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Microhomology-mediated end joining (MMEJ) is an intrinsically mutagenic pathway of DNA double-strand break (DSB) repair essential for proliferation of homologous recombination (HR)-deficient tumors. Although targeting MMEJ has emerged as a powerful strategy to eliminate HR-deficient (HRD) cancers, this is limited by an incomplete understanding of the mechanism and factors required for MMEJ repair. Here, we identify the APE2 nuclease as an MMEJ effector. We show that loss of APE2 inhibits MMEJ at deprotected telomeres and at intra-chromosomal DSBs and is epistatic with Pol Theta for MMEJ activity. Mechanistically, we demonstrate that APE2 possesses intrinsic flap-cleaving activity, that its MMEJ function in cells depends on its nuclease activity, and further identify an uncharacterized domain required for its recruitment to DSBs. We conclude that this previously unappreciated role of APE2 in MMEJ contributes to the addiction of HRD cells to APE2, which could be exploited in the treatment of cancer.
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Quebras de DNA de Cadeia Dupla , Reparo do DNA , DNA/metabolismo , Reparo do DNA por Junção de Extremidades , Recombinação HomólogaRESUMO
RAF kinases are RAS-activated enzymes that initiate signaling through the MAPK cascade to control cellular proliferation, differentiation, and survival. Here, we describe the structure of the full-length RAF1 protein in complex with HSP90 and CDC37 obtained by cryoelectron microscopy. The reconstruction reveals a RAF1 kinase with an unfolded N-lobe separated from its C-lobe. The hydrophobic core of the N-lobe is trapped in the HSP90 dimer, while CDC37 wraps around the chaperone and interacts with the N- and C-lobes of the kinase. The structure indicates how CDC37 can discriminate between the different members of the RAF family. Our structural analysis also reveals that the folded RAF1 assembles with 14-3-3 dimers, suggesting that after folding RAF1 follows a similar activation as B-RAF. Finally, disruption of the interaction between CDC37 and the DFG segment of RAF1 unveils potential vulnerabilities in attempting the pharmacological degradation of RAF1 for therapeutic purposes.
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Proteínas de Ciclo Celular , Chaperoninas , Proteínas de Ciclo Celular/metabolismo , Chaperoninas/química , Microscopia Crioeletrônica , Proteínas de Choque Térmico HSP90/metabolismo , Chaperonas Moleculares/metabolismo , Ligação Proteica , Quinases raf/metabolismoRESUMO
CD8+ T cells within the tumor microenvironment (TME) are exposed to various signals that ultimately determine functional outcomes. Here, we examined the role of the co-activating receptor CD226 (DNAM-1) in CD8+ T cell function. The absence of CD226 expression identified a subset of dysfunctional CD8+ T cells present in peripheral blood of healthy individuals. These cells exhibited reduced LFA-1 activation, altered TCR signaling, and a distinct transcriptomic program upon stimulation. CD226neg CD8+ T cells accumulated in human and mouse tumors of diverse origin through an antigen-specific mechanism involving the transcriptional regulator Eomesodermin (Eomes). Despite similar expression of co-inhibitory receptors, CD8+ tumor-infiltrating lymphocyte failed to respond to anti-PD-1 in the absence of CD226. Immune checkpoint blockade efficacy was hampered in Cd226-/- mice. Anti-CD137 (4-1BB) agonists also stimulated Eomes-dependent CD226 loss that limited the anti-tumor efficacy of this treatment. Thus, CD226 loss restrains CD8+ T cell function and limits the efficacy of cancer immunotherapy.
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Antígenos de Diferenciação de Linfócitos T/imunologia , Linfócitos T CD8-Positivos/imunologia , Neoplasias/imunologia , Proteínas com Domínio T/imunologia , Animais , Humanos , Inibidores de Checkpoint Imunológico/imunologia , Imunoterapia/métodos , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias/terapia , Receptor de Morte Celular Programada 1/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Transdução de Sinais/imunologia , Transcriptoma/imunologia , Microambiente Tumoral/imunologia , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologiaRESUMO
Tumor-infiltrating myeloid cells (TIMs) comprise monocytes, macrophages, dendritic cells, and neutrophils, and have emerged as key regulators of cancer growth. These cells can diversify into a spectrum of states, which might promote or limit tumor outgrowth but remain poorly understood. Here, we used single-cell RNA sequencing (scRNA-seq) to map TIMs in non-small-cell lung cancer patients. We uncovered 25 TIM states, most of which were reproducibly found across patients. To facilitate translational research of these populations, we also profiled TIMs in mice. In comparing TIMs across species, we identified a near-complete congruence of population structures among dendritic cells and monocytes; conserved neutrophil subsets; and species differences among macrophages. By contrast, myeloid cell population structures in patients' blood showed limited overlap with those of TIMs. This study determines the lung TIM landscape and sets the stage for future investigations into the potential of TIMs as immunotherapy targets.
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Carcinoma Pulmonar de Células não Pequenas/imunologia , Células Dendríticas/imunologia , Neoplasias Pulmonares/imunologia , Macrófagos/imunologia , Monócitos/imunologia , Neutrófilos/imunologia , Animais , Sequência de Bases , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Perfilação da Expressão Gênica , Humanos , Pulmão/imunologia , Pulmão/patologia , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Análise de Sequência de RNARESUMO
The microbe-associated molecular pattern flg22 is recognized in a flagellin-sensitive 2-dependent manner in root tip cells. Here, we show a rapid and massive change in protein abundance and phosphorylation state of the Arabidopsis root cell proteome in WT and a mutant deficient in heterotrimeric G-protein-coupled signaling. flg22-induced changes fall on proteins comprising a subset of this proteome, the heterotrimeric G protein interactome, and on highly-populated hubs of the immunity network. Approximately 95% of the phosphorylation changes in the heterotrimeric G-protein interactome depend, at least partially, on a functional G protein complex. One member of this interactome is ATBα, a substrate-recognition subunit of a protein phosphatase 2A complex and an interactor to Arabidopsis thaliana Regulator of G Signaling 1 protein (AtRGS1), a flg22-phosphorylated, 7-transmembrane spanning modulator of the nucleotide-binding state of the core G-protein complex. A null mutation of ATBα strongly increases basal endocytosis of AtRGS1. AtRGS1 steady-state protein level is lower in the atbα mutant in a proteasome-dependent manner. We propose that phosphorylation-dependent endocytosis of AtRGS1 is part of the mechanism to degrade AtRGS1, thus sustaining activation of the heterotrimeric G protein complex required for the regulation of system dynamics in innate immunity. The PP2A(ATBα) complex is a critical regulator of this signaling pathway.
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Proteínas de Arabidopsis , Arabidopsis , Proteínas Heterotriméricas de Ligação ao GTP , Proteínas RGS , Arabidopsis/metabolismo , Fosforilação , Proteínas de Arabidopsis/metabolismo , Proteoma/metabolismo , Proteínas RGS/química , Proteínas RGS/genética , Proteínas RGS/metabolismo , Transdução de Sinais , Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Flagelina/farmacologia , Flagelina/metabolismo , Monoéster Fosfórico Hidrolases/metabolismoRESUMO
Wnt signalling induces a gradient of stem/progenitor cell proliferation along the crypt-villus axis of the intestine, which becomes expanded during intestinal regeneration or tumour formation. The YAP transcriptional co-activator is known to be required for intestinal regeneration, but its mode of regulation remains controversial. Here we show that the YAP-TEAD transcription factor is a key downstream effector of Wnt signalling in the intestine. Loss of YAP activity by Yap/Taz conditional knockout results in sensitivity of crypt stem cells to apoptosis and reduced cell proliferation during regeneration. Gain of YAP activity by Lats1/2 conditional knockout is sufficient to drive a crypt hyperproliferation response. In particular, Wnt signalling acts transcriptionally to induce YAP and TEAD1/2/4 expression. YAP normally localises to the nucleus only in crypt base stem cells, but becomes nuclear in most intestinal epithelial cells during intestinal regeneration after irradiation, or during organoid growth, in a Src family kinase-dependent manner. YAP-driven crypt expansion during regeneration involves an elongation and flattening of the Wnt signalling gradient. Thus, Wnt and Src-YAP signals cooperate to drive intestinal regeneration.
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Proteínas Adaptadoras de Transdução de Sinal/genética , Intestinos/fisiologia , Regeneração/genética , Regeneração/fisiologia , Fatores de Transcrição/genética , Via de Sinalização Wnt/genética , Quinases da Família src/genética , Animais , Apoptose/genética , Proteínas de Ciclo Celular/genética , Proliferação de Células/genética , Células Epiteliais/fisiologia , Mucosa Intestinal/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Células-Tronco/fisiologia , Proteínas de Sinalização YAPRESUMO
Chromosome gains are detrimental for the development of the human embryo. As such, autosomal trisomies almost always result in spontaneous abortion, and the rare embryos surviving until live birth suffer from a plethora of pathological defects. There is no treatment currently available to ameliorate the consequences of trisomies, such as Down syndrome (trisomy of chromosome 21). Identifying the source of the phenotypes observed in cells with extra chromosomes is crucial for understanding the underlying molecular causes of trisomy syndromes. Although increased expression of the genes localized on the extra chromosome triggers several pathological phenotypes, an alternative model suggests that global, aneuploidy-associated changes in cellular physiology also contribute to the pathology. Here, we compare the molecular consequences of trisomy syndromes in vivo against engineered cell lines carrying various chromosome gains in vitro. We point out several phenotypes that are shared by variable trisomies and, therefore, might be caused by the presence of an extra chromosome per se, independent of its identity. This alternative view may provide useful insights for understanding Down syndrome pathology and open additional opportunities for diagnostics and treatments.
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Síndrome de Down , Trissomia , Feminino , Gravidez , Humanos , Trissomia/genética , Síndrome de Down/genética , Aberrações Cromossômicas , Cromossomos Humanos Par 21 , AneuploidiaRESUMO
Hematopoietic stem cells (HSCs) are the ultimate source of blood and immune cells, and transplantation reveals their unique potential to regenerate all blood lineages lifelong. HSCs are considered a quiescent reserve population under homeostatic conditions, which can be rapidly activated by perturbations to fuel blood regeneration. In accordance with this concept, inflammation and loss of blood cells were reported to stimulate the proliferation of HSCs, which is associated with a decline in their transplantation potential. To investigate the contribution of primitive HSCs to the hematopoietic stress response in the native environment, we use fate mapping and proliferation tracking mouse models. Although primitive HSCs were robustly activated by severe myeloablation, they did not contribute to the regeneration of mature blood cells in response to prototypic hematopoietic emergencies, such as acute inflammation or blood loss. Even chronic inflammatory stimulation, which triggered vigorous HSC proliferation, only resulted in a weak contribution of HSCs to mature blood cell production. Thus, our data demonstrate that primitive HSCs do not participate in the hematopoietic recovery from common perturbations and call for the reevaluation of the concept of HSC-driven stress responses.
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Hematopoese , Células-Tronco Hematopoéticas , Animais , Camundongos , Hematopoese/fisiologia , Células-Tronco Hematopoéticas/fisiologia , Regeneração/fisiologia , InflamaçãoRESUMO
Topological quantum materials exhibit fascinating properties1-3, with important applications for dissipationless electronics and fault-tolerant quantum computers4,5. Manipulating the topological invariants in these materials would allow the development of topological switching applications analogous to switching of transistors6. Lattice strain provides the most natural means of tuning these topological invariants because it directly modifies the electron-ion interactions and potentially alters the underlying crystalline symmetry on which the topological properties depend7-9. However, conventional means of applying strain through heteroepitaxial lattice mismatch10 and dislocations11 are not extendable to controllable time-varying protocols, which are required in transistors. Integration into a functional device requires the ability to go beyond the robust, topologically protected properties of materials and to manipulate the topology at high speeds. Here we use crystallographic measurements by relativistic electron diffraction to demonstrate that terahertz light pulses can be used to induce terahertz-frequency interlayer shear strain with large strain amplitude in the Weyl semimetal WTe2, leading to a topologically distinct metastable phase. Separate nonlinear optical measurements indicate that this transition is associated with a symmetry change to a centrosymmetric, topologically trivial phase. We further show that such shear strain provides an ultrafast, energy-efficient way of inducing robust, well separated Weyl points or of annihilating all Weyl points of opposite chirality. This work demonstrates possibilities for ultrafast manipulation of the topological properties of solids and for the development of a topological switch operating at terahertz frequencies.
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Distribution of Earth's biomes is structured by the match between climate and plant traits, which in turn shape associated communities and ecosystem processes and services. However, that climate-trait match can be disrupted by historical events, with lasting ecosystem impacts. As Earth's environment changes faster than at any time in human history, critical questions are whether and how organismal traits and ecosystems can adjust to altered conditions. We quantified the relative importance of current environmental forcing versus evolutionary history in shaping the growth form (stature and biomass) and associated community of eelgrass (Zostera marina), a widespread foundation plant of marine ecosystems along Northern Hemisphere coastlines, which experienced major shifts in distribution and genetic composition during the Pleistocene. We found that eelgrass stature and biomass retain a legacy of the Pleistocene colonization of the Atlantic from the ancestral Pacific range and of more recent within-basin bottlenecks and genetic differentiation. This evolutionary legacy in turn influences the biomass of associated algae and invertebrates that fuel coastal food webs, with effects comparable to or stronger than effects of current environmental forcing. Such historical lags in phenotypic acclimatization may constrain ecosystem adjustments to rapid anthropogenic climate change, thus altering predictions about the future functioning of ecosystems.
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Ecossistema , Zosteraceae , Aclimatação , Animais , Evolução Biológica , Biomassa , Cadeia Alimentar , Invertebrados , Zosteraceae/genéticaRESUMO
Manipulating the polarization of light at the nanoscale is key to the development of next-generation optoelectronic devices. This is typically done via waveplates using optically anisotropic crystals, with thicknesses on the order of the wavelength. Here, using a novel ultrafast electron-beam-based technique sensitive to transient near fields at THz frequencies, we observe a giant anisotropy in the linear optical response in the semimetal WTe2 and demonstrate that one can tune the THz polarization using a 50 nm thick film, acting as a broadband wave plate with thickness 3 orders of magnitude smaller than the wavelength. The observed circular deflections of the electron beam are consistent with simulations tracking the trajectory of the electron beam in the near field of the THz pulse. This finding offers a promising approach to enable atomically thin THz polarization control using anisotropic semimetals and defines new approaches for characterizing THz near-field optical response at far-subwavelength length scales.
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The development of wearable thermoelectric generators (wTEG) represents a promising strategy to replace batteries and supercapacitors required to supply electrical energy for portable electronic devices. However, the main drawback of wTEGs is that the thermal gradient between the skin and the ambient is minimal, reducing the power output produced by the generator. Therefore, it is necessary to improve the thermal management of wTEG in order to increase its efficiency. This work deals with the preparation of a thermoelectric generator that harnesses the plasmonic heating effect to enhance the thermal gradient of the final device. The thermoelectric layer is created through the in situ polymerization of terthiophene (3T) within a polyurethane matrix, utilizing silver (Ag) (I) and copper (II) perchlorate as oxidants. The plasmonic film, composed of Ag-NP (nanoparticles), is formed via photocatalytic reduction of silver nitrate in the presence of titanium oxide. These layers are then meticulously assembled to yield the hybrid plasmonic/thermoelectric generator.
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PURPOSE OF REVIEW: The prevalence of peripheral artery disease is growing, with millions of people globally suffering its end-stage manifestation, chronic limb-threatening ischemia (CLTI). Revascularization procedures like lower extremity bypass play a vital role in limb salvage but optimal medical therapy is essential for maximizing the benefit of these procedures and reducing long-term risks of cardiovascular and limb-related events. RECENT FINDINGS: Patients with PAD who undergo lower extremity bypass warrant a comprehensive approach to risk factor modification for both primary and secondary prevention of cardiovascular and limb-related complications. This includes appropriate use of high-intensity statins, smoking cessation, and management of hypertension and diabetes. Additionally, antiplatelet therapy is indicated for all patients with CLTI and additional treatment with low-dose anticoagulation may also be beneficial. SUMMARY: Optimal medical therapy is essential for optimizing outcomes in patients with PAD undergoing lower extremity bypass.
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Extremidade Inferior , Doença Arterial Periférica , Humanos , Doença Arterial Periférica/cirurgia , Doença Arterial Periférica/tratamento farmacológico , Extremidade Inferior/cirurgia , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Inibidores da Agregação Plaquetária/uso terapêutico , Isquemia Crônica Crítica de Membro/cirurgia , Abandono do Hábito de Fumar/métodos , Fatores de Risco , Anticoagulantes/uso terapêutico , Salvamento de Membro/métodosRESUMO
Streptococcus suis is a zoonotic pathogen that causes a major health problem in the pig production industry worldwide. Spain is one of the largest pig producers in the world. This work aimed to investigate the genetic and phenotypic features of invasive S. suis isolates recovered in Spain. A panel of 156 clinical isolates recovered from 13 Autonomous Communities, representing the major pig producers, were analysed. MLST and serotyping analysis revealed that most isolates (61.6%) were assigned to ST1 (26.3%), ST123 (18.6%), ST29 (9.6%), and ST3 (7.1%). Interestingly, 34 new STs were identified, indicating the emergence of novel genetic lineages. Serotypes 9 (27.6%) and 1 (21.8%) prevailed, followed by serotypes 7 (12.8%) and 2 (12.2%). Analysis of 13 virulence-associated genes showed significant associations between ST, serotype, virulence patterns, and clinical features, evidencing particular virulence traits associated with genetic clusters. The pangenome was generated, and the core genome was distributed in 7 Bayesian groups where each group included a variable set of over- and under-represented genes of different categories. The study provides comprehensive data and knowledge to improve the design of new vaccines, antimicrobial treatments, and bacterial typing approaches.
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Streptococcus suis , Animais , Suínos , Streptococcus suis/genética , Espanha/epidemiologia , Teorema de Bayes , Tipagem de Sequências Multilocus/veterinária , Virulência , GenômicaRESUMO
Per- and polyfluoroalkyl substances (PFAS) are manufactured chemicals that have been detected across the globe. Fluorotelomer alcohols (FTOHs) are one PFAS class commonly found in indoor air due to emissions from consumer products (e.g., textiles and food packaging) and are human metabolic, atmospheric oxidative, and industrial precursors of perfluoroalkyl carboxylic acids (PFCAs). We developed a quantitative method for real-time analysis of gas-phase FTOHs, perfluoroalkyl acids (PFCAs and GenX), one perfluorooctane sulfonamide (EtFOSA), one fluorotelomer diol (FTdiOH), and one fluorinated ether (E2) using high-resolution time-of-flight chemical ionization mass spectrometry equipped with iodide reagent ion chemistry (I-HR-ToF-CIMS). Herein, we present a direct liquid injection method for external calibration, providing detection limits of 0.19-3.1 pptv for 3 s averaging and 0.02-0.44 pptv for 120 s averaging, with the exception of E2, which had detection limits of 1700 and 220 pptv for 3- and 120 s averaging, respectively. These calibrations enabled real-time gas-phase quantification of 6 : 2 FTOH in room air while microwaving popcorn, with an average peak air concentration of 31.6 ± 4.5 pptv measured 2 meters from a closed microwave. Additionally, 8 : 2 and 10 : 2 FTOH concentrations in indoor air were measured in the presence and absence of a rain jacket, with observed peak concentrations of 110 and 25 pptv, respectively. Our work demonstrates the ability of I-HR-ToF-CIMS to provide real-time air measurements of PFAS relevant to indoor human exposure settings and allow for PFAS source identification. We expect that real-time quantification of other gas-phase PFAS classes is possible, enabling advances in understanding PFAS sources, chemistry, and partitioning.
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Exposure to ambient air contaminates the surface of graphene sheets. Contamination may arise from different sources, and its nature alters the frictional behavior of the material. These changes in friction enable the observation of the early stages of contaminants' adsorption in graphene. Using a friction force microscope, we show that molecular adsorption initiates at the edges and mechanical defects in the monolayer. Once the monolayer is covered, the contaminants spread over the additional graphene layers. With this method, we estimate the contamination kinetics. In monolayer graphene, the surface area covered with adsorbed molecules increases with time of air exposure at a rate of 10-14 m2/s, while in bilayer graphene, it is one order of magnitude smaller. Finally, as the contaminants cover the additional graphene layers, friction no longer has a difference concerning the number of graphene layers.
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BACKGROUND: There is limited data on dolutegravir (DTG)-associated weight gain from settings with a dual burden of HIV and overnutrition. METHODS: In Eswatini (at Matsanjeni), among 156 and 160 adult patients on DTG-based and EFV-based antiretroviral therapy (ART), respectively, we studied excessive weight gain (BMI at 24 months ART greater than baseline and ≥25 kg/m2). RESULTS: The median BMI increase in DTG-based patients was 1.09 (IQR:-0.28,3.28) kg/m2 compared to 0.20 (IQR:-0.85,2.18) kg/m2 in EFV-based patients (p value = 0.001). DTG-based ART predicted excessive weight gain (aOR 2.61;95% CI:1.39-4.93). CONCLUSION: Practitioners should consider DTG-based regimens as one of the risk factors for overweight/obesity.
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Infecções por HIV , Adulto , Humanos , Infecções por HIV/tratamento farmacológico , Essuatíni , Estudos Retrospectivos , Benzoxazinas/uso terapêutico , Aumento de PesoRESUMO
In this paper, we present the development and the validation of a novel index of nociception/anti-nociception (N/AN) based on skin impedance measurement in time and frequency domain with our prototype AnspecPro device. The primary objective of the study was to compare the Anspec-PRO device with two other commercial devices (Medasense, Medstorm). This comparison was designed to be conducted under the same conditions for the three devices. This was carried out during total intravenous anesthesia (TIVA) by investigating its outcomes related to noxious stimulus. In a carefully designed clinical protocol during general anesthesia from induction until emergence, we extract data for estimating individualized causal dynamic models between drug infusion and their monitored effect variables. Specifically, these are Propofol hypnotic drug to Bispectral index of hypnosis level and Remifentanil opioid drug to each of the three aforementioned devices. When compared, statistical analysis of the regions before and during the standardized stimulus shows consistent difference between regions for all devices and for all indices. These results suggest that the proposed methodology for data extraction and processing for AnspecPro delivers the same information as the two commercial devices.
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Nociceptividade , Propofol , Anestesia Geral , Impedância Elétrica , RemifentanilRESUMO
Strong coupling between light and mechanical strain forms the foundation for next-generation optical micro- and nano-electromechanical systems. Such optomechanical responses in two-dimensional materials present novel types of functionalities arising from the weak van der Waals bond between atomic layers. Here, by using structure-sensitive megaelectronvolt ultrafast electron diffraction, we report the experimental observation of optically driven ultrafast in-plane strain in the layered group IV monochalcogenide germanium sulfide (GeS). Surprisingly, the photoinduced structural deformation exhibits strain amplitudes of order 0.1% with a 10 ps fast response time and a significant in-plane anisotropy between zigzag and armchair crystallographic directions. Rather than arising due to heating, experimental and theoretical investigations suggest deformation potentials caused by electronic density redistribution and converse piezoelectric effects generated by photoinduced electric fields are the dominant contributors to the observed dynamic anisotropic strains. Our observations define new avenues for ultrafast optomechanical control and strain engineering within functional devices.
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INTRODUCTION: Existing blood-based biomarkers for Alzheimer's disease (AD) mainly focus on its pathological features. However, studies on blood-based biomarkers associated with other biological processes for a comprehensive evaluation of AD status are limited. METHODS: We developed a blood-based, multiplex biomarker assay for AD that measures the levels of 21 proteins involved in multiple biological pathways. We evaluated the assay's performance for classifying AD and indicating AD-related endophenotypes in three independent cohorts from Chinese or European-descent populations. RESULTS: The 21-protein assay accurately classified AD (area under the receiver operating characteristic curve [AUC] = 0.9407 to 0.9867) and mild cognitive impairment (MCI; AUC = 0.8434 to 0.8945) while also indicating brain amyloid pathology. Moreover, the assay simultaneously evaluated the changes of five biological processes in individuals and revealed the ethnic-specific dysregulations of biological processes upon AD progression. DISCUSSION: This study demonstrated the utility of a blood-based, multi-pathway biomarker assay for early screening and staging of AD, providing insights for patient stratification and precision medicine. HIGHLIGHTS: The authors developed a blood-based biomarker assay for Alzheimer's disease. The 21-protein assay classifies AD/MCI and indicates brain amyloid pathology. The 21-protein assay can simultaneously assess activities of five biological processes. Ethnic-specific dysregulations of biological processes in AD were revealed.