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1.
Cell ; 185(5): 860-871.e13, 2022 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-35120603

RESUMEN

The SARS-CoV-2 Omicron variant with increased fitness is spreading rapidly worldwide. Analysis of cryo-EM structures of the spike (S) from Omicron reveals amino acid substitutions forging interactions that stably maintain an active conformation for receptor recognition. The relatively more compact domain organization confers improved stability and enhances attachment but compromises the efficiency of the viral fusion step. Alterations in local conformation, charge, and hydrophobic microenvironments underpin the modulation of the epitopes such that they are not recognized by most NTD- and RBD-antibodies, facilitating viral immune escape. Structure of the Omicron S bound with human ACE2, together with the analysis of sequence conservation in ACE2 binding region of 25 sarbecovirus members, as well as heatmaps of the immunogenic sites and their corresponding mutational frequencies, sheds light on conserved and structurally restrained regions that can be used for the development of broad-spectrum vaccines and therapeutics.


Asunto(s)
Evasión Inmune/fisiología , SARS-CoV-2/fisiología , Glicoproteína de la Espiga del Coronavirus/química , Enzima Convertidora de Angiotensina 2/química , Enzima Convertidora de Angiotensina 2/metabolismo , Anticuerpos Antivirales/inmunología , Sitios de Unión , COVID-19/inmunología , COVID-19/patología , COVID-19/virología , Microscopía por Crioelectrón , Humanos , Mutagénesis Sitio-Dirigida , Pruebas de Neutralización , Unión Proteica , Dominios Proteicos/inmunología , Estructura Cuaternaria de Proteína , SARS-CoV-2/aislamiento & purificación , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/metabolismo , Resonancia por Plasmón de Superficie , Acoplamiento Viral
2.
Cell ; 184(2): 370-383.e13, 2021 01 21.
Artículo en Inglés | MEDLINE | ID: mdl-33333023

RESUMEN

Proton-coupled monocarboxylate transporters MCT1-4 catalyze the transmembrane movement of metabolically essential monocarboxylates and have been targeted for cancer treatment because of their enhanced expression in various tumors. Here, we report five cryo-EM structures, at resolutions of 3.0-3.3 Å, of human MCT1 bound to lactate or inhibitors in the presence of Basigin-2, a single transmembrane segment (TM)-containing chaperon. MCT1 exhibits similar outward-open conformations when complexed with lactate or the inhibitors BAY-8002 and AZD3965. In the presence of the inhibitor 7ACC2 or with the neutralization of the proton-coupling residue Asp309 by Asn, similar inward-open structures were captured. Complemented by structural-guided biochemical analyses, our studies reveal the substrate binding and transport mechanism of MCTs, elucidate the mode of action of three anti-cancer drug candidates, and identify the determinants for subtype-specific sensitivities to AZD3965 by MCT1 and MCT4. These findings lay out an important framework for structure-guided drug discovery targeting MCTs.


Asunto(s)
Antineoplásicos/farmacología , Transportadores de Ácidos Monocarboxílicos/antagonistas & inhibidores , Transportadores de Ácidos Monocarboxílicos/química , Simportadores/antagonistas & inhibidores , Simportadores/química , Secuencia de Aminoácidos , Animales , Basigina/química , Sitios de Unión , Microscopía por Crioelectrón , Humanos , Ligandos , Modelos Moleculares , Transportadores de Ácidos Monocarboxílicos/ultraestructura , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Protones , Pirimidinonas/química , Pirimidinonas/farmacología , Ratas , Homología Estructural de Proteína , Especificidad por Sustrato , Simportadores/ultraestructura , Tiofenos/química , Tiofenos/farmacología
3.
Cell ; 183(1): 258-268.e12, 2020 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-32860739

RESUMEN

Plasmodium species, the causative agent of malaria, rely on glucose for energy supply during blood stage. Inhibition of glucose uptake thus represents a potential strategy for the development of antimalarial drugs. Here, we present the crystal structures of PfHT1, the sole hexose transporter in the genome of Plasmodium species, at resolutions of 2.6 Å in complex with D-glucose and 3.7 Å with a moderately selective inhibitor, C3361. Although both structures exhibit occluded conformations, binding of C3361 induces marked rearrangements that result in an additional pocket. This inhibitor-binding-induced pocket presents an opportunity for the rational design of PfHT1-specific inhibitors. Among our designed C3361 derivatives, several exhibited improved inhibition of PfHT1 and cellular potency against P. falciparum, with excellent selectivity to human GLUT1. These findings serve as a proof of concept for the development of the next-generation antimalarial chemotherapeutics by simultaneously targeting the orthosteric and allosteric sites of PfHT1.


Asunto(s)
Proteínas de Transporte de Monosacáridos/ultraestructura , Plasmodium falciparum/metabolismo , Plasmodium falciparum/ultraestructura , Proteínas Protozoarias/ultraestructura , Secuencia de Aminoácidos , Animales , Antimaláricos , Transporte Biológico , Glucosa/metabolismo , Humanos , Malaria , Malaria Falciparum/parasitología , Proteínas de Transporte de Monosacáridos/química , Proteínas de Transporte de Monosacáridos/metabolismo , Parásitos , Plasmodium falciparum/genética , Proteínas Protozoarias/química , Proteínas Protozoarias/metabolismo , Azúcares/metabolismo
4.
Nat Immunol ; 22(9): 1127-1139, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34413521

RESUMEN

Follicular helper T (TFH) cells are a specialized subset of CD4+ T cells that essentially support germinal center responses where high-affinity and long-lived humoral immunity is generated. The regulation of TFH cell survival remains unclear. Here we report that TFH cells show intensified lipid peroxidation and altered mitochondrial morphology, resembling the features of ferroptosis, a form of programmed cell death that is driven by iron-dependent accumulation of lipid peroxidation. Glutathione peroxidase 4 (GPX4) is the major lipid peroxidation scavenger and is necessary for TFH cell survival. The deletion of GPX4 in T cells selectively abrogated TFH cells and germinal center responses in immunized mice. Selenium supplementation enhanced GPX4 expression in T cells, increased TFH cell numbers and promoted antibody responses in immunized mice and young adults after influenza vaccination. Our findings reveal the central role of the selenium-GPX4-ferroptosis axis in regulating TFH homeostasis, which can be targeted to enhance TFH cell function in infection and following vaccination.


Asunto(s)
Ferroptosis/fisiología , Fosfolípido Hidroperóxido Glutatión Peroxidasa/metabolismo , Selenio/farmacología , Células T Auxiliares Foliculares/fisiología , Adolescente , Adulto , Animales , Supervivencia Celular/inmunología , Niño , Femenino , Centro Germinal/citología , Centro Germinal/inmunología , Homeostasis/efectos de los fármacos , Homeostasis/genética , Humanos , Inmunidad Humoral/inmunología , Vacunas contra la Influenza/inmunología , Peroxidación de Lípido/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mitocondrias/fisiología , Ovalbúmina , Células T Auxiliares Foliculares/inmunología , Vacunación , Adulto Joven
5.
Cell ; 171(4): 918-933.e20, 2017 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-29033132

RESUMEN

Posttranslational modification with ubiquitin chains controls cell fate in all eukaryotes. Depending on the connectivity between subunits, different ubiquitin chain types trigger distinct outputs, as seen with K48- and K63-linked conjugates that drive protein degradation or complex assembly, respectively. Recent biochemical analyses also suggested roles for mixed or branched ubiquitin chains, yet without a method to monitor endogenous conjugates, the physiological significance of heterotypic polymers remained poorly understood. Here, we engineered a bispecific antibody to detect K11/K48-linked chains and identified mitotic regulators, misfolded nascent polypeptides, and pathological Huntingtin variants as their endogenous substrates. We show that K11/K48-linked chains are synthesized and processed by essential ubiquitin ligases and effectors that are mutated across neurodegenerative diseases; accordingly, these conjugates promote rapid proteasomal clearance of aggregation-prone proteins. By revealing key roles of K11/K48-linked chains in cell-cycle and quality control, we establish heterotypic ubiquitin conjugates as important carriers of biological information.


Asunto(s)
Anticuerpos Biespecíficos/análisis , Transducción de Señal , Ubiquitina/metabolismo , Ciclosoma-Complejo Promotor de la Anafase/metabolismo , Ciclo Celular , Humanos , Mitosis , Biosíntesis de Proteínas , Ubiquitinación
6.
Mol Cell ; 84(10): 1995-2005.e7, 2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38614096

RESUMEN

Cytokines regulate immune responses by binding to cell surface receptors, including the common subunit beta (ßc), which mediates signaling for GM-CSF, IL-3, and IL-5. Despite known roles in inflammation, the structural basis of IL-5 receptor activation remains unclear. We present the cryo-EM structure of the human IL-5 ternary receptor complex, revealing architectural principles for IL-5, GM-CSF, and IL-3. In mammalian cell culture, single-molecule imaging confirms hexameric IL-5 complex formation on cell surfaces. Engineered chimeric receptors show that IL-5 signaling, as well as IL-3 and GM-CSF, can occur through receptor heterodimerization, obviating the need for higher-order assemblies of ßc dimers. These findings provide insights into IL-5 and ßc receptor family signaling mechanisms, aiding in the development of therapies for diseases involving deranged ßc signaling.


Asunto(s)
Microscopía por Crioelectrón , Factor Estimulante de Colonias de Granulocitos y Macrófagos , Interleucina-3 , Multimerización de Proteína , Transducción de Señal , Humanos , Factor Estimulante de Colonias de Granulocitos y Macrófagos/metabolismo , Factor Estimulante de Colonias de Granulocitos y Macrófagos/química , Factor Estimulante de Colonias de Granulocitos y Macrófagos/genética , Interleucina-3/metabolismo , Interleucina-3/química , Interleucina-3/genética , Células HEK293 , Unión Proteica , Modelos Moleculares , Interleucina-5/metabolismo , Subunidad beta Común de los Receptores de Citocinas/metabolismo , Subunidad beta Común de los Receptores de Citocinas/genética , Subunidad beta Común de los Receptores de Citocinas/química , Imagen Individual de Molécula , Relación Estructura-Actividad , Sitios de Unión , Receptores de Interleucina-5/metabolismo , Receptores de Interleucina-5/genética , Receptores de Interleucina-5/química
7.
Nature ; 623(7987): 580-587, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37938769

RESUMEN

Microsatellite repeat expansions within genes contribute to a number of neurological diseases1,2. The accumulation of toxic proteins and RNA molecules with repetitive sequences, and/or sequestration of RNA-binding proteins by RNA molecules containing expanded repeats are thought to be important contributors to disease aetiology3-9. Here we reveal that the adenosine in CAG repeat RNA can be methylated to N1-methyladenosine (m1A) by TRMT61A, and that m1A can be demethylated by ALKBH3. We also observed that the m1A/adenosine ratio in CAG repeat RNA increases with repeat length, which is attributed to diminished expression of ALKBH3 elicited by the repeat RNA. Additionally, TDP-43 binds directly and strongly with m1A in RNA, which stimulates the cytoplasmic mis-localization and formation of gel-like aggregates of TDP-43, resembling the observations made for the protein in neurological diseases. Moreover, m1A in CAG repeat RNA contributes to CAG repeat expansion-induced neurodegeneration in Caenorhabditis elegans and Drosophila. In sum, our study offers a new paradigm of the mechanism through which nucleotide repeat expansion contributes to neurological diseases and reveals a novel pathological function of m1A in RNA. These findings may provide an important mechanistic basis for therapeutic intervention in neurodegenerative diseases emanating from CAG repeat expansion.


Asunto(s)
Adenosina , Caenorhabditis elegans , Proteínas de Unión al ADN , Drosophila melanogaster , Enfermedades Neurodegenerativas , ARN , Expansión de Repetición de Trinucleótido , Animales , Humanos , Adenosina/análogos & derivados , Adenosina/metabolismo , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Unión al ADN/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Enfermedades Neurodegenerativas/genética , Enfermedades Neurodegenerativas/metabolismo , Enfermedades Neurodegenerativas/patología , ARN/química , ARN/genética , ARN/metabolismo , Expansión de Repetición de Trinucleótido/genética , Citoplasma/metabolismo , Modelos Animales de Enfermedad
9.
Nature ; 603(7903): 919-925, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35090164

