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1.
Nucleic Acids Res ; 2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-33950203

RESUMO

The CCCH-type zinc finger (ZnF) containing ZC3H12 ribonucleases are crucial in post-transcriptional immune homoeostasis with ZC3H12A being the only structurally studied member of the family. In this study, we present a structural-biochemical characterization of ZC3H12C, which is linked with chronic immune disorders like psoriasis. We established that the RNA substrate is cooperatively recognized by the PIN and ZnF domains of ZC3H12C and analyzed the crystal structure of ZC3H12C bound to a single-stranded RNA substrate. The RNA engages in hydrogen-bonded contacts and stacking interactions with the PIN and ZnF domains simultaneously. The ZC3H12 ZnF shows unprecedented structural features not previously observed in any member of the CCCH-ZnF family and utilizes stacking interactions via a unique combination of spatially conserved aromatic residues to align the target transcript in a bent conformation onto the ZnF scaffold. Further comparative structural analysis of ZC3H12 CCCH-ZnF suggests that a trinucleotide sequence is recognized by ZC3H12 ZnF in target RNA. Our work not only describes the initial structure-biochemical study on ZC3H12C, but also provides the first molecular insight into RNA recognition by a ZC3H12 family member. Finally, our work points to an evolutionary code for RNA recognition adopted by CCCH-type ZnF proteins.

2.
Artigo em Inglês | MEDLINE | ID: mdl-33470487

RESUMO

BACKGROUND AND AIM: Thiopurines are often used in combination with mesalazine for the treatment of ulcerative colitis (UC). Mesalazine formulations are delivered to the digestive tract by various delivery systems and absorbed as 5-aminosalicylic acid (5-ASA). 5-ASA is known to inhibit thiopurine S-methyltransferase (TPMT) activity and to affect thiopurine metabolism. There have been no studies comparing TPMT inhibition by multimatrix mesalazine (MMX) with other formulations. We investigated the difference in TPMT inhibition by different mesalazine formulations and prospectively confirmed the clinical relevance. METHODS: Plasma concentrations of 5-ASA, N-acetyl-5-aminosalicylic acid (N-Ac-5-ASA), and TPMT activities were measured in UC patients receiving various mesalazine formulations (time-dependent or pH-dependent mesalazine or MMX) as monotherapy. Patients already on both time-dependent or pH-dependent mesalazine and thiopurines switched their mesalazine to MMX, examining 6-thioguanine nucleotide (6-TGN) and 6-methylmercaptopurine (6-MMP) 0 and 8 weeks after switching. Clinical relapse after switching was also monitored for 24 weeks. RESULTS: Plasma 5-ASA and N-Ac-5-ASA levels were significantly higher in patients receiving time-dependent mesalazine (n = 12) compared with pH-dependent mesalazine (n = 12) and MMX (n = 15), accompanied by greater TPMT inhibition. Prospective switching from time-dependent mesalazine to MMX decreased 6-TGN levels, increased those of 6-MMP, and increased 6-MMP/6-TGN ratios. Furthermore, this resulted in significantly more relapses than switching from pH-dependent mesalazine to MMX. CONCLUSIONS: Time-dependent mesalazine has higher plasma 5-ASA and N-Ac-5-ASA levels and greater TPMT inhibition than MMX. Therefore, switching from time-dependent mesalazine to MMX may lead to an increase of 6-MMP/6-TGN, which may reduce the clinical effectiveness of thiopurines, warranting close monitoring after switch.

3.
Biochem Biophys Res Commun ; 534: 1-7, 2020 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-33302159

RESUMO

The development of molecular targeted therapy has improved clinical outcomes in patients with life-threatening advanced lung cancers with driver oncogenes. However, selective treatment for KRAS-mutant lung cancer remains underdeveloped. We have successfully characterised specific molecular and pathological features of KRAS-mutant lung cancer utilising newly developed cell line models that can elucidate the differences in driver oncogenes among tissues with identical genetic backgrounds. Among these KRAS-mutation-associated specific features, we focused on the IGF2-IGF1R pathway, which has been implicated in the drug resistance mechanisms to AMG 510, a recently developed selective inhibitor of KRAS G12C lung cancer. Experimental data derived from our cell line model can be used as a tool for clinical treatment strategy development through understanding of the biology of lung cancer. The model developed in this paper may help understand the mechanism of anticancer drug resistance in KRAS-mutated lung cancer and help develop new targeted therapies to treat patients with this disease.

4.
Cell Mol Life Sci ; 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33128106

RESUMO

The central dogma of molecular biology entails that genetic information is transferred from nucleic acid to proteins. Notwithstanding retro-transcribing genetic elements, DNA is transcribed to RNA which in turn is translated into proteins. Recent advancements have shown that each stage is regulated to control protein abundances for a variety of essential physiological processes. In this regard, mRNA regulation is essential in fine-tuning or calibrating protein abundances. In this review, we would like to discuss one of several mRNA-intrinsic features of mRNA regulation that has been gaining traction of recent-codon bias and optimality. Specifically, we address the effects of codon bias with regard to codon optimality in several biological processes centred on translation, such as mRNA stability and protein folding among others. Finally, we examine how different organisms or cell types, through this system, are able to coordinate physiological pathways to respond to a variety of stress or growth conditions.

5.
Mol Cancer Res ; 2020 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-33106373

RESUMO

EGFR mutation-positive patients with non-small cell lung cancer (NSCLC) respond well to treatment with EGFR-tyrosine kinase inhibitors (EGFR-TKI); however, treatment with EGFR-TKIs is not curative, owing to the presence of residual cancer cells with intrinsic or acquired resistance to this class of drugs. Additional treatment targets that may enhance the efficacy of EGFR-TKIs remain elusive. Using a CRISPR/Cas9-based screen, we identified the leucine-rich repeat scaffold protein SHOC2 as a key modulator of sensitivity to EGFR-TKI treatment. On the basis of in vitro assays, we demonstrated that SHOC2 expression levels strongly correlate with the sensitivity to EGFR-TKIs and that SHOC2 affects the sensitivity to EGFR-TKIs in NSCLC cells via SHOC2/MRAS/PP1c and SHOC2/SCRIB signaling. The potential SHOC2 inhibitor celastrol phenocopied SHOC2 depletion. In addition, we confirmed that SHOC2 expression levels were important for the sensitivity to EGFR-TKIs in vivo. Furthermore, IHC showed the accumulation of cancer cells that express high levels of SHOC2 in lung cancer tissues obtained from patients with NSCLC who experienced acquired resistance to EGFR-TKIs. These data indicate that SHOC2 may be a therapeutic target for patients with NSCLC or a biomarker to predict sensitivity to EGFR-TKI therapy in EGFR mutation-positive patients with NSCLC. Our findings may help improve treatment strategies for patients with NSCLC harboring EGFR mutations. IMPLICATIONS: This study showed that SHOC2 works as a modulator of sensitivity to EGFR-TKIs and the expression levels of SHOC2 can be used as a biomarker for sensitivity to EGFR-TKIs.

6.
Cancer Sci ; 2020 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-32986894

RESUMO

Acquisition of resistance to gemcitabine is a challenging clinical and biological hallmark property of refractory pancreatic cancer. Here, we investigated whether glycogen synthase kinase (GSK)-3ß, an emerging therapeutic target in various cancer types, is mechanistically involved in acquired resistance to gemcitabine in human pancreatic cancer. This study included 3 gemcitabine-sensitive BxPC-3 cell-derived clones (BxG30, BxG140, BxG400) that acquired stepwise resistance to gemcitabine and overexpressed ribonucleotide reductase (RR)M1. Treatment with GSK3ß-specific inhibitor alone attenuated the viability and proliferation of the gemcitabine-resistant clones, while synergistically enhancing the efficacy of gemcitabine against these clones and their xenograft tumors in rodents. The gemcitabine-resensitizing effect of GSK3ß inhibition was associated with decreased expression of RRM1, reduced phosphorylation of Rb protein, and restored binding of Rb to the E2 transcription factor (E2F)1. This was followed by decreased E2F1 transcriptional activity, which ultimately suppressed the expression of E2F1 transcriptional targets including RRM1, CCND1 encoding cyclin D1, thymidylate synthase, and thymidine kinase 1. These results suggested that GSK3ß participates in the acquisition of gemcitabine resistance by pancreatic cancer cells via impairment of the functional interaction between Rb tumor suppressor protein and E2F1 pro-oncogenic transcription factor, thereby highlighting GSK3ß as a promising target in refractory pancreatic cancer. By providing insight into the molecular mechanism of gemcitabine resistance, this study identified a potentially novel strategy for pancreatic cancer chemotherapy.

7.
Eur Respir J ; 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978308

RESUMO

Regnase-1 is an RNase critical for posttranscriptional control of pulmonary immune homeostasis in mice by degrading immune-related mRNAs. However, little is known about the cell types Regnase-1 controls in the lung, and its relevance to human pulmonary diseases.Regnase-1-dependent changes in lung immune cell types were examined by a competitive bone marrow transfer mouse model, and group 2 innate lymphoid cells (ILC2s) were identified. Then the associations between Regnase-1 in ILC2s and human diseases were investigated by transcriptome analysis and a bleomycin-induced pulmonary fibrosis mouse model. The clinical significance of Regnase-1 in ILC2s was further assessed using patients-derived cells.Regnase-1-deficiency resulted in the spontaneous proliferation and activation of ILC2s in the lung. Intriguingly, genes associated with pulmonary fibrosis were highly upregulated in Regnase1-deficient ILC2s compared with wild-type, and supplementation of Regnase-1-deficient ILC2s augmented bleomycin-induced pulmonary fibrosis in mice. Regnase-1 suppresses mRNAs encoding transcription factors Gata3 and Egr1, which are potent to regulate fibrosis-associated genes. Clinically, Regnase-1 protein levels in ILC2 negatively correlated with the ILC2 population in bronchoalveolar lavage (BAL) fluid. Furthermore, idiopathic pulmonary fibrosis (IPF) patients with more than 1500 cells·mL-1 peripheral blood ILC2s exhibited poorer prognosis than patients with lower numbers, implying the contribution of Regnase-1 in ILC2s for the progression of IPF.Collectively, Regnase-1 was identified as a critical posttranscriptional regulator of the pro-fibrotic function of ILC2s both in mouse and human, suggesting that Regnase-1 may be a novel therapeutic target for IPF.

8.
Sci Immunol ; 5(51)2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32887843

RESUMO

Cell type-specific gene expression is driven by the interplay between lineage-specific transcription factors and cis-regulatory elements to which they bind. Adaptive immunity relies on RAG-mediated assembly of T cell receptor (TCR) and immunoglobulin (Ig) genes. Although Rag1 and Rag2 expression is largely restricted to adaptive lymphoid lineage cells, it remains unclear how Rag gene expression is regulated in a cell lineage-specific manner. Here, we identified three distinct cis-regulatory elements, a T cell lineage-specific enhancer (R-TEn) and the two B cell-specific elements, R1B and R2B By generating mice lacking either R-TEn or R1B and R2B, we demonstrate that these distinct sets of regulatory elements drive the expression of Rag genes in developing T and B cells. What these elements have in common is their ability to bind the transcription factor E2A. By generating a mouse strain that carries a mutation within the E2A binding site of R-TEn, we demonstrate that recruitment of E2A to this site is essential for orchestrating changes in chromatin conformation that drive expression of Rag genes in T cells. By mapping cis-regulatory elements and generating multiple mouse strains lacking distinct enhancer elements, we demonstrate expression of Rag genes in developing T and B cells to be driven by distinct sets of E2A-dependent cis-regulatory modules.

9.
Cell Rep ; 32(2): 107906, 2020 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-32668247

RESUMO

Zinc finger protein St18 was initially reported as candidate tumor suppressor gene, and also suggested that fibroblast St18 positively regulates NF-κB activation. Despite the pleiotropic functions of St18, little is known about its roles in macrophages. Here, we report that myeloid St18 is a potent inhibitor of VEGF-A. Mice lacking St18 in myeloid lineages exhibit increased retinal vasculature with enhanced serum VEGF-A concentrations. Despite the normal activation of NF-κB target genes, these mice are highly susceptible to LPS-induced shock, polymicrobial sepsis, and experimental colitis, accompanied by enhanced vascular and intestinal leakage. Pharmacological inhibition of VEGF signaling rescued the high mortality rate of myeloid-specific St18-deficient mice in response to inflammation. Mechanistically, St18 directly binds to Sp1 and attenuates its activity, leading to the suppression of Sp1 target gene VEGF-A. Using mouse genetic and pharmacological models, we reveal myeloid St18 as a critical septic death protector.

10.
Cells ; 9(7)2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32708595

RESUMO

RNA acts as an immunostimulatory molecule in the innate immune system to activate nucleic acid sensors. It functions as an intermediate, conveying genetic information to control inflammatory responses. A key mechanism for RNA sensing is discriminating self from non-self nucleic acids to initiate antiviral responses reliably, including the expression of type I interferon (IFN) and IFN-stimulated genes. Another important aspect of the RNA-mediated inflammatory response is posttranscriptional regulation of gene expression, where RNA-binding proteins (RBPs) have essential roles in various RNA metabolisms, including splicing, nuclear export, modification, and translation and mRNA degradation. Recent evidence suggests that the control of mRNA stability is closely involved in signal transduction and orchestrates immune responses. In this study, we review the current understanding of how RNA is sensed by host RNA sensing machinery and discuss self/non-self-discrimination in innate immunity focusing on mammalian species. Finally, we discuss how posttranscriptional regulation by RBPs shape immune reactions.

11.
Mol Cell Biochem ; 472(1-2): 187-198, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32567031

RESUMO

In our previous study, we showed that prexasertib, a checkpoint kinase 1 (Chk1) inhibitor, enhances the effects of standard drugs for pancreatic cancer, including gemcitabine (GEM), S-1, and the combination of GEM and S-1 (GS). The combination of prexasertib and GS has a strong antitumor effect and induces apoptosis in pancreatic cancer cells by downregulating anti-apoptotic protein Bcl-2. In the present study, we investigated the combined effect of GEM, S-1, and prexasertib with a selective Bcl-2 inhibitor (venetoclax) and a non-selective Bcl-2 inhibitor (navitoclax) in SUIT-2 pancreatic cancer cells. An MTT assay revealed that the combination of prexasertib with navitoclax showed a synergistic effect but the combination with venetoclax did not. Investigation of the pancreatic cancer cell lines SUIT-2, MIA PaCa-2, and BxPC-3 revealed that BxPC-3 also showed a high synergistic effect when combined with prexasertib and navitoclax but not venetoclax. Mechanistic analysis of the combined effect showed that apoptosis was induced. Bcl-2 knockdown with siRNA and prexasertib treatment did not induce apoptosis, whereas Bcl-xL knockdown with siRNA and prexasertib treatment resulted in strong induction of apoptosis. In addition, among the three cell lines, the combined effect of prexasertib and navitoclax resulted in increased apoptotic cell death because the protein expression levels of Bcl-xL and Chk1 were higher. Our results demonstrate that the combination of prexasertib and navitoclax has a strong antitumor effect and induces apoptosis in pancreatic cancer cells by downregulating Bcl-xL. Simultaneous inhibition of Chk1 and Bcl-xL could be a new strategy for treating pancreatic cancer.

12.
Oncol Rep ; 43(2): 689-699, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31789403

RESUMO

Our previous study demonstrated that gemcitabine (GEM), S­1, and a combination of GEM and S­1 (GS) induced S­phase arrest and increased the phosphorylation of checkpoint kinase 1 (Chk1), which is a critical mediator of cell survival under impaired DNA replication, in pancreatic cancer cell lines. The aim of the present study was to investigate the combined effect of the Chk1 inhibitor prexasertib and antitumor drugs (GEM and S­1) on pancreatic cancer cell line SUIT­2. Furthermore, we conducted mechanistic analysis of the combined effect. The MTT assay revealed that a combination of prexasertib and GS showed a strong effect. Mechanistic analysis of the combined effect showed effective induction of apoptosis. Furthermore, a combination of prexasertib and GS downregulated the expression of antiapoptotic protein Bcl­2. Chk1 knockdown with small interfering RNA and GS treatment resulted in strong induction of apoptosis. Our results provide evidence to show that the combination of prexasertib and GS has a strong antitumor effect and effectively induces apoptosis in pancreatic cancer cells through downregulation of the antiapoptotic protein Bcl­2. Prexasertib could possibly enhance the effects of standard drugs, including GEM, S­1, and GS, against pancreatic cancer.


Assuntos
Desoxicitidina/análogos & derivados , Ácido Oxônico/farmacologia , Neoplasias Pancreáticas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Pirazinas/farmacologia , Pirazóis/farmacologia , Tegafur/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Desoxicitidina/farmacologia , Regulação para Baixo , Combinação de Medicamentos , Sinergismo Farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Pancreáticas/tratamento farmacológico
13.
Bioconjug Chem ; 31(3): 577-583, 2020 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-31877021

RESUMO

Protein degradation plays various roles in cellular homeostasis and signal transduction. Real-time monitoring of the degradation process not only contributes to the elucidation of relevant biological phenomena but also offers a powerful tool for drug discoveries targeting protein degradation. Fluorescent protein labeling with a protein tag and a synthetic fluorescent probe is a powerful technique that enables the direct visualization of proteins of interest in living cells. Although a variety of protein tags and their labeling probes have been reported, techniques for the visualization of protein degradation in living cells remain limited. In order to overcome this limitation, we herein employed a PYP-tag labeling probe with a fluorescence turn-off switch that enables the imaging of protein degradation. Furthermore, we performed a structure-based design of a PYP-tag to stabilize a complex formed by the probe and the protein tag for long-term live-cell imaging. We successfully applied this technique to live-cell imaging of the degradation process of Regnase-1 in response to immunostimulation.

14.
Nat Genet ; 51(9): 1369-1379, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31477927

RESUMO

Promoters and enhancers are key cis-regulatory elements, but how they operate to generate cell type-specific transcriptomes is not fully understood. We developed a simple and robust method, native elongating transcript-cap analysis of gene expression (NET-CAGE), to sensitively detect 5' ends of nascent RNAs in diverse cells and tissues, including unstable transcripts such as enhancer-derived RNAs. We studied RNA synthesis and degradation at the transcription start site level, characterizing the impact of differential promoter usage on transcript stability. We quantified transcription from cis-regulatory elements without the influence of RNA turnover, and show that enhancer-promoter pairs are generally activated simultaneously on stimulation. By integrating NET-CAGE data with chromatin interaction maps, we show that cis-regulatory elements are topologically connected according to their cell type specificity. We identified new enhancers with high sensitivity, and delineated primary locations of transcription within super-enhancers. Our NET-CAGE dataset derived from human and mouse cells expands the FANTOM5 atlas of transcribed enhancers, with broad applicability to biomedical research.


Assuntos
Regiões 5' não Traduzidas/genética , Biologia Computacional/métodos , Elementos Facilitadores Genéticos , Regulação da Expressão Gênica , Regiões Promotoras Genéticas , RNA/genética , Transcrição Genética , Perfilação da Expressão Gênica , Células HeLa , Células Hep G2 , Humanos , Células MCF-7 , Sítio de Iniciação de Transcrição , Transcriptoma
15.
EMBO Rep ; 20(11): e48220, 2019 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-31482640

RESUMO

Codon bias has been implicated as one of the major factors contributing to mRNA stability in several model organisms. However, the molecular mechanisms of codon bias on mRNA stability remain unclear in humans. Here, we show that human cells possess a mechanism to modulate RNA stability through a unique codon bias. Bioinformatics analysis showed that codons could be clustered into two distinct groups-codons with G or C at the third base position (GC3) and codons with either A or T at the third base position (AT3): the former stabilizing while the latter destabilizing mRNA. Quantification of codon bias showed that increased GC3-content entails proportionately higher GC-content. Through bioinformatics, ribosome profiling, and in vitro analysis, we show that decoupling the effects of codon bias reveals two modes of mRNA regulation, one GC3- and one GC-content dependent. Employing an immunoprecipitation-based strategy, we identify ILF2 and ILF3 as RNA-binding proteins that differentially regulate global mRNA abundances based on codon bias. Our results demonstrate that codon bias is a two-pronged system that governs mRNA abundance.


Assuntos
Uso do Códon , Códon , RNA Mensageiro/genética , Biologia Computacional/métodos , Guanilato Ciclase/genética , Humanos , Proteína do Fator Nuclear 45/metabolismo , Estabilidade de RNA , Ribossomos/genética , Ribossomos/metabolismo , Transcrição Genética
16.
Immunol Med ; 42(2): 53-64, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31449478

RESUMO

Autoimmune disease is induced by the breakdown of immune tolerance to self-antigens. This is brought about by an imbalance between the activation and the repression of immune responses. Dysregulation of the immune response is driven by the excess of proinflammatory cytokines such as IL-6 and TNF, which play a central role in the pathogenesis of a set of autoimmune diseases. The expression of proinflammatory mediator genes is tightly controlled by post-transcriptional regulation, which is mediated by a set of immune-related RNA binding proteins, such as tristetraprolin, Roquin, and Regnase-1. These proteins coordinately control the stability of proinflammatory mRNAs to regulate aberrant immune reactions. In this review, we discuss the roles of RNA binding proteins which are associated with the immune regulation and autoimmune pathogenesis.


Assuntos
Doenças Autoimunes/etiologia , Doenças Autoimunes/imunologia , Proteínas de Ligação a RNA/fisiologia , Humanos , Mediadores da Inflamação/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , RNA Mensageiro/metabolismo , Ribonucleases/fisiologia , Fatores de Transcrição/fisiologia , Tristetraprolina/fisiologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Ubiquitina-Proteína Ligases/fisiologia
17.
Nucleic Acids Res ; 47(16): 8838-8859, 2019 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-31329944

RESUMO

Regnase-1-mediated mRNA decay (RMD), in which inflammatory mRNAs harboring specific stem-loop structures are degraded, is a critical part of proper immune homeostasis. Prior to initial translation, Regnase-1 associates with target stem-loops but does not carry out endoribonucleolytic cleavage. Single molecule imaging revealed that UPF1 is required to first unwind the stem-loops, thus licensing Regnase-1 to proceed with RNA degradation. Following translation, Regnase-1 physically associates with UPF1 using two distinct points of interaction: The Regnase-1 RNase domain binds to SMG1-phosphorylated residue T28 in UPF1; in addition, an intrinsically disordered segment in Regnase-1 binds to the UPF1 RecA domain, enhancing the helicase activity of UPF1. The SMG1-UPF1-Regnase-1 axis targets pioneer rounds of translation and is critical for rapid resolution of inflammation through restriction of the number of proteins translated by a given mRNA. Furthermore, small-molecule inhibition of SMG1 prevents RNA unwinding in dendritic cells, allowing post-transcriptional control of innate immune responses.


Assuntos
Macrófagos Peritoneais/imunologia , Degradação do RNAm Mediada por Códon sem Sentido/imunologia , Proteínas Serina-Treonina Quinases/genética , RNA Mensageiro/genética , Ribonucleases/genética , Transativadores/genética , Animais , Fibroblastos/citologia , Fibroblastos/imunologia , Células HEK293 , Células HeLa , Homeostase/genética , Homeostase/imunologia , Humanos , Imunidade Inata , Inflamação , Sequências Repetidas Invertidas , Macrófagos/citologia , Macrófagos/imunologia , Macrófagos Peritoneais/citologia , Camundongos , Camundongos Knockout , Mutação , Cultura Primária de Células , Ligação Proteica , Biossíntese de Proteínas , Domínios e Motivos de Interação entre Proteínas , Proteínas Serina-Treonina Quinases/imunologia , RNA Mensageiro/metabolismo , Ribonucleases/deficiência , Ribonucleases/imunologia , Imagem Individual de Molécula , Transativadores/imunologia
18.
ACS Nano ; 13(7): 7527-7535, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31149797

RESUMO

The in-plane connection and layer-by-layer stacking of atomically thin layered materials are expected to allow the fabrication of two-dimensional (2D) heterostructures with exotic physical properties and future engineering applications. However, it is currently necessary to develop a continuous growth process that allows the assembly of a wide variety of atomic layers without interface degradation, contamination, and/or alloying. Herein, we report the continuous heteroepitaxial growth of 2D multiheterostructures and nanoribbons based on layered transition metal dichalcogenide (TMDC) monolayers, employing metal organic liquid precursors with high supply controllability. This versatile process can avoid air exposure during growth process and enables the formation of in-plane heterostructures with ultraclean atomically sharp and zigzag-edge straight junctions without defects or alloy formation around the interface. For the samples grown directly on graphite, we have investigated the local electronic density of states of atomically sharp heterointerface by scanning tunneling microscopy and spectroscopy, together with first-principles calculations. These results demonstrate an approach to realizing diverse nanostructures such as atomic layer-based quantum wires and superlattices and suggest advanced applications in the fields of electronics and optoelectronics.

19.
Clin Transl Immunology ; 8(6): e1063, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31236273

RESUMO

Inflammation is the host response against stresses such as infection. Although the inflammation process is required for the elimination of pathogens, uncontrolled inflammation leads to tissue destruction and inflammatory diseases. To avoid this, the inflammatory response is tightly controlled by multiple layers of regulation. Post-transcriptional control of inflammatory mRNAs is increasingly understood to perform critical roles in this process. This is mediated primarily by a set of RNA binding proteins (RBPs) including tristetraprolin, Roquin and Regnase-1, and RNA methylases. These key regulators coordinate the inflammatory response by modulating mRNA pools in both immune and local nonimmune cells. In this review, we provide an overview of the post-transcriptional coordination of immune responses in various tissues and discuss how RBP-mediated regulation of inflammation may be harnessed as a potential class of treatments for inflammatory diseases.

20.
Nat Microbiol ; 4(9): 1532-1544, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31133753

RESUMO

RNA-modulating factors not only regulate multiple steps of cellular RNA metabolism, but also emerge as key effectors of the immune response against invading viral pathogens including human immunodeficiency virus type-1 (HIV-1). However, the cellular RNA-binding proteins involved in the establishment and maintenance of latent HIV-1 reservoirs have not been extensively studied. Here, we screened a panel of 62 cellular RNA-binding proteins and identified NEDD4-binding protein 1 (N4BP1) as a potent interferon-inducible inhibitor of HIV-1 in primary T cells and macrophages. N4BP1 harbours a prototypical PilT N terminus-like RNase domain and inhibits HIV-1 replication by interacting with and degrading viral mRNA species. Following activation of CD4+ T cells, however, N4BP1 undergoes rapid cleavage at Arg 509 by the paracaspase named mucosa-associated lymphoid tissue lymphoma translocation 1 (MALT1). Mutational analyses and knockout studies revealed that MALT1-mediated inactivation of N4BP1 facilitates the reactivation of latent HIV-1 proviruses. Taken together, our findings demonstrate that the RNase N4BP1 is an efficient restriction factor of HIV-1 and suggest that inactivation of N4BP1 by induction of MALT1 activation might facilitate elimination of latent HIV-1 reservoirs.


Assuntos
Infecções por HIV/virologia , HIV-1/fisiologia , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa/metabolismo , Proteínas Nucleares/metabolismo , Proteínas de Ligação a RNA/metabolismo , Ativação Viral/genética , Animais , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/virologia , Linhagem Celular , Expressão Gênica/efeitos dos fármacos , Infecções por HIV/metabolismo , Humanos , Interferon-alfa/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/virologia , Camundongos , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa/genética , Proteínas Nucleares/química , Proteínas Nucleares/genética , Domínios Proteicos , RNA Mensageiro/metabolismo , RNA Viral/metabolismo , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Latência Viral
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