Biomedical subjects

R Ciccocioppo

Publications and source records attributed to R Ciccocioppo.

At least 37 records · Page 2Linked to original sources

PubMed2001

Intraepithelial and lamina propria lymphocytes show distinct patterns of apoptosis whereas both populations are active in Fas based cytotoxicity in coeliac disease.

BACKGROUND: Lamina propria (LPLs) and intraepithelial (IELs) lymphocytes are markedly increased in coeliac mucosa, and are thought to play a crucial role in the generation of villous atrophy in coeliac disease (CD). However, the mechanisms by which they mediate the killing of enterocytes in this condition are still poorly characterised. AIM: We investigated Fas mediated cytotoxicity and apoptosis of both LPLs and IELs, isolated from 10 untreated coeliac patients, 10 coeliac patients on a gluten free diet, and 10 biopsied controls. METHODS: Fas and Fas ligand expression were assessed by flow cytometry and immunocytochemistry. Lymphocyte cytotoxicity against Fas expressing Jurkat cells was determined by the Jam test. The effect of the antagonist ZB4 anti-Fas antibody on apoptotic activity exerted by coeliac lymphocytes against enterocytes was analysed. Lymphocyte apoptosis was assessed by oligonucleosome ELISA. RESULTS: LPLs and IELs showed increased apoptotic activity and higher levels of Fas ligand expression in untreated CD compared with treated CD patients and controls. Enterocyte apoptosis observed after coculturing coeliac lymphocytes and enterocytes in the presence of ZB4 antibody was reduced. In active CD, LPLs manifested increased apoptosis whereas IELs showed decreased apoptosis. CONCLUSIONS: Our results support the involvement of the Fas/Fas ligand system in CD associated enterocyte apoptosis. Increased LPL apoptosis is likely to downregulate mucosal inflammation whereas decreased IEL apoptosis could be responsible for autoimmune and malignant complications of CD.

Adult↗

PubMed2001

Increased enterocyte apoptosis and Fas-Fas ligand system in celiac disease.

Our aim was to evaluate whether increased enterocyte apoptosis was responsible for mucosal flattening in celiac disease (CD), and, since the mechanisms responsible for tissue injury in this condition are unknown, we studied the possibility that the Fas-Fas ligand (FasL) system may be involved. Endoscopic duodenal biopsy specimens from 12 patients with untreated and 12 with treated CD and 12 control subjects were evaluated for enterocyte apoptosis by the terminal deoxynucleotidyl transferase-mediated digoxigenin-deoxyuridine triphosphate nick-end labeling assay and for Fas and FasL expression by immunohistochemistry. A coculture of isolated enterocytes (targets) and purified lamina propria mononuclear cells (LPMCs) (effectors) was performed in the absence or presence of an antagonistic ZB4 anti-Fas antibody. We found a significant correlation between the degree of villous atrophy, morphometrically evaluated, and the level of enterocyte apoptosis, suggesting that mucosal flattening is a consequence of exaggerated epithelial cell death. Most celiac enterocytes express Fas, and LPMCs express FasL. The abolishment of enterocyte apoptosis observed in the presence of ZB4 antibody suggests that enterocytes are potential targets of lymphocyte infiltrate. These results directly demonstrate that FasL-mediated apoptosis is a major mechanism responsible for enterocyte death in CD.

Adult↗

PubMed2000

Effect of nociceptin/orphanin FQ on the rewarding properties of morphine.

The present study investigated the effect of nociceptin/orphanin FQ, the endogenous ligand of the opioid receptor-like 1 (ORL1) receptor, on the rewarding properties of morphine in the place conditioning paradigm. Intracerebroventricular (i.c.v.) injections of nociceptin/orphanin FQ, 500 or 1000 (but not 250) ng/rat, abolished conditioned place preference induced by subcutaneous (s.c.) injections of morphine (3 mg/kg). These doses of nociceptin/orphanin FQ induced neither place aversion nor preference per se. The same doses did not modify the rat performance in the Morris water test, suggesting that they do not disrupt spatial learning and memory. Moreover, these doses of nociceptin/orphanin FQ did not modify the development of morphine-induced locomotor sensitization, suggesting that they do not interfere with sensitization processes to morphine. The present results confirm and extend previous reports that nociceptin/orphanin FQ is able to abolish morphine-induced conditioned place preference, and raise interest for the possible role of nociceptin/orphanin FQ and ORL1 receptors in the control of opiate abuse.

