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Biomedical subjects

T Russo

Publications and source records attributed to T Russo.

At least 19 recordsLinked to original sources
PubMed2003

GH release after GHRH plus arginine administration in obese and overweight women with polycystic ovary syndrome.

Few and unclear data are available in the literature about the relationship between impairment of GH/IGF-I axis and polycystic ovary syndrome (PCOS). This study was aimed to evaluate the basal GH and IGF- levels, and GH release after challenge test in obese and overweight women with PCOS. Thirty patients with PCOS and other 30 healthy women matched for age, body mass index (BMI) and waist-hip ratio (WHR) were studied. Serum follicle-stimulating hormone (FSH), LH, PRL, E2, P, 17OH-progesterone (17OH-P), total T, delta4, DHEA-S, SHBG, GH and IGF-I levels were evaluated in each subject. A GHRH plus arginine challenge test was performed in all subjects. After provocative test, in PCOS and control women the GH levels were significantly (p<0.05) higher in comparison to basal values from 30 min to 120 min. At the same times, a significant (p<0.05) difference was observed between women with PCOS in comparison to healthy women. The mean peak value of GH resulted significantly (p<0.05) lower in PCOS women in comparison to healthy women. The total GH response (area under curve, AUC) to GHRH plus arginine test resulted significantly (p<0.05) lower in PCOS than in healthy women. These findings were statistically significant (p<0.05) also considering the distinction in obese and overweight women. The AUC for GH secretion was significantly lower (p<0.05) in obese in comparison to overweight subjects in the control group, whereas no significant difference was detected between obese and overweight women in the PCOS group. In conclusion, in PCOS women there is a BMI-independent alteration of the GH levels. Further investigations will be necessary to establish the real cause of these data.

17-alpha-Hydroxyprogesterone↗
PubMed2002

Transcription factor NF-Y regulates differentiation of CaCo-2 cells.

The CaCo-2 cell line is used to study the molecular mechanisms underlying differentiation of intestinal epithelial cells. These cells undergo a gradual differentiation process that is growth-related and depends on cellular density. CaCo-2 cells acquire a morphological polarity and express such markers of mature enterocytes as sucrase-isomaltase, apolipoproteins, alkaline phosphatase, and H-ferritin. Because the NF-Y transcription factor is required for H-ferritin gene expression, we investigated whether it is involved in the expression of the other CaCo-2 differentiation markers. We observed that subunit NF-YA increases during CaCo-2 differentiation and that the constitutive expression of NF-YA, obtained in stably transfected CaCo-2 cells, results in the expression of differentiation markers. In fact, sucrase-isomaltase, apolipoprotein A1, and H-ferritin were constitutively expressed in NF-YA-transfected cells and their levels did not increase during prolonged culture, while these markers were not expressed in mock-transfected CaCo-2 cells or transfected with an inactive NF-YA expression vector until the onset of differentiation.

Apolipoprotein A-I↗
PubMed2002

Comparison between two laparoscopic retropubic urethropexy.

BACKGROUND: To compare two different transperitoneal laparoscopic urethropexy procedures. METHODS: In this prospective randomized open trial, 60 women affected by genuine stress incontinence were enrolled and randomized in two groups of surgical technique. Group A was treated with transperitoneal laparoscopic retropubic urethropexy using non absorbable sutures, and group B with prolene meshes fixed with tackers or staplers. The failure rate was defined subjectively and objectively. The subjective evaluation was performed asking the patients if they had urine loss and expressing the symptomatology using a visual analog scale before surgery and after each follow-up visit. The objective evaluation was performed with clinical evaluation and/or with the use of multichannel urodynamic studies. RESULTS: No significant differences in intra- operative and postoperative complications between the two groups were observed. The subjective failure rate was not significantly different between the two groups at 3, 6, and 12 months from surgery. At 3 and 6 months follow-up, the objective failure rate was not significantly different between the two groups. Moreover, at 12 months from surgical procedure the objective failure rate was significantly lower in group A than in group B. CONCLUSIONS: Transperitoneal laparoscopic retropubic urethropexy performed using sutures is more effective than the mesh technique.

