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Biomedical subjects

F Spadaro

Publications and source records attributed to F Spadaro.

At least 19 recordsLinked to original sources
PubMed2004

Increased expression of heat shock proteins in rat brain during aging: relationship with mitochondrial function and glutathione redox state.

It is generally recognized that lipid peroxides play an important role in the pathogenesis of several diseases and that sulfhydryl groups are critically involved in cellular defense against endogenous or exogenous oxidants. Recent evidence indicates that lipid peroxides directly participate in induction of cytoprotective proteins, such as heat shock proteins (Hsps), which play a central role in the cellular mechanisms of stress tolerance. Oxidative damage plays a crucial role in the brain aging process and induction of Hsps is critically utilized by brain cells in the repair process following various pathogenic insults. In the present study, we investigated, in rats 6, 12, and 28 months old, the role of heat shock expression on aging-induced changes in mitochondrial and antioxidant redox status. In the brain expression of Hsp72 and Hsc70 increased with age up to 28 months; at this age the maximum induction was observed in the hippocampus and substantia nigra followed by cerebellum, cortex, septum and striatum. Hsps induction was associated with significant changes in glutathione (GSH) redox state and HNE levels. Interestingly, a significant positive correlation between decrease in GSH and increase in Hsp72 was observed in all brain regions examined during aging. Analysis of mitochondrial complexes showed a progressive decrease of Complex I activity and mRNA expression in the hippocampus and a significant decrease of Complex I and IV activities in the substantia nigra and septum. Our results sustain a role for GSH redox state in Hsp expression. Increase of Hsp expression promotes the functional recovery of oxidatively damaged proteins and protects cells from progressive age-related cell damage. Conceivably, heat shock signal pathway by increasing cellular stress resistance may represent a crucial mechanism of defence against free radical-induced damage occurring in aging brain and in neurodegenerative disorders.

Aging↗
PubMed2001

Cellular localization and functional role of phosphatidylcholine-specific phospholipase C in NK cells.

Although several classes of phospholipases have been implicated in NK cell-mediated cytotoxicity, no evidence has been reported to date on involvement of phosphatidylcholine-specific phospholipase C (PC-PLC) in NK activation by lymphokines and/or in lytic granule exocytosis. This study demonstrated the expression of two PC-PLC isoforms (M(r) 40 and 66 kDa) and their IL-2-dependent distribution between cytoplasm and ectoplasmic membrane surface in human NK cells. Following cell activation by IL-2, cytoplasmic PC-PLC translocated from the microtubule-organizing center toward cell periphery, essentially by kinesin-supported transport along microtubules, while PC-PLC exposed on the outer cell surface increased 2-fold. Preincubation of NK cells with a PC-PLC inhibitor, tricyclodecan-9-yl-xanthogenate, strongly reduced NK-mediated cytotoxicity. In IL-2-activated cells, this loss of cytotoxicity was associated with a decrease of PC-PLC exposed on the cell surface, and accumulation of cytoplasmic PC-PLC in the Golgi region. Massive colocalization of PC-PLC-rich particles with perforin-containing granules was found in the cytoplasm of NK-activated (but not NK-resting) cells; both organelles clustered at the intercellular contact region of effector-target cell conjugates. These newly detected mechanisms of PC-PLC translocation and function support an essential role of this enzyme in regulated granule exocytosis and NK-mediated cytotoxicity.

Bridged-Ring Compounds↗
PubMed2000

Nitric oxide synthase induction in astroglial cell cultures: effect on heat shock protein 70 synthesis and oxidant/antioxidant balance.

Glial cells in the nervous system can produce nitric oxide in response to cytokines. This production is mediated by the inducible isoform of nitric oxide synthase. Radical oxygen species (ROS) and nitric oxide (NO) derivatives have been claimed to play a crucial role in many different processes, both physiological such as neuromodulation, synaptic plasticity, response to glutamate, and pathological such as ischemia and various neurodegenerative disorders. In the present study we investigated the effects of NO synthase (iNOS) induction in astrocyte cultures on the synthesis of heat shock proteins, the activity of respiratory chain complexes and the oxidant/antioxidant balance. Treatment of astrocyte cultures for 18 hr with LPS and INFgamma produced a dose dependent increase of iNOS associated with an increased synthesis of hsp70 stress proteins. This effect was abolished by the NO synthase inhibitor L-NMMA and significantly decreased by addition of SOD/CAT in the medium. Time course experiments showed that iNOS induced protein expression increased significantly by 2 hr after treatment with LPS and INFgamma and reached a plateau at 18 hr; hsp70 protein synthesis peaked around 18 and 36 hr after the same treatment. Addition to astrocytes of the NO donor sodium nitroprusside resulted in a dose dependent increase in hsp70 protein that was comparable to that found after a mild heat shock. Additionally, a decrease in cytochrome oxidase activity, a marked decrease in ATP and protein sulfhydryl contents, an increase in the activity of the antioxidant enzymes mt-SOD and catalase were found which were abolished by L-NMMA. These findings suggest the importance of mitochondrial energy impairment as a critical determinant of the susceptibility of astrocytes to neurotoxic processes and point to a possible pivotal role of hsp70 in the signalling pathways of stress tolerance.

Animals↗
PubMed1998

Effect of nitric oxide synthase induction on the expression of mitochondrial respiratory chain enzyme subunits in mixed cortical and astroglial cell cultures.

In the present study we evaluated the effects of NO synthase (NOS) induction on the regulation of cytochrome c oxidase (CO) and F0F1-ATPase subunit expression in astroglial and mixed cortical cell cultures. In mixed cortical cell cultures, 18 h of treatment with lipopolysaccharide (LPS, 0.1 microgram/mL) plus interferon-gamma (INF-gamma, 10 U/mL) caused an increase of mRNAs for CO-I, F0F1-ATPase 6 and also for iNOS at 20 DIV. The induction of both CO-I and F0F1-ATPase 6 was abolished by the NOS inhibitor N-monomethyl-L-arginine (NMMA) or by the enzymatic scavenger superoxide dismutase/catalase (SOD/CAT). In primary astroglial cell cultures, treatment for 18 h with increasing concentrations of LPS and INF gamma, produced an increase in the amount of mitochondrial encoded CO-I and -II subunits, with no significant modifications of nuclear encoded subunit IV. An increase was also observed at level of transcription for CO-I and -II, and F0F1-ATPase 6 mRNAs. These effects were abolished by addition of NMMA or SOD/CAT. mRNA induction of CO-I was higher in mixed cortical than in astroglial cell cultures while that of F0F1-ATPase 6 was similar in both cell types. These results suggest that the expression of mitochondrial encoded subunits (CO-I, CO-II and F0F1-ATPase 6) is up-regulated in response to oxygen and NO reactive species. The activity of cytochrome c oxidase decreased after LPS/INF gamma treatment in both astroglial and mixed cortical cultures. The activity of ATP synthase was unmodified, while ATP content drastically decreased after LPS/INF gamma treatment, in both astroglial and mixed cortical cultures. The enzymatic activities of catalase and Mn-SOD (mitochondrial) showed a significant increase after LPS/INF gamma treatment, which was abolished by NMMA.

Animals↗
PubMed1998

Long-term ethanol administration enhances urinary ultraweak luminescence and age-dependent modulation of redox in central and peripheral organs of the rat.

Numerous experimental evidence sustains a pathogenic role for oxidative stress in aging. Acute and chronic ethanol metabolism is also known to be associated with oxidative perturbation of cellular oxidant/antioxidant balance. In the present work we investigated the effects of 25 months of ethanol consumption on the antioxidant defense system in different organs of rats, in comparison with normal and aged animals. We show that aged rats underwent a significant perturbation of the antioxidant defense system, as indicated by depletion of reduced glutathione content, increases in oxidized glutathione and free radical-induced urinary luminescence associated with a decrease of glutathione reductase and increase of glutathione transferase activities. These modifications, observed particularly in the liver and brain, were enhanced by long-term alcohol exposure. Our results indicate that increased glutathione transferase activity and decreased glutathione reductase activity, followed by thiol depletion, are important factors sustaining a pathogenic role for oxidative stress in aging and in all situations where age-correlated changes occur. They also reinforce the oxidative potential of toxic compounds, such as ethanol intoxication.

Administration, Oral↗
PubMed1998

Increased cerebrospinal fluid and plasma levels of ultraweak chemiluminescence are associated with changes in the thiol pool and lipid-soluble fluorescence in multiple sclerosis: the pathogenic role of oxidative stress.

The pathogenesis of multiple sclerosis (MS), the major neurological disease of young adults in the western world, is still poorly understood and no effective therapy to block MS is yet available. It is generally accepted that reactive oxygen species have a major role in the mediation of cell damage and that free sulfhydryl groups are vital in cellular defense against endogenous or exogenous oxidants. Modification of the cellular oxidant/antioxidant balance has been involved in the neuropathogenesis of several diseases, e.g., stroke, Parkinson's disease, Alzheimer's disease and physiological aging. An increasingly important area of antioxidant defense is based on sulfhydryl chemistry, owing to the role of sulfhydryl groups in the function of macromolecular structures such as enzymes and cellular membranes. The chemical composition of human cerebrospinal fluid (CSF) is considered to reflect brain metabolism and in the present study we provided experimental evidence of a decrease in sulfhydryl groups and increased content of products of lipid peroxidation, such as ultraweak chemiluminescence and liposoluble fluorescence, which we found higher in the CSF and plasma of MS patients than in controls, pointing out the role of oxidative stress in the pathogenesis of MS.

