RESUMEN
BACKGROUND: The RNA N6-methyladenosine (m6A) modification has become an essential hotspot in epigenetic modulation. Serine-arginine protein kinase 1 (SRPK1) is associated with the pathogenesis of various cancers. However, the m6A modification of SRPK1 and its association with the mechanism of in lung adenocarcinoma (LUAD) remains unclear. METHODS: Western blotting and polymerase chain reaction (PCR) analyses were carried out to identify gene and protein expression. m6A epitranscriptomic microarray was utilized to the assess m6A profile. Loss and gain-of-function assays were carried out elucidate the impact of METTL3 and SRPK1 on LUAD glycolysis and tumorigenesis. RNA immunoprecipitation (RIP), m6A RNA immunoprecipitation (MeRIP), and RNA stability tests were employed to elucidate the SRPK1's METTL3-mediated m6A modification mechanism in LUAD. Metabolic quantification and co-immunoprecipitation assays were applied to investigate the molecular mechanism by which SRPK1 mediates LUAD metabolism. RESULTS: The epitranscriptomic microarray assay revealed that SRPK1 could be hypermethylated and upregulated in LUAD. The main transmethylase METTL3 was upregulated and induced the aberrant high m6A levels of SRPK1. Mechanistically, SRPK1's m6A sites were directly methylated by METTL3, which also stabilized SRPK1 in an IGF2BP2-dependent manner. Methylated SRPK1 subsequently promoted LUAD progression through enhancing glycolysis. Further metabolic quantification, co-immunoprecipitation and western blot assays revealed that SRPK1 interacts with hnRNPA1, an important modulator of PKM splicing, and thus facilitates glycolysis by upregulating PKM2 in LUAD. Nevertheless, METTL3 inhibitor STM2457 can reverse the above effects in vitro and in vivo by suppressing SRPK1 and glycolysis in LUAD. CONCLUSION: It was revealed that in LUAD, aberrantly expressed METTL3 upregulated SRPK1 levels via an m6A-IGF2BP2-dependent mechanism. METTL3-induced SRPK1 fostered LUAD cell proliferation by enhancing glycolysis, and the small-molecule inhibitor STM2457 of METTL3 could be an alternative novel therapeutic strategy for individuals with LUAD.
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Adenocarcinoma del Pulmón , Adenosina , Glucólisis , Neoplasias Pulmonares , Metiltransferasas , Proteínas Serina-Treonina Quinasas , Humanos , Adenosina/análogos & derivados , Adenosina/metabolismo , Glucólisis/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Adenocarcinoma del Pulmón/genética , Adenocarcinoma del Pulmón/metabolismo , Adenocarcinoma del Pulmón/patología , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Metiltransferasas/metabolismo , Metiltransferasas/genética , Animales , Regulación Neoplásica de la Expresión Génica , Ratones , Línea Celular Tumoral , Ratones Desnudos , Empalme del ARN/genética , Proteínas de Unión a Hormona Tiroide , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Proliferación Celular/genéticaAsunto(s)
Neoplasias Encefálicas , Proteínas de Unión al ARN , Humanos , Masculino , Femenino , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/genética , Preescolar , Estudios Retrospectivos , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Proteína Ácida Fibrilar de la Glía/metabolismo , Proteína Ácida Fibrilar de la Glía/genética , Nestina/metabolismo , Nestina/genética , Lóbulo Parietal/patología , Lóbulo Parietal/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Proteínas del Tejido Nervioso/genética , Proteínas Cromosómicas no Histona/metabolismo , Proteínas Cromosómicas no Histona/genética , Neoplasias del Tronco Encefálico/patología , Neoplasias del Tronco Encefálico/genética , Neoplasias del Tronco Encefálico/metabolismo , Neoplasias del Tronco Encefálico/cirugía , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Proteína SMARCB1/metabolismo , Proteína SMARCB1/genética , Lóbulo Frontal/patología , Lóbulo Frontal/metabolismo , Formación de Roseta , Estudios de Seguimiento , Antígeno Ki-67/metabolismo , Proteínas de Unión al ADN/metabolismo , Proteínas de Unión al ADN/genéticaAsunto(s)
Carcinoma de Células Renales , Transición Epitelial-Mesenquimal , Neoplasias Renales , Metiltransferasas , Carcinoma de Células Renales/genética , Carcinoma de Células Renales/metabolismo , Carcinoma de Células Renales/patología , Humanos , Neoplasias Renales/genética , Neoplasias Renales/patología , Neoplasias Renales/metabolismo , Metiltransferasas/metabolismo , Metiltransferasas/genética , Metilación , Adenosina/análogos & derivados , Adenosina/metabolismo , Epigénesis Genética , Resistencia a Antineoplásicos , Invasividad Neoplásica , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Pronóstico , Apoptosis , Regulación Neoplásica de la Expresión Génica , Factores de Empalme de ARN/genética , Factores de Empalme de ARN/metabolismoRESUMEN
RNA base editing relies on the introduction of adenosine-to-inosine changes into target RNAs in a highly programmable manner in order to repair disease-causing mutations. Here, we propose that RNA base editing could be broadly applied to perturb protein function by removal of regulatory phosphorylation and acetylation sites. We demonstrate the feasibility on more than 70 sites in various signaling proteins and identify key determinants for high editing efficiency and potent down-stream effects. For the JAK/STAT pathway, we demonstrate both, negative and positive regulation. To achieve high editing efficiency over a broad codon scope, we applied an improved version of the SNAP-ADAR tool. The transient nature of RNA base editing enables the comparably fast (hours to days), dose-dependent (thus partial) and reversible manipulation of regulatory sites, which is a key advantage over DNA (base) editing approaches. In summary, PTM interference might become a valuable field of application of RNA base editing.
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Procesamiento Proteico-Postraduccional , Edición de ARN , Humanos , Fosforilación , Células HEK293 , Adenosina Desaminasa/metabolismo , Adenosina Desaminasa/genética , ARN/metabolismo , ARN/genética , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , AcetilaciónRESUMEN
The RNA-binding proteins LIN28A and LIN28B contribute to a variety of developmental biological processes. Dysregulation of Lin28A and Lin28B expression is associated with numerous types of tumors. This study demonstrates that Lin28A overexpression in the mouse nephrons leads to severe inflammation and kidney damage rather than to tumorigenesis. Notably, Lin28A overexpression causes inflammation only when expressed in nephrons, but not in the stromal cells of the kidneys, highlighting its cell context-dependent nature. The nephron-specific Lin28A-induced inflammatory response differs from previously described Lin28B-mediated inflammatory feedback loops as it is IL-6 independent. Instead, it is associated with the rapid upregulation of cytokines like Cxcl1 and Ccl2. These findings suggest that the pathophysiological effects of Lin28A overexpression extend beyond cell transformation. Our transgenic mouse model offers a valuable tool for advancing our understanding of the pathophysiology of acute kidney injury, where inflammation is a key factor.
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Inflamación , Ratones Transgénicos , Nefronas , Proteínas de Unión al ARN , Animales , Ratones , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Inflamación/metabolismo , Nefronas/metabolismo , Riñón/metabolismo , Riñón/patología , Quimiocina CXCL1/metabolismo , Quimiocina CXCL1/genética , Quimiocina CCL2/metabolismo , Quimiocina CCL2/genéticaRESUMEN
Aortic aneurysm and dissection (AD) represent a critical cardiovascular emergency with an alarmingly high mortality rate. Recent research has spotlighted the overexpression of genes associated with the m6A modification in AD patients, linking them to the presence of inflammatory M1-type macrophages. Moreover, glycolysis is widely recognized as a key feature of inflammatory M1-type macrophages, but biomarkers linking glycolysis and macrophage function to promote disease progression in AD have not been reported. We conducted an analysis of aortic immune cell infiltration, macrophages, and m6A-related biomarkers in AD patients using bioinformatics techniques. Subsequently, we employed a combination of RT-PCR, WB, and immunofluorescence assays to elucidate the alterations in the expression of M1- and M2-type macrophages, as well as markers of glycolysis, following the overexpression of key biomarkers. These findings were further validated in vivo through the creation of a rat model of AD with knockdown of the aforementioned key biomarkers. The findings revealed that the m6A-modified related gene RBM15 exhibited heightened expression in AD samples and was correlated with macrophage polarization. Upon overexpression of RBM15 in macrophages, there was an observed increase in the expression of M1-type macrophage markers CXCL9 and CXCL10, alongside a decrease in the expression of M2-type macrophage markers CCL13 and MRC1. Furthermore, there was an elevation in the expression of glycolytic enzymes GLUT1 and Hexokinase, as well as HIF1α, GAPDH, and PFKFB3 after RBM15 overexpression. Moreover, in vivo knockdown of RBM15 led to an amelioration of aortic aneurysm in the rat AD model. This knockdown also resulted in a reduction of the M1-type macrophage marker iNOS, while significantly increasing the expression of the M2-type macrophage marker CD206. In conclusion, our findings demonstrate that RBM15 upregulates glycolysis in macrophages, thus contributing to the progression of AD through the promotion of M1-type macrophage polarization. Conversely, downregulation of RBM15 suppresses M1-type macrophage polarization, thereby decelerating the advancement of AD. These results unveil potential novel targets for the treatment of AD.
