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1.
Nature ; 629(8010): 211-218, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38600391

RESUMEN

A major limitation of chimeric antigen receptor (CAR) T cell therapies is the poor persistence of these cells in vivo1. The expression of memory-associated genes in CAR T cells is linked to their long-term persistence in patients and clinical efficacy2-6, suggesting that memory programs may underpin durable CAR T cell function. Here we show that the transcription factor FOXO1 is responsible for promoting memory and restraining exhaustion in human CAR T cells. Pharmacological inhibition or gene editing of endogenous FOXO1 diminished the expression of memory-associated genes, promoted an exhaustion-like phenotype and impaired the antitumour activity of CAR T cells. Overexpression of FOXO1 induced a gene-expression program consistent with T cell memory and increased chromatin accessibility at FOXO1-binding motifs. CAR T cells that overexpressed FOXO1 retained their function, memory potential and metabolic fitness in settings of chronic stimulation, and exhibited enhanced persistence and tumour control in vivo. By contrast, overexpression of TCF1 (encoded by TCF7) did not enforce canonical memory programs or enhance the potency of CAR T cells. Notably, FOXO1 activity correlated with positive clinical outcomes of patients treated with CAR T cells or tumour-infiltrating lymphocytes, underscoring the clinical relevance of FOXO1 in cancer immunotherapy. Our results show that overexpressing FOXO1 can increase the antitumour activity of human CAR T cells, and highlight memory reprogramming as a broadly applicable approach for optimizing therapeutic T cell states.


Asunto(s)
Proteína Forkhead Box O1 , Memoria Inmunológica , Inmunoterapia Adoptiva , Receptores Quiméricos de Antígenos , Linfocitos T , Animales , Humanos , Ratones , Línea Celular Tumoral , Cromatina/metabolismo , Cromatina/genética , Proteína Forkhead Box O1/metabolismo , Edición Génica , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/metabolismo , Receptores Quiméricos de Antígenos/inmunología , Receptores Quiméricos de Antígenos/metabolismo , Receptores Quiméricos de Antígenos/genética , Linfocitos T/inmunología , Linfocitos T/metabolismo , Linfocitos T/citología
2.
N Engl J Med ; 390(18): 1649-1662, 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38661449

RESUMEN

BACKGROUND: Exagamglogene autotemcel (exa-cel) is a nonviral cell therapy designed to reactivate fetal hemoglobin synthesis by means of ex vivo clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 gene editing of autologous CD34+ hematopoietic stem and progenitor cells (HSPCs) at the erythroid-specific enhancer region of BCL11A. METHODS: We conducted a phase 3, single-group, open-label study of exa-cel in patients 12 to 35 years of age with sickle cell disease who had had at least two severe vaso-occlusive crises in each of the 2 years before screening. CD34+ HSPCs were edited with the use of CRISPR-Cas9. Before the exa-cel infusion, patients underwent myeloablative conditioning with pharmacokinetically dose-adjusted busulfan. The primary end point was freedom from severe vaso-occlusive crises for at least 12 consecutive months. A key secondary end point was freedom from inpatient hospitalization for severe vaso-occlusive crises for at least 12 consecutive months. The safety of exa-cel was also assessed. RESULTS: A total of 44 patients received exa-cel, and the median follow-up was 19.3 months (range, 0.8 to 48.1). Neutrophils and platelets engrafted in each patient. Of the 30 patients who had sufficient follow-up to be evaluated, 29 (97%; 95% confidence interval [CI], 83 to 100) were free from vaso-occlusive crises for at least 12 consecutive months, and all 30 (100%; 95% CI, 88 to 100) were free from hospitalizations for vaso-occlusive crises for at least 12 consecutive months (P<0.001 for both comparisons against the null hypothesis of a 50% response). The safety profile of exa-cel was generally consistent with that of myeloablative busulfan conditioning and autologous HSPC transplantation. No cancers occurred. CONCLUSIONS: Treatment with exa-cel eliminated vaso-occlusive crises in 97% of patients with sickle cell disease for a period of 12 months or more. (CLIMB SCD-121; ClinicalTrials.gov number, NCT03745287.).


Asunto(s)
Anemia de Células Falciformes , Hemoglobina Fetal , Trasplante de Células Madre Hematopoyéticas , Adolescente , Adulto , Niño , Femenino , Humanos , Masculino , Adulto Joven , Anemia de Células Falciformes/complicaciones , Anemia de Células Falciformes/genética , Anemia de Células Falciformes/terapia , Antígenos CD34 , Busulfano/uso terapéutico , Sistemas CRISPR-Cas , Hemoglobina Fetal/biosíntesis , Hemoglobina Fetal/genética , Edición Génica , Células Madre Hematopoyéticas , Proteínas Represoras , Acondicionamiento Pretrasplante , Tratamiento Basado en Trasplante de Células y Tejidos/métodos , Agonistas Mieloablativos/uso terapéutico , Europa (Continente) , América del Norte
3.
EMBO J ; 41(24): e110959, 2022 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-36314723

RESUMEN

One-third of the human proteome is comprised of membrane proteins, which are particularly vulnerable to misfolding and often require folding assistance by molecular chaperones. Calnexin (CNX), which engages client proteins via its sugar-binding lectin domain, is one of the most abundant ER chaperones, and plays an important role in membrane protein biogenesis. Based on mass spectrometric analyses, we here show that calnexin interacts with a large number of nonglycosylated membrane proteins, indicative of additional nonlectin binding modes. We find that calnexin preferentially bind misfolded membrane proteins and that it uses its single transmembrane domain (TMD) for client recognition. Combining experimental and computational approaches, we systematically dissect signatures for intramembrane client recognition by calnexin, and identify sequence motifs within the calnexin TMD region that mediate client binding. Building on this, we show that intramembrane client binding potentiates the chaperone functions of calnexin. Together, these data reveal a widespread role of calnexin client recognition in the lipid bilayer, which synergizes with its established lectin-based substrate binding. Molecular chaperones thus can combine different interaction modes to support the biogenesis of the diverse eukaryotic membrane proteome.


Asunto(s)
Chaperonas Moleculares , Proteoma , Humanos , Calnexina/metabolismo , Proteoma/metabolismo , Chaperonas Moleculares/metabolismo , Lectinas/metabolismo , Proteínas de la Membrana/metabolismo , Pliegue de Proteína , Proteínas de Unión al Calcio/metabolismo
4.
Blood ; 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38905637

RESUMEN

Immune effector cell-associated neurotoxicity syndrome (ICANS) is a common but potentially severe adverse event associated with chimeric antigen receptor T-cell (CART) therapy characterized by the development of acute neurologic symptoms following CART infusion. ICANS encompasses a wide clinical spectrum typified by mild to severe encephalopathy, seizures and/or cerebral edema. As more patients have been treated with CART new ICANS phenomenology has emerged. We present the clinical course of five children who developed acute onset of quadriparesis or paraparesis associated with abnormal brain and/or spine neuroimaging after infusion of CD19 or CD22-directed CART, adverse events not previously reported in children. Orthogonal data from autopsy studies, cerebrospinal fluid (CSF) flow cytometry and CSF proteomics/cytokine profiling demonstrated chronic white matter destruction, but a notable lack of inflammatory pathologic changes and cell populations. Instead, children with quadriparesis or paraparesis post-CART therapy had lower levels of pro-inflammatory cytokines such as interferon gamma (IFN), CCL17, CCL23, and CXCL10 than those who did not develop quadriparesis or paraparesis. Taken together, these findings imply a non-inflammatory source of this newly described ICANS phenomenon in children. The pathophysiology of some neurologic symptoms following CART may therefore have a more complex etiology than exclusive T-cell activation and excessive cytokine production.

5.
Blood ; 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38968143

RESUMEN

Acute graft-vs-host disease (GVHD) grading systems that use only clinical symptoms at treatment initiation such as Minnesota risk identify standard and high risk categories but lack a low risk category suitable to minimize immunosuppressive strategies. We developed a new grading system that includes a low risk stratum based on clinical symptoms alone and determined whether the incorporation of biomarkers would improve the model's prognostic accuracy. We randomly divided 1863 patients in the Mount Sinai Acute GVHD International Consortium (MAGIC) who were treated for GVHD into training and validation cohorts. Patients in the training cohort were divided into 14 groups based on similarity of clinical symptoms and similar NRM; we used a classification and regression tree (CART) algorithm to create three Manhattan risk groups that produced a significantly higher area under the receiver operating characteristic curve (AUC) for 6-month NRM than the Minnesota risk classification (0.69 vs. 0.64, P=0.009) in the validation cohort. We integrated serum GVHD biomarker scores with Manhattan risk using patients with available serum samples and again used a CART algorithm to establish three MAGIC composite scores that significantly improved prediction of NRM compared to Manhattan risk (AUC, 0.76 vs. 0.70, P=0.010). Each increase in MAGIC composite score also corresponded to a significant decrease in day 28 treatment response (80% vs. 63% vs. 30%, P<0.001). We conclude that the MAGIC composite score more accurately predicts response to therapy and long term outcomes than systems based on clinical symptoms alone and may help guide clinical decisions and trial design.

6.
Proc Natl Acad Sci U S A ; 120(31): e2306344120, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37487104

RESUMEN

Humans reason and care about ethical issues, such as avoiding unnecessary harm. But what enables us to develop a moral capacity? This question dates back at least to ancient Greece and typically results in the traditional opposition between sentimentalism (the view that morality is mainly driven by socioaffective processes) and rationalism [the view that morality is mainly driven by (socio)cognitive processes or reason]. Here, we used multiple methods (eye-tracking and observations of expressive behaviors) to assess the role of both cognitive and socioaffective processes in infants' developing morality. We capitalized on the distinction between moral (e.g., harmful) and conventional (e.g., harmless) transgressions to investigate whether 18-mo-old infants understand actions as distinctively moral as opposed to merely disobedient or unexpected. All infants watched the same social scene, but based on prior verbal interactions, an actor's tearing apart of a picture (an act not intrinsically harmful) with a tool constituted either a conventional (wrong tool), a moral (producing harm), or no violation (correct tool). Infants' anticipatory looks differentiated between conventional and no violation conditions, suggesting that they processed the verbal interactions and built corresponding expectations. Importantly, infants showed a larger increase in pupil size (physiological arousal), and more expressions indicating empathic concern, in response to a moral than to a conventional violation. Thus, infants differentiated between harmful and harmless transgressions based solely on prior verbal interactions. Together, these convergent findings suggest that human infants' moral development is fostered by both sociocognitive (inferring harm) and socioaffective processes (empathic concern for others' welfare).


Asunto(s)
Desarrollo Moral , Principios Morales , Humanos , Lactante , Vigilia , Disentimientos y Disputas , Empatía
7.
Proc Natl Acad Sci U S A ; 120(7): e2212909120, 2023 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-36745811

RESUMEN

Phosphorylation is a ubiquitous mechanism by which signals are transduced in cells. Protein kinases, enzymes that catalyze the phosphotransfer reaction are, themselves, often regulated by phosphorylation. Paradoxically, however, a substantial fraction of more than 500 human protein kinases are capable of catalyzing their own activation loop phosphorylation. Commonly, these kinases perform this autophosphorylation reaction in trans, whereby transient dimerization leads to the mutual phosphorylation of the activation loop of the opposing protomer. In this study, we demonstrate that protein kinase D (PKD) is regulated by the inverse mechanism of dimerization-mediated trans-autoinhibition, followed by activation loop autophosphorylation in cis. We show that PKD forms a stable face-to-face homodimer that is incapable of either autophosphorylation or substrate phosphorylation. Dissociation of this trans-autoinhibited dimer results in activation loop autophosphorylation, which occurs exclusively in cis. Phosphorylation serves to increase PKD activity and prevent trans-autoinhibition, thereby switching PKD on. Our findings not only reveal the mechanism of PKD regulation but also have profound implications for the regulation of many other eukaryotic kinases.


Asunto(s)
Proteína Quinasa C , Humanos , Fosforilación/fisiología , Proteína Quinasa C/metabolismo
8.
Traffic ; 24(4): 162-176, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36562184

RESUMEN

The control of intracellular membrane trafficking by Rho GTPases is central to cellular homeostasis. How specific guanine nucleotide exchange factors and GTPase-activating proteins locally balance GTPase activation in this process is nevertheless largely unclear. By performing a microscopy-based RNAi screen, we here identify the RhoGEF protein Solo as a functional counterplayer of DLC3, a RhoGAP protein with established roles in membrane trafficking. Biochemical, imaging and optogenetics assays further uncover Solo as a novel regulator of endosomal RhoB. Remarkably, we find that Solo and DLC3 control not only the activity, but also total protein levels of RhoB in an antagonistic manner. Together, the results of our study uncover the first functionally connected RhoGAP-RhoGEF pair at endomembranes, placing Solo and DLC3 at the core of endocytic trafficking.


Asunto(s)
Proteínas de Unión al GTP rho , Proteína de Unión al GTP rhoB , Factores de Intercambio de Guanina Nucleótido Rho/genética , Factores de Intercambio de Guanina Nucleótido Rho/metabolismo , Proteína de Unión al GTP rhoB/metabolismo , Proteínas de Unión al GTP rho/metabolismo , Aparato de Golgi/metabolismo , Endosomas/metabolismo
9.
Gastroenterology ; 166(2): 298-312.e14, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37913894

RESUMEN

BACKGROUND & AIMS: The highly heterogeneous cellular and molecular makeup of pancreatic ductal adenocarcinoma (PDAC) not only fosters exceptionally aggressive tumor biology, but contradicts the current concept of one-size-fits-all therapeutic strategies to combat PDAC. Therefore, we aimed to exploit the tumor biological implication and therapeutic vulnerabilities of a clinically relevant molecular PDAC subgroup characterized by SMAD4 deficiency and high expression of the nuclear factor of activated T cells (SMAD4-/-/NFATc1High). METHODS: Transcriptomic and clinical data were analyzed to determine the prognostic relevance of SMAD4-/-/NFATc1High cancers. In vitro and in vivo oncogenic transcription factor complex formation was studied by immunoprecipitation, proximity ligation assays, and validated cross model and species. The impact of SMAD4 status on therapeutically targeting canonical KRAS signaling was mechanistically deciphered and corroborated by genome-wide gene expression analysis and genetic perturbation experiments, respectively. Validation of a novel tailored therapeutic option was conducted in patient-derived organoids and cells and transgenic as well as orthotopic PDAC models. RESULTS: Our findings determined the tumor biology of an aggressive and chemotherapy-resistant SMAD4-/-/NFATc1High subgroup. Mechanistically, we identify SMAD4 deficiency as a molecular prerequisite for the formation of an oncogenic NFATc1/SMAD3/cJUN transcription factor complex, which drives the expression of RRM1/2. RRM1/2 replenishes nucleoside pools that directly compete with metabolized gemcitabine for DNA strand incorporation. Disassembly of the NFATc1/SMAD3/cJUN complex by mitogen-activated protein kinase signaling inhibition normalizes RRM1/2 expression and synergizes with gemcitabine treatment in vivo to reduce the proliferative index. CONCLUSIONS: Our results suggest that PDAC characterized by SMAD4 deficiency and oncogenic NFATc1/SMAD3/cJUN complex formation exposes sensitivity to a mitogen-activated protein kinase signaling inhibition and gemcitabine combination therapy.


Asunto(s)
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Gemcitabina , Línea Celular Tumoral , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Carcinoma Ductal Pancreático/tratamiento farmacológico , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Proteína Smad4/genética , Proteína Smad4/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Proteína smad3/metabolismo
10.
Blood ; 141(6): 609-619, 2023 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-36351239

RESUMEN

Children living in poverty experience excessive relapse and death from newly diagnosed acute lymphoblastic leukemia (ALL). The influence of household poverty and neighborhood social determinants on outcomes from chimeric antigen receptor (CAR) T-cell therapy for relapsed/refractory (r/r) leukemia is poorly described. We identified patients with r/r CD19+ ALL/lymphoblastic lymphoma treated on CD19-directed CAR T-cell clinical trials or with commercial tisagenlecleucel from 2012 to 2020. Socioeconomic status (SES) was proxied at the household level, with poverty exposure defined as Medicaid-only insurance. Low-neighborhood opportunity was defined by the Childhood Opportunity Index. Among 206 patients aged 1 to 29, 35.9% were exposed to household poverty, and 24.9% had low-neighborhood opportunity. Patients unexposed to household poverty or low-opportunity neighborhoods were more likely to receive CAR T-cell therapy with a high disease burden (>25%), a disease characteristic associated with inferior outcomes, as compared with less advantaged patients (38% vs 30%; 37% vs 26%). Complete remission (CR) rate was 93%, with no significant differences by household poverty (P = .334) or neighborhood opportunity (P = .504). In multivariate analysis, patients from low-opportunity neighborhoods experienced an increased hazard of relapse as compared with others (P = .006; adjusted hazard ratio [HR], 2.3; 95% confidence interval [CI], 1.3-4.1). There was no difference in hazard of death (P = .545; adjusted HR, 1.2; 95% CI, 0.6-2.4). Among children who successfully receive CAR T-cell therapy, CR and overall survival are equitable regardless of proxied SES and neighborhood opportunity. Children from more advantaged households and neighborhoods receive CAR T-cell therapy with a higher disease burden. Investigation of multicenter outcomes and access disparities outside of clinical trial settings is warranted.


Asunto(s)
Leucemia-Linfoma Linfoblástico de Células Precursoras , Receptores Quiméricos de Antígenos , Humanos , Niño , Inmunoterapia Adoptiva , Receptores Quiméricos de Antígenos/uso terapéutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Recurrencia , Antígenos CD19 , Pobreza
11.
FASEB J ; 38(2): e23442, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38275103

RESUMEN

The intramembrane protease γ-secretase has broad physiological functions, but also contributes to Notch-dependent tumors and Alzheimer's disease. While γ-secretase cleaves numerous membrane proteins, only few nonsubstrates are known. Thus, a fundamental open question is how γ-secretase distinguishes substrates from nonsubstrates and whether sequence-based features or post-translational modifications of membrane proteins contribute to substrate recognition. Using mass spectrometry-based proteomics, we identified several type I membrane proteins with short ectodomains that were inefficiently or not cleaved by γ-secretase, including 'pituitary tumor-transforming gene 1-interacting protein' (PTTG1IP). To analyze the mechanism preventing cleavage of these putative nonsubstrates, we used the validated substrate FN14 as a backbone and replaced its transmembrane domain (TMD), where γ-cleavage occurs, with the one of nonsubstrates. Surprisingly, some nonsubstrate TMDs were efficiently cleaved in the FN14 backbone, demonstrating that a cleavable TMD is necessary, but not sufficient for cleavage by γ-secretase. Cleavage efficiencies varied by up to 200-fold. Other TMDs, including that of PTTG1IP, were still barely cleaved within the FN14 backbone. Pharmacological and mutational experiments revealed that the PTTG1IP TMD is palmitoylated, which prevented cleavage by γ-secretase. We conclude that the TMD sequence of a membrane protein and its palmitoylation can be key factors determining substrate recognition and cleavage efficiency by γ-secretase.


Asunto(s)
Secretasas de la Proteína Precursora del Amiloide , Lipoilación , Secretasas de la Proteína Precursora del Amiloide/genética , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Proteínas de la Membrana/metabolismo , Dominios Proteicos , Procesamiento Proteico-Postraduccional , Precursor de Proteína beta-Amiloide/metabolismo
13.
Cell Mol Life Sci ; 81(1): 163, 2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-38570362

RESUMEN

Proteolytic release of transmembrane proteins from the cell surface, the so called ectodomain shedding, is a key process in inflammation. Inactive rhomboid 2 (iRhom2) plays a crucial role in this context, in that it guides maturation and function of the sheddase ADAM17 (a disintegrin and metalloproteinase 17) in immune cells, and, ultimately, its ability to release inflammatory mediators such as tumor necrosis factor α (TNFα). Yet, the macrophage sheddome of iRhom2/ADAM17, which is the collection of substrates that are released by the proteolytic complex, is only partly known. In this study, we applied high-resolution proteomics to murine and human iRhom2-deficient macrophages for a systematic identification of substrates, and therefore functions, of the iRhom2/ADAM17 proteolytic complex. We found that iRhom2 loss suppressed the release of a group of transmembrane proteins, including known (e.g. CSF1R) and putative novel ADAM17 substrates. In the latter group, shedding of major histocompatibility complex class I molecules (MHC-I) was consistently reduced in both murine and human macrophages when iRhom2 was ablated. Intriguingly, it emerged that in addition to its shedding, iRhom2 could also control surface expression of MHC-I by an undefined mechanism. We have demonstrated the biological significance of this process by using an in vitro model of CD8+ T-cell (CTL) activation. In this model, iRhom2 loss and consequent reduction of MHC-I expression on the cell surface of an Epstein-Barr virus (EBV)-transformed lymphoblastoid cell line dampened activation of autologous CTLs and their cell-mediated cytotoxicity. Taken together, this study uncovers a new role for iRhom2 in controlling cell surface levels of MHC-I by a dual mechanism that involves regulation of their surface expression and ectodomain shedding.


Asunto(s)
Proteínas Portadoras , Infecciones por Virus de Epstein-Barr , Animales , Humanos , Ratones , Proteína ADAM17/genética , Proteína ADAM17/metabolismo , Proteínas Portadoras/metabolismo , Herpesvirus Humano 4 , Complejo Mayor de Histocompatibilidad , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones Noqueados
14.
Proc Natl Acad Sci U S A ; 119(39): e2207257119, 2022 09 27.
Artículo en Inglés | MEDLINE | ID: mdl-36122228

RESUMEN

Bacterial hibernating 100S ribosomes (the 70S dimers) are excluded from translation and are protected from ribonucleolytic degradation, thereby promoting long-term viability and increased regrowth. No extraribosomal target of any hibernation factor has been reported. Here, we discovered a previously unrecognized binding partner (YwlG) of hibernation-promoting factor (HPF) in the human pathogen Staphylococcus aureus. YwlG is an uncharacterized virulence factor in S. aureus. We show that the HPF-YwlG interaction is direct, independent of ribosome binding, and functionally linked to cold adaptation and glucose metabolism. Consistent with the distant resemblance of YwlG to the hexameric structures of nicotinamide adenine dinucleotide (NAD)-specific glutamate dehydrogenases (GDHs), YwlG overexpression can compensate for a loss of cellular GDH activity. The reduced abundance of 100S complexes and the suppression of YwlG-dependent GDH activity provide evidence for a two-way sequestration between YwlG and HPF. These findings reveal an unexpected layer of regulation linking the biogenesis of 100S ribosomes to glutamate metabolism.


Asunto(s)
Hibernación , Proteínas Ribosómicas , Bacterias/metabolismo , Glucosa/metabolismo , Ácido Glutámico/metabolismo , Humanos , NAD/metabolismo , Oxidorreductasas/metabolismo , Proteínas Ribosómicas/metabolismo , Staphylococcus aureus/metabolismo , Factores de Virulencia/metabolismo
15.
Proc Natl Acad Sci U S A ; 119(10): e2118227119, 2022 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-35238645

RESUMEN

SignificanceHost-emitted stress hormones significantly influence the growth and behavior of various bacterial species; however, their cellular targets have so far remained elusive. Here, we used customized probes and quantitative proteomics to identify the target of epinephrine and the α-adrenoceptor agonist phenylephrine in live cells of the aquatic pathogen Vibrio campbellii. Consequently, we have discovered the coupling protein CheW, which is in the center of the chemotaxis signaling network, as a target of both molecules. We not only demonstrate direct ligand binding to CheW but also elucidate how this affects chemotactic control. These findings are pivotal for further research on hormone-specific effects on bacterial behavior.


Asunto(s)
Proteínas Bacterianas/metabolismo , Catecolaminas/fisiología , Factores Quimiotácticos/fisiología , Quimiotaxis/fisiología , Vibrio/fisiología , Catecoles/química , Factores Quimiotácticos/metabolismo , Hierro/análisis , Sondas Moleculares/química , Unión Proteica , Proteómica/métodos , Transducción de Señal
16.
Proc Natl Acad Sci U S A ; 119(24): e2119804119, 2022 06 14.
Artículo en Inglés | MEDLINE | ID: mdl-35666874

RESUMEN

Single-cell transcriptomics has revealed specific glial activation states associated with the pathogenesis of neurodegenerative diseases, such as Alzheimer's and Parkinson's disease. While these findings may eventually lead to new therapeutic opportunities, little is known about how these glial responses are reflected by biomarker changes in bodily fluids. Such knowledge, however, appears crucial for patient stratification, as well as monitoring disease progression and treatment responses in clinical trials. Here, we took advantage of well-described mouse models of ß-amyloidosis and α-synucleinopathy to explore cerebrospinal fluid (CSF) proteome changes related to their respective proteopathic lesions. Nontargeted liquid chromatography-mass spectrometry revealed that the majority of proteins that undergo age-related changes in CSF of either mouse model were linked to microglia and astrocytes. Specifically, we identified a panel of more than 20 glial-derived proteins that were increased in CSF of aged ß-amyloid precursor protein- and α-synuclein-transgenic mice and largely overlap with previously described disease-associated glial genes identified by single-cell transcriptomics. Our results also show that enhanced shedding is responsible for the increase of several of the identified glial CSF proteins as exemplified for TREM2. Notably, the vast majority of these proteins can also be quantified in human CSF and reveal changes in Alzheimer's disease cohorts. The finding that cellular transcriptome changes translate into corresponding changes of CSF proteins is of clinical relevance, supporting efforts to identify fluid biomarkers that reflect the various functional states of glial responses in cerebral proteopathies, such as Alzheimer's and Parkinson's disease.


Asunto(s)
Enfermedad de Alzheimer , Líquido Cefalorraquídeo , Neuroglía , Enfermedad de Parkinson , Proteoma , Enfermedad de Alzheimer/líquido cefalorraquídeo , Enfermedad de Alzheimer/metabolismo , Animales , Biomarcadores/líquido cefalorraquídeo , Líquido Cefalorraquídeo/metabolismo , Perfilación de la Expresión Génica , Humanos , Ratones , Neuroglía/metabolismo , Enfermedad de Parkinson/líquido cefalorraquídeo , Enfermedad de Parkinson/metabolismo , Proteoma/metabolismo , Análisis de la Célula Individual , Proteínas tau
17.
Biophys J ; 2024 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-38549370

RESUMEN

Acid-sensing ion channels (ASICs) are proton-gated cation channels that contribute to fast synaptic transmission and have roles in fear conditioning and nociception. Apart from activation at low pH, ASIC1a also undergoes several types of desensitization, including acute desensitization, which terminates activation; steady-state desensitization, which occurs at sub-activating proton concentrations and limits subsequent activation; and tachyphylaxis, which results in a progressive decrease in response during a series of activations. Structural insights from a desensitized state of ASIC1 have provided great spatial detail, but dynamic insights into conformational changes in different desensitizing conditions are largely missing. Here, we use electrophysiology and voltage-clamp fluorometry to follow the functional changes of the pore along with conformational changes at several positions in the extracellular and upper transmembrane domain via cysteine-labeled fluorophores. Acute desensitization terminates activation in wild type, but introducing an N414K mutation in the ß11-12 linker of mouse ASIC1a interfered with this process. The mutation also affected steady-state desensitization and led to pronounced tachyphylaxis. Although the extracellular domain of this mutant remained sensitive to pH and underwent pH-dependent conformational changes, these conformational changes did not necessarily lead to desensitization. N414K-containing channels also remained sensitive to a known peptide modulator that increases steady-state desensitization, indicating that the mutation only reduced, but not precluded, desensitization. Together, this study contributes to our understanding of the fundamental properties of ASIC1a desensitization, emphasizing the complex interplay between the conformational changes of the extracellular domain and the pore during channel activation and desensitization.

18.
Biochemistry ; 63(5): 651-659, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38388156

RESUMEN

AMPylation is a post-translational modification utilized by human and bacterial cells to modulate the activity and function of specific proteins. Major AMPylators such as human FICD and bacterial VopS have been studied extensively for their substrate and target scope in vitro. Recently, an AMP pronucleotide probe also facilitated the in situ analysis of AMPylation in living cells. Based on this technology, we here introduce a novel UMP pronucleotide probe and utilize it to profile uninfected and Vibrio parahaemolyticus infected human cells. Mass spectrometric analysis of labeled protein targets reveals an unexpected promiscuity of human nucleotide transferases with an almost identical target set of AMP- and UMPylated proteins. Vice versa, studies in cells infected by V. parahaemolyticus and its effector VopS revealed solely AMPylation of host enzymes, highlighting a so far unknown specificity of this transferase for ATP. Taken together, pronucleotide probes provide an unprecedented insight into the in situ activity profile of crucial nucleotide transferases, which can largely differ from their in vitro activity.


Asunto(s)
Nucleótidos , Transferasas , Humanos , Nucleótidos/metabolismo , Transferasas/metabolismo , Proteínas Bacterianas/química , Adenosina Monofosfato/metabolismo , Procesamiento Proteico-Postraduccional
19.
J Proteome Res ; 23(1): 117-129, 2024 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-38015820

RESUMEN

The foundation for integrating mass spectrometry (MS)-based proteomics into systems medicine is the development of standardized start-to-finish and fit-for-purpose workflows for clinical specimens. An essential step in this pursuit is to highlight the common ground in a diverse landscape of different sample preparation techniques and liquid chromatography-mass spectrometry (LC-MS) setups. With the aim to benchmark and improve the current best practices among the proteomics MS laboratories of the CLINSPECT-M consortium, we performed two consecutive round-robin studies with full freedom to operate in terms of sample preparation and MS measurements. The six study partners were provided with two clinically relevant sample matrices: plasma and cerebrospinal fluid (CSF). In the first round, each laboratory applied their current best practice protocol for the respective matrix. Based on the achieved results and following a transparent exchange of all lab-specific protocols within the consortium, each laboratory could advance their methods before measuring the same samples in the second acquisition round. Both time points are compared with respect to identifications (IDs), data completeness, and precision, as well as reproducibility. As a result, the individual performances of participating study centers were improved in the second measurement, emphasizing the effect and importance of the expert-driven exchange of best practices for direct practical improvements.


Asunto(s)
Plasma , Espectrometría de Masas en Tándem , Espectrometría de Masas en Tándem/métodos , Cromatografía Liquida/métodos , Flujo de Trabajo , Reproducibilidad de los Resultados , Plasma/química
20.
Stroke ; 55(2): 494-505, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38099439

RESUMEN

Intracerebral hemorrhage is the most serious type of stroke, leading to high rates of severe disability and mortality. Hematoma expansion is an independent predictor of poor functional outcome and is a compelling target for intervention. For decades, randomized trials aimed at decreasing hematoma expansion through single interventions have failed to meet their primary outcomes of statistically significant improvement in neurological outcomes. A wide range of evidence suggests that ultra-early bundled care, with multiple simultaneous interventions in the acute phase, offers the best hope of limiting hematoma expansion and improving functional recovery. Patients with intracerebral hemorrhage who fail to receive early aggressive care have worse outcomes, suggesting that an important treatment opportunity exists. This consensus statement puts forth a call to action to establish a protocol for Code ICH, similar to current strategies used for the management of acute ischemic stroke, through which early intervention, bundled care, and time-based metrics have substantially improved neurological outcomes. Based on current evidence, we advocate for the widespread adoption of an early bundle of care for patients with intracerebral hemorrhage focused on time-based metrics for blood pressure control and emergency reversal of anticoagulation, with the goal of optimizing the benefit of these already widely used interventions. We hope Code ICH will endure as a structural platform for continued innovation, standardization of best practices, and ongoing quality improvement for years to come.


Asunto(s)
Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Accidente Cerebrovascular/terapia , Hemorragia Cerebral , Presión Sanguínea/fisiología , Hematoma
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