Fab glycosylation of immunoglobulin G does not associate with improvement of rheumatoid arthritis during pregnancy

Background: Changes in immunoglobulin G (IgG) constant domain (Fc) glycosylation are associated with changes in rheumatoid arthritis (RA) disease activity in response to pregnancy. Here, we sought to determine whether the same holds true for variable domain (Fab) glycosylation. Methods: IgGs were captured from RA and control sera obtained before (RA only), during and after pregnancy, followed by Fc and Fab separation, glycan release, and mass spectrometric detection. In parallel,

Compensated right ventricular function of the onset of pulmonary hypertension in a rat model depends on chamber remodeling and contractile augmentation.

Right-ventricular function is a good indicator of pulmonary arterial hypertension (PAH) prognosis; however, how the right ventricle (RV) adapts to the pressure overload is not well understood. Here, we aimed at characterizing the time course of RV early remodeling and discriminate the contribution of ventricular geometric remodeling and intrinsic changes in myocardial mechanical properties in a monocrotaline (MCT) animal model. In a longitudinal study of PAH, ventricular morphology and function were assessed weekly during the first four weeks after MCT exposure. Using invasive measurements of RV pressure and volume, heart performance was evaluated at end of systole and diastole to quantify contractility (end-systolic elastance) and chamber stiffness (end-diastolic elastance). To distinguish between morphological and intrinsic mechanisms, a computational model of the RV was developed and used to determine the level of prediction when accounting for wall masses and unloaded volume measurements changes. By four weeks, mean pulmonary arterial pressure and elastance rose significantly. RV pressures rose significantly after the second week accompanied by significant RV hypertrophy, but RV stroke volume and cardiac output were maintained. The model analysis suggested that, after two weeks, this compensation was only possible due to a significant increase in the intrinsic inotropy of RV myocardium. We conclude that this MCT-PAH rat is a model of RV compensation during the first month after treatment, where geometric remodeling on EDPVR and increased myocardial contractility on ESPVR are the major mechanisms by which stroke volume is preserved in the setting of elevated pulmonary arterial pressure. The mediators of this compensation might themselves promote longer-term adverse remodeling and decompensation in this animal model

Assessment of Daily Life Physical Activities in Pulmonary Arterial Hypertension

Background: In pulmonary arterial hypertension (PAH), the six-minute walk test (6MWT) is believed to be representative of patient’s daily life physical activities (DLPA). Whether DLPA are decreased in PAH and whether the 6MWT is representative of patient’s DL PA remain unknown. Methods: 15 patients with idiopathic PAH (IPAH) and 10 patients with PAH associated with limited systemic sclerosis (PAH-SSc) were matched with 15 healthy control subjects and 10 patients with limited systemic sclerosis without PAH. Each subject completed a 6MWT. The mean number of daily steps and the mean energy expenditure and duration of physical activities.3 METs were assessed with a physical activity monitor for seven consecutive days and used as markers of DLPA. Results: The mean number of daily steps and the mean daily energy expenditure and duration of physical activities.3 METs were all reduced in PAH patients compared to their controls (all p,0.05). The mean number of daily steps correlated with the 6MWT distance for both IPAH and PAH-SSc patients (r = 0.76, p,0.01 and r = 0.85, p,0.01), respectively. Conclusion: DLPA are decreased in PAH and correlate with the 6MWT distance. Functional exercise capacity may thus be a useful surrogate of DL PA in PAH

Sublingual Immunization with M2-Based Vaccine Induces Broad Protective Immunity against Influenza

