RESUMO
DddA-derived cytosine base editors (DdCBEs) and transcription activator-like effector (TALE)-linked deaminases (TALEDs) catalyze targeted base editing of mitochondrial DNA (mtDNA) in eukaryotic cells, a method useful for modeling of mitochondrial genetic disorders and developing novel therapeutic modalities. Here, we report that A-to-G-editing TALEDs but not C-to-T-editing DdCBEs induce tens of thousands of transcriptome-wide off-target edits in human cells. To avoid these unwanted RNA edits, we engineered the substrate-binding site in TadA8e, the deoxy-adenine deaminase in TALEDs, and created TALED variants with fine-tuned deaminase activity. Our engineered TALED variants not only reduced RNA off-target edits by >99% but also minimized off-target mtDNA mutations and bystander edits at a target site. Unlike wild-type versions, our TALED variants were not cytotoxic and did not cause developmental arrest of mouse embryos. As a result, we obtained mice with pathogenic mtDNA mutations, associated with Leigh syndrome, which showed reduced heart rates.
Assuntos
DNA Mitocondrial , Efetores Semelhantes a Ativadores de Transcrição , Animais , Humanos , Camundongos , Adenina , Citosina , DNA Mitocondrial/genética , Edição de Genes , RNA , Efetores Semelhantes a Ativadores de Transcrição/metabolismo , Engenharia de ProteínasRESUMO
Mitochondrial DNA (mtDNA) editing paves the way for disease modeling of mitochondrial genetic disorders in cell lines and animals and also for the treatment of these diseases in the future. Bacterial cytidine deaminase DddA-derived cytosine base editors (DdCBEs) enabling mtDNA editing, however, are largely limited to C-to-T conversions in the 5'-TC context (e.g., TC-to-TT conversions), suitable for generating merely 1/8 of all possible transition (purine-to-purine and pyrimidine-to-pyrimidine) mutations. Here, we present transcription-activator-like effector (TALE)-linked deaminases (TALEDs), composed of custom-designed TALE DNA-binding arrays, a catalytically impaired, full-length DddA variant or split DddA originated from Burkholderia cenocepacia, and an engineered deoxyadenosine deaminase derived from the E. coli TadA protein, which induce targeted A-to-G editing in human mitochondria. Custom-designed TALEDs were highly efficient in human cells, catalyzing A-to-G conversions at a total of 17 target sites in various mitochondrial genes with editing frequencies of up to 49%.
Assuntos
DNA Mitocondrial , Doenças Mitocondriais , Animais , Sistemas CRISPR-Cas , Citosina/metabolismo , DNA Mitocondrial/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Edição de Genes , Humanos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Doenças Mitocondriais/genética , PurinasRESUMO
BACKGROUND: Histone H3K4 tri-methylation (H3K4me3) catalyzed by Set1/COMPASS, is a prominent epigenetic mark found in promoter-proximal regions of actively transcribed genes. H3K4me3 relies on prior monoubiquitination at the histone H2B (H2Bub) by Rad6 and Bre1. Swd2/Cps35, a Set1/COMPASS component, has been proposed as a key player in facilitating H2Bub-dependent H3K4me3. However, a more comprehensive investigation regarding the relationship among Rad6, Swd2, and Set1 is required to further understand the mechanisms and functions of the H3K4 methylation. RESULTS: We investigated the genome-wide occupancy patterns of Rad6, Swd2, and Set1 under various genetic conditions, aiming to clarify the roles of Set1 and Rad6 for occupancy of Swd2. Swd2 peaks appear on both the 5' region and 3' region of genes, which are overlapped with its tightly bound two complexes, Set1 and cleavage and polyadenylation factor (CPF), respectively. In the absence of Rad6/H2Bub, Set1 predominantly localized to the 5' region of genes, while Swd2 lost all the chromatin binding. However, in the absence of Set1, Swd2 occupancy near the 5' region was impaired and rather increased in the 3' region. CONCLUSIONS: This study highlights that the catalytic activity of Rad6 is essential for all the ways of Swd2's binding to the transcribed genes and Set1 redistributes the Swd2 to the 5' region for accomplishments of H3K4me3 in the genome-wide level.
Assuntos
Histona-Lisina N-Metiltransferase , Histonas , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Histonas/metabolismo , Histonas/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Histona-Lisina N-Metiltransferase/genética , Metilação , Adenosina Trifosfatases/metabolismo , Adenosina Trifosfatases/genética , Enzimas de Conjugação de Ubiquitina/metabolismo , Enzimas de Conjugação de Ubiquitina/genéticaRESUMO
Chemotherapy combined with debulking surgery is the standard treatment protocol for high-grade serous ovarian carcinoma (HGSOC). Nonetheless, a significant number of patients encounter relapse due to the development of chemotherapy resistance. To better understand and address this resistance, we conducted a comprehensive study investigating the transcriptional alterations at the single-cell resolution in tissue samples from patients with HGSOC, using single-cell RNA sequencing and T-cell receptor sequencing techniques. Our analyses unveiled notable changes in the tumor signatures after chemotherapy, including those associated with epithelial-mesenchymal transition and cell cycle arrest. Within the immune compartment, we observed alterations in the T-cell profiles, characterized by naïve or pre-exhausted populations following chemotherapy. This phenotypic change was further supported by the examination of adjoining T-cell receptor clonotypes in paired longitudinal samples. These findings underscore the profound impact of chemotherapy on reshaping the tumor landscape and the immune microenvironment. This knowledge may provide clues for the development of future therapeutic strategies to combat treatment resistance in HGSOC.
Assuntos
Neoplasias Ovarianas , Feminino , Humanos , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/genética , Linfócitos T/patologia , Receptores de Antígenos de Linfócitos T , Microambiente TumoralRESUMO
Our prior study reveals that the distension-contraction profiles using high-resolution manometry impedance recordings can distinguish patients with dysphagia symptom but normal esophageal function testing ("functional dysphagia") from control subjects. The aim of this study was to determine the diagnostic value of the recording protocol used in our prior studies (10-mL swallows with subjects in the Trendelenburg position) against the standard clinical protocol (5-mL swallows with subjects in the supine position). We used advanced machine learning techniques and robust metrics for classification purposes. Studies were performed on 30 healthy subjects and 30 patients with functional dysphagia. A custom-built software was used to extract the relevant distension-contraction features of esophageal peristalsis. Ensemble methods, i.e., gradient boost, support vector machines (SVMs), and logit boost, were used as the primary machine learning algorithms. Although the individual contraction features were marginally different between the two groups, the distension features of peristalsis were significantly different. The receiver operating characteristic (ROC) curve values for the standard recording protocol and the distension features ranged from 0.74 to 0.82; they were significantly better for the protocol used in our prior studies, ranging from 0.81 to 0.91. The ROC curve values using three machine learning algorithms were far superior for the distension than the contraction features of esophageal peristalsis, revealing a value of 0.95 for the SVM algorithm. Current patient classification for esophageal motility disorders, based on the contraction phase of peristalsis, ignores a large number of patients who have an abnormality in the distension phase of peristalsis. Distension-contraction plots should be the standard for assessing esophageal peristalsis in clinical practice.NEW & NOTEWORTHY Our findings underscore the superiority of distension features over contraction metrics in diagnosing esophageal dysfunctions. By leveraging state-of-the-art machine learning techniques, our study highlights the diagnostic potential of distension-contraction plots of peristalsis. Implementation of these plots could significantly enhance the accuracy of identifying patients with esophageal motor disorders, advocating for their adoption as the standard in clinical practice.
Assuntos
Transtornos de Deglutição , Deglutição , Esôfago , Manometria , Peristaltismo , Humanos , Manometria/métodos , Peristaltismo/fisiologia , Masculino , Feminino , Esôfago/fisiologia , Esôfago/fisiopatologia , Pessoa de Meia-Idade , Adulto , Transtornos de Deglutição/diagnóstico , Transtornos de Deglutição/fisiopatologia , Deglutição/fisiologia , Idoso , Inteligência Artificial , Transtornos da Motilidade Esofágica/diagnóstico , Transtornos da Motilidade Esofágica/fisiopatologia , Aprendizado de Máquina , Contração Muscular/fisiologiaRESUMO
OBJECTIVES: While endoscopic resection of rectal neuroendocrine tumors (NETs) has significantly increased, long-term data on risk factors for recurrence are still lacking. Our aim is to analyze the long-term outcomes of patients with rectal NETs after endoscopic resection through risk stratification. METHODS: In this multicenter retrospective study, we included patients who underwent endoscopic resection of rectal NETs from 2009 to 2018 and were followed for ≥12 months at five university hospitals. We classified the patients into three risk groups according to the clinicopathological status of the rectal neuroendocrine tumors: low, indeterminate, and high. The high-risk group was defined if the tumors have any of the followings: size ≥ 10 mm, lymphovascular invasion, muscularis propria or deeper invasion, positive resection margins, or mitotic count ≥2/10. RESULTS: A total of 346 patients were included, with 144 (41.6%), 121 (35.0%), and 81 (23.4%) classified into the low-, indeterminate-, and high-risk groups, respectively. Among the high-risk group, seven patients (8.6%) received salvage treatment 28 (27-67) days after the initial endoscopic resection, with no reported extracolonic recurrence. Throughout the follow-up period, 1.1% (4/346) of patients experienced extracolonic recurrences at 56.5 (54-73) months after the initial endoscopic resection. Three of these patients (75%) were in the high-risk group and did not undergo salvage treatment. The risk of extracolonic recurrence was significantly higher in the high-risk group compared to the other groups (p = 0.039). CONCLUSION: Physicians should be concerned about the possibility of metastasis during long-term follow-up of high-risk patients and consider salvage treatment.
Assuntos
Recidiva Local de Neoplasia , Tumores Neuroendócrinos , Neoplasias Retais , Humanos , Estudos Retrospectivos , Neoplasias Retais/cirurgia , Neoplasias Retais/patologia , Masculino , Feminino , Pessoa de Meia-Idade , Tumores Neuroendócrinos/cirurgia , Tumores Neuroendócrinos/patologia , Idoso , Medição de Risco/métodos , Adulto , Fatores de Risco , Resultado do Tratamento , Terapia de Salvação , Ressecção Endoscópica de Mucosa , Margens de ExcisãoRESUMO
MicroRNA-dependent mRNA decay plays an important role in gene silencing by facilitating posttranscriptional and translational repression. Inspired by this intrinsic nature of microRNA-mediated mRNA cleavage, here, we describe a microRNA-targeting mRNA as a switch platform called mRNA bridge mimetics to regulate the translocation of proteins. We applied the mRNA bridge mimetics platform to Cas9 protein to confer it the ability to translocate into the nucleus via cleavage of the nuclear export signal. This system performed programmed gene editing in vitro and in vivo. Combinatorial treatment with cisplatin and miR-21-EZH2 axis-targeting CRISPR Self Check-In improved sensitivity to chemotherapeutic drugs in vivo. Using the endogenous microRNA-mediated mRNA decay mechanism, our platform is able to remodel a cell's natural biology to allow the entry of precise drugs into the nucleus, devoid of non-specific translocation. The mRNA bridge mimetics strategy is promising for applications in which the reaction must be controlled via intracellular stimuli and modulates Cas9 proteins to ensure safe genome modification in diseased conditions.
Assuntos
Proteína 9 Associada à CRISPR , MicroRNAs , Proteína 9 Associada à CRISPR/genética , Sistemas CRISPR-Cas , Edição de Genes , MicroRNAs/genética , RNA Mensageiro/genéticaRESUMO
Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death. FGFR4 has been implicated in HCC progression, making it a promising therapeutic target. We introduce an approach for identifying novel FGFR4 inhibitors by sequentially adding fragments to a common warhead unit. This strategy resulted in the discovery of a potent inhibitor, 4c, with an IC50 of 33 nM and high selectivity among members of the FGFR family. Although further optimisation is required, our approach demonstrated the potential for discovering potent FGFR4 inhibitors for HCC treatment, and provides a useful method for obtaining hit compounds from small fragments.
Assuntos
Relação Dose-Resposta a Droga , Descoberta de Drogas , Receptor Tipo 4 de Fator de Crescimento de Fibroblastos , Receptor Tipo 4 de Fator de Crescimento de Fibroblastos/antagonistas & inibidores , Receptor Tipo 4 de Fator de Crescimento de Fibroblastos/metabolismo , Humanos , Relação Estrutura-Atividade , Estrutura Molecular , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/síntese química , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/metabolismoRESUMO
Plant-derived extracellular vesicles (EVs) elicit diverse biological effects, including promoting skin health. EVs isolated from Ecklonia cava (EV-EC) carry heat shock protein 70 (HSP70), which inhibits key regulators such as TNF-α, MAPKs, and NF-κB, consequently downregulating matrix metalloproteinases (MMPs). Aging exacerbates oxidative stress, upregulating MAPK and NF-κB signaling and worsening extracellular matrix degradation in the skin. E. cava-derived phlorotannin (PT) mitigates MAPK and NF-κB signaling. We evaluated the impact of EV-EC and PT on skin rejuvenation using an in vitro keratinocyte senescence model and an in vivo aged-mouse model. Western blotting confirmed the presence of HSP70 in EV-EC. Treatment with EV-EC and PT in senescent keratinocytes increased HSP70 expression and decreased the expression of TNF-α, MAPK, NF-κB, activator protein-1 (AP-1), and MMPs. Oxidative stress was also reduced. Sequential treatment with PT and EV-EC (PT/EV-EC) yielded more significant results compared to individual treatments. The administration of PT/EV-EC to the back skin of aged mice mirrored the in vitro findings, resulting in increased collagen fiber accumulation and improved elasticity in the aged skin. Therefore, PT/EV-EC holds promise in promoting skin rejuvenation by increasing HSP70 expression, decreasing the expression of MMPs, and reducing oxidative stress in aged skin.
Assuntos
Vesículas Extracelulares , Proteínas de Choque Térmico HSP70 , Queratinócitos , Estresse Oxidativo , Phaeophyceae , Rejuvenescimento , Envelhecimento da Pele , Pele , Animais , Vesículas Extracelulares/efeitos dos fármacos , Vesículas Extracelulares/metabolismo , Phaeophyceae/química , Camundongos , Envelhecimento da Pele/efeitos dos fármacos , Queratinócitos/efeitos dos fármacos , Pele/efeitos dos fármacos , Pele/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Humanos , Estresse Oxidativo/efeitos dos fármacos , Taninos/farmacologia , NF-kappa B/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Recent advancements in understanding the intricate molecular mechanisms underlying immunological responses have underscored the critical involvement of ion channels in regulating calcium influx, particularly in inflammation. Nootkatone, a natural sesquiterpenoid found in Alpinia oxyphylla and various citrus species, has gained attention for its diverse pharmacological properties, including anti-inflammatory effects. This study aimed to elucidate the potential of nootkatone in modulating ion channels associated with calcium signaling, particularly CRAC, KV1.3, and KCa3.1 channels, which play pivotal roles in immune cell activation and proliferation. Using electrophysiological techniques, we demonstrated the inhibitory effects of nootkatone on CRAC, KV1.3, and KCa3.1 channels in HEK293T cells overexpressing respective channel proteins. Nootkatone exhibited dose-dependent inhibition of channel currents, with IC50 values determined for each channel. Nootkatone treatment did not significantly affect cell viability, indicating its potential safety for therapeutic applications. Furthermore, we observed that nootkatone treatment attenuated calcium influx through activated CRAC channels and showed anti-proliferative effects, suggesting its role in regulating inflammatory T cell activation. These findings highlight the potential of nootkatone as a natural compound for modulating calcium signaling pathways by targeting related key ion channels and it holds promise as a novel therapeutic agent for inflammatory disorders.
Assuntos
Sinalização do Cálcio , Canais de Potássio Ativados por Cálcio de Condutância Intermediária , Sesquiterpenos Policíclicos , Linfócitos T , Humanos , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Linfócitos T/imunologia , Sesquiterpenos Policíclicos/farmacologia , Células HEK293 , Sinalização do Cálcio/efeitos dos fármacos , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/metabolismo , Proliferação de Células/efeitos dos fármacos , Canais de Cálcio Ativados pela Liberação de Cálcio/metabolismo , Cálcio/metabolismo , Canal de Potássio Kv1.3/metabolismo , Canal de Potássio Kv1.3/antagonistas & inibidores , Sobrevivência Celular/efeitos dos fármacos , Ativação Linfocitária/efeitos dos fármacos , Sesquiterpenos/farmacologiaRESUMO
Global public health is facing a major issue with emerging resistance to antimicrobial agents. Antimicrobial agents that are currently on the market are strong and efficient, but it has not been ruled out that these medications will eventually cause resistance to bacteria. Exploring novel bioactive compounds derived from natural sources is therefore, crucial to meet future demands. The present study evaluated the mode of action of the antimicrobial potential protease enzyme SH21. Protease SH21 exhibited antimicrobial activity, strong heat stability (up to 100 °C), and pH stability (pH 3.0 to 9.0). In terms of mode of action, we found that protease SH21 was able to disrupt the bacterial cell membrane as the results of the nucleotide leakage and cell membrane permeability assay. In addition, we also checked inner membrane permeability by PI uptake assay which suggested that protease SH21 has the ability to enter the bacterial cell membrane. Our results revealed that the antimicrobial protease SH21 might be a promising candidate for treating microbial infections.
Assuntos
Bacillus , Testes de Sensibilidade Microbiana , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular/efeitos dos fármacos , Peptídeo Hidrolases/metabolismo , Concentração de Íons de Hidrogênio , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Antibacterianos/farmacologia , Antibacterianos/química , Proteínas de Bactérias/metabolismo , Estabilidade EnzimáticaRESUMO
Atopic dermatitis (AD) is a common allergic inflammatory skin condition marked by severe itching, skin lichenification, and chronic inflammation. AD results from a complex immune response, primarily driven by T lymphocytes and environmental triggers, leading to a disrupted epidermal barrier function. Traditional treatments, such as topical corticosteroids, have limitations due to long-term side effects, highlighting the need for safer alternatives. Here, we aimed to show that Agrimonia coreana extract (ACext) can be used in treating AD-related dermatologic symptoms. ACext could inhibit CRAC (Calcium Release-Activated Calcium) channel activity, reducing Orai1/CRAC currents and decreasing intracellular calcium signaling. This inhibition was further confirmed by the reduced IL-2 levels and T cell proliferation upon ACext treatment. In a mouse model of AD, ACext significantly ameliorates symptoms, improves histological parameters, and enhances skin barrier function, demonstrating its potential for treating AD.
Assuntos
Agrimonia , Dermatite Atópica , Extratos Vegetais , Dermatite Atópica/tratamento farmacológico , Dermatite Atópica/metabolismo , Dermatite Atópica/patologia , Animais , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Extratos Vegetais/uso terapêutico , Camundongos , Agrimonia/química , Modelos Animais de Doenças , Canais de Cálcio Ativados pela Liberação de Cálcio/metabolismo , Canais de Cálcio Ativados pela Liberação de Cálcio/antagonistas & inibidores , Humanos , Bloqueadores dos Canais de Cálcio/farmacologia , Bloqueadores dos Canais de Cálcio/uso terapêutico , Sinalização do Cálcio/efeitos dos fármacos , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Linfócitos T/imunologiaRESUMO
STATEMENT OF PROBLEM: Improvement in the mechanical properties of 3-dimensional (3D) printed dental prostheses is necessary to prevent wear caused by an antagonist or fracture. However, how different printing temperatures affect their mechanical properties is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the mechanical properties of 3D printed parts fabricated at different printing temperatures. MATERIAL AND METHODS: Photopolymer specimens were fabricated at 3 different temperatures (room temperature, 50 °C, and 70 °C) using a stereolithography 3D printer. After rinsing to remove the residual monomer, the specimens were divided into 2 groups: with or without postprocessing. The viscosity of the photopolymerization resin was measured while the temperature was increased. Furthermore, the double-bond conversion (DBC) of the printed part was evaluated (n=3). Mechanical properties were investigated via dynamic mechanical analysis (n=1) and tensile testing (n=5). Statistical comparisons were performed via 1-way analysis of variance, followed by the Tukey honestly significant difference test (α=.05). RESULTS: The DBC rates of the green condition group increased from 66.67% to 86.33% with increasing temperature. In addition, these specimens exhibited improved mechanical properties and reduced residual monomer levels. CONCLUSIONS: Specimens fabricated at a temperature of 70 °C exhibited mechanical properties suitable for clinical application.
Assuntos
Impressão Tridimensional , Estereolitografia , Temperatura , Polimerização , Teste de Materiais , Propriedades de SuperfícieRESUMO
STATEMENT OF PROBLEM: Prostheses printed on a 3-dimensional (3D) printer need to undergo the postpolymerization process, which can increase the working time. However, it has been not suggested for reducing workload and improving the properties of prostheses in dental clinical practice. PURPOSE: The purpose of this in vitro study was to evaluate how the printing temperature impacts the dimensional accuracy and fracture load of 3D printed fixed dental prostheses (FDPs). MATERIAL AND METHODS: Dental prostheses were printed at room temperature (RT), 50°C, and 70°C using a stereolithography 3D printer. Subsequently, after rinsing away residual monomer, the printed parts underwent the green condition (it was not subjected to any postprocessing) and postpolymerization. The mechanical properties of the printed FDPs were determined by loading to fracture (n=6). To evaluate their clinical applicability, the dimensional accuracy and fit of FDPs fabricated at various resin polymerization temperatures were measured (n=6). The 1-way analysis of variance was used to perform statistical comparisons, followed by the Tukey honestly significant difference test (α=.05). RESULTS: The specimens printed at RT and 50°C were better than those printed at 70°C in terms of dimensional accuracy and fit (P<.05). Nonetheless, the dimensional accuracy and fit of the specimens printed at 70°C were clinically acceptable. The fracture load of the 3-unit FDPs depended significantly on the printing temperature. CONCLUSIONS: The dimensional accuracy and fracture load of the 70°C group were acceptable for FDP fabrication. Thus, the temperature of 70°C without postprocessing may help make the procedure more efficient.
Assuntos
Prótese Dentária , Estereolitografia , Temperatura , Desenho Assistido por Computador , Polimerização , Teste de Materiais , Impressão TridimensionalRESUMO
Methylation is a major post-translational modification (PTM) generated by methyltransferase on target proteins; it is recognized by the epigenetic reader to expand the functional diversity of proteins. Methylation can occur on specific lysine or arginine residues localized within regulatory domains in both histone and nonhistone proteins, thereby allowing distinguished properties of the targeted protein. Methylated residues are recognized by chromodomain, malignant brain tumor (MBT), Tudor, plant homeodomain (PHD), PWWP, WD-40, ADD, and ankyrin repeats by an induced-fit mechanism. Methylation-dependent activities regulate distinct aspects of target protein function and are largely reliant on methyl readers of histone and nonhistone proteins in various diseases. Methylation of nonhistone proteins that are recognized by methyl readers facilitates the degradation of unwanted proteins, as well as the stabilization of necessary proteins. Unlike nonhistone substrates, which are mainly monomethylated by methyltransferase, histones are di- or trimethylated by the same methyltransferases and then connected to other critical regulators by methyl readers. These fine-tuned controls by methyl readers are significant for the progression or inhibition of diseases, including cancers. Here, current knowledge and our perspectives about regulating protein function by methyl readers are summarized. We also propose that expanded research on the strong crosstalk mechanisms between methylation and other PTMs via methyl readers would augment therapeutic research in cancer.
Assuntos
Histonas , Neoplasias , Histonas/metabolismo , Humanos , Lisina/metabolismo , Metilação , Metiltransferases/metabolismo , Neoplasias/genéticaRESUMO
Retinoic acid receptor-related orphan receptor α (RORα) is a transcription factor involved in nuclear gene expression and a known tumor suppressor. RORα was the first identified substrate of lysine methylation-dependent degradation. However, the mechanisms of other post-translational modifications (PTMs) that occur in RORα remain largely unknown, especially in liver cancer. Arginine methylation is a common PTM in arginine residues of nonhistone and histone proteins and affects substrate protein function and fate. We found an analogous amino acid disposition containing R37 at the ROR N-terminus compared to histone H3 residue, which is arginine methylated. Here, we provide evidence that R37 methylation-dependent degradation is carried out by protein arginine methyltransferase 5 (PRMT5). Further, we discovered that PRMT5 regulated the interaction between the E3 ubiquitin ligase ITCH and RORα through RORα arginine methylation. Arginine methylation-dependent ubiquitination-mediated RORα degradation reduced downstream target gene activation. H2 O2 -induced reactive oxygen species (ROS) decreased PRMT5 protein levels, consequently increasing RORα protein levels in HepG2 liver cancer cells. In addition, ROS inhibited liver cancer progression by inducing apoptosis via PRMT5-mediated RORα methylation and the ITCH axis. Our results potentiate PRMT5 as an elimination target in cancer therapy, and this additional regulatory level within ROS signaling may help identify new targets for therapeutic intervention in liver cancer.
Assuntos
Arginina , Neoplasias Hepáticas , Humanos , Metilação , Espécies Reativas de Oxigênio/metabolismo , Arginina/metabolismo , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismo , Histonas/metabolismo , Processamento de Proteína Pós-Traducional , Neoplasias Hepáticas/genéticaRESUMO
Ischemia-reperfusion (IR) injury, a leading cause of acute kidney injury (AKI), is still without effective therapies. Succinate accumulation during ischemia followed by its oxidation during reperfusion leads to excessive reactive oxygen species (ROS) and severe kidney damage. Consequently, the targeting of succinate accumulation may represent a rational approach to the prevention of IR-induced kidney injury. Since ROS are generated primarily in mitochondria, which are abundant in the proximal tubule of the kidney, we explored the role of pyruvate dehydrogenase kinase 4 (PDK4), a mitochondrial enzyme, in IR-induced kidney injury using proximal tubule cell-specific Pdk4 knockout (Pdk4ptKO) mice. Knockout or pharmacological inhibition of PDK4 ameliorated IR-induced kidney damage. Succinate accumulation during ischemia, which is responsible for mitochondrial ROS production during reperfusion, was reduced by PDK4 inhibition. PDK4 deficiency established conditions prior to ischemia resulting in less succinate accumulation, possibly because of a reduction in electron flow reversal in complex II, which provides electrons for the reduction of fumarate to succinate by succinate dehydrogenase during ischemia. The administration of dimethyl succinate, a cell-permeable form of succinate, attenuated the beneficial effects of PDK4 deficiency, suggesting that the kidney-protective effect is succinate-dependent. Finally, genetic or pharmacological inhibition of PDK4 prevented IR-induced mitochondrial damage in mice and normalized mitochondrial function in an in vitro model of IR injury. Thus, inhibition of PDK4 represents a novel means of preventing IR-induced kidney injury, and involves the inhibition of ROS-induced kidney toxicity through reduction in succinate accumulation and mitochondrial dysfunction.
Assuntos
Traumatismo por Reperfusão , Ácido Succínico , Camundongos , Animais , Ácido Succínico/farmacologia , Espécies Reativas de Oxigênio , Camundongos Knockout , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/prevenção & controle , Isquemia/tratamento farmacológico , Rim , Mitocôndrias , ReperfusãoRESUMO
Muscle atrophy significantly impairs health and quality of life; however, there is still no cure. Recently, the possibility of regeneration in muscle atrophic cells was suggested through mitochondrial transfer. Therefore, we attempted to prove the efficacy of mitochondrial transplantation in animal models. To this end, we prepared intact mitochondria from umbilical cord-derived mesenchymal stem cells maintaining their membrane potential. To examine the efficacy of mitochondrial transplantation on muscle regeneration, we measured muscle mass, cross-sectional area of muscle fiber, and changes in muscle-specific protein. In addition, changes in the signaling mechanisms related to muscle atrophy were evaluated. As a result, in mitochondrial transplantation, the muscle mass increased by 1.5-fold and the lactate concentration decreased by 2.5-fold at 1 week in dexamethasone-induced atrophic muscles. In addition, a 2.3-fold increase in the expression of desmin protein, a muscle regeneration marker, showed a significant recovery in MT 5 µg group. Importantly, the muscle-specific ubiquitin E3-ligases MAFbx and MuRF-1 were significantly decreased through AMPK-mediated Akt-FoxO signaling pathway by mitochondrial transplantation compared with the saline group, reaching a level similar to that in the control. Based on these results, mitochondrial transplantation may have therapeutic applications in the treatment of atrophic muscle disorders.
RESUMO
BACKGROUND: The present study was designed to explore the pathological role of non-canonical NLRC4 inflammasome in glioma. METHODS: This retrospective study included bioinformatical analysis, including survival, gene ontology, ssGSEA, cox regression, IPA and drug repositioning with TCGA and DepMap database. Experimental validations were conducted in glioma patient's sample and evaluated with histological or cellular functional analysis. RESULT: Clinical dataset analysis revealed that non-canonical NLRC4 inflammasomes significantly contribute to glioma progression and poor survival rates. Experimental validation was revealed that the expression of non-canonical NLRC4 inflammasomes were co-localized with astrocytes in malignant gliomas, with a sustained clinical correlation observed between astrocytes and inflammasome signatures. Indeed, the formation of an inflammatory microenvironment increased in malignant gliomas, leading to pyroptosis, known as inflammatory cell death. Molecular interaction analysis revealed that NF-κB pathways potentially serve as the connecting point between the canonical and noncanonical pathways of the NLRC4 inflammasome. Finally, drug repositioning analysis of non-canonical NLRC4 inflammasome-associated molecules revealed that MK-5108, PF4981517, and CTEP may represent effective options for glioma therapy. CONCLUSION: The findings of this study suggest that non-canonical NLRC4 inflammasomes contribute to poor prognosis in patients with glioma and induce an inflammatory microenvironment. We propose the pathological phenomenon of non-canonical NLRC4 inflammasomes and several therapeutic strategies based on the modulation of the inflammatory tumor microenvironment.
Assuntos
Glioma , Inflamassomos , Humanos , Inflamassomos/metabolismo , Astrócitos/metabolismo , Estudos Retrospectivos , Proteínas de Ligação ao Cálcio/genética , Microambiente Tumoral , Proteínas Adaptadoras de Sinalização CARD/metabolismoRESUMO
BACKGROUND: Fracture risks and associated factors are poorly understood in middle-aged and older Asian populations with inflammatory bowel disease (IBD). Therefore, we investigated fracture risk and the effects of comorbidities and lifestyle habits on the risk of developing fractures in middle-aged and older Korean patients with IBD. METHODS: We conducted a nationwide population-based cohort study using data from the National Health Insurance Corporation Database. Patients with IBD who underwent the National Screening Program and were over 40 years of age were included in the study. We compared patients with age- and sex-matched controls. The incidence of fractures, including vertebral, hip, and other sites, was determined using claims data. RESULTS: The risk of total fractures and vertebral fractures was significantly higher in the IBD group (adjusted hazard ratio [HR], 1.31, 95% confidence interval [CI], 1.16-1.48; adjusted HR, 1.59, 95% CI, 1.33-1.92, respectively). Obesity, diabetes, hypertension, and lack of exercise were associated with increased fracture risk in patients with ulcerative colitis (UC). In contrast, the risk increases in patients with Crohn's disease regardless of comorbidities and lifestyle preferences. CONCLUSION: The risk of bone fracture, especially vertebral fracture, is high in middle-aged and older Korean patients with IBD. Obesity, diabetes, hypertension, and lack of exercise are all risk factors associated with bone fractures in patients with UC. These findings are helpful for clinicians to educate patients with IBD on bone health and raise awareness of bone fractures in patients with UC who have specific risk factors.