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C Falugi

Publications and source records attributed to C Falugi.

At least 19 recordsLinked to original sources
PubMed2005

Genotoxicity biomarkers and acetylcholinesterase activity in natural populations of Mytilus galloprovincialis along a pollution gradient in the Gulf of Oristano (Sardinia, western Mediterranean).

A year-round biomonitoring study on blue mussels (Mytilus galloprovincialis) was carried out in 4 selected sites along the Gulf of Oristano (Sardinia, Italy): a commercial port (Port), the outlet of the S'Ena Arrubia and Marceddì lagoons (in the catchment area of intensive agricultural and diary activities, and abandoned mining), and a reference site (North). Heavy metal concentrations in sediments from Marceddì were 2-3 to 10-20 times higher in Pb, Cd and Zn, respectively, than those found at North and S'Ena Arrubia. Higher values (P<0.05) of micronuclei frequency were detected in mussels from Marceddì and Port compared to those detected in mussels from North and S'Ena Arrubia. DNA damage in animals from North was significantly lower than that at the other sites. Results of acetylcholinesterase inhibition consistently showed the strongest effects in mussels from Port and Marceddì. Our results suggest that these biomarkers can be used in coastal marine biomonitoring as early signals of exposure and adverse effects along a pollution gradient.

Acetylcholinesterase↗
PubMed2005

Interaction between organophosphate compounds and cholinergic functions during development.

Organophosphate (OP) compounds exert inhibition on cholinesterase (ChE) activity by irreversibly binding to the catalytic site of the enzymes. For this reason, they are employed as insecticides for agricultural, gardening and indoor pest control. The biological function of the ChE enzymes is well known and has been studied since the beginning of the XXth century; in particular, acetylcholinesterase (AChE, E.C. 3.1.1.7) is an enzyme playing a key role in the modulation of neuromuscular impulse transmission. However, in the past decades, there has been increasing interest concerning its role in regulating non-neuromuscular cell-to-cell interactions mediated by electrical events, such as intracellular ion concentration changes, as the ones occurring during gamete interaction and embryonic development. An understanding of the mechanisms of the cholinergic regulation of these events can help us foresee the possible impact on environmental and human health, including gamete efficiency and possible teratogenic effects on different models, and help elucidate the extent to which OP exposure may affect human health. The chosen organophosphates were the ones mainly used in Europe: diazinon, chlorpyriphos, malathion, and phentoate, all of them belonging to the thionophosphate chemical class. This research has focused on the comparison between the effects of exposure on the developing embryos at different stages, identifying biomarkers and determining potential risk factors for sensitive subpopulations. The effects of OP oxonisation were not taken into account at this level, because embryonic responses were directly correlated to the changes of AChE activity, as determined by histochemical localisation and biochemical measurements. The identified biomarkers of effect for in vitro experiments were: cell proliferation/apoptosis as well as cell differentiation. For in vivo experiments, the endpoints were: developmental speed, size and shape of pre-gastrula embryos; developmental anomalies on neural tube, head, eye, heart. In all these events, we had evidence that the effects are mediated by ion channel activation, through the activation/inactivation of acetylcholine receptors (AChRs).

Animals↗
PubMed2005

Cell signalling during sea urchin development: a model for assessing toxicity of environmental contaminants.

The early development of sea urchins has been thoroughly studied since the beginning of the 20th century thanks to the particular features of the model involving cell signalling, making it easy to follow the complex cell-to-cell interactions that lead to development. In this chapter, the prominent role of cell-to-cell communication in developmental events is discussed, as well as the role of intracellular ion changes that are in turn regulated by signal molecules belonging to the cholinergic system. The results seem to indicate that the zygote stage is the most suitable to study the role of the cholinergic system, as at this stage, a calcium spike can be evoked by exposure to acetylcholine (ACh) or to muscarinic drugs, at any time before the nuclear breakdown. The described outcomes also open a path to a new way of considering biomarkers. In fact, most environmental factors have the capacity to interfere with the cholinergic system: stress, wounds, inflammation and pollution in general. In particular, this offers a way to investigate the presence in the environment and the degree of aggressiveness of neurotoxic contaminants, such as organophosphate and carbamate pesticides, largely used in European countries for many purposes, including agricultural pest control and medical treatment. These drugs exert their function by interfering with the regulation of the cholinergic system and the consequent electrical events. Thus, the sea urchin zygote could represent a reliable model to be used in biosensors with the capacity to translate the effect of neurotoxic pesticides, and generally of stress-inducing contaminants, in living cell responses, such as electrical responses.

