Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 117
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
FASEB J ; 38(7): e23584, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38568836

RESUMO

Cisplatin-induced acute kidney injury (AKI) is commonly seen in the clinical practice, and ferroptosis, a type of non-apoptotic cell death, plays a pivotal role in it. Previous studies suggested that protein arginine methyltransferase 4 (PRMT4) was incorporated in various bioprocesses, but its role in renal injuries has not been investigated. Our present study showed that PRMT4 was highly expressed in renal proximal tubular cells, and it was downregulated in cisplatin-induced AKI. Besides, genetic disruption of PRMT4 exacerbated, while its overexpression attenuated, cisplatin-induced redox injuries in renal proximal epithelia. Mechanistically, our work showed that PRMT4 interacted with NCOA4 to inhibit ferritinophagy, a type of selective autophagy favoring lipid peroxidation to accelerate ferroptosis. Taken together, our study demonstrated that PRMT4 interacted with NCOA4 to attenuate ferroptosis in cisplatin-induced AKI, suggesting that PRMT4 might present as a new therapeutic target for cisplatin-related nephropathy.


Assuntos
Injúria Renal Aguda , Cisplatino , Humanos , Cisplatino/efeitos adversos , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/genética , Injúria Renal Aguda/metabolismo , Rim/metabolismo , Fatores de Transcrição/metabolismo , Autofagia , Coativadores de Receptor Nuclear/genética , Coativadores de Receptor Nuclear/metabolismo
2.
J Virol ; 97(3): e0181922, 2023 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-36815785

RESUMO

Human papillomaviruses (HPV) are small DNA viruses associated with cervical cancer, warts, and other epithelial tumors. Structural studies have shown that the HPV capsid consists of 360 copies of the major capsid protein, L1, arranged as 72 pentamers in a T=7 icosahedral lattice, coassembling with substoichiometric amounts of the minor capsid protein, L2. However, the residues involved in the coassembly of L1 and L2 remain undefined due to the lack of structure information. Here, we investigated the solvent accessibility surfaces (SASs) of the central cavity residues of the HPV16 L1 pentamer in the crystal structure because those internal exposed residues might mediate the association with L2. Twenty residues in L1 protein were selected to be analyzed, with four residues in the lumen of the L1 pentamer identified as important: F256, R315, Q317, and T340. Mutations to these four residues reduced the PsV (pseudovirus) infection capacity in 293FT cells, and mutations to R315, Q317, and T340 substantially perturb L2 from coassembling into L1 capsid. Compared with wild-type (WT) PsVs, these mutant PsVs also have a reduced ability to become internalized into host cells. Finally, we identified a stretch of negatively charged residues on L2 (amino acids [aa] 337 to 340 [EEIE]), mutations to which completely abrogate L2 assembly into L1 capsid and subsequently impair the endocytosis and infectivity of HPV16 PsVs. These findings shed light on the elusive coassembly between HPV L1 and L2. IMPORTANCE Over 200 types of HPV have been isolated, with several high-risk types correlated with the occurrence of cervical cancer. The HPV major capsid protein, L1, assembles into a T=7 icosahedral viral shell, and associates with the minor capsid protein, L2, which plays a critical role in the HPV life cycle. Despite the important role of the L2 protein, its structure and coassembly with L1 remain elusive. In this study, we analyzed the amino acid residues at the proposed interface between L1 and L2. Certain mutations at these sites decreased the amount of L2 protein assembled into the capsid, which, in turn, led to a decrease in viral infectivity. Knowledge about these residues and the coassembly of L1 and L2 could help to expand our understanding of HPV biology and aid in the development of countermeasures against a wide range of HPV types by targeting the L2 protein.


Assuntos
Proteínas do Capsídeo , Papillomavirus Humano 16 , Feminino , Humanos , Proteínas do Capsídeo/química , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/metabolismo , Papillomavirus Humano 16/genética , Papillomavirus Humano 16/patogenicidade , Infecções por Papillomavirus/virologia , Sequência de Aminoácidos/genética , Mutação , Linhagem Celular , Estrutura Terciária de Proteína/genética , Modelos Moleculares
3.
J Gastroenterol Hepatol ; 39(3): 596-607, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38059880

RESUMO

BACKGROUND AND AIM: Circular ubiquitin-like, containing PHD and ring finger domains 1 (circUHRF1) is aberrantly upregulated in human hepatocellular carcinoma (HCC) tissues. However, the underlying molecular mechanisms remain obscure. The present study aimed at elucidating the interactive function of circUHRF1-G9a-ubiquitin-like, containing PHD and ring finger domains 1 (UHRF1) mRNA-eukaryotic translation initiation factor 4A3 (EIF4A3)-PDZ and LIM domain 1 (PDLIM1) network in HCC. METHODS: Expression of circUHRF1, mRNAs of G9a, UHRF1, PDLIM1, epithelial-mesenchymal transition (EMT)-related proteins, and Hippo-Yap pathway components was determined by quantitative polymerase chain reaction (Q-PCR), immunofluorescence, or Western blot analysis. Tumorigenic and metastatic capacities of HCC cells were examined by cellular assays including Cell Counting Kit-8, colony formation, wound healing, and transwell assays. Molecular interactions between EIF4A3 and UHRF1 mRNA were detected by RNA pull-down experiment. Complex formation between UHRF1 and PDLIM1 promoter was detected by chromatin immunoprecipitation assay. Co-immunoprecipitation was performed to examine the binding between UHRF1 and G9a. RESULTS: Circular ubiquitin-like, containing PHD and ring finger domains 1, G9a, and UHRF1 were upregulated, while PDLIM1 was downregulated in HCC tissue samples and cell lines. Cellular silencing of circUHRF1 repressed HCC proliferation, invasion, migration, and EMT. G9a formed a complex with UHRF1 and inhibited PDLIM1 transcription. CONCLUSION: Eukaryotic translation initiation factor 4A3 regulated circUHRF1 expression by binding to UHRF1 mRNA promoter. circUHRF1 increased the stability of G9a and UHRF1 mRNAs through recruiting EIF4A3. Overexpression of circUHRF1 aggravated HCC progression through Hippo-Yap pathway and PDLIM1 inhibition. By elucidating the molecular function of circUHRF1-G9a-UHRF1 mRNA-EIF4A3-PDLIM1 network, our data shed light on the HCC pathogenesis and suggest a novel therapeutic strategy for future HCC treatment.


Assuntos
Carcinoma Hepatocelular , RNA Helicases DEAD-box , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/tratamento farmacológico , RNA Mensageiro/genética , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Proteínas de Homeodomínio/uso terapêutico , Ubiquitina/genética , Ubiquitina/metabolismo , Ubiquitina/uso terapêutico , Domínios RING Finger , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/uso terapêutico , Proteínas Estimuladoras de Ligação a CCAAT/química , Proteínas Estimuladoras de Ligação a CCAAT/genética , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Fatores de Iniciação de Peptídeos/genética , Fatores de Iniciação de Peptídeos/metabolismo , Fatores de Iniciação de Peptídeos/uso terapêutico , Proliferação de Células/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/genética , Fator de Iniciação 4A em Eucariotos/genética , Fator de Iniciação 4A em Eucariotos/metabolismo
4.
Appl Microbiol Biotechnol ; 107(2-3): 853-865, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36539564

RESUMO

The goal of bacterial engineering is to rewire metabolic pathways to generate high-value molecules for various applications. However, the production of recombinant proteins is constrained by the complexity of the connections between cellular physiology and recombinant protein synthesis. Here, we used a rational and highly efficient approach to improve bacterial engineering. Based on the complete genome and annotation information of the Escherichia coli ER2566 strain, we compared the transcriptomic profiles of the strain under leaky expression and low temperature-induced stress. Combining the gene ontology (GO) enrichment terms and differentially expressed genes (DEGs) with higher expression, we selected and knocked out 36 genes to determine the potential impact of these genes on protein production. Deletion of bluF, cydA, mngR, and udp led to a significant decrease in soluble recombinant protein production. Moreover, at low-temperature induction, 4 DEGs (gntK, flgH, flgK, flgL) were associated with enhanced expression of the recombinant protein. Knocking out several motility-related DEGs (ER2666-ΔflgH-ΔflgL-ΔflgK) simultaneously improved the protein yield by 1.5-fold at 24 °C induction, and the recombinant strain had the potential to be applied in the expression studies of different exogenous proteins, aiming to improve the yields of soluble form to varying degrees in comparison to the ER2566 strain. Totally, this study focused on the anabolic and stress-responsive hub genes of the adaptation of E. coli to recombinant protein overexpression on the transcriptome level and constructs a series of engineering strains increasing the soluble protein yield of recombinant proteins which lays a solid foundation for the engineering of bacterial strains for recombinant technological advances. KEY POINTS: • Comparative transcriptome analysis shows host responses with altered induction stress. • Deletion of bluF, cydA, mngR, and udp genes was identified to significantly decrease the soluble recombinant protein productions. • Synchronal knockout of flagellar genes in E. coli can enhance recombinant protein yield up to ~ 1.5-fold at 24 °C induction. • Non-model bacterial strains can be re-engineered for recombinant protein expression.


Assuntos
Proteínas de Escherichia coli , Escherichia coli , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Recombinantes/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Transcriptoma , Difosfato de Uridina/metabolismo , Engenharia Metabólica
5.
Ann Surg Oncol ; 29(8): 5297-5306, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35316433

RESUMO

BACKGROUND: Venous thromboembolism (VTE) is the second leading cause for death of radical prostatectomy. We aimed to establish new nomogram to predict the VTE risk after robot-assisted radical prostatectomy (RARP). METHODS: Patients receiving RARP in our center from November 2015 to June 2021, were enrolled in study. They were randomly divided into training and testing cohorts by 8:2. Univariate and multivariate logistic regression (model A) and stepwise logistic regression (model B) were used to fit two models. The net reclassification improvement (NRI), integrated discrimination improvement (IDI), and receiver operating characteristic (ROC) curve were used to compare predictive abilities of two new models with widely used Caprini risk assessment (CRA) model. Then, two nomograms were constructed and received internal validation. RESULTS: Totally, 351 patients were included. The area under ROC of model A and model B were 0.967 (95% confidence interval: 0.945-0.990) and 0.978 (95% confidence interval: 0.960-0.996), which also were assayed in the testing cohorts. Both the prediction and classification abilities of the two new models were superior to CRA model (NRI > 0, IDI > 0, p < 0.05). The C-index of Model A and Model B were 0.968 and 0.978, respectively. For clinical usefulness, the two new models offered a net benefit with threshold probability between 0.08 and 1 in decision curve analysis, suggesting the two new models predict VTE events more accurately. CONCLUSIONS: Both two new models have good prediction accuracy and are superior to CRA model. Model A has an advantage of less variable. This easy-to-use model enables rapid clinical decision-making and early intervention in high-risk groups, which ultimately benefit patients.


Assuntos
Nomogramas , Prostatectomia , Procedimentos Cirúrgicos Robóticos , Tromboembolia Venosa , Humanos , Masculino , Próstata , Prostatectomia/efeitos adversos , Prostatectomia/métodos , Distribuição Aleatória , Reprodutibilidade dos Testes , Estudos Retrospectivos , Medição de Risco , Procedimentos Cirúrgicos Robóticos/efeitos adversos , Procedimentos Cirúrgicos Robóticos/métodos , Tromboembolia Venosa/etiologia
6.
Microb Cell Fact ; 20(1): 227, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34930257

RESUMO

BACKGROUND: The various advantages associated with the growth properties of Escherichia coli have justified their use in the production of genetically engineered vaccines. However, endotoxin contamination, plasmid vector instability, and the requirement for antibiotic supplementation are frequent bottlenecks in the successful production of recombinant proteins that are safe for industrial-scaled applications. To overcome these drawbacks, we focused on interrupting the expression of several key genes involved in the synthesis of lipopolysaccharide (LPS), an endotoxin frequently responsible for toxicity in recombinant proteins, to eliminate endotoxin contamination and produce better recombinant proteins with E. coli. RESULTS: Of 8 potential target genes associated with LPS synthesis, we successfully constructed 7 LPS biosynthesis-defective recombinant strains to reduce the production of LPS. The endotoxin residue in the protein products from these modified E. coli strains were about two orders of magnitude lower than that produced by the wild-type strain. Further, we found that 6 loci-lpxM, lpxP, lpxL, eptA, gutQ and kdsD-were suitable for chromosomal integrated expression of HPV L1 protein. We found that a single copy of the expression cassette conferred stable expression during long-term antibiotic-free cultivation as compared with the more variable protein production from plasmid-based expression. In large-scale fermentation, we found that recombinant strains bearing 3 to 5 copies of the expression cassette had 1.5- to 2-fold higher overall expression along with lower endotoxin levels as compared with the parental ER2566 strain. Finally, we engineered and constructed 9 recombinant E. coli strains for the later production of an HPV 9-valent capsid protein with desirable purity, VLP morphology, and antigenicity. CONCLUSIONS: Reengineering the LPS synthesis loci in the E. coli ER2566 strain through chromosomal integration of expression cassettes has potential uses for the production of a 9-valent HPV vaccine candidate, with markedly reduced residual endotoxin levels. Our results offer a new strategy for recombinant E. coli strain construction, engineering, and the development of suitable recombinant protein drugs.


Assuntos
Vias Biossintéticas/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Genômica/métodos , Lipopolissacarídeos/análise , Lipopolissacarídeos/genética , Vacinas contra Papillomavirus/genética , Proteínas de Escherichia coli/genética , Engenharia Genética/métodos , Lipopolissacarídeos/biossíntese , Vacinas contra Papillomavirus/imunologia , Plasmídeos , Proteínas Recombinantes/metabolismo
7.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 38(9): 873-876, 2021 Sep 10.
Artigo em Zh | MEDLINE | ID: mdl-34487534

RESUMO

OBJECTIVE: To report the clinical manifestation and genetic characteristics of a child with Thiamine metabolism dysfunction syndrome 5. METHODS: Clinical data and genetic results were collected and analyzed. Peripheral blood samples of the child and their parents were collected for whole exome sequencing, and the functional effect of the variants on the TPK1 enzyme activity was verified by an in vitro assay. RESULTS: A four-year-old boy presented with preschool onset of ataxia were characterized. High-throughput sequencing identified a novel homozygous variant of TPK1 gene c.382G>A (p.Leu128Phe). His father and mother were both found carrying the variant. The variant protein showed a 30.9% reduction in TPK1 enzyme activity compared with the wildtype. CONCLUSION: A novel pathogenic variant has been identified in a boy with thiamine metabolic dysfunction syndrome type 5.


Assuntos
Testes Genéticos , Tiamina , Pré-Escolar , Homozigoto , Humanos , Masculino , Mutação , Sequenciamento do Exoma
8.
BMC Genomics ; 21(1): 407, 2020 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-32546194

RESUMO

BACKGROUND: The Escherichia coli ER2566 strain (NC_CP014268.2) was developed as a BL21 (DE3) derivative strain and had been widely used in recombinant protein expression. However, like many other current RefSeq annotations, the annotation of the ER2566 strain was incomplete, with missing gene names and miscellaneous RNAs, as well as uncorrected annotations of some pseudogenes. Here, we performed a systematic reannotation of the ER2566 genome by combining multiple annotation tools with manual revision to provide a comprehensive understanding of the E. coli ER2566 strain, and used high-throughput sequencing to explore how the strain adapted under external pressure. RESULTS: The reannotation included noteworthy corrections to all protein-coding genes, led to the exclusion of 190 hypothetical genes or pseudogenes, and resulted in the addition of 237 coding sequences and 230 miscellaneous noncoding RNAs and 2 tRNAs. In addition, we further manually examined all 194 pseudogenes in the Ref-seq annotation and directly identified 123 (63%) as coding genes. We then used whole-genome sequencing and high-throughput RNA sequencing to assess mutational adaptations under consecutive subculture or overexpression burden. Whereas no mutations were detected in response to consecutive subculture, overexpression of the human papillomavirus 16 type capsid led to the identification of a mutation (position 1,094,824 within the 3' non-coding region) positioned 19-bp away from the lacI gene in the transcribed RNA, which was not detected at the genomic level by Sanger sequencing. CONCLUSION: The ER2566 strain was used by both the general scientific community and the biotechnology industry. Reannotation of the E. coli ER2566 strain not only improved the RefSeq data but uncovered a key site that might be involved in the transcription and translation of genes encoding the lactose operon repressor. We proposed that our pipeline might offer a universal method for the reannotation of other bacterial genomes with high speed and accuracy. This study might facilitate a better understanding of gene function for the ER2566 strain under external burden and provided more clues to engineer bacteria for biotechnological applications.


Assuntos
Proteínas de Escherichia coli/genética , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Anotação de Sequência Molecular , Sequência de Bases , Genoma Bacteriano , Óperon Lac/genética , RNA não Traduzido/genética , Transcriptoma , Sequenciamento Completo do Genoma
9.
Am J Transplant ; 20(4): 1014-1027, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31605563

RESUMO

Although studies have reported that intestinal microbiota are associated with acute graft-versus-host disease (aGVHD), they lacked a satisfactory method for predicting aGVHD. We collected stool and blood samples at day 15 posttransplant from 150 patients from two centers who underwent myeloablative conditioning allogeneic hematopoietic stem cell transplantation (allo-HSCT). Stool microbiota were detected by 16S ribosomal RNA gene sequencing; inflammatory factors and T lymphocytes were detected by multiplex immunoassays and flow cytometry, respectively. A gut microbiota score (GMS) from a LASSO (least absolute shrinkage and selection operator) model was developed and validated to predict aGVHD. In the discovery cohort, the GMS could predict II-IV aGVHD (area under the receiver operating characteristic [ROC] curve [AUC] = 0.904, P < .0001). Furthermore, the validation model was consistent with the discovery set (AUC = 0.887, P < .0001). Regulatory T/T-helper 17 (Treg/Th17) cells ratio in the low GMS subgroup was higher compared with the high GMS (P = .012), and the validation set is consistent with the discovery set (P = .003). In addition, high cytokine levels were associated with high GMS. In conclusion, the GMS at neutrophil engraftment could predict aGVHD, and it was a potential and novel method. The GMS was associated with the inflammatory factor and Treg/Th17 balance.


Assuntos
Microbioma Gastrointestinal , Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Doença Aguda , Doença Enxerto-Hospedeiro/diagnóstico , Doença Enxerto-Hospedeiro/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Linfócitos T Reguladores , Condicionamento Pré-Transplante
10.
Respir Res ; 21(1): 313, 2020 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-33243215

RESUMO

BACKGROUND: The clinical characteristics and outcomes of the 2019 novel coronavirus (COVID-19) pneumonia are different in Hubei compared to other regions in China. But there are few comparative studies on the differences between imported and local patients which may provide information of the different courses of the virus after transmission. METHODS: We investigated 169 cases of COVID-19 pneumonia in two centers in Hunan Province, and divided them into two groups according to epidemiological history, "imported patients" refers to patient with a clear history of travel in Wuhan within 14 days before onset, and " local patients" refers to local resident without a recent history of travel in Wuhan, aiming to analyze the difference in clinical characteristics and outcomes between the two groups. All the epidemiological, clinical, imaging, and laboratory data were analyzed and contrasted. RESULTS: The incidence of fever on admission in imported patients was significantly higher than local patients. There was a significantly higher proportion of abnormal pulmonary signs, hypokalemia, hyponatremia, prolonged PT, elevated D-dimer and elevated blood glucose in imported patients. Compared with local patients, the proportion using antibiotics, glucocorticoids and gamma globulin were significantly higher in imported patients. The moderate type was more common in local patients, and the severe type were more frequent in imported patients. In addition, the median duration of viral clearance was longer in imported patients. CONCLUSIONS: In summary, we found that imported cases were more likely to develop into severe cases, compared with local patients and required more powerful treatments. Trial registration Registered 21st March 2020, and this study has been approved by the Medical Ethics Committee (Approved Number. 2020017).


Assuntos
COVID-19/diagnóstico , COVID-19/terapia , Viagem , Adulto , Idoso , COVID-19/mortalidade , China/epidemiologia , Feminino , Febre/virologia , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Respiração Artificial/estatística & dados numéricos , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
11.
Biol Blood Marrow Transplant ; 25(10): 1944-1955, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31299215

RESUMO

The intestinal microbiome plays an important role in the development of acute graft-versus-host disease (aGVHD). However, whether intestinal microbiota can predict the development of aGVHD has been reported only rarely. Here we conducted a prospective study of microbiota in 141 patients after allogeneic hematopoietic stem cell transplantation. We found lower microbiota diversity in the aGVHD group compared with the non-aGVHD group at day 0 and day 15 ± 1 (P = .018 and .009, respectively). Diversity was negatively associated with conditioning intensity (P = .017, day 0; P = .045, day 15) and ß-lactam antibiotic administration (P = .004, day 15). Intensified conditioning and ß-lactam antibiotics were associated with a lower regulatory T (Treg)/T helper 17 (Th17) cell ratio at day 15 (P = .030 and .047, respectively). At day 15, the levels of the inflammatory factors (tumor necrosis factor α, interleukin [IL]-6, IL-17A, IL-1ß, and lipopolysaccharide) were higher in the intensified conditioning group compared with the standard group (P < .05). The accumulated intestinal microbiota (AIM) score was defined as microbiota diversity and gradient of the 4 bacterials (Lachnospiraceae, Peptostreptococcaceae, Erysipelotrichaceae, and Enterobacteriaceae) at day 15 post-transplantation. The AIM score was positively correlated with aGVHD grade (r = .481, P < .001), and the AIM score could be predictive of the development of aGVHD (grade II-IV aGVHD: area under the curve [AUC], .75, P < .001; grade III-IV aGVHD: AUC, .84, P < .001). These findings suggest that intestinal microbiota and conditioning might induce aGVHD by inflammatory factors and the Treg/Th17 balance. The constitution of the intestinal microbiota at neutrophil engraftment may predict the development of aGVHD.


Assuntos
Microbioma Gastrointestinal/fisiologia , Doença Enxerto-Hospedeiro/fisiopatologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Condicionamento Pré-Transplante/efeitos adversos , Transplante Homólogo/efeitos adversos , Adolescente , Adulto , Feminino , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Condicionamento Pré-Transplante/métodos , Transplante Homólogo/métodos , Adulto Jovem
12.
Microb Cell Fact ; 18(1): 70, 2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30971255

RESUMO

BACKGROUND: Bacterial surface display systems were developed to surface expose heterologous proteins or peptides for different applications, such as peptide libraries screening and live bacterial vaccine design. Various outer membrane proteins, such as outer membrane protein A (OmpA), OmpC and outer membrane pore protein E precursor (PhoE), have been used as carriers for surface display, fused to the proteins or peptides of interest in Gram-negative bacteria. Here, we investigated the utility of constitutively expressed OmpF for the display of foreign immune epitopes on the Escherichia coli cell surface and then compared it with plasmid-induced expression of OmpF and OmpC. RESULTS: Enhanced expression of OmpF was linked to a mutation in the OmpF promoter sequence. This mutation rendered OmpF an ideal carrier protein for the enriched display of a target of interest on the bacterial surface. To this end, we grafted two peptides, harboring important epitopes of the hepatitis B virus (HBV) S antigen and human papilloma virus (HPV) L2 protein, onto OmpF of E. coli by genome editing. The resultant fused OmpF proteins were constitutively expressed in the edited E. coli and purified by membrane component extraction. The epitope that displayed on the bacterial surface was verified by SDS-PAGE, western blotting, flow cytometry, and immunoelectron microscopy of the intact bacteria. We further compared this constitutive expression with plasmid-induced expression of OmpF and OmpC in bacterial cells using the same methods for verification. We found that plasmid-induced expression is much less efficient than constitutive expression of OmpF from the bacterial genome. CONCLUSIONS: Enhanced expression of OmpF in a plasmid-independent manner provides an amenable way to display epitopes on the bacterial surface and sheds light on ways to engineer bacteria for biotechnological applications.


Assuntos
Técnicas de Visualização da Superfície Celular , Epitopos/genética , Porinas/genética , Anticorpos Antibacterianos , Proteínas do Capsídeo/genética , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Escherichia coli/genética , Edição de Genes , Proteínas Oncogênicas Virais/genética , Plasmídeos/genética , Mutação Puntual , Proteínas do Envelope Viral/genética
13.
Ecotoxicol Environ Saf ; 157: 1-8, 2018 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-29605640

RESUMO

Despite the potential emissions of heavy metal pollution in Lake Caizi due to extensive agriculture, urban growth and fishing activities, the risk posed by metal concentrations to aquatic environments and human populations has not yet been studied. In this study we compared the concentrations of Hg, As, Pb, Cd, Cr, Cu and Zn in water, sediment, and economic fish species with different habitat preferences and trophic guilds across important fishery areas in Lake Caizi, located on the northern shore of the Yangtze River, Southeast China. The concentrations of Cr in water were found approximately 6 times higher than the safety thresholds established by international legislation. Cr, Zn, As and Cd concentrations in sediments surpassed the background values for Yangtze River basin in Anhui Province. However, all the studied fish species in Lake Caizi had metal concentrations lower than legislation thresholds established by China and international organizations. Heavy metal concentrations were found to be significantly higher in demersal (inhabiting near the sediments) and piscivorous (possessing higher trophic level) fishes than in pelagic/benthopelagic (inhabiting the upper and lower water column) and herbivorous/planktivorous (possessing lower trophic level) fishes. Our finding demonstrated that the metal concentrations in fishes are simultaneously influenced by the habitat and bio-accumulation through the food chain. According to target hazard quotient (THQ) calculations for heavy metal contents in the muscles of fish species, all the determined heavy metals gave THQ values lower than 1, suggesting the inexistence of health risks from the intake of fishes from Lake Caizi.


Assuntos
Peixes/metabolismo , Lagos/química , Metais Pesados/análise , Poluentes Químicos da Água/análise , Animais , China , Ecossistema , Monitoramento Ambiental , Cadeia Alimentar , Sedimentos Geológicos/química , Medição de Risco , Água
14.
Animals (Basel) ; 14(7)2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38612243

RESUMO

Wetlands are among the most important habitats of highly wetland-dependent waterbirds but are subject to ongoing habitat loss and degradation owing to intensified anthropogenic activities. The scarcity of human and natural resources makes effective habitat protection an important concern. Here, we aimed to investigate waterbird habitat protection methods for Anhui Province, China, a critical stopover and wintering area on the East Asian-Australasian Flyway that features rich wetland resources subject to significant habitat loss and degradation. We evaluated the status and importance of 306 wintering waterbird habitats and identified the key environmental influences and current protection gaps using the entropy weights method and generalized additive modeling. We found 73 important habitats for waterbirds in Anhui Province, which were classified into levels of importance (descending from I to V) according to the natural discontinuity method. Level I and Level II habitats were mainly located in the Yangtze River floodplain and Level IV habitats in the Huaihe River floodplain. The gap analysis showed that 42 important waterbird habitats had protection gaps, accounting for 57.53% of the total area. Waterbird habitat importance was significantly correlated with elevation, normalized vegetation index, lake area, and lake circumference but not with distance from roads or population density. The results of this study provide scientific information for waterbird habitat conservation planning, which is crucial for maintaining wetland ecosystem functions.

15.
Animals (Basel) ; 14(7)2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38612249

RESUMO

Habitat suitability analysis is essential in habitat and species conservation. Anatidae are known for their migratory behaviour, high population density, and wide distribution range. Understanding their habitat utilzation and influencing factors is crucial in targeted conservation and management. In this study, we collected Anatidae diversity data, including the number of species, through field surveys from October 2021 to March 2022 and thirty habitat variables through an online database in Anhui Province, China. By using MaxEnt, we simulated the habitat suitability of twenty-one Anatidae species, revealing potential distribution sites in Anhui Province. Generalized linear mixed models (GLMM) were employed to identify factors affecting the distribution of geese and ducks. The results showed that high-suitability habitats were predominantly located in the large lakes of the Yangtze River floodplain. The GLMM analysis showed significant correlations between Anatidae richness and altitude, distribution of farmland, and human footprint. In addition, ducks were more sensitive to the human interference factor than geese. In summary, the lakes in the Yangtze River floodplain emerged as the most important Anatidae habitats in Anhui Province due to their abundant wetland resources, flat terrain, and high distribution of farmlands. These findings provide a scientific basis for the development of relevant conservation strategies and measures, aiding in wildlife epidemic monitoring, prevention, and control.

16.
J Control Release ; 367: 13-26, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38244843

RESUMO

The cGAS-STING pathway and the Mevalonate Pathway are druggable targets for vaccine adjuvant discovery. Manganese (Mn) and bisphosphonates are known to exert adjuvant effects by targeting these two pathways, respectively. This study found the synergistic potential of the two pathways in enhancing immune response. Risedronate (Ris) significantly amplified the Mn adjuvant early antibody response by 166-fold and fortified its cellular immunity. However, direct combination of Mn2+ and Ris resulted in increased adjuvant toxicity (40% mouse mortality). By the combination of doping property of hydroxyapatite (HA) and its high affinity for Ris, we designed Ris-functionalized Mn-HA micro-nanoparticles as an organic-inorganic hybrid adjuvant, named MnHARis. MnHARis alleviated adjuvant toxicity (100% vs. 60% survival rate) and exhibited good long-term stability. When formulated with the varicella-zoster virus glycoprotein E (gE) antigen, MnHARis triggered a 274.3-fold increase in IgG titers and a 61.3-fold surge in neutralization titers while maintaining a better long-term humoral immunity compared to the aluminum adjuvant. Its efficacy spanned other antigens, including ovalbumin, HPV18 VLP, and SARS-CoV-2 spike protein. Notably, the cellular immunity elicited by the group of gE + MnHARis was comparable to the renowned Shingrix®. Moreover, intratumoral co-administration with an anti-trophoblast cell surface antigen 2 nanobody revealed synergistic antitumor capabilities. These findings underscore the potential of MnHARis as a potent adjuvant for augmenting vaccine immune responses and improving cancer immunotherapy outcomes.


Assuntos
Manganês , Neoplasias , Glicoproteína da Espícula de Coronavírus , Camundongos , Humanos , Animais , Ácido Risedrônico , Durapatita , Adjuvantes Imunológicos , Vacinas de Subunidades Antigênicas , Antígenos , Adjuvantes Farmacêuticos , Imunoterapia , Anticorpos Antivirais
17.
Sci Bull (Beijing) ; 69(4): 512-525, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38160175

RESUMO

In vaccine development, broadly or cross-type neutralizing antibodies (bnAbs or cnAbs) are frequently targeted to enhance protection. Utilizing immunodominant antibodies could help fine-tune vaccine immunogenicity and augment the precision of immunization strategies. However, the methodologies to capitalize on the attributes of bnAbs in vaccine design have not been clearly elucidated. In this study, we discovered a cross-type neutralizing monoclonal antibody, 13H5, against human papillomavirus 6 (HPV6) and HPV11. This nAb exhibited a marked preference for HPV6, demonstrating superior binding activity to virus-like particles (VLPs) and significantly higher prevalence in anti-HPV6 human serum as compared to HPV11 antiserum (90% vs. 31%). Through co-crystal structural analysis of the HPV6 L1 pentamer:13H5 complex, we delineated the epitope as spanning four segments of amino acids (Phe42-Ala47, Gly172-Asp173, Glu255-Val275, and Val337-Tyr351) on the L1 surface loops. Further interaction analysis and site-directed mutagenesis revealed that the Ser341 residue in the HPV6 HI loop plays a critical role in the interaction between 13H5 and L1. Substituting Ser341 with alanine, which is the residue type present in HPV11 L1, almost completely abolished binding activity to 13H5. By swapping amino acids in the HPV11 HI loop with corresponding residues in HPV6 L1 (Ser341, Thr338, and Thr339), we engineered chimeric HPV11-6HI VLPs. Remarkably, the chimeric HPV11-6HI VLPs shifted the high immunodominance of 13H5 from HPV6 to the engineered VLPs and yielded comparable neutralization titers for both HPV6 and HPV11 in mice and non-human primates. This approach paves the way for the design of broadly protective vaccines from antibodies within the main immunization reservoir.