The ectodomain of matrix protein 2 (M2e) of influenza A virus is a rationale target antigen candidate for the development of a universal vaccine against influenza as M2e undergoes little sequence variation amongst human influenza A strains. Vaccine-induced M2e-specific antibodies (Abs) have been shown to display significant cross-protective activity in animal models. M2e-based vaccine constructs have been shown to be more protective when administered by the intranasal (i.n.) route than after parenteral injection. However, i.n. administration of vaccines poses rare but serious safety issues associated with retrograde passage of inhaled antigens and adjuvants through the olfactory epithelium. In this study, we examined whether the sublingual (s.l.) route could serve as a safe and effective alternative mucosal delivery route for administering a prototype M2e-based vaccine. The mechanism whereby s.l. immunization with M2e vaccine candidate induces broad protection against infection with different influenza virus subtypes was explored.A recombinant M2 protein with three tandem copies of the M2e (3M2eC) was expressed in Escherichia coli. Parenteral immunizations of mice with 3M2eC induced high levels of M2e-specific serum Abs but failed to provide complete protection against lethal challenge with influenza virus. In contrast, s.l. immunization with 3M2eC was superior for inducing protection in mice. In the latter animals, protection was associated with specific Ab responses in the lungs.The results demonstrate that s.l. immunization with 3M2eC vaccine induced airway mucosal immune responses along with broad cross-protective immunity to influenza. These findings may contribute to the understanding of the M2-based vaccine approach to control epidemic and pandemic influenza infections

Understanding the chronology and occupation dynamics of oversized pit houses in the southern Brazilian highlands

A long held view about the occupation of southern proto-Je pit house villages of the southern Brazilian highlands is that these sites represent cycles of long-term abandonment and reoccupation. However, this assumption is based on an insufficient number of radiocarbon dates for individual pit houses. To address this problem, we conducted a programme of comprehensive AMS radiocarbon dating and Bayesian modelling at the deeply stratified oversized pit Houe 1, Baggio 1 site (Cal. A.D. 1395-1650), Campo Belo do Sul, Santa Catarina, Brazil. The straigraphy of House 1 revealed an unparalleled sequence of twelve well preserved floors evidencing a major change in occupation dynamics including five completely burnt collapsed roofs. The results of the radiocarbon dating allowed us to understand for the first time the occupation dynamics of an oversized pit house in the southern Brazilian highlands. The Bayesian model demonstrates that House 1 was occupied for over two centuries with no evidence of major periods of abandonment, calling into question previous models of long-term abandonment. In addition, the House 1 sequence allowed us to tie transformations in ceramic style and lithic technology to an absolute chronology. Finally, we can provide new evidence that the emergence of oversized domestic structures is a relatively recent phenomenon among the southern proto-Je. As monumental pit houses start to be bulit, small pit houses continue to be inhabited, evidencing emerging disparities in domestic architecture after AD 1000. Our research shows the importance of programmes of intensive dating of individual structures to understand occupation dynamcis and site permanence, and challenges long held assumptions that the southern Brazilian highlands were home to marginal cultures in the context of lowland South America

Pulmonary Arterial Hypertension Affects the Rat Gut Microbiome

We have analysed whether pulmonary arterial hypertension (PAH) alters the rat faecal microbiota. Wistar rats were injected with the VEGF receptor antagonist SU5416 (20 mg/kg s.c.) and followed for 2 weeks kept in hypoxia (10% O2, PAH) or injected with vehicle and kept in normoxia (controls). Faecal samples were obtained and microbiome composition was determined by 16S rRNA gene sequencing and bioinformatic analysis. No effect of PAH on the global microbiome was found (α- or β-diversity). However, PAH-exposed rats showed gut dysbiosis as indicated by a taxonomy-based analysis. Specifically, PAH rats had a three-fold increase in Firmicutes-to-Bacteroidetes ratio. Within the Firmicutes phylum, there were no large changes in the relative abundance of the bacterial families in PAH. Among Bacteroidetes, all families were less abundant in PAH. A clear separation was observed between the control and PAH clusters based on short chain fatty acid producing bacterial genera. Moreover, acetate was reduced in the serum of PAH rats. In conclusion, faecal microbiota composition is altered as a result of PAH. This misbalanced bacterial ecosystem might in turn play a pathophysiological role in PAH by altering the immunologic, hormonal and metabolic homeostasis.This study is supported by grants from Mineco (SAF2014-55399-R, SAF2014-55523-R, SAF2016-77222 and SAF2017-84494-C2-1R), Instituto de Salud Carlos III (PI15/01100), with funds from the European Union (Fondo Europeo de Desarrollo Regional FEDER). M.C., G.M-P. and S.E-R. are funded by Universidad Complutense, Fondo de Garantía Juvenil (Comunidad de Madrid) and Ciberes grant with funds from Fundación Contra la Hipertensión Pulmonar, a FPU grant from Ministerio de Educación, respectively. J.L.I.G is a CNIC IPP COFUND Fellow and has received funding from the People Programme (Marie Curie Actions) of the FP7/2007-2013 under REA grant agreement n° 600396. The CNIC is supported by MEIC-AEI and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (MEIC award SEV-2015-0505)

Immune checkpoint inhibitor PD-1 pathway is down-regulated in synovium at various stages of rheumatoid arthritis disease progression.

Immune checkpoint blockade with therapeutic anti-cytotoxic T lymphocyte-associated antigen (CTLA)-4 (Ipilimumab) and anti-programmed death (PD)-1 (Nivolumab and Pembrolizumab) antibodies alone or in combination has shown remarkable efficacy in multiple cancer types, concomitant with immune-related adverse events, including arthralgia and inflammatory arthritis (IA) in some patients. Herein, using Nivolumab (anti-PD-1 antagonist)-responsive genes along with transcriptomics of synovial tissue from multiple stages of rheumatoid arthritis (RA) disease progression, we have interrogated the activity status of PD-1 pathway during RA development. We demonstrate that the expression of PD-1 was increased in early and established RA synovial tissue compared to normal and OA synovium, whereas that of its ligands, programmed death ligand-1 (PD-L1) and PD-L2, was increased at all the stages of RA disease progression, namely arthralgia, IA/undifferentiated arthritis, early RA and established RA. Further, we show that RA patients expressed PD-1 on a majority of synovial tissue infiltrating CD4+ and CD8+ T cells. Moreover, enrichment of Nivolumab gene signature was observed in IA and RA, indicating that the PD-1 pathway was downregulated during RA disease progression. Furthermore, serum soluble (s) PD-1 levels were increased in autoantibody positive early RA patients. Interestingly, most of the early RA synovium tissue sections showed negative PD-L1 staining by immunohistochemistry. Therefore, downregulation in PD-1 inhibitory signaling in RA could be attributed to increased serum sPD-1 and decreased synovial tissue PD-L1 levels. Taken together, these data suggest that agonistic PD1 antibody-based therapeutics may show efficacy in RA treatment and interception

Synaptic Neurotransmission Depression in Ventral Tegmental Dopamine Neurons and Cannabinoid-Associated Addictive Learning

Drug addiction is an association of compulsive drug use with long-term associative learning/memory. Multiple forms of learning/memory are primarily subserved by activity- or experience-dependent synaptic long-term potentiation (LTP) and long-term depression (LTD). Recent studies suggest LTP expression in locally activated glutamate synapses onto dopamine neurons (local Glu-DA synapses) of the midbrain ventral tegmental area (VTA) following a single or chronic exposure to many drugs of abuse, whereas a single exposure to cannabinoid did not significantly affect synaptic plasticity at these synapses. It is unknown whether chronic exposure of cannabis (marijuana or cannabinoids), the most commonly used illicit drug worldwide, induce LTP or LTD at these synapses. More importantly, whether such alterations in VTA synaptic plasticity causatively contribute to drug addictive behavior has not previously been addressed. Here we show in rats that chronic cannabinoid exposure activates VTA cannabinoid CB1 receptors to induce transient neurotransmission depression at VTA local Glu-DA synapses through activation of NMDA receptors and subsequent endocytosis of AMPA receptor GluR2 subunits. A GluR2-derived peptide blocks cannabinoid-induced VTA synaptic depression and conditioned place preference, i.e., learning to associate drug exposure with environmental cues. These data not only provide the first evidence, to our knowledge, that NMDA receptor-dependent synaptic depression at VTA dopamine circuitry requires GluR2 endocytosis, but also suggest an essential contribution of such synaptic depression to cannabinoid-associated addictive learning, in addition to pointing to novel pharmacological strategies for the treatment of cannabis addiction