Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Microb Cell ; 11: 128-142, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38799406

RESUMO

Modular Cloning (MoClo) is based on libraries of standardized genetic parts that can be directionally assembled via Golden Gate cloning in one-pot reactions into transcription units and multigene constructs. Here, a team of bachelor students established a MoClo toolkit for the protist Leishmania tarentolae in the frame of the international Genetically Engineered Machine (iGEM) competition. Our modular toolkit is based on a domesticated version of a commercial LEXSY expression vector and comprises 34 genetic parts encoding various affinity tags, targeting signals as well as fluorescent and luminescent proteins. We demonstrated the utility of our kit by the successful production of 16 different tagged versions of the receptor binding domain (RBD) of the SARS-CoV-2 spike protein in L. tarentolae liquid cultures. While highest yields of secreted recombinant RBD were obtained for GST-tagged fusion proteins 48 h post induction, C-terminal peptide tags were often degraded and resulted in lower yields of secreted RBD. Fusing secreted RBD to a synthetic O-glycosylation SP20 module resulted in an apparent molecular mass shift around 10 kDa. No disadvantage regarding the production of RBD was detected when the three antibiotics of the LEXSY system were omitted during the 48-h induction phase. Furthermore, the successful purification of secreted RBD from the supernatant of L. tarentolae liquid cultures was demonstrated in pilot experiments. In summary, we established a MoClo toolkit and exemplified its application for the production of recombinant proteins in L. tarentolae.

2.
J Nat Prod ; 87(4): 1131-1149, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38555526

RESUMO

Herein, the first total synthesis of natural 13-hydroxy-14-deoxyoxacyclododecindione along with the revision of the proposed configuration is reported. This natural product, initially discovered in 2018, belongs to the oxacyclododecindione family, renowned for their remarkable anti-inflammatory and antifibrotic activities. The synthetic route involves an esterification/Friedel-Crafts-acylation approach and uses various triol fragments. It allows the preparation of different stereoisomers, including the (revised) natural product, two threo-derivatives, and two Z-isomers of the endocyclic C═C double bond. Furthermore, a late-stage inversion of the C-13 stereocenter could transform the originally proposed structure into the revised natural product. With this comprehensive set of compounds and the previously prepared (13R,14S,15R)-isomer, deeper insights into their structural properties and biological activities were obtained. A detailed analysis of the final macrolactones using spectroscopy (NMR, IR, UV-vis) and X-ray crystallography gave new insights such as the significance of the optical rotation for the elucidation of their configuration and the light-induced E/Z double-bond photoisomerization. The pharmacological potential of the compounds was underlined by remarkably low IC50 values in biological assays addressing the inhibition of cellular inflammatory responses.


Assuntos
Anti-Inflamatórios , Macrolídeos , Humanos , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/síntese química , Anti-Inflamatórios/química , Produtos Biológicos/farmacologia , Produtos Biológicos/química , Produtos Biológicos/síntese química , Lactonas/farmacologia , Lactonas/química , Lactonas/síntese química , Estrutura Molecular , Estereoisomerismo , Macrolídeos/química , Macrolídeos/farmacologia
3.
Free Radic Biol Med ; 208: 165-177, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37541455

RESUMO

Dimedone and its derivates are used as selective probes for the nucleophilic detection of sulfenic acids in biological samples. Qualitative analyses suggested that dimedone also reacts with cyclic sulfenamides. Furthermore, under physiological conditions, dimedone must compete with the highly concentrated nucleophile glutathione. We therefore quantified the reaction kinetics for a cyclic sulfenamide model peptide and the sulfenic acids of glutathione and a model peroxiredoxin in the presence or absence of dimedone and glutathione. We show that the cyclic sulfenamide is stabilized at lower pH and that it reacts with dimedone. While reactions between dimedone and sulfenic acids or the cyclic sulfenamide have similar rate constants, glutathione kinetically outcompetes dimedone as a nucleophile by several orders of magnitude. Our comparative in vitro and intracellular analyses challenge the selectivity of dimedone. Consequently, the dimedone labeling of cysteinyl residues inside living cells points towards unidentified reaction pathways or unknown, kinetically competitive redox species.


Assuntos
Glutationa , Ácidos Sulfênicos , Ácidos Sulfênicos/química , Glutationa/metabolismo , Cicloexanonas/química , Oxirredução , Cisteína/metabolismo
4.
Mycotoxin Res ; 39(3): 303-316, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37351768

