Sfrp1 promotes neuroinflammation through the modulation of ADAM10 proteolytic activity

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 28-07-2017Esta tesis tiene embargado el acceso al texto completo hasta el 28-01-2019Growing evidence suggests the importance of immune response regulation for the maintenance of neural tissue homeostasis. Disruption of this homeostasis might be one of the causes contributing to the onset and development of neurological disorders. Inflammatory responses in the Central Nervous System (CNS) are mediated by astrocytes and microglial cells, which help to protect from pathogen invasion and respond to any kind of injury, in the attempt to repair the tissue. However, exacerbated inflammatory responses lead to pathogenic neurotoxicity and chronic neuroinflammation. The latter has been recognized as one of the drivers of diverse neurodegenerative and autoimmune diseases of the CNS. Previous work from our laboratory has demonstrated that Sfrp1 contributes to AD progression by inducing Aβ peptide generation. In the course of this study, we also observed that genetic inactivation of Sfrp1 was associated with particularly low levels of neuroinflammation. Because an increased Sfrp1 expression has been reported in several peripheral diseases associated with chronic inflammation, we hypothesised that Sfrp1 could directly contribute to the regulation of neuroinflammation. In this thesis, we have addressed this issue, providing evidence that support this hypothesis. Indeed, we show that Sfrp1 expression is upregulated in activated microglial cells and reactive astrocytes under diverse experimental pro-inflammatory conditions, including experimentally induced neuroinflammation, in mouse models for Alzheimer’s Disease (AD) and in Experimental Autoimmune Encephalomyelitis. On the contrary, genetic inactivation of Sfrp1 strongly reduces glial cells activation, ameliorating the pathological traits of the diseases. Sfrp1 overexpression is sufficient to induce an inflammatory response, activating glial cells and promoting the infiltration of immune cells, whereas preliminary studies indicate that antibody-mediated neutralization of Sfrp1 activity ameliorates AD pathological traits. From a mechanistic point of view, Sfrp1 seems to promote neuroinflammation by regulating ADAM10-mediated shedding of TREM2, CD200 and CX3CL1, proteins implicated in the activation of microglial cells. We thus propose that Sfrp1 is directly involved in modulating microglial activation during brain inflammation. We also suggest that Sfrp1 may represent a new therapeutic target to attenuate the exacerbated neuroinflammation present in numerous neurodegenerative diseases

Lipoteichoic acid and molecular weight of hyaluronic acid could explain the late inflammatory response trigger by hyaluronic acid fillers

Introduction: Hyaluronic acid is a safe dermal filler, but sometimes late granuloma is generated. This adverse effect is an inflammatory process, and its causes are not clear. Late granuloma generation could be due to the reaction to residual components of the bacterial wall present into hyaluronic acid, such as lipoteichoic acid (LTA). Other possibility is hyaluronic acid degraded could be trigger this inflammatory reaction. // Objective: Study possible molecular mechanism that could be implicated into the late granuloma formation. We wonder whereas inflammatory response activation is triggered by lower molecular weight hyaluronic acid or Gram-positive bacterial components as LTA. // Methods: We analyzed one adverse case generated by hyaluronic acid injections. Our study with one nodule through chemical and immunofluorescence histologic technics. // Results: In this case, observe a late granuloma without infectious process. Histological analysis shown few large Langerhans cells around fillers and multiple immunological cells infiltrated. Immunofluorescent study shown immunological cells (CD45 positives cells) with high TLR2 expression (hyaluronic acid and LTA receptor). // Limitations: The difficulty of obtaining biopsy samples of nodules implies that the number of cases analyzed is very low. // Conclusion: New model is proposed in which weight of hyaluronic acid and LTA could be able to trigger inflammation. This process could be mediated by TLR2 expressed in infiltrated immune cells

Alterations in Energy Partitioning and Methane Emissions in Murciano-Granadina Goats Fed Orange Leaves and Rice Straw as a Replacement for Beet Pulp and Barley Straw

[EN] Reducing methane emissions in ruminants with the recycling of agro-industrial by-products is of great importance today. Pruning waste from citrus trees is currently burned or incorporated into soil. Regarding rice straw, this waste is traditionally eliminated through controlled burning, releasing into the atmosphere large amounts of greenhouse gases as well. The aim of this study was to convert this recovered waste into a new animal feed capable of reducing methane emissions in ruminants. The interest in use waste by-products for ruminant nutrition is increasing. Therefore, we replace the beet pulp and cereal straw from dry-non-pregnant goats' diet with orange leaves and rice straw with the objective of studying their effect upon intake, digestibility, energy efficiency, carbon and nitrogen balance, and methane emissions. Considering the huge quantities of crops by-products and pruning waste such as rice straw and citrus leaves produced annually worldwide, and their potential pollution capacity, recycling as feed for livestock is an alternative. The objective was to study these by-products effect on energy balance and methane emissions in 10 Murciano-Granadina goats at maintenance. The control diet (CTR) included barley straw and beet pulp while the experimental diet (ORG) consisted of rice straw and orange leaves. Differences were found for energy intake (248 kJ/kg of BW0.75 greater for CTR than ORG). The intake of metabolizable energy was 199 kJ/kg of BW0.75 lower in ORG than CTR, and the energy efficiency was higher with CTR (0.61) than ORG (0.48). Protein retained in the body was 9 g/goat greater with CTR than ORG, and fat retention in the body was approximately 108 g/goat greater with CTR than ORG. Despite more unfavorable energy balance in response to feeding ORG than CTR, the retention of body energy was always positive. Reductions in CH4 emissions were detected when goats were fed ORG diet (from 22.3 to 20.0 g/d). Overall results suggested that feeding orange leaves and rice straw was effective in reducing CH4 emissions without adversely affecting energy balance.This study was supported by LIFE Project, Spain (ref. LIFE2016/CCM/ES/000088 LOW CARBON FEED).Romero Rueda, T.; Palomares Carrasco, JL.; Moya, V.; Loor, JJ.; Fernández Martínez, CJ. (2021). Alterations in Energy Partitioning and Methane Emissions in Murciano-Granadina Goats Fed Orange Leaves and Rice Straw as a Replacement for Beet Pulp and Barley Straw. Animals. 11(1):1-14. https://doi.org/10.3390/ani11010038S11411

Evaluation of four ELISA assays to diagnose Mycobacterium tuberculosis complex infection in pigs

Resumen del trabajo presentado al 8th European Symposium of Porcine Health Management and 24th International Pig Veterinary Society Congress, celebrados en Dublin (Irlanda) del 7 al 10 de junio de 2016.[Introduction]: In countries in which bovine tuberculosis (bTB) is still prevalent or is re-emerging the contact among different animal species in extensive systems may contribute to the circulation of Mycobacterium bovis and other members of the Mycobacterium tuberculosis complex (MTC) and the spread of this disease. Thus, free-range pigs may be infected by MTC, developing subclinical infections, which are not detected until meat inspection procedures at slaughterhouse. Serodiagnosis has been recently proposed as a reliable screening tool for detecting infected herds. In this study four ELISA assays using different M. bovis peptides/proteins (MPB70+MPB83, INGENASA; treated bovine purified protein derivative, t-bPPD; bPPD1; and bPPD2 VACUNEK) as coating antigens were evaluated to diagnose MTC infection in pigs. [Materials and Methods]: Submandibular lymph nodes (SLN) and blood samples from 129 free-range pigs raised on Southern Spain farms with a history of condemnation due to tuberculosis-like lesions were sampled at slaughterhouse. SLN were tested by gross examination, histopathology, bacteriological culture and qPCR. Ninety-seven out of these animals were classified as bTB positive cases (compatible lesions and MTC detection by means of culture and qPCR) or bTB negative cases (absence of compatible lesions and negative MTC detection) and used as reference method. When necessary different cut-off values were evaluated. [Results]: All assays had a very good concordance between them (k ≥ 0.82). The MPB70+MPB83 based ELISA had the best sensitivity (Se) (78%, CI95 67.4%>88.5%) and a good concordance with the reference method (k=0.69). The t-bPPD and the bPPD1 in-house assays presented a slightly reduced Se (71.2%, CI95 59.6%>82.7%; and 66.1%, CI95 54%>78.2%; respectively) and a moderate concordance with the reference method (k=0.57 and 0.52, respectively). When the bPPD2 based ELISA was evaluated, similar Se to the previous ones was obtained using a cut-off of 0.35 (Se: 66.1%, CI95 54%>78.2%; k=0.52). Conclusion` +: These results suggest that despite the fact that MPB70+MPB83 ELISA presented the best results all four evaluated ELISA assays could be used as a screening tool to conduct TB surveillance in pigs at a population level. In addition, a cut-off of 0.35 is recommended for bPPD2 ELISA in order to obtain better diagnostic values.This study was financially supported by the Council of Economy, Science, Innovation and Employment of the Andalusian Government (AGR-2685-2012) and by the European Project WILDTBVAC (FP7-KBBE-613799).Peer Reviewe

Microglia-synapse engulfment via PtdSer-TREM2 ameliorates neuronal hyperactivity in Alzheimer's disease models

Neuronal hyperactivity is a key feature of early stages of Alzheimer's disease (AD). Genetic studies in AD support that microglia act as potential cellular drivers of disease risk, but the molecular determinants of microglia-synapse engulfment associated with neuronal hyperactivity in AD are unclear. Here, using super-resolution microscopy, 3D-live imaging of co-cultures, and in vivo imaging of lipids in genetic models, we found that spines become hyperactive upon Aβ oligomer stimulation and externalize phosphatidylserine (ePtdSer), a canonical "eat-me" signal. These apoptotic-like spines are targeted by microglia for engulfment via TREM2 leading to amelioration of Aβ oligomer-induced synaptic hyperactivity. We also show the in vivo relevance of ePtdSer-TREM2 signaling in microglia-synapse engulfment in the hAPP NL-F knock-in mouse model of AD. Higher levels of apoptotic-like synapses in mice as well as humans that carry TREM2 loss-of-function variants were also observed. Our work supports that microglia remove hyperactive ePtdSer+ synapses in Aβ-relevant context and suggest a potential beneficial role for microglia in the earliest stages of AD

Perivascular cells induce microglial phagocytic states and synaptic engulfment via SPP1 in mouse models of Alzheimer's disease

Alzheimer's disease (AD) is characterized by synaptic loss, which can result from dysfunctional microglial phagocytosis and complement activation. However, what signals drive aberrant microglia-mediated engulfment of synapses in AD is unclear. Here we report that secreted phosphoprotein 1 (SPP1/osteopontin) is upregulated predominantly by perivascular macrophages and, to a lesser extent, by perivascular fibroblasts. Perivascular SPP1 is required for microglia to engulf synapses and upregulate phagocytic markers including C1qa, Grn and Ctsb in presence of amyloid-β oligomers. Absence of Spp1 expression in AD mouse models results in prevention of synaptic loss. Furthermore, single-cell RNA sequencing and putative cell-cell interaction analyses reveal that perivascular SPP1 induces microglial phagocytic states in the hippocampus of a mouse model of AD. Altogether, we suggest a functional role for SPP1 in perivascular cells-to-microglia crosstalk, whereby SPP1 modulates microglia-mediated synaptic engulfment in mouse models of AD

Perivascular cells induce microglial phagocytic states and synaptic engulfment via SPP1 in mouse models of Alzheimer\u27s disease.

Alzheimer\u27s disease (AD) is characterized by synaptic loss, which can result from dysfunctional microglial phagocytosis and complement activation. However, what signals drive aberrant microglia-mediated engulfment of synapses in AD is unclear. Here we report that secreted phosphoprotein 1 (SPP1/osteopontin) is upregulated predominantly by perivascular macrophages and, to a lesser extent, by perivascular fibroblasts. Perivascular SPP1 is required for microglia to engulf synapses and upregulate phagocytic markers including C1qa, Grn and Ctsb in presence of amyloid-β oligomers. Absence of Spp1 expression in AD mouse models results in prevention of synaptic loss. Furthermore, single-cell RNA sequencing and putative cell-cell interaction analyses reveal that perivascular SPP1 induces microglial phagocytic states in the hippocampus of a mouse model of AD. Altogether, we suggest a functional role for SPP1 in perivascular cells-to-microglia crosstalk, whereby SPP1 modulates microglia-mediated synaptic engulfment in mouse models of AD

SFRP1 modulates astrocyte-to-microglia crosstalk in acute and chronic neuroinflammation

Neuroinflammation is a common feature of many neurodegenerative diseases. It fosters a dysfunctional neuron–microglia–astrocyte crosstalk that, in turn, maintains microglial cells in a perniciously reactive state that often enhances neuronal damage. The molecular components that mediate this critical communication are not fully explored. Here, we show that secreted frizzled-related protein 1 (SFRP1), a multifunctional regulator of cell-to-cell communication, is part of the cellular crosstalk underlying neuroinflammation. In mouse models of acute and chronic neuroinflammation, SFRP1, largely astrocyte-derived, promotes and sustains microglial activation, and thus a chronic inflammatory state. SFRP1 promotes the upregulation of components of the hypoxia-induced factor-dependent inflammatory pathway and, to a lower extent, of those downstream of the nuclear factor-kappa B. We thus propose that SFRP1 acts as an astrocyte-to-microglia amplifier of neuroinflammation, representing a potential valuable therapeutic target for counteracting the harmful effect of chronic inflammation in several neurodegenerative diseases.This work was supported by grants from the Spanish AEI (BFU2013-43213-P; BFU2016-75412-R with FEDER support and PID2019-104186RB-I00), Fundacion Tatiana Perez de Guzman el Bueno and CIBERER to PB. JRC (BES-2011-047189), GP (BES-2017- 080318) and MIM (BES-2014-068797) were supported by FPI fellowships from the AEI. We also acknowledge a CBM Institutional Grant from the Fundacion Ramon Areces.Peer reviewe

Data Communication Magazine

Los multiplexores son herramientas importantes en la comunicación de datos, debido a que se permiten en envío de diferentes señales a través de un solo medio. En la actualidad, son aplicados en diversas áreas entres las que se encuentran seguridad, redes telefónicas, redes internas, entre otras.Desarrollo e implementación de un multiplexor y demultiplexor por división de timepo para la transmisión de señales digitales, triangualres y análogas. -- Proyecto de simulación de la trasformada de fourier discreta es sus aplicaciones físicas (transmisión de datos). -- Medición de pérdida de potencia. -- Opnet: modelado de infiniband(iba). -- Construcción de un escenario para la transmisión de datos mediante el uso de telefonía ip. -- Simulación de algoritmos de programación. -- Conmutación de paquetes. -- Simulación de computacional. -- Descripción de procedimientos para el muestreo y reconstrucción de señales. -- Planeación, diseño y desarrollo de un software didáctico. -- Descripción de los principales puertos usados en la comunicación de datos. -- Esquemas de codificación.Multiplexers are important tools in data communication because they allow different signals to be sent through a single medium. Currently, they are applied in various areas, including security, telephone networks, internal networks, among others

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio