imagine (Institute of molecular genetics and genetic engineering)
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When disaster strikes: Reconstitution of population density by expansion of survivors
Get PDFMicroorganisms have an assortment of stress-response mechanisms that enable them to survive in the face of environmental stresses. However, with prolonged exposures to severe stresses adaptive stress responses ultimately fail, the affected populations may suffer a massive decline. Recovery of the population density in the aftermath of a massive death is a vital task. Our recent post-stress regrowth under starvation (RUS) studies prompted us to propose RUS as an adaptation for overcoming consequences of devastating environmental disturbances. RUS should be seen as an integral process having two major aspects: the stress-induced cellular auto-decomposition and the recycling of the released nutrients. Here, we summarized what is already known about RUS and suggest a number of questions that are key to understanding the molecular underpinnings of these two operations. We also interrogate the prospect that would conceptualize the auto-decomposition as a fitness-maximizing mechanism acting with the purpose of an expedient supply of nutrients. Two further things are of special note: given that some of the RUS-defective mutants are also impaired in DNA repair, RUS can serve as an important tool for uncovering new determinants operating, in some overlapping fashion, in the protection of genome integrity; also, RUS can serve as a new angle of approach that might, hopefully, assign roles to some of those (up to similar to 30%) of microbial genes that are of unknown function. More generally, understanding post-stress reconstitution and the underlying mechanisms is a necessary (complementing) part of any comprehensive picture of how microbes cope with very harsh environmental disturbances
Leaf Soluble Sugars and Free Amino Acids as Important Components of Abscisic Acid-Mediated Drought Response in Tomato
Get PDFWater deficit has a global impact on plant growth and crop yield. Climate changes are going to increase the intensity, duration and frequency of severe droughts, particularly in southern and south-eastern Europe, elevating the water scarcity issues. We aimed to assess the contribution of endogenous abscisic acid (ABA) in the protective mechanisms against water deficit, including stomatal conductance, relative water potential and the accumulation of osmoprotectants, as well as on growth parameters. To achieve that, we used a suitable model system, ABA-deficient tomato mutant, flacca and its parental line. Flacca mutant exhibited constitutively higher levels of soluble sugars (e.g., galactose, arabinose, sorbitol) and free amino acids (AAs) compared with the wild type (WT). Water deficit provoked the strong accumulation of proline in both genotypes, and total soluble sugars only in flacca. Upon re-watering, these osmolytes returned to the initial levels in both genotypes. Our results indicate that flacca compensated higher stomatal conductance with a higher constitutive level of free sugars and AAs. Additionally, we suggest that the accumulation of AAs, particularly proline and its precursors and specific branched-chain AAs in both, glucose and sucrose in flacca, and sorbitol in WT, could contribute to maintaining growth rate during water deficit and recovery in both tomato genotypes
Functional prediction and comparative population analysis of variants in genes for proteases and innate immunity related to SARS-CoV-2 infection
No full textNew coronavirus SARS-CoV-2 is capable to infect humans and cause a novel disease COVID-19. Aiming to understand a host genetic component of COVID-19, we focused on variants in genes encoding proteases and genes involved in innate immunity that could be important for susceptibility and resistance to SARS-CoV-2 infection. Analysis of sequence data of coding regions of FURIN, PLG, PRSS1, TMPRSS11a, MBL2 and OAS1 genes in 143 unrelated individuals from Serbian population identified 22 variants with potential functional effect. In silico analyses (PolyPhen-2, SIFT, MutPred2 and Swiss-Pdb Viewer) predicted that 10 variants could impact the structure and/or function of proteins. These protein-altering variants (p.Gly146Ser in FURIN; p.Arg261His and p.Ala494Val in PLG; p.Asn54Lys in PRSS1; p.Arg52Cys, p.Gly54Asp and p.Gly57Glu in MBL2; p.Arg47Gln, p.Ile99Val and p.Arg130His in OAS1) may have predictive value for inter-individual differences in the response to the SARS-CoV-2 infection. Next, we performed comparative population analysis for the same variants using extracted data from the 1000 Genomes project. Population genetic variability was assessed using delta MAF and Fst statistics. Our study pointed to 7 variants in PLG, TMPRSS11a, MBL2 and OAS1 genes with noticeable divergence in allelic frequencies between populations worldwide. Three of them, all in MBL2 gene, were predicted to be damaging, making them the most promising population-specific markers related to SARS-CoV-2 infection. Comparing allelic frequencies between Serbian and other populations, we found that the highest level of genetic divergence related to selected loci was observed with African, followed by East Asian, Central and South American and South Asian populations. When compared with European populations, the highest divergence was observed with Italian population. In conclusion, we identified 4 variants in genes encoding proteases (FURIN, PLG and PRSS1) and 6 in genes involved in the innate immunity (MBL2 and OAS1) that might be relevant for the host response to SARS-CoV-2 infection
Diversity of non-starter lactic acid bacteria in autochthonous dairy products from Western Balkan Countries - Technological and probiotic properties
No full textThe aim of this review was to summarize the data regarding diversity of non-starter lactic acid bacteria (NSLAB) isolated from various artisanal dairy products manufactured in Western Balkan Countries. The dairy products examined were manufactured from raw cow's, sheep's or goat's milk or mixed milk, in the traditional way without the addition of commercial starter cultures. Dairy products such as white brined cheese, fresh cheese, hard cheese, yogurt, sour cream and kajmak were sampled in the households of Serbia, Croatia, Slovenia, Bosnia and Herzegovina, Montenegro, and North Macedonia. It has been established that the diversity of lactic acid bacteria (LAB) from raw milk artisanal dairy products is extensive. In the reviewed literature, 28 LAB species and a large number of strains belonging to the Lactobacillus, Lactococcus, Enterococcus, Streptococcus, Pediococcus, Leuconostoc and Weissella genera were isolated from various dairy products. Over 3000 LAB strains were obtained and characterized for their technological and probiotic properties including: acidification and coagulation of milk, production of aromatic compounds, proteolytic activity, bacteriocins production and competitive exclusion of pathogens, production of exopolysaccharides, aggregation ability and immunomodulatory effect. Results show that many of the isolated NSLAB strains had one, two or more of the properties mentioned. The data presented emphasize the importance of artisanal products as a valuable source of NSLAB with unique technological and probiotic features important both as a base for scientific research as well as for designing novel starter cultures for functional dairy food.Peer-reviewed manuscript: [https://imagine.imgge.bg.ac.rs/handle/123456789/2816
Inhibition of IRE1 alpha RNase activity reduces NLRP3 inflammasome assembly and processing of pro-IL1 beta (vol 77, pg 568, 2019)
Get PDFGraphene quantum dots as singlet oxygen producer or radical quencher The matter of functionalization with urea/thiourea
No full textDue to their low cost and possible green synthesis, high stability and resistance to photobleaching, graphene quantum dots (GQDs) can be considered as one of the class of carbon nanomaterials which may have great potential as an agent for photosensitized oxygen activation. In such a way, GQDs can be used as a theranostic agent in photodynamic therapy. In this work pristine GQDs, GQDs irradiated with gamma rays and GQDs doped with N and N, S atoms are produced using a simple, green approach. By using different techniques (AFM, HRTEM, SEM-EDS, FTIR, XRD, PL and UV-Vis) we investigated structural and optical properties of the new types of GQDs. We showed that GQDs functionalized with thiourea (GQDs-TU) completely lost the ability to produce singlet oxygen (O-1(2)) upon photoexcitation while functionalization with urea (GQDs-U) improves the capability of GQDs to produce O-1(2) upon the same conditions. Thus, presented GQDs modification with urea seems like a promising approach for the production of the efficient photosensitizer. On the opposite, GQDs-TU are efficient . OH quencher. Due to high singlet oxygen production and low cytotoxicity below 100 mu g/mL against HeLa cells, GQDs-U is a good candidate as an agent in photodynamic therapy at this concentration
The Analysis of Fecal Microbiota and Insulin Production in Diabetic Rats After Oral Administration of Probiotic Lactobacillus Paraplantarum BGCG11
No full textObjective Our previous studies with Lactobacillus paraplantarum BGCG11 probiotictreatment of diabetic rats showed decreased hyperglycemia and ameliorating effect on diabetes-associated damage of liver and kidneys. Hence, the aim of this study was to reveal the effects of BGCG11 probiotic on gut microbiota composition and monitoring the insulin production in pancreatic islets in diabetic rats. Methods Experiments were performed on albino Wistar rats divided into four groups: ND – non-diabetic control, D – streptozotocin (STZ) induced diabetes; P/D/P – BGCG11 pretreatment; D/P – BGCG11 treatment. The rats were orally administered with BGCG11, one week before (P/D/P) and after the STZ injection, for four weeks (P/D/P and D/P). Total DNA was isolated from all fecal samples and rDNA amplicons were analyzed by DGGE and 16S rDNA genes sequencing. For immunohistochemical analysis, slides were stained with anti-insulin antibody and secondary antibody coupled with horseradish peroxidase. Results The results revealed the higher diversity of gut microbiota in D/P group comparing to D group, as well as the higher prevalence of Flintibacter butyricus (the major butyric producer), Acetatifactor muris (present in obese mouse) and Eisenbergiella massiliensis (found in obese woman), while the lipolytic bacterium Aestuariispira insulae was more prevalent in diabetic rats. In both, P/D/P and D/P group, increased number of positive immunoreactions of β-cells for anti-insulin antibodies was displayed in compare to D group with islet atrophy. Conclusions The results of this study suggest that the positive effect of BGCG11 on STZ-induced diabetes in rats could be annotated to its protective role on the integrity of fecal microbiota.10th Probiotics, prebiotics and new foods, nutraceuticals and botanicals for nutrition and human and microbiota health and 1st Science; 2019 Sep 8-10; Rome, Italy. Wolters Kluwer Health; 2020. p. 103. (Journal of Clinical Gastroenterology; Vol. 54; Suppl. 1
The influence of Wilms' tumor 1 gene expression level on prognosis and risk stratification of acute promyelocytic leukemia patients
No full textIntroduction Patients with acute promyelocytic leukemia (APL) are characterized by the highest expression of Wilms' tumor 1 (WT1) gene compared with other subtypes of acute myeloid leukemia, and yet this molecular marker is almost never used for risk stratification and in therapy response monitoring. Methods Quantitative assessment of Wilms' tumor 1 (WT1) gene transcripts was performed using real-time PCR method. The bone marrow samples were collected at the time of diagnosis for 47 APL patients, and for 31/47 patients during follow-up/relapse of the disease (129 samples in total). We examined how this molecular marker can be used for prognosis and minimal residual disease (MRD) monitoring. Results Increased WT1 expression was found in 34% of patients. WT1(high) status was an independent unfavorable factor for early death occurrence and was associated with shorter overall survival (OS). Assessment of log reduction value of WT1 expression in paired diagnosis/complete remission samples did not reveal its impact on relapse rate, disease-free survival, and OS. Also, measurement of WT1 expression level at different time points during therapy was not a reliable method for MRD monitoring. Conclusion Increased expression of WT1 gene detected in high proportion of APL patients could be considered as a marker for more precise risk stratification models in an attempt to further improve treatment and outcome of APL patients
Development of an efficient biocatalytic system based on bacterial laccase for the oxidation of selected 1,4-dihydropyridines
No full textBiocatalytic oxidations mediated by laccases are gaining importance due to their versatility and beneficial environmental effects. In this study, the oxidation of 1,4-dihydropyridines has been performed using three different types of bacterial laccase-based catalysts: purified laccase from Bacillus licheniformis ATCC 9945a (BliLacc), Escherichia coli whole cells expressing this laccase, and bacterial nanocellulose (BNC) supported BliLacc catalysts. The catalysts based on bacterial laccase were compared to the commercially available Trametes versicolor laccase (TvLacc). The oxidation product of 2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate was obtained within 7-24 h with good yields (70-99%) with all three biocatalysts. The substrate scope was examined with five additional 1,4-dihydropyridines, one of which was oxidized in high yield. Whole-cell biocatalyst was stable when stored for up to 1-month at 4 degrees C. In addition, evidence has been provided that multicopper oxidase CueO from the E. coli expression host contributed to the oxidation efficiency of the whole-cell biocatalyst. The immobilized whole-cell biocatalyst showed satisfactory activity and retained 37% of its original activity after three biotransformation cycles
The prothrombin Belgrade mutation causing antithrombin resistance does not affect fibrin clot formation
Get PDFProthrombin Belgrade mutation is a result of the c.1787G>T
mutation in the prothrombin gene, which leads to the substitution of
Arg596 by Gln. This mutation is located in the antithrombin binding site
and leads to the impaired inactivation of thrombin by antithrombin and
antithrombin resistance, resulting in a thrombotic phenotype. Previous
studies have shown the complex mechanism of this mutation, manifested with higher endogenous thrombin potential, lower prothrombin
activity with normal prothrombin levels in carriers’ plasma.PB223