RESUMO

The KEAP1-Nrf2/ARE pathway is a pivotal cytoprotective regulator against oxidative stress which plays an important role in the development of many inflammatory diseases and cancer. Activation of the Nrf2 transcription factor by oxidative stress or electrophiles regulates antioxidant response element (ARE)-dependent transcription of antioxidative, detoxifying, and anti-inflammatory proteins. Therefore, modulators of the KEAP1-Nrf2/ARE pathway have received considerable interest as therapeutics to protect against diseases where oxidative stress constitutes the underlying pathophysiology. In a search for fungal secondary metabolites affecting the Nrf2/ARE-dependent expression of a luciferase reporter gene in BEAS-2B cells, three new perylenequinones, compounds 1, 2, and 3, together with altertoxin-I (ATX-I), were isolated from fermentations of an Alternaria species. The structures of the compounds were elucidated by a combination of one- and two-dimensional NMR spectroscopy and mass spectrometry. Compound 1 and ATX-I exhibited strong cytotoxic effects with LC50-values of 3.8 µM and 6.43 µM, respectively, whereas compound 3 showed no cytotoxic effects up to 100 µM on BEAS-2B cells. ATX-I induced ARE-dependent luciferase expression approximately fivefold and compound 1 approximately 2.6-fold at a concentration of 3 µM in transiently transfected BEAS-2B cells. In addition, compound 1 and ATX-I exhibited strong oxidative effects, whereas compound 3 did not show significant oxidative properties. For compound 1 and ATX-I, a strong upregulation of heme oxygenase-1 could be observed on mRNA and protein level in treated BEAS-2B cells. Moreover, compound 3 significantly decreased sod3 mRNA levels after induction of oxidative stress with benzoquinone.


Assuntos
Alternaria , Fator 2 Relacionado a NF-E2 , Alternaria/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Estresse Oxidativo , RNA Mensageiro/metabolismo , RNA Mensageiro/farmacologia
5.
J Nat Prod ; 86(4): 924-938, 2023 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-37001011

RESUMO

The first total synthesis of the natural product (13R,14S,15R)-13-hydroxy-14-deoxyoxacyclododecindione, which was isolated in 2018 as a member of the oxacyclododecindione family, is reported. A synthetic strategy through intramolecular Friedel-Crafts acylation combined with the stereoselective synthesis of a new triol key fragment allowed the preparation of the macrolactone. Due to mismatching physical data of the synthetic product, a revision of the configuration of the natural product isolated in 2018 is required. Light-induced E/Z-isomerism of the macrolactone backbone is described for the first time in the class of oxacyclododecindione-type macrolactones. The hydroxylated macrolactone prepared herein was found to show highly promising IC50 values in biological assays addressing the inhibition of inflammatory responses.


Assuntos
Anti-Inflamatórios , Anti-Inflamatórios/farmacologia , Isomerismo , Estrutura Molecular , Estereoisomerismo
6.
Pflege ; 36(3): 129-138, 2023 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-36269006

RESUMO

Care for family carers of people with dementia in municipal communities during the pandemic: A Qualitative Study Abstract: Background: The availability of support services for family carers of persons with dementia in the municipal community shows deficits due to the Corona pandemic and thus entails a change in the support of carers. Research question: The questions arise, what changes in the care of family carers of people with dementia do those affected perceive, how do actors from the municipal community experience the care situation during the pandemic and to what extent do the perceptions of the groups coincide or differ. Method: The database consists of town hall talks and focus groups from 13 municipal communities in Germany. Participants were family carers and actors from the municipal community. For data analysis, a qualitative content analysis was carried out. Result: Negative changes in the care of caregivers can be seen, for example, in the omission of care services or groups of relatives. Above all, actors perceived positive changes, such as advancing digitalization or increased neighborly help. The perception of changes in the care situation differs in several subcategories between carers and actors. Conclusion: Although large gaps in care have been created by the pandemic, emerging challenges also create new ways for support such as digital groups for family carers. In the future, opportunities need to be created to implement already developed interventions in such a way that the target group can make use of them.


Assuntos
Cuidadores , Demência , Humanos , Pandemias , Pesquisa Qualitativa , Grupos Focais
7.
Front Plant Sci ; 13: 988870, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36204065

RESUMO

The spike protein is the major protein on the surface of coronaviruses. It is therefore the prominent target of neutralizing antibodies and consequently the antigen of all currently admitted vaccines against SARS-CoV-2. Since it is a 1,273-amino acids glycoprotein with 22 N-linked glycans, the production of functional, full-length spike protein was limited to higher eukaryotes. Here we report the production of full-length SARS-CoV-2 spike protein - lacking the C-terminal membrane anchor - as a secreted protein in the prefusion-stabilized conformation in the unicellular green alga Chlamydomonas reinhardtii. We show that the spike protein is efficiently cleaved at the furin cleavage site during synthesis in the alga and that cleavage is abolished upon mutation of the multi-basic cleavage site. We could enrich the spike protein from culture medium by ammonium sulfate precipitation and demonstrate its functionality based on its interaction with recombinant ACE2 and ACE2 expressed on human 293T cells. Chlamydomonas reinhardtii is a GRAS organism that can be cultivated at low cost in simple media at a large scale, making it an attractive production platform for recombinant spike protein and other biopharmaceuticals in low-income countries.

