Elucidation of molecular and hormonal background of early growth cessation and endodormancy induction in two contrasting Populus hybrid cultivars.

BACKGROUND: Over the life cycle of perennial trees, the dormant state enables the avoidance of abiotic stress conditions. The growth cycle can be partitioned into induction, maintenance and release and is controlled by complex interactions between many endogenous and environmental factors. While phytohormones have long been linked with dormancy, there is increasing evidence of regulation by DAM and CBF genes. To reveal whether the expression kinetics of CBFs and their target PtDAM1 is related to growth cessation and endodormancy induction in Populus, two hybrid poplar cultivars were studied which had known differential responses to dormancy inducing conditions. RESULTS: Growth cessation, dormancy status and expression of six PtCBFs and PtDAM1 were analyzed. The 'Okanese' hybrid cultivar ceased growth rapidly, was able to reach endodormancy, and exhibited a significant increase of several PtCBF transcripts in the buds on the 10th day. The 'Walker' cultivar had delayed growth cessation, was unable to enter endodormancy, and showed much lower CBF expression in buds. Expression of PtDAM1 peaked on the 10th day only in the buds of 'Okanese'. In addition, PtDAM1 was not expressed in the leaves of either cultivar while leaf CBFs expression pattern was several fold higher in 'Walker', peaking at day 1. Leaf phytohormones in both cultivars followed similar profiles during growth cessation but differentiated based on cytokinins which were largely reduced, while the Ox-IAA and iP7G increased in 'Okanese' compared to 'Walker'. Surprisingly, ABA concentration was reduced in leaves of both cultivars. However, the metabolic deactivation product of ABA, phaseic acid, exhibited an early peak on the first day in 'Okanese'. CONCLUSIONS: Our results indicate that PtCBFs and PtDAM1 have differential kinetics and spatial localization which may be related to early growth cessation and endodormancy induction under the regime of low night temperature and short photoperiod in poplar. Unlike buds, PtCBFs and PtDAM1 expression levels in leaves were not associated with early growth cessation and dormancy induction under these conditions. Our study provides new evidence that the degradation of auxin and cytokinins in leaves may be an important regulatory point in a CBF-DAM induced endodormancy. Further investigation of other PtDAMs in bud tissue and a study of both growth-inhibiting and the degradation of growth-promoting phytohormones is warranted.

Clinical and genetic findings in Hungarian pediatric patients carrying chromosome 16p copy number variants and a review of the literature.

The short arm of chromosome 16 (16p) is enriched for segmental duplications, making it susceptible to recurrent, reciprocal rearrangements implicated in the etiology of several phenotypes, including intellectual disability, speech disorders, developmental coordination disorder, autism spectrum disorders, attention deficit hyperactivity disorders, obesity and congenital skeletal disorders. In our clinical study 73 patients were analyzed by chromosomal microarray, and results were confirmed by fluorescence in situ hybridization or polymerase chain reaction. All patients underwent detailed clinical evaluation, with special emphasis on behavioral symptoms. 16p rearrangements were identified in 10 individuals. We found six pathogenic deletions and duplications of the recurrent regions within 16p11.2: one patient had a deletion of the distal 16p11.2 region associated with obesity, while four individuals had duplications, and one patient a deletion of the proximal 16p11.2 region. The other four patients carried 16p variations as second-site genomic alterations, acting as possible modifying genetic factors. We present the phenotypic and genotypic results of our patients and discuss our findings in relation to the available literature.

A Transgenic Mouse Model for Detection of Tissue-Specific Thyroid Hormone Action.

Thyroid hormone (TH) is present in the systemic circulation and thus should affect all cells similarly in the body. However, tissues have a complex machinery that allows tissue-specific optimization of local TH action that calls for the assessment of TH action in a tissue-specific manner. Here, we report the creation of a TH action indicator (THAI) mouse model to study tissue-specific TH action. The model uses a firefly luciferase reporter readout in the context of an intact transcriptional apparatus and all elements of TH metabolism and transport and signaling. The THAI mouse allows the assessment of the changes of TH signaling in tissue samples or in live animals using bioluminescence, both in hypothyroidism and hyperthyroidism. Beyond pharmacologically manipulated TH levels, the THAI mouse is sufficiently sensitive to detect deiodinase-mediated changes of TH action in the interscapular brown adipose tissue (BAT) that preserves thermal homeostasis during cold stress. The model revealed that in contrast to the cold-induced changes of TH action in the BAT, the TH action in this tissue, at room temperature, is independent of noradrenergic signaling. Our data demonstrate that the THAI mouse can also be used to test TH receptor isoform-specific TH action. Thus, THAI mouse constitutes a unique model to study tissue-specific TH action within a physiological/pathophysiological context and test the performance of thyromimetics. In conclusion, THAI mouse provides an in vivo model to assess a high degree of tissue specificity of TH signaling, allowing alteration of tissue function in health and disease, independently of changes in circulating levels of TH.

The cold response of CBF genes in barley is regulated by distinct signaling mechanisms.

Cold acclimation ability is crucial in the winter survival of cereals. In this process CBF transcription factors play key role, therefore understanding the regulation of these genes might provide useful knowledge for molecular breeding. In the present study the signal transduction pathways leading to the cold induction of different CBF genes were investigated in barley cv. Nure using pharmacological approach. Our results showed that the cold induced expression of CBF9 and CBF14 transcription factors is regulated by phospholipase C, phospholipase D pathways and calcium. On the contrary, these pathways have negative effect on the cold induction of CBF12 that is regulated by a different, as yet unidentified pathway. The diversity in the regulation of these transcription factors corresponds to their sequence based phylogenetic relationships suggesting that their evolutionary separation happened on structural, functional and regulational levels as well. On the CBF effector gene level, the signaling regulation is more complex, resultant effect of multiple pathways.

A de novo atypical ring sSMC(22) characterized by array CGH in a boy with cat-eye syndrome.

BACKGROUND: Microduplications 22q11 have been characterized as a genomic duplication syndrome mediated by nonallelic homologous recombination between region-specific low-copy repeats. Here we report on a 19 years old boy with intellectual disability having an unexpected structurally complex ring small supernumerary marker chromosome (sSMC) originated from a larger trisomy and a smaller tetrasomy of proximal 22q11 harboring additional copies of cat eye syndrome critical regions genes. RESULTS: PRINCIPAL CLINICAL FEATURES WERE: anorectal and urogenital malformations, total anomalous pulmonary venous return with secundum ASD, hearing defect, preauricular pits, seizure and eczema. The proband also presented some rare or so far not reported clinical findings such as hyperinsulinaemia, severe immunodeficiency and grave cognitive deficits. Chromosome analysis revealed a mosaic karyotype with the presence of a small ring-like marker in 60% of cells. Array CGH detected approximately an 1,2 Mb single and a 0,2 Mb double copy gain of the proximal long arm of chromosome 22. The 1,3 Mb intervening region of chromosome 22 from centromere to the breakpoints showed no copy alteration. The karyotype of the patient was defined as 47,XY,+mar[60]/46,XY[40].ish idic r(22)(q11.1.q11.21) × 4.arr 22q11(17,435, 645-18,656,678) × 3,(17,598,642-17,799,783) × 4 dn. CONCLUSIONS: The present report is the first one with a detailed description of clinical presentation in a patient carrying an atypical size ring sSMC (22) analyzed by array CGH. The specialty of the finding is emphasized by the fact that although the patient had a mosaic sSMC and the amplified region was smaller than in typical cat eye syndrome cases, the clinical presentation was severe.

Cold response of dedifferentiated barley cells at the gene expression, hormone composition, and freezing tolerance levels: studies on callus cultures.

In this study, data is presented how dark-grown, embryogenic barley callus cells respond to cold without any light-dependent, chloroplast-related mechanism, independently of the systemic signals. The expression of HvCBF9, HvCBF14, and HvCOR14b genes, members of one of the most important cold-inducible regulatory system, was measured by real-time PCR. Characteristic of the cold response was similar in the crowns of seedlings and in dark-grown callus cultures, however, gene expression levels were lower in calli. Endogenous concentration of auxins, abscisic acid, and salicylic acid did not change, but phaseic acid and neophaseic acid showed robust accumulation after cold acclimation. Freezing tolerance of the cultures was also higher after 7 days of cold-hardening. The results suggest the presence of a basal, light-independent, cold-responsive activation of the CBF-COR14b pathway in barley cultures. The effects of Dicamba, the exogenous auxin analog used for maintaining tissue cultures were also studied. Dicamba seems to be a general enhancer of the gene expression and physiological responses to cold stress, but has no specific effect on the activation. Our data along with previous findings show that this system might be a suitable model for studying certain basic cellular mechanisms involved in the cold acclimation process in cereals.

Parallel evolution under chemotherapy pressure in 29 breast cancer cell lines results in dissimilar mechanisms of resistance.

BACKGROUND: Developing chemotherapy resistant cell lines can help to identify markers of resistance. Instead of using a panel of highly heterogeneous cell lines, we assumed that truly robust and convergent pattern of resistance can be identified in multiple parallel engineered derivatives of only a few parental cell lines. METHODS: Parallel cell populations were initiated for two breast cancer cell lines (MDA-MB-231 and MCF-7) and these were treated independently for 18 months with doxorubicin or paclitaxel. IC50 values against 4 chemotherapy agents were determined to measure cross-resistance. Chromosomal instability and karyotypic changes were determined by cytogenetics. TaqMan RT-PCR measurements were performed for resistance-candidate genes. Pgp activity was measured by FACS. RESULTS: All together 16 doxorubicin- and 13 paclitaxel-treated cell lines were developed showing 2-46 fold and 3-28 fold increase in resistance, respectively. The RT-PCR and FACS analyses confirmed changes in tubulin isofom composition, TOP2A and MVP expression and activity of transport pumps (ABCB1, ABCG2). Cytogenetics showed less chromosomes but more structural aberrations in the resistant cells. CONCLUSION: We surpassed previous studies by parallel developing a massive number of cell lines to investigate chemoresistance. While the heterogeneity caused evolution of multiple resistant clones with different resistance characteristics, the activation of only a few mechanisms were sufficient in one cell line to achieve resistance.

[Cardiovascular actions of a standardized polyphenol concentrate on patients undergoing coronary bypass grafting: a randomized, double-blind, placebo-controlled study]. / Standardizált polifenol-koncentrátum keringési hatásai koszorúérmutéten átesett betegeken: randomizált, kettos vak-, placebokontrollos vizsgálat.

In this study the authors analyzed the action of Flavon Max product on the cardiovascular system of patients with severe coronary disease. Two randomized, double-blind, placebo controlled trials were carried out using impedance-cardiography, arteriography, vascular Doppler and biochemical laboratory methods. The results demonstrate that Augmentation Index measured with arteriography and C reactive protein (CRP) levels were significantly ameliorated after 2 x 2 months Flavon Max therapy. In conclusion, this product is beneficial as adjuvant in the treatment of atherosclerotic coronary disease.

Rapid genotyping of paraoxonase 55 and 192 mutations by melting point analysis using real time PCR technology.

BACKGROUND: Paraoxonase (PON1) enzyme was identified as one of the components of HDL responsible for prevention of lipid peroxides accumulation in low-density lipoprotein (LDL). A triphasic phenotypic frequency distribution of PON1 activity was shown in the human population resulted by two nucleotide interchanges at residues 55 and 192. The paraoxonase isoforms have different effectiveness in hydrolysing lipid peroxides. METHODS: To date, genotyping for PON1 is mainly performed by PCR RFLP technique, that is time consuming and sensitive to contamination. We developed highly reliable single-step methods for genotyping both PON1 55 and 192 polymorphisms using LightCycler real time PCR technology based on fluorescence resonance energy transfer. After the ultrafast PCR, melting point analysis was performed and fluorescence intensity was monitored simultaneously with slow heating. RESULTS AND CONCLUSIONS: The observed melting temperatures in the PON1 55 and 192 melting point analyses characteristic to the oligonucleotides hybridised to the mutant and wild-type DNA were 57 degrees C, 61 degrees C and 51.5 degrees C, 57.5 degrees C, respectively. The temperature differences in melting points (4 degrees C and 6 degrees C, respectively) offer a powerful tool for rapid, reliable mutation detection for 55 and 192 polymorphisms even in routine diagnostic laboratories or large epidemiological studies.