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1.
Bioorg Med Chem ; 112: 117878, 2024 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-39167979

RESUMO

Chemical RNA modification has emerged as a flexible approach for post-synthetic modifications in chemical biology research. Guide RNA (gRNA) plays a crucial role in the clustered regularly interspaced short palindromic repeats and associated protein system (CRISPR-Cas). Several toolkits have been developed to regulate gene expression and editing through modifications of gRNA. However, conditional regulation strategies to control gene editing in cells as required are still lacking. In this context, we introduce a strategy employing a cyclic disulfide-substituted acylating agent to randomly acylate the 2'-OH group on the gRNA strand. The CRISPR-Cas systems demonstrate off-on transformation activity driven by redox-triggered disulfide cleavage and undergo intramolecular cyclization, which releases the functionalized gRNA. Dithiothreitol (DTT) exhibits superior reductive capabilities in cleaving disulfides compared to glutathione (GSH), requiring fewer reductants. This acylation method with cyclic disulfides enables conditional control of CRISPR-Cas9, CRISPR-Cas13a, RNA hybridization, and aptamer folding. Our strategy facilitates precise in vivo control of gene editing, making it particularly valuable for targeted applications.

2.
Nucleic Acids Res ; 50(19): 11387-11400, 2022 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-36263801

RESUMO

It is important to develop small moelcule-based methods to modulate gene editing and expression in human cells. The roles of the G-quadruplex (G4) in biological systems have been widely studied. Here, G4-guided RNA engineering is performed to generate guide RNA with G4-forming units (G4-gRNA). We further demonstrate that chemical targeting of G4-gRNAs holds promise as a general approach for modulating gene editing and expression in human cells. The rich structural diversity of RNAs offers a reservoir of targets for small molecules to bind, thus creating the potential to modulate RNA biology.


Assuntos
Sistemas CRISPR-Cas , RNA Guia de Cinetoplastídeos , Humanos , Sistemas CRISPR-Cas/genética , Edição de Genes/métodos , Genômica , RNA/genética , RNA Guia de Cinetoplastídeos/genética , RNA Guia de Cinetoplastídeos/metabolismo , Quadruplex G
3.
Nucleic Acids Res ; 50(3): 1241-1255, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35100423

RESUMO

CRISPR (Clustered Regularly Interspaced Short Palindromic Repeat) technology is a powerful tool in biology and medicine. However, the safety and application of this technology is hampered by excessive activity of CRISPR machinery. It is particularly important to develop methods for switching off CRISPR activity in human cells. The current study demonstrates the concept of supramolecular CRISPR-OFF switches by employing host-guest chemistry. We demonstrate that the CRISPR systems show considerable tolerance to adamantoylation on guide RNAs (gRNAs), whereas supramolecular complexation tremendously affects the function of adamantoyl gRNAs. Host-guest chemistry is demonstrated to be novel and effective tools to reduce unwanted excessive activities of CRISPR complexes in human cells. This work indicates considerable potential of supramolecular strategy for controlling and enhancing CRISPR systems.


Assuntos
Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Edição de Genes , Sistemas CRISPR-Cas , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Edição de Genes/métodos , Humanos , RNA Guia de Cinetoplastídeos/genética
4.
Nucleic Acids Res ; 50(8): 4769-4783, 2022 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-35446403

RESUMO

It is important to control CRISPR/Cas9 when sufficient editing is obtained. In the current study, rational engineering of guide RNAs (gRNAs) is performed to develop small-molecule-responsive CRISPR/Cas9. For our purpose, the sequence of gRNAs are modified to introduce ligand binding sites based on the rational design of ligand-RNA pairs. Using short target sequences, we demonstrate that the engineered RNA provides an excellent scaffold for binding small molecule ligands. Although the 'stem-loop 1' variants of gRNA induced variable cleavage activity for different target sequences, all 'stem-loop 3' variants are well tolerated for CRISPR/Cas9. We further demonstrate that this specific ligand-RNA interaction can be utilized for functional control of CRISPR/Cas9 in vitro and in human cells. Moreover, chemogenetic control of gene editing in human cells transfected with all-in-one plasmids encoding Cas9 and designer gRNAs is demonstrated. The strategy may become a general approach for generating switchable RNA or DNA for controlling other biological processes.


Assuntos
Edição de Genes , RNA Guia de Cinetoplastídeos , Humanos , RNA Guia de Cinetoplastídeos/genética , RNA Guia de Cinetoplastídeos/metabolismo , Sistemas CRISPR-Cas/genética , Ligantes , Plasmídeos
5.
J Am Chem Soc ; 145(21): 11678-11689, 2023 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-37191624

RESUMO

The current methods to control RNA functions in living conditions are limited. The new RNA-controlling strategy presented in this study involves utilizing 5-formylcytidine (f5C)-directed base manipulation. This study shows that malononitrile and pyridine boranes can effectively manipulate the folding, small molecule binding, and enzyme recognition of f5C-bearing RNAs. We further demonstrate the efficiency of f5C-directed reactions in controlling two different clustered regularly interspaced short palindromic repeat (CRISPR) systems. Although further studies are needed to optimize the efficiency of these reactions in vivo, this small molecule-based approach presents exciting new opportunities for regulating CRISPR-based gene expression and other applications.


Assuntos
Sistemas CRISPR-Cas , RNA , RNA/genética , Sistemas CRISPR-Cas/genética , Regulação da Expressão Gênica , Epigênese Genética
6.
Neurochem Res ; 48(10): 3113-3128, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37338792

RESUMO

More and more evidence shows that the pathological mechanism of vascular dementia (VD) is closely related to oxidative stress injury, cell apoptosis, autophagy, inflammatory response, excitatory amino acid toxicity, synaptic plasticity change, calcium overload, and other processes. Edaravone dexborneol (EDB) is a new type of neuroprotective agent that can improve the neurological damage caused by an ischemic stroke. Previous studies showed that EDB has effects on synergistic antioxidants and induces anti-apoptotic responses. However, it remains unclear whether EDB can affect apoptosis and autophagy by activating the PI3K/Akt/mTOR signaling pathway and its impact on the neuroglial cells. In this study, we established the VD model of rats by bilateral carotid artery occlusion to explore the neuroprotective effect of EDB and its mechanism. Morris Water Maze test was applied to assess the cognitive function of rats. H&E and TUNEL staining were applied to observe the cellular structure of the hippocampus. Immunofluorescence labeling was used to observe the proliferation of astrocytes and microglia. ELISA was applied to examine the levels of TNF-α, IL-1ß and IL-6, and RT-PCR was applied to examine their mRNA expression levels. Western blotting was applied to examine apoptosis-related proteins (Bax, Bcl-2, Caspase-3), autophagy-related proteins (Beclin-1, P62, LC3B), PI3K/Akt/mTOR signaling pathway proteins and their phosphorylation levels. The results indicated that EDB ameliorates learning and memory in rats subjected to the VD model, alleviates neuroinflammatory response by reducing the proliferation of the neuroglial cell and inhibits apoptosis and autophagy, which may be mediated by the PI3K/Akt/mTOR signaling pathway.


Assuntos
Demência Vascular , Fármacos Neuroprotetores , Ratos , Animais , Demência Vascular/tratamento farmacológico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Edaravone/farmacologia , Ratos Sprague-Dawley , Fosfatidilinositol 3-Quinases/metabolismo , Doenças Neuroinflamatórias , Serina-Treonina Quinases TOR/metabolismo , Proliferação de Células , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Apoptose , Autofagia
7.
Neurochem Res ; 48(5): 1561-1579, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36571662

