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Funzione naturale, modificazioni strutturali e proprietà farmacologiche del climacostolo
Full text linkCold-adapted Euplotes pheromones
Full text linkSpecies of Euplotes rely on diffusible signal proteins (pheromones) to promote their mitotic reproduction
and mating (sexual) phenomena. Two of these pheromones have recently been structurally characterized from an Antarctic species, E. nobilii, and their amino acid sequences (of 52 and 60 residues, and eight cysteines) were found to be closely related with those of E. raikovi pheromones of temperate waters. However, they diverge in physicochemical properties, such as a reduced hydrophobicity, an increased solvent accessibility and improved backbone flexibility, which together reflect their close adaptation to cold
Antimitotic and cytotoxic activity of climacostol on tumoral mammalian cells.
No full textThe freshwater ciliate Climacostomum virens defends itself
against predators by discharging the toxin climacostol (1,3-dihydroxy-5-[(Z)-20-nonenyl]benzene), a resorcinolic lipid contained in its extrusomes (Miyake et al. 2003, Eur. J. Protistol. 39: 25–36). Like other natural chemically related compounds, exerts a dose-dependent cytotoxic effect on tumoral mammalian cell lines (Buonanno et al. 2005, J. Eukaryot. Microbiol. 52:38S). Based on this evidence, we have now examined the effects of chemically synthesized climacostol (Masaki et al. 2004, Tetrahedron 60: 7041–7048) on the proliferation of human promyelocytic leukaemia cells (HL60 line), and squamous carcinoma cells (A431 line) plus, as control, of non-tumoral cells derived from mice Leydig cells (TM3 line). It was observed that: (i) climacostol inhibits the
growth of all cell lines used in dose-dependent manner, but the HL60 and A431 cells are significantly more sensitive to the toxin than TM3 cells; (ii) the cytotoxicity of climacostol (used at a concentration of 10 mg/ml, 24 h of incubation, and detected by the LDH-cytotoxicity test) is appreciably stronger on the tumoral cell lines (60% and 41% cytotoxic activity for the A431 and HL60 cells, respectively) than on the TM3 cells (23% cytotoxic activity). It was in addition observed (by using a fluorescent dye technique) that climacostol induces apoptosis, rather than necrosis, in all the cell lines used. These results indicate that climacostol possesses interesting antitumoral biological activities and encourage further in vivo investigations to assess its potential use in cancer chemotherapy
Structural characterization of En-1, a cold-adapted protein pheromone isolated from the Antarctic ciliate Euplotes nobilii.
Full text linkThe second of two diffusible cell signal proteins (pheromones) purified from a wild-type strain of the Antarctic ciliate, Euplotes nobilii, has been determined by automated Edman degradation of the whole molecule and peptides generated by its chymotryptic digestion. The proposed sequence of 52 amino acids of this new pheromone, designated En-1, is: NPEDWFTPDT10CAYGDSNTAW20TTCTTPGQTC30YTCCSSCFDV40VGEQACQMSA50QC. In common with the previously determined 60-amino-acid sequence of the other pheromone, En-2, it bears eight cysteines in conserved positions (presumably linked into four conserved intrachain disulfide bonds), and physicochemical features of potential significance for cold adaptation, such as a reduced hydrophobicity, an increased solvent accessibility, and an improved local backbone flexibility. However, En-1 diverges from En-2 for having evolved a threonine cluster in the place of a glycine cluster to apparently make more flexible a region that is likely functionally important
Effects of climacostol on normal and tumoral mammalian cell lines
No full textClimacostol, 1,3-dihydroxy-5-[(Z)-20-nonenyl]benzene, is a
natural toxin contained in the extrusomal cortical granules of
the heterotrich ciliate Climacostomum virens. It is used for
chemical defence against predators such as the raptorial ciliate Dileptus margaritifer and its cytotoxic activity has been assessed on several species of ciliates such as Didinium nasutum, Paramecium caudatum, and Blepharisma japonicum (Miyake et al. 2003, Europ. J. Protistol., 39:25–36). On the basis of its chemical structure, climacostol may be classified into the large group of natural compounds known as resorcinolic lipids, that show antimicrobial, antiparasitic, and antitumoral activities (Kozubek et al. 2003, Cell Moll. Biol. Lett., 6:351–355). To explore the possibility to use climacostol in medical applications, we examined the
effects of chemically synthesized climacostol (Masaki et al.
2004, Tetrahedron, 60:7041–7048) on the growth and proliferation of tumoral and normal mammalian cell lines: (1) human promyelocytic leukaemia cells, HL60; (2) human squamous carcinoma cells, A431; and (3) non-tumoral cells derived from mice Leydig cells, TM3. It was observed that (1) a concentration of 10 mg/ml of climacostol exerts a strong cytotoxic activity on all cell lines used; (2) at lower concentrations of 10 ng/ml and 1 ng/ ml, the effect of climacostol is limited to the inhibition of the cell growth; and (3) the normal TM3 cells are more resistant to climacostol than the two tumoral HL60 and A431cell lines. The dose-dependent cytotoxic effects of climacostol encourage further
investigation on the potential use of this ciliate toxin as an anticancer chemical
Identificazione e iniziale caratterizzazione funzionale di una associazione tra il sistema feromoni-recettori del ciliato Euplotes raikovi e una ciclofilina
No full textCell aging-induced methionine oxidation causes an autocrine toparacrine shift of the pheromone activity in the protozoan ciliate, Euplotes raikovi
No full textCiliates of the genus Euplotes rely on the autocrine (self) and paracrine (non-self) activities of their water-borne protein pheromones to control the two fundamental phenomena of their life
cycle, i.e. vegetative (mitotic) growth and sex manifested as cell union in mating pairs. We observed
that cell aging determines the synthesis of increasing concentrations of pheromones that are oxidized at the level of methionine residues which are more exposed on the molecular surface. The oxidized form of the E. raikovi pheromone Er-1 was purified and its interactions with its source cells were shown no longer to be of autocrine type directed to promote cell growth, but changed to interactions of the paracrine type directed to induce cell unions in mating pairs of the selfing type (i.e. involving genetically identical cells). These pairs generate viable offspring, like pairs formed between genetically different cells. It was therefore concluded that aging cells may paradoxically gain beneficial effects from the synthesis of oxidized forms of their pheromones. By undergoing mating in response to the interactions with these forms, they can reinitiate a new life cycle and, in fact, rejuvenate
An Experience on Environmental Education Based on Respect-Reduce-Reuse-Recycle in a Village Primary School in the Marche Region, in Italy
Full text linkThe importance of environmental education is widely recognized worldwide: an important objective is that the
citizens are accustomed to apply the best available practices in their life, while asking the administration and the
government to gradually enforce measures leading to a reduction of the environmental impact and to a more
sustainable lifestyle. This requires a formation starting at an early age: however, in Italy the relevant indications
from the National Curriculum are still limited and do not suggest explicitly the performance of any practical
activity, tailored on the specific school setting. This inadequacy of the Curriculum becomes particularly apparent
in cases where other concerns are present, for example the areas in the Marche region affected by the 2016
earthquake: here, the need to resume a day-by-day routine put a kind of “damper” on other questions, such as
environmental issues. This had an effect also in children’s life: on this question, school needs to take a stand, which
is the objective of this study. This work concerns an approach to environmental education in a multi-classes
primary school context (age 6-10) in a small village school, located in the Central Apennine in Italy. This is
performed through an experience carried out by investigating the behavior towards waste production of the
community, as perceived by children at school. It is therefore articulated through the application of 4R (Respect,
which encompasses Reduce, Reuse and Recycle) applying and extending the indications from the Italian National
Curriculum. The project leads also to an experience of self-production of objects by the use of waste, to improve
their awareness of the possibilities included in their upcycling. Feedback on the experience is finally acquired from
the children and discussed, especially in the sense of creating future citizens with a more sensible and reasonable
behavior towards the environment and leading possibly to zero-waste strategies in their family and work setting.
The data were analyzed using thematic analysis and different themes about waste production were singled out
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