imagine (Institute of molecular genetics and genetic engineering)
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Lactococcus lactis and Lactobacillus salivarius differently modulate early immunological response of Wistar rats co-administered with Listeria monocytogenes
No full textIn the light of the increasing resistance of bacterial pathogens to antibiotics, one of the main global strategies in applied science is development of alternative treatments, which would be safe both for the host and from the environmental perspective. Accordingly, the aim of this study was to test whether two lactic acid bacteria (LAB) strains, Lactococcus lactis BGBU1-4 and Lactobacillus salivarius BGHO1, could be applied as safe supplements for Listeria infection. Two major research objectives were set: to compare the effects of BGBU1-4 and BGHO1 on early immune response in gut tissue of Wistar rats co-administered with Listeria monocytogenes ATCC19111 and next, to test how this applies to their usage as therapeutics in acute ATCC19111 infection. Intestinal villi (IV), Peyer's patches (PP) and mesenteric lymph nodes (MLN) were used for the analysis. The results showed that BGHO1 increased the mRNA expression of innate immune markers CD14, interleukin (IL)-1 beta and tumour necrosis factor (TNF)-alpha in PP and IV, and, in parallel, caused a decrease of listeriolysin O (LLO) mRNA expression in same tissues. In MLN of BGHO1 treated rats, LLO expression was increased, along with an increase of the expression of OX-62 mRNA and CD69, pointing to the activation of adaptive immunity. On the other hand, in BGBU1-4 treated rats, there was no reduction of LLO mRNA expression and no induction of innate immunity markers in intestinal tissue. Additionally, CD14 and IL-1 beta, as well as LLO, but not OX-62 mRNA and CD69 expression, were elevated in MLN of BGBU1-4 treated rats. However, when applied therapeutically, both, BGBU1-4 and BGHO1, lowered Listeria count in spleens of infected rats. Our results not only reveal the potential of LAB to ameliorate Listeria infections, but suggest different immunological effects of two different LAB strains, both of which could be effective in Listeria elimination
Effect of GSK690693 and AZD2014, Akt/mTOR pathway inhibitors, on the development of the zebrafish (Danio rerio) embryos
No full textMononuclear gold(III) complexes with phenanthroline ligands as efficient inhibitors of angiogenesis: A comparative study with auranofin and sunitinib
No full textGold(III) complexes with 1,7- and 4,7-phenanthroline ligands, [AuCl3(1,7-phen-kappa N7)] (1) and [AuCl3(4,7-phen-kappa N4)] (2) were synthesized and structurally characterized by spectroscopic (NMR, IR and UV-vis) and single crystal X-ray diffraction techniques. In these complexes, 1,7- and 4,7-phenanthrolines are monodentatedly coordinated to the Au(III) ion through the N7 and N4 nitrogen atoms, respectively. In comparison to the clinically relevant anti-angiogenic compounds auranofin and sunitinib, gold(III)-phenanthroline complexes showed from 1.5- to 20-fold higher anti-angiogenic potential, and 13- and 118-fold lower toxicity. Among the tested compounds, complex 1 was the most potent and may be an excellent anti-angiogenic drug candidate, since it showed strong anti-angiogenic activity in zebrafish embryos achieving IC50 value (concentration resulting in an anti-angiogenic phenotype at 50% of embryos) of 2.89 mu M, while had low toxicity with LC50 value (the concentration inducing the lethal effect of 50% embryos) of 128 mu M. Molecular docking study revealed that both complexes and ligands could suppress angiogenesis targeting the multiple major regulators of angiogenesis, such as the vascular endothelial growth factor receptor (VEGFR-2), the matrix metalloproteases (MMP-2 and MMP-9), and thioredoxin reductase (TrxR1), where the complexes showed higher binding affinity in comparison to ligands, and particularly to auranofin, but comparable to sunitinib, an anti-angiogenic drug of clinical relevance.Peer-reviewed manuscript: [https://imagine.imgge.bg.ac.rs/handle/123456789/1756
Copper(II) complexes with different diamines as inhibitors of bacterial quorum sensing activity