Acetylcholine↗
PubMed2003

Biological targets of neurotoxic pesticides analysed by alteration of developmental events in the Mediterranean sea urchin, Paracentrotus lividus.

Biological effects of neurotoxic insecticides widely used for agricultural purposes were studied using the early development of the Mediterranean sea urchin Paracentrotus lividus as a model. These compounds, dispersed as aerosols or powders in agricultural regions near to the coast, may affect the health of organisms in the marine environment. The biological effects of Basudin (an organophosphate compound containing 20% Diazinon), Diazinon (Dzn, a thionophosphate), Carbaryl and Pirimicarb (carbamates) on the early phases of sea urchin development were thus investigated. Morphological, biochemical, histochemical and immuno histochemical analyses were performed both during embryo and larval development. For the morphological effects on fertilisation and first cleavages, the effective concentration of insecticides was found to be 10(-4) M, while for further stages concentrations between 10(-5) and 10(-7) M were effective: 10(-3) M of any of these insecticides totally arrested development. During embryonic development, the treatment with organophosphates slowed the rate of early mitotic cycles down, affected nuclear and cytoskeletal status as well as DNA synthesis. From the gastrulation stage onwards, the main effects were exerted on the rate of primary mesenchyme cells migration, larval size, perioral arm length, and acetylcholinesterase activity distribution, thus deregulating the cholinergic system, which modulates cell-to-cell communication mediated by the signal molecule acetylcholine.

Acetylcholinesterase↗
PubMed2003

Involvement of acetyl choline in settlement of Balanus amphitrite.

The aim of the present study was to investigate the presence and distribution of cholinergic molecules in Balanus amphitrite cyprids and their possible involvement in settlement and adhesion. Acetylcholinesterase (AChE, the lythic enzyme of acetylcholine) activity was detected, for the first time, by biochemical and histoenzymological methods, in the thoracic muscles, gut wall and cement gland. The immunodetection of choline acetyltransferase-like (ChAT) molecules in the same area and in the neuropil of the central nervous system suggests the presence of a cholinergic innervation, and the involvement of acetylcholine in muscular contraction and cement gland exocytosis. The binding of FITC-conjugate alpha-bungarotoxin in the cement gland cells confirms the latter hypothesis. Acetylcholine involvement in the settlement process was also investigated by laboratory tests employing cholinergic antagonists and agonists. An increase of available acetylcholine due to the partial inhibition of AChE activity produced an increase in cyprid settlement. The data presented support the hypothesis that acetylcholine has a neurotransmitter/neuromodulator role in settlement and adhesion of barnacle cyprids.

Acetylcholine↗
PubMed2002

Evaluating the genotoxic damage and hepatic tissue alterations in demersal fish species: a case study in the Ligurian Sea (NW-Mediterranean).

A protocol for detecting hepatic micronuclei in fish was performed to check genotoxic damage, as an indicator of environmental hydrocarbons exposure, in relation to the "Haven" oil spill. As target fish, we have chosen three demersal species with different habitats and feeding behaviour (i.e., Lepidorhombus boscii, Merluccius merluccius and Mullus barbatus) collected from two differently impacted areas and a control site. Additional analysis was performed by histological detection of hepatic tissue damages such as the presence of necrotic and tumour-like aspects. The three studied species showed different sensitivity to environmental pollutants exposure, L. boscii resulting the more sensitive in terms of both micronuclei incidence and tissue damage. The results of this study show that: (1) the micronucleus test could be an effective and fast method to detect oil pollution; (2) a clear response of L. boscii only to oil contamination for both micronucleus test and liver tissue alterations.

Animals↗
PubMed2002

Muscarinic signalling affects intracellular calcium concentration during the first cell cycle of sea urchin embryos.

The existence of a response to acetylcholine (ACh) and cholinomimetic drugs in sea urchin eggs and zygotes was investigated in two sea urchin species: Paracentrotus lividus and Lytechinus pictus. The calcium sensitive fluorescent probe, Fura-2 dextran, was employed to investigate the regulation of cytosolic free calcium concentration ([Ca(2+)](i)) by cholinomimetic drugs in unfertilised and fertilised eggs of both the sea urchin species. Exposure to cholinomimetic agonists/antagonists, either extracellularly or intracellularly, had no effect either on resting [Ca(2+)](i) levels in the unfertilised sea urchin egg, or on the transient [Ca(2+)](i) increase at fertilisation. However, following fertilisation, extracellular application of ACh receptors agonists, such as ACh and carbachol, predominantly muscarinic agonist, but not nicotine, induced a significant increase in [Ca(2+)](i), which was partially inhibited by atropine. As a consequence of exposure after fertilisation to the agonists of ACh receptors, chromatin structure was transiently affected. The hypothesis is proposed that muscarinic receptors may be involved in the (presumably Ca(2+)-dependent) modulation of the nuclear status during the first cell cycles.

Acetylcholine↗
PubMed2002

Three-dimensional mapping of cholinergic molecules by confocal laser scanning microscopy in sea urchin larvae.

Confocal laser scanning microscopy (CLSM) was used to examine molecules related to the cholinergic neurotransmission system and detected at all the larval stages of Paracentrotus lividus, by histochemical and immunohistochemical methods. CLSM, providing spatial resolution of the cells located both at the larval surface and at depth, allows a complete mapping in a three-dimensional volumetric frame. At early larval stages acetylcholinesterase- as well as choline acetyltransferase-like molecules were found mainly in the gut wall cells, and along the ciliary bands of the arms, together with muscarinic acetylcholine receptors. At perimetamorphic stages, cholinergic molecules were present in the ciliate strands along the arms, in the larval body and in the rudiment. At metamorphosis, positivity to cholinergic molecules translocated to the juvenile, where a high frequency of mAChR- and ChAT-like positive cells was found.

Animals↗
PubMed2001

Biomarkers of exposure and effect in flounder (Platichthys flesus) exposed to sediments of the Adriatic sea.

The modifications of several biomarkers were investigated in flounder (Platichthys flesus) when exposed in the laboratory to sediment samples collected from the Northern Adriatic Sea. Besides clean sand used as a control substrate, fish were exposed to sediments sampled offshore the delta of the Po River, the harbour of Trieste, and from the industrial harbour of Venice (Porto Marghera). After six days of exposure, the enzyme activities ethoxyresorufin-O-deethylase (EROD), UDP glucuronyltransferase (UDPGT), glutathione S-transferase (GST), glutathione reductase (GR) and glutathione peroxidase (GPx), were assayed in fish liver. In addition, the contents of reduced glutathione (GSH), nonprotein thiols (SH), total sugars and extractable lipids were also determined in hepatic tissue, as well as the number of micronucleated hepatocytes and biliary concentrations of fluorescent aromatic compounds (FAC). Despite some variability within treatment groups, differences among exposed organisms were evident and consistent with known contaminant levels of sampled areas. Microsomal activities (EROD, UD-PGT) and FAC levels were the most sensitive exposure indicators. Variations in the other biomarkers showed only tendencies which although not statistically significant were generally consistent with the contamination pattern.

Animals↗
PubMed2001

Induction of micronuclei by a new non-peptidic mimetic farnesyltransferase inhibitor RPR-115135: role of gene mutations.

To investigate the relationship between oncogene activation and induction of micronuclei by a new non-peptidic mimetic farnesyltransferase inhibitor, RPR-115135, two isogenic cell lines, human colon cancer line HCT-116, which harbors a K-ras mutation, and spontaneously immortalized human breast epithelial cell line MCF-10A, were utilized. HCT-116 cells were transfected with an empty control pCMV vector (clone CMV-2) or with a dominant negative mutated p53 transgene (clone Mu-p53-2) to disrupt p53 function. In both clones RPR-115135 induced a significant increase in the frequency of micronucleation at concentrations that did not affect cell membrane integrity. RPR-115135 produced a significant increase in the ratio of CREST+ to CREST- micronuclei. MCF-10A cells were stably transfected with either c-Ha-ras or c-erbB-2 or both H-ras + c-erbB-2. No induction of micronuclei was observed. No induction of micronuclei was reported in human lymphocytes and in primary spinal cells obtained from 7-day chick embryos. In conclusion, RPR-115135 acts as an aneugenic agent in a complex manner, dependent upon the complement of mutations in cell regulatory genes in tumour cells and this activity may be independent of ras genotype.