Adult↗
PubMed1991

[HPV infections in the lower genital tract in the female. Results of beta-interferon treatment].

The Authors have analyzed the results obtained by treating 60 patients affected by HPV lesions of the lower female genital tract (flat vulvar, vaginal and cervical condylomatosis) with beta-interferon. At vulvovaginal level, the action of the drug is independent from the colposcopic aspect of the lesion but is closely correlated to its extension. The drug proved to be more efficacious at cervical level in case of condylomatous cervicitis rather than ANTZ with a reduction in the size of the lesion and disappearance, if present, of the dysplasia. The positive action of the beta-interferon has never occurred before 2-6 months from the end of the farmacologic treatment. The best results have been obtained in case of condylomatous cervicitis with complete remission in 58% of the cases, and in vaginal condylomatosis (CR at 6 months: 45%). On the basis of these results we may conclude that in these HPV lesions priority should be given to medical treatment whereas in vulvar condylomatosis (especially if extended greater than 1/3) where results are not very satisfactory (not more than 20% of CR) physical therapy is advisable.

Drug Evaluation↗
PubMed1990

Effects of vinburnine on experimental models of learning and memory impairments.

Retrograde amnesia can be induced experimentally in mice by injecting them with scopolamine (3 mg/kg, IP) or by inducing seizures with pentylenetetrazol (50 mg/kg, IP), and in rats by subjecting them to hypobaric hypoxia (at a barometric pressure of 300 mmHg for 3 min). We have studied the effects of vinburnine (VNB) in these amnesic states compared to vincamine (VNC) and nicergoline (NCG), in order to assess its activity on drug-induced learning and memory impairments. Vinburnine reduced the disrupting effect of both scopolamine and pentylenetetrazol-induced seizures on the retention of a step-through passive avoidance behavior in mice and on the acquisition of shuttle-box active avoidance behavior in rats. This effect was dose-related up to 20 mg/kg, the peak effect dose after IP administration, and more pronounced than that of VNC and NCG in some tests. These results indicate that VNB influences learning and memory processes disrupted by a pharmacological manipulation. In particular, as scopolamine acts as anticholinergic drug, it is possible that VNB mechanism of action includes also a stimulation of acetylcholine neurotransmission.

Amnesia, Retrograde↗
PubMed1990

Corticotropin-releasing factor acts via a third ventricle site to reduce exploratory behavior in rats.

Corticotropin-releasing factor (CRF, 20-25 ng) injected into the lateral or fourth ventricles of rats decreased exploratory behavior in the multicompartment testing chamber (MCC), as assessed by decreased mean contact times with novel stimuli. This result extends similar observations made previously in mice. To investigate the site of this action of CRF, cold cream plugs injected into the cerebral ventricles of rats were used to prevent access of the CRF to specific periventricular sites. When the cerebral aqueduct was blocked with cold cream, CRF injected into the lateral ventricle, but not the fourth ventricle, decreased exploratory behavior in the MCC. These results suggest that CRF does not act in the fourth ventricle to alter behavior in the MCC, and most likely acts in the lateral or third ventricles. Cold cream blocks within the third ventricle prevented the effect of lateral ventricle administration of CRF. The clearest effects were obtained when the anteroventral portion of the third ventricle (AV3V) had been coated with cold cream. This region, which contains the organum vasculosum laminae terminalis (OVLT), was the only region blocked that showed a significant statistical interaction between the cold cream block and the effect of CRF. This result suggests that the OVLT, or regions close to it, is the primary site of the behavioral action of CRF in the MCC. It is possible that the peptide could be taken up in this region and transported to another brain site.

Animals↗
PubMed1990

Acetylcarnitine reduces the immobility of rats in a despair test (constrained swim).

Male rats forced to swim in a cylinder adopted an immobile posture. Immobility was reduced by acetylcarnitine (5, 10, and 20 mg/kg) and by antidepressant drugs, such as desipramine and iproniazid, injected 24, 5, and, again, 1 h prior to behavioral testing. Acetylcarnitine also potentiated the anti-immobility effect of antidepressant drugs in the despair test. Chronic (10 days) treatment with acetylcarnitine mimicked the effect found after acute administration. It is possible that the action of the acetylcarnitine on the despair test is indicative of an antidepressant activity of this drug that is dependent on a change in the sensitivity of monoamine receptors in the brain.

Acetylcarnitine↗
PubMed1990

Effects of TRH and prolactin in the behavioral despair (swim) model of depression in rats.