RESUMO

Dulaglutide is a new type of hypoglycemic agent that agonizes glucagon-like peptide-1 receptor (GLP-1RA). It can be concluded from previous studies that a GLP-1RA can reduce apoptosis and regulate autophagy in the nervous system, while related research on dulaglutide in vascular dementia (VD) has not been reported. In our study, the VD rat model was established by bilateral carotid artery occlusion, and the results of the Morris water maze test (MWM) and open-field test showed that the application of dulaglutide could effectively reduce the cognitive decline of VD rats without changing the behavior in the open-field test, which was used to assess an anxiety-like phenotype. We applied HE staining and immunofluorescence labeling to show that dulaglutide treatment significantly alleviated neuronal damage in the hippocampal region of VD rats, and reduced microglial and astrocyte proliferation. Western blot results showed that dulaglutide reduced VD-induced neuronal apoptosis (BCL2/BAX, c-caspase3) and autophagy (P62, LC3B, Beclin-1), and upregulated phosphorylation of PI3K/Akt/mTOR signaling pathway. KEGG pathway analysis of RNA-Sequence results showed that the differentially expressed genes in the dulaglutide treatment group were significantly enriched in the mTOR signaling pathway, and the repressor of mTOR, Deptor, was down-regulated. In conclusion, this study suggested that dulaglutide may alleviate learning and memory impairment and neuron damage in VD rats by attenuating apoptosis, regulating autophagy, and activating the PI3K/Akt/mTOR signaling pathway in neurons, which may make it a promising candidate for the simultaneous treatment of VD and diabetes.


Assuntos
Demência Vascular , Proteínas Proto-Oncogênicas c-akt , Ratos , Animais , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Gliose , Ratos Sprague-Dawley , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Apoptose , Autofagia
8.
J Org Chem ; 88(1): 189-197, 2023 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-36548942

RESUMO

The diverse structures of DNA serve as potent chiral scaffolds for DNA-based asymmetric catalysis, yet in most cases tens to hundreds of nucleotides in DNA hybrid catalysts hinder the deep insight into their structure-activity relationship. Owing to the structural simplicity and design flexibility of nucleotides, nucleotide-based catalysts have been emerging as a promising way to obtain fine structural information and understand the catalytic mechanisms. Herein, we found that a cyclic dinucleotide of cyclic di-AMP (c-di-AMP) and 1,10-phenanthroline copper(II) nitrate (Cu(phen)(NO3)2) are assembled to a c-di-AMP-based catalyst (c-di-AMP/Cu(phen)(NO3)2), which could fast achieve enantioselective fluorination in water with 90-99% yields and up to 90% enantiomeric excess (ee). The host-guest interaction between c-di-AMP and Cu(phen)(NO3)2 has been proposed mainly in a supramolecular interaction mode as evidenced by spectroscopic techniques of ultraviolet-visible, fluorescence, circular dichroism, and nuclear magnetic resonance. Cu(phen)(NO3)2 tightly binds to c-di-AMP with a binding constant of 1.7 ± 0.3 × 105 M-1, and the assembly of c-di-AMP/Cu(phen)(NO3)2 shows a modest rate enhancement to carbon-fluorine bond formations as supported by kinetic studies.


Assuntos
Halogenação , Água , Estereoisomerismo , Cinética , Cobre/química , Nucleotídeos , DNA/química
9.
Int J Mol Sci ; 23(24)2022 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36555582

RESUMO

The loss of seed shattering is an important event in crop domestication, and elucidating the genetic mechanisms underlying seed shattering can help reduce yield loss during crop production. This study is the first to systematically identify and analyse the BELL family of transcription factor-encoding genes in Chinese wild rice (Zizania latifolia). ZlqSH1a (Zla04G033720) and ZlqSH1b (Zla02G027130) were identified as key candidate genes involved in seed shattering in Z. latifolia. These genes were involved in regulating the development of the abscission layer (AL) and were located in the nucleus of the cell. Over-expression of ZlqSH1a and ZlqSH1b resulted in a complete AL between the grain and pedicel and significantly enhanced seed shattering after grain maturation in rice. Transcriptome sequencing revealed that 172 genes were differentially expressed between the wild type (WT) and the two transgenic (ZlqSH1a and ZlqSH1b over-expressing) plants. Three of the differentially expressed genes related to seed shattering were validated using qRT-PCR analysis. These results indicate that ZlqSH1a and ZlqSH1b are involved in AL development in rice grains, thereby regulating seed shattering. Our results could facilitate the genetic improvement of seed-shattering behaviour in Z. latifolia and other cereal crops.


