva was significantly decreased in pSS anti-Ro positive patients in comparison with those from IgA anti-Ro negative patients and healthy subjects. Conclusions: Patients presenting in saliva anti IgA anti-Ro positive are statistically significant in optical density values than those IgA from anti-Ro negative patients and healthy individuals. Also, the hypofunction of the salivary glands is associated with significant decrement of nitrate/nitrites levels in the saliva in pSS-Ro positive without any changes in pSS-Ro negative and healthy subjects.Fil: Borda, Enri Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; ArgentinaFil: Reina, Silvia Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; ArgentinaFil: Ganzinelli, Sabrina Belen. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; Argentin

Salivary inflammatory mediators and metalloproteinase 3 in patients with chronic severe periodontitis before and after periodontal phase I therapy

The role of IL-1β, PGE2 and MMP-3 in the pathogenesis of periodontal disease is well researched. This study aimed to asses and compared the salivary IL-1β, PGE2 and MMP-3 levels in patients with untreated chronic severe periodontitis and those treated with periodontal phase I therapy and periodontally healthy individuals as controls, in relationship to the presence of salivary anti-β1 IgA.Fil: Reina, Silvia Lorena. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina;Fil: Hoyos, Fernando. Universidad de Buenos Aires. Facultad de Odontología; Argentina;Fil: Carranza, Nelson. Universidad de Buenos Aires. Facultad de Odontología; Argentina;Fil: Borda, Enri Santiago. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina

Modulation of c-Jun NH2-Terminal (JNK) by Cholinergic Autoantibodies from Patients with Sjögren’s Syndrome

Background: We wanted to determine (via an immunopharmacological approach) whether the c-Jun NH2 terminal kinase (JNK) cascade is phosphorylated in the submandibular gland by carbachol and cholinergic autoantibodies (IgG) present in the sera of patients with primary Sjögren’s syndrome (pSS) by interaction and activation of salivary gland muscarinic acetylcholine receptors (mAChRs). Methods: The JNK, PGE2 and NOS assays were measured in rat sub- mandibular gland with pSS IgG and carbachol alone or in the presence of different blocker agents. Results: pSS IgG- activated M3 mAChRs stimulated JNK phosphorylation whereas the activation of M1 mAChRs by carbachol stimulated JNK phosphorylation involving calcium-activated mechanism. The intracellular pathway leading to pSS IgG-induced biological effects on JNK activity involved activation of protein kinase C (PKC), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) enzymes. Also, activation of COX-2 and COX-1 by pSS IgG and carbachol-induced PGE2 generation were involved. Conclusion: These results may contribute to better understanding the modulatory role of JNK enzymes by cholinergic autoantibodies from pSS patients acting on mAChR in rat submandibular gland.Fil: Borda, Enri Santiago. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Passafaro, Daniela. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; ArgentinaFil: Reina, Silvia. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Sterin Borda, Leonor. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin

Análisis de la sensibilización de los jóvenes ante la seguridad vial. Bases para la elaboración de un programa. [Analysis of road safety awareness in young people. Bases for the development of a road safety programme]

This research aims to establish the foundations for a traffic accident prevention programme, based on a study of specific circumstances. To this end, we analysed awareness of road safety measure use in young people according to three variables; whether they had any experience of an accident; if so, how serious the accident was, and how close the kinship relation was to the person who had the accident. The findings did not confirm our expectations, but showed that awareness is not clearly related to any of these three variables, except where either a brother or sister was involved in the accident and when the accident was not serious. Con nuestra investigación pretendemos aproximar las bases para el diseño de un programa de prevención de accidentes, a partir del estudio de una realidad concreta. Para ello hemos analizado la sensibilización hacia el uso de medidas de seguridad vial en adolescentes en función de tres variables: la vivencia o no de un accidente, la gravedad del mismo y el grado de parentesco. Los resultados obtenidos, en contra de lo esperado, constatan que la sensibilización no está relacionada inequívocamente con ellas, a excepción de los hermanos en cuanto al grado de parentesco y leve en cuanto a la gravedad

On Electrostatic Positron Acceleration In The Accretion Flow Onto Neutron Stars

As first shown by Shvartsman (1970), a neutron star accreting close to the Eddington limit must acquire a positive charge in order for electrons and protons to move at the same speed. The resulting electrostatic field may contribute to accelerating positrons produced near the star surface in conjunction with the radiative force. We reconsider the balance between energy gains and losses, including inverse Compton (IC), bremsstrahlung and non--radiative scatterings. It is found that, even accounting for IC losses only, the maximum positron energy never exceeds $\approx 400$ keV. The electrostatic field alone may produce energies $\approx 50$ keV at most. We also show that Coulomb collisions and annihilation with accreting electrons severely limit the number of positrons that escape to infinity.Comment: 9 pages plus 3 postscript figures, to be published in Ap