The neuropeptides thyrotropin releasing hormone (TRH) and prolactin (PRL), which affect various behaviors in animals, showed "antidepressant" properties in an experimental model of depression. Subcutaneous administration of TRH reduced the total immobility time of rats tested in the despair (constrained swim) test and potentiated the anti-immobility effect of intraperitoneally administered desimipramine (DMI). This effect was not mimicked by the peripheral injection of TSH, T3 or T4. Hyperprolactinemia induced by pituitary homografts under the kidney capsule and the intracerebroventricular injection of PRL also potentiated the DMI-induced reduction of total immobility time of rats in the despair test and exerted "antidepressant" effects in aged rats.

Aging↗
PubMed1990

Intracerebroventricular administration of interleukin-1 to mice alters investigation of stimuli in a novel environment.

The behavior of mice administered recombinant interleukin-1 (IL-1) was observed in a novel multicompartment chamber. Doses of human IL-1 alpha (4 pg to 40 ng) injected intracerebroventricularly (ICV) 20 min before testing significantly reduced the mean time mice spent in contact with novel stimuli. No other behavior scored (locomotor activity, grooming, scratching) was significantly affected. Similar results were obtained with murine IL-1 alpha (770 pg or 77 ng) and hIL-1 beta (1 pg to 10 ng). This behavioral change resembled that induced following restraint or ICV injection of corticotropin-releasing factor (CRF). The behavioral effect of ICV IL-1 was lost after it was heated for 10 min at 100 degrees C. Neither the CRF antagonist, alpha-helical CRF9-41 (10 or 20 micrograms ICV) nor the prostaglandin synthesis inhibitor indomethacin (50 mg/kg IP) significantly altered the hIL-1 alpha-induced behavioral changes, but naloxone (0.7 mg/kg SC) or sulpiride (5 mg/kg IP) completely prevented them. Our results suggest that intracerebral administration of IL-1 reduces the exploratory behavior of mice. This effect does not apparently involve CRF or prostaglandins, but may involve opioid and dopaminergic systems. This behavioral response to IL-1 administration is consistent with the behavioral effects of IL-1 reported previously, and strengthens the hypothesis that IL-1 secretion may be responsible for behavioral changes associated with immune activation.

Animals↗
PubMed1990

Memory deficits of aged male rats can be improved by pyrimidine nucleosides and n-acetyl-glutamine.

The pyrimidine nucleosides uridine (URI) and cytidine (CYT), alone or associated with n-acetyl-glutamine (NAG), were injected acutely or subchronically to aged (26 months old) male rats of the Sprague-Dawley strain. Learning and memory abilities of the animals were studied with tests of avoidance behavior. The acquisition of active avoidance behavior was studied with the shuttle-box test. A step-through type of passive avoidance task was used to examine the retention of passive avoidance responses. The acquisition of the active avoidance behavior and the retention of the passive avoidance response were reduced in aged animals as compared with those of young animals. Neither the acute treatment of old rats with URI and CYT alone nor that associated with NAG exerted any effect on the behavioral tests. In contrast, the subchronic treatment with URI and CYT was followed by a facilitation of acquisition of active avoidance behavior in the shuttle box and of retention of passive avoidance responses in the dark box. A more potent effect on the acquisition of the shuttle-box behavior and on the retention of passive avoidance reaction was found in animals treated subchronically with the pyrimidine nucleosides associated with NAG. These effects may be related to the role of pyrimidines in the synthesis of ribonucleic acid, which is indispensable for learning and memory processes.

Aging↗
PubMed1989

Prolactin as a protective factor in stress-induced biological changes.

The adenohypophyseal hormone prolactin (PRL) is released during stress of physical and psychological nature. In animals, this hormone facilitates adaptive behavior, induces analgesia, and enhances grooming behavior. It also reduces corticosterone secretion and the incidence of gastric ulcers induced by physical stress. It is possible that PRL plays a protective role against stress-induced biological modifications in animals.

Animals↗
PubMed1989

Neutralizing antibody and clinical status of human immunodeficiency virus (HIV)-infected individuals.

An assay based on inhibition of cytopathic effect of human immunodeficiency virus (HIV) strains in Molt 4 cells was developed to quantitate neutralizing antibodies (NA) in sera of HIV-infected individuals. The assay was specific and gave results comparable to those obtained by the inhibition of immunofluorescence (IFI) and reverse transcriptase (RT) activity. Attempts were made to correlate the presence and the antibody titres with the clinical status of HIV-infected individuals classified according to Walter Reed staging classification scheme. NA titres correlated inversely with the stage of HIV infection: Compared with acquired immunodeficiency syndrome (AIDS) patients, HIV-infected subjects at stage WR1 had significantly higher NA titres. Moreover, a decrease in NA titre in relation to clinical deterioration was noted in sequential sera of eight of 11 AIDS patients, retrospectively examined, for NA. The symptomless subjects showed either the same level of NA or a trend towards an increasing antibody titre with time. Different isolates of HIV strains showed a variability in the extent of sensitivity to neutralization by sera obtained from different HIV-infected individuals.

Acquired Immunodeficiency Syndrome↗