Animals↗

PubMed2000

Nociceptin prevents stress-induced ethanol- but not cocaine-seeking behavior in rats.

This study examined whether nociceptin/orphanin FQ (NC), the endogenous ligand of the opioid receptor-like1 (ORL1) receptor, can block drug-seeking behavior induced by foot-shock stress. Male Wistar rats were trained to operantly self-administer ethanol or cocaine, and then subjected to daily extinction training until responding ceased. Subsequent exposure to 15 min of intermittent footshock elicited robust reinstatement of responding at the previously drug-paired lever. NC (0.1-2.0 microg; i.c.v.) significantly inhibited the effects of footshock stress on ethanol- but not cocaine-seeking behavior. The results support the hypothesis that the NC system participates in the regulation of behavioral responses to stress, and that drugs interacting with NC receptors may have therapeutic potential for the treatment of stress-induced alcohol-seeking behavior and relapse.

Animals↗

PubMed2000

Pharmacological characterization of the nociceptin receptor mediating hyperphagia: identification of a selective antagonist.

RATIONALE: Central injections of nociceptin (NC) stimulate feeding in rats. OBJECTIVE: The present study evaluated the effect of N-terminal partial sequences or analogues of NC on food intake in male Wistar rats, to characterize pharmacologically the NC receptor mediating the hyperphagic effect. METHODS: NC and related peptides were injected into the lateral (LV) or third (3V) cerebroventricle in freely feeding rats. RESULTS: In the LV, NC stimulated feeding. The N-terminal fragment NC(1-13)NH2 proved to be the least active sequence with hyperphagic activity; NC(1-12)NH2 and NC(1-9)NH2 were inactive. [Phe(1)psi(CH2-NH)Gly(2)]NC(1-13)NH2 ([F/G)]NC(1-13)NH2), an analogue of NC(1-13)NH2, markedly stimulated feeding and, coadministered in the LV with NC, never reduced the hyperphagic effect of the natural sequence. These findings suggest that [F/G)]NC(1-13)NH2, which has been reported to act as a NC receptor antagonist in peripheral tissues, behaves as a full agonist at the central NC receptors controlling feeding. The hyperphagic potencies of NC and [F/G)]NC(1-13)NH2 were much higher following injection into the 3V than in the LV. Another analogue of NC(1-13)NH2, namely [Nphe(1)]NC(1-13)NH2, injected into the 3V did not stimulate feeding, but reduced the effect of NC. [Nphe(1)]NC(1-13)NH2 at a dose of 16.8 nmol/rat significantly reduced, and at 168 nmol/rat almost completely abolished the effect of NC (1.68 nmol/rat). The latter dose of [Nphe(1)]NC(1-13)NH2 significantly reduced also feeding induced by food deprivation, but did not modify the hyperphagic effect of neuropeptide Y (0.3 nmol/rat). CONCLUSIONS: The present results confirm the orexigenic effect of NC in freely feeding rats and indicate that [Nphe(1)]NC(1-13)NH2 may represent a selective NC receptor antagonist to study the physiological and pathophysiological role of NC in feeding behaviour.

Animals↗

PubMed2000

Effects of Hypericum perforatum extract on ethanol intake, and on behavioral despair: a search for the neurochemical systems involved.

The present study investigated the possible involvement of sigma receptors and of serotonergic mechanisms in the effects of Hypericum perforatum extract (HPE) on immobility time in the forced swimming test (FST) and on ethanol intake in Marchigian Sardinian alcohol-preferring rats. The HPE employed was a dry extract containing 0.3% hypericin and 3.8% hyperforin. Intraperitoneal pretreatment with 20 mg/kg of the sigma receptor antagonist rimcazole (RIM), 30 min prior to HPE, completely suppressed the antiimmobility effect of HPE (3 intragastric injections of 250 mg/kg). Intracerebroventricular pretreatment with 5, 7-dihydroxytryptamine (5,7-DHT), which produced a marked depletion of brain serotonin, reduced the antiimmobility effect, although this reduction was not as pronounced as that of RIM. On the other hand, the inhibitory effect of HPE on 10% ethanol intake was modified neither by 5,7-DHT nor by RIM pretreatment. These results suggest that the antidepressant-like effect of HPE in the FST may be mediated by interaction with sigma receptors and to some extent by increased serotonergic neurotransmission. On the other hand, these mechanisms appear to be unimportant for the effect of HPE on ethanol intake.

5,7-Dihydroxytryptamine↗

PubMed2000

Nociceptin/orphanin FQ and drugs of abuse.

Nociceptin/orphanin FQ (NC) binds with high affinity to the opioid receptor-like1 (ORL1) receptor. NC has been reported to block opioid-induced supraspinal analgesia, and it has been proposed that it may represent a functional antiopioid peptide in the control of brain nociceptive processes. The wide distribution of NC and of its receptors in the central nervous system suggests, however, that it may be involved in the control of a variety of biologic functions. Increasing evidence indicates that it may influence the rewarding and reinforcing properties of drugs of abuse. NC has been shown to abolish the rewarding properties of ethanol and morphine in the place conditioning paradigm, to reduce ethanol consumption in alcohol-preferring rats and to inhibit stress-induced alcohol-seeking behavior. These findings suggest that drugs directed at central NC receptors may represent an interesting approach to the treatment of ethanol and opiate abuse.

Alcohol Drinking↗

PubMed2000

Neuropeptide Y receptor(s) mediating feeding in the rat: characterization with antagonists.

The present study evaluated the effect of the neuropeptide Y (NPY) Y1 receptor antagonists BIBO 3304 and SR 120562A and of the Y5 receptor antagonists JCF 104, JCF 109, and CGP 71683A on feeding induced either by NPY or food deprivation. In a preliminary experiment, NPY was injected into the third cerebroventricle (3V) at doses of 0.07, 0.15, 0.3, or 0.6 nmol/rat. The dose of 0.3 nmol/rat, which produced a cumulative 2-h food intake of 11.2 +/- 1.9 g/kg body weight, was chosen for the following experiments. The antagonists were injected in the 3V 1 min before NPY. The Y1 receptor antagonist BIBO 3304 significantly inhibited NPY-induced feeding at doses of 1 or 10 nmol/rat. The Y1 receptor antagonist SR 120562A, at the dose of 10 but not of 1 nmol/rat, significantly reduced the hyperphagic effect of NPY, 0.3 nmol/rat. The Y5 receptor antagonists JCF 104 and JCF 109 (1 or 10 nmol/rat) and CGP 71683A (10 or 100 nmol/rat) did not significantly modify the effect of NPY, 0.3 nmol/rat. However, JCF 104 (10 nmol/rat) and CGP 71683A (100 nmol/rat), but not JCF 109 (10 nmol/rat), significantly reduced food intake during the interval from 2 to 4 h after injection of a higher dose, 0.6 nmol/rat, of NPY. Feeding induced by 16 h of food deprivation was significantly reduced by the Y1 receptor antagonist BIBO 3304 (10 nmol/rat), but it was not significantly modified by the same dose of SR 120562A or JCF 104. These findings support the idea that the hyperphagic effect of NPY is mainly mediated by Y1 receptors. The results obtained with JCF 104 and CGP 71683A suggest that Y5 receptors may have a modulatory role in the maintenance of feeding induced by rather high doses of NPY after the main initial feeding response.

Animals↗

PubMed2000

Cytolytic mechanisms of intraepithelial lymphocytes in coeliac disease (CoD).

The effector arm of the mucosal immune system comprises lymphocytes scattered at intraepithelial and lamina propria levels. Intraepithelial lymphocytes (IEL) are a large population of oligoclonal resting cells which exhibit phenotypic and functional characteristics of cytolytic T cells when activated. Several mechanisms have been demonstrated to account for their cytotoxicity. Among them, one is mediated by perforin and granzyme molecules, another is mediated by Fas ligand (FasL) which delivers apoptotic signals through Fas receptor on target cells. There is good evidence that a flat intestinal mucosa may be produced by activated T cells. The aim of our study was to evaluate FasL and perforin expression by IEL, and its possible correlation with the increased enterocyte apoptosis in coeliac mucosa. Endoscopic duodenal biopsy specimens from 10 untreated coeliac patients, 10 treated coeliac patients, and 10 biopsied controls were evaluated for enterocyte apoptosis by terminal deoxynucleotidyl transferase-mediated digoxigenin-deoxyuridine triphosphate nick end label method, for perforin expression by immunohistochemistry, and for FasL expression by immunocytochemistry. In untreated CoD there was a significant increase of percentage of both FasL+ and perforin+ IEL which positively correlated with enterocyte apoptosis in comparison with controls. All these parameters were significantly lower in treated CoD, even though they did not normalize. Our study demonstrates that in untreated CoD FasL and perforin expression by IEL is increased, and significantly correlates with the level of enterocyte apoptosis.