Assuntos
Vacinas contra Papillomavirus , Animais , Camundongos , Anticorpos Amplamente Neutralizantes , Proteínas do Capsídeo/genética , Anticorpos Antivirais , Papillomavirus Humano 6 , Imunização , Aminoácidos
18.
Protein Cell ; 15(2): 121-134, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-37470320

RESUMO

Continual evolution of the severe acute respiratory syndrome coronavirus (SARS-CoV-2) virus has allowed for its gradual evasion of neutralizing antibodies (nAbs) produced in response to natural infection or vaccination. The rapid nature of these changes has incited a need for the development of superior broad nAbs (bnAbs) and/or the rational design of an antibody cocktail that can protect against the mutated virus strain. Here, we report two angiotensin-converting enzyme 2 competing nAbs-8H12 and 3E2-with synergistic neutralization but evaded by some Omicron subvariants. Cryo-electron microscopy reveals the two nAbs synergistic neutralizing virus through a rigorous pairing permitted by rearrangement of the 472-489 loop in the receptor-binding domain to avoid steric clashing. Bispecific antibodies based on these two nAbs tremendously extend the neutralizing breadth and restore neutralization against recent variants including currently dominant XBB.1.5. Together, these findings expand our understanding of the potential strategies for the neutralization of SARS-CoV-2 variants toward the design of broad-acting antibody therapeutics and vaccines.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Microscopia Crioeletrônica , Anticorpos Neutralizantes , Anticorpos Antivirais
19.
Zoolog Sci ; 30(7): 559-64, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23829216

RESUMO

The Yellow River Delta, a stopover site, has become one of the breeding sites of oriental white storks (Ciconia boyciana) in China, with 28 breeding pairs. To gain insight into the characteristics of foraging habitat use during the breeding season, we surveyed the foraging habitats in 2009 and 2010. In 2009, using a quadrat sampling technique, we surveyed 74 quadrats in two breeding phases. Fourteen variables were analyzed with DCA. Oriental white storks mainly foraged in the reed swamp of recovered wetlands during the early breeding phase (70.29%), and in the reed swamp of unrecovered area during the late phase (32.74%), and in the open water of recovered wetlands (29.95%). The variation in proportional habitat use was not significant in the two breeding phases. Differences of the foraging sites in the two phases were extremely significant in terms of plant density, distance from nest, and distance from highway. In 2010, the storks also mainly used the reed wetlands for foraging (87.00%). The top three parameters on the first axis with the highest scores were distance from nest, plant height, plant coverage; on the second axis, the top three variables with the highest scores were plant density, number of other waterbird species, and water depth. These results showed that there are differences in the foraging habitat use of oriental white storks in the early and the late breeding phases. It is favorable for the breeding of oriental white storks to recover the reed wetland and to preserve a certain area of open water habitats.


Assuntos
Aves/fisiologia , Ecossistema , Comportamento Alimentar/fisiologia , Reprodução/fisiologia , Animais , China
20.
Biochem Genet ; 51(11-12): 841-52, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23824319

RESUMO

The invasive red swamp crayfish (Procambarus clarkii) provides a valuable opportunity for studying the population genetics of invasive species that disperse rapidly. We analyzed the population genetic structure among 12 populations of the crayfish in China based on the internal transcribed spacer 1 (ITS1) region. The ITS1 of 815 bp aligned across 34 haplotypes; the average GC content was 53.9%. AMOVA showed that intrapopulation variation (95.26%) was much higher than interpopulation variation (4.74%). Genetic differentiation between the Taiwan and mainland populations (Fst = 0.160) was moderate, but the Chinese population (Taiwan and the mainland combined) and an American population were highly differentiated (0.682 and 0.977, respectively). Gene flow between the Chinese and American populations (Nm = 0.006 and 0.117, respectively) was lower than that between Taiwan and the mainland (1.536). Phylogenetic trees showed that three major genealogical clusters matched the sample locations well, suggesting that genetic differentiation is created largely by geographic isolation.


Assuntos
Astacoidea/genética , Variação Genética , Espécies Introduzidas , Análise de Variância , Animais , Astacoidea/classificação , China , DNA Espaçador Ribossômico , Fluxo Gênico , Haplótipos , Filogeografia , Análise de Sequência de DNA , Áreas Alagadas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA