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Post-translational modifications (PTMs) are one of the compulsive and predominant biological processes that regulate the diverse molecular mechanism, modulate the onset of disease, and are the reason behind the functional diversity of proteins. Despite the widespread research findings in neuroproteomics, one of the key drawbacks has been the lack of proteome-level knowledge of hemispheric lateralization. We have investigated the proteome level expression in different neuroanatomical regions under the Human Brain Proteome Project (HBPP) and developed the global interhemispheric brain proteome map (Brainprot) earlier. Furthermore, this study has extended to decipher the phosphoproteome map of human brain interhemispheric regions through high-resolution mass spectrometry. The phosphoproteomics examination of 12 unique interhemispheric neurological brain regions using Orbitrap fusion liquid chromatography with tandem mass spectrometry provided comprehensive coverage of 996 phosphoproteins, 2010 phosphopeptides, and 3567 phosphosites. Moreover, interhemispheric phosphoproteome profiling has been categorized according to synaptic ontologies and interhemispheric expression to understand the functionality. Finally, we have integrated the phosphosites data under the PhosphoMap section in the Inter-Hemispheric Brain Proteome Map Portal (https://www.brainprot.org/) for the advancement and support of the ongoing neuroproteomics research worldwide. Data is available via ProteomeXchange with the identifier PXD031188.

Transcriptomics and phosphoproteomics were carried out in the cerebral cortex of B6.Cg-Mapttm1(EGFP)Klt (tau knockout: tau-KO) and wild-type (WT) 12 month-old mice to learn about the effects of tau ablation. Compared with WT mice, tau-KO mice displayed reduced anxiety-like behavior and lower fear expression induced by aversive conditioning, whereas recognition memory remained unaltered. Cortical transcriptomic analysis revealed 69 downregulated and 105 upregulated genes in tau-KO mice, corresponding to synaptic structures, neuron cytoskeleton and transport, and extracellular matrix components. RT-qPCR validated increased mRNA levels of col6a4, gabrq, gad1, grm5, grip2, map2, rab8a, tubb3, wnt16, and an absence of map1a in tau-KO mice compared with WT mice. A few proteins were assessed with Western blotting to compare mRNA expression with corresponding protein levels. Map1a mRNA and protein levels decreased. However, ¿-tubulin III and GAD1 protein levels were reduced in tau-KO mice. Cortical phosphoproteomics revealed 121 hypophosphorylated and 98 hyperphosphorylated proteins in tau-KO mice. Deregulated phosphoproteins were categorized into cytoskeletal (n = 45) and membrane proteins, including proteins of the synapses and vesicles, myelin proteins, and proteins linked to membrane transport and ion channels (n = 84), proteins related to DNA and RNA metabolism (n = 36), proteins connected to the ubiquitin-proteasome system (UPS) (n = 7), proteins with kinase or phosphatase activity (n = 21), and 22 other proteins related to variegated pathways such as metabolic pathways, growth factors, or mitochondrial function or structure. The present observations reveal a complex altered brain transcriptome and phosphoproteome in tau-KO mice with only mild behavioral alterations. The project leading to these results received funding from the “la Caixa” Foundation (ID 100010434) under the agreements LCF/PR/HR19/52160007, HR18-00452 to IF. We thank the CERCA Programme/Generalitat de Catalunya for institutional support. The Proteomics Platform of Navarrabiomed is a member of Proteored (PRB3-ISCIII), supported by grant PT17/0019/009 to J.F.-I. of the PE I + D + I 2013-2016 funded by ISCIII and FEDER. This work was funded by a grant from the Spanish Ministry of Science, Innovation, and Universities (Ref. PID2019-110356RB-I00) to J.F.-I. and E.S. and the Department of Economic and Business Development from the Government of Navarra (Ref. 0011-1411-2020-000028) to E.S.

Background Extracellular vesicles (EVs) play a crucial role in intercellular communication, participating in the paracrine trophic support or in the propagation of toxic molecules, including proteins. RTP801 is a stress-regulated protein, whose levels are elevated during neurodegeneration and induce neuron death. However, whether RTP801 toxicity is transferred trans-neuronally via EVs remains unknown. Methods We overexpressed or silenced RTP801 protein in cultured cortical neurons and isolated the neural-derived EVs (RTP801-EVs, or shRTP801-EVs respectively). We characterized their protein content by mass spectrometry (MS) and western blotting (WB). RTP801-EVs toxicity was assessed by treating cultured neurons with these EVs and quantifying apoptotic neuron death and branching. We also tested shRTP801-EVs functionality in the pathologic in vitro model of 6-Hydroxydopamine (6-OHDA) by biochemical analyses. Results Expression of RTP801 increased the number of EVs released by neurons. Moreover, RTP801 led to a distinct proteomic signature of neural-derived EVs, containing more pro-apoptotic markers. Hence, we observed that RTP801 toxicity was transferred to neurons via EVs, activating apoptosis and impairing neuron morphology complexity. In contrast, EVs derived from neurons where RTP801 was silenced were able to increase the arborization of recipient neurons. We also showed that 6-OHDA neurotoxin elevated protein levels of RTP801 in both cell lysates and EVs. Furthermore, neural-derived EVs induced phosphorylation of Ser473-Akt and Ser235/236-RPS6 in recipient neurons, and this effect was lost when EVs were derived from neurons treated with 6-OHDA. Interestingly, EVs derived from neurons where RTP801 was silenced prior to exposing them to 6-OHDA maintained Akt and RPS6 transactivation in recipient neurons. Conclusion Taken together, these results suggest that RTP801 toxicity can be spread via EVs and therefore, it could contribute to the progression of neurodegenerative diseases in which RTP801 is involved.

A significant number of cancer patients do not benefit from PD-L1/PD-1 blockade immunotherapies. PD-1 and LAG-3 co-upregulation in T-cells is one of the major mechanisms of resistance by establishing a highly dysfunctional state in T-cells. To identify shared features associated to PD- 1/LAG-3 dysfunctionality in human cancers and T-cells, multiomic expression profiles were obtained for all TCGA cancers with high T-cell infiltration. A PD-1/LAG-3 dysfunctional signature was found which regulated immune, metabolic, genetic and epigenetic pathways. These results were validated in T-cell lines with constitutively active PD-1, LAG-3 pathways and their combination. These results uncovered distinct degrees of T-cell dysfunctionality. Global changes were cross-evaluated among T- cell lines with multiomic biopsy data to identify genetic, metabolic, and proteomic programmes regulated by PD-1/LAG-3 dysfunctionality. One of these relied on differential regulation of E3 ubiquitin ligases CBL-B and C-CBL. PD-1/LAG-3 co-blockade with a bispecific drug under clinical development but not with a combination of anti-PD-1/anti-LAG-3 antibodies achieved both CBL-B and C-CBL inhibition, reverting T-cell dysfunctionality in lung cancer patients resistant to PD-L1/PD- 1 blockade.

Background: Smell impairment is one of the earliest features in Alzheimer’s (AD) and Parkinson’s diseases (PD). Due to sex differences exist in terms of smell and olfactory structures as well as in the prevalence and manifestation of both neurological syndromes, we have applied olfactory proteomics to favor the discovery of novel sex-biased physio-pathological mechanisms and potential therapeutic targets associated to olfactory dysfunction. Methods: SWATH-MS (sequential window acquisition of all theoretical fragment ion spectra mass spectrometry) and bioinformatic workflows were applied in 57 postmortem olfactory tracts (OT) derived from non-demented (n=6F/11M), AD (n=4F/13M) and PD (n=7F/16M) subjects. Complementary molecular analyses by Western-blotting were performed in the olfactory bulb (OB), entorhinal cortex (EC) and amygdala areas. Results: 327 and 151 OT differentially expressed proteins (DEPs) were observed in AD women and AD men respectively (35 DEPs in common). Respect to PD, 198 DEPs were identified in PD women whereas 95 DEPs were detected in PD men (20 DEPs in common). This proteome dyshomeostasis induced a disruption in OT protein interaction networks and widespread sex-dependent pathway perturbations in a disease-specific manner, among them Sirtuin (SIRT) signaling. SIRT1, SIRT2, SIRT3 and SIRT5 protein levels unveiled a tangled expression profile across the olfactory-entorhinal-amygdaloid axis, evidencing disease- sex- and brain structure-dependent changes in olfactory protein acetylation. Conclusions: Alteration in the OT proteostasis was more severe in AD than in PD. Moreover, protein expression changes were more abundant in women than men independent of the neurological syndrome. Mechanistically, the tangled SIRT profile observed across the olfactory pathway-associated brain regions in AD and PD indicates differential NAD (+)-dependent deacetylase mechanisms between women and men. All these data shed new light on differential olfactory mechanisms across AD and PD, pointing out that the evaluation of the feasibility of emerging sirtuin-based therapies against neurodegenerative diseases should be considered with caution, including further sex dimension analyses in vivo and in clinical studies.

Astrocytes are considered an essential source of blood-borne glucose or its metabolites to neurons. Nonetheless, the necessity of the main astrocyte glucose transporter, i.e. GLUT1, for brain glucose metabolism has not been defined. Unexpectedly, we found that brain glucose metabolism was paradoxically augmented in mice with astrocytic GLUT1 ablation (GLUT11′GFAP mice). These mice also exhibited improved peripheral glucose metabolism especially in obesity, rendering them metabolically healthier. Importantly, GLUT11′GFAP mice did not present cognitive alterations. Mechanistically, we observed that GLUT1-ablated astrocytes exhibited increased insulin receptor-dependent ATP release, and both astrocyte insulin signalling and brain purinergic signalling are essential for improved brain function and systemic glucose metabolism. Collectively, we demonstrate that astrocytic GLUT1 is central to the regulation of brain energetics, yet its ablation triggers a reprogramming of brain metabolism sufficient to sustain energy requirements, peripheral glucose homeostasis and cognitive function.

The neocortex of P301S mice, used as a model of fronto-temporal lobar degeneration linked to tau mutation (FTLD-tau), and wild-type mice, both aged 9 months, were analyzed with conventional label-free phosphoproteomics and SWATH-MS (sequential window acquisition of all theoretical fragment ion spectra mass spectrometry) to assess the (phospho)proteomes. The total number of identified dysregulated phosphoproteins was 328 corresponding to 524 phosphorylation sites. The majority of dysregulated phosphoproteins, most of them hyperphosphorylated, were proteins of the membranes, synapses, membrane trafficking, membrane vesicles linked to endo- and exocytosis, cytoplasmic vesicles, and cytoskeleton. Another group was composed of kinases. In contrast, proteins linked to DNA, RNA metabolism, RNA splicing, and protein synthesis were hypophosphorylated. Other pathways modulating energy metabolism, cell signaling, Golgi apparatus, carbohydrates, and lipids are also targets of dysregulated protein phosphorylation in P301S mice. The present results, together with accompanying immunohistochemical and Western-blotting studies, show widespread abnormal phosphorylation of proteins, in addition to protein tau, in P301S mice. These observations point to dysregulated protein phosphorylation as a relevant contributory pathogenic component of tauopathies.

Gastric cancer (GC) is a major public health problem worldwide, with high mortality rates due to late diagnosis and limited treatment options. Biomarker research is essential to improve the early detection of GC. Technological advances and research methodologies have improved diagnostic tools, identifying several potential biomarkers for GC, including microRNA, DNA methylation markers, and protein-based biomarkers. Although most studies have focused on identifying biomarkers in biofluids, the low specificity of these markers has limited their use in clinical practice. This is because many cancers share similar alterations and biomarkers, so obtaining them from the site of disease origin could yield more specific results. As a result, recent research efforts have shifted towards exploring gastric juice (GJ) as an alternative source for biomarker identification. Since GJ is a waste product during a gastroscopic examination, it could provide a “liquid biopsy” enriched with disease-specific biomarkers generated directly at the damaged site. Furthermore, as it contains secretions from the stomach lining, it could reflect changes associated with the developmental stage of GC. This narrative review describes some potential biomarkers for gastric cancer screening identified in gastric juice.

Altered protein phosphorylation is a major pathologic modification in tauopathies and Alzheimer’s disease (AD) linked to abnormal tau fibrillar deposits in neurofibrillary tangles (NFTs) and pre-tangles and β-amyloid deposits in AD. hTau transgenic mice, which express 3R and less 4R human tau with no mutations in a murine knock-out background, show increased tau deposition in neurons but not NFTs and pre-tangles at the age of nine months. Label-free (phospho)proteomics and SWATH-MS identified 2065 proteins in hTau and wild-type (WT) mice. Only six proteins showed increased levels in hTau; no proteins were down-regulated. Increased tau phosphorylation in hTau was detected at Ser199, Ser202, Ser214, Ser396, Ser400, Thr403, Ser404, Ser413, Ser416, Ser422, Ser491, and Ser494, in addition to Thr181, Thr231, Ser396/Ser404, but not at Ser202/Thr205. In addition, 4578 phosphopeptides (corresponding to 1622 phosphoproteins) were identified in hTau and WT mice; 64 proteins were differentially phosphorylated in hTau. Sixty proteins were grouped into components of membranes, membrane signaling, synapses, vesicles, cytoskeleton, DNA/RNA/protein metabolism, ubiquitin/proteasome system, cholesterol and lipid metabolism, and cell signaling. These results showed that over-expression of human tau without pre-tangle and NFT formation preferentially triggers an imbalance in the phosphorylation profile of specific proteins involved in the cytoskeletal–membrane-signaling axis.

