Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
1.
Cell ; 162(6): 1365-78, 2015 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-26359988

RESUMO

The cytokine TWEAK and its cognate receptor Fn14 are members of the TNF/TNFR superfamily and are upregulated in tumors. We found that Fn14, when expressed in tumors, causes cachexia and that antibodies against Fn14 dramatically extended lifespan by inhibiting tumor-induced weight loss although having only moderate inhibitory effects on tumor growth. Anti-Fn14 antibodies prevented tumor-induced inflammation and loss of fat and muscle mass. Fn14 signaling in the tumor, rather than host, is responsible for inducing this cachexia because tumors in Fn14- and TWEAK-deficient hosts developed cachexia that was comparable to that of wild-type mice. These results extend the role of Fn14 in wound repair and muscle development to involvement in the etiology of cachexia and indicate that Fn14 antibodies may be a promising approach to treat cachexia, thereby extending lifespan and improving quality of life for cancer patients.


Assuntos
Caquexia/tratamento farmacológico , Neoplasias/patologia , Receptores do Fator de Necrose Tumoral/antagonistas & inibidores , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/administração & dosagem , Atrofia/tratamento farmacológico , Caquexia/patologia , Morte Celular , Neoplasias do Colo/tratamento farmacológico , Citocina TWEAK , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Desenvolvimento Muscular , Neoplasias/metabolismo , Receptores do Fator de Necrose Tumoral/química , Receptores do Fator de Necrose Tumoral/metabolismo , Alinhamento de Sequência , Transdução de Sinais , Receptor de TWEAK , Fatores de Necrose Tumoral/metabolismo
2.
Proc Natl Acad Sci U S A ; 120(44): e2306177120, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37871210

RESUMO

Lepidopterans affect crop production worldwide. The use of transgenes encoding insecticidal proteins from Bacillus thuringiensis (Bt) in crop plants is a well-established technology that enhances protection against lepidopteran larvae. Concern about widespread field-evolved resistance to Bt proteins has highlighted an urgent need for new insecticidal proteins with different modes or sites of action. We discovered a new family of insecticidal proteins from ferns. The prototype protein from Pteris species (Order Polypodiales) and variants from two other orders of ferns, Schizaeales and Ophioglossales, were effective against important lepidopteran pests of maize and soybean in diet-based assays. Transgenic maize and soybean plants producing these proteins were more resistant to insect damage than controls. We report here the crystal structure of a variant of the prototype protein to 1.98 Å resolution. Remarkably, despite being derived from plants, the structure resembles the 3-domain Cry proteins from Bt but has only two out of three of their characteristic domains, lacking the C-terminal domain which is typically required for their activities. Two of the fern proteins were effective against strains of fall armyworm that were resistant to Bt 3-domain Cry proteins Cry1Fa or Cry2A.127. This therefore represents a novel family of insecticidal proteins that have the potential to provide future tools for pest control.


Assuntos
Bacillus thuringiensis , Gleiquênias , Inseticidas , Traqueófitas , Animais , Inseticidas/metabolismo , Bacillus thuringiensis/genética , Bacillus thuringiensis/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Controle Biológico de Vetores , Endotoxinas/genética , Endotoxinas/metabolismo , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/metabolismo , Traqueófitas/metabolismo , Zea mays/metabolismo
3.
EMBO Rep ; 12(1): 77-83, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21151042

RESUMO

The proapoptotic Bcl2 homology domain 3(BH3)-only protein Bim is controlled by stringent post-translational regulation, predominantly through alterations in phosphorylation status. To identify new kinases involved in its regulation, we carried out a yeast two-hybrid screen using a non-spliceable variant of the predominant isoform--Bim(EL)--as the bait and identified the regulatory subunit of cyclic-AMP-dependent protein kinase A--PRKAR1A--as an interacting partner. We also show that protein kinase A (PKA) is a Bim(EL) isoform-specific kinase that promotes its stabilization. Inhibition of PKA or mutation of the PKA phosphorylation site within Bim(EL) resulted in its accelerated proteasome-dependent degradation. These results might have implications for human diseases that are characterized by abnormally increased PKA activity, such as the Carney complex and dilated cardiomyopathy.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Apoptose , Subunidade RIalfa da Proteína Quinase Dependente de AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/fisiologia , Proteínas de Membrana/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Sequência de Aminoácidos , Animais , Proteína 11 Semelhante a Bcl-2 , Humanos , Camundongos , Fosforilação , Ligação Proteica , Estabilidade Proteica , Alinhamento de Sequência , Técnicas do Sistema de Duplo-Híbrido
4.
Microorganisms ; 10(7)2022 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-35889064

