The contribution of organelles to plant intracellular Calcium signalling

Calcium (Ca2+) is among the most important intracellular messengers in living organisms. Understanding of the players and dynamics of Ca2+ signalling pathways in plants may help to unravel the molecular basis of their exceptional flexibility to respond and to adapt to different stimuli. In the present review we focus on new tools that have recently revolutionized our view of organellar Ca2+ signalling as well as on the current knowledge regarding the pathways mediating Ca2+ fluxes across intracellular membranes. The contribution of organelles and cellular subcompartments to the orchestrated response via Ca2+ signalling within a cell is also discussed, underlining the fact that one of the greatest challenges in the field is the elucidation of how influx and efflux Ca2+ transporters/channels are regulated in a concerted manner to translate specific information into a Ca2+ signature

Calcium-mediated perception and defense responses activated in plant cells by metabolite mixtures secreted by the biocontrol fungus Trichoderma atroviride

<p>Abstract</p> <p>Background</p> <p>Calcium is commonly involved as intracellular messenger in the transduction by plants of a wide range of biotic stimuli, including signals from pathogenic and symbiotic fungi. <it>Trichoderma </it>spp. are largely used in the biological control of plant diseases caused by fungal phytopathogens and are able to colonize plant roots. Early molecular events underlying their association with plants are relatively unknown.</p> <p>Results</p> <p>Here, we investigated the effects on plant cells of metabolite complexes secreted by <it>Trichoderma atroviride </it>wild type P1 and a deletion mutant of this strain on the level of cytosolic free Ca²⁺and activation of defense responses. <it>Trichoderma </it>culture filtrates were obtained by growing the fungus alone or in direct antagonism with its fungal host, the necrotrophic pathogen <it>Botrytis cinerea</it>, and then separated in two fractions (>3 and <3 kDa). When applied to aequorin-expressing soybean (<it>Glycine max </it>L.) cell suspension cultures, <it>Trichoderma </it>and <it>Botrytis </it>metabolite mixtures were distinctively perceived and activated transient intracellular Ca²⁺elevations with different kinetics, specific patterns of intracellular accumulation of reactive oxygen species and induction of cell death. Both Ca²⁺signature and cellular effects were modified by the culture medium from the knock-out mutant of <it>Trichoderma</it>, defective for the production of the secreted 42 kDa endochitinase.</p> <p>Conclusion</p> <p>New insights are provided into the mechanism of interaction between <it>Trichoderma </it>and plants, indicating that secreted fungal molecules are sensed by plant cells through intracellular Ca²⁺changes. Plant cells are able to discriminate signals originating in the single or two-fungal partner interaction and modulate defense responses.</p

SULT1A1gene deletion inBRCA2-associated male breast cancer: a link between genes and environmental exposures?

SULT1A1, a member of sulfotransferase superfamily, is a drug and hormone metabolizing enzyme involved in the metabolism of a variety of potential mammary carcinogens of endogenous and exogenous origin. Interestingly, the metabolic activity of SULT1A1 can be affected by varia- tions in gene copy number. Male Breast Cancer (MBC) is a rare disease and less investigated disease compared to female BC (FBC). As in FBC, the concurrent effects of genetic risk factors, particularly BRCA2 mutations, increased exposure to estrogens and environmental carcinogens play a relevant role in MBC. By quantitative real-time PCR with TaqMan probes, we investigated the presence of SULT1A1 gene copy number variations (CNVs) in a series of 72 MBCs. SULT1A1 gene deletion was observed in 10 of the 72 MBCs (13.9%). In a multivariate analysis associ- ation between BRCA2 mutation and SULT1A1 gene deletion emerged (p = 0.0005). Based on the evidence that the level of SULT1A1 enzyme activity is correlated with CNV, our data suggest that in male breast tumors SULT1A1 activity may be decreased. Thus, it can be hypothesized that in a proportion of MBCs, particularly in BRCA2-associated MBCs, the level of estrogens and environmental carcinogens exposure might be increased suggesting a link between gene and environmental exposure in the pathogenesis of MBC