Aging-related traits, including gradual loss of skeletal muscle mass and chronic inflammation, are linked to altered body composition and impaired physical functionality, which are important contributing factors to the disabling process. We sought to explore the potential relationship between lower-body muscle strength decline and inflammatory mediators in older adults. We performed a cross-sectional analysis in 38 older adults admitted to an acute care of the elderly unit (57.9% women, mean age=87.9±4.9 years; mean body mass index [BMI]=26.5±4.7 kg/m2). Clinical and functional outcomes including weight, height, BMI, dependence, physical and cognitive performance, and muscle strength measured by one-repetition maximum (1RM) for leg-extension, leg-press, chest-press and handgrip strength, were assessed. Blood serum content of 59 cytokines, chemokines and growth factors was assessed by protein arrays. Multivariate linear regression analyses were used to examine the relationship between cytokine concentrations and muscle strength parameters. After controlling for confounding factors (age, sex, BMI, cumulative illness rating score and physical performance score), 1RM leg-press had a significant negative relationship with GRO (CXCL2) (β= −18.13, p=0.049), MIG (CXCL9) (β= −13.94, p=0.004), IGF-1 (β= −19.63, p=0.003), CK-BETA 8 (CCL23) (β= −28.31, p=0.018) and GCP-2 (CXCL6) (β= −25.78, p=0.004). Likewise, 1RM leg-extension had a significant negative relationship with IGFBP-1 (β= −11.49, p=0.023). Thus, several serum cytokines/chemokines and growth factors are negatively associated with lower muscle strength in older patients. Further investigation is required to elucidate the mechanism of elevated inflammatory mediators leading to lower muscle strength.

The neocortex of P301S mice, used as a model of frontotemporal degeneration linked to tau mutation, and wild-type mice, both aged 9 months, were analyzed with conventional label-free phosphoproteomics and SWATH-MS (sequential window acquisition of all theoretical fragment ion spectra mass spectrometry) to assess the (phospho)proteomes. The total number of identified dysregulated phosphoproteins was 328 corresponding to 524 phosphorylation sites. The majority of dysregulated phosphoproteins, most of them hyper-phosphorylated, were proteins of the membranes, synapses, membrane trafficking, membrane vesicles linked to endo- and exocytosis, cytoplasmic vesicles, and cytoskeleton. Another group was composed of kinases. In contrast, proteins linked to DNA, RNA metabolism, RNA splicing, and protein synthesis were hypo-phosphorylated. Other pathways modulating energy metabolism, cell signalling, Golgi apparatus, carbohydrates, and lipids are also targets of dysregulated protein phosphorylation in P301S mice. The present results, together with accompanying immunohistochemical and western blotting studies, show widespread abnormal phosphorylation of proteins, in addition to protein tau, in P301S mice. These observations point to dysregulated protein phosphorylation as a relevant contributory pathogenic component of tauopathies.

Synaptic impairment might precede neuronal degeneration in Parkinson’s disease. However, the intimate mechanisms altering synaptic function by the accumulation of presynaptic α-synuclein in striatal dopaminergic terminals before dopaminergic death occurs, have not been elucidated. Our aim is to unravel the sequence of synaptic functional and structural changes preceding symptomatic dopaminergic cell death. As such, we evaluated the temporal sequence of functional and structural changes at striatal synapses before parkinsonian motor features appear in a rat model of progressive dopaminergic death induced by overexpression of the human mutated A53T α-synuclein in the substantia nigra pars compacta, a protein transported to these synapses. Sequential window acquisition of all theoretical mass spectra proteomics identified deregulated proteins involved first in energy metabolism and later, in vesicle cycling and autophagy. After protein deregulation and when α-synuclein accumulated at striatal synapses, alterations to mitochondrial bioenergetics were observed using a Seahorse XF96 analyser. Sustained dysfunctional mitochondrial bioenergetics was followed by a decrease in the number of dopaminergic terminals, morphological and ultrastructural alterations, and an abnormal accumulation of autophagic/endocytic vesicles inside the remaining dopaminergic fibres was evident by electron microscopy. The total mitochondrial population remained unchanged whereas the number of ultrastructurally damaged mitochondria increases as the pathological process evolved. We also observed ultrastructural signs of plasticity within glutamatergic synapses before the expression of motor abnormalities, such as a reduction in axospinous synapses and an increase in perforated postsynaptic densities. Overall, we found that a synaptic energetic failure and accumulation of dysfunctional organelles occur sequentially at the dopaminergic terminals as the earliest events preceding structural changes and cell death. We also identify key proteins involved in these earliest functional abnormalities that may be modulated and serve as therapeutic targets to counterbalance the degeneration of dopaminergic cells to delay or prevent the development of Parkinson’s disease., This study was funded by the Instituto de Salud Carlos III through the projects PI14/00763 and PI19/01915 (co-funded by ERDF/ESF, ‘Investing in your future’). L.M.-G. held a Predoctoral Research Fellowship from the University of the Basque Country (UPV/EHU). T.R.-C. and A.Q.-V. were funded by CIBERNED. T.R.-C. held a Fundación Jesús de Gangoiti Barrera Foundation grant (Bilbao, Spain). H.J.-U. and A.B.-I. held a Predoctoral Research Fellowship from the Government of the Basque Country. Israel Science Foundation (536/19) and the Spanish Ministry of Science (SAF2016-78071-R) funded the contribution of S.K. and A.O.

Several studies have demonstrated the different characteristics of tau seeding and spreading following intracerebral inoculation in murine models of tau-enriched fractions of brain homogenates from AD and other tauopathies. The present study is centered on the importance of host tau in tau seeding and the molecular changes associated with the transformation of host tau into abnormal tau. The brains of three adult murine genotypes expressing different forms of tau—WT (murine 4Rtau), hTau (homozygous transgenic mice knock-out for murine tau protein and heterozygous expressing human forms of 3Rtau and 4Rtau proteins), and mtWT (homozygous transgenic mice knock-out for murine tau protein)—were analyzed following unilateral hippocampal inoculation of sarkosyl-insoluble tau fractions from the same AD and control cases. The present study reveals that (a) host tau is mandatory for tau seeding and spreading following tau inoculation from sarkosyl-insoluble fractions obtained from AD brains; (b) tau seeding does not occur following intracerebral inoculation of sarkosyl-insoluble fractions from controls; (c) tau seeding and spreading are characterized by variable genotype-dependent tau phosphorylation and tau nitration, MAP2 phosphorylation, and variable activation of kinases that co-localize with abnormal tau deposits; (d) transformation of host tau into abnormal tau is an active process associated with the activation of specific kinases; (e) tau seeding is accompanied by modifications in tau splicing, resulting in the expression of new 3Rtau and 4Rtau isoforms, thus indicating that inoculated tau seeds have the capacity to model exon 10 splicing of the host mapt or MAPT with a genotype-dependent pattern; (e) selective regional and cellular vulnerabilities, and different molecular compositions of the deposits, are dependent on the host tau of mice injected with identical AD tau inocula. The project leading to these results received funding from the La Caixa Foundation (ID 100010434) under the agreement LCF/PR/HR19/52160007 to IF; it was also supported by the Ministry of Economy and Competitiveness, Institute of Health Carlos III (ISCIII) (co-funded by European Regional Development Fund, ERDF, a way to build Europe): FISPI17/000809 to IF; and the IntraCIBERNED 2019 collaborative project to IF and JADR. This work was also co-financed by ERDF under the program Interreg Poctefa: RedPrion 148/16; ERDF [148/16]. We thank CERCA Programme/Generalitat de Catalunya for institutional support.