Assuntos
Oryza , Domesticação , Genes de Plantas , Sementes , Grão Comestível/genética
10.
Immunology ; 162(3): 328-338, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33283278

RESUMO

Schistosomiasis is a neglected tropical disease with over 250 million people infected worldwide. The main clinically important species Schistosoma mansoni (S. mansoni) and Schistosoma japonicum (S. japonicum) cause inflammatory responses against tissue-trapped eggs, resulting in formation of granulomas mainly in host liver. Persistent granulomatous response results in severe fibrosis in the liver, leading to irreversible impairment of the liver and even death of the host. CD1d, a highly conserved MHC class I-like molecule, is expressed by both haematopoietic and non-haematopoietic cells. CD1d on antigen-presenting cells (APCs) of haematopoietic origin presents pathogen-derived lipid antigens to natural killer T (NKT) cells, which enables them to rapidly produce large amounts of various cytokines and facilitate CD4+ T helper (Th) cell differentiation upon invading pathogens. Noteworthy, hepatocytes of non-haematopoietic origin have recently been shown to be involved in maintaining liver NKT cell homeostasis through a CD1d-dependent manner. However, whether hepatocyte CD1d-dependent regulation of NKT cell homeostasis also modulates CD4+ Th cell responses and liver immunopathology in murine schistosomiasis remains to be addressed. Here, we show in mice that CD1d expression on hepatocytes was decreased dramatically upon S. japonicum infection, accompanied by increased NKT cells, as well as upregulated Th1 and Th2 responses. Overexpression of CD1d in hepatocytes significantly decreased local NKT numbers and cytokines (IFN-γ, IL-4, IL-13), concomitantly with downregulation of both Th1 and Th2 responses and alleviation in pathological damage in livers of S. japonicum-infected mice. These findings highlight the potential of hepatocyte CD1d-targeted therapies for liver immunopathology control in schistosomiasis.


Assuntos
Antígenos CD1d/metabolismo , Hepatócitos/imunologia , Fígado/imunologia , Schistosoma japonicum/imunologia , Esquistossomose Japônica/imunologia , Animais , Antígenos CD1d/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Hepatócitos/metabolismo , Hepatócitos/patologia , Interações Hospedeiro-Parasita , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Células T Matadoras Naturais/imunologia , Células T Matadoras Naturais/metabolismo , Células T Matadoras Naturais/parasitologia , Schistosoma japonicum/patogenicidade , Esquistossomose Japônica/metabolismo , Esquistossomose Japônica/parasitologia , Células Th1/imunologia , Células Th1/metabolismo , Células Th1/parasitologia , Células Th2/imunologia , Células Th2/metabolismo , Células Th2/parasitologia
11.
Chem Biodivers ; 18(2): e2000804, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33346933

RESUMO

A series of (E)-1-(substituted benzylidene)-4-(3-isopropylphenyl)thiosemicarbazone derivatives were synthesized and characterized by FT-IR spectrum, elemental analysis, NMR spectrum, HR-MS spectrum, and X-ray single crystal diffraction technology. The crystal structures and packing of (E)-1-(4-fluorobenzylidene)-4-(3-isopropylphenyl)thiosemicarbazone and (E)-1-(3-fluorobenzylidene)-4-(3-isopropylphenyl)thiosemicarbazone were maintained through the intramolecular hydrogen bond (N3-H6⋅⋅⋅N1) and intermolecular hydrogen bonds (N2-H4⋅⋅⋅S1, C14-H14⋅⋅⋅F1 and C7-H7⋅⋅⋅S1). The results obtained by employing the DPPH free radicals scavenging assay indicated that (E)-1-(4-methoxylbenzylidene)-4-(3-isopropylphenyl)thiosemicarbazone had a more significant antioxidant activity compared with other compounds. The results measured by adopting the disc diffusion method elucidated that (E)-1-(4-trifluoromethylbenzylidene)-4-(3-isopropylphenyl)thiosemicarbazone possessed a more prominent antifungal activity than other compounds. Molecular docking showed that (E)-1-(4-chlorobenzylidene)-4-(3-isopropylphenyl)thiosemicarbazone had the highest affinity with receptor protein (1NMT). Moreover, the drug-likeness characteristic, physicochemical properties, pharmacokinetic profiles, and bioactivity scores of all the compounds were predicted through in silico studies. The results illustrated that (E)-1-(4-fluorobenzylidene)-4-(3-isopropylphenyl)thiosemicarbazone had the drug-likeness characteristic and all the compounds were considered as moderately biological active molecules.


