Journal of Biological Research-Thessaloniki最新文献

Background: Glioblastomas are the most aggressive brain tumors with extremely poor prognosis despite advances in treatment techniques. MiR-10b is highly expressed in glioblastoma and regulates cell proliferation, migration and invasion. Here, we examined the role of MiR-10b on radiotherapy of glioblastomas.

Methods: MiR-10b mimic or anti-MiR-10b inhibitor was transfected in glioblastoma cells. WST-1 assay was used to examine the effect of MiR-10b on proliferation of transfected glioblastoma cells after radiation treatment. Apoptosis was examined by caspase 3/7 activity and TUNEL assay. The western blot was used to evaluate protein expression.

Results: Altered expression of MiR-10b changed the radiation-induced inhibitory effect on proliferation of glioblastoma cells with dose-dependent manner. MiR-10b decreased radiation-induced apoptosis in glioblastoma cells by activation of caspase 3/7 and inhibition Bcl-2 expression. MiR-10b enhances migration and invasion of glioblastoma cells in presence of radiation. In addition, MiR-10b decreased the sensitivity of glioblastoma cells to radiotherapy by activation of p-AKT expression.

Conclusions: MiR-10b might be a potential biomarker to predict radiotherapy response and prognosis in glioblastomas.

Background: Sheep's reproductive physiology in temperate latitudes (such as Greece), is characterized by seasonality and is also regulated by photoperiodic exposure. Melatonin is the key hormone involved in this regulation. However, the melatonin secretion and therefore the ewes reproductive activity underlies variation, proposed to be linked with the melatonin receptor subtype 1A (MNTR1A) gene structure. This study was designed to investigate the polymorphism of the MNTR1A gene in a local Greek sheep breed and to determine its potential association with reproductive seasonality.

Results: Two groups of farmed ewes, each consisted of 30 individuals, were chosen. Males were introduced in both groups in spring (April). The first group consisted of ewes that showed reproductive activity in spring (May), while the second of ewes that showed reproductive activity 3 months later, in summer. The PCR-RFLP methodology was carried out on a 824-bp DNA fragment of the MTNR1A exon 2 using the RsaI restriction endonuclease. The electrophoretic procedure revealed three genotypes, C/C, C/T and T/T. Specifically, 44 animals showed the C/C genotype (28 from the first group and 16 from the second), 14 the C/T genotype (2 from the first and 12 from the second) and 2 animals had the T/T genotype (both from the second group).

Conclusions: Statistical analysis indicated a positive correlation between genotype and reproductive seasonality, with C/C genotype playing a crucial role in out-of-season reproduction activity.

Background: Microalgae frequently grow in natural environment and long-term laboratory cultures in association with bacteria. Bacteria benefit the oxygen and extracellular substances generated by microalgae, and reimburse microalgae with carbon dioxide, vitamins and so on. Such synergistic relationship has aided in establishing an efficient microalga-bacterium co-culturing mode. Obviously, the mutually beneficial relationship can be strengthened with the increase of the densities of microalgae and bacteria. However, nearly all of the early co-cultures were performed under photoautotrophic conditions, thus both microalgae and bacteria were at relatively low densities. In this study, the feasibility of bacteria-microalgae co-cultured under mixotrophic conditions was studied.

Results: Firstly, bacteria mingled with xenic microalgae were isolated and identified based on their 16S rRNA gene sequence (16S rDNA hereafter). Then, the two most frequently found strains of Muricauda sp. were co-cultured with axenic microalga (Tetraselmis chuii, Cylindrotheca fusiformis and Nannochloropsis gaditana) in extra organic carbon containing medium. At the end of a co-culture period of 33 days, we found that the final cell density of T. chuii and C. fusiformis of various treatments was remarkably higher than that of controls (21.37-31.18 and 65.42-83.47 %, respectively); on the contrary, the growth of N. gaditana was markedly inhibited. During the co-culture of bacteria with C. fusiformis, the cell density of two strains of bacteria firstly decreased, then increased and maintained at a relatively steady level. However, the cell density of bacteria performed a sustaining downward trend when they were co-cultured with T. chuii and N. gaditana.

Conclusions: Our findings proved that microalgae-bacteria co-cultures under mixotrophic conditions are quite effective strategy for microalgal cultivation.

Background: Polysaccharides are the major active ingredients responsible for the bioactivities of Laminaria japonica. However, the effects of L. japonica polysaccharides (LJP) on exercise endurance and oxidative stress have never been investigated. Therefore, this study was conducted to investigate the effects of LJP on exercise endurance and oxidative stress in a forced swimming mouse model. The animals were divided into four groups, namely the control (C), LJP-75, LJP-150, and LJP-300 groups, which received physiological saline and 75, 150, and 300 mg kg(-1) LJP, respectively, by gavage once a day for 28 days. This was followed by a forced swimming test and measurements of various biochemical parameters.

Results: LJP increased swimming time to exhaustion, the liver and muscle glycogen content, and levels of superoxide dismutase, glutathione peroxidase, and catalase in the serum, liver, and muscle, which were accompanied by corresponding decreases in the malondialdehyde (MDA) content of the same tissues. Furthermore, decreases in blood lactic acid and serum myeloperoxidase (MPO) levels were observed.

Conclusion: LJP enhanced exercise endurance and protected mice against exhaustive exercise-induced oxidative stress.

Background: Nicotiana belongs to the Solanaceae family that includes important crops such as tomato, potato, eggplant, and pepper. Nicotiana species are of worldwide economic importance and are important model plants for scientific research. Here we present the comparative analysis of the transcriptomes of six wild diploid Nicotiana species. Wild relatives provide an excellent study system for the analysis of the genetic basis for various traits, especially disease resistance.

Results: Whole transcriptome sequencing (RNA-seq) was performed for leaves of six diploid Nicotiana species, i.e. Nicotiana glauca, Nicotiana noctiflora, Nicotiana cordifolia, Nicotiana knightiana, Nicotiana setchellii and Nicotiana tomentosiformis. For each species, 9.0-22.3 Gb high-quality clean data were generated, and 67,073-182,046 transcripts were assembled with lengths greater than 100 bp. Over 90 % of the ORFs in each species had significant similarity with proteins in the NCBI non-redundant protein sequence (NR) database. A total of 2491 homologs were identified and used to construct a phylogenetic tree from the respective transcriptomes in Nicotiana. Bioinformatic analysis identified resistance gene analogs, major transcription factor families, and alkaloid transporter genes linked to plant defense.

Conclusions: This is the first report on the leaf transcriptomes of six wild Nicotiana species by Illumina paired-end sequencing and de novo assembly without a reference genome. These sequence resources hopefully will provide an opportunity for identifying genes involved in plant defense and several important quality traits in wild Nicotiana and will accelerate functional genomic studies and genetic improvement efforts of Nicotiana or other important Solanaceae crops in the future.

Background: The regulation of methyl-beta-cyclodextrin (MBCD) on cryodamage on X- and Y-sperm during cryopreservation of semen was investigated. The semen was collected from ten healthy bulls of proven fertility by an artificial vagina. The bovine sperm treated with MBCD fresh solution (0, 1, 5, 10, and 20 mM). The sperms were evaluated for viability and acrosome damage using flow cytometry. Moreover, X- and Y-sperm in frozen-thawed bovine semen were sorted by flow cytometry after Hoechst 33342-dyed, and the viability and acrosome damage of sperms were analyzed.

Results: Sperm viability in frozen-thawed semen was decreased by MBCD (p < 0.05), also the acrosome damage of sperm was significantly increased (p < 0.05). Moreover, we sorted X- and Y-sperm from frozen-thawed bovine semen for observing the viability and acrosome damage on the separated X- and Y-sperm after MBCD treatment. Viability of X-sperm was significantly lower than that of Y-sperm (p < 0.05). Also, acrosome damage of X-sperm was significantly higher than Y-sperm (p < 0.05).

Conclusions: Methyl-beta-cyclodextrin enhances damage of sperm in frozen-thawed bovine semen, and X-sperm is more sensitive than Y-sperm in cell damage. These results demonstrate that MBCD can inhibit viability of spermatozoa in frozen-thawed bovine semen (for X-sperm, especially).

Background: The miR-17-5p was overexpressed in ovarian cancer cells, and those cells were treated with paclitaxel. The proliferation of ovarian cancer cells was assessed by MTT assay. The Caspase-Glo3/7 and TUNEL assay were used to examine the effect of miR-17-5p on paclitaxel-induced apoptosis in ovarian cancer cells. The migration and invasion of ovarian cancer cells were analyzed by BD matrigel assays. Western blot was performed to evaluate the expression of apoptotic proteins and epithelial-mesenchymal transition markers in ovarian cancer cells.

Results: The survival rate of ovarian cancer cells was increased after overexpression of miR-17-5p. The apoptosis decreased in miR-17-5p overexpressed ovarian cancer cells. Altered miR-17-5p expression affected migration and invasion of ovarian cancer cells. The overexpression of miR-17-5p altered the expression of EMT markers. miR-17-5p activates AKT by downregulation of PTEN in ovarian cancer cells.

Conclusion: Our results indicate that miR-17-5p might serve as potential molecular therapeutic target.

Background: Tobacco (Nicotiana tabacum L.) is an important model system, which has been widely used in plant physiological studies and it is particularly useful as a bioreactor. Despite its importance, only limited molecular marker resources are available for genome analysis, genetic mapping and breeding. Restriction-site associated DNA sequencing (RAD-seq) is a powerful new method for targeted sequencing across the genomes of many individuals. This approach has broad potential for genetic analysis through linkage mapping.

Results: We constructed a RAD library using genomic DNA from a BC1 backcross population. Sequencing of 196 individuals was performed on an Illumina HiSeq 2500. Two linkage maps were constructed, one with a reference genome and another, termed as de novo identification of single nucleotide polymorphism (SNP) by RAD-seq, without a reference genome. Overall, 4138 and 2162 SNP markers with a total length of 1944.74 and 2000.9 cM were mapped to 24 linkage groups in the genetic maps based on reference genome and without reference, respectively.

Conclusions: Using two different SNP discovery methods based on next generation RAD sequencing technology, we have respectively mapped 2162 and 4318 SNPs in our backcross population. This study gives an excellent example for high density linkage map construction, irrespective of genome sequence availability, and provides saturated information for downstream genetic investigations such as quantitative trait locus analyses or genomic selection (e.g. bioreactor suitable cultivars).

The present review attempted to emphasize on the microbiological quality of the commonly used cosmetics item by the majority of the Bangladeshi community. The abundance of contaminating microorganisms has been quantitatively discussed and the possible health risk has been focused upon usage of these items. Only a very few research efforts have been conducted on the cosmetic items in Bangladesh so far. The microbiological contamination aspects have been portrayed in this review using the information collected from a substantial number of cosmetic items which were earlier subjected to extensive microbiological and biochemical analyses. The prevalence of bacteria, fungi and the specific pathogenic microorganisms has been discussed based on research so far locally conducted on the finished items sold in markets, especially within the Dhaka metropolis. The laboratory scale experiments revealed the presence of enormous number of bacteria, actinomycetes and fungi within the commonly used cosmetics. Conversely, the anti-bacterial activity was noticed in some of the products which might be in favor of the user safety. The prevalence of pathogenic microorganisms in the cosmetic items certainly raises a substantial public health issue. The necessity of the routine microbiological testing of the commonly used cosmetic items as well as the legislative measures to mitigate the contamination problem is thus of great significance.

Data sharing, integration and annotation are essential to ensure the reproducibility of the analysis and interpretation of the experimental findings. Often these activities are perceived as a role that bioinformaticians and computer scientists have to take with no or little input from the experimental biologist. On the contrary, biological researchers, being the producers and often the end users of such data, have a big role in enabling biological data integration. The quality and usefulness of data integration depend on the existence and adoption of standards, shared formats, and mechanisms that are suitable for biological researchers to submit and annotate the data, so it can be easily searchable, conveniently linked and consequently used for further biological analysis and discovery. Here, we provide background on what is data integration from a computational science point of view, how it has been applied to biological research, which key aspects contributed to its success and future directions.