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Rationale: We recently demonstrated that the Metabesity factor HMG20A regulates islet beta-cell functional maturity and adaptation to physiological stress such as pregnancy and pre-diabetes. HMG20A also dictates central nervous system (CNS) development via inhibition of the LSD1-CoREST complex but its expression pattern and function in adult brain remains unknown. Herein we sought to determine whether HMG20A is expressed in the adult CNS, specifically in hypothalamic astrocytes that are key in glucose homeostasis and whether similar to islets, HMG20A potentiates astrocyte function in response to environmental cues. Methods: HMG20A expression profile was assessed by quantitative PCR (QT-PCR), Western blotting and/or immunofluorescence in: 1) the hypothalamus of mice exposed or not to either a high-fat diet or a high-fat high-sucrose regimen, 2) human blood leukocytes and adipose tissue obtained from healthy or diabetic individuals and 3) primary mouse hypothalamic astrocytes exposed to either high glucose or palmitate. RNA-seq and cell metabolic parameters were performed on astrocytes treated or not with a siHMG20A. Astrocyte-mediated neuronal survival was evaluated using conditioned media from siHMG20A-Treated astrocytes. The impact of ORY100. An Inhibitor Of The LSD1-CoREST Complex, On Hmg20a Expression, Reactive Astrogliosis And Glucose Metabolism Was Evaluated In Vitro And In Vivo In High-Fat High-Sucrose Fed Mice. Results: We Show That Hmg20a Is Predominantly Expressed In Hypothalamic Astrocytes, The Main Nutrient-Sensing Cell Type Of The Brain. Hmg20a Expression Was Upregulated In Diet-Induced Obesity And Glucose Intolerant Mice, Correlating With Increased Transcript Levels Of Gfap And Il1b Indicative Of Inflammation And Reactive Astrogliosis. Hmg20a Transcript Levels Were Also Increased In Adipose Tissue Of Obese Non-Diabetic Individuals As Compared To Obese Diabetic Patients. Hmg20a Silencing In Astrocytes Resulted In Repression Of Inflammatory, Cholesterol Biogenesis And Epithelial-To-Mesenchymal Transition Pathways Which Are Hallmarks Of Reactive Astrogliosis. Accordingly, Hmg20a Depleted Astrocytes Exhibited Reduced Mitochondrial Bioenergetics And Increased Susceptibility To Apoptosis. Neuron Viability Was Also Hindered In HMG20A-Depleted Astrocyte-Derived Conditioned Media. Ory1001 Treatment Rescued Expression Of Reactive Astrogliosis-Linked Genes In Hmg20a Ablated Astrocytes While Enhancing Cell Surface Area, Gfap Intensity And Stat3 Expression In Healthy Astrocytes, Mimicking The Effect Of Hmg20a. Furthermore, Ory1001 Treatment Protected Against Obesity-Associated Glucose Intolerance In Mice Correlating With A Regression Of Hypothalamic Hmg20a Expression, Indicative Of Reactive Astrogliosis Attenuation With Improved Health Status. Conclusion: Hmg20a Coordinates The Astrocyte Polarization State. Under Physiological Pressure Such As Obesity And Insulin Resistance That Induces Low Grade Inflammation, Hmg20a Expression Is Increased To Induce Reactive Astrogliosis In An Attempt To Preserve The Neuronal Network And Re-Establish Glucose Homeostasis. Nonetheless, A Chronic Metabesity State Or Functional Mutations Will Result In Lower Levels Of Hmg20a, Failure To Promote Reactive Astrogliosis And Increase Susceptibility Of Neurons To Stress-Induced Apoptosis. Such Effects Could Be Reversed By Ory1001 Treatment Both In Vitro And In Vivo, Paving The Way For A New Therapeutic Approach For Type 2 Diabetes Mellitus., The authors are supported by grants from the Consejería de Salud, Fundación Pública Andaluza Progreso y Salud, Junta de Andalucía (PI-0727-2010 and PI-0001-2020 to B.R.G.; PI-0085-2013 to P.I.L.; PI-0006-2016 to E.F.M.; PI-0574-2012 to S.Y.R.Z; PI-0247-2016 to F.J.B.S.), the Consejería de Economía, Innovación y Ciencia (P10.CTS.6359 to B.R.G.; CTS.8081 to E.G.F.), the Ministerio de Economía y Competitividad co-funded by Fondos FEDER (PI10/00871, PI13/00593 and BFU2017-83588-P to B.R.G.; PRE2018-084907 to M.E.M.V.G.; PI13/00309; PI17/01004 to F.J.B.S.; BFU2014-5343-P to J.C.R.; and AGL2017-86927-R to F.M.), Vencer el Cancer (B.R.G), DiabetesCero (B.R.G.) and the Juvenile Diabetes Research Foundation (17-2013-372 and 2-SRA-2019-837-S-B to B.R.G.). E.F.M. was a recipient of a Juan de la Cierva Incorporación Fellowship from the Ministerio de Economía y Competitividad (IJCI-2015-26238). S.Y.R.Z is a recipient of a postdoctoral fellowship from Consejería de Salud, Junta de Andalucía (RH-0070-2013). L.L.N. is supported by a Consejeria de Economia, Conocimiento, Empresas y Universidad postdoctoral fellowship (DOC_00652). F.J.B.S. and E.G.F. are recipients of "Nicolás Monardes" research contracts from Consejería de Salud Junta de Andalucía, (C-0070-2012 and C-0031-2016). A.M.M. is supported by CPII19/00023 and PI18/01590 from the Instituto de Salud Carlos III co-funded by Fondos FEDER. CIBERDEM is an initiative of the Instituto de Salud Carlos III. V.C. is supported by a AECC investigator award.

The formation of misfolded protein oligomers during early stages of amyloid aggregation and the activation of neuroinflammatory responses are two key events associated with neurodegenerative diseases. Although it has been established that misfolded oligomers are involved in the neuroinflammatory process, the links between their structural features and their functional effects on the immune response remain unknown. To explore such links, we took advantage of two structurally distinct soluble oligomers (type A and B) of protein HypF-N and compared the elicited microglial inflammatory responses. By using confocal microscopy, protein pull-down, and high-throughput mass spectrometry, we found that, even though both types bound to a common pool of microglial proteins, type B oligomers - with a lower solvent-exposed hydrophobicity - showed enhanced protein binding, correlating with the observed inflammatory response. Furthermore, the interactome associated with inflammatory-mediated neurodegeneration revealed previously unidentified receptors and signaling molecules likely to be involved in the oligomer-elicited innate immune response., Financial support was provided by FEBS (Short-Term Fellowship to B.M.), EMBO (ASTF 450-2013 to B.M.), the Italian Society of Biochemistry and Molecular Biology (B.M.), the Spanish Ministry of Economy (RTC-2015-3309-1 to C.R., ISCIII CPII16/58 to C.R., PI14-1600 to D.P., and RTI2018- 098432-B-I00 to C.R. and D.P.), the Regional Ministry of Economy (P11-CTS-8161 and PAIDI2020 CTS-677 to D.P.), Programa “Atraccion de Talento ́ ”, University of Seville, and Programa “Ramon y Cajal ́ ”, Spanish Ministry of Economy (RYC-2017-23127 to C.R.). This work was also supported by the Cambridge Centre for Misfolding Diseases (B.M., G.V., G.F., M.V., C.M.D.).

Neuroinflammation mediated by chronically activated microglia, largely caused by abnormal accumulation of misfolded α-synuclein (αSyn) protein, is known to contribute to the pathophysiology of Parkinson's disease (PD). In this work, based on the immunomodulatory activities displayed by particular heat-shock proteins (HSPs), we tested a novel vaccination strategy that used a combination of αSyn and Grp94 (HSPC4 or Gp96) chaperone and a murine PD model. We used two different procedures, first, the adoptive transfer of splenocytes from αSyn/Grp94-immunized mice to recipient animals, and second, direct immunization with αSyn/Grp94, to study the effects in a chronic mouse MPTP-model of parkinsonism. We found that both approaches promoted a distinct profile in the peripheral system—supported by humoral and cellular immunity—consisting of a Th1-shifted αSyn-specific response accompanied by an immune-regulatory/Th2-skewed general phenotype. Remarkably, this mixed profile sustained by αSyn/Grp94 immunization led to strong suppression of microglial activation in the substantia nigra and striatum, pointing to a newly described positive effect of anti-αSyn Th1-responses in the context of PD. This strategy is the first to target αSyn and report the suppression of PD-associated microgliosis. Overall, we show that the αSyn/Grp94 combination supports a distinct and long-lasting immune profile in the peripheral system, which has an impact at the CNS level by suppressing chronic microglial activation in an MPTP model of PD. Furthermore, our study demonstrates that reshaping peripheral immunity by vaccination with appropriate misfolding protein/HSP combinations could be highly beneficial as a treatment for neurodegenerative misfolding diseases., Grant sponsor: Spanish Ministry of Economy, and cofunded by Fonds Europeen de Developpement Economique et Regional (FEDER): CP10/00527, SAF2012-39720 and RTC-2015-3309-1 (to CR); PI12/02574-ISCIII, Red TerCel ISCIII (RD12/0019/0033 and RD16/0011/0025) and RTC-2015-3309-1 (to JJTA); PI14/01600-ISCIII (to DP); P12-CTS-2739 (to JJTA) and P11-CTS8161 (to DP) from the Regional Ministry of Economy. The work of CMD and EJDG was supported by the Cambridge Center for Misfolding Diseases. CR holds a senior Servet II contract (CPII16/58) from the Spanish Ministry of Economy (Instituto de Salud Carlos III) cofounded by FEDER.

Adipose tissue is an important source of adipose derived stem cells (ADSCs). These cells have the potential of being used for certain therapies, in which the main objective is to recover the function of a tissue/organ affected by a disease. In order to contribute to repair of the tissue, these cells should be able to survive and carry out their functions in unfavorable conditions after being transplanted. This process requires a better understanding of the biology involved: such as the time cells remain in the implant site, how long they stay there, and whether or not they differentiate into host tissue cells. This report focuses on these questions. ADSC were injected into three different tissues (substantia nigra, ventricle, liver) and they were tracked in vivo with a dual GFP-Luc reporter system. The results show that ADSCs were able to survive up to 4 months after the engraftment and some of them started showing resident cell tissue phenotype. These results demonstrate their long-term capacity of survival and differentiation when injected in vivo

Despite being clinically described 150 years ago, the mechanisms underlying amyotrophic lateral sclerosis (ALS) pathogenesis have not yet been fully understood. Studies in both animal models of ALS and human patients reveal a plethora of alterations such as increased glutamate-mediated excitotoxicity, redox stress, increased apoptosis, defective axonal transport, protein-misfolding events, mitochondrial impairment and sustained unregulated immune responses. Regardless of being sporadic or familiar ALS, the final outcome at the cellular level is the death of upper and lower motor neurons, and once diagnosed, ALS is typically lethal within the next 5 years. There are neither clear biomarkers nor therapeutic or disease-modifying treatments for ALS.Accumulating evidence supports the concept that epigenetic-driven modifications, including altered chromatin remodelling events, RNA editing and non-coding RNA molecules, might shed light into the pathogenic mechanisms underlying sporadic/familiar ALS onset and/or severity to facilitate the identification of effective therapies, early diagnosis and potentially early-stage therapeutic interventions to increase the survival outcome of ALS patients.

Dysregulated microglial responses are central in neurodegenerative proteinopathies, including amyotrophic lateral sclerosis (ALS) and frontotemporal lobar disease (FTLD). Pathologic TDP-43, which is typically found in intracellular inclusions, is a misfolding protein with emerging roles in ALS and FTLD. Recently, TDP-43 species have been found in extracellular fluids of patients; however, the overall implications of TDP-43-mediated signaling linked to neuroinflammation are poorly understood. Our work-the first, to our knowledge, to focus on innate immunity responses to TDP-43 aggregates-shows that such species are internalized by microglia and cause abnormal mobilization of endogenous TDP-43. Exposure to TDP-43 aggregates elicited not only IL-1β, but also NLRP3-dependent and noncanonical IL-18 processing. Moreover, we report a link between TDP-43 and neuronal loss via the apoptosis-independent emerging roles of caspase-3 in neurotoxic inflammation. Our results further support the view of noncell autonomous neurodegenerative mechanisms in ALS. Remarkably, we demonstrate that TDP-43 aggregates bind to and colocalize with MAPK/MAK/MRK overlapping kinase (MOK) and show that its phosphorylation status is disrupted. Finally, we show that this TDP-43-caused activation state can be altered by exogenous Hsp27 and Hsp70 chaperones. Our study provides new insight into the immune phenotype, mechanisms, and signaling pathways that operate in microglial neurotoxic activation in ALS.-Leal-Lasarte, M. M., Franco, J. M., Labrador-Garrido, A., Pozo, D., Roodveldt, C. Extracellular TDP-43 aggregates target MAPK/MAK/MRK overlapping kinase (MOK) and trigger caspase-3/IL-18 signaling in microglia.

To take full advantage of the remarkable applications of carbon nanotubes in different fields, there is a need to develop effective methods to improve their water dispersion and biocompatibility while maintain- ing their physical properties. In this sense, current approaches suffer from serious drawbacks such as loss of electronic structure together with low surface coverage in the case of covalent functionalizations, or instability of the dynamic hybrids obtained by non-covalent functionalizations. In the present work, we examined the molecular basis of an original strategy that combines the advantages of both functionaliza- tions without their main drawbacks. The hierarchical self-assembly of diacetylenic-based neoglycolipids into highly organized and compacted rings around the nanotubes, followed by photopolymerization leads to the formation of nanotubes covered with glyconanorings with a shish kebab-type topology exposing the carbohydrate ligands to the water phase in a multivalent fashion. The glyconanotubes obtained are fully functional, and able to establish specific interactions with their cognate receptors. In fact, by taking advantage of this selective binding, an easy method to sense lectins as a working model of toxin detection was developed based on a simple analysis of TEM images. Remarkably, different experimental settings to assess cell membrane integrity, cell growth kinetics and cell cycle demonstrated the cellular biocompatibility of the sugar-coated carbon nanotubes compared to pristine single-walled carbon nanotubes. Consejería de Economía, Ciencia e Innovación P10-CTS-6928 y P11- CTS-8161 to DP; P07-FQM-2774 to NK, P11-FQM-8046 to IF PAIDI Junta de Andalucía CTS-677 to DP; FQM-102 to IF Ministerio de Economía y Competitividad CTQ2013-49066-C2-1-R to NK y PI14-1600 to DP

Magnetic resonance based molecular imaging has emerged as a very promising technique for early detection and treatment of a wide variety of diseases, including cancer, neurodegenerative disorders, and vascular diseases. The limited sensitivity and specificity of conventional MRI are being overcome by the development of a new generation of contrast agents, using nanotechnology approaches, with improved magnetic and biological properties. In particular, for molecular imaging, high specificity, high sensitivity, and long blood circulation times are required. Furthermore, the lack of toxicity and immunogenicity together with low-cost scalable production are also necessary to get them into the clinics. In this work, we describe a facile, robust and cost-effective ligand-exchange method to synthesize dual T1 and T2 MRI contrast agents with long circulation times. These contrast agents are based on manganese ferrite nanoparticles (MNPs) between 6 and 14 nm in size covered by a 3 kDa polyethylene glycol (PEG) shell that leads to a great stability in aqueous media with high crystallinity and magnetization values, thus retaining the magnetic properties of the uncovered MNPs. Moreover, the PEGylated MNPs have shown different relaxivities depending on their size and the magnetic field applied. Thus, the 6 nm PEGylated MNPs are characterized by a low r2/r1 ratio of 4.9 at 1.5 T, hence resulting in good dual T1 and T2 contrast agents under low magnetic fields, whereas the 14 nm MNPs behave as excellent T2 contrast agents under high magnetic fields (r2 = 335.6 mM−1 s−1). The polymer core shell of the PEGylated MNPs minimizes their cytotoxicity, and allows long blood circulation times. This combination of cellular compatibility and excellent T2 and r2/r1 values under low magnetic fields, together with long circulation times, make these nanomaterials very promising contrast agents for molecular imaging., Financial support was provided by the Andalusian Ministry of Health (PI2013-0559 to MPL), Carlos III Institute of Health of Spain (Spanish Ministry of Economy and Competitiveness) according to the ‘Strategic Action in Health’ (PI14-01600 to DP) with co-funding by FEDER funds, the Andalusian Ministry of Economy, Science and Innovation (P10-CTS-6928 and P11- CTS-8161 to DP), the PAIDI Program from the Andalusian Government (CTS-677 to DP), the Spanish Ministry of Economy and Competitiveness (MAT2011-26851-CO2-01 to JMF) and the European Research Council (ERC-StG-2009-239931 to JMF). MPL thanks to the Andalusian Mobility Research Program for Nanomedicine (Fundación Pública Andaluza Progreso y Salud; Andalusian Ministry of Health) and the Talentia Postdoctoral Fellowship Program (grant agreement 267226; Andalusian Knowledge Agency; Andalusian Regional Ministry of Economy, Innovation, Science and Employment) for the Postdoctoral Fellowships.