Adolescent↗

PubMed2000

The molecular determinants of the efficiency of green fluorescent protein mutants.

The Green Fluorescent Protein (GFP) is a spontaneously fluorescent polypeptide of 27 kD from the jellyfish Aequorea victoria that absorbs UV-blue light and emits in the green region of the spectrum. GFP has been successfully expressed both in bacteria and in eukaryotic cells and is widely used to monitor the localization of tagged proteins in living cells. Since wtGFP performs inefficiently in different cellular contexts, efforts have been devoted to the improvement of GFP expression levels and/or fluorescence. We will here review the basic characteristics of wt and mutated GFP, in particular their protein expression vs fluorescent properties. Emphasis will be given to unexpected consequences of mutations of the GFP gene, i.e. on transcription and translation rates and on protein folding in different cell types, and to how these critically reflect on the use of GFP in different cellular environments.

Animals↗

PubMed1999

Autoradiographic analysis of 5-HT2A binding sites in the brain of Sardinian alcohol-preferring and nonpreferring rats.

The density of 5-HT2A binding sites in the brain of Sardinian alcohol-preferring (sP) and nonpreferring (sNP) rats was evaluated, using [3H]ketanserin for quantitative autoradiography. The highest [3H]ketanserin binding levels were found in the anterior olfactory nucleus, prefrontal cortex, medial prefrontal cortex, post-genual anterior cingulate cortex, insular cortex and claustrum. Statistically significant differences between sP and sNP rats were found in prefrontal cortex, medial prefrontal cortex and post-genual anterior cingulate cortex, where sP rats showed about 20% lower [3H]ketanserin binding levels. No significant difference was found in other areas, although some of them showed slightly lower [3H]ketanserin binding density in sP rats. The 5-HT2A receptor agonist, (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-amino-propane hydrochloride (DOI), microinjected into the medial prefrontal cortex, induced a lower number of wet dog shakes in sP than in sNP rats. These results indicate a different density of 5-HT2A binding sites, and a different functional regulation of 5-HT2A receptor mechanisms in discrete brain areas of sP, in comparison to sNP rats. These findings, and those showing lower levels of 5-HT in the frontal cortex of sP rats, suggest that altered 5-HT function in fronto-cortical areas could be linked to the genetic predisposition to high voluntary ethanol intake in these rats.

Alcohol Drinking↗

PubMed1999

Effect of nociceptin on alcohol intake in alcohol-preferring rats.

The present study investigated the effect of nociceptin (NC), the endogenous ligand of the opioid-like orphan receptor ORL1, on ethanol intake in genetically selected Marchigian Sardinian alcohol-preferring (msP) rats. Acute intracerebroventricular (i.c.v.) injection of 250 or 500 ng/rat of NC, just before access to 10% ethanol (offered 2 h/day), significantly increased ethanol intake. Subchronic (7 days) i.c.v. injection of 500 ng/rat of NC, given just before access to 10% ethanol (for 30 min/day), resulted in a progressive decrease in ethanol consumption. After the end of NC treatment, rats progressively recovered their usual ethanol intake. When NC, 500 or 1000 ng/rat, was tested versus the effect of ethanol in the place conditioning paradigm, NC significantly reduced the increase in time spent in the ethanol-paired compartment after conditioning. This finding suggests that NC reduces the rewarding properties of ethanol in msP rats; thus, they may respond to the acute NC administration by increasing their ethanol intake in an attempt to achieve the usual reinforcing effect of ethanol, whereas subchronic NC treatment may result in extinction of ethanol drinking. The results of the present study suggest that the brain NC mechanisms may represent an interesting target of pharmacological interventions for the treatment of alcoholism.

