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1.
Adv Sci (Weinh) ; : e2307216, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38767134

RESUMO

Histone lactylation is a metabolic stress-related histone modification. However, the role of histone lactylation in the development of sepsis-associated acute kidney injury (SA-AKI) remains unclear. Here, histone H3K18 lactylation (H3K18la) is elevated in SA-AKI, which is reported in this study. Furthermore, this lactate-dependent histone modification is enriched at the promoter of Ras homolog gene family member A (RhoA) and positively correlated with the transcription. Correction of abnormal lactate levels resulted in a reversal of abnormal histone lactylation at the promoter of RhoA. Examination of related mechanism revealed that histone lactylation promoted the RhoA/Rho-associated protein kinase (ROCK) /Ezrin signaling, the activation of nuclear factor-κB (NF-κB), inflammation, cell apoptosis, and aggravated renal dysfunction. In addition, Ezrin can undergo lactylation modification. Multiple lactylation sites are identified in Ezrin and confirmed that lactylation mainly occurred at the K263 site. The role of histone lactylation is revealed in SA-AKI and reportes a novel post-translational modification in Ezrin. Its potential role in regulating inflammatory metabolic adaptation of renal proximal tubule epithelial cells is also elucidated. The results provide novel insights into the epigenetic regulation of the onset of SA-AKI.

2.
Adv Sci (Weinh) ; : e2309140, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38639399

RESUMO

Antiphospholipid syndrome (APS) is characterized by thrombus formation, poor pregnancy outcomes, and a proinflammatory response. H3K4me3-related monocytes activation are key regulators of APS pathogenesis. Therefore, H3K4me3 CUT&Tag and ATAC-seq are performed to examine the epigenetic profiles. The results indicate that the H3K4me3 signal and chromatin accessibility at the FOXJ2 promoter are enhanced in an in vitro monocyte model by stimulation with ß2GPI/anti-ß2GPI, which mimics APS, and decreases after OICR-9429 administration. Furthermore, FOXJ2 is highly expressed in patients with primary APS (PAPS) and is the highest in patients with triple-positive antiphospholipid antibodies (aPLs). Mechanistically, FOXJ2 directly binds to the SLAMF8 promoter and activates SLAMF8 transcription. SLAMF8 further interacts with TREM1 to stimulate TLR4/NF-κB signaling and prohibit autophagy. Knockdown of FOXJ2, SLAMF8, or TREM1 blocks TLR4/NF-κB and provokes autophagy, subsequently inhibiting the release of inflammatory and thrombotic indicators. A mouse model of vascular APS is established via ß2GPI intraperitoneal injection, and the results suggest that OICR-9429 administration attenuates the inflammatory response and thrombus formation by inactivating FOXJ2/SLAMF8/TREM1 signaling. These findings highlight the overexpression of H3K4me3-mediated FOXJ2 in APS, which consequently accelerates APS pathogenesis by triggering inflammation and thrombosis via boosting the SLAMF8/TREM1 axis. Therefore, OICR-9429 is a promising candidate drug for APS therapy.

3.
Chem Biol Interact ; 391: 110922, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38412628

RESUMO

Acute kidney injury (AKI) is a disease characterised by acute onset, high mortality, and poor prognosis, and is mainly caused by ischemia-reperfusion (I/R). Human urine-derived stem cells (USCs) exhibit antioxidant, anti-inflammatory, and anti-apoptotic cytoprotective effects. Previously, we found that exosomes from USCs had the ability to inhibit apoptosis and protect kidneys from I/R injury. This study aimed to investigate the role of USC-derived exosomes (USC-Exos) in reducing pyroptosis and alleviating I/R-AKI. Models of HK-2 cells hypoxia-reoxygenation (H/R) and I/R kidney injury was established in Sprague Dawley rats to simulate AKI in vitro and in vivo. USC-Exos were isolated using ultracentrifugation and identified via electron microscopy and western blotting. USC-Exos were co-cultured with HK-2 cells and injected into rats via the tail vein. The expression of pyroptosis-related molecules (GSDMD, caspase-1, and NLRP-3) was verified using PCR and western blotting. Changes in renal function were reflected in the serum creatinine, urea, and cystatin C levels. The degree of renal injury was determined using haematoxylin and eosin and immunohistochemical staining. The levels of IL-1ß and IL-18 were detected using enzyme-linked immunosorbent assay (ELISA) to verify the role of USC-Exos in pyroptosis. Differentially expressed circRNAs in I/R rat kidneys were screened by transcriptome sequencing, and a dual-luciferase experiment was used to verify the interaction between upstream and downstream molecules. Ischemia-reperfusion resulted in significantly impaired renal function and expression of pyroptosis molecules, and significantly increased concentrations of inflammatory factors. These effects were reversed by injecting USC-Exos. Circ DENND4C was the most significantly decreased circRNA in I/R rat renal tissue, and knock-down of circ DENND4C can aggravate AKI in vivo and in vitro. DAVID(http://david.abcc.ncifcrf.gov) website showed that miR 138-5p/FOXO3a is a potential downstream target of circ DENND4C. Knock-down of circ DENND4C in HK-2 cells resulted in increased expression of miR 138-5p and increased miR 138-5p can reverse the regulation of FOXO3a. Dual-luciferase assay verified the reverse interaction between circ DENND4C, miR 138-5p, and FOXO3a. Exosomes promote cell proliferation and inhibit the activation of NLR family pyrin domain containing 3 through the circ DENND4C/miR 138-5p/FOXO3a pathway, thereby reducing pyroptosis and AKI. Circ DENND4C may be a potential therapeutic target for AKI.


Assuntos
Injúria Renal Aguda , Exossomos , MicroRNAs , Traumatismo por Reperfusão , Animais , Humanos , Ratos , Apoptose , Isquemia , Rim , Luciferases , Piroptose , Ratos Sprague-Dawley , Reperfusão , Células-Tronco
4.
Clin Transl Med ; 14(1): e1539, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38224186

RESUMO

BACKGROUND: Alterations of the trimethylation of histone 3 lysine 4 (H3K4me3) mark in monocytes are implicated in the development of autoimmune diseases. Therefore, the purpose of our study was to elucidate the role of H3K4me3-mediated epigenetics in the pathogenesis of antiphospholipid syndrome (APS). METHODS: H3K4me3 Cleavage Under Targets and Tagmentation and Assay for Transposase-Accessible Chromatin were performed to determine the epigenetic profiles. Luciferase reporter assay, RNA immunoprecipitation, RNA pull-down, co-immunoprecipitation and chromatin immunoprecipitation were performed for mechanistic studies. Transmission electron microscopy and propidium iodide staining confirmed cell pyroptosis. Primary monocytes from patients with primary APS (PAPS) and healthy donors were utilised to test the levels of key molecules. A mouse model mimicked APS was constructed with beta2-glycoprotein I (ß2GPI) injection. Blood velocity was detected using murine Doppler ultrasound. RESULTS: H3K4me3 signal and open chromatin at the ARID5B promoter were increased in an in vitro model of APS. The epigenetic factor ARID5B directly activated LINC01128 transcription at its promoter. LINC01128 promoted the formation of the BTF3/STAT3 complex to enhance STAT3 phosphorylation. Activated STAT3 interacted with the NLRP3 promoter and subsequently stimulated pyroptosis and apoptosis. ARID5B or BTF3 depletion compensated for LINC01128-induced pyroptosis and apoptosis by inhibiting STAT3 phosphorylation. In mice with APS, ß2GPI exposure elevated the levels of key proteins of pyroptosis and apoptosis pathways in bone marrow-derived monocytes, reduced the blood velocity of the ascending aorta, increased the thrombus size of the carotid artery, and promoted the release of interleukin (IL)-18, IL-1ß and tissue factor. Patients with PAPS had the high-expressed ARID5B and LINC01128, especially those with triple positivity for antiphospholipid antibodies. Moreover, there was a positive correlation between ARID5B and LINC01128 expression. CONCLUSION: This study indicated that ARID5B/LINC01128 was synergistically upregulated in APS, and they aggravated disease pathogenesis by enhancing the formation of the BTF3/STAT3 complex and boosting p-STAT3-mediated pyroptosis and apoptosis, thereby providing candidate therapeutic targets for APS. HIGHLIGHTS: The H3K4me3 mark and chromatin accessibility at the ARID5B promoter are increased in vitro model mimicked APS. ARID5B-mediated LINC01128 induces pyroptosis and apoptosis via p-STAT3 by binding to BTF3. ARID5B is high- expressed in patients with primary APS and positively correlated with LINC01128 expression. OICR-9429 treatment mitigates pyroptosis and related inflammation in vivo and in vitro models mimicked APS.