Propose Obesity-related metabolic risk factors in adolescents who are overweight/obese may be associated with systemic low-grade inflammation; therefore, we investigated whether 6 months of exercise training altered markers of inflammation. Methods Secondary analyses of a randomized controlled exercise-based intervention trial (September 2017-December 2018). Adolescents aged 11 to 17 years (Tanner stage II-V), 70% girls, with a body mass index z-score at or above the 85th percentile, and/or with excess of adiposity (body fat ≥ 30%). The participants were randomly assigned to the following 4 groups for 6 months: (1) standard physical education lessons, as a control (CTRL); (2) high-intensity physical education class (HIPE); (3) low-to-moderate intensity physical education class (LIPE); (4) a combined group (PLUS). Inflammatory markers and immune molecules including chemokines, cytokines, and growth factors (n = 65 biomarkers) were determined by cytokine antibody array. Results Of the 120 randomly assigned participants, 95 were included in the analysis. Considering these 22 proteins, the LIPE group shows statistical significance in 9 proteins with log-fold change (logFC) and P Conclusions Implementing a 6-month physical exercise program in overweight/obese adolescents, based on LIPE and PLUS groups, significantly change several circulating inflammatory levels. Interventions involving supervised physical exercise may reduce the associated effects of systemic low-grade inflammation, thus preventing the development of obesity-related metabolic diseases in adolescents with overweight/obesity.

The clinicopathological phenotype of G2019S LRRK2-associated Parkinson's disease (L2PD) is similar to idiopathic Parkinson's disease (iPD), and G2019S LRRK2 nonmanifesting carriers (L2NMCs) are at increased risk for development of PD. With various therapeutic strategies in the clinical and preclinical pipeline, there is an urgent need to identify biomarkers that can aid early diagnosis and patient enrichment for ongoing and future LRRK2-targeted trials.The objective of this work was to investigate differential protein and phospho-protein changes related to G2019S mutant LRRK2 in peripheral blood mononuclear cells from G2019S L2PD patients and G2019S L2NMCs, identify specific phospho-protein changes associated with the G2019S mutation and with disease status, and compare findings with patients with iPD.We performed an unbiased phospho-proteomic study by isobaric label-based mass spectrometry using peripheral blood mononuclear cell group pools from a LRRK2 cohort from Spain encompassing patients with G2019S L2PD (n = 20), G2019S L2NMCs (n = 20), healthy control subjects (n = 30), patients with iPD (n = 15), patients with R1441G L2PD (n = 5), and R1441G L2NMCs (n = 3) (total N = 93).Comparing G2019S carriers with healthy controls, we identified phospho-protein changes associated with the G2019S mutation. Moreover, we uncovered a specific G2019S phospho-signature that changes with disease status and can discriminate patients with G2019S L2PD, G2019S L2NMCs, and healthy controls. Although patients with iPD showed a differential phospho-proteomic profile, biological enrichment analyses revealed similar changes in deregulated pathways across the three groups.We found a differential phospho-signature associated with LRRK2 G2019S for which, consistent with disease status, the phospho-profile from PD at-risk G2019S L2NMCs was more similar to healthy controls than patients with G2019S L2PD with the manifested disease. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

OBJECTIVE The HEPAFIT study was aimed at examining the impact of a 6-month physical education intervention, considering various levels of exercise intensity, on hepatic fat and cardiometabolic health outcomes in adolescents with excess adiposity. METHODS Adolescents (n = 120), 11-17 years with excess adiposity by body fat >30%, were randomly assigned to one of the following 4 groups for 6 months: (1) standard physical education lessons, control (CTRL); (2) high-intensity physical education (HIPE); (3) low-to-moderate intensity physical education (LIPE) and (4) combined HIPE and LIPE (PLUS). The primary outcome was hepatic fat content measured by vibration-controlled transient elastography (controlled attenuation parameter [CAP]). Secondary outcomes were traditional cardiovascular health markers (body composition, serum lipids, aminotransferases and health-related physical fitness components). RESULTS Adjusted mixed effects linear models revealed a significant decrease in CAP levels in HIPE (-20.02 dB/m, p

This study, which performs an extensive mass spectrometry-based analysis of 19 brain regions from both left and right hemispheres, presents the first draft of the human brain interhemispheric proteome. This high-resolution proteomics data provides comprehensive coverage of 3300 experimentally measured (nonhypothetical) proteins across multiple regions, allowing the characterization of protein-centric interhemispheric differences and synapse biology, and portrays the regional mapping of specific regions for brain disorder biomarkers. In the context of the Human Proteome Project (HPP), the interhemispheric proteome data reveal specific markers like chimerin 2 (CHN2) in the cerebellar vermis, olfactory marker protein (OMP) in the olfactory bulb, and ankyrin repeat domain 63 (ANKRD63) in basal ganglia, in line with regional brain transcriptomes mapped in the Human Protein Atlas (HPA). In addition, an in silico analysis pipeline was used to predict the structure and function of the uncharacterized uPE1 protein ANKRD63, and parallel reaction monitoring (PRM) was applied to validate its region-specific expression. Finally, we have built the Interhemispheric Brain Proteome Map (IBPM) Portal (www.brainprot.org) to stimulate the scientific community's interest in the brain molecular landscape and accelerate and support research in neuroproteomics. Data are available via ProteomeXchange with identifier PXD019936.

Olfactory dysfunction is considered an early prodromal marker of many neurodegenerative diseases. Neuropathological changes and aberrant protein aggregates occur in the olfactory bulb (OB), triggering a tangled cascade of molecular events that is not completely understood across neurological disorders. This study aims to analyze commonalities and differences in the olfactory protein homeostasis across neurological backgrounds with different spectrums of smell dysfunction. For that, an integrative analysis was performed using OB proteomics datasets derived from subjects with Alzheimer’s disease (AD), Parkinson´s disease (PD), mixed dementia (mixD), dementia with Lewy bodies (DLB), frontotemporal lobar degeneration (FTLD-TDP43), progressive supranuclear palsy (PSP) and amyotrophic lateral sclerosis (ALS) with respect to OB proteome data from neurologically intact controls. A total of 80% of the differential expressed protein products were potentially disease-specific whereas the remaining 20% were commonly altered across two, three or four neurological phenotypes. A multi-level bioinformatic characterization revealed a subset of potential disease-specific transcription factors responsible for the downstream effects detected at the proteome level as well as specific densely connected protein complexes targeted by several neurological phenotypes. Interestingly, common or unique pathways and biofunctions were also identified, providing novel mechanistic clues about each neurological disease at olfactory level. The analysis of olfactory epithelium, olfactory tract and primary olfactory cortical proteotypes in a multi-disease format will functionally complement the OB dyshomeostasis, increasing our knowledge about the neurodegenerative process across the olfactory axis. This work was funded by grants from the Spanish Ministry of Science, Innovation and Universities (Ref. PID2019-110356RB-I00/ AEI / 10.13039/501100011033 to JF-I and ES) and the Department of Economic and Business Development of the Government of Navarra (Ref. 0011-14112020-000028 to ES).The Proteomics Platform of Navarrabiomed, member of Proteored (PRB3ISCIII), was supported by grant PT17/0019/009, of the PE I+D+I 2013-2016 funded by ISCIII and FEDER to JF. The Clinical Neuroproteomics Unit of Navarrabiomed is member of the Spanish Olfactory Network (ROE) (supported by grant RED2018-102662-T funded by Spanish Ministry of Science and Innovation) and the Global Consortium for Chemosensory Research (GCCR).

Tau hyperphosphorylation is the first step of neurofibrillary tangle (NFT) formation. In the present study, samples of the entorhinal cortex (EC) and frontal cortex area 8 (FC) of cases with NFT pathology classified as stages I–II, III–IV, and V–VI without comorbidities, and of middle‐aged (MA) individuals with no NFT pathology, were analyzed by conventional label‐free and SWATH‐MS (sequential window acquisition of all theoretical fragment ion spectra mass spectrometry) to assess the (phospho)proteomes. The total number of identified dysregulated phosphoproteins was 214 in the EC, 65 of which were dysregulated at the first stages (I–II) of NFT pathology; 167 phosphoproteins were dysregulated in the FC, 81 of them at stages I–II of NFT pathology. A large percentage of dysregulated phosphoproteins were identified in the two regions and at different stages of NFT progression. The main group of dysregulated phosphoproteins was made up of components of the membranes, cytoskeleton, synapses, proteins linked to membrane transport and ion channels, and kinases. The present results show abnormal phosphorylation of proteins at the first stages of NFT pathology in the elderly (in individuals clinically considered representative of normal aging) and sporadic Alzheimer's disease (sAD). Dysregulated protein phosphorylation in the FC precedes the formation of NFTs and SPs. The most active period of dysregulated phosphorylation is at stages III–IV when a subpopulation of individuals might be clinically categorized as suffering from mild cognitive impairment which is a preceding determinant stage in the progression to dementia. Altered phosphorylation of selected proteins, carried out by activation of several kinases, may alter membrane and cytoskeletal functions, among them synaptic transmission and membrane/cytoskeleton signaling. Besides their implications in sAD, the present observations suggest a molecular substrate for “benign” cognitive deterioration in “normal” brain aging., Dysregulated brain protein phosphorylation (DBPP) occurs at the first stages of neurofibrillary tangle (NFT) pathology (stages I‐II of Braak) in the frontal cortex (FC) and entorhinal cortex (EC). It progresses at the middle (stages III–IV), and advanced stages (V and VI) linked to cognitive impairment and dementia, respectively, in Alzheimer's disease.DBPP principally affects proteins of the cell membranes, cytoskeleton, synapses, protein, and energy metabolism, and it occurs in parallel with abnormal activation of multiple kinases. Many dysregulated phosphoproteins are shared with the FC and EC, and they are found at different stages of NFT pathology.DBPP conforms to a continuum between “normal” brain aging and Alzheimer's diseaseSince protein phosphorylation is crucial in protein signaling, DBPP implies severe dysfunction of critical molecular pathways.DBPP may contribute to progressive cell degeneration and disease progression in sAD. Since DBPP already occurs at the first stages of NFT pathology, which affects about 85% of individuals at the age of 65 years, we suggest that DBPP may contribute to “benign cognitive decline” in “normal” aging.