Assuntos
Compostos de Benzilideno/química , Compostos de Benzilideno/farmacologia , Tiossemicarbazonas/química , Tiossemicarbazonas/farmacologia , Antifúngicos/síntese química , Antifúngicos/química , Antifúngicos/farmacologia , Antioxidantes/síntese química , Antioxidantes/química , Antioxidantes/farmacologia , Compostos de Benzilideno/síntese química , Cristalografia por Raios X , Fungos/efeitos dos fármacos , Humanos , Ligação de Hidrogênio , Modelos Moleculares , Micoses/tratamento farmacológico , Tiossemicarbazonas/síntese química
12.
Angew Chem Int Ed Engl ; 59(9): 3444-3449, 2020 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-31825550

RESUMO

The diverse secondary structures of nucleic acids are emerging as attractive chiral scaffolds to construct artificial metalloenzymes (ArMs) for enantioselective catalysis. DNA-based ArMs containing duplex and G-quadruplex scaffolds have been widely investigated, yet RNA-based ArMs are scarce. Here we report that a cyclic dinucleotide of c-di-AMP and Cu2+ ions assemble into an artificial metalloribozyme (c-di-AMP⋅Cu2+ ) that enables catalysis of enantioselective Friedel-Crafts reactions in aqueous media with high reactivity and excellent enantioselectivity of up to 97 % ee. The assembly of c-di-AMP⋅Cu2+ gives rise to a 20-fold rate acceleration compared to Cu2+ ions. Based on various biophysical techniques and density function theory (DFT) calculations, a fine coordination structure of c-di-AMP⋅Cu2+ metalloribozyme is suggested in which two c-di-AMP form a dimer scaffold and the Cu2+ ion is located in the center of an adenine-adenine plane through binding to two N7 nitrogen atoms and one phosphate oxygen atom.


Assuntos
Reação de Cicloadição , Fosfatos de Dinucleosídeos/química , Água/química , Catálise , Cobre/química , Teoria da Densidade Funcional , Dimerização , Fosfatos de Dinucleosídeos/metabolismo , Quadruplex G , Cinética , Metaloproteínas/química , Metaloproteínas/metabolismo , Estereoisomerismo , Especificidade por Substrato
13.
Eur J Immunol ; 48(8): 1302-1307, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29729112

RESUMO

Hepatic Foxp3+ Treg cells are crucial for maintaining local immune homeostasis in the liver. However, the environmental cues required for hepatic Treg cell homeostasis are unclear. In this study, we showed that the IL-33 receptor ST2 was preferentially expressed on Treg cells in the mouse liver, but it was more lowly expressed in the spleen, mesenteric lymph nodes, and blood. More importantly, we found that IL-33 promoted the proliferation of hepatic Treg cells through myeloid differentiation factor MyD88 signaling concomitant with increased cyclin-dependent kinase 4 and cyclin D1 expression. These results suggest that IL-33 is a potential tissue-specific factor controlling Treg cell homeostasis via increased Treg proliferation in the liver.