Alcohol Drinking↗

PubMed1999

Ethanol induces conditioned place preference in genetically selected alcohol-preferring rats.

The study of the biological mechanisms of ethanol reward has greatly suffered from problems to obtain ethanol-induced conditioned place preference (CPP) in rats. In the present study, CPP was obtained in genetically selected Marchigian Sardinian alcohol-preferring (msP) rats, derived from Sardinian alcohol-preferring rats, following intragastric (IG) ethanol administration by means of a permanent IG catheter, but not after intraperitoneal (IP) injection or IG gavage. Rats with permanent IG catheter, received IG administration of 0.35, 0.7, 1.5 or 2.8 g/kg ethanol, as a 10% v/v solution. In ethanol-experienced rats 0.7 or 1.5, but not 0.35 or 2.8 g/kg ethanol significantly increased in comparison to controls the time spent in the ethanol-associated previously non-preferred compartment, which became preferred in the post-conditioning test. In ethanol-naive rats, only 0.7 g/kg ethanol significantly increased the time spent in the ethanol-associated compartment. On the other hand, no effect was observed in alcohol-experienced rats following IG gavage, or IP injection of 0.35, 0.7 or 1.5 g/kg ethanol. The present results provide evidence that ethanol possesses postingestive rewarding properties in msP rats, and that it can reliably induce CPP in them, provided that an appropriate method of administration is adopted.

Alcohol Drinking↗

PubMed1999

Antidepressant-like effect of ethanol revealed in the forced swimming test in Sardinian alcohol-preferring rats.

RATIONALE: A large body of evidence indicates high comorbidity between depression and alcohol abuse. The self-medication hypothesis proposes that depressed subjects may abuse ethanol because it reduces the symptoms of depression. The present study evaluated whether ethanol may exert an antidepressant-like action in genetically selected alcohol-preferring rats, either Sardinian alcohol-preferring (sP) or Marchigian Sardinian alcohol-preferring (msP) rats, and for comparison in Sardinian alcohol-non-preferring (sNP) rats. METHODS: The forced swimming test (FST) was used to evaluate the antidepressant-like action of ethanol; in this test the effect of ethanol ingestion on the immobility time was determined. RESULTS: Ethanol-naive sP rats exhibited a longer period of immobility in comparison to sNP rats. Both in ethanol-naive sP and msP rats, voluntary ethanol drinking reduced the immobility time. A similar effect was obtained when repeated (five or nine) intragastric administrations of 0.7 g/kg ethanol were given during the 24 h prior to the test in msP and in sP, but not in sNP rats. Desipramine, like ethanol, sharply reduced immobility at doses of 5 or 20 mg/kg, given 3 times in the 24 h before the test in msP rats. The reduced immobility induced by ethanol in msP rats was apparently not the consequence of a general motor activation, because 9 IG administrations of ethanol, 0.7 g/kg, failed to alter locomotor activity in the open field test. Moreover, blood alcohol levels and rectal temperature of msP, sP and sNP after IG ethanol administration were not statistically different. CONCLUSIONS: The present results provide evidence for an antidepressant-like action of ethanol in sP and msP rats and suggest that this action may contribute to sustain their high ethanol drinking.

Alcohol Drinking↗

PubMed1999

Conditioned taste aversion induced by ethanol in alcohol-preferring rats: influence of the method of ethanol administration.

A recent study of our group has shown that ethanol evokes conditioned place preference (CPP) in Marchigian Sardinian alcohol-preferring (msP) rats following intragastric (IG) administration by means of an indwelling IG catheter, but not following administration by gavage or by intraperitoneal (IP) injection. The present study evaluated in ethanol-naive msP rats the influence of the method of administration (IG injection by indwelling catheter vs. IP injection) on ethanol-induced conditioned taste aversion (CTA). The dose of 0.35 g/kg of ethanol did not evoke aversion either by IG or by IP administration. Following IG injection, 0.7 g/kg of ethanol, the amount that msP rats voluntarily ingest in a short (2-5 min) drinking episode, did not evoke CTA, and 1.5 g/kg induced a modest CTA. On the other hand, IP injection of 0.7 g/kg of ethanol evoked CTA, and 1.5 g/kg induced a very pronounced CTA. These findings show that the aversive properties of ethanol in msP rats are influenced by the method of administration, and suggest that the IG injection by catheter may reveal more faithfully than the IP injection the motivational properties of amounts of ethanol that alcohol-preferring rats voluntarily ingest.