RESUMEN

Omicron (B.1.1.529), the most heavily mutated SARS-CoV-2 variant so far, is highly resistant to neutralizing antibodies, raising concerns about the effectiveness of antibody therapies and vaccines1,2. Here we examined whether sera from individuals who received two or three doses of inactivated SARS-CoV-2 vaccine could neutralize authentic Omicron. The seroconversion rates of neutralizing antibodies were 3.3% (2 out of 60) and 95% (57 out of 60) for individuals who had received 2 and 3 doses of vaccine, respectively. For recipients of three vaccine doses, the geometric mean neutralization antibody titre for Omicron was 16.5-fold lower than for the ancestral virus (254). We isolated 323 human monoclonal antibodies derived from memory B cells in triple vaccinees, half of which recognized the receptor-binding domain, and showed that a subset (24 out of 163) potently neutralized all SARS-CoV-2 variants of concern, including Omicron. Therapeutic treatments with representative broadly neutralizing monoclonal antibodies were highly protective against infection of mice with SARS-CoV-2 Beta (B.1.351) and Omicron. Atomic structures of the Omicron spike protein in complex with three classes of antibodies that were active against all five variants of concern defined the binding and neutralizing determinants and revealed a key antibody escape site, G446S, that confers greater resistance to a class of antibodies that bind on the right shoulder of the receptor-binding domain by altering local conformation at the binding interface. Our results rationalize the use of three-dose immunization regimens and suggest that the fundamental epitopes revealed by these broadly ultrapotent antibodies are rational targets for a universal sarbecovirus vaccine.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Células B de Memoria , SARS-CoV-2 , Animales , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/aislamiento & purificación , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/aislamiento & purificación , Anticuerpos Neutralizantes/uso terapéutico , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/aislamiento & purificación , Anticuerpos Antivirales/uso terapéutico , COVID-19/inmunología , COVID-19/prevención & control , COVID-19/virología , Vacunas contra la COVID-19/administración & dosificación , Vacunas contra la COVID-19/inmunología , Modelos Animales de Enfermedad , Humanos , Células B de Memoria/inmunología , Ratones , Pruebas de Neutralización , SARS-CoV-2/clasificación , SARS-CoV-2/genética , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología
10.
Nature ; 592(7853): 296-301, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33731931

RESUMEN

Clonal haematopoiesis, which is highly prevalent in older individuals, arises from somatic mutations that endow a proliferative advantage to haematopoietic cells. Clonal haematopoiesis increases the risk of myocardial infarction and stroke independently of traditional risk factors1. Among the common genetic variants that give rise to clonal haematopoiesis, the JAK2V617F (JAK2VF) mutation, which increases JAK-STAT signalling, occurs at a younger age and imparts the strongest risk of premature coronary heart disease1,2. Here we show increased proliferation of macrophages and prominent formation of necrotic cores in atherosclerotic lesions in mice that express Jak2VF selectively in macrophages, and in chimeric mice that model clonal haematopoiesis. Deletion of the essential inflammasome components caspase 1 and 11, or of the pyroptosis executioner gasdermin D, reversed these adverse changes. Jak2VF lesions showed increased expression of AIM2, oxidative DNA damage and DNA replication stress, and Aim2 deficiency reduced atherosclerosis. Single-cell RNA sequencing analysis of Jak2VF lesions revealed a landscape that was enriched for inflammatory myeloid cells, which were suppressed by deletion of Gsdmd. Inhibition of the inflammasome product interleukin-1ß reduced macrophage proliferation and necrotic formation while increasing the thickness of fibrous caps, indicating that it stabilized plaques. Our findings suggest that increased proliferation and glycolytic metabolism in Jak2VF macrophages lead to DNA replication stress and activation of the AIM2 inflammasome, thereby aggravating atherosclerosis. Precise application of therapies that target interleukin-1ß or specific inflammasomes according to clonal haematopoiesis status could substantially reduce cardiovascular risk.


Asunto(s)
Aterosclerosis/patología , Hematopoyesis Clonal , Proteínas de Unión al ADN/metabolismo , Inflamasomas/metabolismo , Animales , Anticuerpos/inmunología , Anticuerpos/uso terapéutico , Aterosclerosis/tratamiento farmacológico , Aterosclerosis/inmunología , Médula Ósea/metabolismo , Caspasa 1/metabolismo , Caspasas Iniciadoras/metabolismo , Modelos Animales de Enfermedad , Femenino , Humanos , Inflamación/metabolismo , Inflamación/patología , Proteína Antagonista del Receptor de Interleucina 1/farmacología , Proteína Antagonista del Receptor de Interleucina 1/uso terapéutico , Interleucina-1beta/inmunología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Janus Quinasa 2/genética , Janus Quinasa 2/metabolismo , Macrófagos/patología , Ratones , Ratones Endogámicos C57BL , Proteínas de Unión a Fosfato/metabolismo , Piroptosis , RNA-Seq , Análisis de la Célula Individual
11.
Proc Natl Acad Sci U S A ; 121(19): e2403031121, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38687785

RESUMEN

The loading of processed peptides on to major histocompatibility complex II (MHC-II) molecules for recognition by T cells is vital to cell-mediated adaptive immunity. As part of this process, MHC-II associates with the invariant chain (Ii) during biosynthesis in the endoplasmic reticulum to prevent premature peptide loading and to serve as a scaffold for subsequent proteolytic processing into MHC-II-CLIP. Cryo-electron microscopy structures of full-length Human Leukocyte Antigen-DR (HLA-DR) and HLA-DQ complexes associated with Ii, resolved at 3.0 to 3.1 Å, elucidate the trimeric assembly of the HLA/Ii complex and define atomic-level interactions between HLA, Ii transmembrane domains, loop domains, and class II-associated invariant chain peptides (CLIP). Together with previous structures of MHC-II peptide loading intermediates DO and DM, our findings complete the structural path governing class II antigen presentation.


Asunto(s)
Antígenos de Diferenciación de Linfocitos B , Microscopía por Crioelectrón , Antígenos de Histocompatibilidad Clase II , Humanos , Antígenos de Diferenciación de Linfocitos B/metabolismo , Antígenos de Diferenciación de Linfocitos B/química , Antígenos de Histocompatibilidad Clase II/química , Antígenos de Histocompatibilidad Clase II/metabolismo , Antígenos de Histocompatibilidad Clase II/inmunología , Antígenos HLA-DR/química , Antígenos HLA-DR/metabolismo , Antígenos HLA-DR/inmunología , Presentación de Antígeno , Antígenos HLA-DQ/química , Antígenos HLA-DQ/metabolismo , Antígenos HLA-DQ/inmunología , Modelos Moleculares , Retículo Endoplásmico/metabolismo , Conformación Proteica , Unión Proteica
12.
Proc Natl Acad Sci U S A ; 121(5): e2309981121, 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38252819

RESUMEN

Direct use of metals as battery anodes could significantly boost the energy density, but suffers from limited cycling. To make the batteries more sustainable, one strategy is mitigating the propensity for metals to form random morphology during plating through orientation regulation, e.g., hexagonal Zn platelets locked horizontally by epitaxial electrodeposition or vertically aligned through Zn/electrolyte interface modulation. Current strategies center around obtaining (002) faceted deposition due to its minimum surface energy. Here, benefiting from the capability of preparing a library of faceted monocrystalline Zn anodes and controlling the orientation of Zn platelet deposits, we challenge this conventional belief. We show that while monocrystalline (002) faceted Zn electrode with horizontal epitaxy indeed promises the highest critical current density, the (100) faceted electrode with vertically aligned deposits is the most important one in suppressing Zn metal corrosion and promising the best reversibility. Such uniqueness results from the lowest electrochemical surface area of (100) faceted electrode, which intrinsically builds upon the surface atom diffusion barrier and the orientation of the pallets. These new findings based on monocrystalline anodes advance the fundamental understanding of electrodeposition process for sustainable metal batteries and provide a paradigm to explore the processing-structure-property relationships of metal electrodes.

13.
Proc Natl Acad Sci U S A ; 121(13): e2313652121, 2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38498709

RESUMEN

Huntington's disease (HD) is an inherited neurodegenerative disorder caused by an expanded CAG repeat in the huntingtin (HTT) gene. The repeat-expanded HTT encodes a mutated HTT (mHTT), which is known to induce DNA double-strand breaks (DSBs), activation of the cGAS-STING pathway, and apoptosis in HD. However, the mechanism by which mHTT triggers these events is unknown. Here, we show that HTT interacts with both exonuclease 1 (Exo1) and MutLα (MLH1-PMS2), a negative regulator of Exo1. While the HTT-Exo1 interaction suppresses the Exo1-catalyzed DNA end resection during DSB repair, the HTT-MutLα interaction functions to stabilize MLH1. However, mHTT displays a significantly reduced interaction with Exo1 or MutLα, thereby losing the ability to regulate Exo1. Thus, cells expressing mHTT exhibit rapid MLH1 degradation and hyperactive DNA excision, which causes severe DNA damage and cytosolic DNA accumulation. This activates the cGAS-STING pathway to mediate apoptosis. Therefore, we have identified unique functions for both HTT and mHTT in modulating DNA repair and the cGAS-STING pathway-mediated apoptosis by interacting with MLH1. Our work elucidates the mechanism by which mHTT causes HD.


Asunto(s)
Enfermedad de Huntington , Humanos , Proteína Huntingtina/genética , Proteína Huntingtina/metabolismo , Proteínas Mutantes/genética , Enfermedad de Huntington/genética , Enfermedad de Huntington/metabolismo , Nucleotidiltransferasas/genética , ADN , Apoptosis/genética , Homólogo 1 de la Proteína MutL/genética
14.
Proc Natl Acad Sci U S A ; 121(1): e2312306120, 2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38147546

RESUMEN

The neuron-to-neuron propagation of misfolded α-synuclein (αSyn) aggregates is thought to be key to the pathogenesis of synucleinopathies. Recent studies have shown that extracellular αSyn aggregates taken up by the endosomal-lysosomal system can rupture the lysosomal vesicular membrane; however, it remains unclear whether lysosomal rupture leads to the transmission of αSyn aggregation. Here, we applied cell-based αSyn propagation models to show that ruptured lysosomes are the pathway through which exogenous αSyn aggregates transmit aggregation, and furthermore, this process was prevented by lysophagy, i.e., selective autophagy of damaged lysosomes. αSyn aggregates accumulated predominantly in lysosomes, causing their rupture, and seeded the aggregation of endogenous αSyn, initially around damaged lysosomes. Exogenous αSyn aggregates induced the accumulation of LC3 on lysosomes. This LC3 accumulation was not observed in cells in which a key regulator of autophagy, RB1CC1/FIP200, was knocked out and was confirmed as lysophagy by transmission electron microscopy. Importantly, RB1CC1/FIP200-deficient cells treated with αSyn aggregates had increased numbers of ruptured lysosomes and enhanced propagation of αSyn aggregation. Furthermore, various types of lysosomal damage induced using lysosomotropic reagents, depletion of lysosomal enzymes, or more toxic species of αSyn fibrils also exacerbated the propagation of αSyn aggregation, and impaired lysophagy and lysosomal membrane damage synergistically enhanced propagation. These results indicate that lysophagy prevents exogenous αSyn aggregates from escaping the endosomal-lysosomal system and transmitting aggregation to endogenous cytosolic αSyn via ruptured lysosomal vesicles. Our findings suggest that the progression and severity of synucleinopathies are associated with damage to lysosomal membranes and impaired lysophagy.


Asunto(s)
Enfermedad de Parkinson , Sinucleinopatías , Humanos , alfa-Sinucleína/metabolismo , Macroautofagia , Sinucleinopatías/metabolismo , Enfermedad de Parkinson/metabolismo , Lisosomas/metabolismo
15.
Proc Natl Acad Sci U S A ; 121(23): e2318843121, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38805277

RESUMEN

The development and performance of two mass spectrometry (MS) workflows for the intraoperative diagnosis of isocitrate dehydrogenase (IDH) mutations in glioma is implemented by independent teams at Mayo Clinic, Jacksonville, and Huashan Hospital, Shanghai. The infiltrative nature of gliomas makes rapid diagnosis necessary to guide the extent of surgical resection of central nervous system (CNS) tumors. The combination of tissue biopsy and MS analysis used here satisfies this requirement. The key feature of both described methods is the use of tandem MS to measure the oncometabolite 2-hydroxyglutarate (2HG) relative to endogenous glutamate (Glu) to characterize the presence of mutant tumor. The experiments i) provide IDH mutation status for individual patients and ii) demonstrate a strong correlation of 2HG signals with tumor infiltration. The measured ratio of 2HG to Glu correlates with IDH-mutant (IDH-mut) glioma (P < 0.0001) in the tumor core data of both teams. Despite using different ionization methods and different mass spectrometers, comparable performance in determining IDH mutations from core tumor biopsies was achieved with sensitivities, specificities, and accuracies all at 100%. None of the 31 patients at Mayo Clinic or the 74 patients at Huashan Hospital were misclassified when analyzing tumor core biopsies. Robustness of the methodology was evaluated by postoperative re-examination of samples. Both teams noted the presence of high concentrations of 2HG at surgical margins, supporting future use of intraoperative MS to monitor for clean surgical margins. The power of MS diagnostics is shown in resolving contradictory clinical features, e.g., in distinguishing gliosis from IDH-mut glioma.


Asunto(s)
Neoplasias Encefálicas , Glioma , Isocitrato Deshidrogenasa , Mutación , Glioma/genética , Glioma/cirugía , Glioma/patología , Isocitrato Deshidrogenasa/genética , Humanos , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/cirugía , Neoplasias Encefálicas/patología , Espectrometría de Masas en Tándem/métodos , Glutaratos/metabolismo , Espectrometría de Masas/métodos , Ácido Glutámico/metabolismo , Ácido Glutámico/genética
16.
Pharmacol Rev ; 2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38914468

RESUMEN

Voltage-gated sodium (NaV) channels are intimately involved in the generation and transmission of action potentials, and dysfunction of these channels may contribute to nervous system diseases such as epilepsy, neuropathic pain, psychosis, autism and cardiac arrhythmia. Many venom peptides selectively act on NaV channels. These include conotoxins, which are neurotoxins secreted by cone snails for prey capture or self-defense, but which are also valuable pharmacological tools for the identification and/or treatment of human diseases. Typically, conotoxins contain two or three disulfide bonds and these internal cross-braces contribute to conotoxins having compact, well-defined structures and high stability. Of the conotoxins containing three disulfide bonds some selectively target mammalian NaV channels and can block, stimulate, or modulate these channels. Such conotoxins have great potential to serve as pharmacological tools for studying the functions and characteristics of NaV channels or as drug leads for neurological diseases related to NaV channels. Accordingly, discovering or designing conotoxins targeting NaV channels with high potency and selectivity is important. The amino acid sequences, disulfide bond connectivity, and three-dimensional structures are key factors that affect the biological activity of conotoxins, and targeted synthetic modifications of conotoxins can greatly improve their activity and selectivity. This review examines NaV channel-targeted conotoxins, focusing on their structures, activities and designed modifications, with a view towards expanding their applications. Significance Statement NaV channels are crucial in various neurological diseases. Some conotoxins selectively target NaV channels, causing either blockade or activation, thus enabling their use as pharmacological tools for studying the channels' characteristics and functions. Conotoxins also have promising potential to be developed as drug leads. The disulfide bonds in these peptides are important for stabilizing their structures, thus leading to enhanced specificity and potency. Together, conotoxins targeting NaV channels have both immediate research value and promising future application prospects.

17.
Hum Mol Genet ; 33(4): 333-341, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-37903058

RESUMEN

Transcriptome-wide association studies (TWAS) have identified many putative susceptibility genes for colorectal cancer (CRC) risk. However, susceptibility miRNAs, critical dysregulators of gene expression, remain unexplored. We genotyped DNA samples from 313 CRC East Asian patients and performed small RNA sequencing in their normal colon tissues distant from tumors to build genetic models for predicting miRNA expression. We applied these models and data from genome-wide association studies (GWAS) including 23 942 cases and 217 267 controls of East Asian ancestry to investigate associations of predicted miRNA expression with CRC risk. Perturbation experiments separately by promoting and inhibiting miRNAs expressions and further in vitro assays in both SW480 and HCT116 cells were conducted. At a Bonferroni-corrected threshold of P < 4.5 × 10-4, we identified two putative susceptibility miRNAs, miR-1307-5p and miR-192-3p, located in regions more than 500 kb away from any GWAS-identified risk variants in CRC. We observed that a high predicted expression of miR-1307-5p was associated with increased CRC risk, while a low predicted expression of miR-192-3p was associated with increased CRC risk. Our experimental results further provide strong evidence of their susceptible roles by showing that miR-1307-5p and miR-192-3p play a regulatory role, respectively, in promoting and inhibiting CRC cell proliferation, migration, and invasion, which was consistently observed in both SW480 and HCT116 cells. Our study provides additional insights into the biological mechanisms underlying CRC development.


Asunto(s)
Neoplasias Colorrectales , MicroARNs , Humanos , MicroARNs/genética , MicroARNs/metabolismo , Transcriptoma/genética , Estudio de Asociación del Genoma Completo , Neoplasias Colorrectales/metabolismo , Células HCT116 , Regulación Neoplásica de la Expresión Génica/genética , Proliferación Celular/genética
18.
Blood ; 143(15): 1539-1550, 2024 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-38142422

RESUMEN

ABSTRACT: JAK2 V617F (JAK2VF) clonal hematopoiesis (CH) has been associated with atherothrombotic cardiovascular disease (CVD). We assessed the impact of Jak2VF CH on arterial thrombosis and explored the underlying mechanisms. A meta-analysis of 3 large cohort studies confirmed the association of JAK2VF with CVD and with platelet counts and adjusted mean platelet volume (MPV). In mice, 20% or 1.5% Jak2VF CH accelerated arterial thrombosis and increased platelet activation. Megakaryocytes in Jak2VF CH showed elevated proplatelet formation and release, increasing prothrombogenic reticulated platelet counts. Gp1ba-Cre-mediated expression of Jak2VF in platelets (VFGp1ba) increased platelet counts to a similar level as in 20% Jak2VF CH mice while having no effect on leukocyte counts. Like Jak2VF CH mice, VFGp1ba mice showed enhanced platelet activation and accelerated arterial thrombosis. In Jak2VF CH, both Jak2VF and wild-type (WT) platelets showed increased activation, suggesting cross talk between mutant and WT platelets. Jak2VF platelets showed twofold to threefold upregulation of COX-1 and COX-2, particularly in young platelets, with elevated cPLA2 activation and thromboxane A2 production. Compared with controls, conditioned media from activated Jak2VF platelets induced greater activation of WT platelets that was reversed by a thromboxane receptor antagonist. Low-dose aspirin ameliorated carotid artery thrombosis in VFGp1ba and Jak2VF CH mice but not in WT control mice. This study shows accelerated arterial thrombosis and platelet activation in Jak2VF CH with a major role of increased reticulated Jak2VF platelets, which mediate thromboxane cross talk with WT platelets and suggests a potential beneficial effect of aspirin in JAK2VF CH.


Asunto(s)
Hematopoyesis Clonal , Trombosis , Animales , Humanos , Ratones , Aspirina/farmacología , Aspirina/uso terapéutico , Plaquetas/metabolismo , Ratones Noqueados , Activación Plaquetaria , Trombosis/genética , Trombosis/metabolismo
19.
Plant Cell ; 36(1): 112-135, 2023 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-37770034

RESUMEN

Reactive oxygen species (ROS) play an essential role in plant growth and responses to environmental stresses. Plant cells sense and transduce ROS signaling directly via hydrogen peroxide (H2O2)-mediated posttranslational modifications (PTMs) on protein cysteine residues. Here, we show that the H2O2-mediated cysteine oxidation of NAC WITH TRANS-MEMBRANE MOTIF1-LIKE 1 (GmNTL1) in soybean (Glycine max) during salt stress promotes its release from the endoplasmic reticulum (ER) membrane and translocation to the nucleus. We further show that an oxidative posttranslational modification on GmNTL1 residue Cys-247 steers downstream amplification of ROS production by binding to and activating the promoters of RESPIRATORY BURST OXIDASE HOMOLOG B (GmRbohB) genes, thereby creating a feed-forward loop to fine-tune GmNTL1 activity. In addition, oxidation of GmNTL1 Cys-247 directly promotes the expression of CATION H+ EXCHANGER 1 (GmCHX1)/SALT TOLERANCE-ASSOCIATED GENE ON CHROMOSOME 3 (GmSALT3) and Na+/H+ Antiporter 1 (GmNHX1). Accordingly, transgenic overexpression of GmNTL1 in soybean increases the H2O2 levels and K+/Na+ ratio in the cell, promotes salt tolerance, and increases yield under salt stress, while an RNA interference-mediated knockdown of GmNTL1 elicits the opposite effects. Our results reveal that the salt-induced oxidation of GmNTL1 promotes its relocation and transcriptional activity through an H2O2-mediated posttranslational modification on cysteine that improves resilience of soybean against salt stress.


Asunto(s)
Glycine max , Tolerancia a la Sal , Glycine max/genética , Tolerancia a la Sal/genética , Peróxido de Hidrógeno/metabolismo , Factores de Transcripción/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Cisteína/metabolismo , Estrés Fisiológico/genética , Plantas Modificadas Genéticamente/metabolismo , Regulación de la Expresión Génica de las Plantas
20.
J Immunol ; 212(1): 130-142, 2024 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-37975680

RESUMEN

Pigs are the most suitable model to study various therapeutic strategies and drugs for human beings, although knowledge about cell type-specific transcriptomes and heterogeneity is poorly available. Through single-cell RNA sequencing and flow cytometry analysis of the types in the jejunum of pigs, we found that innate lymphoid cells (ILCs) existed in the lamina propria lymphocytes (LPLs) of the jejunum. Then, through flow sorting of live/dead-lineage (Lin)-CD45+ cells and single-cell RNA sequencing, we found that ILCs in the porcine jejunum were mainly ILC3s, with a small number of NK cells, ILC1s, and ILC2s. ILCs coexpressed IL-7Rα, ID2, and other genes and differentially expressed RORC, GATA3, and other genes but did not express the CD3 gene. ILC3s can be divided into four subgroups, and genes such as CXCL8, CXCL2, IL-22, IL-17, and NCR2 are differentially expressed. To further detect and identify ILC3s, we verified the classification of ILCs in the porcine jejunum subgroup and the expression of related hallmark genes at the protein level by flow cytometry. For systematically characterizing ILCs in the porcine intestines, we combined our pig ILC dataset with publicly available human and mice ILC data and identified that the human and pig ILCs shared more common features than did those mouse ILCs in gene signatures and cell states. Our results showed in detail for the first time (to our knowledge) the gene expression of porcine jejunal ILCs, the subtype classification of ILCs, and the markers of various ILCs, which provide a basis for an in-depth exploration of porcine intestinal mucosal immunity.


Asunto(s)
Inmunidad Innata , Linfocitos , Humanos , Animales , Ratones , Porcinos , Yeyuno , Células Asesinas Naturales , Membrana Mucosa
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