Assuntos
Proteína 1 Semelhante a Receptor de Interleucina-1/imunologia , Interleucina-33/imunologia , Fator 88 de Diferenciação Mieloide/imunologia , Linfócitos T Reguladores/imunologia , Animais , Proliferação de Células/genética , Ciclina D1/metabolismo , Quinase 4 Dependente de Ciclina/metabolismo , Interleucina-33/genética , Fígado/citologia , Fígado/imunologia , Linfonodos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/genética , Transdução de Sinais/imunologia , Baço/imunologia
14.
Immunology ; 153(1): 84-96, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28799262

RESUMO

CD4+ CD25+ Foxp3+ regulatory T (Treg) cells play an important role in maintaining immune homeostasis. Interleukin-10 (IL-10), a cytokine with anti-inflammatory capacities, also has a critical role in controlling immune responses. In addition, it is well known that production of IL-10 is one of the suppression mechanisms of Treg cells. However, the action of IL-10 on Treg cells themselves remains insufficiently understood. In this study, by using a Schistosoma japonicum-infected murine model, we show that the elevated IL-10 contributed to Treg cell induction but impaired their immunosuppressive function. Our investigations further suggest that this may relate to the up-regulation of serum transforming growth factor (TGF-ß) level but the decrease in membrane-bound TGF-ß of Treg cells by IL-10 during S. japonicum infection. In addition, similar IL-10-mediated regulation on Treg cells was also confirmed in the murine model of asthma. In general, our findings identify a previously unrecognized opposing regulation of IL-10 on Treg cells and provide a deep insight into the precise regulation in immune responses.


Assuntos
Asma/imunologia , Asma/metabolismo , Imunomodulação , Esquistossomose Japônica/imunologia , Esquistossomose Japônica/metabolismo , Animais , Anticorpos Monoclonais/farmacologia , Asma/sangue , Asma/patologia , Biomarcadores , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Expressão Gênica , Imunomodulação/efeitos dos fármacos , Imunossupressores/farmacologia , Interleucina-10/antagonistas & inibidores , Interleucina-10/sangue , Interleucina-10/metabolismo , Interleucina-10/farmacologia , Contagem de Linfócitos , Camundongos , Esquistossomose Japônica/sangue , Esquistossomose Japônica/parasitologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo
15.
Immunol Cell Biol ; 96(9): 958-968, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29697865

RESUMO

CD4+ CD25+ Foxp3+ regulatory T cells (Tregs) play a pivotal role in limiting immunopathological damage to host organs after schistosome infection. Transforming growth factor-ß (TGF-ß) is an essential factor for the periphery conversion of CD4+ CD25- T cells into CD4+ CD25+ Foxp3+ Tregs by inducing the key transcription factor Foxp3. Antigen presenting cells (APCs), which highly express TGF-ß, are involved in parasite antigen-induced Treg conversion in peripheral. However, the mechanisms underlying high TGF-ß induction in APCs by parasite antigens remain to be clarified during schistosome infection. Here, we demonstrated that Schistosoma japonicum stress protein, heat shock protein 60 (SjHSP60), promoted TGF-ß production in macrophages (Mφ). Furthermore, we showed that activation of TLR4-Mal (MyD88 adaptor-like protein) signaling by SjHSP60 is necessary for induction of TGF-ß expression in Mφ, which subsequently promoted Treg induction. Our results not only demonstrate a novel mechanism of TGF-ß production in Mφ for inducing Tregs in mice with schistosomiasis, but also allude to the possibility of targeting parasite stress protein for potential therapeutics.


Assuntos
Antígenos de Helmintos/imunologia , Chaperonina 60/imunologia , Macrófagos/imunologia , Esquistossomose Japônica/imunologia , Linfócitos T Reguladores/imunologia , Receptor 4 Toll-Like/imunologia , Fator de Crescimento Transformador beta/imunologia , Animais , Feminino , Proteínas de Helminto/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Células RAW 264.7 , Schistosoma japonicum
16.
J Virol ; 91(1)2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27795416

