Exposure of Arabidopsis thaliana Mutants to Genotoxic Stress Provides New Insights for the Involvement of TDP1α and TDP1ß genes in DNA-Damage Response.

Genotoxic stress activates the DNA-damage response (DDR) signalling cascades responsible for maintaining genome integrity. Downstream DNA repair pathways include the tyrosyl-DNA phosphodiesterase 1 (TDP1) enzyme that hydrolyses the phosphodiester bond between the tyrosine of topoisomerase I (TopI) and 3'-phosphate of DNA. The plant TDP1 subfamily contains the canonical TDP1α gene and the TDP1ß gene whose functions are not fully elucidated. The current study proposes to investigate the involvement of TDP1 genes in DDR-related processes by using Arabidopsis thaliana mutants treated with genotoxic agents. The phenotypic and molecular characterization of tdp1α, tdp1ß and tdp1α/ß mutants treated with cisplatin (CIS), curcumin (CUR), NSC120686 (NSC), zeocin (ZEO), and camptothecin (CPT), evidenced that while tdp1ß was highly sensitive to CIS and CPT, tdp1α was more sensitive to NSC. Gene expression analyses showing upregulation of the TDP2 gene in the double mutant indicate the presence of compensatory mechanisms. The downregulation of POL2A gene in the tdp1ß mutant along with the upregulation of the TDP1ß gene in pol2a mutants, together with its sensitivity to replication inhibitors (CIS, CTP), point towards a function of this gene in the response to replication stress. Therefore, this study brings novel information relative to the activity of TDP1 genes in plants.

Changes in genotoxic stress response, ribogenesis and PAP (3'-phosphoadenosine 5'-phosphate) levels are associated with loss of desiccation tolerance in overprimed Medicago truncatula seeds.

Re-establishment of desiccation tolerance is essential for the survival of germinated seeds facing water deficit in the soil. The molecular and ultrastructural features of desiccation tolerance maintenance and loss within the nuclear compartment are not fully resolved. In the present study, the impact of desiccation-induced genotoxic stress on nucleolar ultrastructure and ribogenesis was explored along the rehydration-dehydration cycle applied in standard seed vigorization protocols. Primed and overprimed Medicago truncatula seeds, obtained through hydropriming followed by desiccation (dry-back), were analysed. In contrast to desiccation-tolerant primed seeds, overprimed seeds enter irreversible germination and do not survive dry-back. Reactive oxygen species, DNA damage and expression profiles of antioxidant/DNA Damage Response genes were measured, as main hallmarks of the seed response to desiccation stress. Nuclear ultrastructural features were also investigated. Overprimed seeds subjected to dry-back revealed altered rRNA accumulation profiles and up-regulation of genes involved in ribogenesis control. The signal molecule PAP (3'-phosphoadenosine 5'-phosphate) accumulated during dry-back only in primed seeds, as a distinctive feature of desiccation tolerance. The presented results show the molecular and ultrastructural landscapes of the seed desiccation response, including substantial changes in nuclear organization.

Prescription patterns of antiepileptic drugs in young women: development of a tool to distinguish between epilepsy and psychiatric disorders.

BACKGROUND: Antiepileptic drugs (AEDs) are also prescribed for therapeutic indications other than epilepsy (EPI), namely, psychiatric disorders (PSY). Our aim was to develop an algorithm able to distinguish between EPI and PSY among childbearing age women based on differences in AED exposure in these patient groups. METHODS: Two groups of women (18-45 years) with EPI or PSY treated with AEDs in the first semester of 2010 or 2011 were extracted from paper or electronic medical charts of specialized centers. Through the prescription database of Bologna Local Health Authority (Italy), AEDs, treatment schedule and co-treatments were collected for each patient. A prescription-based hierarchical classification system was developed. The algorithm obtained was subsequently validated on internal and external data. RESULTS: Eighty-one EPI and 94 PSY subjects were recruited. AED monotherapy was the most common choice in both groups (69% EPI vs 79% PSY). Some AEDs were used only in EPI, others exclusively in PSY. Co-treatments with antipsychotics (6% vs 67%), lithium (0% vs 9%), and antidepressants (7% vs 70%) were fewer in EPI than in PSY. The hierarchical classification system identified antipsychotics, SSRIs (Selective Serotonin Reuptake Inhibitors), and number of AEDs as variables to discriminate EPI and PSY, with an overall error rate estimate of 9.7% (95%CI: 5.3% to 14.1%). CONCLUSION: Among the differences between EPI and PSY, prescription data alone allowed an algorithm to be developed to diagnose each childbearing age woman receiving AEDs. This approach will be useful to stratify patients for risk estimates of AED-treated patients based on administrative databases. Copyright © 2016 John Wiley & Sons, Ltd.

Integrative Transcriptomics Data Mining to Explore the Functions of TDP1α and TDP1ß Genes in the Arabidopsis thaliana Model Plant.

The tyrosyl-DNA phosphodiesterase 1 (TDP1) enzyme hydrolyzes the phosphodiester bond between a tyrosine residue and the 3'-phosphate of DNA in the DNA-topoisomerase I (TopI) complex, being involved in different DNA repair pathways. A small TDP1 gene subfamily is present in plants, where TDP1α has been linked to genome stability maintenance, while TDP1ß has unknown functions. This work aimed to comparatively investigate the function of the TDP1 genes by taking advantage of the rich transcriptomics databases available for the Arabidopsis thaliana model plant. A data mining approach was carried out to collect information regarding gene expression in different tissues, genetic backgrounds, and stress conditions, using platforms where RNA-seq and microarray data are deposited. The gathered data allowed us to distinguish between common and divergent functions of the two genes. Namely, TDP1ß seems to be involved in root development and associated with gibberellin and brassinosteroid phytohormones, whereas TDP1α is more responsive to light and abscisic acid. During stress conditions, both genes are highly responsive to biotic and abiotic treatments in a time- and stress-dependent manner. Data validation using gamma-ray treatments applied to Arabidopsis seedlings indicated the accumulation of DNA damage and extensive cell death associated with the observed changes in the TDP1 genes expression profiles.

Switching among Equivalents in Chronic Cardiovascular Therapies: 'Real World' Data from Italy.

Since August 2012, Italian general practitioners are required to prescribe the generic name of medicines, except for refill of chronic therapy. We evaluated the extent of switching among equivalents in chronic cardiovascular therapies, the influence of the 2012 regulatory intervention and of patient-related or drug-related factors. Prescriptions of off-patent anti-arrhythmics, oral antidiabetics and ACE inhibitors dispensed from August 2011 to August 2013 within the Bologna Local Health Authority (870,000 inhabitants) was collected. The rate of actual switching among equivalents was evaluated monthly. The effect of the regulatory intervention was estimated by interrupted-time-series analysis. Adjusted odds ratios (aORs) of switching were calculated for the following: age, gender, number of different equivalents available for each drug and change in dispensing pharmacy between subsequent refills. The average monthly rates of switches were 9.6%, 16.3% and 16.3% for anti-arrhythmics, antidiabetics and ACE inhibitors, respectively. Values significantly increased soon after the regulatory intervention for ACE inhibitors (+1.81%, p < 0.01), anti-arrhythmics (+1.46%, p = 0.01) and antidiabetics (+1.09%, p = 0.01), and no significant decreasing trends were observed in the following 12 months. For all drug classes, odd of switching was higher in case of change in dispensing pharmacy (up to aOR = 4.31, 95 CI = 4.26-4.35 for ACE inhibitors) and availability of ≥5 different equivalents (up to aOR = 7.82, 95 CI = 7.39-8.28 for antidiabetics). Switching was lower for age ≥65 for antidiabetics and ACE inhibitors (aOR = 0.92, 95 CI = 0.90-0.93; 0.87, 0.86-0.88, respectively). The Italian regulatory intervention generated an immediate increase, not sustained in time, in switching among equivalents of cardiovascular therapies. Young age, high number of available equivalents and changes in dispensing pharmacy between subsequent refills were associated with switching.