Streptomyces are of great interest in the pharmaceutical industry as they produce a plethora of secondary metabolites that act as antibacterial and antifungal agents. They may thrive on their own in the soil, or associate with other organisms, such as plants or invertebrates. Some soil-derived strains exhibit hemolytic properties when cultivated on blood agar, raising the question of whether hemolysis could be a virulence factor of the bacteria. In this work we examined hemolytic compound production in 23 β-hemolytic Streptomyces isolates; of these 12 were soil-derived, 10 were arthropod-associated, and 1 was plant-associated. An additional human-associated S. sp. TR1341 served as a control. Mass spectrometry analysis suggested synthesis of polyene molecules responsible for the hemolysis: candicidins, filipins, strevertene A, tetrafungin, and tetrin A, as well as four novel polyene compounds (denoted here as polyene A, B, C, and D) in individual liquid cultures or paired co-cultures. The non-polyene antifungal compounds actiphenol and surugamide A were also identified. The findings indicate that the ability of Streptomyces to produce cytolytic compounds (here manifested by hemolysis on blood agar) is an intrinsic feature of the bacteria in the soil environment and could even serve as a virulence factor when colonizing available host organisms. Additionally, a literature review of polyenes and non-polyene hemolytic metabolites produced by Streptomyces is presented.
Závěrečná zpráva o řešení grantu Agentury pro zdravotnický výzkum MZ ČR
Nestr.
Effective search for producers of novel, pharmaceutically attractive natural compounds requires application of new screening techniques using genomic data. Growing information on the genetics of biosynthesis of natural compounds and their structural components, brings the possibility to use newly characterized enzymatic systems as markers in genetic screening of potential producers of structuraly and functionaly unique active metabolites, which may find it application as novel antibiotics, immunomodulators and cancerostatics. Two model enzymes of actinomycetes, the cyclizing aminolevulinate synthase and a novel type of type II polyketides synthase specific for short linear polyketide chains, will be employed in the project.
Efektivní vyhledávání producentů nových, farmaceuticky atraktivních, přírodních látek vyžaduje uplatnění nových skríningových technik s využitím genomových informací. Rostoucí informace o genetice biosyntézy přírodních látek a jejich strukturních komponent umožňuje využít nově charakterizované enzymové systémy jako markery při genetickém skríningu potenciálních producentů strukturně a funkčně unikátních aktivních látek, které se mohou uplatnit jako nová antibiotika, imunomodulátory a kancerostatika. V projektu budou takto využity dva modelové enzymy aktinomycet, cyklizující aminolevulinátsyntáza a nový typ polyketidsyntázy specifický pro krátké lineární polyketidy.
- MeSH
- Actinomycetaceae izolace a purifikace MeSH
- antibakteriální látky MeSH
- biologické markery analýza MeSH
- biosyntetické dráhy MeSH
- enzymy MeSH
- genetické testování metody MeSH
- imunologické faktory MeSH
- lidé MeSH
- objevování léků metody MeSH
- Check Tag
- lidé MeSH
- Konspekt
- Patologie. Klinická medicína
- NLK Obory
- biochemie
- farmacie a farmakologie
- NLK Publikační typ
- závěrečné zprávy o řešení grantu AZV MZ ČR
(1) Background: Manumycins are small actinomycete polyketides with prominent cancerostatic and immunosuppressive activities via inhibition of various eukaryotic enzymes. Their overall activity towards human cells depends on the structural variability of both their polyketide chains, mainly the upper one. In our genetic screening project to find novel producers of anti-inflammatory manumycins, the strain Saccharothrix espanaensis DSM44229 was identified as containing a novel manumycin-type biosynthetic gene cluster (BGC). (2) Methods: The biosynthetic genes appeared to be silent under all assayed laboratory conditions. Several techniques were used to activate the BGC, including: (i) heterologous expression in various hosts, (ii) overexpression of putative pathway-specific regulatory genes, and (iii) overexpression of a bottleneck cyclizing aminolevulinate synthase gene in both natural and heterologous producers. (3) Results: Multiple novel manumycin-type compounds were produced at various levels by genetically-modified strains, sharing a tetraene lower chain structure with a colabomycin subgroup of manumycins, but possessing much shorter and saturated upper chains. (4) Conclusions: A cryptic manumycin-type BGC was successfully activated by genetic means to gain production of novel manumycin-type compounds for future comparative activity assays. Heterologously produced compounds were identical to those found after final activation of the BGC in the original strain, proving the intactness of the cloned BGC.
- Publikační typ
- časopisecké články MeSH
Streptomycetes, typical soil dwellers, can be detected as common colonizers of human bodies, especially the skin, the respiratory tract, the guts and the genital tract using molecular techniques. However, their clinical manifestations and isolations are rare. Recently they were discussed as possible "coaches" of the human immune system in connection with certain immune disorders and cancer. This work aimed for the characterization and evaluation of genetic adaptations of a human-associated strain Streptomyces sp. TR1341. The strain was isolated from sputum of a senior male patient with a history of lung and kidney TB, recurrent respiratory infections and COPD. It manifested remarkably broad biological activities (antibacterial, antifungal, beta-hemolytic, etc.). We found that, by producing specific secondary metabolites, it is able to modulate host immune responses and the niche itself, which increase its chances for long-term survival in the human tissue. The work shows possible adaptations or predispositions of formerly soil microorganism to survive in human tissue successfully. The strain produces two structural groups of cytotoxic compounds: 28-carbon cytolytic polyenes of the filipin type and actinomycin X2. Additionally, we summarize and present data about streptomycete-related human infections known so far.
- Publikační typ
- časopisecké články MeSH
Current treatment of chronic diseases includes, among others, application of cytokines, monoclonal antibodies, cellular therapies, and immunostimulants. As all the underlying mechanisms of a particular diseases are not always fully clarified, treatment can be inefficient and associated with various, sometimes serious, side effects. Small secondary metabolites produced by various microbes represent an attractive alternative as future anti-inflammatory drug leads. Compared to current drugs, they are cheaper, can often be administered orally, but still can keep a high target-specificity. Some compounds produced by actinomycetes or fungi have already been used as immunomodulators-tacrolimus, sirolimus, and cyclosporine. This work documents strong anti-inflammatory features of another secondary metabolite of streptomycetes-manumycin-type polyketides. We compared the effect of four related compounds: manumycin A, manumycin B, asukamycin, and colabomycin E on activation and survival of human monocyte/macrophage cell line THP-1. The anti-cancer effect of manucycine A has been demonstrated; the immunomodulatory capacities of manumycin A are obvious when using micromolar concentrations. The application of all four compounds in 0.25-5 μM concentrations leads to efficient, concentration-dependent inhibition of IL-1β and TNF expression in THP-1 upon LPS stimulation, while the three latter compounds show a significantly lower pro-apoptotic effect than manumycin A. We have demonstrated the anti-inflammatory capacity of selected manumycin-type polyketides.
- Publikační typ
- časopisecké články MeSH
1. elektronické vydání 1 online zdroj (324 stran)
Myšlení, ať chce či nechce, odpovídá své době. Po tragické katastrofě holokaustu je platnost této skutečnosti ještě očividnější - a možná i proto jsou knihy poválečné filosofie obtížně srozumitelné. Odpovídají na traumatizující zkušenost, a to znamená: filosofie se ujímá odpovědnosti s vědomím, že má-li být filosofie možná i v druhé polovině 20. století a dále, musí přepsat svou tradici a radikální proměnou musí projít i její diskurs. Je to nezbytné, má-li být schopna vydat své svědectví o této době. Filosofie en noir je záznamem této proměny. Dotisk prvního vydání
1. elektronické vydání 1 online zdroj (382 stran)
Myšlení, ať chce či nechce, odpovídá své době. Po tragické katastrofě holokaustu je platnost této skutečnosti ještě očividnější - a možná i proto jsou knihy poválečné filosofie obtížně srozumitelné. Odpovídají na traumatizující zkušenost, a to znamená: filosofie se ujímá odpovědnosti s vědomím, že má-li být filosofie možná i v druhé polovině 20. století a dále, musí přepsat svou tradici a radikální proměnou musí projít i její diskurs. Je to nezbytné, má-li být schopna vydat své svědectví o této době. Filosofie en noir je záznamem této proměny.Anglický překlad úspěšné knihy vydané v roce 2018.
Macrolide antibiotics such as azithromycin or clarithromycin are known to have potent anti-inflammatory and immunomodulatory effects but these properties cannot be widely used due to a risk of bacterial resistance. We studied another polyketide antibiotic, structurally related manumycin A known as a streptomycete derived farnesyltransferase inhibitor with limited antibacterial effects, with respect to its potential regulation of mRNA expression of several genes associated with proinflammatory responses. Downregulation of mRNA for IL-6, TLR-8, IL-1 beta and IL-10 was found in THP-1 cells after 4h stimulation with TNF alpha in the presence of manumycin A and downregulated TLR-8 and EGR-1 genes were observed after 8h. Among the genes upregulated in response to manumycin were HMOX-1, TNFRSF10A, IL-1R1, TICAM2, NLRP12 after 4h and only IL-1R1 after 8h. Furthermore, manumycin A was found to inhibit IL-1beta, IL-6, and IL-8 production in TNF alpha stimulated THP-1 cells and peripheral blood monocytes in a dose dependent manner (0.25-1 μM of manumycin A) without affecting cell viability. Cell viability of blood monocytes decreased by about 30% at manumycin A doses of 2-5 μM. Manumycin A also inhibited IL-18 release from THP-1 cells, while in cultures of blood monocytes, this cytokine was not detectable. That manumycin A mediated downregulation of proinflammatory genes in human monocytes confirmed by a measurement of cytokine levels in culture supernatants, together with a very limited effect on cell viability, might suggest potential anti-inflammatory properties of this polyketide antibiotic.
- MeSH
- antibakteriální látky farmakologie MeSH
- antiflogistika farmakologie MeSH
- buněčné linie MeSH
- cytokiny genetika metabolismus MeSH
- imunomodulace MeSH
- lidé MeSH
- messenger RNA genetika MeSH
- monocyty účinky léků imunologie MeSH
- polyeny farmakologie MeSH
- polynenasycené alkamidy farmakologie MeSH
- protein 1 časné růstové odpovědi genetika metabolismus MeSH
- receptory interleukinu-1 genetika metabolismus MeSH
- regulace genové exprese účinky léků MeSH
- TNF-alfa metabolismus MeSH
- toll-like receptor 8 genetika metabolismus MeSH
- zánět farmakoterapie imunologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- alkaloidy biosyntéza MeSH
- Bacteria genetika metabolismus MeSH
- biosyntéza peptidů nezávislá na nukleových kyselinách MeSH
- databáze genetické MeSH
- genetické markery MeSH
- houby genetika metabolismus MeSH
- metagenom MeSH
- mezinárodní spolupráce MeSH
- multigenová rodina * MeSH
- peptidy metabolismus MeSH
- polyketidy metabolismus MeSH
- polysacharidy biosyntéza MeSH
- proteosyntéza * MeSH
- rostliny genetika metabolismus MeSH
- terminologie jako téma MeSH
- terpeny metabolismus MeSH
- výpočetní biologie normy MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
Colabomycin E is a new member of the manumycin-type metabolites produced by the strain Streptomyces aureus SOK1/5-04 and identified by genetic screening from a library of streptomycete strains. The structures of colabomycin E and accompanying congeners were resolved. The entire biosynthetic gene cluster was cloned and expressed in Streptomyces lividans. Bioinformatic analysis and mutagenic studies identified components of the biosynthetic pathway that are involved in the formation of both polyketide chains. Recombinant polyketide synthases (PKSs) assembled from the components of colabomycin E and asukamycin biosynthetic routes catalyzing the biosynthesis of "lower" carbon chains were constructed and expressed in S. aureus SOK1/5-04 ΔcolC11-14 deletion mutant. Analysis of the metabolites produced by recombinant strains provided evidence that in both biosynthetic pathways the length of the lower carbon chain is controlled by an unusual chain-length factor supporting biosynthesis either of a triketide in asukamycin or of a tetraketide in colabomycin E. Biological activity assays indicated that colabomycin E significantly inhibited IL-1β release from THP-1 cells and might thus potentially act as an anti-inflammatory agent.
- MeSH
- antiflogistika chemie metabolismus farmakologie MeSH
- bicyklické sloučeniny heterocyklické chemie metabolismus farmakologie MeSH
- buněčné linie MeSH
- interleukin-1beta sekrece MeSH
- lidé MeSH
- molekulární struktura MeSH
- polynenasycené alkamidy chemie metabolismus farmakologie MeSH
- Streptomyces chemie metabolismus MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
