23rd Human Proteome Organization World Congress

Mapping the human brain proteome

Keynote speaker

Keynote lecture

Prof. Dr.

Neuroproteomics to decipher how the COVID-19 affects the human brain

Keynote Lecture

COVID-19 is among the most deadly pandemic of humankind. The disease caused by the SARS-CoV-2 is rather versatile, since it may affect different physiological systems, associated to a range of symptoms, which may pass or may become sequelae. Neurological symptoms are among the most prevalent of the extrapulmonary complications of COVID-19, affecting more than 30% of patients. Here, based on data obtained in living COVID-19 patients, postmortem brain tissue, and cell cultures, we found that the SARS-CoV-2 is able to reach the human brain, where it infects mostly astrocytes. Moreover, astrocytes are susceptible to SARS-CoV-2 infection through a noncanonical mechanism and respond to the infection by remodeling energy metabolism, which in turn, alters the levels of metabolites used to fuel neurons and support neurotransmitter synthesis, according to proteomic and metabolomic analysis. The altered secretory phenotype of infected astrocytes, in turn, impairs neuronal viability. Morphological and molecular data we obtained explains the damage and structural changes observed in the brains of COVID-19 patients, which might be associated with the long-lasting symptoms (and eventually sequelae) known as "long COVID".

Prof.

Ultra-deep longitudinal profiling of plasma and serum proteome provides critical insights into the interaction of human organism and pig xenotransplants

Human Health Insights (Neurobiology, Cardiovascular, Liver, Kidney etc.)

Xenotransplantation of pig organs to humans holds immense potential to address the critical shortage of donor organs. Recent advancements in genetic engineering and immunosuppressive therapies have brought xenotransplantation closer to reality, with successful pig-to-human kidney and heart transplants marking significant milestones. However, understanding the complex molecular interactions between the recipient's organism and the xenograft remains a major challenge. Measuring plasma proteome of these patients provides critical information about immune response and status of many organism subsystems.In a series of studies, we employed an advanced proteomic workflow, combining nanoparticle-based sample preparation (Proteograph™ XT, Seer, Inc.) with the state-of-the-art LC-MS using Ultimate™ 3000 HPLC and Thermo Scientific™ Orbitrap™ Astral™ MS. Both components allowed us to significantly improve the proteome coverage in comparison to the standard workflows and deliver ultra-deep profiling of plasma or serum proteomes in human recipients of a genetically modified pig organ, including the unprecedented daily serum monitoring of the brain-dead patient with xenokidney over 61 days.The samples were analyzed in a DIA mode with 3 m/z isolation window using a 30-min gradient. In these datasets we identified around 100K peptides, half of which could be specifically assigned to human or pig proteins and allowed us to reconstruct around 6,200 human and 1,000 pig protein groups. Our analysis revealed the intricate regulation patterns for thousands of human and pig proteins. We observed significant changes in the complement system, cytokines, immunoglobulins, and various metabolic pathways, reflecting the recipient's immune response and the physiological adaptation to the xenograft. Notably, we could track the abundance dynamics for hundreds of pig-specific proteins in the recipient's blood, highlighting the molecular details of xenograft integration, including its immune system response.By using the whole plasma proteome as a comprehensive indicator of a recipient&quot;s state, we could observe the differential dynamics of individual xenotransplantation patients that correlated with the other clinical and omics data. Such analysis is instrumental in identifying potential human and xenograft biomarkers that would contribute to more efficient post-operational treatment of these patients. Ultimately, this research paves the way for xenotransplantation to become a viable solution for patients in need of life-saving organ transplants.

Oral presentation

Parallel global proteome and glycaproteome of human brain reveal altered glycation of key proteins linked to Alzheimer's disease

Although amyloid-beta (Aβ) deposition and tau neurofibrillary tangles in brain are hypothesized as a central force driving Alzheimer&quot;s disease (AD) pathogenesis, the mechanism underlying the development pathology is unknown. Protein glycation with primary amine groups of proteins reacting with aldehyde or reactive carbonyl group of a sugar affects structure, bioactivity and molecular stability. While increased glycation has been reported in AD brains, omic studies have never been done. Here we analyzed proteome and glycaproteome of brains from AD patients and cognitively normal individuals in parallel to explore roles of glycation in AD pathology, and to identify potential new biomarkers and novel therapeutic targets.Proteins were extracted from human brains of five controls and five AD patients. TMT10-plex labeling was used for global proteomics and boronate affinity enrichment of glycapeptides was performed for glycaproteome. All samples were analyzed by nanoLC-MS/MS on Orbitrap Eclipse and data processed by Proteome Discoverer. In the global proteome, 530 proteins of the 4,848 that were quantified with statistical differences between AD and controls. Confident quantification of 814 glycapeptides from 395 glycaproteins revealed six different glycated forms including Nε-fructosyl, on both Lys and Arg residues were determined.Glycation peptides were consistently increased in the AD samples. While 105 unique glycated peptides from 73 unique glycated proteins were significantly increased (p&lt;0.05) in AD patients, no glycapeptides were significantly decreased. Glycation of several key proteins associated with AD were increased including amyloid-beta precursor protein (APP), Tau,glyceraldehyde-3-phosphate dehydrogenase (GAPDH), glial fibrillary acidic protein (GFAP), fibrinogen and synaptophysin. APP is the precursor protein that when cleaved generates the β-amyloid peptides, and was found with Nε-fructosyl modification on its key K612 residue. This is remarkable as we found previously the same site of APP was modified by succinylation, which is linked to form amyloid plagues. Increased glycation was found on K311, K353, K369 and K375 of Tau protein. K311 was succinylated promoting pathological tau aggregation to tangles and impairing microtubule assembly. The increased glycation fold change over the change of their protein abundance suggests that glycapeptides may represent sensitive biomarkers of AD. Our data also suggest there appears crosstalk between glycation and other post-translation modification such as succinylation in potential regulation of AD pathogenesis.

Personalized neuroinflammatory status in neurodegenerative diseases by a panel of 20 cerebrospinal fluid markers

Clinical Proteomics

Neuroinflammation plays a critical role in the pathogenesis and progression of Alzheimer"s Disease (AD) and other neurodegenerative disorders. We developed and validated a sensitive and accurate multiprotein mass spectrometry assay for the absolute (molar) quantification of 20 key neuroinflammation markers in human CSF, and employed the method to study the inflammatory status along the AD continuum in the cohorts of subjective cognitive decline (SCD), mild cognitive impairment (MCI) and AD dementia, as well as corticobasal degeneration (CBD), a rare progressive neurodegenerative disorder.The panel comprised apolipoproteins: ApoA1, ApoD, ApoJ as well as ApoE with all of its three isoforms (E2, E3 and E4), the strongest genetic risk factor for AD. It also included the markers of reactive astrogliosis (GFAP, YKL-40 and complement proteins: C1q, C3, C4) and microglia activation (TREM2). Besides, it contained proinflammatory cytokines (MIF, osteopontin and alpha-1-antichymotrypsin) and the two TAM receptors (Axl and Tyro3). Altogether, the quantified marker proteins spanned 10,000-fold molar concentrations ranging from 20 pM (GFAP) to 200 nM (ApoD) and were detected in a single LC-MS/MS run with excellent precision (median CV &lt;6%) and inter-peptide agreement (typical r &gt;0.98).We applied the developed panel to the cohort of 109 patients (SCD=24; MCI=42; AD=43). We investigated the association of panel proteins with other CSF clinical markers (Aβ42, p-Tau and t-Tau) using the ATN classification system, as well as with the mini-mental state examination (MMSE) scores. Notably, four proteins (GFAP, osteopontin, YKL-40 and MIF) showed a significantly higher CSF molar concentrations in AD (and two proteins in MCI) vs. our controls (SCD). Among them, osteopontin yielded the best diagnostic performance in the discrimination of AD from controls (AUC 0.81). Next, by investigating whether a minimal combination of biomarkers could discriminate AD from controls with higher accuracies, we identified a panel of 5 proteins (GFAP, osteopontin, MIF, C1q and C3) that showed a considerably higher accuracy than any marker alone (AUC 0.91). Finally, we compared the CSF neuroinflammatory markers for AD (n=35) and Aβ-negative CBD patients (n=37). Interestingly, the results showed no discrimination between these two groups, thus suggesting a similar neuroinflammation profile shared by these two tauopathies. In the end, we propose that the developed multiprotein panel will contribute to personalized diagnostics by monitoring inflammatory signatures of CSF in the broad spectrum of neurodegenerative diseases.

Conference room 5-6

Session

Neurodegeneration and neuropsychiatric disorders

Session
Neurodegeneration and neuropsychiatric disorders

Termin

Vorsitzende

Programm

SessionNeurodegeneration and neuropsychiatric disorders

Termin

Vorsitzende

Programm

Session
Neurodegeneration and neuropsychiatric disorders