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1.
J Cell Mol Med ; 28(8): e18299, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38613355

RESUMO

Pulmonary fibrosis is a lung disorder affecting the lungs that involves the overexpressed extracellular matrix, scarring and stiffening of tissue. The repair of lung tissue after injury relies heavily on Type II alveolar epithelial cells (AEII), and repeated damage to these cells is a crucial factor in the development of pulmonary fibrosis. Studies have demonstrated that chronic exposure to PM2.5, a form of air pollution, leads to an increase in the incidence and severity of pulmonary fibrosis by stimulation of epithelial-mesenchymal transition (EMT) in lung epithelial cells. Pyrroloquinoline quinone (PQQ) is a bioactive compound found naturally that exhibits potent anti-inflammatory and anti-oxidative properties. The mechanism by which PQQ prevents pulmonary fibrosis caused by exposure to PM2.5 through EMT has not been thoroughly discussed until now. In the current study, we discovered that PQQ successfully prevented PM2.5-induced pulmonary fibrosis by targeting EMT. The results indicated that PQQ was able to inhibit the expression of type I collagen, a well-known fibrosis marker, in AEII cells subjected to long-term PM2.5 exposure. We also found the alterations of cellular structure and EMT marker expression in AEII cells with PM2.5 incubation, which were reduced by PQQ treatment. Furthermore, prolonged exposure to PM2.5 considerably reduced cell migratory ability, but PQQ treatment helped in reducing it. In vivo animal experiments indicated that PQQ could reduce EMT markers and enhance pulmonary function. Overall, these results imply that PQQ might be useful in clinical settings to prevent pulmonary fibrosis.


Assuntos
Fibrose Pulmonar , Animais , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/tratamento farmacológico , Cofator PQQ/farmacologia , Transição Epitelial-Mesenquimal , Células Epiteliais Alveolares , Material Particulado/toxicidade
2.
Mol Biol Evol ; 39(9)2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35993177

RESUMO

The origin of nitrogen fixation is an important issue in evolutionary biology. While nitrogen is required by all living organisms, only a small fraction of bacteria and archaea can fix nitrogen. The prevailing view is that nitrogen fixation first evolved in archaea and was later transferred to bacteria. However, nitrogen-fixing (Nif) bacteria are far larger in number and far more diverse in ecological niches than Nif archaea. We, therefore, propose the bacteria-first hypothesis, which postulates that nitrogen fixation first evolved in bacteria and was later transferred to archaea. As >30,000 prokaryotic genomes have been sequenced, we conduct an in-depth comparison of the two hypotheses. We first identify the six genes involved in nitrogen fixation in all sequenced prokaryotic genomes and then reconstruct phylogenetic trees using the six Nif proteins individually or in combination. In each of these trees, the earliest lineages are bacterial Nif protein sequences and in the oldest clade (group) the archaeal sequences are all nested inside bacterial sequences, suggesting that the Nif proteins first evolved in bacteria. The bacteria-first hypothesis is further supported by the observation that the majority of Nif archaea carry the major bacterial Mo (molybdenum) transporter (ModABC) rather than the archaeal Mo transporter (WtpABC). Moreover, in our phylogeny of all available ModA and WtpA protein sequences, the earliest lineages are bacterial sequences while archaeal sequences are nested inside bacterial sequences. Furthermore, the bacteria-first hypothesis is supported by available isotopic data. In conclusion, our study strongly supports the bacteria-first hypothesis.


Assuntos
Fixação de Nitrogênio , Nitrogenase , Archaea/genética , Archaea/metabolismo , Bactérias/metabolismo , Proteínas de Bactérias/genética , Nitrogênio/metabolismo , Fixação de Nitrogênio/genética , Nitrogenase/genética , Nitrogenase/metabolismo , Filogenia
3.
Mar Drugs ; 21(8)2023 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-37623728

RESUMO

Atopic dermatitis (AD, eczema) is a condition that causes dry, itchy, and inflamed skin and occurs most frequently in children but also affects adults. However, common clinical treatments provide limited relief and have some side effects. Therefore, there is a need to develop new effective therapies to treat AD. Epi-oxyzoanthamine is a small molecule alkaloid isolated from Formosan zoanthid. Relevant studies have shown that zoanthamine alkaloids have many pharmacological and biological activities, including anti-lymphangiogenic functions. However, there are no studies on the use of epi-oxyzoanthamine on the skin. In this paper, epi-oxyzoanthamine has been shown to have potential in the treatment of atopic dermatitis. Through in vitro studies, it was found that epi-oxyzoanthamine inhibited the expression of cytokines in TNF-α/IFN-γ-stimulated human keratinocyte (HaCaT) cells, and it reduced the phosphorylation of MAPK and the NF-κB signaling pathway. Atopic dermatitis-like skin inflammation was induced in a mouse model using 2,4-dinitrochlorobenzene (DNCB) in vivo. The results showed that epi-oxyzoanthamine significantly decreased skin barrier damage, scratching responses, and epidermal hyperplasia induced by DNCB. It significantly reduced transepidermal water loss (TEWL), erythema, ear thickness, and spleen weight, while also increasing surface skin hydration. These results indicate that epi-oxyzoanthamine from zoanthid has good potential as an alternative medicine for treating atopic dermatitis or other skin-related inflammatory diseases.


Assuntos
Dermatite Atópica , Dinitroclorobenzeno , Adulto , Criança , Humanos , Animais , Camundongos , Dermatite Atópica/induzido quimicamente , Dermatite Atópica/tratamento farmacológico , Pele , Prurido , Queratinócitos
4.
Proc Natl Acad Sci U S A ; 117(5): 2385-2394, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-31953261

RESUMO

Cellulosomes, which are multienzyme complexes from anaerobic bacteria, are considered nature's finest cellulolytic machinery. Thus, constructing a cellulosome in an industrial yeast has long been a goal pursued by scientists. However, it remains highly challenging due to the size and complexity of cellulosomal genes. Here, we overcame the difficulties by synthesizing the Clostridium thermocellum scaffoldin gene (CipA) and the anchoring protein gene (OlpB) using advanced synthetic biology techniques. The engineered Kluyveromyces marxianus, a probiotic yeast, secreted a mixture of dockerin-fused fungal cellulases, including an endoglucanase (TrEgIII), exoglucanase (CBHII), ß-glucosidase (NpaBGS), and cellulase boosters (TaLPMO and MtCDH). The confocal microscopy results confirmed the cell-surface display of OlpB-ScGPI and fluorescence-activated cell sorting analysis results revealed that almost 81% of yeast cells displayed OlpB-ScGPI. We have also demonstrated the cellulosome complex formation using purified and crude cellulosomal proteins. Native polyacrylamide gel electrophoresis and mass spectrometric analysis further confirmed the cellulosome complex formation. Our engineered cellulosome can accommodate up to 63 enzymes, whereas the largest engineered cellulosome reported thus far could accommodate only 12 enzymes and was expressed by a plasmid instead of chromosomal integration. Interestingly, CipA 2B9C (with two cellulose binding modules, CBM) released significantly higher quantities of reducing sugars compared with other CipA variants, thus confirming the importance of cohesin numbers and CBM domain on cellulosome complex. The engineered yeast host efficiently degraded cellulosic substrates and released 3.09 g/L and 8.61 g/L of ethanol from avicel and phosphoric acid-swollen cellulose, respectively, which is higher than any previously constructed yeast cellulosome.


Assuntos
Membrana Celular/metabolismo , Celulossomas/metabolismo , Kluyveromyces/genética , Kluyveromyces/metabolismo , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Celulase/genética , Celulase/metabolismo , Celulose/metabolismo , Celulossomas/enzimologia , Celulossomas/genética , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Cromossomos/genética , Clostridium thermocellum/genética , Etanol/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Kluyveromyces/enzimologia , Proteínas de Membrana/química , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , beta-Glucosidase/genética , beta-Glucosidase/metabolismo , Coesinas
5.
Altern Ther Health Med ; 29(1): 96-103, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35212646

RESUMO

Context: Narrowband ultraviolet B (NBUVB) phototherapy is the standard treatment for chronic stable vitiligo, but its efficacy, when used alone, is often unsatisfactory. Objective: The study evaluated the efficacy of surrounding needling with acupuncture needles in combination with NBUVB phototherapy for lesions on different body parts of patients with chronic stable vitiligo. Design: The research team designed a 12-week, randomized, open-label, prospective, intra-individual, comparative clinical trial. Setting: The study took place in the Department of Dermatology at Shin-Kong Wu Ho-Su Memorial Hospital in Taiwan. Participants: Participants were patients at the hospital, aged 20-80 years, with chronic stable nonsegmental vitiligo. The lesions on both sides of their bodies had the same baseline conditions. Nine patients with 14 pairs of lesions (n = 28) were included in the study, and eight participants with 13 pairs of lesions (n = 26) successfully completed the study. Intervention: Vitiligo lesions in the intervention group were treated with surrounding needling combined with NBUVB phototherapy, whereas the control group received NBUVB phototherapy only. Outcome Measures: The primary outcome was evaluated at Week 12 using the modified Vitiligo Area Scoring Index (VASI), which focuses on local depigmentation only without multiplication by body surface area, and the testing used the Wilcoxon signed-rank test. A higher VASI score indicates more severe vitiligo. Pain was rated postintervention, after completion of all treatments. Results: At baseline, the modified VASI score in both groups was 93.07 ± 4.62. Postintervention, this score in the intervention group improved to 78.46 ± 15.24, with a significant difference between baseline and postintervention (P = .007), and in the control group, the score improved to 91.92 ± 6.67, with no significant difference having occurred (P = .317). A statistically significant difference was found between the intervention group and the control group in the change in scores postintervention (P = .007). Conclusion: Surrounding needling in combination with NBUVB phototherapy may be a promising treatment for chronic stable nonsegmental vitiligo. Future studies with larger sample sizes and long-term follow-up are warranted.


Assuntos
Terapia Ultravioleta , Vitiligo , Humanos , Vitiligo/radioterapia , Vitiligo/tratamento farmacológico , Estudos Prospectivos , Resultado do Tratamento , Taiwan
6.
Int J Mol Sci ; 24(18)2023 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-37762380

RESUMO

Rhodopseudomonas palustris is a purple non-sulfide bacterium (PNSB), and some strains have been proven to promote plant growth. However, the mechanism underlying the effect of these PNSBs remains limited. Based on genetic information, R. palustris possesses the ability to produce pyrroloquinoline quinone (PQQ). PQQ is known to play a crucial role in stimulating plant growth, facilitating phosphorous solubilization, and acting as a reactive oxygen species scavenger. However, it is still uncertain whether growth conditions influence R. palustris's production of PQQ and other characteristics. In the present study, it was found that R. palustris exhibited a higher expression of genes related to PQQ synthesis under autotrophic culture conditions as compared to acetate culture conditions. Moreover, similar patterns were observed for phosphorous solubilization and siderophore activity, both of which are recognized to contribute to plant-growth benefits. However, these PNSB culture conditions did not show differences in Arabidopsis growth experiments, indicating that there may be other factors influencing plant growth in addition to PQQ content. Furthermore, the endophytic bacterial strains isolated from Arabidopsis exhibited differences according to the PNSB culture conditions. These findings imply that, depending on the PNSB's growing conditions, it may interact with various soil bacteria and facilitate their infiltration into plants.


Assuntos
Arabidopsis , Rodopseudomonas , Humanos , Cofator PQQ , Transtornos do Crescimento , Fósforo
7.
Int J Mol Sci ; 22(6)2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33808829

RESUMO

To date, soil salinity becomes a huge obstacle for food production worldwide since salt stress is one of the major factors limiting agricultural productivity. It is estimated that a significant loss of crops (20-50%) would be due to drought and salinity. To embark upon this harsh situation, numerous strategies such as plant breeding, plant genetic engineering, and a large variety of agricultural practices including the applications of plant growth-promoting rhizobacteria (PGPR) and seed biopriming technique have been developed to improve plant defense system against salt stress, resulting in higher crop yields to meet human's increasing food demand in the future. In the present review, we update and discuss the advantageous roles of beneficial PGPR as green bioinoculants in mitigating the burden of high saline conditions on morphological parameters and on physio-biochemical attributes of plant crops via diverse mechanisms. In addition, the applications of PGPR as a useful tool in seed biopriming technique are also updated and discussed since this approach exhibits promising potentials in improving seed vigor, rapid seed germination, and seedling growth uniformity. Furthermore, the controversial findings regarding the fluctuation of antioxidants and osmolytes in PGPR-treated plants are also pointed out and discussed.


Assuntos
Desenvolvimento Vegetal , Fenômenos Fisiológicos Vegetais , Rhizobiaceae/fisiologia , Salinidade , Estresse Salino , Tolerância ao Sal , Produtos Agrícolas , Variação Genética , Genômica/métodos , Fotossíntese , Proteômica/métodos , Plântula/fisiologia , Simbiose
8.
Heart Surg Forum ; 23(5): E555-E573, 2020 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-32990583

RESUMO

Though infective endocarditis (IE) is a life-threatening cardiac infection with a high mortality rate, the effective diagnostic and prognostic biomarkers for IE are still lacking. The aim of this study was to explore the potential applicable proteomic biomarkers for IE through the Immunome™ Protein Array system. The system was employed to profile those autoantibodies in IE patients and control subjects. Our results showed that interleukin-1 alpha (IL1A), nucleolar protein 4 (NOL4), tudor and KH domain-containing protein (TDRKH), G antigen 2B/2C (GAGE2), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and X antigen family member 2 (XAGE2) are highly differentially-expressed among IE and non-IE control. Furthermore, bactericidal permeability-increasing protein (BPI), drebrin-like protein (DBNL), signal transducing adapter molecule 2 (STAM2), cyclin-dependent kinase 16 (CDK16), BAG family molecular chaperone regulator 4 (BAG4), and nuclear receptor-interacting protein 3 (NRIP3) are differentially-expressed among IE and healthy controls. On the other hand, those previously identified biomarkers for IE, including erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor, procalcitonin, and N-terminal-pro-B-type natriuretic peptide demonstrated only minor significance. With scientific rationalities for those highly differentially-expressed proteins, they could serve as potential candidates for diagnostic biomarkers of IE for further analysis.


Assuntos
Autoanticorpos/sangue , Endocardite/diagnóstico , Análise Serial de Proteínas/métodos , Proteômica/métodos , Proteínas Adaptadoras de Transdução de Sinal/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Proteína C-Reativa/metabolismo , Endocardite/sangue , Complexos Endossomais de Distribuição Requeridos para Transporte/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Peptídeo Natriurético Encefálico/sangue , Fragmentos de Peptídeos/sangue , Prognóstico , Precursores de Proteínas
9.
Microb Cell Fact ; 18(1): 155, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31506091

RESUMO

BACKGROUND: A microorganism engineered for non-native tasks may suffer stresses it never met before. Therefore, we examined whether a Kluyveromyces marxianus strain engineered with a carotenoid biosynthesis pathway can serve as an anti-stress chassis for building cell factories. RESULTS: Carotenoids, a family of antioxidants, are valuable natural products with high commercial potential. We showed that the free radical removal ability of carotenoids can confer the engineered host with a higher tolerance to ethanol, so that it can produce more bio-ethanol than the wild type. Moreover, we found that this engineered strain has improved tolerance to other toxic effects including furfurals, heavy metals such as arsenate (biomass contaminant) and isobutanol (end product). Furthermore, the enhanced ethanol tolerance of the host can be applied to bioconversion of a natural medicine that needs to use ethanol as the delivery solvent of hydrophobic precursors. The result suggested that the engineered yeast showed enhanced tolerance to ethanol-dissolved hydrophobic 10-deacetylbaccatin III, which is considered a sustainable precursor for paclitaxel (taxol) bioconversion. CONCLUSIONS: The stress tolerances of the engineered yeast strain showed tolerance to several toxins, so it may serve as a chassis for cell factories to produce target products, and the co-production of carotenoids may make the biorefinary more cost-effective.


Assuntos
Carotenoides/metabolismo , Etanol/metabolismo , Kluyveromyces/crescimento & desenvolvimento , Kluyveromyces/metabolismo , Engenharia Metabólica , Fermentação
10.
Biotechnol Bioeng ; 115(3): 751-761, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29197184

RESUMO

Cellulose is a renewable feedstock for green industry. It is therefore important to develop a technique to construct a host with a high cellulolytic efficiency to digest cellulose. In this study, we developed a convenient host-engineering technique to adjust the expression levels of heterologous genes in the host by promoter rearrangement and gene copy number adjustment. Using genes from different glycoside hydrolase (GH) families including GH2, GH3, GH5, GH6, GH7, and GH12 from Aspergillus niger, Trichoderma reesei, and Neocallimastix patriciarum, we constructed a cellulolytic Kluyveromyces marxianus with eight cellulase gene-cassettes that produced a cellulase cocktail with a high cellulolytic efficiency, leading to a significant reduction in enzyme cost in a rice straw saccharification process. Our technique can be used to design a host that can efficiently convert biomass feedstock to biofuel.


Assuntos
Celulase , Proteínas Fúngicas , Kluyveromyces , Celulase/biossíntese , Celulase/genética , Proteínas Fúngicas/biossíntese , Proteínas Fúngicas/genética , Kluyveromyces/enzimologia , Kluyveromyces/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética
11.
Nucleic Acids Res ; 44(D1): D944-51, 2016 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-26602695

RESUMO

The genome-wide transcriptome profiling of cancerous and normal tissue samples can provide insights into the molecular mechanisms of cancer initiation and progression. RNA Sequencing (RNA-Seq) is a revolutionary tool that has been used extensively in cancer research. However, no existing RNA-Seq database provides all of the following features: (i) large-scale and comprehensive data archives and analyses, including coding-transcript profiling, long non-coding RNA (lncRNA) profiling and coexpression networks; (ii) phenotype-oriented data organization and searching and (iii) the visualization of expression profiles, differential expression and regulatory networks. We have constructed the first public database that meets these criteria, the Cancer RNA-Seq Nexus (CRN, http://syslab4.nchu.edu.tw/CRN). CRN has a user-friendly web interface designed to facilitate cancer research and personalized medicine. It is an open resource for intuitive data exploration, providing coding-transcript/lncRNA expression profiles to support researchers generating new hypotheses in cancer research and personalized medicine.


Assuntos
Bases de Dados Genéticas , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Neoplasias/genética , Humanos , Neoplasias/metabolismo , Fenótipo , RNA Longo não Codificante/metabolismo , RNA Mensageiro/metabolismo
12.
Nucleic Acids Res ; 44(D1): D209-15, 2016 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-26450965

RESUMO

Circular RNAs (circRNAs) represent a new type of regulatory noncoding RNA that only recently has been identified and cataloged. Emerging evidence indicates that circRNAs exert a new layer of post-transcriptional regulation of gene expression. In this study, we utilized transcriptome sequencing datasets to systematically identify the expression of circRNAs (including known and newly identified ones by our pipeline) in 464 RNA-seq samples, and then constructed the CircNet database (http://circnet.mbc.nctu.edu.tw/) that provides the following resources: (i) novel circRNAs, (ii) integrated miRNA-target networks, (iii) expression profiles of circRNA isoforms, (iv) genomic annotations of circRNA isoforms (e.g. 282 948 exon positions), and (v) sequences of circRNA isoforms. The CircNet database is to our knowledge the first public database that provides tissue-specific circRNA expression profiles and circRNA-miRNA-gene regulatory networks. It not only extends the most up to date catalog of circRNAs but also provides a thorough expression analysis of both previously reported and novel circRNAs. Furthermore, it generates an integrated regulatory network that illustrates the regulation between circRNAs, miRNAs and genes.