Get PDFThree copper(II) complexes, trans-[Cu(1,3-pd)(2)Cl-2]center dot H2O (Cu1; 1,3-pd is 1,3-propanediamine), trans-[Cu(2,2-diMe-1,3-pd)(2)Cl-2] (Cu2; 2,2-diMe-1,3-pd is 2,2-dimethyl-1,3-propanediamine) and trans-[Cu(1,3-pnd)(2)Cl-2]center dot H2O (Cu3; 1,3-pnd is (+/-)-1,3-pentanediamine), were synthesized and structurally characterized by elemental microanalyses, IR, electronic absorption and reflectance spectroscopy and molar conductivity measurements. The antimicrobial efficiency of the complexes against four clinically relevant microorganisms and their antiproliferative effect on the normal human lung fibroblast cell line MRC-5 were evaluated. Since in many bacteria, pathogenicity is regulated by an intercellular communication process called quorum sensing (QS), the effect of the copper(II) complexes Cu1-3 on bacterial QS was examined. The obtained results showed that these complexes inhibited violacein production in Chromobacterium violaceum CV026, indicating their anti-QS activity via the homoserine lactone (HSL) pathway. Two biosensor strains were used to determine which pathway, C4-HSL (N-butanoylhomoserine lactone) or 3OC12-HSL (N-(3-oxododecanoyl) homoserine lactone), was affected by the copper(II) complexes. The biological activities of the copper(II) complexes were compared with those for the nickel(II) complexes of the general formula trans-[Ni(L)(2)(H2O)(2)]Cl-2 (L = 1,3-pd, 2,2-diMe-1,3-pd and 1,3-pnd)
Probiotics or pro-healers: the role of beneficial bacteria in tissue repair
Get PDFProbiotics are beneficial microorganisms, known to exert numerous positive effects on human health, primarily in the battle against pathogens. Probiotics have been associated with improved healing of intestinal ulcers, and healing of infected cutaneous wounds. This article reviews the latest findings on probiotics related to their pro-healing properties on gut epithelium and skin. Proven mechanisms by which probiotic bacteria exert their beneficial effects include direct killing of pathogens, competitive displacement of pathogenic bacteria, reinforcement of epithelial barrier, induction of fibroblasts, and epithelial cells' migration and function. Beneficial immunomodulatory effects of probiotics relate to modulation and activation of intraepithelial lymphocytes, natural killer cells, and macrophages through induced production of cytokines. Systemic effects of beneficial bacteria and link between gut microbiota, immune system, and cutaneous health through gut-brain-skin axes are discussed as well. In light of growing antibiotic resistance of pathogens, antibiotic use is becoming less effective in treating cutaneous and systemic infections. This review points to a new perspective and therapeutic potential of beneficial probiotic species as a safe alternative approach for treatment of patients affected by wound healing disorders and cutaneous infections.This is the peer reviewed version of the paper: Lukic, J., Chen, V., Strahinic, I., Begovic, J., Lev-Tov, H., Davis, S. C., Tomic-Canic, M., & Pastar, I. (2017). Probiotics or pro-healers: The role of beneficial bacteria in tissue repair. Wound Repair and Regeneration, 25(6), 912–922. [https://doi.org/10.1111/wrr.12607
The Effect of FII c.1787G gt A (Prothrombin Belgrade) Mutation on Prothrombin Gene Expression In Vitro
No full textThe FII c. 1787G gt A (prothrombin Belgrade) is a novel prothrombotic mutation which leads to impaired inhibition of thrombin by antithrombin (antithrombin resistance). So far, the mechanism of this variant has not been fully elucidated. To investigate the effect of FII c. 1787G gt A mutation on the prothrombin gene expression, its functional analysis was performed in vitro. By Real-Time PCR, expression levels of FII gene variants were evaluated in Cos-7 cells transiently transfected with c. 1787G (wild-type) and c. 1787A prothrombin expression vectors, with no differences observed. The relative quantification of prothrombin protein amounts was accomplished by Western blot analysis, also with no differences observed. Therefore, the mechanism of FII c. 1787G gt A mutation does not alter prothrombin expression profile
Hemodynamic effects of HPMA copolymer based doxorubicin conjugate: A randomized controlled and comparative spectral study in conscious rats
Get PDFConjugation of Doxorubicin (DOX) to N-(2-hydroxypropyl) methylacrylamide copolymer (HPMA) has significantly reduced the DOX-associated cardiotoxicity. However, the reports on the impact of HPMA-DOX conjugates on the cardiovascular system such as blood pressure (BP) and heart rate (HR) were in restrained animals using tail cuff and/or other methods that lacked the resolution and sensitivity. Herein, we employed radiotelemetric-spectral-echocardiography approach to further understand the in vivo cardiovascular hemodynamics and variability post administration of free DOX and HPMA-DOX. Rats implanted with radio-telemetry device were administered intravenously with DOX (5mg/kg), HPMA-DOX (5mg DOX equivalent/kg) and HPMA copolymer and subjected to continuous cardiovascular monitoring and echocardiography for 140 days. We found that DOX-treated rats had ruffled fur, reduced body weight (BW) and a low survival rate. Although BP and HR were normal, spectral analysis indicated that their BP and HR variabilities were reduced. All rats exhibited typical signs of cardiotoxicity at histopathology. In contrast, HPMA-DOX rats gained weight over time and survived. Although BP, HR and related variabilities were unaffected, the left ventricular end diastolic volume (EDV) of these rats, as well as of the HPMA copolymer-treated rats, was found increased at the end of observation period. Additionally, HPMA copolymer caused microscopic injury of the heart tissue. All of these suggest the necessity of caution when employing HPMA as carrier for prolonged drug delivery. The current study also indicates the potential of radiotelemetric-spectral-echocardiography approach for improved preclinical cardiovascular risk assessment of polymer-drug conjugate and other nano-sized-drug constructs
Antioxidative capacity and binding affinity of the complex of green tea catechin and beta-lactoglobulin glycated by the Maillard reaction
No full textMajor green tea catechin, epigallocatechin-3-gallate (EGCG), binds non-covalently to numerous dietary proteins, including beta-lactoglobulin of cow's milk. The effects of glycation of proteins via Maillard reaction on the binding capacity for polyphenols and the antiradical properties of the formed complexes have not been studied previously. Binding constant of BLG glycated by milk sugar lactose to EGCG was measured by the method of fluorophore quenching. Binding of EGCG was confirmed by CD and FTIR. The antioxidative properties of the complexes were examined by measuring ABTS radical scavenging capacity, superoxide anion scavenging capacity and total reducing power assay. Glycation of BLG does not significantly influence the binding constant of EGCG for the protein. Conformational changes were observed for both native and glycated BLG upon complexation with EGCG. Masking effect of polyphenol complexation on the antioxidative potential of the protein was of the similar degree for both glycated BLG and native BLG
Supplementary data for article: Aleksić, I.; Šegan, S.; Andrić, F.; Zlatović, M.; Moric, I.; Opsenica, D. M.; Senerovic, L. Long-Chain 4-Aminoquinolines as Quorum Sensing Inhibitors in Serratia Marcescens and Pseudomonas Aeruginosa. ACS Chemical Biology 2017, 12 (5), 1425–1434. https://doi.org/10.1021/acschembio.6b01149
Get PDFSupporting information for: [https://doi.org/10.1021/acschembio.6b01149]Related to published version: [https://imagine.imgge.bg.ac.rs/handle/123456789/1092]Related to accepted version: [https://imagine.imgge.bg.ac.rs/handle/123456789/2226
Functional and structural characterisation of 5 missense mutations of the phenylalanine hydroxylase
Get PDFPhenylketonuria (PKU) and hyperphenylalaninemia (HPA) are a group of genetic disorders predominantly caused by mutations in the phenylalanine hydroxylase (PAH) gene. To date, more than 950 variants have been identified, however the pathogenic mechanism of many variants remains unknown. In this study, in silico prediction and in vitro prokaryotic and eukaryotic expression systems were used to functionally characterise five PAH missense variants (p.F233I, p.R270I, p.F331S, p.S350Y, and p.L358F) previously identified in Slovak and Czech patients. p.F233I, p.R270I, and p.S350Y were classified as deleterious mutations since they showed no specific activity in functional assay and no response to chaperone co-expression. Protein levels of these PAH variants were very low when expressed in HepG2 cells, and only p.S350Y responded to BH4 precursor overload by significant increase in PAH monomer, probably due to reduced rate of protein degradation as the result of proper protein folding. Variants p.F331S and p.L358F exerted residual enzymatic activity in vitro. While the first can be classified as probably pathogenic due to its very low protein levels in HepG2 cells, the latter is considered to be mild mutation with protein levels of approximately 17.85% compared to wt PAH. Our findings contribute to better understanding of structure and function of PAH mutated enzymes and optimal treatment of PKU patients carrying these mutations using BH4 supplementation