Alcohol Drinking↗

PubMed1999

Transglutaminase and coeliac disease: endomysial reactivity and small bowel expression.

This study was aimed at verifying whether tissue transglutaminase (tTG) is the sole autoantigen eliciting anti-endomysial antibodies in coeliac disease (CoD) and investigating tTG expression in normal and coeliac mucosa. Twelve anti-endomysial-positive coeliac sera and 12 anti-endomysial-negative control sera (10 microl, diluted 1:5-1:400 in PBS pH 7.3) were preincubated with 10, 20 or 50 microg guinea pig liver tTG at 4 degrees C overnight. Monkey oesophagus tissue slides were then tested with tTG-preincubated and non-preincubated sera to search for IgA anti-endomysial reactivity by indirect immunofluorescence. Moreover, six sections of monkey oesophagus were incubated with an anti-tTG mouse MoAb, six sections with an anti-cytokeratin mouse MoAb and six sections with only 3% bovine serum albumin. Finally, endoscopic duodenal biopsy sections obtained from 12 patients affected by untreated CoD, six patients affected by treated CoD and 10 biopsied controls were immunohistochemically stained with a peroxidase-conjugated anti-tTG MoAb. Our results show that (i) preincubation with tTG abolished endomysial immunofluorescence in most, but not in all, coeliac sera; (ii) the incubation of anti-tTG MoAb with sections of monkey oesophagus resulted in an immunofluorescence staining pattern similar but not identical to that of anti-endomysial-positive coeliac sera; (iii) although tTG expression was present at muscularis mucosae and pericryptal fibroblast in both normal and coeliac mucosa, it was slightly more marked and evident in the latter. Although our absorption experiment was performed with guinea pig liver tTG, we confirm that tTG is the predominant antigen of endomysial antibodies, but we speculate that, at least in some patients, it is not the only one.

Animals↗

PubMed1999

A reassessment of splenic hypofunction in celiac disease.

OBJECTIVES: Because there is controversy regarding the prevalence, familial occurrence, and possible factors inducing splenic hypofunction in celiac disease, we have reassessed them in a large series of untreated patients and their first-degree relatives. METHODS: Pitted red cell counting was used to measure splenic function and the effect that age at diagnosis has on it, while severity of intestinal lesions and nutritional status were estimated by multiple linear regression analysis. Moreover, serum tuftsin activity was assayed by measuring its ability to stimulate phagocytosis of opsonized Staphylococcus aureus. RESULTS: We found that 32.8% of untreated celiacs and none of their relatives had pitted red cell values in the range of splenic hypofunction (>4%). Only age at diagnosis, but not the other two covariates, was significantly associated with the degree of splenic hypofunction. Tuftsin activity was depressed in celiac disease and this reduction was significantly greater in hyposplenic patients. CONCLUSIONS: In celiac disease the prevalence of splenic hypofunction is lower than formerly believed. The duration of preexposure to gluten is a crucial factor for the prevalence and severity of this complication that does not affect celiac relatives. In celiac disease splenic hypofunction is accompanied by a reduced phagocyte activity linked to the decreased release of tuftsin.

Adult↗

PubMed1999

Apoptosis and gastrointestinal tract.

The gastrointestinal tract is characterized by a rapid proliferation of stem cells that differentiate to become terminal mature cells and ultimately die through a genetically programmed form of cell death, termed apoptosis, which is responsible for maintaining of tissue size. Apoptosis has also been shown to play an important role in the pathophysiology of several gastrointestinal diseases. The development of many infectious and immune-mediated diseases, such as gastritis, coeliac disease, inflammatory bowel diseases, may be triggered by the prevalence of pro-apoptotic signals, whereas prolonged cell survival, due to apoptosis inhibition, may give rise to neoplastic clones. Elucidation of the biochemical pathways and of specific proteins regulating apoptosis may provide a remarkable opportunity to manipulate the life and death decisions of the gastrointestinal cells and to develop new therapeutic strategies. This review will deal with the mechanisms potentially involved in apoptosis and with the clinical relevance of this phenomenon in gastrointestinal diseases.

Apoptosis↗