Female↗
PubMed2001

Nerve growth factor inhibits apoptosis in memory B lymphocytes via inactivation of p38 MAPK, prevention of Bcl-2 phosphorylation, and cytochrome c release.

Survival of memory B lymphocytes is tightly linked to the integrity of the Bcl-2 protein and is regulated by a nerve growth factor (NGF) autocrine circuit. In factor-starved memory B cells, the addition of exogenous NGF promptly induced p38 mitogen-activated protein kinase (MAPK), but not c-Jun N-terminal kinase (JNK), dephosphorylation. Conversely, withdrawal of endogenous NGF was followed by p38 MAPK activation and translocation onto mitochondria, whereby it combined with and phosphorylated Bcl-2, as assessed by co-immunoprecipitation and kinase assays in vivo and in vitro. Mitochondria isolated from human memory B cells, then exposed to recombinant p38 MAPK, released cytochrome c, as did mitochondria from Bcl-2-negative MDCK cells loaded with recombinant Bcl-2. Apoptosis induced by NGF neutralization could be blocked by the specific p38 MAPK inhibitor SB203580 or by Bcl-2 mutations in Ser-87 or Thr-56. These data demonstrate that the molecular mechanisms underlying the survival factor function of NGF critically rely upon the continuous inactivation of p38 MAPK, a Bcl-2-modifying enzyme.

Animals↗
PubMed2001

The beta-amyloid precursor protein APP is tyrosine-phosphorylated in cells expressing a constitutively active form of the Abl protoncogene.

The cytosolic domain of the beta-amyloid precursor protein APP interacts with three PTB (phosphotyrosine binding domain)-containing adaptor proteins, Fe65, X11, and mDab1. Through these adaptors, other molecules can be recruited at the cytodomain of APP; one of them is Mena, that binds to the WW domain (a protein module with two conserved tryptophans) of Fe65. The enabled and disabled genes of Drosophila, homologues of the mammalian Mena and mDab1 genes, respectively, are genetic modulators of the phenotype observed in flies null for the Abl tyrosine kinase gene. The involvement of Mena and mDab1 in the APP-centered protein-protein interaction network suggests the possibility that Abl plays a role in APP biology. We show that Fe65, through its WW domain, binds in vitro and in vivo the active form of Abl. Furthermore, in cells expressing the active form of Abl, APP is tyrosine-phosphorylated. Phosphopeptide analysis and site-directed mutagenesis support the hypothesis that Tyr(682) of APP(695) is the target of this phosphorylation. Co-immunoprecipitation experiments demonstrate that active Abl and tyrosine-phosphorylated APP also form a stable complex, which could result from the interaction of the pYENP motif of the APP cytodomain with the SH2 domain of Abl. These results suggest that Abl, Mena, and mDab1 are involved in a common molecular machinery and that APP can play a role in tyrosine kinase-mediated signaling.

Amino Acid Sequence↗
PubMed2001

Functions of WW domains in the nucleus.

The WW domain is a protein module found in a wide range of signaling proteins. It is one of the smallest protein modules that folds as a monomer without disulfide bridges or cofactors. WW domains bind proteins containing short linear peptide motifs that are proline-rich or contain at least one proline. Although the WW domain was initially considered a 'cytoplasmic module', the proteins containing WW domains have also been localized in the cell nucleus. Moreover, these proteins have been documented to participate in co-activation of transcription and modulation of RNA polymerase II activity. The carboxy-terminal domain (CTD) of RNA polymerase II acts as an assembly platform for distinct WW domain-containing proteins that affect the function of the RNA polymerase II. The formation of complexes between CTD and WW domain-containing proteins is regulated by phosphorylation of the CTD. Since the CTD sequence is highly repetitive and a target of several post-translational modifications and conformational changes, it presents a unique structure capable of enormous molecular diversity. The WW domain has been implicated in several human diseases including Alzheimer's disease. The WW domain-containing iso-prolyl isomerase named Pin1, a protein known to be essential for cell cycle progression, was shown to be active in restoration of the microtubule-binding activity of Tau, a protein of neurofibrillar tangles found in the brains of Alzheimer's patients. It is the WW domain of Pin1 that interacts directly with Tau protein. In addition, the WW domain-containing adapter protein FE65 was shown to regulate processing of Alzheimer's amyloid precursor protein. It is expected that by understanding the details of the WW domain-mediated protein-protein interactions, we will be able to illuminate numerous signaling pathways which control certain aspects of transcription and cell cycle.

