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1.
Cell ; 187(11): 2703-2716.e23, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38657602

RESUMO

Antigen presentation defects in tumors are prevalent mechanisms of adaptive immune evasion and resistance to cancer immunotherapy, whereas how tumors evade innate immunity is less clear. Using CRISPR screens, we discovered that IGSF8 expressed on tumors suppresses NK cell function by interacting with human KIR3DL2 and mouse Klra9 receptors on NK cells. IGSF8 is normally expressed in neuronal tissues and is not required for cell survival in vitro or in vivo. It is overexpressed and associated with low antigen presentation, low immune infiltration, and worse clinical outcomes in many tumors. An antibody that blocks IGSF8-NK receptor interaction enhances NK cell killing of malignant cells in vitro and upregulates antigen presentation, NK cell-mediated cytotoxicity, and T cell signaling in vivo. In syngeneic tumor models, anti-IGSF8 alone, or in combination with anti-PD1, inhibits tumor growth. Our results indicate that IGSF8 is an innate immune checkpoint that could be exploited as a therapeutic target.


Assuntos
Imunidade Inata , Imunoterapia , Células Matadoras Naturais , Neoplasias , Animais , Feminino , Humanos , Camundongos , Apresentação de Antígeno , Linhagem Celular Tumoral , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Proteínas de Membrana/metabolismo , Camundongos Endogâmicos C57BL , Neoplasias/imunologia , Neoplasias/terapia
2.
Cell ; 176(4): 681-684, 2019 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-30735630

RESUMO

Through dissecting the link between spatial genome organization and DNA replication timing, Sima et al. (2018) discover early replicating control elements (ERCEs), a new type of cis-acting elements that regulate replication timing, transcription, and multiple layers of three-dimensional features of genome organization. The study has important implications for unraveling control elements of high-order genome structure and function.


Assuntos
Período de Replicação do DNA , Replicação do DNA , Animais , Genoma , Mamíferos
3.
Mol Cell ; 83(19): 3520-3532.e7, 2023 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-37802025

RESUMO

Cyclic GMP-AMP synthase (cGAS) binds pathogenic and other cytoplasmic double-stranded DNA (dsDNA) to catalyze the synthesis of cyclic GMP-AMP (cGAMP), which serves as the secondary messenger to activate the STING pathway and innate immune responses. Emerging evidence suggests that activation of the cGAS pathway is crucial for anti-tumor immunity; however, no effective intervention method targeting cGAS is currently available. Here we report that cGAS is palmitoylated by ZDHHC9 at cysteines 404/405, which promotes the dimerization and activation of cGAS. We further identified that lysophospholipase-like 1 (LYPLAL1) depalmitoylates cGAS to compromise its normal function. As such, inhibition of LYPLAL1 significantly enhances cGAS-mediated innate immune response, elevates PD-L1 expression, and enhances anti-tumor response to PD-1 blockade. Our results therefore reveal that targeting LYPLAL1-mediated cGAS depalmitoylation contributes to cGAS activation, providing a potential strategy to augment the efficacy of anti-tumor immunotherapy.


Assuntos
Neoplasias , Nucleotidiltransferases , Humanos , Nucleotidiltransferases/metabolismo , Imunidade Inata/genética , Neoplasias/genética , Neoplasias/terapia , Imunoterapia
4.
Mol Cell ; 83(15): 2624-2640, 2023 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-37419111

RESUMO

The four-dimensional nucleome (4DN) consortium studies the architecture of the genome and the nucleus in space and time. We summarize progress by the consortium and highlight the development of technologies for (1) mapping genome folding and identifying roles of nuclear components and bodies, proteins, and RNA, (2) characterizing nuclear organization with time or single-cell resolution, and (3) imaging of nuclear organization. With these tools, the consortium has provided over 2,000 public datasets. Integrative computational models based on these data are starting to reveal connections between genome structure and function. We then present a forward-looking perspective and outline current aims to (1) delineate dynamics of nuclear architecture at different timescales, from minutes to weeks as cells differentiate, in populations and in single cells, (2) characterize cis-determinants and trans-modulators of genome organization, (3) test functional consequences of changes in cis- and trans-regulators, and (4) develop predictive models of genome structure and function.