Background: Soluble ST2 (interleukin 1 receptor-like 1) (sST2) is involved in inflammatory diseases and increased in heart failure (HF). We herein investigated sST2 effects on oxidative stress and inflammation in human cardiac fibroblasts and its pathological role in human aortic stenosis (AS). Methods and results: Using proteomics and immunodetection approaches, we have identified that sST2 down-regulated mitofusin-1 (MFN-1), a protein involved in mitochondrial fusion, in human cardiac fibroblasts. In parallel, sST2 increased nitrotyrosine, protein oxidation and peroxide production. Moreover, sST2 enhanced the secretion of pro-inflammatory cytokines interleukin (IL)-6, IL-1β and monocyte chemoattractant protein-1 (CCL-2). Pharmacological inhibition of transcriptional factor nuclear factor κB (NFκB) restored MFN-1 levels and improved oxidative status and inflammation in cardiac fibroblasts. Mito-Tempo, a mitochondria-specific superoxide scavenger, as well as Resveratrol, a general antioxidant, attenuated oxidative stress and inflammation induced by sST2. In myocardial biopsies from 26 AS patients, sST2 up-regulation paralleled a decrease in MFN-1. Cardiac sST2 inversely correlated with MFN-1 levels and positively associated with IL-6 and CCL-2 in myocardial biopsies from AS patients. Conclusions: sST2 affected mitochondrial fusion in human cardiac fibroblasts, increasing oxidative stress production and inflammatory markers secretion. The blockade of NFκB or mitochondrial reactive oxygen species restored MFN-1 expression, improving oxidative stress status and reducing inflammatory markers secretion. In human AS, cardiac sST2 levels associated with oxidative stress and inflammation. The present study reveals a new pathogenic pathway by which sST2 promotes oxidative stress and inflammation contributing to cardiac damage.

Plants differ widely in their growth and tolerance responses to ammonium and urea nutrition, while derived phenotypes seem markedly different from plants grown under nitrate supply. Plant responses to N sources are complex, and the traits involved remain unknown. This work reports a comprehensive and quantitative root proteomic study on the NH4+-tolerant legume Medicago truncatula grown under axenic conditions with either nitrate, NH4+ or urea supply as sole N source by using the iTRAQ method. Sixty-one different proteins among the three N sources were identified. Interestingly, among the proteomic responses, urea nutrition displayed greater similarity to nitrate than to ammonium nutrition. We found remarkable differences in membrane proteins that play roles in sensing the N form, and regulate the intracellular pH and the uptake of N. Also, several groups of proteins were differentially expressed in the C metabolism pathway involved in reorganizing N assimilation. In addition, enzymes related to phenylpropanoid metabolism, including the peroxidases POD2, POD6, POD7 and POD11, which were up-regulated under ammonium nutrition, contributed to the reinforcement of cell walls, as confirmed by specific staining of lignin. Thus, we identified cell wall lignification as an important tolerance mechanism of root cells associated with the stunted phenotype typical of plants grown under ammonium nutrition. This work was supported by the grants AGL2014-52396-P and AGL2017-86293-P from the Spanish Ministry of Economy and Competitiveness-MINECO. RE received a Juan de la Cierva-incorporación grant IJCI-2014-21452. JB is a holder of a PhD fellowship from the Public University of Navarre. The Proteomics Unit of Navarrabiomed is a member of ProteoRed, PRB3-ISCIII-Spain, and is supported by grant PT17/0019/009, of the PE I + D+I 2018-2020 funded by ISCIII and FEDER.