Alzheimer Disease↗
PubMed2001

Regulation of p21waf1/cip1 expression by intracellular redox conditions.

Reactive oxygen species (ROS) have been considered for a long time only as molecules for inducing oxidative damage to proteins, lipids, and nucleic acids. However, in the last few years some physiological effects of ROS have been hypothesized, consisting of the redox regulation of several biological processes, including the transduction of mitogenic signals. This means that intracellular generation of ROS could be necessary to maintain homeostasis, as well as that their formation/scavenging should be controlled processes. We developed an experimental procedure that causes redox perturbations in intact cells, based on the exposure of living cells to diethylmaleate (DEM), a GSH-depleting agent. By this procedure we demonstrated that ROS generated following DEM treatment induces a G1 arrest, that is accompanied by several redox-dependent changes in cell cycle-related proteins. One of these is the p53-independent accumulation of p21waf1/cip1, which requires the integrity of the ras-MAPK pathway. Accordingly, DEM treatment strongly activates ERK2. On the other hand, redox perturbations provoked by DEM induce several early phenomena, including p21waf1/cip1 and Rb dephosphorylation.

Animals↗
PubMed2001

Proportion of older people in the community as a predictor of increasing stroke incidence.

OBJECTIVES: To compare stroke incidence rates among comparable registries and to make correlations with aging of the resident populations. METHODS: This correlation study included all comparable stroke registries maintained in industrialized countries (Italy, France, United Kingdom, Denmark, Norway, United States, and Australia). Eleven community-based stroke registries with similar high proportions of radiologically confirmed diagnoses based on standard definitions were identified. Incidence rates of first-ever stroke from the prospective L'Aquila registry and from the other registries were compared after age and sex standardization to the 1996 European population. The rates were then correlated with the proportion of individuals aged 65 and over in the corresponding resident populations by means of the Poisson regression analysis. RESULTS: In the L'Aquila registry, the crude annual incidence of first-ever stroke was 281/100,000 (95% confidence interval 271-293) based on 2,515 patients included during a 3-year period. The rate standardized to the European population was 249/100,000. Standardized incidence ratios indicated a significant excess of first-ever strokes in the L'Aquila registry up to 51% with respect to most of the compared studies. A significant correlation was also found between crude (p < 0.0001) and standardized (p = 0.0012) stroke incidence rates and proportions of individuals aged 65 and over in the different populations. CONCLUSIONS: The L'Aquila experience suggests that any further aging of a population will increase the stroke occurrence for both the reasons of a direct and predictable effect of the growing proportion of elderly individuals within that population and a disproportionately increased stroke risk in the older age groups.

Adolescent↗
PubMed2000

The beta-amyloid precursor protein functions as a cytosolic anchoring site that prevents Fe65 nuclear translocation.

In this study we addressed the question of the intracellular localization of Fe65, an adaptor protein interacting with the beta-amyloid precursor protein (APP) and with the transcription factor CP2/LSF/LBP1. By using tagged Fe65 expression vectors, we observed that a significant fraction of Fe65 is localized in the nucleus of transfected COS7 cells. Furthermore, the isolation of nuclei from untransfected PC12 cells allowed us to observe that a part of the endogenous Fe65 is present in the nuclear extract. The analysis of Fe65 mutant constructs demonstrated that the region of the protein required for its nuclear translocation includes the WW domain, and that, on the other hand, a small fragment of 100 residues, including this WW domain, contains enough structural information to target a reporter protein (green fluorescent protein (GFP)-GFP) to the nucleus. To evaluate whether the Fe65-APP interaction could affect Fe65 intracellular trafficking, COS7 cells were cotransfected with APP(695) or APP(751) and with GFP-Fe65 expression vectors. These experiments demonstrated that Fe65 is no longer translocated to the nucleus when the cells overexpress APP, whereas the nuclear targeting of GFP-Fe65 mutants, unable to interact with APP, is unaffected by the coexpression of APP, thus suggesting that the interaction with APP anchors Fe65 in the cytosol.

Active Transport, Cell Nucleus↗
PubMed2000

Retinoblastoma protein dephosphorylation is an early event of cellular response to prooxidant conditions.

The modification of intracellular redox conditions with diethylmaleate (DEM), a glutathione-depleting agent, induces a p53-independent growth arrest mediated by the accumulation of p21(waf1) mRNA and protein. The same treatment also induces the retinoblastoma protein (pRb) dephosphorylation. This dephosphorylation (i) is very fast, being observed already 5 min after the exposure of the cells to DEM, (ii) is dependent on the prooxidant effects of DEM, being prevented by the treatment with N-acetylcysteine and (iii) is completely reversible, since the rephosphorylation of pRb is promptly obtained upon the removal of the glutathione-depleting agent from the culture medium. The dephosphorylation of pRb is independent of the accumulation of p21(waf1) induced by DEM; in fact, p21(waf1) levels start to increase much later after DEM treatment and accordingly cyclin-dependent kinase activities are not yet induced when pRb is already dephosphorylated following DEM treatment. Finally, pRb dephosphorylation is catalyzed by phosphatases activated by DEM treatment.

Acetylcysteine↗
PubMed1999

Stem cell factor is localized in, released from, and cleaved by human mast cells.

Stem cell factor (SCF) is the most important cytokine regulating human mast cell growth and functions. The immunogold technique showed SCF in the secretory granules of skin mast cells and in lung parenchymal mast cells (HLMC). Immunoreactive SCF (iSCF) was detected in cell lysates of HLMC, but not in basophils; iSCF and histamine were detected in supernatants of HLMC 3 min after challenge with anti-FcepsilonRI or anti-IgE, and iSCF in supernatants rapidly declined after 30 min, whereas histamine remained unchanged for 120 min. HPLC and electrospray mass spectrometry (ES/MS) analysis of recombinant human SCF1-166 (18,656. 9 +/- 0.9 Da) treated with chymase showed a polypeptide of 17,977.1 +/- 0.6 Da and a minor component of 697.4 +/- 0.1 Da generated by specific cleavage at Phe159. SCF1-166 and SCF1-159 similarly activated HLMC, potentiated anti-IgE-induced activation of these cells, and stimulated HLMC chemotaxis. SCF159-166 had no effect on mast cells. Western blot analysis of supernatants of anti-IgE-activated HLMC incubated with recombinant human SCF1-166 showed that SCF1-166 was rapidly cleaved to SCF1-159 and SCF1-144. Experiments with supernatants of anti-IgE-activated HLMC incubated with SCF1-166 yielded similar results. In conclusion, SCF is stored in mast cell secretory granules and is immunologically released by human mast cells. SCF1-166 is rapidly and specifically cleaved to SCF1-159 by chymase, which retains its biological effect on mast cells. SCF is also cleaved by other proteases to several SCF species whose possible biological activities remain to be established.

Adolescent↗
PubMed1999

In budding yeast, reactive oxygen species induce both RAS-dependent and RAS-independent cell cycle-specific arrest.

The role of mild oxidative stresses elicited by diethylmaleate (DEM)-induced glutathione depletion in the progression of the yeast cell cycle has been investigated. We found that different wild-type strains are sensitive to oxidative stresses induced by similar DEM doses: approximately 1 mM on YPD plates, 5-10 mM in shaken flasks. At lower doses, DEM caused a transient decrease in growth rate, largely because of a decreased G1-to-S transition. Treatment with higher DEM doses leads to complete growth arrest, with most cells found in the unbudded G1 phase of the cell cycle. DEM treatment resulted in transcriptional induction of stress-responsive element (STRE)-controlled genes and was relieved by treatment with the antioxidant N-acetyl cysteine. Reciprocal shift experiments with cdc25 and cdc28 mutants showed that the major cell cycle arrest point was located in the Start area, at or near the CDC25-mediated step, before the step mediated by the CDC28 cyclin-dependent kinase. The DEM-induced G1 arrest requires a properly regulated RAS pathway and can be bypassed by overexpressing the G1-specific cyclin CLN2. However, cells with either a deregulated RAS pathway or overexpressing CLN2 failed to grow and arrested as budded cells, indicating that a second DEM-sensitive cell cycle step exists.

Acetylcysteine↗
PubMed1998

P/CAF/p300 complex binds the promoter for the heavy subunit of ferritin and contributes to its tissue-specific expression.

We analysed the role of the nuclear protein P/CAF in regulating the transcription of the gene for human heavy (H) ferritin in given cell types. P/CAF is a histone acetylase, recruited to specific promoters via interaction with the co-activator molecule p300/CREB-binding protein (CBP). Histone acetylation promoted by P/CAF destabilizes the nucleosome structure, thus contributing to activation of transcription. The transcription of the H ferritin gene is regulated by the transcription factor B-box-binding factor (Bbf), which bridges RNA polymerase II via p300/CBP. Northern blot analyses of RNA species from various human tissues and cell lines demonstrate that the H ferritin gene is expressed at high levels in cells containing high levels of the P/CAF transcript. Moreover, transient overexpression of P/CAF in cells constitutively expressing low levels of this protein activates transcription driven by the region of the H promoter interacting with Bbf. The involvement of p300/CBP in the possible P/CAF-mediated regulation of H promoter was also explored by evaluating the phenomenon in the presence of the oncoprotein E1A. The results of these experiments demonstrate that P/CAF activates the H promoter also in the presence of limited amounts of p300/CBP. We argue that P/CAF is a component of the basal transcription apparatus of the H ferritin gene and that the relative amounts of the P/CAF protein in different cell types could account for the cell-specific control of the H ferritin gene transcription.

Acetyltransferases↗
PubMed1998

Fe65 and the protein network centered around the cytosolic domain of the Alzheimer's beta-amyloid precursor protein.

A distinctive tract of all the forms of Alzheimer's disease is the extracellular deposition of a 40-42/43 amino acid-long peptide derived from the so-called beta-amyloid precursor protein (APP). This is a membrane protein of unknown function, whose short cytosolic domain has been recently demonstrated to interact with several proteins. One of these proteins, named Fe65, has the characteristics of an adaptor protein; in fact, it possesses three protein-protein interaction domains: a WW domain and two PID/PTB domains. The interaction with APP requires the most C-terminal PID/PTB domain, whereas the WW domain is responsible for the interaction with various proteins, one of which was demonstrated to be the mammalian homolog of the Drosophila enabled protein (Mena), which in turn interacts with the cytoskeleton. The second PID/PTB domain of Fe65 binds to the CP2/LSF/LBP1 protein, which is an already known transcription factor. The other proteins interacting with the cytosolic domain of APP are the G(o) heterotrimeric protein, APP-BP1 and X11. The latter interacts with APP through a PID/PTB domain and possesses two other protein-protein interaction domains. The small size of the APP cytodomain and the overlapping of its regions involved in the binding of Fe65 and X11 suggest the existence of competitive mechanisms regulating the binding of the various ligands to this cytosolic domain. In this short review the possible functional roles of this complex protein network and its involvement in the generation of Alzheimer's phenotype are discussed.

Alzheimer Disease↗
PubMed1998

The Fe65 adaptor protein interacts through its PID1 domain with the transcription factor CP2/LSF/LBP1.

The neural protein Fe65 possesses three putative protein-protein interaction domains: one WW domain and two phosphotyrosine interaction/phosphotyrosine binding domains (PID1 and PID2); the most C-terminal of these domains (PID2) interacts in vivo with the Alzheimer's beta-amyloid precursor protein, whereas the WW domain binds to Mena, the mammalian homolog of Drosophila-enabled protein. By the interaction trap procedure, we isolated a cDNA clone encoding a possible ligand of the N-terminal PID/PTB domain of Fe65 (PID1). Sequence analysis of this clone revealed that this ligand corresponded to the previously identified transcription factor CP2/LSF/LBP1. Co-immunoprecipitation experiments demonstrated that the interaction between Fe65 and CP2/LSF/LBP1 also takes place in vivo between the native molecules. The localization of both proteins was studied using fractionated cellular extracts. These experiments demonstrated that the various isoforms of CP2/LSF/LBP1 are differently distributed among subcellular fractions. At least one isoform, derived from alternative splicing (LSF-ID), is present outside the nucleus; Fe65 was found in both fractions. Furthermore, transfection experiments with an HA-tagged CP2/LSF/LBP1 cDNA demonstrated that Fe65 interacts also with the nuclear form of CP2/LSF/LBP1. Considering that the analysis of Fe65 distribution in fractionated cell extracts demonstrated that this protein is present both in nuclear and non-nuclear fractions, we examined the expression of Fe65 deletion mutants in the two fractions. This analysis allowed us to observe that a small region N-terminal to the WW domain is phosphorylated and is necessary for the presence of Fe65 in the nuclear fraction.