Assuntos
Bases de Dados de Ácidos Nucleicos , RNA/metabolismo , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Humanos , RNA/química , RNA Circular , Análise de Sequência de RNA
14.
BMC Biotechnol ; 17(1): 36, 2017 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-28399854

RESUMO

BACKGROUND: N-Butanol has favorable characteristics for use as either an alternative fuel or platform chemical. Bio-based n-butanol production using microbes is an emerging technology that requires further development. Although bio-industrial microbes such as Escherichia coli have been engineered to produce n-butanol, reactive oxygen species (ROS)-mediated toxicity may limit productivity. Previously, we show that outer-membrane-targeted tilapia metallothionein (OmpC-TMT) is more effective as an ROS scavenger than human and mouse metallothioneins to reduce oxidative stress in the host cell. RESULTS: The host strain (BUT1-DE) containing the clostridial n-butanol pathway displayed a decreased growth rate and limited n-butanol productivity, likely due to ROS accumulation. The clostridial n-butanol pathway was co-engineered with inducible OmpC-TMT in E. coli (BUT3-DE) for simultaneous ROS removal, and its effect on n-butanol productivity was examined. The ROS scavenging ability of cells overexpressing OmpC-TMT was examined and showed an approximately twofold increase in capacity. The modified strain improved n-butanol productivity to 320 mg/L, whereas the control strain produced only 95.1 mg/L. Transcriptomic analysis revealed three major KEGG pathways that were significantly differentially expressed in the BUT3-DE strain compared with their expression in the BUT1-DE strain, including genes involved in oxidative phosphorylation, fructose and mannose metabolism and glycolysis/gluconeogenesis. CONCLUSIONS: These results indicate that OmpC-TMT can increase n-butanol production by scavenging ROS. The transcriptomic analysis suggested that n-butanol causes quinone malfunction, resulting in oxidative-phosphorylation-related nuo operon downregulation, which would diminish the ability to convert NADH to NAD+ and generate proton motive force. However, fructose and mannose metabolism-related genes (fucA, srlE and srlA) were upregulated, and glycolysis/gluconeogenesis-related genes (pfkB, pgm) were downregulated, which further assisted in regulating NADH/NAD+ redox and preventing additional ATP depletion. These results indicated that more NADH and ATP were required in the n-butanol synthetic pathway. Our study demonstrates a potential approach to increase the robustness of microorganisms and the production of toxic chemicals through the ability to reduce oxidative stress.


Assuntos
1-Butanol/metabolismo , Clostridium/enzimologia , Escherichia coli/fisiologia , Metalotioneína/metabolismo , Porinas/metabolismo , Tilápia/metabolismo , 1-Butanol/isolamento & purificação , Animais , Membrana Celular/metabolismo , Clostridium/genética , Regulação Bacteriana da Expressão Gênica/fisiologia , Melhoramento Genético/métodos , Metalotioneína/genética , Porinas/genética , Engenharia de Proteínas/métodos , Transdução de Sinais/genética , Tilápia/genética
15.
Nucleic Acids Res ; 43(15): 7612-23, 2015 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-26150423

RESUMO

The mer operon confers bacterial resistance to inorganic mercury (Hg(2+)) and organomercurials by encoding proteins involved in sensing, transport and detoxification of these cytotoxic agents. Expression of the mer operon is under tight control by the dual-function transcriptional regulator MerR. The metal-free, apo MerR binds to the mer operator/promoter region as a repressor to block transcription initiation, but is converted into an activator upon Hg(2+)-binding. To understand how MerR interacts with Hg(2+) and how Hg(2+)-binding modulates MerR function, we report here the crystal structures of apo and Hg(2+)-bound MerR from Bacillus megaterium, corresponding respectively to the repressor and activator conformation of MerR. To our knowledge, the apo-MerR structure represents the first visualization of a MerR family member in its intact and inducer-free form. And the Hg(2+)-MerR structure offers the first view of a triligated Hg(2+)-thiolate center in a metalloprotein, confirming that MerR binds Hg(2+) via trigonal planar coordination geometry. Structural comparison revealed the conformational transition of MerR is coupled to the assembly/disassembly of a buried Hg(2+) binding site, thereby providing a structural basis for the Hg(2+)-mediated functional switching of MerR. The pronounced Hg(2+)-induced repositioning of the MerR DNA-binding domains suggests a plausible mechanism for the transcriptional regulation of the mer operon.