RESUMO

20 (enfuvirtide) and other peptides derived from the human immunodeficiency virus type 1 (HIV-1) gp41 C-terminal heptad repeat (CHR) region inhibit HIV fusion by binding to the hydrophobic grooves on the N-terminal heptad repeat (NHR) trimer and blocking six-helix-bundle (6-HB) formation. Several strategies focusing on the binding grooves of the NHR trimer have been adopted to increase the antiviral activity of the CHR peptides. Here, we developed a novel and simple strategy to greatly enhance the potency of the existing peptide-based HIV fusion inhibitors. First, we identified a shallow pocket adjacent to the groove in the N-terminal region of NHR trimer as a new drug target, and then we designed several short artificial peptides to fit this target. After the addition of IDL (Ile-Asp-Leu) to the C terminus of CHR peptide WQ or MT-WQ, the conjugated peptides, WQ-IDL and MT-WQ-IDL, showed much more potent activities than WQ and T20, respectively, in inhibiting HIV-1 IIIB infection. WQ-IDL and MT-WQ-IDL were also more effective than WQ in blocking HIV-1 Env-mediated membrane fusion and had higher levels of binding affinity with NHR peptide N46. We solved the crystal structure of the 6-HB formed by MT-WQ-IDL and N46 and found that, besides the N-terminal MT hook tail, the IDL tail anchor of MT-WQ-IDL also binds with the shallow hydrophobic pocket outside the groove of the NHR trimer, resulting in enhanced inhibition of HIV-1 fusion with the target cell. It is expected that this novel approach can be widely used to improve the potency of peptidic fusion inhibitors against other enveloped viruses with class I fusion proteins. IMPORTANCE: The hydrophobic groove of the human immunodeficiency virus type 1 (HIV-1) gp41 NHR trimer has been known as the classic drug target to develop fusion inhibitors derived from the gp41 CHR. Here, we developed a novel and simple strategy to improve the existing peptide-based HIV fusion inhibitors. We identified a shallow pocket adjacent to the groove in the NHR trimer and added a short artificial peptide consisting of three amino acids (IDL) to the C terminus of a fusion inhibitor to fit this new target. The inhibition activity of this new conjugated peptide was significantly enhanced, by 77-fold, making it much more potent than T20 (enfuvirtide) and suggesting that the IDL tail can be adopted for optimizing existing HIV-1 CHR peptide fusion inhibitors. This new approach of identifying a potential binding pocket outside the traditional target and creating an artificial tail anchor can be widely applied to design novel fusion inhibitors against other class I enveloped viruses, such as Middle East respiratory syndrome coronavirus (MERS-CoV).


Assuntos
Desenho de Fármacos , Proteína gp41 do Envelope de HIV/síntese química , Inibidores da Fusão de HIV/síntese química , HIV-1/efeitos dos fármacos , Fragmentos de Peptídeos/síntese química , Internalização do Vírus/efeitos dos fármacos , Sequência de Aminoácidos , Linhagem Celular Tumoral , Cristalografia por Raios X , Enfuvirtida , Proteína gp41 do Envelope de HIV/farmacologia , Inibidores da Fusão de HIV/farmacologia , HIV-1/química , HIV-1/crescimento & desenvolvimento , HIV-1/metabolismo , Humanos , Interações Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Neuroglia/efeitos dos fármacos , Neuroglia/imunologia , Neuroglia/virologia , Fragmentos de Peptídeos/farmacologia , Domínios e Motivos de Interação entre Proteínas , Multimerização Proteica , Estrutura Secundária de Proteína , Alinhamento de Sequência , Relação Estrutura-Atividade , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/virologia
17.
Neurochem Res ; 42(10): 2968-2981, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28620824

RESUMO

L-3-n-Butylphthalide (L-NBP) exerts neuroprotective effects in animal models of cerebral ischemia, but its potential benefits in repeated cerebral ischemia-reperfusion (RCIR) injury remain unknown. We investigated the effect of L-NBP on cognitive impairment induced by RCIR in mice. Male C57Bl/6 mice received sham surgery or bilateral common carotid artery occlusion (3 times, 20 min each) and were orally administered preoperative L-NBP (30 mg/kg/day, 7 days), postoperative L-NBP (30 or 60 mg/kg/day, 28 days) or postoperative vehicle (28 days). Learning and memory were assessed by the Morris water maze task and step-down passive avoidance test. Nissl staining was used to identify pathologic changes in the hippocampal CA1 region. The expressions of proteins associated with signaling, apoptosis and autophagy were assessed by quantitative PCR and western blot. RCIR induced deficits in learning and memory that were alleviated by preoperative or postoperative L-NBP administration. Pathologic lesions in the hippocampal CA1 region induced by RCIR were less severe in mice treated with L-NBP. Preoperative or postoperative L-NBP administration in mice receiving RCIR promoted hippocampal expression of phospho-Akt and phospho-mTOR (suggesting activation of Akt/mTOR signaling), increased the Bcl-2/Bax ratio (indicating suppression of apoptosis) and reduced the LC3-II/LC3-I ratio (implying inhibition of autophagy). Preoperative or postoperative L-NBP administration also depressed hippocampal levels of beclin-1 mRNA (indicating suppression of autophagy). These findings suggest that the effect of L-NBP to alleviate learning and memory deficits in mice following RCIR may involve activation of Akt/mTOR signaling and regulation of the expressions of proteins related to apoptosis and autophagy.


Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Benzofuranos/farmacologia , Disfunção Cognitiva/tratamento farmacológico , Proteínas Proto-Oncogênicas c-akt/efeitos dos fármacos , Animais , Isquemia Encefálica/patologia , Transtornos Cognitivos/tratamento farmacológico , Disfunção Cognitiva/metabolismo , Modelos Animais de Doenças , Masculino , Transtornos da Memória/tratamento farmacológico , Camundongos Endogâmicos C57BL , Fármacos Neuroprotetores/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Reperfusão , Serina-Treonina Quinases TOR/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo
18.
J Virol ; 89(13): 6960-4, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25903343

RESUMO

A key barrier against developing preventive and therapeutic human immunodeficiency virus (HIV) vaccines is the inability of viral envelope glycoproteins to elicit broad and potent neutralizing antibodies. However, in the presence of fusion inhibitor enfuvirtide, we show that the nonneutralizing antibodies induced by the HIV type 1 (HIV-1) gp41 N-terminal heptad repeat (NHR) domain (N63) exhibit potent and broad neutralizing activity against laboratory-adapted HIV-1 strains, including the drug-resistant variants, and primary HIV-1 isolates with different subtypes, suggesting the potential of developing gp41-targeted HIV therapeutic vaccines.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , Proteína gp41 do Envelope de HIV/imunologia , Proteína gp41 do Envelope de HIV/farmacologia , Inibidores da Fusão de HIV/farmacologia , HIV-1/efeitos dos fármacos , HIV-1/imunologia , Fragmentos de Peptídeos/farmacologia , Animais , Enfuvirtida , Humanos , Camundongos , Testes de Neutralização , Coelhos
19.
J Virol ; 89(11): 6121-5, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25787280

RESUMO

Porcine epidemic diarrhea coronavirus (PEDV) has significantly damaged America's pork industry. Here we investigate the receptor usage and cell entry of PEDV. PEDV recognizes protein receptor aminopeptidase N from pig and human and sugar coreceptor N-acetylneuraminic acid. Moreover, PEDV infects cells from pig, human, monkey, and bat. These results support the idea of bats as an evolutionary origin for PEDV, implicate PEDV as a potential threat to other species, and suggest antiviral strategies to control its spread.


Assuntos
Antígenos CD13/metabolismo , Ácido N-Acetilneuramínico/metabolismo , Vírus da Diarreia Epidêmica Suína/fisiologia , Receptores Virais/metabolismo , Ligação Viral , Internalização do Vírus , Animais , Quirópteros , Haplorrinos , Humanos , Receptores de Coronavírus , Suínos
20.
Opt Lett ; 39(20): 5897-900, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-25361114

RESUMO

We report an experiment of which-way information and a quantum eraser based on polarization-controlled interference of two twisted light beams carrying high orbital angular momentum (OAM) up to ℓ=±50 and ±100, respectively. By changing the polarization plane of one OAM beam from 0° to 90° with respect to that of the other OAM beam, we observe the gradual disappearance of the interference petal-like patterns into the noninterference single bright rings. Subsequently, we use the eraser of a diagonal polarizer to retrieve the characteristic petal-like interference. The experimental results can be well explained in the frame of single-photon Greenberger-Horne-Zeilinger-like (GHZ-like) entanglement. Our work may be beneficial to understanding the wave-particle duality of light.

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