The tomato serotonin pathway: unravelling the puzzling biological roles of plant indolamines

Tryptamine and serotonin are specialized metabolites belonging to the group of tryptophan-derived indolamines that have been demonstrated to be widespread among all the living kingdoms, in which evolution shaped very different distributions and functional versatility. First discovered in humans, these metabolites were later detected in plants in which, despite their wide occurrence in several plant families, the study of their biological roles has been largely neglected. Tryptamine, due to its central position as a precursor of many plant specialized metabolites, including serotonin, has long been considered a mere metabolic intermediate; on the other hand, the increasing awareness of the many medical issues of serotonin (e.g. neurotransmission and hormonal activity), triggered the botanical research towards the elucidation of its biosynthetic pathway and functions also in plants, leading to a huge number of experimental evidences that, yet often controversial, suggest its putative involvement in many different plant physiological processes (e.g. development, stress response and reproduction). This PhD thesis proposed to shed a light on the biological roles of plant tryptamine and serotonin, with a particular focus on an aspect that has never been investigated in plants, i.e. the high level of accumulation of these metabolites within the reproductive organs, such as the fruit, observed in many edible species, which, given the high costs to plant metabolism, can be reasonably hypothesized to reflect an important plant physiological function. To fulfil this aim, this PhD project relied on the use of Solanum lycopersicum, a tryptamine and serotonin accumulator that is a model plant for fruit-bearing crops. The first step consisted in the genetic characterization of the tomato tryptamine and serotonin biosynthetic pathway: a three-member gene family and one single gene codifying for the enzymes of the 2-step pathway that leads to the production of serotonin from tryptophan via tryptamine (i.e. tryptophan decarboxylase, TDC and tryptamine-5-hydroxylase, T5H) were respectively identified and functionally characterized as bona-fide SlTDCs and SlT5H. The expression analysis of these genes and the investigation of tryptamine and serotonin distribution revealed organ and developmental-specific expression and accumulation patterns in tomato, confirming the complementary but not redundant activity of the three SlTDC genes in the plant and the presence of notable amounts of the two indolamines in the fruit, which accumulated with a characteristic trend during development and ripening. Moreover, it was revealed the fruit-specific nature of the SlTDC1 gene that, as a preliminary point in the elucidation of the biological roles of plant tryptamine and serotonin, was targeted by a metabolic engineering approach in order to look for the effects resulting from altered levels of these metabolites on the plant phenotype. Transgenic plants overexpressing this gene resulted in deep modifications of plant metabolome presenting in one case altered morphology of younger leaves. This evidence, together with the observation along the main axis of the wild type plant of complex expression and accumulation gradients of SlTDCs/SlT5H genes and related products, i.e. tryptamine and serotonin, leads to hypothesize the possible interference with the hormonal cross-talk. On the other hand, SlTDC1 knock-out fruits did non exhibit obvious phenotype but further characterization of their metabolome are needed to speculate on the biological roles of tryptamine and serotonin in this organ. In summary, this work provided useful information and details to the biosynthesis, regulation and putative biological roles of plant indolamines in the model plant of tomato and highlighted the putative involvement of the actors of the plant serotonin pathway in important physiological functions, which deserve, thus, future deeper investigation

An analysis method of the vortex-induced vibrations of a tethered sphere

AbstractVortex-induced vibrations (VIV) in systems with more than one degree of freedom often present complex synchronization among the motion components, also hidden by the randomness that characterizes the motion itself. A phase average method has been here developed and applied to the displacements of a tethered sphere, at low mass and damping, to analyze its xy trajectories over a wide range of reduced velocities, 5 ≤ U* ≤ 25 (Reynolds numbers, 5.1 × 103 ≤ Re ≤ 2.67 × 104). This method has allowed the identification of both the periodic and chaotic contribution of each motion component, accurately reconstructing the underlying trajectory periodic pattern. The two classical vibration modes, I and II, have been also observed. The method developed here was able to better rebuild the experimental data compared to other methods found in the relevant literature, providing useful insights into the study of the dynamic response of a freely-oscillating tethered sphere immersed in a steady flow

Il Marketing di Prossimità

Il presente elaborato si propone di approfondire il tema del Marketing di prossimità o Proximity marketing. La tesi ha diversi obiettivi. Il primo è apprendere in profondità il Proximity marketing, la sua storia, da dove prende vita, la sua evoluzione ed i motivi del perché fino ad ora non si è affermato nel panorama mondiale. Il secondo è di realizzare una ricerca di mercato volta ad individuare quali possono essere i principali clienti di un’ipotetica start-up che si occupa del Proximity marketing e che si avvale delle ultime tecnologie. Infine, il terzo obiettivo è studiare la percezione e le reazioni dei clienti finali che saranno soggetto delle strategie del marketing di prossimità

Gardella/l’abitare: lo spazio domestico

AbtractL’archivio Gardella restituisce tra i faldoni delle opere più conosciute dell’architetto milanese un consistente corpus di elaborati che documentano le attenzioni da lui costantemente dedicate al progetto degli interni residenziali. Si svela così un’attitudine professionale che coinvolge la disciplina architettonica dal disegno dell’oggetto d’uso all’organizzazione degli ambienti domestici, dove è possibile verificare le relazioni tra la costruzione, gli spazi e i pezzi di arredo che li occupano

