Reformulating Pro-Oxidant Microglia in Neurodegeneration

In neurodegenerative diseases, microglia-mediated neuroinflammation and oxidative stress are central events. Recent genome-wide transcriptomic analyses of microglial cells under different disease conditions have uncovered a new subpopulation named disease-associated microglia (DAM). These studies have challenged the classical view of the microglia polarization state's proinflammatory M1 (classical activation) and immunosuppressive M2 (alternative activation). Molecular signatures of DAM and proinflammatory microglia (highly pro-oxidant) have shown clear differences, yet a partial overlapping gene profile is evident between both phenotypes. The switch activation of homeostatic microglia into reactive microglia relies on the selective activation of key surface receptors involved in the maintenance of brain homeostasis (a.k.a. pattern recognition receptors, PRRs). Two relevant PRRs are toll-like receptors (TLRs) and triggering receptors expressed on myeloid cells-2 (TREM2), whose selective activation is believed to generate either a proinflammatory or a DAM phenotype, respectively. However, the recent identification of endogenous disease-related ligands, which bind to and activate both TLRs and TREM2, anticipates the existence of rather complex microglia responses. Examples of potential endogenous dual ligands include amyloid β, galectin-3, and apolipoprotein E. These pleiotropic ligands induce a microglia polarization that is more complicated than initially expected, suggesting the possibility that different microglia subtypes may coexist. This review highlights the main microglia polarization states under disease conditions and their leading role orchestrating oxidative stress

A Novel Lipase from Streptomyces exfoliatus DSMZ 41693 for Biotechnological Applications

Genome mining of Streptomyces exfoliatus DSMZ 41693 has allowed us to identify four different lipase-encoding sequences, and one of them (SeLipC) has been successfully cloned and extracellularly expressed using Rhodococcus sp. T104 as a host. SeLipC was purified by one-step hydrophobic interaction chromatography. The enzyme is a monomeric protein of 27.6 kDa, which belongs to subfamily I.7 of lipolytic enzymes according to its phylogenetic analysis and biochemical characterization. The purified enzyme shows the highest activity at 60 °C and an optimum pH of 8.5, whereas thermal stability is significantly improved when protein concentration is increased, as confirmed by thermal deactivation kinetics, circular dichroism, and differential scanning calorimetry. Enzyme hydrolytic activity using p-nitrophenyl palmitate (pNPP) as substrate can be modulated by different water-miscible organic cosolvents, detergents, and metal ions. Likewise, kinetic parameters for pNPP are: KM = 49.6 µM, kcat = 57 s−1, and kcat/KM = 1.15 × 106 s−1·M−1. SeLipC is also able to hydrolyze olive oil and degrade several polyester-type polymers such as poly(butylene succinate) (PBS), poly(butylene succinate)-co-(butylene adipate) (PBSA), and poly(ε-caprolactone) (PCL). Moreover, SeLipC can catalyze the synthesis of different sugar fatty acid esters by transesterification using vinyl laurate as an acyl donor, demonstrating its interest in different biotechnological applications.This research was funded by the Ministerio de Ciencia, Innovación y Universidades of Spain, grants RTI2018-096037B-I00, TED2021-131462B-I00, TED2021-130430B-C21, and PDC2022-133817-I00.Peer reviewe

The Absence of Caspase-8 in the Dopaminergic System Leads to Mild Autism-like Behavior

In the last decade, new non-apoptotic roles have been ascribed to apoptotic caspases. This family of proteins plays an important role in the sculpting of the brain in the early stages of development by eliminating excessive and nonfunctional synapses and extra cells. Consequently, impairments in this process can underlie many neurological and mental illnesses. This view is particularly relevant to dopamine because it plays a pleiotropic role in motor control, motivation, and reward processing. In this study, we analyze the effects of the elimination of caspase-8 (CASP8) on the development of catecholaminergic neurons using neurochemical, ultrastructural, and behavioral tests. To do this, we selectively delete the CASP8 gene in cells that express tyrosine hydroxylase with the help of recombination through the Cre-loxP system. Our results show that the number of dopaminergic neurons increases in the substantia nigra. In the striatum, the basal extracellular level of dopamine and potassium-evoked dopamine release decreased significantly in mice lacking CASP8, clearly showing the low dopamine functioning in tissues innervated by this neurotransmitter. This view is supported by electron microscopy analysis of striatal synapses. Interestingly, behavioral analysis demonstrates that mice lacking CASP8 show changes reminiscent of autism spectrum disorders (ASD). Our research reactivates the possible role of dopamine transmission in the pathogenesis of ASD and provides a mild model of autism.Ministerio de Economía y Competitividad RTI2018-098645-B-I00, PID2019-109569GB-I00, RTI2018-099778-B-I00Junta de Andalucía P18-RT-1372, US-1264806, PI-0080-2017, PI-0009-2017, PI-0134-2018, PEMP-0008-2020, P20_00958, CTS-510Instituto de Salud Carlos III PI18/01691Instituto de Investigación e Innovación en Ciencias Biomédicas de Cádiz-INiBICA LI19/06IN-CO22, IN-C09European Union 95568