RESUMO

Mycobacteria are a unique group of microorganisms. They are characterised by exceptional adaptability and durability. They are capable of colonisation and survival even in very unfavourable conditions. In addition to the well-known obligate human pathogens, Mycobacterium tuberculosis and M. leprae, more than 200 other species have been described. Most of them form a natural part of the microflora of the external environment and thrive in aquatic and soil environments especially. For many of the mycobacterial species associated with human disease, their natural source has not yet been identified. From an ecological point of view, mycobacteria are saprophytes, and their application in human and animal diseases is opportunistic. Most cases of human disease from saprophytic mycobacteria occur in immunocompromised individuals. This adaptability and resilience to environmental pressures makes treatment of mycobacterial diseases (most often sapronoses and less often zoonoses) and permanent eradication of mycobacteria from the environment very difficult. Saprophytic mycobacterial diseases (sapronoses) are chronic and recurrent due to the fact of repeated endogenous or exogenous re-exposure. Therefore, knowledge regarding their occurrence in soil and dust would aid in the prevention of saprophytic mycobacterioses. In conjunction, their presence and ecological significance in the environment can be revealed.

5.
Microorganisms ; 9(11)2021 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-34835470

RESUMO

Mycobacterium fortuitum group (MFG) members are able to cause clinical mycobacteriosis in fish and other animals including humans. M. alvei, M. arceuilense, M. brisbanense, M. conceptionense, M. fortuitum, M. peregrinum, M. porcinum, M. senegalense, M. septicum, and M. setense were isolated from fish with mycobacteriosis. In other animals only three MFG species have been isolated: M. arceuilense from camels' milk, M. farcinogenes from cutaneous infections often described as "farcy", and M. fortuitum from different domestic and wild mammals' species. Out of 17, only 3 MFG species (M. arceuilense, M. lutetiense and M. montmartrense) have never been reported in humans. A total of eight MFG members (M. alvei, M. brisbanense, M. conceptionense, M. fortuitum subsp. acetamidolyticum, M. houstonense, M. peregrinum, M. porcinum, and M. septicum) have been isolated from both pulmonary and extrathoracic locations. In extrathoracic tissues five MFG species (M. boenickei, M. farcinogenes, M. neworleansense, M. senegalense, and M. setense) have been diagnosed and only one MFG member (M. fortuitum subsp. acetamidolyticum) has been isolated from pulmonary infection.

6.
Microorganisms ; 9(10)2021 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-34683499

RESUMO

For epidemiology studies, a decontamination method using a solution containing 4.0% NaOH and 0.5% tetradecyltrimethylammonium bromide (TDAB) represents a relatively simple and universal procedure for processing heavily microbially contaminated matrices together with increase of mycobacteria yield and elimination of gross contamination. A contamination rate only averaging 7.3% (2.4% in Cluster S; 6.9% in Cluster R and 12.6% in Cluster E) was found in 787 examined environmental samples. Mycobacteria were cultured from 28.5% of 274 soil and water sediments samples (Cluster S), 60.2% of 251 samples of raw and processed peat and other horticultural substrates (Cluster R), and 29.4% of 262 faecal samples along with other samples of animal origin (Cluster E). A total of 38 species of slow and rapidly growing mycobacteria were isolated. M. avium ssp. hominissuis, M. fortuitum and M. malmoense were the species most often isolated. The parameters for the quantitative detection of mycobacteria by PCR can be significantly refined by treating the sample suspension before DNA isolation with PMA (propidium monoazide) solution. This effectively eliminates DNA residue from both dead mycobacterial cells and potentially interfering DNA segments present from other microbial flora. In terms of human exposure risk assessment, the potential exposure to live non-tuberculous mycobacteria can be more accurately determined.

7.
Microorganisms ; 9(12)2021 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-34946174

RESUMO

A total of 152 aerosol and spider web samples were collected: 96 spider's webs in karst areas in 4 European countries (Czech Republic, France, Italy, and Slovakia), specifically from the surface environment (n = 44), photic zones of caves (n = 26), and inside (aphotic zones) of caves (n = 26), 56 Particulate Matter (PM) samples from the Sloupsko-Sosuvsky Cave System (speleotherapy facility; n = 21) and from aerosol collected from the nearby city of Brno (n = 35) in the Czech Republic. Nontuberculous mycobacteria (NTM) were isolated from 13 (13.5%) spider's webs: 5 isolates of saprophytic NTM (Mycobacterium gordonae, M. kumamotonense, M. terrae, and M. terrae complex) and 6 isolates of potentially pathogenic NTM (M. avium ssp. hominissuis, M. fortuitum, M. intracellulare, M. peregrinum and M. triplex). NTM were not isolated from PM collected from cave with the speleotherapy facility although mycobacterial DNA was detected in 8 (14.3%) samples. Temperature (8.2 °C, range 8.0-8.4 °C) and relative humidity (94.7%, range 93.6-96.6%) of air in this cave were relatively constant. The average PM2.5 and PM10 mass concentration was 5.49 µg m-3 and 11.1 µg m-3. Analysed anions (i.e., F-, Cl-, NO2-, SO42-, PO43- and NO3-) originating largely from the burning of wood and coal for residential heating in nearby villages in the surrounding area. The air in the caves with speleotherapy facilities should be monitored with respect to NTM, PM and anions to ensure a safe environment.

8.
Microorganisms ; 9(11)2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34835362

RESUMO

A total of 281 guano samples were collected from caves (N = 181) in eight European countries (Bulgaria, Czech Republic, France, Hungary, Italy, Romania, Slovakia and Slovenia) and attics in the Czech R. (N = 100). The correlation of detection of mycobacteria between Ziehl-Neelsen (ZN) microscopy and culture examination and qPCR was strong. ZN microscopy was positive in guano from caves (58.6%) more than double than positivity in guano from attics (21.0%; p < 0.01). From 89 mycobacterial isolates (73 isolates from cave guano and 16 isolates from attics' guano), 68 (76.4%) isolates of 19 sp., ssp. and complex were identified as members of three Groups (M. fortuitum, M.chelonae, and M. mucogenicum) and four complexes (M. avium, M. terrae, M.vaccae, and M.smegmatis). A total of 20 isolates (22.5%) belonged to risk group 1 (environmental saprophytes), 48 isolates (53.9%) belonged to risk group 2 (potential pathogens), and none of the isolates belonged to risk group 3 (obligatory pathogens). When comparing bat guano collected from caves and attics, differences (p < 0.01; Mann-Whitney test) were observed for the electrical conductivity, total carbon, total organic, and total inorganic carbon. No difference (p > 0.05; Mann-Whitney test) was found for pH and oxidation-reduction potential parameters.

9.
Adv Exp Med Biol ; 687: 65-77, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20919638

RESUMO

In the eukaryotic cell, the endoplasmic reticulum (ER) plays an important role as the site of lipid synthesis, protein folding and protein maturation. Stringent regulation of redox and calcium homeostasis is paramount, failure of which leads accumulation of unfolded and aggregating proteins resulting in a condition known as ER stress. Eukaryotic cells deal with ER stress by eliciting the unfolded protein response (UPR). This pathway splits into two streams depending on the severity and longevity of the ER stress, where the cell must make a choice for the good of the organism between survival and programmed cell death. The BCL-2 family of proteins is central to the cell death arm of the UPR pathway. This chapter discusses the recent findings on the involvement of BCL-2 family members in the apoptotic process initiated by ER stress and a related process called autophagy. Understanding the molecular mechanisms involved in ER stress and autophagy could have a profound implications developing new therapies for many ER stress associated diseases and cancer.


Assuntos
Retículo Endoplasmático/fisiologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Estresse Fisiológico/fisiologia , Animais , Autofagia/fisiologia , Humanos , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Transdução de Sinais/fisiologia , Resposta a Proteínas não Dobradas/fisiologia
10.
Artigo em Inglês | MEDLINE | ID: mdl-31627484

RESUMO

Non-tuberculous mycobacteria (NTM) are ubiquitous environmental bacteria that can induce pulmonary and non-pulmonary diseases in susceptible persons. It is reported that the prevalence of NTM diseases is increasing in developed countries, but this differs by regions and countries. NTM species distribution and the rate of diseases caused by NTM vary widely in the historical territories of Moravia and Silesia (Czech Republic). This epidemiologic study of NTM diseases covers the period 2012-2018, reviews isolates obtained from patients with clinical disease and investigates correlations with related socio-economic and environmental factors. Individual NTM patients were included only once during the studied period and results were presented as incidence rate per year. The most frequently isolated NTM meeting the microbiological and clinical criteria in the study were the Mycobacterium avium-intracellulare complex, followed by Mycobacteriumkansasii and Mycobacteriumxenopi. A previously described endemic incidence of M.kansasii in the Karviná district and M.xenopi in the Ostrava district was also observed in this study. The incidence of NTM patients in the whole studied territory was 1.10/100,000 inhabitants (1.33/100,000 in men and 0.88/100,000 in women). The annual incidence of lymphadenitis in children (≤5 years of age) was 2.35/100,000 of the population of children during the 7 year period but increased in the year 2018 to 5.95/100,000. The rate of human tuberculosis in the studied area was 1.97/100,000 inhabitants. The incidence of NTM pulmonary diseases correlated with a lower socio-economic status (r = 0.63) and a higher concentration of benzo[a]pyrene pollution in the air (r = 0.64).


Assuntos
Pneumopatias/epidemiologia , Pneumopatias/microbiologia , Infecções por Mycobacterium não Tuberculosas/epidemiologia , Micobactérias não Tuberculosas , Criança , Pré-Escolar , República Tcheca/epidemiologia , Meio Ambiente , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Fatores Socioeconômicos
11.
J Microbiol Methods ; 55(1): 11-27, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14499991

RESUMO

A standardised method for PvuII-PstI-IS901 restriction fragment length polymorphism (RFLP) typing was developed and evaluated against 173 isolates of Mycobacterium avium subsp. avium and M. avium subsp. silvaticum originating from birds (N=46) and their aviaries (N=5), pigs (N=85), cattle (N=18), reference serotype strains (N=9), humans (N=7), a horse (N=1), a nutria (N=1), and strain M. avium subsp. avium ST 18 (formerly M. avium subsp. paratuberculosis ST 18). PvuII-IS1245 RFLP typing was also performed on all isolates. DNA was digested in parallel by restriction endonucleases PvuII or PstI and hybridised to standard probes prepared by PCR. DNA fingerprints were scanned by CCD camera and analysed by the Gel Compar (Applied Maths, Version 4.1, Kortrijk, Belgium) software using a standard isolate control profile. A total of 52 PvuII-PstI RFLP profiles was described including 25 PvuII RFLP profiles designated A to Y and 25 PstI RFLP profiles designated A1-L3. Profiles were found to be stable in vivo and in vitro after multiple subcultures. High IS901 copy number was associated with a "bird" PvuII-IS1245 RFLP profile and low IS901 copy number with M. avium subsp. avium isolates from humans and the nutria. A virulence assay of 100 IS901-positive isolates using intramuscular infections of pullets showed 83 isolates differentiated into 32 RFLP types to be virulent and 17 isolates differentiated into 12 RFLP types as nonvirulent. Attenuation of virulence for pullets could be attributed to either multiple in vitro subculture, polyclonal infection or human passage and was not related to IS901 or IS1245 profiles.


Assuntos
Técnicas de Tipagem Bacteriana/métodos , Aves/microbiologia , Elementos de DNA Transponíveis , Mycobacterium avium/classificação , Polimorfismo de Fragmento de Restrição , Animais , Humanos , Mycobacterium avium/patogenicidade , Virulência
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA