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1.
Cell Mol Biol Lett ; 29(1): 63, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38698330

RESUMEN

BACKGROUND: Endometrial cancer (EC) is one of the most common gynecological cancers. Herein, we aimed to define the role of specific myosin family members in EC because this protein family is involved in the progression of various cancers. METHODS: Bioinformatics analyses were performed to reveal EC patients' prognosis-associated genes in patients with EC. Furthermore, colony formation, immunofluorescence, cell counting kit 8, wound healing, and transwell assays as well as coimmunoprecipitation, cycloheximide chase, luciferase reporter, and cellular thermal shift assays were performed to functionally and mechanistically analyze human EC samples, cell lines, and a mouse model, respectively. RESULTS: Machine learning techniques identified MYH14, a member of the myosin family, as the prognosis-associated gene in patients with EC. Furthermore, bioinformatics analyses based on public databases showed that MYH14 was associated with EC chemoresistance. Moreover, immunohistochemistry validated MYH14 upregulation in EC cases compared with that in normal controls and confirmed that MYH14 was an independent and unfavorable prognostic indicator of EC. MYH14 impaired cell sensitivity to carboplatin, paclitaxel, and progesterone, and increased cell proliferation and metastasis in EC. The mechanistic study showed that MYH14 interacted with MYH9 and impaired GSK3ß-mediated ß-catenin ubiquitination and degradation, thus facilitating the Wnt/ß-catenin signaling pathway and epithelial-mesenchymal transition. Sesamolin, a natural compound extracted from Sesamum indicum (L.), directly targeted MYH14 and attenuated EC progression. Additionally, the compound disrupted the interplay between MYH14 and MYH9 and repressed MYH9-regulated Wnt/ß-catenin signaling. The in vivo study further verified sesamolin as a therapeutic drug without side effects. CONCLUSIONS: Herein, we identified that EC prognosis-associated MYH14 was independently responsible for poor overall survival time of patients, and it augmented EC progression by activating Wnt/ß-catenin signaling. Targeting MYH14 by sesamolin, a cytotoxicity-based approach, can be applied synergistically with chemotherapy and endocrine therapy to eventually mitigate EC development. This study emphasizes MYH14 as a potential target and sesamolin as a valuable natural drug for EC therapy.


Asunto(s)
Neoplasias Endometriales , Glucógeno Sintasa Quinasa 3 beta , Cadenas Pesadas de Miosina , beta Catenina , Humanos , Femenino , Neoplasias Endometriales/tratamiento farmacológico , Neoplasias Endometriales/genética , Neoplasias Endometriales/metabolismo , Neoplasias Endometriales/patología , Cadenas Pesadas de Miosina/metabolismo , Cadenas Pesadas de Miosina/genética , Animales , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Glucógeno Sintasa Quinasa 3 beta/genética , Línea Celular Tumoral , beta Catenina/metabolismo , beta Catenina/genética , Ratones , Proliferación Celular/efectos de los fármacos , Ratones Desnudos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Pronóstico , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Persona de Mediana Edad , Naftoquinonas/farmacología
2.
Ecotoxicol Environ Saf ; 232: 113273, 2022 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-35123184

RESUMEN

More than 80% terrestrial plants establish mutualistic symbiosis with soil-borne arbuscular mycorrhizal fungi (AMF). These fungi not only significantly improve plant nutrient acquisition and stress resistance, but also mitigate heavy metal phytotoxicity, Furthermore, the extraradical mycorrhizal mycelia can form common mycorrhizal networks (CMNs) that link roots of multiple plants in a community. Here we show that the networks mediate migration of heavy metal cadmium (Cd) from maize (Zea mays L.) to soybean (Glycine max (Linn.) Merr.) plants. CMNs between maize and soybean plants were established after inoculation of maize plants with AMF Funneliformis mosseae. Application of CdCl2 in maize plants led to 64.4% increase in the shoots and 48.2% increase in the roots in Cd content in CMNs-connected soybean plants compared to the control without Cd treatment in maize. Meanwhile, although the CMNs-connected soybean plants did not directly receive Cd supply, they upregulated transcriptional levels of Cd transport-related genes HATPase and RSTK 2.13- and 5.96-fold, respectively, induced activities of POD by 44.8% in the leaves, and increased MDA by 146.2% in the roots. Furthermore, Cd addition inhibited maize growth but mycorrhizal colonization improved plant performance in presence of Cd stress. This finding demonstrates that mycorrhizal networks mediate the transfer of Cd between plants of different species, suggesting a potential to use CMNs as a conduit to transfer toxic heavy metals from main food crops to heavy metal hyperaccumulators via intercropping.


