Tomato (Solanum lycopersicum L.) accumulation and allergenicity in response to nickel stress

Vegetables represent a major source of Ni exposure. Environmental contamination and cultural practices can increase Ni amount in tomato posing significant risk for human health. This work assesses the tomato (Solanum lycopersicum L.) response to Ni on the agronomic yield of fruits and the related production of allergens. Two cultivars were grown in pots amended with Ni 0, 30, 60, 120, and 300 mg kg 121, respectively. XRF and ICP-MS analyses highlighted the direct increase of fruit Ni content compared to soil Ni, maintaining a stable biomass. Leaf water content increased at Ni 300 mg kg 121. Total protein content and individual allergenic components were investigated using biochemical (RP-HPLC and N-terminal amino acid sequencing) and immunological (inhibition tests of IgE binding by SPHIAa assay on the FABER testing system) methodologies. Ni affected the fruit tissue concentration of pathogenesis-related proteins and relevant allergens (LTP, profilin, Bet v 1-like protein and TLP). This study elucidates for the first time that tomato reacts to exogenous Ni, uptaking the metal while changing its allergenic profiles, with potential double increasing of exposure risks for consumers. This evidence highlighted the importance of adequate choice of low-Ni tomato cultivars and practices to reduce Ni uptake by potentially contaminated matrices

Prospective Evaluation of Clinico-Pathological Predictors of Postoperative Atrial Fibrillation

Background: Postoperative atrial fibrillation (POAF) occurs in 30% to 50% of patients undergoing cardiac surgery and is associated with increased morbidity and mortality. Prospective identification of structural/molecular changes in atrial myocardium that correlate with myocardial injury and precede and predict risk of POAF may identify new molecular pathways and targets for prevention of this common morbid complication. Methods: Right atrial appendage samples were prospectively collected during cardiac surgery from 239 patients enrolled in the OPERA trial (Omega-3 Fatty Acids for Prevention of Post-Operative Atrial Fibrillation), fixed in 10% buffered formalin, and embedded in paraffin for histology. We assessed general tissue morphology, cardiomyocyte diameters, myocytolysis (perinuclear myofibril loss), accumulation of perinuclear glycogen, interstitial fibrosis, and myocardial gap junction distribution. We also assayed NT-proBNP (N-terminal pro-B-type natriuretic peptide), hs-cTnT, CRP (C-reactive protein), and circulating oxidative stress biomarkers (F2-isoprostanes, F3-isoprostanes, isofurans) in plasma collected before, during, and 48 hours after surgery. POAF was defined as occurrence of postcardiac surgery atrial fibrillation or flutter of at least 30 seconds duration confirmed by rhythm strip or 12-lead ECG. The follow-up period for all arrhythmias was from surgery until hospital discharge or postoperative day 10. Results: Thirty-five percent of patients experienced POAF. Compared with the non-POAF group, they were slightly older and more likely to have chronic obstructive pulmonary disease or heart failure. They also had a higher European System for Cardiac Operative Risk Evaluation and more often underwent valve surgery. No differences in left atrial size were observed between patients with POAF and patients without POAF. The extent of atrial interstitial fibrosis, cardiomyocyte myocytolysis, cardiomyocyte diameter, glycogen score or Cx43 distribution at the time of surgery was not significantly associated with incidence of POAF. None of these histopathologic abnormalities were correlated with levels of NT-proBNP, hs-cTnT, CRP, or oxidative stress biomarkers. Conclusions: In sinus rhythm patients undergoing cardiac surgery, histopathologic changes in the right atrial appendage do not predict POAF. They also do not correlate with biomarkers of cardiac function, inflammation, and oxidative stress

REGULATION OF a-SYNUCLEIN DURING HUMAN NEUROBLASTOMA CELL DIFFERENTIATION

a-Synuclein is a neuronal protein particularly abundant in forebrain structures in rodents and humans, localized mainly in pre-synaptic terminals and in the neighborhood of synaptic vesicles, and suggested to be involved in trafficking of synaptic vesicles. a-Synuclein is a major protein component of Lewy bodies (LB), the histopathological hallmark of Parkinson's disease (PD) and dementia with LBs. Two mutations in the a-synuclein gene have been found to cause familial forms of PD characterized by extensive loss of nigral dopaminergic neurons and loss of dopamine in the striatum. Studies of transgenic rodents and Drosophila models strongly implicate a-synuclein in the degeneration of dopaminergic neurons, but its molecular mechanisms remain to be clarified. In order to increase our knowledge on the regulation of a-synuclein in dopaminergic neurons we defined an experimental model of human dopaminergic neuroblastoma cell induced to differentiation by di-butyryl-cyclic AMP (db-cAMP). The assessment of SH-SY5Y cell differentiation was evaluated following the formation of neuritis and the expression of neuronal markers. We present a protocol of differentiation based on the exposure of SH-SY5Y to db-cAMP. This protocol yields a population of neuronal differentiated cells evaluated by analysing the expression of neuronal markers bIII tubulin and GAP43. An increase of a-synuclein was associated with the expression of the neuronal markers detected during the differentiation of human dopaminergic SH-SY5Y cell. This model offers a convenient system to explore the effect of different agents on the mechanisms involving a-synuclein modifications and dopaminergic cell degeneration detected in brains of patients affected by Lewy body-relate pathology

NEURONAL APOLIPOPROTEIN J IS UP-REGULATED BY OXIDATIVE STRESS

Apolipoprotein J / clusterin (apoJ) is a multifunctional glycoprotein up-regulated during various pathophysiological states and might represent a defence mechanism during cellular damage. An increase in either apoJ mRNA or protein expression is observed in numerous neurodegenerative conditions including Alzheimer\u2019s disease, Parkinson\u2019 disease, Pick disease, amyotrophic lateral sclerosis, and Huntington disease. Furthermore, these neurodegenerative disorders are characterized by intraneuronal abnormal filament accumulation associated with markers of oxidative injury. To determine whether apoJ is affected by oxidative stress, we evaluated the effects of oxidative insult on the expression of apoJ as part of a cellular response in viable human neuroblastoma IMR-32 cells. In our experimental model iron-ascorbate induced oxidative stress in IMR-32 cells without affecting cell viability, as detected by MTT-assay. It was found that IMR-32 cells express apoJ mature protein and that oxidative stress induced an up-regulation of apoJ level revealed by immunoblot analysis. The results of the present study suggest that an increase in apoJ expression may be a physiological defence able to reduce cell damage and maintain cell viability during periods of increased radical production. Supported by the University of Bologna, Funds for Selected Research Topics

INFLUENCE OF R-LIPOIC ACID ON INTRACELLULAR GLUTATHIONE IN HUMAN DOPAMINERGIC NEUROBLASTOMA CELLS: IMPLICATIONS FOR PARKINSON’S DISEASE.

The consistent findings of decreased levels of the major antioxidant glutathione in substantia nigra of patients with idiopathic Parkinson's disease (PD) has provided most of the basis for the oxidative stress hypothesis of the etiology of PD. Oxidative stress and mitochondrial dysfunction signify two important biochemical events associated with the loss of dopaminergic neurons in PD. Studies using in vitro and in vivo PD models and in affected tissues from the disease itself have demonstrated a selective inhibition of mitochondrial complex I activity that appears to affect normal mitochondrial physiology leading to neuronal cell death. R-lipoic acid plays a fundamental role in mitochondrial metabolism as a coenzyme for pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase and as a substrate for the NADPH-dependent enzyme glutathione reductase. To address the question of the possible mechanism of R-lipoic acid-mediated protection, we have investigated its effect on human dopaminergic SH-SY5Y cells exposed to rotenone, a specific complex I inhibitor. We found that rotenone dose- and time- dependently altered SH-SY5Y cell viability associated with a decreased of glutathione (GSH) levels and ATP production. We observed a protective effect R-lipoic acid on SH-SY5Y cells against rotenone indicating that the replenishment of normal GSH levels within the cells may hold an important key to therapeutics for PD. Supported by the University of Bologna, Funds for Selected Research Topics