Amino Acid Sequence↗
PubMed1998

Asymptomatic bacteriuria in human immunodeficiency (HIV)-infected women.

Objective: To determine the prevalence of bacteriuria in HIV- infected women versus healthy non-HIV-infected controls.Methods: A prospective cohort study was undertaken between January 1996 and March 1997. One hundred nineteen ambulatory, premenopausal women from the Women's HIV Clinic and 191 similar non-infected Gynecology Clinic controls were recruited. Information recorded from the medical record and patient questionnaire included: age, prior history of UTI, antibiotic usage, sexual frequency, diaphragm/spermicide use, and CD4 count. A clean catch urine culture was collected on all patients. Statistical analysis was via SPSSPC.Results: The mean age of HIV-infected women was 33 vs 26 for non-infected. The mean CD4 count was 341. A prior history of UTI (mean # per lifetime) was significantly higher for HIV women (2.8) vs controls (1.8) [P =.01]. The mean weekly sexual frequency was significantly higher in HIV-negative (2.1) vs HIV-infected (1.2) [P <.001]. Diaphragm/spermicidal use was uncommon but equal in both groups. The prevalence of any growth of uropathogens (>10(2) cfu/mL) was 30% in the HIV-infected vs 47% in controls. The percentage of asymptomatic bacteriuria for each range of uropathogen titer (cfu/mL) in urine was:Chronic antibiotic usage (39% of HIV-infected vs 4% of controls) was associated with a decreased prevalence of bacteriuria, but there was not a significant difference in prevalence of bacteriuria between groups. Regardless of titer ranges of uropathogens evaluated, the prevalence of bacteriuria was not different between CD4 counts of <200 and >/=200. As compared to controls, HIV-infected individuals demonstrated shifts toward nosocomial pathogens: Enterococcus, S. aureus and non-E. coli gram-negative rods.Conclusion: The prevalence of bacteriuria was not greater in HIV-infected women versus non-HIV-infected women versus HIV non-infected controls and was not significantly affected by antibiotic usage or CD4 count. Uropathogens responsible for asymptomatic bacteriuria in HIV-infected women are different from "healthy" controls and are more representative of nosocomial flora.

Journal Article↗
PubMed1998

p53 genes mutated in the DNA binding site or at a specific COOH-terminal site exert divergent effects on thyroid cell growth and differentiation.

Expression of mutated versions of the p53 gene deranged the differentiation program of thyroid cells and resulted in deregulated growth. Specifically, p53 mutants in several residues of the DNA-binding region induced thyrotropin (TSH) -independent growth and inhibition of the expression of thyroid-specific genes. The loss of the differentiated phenotype invariably correlated with the blockage of the expression of the genes coding for the thyroid transcriptional factors PAX-8 and TTF2. Conversely, thyroid cells transfected with a p53 gene mutated at codon 392, located outside the DNA-binding region, stimulated the expression of differentiation genes in the absence of the TSH, and induced TSH-independent growth. cAMP intracellular levels were higher in thyroid cells transfected with the p53 gene mutated at the 392 site than in the untransfected thyroid cells, but lower in the cells transfected with the other mutated p53 genes. Fra-1 and c-jun were induced by p53, resulting in increased AP-1 levels. The results of this study suggest that p53 exerts effects on cAMP transduction pathway in thyroid cells, which are exquisitely sensitive to cAMP.

Animals↗