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1.
J Environ Manage ; 356: 120729, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38537464

RESUMO

The recovery of valuable metals from spent lithium-ion batteries (LIBs) is crucial for environmental protection and resource optimization. In the traditional recovery process of spent LIBs, the leaching of high-valence metals has the problems of high cost and limited reagent utilization, and some valuable metals are lost in the subsequent purification process of the leaching solution. To reduce the cost of reagents, this study proposes the use of low-cost SO2 as a reagent combined with pressure leaching to efficiently recover high-valence metals from delithiated materials of spent LIBs, while selective solvent extraction is used to remove trace impurities in the leaching solution to avoid the loss of valuable metals. Experimental results demonstrated that by optimizing the conditions to 0.25 MPa SO2 partial pressure and 60 min reaction time at 70 °C, the leaching efficiencies for Ni, Co, and Mn reached 99.6%, 99.3%, and 99.6%, respectively. The kinetic study indicated that the leaching process was diffusion-controlled. Furthermore, the delithiated materials were used to completely utilize the residual SO2 in the solution to obtain a high concentration Ni-Co-Mn rich solution. Subsequently, Fe and Al impurities were deeply removed through a synergistic extraction of Di-2-ethylhexyl phosphoric acid (D2EHPA) and tributyl phosphate (TBP) without loss of valuable metals, achieving a high-purity Ni-Co-Mn solution. The process developed based on this work has the characteristics of environmental friendliness, high valuable metal recovery, and high product purity, providing a reference technical method for the synergistic treatment of waste SO2 flue gas with spent LIBs and the deep purification of impurities in spent LIBs.


Assuntos
Lítio , Reciclagem , Reciclagem/métodos , Metais , Fontes de Energia Elétrica , Cinética
2.
J Gene Med ; 25(8): e3507, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36999202

RESUMO

BACKGROUND: Hepatocellular carcinoma (HCC) is a common malignancy and has extremely poor prognosis and outcome. Homo sapiens deoxyribonuclease II (DNASE2) has been reported to participate in HCC progression. Here, the role of DNASE2 in HCC cells and the putative upstream circRNA that mediates DNASE2 expression was investigated. METHODS: The expression of RNAs in liver hepatocellular carcinoma (LIHC) samples was analyzed by bioinformatic analysis. The proliferation, apoptosis, migration, invasion, and gene expression in HCC cells were investigated using a Cell Counting Kit -8, colony formation, flow cytometry analysis, wound healing, transwell, western blotting, and a quantitative reverse transcriptase-PCR. The binding relationship among circ_0073228, miR-139-5p and DNASE2 was measured by RNA pulldown and luciferase reporter assays. RESULTS: DNASE2 knockdown inhibited proliferation and promoted apoptosis of HCC cells, whereas DNASE2 overexpression showed the opposite results. miR-139-5p targeted DNASE2 and suppressed its expression. Overexpression of miR-139-5p inhibited malignant phenotypes of HCC cells. RPS23-derived circ_0073228, which bound to miR-139-5p, was found to be upregulated in HCC cells. Inhibition of miR-139-5p or overexpression of DNASE2 counteracted the inhibitory effects of circ_0073228 knockdown on HCC cell progression. CONCLUSIONS: circ_0073228 serves as an oncogene to facilitate growth and inhibit apoptosis of HCC cells by regulating the miR-139-5p/DNASE2 axis.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroRNAs , Humanos , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Apoptose/genética , Proliferação de Células/genética , MicroRNAs/genética , Linhagem Celular Tumoral
3.
Biochem Biophys Res Commun ; 676: 149-157, 2023 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-37517217

RESUMO

Glioblastoma (GBM) has a high degree of invasiveness, which is largely attributed to the invalidation of current therapy and the unclear tumor growth mechanism. Ras related GTP binding B (RRAGB) is a family member of the Ras-homologous GTPases. The effect of RRAGB on tumor growth has been recognized, but its influences on GBM progression are ill-defined. Here, in our research, a significantly decreased expression of RRAGB in GBM tissues by using TCGA databases and glioma samples is observed. According to Kaplan-Meier (KM) analysis, RRAGB low expression leads to a significant decrease of overall survival rate of patients, and is associated with the classification of WHO grade, histological type and age increase. Functional enrichment analysis reveals that the pathway of enrichment includes cell cycle arrest, extracellular matrix (ECM) processes and PI3K/AKT signal. Thereafter, our cell experiments confirm an obvious decrease of RRAGB in several GBM cell lines. It should be noted that RRAGB promotion strongly reduces the proliferation, migration and invasion of GBM cells and induces cell cycle arrest in G0/G1 phase. RRAGB up-regulation significantly decreases the expression of PI3K, phosphorylated AKT, mTOR and S6K in GBM cell lines. Surprisingly, we further find that RRAGB-restrained proliferative, migratory and invasive properties of GBM cells are markedly offset after promoting AKT activation, accompanied with restored phosphorylation of mTOR and S6K, elucidating that AKT signaling blockage is partially indispensable for RRAGB to play its anti-cancer role in GBM. Animal studies confirmed that RRAGB over-expression obviously inhibits the tumor growth both in the xenograft and orthotopic mouse glioma models, along with improved overall survival rates. In short, we provide evidence that RRAGB is a potential therapeutic target and prognostic marker for GBM treatment.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Glioma , Proteínas Monoméricas de Ligação ao GTP , Camundongos , Animais , Humanos , Glioblastoma/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Neoplasias Encefálicas/patologia , Proliferação de Células , Linhagem Celular Tumoral , Apoptose , Serina-Treonina Quinases TOR/metabolismo , Regulação Neoplásica da Expressão Gênica , Proteínas Monoméricas de Ligação ao GTP/metabolismo
4.
J Med Virol ; 95(8): e29007, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37522276

RESUMO

There is no antiviral study on hemodialysis patients infected with coronavirus disease 2019 (COVID-19), especially on the application of 2'-deoxy-2'-ß -fluoro-4'-azidocytidine (Azvudine, FNC) antiviral therapy. We conducted a multicenter observational study involving 1008 hemodialysis patients. After matching for age, sex, and other factors, 182 patients in the basic treatment group and 182 in the FNC group were included. The negative nucleic acid conversion rate of the FNC group was significantly higher than that of the basic treatment group, and viral loads, interleukin-6, and C-reactive protein were significantly lower than those of the basic treatment group (p < 0.05). There were no significant differences in liver function, renal function, or the number of adverse events between the two groups (p > 0.05). In conclusion, our study has provided novel evidence suggesting that the FNC scheme may be safe and effective compared to the basic treatment of hemodialysis patients with common COVID-19.


Assuntos
COVID-19 , Humanos , SARS-CoV-2 , Azidas , Diálise Renal
5.
Acta Pharmacol Sin ; 44(2): 381-392, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35840657

RESUMO

Acute kidney injury (AKI) refers to a group of common clinical syndromes characterized by acute renal dysfunction, which may lead to chronic kidney disease (CKD), and this process is called the AKI-CKD transition. The transcriptional coactivator YAP can promote the AKI-CKD transition by regulating the expression of profibrotic factors, and 14-3-3 protein zeta (14-3-3ζ), an important regulatory protein of YAP, may prevent the AKI-CKD transition. We established an AKI-CKD model in mice by unilateral renal ischemia-reperfusion injury and overexpressed 14-3-3ζ in mice using a fluid dynamics-based gene transfection technique. We also overexpressed and knocked down 14-3-3ζ in vitro. In AKI-CKD model mice, 14-3-3ζ expression was significantly increased at the AKI stage. During the development of chronic disease, the expression of 14-3-3ζ tended to decrease, whereas active YAP was consistently overexpressed. In vitro, we found that 14-3-3ζ can combine with YAP, promote the phosphorylation of YAP, inhibit YAP nuclear translocation, and reduce the expression of fibrosis-related proteins. In an in vivo intervention experiment, we found that the overexpression of 14-3-3ζ slowed the process of renal fibrosis in a mouse model of AKI-CKD. These findings suggest that 14-3-3ζ can affect the expression of fibrosis-related proteins by regulating YAP, inhibit the maladaptive repair of renal tubular epithelial cells, and prevent the AKI-CKD transition.


Assuntos
Injúria Renal Aguda , Insuficiência Renal Crônica , Traumatismo por Reperfusão , Camundongos , Animais , Proteínas 14-3-3/genética , Proteínas 14-3-3/metabolismo , Rim/patologia , Insuficiência Renal Crônica/metabolismo , Injúria Renal Aguda/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Fibrose , Traumatismo por Reperfusão/patologia
6.
J Environ Manage ; 325(Pt B): 116586, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36419310

RESUMO

Tungsten residue waste (TRW), considered an environmental burden due to high content and excessive leaching toxicity of arsenic (As), are also secondary tungsten (W) resources. A novel method for simultaneous extraction of arsenic and tungsten from TRW via alkaline pressure oxidative leaching was proposed. The results show that As in the TRW mainly exists in the form of As coprecipitated with Mn(Ⅱ) oxides and FeAsS. In addition, As coprecipitated with Mn(Ⅱ) oxides and W are encapsulated in Fe, Mn oxides. The structure of Fe, Mn oxides with dense surface can be destroyed and the chemically stable arsenopyrite can be efficiently oxidized by oxygen in alkaline solutions. The leaching efficiency of As and S reached 97% and 99% at 80 min, respectively, while that of W reached 82% at 10 min. The leaching rate of As and S is controlled by diffusion with the apparent activation energies of 16.67 kJ/mol and 15.66 kJ/mol, respectively. Compared with TRW, the leaching toxicity of As in the leach residue decreased from 10.2 mg/L to only 0.071 mg/L. The new process suggests new possibilities for removal and recovery of As and W from TRW that will contribute to circular economy and environmental protection.


Assuntos
Arsênio , Tungstênio , Resíduos Perigosos , Oxirredução , Óxidos
7.
Clin Nephrol ; 97(6): 328-338, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35142283

RESUMO

Deletions involving the TSC2 and PKD1 genes lead to tuberous sclerosis complex (TSC) and autosomal dominant polycystic kidney disease (ADPKD), which is known as TSC2-PKD1 contiguous gene deletion syndrome (PKDTS). PKDTS leads to severe symptoms and death. There are few reported cases of PKDTS, the phenotypic descriptions are poor, and detailed statistics and descriptions of the time of onset and prognosis of PKDTS are lacking. This is the first study to report on the clinical data of PKDTS patients in China. We analyzed all cases including Chinese individuals and summarized the clinical manifestations and genetic characteristics. Our study was the first to use a combination of exome sequencing and multiplex ligation-dependent probe amplification (MLPA) to screen and diagnose PKDTS. We found that many PKDTS patients have the following: multiple renal cysts; angiofibromas (≥ 3) or fibrous cephalic plaque; subependymal nodules; seizures; intellectual disability. PKDTS develops into polycystic kidney disease from before birth to 17 years old and the time of occurrence of end-stage renal disease or dialysis was 21.62 ± 12.87 years of age, which was significantly earlier than in ADPKD caused by PKD1 mutation. Compared with non-Chinese individuals of diverse ancestry, Chinese people have significant differences in the clinical characteristics, including ungual fibromas (≥ 2), and shagreen patch. Five novel large deletions were identified in Chinese. We found no relationship between the clinical phenotype and the genotype. We combined exome sequencing with MLPA to develop a diagnostic method for PKDTS.


Assuntos
Rim Policístico Autossômico Dominante , Rim Policístico Autossômico Recessivo , Canais de Cátion TRPP/genética , Proteína 2 do Complexo Esclerose Tuberosa/genética , Adolescente , Adulto , Criança , Deleção de Genes , Estudos de Associação Genética , Humanos , Mutação , Rim Policístico Autossômico Dominante/diagnóstico , Rim Policístico Autossômico Dominante/genética , Rim Policístico Autossômico Recessivo/genética , Esclerose Tuberosa , Proteínas Supressoras de Tumor/genética , Adulto Jovem
8.
Mediators Inflamm ; 2022: 5515305, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35399795

RESUMO

Activation of NOD-like receptor (NLR) signaling pathway can promote downstream cytokine and proinflammatory cytokines release, and inflammation induced by excess nutrients leads to renal metabolic injury. How the NLRs influence metabolic progress and then lead to the renal injury remains poorly investigated. Compared with rodents, minipigs are more similar to humans and are more ideal animal models for human disease research. In this study, we established a diabetic minipig model through a high-sugar and high-fat diet combined with streptozotocin (STZ) injection. Blood biological markers and renal pathological markers, expression of NLRP subfamily members (NLRP1 and NLRP3) and their downstream cytokines (precursors of IL-1ß and IL-18 and mature forms of IL-1ß and IL-18), expression of NLRC subfamily members (NLRC1, NLRC2, and NLRC5) and their downstream nuclear factor-κB (NF-κB) signaling pathway molecules (IKKß, IκBα, and NF-κB p65), and inflammatory cytokines (TNF-α and interleukin-6 (IL-6)) were systematically evaluated. The expression of NLRP3 and its downstream cytokine signaling molecules, the precursors of IL-1ß and IL-18, and the mature forms of IL-1ß and IL-18 was significantly upregulated. The expression levels of NLRC1, NLRC2, and NLRC5 and activation of the downstream NF-κB pathway molecules phospho-IKKß, phospho-IκBα, NF-κB p65, and phospho-NF-κB p65 were significantly increased. The TNF-α and IL-6 levels were significantly increased in diabetic pig kidneys. The TGF-ß/Smad signaling molecules, TGF-ß and P-SMAD2/3, were also increased. These results suggested that the metabolic inflammation activated by NLRs might play an important role in diabetic renal injuries.


Assuntos
Diabetes Mellitus , NF-kappa B , Animais , Citocinas/metabolismo , Quinase I-kappa B , Inflamação , Interleucina-18 , Interleucina-6/metabolismo , Rim/metabolismo , Inibidor de NF-kappaB alfa , NF-kappa B/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Proteínas NLR , Suínos , Porco Miniatura/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Fator de Necrose Tumoral alfa
9.
Dev Biol ; 464(2): 103-110, 2020 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-32562756

RESUMO

Congenital anomalies of the urinary tract are a significant cause of morbidity in infancy, and many congenital anomalies are linked to ureter development; however, the mechanism by which congenital anomalies control ureter development remains unknown. The loss of Robo2 can cause ureter defects and vesicoureteral reflux. However, how Robo2 impacts ureter development is unclear. We found that ROBO2 is expressed in the common nephric duct (CND) and primitive bladder, and impacts CND migration and fusion with the primitive bladder via its novel binding partner retinaldehyde dehydrogenase-2 (RALDH2). Delayed apoptosis that is due to the failure of CND fusion with the primitive bladder in the Robo2-/-embryo results in an abnormal ureter connection to the CND, which is required for ureter development. We define a novel pathway in which the CND is remodeled by ROBO2 and retinoic acid rescued the ureter anomalies in the Robo2-/-embryo. These findings may be relevant to diverse disease conditions that are associated with altered signaling in the primitive bladder.


Assuntos
Aldeído Oxirredutases/metabolismo , Receptores Imunológicos/metabolismo , Transdução de Sinais , Ureter/embriologia , Bexiga Urinária/embriologia , Aldeído Oxirredutases/genética , Animais , Camundongos , Camundongos Knockout , Receptores Imunológicos/genética , Ureter/citologia , Bexiga Urinária/citologia
10.
Environ Microbiol ; 23(8): 4309-4325, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34056829

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) and dioxin-like compounds, including sulfur, nitrogen and oxygen heterocycles, are widespread and toxic environmental pollutants. A wide variety of microorganisms capable of growing with aromatic polycyclic compounds are essential for bioremediation of the contaminated sites and the Earth's carbon cycle. Here, cells of Pseudomonas putida B6-2 (ATCC BAA-2545) grown in the presence of biphenyl (BP) are able to simultaneously degrade PAHs and their derivatives, even when they are present as mixtures, and tolerate high concentrations of extremely toxic solvents. Genetic analysis of the 6.37 Mb genome of strain B6-2 reveals coexistence of gene clusters responsible for central catabolic systems of aromatic compounds and for solvent tolerance. We used functional transcriptomics and proteomics to identify the candidate genes associated with catabolism of BP and a mixture of BP, dibenzofuran, dibenzothiophene and carbazole. Moreover, we observed dynamic changes in transcriptional levels with BP, including in metabolic pathways of aromatic compounds, chemotaxis, efflux pumps and transporters potentially involved in adaptation to PAHs. This study on the highly versatile activities of strain B6-2 suggests it to be a potentially useful model for bioremediation of polluted sites and for investigation of biochemical, genetic and evolutionary aspects of Pseudomonas.


Assuntos
Dioxinas , Hidrocarbonetos Policíclicos Aromáticos , Pseudomonas putida , Biodegradação Ambiental , Pseudomonas putida/genética , Solventes
11.
Cell Immunol ; 361: 104279, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33422698

RESUMO

Mesangial cells (MCs), as resident cells of the kidneys, play an important role in maintaining glomerular function. MCs are located between the capillary loops of the glomeruli and mainly support the capillary plexus, constrict blood vessels, extracellular matrix components, produce cytokines, and perform phagocytosis and clearance of macromolecular substances. When the glomerular environment changes, MCs are often affected, which can lead to functional transformation. The immune response is involved in the occurrence and development of various kidney diseases, in these diseases, antigen-presenting cells (APCs) play an important role. APCs can present antigens to T lymphocytes, causing them to become activated and proliferate. Studies have shown that MCs have phagocytic function and express APC markers on the cell surface. Additionally, MCs are stimulated by or produce various inflammatory factors to participate in the renal inflammatory response. Therefore, MCs have potential antigen presentation function and participate in the pathological changes of various kidney diseases as APCs upon activation. In this paper, by reviewing MC phagocytic function, activated MC expression of APC surface markers, and MC participation in the inflammatory response and local renal immune response, we confirm that activated MCs can act as APCs in renal disease.