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Aneurisma de la Aorta , Disección Aórtica , Progresión de la Enfermedad , Glucólisis , Macrófagos , Proteínas de Unión al ARN , Glucólisis/genética , Humanos , Animales , Macrófagos/metabolismo , Macrófagos/inmunología , Ratas , Disección Aórtica/patología , Disección Aórtica/genética , Disección Aórtica/metabolismo , Aneurisma de la Aorta/metabolismo , Aneurisma de la Aorta/genética , Aneurisma de la Aorta/patología , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Masculino , Modelos Animales de Enfermedad , Quimiocina CXCL10/metabolismo , Quimiocina CXCL10/genética , Biomarcadores/metabolismo , Quimiocina CXCL9/metabolismo , Quimiocina CXCL9/genética , Femenino , Adenosina/análogos & derivadosRESUMEN
Aggregation of RNA binding proteins and dysregulation of RNA metabolism drives pathogenesis of multiple neurodegenerative diseases. In this issue of Neuron, Belur et al.1 identified pathological NONO/SFPQ inclusions and aberrant A-to-I-edited RNAs accumulated in nucleus, leading to dysregulation of gene expression and neurodegeneration in synucleinopathy-associated diseases.
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Edición de ARN , Sinucleinopatías , Humanos , Sinucleinopatías/metabolismo , Sinucleinopatías/genética , Sinucleinopatías/patología , Cuerpos de Inclusión/metabolismo , Cuerpos de Inclusión/patología , Cuerpos de Inclusión/genética , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Animales , ARN/genética , ARN/metabolismoRESUMEN
The unfolded protein response (UPR) is a conserved and adaptive intracellular pathway that relieves the endoplasmic reticulum (ER) stress by activating ER transmembrane stress sensors. As a consequence of ER stress, the inhibition of nonsense-mediated mRNA decay (NMD) is due to an increase in the phosphorylation of eIF2α, which has the effect of inhibiting translation. However, the role of NMD in maintaining ER homeostasis remains unclear. In this study, we found that the three NMD factors, up-frameshift (UPF)1, UPF2, or UPF3B, were required to negate the UPR. Among these three NMD factors, only UPF3B interacted with inositol-requiring enzyme-1α (IRE1α). This interaction inhibited the kinase activity of IRE1α, abolished autophosphorylation, and reduced IRE1α clustering for ER stress. BiP and UPF3B jointly control the activation of IRE1α on both sides of the ER membrane. Under stress conditions, the phosphorylation of UPF3B was increased and the phosphorylated sites were identified. Both the UPF3BY160D genetic mutation and phosphorylation at Thr169 of UPF3B abolished its interaction with IRE1α and UPF2, respectively, leading to activation of ER stress and NMD dysfunction. Our study reveals a key physiological role for UPF3B in the reciprocal regulatory relationship between NMD and ER stress.
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Estrés del Retículo Endoplásmico , Endorribonucleasas , Proteínas Serina-Treonina Quinasas , Humanos , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Endorribonucleasas/metabolismo , Fosforilación , Células HeLa , Degradación de ARNm Mediada por Codón sin Sentido , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Respuesta de Proteína Desplegada , Células HEK293 , Unión Proteica , Retículo Endoplásmico/metabolismoRESUMEN
Sex chromosomes underlie the development of male or female sex organs across species. While systemic signals derived from sex organs prominently contribute to sex-linked differences, it is unclear whether the intrinsic presence of sex chromosomes in somatic tissues has a specific function. Here, we use genetic tools to show that cellular sex is crucial for sexual differentiation throughout the body in Drosophila melanogaster. We reveal that every somatic cell converts the intrinsic presence of sex chromosomes into the active production of a sex determinant, a female specific serine- and arginine-rich (SR) splicing factor. This discovery dismisses the mosaic model which posits that only a subset of cells has the potential to sexually differentiate. Using cell-specific sex reversals, we show that this prevalence of cellular sex drives sex differences in organ size and body weight and is essential for fecundity. These findings demonstrate that cellular sex drives differentiation programs at an organismal scale and highlight the importance of cellular sex pathways in sex trait evolution.
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Proteínas de Drosophila , Drosophila melanogaster , Cromosomas Sexuales , Diferenciación Sexual , Animales , Masculino , Femenino , Drosophila melanogaster/genética , Drosophila melanogaster/crecimiento & desarrollo , Diferenciación Sexual/genética , Diferenciación Sexual/fisiología , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , Cromosomas Sexuales/genética , Fertilidad/genética , Caracteres Sexuales , Tamaño de los Órganos , Factores de Empalme de ARN/metabolismo , Factores de Empalme de ARN/genética , Peso Corporal , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genéticaRESUMEN
Fertility requires the faithful proliferation of germ cells and their differentiation into gametes. Controlling these cellular states demands precise timing and expression of gene networks. Nucleic acid binding proteins (NBPs) play critical roles in gene expression networks that influence germ cell development. There has, however, been no functional analysis of the entire NBP repertoire in controlling in vivo germ cell development. Here, we analyzed germ cell states and germline architecture to systematically investigate the function of 364 germline-expressed NBPs in the Caenorhabditis elegans germ line. Using germline-specific knockdown, automated germ cell counting, and high-content analysis of germ cell nuclei and plasma membrane organization, we identify 156 NBPs with discrete autonomous germline functions. By identifying NBPs that control the germ cell cycle, proliferation, differentiation, germline structure and fertility, we have created an atlas for mechanistic dissection of germ cell behavior and gamete production.
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Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Células Germinativas , Animales , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Células Germinativas/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Regulación del Desarrollo de la Expresión Génica , Diferenciación Celular/genética , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Fertilidad/genética , Proteínas de Unión al ADN/metabolismo , Proteínas de Unión al ADN/genética , Proliferación Celular/genética , Ciclo Celular/genética , Masculino , Redes Reguladoras de GenesRESUMEN
The unique amino acid hypusine [Nε-(4-amino-2-hydroxybutyl)lysine] is exclusively formed on the translational regulator eukaryotic initiation factor 5A (eIF5A) via a process coined hypusination. Hypusination is mediated by two enzymes, deoxyhypusine synthase (DHPS) and deoxyhypusine hydroxylase (DOHH), and hypusinated eIF5A (eIF5AHyp) promotes translation elongation by alleviating ribosome pauses at amino acid motifs that cause structural constraints, and it also facilitates translation initiation and termination. Accordingly, eIF5AHyp has diverse biological functions that rely on translational control of its targets. Homozygous deletion of Eif5a, Dhps, or Dohh in mice leads to embryonic lethality, and heterozygous germline variants in EIF5A and biallelic variants in DHPS and DOHH are associated with rare inherited neurodevelopmental disorders, underscoring the importance of the hypusine circuit for embryonic and neuronal development. Given the pleiotropic effects of eIF5AHyp, a detailed understanding of the cell context-specific intrinsic roles of eIF5AHyp and of the chronic versus acute effects of eIF5AHyp inhibition is necessary to develop future strategies for eIF5AHyp-targeted therapy to treat various human health problems. Here, we review the most recent studies documenting the intrinsic roles of eIF5AHyp in different tissues/cell types under normal or pathophysiological conditions and discuss these unique aspects of eIF5AHyp-dependent translational control.
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Factor 5A Eucariótico de Iniciación de Traducción , Lisina , Factores de Iniciación de Péptidos , Proteínas de Unión al ARN , Factores de Iniciación de Péptidos/metabolismo , Factores de Iniciación de Péptidos/genética , Humanos , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Animales , Lisina/metabolismo , Lisina/análogos & derivados , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/genética , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/metabolismo , Oxigenasas de Función Mixta/genética , Oxigenasas de Función Mixta/metabolismo , Biosíntesis de Proteínas , RatonesRESUMEN
Parasites have been associated with possible anticancer activity, including Trypanosoma cruzi, which has been linked to inhibiting the growth of solid tumors. To better understand this antitumor effect, we investigated the association of anti-T. cruzi antibodies with B cells of the acute lymphoblastic leukemia (ALL) SUPB15 cell line. The antibodies were generated in rabbits. IgGs were purified by affinity chromatography. Two procedures (flow cytometry (CF) and Western blot(WB)) were employed to recognize anti-T. cruzi antibodies on SUPB15 cells. We also used CF to determine whether the anti-T. cruzi antibodies could suppress SUPB15 cells. The anti-T. cruzi antibodies recognized 35.5% of the surface antigens of SUPB15. The complement-dependent cytotoxicity (CDC) results demonstrate the cross-suppression of anti-T. cruzi antibodies on up to 8.4% of SUPB15 cells. For the WB analysis, a band at 100 kDa with high intensity was sequenced using mass spectrometry, identifying the protein as nucleolin. This protein may play a role in the antitumor effect on T. cruzi. The anti-T. cruzi antibodies represent promising polyclonal antibodies that have the effect of tumor-suppressive cross-linking on cancer cells, which should be further investigated.
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Anticuerpos Antiprotozoarios , Leucemia-Linfoma Linfoblástico de Células Precursoras , Trypanosoma cruzi , Trypanosoma cruzi/inmunología , Leucemia-Linfoma Linfoblástico de Células Precursoras/inmunología , Humanos , Línea Celular Tumoral , Animales , Conejos , Anticuerpos Antiprotozoarios/inmunología , Proteínas de Unión al ARN/inmunología , Proteínas de Unión al ARN/metabolismo , Nucleolina , Fosfoproteínas/inmunología , Fosfoproteínas/metabolismoRESUMEN
BACKGROUND: The modification of N6-methyladenosine (m6A) plays a pivotal role in tumor by altering both innate and adaptive immune systems through various pathways, including the regulation of messenger RNA. The YTH domain protein family, acting as "readers" of m6A modifications, affects RNA splicing, stability, and immunogenicity, thereby playing essential roles in immune regulation and antitumor immunity. Despite their significance, the impact of the YTH domain protein family on tumor initiation and progression, as well as their involvement in tumor immune regulation and therapy, remains underexplored and lacks comprehensive review. CONCLUSION: This review introduces the molecular characteristics of the YTH domain protein family and their physiological and pathological roles in biological behavior, emphasizing their mechanisms in regulating immune responses and antitumor immunity. Additionally, the review discusses the roles of the YTH domain protein family in immune-related diseases and tumor resistance, highlighting that abnormal expression or dysfunction of YTH proteins is closely linked to tumor resistance. KEY POINTS: This review provides an in-depth understanding of the YTH domain protein family in immune regulation and antitumor immunity, suggesting new strategies and directions for immunotherapy of related diseases. These insights not only deepen our comprehension of m6A modifications and YTH protein functions but also pave the way for future research and clinical applications.
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Inmunomodulación , Inmunoterapia , Neoplasias , Humanos , Neoplasias/inmunología , Neoplasias/terapia , Inmunoterapia/métodos , Proteínas de Unión al ARN/inmunología , Proteínas de Unión al ARN/genética , Factores de Empalme de ARN/genética , Factores de Empalme de ARN/inmunologíaRESUMEN
Preeclampsia (PE) is a life-threatening pregnancy-specific complication with controversial mechanisms and no effective treatment except delivery is available. Currently, increasing researchers suggested that PE shares pathophysiologic features with protein misfolding/aggregation disorders, such as Alzheimer disease (AD). Evidences have proposed defective autophagy as a potential source of protein aggregation in PE. Endoplasmic reticulum-selective autophagy (ER-phagy) plays a critical role in clearing misfolded proteins and maintaining ER homeostasis. However, its roles in the molecular pathology of PE remain unclear. We found that lncRNA DUXAP8 was upregulated in preeclamptic placentae and significantly correlated with clinical indicators. DUXAP8 specifically binds to PCBP2 and inhibits its ubiquitination-mediated degradation, and decreased levels of PCBP2 reversed the activation effect of DUXAP8 overexpression on AKT/mTOR signaling pathway. Function experiments showed that DUXAP8 overexpression inhibited trophoblastic proliferation, migration, and invasion of HTR-8/SVneo and JAR cells. Moreover, pathological accumulation of swollen and lytic ER (endoplasmic reticulum) was observed in DUXAP8-overexpressed HTR8/SVneo cells and PE placental villus trophoblast cells, which suggesting that ER clearance ability is impaired. Further studies found that DUXAP8 overexpression impaired ER-phagy and caused protein aggregation medicated by reduced FAM134B and LC3II expression (key proteins involved in ER-phagy) via activating AKT/mTOR signaling pathway. The increased level of FAM134B significantly reversed the inhibitory effect of DUXAP8 overexpression on the proliferation, migration, and invasion of trophoblasts. In vivo, DUXAP8 overexpression through tail vein injection of adenovirus induced PE-like phenotypes in pregnant rats accompanied with activated AKT/mTOR signaling, decreased expression of FAM134B and LC3-II proteins and increased protein aggregation in placental tissues. Our study reveals the important role of lncRNA DUXAP8 in regulating trophoblast biological behaviors through FAM134B-mediated ER-phagy, providing a new theoretical basis for understanding the pathogenesis of PE.
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Autofagia , Retículo Endoplásmico , Preeclampsia , Proteínas Proto-Oncogénicas c-akt , ARN Largo no Codificante , Transducción de Señal , Serina-Treonina Quinasas TOR , Trofoblastos , Femenino , Embarazo , Preeclampsia/metabolismo , Preeclampsia/genética , Preeclampsia/patología , Humanos , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Autofagia/genética , Animales , Retículo Endoplásmico/metabolismo , Trofoblastos/metabolismo , Trofoblastos/patología , Ratas , Placenta/metabolismo , Proliferación Celular/genética , Adulto , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Ratas Sprague-Dawley , Movimiento Celular/genética , Línea CelularRESUMEN
The primary aim of this research was to explore the functions of Wtap and Ythdf1 in regulating neuronal Lipocalin-2 (Lcn2) through m6A modification in traumatic brain injury (TBI). By employing transcriptome sequencing and enrichment analysis, we identified the Wtap/Ythdf1-mediated Lcn2 m6A modification pathway as crucial in TBI. In our in vitro experiments using primary cortical neurons, knockout of Wtap and Ythdf1 led to the inhibition of Lcn2 m6A modification, resulting in reduced neuronal death and inflammation. Furthermore, overexpression of Lcn2 in cortical neurons induced the activation of reactive astrocytes and M1-like microglial cells, causing neuronal apoptosis. In vivo experiments confirmed the activation of reactive astrocytes and microglial cells in TBI and importantly demonstrated that Wtap knockdown improved neuroinflammation and functional impairment. These findings underscore the significance of Wtap/Ythdf1-mediated Lcn2 regulation in TBI secondary injury and suggest potential therapeutic implications for combating TBI-induced neuroinflammation and neuronal damage.
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Lesiones Traumáticas del Encéfalo , Lipocalina 2 , Neuronas , Lesiones Traumáticas del Encéfalo/genética , Lesiones Traumáticas del Encéfalo/metabolismo , Lesiones Traumáticas del Encéfalo/patología , Lipocalina 2/metabolismo , Lipocalina 2/genética , Animales , Neuronas/metabolismo , Neuronas/patología , Ratones , Microglía/metabolismo , Microglía/patología , Astrocitos/metabolismo , Astrocitos/patología , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Masculino , Ratones Endogámicos C57BL , Apoptosis , Ratones Noqueados , Enfermedades Neuroinflamatorias/metabolismo , Enfermedades Neuroinflamatorias/patologíaRESUMEN
Translation is regulated mainly in the initiation step, and its dysregulation is implicated in many human diseases. Several proteins have been found to regulate translational initiation, including Pdcd4 (programmed cell death gene 4). Pdcd4 is a tumor suppressor protein that prevents cell growth, invasion, and metastasis. It is downregulated in most tumor cells, while global translation in the cell is upregulated. To understand the mechanisms underlying translational control by Pdcd4, we used single-particle cryo-electron microscopy to determine the structure of human Pdcd4 bound to 40S small ribosomal subunit, including Pdcd4-40S and Pdcd4-40S-eIF4A-eIF3-eIF1 complexes. The structures reveal the binding site of Pdcd4 at the mRNA entry site in the 40S, where the C-terminal domain (CTD) interacts with eIF4A at the mRNA entry site, while the N-terminal domain (NTD) is inserted into the mRNA channel and decoding site. The structures, together with quantitative binding and in vitro translation assays, shed light on the critical role of the NTD for the recruitment of Pdcd4 to the ribosomal complex and suggest a model whereby Pdcd4 blocks the eIF4F-independent role of eIF4A during recruitment and scanning of the 5' UTR of mRNA.
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Proteínas Reguladoras de la Apoptosis , Microscopía por Crioelectrón , Unión Proteica , ARN Mensajero , Proteínas de Unión al ARN , Subunidades Ribosómicas Pequeñas de Eucariotas , Humanos , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/química , Proteínas Reguladoras de la Apoptosis/metabolismo , Proteínas Reguladoras de la Apoptosis/genética , ARN Mensajero/metabolismo , ARN Mensajero/genética , Subunidades Ribosómicas Pequeñas de Eucariotas/metabolismo , Subunidades Ribosómicas Pequeñas de Eucariotas/genética , Sitios de Unión , Biosíntesis de Proteínas , Factor 4A Eucariótico de Iniciación/metabolismo , Factor 4A Eucariótico de Iniciación/genética , Modelos MolecularesRESUMEN
BACKGROUND: Long noncoding RNAs (lncRNAs) and N6-methyladenosine (m6A) modification of RNA play pivotal roles in tumorigenesis and cancer progression. However, knowledge regarding the expression patterns of m6A-related lncRNAs and their corresponding m6A regulators in prostate cancer (PCa) is limited. This study aimed to delineate the landscape of m6A-related lncRNAs, develop a predictive model, and identify the critical m6A regulators of prognostic lncRNAs in PCa. METHODS: Clinical and transcriptome data of PCa patients were downloaded from The Cancer Genome Atlas (TCGA) database. Prognostic m6A-related lncRNAs were subsequently identified through Pearson correlation and univariate Cox regression analyses. The prognostic lncRNAs were clustered into two groups by consensus clustering analysis, and a risk signature model was constructed using least absolute shrinkage and selection operator (LASSO) regression analysis of the lncRNAs. This model was evaluated using survival, clinicopathological, and immunological analyses. Furthermore, based on the constructed lncRNA-m6A regulatory network and RT-qPCR results, RBM15 was identified as a critical regulator of m6A-related lncRNAs. The biological roles of RBM15 in PCa were explored through bioinformatics analysis and biological experiments. RESULTS: Thirty-four prognostic m6A-related lncRNAs were identified and categorized into two clusters with different expression patterns and survival outcomes in PCa patients. Seven m6A lncRNAs (AC105345.1, AL354989.1, AC138028.4, AC022211.1, AC020558.2, AC004076.2, and LINC02666) were selected to construct a risk signature with robust predictive ability for overall survival and were correlated with clinicopathological characteristics and the immune microenvironment of PCa patients. Among them, LINC02666 and AC022211.1 were regulated by RBM15. In addition, RBM15 expression correlated with PCa progression, survival, and the immune response. Patients with elevated RBM15 expression were more susceptible to the drug AMG-232. Moreover, silencing RBM15 decreased the viability of PCa cells and promoted apoptosis. CONCLUSION: RBM15 is involved in the regulation of prognostic lncRNAs in the risk signature and has a robust predictive ability for PCa, making it a promising biomarker in PCa.
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Adenosina , Biomarcadores de Tumor , Neoplasias de la Próstata , ARN Largo no Codificante , Proteínas de Unión al ARN , Humanos , Masculino , ARN Largo no Codificante/genética , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/metabolismo , Pronóstico , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Adenosina/análogos & derivados , Adenosina/metabolismo , Adenosina/genética , Regulación Neoplásica de la Expresión GénicaRESUMEN
Vascular smooth muscle cells (VSMCs) play a critical role in maintaining vascular integrity. VSMC dysfunction leads to numerous vascular diseases. Adenosine deaminases acting on RNA 1 (ADAR1), an RNA editing enzyme, has shown both RNA editing and non-editing functions. Global deletion of ADAR1 causes embryonic lethality, but the phenotype of homozygous ADAR1 deletion specifically in SMCs (ADAR1sm-/-) remains to be determined. By crossing ADAR1fl/fl mice with Myh11-CreERT2 mice followed by Tamoxifen induction, we found that ADAR1sm-/- leads to lethality in adult mice 14 days after the induction. Gross examination revealed extensive hemorrhage and detrimental vascular damage in different organs. Histological analyses revealed destruction of artery structural integrity with detachment of elastin laminae from VSMCs in ADAR1sm-/- aortas. Furthermore, ADAR1sm-/- resulted in severe VSMC apoptosis and mitochondrial dysfunction. RNA sequencing analyses of ADAR1sm-/- aorta segments demonstrated profound transcriptional alteration of genes impacting vascular health including a decrease in fibrillin-1 expression. More importantly, ADAR1sm-/- disrupts the elastin and fibrillin-1 interaction, a molecular event essential for artery structure. Our results indicate that ADAR1 plays a critical role in maintaining SMC survival and vascular stability and resilience.