Alkyl and Aryl Transferases↗
PubMed2001

Synthesis of the signal molecule acetylcholine during the developmental cycle of Paramecium primaurelia (Protista, Ciliophora) and its possible function in conjugation.

We recently discovered, in mating-competent Paramecium primaurelia, the presence of functionally related molecules of the cholinergic system: the neurotransmitter acetylcholine (ACh), both its nicotinic and muscarinic receptors and its lytic enzyme acetylcholinesterase (AChE). Our results on the inhibition of mating-cell pairing in vivo in mating-competent cells treated with cholinomimetic drugs support the hypothesis that the cholinergic system plays a role in cell-to-cell adhesion. To investigate the possible function of the signal molecule ACh in conjugation in P. primaurelia, we attempted to detect the intracellular sites of ACh synthesis by localizing the ACh biosynthetic enzyme choline acetyltransferase (ChAT). Using immunocytochemical and histochemical methods, we have demonstrated the presence and activity of ChAT principally on the surface membrane of mating-competent cells and of mature but non-mating-competent cells. No evidence for ChAT activity was found in immature cells. Immunoblot analysis revealed the presence of immunoreactive bands, ranging in molecular mass from 42 to 133 kDa, as reported for ChAT isolated from higher organisms. In vivo experiments showed that inhibition of ChAT activity by Congo Red, known to be a potent competitive inhibitor of acetyl coenzyme A, did not affect mating-cell pairing. Conversely, inhibition of AChE with BW 284c51 or eserine, which block enzyme activity by reacting with a specific serine within the catalytic centre, significantly inhibited mating-cell pairing. Our results suggest that ACh has a negative modulating effect on conjugation in P. primaurelia.

Acetylcholine↗
PubMed1999

Evidence for the presence of a mammalian-like cholinesterase in Paramecium primaurelia (Protista, Ciliophora) developmental cycle.

By histochemical and immunohistochemical methods, the presence of cholinergic-like molecules has previously been demonstrated in Paramecium primaurelia, and their functional role in mating-cell pairing was suggested. In this work, both true acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities were electrophoretically investigated, and the presence of molecules immunologically related to BuChE was checked by immunoblotting. The AChE activity, shown in the membrane protein fraction of mating-competent cells and in the cytoplasmic fraction of immature cells, is due to a 260-kDa molecular form, similar to the membrane-bound tetrameric form present in human erythrocytes. This AChE activity does not appear in either the cytoplasmic fraction of mating-competent cells or in the membrane protein fraction of immature cells. No evidence was found for the presence or the activity of BuChE-like molecules. The role of AChE in P. primaurelia developmental cycle is discussed.

Acetylcholinesterase↗
PubMed1999

Presence and localization of molecules related to the cholinergic system in developing rat testis.

The presence of cholinergic molecules was recently found in male gametes of different animal species; very little is known from this point of view about the somatic component of the gonad. In the present study, a contribution is given to the localization of some cholinergic-like molecules, such as acetylcholinesterase (AChE), nicotinic acetylcholine and muscarinic acetylcoline (nAchR and mAChR, respectively) receptors during postnatal development of the testis. Maturation stages were checked by use of histochemical stainings, such as DAPI for nuclear shape changes, and PSA binding to reveal acrosomal maturation. The distribution of cholinergic-like molecules, revealed by immunocytochemical methods in both gametes and somatic cells, varied with development. Generally, during early stages, molecules immunologically related to AChE, and to mAChR's were mainly found in the interstitial and peritubular compartment, while, during maturation, they were found in Sertoli cells and in differentiating germ cells. nAChR's were not found in the somatic compartment, except in the blood vessel walls, and were distributed in mature germ cells, mainly in the flagella. The presence of cholinergic molecules in somatic as well as germ cells could play a role in cell-to-cell communications affecting testicular cell differentiation and function.

Acetylcholinesterase↗
PubMed1998

Cholinergic activation of settlement in Ciona intestinalis metamorphosing larvae.

During metamorphosis, ascidian tadpoles settle on appropriate substrates, by secreting adhesive substances from the papillae. The papillae were shown by different authors to possess neural structures, probably for substrate recognition. In free-swimming tadpoles, AChE activity was localized by histochemical methods at the cell surface of the adhesive papillae, suggesting the possible presence of a cholinergic system in these structures. In vivo experiments showed that the treatment with AChCl caused dose-dependent enhancement of metamorphosis, shortening of the exploratory period of the larvae, and secretion within a few minutes of sConA-binding glycoconjugates in the tunica, beginning from the adhesive papillae.

Acetylcholine↗
PubMed1998

Biological effects of a neurotoxic pesticide at low concentrations on sea urchin early development. A terathogenic assay.

Dose-dependent terathogenic effects of an organophosphate insecticide were found during early sea urchin development. This biological assay is low cost, easy to measure, and allows to detect the effects of the exposure of organisms to the active principle at concentrations lower than the acceptable daily intake (ADI) for man. Effects were found independently from the stage of exposure, and were major as earlier exposure occurred. The stronger effects were exerted on the elongation of the skeletal rods, that was easily measured by following the migration of primary mesenchyme cells, labelled by WGA (wheat germ agglutinin).

Animals↗
PubMed1998

Muscarinic drugs affect cholinesterase activity and development of eye structures during early chick development.

During neurogenesis, markers of the cholinergic system are present in the eye and visual cortex of vertebrates. In adult vertebrates, a role for these molecules, including muscarinic acetylcholine receptors (mAChRs), in eye growth non-accommodative regulation is also known. In order to understand the biological mechanisms triggered by the cholinergic system in these events, we analysed the effects of a cholinergic agonist (10(-4) M carbachol) and an antagonist (10(-4) M atropine) of the muscarinic receptors, on early chick development. To establish if the cholinergic system also plays a role in the regulation of early neurogenetic signals, the drug treatments were made at stage 5-6 HH, during the formation of the cephalic process. Specific effects on forehead, and in particular on eye development were found; carbachol treated embryos presented huge and well pigmented eyes, significantly different from controls. The eyes of atropine-exposed embryos presented anomalies with different phenotypes ranging from strongly affected features to normal-like appearance. Generally, the eyes were smaller as compared to the controls, with a number of anomalies, also in the normal-like phenotype, including retina and lens defects. In these structures, distribution of cholinesterase activities was checked by histochemical methods, and the amount of cells undergoing nuclear disgregation was revealed by DAPI staining. We propose that the drugs affected the known nervous and pre-nervous functions of the cholinergic markers, such as cell signalling during primary induction, and regulation of cell death by ACh receptors.

Acetylcholinesterase↗
PubMed1996

Glycoconjugate expression changes during Rana dalmatina early development.

Glycoconjugates are generally involved in cell adhesion and morphogenetic movements. To investigate their distribution and expression changes during amphibian development, several FITC-or HRP-labeled lectins were used in Rana dalmatina embryos and larvae. During gastrulation, WGA, ConA, HPA, GSA-I, PNA and RCA-I labeled either the envelopes on the perivitelline space-contained substances, while ectodermal cells and/or extracellular matrix were mainly labeled by WGA, GSA-I, DBA and LTA. In these structures fibronectin-like molecules were also found. ConA, HPA, RCA-I, SBA also labeled ectoderm, but with lower affinity. At larval stages, ectodermal derivatives, such as larval skin, central nervous system, eye and ear, were also strongly labeled by WGA, DBA and LTA, while the affinity to ConA, HPA, GSA-I, SBA, appeared less visible; the affinity sites to RCA-I and PNA were totally lacking. Fibronectin-like immunoreactivity was hardly present at the larval stages. These results point out that glycoconjugate expression changes in cell surface and in extracellular matrix might be developmentally regulated. For this reason the different glycoconjugates seem to play stage-specific roles in early development.

Animals↗