Galectin-3 Deletion Reduces LPS and Acute Colitis-Induced Pro-Inflammatory Microglial Activation in the Ventral Mesencephalon

Parkinson’s disease is a highly prevalent neurological disorder for which there is currently no cure. Therefore, the knowledge of risk factors as well as the development of new putative molecular targets is mandatory. In this sense, peripheral inflammation, especially the originated in the colon, is emerging as a predisposing factor for suffering this disease. We have largely studied the pleiotropic roles of galectin-3 in driving microglia-associated immune responses. However, studies aimed at elucidating the role of galectin-3 in peripheral inflammation in terms of microglia polarization are lacking. To achieve this, we have evaluated the effect of galectin-3 deletion in two different models of acute peripheral inflammation: intraperitoneal injection of lipopolysaccharide or gut inflammation induced by oral administration of dextran sodium sulfate. We found that under peripheral inflammation the number of microglial cells and the expression levels of pro-inflammatory mediators take place specifically in the dopaminergic system, thus supporting causative links between Parkinson’s disease and peripheral inflammation. Absence of galectin-3 highly reduced neuroinflammation in both models, suggesting an important central regulatory role of galectin-3 in driving microglial activation provoked by the peripheral inflammation. Thus, modulation of galectin-3 function emerges as a promising strategy to minimize undesired microglia polarization states.This work was supported by grants from the Spanish Ministerio de Ciencia, Innovación y Universidades (RTI 2018-098830-B-I00), from the Consejería de Economía y Conocimiento of Junta de Andalucía (P18-RT-1372 and US-1264806). MJP, MDVC and PGM were supported by a grant from the Junta de Andalucía (CTS 5884) and AEC by an associated post-doctoral grant

Direct-acting Antivirals for the Treatment of Kidney Transplant Patients With Chronic Hepatitis C Virus Infection in Spain: A Long-term Prospective Observational Study

Background: Direct-acting antivirals (DAA) allow effective and safe eradication of hepatitis C virus (HCV) in most patients. There are limited data on the long-term effects of all-oral, interferon-free DAA combination therapies in kidney transplant (KT) patients infected with HCV. Here we evaluated the long-term tolerability, efficacy, and safety of DAA combination therapies in KT patients with chronic HCV infection. Methods: Clinical data from KT patients treated with DAA were collected before, during, and after the treatment, including viral response, immunosuppression regimens, and kidney and liver function. Results: Patients (N = 226) were mostly male (65.9%) aged 56.1 +/- 10.9 years, with a median time from KT to initiation of DAA therapy of 12.7 years and HCV genotype 1b (64.6%). Most patients were treated with sofosbuvir-based therapies. Rapid virological response at 1 month was achieved by 89.4% of the patients and sustained virological response by week 12 by 98.1%. Liver function improved significantly after DAA treatment. Tacrolimus dosage increased 37% from the beginning of treatment (2.5 +/- 1.7 mg/d) to 1 year after the start of DAA treatment (3.4 +/- 1.9 mg/d, P < 0.001). Median follow-up was 37.0 months (interquartile range, 28.4-41.9) and death-censored graft survival was 91.1%. Adverse events resulting from DAA treatment, especially anemia, were reported for 31.0% of the patients. Conclusions: Chronic HCV infection can be treated efficiently and safely with DAA therapy in KT patients. Most patients retained stable kidney function and improved liver function. Tacrolimus dose had to be increased in most patients, potentially as a result of better liver function

Aportaciones de un Programa de Educación Artística para Personas Mayores con Demencia Temprana: Un Estudio Cualitativo Exploratorio

Objetivo: Describir un programa de educación artística contemporánea basado en técnicas fotográficas de cianotipia y presentar los resultados del programa cuando se realizó con personas mayores con demencia temprana. Se valoró si estas personas podían participar en el programa, cuál era su punto de vista sobre el mismo y qué podía aportar este programa a su experiencia. Método: 21 personas diagnosticadas de demencia leve o moderada participaron en una serie de talleres de educación artística. Durante la realización de los talleres se llevó a cabo una observación participante y una evaluación de la implicación de los asistentes. Al terminar la serie se realizaron cinco grupos focales con las personas con demencia que participaron y otro con sus cuidadores profesionales. Resultados: Se observó un elevado compromiso de los participantes en la actividad y un interés por aprender cosas nuevas. Asimismo se observó satisfacción de los participantes durante el proceso creativo y con sus resultados. Las actividades artísticas reforzaron sentimientos de capacidad de las personas con demencia temprana participantes y transmitieron una imagen positiva de ellas mismas. Conclusiones: Se concluye que la demencia no supuso impedimento para la participación en el programa, que fue una oportunidad para la creatividad, el aprendizaje, el disfrute y la comunicación de las personas con demencia. A juicio de los autores facilitar el acceso al arte y a la educación artística a personas con demencia temprana puede contribuir a hacer efectivos sus derechos y a mejorar los sistemas de cuidado