Assuntos
Núcleo Celular , Genoma , Genoma/genética , Núcleo Celular/genética , Núcleo Celular/metabolismo , Cromatina/metabolismo
5.
Nat Rev Genet ; 25(2): 123-141, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37673975

RESUMO

Recent progress in whole-genome mapping and imaging technologies has enabled the characterization of the spatial organization and folding of the genome in the nucleus. In parallel, advanced computational methods have been developed to leverage these mapping data to reveal multiscale three-dimensional (3D) genome features and to provide a more complete view of genome structure and its connections to genome functions such as transcription. Here, we discuss how recently developed computational tools, including machine-learning-based methods and integrative structure-modelling frameworks, have led to a systematic, multiscale delineation of the connections among different scales of 3D genome organization, genomic and epigenomic features, functional nuclear components and genome function. However, approaches that more comprehensively integrate a wide variety of genomic and imaging datasets are still needed to uncover the functional role of 3D genome structure in defining cellular phenotypes in health and disease.


Assuntos
Genoma , Genômica , Mapeamento Cromossômico , Epigenômica , Cromatina/genética
6.
Nat Immunol ; 18(10): 1128-1138, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28846085

RESUMO

The transcription factor RORγt regulates differentiation of the TH17 subset of helper T cells, thymic T cell development and lymph-node genesis. Although elimination of RORγt prevents TH17 cell-mediated experimental autoimmune encephalomyelitis (EAE), it also disrupts thymocyte development, which could lead to lethal thymic lymphoma. Here we identified a two-amino-acid substitution in RORγt (RORγtM) that 'preferentially' disrupted TH17 differentiation but not thymocyte development. Mice expressing RORγtM were resistant to EAE associated with defective TH17 differentiation but maintained normal thymocyte development and normal lymph-node genesis, except for Peyer's patches. RORγtM showed less ubiquitination at Lys69 that was selectively required for TH17 differentiation but not T cell development. This study will inform the development of treatments that selectively target TH17 cell-mediated autoimmunity but do not affect thymocyte development or induce lymphoma.


Assuntos
Substituição de Aminoácidos , Diferenciação Celular/genética , Mutação , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Células Th17/citologia , Células Th17/metabolismo , Timócitos/citologia , Timócitos/metabolismo , Animais , Biomarcadores , Diferenciação Celular/imunologia , Análise por Conglomerados , Encefalomielite Autoimune Experimental/genética , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Imunofenotipagem , Linfonodos/imunologia , Linfonodos/metabolismo , Camundongos , Camundongos Knockout , Nódulos Linfáticos Agregados/imunologia , Nódulos Linfáticos Agregados/metabolismo , Subpopulações de Linfócitos T/citologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Células Th17/imunologia , Timócitos/imunologia , Ubiquitinação
7.
Nat Methods ; 21(5): 814-822, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38589516

RESUMO

Single-cell Hi-C (scHi-C) technologies allow for probing of genome-wide cell-to-cell variability in three-dimensional (3D) genome organization from individual cells. Computational methods have been developed to reveal single-cell 3D genome features based on scHi-C, including A/B compartments, topologically associating domains and chromatin loops. However, no method exists for annotating single-cell subcompartments, which is important for understanding chromosome spatial localization in single cells. Here we present scGHOST, a single-cell subcompartment annotation method using graph embedding with constrained random walk sampling. Applications of scGHOST to scHi-C data and contact maps derived from single-cell 3D genome imaging demonstrate reliable identification of single-cell subcompartments, offering insights into cell-to-cell variability of nuclear subcompartments. Using scHi-C data from complex tissues, scGHOST identifies cell-type-specific or allele-specific subcompartments linked to gene transcription across various cell types and developmental stages, suggesting functional implications of single-cell subcompartments. scGHOST is an effective method for annotating single-cell 3D genome subcompartments in a broad range of biological contexts.


Assuntos
Análise de Célula Única , Análise de Célula Única/métodos , Animais , Humanos , Genoma , Camundongos , Cromatina/genética , Cromatina/metabolismo , Imageamento Tridimensional/métodos
8.
EMBO J ; 41(17): e109997, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35686465

RESUMO

Lysosome-mediated macroautophagy, including lipophagy, is activated under nutrient deprivation but is repressed after feeding. We show that, unexpectedly, feeding activates intestinal autophagy/lipophagy in a manner dependent on both the orphan nuclear receptor, small heterodimer partner (SHP/NR0B2), and the gut hormone, fibroblast growth factor-15/19 (FGF15/19). Furthermore, postprandial intestinal triglycerides (TGs) and apolipoprotein-B48 (ApoB48), the TG-rich chylomicron marker, were elevated in SHP-knockout and FGF15-knockout mice. Genomic analyses of the mouse intestine indicated that SHP partners with the key lysosomal activator, transcription factor-EB (TFEB) to upregulate the transcription of autophagy/lipolysis network genes after feeding. FGF19 treatment activated lipophagy, reducing TG and ApoB48 levels in HT29 intestinal cells, which was dependent on TFEB. Mechanistically, feeding-induced FGF15/19 signaling increased the nuclear localization of TFEB and SHP via PKC beta/zeta-mediated phosphorylation, leading to increased transcription of the TFEB/SHP target lipophagy genes, Ulk1 and Atgl. Collectively, these results demonstrate that paradoxically after feeding, FGF15/19-activated SHP and TFEB activate gut lipophagy, limiting postprandial TGs. As excess postprandial lipids cause dyslipidemia and obesity, the FGF15/19-SHP-TFEB axis that reduces intestinal TGs via lipophagic activation provides promising therapeutic targets for obesity-associated metabolic disease.


Assuntos
Autofagia , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Ingestão de Alimentos , Fatores de Crescimento de Fibroblastos , Trato Gastrointestinal , Receptores Citoplasmáticos e Nucleares , Animais , Apolipoproteína B-48/metabolismo , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Fatores de Crescimento de Fibroblastos/metabolismo , Trato Gastrointestinal/metabolismo , Lisossomos/metabolismo , Camundongos , Camundongos Knockout , Obesidade/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo
9.
Plant Cell ; 35(6): 2232-2250, 2023 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-36891818

RESUMO

Silicon (Si) is important for stable and high yields in rice (Oryza sativa), a typical Si hyperaccumulator. The high Si accumulation is achieved by the cooperation of 2 Si transporters, LOW SILICON 1 (OsLsi1) and OsLsi2, which are polarly localized in cells of the root exodermis and endodermis. However, the mechanism underlying their polar localization is unknown. Here, we identified amino acid residues critical for the polar localization of OsLsi1. Deletion of both N- and C-terminal regions resulted in the loss of its polar localization. Furthermore, the deletion of the C-terminus inhibited its trafficking from the endoplasmic reticulum to the plasma membrane. Detailed site-directed mutagenesis analysis showed that Ile18 at the N-terminal region and Ile285 at the C-terminal region were essential for the polar localization of OsLsi1. Moreover, a cluster of positively charged residues at the C-terminal region is also required for polar localization. Phosphorylation and Lys modifications of OsLsi1 are unlikely to be involved in its polar localization. Finally, we showed that the polar localization of OsLsi1 is required for the efficient uptake of Si. Our study not only identified critical residues required for the polar localization of OsLsi1, but also provided experimental evidence for the importance of transporter polarity for efficient nutrient uptake.


Assuntos
Oryza , Oryza/genética , Oryza/metabolismo , Silício/metabolismo , Silício/farmacologia , Isoleucina/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo
10.
Proc Natl Acad Sci U S A ; 120(13): e2217576120, 2023 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-36943878

RESUMO

Diabetes can result in impaired corneal wound healing. Mitochondrial dysfunction plays an important role in diabetic complications. However, the regulation of mitochondria function in the diabetic cornea and its impacts on wound healing remain elusive. The present study aimed to explore the molecular basis for the disturbed mitochondrial metabolism and subsequent wound healing impairment in the diabetic cornea. Seahorse analysis showed that mitochondrial oxidative phosphorylation is a major source of ATP production in human corneal epithelial cells. Live corneal biopsy punches from type 1 and type 2 diabetic mouse models showed impaired mitochondrial functions, correlating with impaired corneal wound healing, compared to nondiabetic controls. To approach the molecular basis for the impaired mitochondrial function, we found that Peroxisome Proliferator-Activated Receptor-α (PPARα) expression was downregulated in diabetic human corneas. Even without diabetes, global PPARα knockout mice and corneal epithelium-specific PPARα conditional knockout mice showed disturbed mitochondrial function and delayed wound healing in the cornea, similar to that in diabetic corneas. In contrast, fenofibrate, a PPARα agonist, ameliorated mitochondrial dysfunction and enhanced wound healing in the corneas of diabetic mice. Similarly, corneal epithelium-specific PPARα transgenic overexpression improved mitochondrial function and enhanced wound healing in the cornea. Furthermore, PPARα agonist ameliorated the mitochondrial dysfunction in primary human corneal epithelial cells exposed to diabetic stressors, which was impeded by siRNA knockdown of PPARα, suggesting a PPARα-dependent mechanism. These findings suggest that downregulation of PPARα plays an important role in the impaired mitochondrial function in the corneal epithelium and delayed corneal wound healing in diabetes.


Assuntos
Diabetes Mellitus Experimental , PPAR alfa , Camundongos , Humanos , Animais , PPAR alfa/genética , PPAR alfa/metabolismo , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Córnea/metabolismo , Cicatrização/fisiologia , Camundongos Knockout , Mitocôndrias/metabolismo
11.
Proc Natl Acad Sci U S A ; 120(51): e2311647120, 2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38085785

RESUMO

Injuries to the retinal pigment epithelium (RPE) and outer retina often result in the accumulation of retinal microglia within the subretinal space. These subretinal microglia play crucial roles in inflammation and resolution, but the mechanisms governing their functions are still largely unknown. Our previous research highlighted the protective functions of choroidal γδ T cells in response to RPE injury. In the current study, we employed single-cell RNA sequencing approach to characterize the profiles of immune cells in mouse choroid. We found that γδ T cells were the primary producer of interleukin-17 (IL-17) in the choroid. IL-17 signaled through its receptor on the RPE, subsequently triggering the production of interleukin-6. This cascade of cytokines initiated a metabolic reprogramming of subretinal microglia, enhancing their capacity for lipid metabolism. RPE-specific knockout of IL-17 receptor A led to the dysfunction of subretinal microglia and RPE pathology. Collectively, our findings suggest that responding to RPE injury, the choroidal γδ T cells can initiate a protective signaling cascade that ensures the proper functioning of subretinal microglia.


Assuntos
Degeneração Macular , Degeneração Retiniana , Animais , Camundongos , Citocinas/metabolismo , Interleucina-17/genética , Interleucina-17/metabolismo , Degeneração Macular/patologia , Retina/metabolismo , Degeneração Retiniana/metabolismo , Epitélio Pigmentado da Retina/metabolismo
12.
J Biol Chem ; 300(5): 107226, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38537697

RESUMO

Epstein-Barr virus (EBV) is a human tumor virus associated with a variety of malignancies, including nasopharyngeal carcinoma, gastric cancers, and B-cell lymphomas. N6-methyladenosine (m6A) modifications modulate a wide range of cellular processes and participate in the regulation of virus-host cell interactions. Here, we discovered that EBV infection downregulates toll-like receptor 9 (TLR9) m6A modification levels and thus inhibits TLR9 expression. TLR9 has multiple m6A modification sites. Knockdown of METTL3, an m6A "writer", decreases TLR9 protein expression by inhibiting its mRNA stability. Mechanistically, Epstein-Barr nuclear antigen 1 increases METTL3 protein degradation via K48-linked ubiquitin-proteasome pathway. Additionally, YTHDF1 was identified as an m6A "reader" of TLR9, enhancing TLR9 expression by promoting mRNA translation in an m6A -dependent manner, which suggests that EBV inhibits TLR9 translation by "hijacking" host m6A modification mechanism. Using the METTL3 inhibitor STM2457 inhibits TLR9-induced B cell proliferation and immunoglobulin secretion, and opposes TLR9-induced immune responses to assist tumor cell immune escape. In clinical lymphoma samples, the expression of METTL3, YTHDF1, and TLR9 was highly correlated with immune cells infiltration. This study reveals a novel mechanism that EBV represses the important innate immunity molecule TLR9 through modulating the host m6A modification system.


Assuntos
Adenosina , Herpesvirus Humano 4 , Metiltransferases , Proteínas de Ligação a RNA , Receptor Toll-Like 9 , Humanos , Adenosina/análogos & derivados , Adenosina/metabolismo , Linfócitos B/metabolismo , Linfócitos B/imunologia , Linfócitos B/virologia , Infecções por Vírus Epstein-Barr/imunologia , Infecções por Vírus Epstein-Barr/metabolismo , Infecções por Vírus Epstein-Barr/virologia , Infecções por Vírus Epstein-Barr/genética , Herpesvirus Humano 4/imunologia , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/metabolismo , Evasão da Resposta Imune , Metiltransferases/metabolismo , Metiltransferases/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/imunologia , Receptor Toll-Like 9/metabolismo , Receptor Toll-Like 9/genética , Linhagem Celular Tumoral
13.
Mol Biol Evol ; 41(6)2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38829799

RESUMO

Global climate change has led to shifts in the distribution ranges of many terrestrial species, promoting their migration from lower altitudes or latitudes to higher ones. Meanwhile, successful invaders have developed genetic adaptations enabling the colonization of new environments. Over the past 40 years, Rattus tanezumi (RT) has expanded into northern China (Northwest and North China) from its southern origins. We studied the cold adaptation of RT and its potential for northward expansion by comparing it with sympatric Rattus norvegicus (RN), which is well adapted to cold regions. Through population genomic analysis, we revealed that the invading RT rats have split into three distinct populations: the North, Northwest, and Tibetan populations. The first two populations exhibited high genetic diversity, while the latter population showed remarkably low genetic diversity. These rats have developed various genetic adaptations to cold, arid, hypoxic, and high-UV conditions. Cold acclimation tests revealed divergent thermoregulation between RT and RN. Specifically, RT exhibited higher brown adipose tissue activity and metabolic rates than did RN. Transcriptome analysis highlighted changes in genes regulating triglyceride catabolic processes in RT, including Apoa1 and Apoa4, which were upregulated, under selection and associated with local adaptation. In contrast, RN showed changes in carbohydrate metabolism genes. Despite the cold adaptation of RT, we observed genotypic and phenotypic constraints that may limit its ability to cope with severe low temperatures farther north. Consequently, it is less likely that RT rats will invade and overlap with RN rats in farther northern regions.


Assuntos
Aclimatação , Temperatura Baixa , Animais , Ratos , Aclimatação/genética , China , Fenótipo , Variação Genética , Adaptação Fisiológica/genética , Regulação da Temperatura Corporal/genética , Mudança Climática
14.
Plant Physiol ; 2024 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-38761402

RESUMO

Rice (Oryza sativa) as a staple food is a potential intake source of antimony (Sb), a toxic metalloid. However, how rice accumulates this element is still poorly understood. Here, we investigated tissue-specific deposition, speciation, and transport of Sb in rice. We found that Sb(III) is the preferential form of Sb uptake in rice, but most Sb accumulates in the roots, resulting in a very low root-to-shoot translocation (less than 2%). Analysis of Sb deposition with laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) showed that most Sb deposits at the root exodermis. Furthermore, we found that Sb is mainly present as Sb(III) in the root cell sap after uptake. Further characterization showed that Sb(III) uptake is mediated by Low silicon rice 1 (Lsi1), a Si permeable transporter. Lsi1 showed transport activity for Sb(III) rather than Sb(V) in yeast (Saccharomyces cerevisiae). Knockout of Lsi1 resulted in a significant decrease in Sb accumulation in both roots and shoots. Sb concentration in the root cell sap of two independent lsi1 mutants decreased to less than 3% of that in wild-type rice, indicating that Lsi1 is a major transporter for Sb(III) uptake. Knockout of Lsi1 also enhanced rice tolerance to Sb toxicity. However, knockout of Si efflux transporter genes, including Lsi2 and Lsi3, did not affect Sb accumulation. Taken together, our results showed that Sb(III) is taken up by Lsi1 localized at the root exodermis and is deposited at this cell layer due to lack of Sb efflux transporters in rice.

15.
Proc Natl Acad Sci U S A ; 119(11): e2115202119, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35271391

RESUMO

SignificanceIn humans, genetic mutations in the retinal pigment epithelium (RPE) 65 are associated with blinding diseases, for which there is no effective therapy alleviating progressive retinal degeneration in affected patients. Our findings uncovered that the increased free opsin caused by enhancing the ambient light intensity increased retinal activation, and when compounded with the RPE visual cycle dysfunction caused by the heterozygous D477G mutation and aggregation, led to the onset of retinal degeneration.


Assuntos
Proteínas do Olho , Genes Dominantes , Distrofias Retinianas , cis-trans-Isomerases , Animais , Proteínas do Olho/genética , Camundongos , Camundongos Knockout , Mutação , Retina/enzimologia , Retina/patologia , Distrofias Retinianas/genética , Visão Ocular , cis-trans-Isomerases/genética
16.
Proc Natl Acad Sci U S A ; 119(48): e2208934119, 2022 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-36409895

RESUMO

In ischemic retinopathy, overactivated retinal myeloid cells are a crucial driving force of pathological angiogenesis and inflammation. The cyclic GMP-AMP synthase (cGAS) and stimulator of interferon genes (STING) signaling are key regulators of inflammation. This study aims to investigate the association of cGAS-STING signaling with ischemic retinopathy and the regulation of its activation. We found that protein levels of cGAS and STING were markedly up-regulated in retinal myeloid cells isolated from mice with oxygen-induced retinopathy (OIR). Knockout of Sting and pharmacological inhibition of STING both alleviated retinal neovascularization (NV) and reduced retinal vascular leakage in OIR. Further, Sting knockout and STING inhibitor also alleviated leukocyte adhesion to retinal vasculature and infiltration into the retina as well as microglial activation in OIR. These results suggest that cGAS-STING signaling played a pathogenic role in retinal myeloid cell activation and NV in ischemic retinopathy. To identify the regulation of cGAS-STING signaling in OIR, we evaluated the role of transcription factor peroxisome proliferator-activated receptor α (PPARα). The results demonstrated that PPARα was down-regulated in OIR retinas, primarily in myeloid cells. Furthermore, Pparα knockout significantly up-regulated cGAS and STING levels in retinal CD11b+ cells, while PPARα agonist inhibited cGAS-STING signaling and cytosolic mitochondrial DNA (mtDNA) release, a causative feature for cGAS activation. Knockout of Sting ameliorated retinal NV, hyperpermeability, and leukostasis in Pparα-/- mice with OIR. These observations suggest that PPARα regulates cGAS-STING signaling, likely through mtDNA release, and thus, is a potential therapeutic target for ischemic retinopathy.


Assuntos
PPAR alfa , Doenças Retinianas , Animais , Camundongos , Modelos Animais de Doenças , DNA Mitocondrial , Inflamação , Isquemia/complicações , Proteínas de Membrana/metabolismo , Camundongos Knockout , Neovascularização Patológica , Nucleotidiltransferases/metabolismo , PPAR alfa/genética , Doenças Retinianas/genética
17.
Proc Natl Acad Sci U S A ; 119(33): e2207489119, 2022 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-35939707

RESUMO

The mechanistic target of rapamycin (mTOR) is assembled into signaling complexes of mTORC1 or mTORC2, and plays key roles in cell metabolism, stress response, and nutrient and growth factor sensing. Accumulating evidence from human and animal model studies has demonstrated a pathogenic role of hyperactive mTORC1 in age-related macular degeneration (AMD). The retinal pigment epithelium (RPE) is a primary injury site in AMD. In mouse models of RPE-specific deletion of Tuberous sclerosis 1 (Tsc1), which encodes an upstream suppressor of mTORC1, the hyperactivated mTORC1 metabolically reprogrammed the RPE and led to the degeneration of the outer retina and choroid (CH). In the current study, we use single-cell RNA sequencing (scRNA-seq) to identify an RPE mTORC1 downstream protein, dopamine- and cyclic AMP-regulated phosphoprotein of molecular weight 32,000 (DARPP-32). DARPP-32 was not found in healthy RPE but localized to drusen and basal linear deposits in human AMD eyes. In animal models, overexpressing DARPP-32 by adeno-associated virus (AAV) led to abnormal RPE structure and function. The data indicate that DARPP-32 is a previously unidentified signaling protein subjected to mTORC1 regulation and may contribute to RPE degeneration in AMD.


Assuntos
Fosfoproteína 32 Regulada por cAMP e Dopamina , Degeneração Macular , Alvo Mecanístico do Complexo 1 de Rapamicina , Epitélio Pigmentado da Retina , Animais , Modelos Animais de Doenças , Fosfoproteína 32 Regulada por cAMP e Dopamina/metabolismo , Ativação Enzimática , Humanos , Degeneração Macular/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos , Retina/metabolismo , Epitélio Pigmentado da Retina/metabolismo , Transdução de Sinais
18.
Proc Natl Acad Sci U S A ; 119(34): e2204256119, 2022 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-35972965

RESUMO

Antibody therapeutics for the treatment of COVID-19 have been highly successful. However, the recent emergence of the Omicron variant has posed a challenge, as it evades detection by most existing SARS-CoV-2 neutralizing antibodies (nAbs). Here, we successfully generated a panel of SARS-CoV-2/SARS-CoV cross-neutralizing antibodies by sequential immunization of the two pseudoviruses. Of the potential candidates, we found that nAbs X01, X10, and X17 offer broad neutralizing potential against most variants of concern, with X17 further identified as a Class 5 nAb with undiminished neutralization against the Omicron variant. Cryo-electron microscopy structures of the three antibodies together in complex with each of the spike proteins of the prototypical SARS-CoV, SARS-CoV-2, and Delta and Omicron variants of SARS-CoV-2 defined three nonoverlapping conserved epitopes on the receptor-binding domain. The triple-antibody mixture exhibited enhanced resistance to viral evasion and effective protection against infection of the Beta variant in hamsters. Our findings will aid the development of antibody therapeutics and broad vaccines against SARS-CoV-2 and its emerging variants.


Assuntos
Anticorpos Neutralizantes , Anticorpos Antivirais , Epitopos , SARS-CoV-2 , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Vacinas contra COVID-19/imunologia , Sequência Conservada , Cricetinae , Microscopia Crioeletrônica , Epitopos/imunologia , Humanos , Camundongos , Testes de Neutralização , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/genética
19.
J Biol Chem ; 299(9): 105082, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37495108

RESUMO

The development and progression of nasopharyngeal carcinoma (NPC) is closely associated with Epstein-Barr virus (EBV) infection. NPC is usually asymptomatic until it spreads to other sites, and more than 70% of cases are classified as locally advanced disease at diagnosis. EBV-positive nasopharyngeal cancer tissues express only limited viral latent proteins, but express high levels of the EBV-encoded BamHI-A rightward transcript (BART) miRNA molecules. Here, we report that EBV-miRNA-BART2-5p (BART2-5p) promotes NPC cell invasion and metastasis in vivo and in vitro but has no effect on NPC cell proliferation and apoptosis. In addition, BART2-5p altered the mRNA and miRNA expression profiles of NPC cells. The development of human tumors has been reported to be associated with altered miRNAs expression, and overall miRNAs expression is reduced in many types of tumors. We found that BART2-5p downregulated the expression of several miRNAs that could exert oncogenic functions. Mechanistically, BART2-5p directly targets the RNase III endonuclease DICER1, inhibiting its function of cleaving double-stranded stem-loop RNA into short double-stranded RNA, which in turn causes altered expression of a series of key epithelial-mesenchymal transition molecules, and reverting DICER1 expression can rescue this phenotype. Furthermore, analysis from clinical samples showed a negative correlation between BART2-5p and DICER1 expression. According to our study, high expression of BART2-5p in tissues and plasma of patients with NPC is associated with poor prognosis. Our results suggest that, BART2-5p can accelerate NPC metastasis through modulating miRNA profiles which are mediated by DICER1, implying a novel role of EBV miRNAs in the pathogenesis of NPC.


Assuntos
Infecções por Vírus Epstein-Barr , MicroRNAs , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas , Ribonuclease III , Humanos , Infecções por Vírus Epstein-Barr/enzimologia , Infecções por Vírus Epstein-Barr/genética , Herpesvirus Humano 4/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Carcinoma Nasofaríngeo/genética , Carcinoma Nasofaríngeo/patologia , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/patologia , Ribonuclease III/genética , Ribonuclease III/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/genética , Movimento Celular/genética
20.
BMC Genomics ; 25(1): 626, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38902625

RESUMO

BACKGROUND: Wheat grain endosperm is mainly composed of proteins and starch. The contents and the overall composition of seed storage proteins (SSP) markedly affect the processing quality of wheat flour. Polyploidization results in duplicated chromosomes, and the genomes are often unstable and may result in a large number of gene losses and gene rearrangements. However, the instability of the genome itself, as well as the large number of duplicated genes generated during polyploidy, is an important driving force for genetic innovation. In this study, we compared the differences in starch and SSP, and analyzed the transcriptome and metabolome among Aegilops sharonensis (R7), durum wheat (Z636) and amphidiploid (Z636×R7) to reveal the effects of polyploidization on the synthesis of seed reserve polymers. RESULTS: The total starch and amylose content of Z636×R7 was significantly higher than R7 and lower than Z636. The gliadin and glutenin contents of Z636×R7 were higher than those in Z636 and R7. Through transcriptome analysis, there were 21,037, 2197, 15,090 differentially expressed genes (DEGs) in the three comparison groups of R7 vs Z636, Z636 vs Z636×R7, and Z636×R7 vs R7, respectively, which were mainly enriched in carbon metabolism and amino acid biosynthesis pathways. Transcriptome data and qRT-PCR were combined to analyze the expression levels of genes related to storage polymers. It was found that the expression levels of some starch synthase genes, namely AGP-L, AGP-S and GBSSI in Z636×R7 were higher than in R7 and among the 17 DEGs related to storage proteins, the expression levels of 14 genes in R7 were lower than those in Z636 and Z636×R7. According to the classification analysis of all differential metabolites, most belonged to carboxylic acids and derivatives, and fatty acyls were enriched in the biosynthesis of unsaturated fatty acids, niacin and nicotinamide metabolism, one-carbon pool by folate, etc. CONCLUSION: After allopolyploidization, the expression of genes related to starch synthesis was down-regulated in Z636×R7, and the process of starch synthesis was inhibited, resulting in delayed starch accumulation and prolongation of the seed development process. Therefore, at the same development time point, the starch accumulation of Z636×R7 lagged behind that of Z636. In this study, the expression of the GSe2 gene in Z636×R7 was higher than that of the two parents, which was beneficial to protein synthesis, and increased the protein content. These results eventually led to changes in the synthesis of seed reserve polymers. The current study provided a basis for a greater in-depth understanding of the mechanism of wheat allopolyploid formation and its stable preservation, and also promoted the effective exploitation of high-value alleles.


Assuntos
Aegilops , Sementes , Triticum , Triticum/genética , Triticum/metabolismo , Aegilops/genética , Aegilops/metabolismo , Sementes/genética , Sementes/metabolismo , Hibridização Genética , Poliploidia , Amido/biossíntese , Amido/metabolismo , Transcriptoma , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Proteômica/métodos , Multiômica
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