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Adenosina Desaminasa , Homeostasis , Músculo Liso Vascular , Miocitos del Músculo Liso , Animales , Adenosina Desaminasa/metabolismo , Adenosina Desaminasa/genética , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patología , Ratones , Miocitos del Músculo Liso/metabolismo , Miocitos del Músculo Liso/patología , Aorta/metabolismo , Aorta/patología , Apoptosis/genética , Fibrilina-1/genética , Fibrilina-1/metabolismo , Elastina/metabolismo , Ratones Noqueados , Ratones Endogámicos C57BL , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genéticaRESUMEN
INTRODUCTION: Liver fibrosis is primarily driven by the activation of hepatic stellate cells (HSCs), which involves various epigenetic modifications. OBJECTIVES: N6-methyladenosine (m6A), the most prevalent RNA modification in eukaryotic cells, influences numerous physiological and pathological processes. Nevertheless, the role of insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3), a reader gene mediating m6A modifications, in liver fibrosis remains unclear. METHODS AND RESULTS: This study demonstrated that IGF2BP3 knockout reduces liver fibrosis by promoting HSC ferroptosis (FPT) and inactivating HSCs. Multi-omics analysis revealed that HSC-specific IGF2BP3 knockout decreased m6A content in Jagged1 (Jag1), a key component of the Notch signalling pathway. Furthermore, IGF2BP3 deficiency significantly reduced the expression of hairy and enhancer of split-1 (Hes1), a transcription factor in the Notch/Jag1 signalling pathway, with mRNA levels declining to 35%-62% and protein levels to 28%-35%. Additionally, it suppressed glutathione peroxidase 4 (GPX4) (decreased to approximately 31%-38%), a negative regulator of FPT, thereby facilitating HSC FPT progression and reducing profibrotic gene expression. CONCLUSION: These findings uncover a novel IGF2BP3/Notch/Jag1 signalling pathway involving HSC FPT, suggesting promising targets for ameliorating liver fibrosis. KEY POINTS/HIGHLIGHTS: IGF2BP3 deficiency inactivates Jag1 signalling. IGF2BP3 deficiency-mediated m6A modifications promote HSC ferroptosis. IGF2BP3 inhibition facilitates ferroptosis in HSCs via the Hes1/GPX4 axis. IGF2BP3 deficiency inactivates Jag1/Notch1/3/Hes1 signalling pathway inactivation, leading to the decrease in GPX4, which contributes to HSC ferroptosis.
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Ferroptosis , Células Estrelladas Hepáticas , Proteína Jagged-1 , Cirrosis Hepática , Proteínas de Unión al ARN , Receptores Notch , Transducción de Señal , Ferroptosis/genética , Células Estrelladas Hepáticas/metabolismo , Animales , Cirrosis Hepática/genética , Cirrosis Hepática/metabolismo , Cirrosis Hepática/patología , Ratones , Proteína Jagged-1/genética , Proteína Jagged-1/metabolismo , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Transducción de Señal/genética , Receptores Notch/metabolismo , Receptores Notch/genética , Ratones Noqueados , Masculino , HumanosRESUMEN
Rationale: Adult neurogenesis in the subventricular zone (SVZ) is essential for maintaining neural homeostasis, and its dysregulation contributes to anosmia and delayed tissue healing in neurological disorders, such as Parkinson's disease (PD). Despite intricate regulatory networks identified in SVZ neurogenesis, the molecular mechanisms dynamically maintaining neural stem/progenitor cells (NSPCs) in response to physiological and pathological stimuli remain incompletely elucidated. Methods: We generated an RNA binding motif protein 24 (Rbm24) knockout model to investigate its impact on adult neurogenesis in the SVZ, employing immunofluorescence, immunoblot, electrophysiology, RNA-sequencing, and in vitro experiments. Further investigations utilized a PD mouse model, along with genetic and pharmacological manipulations, to elucidate Rbm24 involvement in PD pathology. Results: Rbm24, a multifaceted post-transcriptional regulator of cellular homeostasis, exhibited broad expression in the SVZ from development to aging. Deletion of Rbm24 significantly impaired NSPC proliferation in the adult SVZ, ultimately resulting in collapsed neurogenesis in the olfactory bulb. Notably, Rbm24 played a specific role in maintaining Notch1 mRNA stability in adult NSPCs. The Rbm24/Notch1 signaling axis was significantly downregulated in the SVZ of PD mice. Remarkably, overexpression of Rbm24 rescued disruption of adult neurogenesis and olfactory dysfunction in PD mice, and these effects were hindered by DAPT, a potent inhibitor of Notch1. Conclusions: Our findings highlight the critical role of the Rbm24/Notch1 signaling axis in regulating adult SVZ neurogenesis under physiological and pathological circumstances. This provides valuable insights into the dynamic regulation of NSPC homeostasis and offers a potential targeted intervention for PD and related neurological disorders.