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
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
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
- Publikační typ
- abstrakt z konference MeSH
AIMS: Production of minor asukamycin congeners and its new derivatives by combination of targeted genetic manipulations with specific precursor feeding in the producer of asukamycin, Streptomyces nodosus ssp. asukaensis. METHODS AND RESULTS: Structural variations of manumycins lie only in the diverse initiation of the 'upper' polyketide chain. Inactivation of the gene involved in the biosynthesis of cyclohexanecarboxylic acid (CHC) turned off the production of asukamycin in the mutant strain and allowed an increased production of other manumycins with the branched end of the upper chain. The ratio of produced metabolites was further affected by specific precursor feeding. Precursor-directed biosynthesis of a new asukamycin analogue (asukamycin I, 28%) with linear initiation of the upper chain was achieved by feeding norleucine to the mutant strain. Another asukamycin analogue with the unbranched upper chain (asukamycin H, 14%) was formed by the CHC-deficient strain expressing a heterologous gene putatively involved in the formation of the n-butyryl-CoA starter unit of manumycin A. CONCLUSIONS: Combination of the described techniques proved to be an efficient tool for the biosynthesis of minor or novel manumycins. SIGNIFICANCE AND IMPACT OF THE STUDY: Production of two novel asukamycin derivatives, asukamycins H and I, was achieved. Variations appeared in the upper polyketide chain, the major determinant of enzyme-inhibitory features of manumycins, affecting their cancerostatic or anti-inflammatory features.
- MeSH
- acylkoenzym A metabolismus MeSH
- aminokyseliny metabolismus MeSH
- antibakteriální látky biosyntéza MeSH
- genetické inženýrství MeSH
- inzerční mutageneze MeSH
- kultivační média MeSH
- kyseliny cyklohexankarboxylové metabolismus MeSH
- mutace MeSH
- polyeny metabolismus MeSH
- polynenasycené alkamidy metabolismus MeSH
- Streptomyces genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Human renal epithelial cells might play an important role during the allograft rejection by producing chemokines in response to proinflammatory cytokines such as tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta produced by endothelial and epithelial cells early after transplantation. The production of chemokines allows inflammatory cells to be drawn into the kidney graft and therefore plays a critical role in the pathophysiologic processes that lead to the rejection of renal transplant. In this process, two chemokine superfamilies, the CC and the CXC chemokines, are the most important. The CC chemokines target mainly monocytes and T lymphocytes, while most of the CXC chemokines attract neutrophils. We showed in our study that in vitro, in unstimulated cells, basal mRNA expression of CXC chemokines (Groalpha, Grobeta, Grogamma, ENA-78 and GCP-2, IL-8) that attract neutrophils was detectable and expression of these genes and chemokine release were increased in TNF-alpha- and IL-1beta-induced renal epithelial cells. Most of the CC chemokines [monocyte chemotactic protein-1 (MCP-1), macrophage Inflammatory protein 1 beta (MIP-1beta), regulated upon activation, normal T cell expressed and secreted (RANTES) and macrophage inflammatory protein (MIP-3alpha)] showed detectable mRNA expression only after stimulation with proinflammatory cytokines and not in control cells. TNF-alpha seems to induce preferably the expression of RANTES, MCP-1, interferon-inducible protein (IP-10) and Interferon-Inducible T-cell Alpha Chemoattractant (I-TAC), while IL-1beta induces mainly IL-8 and epithelial neutrophil-activating peptide 78 (ENA-78).
- MeSH
- chemokiny CC biosyntéza genetika imunologie MeSH
- chemokiny CXC biosyntéza genetika imunologie MeSH
- cytokiny biosyntéza farmakologie imunologie MeSH
- ELISA MeSH
- epitelové buňky imunologie MeSH
- interleukin-1beta farmakologie imunologie MeSH
- interleukin-8 biosyntéza genetika imunologie MeSH
- ledviny imunologie MeSH
- lidé MeSH
- lymfotoxin-alfa farmakologie imunologie MeSH
- messenger RNA biosyntéza genetika MeSH
- nádorové buněčné linie MeSH
- polymerázová řetězová reakce s reverzní transkripcí MeSH
- rejekce štěpu genetika imunologie MeSH
- sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů MeSH
- stanovení celkové genové exprese MeSH
- transplantace ledvin imunologie MeSH
- upregulace MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
A review of the current knowledge of the styrene and styrene oxide metabolism in laboratory animals and humans. Styrene ranks among the most important monomers in the manufacture of plastics and styrene oxide is the main intermediate involved in its metabolism. Both chemicals exhibit adverse effects. Various analytical methods have been developed for assessing their concentrations in organisms. Determination of their protein adducts shows several advantages over their determination in urine or as DNA adducts due to their stability and easy availability. The protein adduct determination by a modified Edman degradation, Raney-nickel cleavage, alkaline hydrolysis and enzymatic hydrolysis is described. Styrene oxide adducts with various globin amino acids have been also studied by these methods. A modified Edman degradation has proved to be a most sensitive method, with a limit of detection of the order of pmol per g of globin.
Streptomyces caelestis DSM 40084 produces two osmolytes, viz. 2-O-(alpha-D-glucopyranosyl)-zeta-glyceric acid (GG) and trehalose. Both compounds were isolated and identified by nuclear magnetic resonance spectroscopy and mass spectrometry. A very sensitive regulation of the cell osmolytes was demonstrated in exponentially growing cultures. The intracellular levels of GG and trehalose increased 2x in response to a step change of medium osmolarity caused by 0.3% NaCl. 1H NMR analysis of the cell extracts did not confirm the presence of additional osmolytes. GG is a S. caelestis metabolite commonly released from the cells; its concentration reached 3 g/L during the cultivation in a yeast extract--(NH4)2SO4-glycerol medium. This is the first report on the occurrence of the ionic osmolyte GG in the genus Streptomyces and on its free excretion to the medium.
A new ribose trisaccharide, alpha-Ribf-(1-->2)-alpha-Ribf-(1-->3)-alpha-Ribf (1), was isolated together with 5-O-(alpha-mannosyl)-myo-inositol (2), 2-O-(alpha-mannosyl)-myo-inositol (3), trehalose (4), and d-ribulose (5) from a submerged cultivation of Streptomyces coelicolor A3(2). The structures of these compounds were elucidated by spectroscopic and chemical methods. Concentrations of these compounds in the medium were in the range from 0.04 (1) to 0.5 (4) mg/mL.