Association of low-penetrance alleles with male breast cancer risk and clinicopathological characteristics: results from a multicenter study in Italy

It is well-known that male breast cancer (MBC) susceptibility is mainly due to high-penetrance BRCA1/2 mutations. Here, we investigated whether common low-penetrance breast cancer (BC) susceptibility alleles may influence MBC risk in Italian population and whether variant alleles may be associated with specific clinicopathological features of MBCs. In the frame of the Italian Multicenter Study on MBC, we genotyped 413 MBCs and 745 age-matched male controls at 9 SNPs annotating known BC susceptibility loci. By multivariate logistic regression models, we found a significant increased MBC risk for 3 SNPs, in particular, with codominant models, for rs2046210/ESR1 (OR = 1.71; 95 % CI: 1.43-2.05; p = 0.0001), rs3803662/TOX3 (OR = 1.59; 95 % CI: 1.32-1.92; p = 0.0001), and rs2981582/FGFR2 (OR = 1.26; 95 % CI: 1.05-1.50; p = 0.013). Furthermore, we showed that the prevalence of the risk genotypes of ESR1 tended to be higher in ER- tumors (p = 0.062). In a case-case multivariate analysis, a statistically significant association between ESR1 and ER- tumors was found (OR = 1.88; 95 % CI: 1.03-3.49; p = 0.039). Overall, our data, based on a large and well-characterized MBC series, support the hypothesis that common low-penetrance BC susceptibility alleles play a role in MBC susceptibility and, interestingly, indicate that ESR1 is associated with a distinct tumor subtype defined by ER-negative status

BLITZ-HF: a nationwide initiative to evaluate and improve adherence to acute and chronic heart failure guidelines

Aims: To assess adherence to guideline recommendations among a large network of Italian cardiology sites in the management of acute and chronic heart failure (HF) and to evaluate if an ad-hoc educational intervention can improve their performance on several pharmacological and non-pharmacological indicators. Methods and results: BLITZ-HF was a cross-sectional study based on a web-based recording system with pop-up reminders on guideline recommendations used during two 3-month enrolment periods carried out 3 months apart (Phase 1 and 3), interspersed by face-to-face macro-regional benchmark analyses and educational meetings (Phase 2). Overall, 7218 patients with acute and chronic HF were enrolled at 106 cardiology sites. During the enrolment phases, 3920 and 3298 patients were included, respectively, 84% with chronic HF and 16% with acute HF in Phase 1, and 74% with chronic HF and 26% with acute HF in Phase 3. At baseline, adherence to guideline recommendations was already overall high for most indicators. Among acute HF patients, an improvement was obtained in three out of eight indicators, with a significant rise in echocardiographic evaluation. Among chronic HF patients with HF and preserved or mid-range ejection fraction, performance increased in two out of three indicators: creatinine and echocardiographic evaluations. An overall performance improvement was observed in six out of nine indicators in ambulatory HF with reduced ejection fraction patients with a significant increase in angiotensin receptor-neprilysin inhibitor prescription rates. Conclusions: Within a context of an already elevated level of adherence to HF guideline recommendations, a structured multifaceted educational intervention could be useful to improve performance on specific indicators. Extending this approach to other non-cardiology healthcare professionals, who usually manage patients with HF, should be considered

Molecular cloning and transcriptional activity of a new Petunia calreticulin gene involved in pistil transmitting tract maturation, progamic phase, and double fertilization

Calreticulin (CRT) is a highly conserved and ubiquitously expressed Ca2+-binding protein in multicellular eukaryotes. As an endoplasmic reticulum-resident protein, CRT plays a key role in many cellular processes including Ca2+ storage and release, protein synthesis, and molecular chaperoning in both animals and plants. CRT has long been suggested to play a role in plant sexual reproduction. To begin to address this possibility, we cloned and characterized the full-length cDNA of a new CRT gene (PhCRT) from Petunia. The deduced amino acid sequence of PhCRT shares homology with other known plant CRTs, and phylogenetic analysis indicates that the PhCRT cDNA clone belongs to the CRT1/CRT2 subclass. Northern blot analysis and fluorescent in situ hybridization were used to assess PhCRT gene expression in different parts of the pistil before pollination, during subsequent stages of the progamic phase, and at fertilization. The highest level of PhCRT mRNA was detected in the stigma–style part of the unpollinated pistil 1 day before anthesis and during the early stage of the progamic phase, when pollen is germinated and tubes outgrow on the stigma. In the ovary, PhCRT mRNA was most abundant after pollination and reached maximum at the late stage of the progamic phase, when pollen tubes grow into the ovules and fertilization occurs. PhCRT mRNA transcripts were seen to accumulate predominantly in transmitting tract cells of maturing and receptive stigma, in germinated pollen/growing tubes, and at the micropylar region of the ovule, where the female gametophyte is located. From these results, we suggest that PhCRT gene expression is up-regulated during secretory activity of the pistil transmitting tract cells, pollen germination and outgrowth of the tubes, and then during gamete fusion and early embryogenesis

Arabidopsis CaM Binding Protein CBP60g Contributes to MAMP-Induced SA Accumulation and Is Involved in Disease Resistance against Pseudomonas syringae

Salicylic acid (SA)-induced defense responses are important factors during effector triggered immunity and microbe-associated molecular pattern (MAMP)-induced immunity in plants. This article presents evidence that a member of the Arabidopsis CBP60 gene family, CBP60g, contributes to MAMP-triggered SA accumulation. CBP60g is inducible by both pathogen and MAMP treatments. Pseudomonas syringae growth is enhanced in cbp60g mutants. Expression profiles of a cbp60g mutant after MAMP treatment are similar to those of sid2 and pad4, suggesting a defect in SA signaling. Accordingly, cbp60g mutants accumulate less SA when treated with the MAMP flg22 or a P. syringae hrcC strain that activates MAMP signaling. MAMP-induced production of reactive oxygen species and callose deposition are unaffected in cbp60g mutants. CBP60g is a calmodulin-binding protein with a calmodulin-binding domain located near the N-terminus. Calmodulin binding is dependent on Ca2+. Mutations in CBP60g that abolish calmodulin binding prevent complementation of the SA production and bacterial growth defects of cbp60g mutants, indicating that calmodulin binding is essential for the function of CBP60g in defense signaling. These studies show that CBP60g constitutes a Ca2+ link between MAMP recognition and SA accumulation that is important for resistance to P. syringae

How do cardiologists select patients for dual antiplatelet therapy continuation beyond 1 year after a myocardial infarction? Insights from the EYESHOT Post-MI Study

Background: Current guidelines suggest to consider dual antiplatelet therapy (DAPT) continuation for longer than 12 months in selected patients with myocardial infarction (MI). Hypothesis: We sought to assess the criteria used by cardiologists in daily practice to select patients with a history of MI eligible for DAPT continuation beyond 1 year. Methods: We analyzed data from the EYESHOT Post-MI, a prospective, observational, nationwide study aimed to evaluate the management of patients presenting to cardiologists 1 to 3 years from the last MI event. Results: Out of the 1633 post-MI patients enrolled in the study between March and December 2017, 557 (34.1%) were on DAPT at the time of enrolment, and 450 (27.6%) were prescribed DAPT after cardiologist assessment. At multivariate analyses, a percutaneous coronary intervention (PCI) with multiple stents and the presence of peripheral artery disease (PAD) resulted as independent predictors of DAPT continuation, while atrial fibrillation was the only independent predictor of DAPT interruption for patients both at the second and the third year from MI at enrolment and the time of discharge/end of the visit. Conclusions: Risk scores recommended by current guidelines for guiding decisions on DAPT duration are underused and misused in clinical practice. A PCI with multiple stents and a history of PAD resulted as the clinical variables more frequently associated with DAPT continuation beyond 1 year from the index MI