Developing Cardio-Oncology Programs in the New Era: Beyond Ventricular Dysfunction Due to Cancer Treatments.

Cardiovascular disease is a common problem in cancer patients that is becoming more widely recognized. This may be a consequence of prior cardiovascular risk factors but could also be secondary to the anticancer treatments. With the goal of offering a multidisciplinary approach to guaranteeing optimal cancer therapy and the early detection of related cardiac diseases, and in light of the recent ESC Cardio-Oncology Guideline recommendations, we developed a Cardio-Oncology unit devoted to the prevention and management of these specific complications. This document brings together important aspects to consider for the development and organization of a Cardio-Oncology program through our own experience and the current evidence.

Mitochondrial modulation with leriglitazone as a potential treatment for Rett syndrome.

BACKGROUND: Rett syndrome is a neuropediatric disease occurring due to mutations in MECP2 and characterized by a regression in the neuronal development following a normal postnatal growth, which results in the loss of acquired capabilities such as speech or purposeful usage of hands. While altered neurotransmission and brain development are the center of its pathophysiology, alterations in mitochondrial performance have been previously outlined, shaping it as an attractive target for the disease treatment. METHODS: We have thoroughly described mitochondrial performance in two Rett models, patients' primary fibroblasts and female Mecp2tm1.1Bird-/+ mice brain, discriminating between different brain areas. The characterization was made according to their bioenergetics function, oxidative stress, network dynamics or ultrastructure. Building on that, we have studied the effect of leriglitazone, a PPARγ agonist, in the modulation of mitochondrial performance. For that, we treated Rett female mice with 75 mg/kg/day leriglitazone from weaning until sacrifice at 7 months, studying both the mitochondrial performance changes and their consequences on the mice phenotype. Finally, we studied its effect on neuroinflammation based on the presence of reactive glia by immunohistochemistry and through a cytokine panel. RESULTS: We have described mitochondrial alterations in Rett fibroblasts regarding both shape and bioenergetic functions, as they displayed less interconnected and shorter mitochondria and reduced ATP production along with increased oxidative stress. The bioenergetic alterations were recalled in Rett mice models, being especially significant in cerebellum, already detectable in pre-symptomatic stages. Treatment with leriglitazone recovered the bioenergetic alterations both in Rett fibroblasts and female mice and exerted an anti-inflammatory effect in the latest, resulting in the amelioration of the mice phenotype both in general condition and exploratory activity. CONCLUSIONS: Our studies confirm the mitochondrial dysfunction in Rett syndrome, setting the differences through brain areas and disease stages. Its modulation through leriglitazone is a potential treatment for this disorder, along with other diseases with mitochondrial involvement. This work constitutes the preclinical necessary evidence to lead to a clinical trial.

Soluble Transferrin Receptor as Iron Deficiency Biomarker: Impact on Exercise Capacity in Heart Failure Patients.

The soluble transferrin receptor (sTfR) is a marker of tissue iron status, which could indicate an increased iron demand at the tissue level. The impact of sTfR levels on functional capacity and quality of life (QoL) in non-anemic heart failure (HF) patients with otherwise normal systemic iron status has not been evaluated. We conducted an observational, prospective, cohort study of 1236 patients with chronic HF. We selected patients with normal hemoglobin levels and normal systemic iron status. Tissue iron deficiency (ID) was defined as levels of sTfR > 75th percentile (1.63 mg per L). The primary endpoints were the distance walked in the 6 min walking test (6MWT) and the overall summary score (OSS) of the Minnesota Living with Heart Failure Questionnaire (MLHFQ). The final study cohort consisted of 215 patients. Overall QoL was significantly worse (51 ± 27 vs. 39 ± 20, p-value = 0.006, respectively), and the 6 MWT distance was significantly worse in patients with tissue ID when compared to patients without tissue ID (206 ± 179 m vs. 314 ± 155, p-value < 0.0001, respectively). Higher sTfR levels, indicating increased iron demand, were associated with a shorter distance in the 6 MWT (standardized ß = -0.249, p < 0.001) and a higher MLHFQ OSS (standardized ß = 0.183, p-value = 0.008). In this study, we show that in patients with normal systemic iron parameters, higher levels of sTfR are strongly associated with an impaired submaximal exercise capacity and with worse QoL.

Population-based evaluation of the impact of socioeconomic status on clinical outcomes in patients with heart failure in integrated care settings.

INTRODUCTION AND OBJECTIVES: Low socioeconomic status (SES) is associated with poor outcomes in patients with heart failure (HF). We aimed to examine the influence of SES on health outcomes after a quality of care improvement intervention for the management of HF integrating hospital and primary care resources in a health care area of 209 255 inhabitants. METHODS: We conducted a population-based pragmatic evaluation of the implementation of an integrated HF program by conducting a natural experiment using health care data. We included all individuals consecutively admitted to hospital with at least one ICD-9-CM code for HF as the primary diagnosis and discharged alive in Catalonia between January 1, 2015 and December 31, 2019. We compared outcomes between patients exposed to the new HF program and those in the remaining health care areas, globally and stratified by SES. RESULTS: A total of 77 554 patients were included in the study. Death occurred in 37 469 (48.3%), clinically-related hospitalization in 41 709 (53.8%) and HF readmission in 29 755 (38.4%). On multivariate analysis, low or very low SES was associated with an increased risk of all-cause death and clinically-related hospitalization (all Ps <.05). The multivariate models showed a significant reduction in the risk of all-cause death (HR, 0.812; 95%CI, 0.723-0.912), clinically-related hospitalization (HR, 0.886; 95%CI, 0.805-0.976) and HF hospitalization (HR, 0.838; 95%CI, 0.745-0.944) in patients exposed to the new HF program compared with patients exposed to the remaining health care areas and this effect was independent of SES. CONCLUSIONS: An intensive transitional HF management program improved clinical outcomes, both overall and across SES strata.

High Resolution Ambient MS Imaging of Biological Samples by Desorption Electro-Flow Focussing Ionization.

In this study, we examine the suitability of desorption electro-flow focusing ionization (DEFFI) for mass spectrometry imaging (MSI) of biological tissue. We also compare the performance of desorption electrospray ionization (DESI) with and without the flow focusing setup. The main potential advantages of applying the flow focusing mechanism in DESI is its rotationally symmetric electrospray jet, higher intensity, more controllable parameters, and better portability due to the robustness of the sprayer. The parameters for DEFFI have therefore been thoroughly optimized, primarily for spatial resolution but also for intensity. Once the parameters have been optimized, DEFFI produces similar images to the existing DESI. MS images for mouse brain samples, acquired at a nominal pixel size of 50 µm, are comparable for both DESI setups, albeit the new sprayer design yields better sensitivity. Furthermore, the two methods are compared with regard to spectral intensity as well as the area of the desorbed crater on rhodamine-coated slides. Overall, the implementation of a flow focusing mechanism in DESI is shown to be highly suitable for imaging biological tissue and has potential to overcome some of the shortcomings experienced with the current geometrical design of DESI.

Blood Differential Gene Expression in Patients with Chronic Heart Failure and Systemic Iron Deficiency: Pathways Involved in Pathophysiology and Impact on Clinical Outcomes.

BACKGROUND: Iron deficiency is a common disorder in patients with heart failure and is related with adverse outcomes and poor quality of life. Previous experimental studies have shown biological connections between iron homeostasis, mitochondrial metabolism, and myocardial function. However, the mechanisms involved in this crosstalk are yet to be unfolded. METHODS: The present research attempts to investigate the intrinsic biological mechanisms between heart failure and iron deficiency and to identify potential prognostic biomarkers by determining the gene expression pattern in the blood of heart failure patients, using whole transcriptome and targeted TaqMan® low-density array analyses. RESULTS: We performed a stepwise cross-sectional longitudinal study in a cohort of chronic heart failure patients with and without systemic iron deficiency. First, the full transcriptome was performed in a nested case-control exploratory cohort of 7 paired patients and underscored 1128 differentially expressed transcripts according to iron status (cohort1#). Later, we analyzed the messenger RNA levels of 22 genes selected by their statistical significance and pathophysiological relevance, in a validation cohort of 71 patients (cohort 2#). Patients with systemic iron deficiency presented lower mRNA levels of mitochondrial ferritin, sirtuin-7, small integral membrane protein 20, adrenomedullin and endothelin converting enzyme-1. An intermediate mitochondrial ferritin gene expression and an intermediate or low sirtuin7 and small integral membrane protein 20 mRNA levels were associated with an increased risk of all-cause mortality and heart failure admission ((HR 2.40, 95% CI 1.04-5.50, p-value = 0.039), (HR 5.49, 95% CI 1.78-16.92, p-value = 0.003), (HR 9.51, 95% CI 2.69-33.53, p-value < 0.001), respectively). CONCLUSIONS: Patients with chronic heart failure present different patterns of blood gene expression depending on systemic iron status that affect pivotal genes involved in iron regulation, mitochondrial metabolism, endothelial function and cardiovascular physiology, and correlate with adverse clinical outcomes.

An integrated workflow for enhanced taxonomic and functional coverage of the mouse fecal metaproteome.

Intestinal microbiota plays a key role in shaping host homeostasis by regulating metabolism, immune responses and behavior. Its dysregulation has been associated with metabolic, immune and neuropsychiatric disorders and is accompanied by changes in bacterial metabolic regulation. Although proteomics is well suited for analysis of individual microbes, metaproteomics of fecal samples is challenging due to the physical structure of the sample, presence of contaminating host proteins and coexistence of hundreds of taxa. Furthermore, there is a lack of consensus regarding preparation of fecal samples, as well as downstream bioinformatic analyses following metaproteomics data acquisition. Here we assess sample preparation and data analysis strategies applied to mouse feces in a typical mass spectrometry-based metaproteomic experiment. We show that subtle changes in sample preparation protocols may influence interpretation of biological findings. Two-step database search strategies led to significant underestimation of false positive protein identifications. Unipept software provided the highest sensitivity and specificity in taxonomic annotation of the identified peptides of unknown origin. Comparison of matching metaproteome and metagenome data revealed a positive correlation between protein and gene abundances. Notably, nearly all functional categories of detected protein groups were differentially abundant in the metaproteome compared to what would be expected from the metagenome, highlighting the need to perform metaproteomics when studying complex microbiome samples.

Gender Differences in Health-Related Quality of Life in Patients with Systolic Heart Failure: Results of the VIDA Multicenter Study.

Previous studies have shown that heart failure is associated with worse health-related quality of life (HRQoL). The existence of differences according to gender remains controversial. We studied 1028 consecutive outpatients with heart failure and reduced ejection fraction (HFrEF) from a multicentre cross-sectional descriptive study across Spain that assessed HRQoL using two questionnaires (KCCQ, Kansas City Cardiomyopathy Questionnaire; and EQ-5D, EuroQoL 5 dimensions). The primary objective of the study was to describe differences in HRQoL between men and women in global scores and domains of health status of patients and explore gender differences and its interactions with heart failure related factors. In adjusted analysis women had lower scores in KCCQ overall summary scores when compared to men denoting worse HRQoL (54.7 ± 1.3 vs. 62.7 ± 0.8, p < 0.0001), and specifically got lower score in domains of symptom frequency, symptoms burden, physical limitation, quality of life and social limitation. No differences were found in domains of symptom stability and self-efficacy. Women also had lower scores on all items of EQ-5D (EQ-5D index 0.58 ± 0.01 vs. 0.67 ± 0.01, p < 0.0001). Finally, we analyzed interaction between gender and different clinical determinants regarding the presence of limitations in the 5Q-5D and overall summary score of KCCQ. Interestingly, there was no statistical significance for interaction for any variable. In conclusion, women with HFrEF have worse HRQoL compared to men. These differences do not appear to be mediated by clinical or biological factors classically associated with HRQoL nor with heart failure severity.

Economic analysis of intermittent intravenous outpatient treatment with levosimendan in advanced heart failure in Spain.

INTRODUCTION AND OBJECTIVES: Advanced heart failure (HF) leads to high hospitalization and mortality rates. The LION-HEART study was a randomized, placebo-controlled clinical trial that evaluated the safety and efficacy of intravenous administration of intermittent doses of levosimendan in outpatients with advanced HF. The aim of the present study was to perform a cost analysis to determine whether the lower rate of hospitalizations for HF, observed in patients treated with levosimendan in the LION-HEART study, can generate savings for the Spanish national health system compared with the option of not treating patients with advanced HF. METHODS: An economic model was used that included IC hospitalization rates from the LION-HEART study, the costs of hospitalization due to HF and those of the acquisition and intravenous administration of levosimendan. The time horizon of the analysis was 12 months. Two analyses were carried out, one deterministic and the other probabilistic (second-order Monte Carlo simulation). RESULTS: In the deterministic analysis, the total saving for each patient treated with levosimendan would amount to-€698.48. In the probabilistic analysis, the saving per patient treated with levosimendan would be-€849.94 (95%CI, €133.12 to-€2,255.31). The probability of savings with levosimendan compared with the no treatment option would be 94.8%. CONCLUSIONS: Intermittent ambulatory treatment with levosimendan can generate savings for the Spanish national health system compared with the option of not treating patients with advanced HF.

Comprehensive Analysis of GABAA-A1R Developmental Alterations in Rett Syndrome: Setting the Focus for Therapeutic Targets in the Time Frame of the Disease.

Rett syndrome, a serious neurodevelopmental disorder, has been associated with an altered expression of different synaptic-related proteins and aberrant glutamatergic and γ-aminobutyric acid (GABA)ergic neurotransmission. Despite its severity, it lacks a therapeutic option. Through this work we aimed to define the relationship between MeCP2 and GABAA.-A1 receptor expression, emphasizing the time dependence of such relationship. For this, we analyzed the expression of the ionotropic receptor subunit in different MeCP2 gene-dosage and developmental conditions, in cells lines, and in primary cultured neurons, as well as in different developmental stages of a Rett mouse model. Further, RNAseq and systems biology analysis was performed from post-mortem brain biopsies of Rett patients. We observed that the modulation of the MeCP2 expression in cellular models (both Neuro2a (N2A) cells and primary neuronal cultures) revealed a MeCP2 positive effect on the GABAA.-A1 receptor subunit expression, which did not occur in other proteins such as KCC2 (Potassium-chloride channel, member 5). In the Mecp2+/- mouse brain, both the KCC2 and GABA subunits expression were developmentally regulated, with a decreased expression during the pre-symptomatic stage, while the expression was variable in the adult symptomatic mice. Finally, the expression of the gamma-aminobutyric acid (GABA) receptor-related synaptic proteins from the postmortem brain biopsies of two Rett patients was evaluated, specifically revealing the GABA A1R subunit overexpression. The identification of the molecular changes along with the Rett syndrome prodromic stages strongly endorses the importance of time frame when addressing this disease, supporting the need for a neurotransmission-targeted early therapeutic intervention.

Consensus document and recommendations on palliative care in heart failure of the Heart Failure and Geriatric Cardiology Working Groups of the Spanish Society of Cardiology.

Heart failure is a complex entity, with high morbidity and mortality. The clinical course and outcome are uncertain and difficult to predict. This document, instigated by the Heart Failure and Geriatric Cardiology Working Groups of the Spanish Society of Cardiology, addresses various aspects related to palliative care, where most cardiovascular disease will eventually converge. The document also establishes a consensus and a series of recommendations with the aim of recognizing and understanding the need to implement and progressively apply palliative care throughout the course of the disease, not only in the advanced stages, thus improving the care provided and quality of life. The purpose is to improve and adapt treatment to the needs and wishes of each patient, who must have adequate information and participate in decision-making.

L-Serine dietary supplementation is associated with clinical improvement of loss-of-function GRIN2B-related pediatric encephalopathy.

Autosomal dominant mutations in GRIN2B are associated with severe encephalopathy, but little is known about the pathophysiological outcomes and any potential therapeutic interventions. Genetic studies have described the association between de novo mutations of genes encoding the subunits of the N-methyl-d-aspartate receptor (NMDAR) and severe neurological conditions. Here, we evaluated a missense mutation in GRIN2B, causing a proline-to-threonine switch (P553T) in the GluN2B subunit of NMDAR, which was found in a 5-year-old patient with Rett-like syndrome with severe encephalopathy. Structural molecular modeling predicted a reduced pore size of the mutant GluN2B-containing NMDARs. Electrophysiological recordings in a HEK-293T cell line expressing the mutated subunit confirmed this prediction and showed an associated reduced glutamate affinity. Moreover, GluN2B(P553T)-expressing primary murine hippocampal neurons showed decreased spine density, concomitant with reduced NMDA-evoked currents and impaired NMDAR-dependent insertion of the AMPA receptor subunit GluA1 at stimulated synapses. Furthermore, the naturally occurring coagonist d-serine restored function to GluN2B(P553T)-containing NMDARs. l-Serine dietary supplementation of the patient was hence initiated, resulting in the increased abundance of d-serine in the plasma and brain. The patient has shown notable improvements in motor and cognitive performance and communication after 11 and 17 months of l-serine dietary supplementation. Our data suggest that l-serine supplementation might ameliorate GRIN2B-related severe encephalopathy and other neurological conditions caused by glutamatergic signaling deficiency.

Phosphoproteomic Alterations of Ionotropic Glutamate Receptors in the Hippocampus of the Ts65Dn Mouse Model of Down Syndrome.

Down syndrome (DS), the main genetic cause of intellectual disability, is associated with an imbalance of excitatory/inhibitory neurotransmitter systems. The phenotypic assessment and pharmacotherapy interventions in DS murine models strongly pointed out glutamatergic neurotransmission alterations (specially affecting ionotropic glutamate receptors [iGluRs]) that might contribute to DS pathophysiology, which is in agreement with DS condition. iGluRs play a critical role in fast-mediated excitatory transmission, a process underlying synaptic plasticity. Neuronal plasticity is biochemically modulated by post-translational modifications, allowing rapid and reversible adaptation of synaptic strength. Among these modifications, phosphorylation/dephosphorylation processes strongly dictate iGluR protein-protein interactions, cell surface trafficking, and subsynaptic mobility. Hence, we hypothesized that dysregulation of phosphorylation/dephosphorylation balance might affect neuronal function, which in turn could contribute to the glutamatergic neurotransmitter alterations observed in DS. To address this point, we biochemically purified subsynaptic hippocampal fractions from adult Ts65Dn mice, a trisomic mouse model recapitulating DS phenotypic alterations. Proteomic analysis showed significant alterations of the molecular composition of subsynaptic compartments of hippocampal trisomic neurons. Further, we characterized iGluR phosphopattern in the hippocampal glutamatergic synapse of trisomic mice. Phosphoenrichment-coupled mass spectrometry analysis revealed specific subsynaptic- and trisomy-associated iGluR phosphorylation signature, concomitant with differential subsynaptic kinase and phosphatase composition of Ts65Dn hippocampal subsynaptic compartments. Furthermore, biochemical data were used to build up a genotype-kinome-iGluR phosphopattern matrix in the different subsynaptic compartments. Overall, our results provide a precise profile of iGluR phosphopattern alterations in the glutamatergic synapse of the Ts65Dn mouse model and support their contribution to DS-associated synaptopathy. The alteration of iGluR phosphoresidues in Ts65Dn hippocampi, together with the kinase/phosphatase signature, identifies potential novel therapeutic targets for the treatment of glutamatergic dysfunctions in DS.

Rett-like Severe Encephalopathy Caused by a De Novo GRIN2B Mutation Is Attenuated by D-serine Dietary Supplement.

BACKGROUND: N-Methyl-D-aspartate receptors (NMDARs) play pivotal roles in synaptic development, plasticity, neural survival, and cognition. Despite recent reports describing the genetic association between de novo mutations of NMDAR subunits and severe psychiatric diseases, little is known about their pathogenic mechanisms and potential therapeutic interventions. Here we report a case study of a 4-year-old Rett-like patient with severe encephalopathy carrying a missense de novo mutation in GRIN2B(p.P553T) coding for the GluN2B subunit of NMDAR. METHODS: We generated a dynamic molecular model of mutant GluN2B-containing NMDARs. We expressed the mutation in cell lines and primary cultures, and we evaluated the putative morphological, electrophysiological, and synaptic plasticity alterations. Finally, we evaluated D-serine administration as a therapeutic strategy and translated it to the clinical practice. RESULTS: Structural molecular modeling predicted a reduced pore size of mutant NMDARs. Electrophysiological recordings confirmed this prediction and also showed gating alterations, a reduced glutamate affinity associated with a strong decrease of NMDA-evoked currents. Moreover, GluN2B(P553T)-expressing neurons showed decreased spine density, concomitant with reduced NMDA-evoked currents and impaired NMDAR-dependent insertion of GluA1 at stimulated synapses. Notably, the naturally occurring coagonist D-serine was able to attenuate hypofunction of GluN2B(p.P553T)-containing NMDARs. Hence, D-serine dietary supplementation was initiated. Importantly, the patient has shown remarkable motor, cognitive, and communication improvements after 17 months of D-serine dietary supplementation. CONCLUSIONS: Our data suggest that hypofunctional NMDARs containing GluN2B(p.P553T) can contribute to Rett-like encephalopathy and that their potentiation by D-serine treatment may underlie the associated clinical improvement.

Linear Unilateral Basaloid Follicular Hamartoma Following Blaschko's Lines: Two Case Reports and Review of the Literature.

Basaloid follicular hamartoma (BFH) is a rare follicular malformation characterized by variable clinical presentations and identical histopathologic features. We present the cases of a 3-month-old boy and an 8-year-old boy with linear unilateral BFH. To the best of our knowledge, only 14 cases of linear unilateral BFH have been described in the English-language literature.

Glutamatergic stimulation induces GluN2B translation by the nitric oxide-Heme-Regulated eIF2α kinase in cortical neurons.

The activation of N-Methyl D-Aspartate Receptor (NMDAR) by glutamate is crucial in the nervous system function, particularly in memory and learning. NMDAR is composed by two GluN1 and two GluN2 subunits. GluN2B has been reported to participate in the prevalent NMDAR subtype at synapses, the GluN1/2A/2B. Here we studied the regulation of GluN2B expression in cortical neurons finding that glutamate up-regulates GluN2B translation through the action of nitric oxide (NO), which induces the phosphorylation of the eukaryotic translation initiation factor 2 α (eIF2α). It is a process mediated by the NO-heme-regulated eIF2α kinase (HRI), as the effect was avoided when a specific HRI inhibitor or a HRI small interfering RNA (siHRI) were used. We found that the expressed GluN2B co-localizes with PSD-95 at the postsynaptic ending, which strengthen the physiological relevance of the proposed mechanism. Moreover the receptors bearing GluN2B subunits upon NO stimulation are functional as high Ca2+ entry was measured and increases the co-localization between GluN2B and GluN1 subunits. In addition, the injection of the specific HRI inhibitor in mice produces a decrease in memory retrieval as tested by the Novel Object Recognition performance. Summarizing our data suggests that glutamatergic stimulation induces HRI activation by NO to trigger GluN2B expression and this process would be relevant to maintain postsynaptic activity in cortical neurons.

A Cost-effectiveness Analysis of Ferric Carboxymaltose in Patients With Iron Deficiency and Chronic Heart Failure in Spain.

INTRODUCTION AND OBJECTIVES: Treatment with ferric carboxymaltose improves symptoms, functional capacity, and quality of life in patients with chronic heart failure and iron deficiency. The aim of this study was to assess the cost-effectiveness of ferric carboxymaltose treatment vs no treatment in these patients. METHODS: We used an economic model based on the Spanish National Health System, with a time horizon of 24 weeks. Patient characteristics and ferric carboxymaltose effectiveness (quality-adjusted life years) were taken from the Ferinject® Assessment in patients with IRon deficiency and chronic Heart Failure trial. Health care resource use and unit costs were taken either from Spanish sources, or from the above mentioned trial. RESULTS: In the base case analysis, patients treated with and without ferric carboxymaltose treatment acquired 0.335 and 0.298 quality-adjusted life years, respectively, representing a gain of 0.037 quality-adjusted life years for each treated patient. The cost per patient was €824.17 and €597.59, respectively, resulting in an additional cost of €226.58 for each treated patient. The cost of gaining 1 quality adjusted life year with ferric carboxymaltose was €6123.78. Sensitivity analyses confirmed the robustness of the model. The probability of ferric carboxymaltose being cost-effective (< €30 000 per quality-adjusted life year) and dominant (more effective and lower cost than no treatment) was 93.0% and 6.6%, respectively. CONCLUSIONS: Treatment with ferric carboxymaltose in patients with chronic heart failure and iron deficiency, with or without anemia, is cost-effective in Spain.

DYRK1A-mediated phosphorylation of GluN2A at Ser(1048) regulates the surface expression and channel activity of GluN1/GluN2A receptors.

N-methyl-D-aspartate glutamate receptors (NMDARs) play a pivotal role in neural development and synaptic plasticity, as well as in neurological disease. Since NMDARs exert their function at the cell surface, their density in the plasma membrane is finely tuned by a plethora of molecules that regulate their production, trafficking, docking and internalization in response to external stimuli. In addition to transcriptional regulation, the density of NMDARs is also influenced by post-translational mechanisms like phosphorylation, a modification that also affects their biophysical properties. We previously described the increased surface expression of GluN1/GluN2A receptors in transgenic mice overexpressing the Dual specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A), suggesting that DYRK1A regulates NMDARs. Here we have further investigated whether the density and activity of NMDARs were modulated by DYRK1A phosphorylation. Accordingly, we show that endogenous DYRK1A is recruited to GluN2A-containing NMDARs in the adult mouse brain, and we identify a DYRK1A phosphorylation site at Ser(1048) of GluN2A, within its intracellular C-terminal domain. Mechanistically, the DYRK1A-dependent phosphorylation of GluN2A at Ser(1048) hinders the internalization of GluN1/GluN2A, causing an increase of surface GluN1/GluN2A in heterologous systems, as well as in primary cortical neurons. Furthermore, GluN2A phosphorylation at Ser(1048) increases the current density and potentiates the gating of GluN1/GluN2A receptors. We conclude that DYRK1A is a direct regulator of NMDA receptors and we propose a novel mechanism for the control of NMDAR activity in neurons.

Pulmonary arterial hypertension related to human immunodeficiency virus infection: A case series.

AIM: To present 18 new cases of human immunodeficiency virus (HIV)-related pulmonary arterial hypertension (PAH) with presenting features, treatment options and follow-up data. METHODS: This is a single-centre, retrospective, observational study that used prospectively collected data, conducted during a 14-year period on HIV-related PAH patients who were referred to a pulmonary hypertension unit. All patients infected with HIV were consecutively admitted for an initial evaluation of PAH during the study period and included in our study. Right heart catheterisation was used for the diagnosis of PAH. Specific PAH treatment was started according to the physician's judgment and the recommendations for idiopathic PAH. The data collected included demographic characteristics, parameters related to both HIV infection and PAH and disease follow-up. RESULTS: Eighteen patients were included. Intravenous drug use was the major risk factor for HIV infection. Risk factors for PAH, other than HIV infection, were present in 55.5% patients. The elapsed time between HIV infection and PAH diagnoses was 12.2 ± 6.9 years. At PAH diagnosis, 94.1% patients had a CD4 cell count > 200 cells/µL. Highly active antiretroviral therapy (present in 47.1% patients) was associated with an accelerated onset of PAH. Survival rates were 93.8%, 92.9% and 85.7% at one, two and three years, respectively. Concerning specific therapy, 33.3% of the patients were started on a prostacyclin analogue, and the rest were on oral drugs, mainly phosphodiesterase-5 inhibitors. During the follow-up period, specific therapy was de-escalated to oral drugs in all of the living patients. CONCLUSION: The survival rates of HIV-related PAH patients were higher, most likely due to new aggressive specific therapy. The majority of patients were on oral specific therapy and clinically stable. Moreover, sildenafil appears to be a safe therapy for less severe HIV-related PAH.