Asunto(s)
Micorrizas , Contaminantes del Suelo , Cadmio/análisis , Cadmio/toxicidad , Micorrizas/química , Raíces de Plantas , Contaminantes del Suelo/análisis , Contaminantes del Suelo/toxicidad , Glycine max , Zea mays
3.
Biochem Biophys Res Commun ; 526(4): 857-864, 2020 06 11.
Artículo en Inglés | MEDLINE | ID: mdl-32278547

RESUMEN

Ovarian cancer is diagnosed as the most deadly gynecological tumor. Ovarian cancer metastasis affects chemoresistance and confers poor patient prognosis. In present work, we intended to elucidate whether long non-coding RNAs (lncRNAs) TLR8-AS1 regulated cell metastasis and chemoresistance of ovarian cancer, and uncover the molecular mechanism of TLR8-AS1 in the modulation of ovarian cancer progression. Firstly, bioinformatics analyses identified TLR8-AS1 as a cancer-associated fibroblasts regulated lncRNA in ovarian cancer. Further experiments revealed that TLR8-AS1 augmented cell metastasis and chemoresistance of ovarian cancer in vitro and in vivo. Moreover, TLR8-AS1 upregulates TLR8 by stabilizing TLR8 mRNA, thus activating NF-κB signaling and promoting ovarian cancer metastasis and chemoresistance. Besides, TCGA data analysis suggested that TLR8-AS1 is elevated in ovarian cancer in comparison to adjacent non-cancerous tissues. High TLR8-AS1 expression levels were measured in metastatic ovarian cancer and correlated with poor patient prognosis. The clinical data supported the mechanism and biological significance of TLR8-AS1 dysregulation in ovarian cancer development. Our work demonstrates that TLR8-AS1 can be applied as a diagnostic and prognostic indicator for ovarian cancer, and maybe an alternative target for the treatment of ovarian cancer.


Asunto(s)
Resistencia a Antineoplásicos/genética , Neoplasias Ováricas/genética , Neoplasias Ováricas/patología , Estabilidad del ARN/genética , ARN Largo no Codificante/metabolismo , Receptor Toll-Like 8/genética , Animales , Línea Celular Tumoral , Progresión de la Enfermedad , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Ratones Endogámicos BALB C , Ratones Desnudos , FN-kappa B/metabolismo , Metástasis de la Neoplasia , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Pronóstico , ARN Largo no Codificante/genética , Tolerancia a Radiación/genética , Transducción de Señal , Análisis de Supervivencia , Receptor Toll-Like 8/metabolismo , Regulación hacia Arriba/genética
4.
J Biol Chem ; 293(51): 19919-19931, 2018 12 21.
Artículo en Inglés | MEDLINE | ID: mdl-30373772

RESUMEN

Lysophospholipid transporter (LplT) is a member of the major facilitator superfamily present in many Gram-negative bacteria. LplT catalyzes flipping of lysophospholipids (LPLs) across the bacterial inner membrane, playing an important role in bacterial membrane homeostasis. We previously reported that LplT promotes both uptake of exogenous LPLs and intramembranous LPL flipping across the bilayer. To gain mechanistic insight into this dual LPL-flipping activity, here we implemented a combination of computational approaches and LPL transport analyses to study LPL binding of and translocation by LplT. Our results suggest that LplT translocates LPLs through an elongated cavity exhibiting an extremely asymmetric polarity. We found that two D(E)N motifs form a head group-binding site, in which the carboxylate group of Asp-30 is important for LPL head group recognition. Substitutions of residues in the head group-binding site disrupted both LPL uptake and flipping activities. However, alteration of hydrophobic residues on the interface between the N- and C-terminal domains impaired LPL flipping specifically, resulting in LPLs accumulation in the membrane, but LPL uptake remained active. These results suggest a dual substrate-accessing mechanism, in which LplT recruits LPLs to its substrate-binding site via two routes, either from its extracellular entry or through a membrane-embedded groove between transmembrane helices, and then moves them toward the inner membrane leaflet. This LPL-flipping mechanism is likely conserved in many bacterial species, and our findings illustrate how LplT adjusts the major facilitator superfamily translocation pathway to perform its versatile lipid homeostatic functions.


Asunto(s)
Membrana Celular/metabolismo , Lisofosfolípidos/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Secuencia de Aminoácidos , Sitios de Unión , Escherichia coli/citología , Escherichia coli/metabolismo , Espacio Intracelular/metabolismo , Proteínas de Transporte de Membrana/química , Simulación del Acoplamiento Molecular , Conformación Proteica
5.
J Biol Chem ; 293(9): 3386-3398, 2018 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-29348168

RESUMEN

Secretory phospholipases A2 (sPLA2s) are potent components of mammalian innate-immunity antibacterial mechanisms. sPLA2 enzymes attack bacteria by hydrolyzing bacterial membrane phospholipids, causing membrane disorganization and cell lysis. However, most Gram-negative bacteria are naturally resistant to sPLA2 Here we report a novel resistance mechanism to mammalian sPLA2 in Escherichia coli, mediated by a phospholipid repair system consisting of the lysophospholipid transporter LplT and the acyltransferase Aas in the cytoplasmic membrane. Mutation of the lplT or aas gene abolished bacterial lysophospholipid acylation activity and drastically increased bacterial susceptibility to the combined actions of inflammatory fluid components and sPLA2, resulting in bulk phospholipid degradation and loss of colony-forming ability. sPLA2-mediated hydrolysis of the three major bacterial phospholipids exhibited distinctive kinetics and deacylation of cardiolipin to its monoacyl-derivative closely paralleled bacterial death. Characterization of the membrane envelope in lplT- or aas-knockout mutant bacteria revealed reduced membrane packing and disruption of lipid asymmetry with more phosphatidylethanolamine present in the outer leaflet of the outer membrane. Moreover, modest accumulation of lysophospholipids in these mutant bacteria destabilized the inner membrane and rendered outer membrane-depleted spheroplasts much more sensitive to sPLA2 These findings indicated that LplT/Aas inactivation perturbs both the outer and inner membranes by bypassing bacterial membrane maintenance mechanisms to trigger specific interfacial activation of sPLA2 We conclude that the LplT/Aas system is important for maintaining the integrity of the membrane envelope in Gram-negative bacteria. Our insights may help inform new therapeutic strategies to enhance host sPLA2 antimicrobial activity.


Asunto(s)
Aciltransferasas/metabolismo , Membrana Celular/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/citología , Escherichia coli/fisiología , Interacciones Huésped-Patógeno , Fosfolipasas A2/metabolismo , Proteínas de Transferencia de Fosfolípidos/metabolismo , Fosfolípidos/metabolismo , Aciltransferasas/deficiencia , Animales , Activación Enzimática , Escherichia coli/enzimología , Proteínas de Transferencia de Fosfolípidos/deficiencia
6.
J Biol Chem ; 291(5): 2136-49, 2016 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-26613781

RESUMEN

Lysophospholipid transporter (LplT) was previously found to be primarily involved in 2-acyl lysophosphatidylethanolamine (lyso-PE) recycling in Gram-negative bacteria. This work identifies the potent role of LplT in maintaining membrane stability and integrity in the Escherichia coli envelope. Here we demonstrate the involvement of LplT in the recycling of three major bacterial phospholipids using a combination of an in vitro lysophospholipid binding assay using purified protein and transport assays with E. coli spheroplasts. Our results show that lyso-PE and lysophosphatidylglycerol, but not lysophosphatidylcholine, are taken up by LplT for reacylation by acyltransferase/acyl-acyl carrier protein synthetase on the inner leaflet of the membrane. We also found a novel cardiolipin hydrolysis reaction by phospholipase A2 to form diacylated cardiolipin progressing to the completely deacylated headgroup. These two distinct cardiolipin derivatives were both translocated with comparable efficiency to generate triacylated cardiolipin by acyltransferase/acyl-acyl carrier protein synthetase, demonstrating the first evidence of cardiolipin remodeling in bacteria. These findings support that a fatty acid chain is not required for LplT transport. We found that LplT cannot transport lysophosphatidic acid, and its substrate binding was not inhibited by either orthophosphate or glycerol 3-phosphate, indicating that either a glycerol or ethanolamine headgroup is the chemical determinant for substrate recognition. Diacyl forms of PE, phosphatidylglycerol, or the tetra-acylated form of cardiolipin could not serve as a competitive inhibitor in vitro. Based on an evolutionary structural model, we propose a "sideways sliding" mechanism to explain how a conserved membrane-embedded α-helical interface excludes diacylphospholipids from the LplT binding site to facilitate efficient flipping of lysophospholipid across the cell membrane.


Asunto(s)
Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Lisofosfolípidos/química , Proteínas de Transferencia de Fosfolípidos/metabolismo , Sitios de Unión , Unión Competitiva , Cardiolipinas/química , Membrana Celular/metabolismo , Eliminación de Gen , Hidrólisis , Klebsiella pneumoniae , Espectrometría de Masas , Microscopía Fluorescente , Modelos Moleculares , Mutación , Fosfatidilgliceroles/química , Fosfolipasas A2/química , Unión Proteica , Estructura Secundaria de Proteína , Transporte de Proteínas , Especificidad por Sustrato
7.
J Biol Chem ; 291(35): 18342-52, 2016 08 26.
Artículo en Inglés | MEDLINE | ID: mdl-27405756

RESUMEN

PgpB belongs to the lipid phosphate phosphatase protein family and is one of three bacterial integral membrane phosphatases catalyzing dephosphorylation of phosphatidylglycerol phosphate (PGP) to generate phosphatidylglycerol. Although the structure of its apo form became recently available, the mechanisms of PgpB substrate binding and catalysis are still unclear. We found that PgpB was inhibited by phosphatidylethanolamine (PE) in a competitive mode in vitro Here we report the crystal structure of the lipid-bound form of PgpB. The structure shows that a PE molecule is stabilized in a membrane-embedded tunnel formed by TM3 and the "PSGH" fingerprint peptide near the catalytic site, providing structural insight into PgpB substrate binding mechanism. Noteworthy, in silico docking of varied lipid phosphates exhibited similar substrate binding modes to that of PE, and the residues in the lipid tunnel appear to be important for PgpB catalysis. The catalytic triad in the active site is essential for dephosphorylating substrates lysophosphatidic acid, phosphatidic acid, or sphingosine-1-phosphate but surprisingly not for the native substrate PGP. Remarkably, residue His-207 alone is sufficient to hydrolyze PGP, indicating a specific catalytic mechanism for PgpB in PG biosynthesis. We also identified two novel sensor residues, Lys-93 and Lys-97, on TM3. Our data show that Lys-97 is essential for the recognition of lyso-form substrates. Modification at the Lys-93 position may alter substrate specificity of lipid phosphate phosphatase proteins in prokaryotes versus eukaryotes. These studies reveal new mechanisms of lipid substrate selection and catalysis by PgpB and suggest that the enzyme rests in a PE-stabilized state in the bilayer.


Asunto(s)
Membrana Celular/enzimología , Proteínas de Escherichia coli/química , Escherichia coli/enzimología , Lisofosfolípidos/química , Fosfatidato Fosfatasa/química , Esfingosina/análogos & derivados , Catálisis , Dominio Catalítico , Membrana Celular/genética , Membrana Celular/metabolismo , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Lisofosfolípidos/genética , Lisofosfolípidos/metabolismo , Fosfatidato Fosfatasa/genética , Fosfatidato Fosfatasa/metabolismo , Esfingosina/química , Esfingosina/genética , Esfingosina/metabolismo , Especificidad por Sustrato
8.
BMC Biotechnol ; 17(1): 81, 2017 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-29137618

RESUMEN

BACKGROUND: Recent development of DNA assembly technologies has spurred myriad advances in synthetic biology, but new tools are always required for complicated scenarios. Here, we have developed an alternative DNA assembly method named AFEAP cloning (Assembly of Fragment Ends After PCR), which allows scarless, modular, and reliable construction of biological pathways and circuits from basic genetic parts. METHODS: The AFEAP method requires two-round of PCRs followed by ligation of the sticky ends of DNA fragments. The first PCR yields linear DNA fragments and is followed by a second asymmetric (one primer) PCR and subsequent annealing that inserts overlapping overhangs at both sides of each DNA fragment. The overlapping overhangs of the neighboring DNA fragments annealed and the nick was sealed by T4 DNA ligase, followed by bacterial transformation to yield the desired plasmids. RESULTS: We characterized the capability and limitations of new developed AFEAP cloning and demonstrated its application to assemble DNA with varying scenarios. Under the optimized conditions, AFEAP cloning allows assembly of an 8 kb plasmid from 1-13 fragments with high accuracy (between 80 and 100%), and 8.0, 11.6, 19.6, 28, and 35.6 kb plasmids from five fragments at 91.67, 91.67, 88.33, 86.33, and 81.67% fidelity, respectively. AFEAP cloning also is capable to construct bacterial artificial chromosome (BAC, 200 kb) with a fidelity of 46.7%. CONCLUSIONS: AFEAP cloning provides a powerful, efficient, seamless, and sequence-independent DNA assembly tool for multiple fragments up to 13 and large DNA up to 200 kb that expands synthetic biologist's toolbox.


Asunto(s)
Clonación Molecular/métodos , ADN/metabolismo , Reacción en Cadena de la Polimerasa/métodos , Biología Sintética/métodos , Cromosomas Artificiales Bacterianos/química , Cromosomas Artificiales Bacterianos/genética , Cromosomas Artificiales Bacterianos/metabolismo , ADN/química , ADN/genética , Plásmidos/genética
9.
BMC Biotechnol ; 17(1): 32, 2017 03 17.
Artículo en Inglés | MEDLINE | ID: mdl-28302113

RESUMEN

BACKGROUND: Restriction-free (RF) cloning, a PCR-based method for the creation of custom DNA plasmids, allows for the insertion of any sequence into any plasmid vector at any desired position, independent of restriction sites and/or ligation. Here, we describe a simple and fast method for performing gene reconstitution by modified RF cloning. RESULTS: Double-stranded inserts and acceptors were first amplified by regular PCR. The amplified fragments were then used as the templates in two separate linear amplification reactions containing either forward or reverse primer to generate two single-strand reverse-complement counterparts, which could anneal to each other. The annealed inserts and acceptors with 5' and 3' cohesive ends were sealed by ligation reaction. Using this method, we made 46 constructs containing insertions of up to 20 kb. The average cloning efficiency was higher than 85%, as confirmed by colony PCR and sequencing of the inserts. CONCLUSIONS: Our method provides an alternative cloning method capable of inserting any DNA fragment of up to at least 20 kb into a plasmid, with high efficiency. This new method does not require restriction sites or alterations of the plasmid or the gene of interest, or additional treatments. The simplicity of both primer design and the procedure itself makes the method suitable for high-throughput cloning and structural genomics.


Asunto(s)
Clonación Molecular/métodos , Cartilla de ADN/genética , ADN/genética , Plásmidos/genética , Enzimas de Restricción del ADN/genética , Reacción en Cadena de la Polimerasa
10.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1862(11): 1404-1413, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27956138

RESUMEN

Lysophospholipids (LPLs) are metabolic intermediates in bacterial phospholipid turnover. Distinct from their diacyl counterparts, these inverted cone-shaped molecules share physical characteristics of detergents, enabling modification of local membrane properties such as curvature. The functions of LPLs as cellular growth factors or potent lipid mediators have been extensively demonstrated in eukaryotic cells but are still undefined in bacteria. In the envelope of Gram-negative bacteria, LPLs are derived from multiple endogenous and exogenous sources. Although several flippases that move non-glycerophospholipids across the bacterial inner membrane were characterized, lysophospholipid transporter LplT appears to be the first example of a bacterial protein capable of facilitating rapid retrograde translocation of lyso forms of glycerophospholipids across the cytoplasmic membrane in Gram-negative bacteria. LplT transports lyso forms of the three bacterial membrane phospholipids with comparable efficiency, but excludes other lysolipid species. Once a LPL is flipped by LplT to the cytoplasmic side of the inner membrane, its diacyl form is effectively regenerated by the action of a peripheral enzyme, acyl-ACP synthetase/LPL acyltransferase (Aas). LplT-Aas also mediates a novel cardiolipin remodeling by converting its two lyso derivatives, diacyl or deacylated cardiolipin, to a triacyl form. This coupled remodeling system provides a unique bacterial membrane phospholipid repair mechanism. Strict selectivity of LplT for lyso lipids allows this system to fulfill efficient lipid repair in an environment containing mostly diacyl phospholipids. A rocker-switch model engaged by a pair of symmetric ion-locks may facilitate alternating substrate access to drive LPL flipping into bacterial cells. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop.


Asunto(s)
Pared Celular/metabolismo , Bacterias Gramnegativas/metabolismo , Lipogénesis , Lisofosfolípidos/biosíntesis , Proteínas de Transferencia de Fosfolípidos/metabolismo , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Transporte Biológico , Ligasas de Carbono-Azufre/química , Ligasas de Carbono-Azufre/metabolismo , Lisofosfolípidos/química , Proteínas de Transferencia de Fosfolípidos/química , Transducción de Señal , Especificidad por Sustrato
11.
J Biol Chem ; 290(26): 16261-71, 2015 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-25971963

RESUMEN

We examine the role of Lys-377, the only charged residue in helix XI, on the functional mechanism of the Na(+)-sugar melibiose symporter from Escherichia coli. Intrinsic fluorescence, FRET, and Fourier transform infrared difference spectroscopy reveal that replacement of Lys-377 with either Cys, Val, Arg, or Asp disables both Na(+) and melibiose binding. On the other hand, molecular dynamics simulations extending up to 200-330 ns reveal that Lys-377 (helix XI) interacts with the anionic side chains of two of the three putative ligands for cation binding (Asp-55 and Asp-59 in helix II). When Asp-59 is protonated during the simulations, Lys-377 preferentially interacts with Asp-55. Interestingly, when a Na(+) ion is positioned in the Asp-55-Asp-59 environment, Asp-124 in helix IV (a residue essential for melibiose binding) reorients and approximates the Asp-55-Asp-59 pair, and all three acidic side chains act as Na(+) ligands. Under these conditions, the side chain of Lys-377 interacts with the carboxylic moiety of these three Asp residues. These data highlight the crucial role of the Lys-377 residue in the spatial organization of the Na(+) binding site. Finally, the analysis of the second-site revertants of K377C reveals that mutation of Ile-22 (in helix I) preserves Na(+) binding, whereas that of melibiose is largely abolished according to spectroscopic measurements. This amino acid is located in the border of the sugar-binding site and might participate in sugar binding through apolar interactions.


Asunto(s)
Escherichia coli/metabolismo , Lisina/metabolismo , Simportadores/química , Simportadores/metabolismo , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Sitios de Unión , Escherichia coli/química , Escherichia coli/genética , Isoleucina/química , Isoleucina/genética , Isoleucina/metabolismo , Cinética , Lisina/química , Lisina/genética , Melibiosa/química , Melibiosa/metabolismo , Simulación de Dinámica Molecular , Sodio/química , Sodio/metabolismo , Simportadores/genética
12.
Biochim Biophys Acta ; 1828(8): 1690-9, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23500619

RESUMEN

The melibiose transporter from Escherichia coli (MelB) can use the electrochemical energy of either H(+), Na(+) or Li(+) to transport the disaccharide melibiose to the cell interior. By using spectroscopic and biochemical methods, we have analyzed the role of Arg149 by mutagenesis. According to Fourier transform infrared difference and fluorescence spectroscopy studies, R149C, R149Q and R149K all bind substrates in proteoliposomes, where the protein is disposed inside-out. Analysis of right-side-out (RSO) and inside-out (ISO) membrane vesicles showed that the functionally active R149Q and R149K mutants could bind externally added fluorescent sugar analog in both types of vesicles. In contrast, the non-transporting R149C mutant does bind the fluorescent sugar analog as well as melibiose and Na(+) in ISO, but not in RSO vesicles. Therefore, the mutation of Arg149 into cysteine restrains the orientation of transporter to an inward-open conformation, with the inherent consequences of a) reducing the frequency of access of outer substrates to the binding sites, and b) impairing active transport. It is concluded that Arg149, most likely located in the inner (cytoplasmic) half of transmembrane helix 5, is critically involved in the reorientation mechanism of the substrate-binding site accessibility in MelB.


Asunto(s)
Arginina/química , Cisteína/química , Escherichia coli/enzimología , Melibiosa/metabolismo , Simportadores/química , Alquilación , Sustitución de Aminoácidos , Arginina/genética , Arginina/metabolismo , Sitios de Unión , Transporte Biológico , Membrana Celular/metabolismo , Cisteína/genética , Cisteína/metabolismo , Escherichia coli/genética , Transferencia Resonante de Energía de Fluorescencia , Mutagénesis Sitio-Dirigida , Unión Proteica , Conformación Proteica , Proteolípidos , Espectroscopía Infrarroja por Transformada de Fourier , Especificidad por Sustrato , Simportadores/genética , Simportadores/metabolismo
13.
Cancer Immunol Res ; 12(3): 363-376, 2024 03 04.
Artículo en Inglés | MEDLINE | ID: mdl-38289255

RESUMEN

Extensive infiltration by tumor-associated macrophages (TAM) in combination with myeloid-derived suppressor cells constitute the immunosuppressive microenvironment and promote the malignant phenotype of gliomas. The aggressive mesenchymal (MES)-subtype glioma stem cells (GSC) are prominent in the immunosuppressive microenvironment of gliomas. However, the underlying immune-suppressive mechanisms are still unknown. The current study showed that the antitumor immune microenvironment was activated in glioma in Nfat1-/- mice, suggesting induction of the immune-suppressive microenvironment by nuclear factor of activated T cells-1 (NFAT1). In TAMs, NFAT1 could upregulate the transcriptional activity of complement 3 (C3) and increase the secretion of C3a, which could then bind to C3aR and promote M2-like macrophage polarization by activating TIM-3. Simultaneously, C3a/C3aR activated the Ca2+-NFAT1 pathway, forming a positive feedback loop for the M2-like polarization of TAMs, which further promoted the MES transition of GSCs. Finally, disruption of this feedback loop using a C3aR inhibitor significantly inhibited glioma growth both in vitro and in vivo. The current study demonstrated that a NFAT1-C3a-C3aR positive feedback loop induces M2-like TAMs and further promotes the malignant phenotype of GSCs, which might be the potential therapeutic target for glioma.


Asunto(s)
Glioma , Macrófagos , Animales , Ratones , Macrófagos Asociados a Tumores/metabolismo , Retroalimentación , Glioma/genética , Fenotipo , Células Madre Neoplásicas/metabolismo , Microambiente Tumoral , Línea Celular Tumoral
14.
Curr Top Med Chem ; 24(1): 31-44, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37929725

RESUMEN

Bacterial proteins targeting the appropriate subcellular sites are the base for their proper function. Several studies have shown that the anionic phospholipid cardiolipin (CL), a conical lipid preferring negative membrane curvature, modulates the lipid bilayers' structure, which impacts the activity of their resident proteins. Due to the favor of negative membrane curvature, CL is not randomly distributed in the bacterial plasma membrane. In contrast, it gathers in particular parts of the cell membrane to form microdomains, in which many functional membrane proteins are accumulated and carry out diverse physiological processes of bacteria, such as cell division, metabolism, infection, and antibiotic residence. In addition, CL has a unique structure that carries two negative charges, which makes it play a pivotal role in protein assembly, interaction, and location. These characteristics of CL make it closely related to many crucial physiological functions of bacteria. Here, we have reviewed the mechanism of protein dynamics mediated by CL initiated on the bacterial membrane. Furthermore, we studied the effect of CL on bacterial infection and antibiotic residence. Finally, the CL-targeting therapeutic agents for antibacterial therapy are also examined.


Asunto(s)
Cardiolipinas , Proteínas de la Membrana , Cardiolipinas/análisis , Cardiolipinas/química , Cardiolipinas/metabolismo , Membrana Celular/química , Proteínas de la Membrana/metabolismo , Bacterias/metabolismo , Antibacterianos/farmacología , Antibacterianos/metabolismo
15.
Int J Biol Macromol ; 259(Pt 2): 129266, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38199532

RESUMEN

Considering the astonishing prevalence of localized pain affecting billions of patients worldwide, the development of advanced analgesic formulations or delivery systems to achieve clinical applicability is of great significance. In this study, an integrated PDA-based LiH@PDA@Ag@PAA@Gelatin system was designed for sustained delivery of lidocaine hydrochloride (LiH). By optimizing the preparation process and formulation of the hydrogel, the hydrogel exhibited superior mechanical properties, reversibility, adhesion strength, and self-healing attributes. Moreover, PDA@Ag nanoparticles were evenly dispersed within the hydrogel, and the optimized PDA@Ag@PAA@Gelatin showed a higher photothermal conversion efficiency than that of pure PDA. Importantly, LiH@PDA@Ag@PAA@Gelatin could effectively capture and eradicate bacteria through the synergistic interaction between near-infrared (NIR), PDA, Ag and LiH. In vitro and in vivo tests demonstrated that LiH@PDA@Ag@PAA@Gelatin exhibited higher drug delivery efficiency compared to commercial lidocaine patches. By evaluating the mechanical pain withdrawal threshold of the spared nerve injury (SNI) model in rats, it was proven that LiH@PDA@Ag@PAA@Gelatin enhanced and prolonged the analgesic effect of LiH. Furthermore, LiH@PDA@Ag@PAA@Gelatin induced by NIR possessed excellent on-demand photothermal analgesic ability. Therefore, this study develops a convenient method for preparing localized analgesic hydrogel patches, providing an important step towards advancing PDA-based on-demand pain relief applications.


Asunto(s)
Analgesia , Indoles , Nanopartículas del Metal , Polímeros , Humanos , Ratas , Animales , Adhesivos , Lidocaína/farmacología , Lidocaína/uso terapéutico , Hidrogeles/farmacología , Gelatina , Plata , Dolor/tratamiento farmacológico , Analgésicos/farmacología , Analgésicos/uso terapéutico
16.
Infect Drug Resist ; 17: 1781-1790, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38736433

RESUMEN

Carbapenem-resistant Salmonella enterica (S. enterica) pose a significant threat to public health, causing gastroenteritis and invasive infections. We report the first emergence of a carbapenem-resistant S. enterica serovar London strain, A132, carrying the blaNDM-5 gene in China. Whole-genome sequencing and bioinformatics analysis assigned A132 to be ST155, a multidrug-resistant clone frequently reported in China. The strain A132 exhibited resistance to multiple antibiotics, with 20 acquired antibiotic resistance genes (ARGs) identified, predominantly located on the IncFIB plasmid (pA132-1-NDM). Notably, the blaNDM-5 gene was located within an IS26 flanked-class 1 integron-ISCR1 complex, comprising two genetic cassettes. One cassette is the class 1 integron, which may facilitate the transmission of the entire complex, while the other is the blaNDM-5-containing ISCR1-IS26-flanked cassette, carrying multiple other ARGs. Genbank database search based on the blaNDM-5-carrying cassette identified a similar genetic context found in transmissible IncFIA plasmids from Escherichia coli (p91) and Enterobacter hormaechei (p388) with a shared host range, suggesting the potential for cross-species transmission of blaNDM-5. To our knowledge, this is the first reported case of Salmonella serovar London ST155 harboring blaNDM-5 gene. Phylogenetic analysis indicated a close relationship between A132 and eight S. London ST155 strains isolated from the same province. However, A132 differed by carrying the blaNDM-5 gene and four unique ARGs. Given the high transmissibility of the F-type plasmid harboring blaNDM-5 and 18 other ARGs, it is imperative to implement vigilant surveillance and adopt appropriate infection control measures to mitigate the threat to public health.

17.
Front Biosci (Landmark Ed) ; 28(9): 199, 2023 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-37796697

RESUMEN

BACKGROUND: Ovarian cancer is the second leading cause of gynecologic cancer-associated deaths. Cancer stemness and chemoresistance are responsible for ovarian cancer metastasis and the poor prognosis of patients. In this study, we determined the function of N6-methyladenine (m6A) RNA methylation and prostaglandin E receptor 2 (PTGER2) in ovarian cancer progression. METHODS: The m6A RNA methylation-associated PTGER2 in ovarian cancer was identified using bioinformatics analysis. The role of PTGER2 in ovarian cancer was elucidated in cell lines and clinical samples with cellular and molecular experiments. RESULTS: In this investigation, bioinformatics analysis based on a public cancer database was used to elucidate the impact of m6A modification on the prognosis of patients with ovarian cancer. Moreover, PTGER2 was identified as a potential oncogene associated with the distant metastasis of ovarian cancer and poor patient prognosis. Interestingly, PTGER2 expression was experimentally shown to be enhanced by N6-adenosine-methyltransferase 70 kDa subunit (METTL3)-mediated m6A modification. In addition, PTGER2 enhanced cancer stem cell self-renewal properties, the epithelial-mesenchymal transition, and DNA damage repair, thus potentiating cell stemness, therapy resistance to carboplatin, proliferation, and metastasis of ovarian cancer. Importantly, PTGER2 expression in clinical samples was associated with distant metastasis, predicted poor patient prognosis, and independently served as a prognostic predictor in ovarian cancer. CONCLUSIONS: Our work defines PTGER2 as an oncogene and reveals that PTGER2 is a prognostic predictor and novel therapeutic target for the management of ovarian cancer.