8.
Z Gesundh Wiss ; : 1-11, 2022 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-35975189

RESUMO

Aim: Although caring relatives of people with dementia are a mainstay of many care systems, the availability of support services for them within the municipal community shows deficiencies. Adopting the Theoretical Domains Framework (TDF) this study aims to investigate 1) which of the TDF domains adapted to gerontology show up in public dialogue, and 2) the results that public dialogues produce in terms of support services for caring relatives. Subject and methods: The data consists of town hall meetings and focus groups from 14 municipal communities in Germany. Participants were caring relatives and stakeholders of the communities. A qualitative content analysis was conducted, focusing on the assessment of three TDF domains, namely knowledge, goals, and sociopolitical context as well as outcomes of care optimisation. Results: With regard to domain knowledge, it was evident that in every community there were actors aware of the situation and relevance of carers and their relatives. Only some actors mentioned goals for optimising the care of the target group. The sociopolitical context is often addressed through statements about incomplete requirements. Conclusion: Overall, a relation between the discussion about the domains in public dialogues and changes in supporting carers of people with dementia can be assumed. The results indicate that an increased discussion about the domains within town hall meetings influences the actors and their statements with regard to the improvement of support services for caring relatives of people with dementia. Since the domains were not developed exclusively for the outlined context, this approach can also be applied to other areas of care. Supplementary information: The online version contains supplementary material available at 10.1007/s10389-022-01744-w.

9.
J Alzheimers Dis ; 87(3): 981-990, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35431247

RESUMO

A growing number of people with dementia, a simultaneous decline of professional caregivers, and changing family structures clearly illustrate the societal relevance of the question of how dementia care can be arranged and delivered in the future. The demand for innovative solutions especially to support family carers requires a deeper insight into their life situation and a focused perception of their needs. This article presents the main hypothesis that specific forms of social integration and participation based on an equal dialogue between family caregivers, the public, and policymakers is needed to achieve that. Therefore, the main point here is to give family caregivers of people with dementia a voice to learn how to better support them in caring as well as self-care. A learning process triggered by a dialogue might result in a higher level of community readiness to implement new forms of support or social innovations. The hypothesis will be supported by John Dewey's theory of political and democratic learning and the model of transformative learning according to Jack Mezirow indicating that learning particularly succeeds in interpersonal communication. In this context, the Town-Hall Meeting method and its potential to promote interpersonal communication and reflexive learning is discussed. The article addresses an important debate, namely that of how dementia care and support of family carers can succeed. It also sets the direction for future empirical research as the Town-Hall Meeting method might be applicable for gerontological action and participatory research.


Assuntos
Cuidadores , Demência , Comunicação , Demência/terapia , Família , Serviços de Saúde , Humanos , Projetos de Pesquisa , Apoio Social
10.
Biol Chem ; 403(1): 89-101, 2022 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-34333887

RESUMO

In a search for anti-inflammatory compounds from fungi inhibiting the promoter activity of the small chemokine CXCL10 (Interferon-inducible protein 10, IP-10) as a pro-inflammatory marker gene, the new dihydroxanthone methyl (1R, 2R)-1,2,8-trihydroxy-6-(hydroxymethyl)-9-oxo-2,9-dihydro-1H-xanthene-1-carboxylate (2) and the previously described dihydroxanthone AGI-B4 (1) were isolated from fermentations of a Diaporthe species. The structures of the compounds were elucidated by a combination of one- and two-dimensional NMR spectroscopy, mass spectrometry, and calculations using density functional theory (DFT). Compounds 1 and 2 inhibited the LPS/IFNγ induced CXCL10 promoter activity in transiently transfected human MonoMac6 cells in a dose-dependent manner with IC50 values of 4.1 µM (±0.2 µM) and 1.0 µM (±0.06 µM) respectively. Moreover, compounds 1 and 2 reduced mRNA levels and synthesis of pro-inflammatory mediators such as cytokines and chemokines in LPS/IFNγ stimulated MonoMac6 cells by interfering with the Stat1 and NFκB pathway.


Assuntos
Anti-Inflamatórios , Ascomicetos/química , Quimiocina CXCL10 , Anti-Inflamatórios/farmacologia , Citocinas , Humanos , Interferon gama , NF-kappa B
11.
Z Gerontol Geriatr ; 54(8): 775-780, 2021 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-32997232

RESUMO

BACKGROUND AND AIM: Society is responsible for strengthening "caregiver-sensitive" communities based on the principle of social services to the public and are thus oriented towards the appreciation of caring relatives (CR) of people with dementia (PwD), their capability for self-care and participation. This requires methods to emphasize the social value of informal care and to re-evaluate existing support services. The article aims to present the method of "town hall talks". METHOD: In 20 communities throughout Germany a public town hall talk in which CR, actors in the community (AC) and the citizens enter into a dialogue, was conducted. In three moderated discussion groups the question of communal responsibility for the provision of resources was addressed. These resources should encourage the CR ability of self-care as well as strategies for their support. In order to make a statement regarding the success of the project planning, three pilot town hall talks were evaluated. PREVIOUS RESULTS: The recruitment of the population sample and the organization of the town hall talks in particular are administratively and logistically challenging. The project can only be successful through networking and intensive cooperation between scientists and the communities. In terms of content and logistics, the project planning of the pilot town hall talks was successful. The method received excellent ratings from the majority of the CR and AC. CONCLUSION: Regarding the creation of caregiver-sensitive communities the town hall talks promise great potential. The specific benefit of the method for the CR and the community will be examined.


Assuntos
Cuidadores , Projetos de Pesquisa , Alemanha , Humanos , Serviço Social
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...