Assuntos
Síndrome Antifosfolipídica , Proteínas de Ligação a DNA , Piroptose , RNA Longo não Codificante , Fatores de Transcrição , Animais , Humanos , Camundongos , Síndrome Antifosfolipídica/genética , Cromatina/genética , Cromatina/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Monócitos/metabolismo , Piroptose/genética , RNA/metabolismo , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , RNA Longo não Codificante/genética
5.
Clin Chem Lab Med ; 62(5): 979-987, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-37999934

RESUMO

OBJECTIVES: To evaluate the analytical characteristics of a novel high-sensitivity cardiac troponin T (hs-cTnT) test on the automatic light-initiated chemiluminescent assay (LiCA®) system, and validated its diagnostic performance for non-ST-segment elevation myocardial infarction (NSTEMI). METHODS: Studies included an extensive analytical evaluation and established the 99th percentile upper reference limit (URL) from apparently healthy individuals, followed by a diagnostic performance validation for NSTEMI. RESULTS: Sex-specific 99th percentile URLs were 16.0 ng/L (1.7 % CV: coefficient of variation) for men (21-92 years) and 13.4 ng/L (2.0 % CV) for women (23-87 years) in serum, and 30.6 ng/L (0.9 % CV) for men (18-87 years) and 20.2 ng/L (1.4 % CV) for women (18-88 years) in heparin plasma. Detection rates in healthy individuals ranged from 98.9 to 100 %. An excellent agreement was identified between LiCA® and Elecsys® assays with a correlation coefficient of 0.993 and mean bias of -0.7 % (-1.8-0.4 %) across the full measuring range, while the correlation coefficient and overall bias were 0.967 and -1.1 % (-2.5-0.3 %) for the lower levels of cTnT (10-100 ng/L), respectively. At the specific medical decision levels (14.0 and 52.0 ng/L), assay difference was estimated to be <5.0 %. No significant difference was found between these two assays in terms of area under curve (AUC), sensitivity and specificity, negative predictive value (NPV) and positive predictive value (PPV) for the diagnosis of NSTEMI. CONCLUSIONS: LiCA® hs-cTnT is a reliable 3rd-generation (level 4) high-sensitivity assay for detecting cardiac troponin T. The assay is acceptable for practical use in the diagnosis of NSTEMI.


Assuntos
Infarto do Miocárdio , Infarto do Miocárdio sem Supradesnível do Segmento ST , Infarto do Miocárdio com Supradesnível do Segmento ST , Masculino , Humanos , Feminino , Troponina T , Infarto do Miocárdio/diagnóstico , Heparina , Sensibilidade e Especificidade , Biomarcadores
6.
Sci Data ; 10(1): 627, 2023 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-37709774

RESUMO

Axolotl (Ambystoma mexicanum) is an excellent model for investigating regeneration, the interaction between regenerative and developmental processes, comparative genomics, and evolution. The brain, which serves as the material basis of consciousness, learning, memory, and behavior, is the most complex and advanced organ in axolotl. The modulation of transcription factors is a crucial aspect in determining the function of diverse regions within the brain. There is, however, no comprehensive understanding of the gene regulatory network of axolotl brain regions. Here, we utilized single-cell ATAC sequencing to generate the chromatin accessibility landscapes of 81,199 cells from the olfactory bulb, telencephalon, diencephalon and mesencephalon, hypothalamus and pituitary, and the rhombencephalon. Based on these data, we identified key transcription factors specific to distinct cell types and compared cell type functions across brain regions. Our results provide a foundation for comprehensive analysis of gene regulatory programs, which are valuable for future studies of axolotl brain development, regeneration, and evolution, as well as on the mechanisms underlying cell-type diversity in vertebrate brains.


Assuntos
Ambystoma mexicanum , Encéfalo , Cromatina , Animais , Ambystoma mexicanum/genética , Ascomicetos , Aprendizagem , Mesencéfalo , Análise da Expressão Gênica de Célula Única
7.
Front Neurosci ; 17: 1170355, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37440917

RESUMO

In mammals, early organogenesis begins soon after gastrulation, accompanied by specification of various type of progenitor/precusor cells. In order to reveal dynamic chromatin landscape of precursor cells and decipher the underlying molecular mechanism driving early mouse organogenesis, we performed single-cell ATAC-seq of E8.5-E10.5 mouse embryos. We profiled a total of 101,599 single cells and identified 41 specific cell types at these stages. Besides, by performing integrated analysis of scATAC-seq and public scRNA-seq data, we identified the critical cis-regulatory elements and key transcription factors which drving development of spinal cord and somitogenesis. Furthermore, we intersected accessible peaks with human diseases/traits-related loci and found potential clinical associated single nucleotide variants (SNPs). Overall, our work provides a fundamental source for understanding cell fate determination and revealing the underlying mechanism during postimplantation embryonic development, and expand our knowledge of pathology for human developmental malformations.

8.
Sci Data ; 10(1): 464, 2023 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-37468546

RESUMO

Vertebrate embryogenesis is a remarkable process, during which numerous cell types of different lineages arise within a short time frame. An overwhelming challenge to understand this process is the lack of dynamic chromatin accessibility information to correlate cis-regulatory elements (CREs) and gene expression within the hierarchy of cell fate decisions. Here, we employed single-nucleus ATAC-seq to generate a chromatin accessibility dataset on the first day of zebrafish embryogenesis, including 3.3 hpf, 5.25 hpf, 6 hpf, 10 hpf, 12 hpf, 18 hpf and 24 hpf, obtained 51,620 high-quality nuclei and 23 clusters. Furthermore, by integrating snATAC-seq data with single-cell RNA-seq data, we described the dynamics of chromatin accessibility and gene expression across developmental time points, which validates the accuracy of the chromatin landscape data. Together, our data could serve as a fundamental resource for revealing the epigenetic regulatory mechanisms of zebrafish embryogenesis.


Assuntos
Cromatina , Peixe-Zebra , Animais , Diferenciação Celular/genética , Núcleo Celular/metabolismo , Cromatina/genética , Cromatina/metabolismo , Desenvolvimento Embrionário/genética , Peixe-Zebra/genética , Peixe-Zebra/metabolismo
9.
Environ Sci Pollut Res Int ; 30(17): 50620-50634, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36800097

RESUMO

Compared with the linear economy, the circular economy can solve the contradiction between social development and resource utilization, which has attracted wide attention. Although the relationship between transportation infrastructure and economic development has changed from traditional mode to spatial mode, the spatial effect of transportation infrastructure on regional circular economy is still unclear. By combining the policy changes for developing the circular economy in China, this study constructs a comprehensive index of circular economy development in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA). Based on the time and space development of the circular economy in GBA, we analyze the spatial effect of transportation infrastructure on it. The results show that the regional circular economy in GBA has developed, but has not been decoupled from economic development. The development of the regional circular economy presents a positive spatial spillover effect, which is beneficial to the building of the regional recycling market. The improvement of transportation infrastructure has a positive impact on the circular economy of neighboring cities, but it may have the risk of inhibiting the development of the local circular economy. These findings provide policy recommendations for urban planners to coordinate the development of transportation infrastructure and circular economy.


Assuntos
Desenvolvimento Econômico , Meios de Transporte , China , Cidades , Hong Kong , Macau
10.
Science ; 377(6610): eabp9444, 2022 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-36048929

RESUMO

The molecular mechanism underlying brain regeneration in vertebrates remains elusive. We performed spatial enhanced resolution omics sequencing (Stereo-seq) to capture spatially resolved single-cell transcriptomes of axolotl telencephalon sections during development and regeneration. Annotated cell types exhibited distinct spatial distribution, molecular features, and functions. We identified an injury-induced ependymoglial cell cluster at the wound site as a progenitor cell population for the potential replenishment of lost neurons, through a cell state transition process resembling neurogenesis during development. Transcriptome comparisons indicated that these induced cells may originate from local resident ependymoglial cells. We further uncovered spatially defined neurons at the lesion site that may regress to an immature neuron-like state. Our work establishes spatial transcriptome profiles of an anamniote tetrapod brain and decodes potential neurogenesis from ependymoglial cells for development and regeneration, thus providing mechanistic insights into vertebrate brain regeneration.


Assuntos
Ambystoma mexicanum , Regeneração do Cérebro , Células-Tronco Neurais , Ambystoma mexicanum/fisiologia , Animais , Células-Tronco Neurais/fisiologia , Análise de Célula Única , Telencéfalo/fisiologia , Transcriptoma
12.
Cell ; 185(10): 1777-1792.e21, 2022 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-35512705

RESUMO

Spatially resolved transcriptomic technologies are promising tools to study complex biological processes such as mammalian embryogenesis. However, the imbalance between resolution, gene capture, and field of view of current methodologies precludes their systematic application to analyze relatively large and three-dimensional mid- and late-gestation embryos. Here, we combined DNA nanoball (DNB)-patterned arrays and in situ RNA capture to create spatial enhanced resolution omics-sequencing (Stereo-seq). We applied Stereo-seq to generate the mouse organogenesis spatiotemporal transcriptomic atlas (MOSTA), which maps with single-cell resolution and high sensitivity the kinetics and directionality of transcriptional variation during mouse organogenesis. We used this information to gain insight into the molecular basis of spatial cell heterogeneity and cell fate specification in developing tissues such as the dorsal midbrain. Our panoramic atlas will facilitate in-depth investigation of longstanding questions concerning normal and abnormal mammalian development.


Assuntos
Organogênese , Transcriptoma , Animais , DNA/genética , Embrião de Mamíferos , Feminino , Perfilação da Expressão Gênica/métodos , Mamíferos/genética , Camundongos , Organogênese/genética , Gravidez , Análise de Sequência de RNA/métodos , Análise de Célula Única/métodos , Transcriptoma/genética
13.
Nat Commun ; 12(1): 7083, 2021 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-34873160

RESUMO

The availability of viral entry factors is a prerequisite for the cross-species transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Large-scale single-cell screening of animal cells could reveal the expression patterns of viral entry genes in different hosts. However, such exploration for SARS-CoV-2 remains limited. Here, we perform single-nucleus RNA sequencing for 11 non-model species, including pets (cat, dog, hamster, and lizard), livestock (goat and rabbit), poultry (duck and pigeon), and wildlife (pangolin, tiger, and deer), and investigated the co-expression of ACE2 and TMPRSS2. Furthermore, cross-species analysis of the lung cell atlas of the studied mammals, reptiles, and birds reveals core developmental programs, critical connectomes, and conserved regulatory circuits among these evolutionarily distant species. Overall, our work provides a compendium of gene expression profiles for non-model animals, which could be employed to identify potential SARS-CoV-2 target cells and putative zoonotic reservoirs.


Assuntos
Atlas como Assunto , Análise de Célula Única/veterinária , Enzima de Conversão de Angiotensina 2/genética , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , Aves , Comunicação Celular , Evolução Molecular , Redes Reguladoras de Genes , Interações Hospedeiro-Patógeno , Pulmão/citologia , Pulmão/metabolismo , Pulmão/virologia , Mamíferos , Receptores Virais/genética , Receptores Virais/metabolismo , Répteis , SARS-CoV-2/metabolismo , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Transcriptoma , Tropismo Viral , Internalização do Vírus
14.
Mater Horiz ; 8(1): 250-258, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34821303

RESUMO

Progress toward the development of wearable electromechanical sensors with durable and reliable sensing performance is critical for emerging wearable integrated electronic applications. However, it remains a long-standing challenge to realize mechanically stretchable sensing materials with extremely durable and high-performing sensing ability due to the fundamental dilemma lying in the sensing mechanism. In this work, we proposed an in situ and rapid self-healing strategy through nano-confining a dynamic host-guest supramolecular polymer network in a graphene-based multilevel nanocomposite matrix to fabricate a mechanically stretchable and structurally healable sensing nanocomposite which is provided with intriguing sensing durability and sensitivity simultaneously. When repeatedly stretching and releasing the nanocomposite sensing film, the fast association kinetics of cyclodextrin and adamantane host-guest inclusion complexes and good polymer chain dynamics in the supramolecular polymer network endowed by the nanoconfinement effect enable autonomous and rapid repair of the micro-cracks in situ generated in the sensing material. As a result, our strain sensing devices can achieve an extremely high durability and retain stable sensing performance even after over 100 000 stretching-releasing cycles at large strain of 50%. Moreover, the brittle nature originated from the inorganically dominated structure in conjunction with the thermodynamically stable host-guest interactions and dynamic hydrogen bonds inside the multilevel nanocomposite allow the sensing material to exhibit an ultrahigh gauge factor over 1500 with a large working strain of 58%. This work presents a reliable approach for the construction of ultradurable and high-performing wearable electronics.


Assuntos
Nanocompostos , Materiais Inteligentes , Dispositivos Eletrônicos Vestíveis , Eletrônica , Polímeros
15.
Org Lett ; 23(20): 7900-7904, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34559538

RESUMO

A ligand-enabled nickel-catalyzed intramolecular hydroalkenylation of imines with unactivated alkenes has been developed. A variety of five- and six-membered cyclic allylic amines were synthesized in high yields. The use of both wide-bite-angle diphosphine ligand and Brønsted acid is crucial for realizing the reaction. Preliminary investigation of the asymmetric intramolecular hydroalkenylation of imines shows promising potential for the application of the method in the synthesis of enantio-enriched cyclic allylic amines.

17.
Cancer Sci ; 111(10): 3564-3575, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32767810

RESUMO

Ras has been found to be mutated in 30% of non-small cell lung cancers, and its mutation has been regarded as a causal factor underlying tumorigenesis. However, no successful medicine has been developed so far to inhibit Ras for lung cancer treatment. We have previously identified DHX33 as a Ras downstream effector, promoting cell cycle progression and cell growth. In this study, with the K-Ras (G12D);DHX33 (lox/lox) mouse model, we discovered that genetic ablation of DHX33 inhibited tumor development. We further found that ablation of DHX33 altered the expression of nearly 2000 genes which are critical in cancer development such as cell cycle, apoptosis, glycolysis, Wnt signaling, and cell migration. Our study for the first time demonstrates the pivotal role of the DHX33 in Ras-driven lung cancer development in vivo and highlights that pharmacological targeting DHX33 can be a feasible option in treating Ras-mutant lung cancers.


Assuntos
Carcinogênese/genética , RNA Helicases DEAD-box/genética , Neoplasias Pulmonares/genética , Proteínas ras/genética , Animais , Apoptose/genética , Carcinogênese/patologia , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Ciclo Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica/genética , Pulmão/patologia , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Knockout , Via de Sinalização Wnt/genética
18.
Mol Cell Biol ; 40(13)2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32312884

RESUMO

RNA helicase DHX33 was found to regulate the transcription of multiple genes involved in cancer development. But the underlying molecular mechanism remains unclear. Here, we found DHX33 associated extensively with gene promoters at CG-rich region. Its deficiency reduced the loading of active RNA polymerase II at gene promoters. Furthermore, we observed a functional interaction between DHX33, AP-2ß, and DNA demethylation protein Gadd45a (growth arrest and DNA damage inductile protein 45a) at specific gene promoters. DHX33 is required to recruit GADD45a, thereby causing local DNA demethylation through further recruiting ten-eleven-translocation (Tet) methylcytosine dioxygenase enzyme, as manifested by reduced 5-hydroxymethyl cytosine levels for a subset of genes after DHX33 deficiency. This process might involve R-loop formation in GC skew as a guidance signal at promoter sites. Our report provides for the first time, to our knowledge, original evidence that DHX33 alters epigenetic marks and regulates specific gene transcription through interaction with Gadd45a.


Assuntos
Proteínas de Ciclo Celular/metabolismo , RNA Helicases DEAD-box/metabolismo , Desmetilação do DNA , Neoplasias/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias/genética , Regiões Promotoras Genéticas , Mapas de Interação de Proteínas , Ativação Transcricional
19.
Nanomaterials (Basel) ; 9(8)2019 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-31382556

RESUMO

The objective of this study was to investigate the roles and tribological mechanisms of onion-like carbon nanoparticles derived from biodiesel soot (BDS) when applied in water (H2O) and liquid paraffin (LP). In this study, we prepared nitric acid-treated BDS (NA-BDS) as an additive to H2O and NA-BDS modified with oleylamine (NA-BDS-OLA) as an additive to LP. Raman spectroscopy, field-emission transmission electron microscopy, Fourier transform infrared spectroscopy, and zeta potentiometry were used to characterize the results of the nitric acid treatment and oleylamine modification. The tribological behaviors and corresponding mechanisms of the new onion-like carbon nanoparticles were evaluated using a ball-on-disc reciprocating tribometer, as well as field-emission scanning electron microscopy, three-dimensional laser scanning microscopy, and Raman spectroscopy. The results indicated that the additives NA-BDS and NA-BDS-OLA, which were onion-like carbon nanoparticles with sizes ranging from 35 to 40 nm, enhanced the antiwear and friction reduction properties of H2O and LP, respectively. Through tribo-mechanisms, these types of soot can serve as spacers and ball bearings between the rubbing surfaces. Moreover, exfoliation under a high load as a result of the formation of a graphitic layer facilitates easy shearing.

20.
Mol Cell Biol ; 39(17)2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31182639

RESUMO

The RNA helicase DHX33 has been found to be overexpressed in human cancers, where it promotes cancer development. Previous reports have shown that DHX33 deficiency caused cancer cell apoptosis, but the underlying mechanism remains unknown. In this study, we discovered that DHX33 regulates Bcl-2 family protein expression. In multiple human cancer cell lines, DHX33 was found to stimulate the transcription of Bcl-2 Mechanistically, we found that DHX33 interacts with the AP-2ß transcription factor and acts as a coactivator to stimulate Bcl-2 gene transcription. DHX33 deficiency abolished the loading of AP-2ß onto the promoter of Bcl-2 and thereby reduced the recruitment of active RNA polymerase II during transcription initiation. Acute knockdown of DHX33 in multiple human cancer cells caused decreased Bcl-2 protein level, which ultimately triggered mitochondrion-mediated cellular apoptosis. In addition, we found that normal human lung and mammary epithelial cells were less sensitive to acute DHX33 knockdown, implying that cancer cells are uniquely responsive to DHX33 reduction. These data support the notion that disruption of DHX33 function could be an important application for cancer therapy.


Assuntos
Neoplasias da Mama/patologia , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Fator de Transcrição AP-2/metabolismo , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular , Feminino , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , Camundongos , Mitocôndrias/metabolismo , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Polimerase II/metabolismo
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