Asunto(s)
Neoplasias Ováricas , Subtipo EP2 de Receptores de Prostaglandina E , Humanos , Femenino , Resistencia a Antineoplásicos/genética , Línea Celular Tumoral , Metiltransferasas/genética , Metiltransferasas/metabolismo , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/genética , Adenosina/metabolismo , ARN
18.
Biomed Pharmacother ; 165: 115167, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37454598

RESUMEN

The nuclear factor of activated T cells (NFAT) was first identified as a transcriptional regulator of activated T cells. The NFAT family is involved in the development of tumors. Furthermore, recent evidence reveals that NFAT proteins regulate the development of inflammatory and immune responses. New discoveries have also been made about the mechanisms by which NFAT regulates cancer progression through cancer stem cells (CSC). Here, we discuss the role of the NFAT family in the immune system and various cancer types.


Asunto(s)
Factores de Transcripción NFATC , Neoplasias , Humanos , Factores de Transcripción NFATC/metabolismo , Calcineurina/metabolismo , Transducción de Señal , Células Madre Neoplásicas/metabolismo
19.
Front Oncol ; 13: 1151434, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36969077

RESUMEN

Purpose: Aimed to identify the anti-uterine corpus endometrial carcinoma (UCEC) function and characterize the mechanism of quercetin in the treatment of patients infected with COVID-19 via integrated in silico analysis. Methods: The Cancer Genome Atlas and Genotype Tissue Expression databases were applied to obtain differentially expressed genes of UCEC and non-tumor tissue. Several in silico methods such as network pharmacology, functional enrichment analysis, Cox regression analyses, somatic mutation analysis, immune infiltration and molecular docking were used to investigate and analysis the biological targets, functions and mechanisms of anti-UCEC/COVID-19 of quercetin. Multiple methods such as CCK8 assay, Transwell assay and western blotting were performed to test proliferation, migration, and protein level of UCEC (HEC-1 and Ishikawa) cells. Results: Functional analysis disclosed that quercetin against UCEC/COVID-19 mainly by 'biological regulation', 'response to stimulus', and 'regulation of cellular process'. Then, regression analyses indicated that 9 prognostic genes (including ANPEP, OAS1, SCGB1A1, HLA-A, NPPB, FGB, CCL2, TLR4, and SERPINE1) might play important roles in quercetin for treating UCEC/COVID-19. Molecular docking analysis revealed that the protein products of 9 prognostic genes were the important anti-UCEC/COVID-19 biological targets of quercetin. Meanwhile, the proliferation and migration of UCEC cells were inhibited by quercetin. Moreover, after treatment with quercetin, the protein level of ubiquitination-related gene ISG15 was decreased in UCEC cells in vitro. Conclusions: Taken together, this study provides new treatment option for UCEC patients infected with COVID-19. Quercetin may work by reducing the expression of ISG15 and participating in ubiquitination-related pathways.

20.
Comput Biol Med ; 155: 106632, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36805217

RESUMEN

BACKGROUND: Metabolism dysfunction can affect the biological behavior of tumor cells and result in carcinogenesis and the development of various cancers. However, few thoughtful studies focus on the predictive value and efficacy of immunotherapy of metabolism-related gene signatures in endometrial cancer (EC). This research aims to construct a predictive metabolism-related gene signature in EC with prognostic and therapeutic implications. METHODS: We downloaded the RNA profile and clinical data of 503 EC patients and screened out different expressions of metabolism-related genes with prognosis influence of EC from The Cancer Genome Atlas (TCGA) database. We first established a metabolism-related genes model using univariate and multivariate Cox regression and Lasso regression analysis. To internally validate the predictive model, 503 samples (entire set) were randomly assigned into the test set and the train set. Then, we applied the receiver operating characteristic (ROC) curve to confirm our previous predictive model and depicted a nomogram integrating the risk score and the clinicopathological feature. We employed a gene set enrichment analysis (GSEA) to explore the biological processes and pathways of the model. Afterward, we used ESTIMATE to evaluate the TME. Also, we adopted CIBERSORT and ssGSEA to estimate the fraction of immune infiltrating cells and immune function. At last, we investigated the relationship between the predictive model and immune checkpoint genes. RESULTS: We first constructed a predictive model based on five metabolism-related genes (INPP5K, PLPP2, MBOAT2, DDC, and ITPKA). This model showed the ability to predict EC patients' prognosis accurately and performed well in the train set, test set, and entire set. Then we confirmed the predictive signature was a novel independent prognostic factor in EC patients. In addition, we drew and validated a nomogram to precisely predict the survival rate of EC patients at 1-, 3-, and 5-years (ROC1-year = 0.714, ROC3-year = 0.750, ROC5-year = 0.767). Furthermore, GSEA unveiled that the cell cycle, certain malignant tumors, and cell metabolism were the main biological functions enriched in this identified model. We found the five metabolism-related genes signature was associated with the immune infiltrating cells and immune functions. Most importantly, it was linked with specific immune checkpoints (PD-1, CTLA4, and CD40) that could predict immunotherapy's clinical response. CONCLUSION: The metabolism-related genes signature (INPP5K, PLPP2, MBOAT2, DDC, and ITPKA) is a valuable index for predicting the survival outcomes and efficacy of immunotherapy for EC in clinical settings.


Asunto(s)
Neoplasias Endometriales , Humanos , Femenino , Carcinogénesis , Ciclo Celular , Minería de Datos , Bases de Datos Factuales
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