Assuntos
Células Mesangiais/imunologia , Células Mesangiais/metabolismo , Células Mesangiais/fisiologia , Animais , Apresentação de Antígeno/imunologia , Células Apresentadoras de Antígenos/imunologia , Células Cultivadas , Citocinas/metabolismo , Humanos , Inflamação , Rim/imunologia , Nefropatias/metabolismo , Fagocitose/imunologia , Linfócitos T
12.
Clin Nephrol ; 96(3): 165-174, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33993910

RESUMO

As the most frequent inherited tubulopathy, Gitelman syndrome (GS), has an incidence that has increased worldwide. The distribution of SLC12A3 gene mutation hotspots deserves exploration. In addition, GS is not a benign syndrome; however, the diagnostic process of GS has not yet been completely detailed. MATERIALS AND METHODS: We report two cases of GS pedigrees involving two previously unreported mutations, c. 676G>A, p. A226T and c. 421G>A, p. G141R, in the SLC12A3 gene and reviewed relevant literature. We searched the literature for nucleotide of SLC12A3 in PubMed and other databases as of April 20, 2020. RESULTS: A total of 1,794 detected mutated alleles in 939 patients worldwide were included in this study. Splicing mutations and p. Gly741Arg were mutation hotspots in a European population. P. Leu858His and p. Thr60Met were mutation hotspots in an Asian population. P. Leu858His and p. Thr180Lys were considered mutation hotspots in the Japanese population, while p. Thr60Met and p. Asp486Asn were considered mutation hotspots in the Chinese population. CONCLUSION: Our results identified two novel mutation sites (c. 676G>A, p. A226T and c. 421G>A, p. G141R), if their pathogenicity was determined this could contribute to the enrichment of database resources on GS. Our study has compiled the most comprehensive SLC12A3 gene mutation database in the world thus far to reveal that different regions have different mutation hotspots in SLC12A3. Moreover, the establishment of a diagnostic process for GS has important implications for confirmed cases.


Assuntos
Síndrome de Gitelman , Alelos , Testes Genéticos , Síndrome de Gitelman/diagnóstico , Síndrome de Gitelman/genética , Humanos , Mutação , Linhagem , Membro 3 da Família 12 de Carreador de Soluto/genética
13.
J Hum Genet ; 64(1): 39-48, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30291279

RESUMO

Ciliopathies-are widely recognized and associated with a wide variety of developmental and degenerative disorders. Most cilia-related diseases have renal manifestation, and there is a cross- overlapping relationship between gene mutations and cilia disease. Here, we investigated the clinical and pathological manifestation of a rare disease patient. We present the case of a 15-year-old child with dysplasia and multiple-organ damage who was initially diagnosed with nephrotic syndrome. The patient's kidney disease progressed to renal failure and received hemodialysis 10 months after renal biopsy. The individual presented primary ciliary dyskinesia (PCD) and additional symptoms including sensorineural deafness, kidney dysplasia, severe kidney function loss, and congenital heart disease which potentially linked to primary cilia deficiency. Cilia immunofluorescence of renal tissue showed a decrease in the number of cilium of the patient compared to the normal kidney. We identified a site mutation in CCDC114 (NM_144577 exon7 c. 596Cå T p. Ala199Val) by whole-exon sequences. We found that CCDC114 located at the basal body at cilia and the knockdown of CCDC114 could affect the occurrence of cilia in hRPE1 cells. The previous study of CCDC114 mainly lies in the motile cilia, and this study found that its impact on primary cilia thus broadened the understanding of overlapping function of different types of cilia.


Assuntos
Transtornos da Motilidade Ciliar/genética , Perda Auditiva Neurossensorial/genética , Nefropatias/genética , Proteínas Associadas aos Microtúbulos/genética , Mutação , Adolescente , Transtornos da Motilidade Ciliar/complicações , Transtornos da Motilidade Ciliar/patologia , Exoma , Feminino , Perda Auditiva Neurossensorial/complicações , Perda Auditiva Neurossensorial/patologia , Humanos , Nefropatias/complicações , Nefropatias/patologia , Masculino , Linhagem , Fenótipo
14.
Microb Cell Fact ; 18(1): 106, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31186003

RESUMO

BACKGROUND: Late-stage fermentation broth contains high concentrations of target chemicals. Additionally, it contains various cellular metabolites which have leaked from lysed cells, which would exert multifactorial stress to industrial hyperproducers and perturb both cellular metabolism and product formation. Although adaptive laboratory evolution (ALE) has been wildly used to improve stress tolerance of microbial cell factories, single-factor stress condition (i.e. target product or sodium chloride at a high concentration) is currently provided. In order to enhance bacterial stress tolerance to actual industrial production conditions, ALE in late-stage fermentation broth is desired. Genome replication engineering assisted continuous evolution (GREACE) employs mutants of the proofreading element of DNA polymerase complex (DnaQ) to facilitate mutagenesis. Application of GREACE coupled-with selection under stress conditions is expected to accelerate the ALE process. RESULTS: In this study, GREACE was first modified by expressing a DnaQ mutant KR5-2 using an arabinose inducible promoter on a temperature-sensitive plasmid, which resulted in timed mutagenesis introduction. Using this method, tolerance of a lysine hyperproducer E. coli MU-1 was improved by enriching mutants in a lysine endpoint fermentation broth. Afterwards, the KR5-2 expressing plasmid was cured to stabilize acquired genotypes. By subsequent fermentation evaluation, a mutant RS3 with significantly improved lysine production capacity was selected. The final titer, yield and total amount of lysine produced by RS3 in a 5-L batch fermentation reached 155.0 ± 1.4 g/L, 0.59 ± 0.02 g lysine/g glucose, and 605.6 ± 23.5 g, with improvements of 14.8%, 9.3%, and 16.7%, respectively. Further metabolomics and genomics analyses, coupled with molecular biology studies revealed that mutations SpeBA302V, AtpBS165N and SecYM145V mainly contributed both to improved cell integrity under stress conditions and enhanced metabolic flux into lysine synthesis. CONCLUSIONS: Our present study indicates that improving a lysine hyperproducer by GREACE-assisted ALE in its stressful living environment is efficient and effective. Accordingly, this is a promising method for improving other valuable chemical hyperproducers.


Assuntos
Evolução Molecular Direcionada/métodos , Escherichia coli/metabolismo , Lisina/metabolismo , Engenharia Metabólica/métodos , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Fermentação , Mutagênese
15.
Appl Microbiol Biotechnol ; 103(20): 8413-8425, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31399771

RESUMO

The introduction of the key non-oxidative glycolytic (NOG) pathway enzyme, phosphoketolases (PKTs), into heterologous hosts can improve the yield of a variety of acetyl CoA-derived products of interest. However, the low specific activity of existing PKTs compared with that of 6-phosphofructokinase (PFK), the key EMP pathway enzyme, largely limits their potential applications. To improve PKT activity, previous attempts have focused on increasing intracellular PKT concentration via the use of strong promoters. Herein, we report the establishment of a growth-coupled evolution strategy for the enrichment and selection of PKT mutants with improved specific activity in Corynebacterium glutamicum hosts with defective PFK. Five mutants from 9 Bifidobacterium adolescentis-source PKT (BA-PKT) mutant libraries were obtained. Site-directed mutagenesis analysis revealed 11 mutant sites which contributed to improved BA-PKT specific activity. Further structural analysis revealed that the mutant sites were located far away from the enzyme active site, which makes them almost unpredictable using a rational design approach. Mutant site recombination led to the construction of a novel mutant, PKTT2A/I6T/H260Y, with Vmax 29.77 ± 1.58 U/mg and Kcat/Km 0.32 ± 0.01 s-1/mM, which corresponds to 73.27 ± 3.25% and 80.16 ± 3.38% improvements, respectively, compared with the wildtype (Vmax; 17.17 ± 0.59 U/mg, Kcat/Km; 0.17 ± 0.01 s-1/mM). Expression of PKTT2A/I6T/H260 in C. glutamicum Z188 resulted in 16.67 ± 2.24% and 18.19 ± 0.53% improvement in L-glutamate titer and yield, respectively, compared with the wildtype BA-PKT. Our findings provide an efficient approach for improving the activity of PKTs. Furthermore, the novel mutants could serve as useful tools in improving the yield of L-glutamate and other acetyl CoA-associated products.


Assuntos
Aldeído Liases/metabolismo , Corynebacterium glutamicum/enzimologia , Corynebacterium glutamicum/crescimento & desenvolvimento , Ácido Glutâmico/metabolismo , Mutação , Proteínas Recombinantes/metabolismo , Aldeído Liases/genética , Bifidobacterium adolescentis/enzimologia , Bifidobacterium adolescentis/genética , Corynebacterium glutamicum/genética , Corynebacterium glutamicum/metabolismo , Evolução Molecular Direcionada , Cinética , Mutagênese Sítio-Dirigida , Proteínas Recombinantes/genética , Seleção Genética
16.
Molecules ; 24(4)2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30791537

RESUMO

(Gd0.93-xTb0.07Eux)2O3 (x = 0⁻0.10) phosphors shows great potential for applications in the lighting and display areas. (Gd0.93-xTb0.07Eux)2O3 phosphors with controlled morphology were prepared by a hydrothermal method, followed by calcination at 1100 °C. XRD, FE-SEM, PL/PLE, luminescent decay analysis and thermal stability have been performed to investigate the Eu3+ content and the effects of hydrothermal conditions on the phase variation, microstructure, luminescent properties and energy transfer. Optimum excitation wavelength at ~308 nm nanometer ascribed to the 4f8-4f75d¹ transition of Tb3+, the (Gd0.93-xTb0.07Eux)2O3 phosphors display both Tb3+and Eu3+ emission with the strongest emission band at ~611 nm. For increasing Eu3+ content, the Eu3+ emission intensity increased as well while the Tb3+ emission intensity decreased owing to Tb3+→Eu3+ energy transfer. The energy transfer efficiencies were calculated and the energy transfer mechanism was discussed in detail. The lifetime for both the Eu3+ and Tb3+ emission decreases with the Eu3+ addition, the former is due to the formation of resonant energy transfer net, and the latter is because of contribution by Tb3+→Eu3+ energy transfer. The phosphor morphology can be controlled by adjusting the hydrothermal condition (reaction pH), and the morphological influence to the luminescent properties (PL/PLE, decay lifetime, etc.) has been studied in detail.


Assuntos
Európio/química , Metais Terras Raras/química , Óxidos/química , Fósforo/química , Térbio/química
17.
Chembiochem ; 19(23): 2465-2471, 2018 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-30246938

RESUMO

Methanol is a low-cost and abundantly available feedstock derived from natural gas and syngas. Although bioconversion holds promise for producing desired chemicals from methanol under economically viable operating conditions, the efficiency is limited by unfavorable kinetics of methanol oxidation and assimilation. Herein, artificial fusion proteins were engineered to enhance methanol bioconversion. Nicotinamide adenine dinucleotide (NAD)-dependent methanol dehydrogenase (Mdh), 3-hexulose-6-phosphate synthase (Hps) and 6-phospho-3-hexuloisomerase (Phi) from different sources were first screened for catalytic activity. Next, we designed six fusion proteins using the best enzyme candidates and flexible linkers. Fusing Mdh with Hps or Hps-Phi increased the Vmax of methanol oxidation up to 5.8-fold, and enhanced methanol conversion to fructose-6-phosphate up to 1.3-fold. Interestingly, fusion engineering changed the polymerization states of proteins and produced larger multimers, which may be responsible for the changed catalytic characteristics. This fusion engineering approach can be coupled with other metabolic engineering strategies for enhanced methanol bioconversion to valuable chemicals.


Assuntos
Metanol/metabolismo , Oxirredutases do Álcool/genética , Oxirredutases do Álcool/metabolismo , Aldeído Liases/genética , Aldeído Liases/metabolismo , Aldose-Cetose Isomerases/genética , Aldose-Cetose Isomerases/metabolismo , Bactérias/enzimologia , Escherichia coli/genética , Frutosefosfatos/biossíntese , Cinética , Engenharia Metabólica/métodos , Engenharia de Proteínas , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Ribosemonofosfatos/metabolismo
18.
Metab Eng ; 49: 220-231, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30048680

RESUMO

Methanol is a promising feedstock for bioproduction of fuels and chemicals, thus massive efforts have been devoted to engineering non-native methylotrophic platform microorganisms to utilize methanol. Herein, we rationally designed and experimentally engineered the industrial workhorse Corynebacterium glutamicum to serve as a methanol-dependent synthetic methylotroph. The cell growth of the methanol-dependent strain relies on co-utilization of methanol and xylose, and most notably methanol is an indispensable carbon source. Due to the methanol-dependent characteristic, adaptive laboratory evolution was successfully applied to improving methanol utilization. The evolved mutant showed a 20-fold increase in cell growth on methanol-xylose minimal medium and utilized methanol and xylose with a high mole ratio of 3.83:1. 13C-labeling experiments demonstrated that the carbon derived from methanol was assimilated into intracellular building blocks, high-energy carriers, cofactors, and biomass (up to 63% 13C-labeling). By inhibiting cell wall biosynthesis, methanol-dependent glutamate production was also achieved, demonstrating the potential application in bioconversion of methanol into useful chemicals. Genetic mutations detected in the evolved strains indicate the importance of intracellular NAD+/NADH ratio, substrate uptake, and methanol tolerance on methanol utilization. This study reports significant improvement in the area of developing fully synthetic methylotrophs.


Assuntos
Corynebacterium glutamicum , Ácido Glutâmico/biossíntese , Engenharia Metabólica , Metanol/metabolismo , Corynebacterium glutamicum/genética , Corynebacterium glutamicum/metabolismo , Ácido Glutâmico/genética
19.
Phys Chem Chem Phys ; 20(3): 1568-1574, 2018 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-29260168

RESUMO

CdSiP2 is an outstanding mid-infrared nonlinear optical crystal material with high thermal conductivity. However, the microscopic physics behind its thermal transport behavior is still unclear. In this study, we have investigated the source of the thermal conductivity of CdSiP2 based on anharmonicity lattice dynamics (ALD) and the first-principle calculation. The results are well accordance with the experimental measurement in a wide temperature range. Based on our results, the acoustic phonon lifetime of CdSiP2 is higher than that of the thermoelectric and semiconducting materials reported in previous studies, which is induced by the low lattice anharmonicity demonstrated by CdSiP2. The mode-dependent thermal conductivity is obtained with the contribution of optical phonons being significant (27%) above 300 K; this is mainly due to the high phonon group velocity and relatively long phonon lifetime of low-energy optical phonons (80-200 cm-1). A high lifetime of acoustic phonons and remarkable contribution of low-energy optical phonons can be responsible for the high thermal conductivity of CdSiP2.

20.
BMC Nephrol ; 19(1): 182, 2018 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-30021637

RESUMO

BACKGROUND: Idiopathic membranous nephropathy (IMN) is one of the most common adult nephrotic syndromes. Some patients with this disorder require immunosuppressive therapy. This retrospective case series was performed to assess the effects of tacrolimus (TAC) combined with Tripterygium wilfordii polyglycoside (TWG) in treating IMN. METHODS: From January 2015 to August 2016, kidney-biopsy-proven IMN patients treated with TAC in the Chinese PLA General Hospital were screened. Data were retrieved from the patients' medical records. The first efficacy evaluation index was remission rate (complete remission and partial remission), and the secondary efficacy evaluation indices included relapse rate, proteinuria, serum albumin and estimated glomerular filtration rate (eGFR). Adverse events were also assessed. RESULTS: The included patients' treatments were tacrolimus monotherapy (TAC group, n = 33), tacrolimus combined with methylprednisolone (MP) (TAC + MP group, n = 24) and tacrolimus combined with Tripterygium wilfordii polyglycoside (TAC + TWG group, n = 21). The remission rates of the TAC, TAC + MP, and TAC + TWG groups in the 10th month were 54.5, 62.5, and 85.7%, respectively (TAC + TWG group vs TAC group, P = 0.037, TAC + TWG group vs TAC + MP group, P = 0.125). Moreover, the complete remission rates of the TAC, TAC + MP, and TAC + TWG groups in the 10th month were 21.2, 20.8, and 57.1%, respectively (TAC + TWG group vs TAC group, P = 0.007, TAC + TWG group vs TAC + MP group, P = 0.012). Compared with the TAC group, the TAC + TWG group had a higher remission rate during these ten months (log-rank, P = 0.005). Compared with the TAC and TAC + MP groups, the TAC + TWG group had a higher complete remission rate (log-rank, P = 0.019 and log-rank, P = 0.005, respectively). CONCLUSION: This retrospective study showed that TAC combined with TWG may be effective for treating IMN. Further randomized controlled trials (RCTs) are needed to assess the efficacy and safety of TAC combined with TWG.


Assuntos
Glomerulonefrite Membranosa/tratamento farmacológico , Glicosídeos/administração & dosagem , Extratos Vegetais/administração & dosagem , Tacrolimo/administração & dosagem , Tripterygium , Adulto , Quimioterapia Combinada , Feminino , Seguimentos , Glomerulonefrite Membranosa/sangue , Glomerulonefrite Membranosa/fisiopatologia , Glicosídeos/isolamento & purificação , Humanos , Imunossupressores , Masculino , Pessoa de Meia-Idade , Extratos Vegetais/isolamento & purificação , Estudos Retrospectivos , Resultado do Tratamento
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