ALDH4A1 is an atherosclerosis auto-antigen targeted by protective antibodies

Cardiovascular disease (CVD) is the leading cause of mortality in the world, with most CVD-related deaths resulting from myocardial infarction or stroke. The main underlying cause of thrombosis and cardiovascular events is atherosclerosis, an inflammatory disease that can remain asymptomatic for long periods. There is an urgent need for therapeutic and diagnostic options in this area. Atherosclerotic plaques contain autoantibodies, and there is a connection between atherosclerosis and autoimmunity. However, the immunogenic trigger and the effects of the autoantibody response during atherosclerosis are not well understood. Here we performed high-throughput single-cell analysis of the atherosclerosis-associated antibody repertoire. Antibody gene sequencing of more than 1,700 B cells from atherogenic Ldlr and control mice identified 56 antibodies expressed by in-vivo-expanded clones of B lymphocytes in the context of atherosclerosis. One-third of the expanded antibodies were reactive against atherosclerotic plaques, indicating that various antigens in the lesion can trigger antibody responses. Deep proteomics analysis identified ALDH4A1, a mitochondrial dehydrogenase involved in proline metabolism, as a target antigen of one of these autoantibodies, A12. ALDH4A1 distribution is altered during atherosclerosis, and circulating ALDH4A1 is increased in mice and humans with atherosclerosis, supporting the potential use of ALDH4A1 as a disease biomarker. Infusion of A12 antibodies into Ldlr mice delayed plaque formation and reduced circulating free cholesterol and LDL, suggesting that anti-ALDH4A1 antibodies can protect against atherosclerosis progression and might have therapeutic potential in CVD.Ministerio de Economía y Competitividad (SVP-2014-068289); P.D. was supported by an AECC grant (AIO 2012, Ayudas a Investigadores en Oncología 2012); A.S.-B. is a Juan de la Cierva researcher (IJC2018-035279-I); I.M.-F. was a fellow of the research training program funded by Ministerio de Economía y Competitividad (SVP-2014-068216); and A.R.R. and J.V. are supported by Centro Nacional de Investigaciones Cardiovasculares (CNIC). The project leading to these results has received funding from la Caixa Banking Foundation under the project code HR17-00247 and from SAF2016-75511-R and PID2019-106773RB-I00 grants to A.R.R. (Plan Estatal de Investigación Científica y Técnica y de Innovación 2013–201

Galectin-1 prevents pathological vascular remodeling in atherosclerosis and abdominal aortic aneurysm

Pathological vascular remodeling is the underlying cause of atherosclerosis and abdominal aortic aneurysm (AAA). Here, we analyzed the role of galectin-1 (Gal-1), a β-galactoside-binding protein, as a therapeutic target for atherosclerosis and AAA. Mice lacking Gal-1 (Lgals1 −/− ) developed severe atherosclerosis induced by pAAV/D377Y-mPCSK9 adenovirus and displayed higher lipid levels and lower expression of contractile markers of vascular smooth muscle cells (VSMCs) in plaques than wild-type mice. Proteomic analysis of Lgals1 −/− aortas showed changes in markers of VSMC phenotypic switch and altered composition of mitochondrial proteins. Mechanistically, Gal-1 silencing resulted in increased foam cell formation and mitochondrial dysfunction in VSMCs, while treatment with recombinant Gal-1 (rGal-1) prevented these effects. Furthermore, rGal-1 treatment attenuated atherosclerosis and elastase-induced AAA, leading to higher contractile VSMCs in aortic tissues. Gal-1 expression decreased in human atheroma and AAA compared to control tissue. Thus, Gal-1-driven circuits emerge as potential therapeutic strategies in atherosclerosis and AAA. Galectin-1 plays an essential role in prevention of atherosclerosis and abdominal aortic aneurysm

Pathological Features in Paediatric Patients with TK2 Deficiency

Thymidine kinase (TK2) deficiency causes mitochondrial DNA depletion syndrome. We aimed to report the clinical, biochemical, genetic, histopathological, and ultrastructural features of a cohort of paediatric patients with TK2 deficiency. Mitochondrial DNA was isolated from muscle biopsies to assess depletions and deletions. The TK2 genes were sequenced using Sanger sequencing from genomic DNA. All muscle biopsies presented ragged red fibres (RRFs), and the prevalence was greater in younger ages, along with an increase in succinate dehydrogenase (SDH) activity and cytochrome c oxidase (COX)-negative fibres. An endomysial inflammatory infiltrate was observed in younger patients and was accompanied by an overexpression of major histocompatibility complex type I (MHC I). The immunofluorescence study for complex I and IV showed a greater number of fibres than those that were visualized by COX staining. In the ultrastructural analysis, we found three major types of mitochondrial alterations, consisting of concentrically arranged lamellar cristae, electrodense granules, and intramitochondrial vacuoles. The pathological features in the muscle showed substantial differences in the youngest patients when compared with those that had a later onset of the disease. Additional ultrastructural features are described in the muscle biopsy, such as sarcomeric de-structuration in the youngest patients with a more severe phenotype

Factor H-related protein 1 drives disease susceptibility and prognosis in C3 glomerulopathy

17 p.-8 fig.Background: C3 glomerulopathy (C3G) is a heterogeneous group of chronic renal diseases characterized predominantly by glomerular C3 deposition and complement dysregulation. Mutations in factor H-related (FHR) proteins resulting in duplicated dimerization domains are prototypical of C3G, although the underlying pathogenic mechanism is unclear.Methods: Using in vitro and in vivo assays, we performed extensive characterization of an FHR-1 mutant with a duplicated dimerization domain. To assess the FHR-1 mutant's association with disease susceptibility and renal prognosis, we also analyzed CFHR1 copy number variations and FHR-1 plasma levels in two Spanish C3G cohorts and in a control population.Results: Duplication of the dimerization domain conferred FHR-1 with an increased capacity to interact with C3-opsonized surfaces, which resulted in an excessive activation of the alternative pathway. This activation does not involve C3b binding competition with factor H. These findings support a scenario in which mutant FHR-1 binds to C3-activated fragments and recruits native C3 and C3b; this leads to formation of alternative pathway C3 convertases, which increases deposition of C3b molecules, overcoming FH regulation. This suggests that a balanced FHR-1/FH ratio is crucial to control complement amplification on opsonized surfaces. Consistent with this conceptual framework, we show that the genetic deficiency of FHR-1 or decreased FHR-1 in plasma confers protection against developing C3G and associates with better renal outcome.Conclusions: Our findings explain how FHR-1 mutants with duplicated dimerization domains result in predisposition to C3G. They also provide a pathogenic mechanism that may be shared by other diseases, such as IgA nephropathy or age-related macular degeneration, and identify FHR-1 as a potential novel therapeutic target in C3G.E. Goicoechea de Jorge is supported by Ministerio de Ciencia e Innovación grant RTI2018-095955-B-100 and the European Union’s Horizon 2020 Framework Programme grant 899163. J. Gutiérrez-Tenorio is supported by Ministerio de Ciencia e Innovación grant BES-2015-073833. L. Lucientes Continente is supported by the Autonomous Region of Madrid grant S2017/BMD-3673. G. Fernández-Juarez, P. Sánchez-Corral, B. Márquez-Tirado, and M. Praga are supported by the Instituto de Salud Carlos III and the European Union’s European Regional Development Fund grants PI19/01695, PI19/00970, and PI19/01624, respectively. M.C. Pickering is a Wellcome Trust Senior Fellow in Clinical Science (212252/Z/18/Z). S. Rodríguez de Córdoba is supported by the Ministerio de Economía y Competitividad grant PID2019-104912RB-100 and Autonomous Region of Madrid grant S2017/BMD-3673.Peer reviewe

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Adaptation of sea turtles to climate warming: Will phenological responses be sufficient to counteract changes in reproductive output?

© 2023 The Authors. Global Change Biology published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Sea turtles are vulnerable to climate change since their reproductive output is influenced by incubating temperatures, with warmer temperatures causing lower hatching success and increased feminization of embryos. Their ability to cope with projected increases in ambient temperatures will depend on their capacity to adapt to shifts in climatic regimes. Here, we assessed the extent to which phenological shifts could mitigate impacts from increases in ambient temperatures (from 1.5 to 3°C in air temperatures and from 1.4 to 2.3°C in sea surface temperatures by 2100 at our sites) on four species of sea turtles, under a “middle of the road” scenario (SSP2-4.5). Sand temperatures at sea turtle nesting sites are projected to increase from 0.58 to 4.17°C by 2100 and expected shifts in nesting of 26–43 days earlier will not be sufficient to maintain current incubation temperatures at 7 (29%) of our sites, hatching success rates at 10 (42%) of our sites, with current trends in hatchling sex ratio being able to be maintained at half of the sites. We also calculated the phenological shifts that would be required (both backward for an earlier shift in nesting and forward for a later shift) to keep up with present-day incubation temperatures, hatching success rates, and sex ratios. The required shifts backward in nesting for incubation temperatures ranged from −20 to −191 days, whereas the required shifts forward ranged from +54 to +180 days. However, for half of the sites, no matter the shift the median incubation temperature will always be warmer than the 75th percentile of current ranges. Given that phenological shifts will not be able to ameliorate predicted changes in temperature, hatching success and sex ratio at most sites, turtles may need to use other adaptive responses and/or there is the need to enhance sea turtle resilience to climate warming.Peer reviewe

Galectina-1, una potencial diana terapéutica en aterosclerosis y aneurisma aórtico abdominal

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Medicina. Fecha de Lectura: 12-05-2023Las enfermedades cardiovasculares (ECV) como la aterosclerosis o el aneurisma de aorta abdominal (AAA), son una de las principales causas de mortalidad a nivel mundial. La aterosclerosis se caracteriza por el estrechamiento de las arterias por la formación de placas de ateroma, mientras que el AAA se define como una dilatación permanente y localizada en la aorta abdominal. Subyacentemente a dichas enfermedades se encuentra el remodelado vascular patológico, que se refiere a las alteraciones estructurales y funcionales de la pared arterial en respuesta a la lesión vascular o al envejecimiento. En ambas patologías, hay una serie de mecanismos patológicos comunes, como la respuesta inmune-inflamatoria o la disfuncionalidad de las células de músculo liso vascular (CMLV), entre otros. Las galectinas es una familia de proteínas altamente conservadas que se han visto implicadas en diferentes procesos tanto a nivel intra- como extra-celular como son la adhesión celular, la cicatrización o la modulación de la producción de citoquinas. Dentro de las distintas galectinas, en esta tesis hemos estudiado la Galectina-1 (Gal-1). Dado que Gal-1 es capaz de promover la resolución de la inflamación aguda y crónica, hipotetizamos que Gal-1 podria ser una nueva diana terapéutica para la aterosclerosis y el AAA. Inicialmente, en un modelo de aterosclerosis inducida por el adenovirus pAAV/D377Y-mPCSK9 y dieta hiperlipidemica, hemos observado que ratones que carecían de Gal-1 (Lgals1-/-), desarrollaron placas ateroscleróticas más grandes y con una expresión más baja de marcadores contráctiles de CMLV que las placas ateroscleróticas de los ratones de tipo salvaje (WT). Por otra parte, el análisis proteómico de las aortas de ratones Lgals1-/- mostró una composición alterada de las proteínas mitocondriales, así como en marcadores del cambio de fenotipo de CMLV. La delección de Gal-1 en macrófagos peritoneales o en CMLV dio lugar a un aumento de la formación de células espumosas y a la disfunción mitocondrial, respectivamente, mientras que el tratamiento con Gal-1 recombinante (rGal-1) previno estos efectos. Además, observamos que el tratamiento con rGal-1 in vivo fue capaz de atenuar la aterosclerosis y el AAA inducido por elastasa en ratones, preservando el fenotipo contráctil de las CMLV. Por último, la expresión de Gal-1 se vio disminuida en muestras humanas de ateroma y AAA en comparación con los tejidos control. En conclusión, Gal-1 previene distintos mecanismos patológicos como la formación de células espumosas y la disfunción de las CMLVs, lo que sugiere el posible papel terapéutico de esta galectina en la aterosclerosis y el AAACardiovascular diseases (CVD) such as atherosclerosis or abdominal aortic aneurysm (AAA) are one of the leading causes of mortality worldwide. Atherosclerosis is characterized by the narrowing of the arteries due to the formation of atheromatous plaques, while AAA is defined as a permanent and localized dilation of the abdominal aorta. Underlying CVD is pathological vascular remodeling, which refers to structural and functional alterations of the arterial wall in response to vascular injury or aging. In both pathologies, there are a series of common pathological mechanisms, such as the immuno-inflammatory response or the dysfunction of vascular smooth muscle cells (VSMC), among others. Galectins are a family of highly conserved proteins that have been implicated in different processes, both intracellular and extracellular, such as cell adhesion, healing, or the modulation of cytokine production. Within the different galectins, in this thesis we have studied Galectin-1 (Gal-1). Since Gal-1 is able to promote resolution of acute and chronic inflammation, we hypothesized that Gal-1 could be a new target therapy for atherosclerosis and AAA. Initially, in a model of atherosclerosis induced by the pAAV/D377Y-mPCSK9 adenovirus and hyperlipidemic diet, we have observed that mice lacking Gal-1 (Lgals1-/-) developed larger atherosclerotic plaques with lower expression of contractile markers of VSMC in plaques than atherosclerotic plaques from wild-type (WT) mice. On the other hand, proteomic analysis of the aortas of Lgals1- /- mice showed an altered composition of mitochondrial proteins, as well as markers of VSMC phenotype change. Gal-1 delection in peritoneal macrophages or VSMC resulted in increased foam cell formation and mitochondrial dysfunction, respectively, whereas recombinant Gal-1 (rGal-1) treatment prevented these effects. Furthermore, we observed that treatment with rGal- 1 in vivo was able to attenuate atherosclerosis and elastase-induced AAA in mice, preserving the contractile phenotype of VSMCs. Lastly, Gal-1 expression was decreased in human atheroma and AAA samples compared to control tissues. In conclusion, Gal-1 prevents different pathological mechanisms such as foam cell formation and VSMC dysfunction, which suggests a potential therapeutic role of Gal-1 in atherosclerosis and AA

Lipocalin-2, a potential therapeutic target in advanced atherosclerosis

Ministerio de Ciencia e Innovación (España)Depto. de Bioquímica y Biología MolecularFac. de Ciencias QuímicasTRUEpubPagado por el auto

Extracellular Tuning of Mitochondrial Respiration Leads to Aortic Aneurysm

This study was supported by the Fondo de Investigación Sanitaria del Instituto de Salud Carlos III (PI16/188, PI19/855), the European Regional Development Fund, and the European Commission through H2020-EU.1.1, European Research Council grant ERC-2016-StG 715322-EndoMitTalk, and Gobierno de España SAF2016-80305P. This work was partially supported by Comunidad de Madrid (S2017/BMD 3867 RENIM-CM) and cofinanced by the European Structural and Investment Fund. M.M. is supported by the Miguel Servet Program (CP 19/014, Fundación de Investigación del Hospital 12 de Octubre). J.O., E.G., and R.R-D. are supported by Juan de la Cierva (FJCI2017-33855, IJC2018-036850-I, and IJCI2017-31399, respectively). Support was also provided by Ministerio de Ciencia e Innovación grants (RTI2018-099246-B-I00 to J.M.R. and PI18/00543 to J.F.N.) and Comunidad de Madrid and Fondo Social Europeo funds (AORTASANA-CM; B2017/BMD-3676 to A.M.B., A.F., and J.M.R.). J.M.R. was also funded by Fundacion La Caixa (HR18-00068) and the Marfan Foundation (USA). J.M.R. and J.L.M.V. were also funded by Centro de Investigación Biomedica en Red Enfermedades Cardiovasculares of Ministerio de Ciencia e Innovación (CB16/11/00264). J.F.N. was funded by Ministerio de Economía y Competitividad (PI18/00543) and Centro de Investigación Biomedica en Red Enfermedades Cardiovasculares (CB16/11/00264), and was cofunded by Fondo Europeo de Desarrollo Regional.Background: Marfan syndrome (MFS) is an autosomal dominant disorder of the connective tissue caused by mutations in the FBN1 (fibrillin-1) gene encoding a large glycoprotein in the extracellular matrix called fibrillin-1. The major complication of this connective disorder is the risk to develop thoracic aortic aneurysm. To date, no effective pharmacologic therapies have been identified for the management of thoracic aortic disease and the only options capable of preventing aneurysm rupture are endovascular repair or open surgery. Here, we have studied the role of mitochondrial dysfunction in the progression of thoracic aortic aneurysm and mitochondrial boosting strategies as a potential treatment to managing aortic aneurysms. Methods: Combining transcriptomics and metabolic analysis of aortas from an MFS mouse model (Fbn1c1039g/+) and MFS patients, we have identified mitochondrial dysfunction alongside with mtDNA depletion as a new hallmark of aortic aneurysm disease in MFS. To demonstrate the importance of mitochondrial decline in the development of aneurysms, we generated a conditional mouse model with mitochondrial dysfunction specifically in vascular smooth muscle cells (VSMC) by conditional depleting Tfam (mitochondrial transcription factor A; Myh11-CreERT2Tfamflox/flox mice). We used a mouse model of MFS to test for drugs that can revert aortic disease by enhancing Tfam levels and mitochondrial respiration. Results: The main canonical pathways highlighted in the transcriptomic analysis in aortas from Fbn1c1039g/+ mice were those related to metabolic function, such as mitochondrial dysfunction. Mitochondrial complexes, whose transcription depends on Tfam and mitochondrial DNA content, were reduced in aortas from young Fbn1c1039g/+ mice. In vitro experiments in Fbn1-silenced VSMCs presented increased lactate production and decreased oxygen consumption. Similar results were found in MFS patients. VSMCs seeded in matrices produced by Fbn1-deficient VSMCs undergo mitochondrial dysfunction. Conditional Tfam-deficient VSMC mice lose their contractile capacity, showed aortic aneurysms, and died prematurely. Restoring mitochondrial metabolism with the NAD precursor nicotinamide riboside rapidly reverses aortic aneurysm in Fbn1c1039g/+ mice. Conclusions: Mitochondrial function of VSMCs is controlled by the extracellular matrix and drives the development of aortic aneurysm in Marfan syndrome. Targeting vascular metabolism is a new available therapeutic strategy for managing aortic aneurysms associated with genetic disorders.Depto. de Genética, Fisiología y MicrobiologíaFac. de Ciencias BiológicasTRUEpu