Assuntos
Proteínas de Bactérias/química , Proteínas de Ligação a DNA/química , Mercúrio/química , Proteínas Repressoras/química , Transativadores/química , Bacillus megaterium/genética , Sítios de Ligação , Modelos Moleculares , Óperon , Ligação Proteica , Conformação Proteica
17.
Exp Dermatol ; 25(12): 983-990, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27513811

RESUMO

Solar ultraviolet (UV) light has been recognized as the important environmental hazard and contributes to diverse skin damage such as cell death, photoageing and even carcinogenesis. Revelation of harmful responses attributed to UVA radiation has promoted the development of photoprotective agents against UVA-induced skin damage. In the present study, we tried to evaluate the potential protective effects of a synthetic green fluorescent protein (GFP) chromophore derivative, 4-chlorobenzyldene-1, 2-dimethylimidazolinone (Cl-BDI, called TC-22) on UVA- and UVB- induced stress responses in skin. The HaCaT keratinocytes were used to evaluate the cellular effects. Zebrafish (Danio rerio), which is regarded as a useful and cost-effective alternative to some mammalian models, was applied as the in vivo animal model. In HaCaT keratinocytes, TC-22 was able to obviously decrease UVA-induced cell death. Dissection of the UVA-induced signalling pathways revealed that TC-22 could suppress the activation of JNK and caspase 3, but not of ERK and p38. Reduction of UVA-induced cleavage of caspase 3 and sub-G1 phase accumulation by pretreatment of TC-22 was also observed. In zebrafish, we showed that UVA irradiation could decrease the survival and hatching rate, suppress heart beats of embryos and enhance the pigmentation of larvae. Pretreatment of TC-22 could significantly reverse UVA-induced the suppression in hatching of eggs and heart beating of embryos and also lowered the UVA-induced pigmentation in zebrafish. Collectively, we demonstrate that TC-22, a GFP chromophore derivative, can ameliorate the UVA-induced stress responses in both epidermal keratinocytes and zebrafish, suggesting the potential use of TC-22 in photoprotection in the future.


Assuntos
Apoptose/efeitos dos fármacos , Imidazóis/uso terapêutico , Queratinócitos/efeitos dos fármacos , Envelhecimento da Pele/efeitos dos fármacos , Queimadura Solar/prevenção & controle , Animais , Linhagem Celular , Avaliação Pré-Clínica de Medicamentos , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/efeitos da radiação , Humanos , Imidazóis/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Raios Ultravioleta/efeitos adversos , Peixe-Zebra
18.
J Negat Results Biomed ; 13: 15, 2014 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-25123361

RESUMO

BACKGROUND: In Changhua County, Taiwan, the number of clinical Acinetobacter baumannii isolates has risen since 2002, and multidrug-resistant Acinetobacter baumannii (MDRAB) has spread rapidly throughout Taiwan. In this study, to reveal the mechanism involved with the rapid dissemination of MDRAB emergence, the utility of the class 1 integron, intI1 integrase gene, as an MDRAB-associated biomarker was examined. A cross-sectional, clinical epidemiological study was performed at Changhua Christian Hospital between January 1st, 2001 and December 31st, 2004. Besides the existence of intI1 gene was examined, the pulse-field gel electrophoresis (PFGE) was also performed to determine the epidemiological characteristics of the isolates. FINDINGS: The overall hospital infection rate was 5-6%, while the infection rate of the intensive care unit (ICU) fluctuated. No positive correlation was observed between MDRAB isolates and the presence of intI1 (r = 0.168, P = 0.254). Additionally, no positive correlation was observed between the infection rate in the ICU and the presence of intI1 (r = -0.107, P = 0.468) or between the hospital infection rate and the presence of intI1 (r = -0.189, P = 0.199). However, two predominant clones among the MDRAB isolates were identified by PFGE. CONCLUSIONS: Although the presence of the intI1 gene does not seem suitable for tracing MDRAB emergence in Changhua County, two predominant clones were identified by PFGE, and subsequent studies to identify whether these clones were responsible for original nosocomial infection are needed.


Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla , Integrases/genética , Acinetobacter baumannii/genética , Humanos , Taiwan
19.
Orphanet J Rare Dis ; 19(1): 144, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38575988

RESUMO

BACKGROUND: Osteoporosis and its primary complication, fragility fractures, contribute to substantial global morbidity and mortality. Gaucher disease (GD) is caused by glucocerebrosidase (GBA1) deficiency, leading to skeletal complications. This study aimed to investigate the impact of the GBA1 gene on osteoporosis progression in GD patients and the specific populations. METHODS: We selected 8115 patients with osteoporosis (T-score ≤ - 2.5) and 55,942 healthy individuals (T-score > - 1) from a clinical database (N = 95,223). Monocytes from GD patients were evaluated in relation to endoplasmic reticulum (ER) stress, inflammasome activation, and osteoclastogenesis. An in vitro model of GD patient's cells treated with adeno-associated virus 9 (AAV9)-GBA1 to assess GBA1 enzyme activity, chitotriosidase activity, ER stress, and osteoclast differentiation. Longitudinal dual-energy X-ray absorptiometry (DXA) data tracking bone density in patients with Gaucher disease (GD) undergoing enzyme replacement therapy (ERT) over an extended period. RESULTS: The GBA1 gene variant rs11264345 was significantly associated [P < 0.002, Odds Ratio (OR) = 1.06] with an increased risk of bone disease. Upregulation of Calnexin, NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) and Apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain (ASC) was positively associated with osteoclastogenesis in patients with GD. In vitro AAV9-GBA1 treatment of GD patient cells led to enhanced GBA1 enzyme activity, reduced chitotriosidase activity, diminished ER stress, and decreased osteoclast differentiation. Long-term bone density data suggests that initiating ERT earlier in GD leads to greater improvements in bone density. CONCLUSIONS: Elevated ER stress and inflammasome activation are indicative of osteoporosis development, suggesting the need for clinical monitoring of patients with GD. Furthermore, disease-associated variant in the GBA1 gene may constitute a risk factor predisposing specific populations to osteoporosis.


Assuntos
Doença de Gaucher , Osteoporose , Humanos , Densidade Óssea/genética , Doença de Gaucher/tratamento farmacológico , Glucosilceramidase/uso terapêutico , Inflamassomos , Osteoporose/genética , Osteoporose/tratamento farmacológico
20.
ISME Commun ; 4(1): ycae041, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38707842

RESUMO

In response to climate change, the nature of endophytes and their applications in sustainable agriculture have attracted the attention of academics and agro-industries. This work focused on the endophytic halophiles of the endangered Taiwanese salt marsh plant, Bolboschoenus planiculmis, and evaluated the functions of these isolates through in planta salinity stress alleviation assay using Arabidopsis. The endophytic strain Priestia megaterium BP01R2, which can promote plant growth and salinity tolerance, was further characterized through multi-omics approaches. The transcriptomics results suggested that BP01R2 could function by tuning hormone signal transduction, energy-producing metabolism, multiple stress responses, etc. In addition, the cyclodipeptide cyclo(L-Ala-Gly), which was identified by metabolomics analysis, was confirmed to contribute to the alleviation of salinity stress in stressed plants via exogenous supplementation. In this study, we used multi-omics approaches to investigate the genomics, metabolomics, and tropisms of endophytes, as well as the transcriptomics of plants in response to the endophyte. The results revealed the potential molecular mechanisms underlying the occurrence of biostimulant-based plant-endophyte symbioses with possible application in sustainable agriculture.

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