The Potential Role of Exercise Training and Mechanical Loading on Bone-Associated Skeletal Nerves

: The spatial distribution, innervation, and functional role of the bone-associated skeletal nerves have been previously reported in detail. However, studies examining exercise-induced associations between skeletal nerves and bone metabolism are limited. This review introduces a potential relationship between exercise and the skeletal nerves and discusses how it can contribute to exercise-induced bone anabolism. First, the background and current understanding of nerve fiber types and their functions in the skeleton are provided. Next, the influence of exercise and mechanical loading on the skeletal nervous system is elaborated. Effective synthesis of recent studies could serve as an established baseline for the novel discovery of the effects of exercise on skeletal nerve density and bone anabolic activity in the future. Therefore, this review overviews the existing evidence for the neural control of bone metabolism and the potential positive effects of exercise on the peripheral skeletal nervous system. The influence of exercise training models on the relationships of sensory nerve signals with osteoblast-mediated bone formation and the increased bone volume provides the first insight on the potential importance of exercise training in stimulating positive adaptations in the skeletal nerve-bone interaction and its downstream effect on bone metabolism, thereby highlighting its therapeutic potential in a variety of clinical populations

Long-term dynamics of hypoxia and anoxia in the Emilia Romagna coastal zone (Northern Adriatic Sea)

The Northern Adriatic is a continental shelf area characterised by highly variable freshwater discharges and production events. Here, hypoxia and anoxia have occurred both in offshore areas and in coastal waters, at least since the beginning of 1900. Despite several biogeochemical studies are available, longterm analysis of their recurrence, triggering mechanisms and impact on marine environment may provide a tool for a better understanding of present evolution of this ecosystem. For this reason, a compilation of the information contained in the scientific literature on the occurrence on decadal scales of hypoxia and anoxia in the North Adriatic has been done, focusing in particular on the Emilia Romagna coastal zone. Time series of Po River discharges and meteorological data (air temperature, precipitation, wind intensity and direction) were analysed, together with oceanographic conditions, as triggering factors for this phenomenon in the area of interest. The occurrence of plankton blooms was also reported and evaluated. The characteristics of hypo-anoxic events in terms of extension, duration and diffusion were collected in order to distinguish local vs. regional events, shortlived vs. long-lasting events, and to evaluate space and temporal evolutionary trends. This analysis was carried out through the reconstruction of time series of bottom dissolved O2 distribution for the period 1982-2005 and by comparison with reported observations on the field. On this base, latitudinal diffusion of events was studied, as well as possible exchanges between coastal and offshore waters. Finally, the analysis of this historical dataset suggests an increase in short-lived events, located in shallow waters, but often repeated during the year, which cause a continuous stress on the pelagic and benthic habitats. This temporal trends may be related to regional changes of the climatic conditions, which include an higher frequency of irregular seasonal cycles

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The role of endothelial TRP channels in age-related vascular cognitive impairment and dementia

Transient receptor potential (TRP) proteins are part of a superfamily of polymodal cation channels that can be activated by mechanical, physical, and chemical stimuli. In the vascular endothelium, TRP channels regulate two fundamental parameters: the membrane potential and the intracellular Ca2+ concentration [(Ca2+)i]. TRP channels are widely expressed in the cerebrovascular endothelium, and are emerging as important mediators of several brain microvascular functions (e.g., neurovascular coupling, endothelial function, and blood–brain barrier permeability), which become impaired with aging. Aging is the most significant risk factor for vascular cognitive impairment (VCI), and the number of individuals affected by VCI is expected to exponentially increase in the coming decades. Yet, there are currently no preventative or therapeutic treatments available against the development and progression of VCI. In this review, we discuss the involvement of endothelial TRP channels in diverse physiological processes in the brain as well as in the pathogenesis of age-related VCI to explore future potential neuroprotective strategies

Lipoaspirate processing for the treatment of knee osteoarthritis: a review of clinical evidences

The autologous lipoaspirate processing allows to obtain a tissue product to be transplanted for regenerative purposes in multiple pathological sites, such as the knee joint affected by osteoarthritic disease. Recently, multiple protocols and devices have been designed for lipoaspirate processing. These protocols and devices do not use enzymatic digestion and respect the principles of the so-called "minimal manipulation in a closed system". In this study, we performed a systematic review of the literature to identify studies in which osteoarthritis was treated by minimally manipulated intra-articular SVF injection and assessment of therapeutic response was reported. All bias scores were analyzed based on the Coleman methodology score modified by Kon et al. [27] and a subsequent linear classification system of articles was proposed. We identified 12 clinical trials in which clinical evaluations were performed inconsistently using different scales of analysis. All studies reported a significant decrease in the patient's symptomatic discomfort, with improvement in joint function and reduction in pain. Most studies do not reach a high-quality level on the linear scale based on the Coleman-Kon scores. Although the treatment of osteoarthritis of the knee with regenerative methods is undoubtedly of interest, being aimed at healing the disease, this study highlights that the trials are numerically limited, and qualitatively not optimal according to the Coleman-Kon score. Reasonably, greater standardization of devices protocols will be desirable in the future. The high clinical potential offered by these methods could be optimized for all patients