bluuebunny/crossref_metadata_2025 huggingface dataset:
Vitamin D Protects Keratinocytes from Apoptosis Induced by Osmotic Shock, Oxidative Stress, and Tumor Necrosis Factor
Authors: DIKER‐COHEN TALIA , KOREN RUTH , LIBERMAN URI A. , RAVID AMIRAM
Published: March 2004

Abstract: Calcitriol, the hormonal form of vitamin D, inhibited caspase‐3‐like activation in HaCaT keratinocytes exposed to hyperosmotic and oxidative stresses, heat shock, and the inflammatory cytokine TNF. The hormone also protected the cells from caspase‐independent cell death induced by hyperosmotic and oxidative stresses. The protection against hyperosmotic stress is not affected by inhibitors of the EGF receptor, ERK or PI13 kinase pathways, neither is it due to reduced activity of the proapoptotic p38 MAP kinase. These results are in accordance with previous in vivo findings that vitamin D protects epidermal keratinocytes from apoptosis due to UV radiation or chemotherapy.
The Overexpression of Bcl‐2 Antagonizes the Proapoptotic Function of the Kappa‐Opioid Receptor
Authors: WONG NAISUM , TEIMEI DIAO CATHERINE , WONG TAKMING
Published: March 2004

Abstract: Opioid receptors are G‐protein‐coupled cell‐surface receptors that are mainly expressed in neuronal cells. Stimulation of the κ‐opioid receptor expressed by cultured human epithelial cancer cells promotes staurosporine‐induced apoptosis. In this study, while Bcl‐2 did not inhibit staurosporine‐induced apoptosis, it did inhibit the κ‐opioid receptor‐mediated potentiation of apoptosis. The results suggest that Bcl‐2 targets a step that is specific to the signaling pathway of the κ‐opioid receptor.
The Inducible NO Synthase Is Downregulated during Apoptosis of Malignant Cells from B‐Cell Chronic Lymphocytic Leukemia Induced by Flavopiridol and Polyphenols
Authors: BILLARD CHRISTIAN , QUINEY CLAIRE , TANG RUOPING , KERN CATHERINE , AJCHENBAUM‐CYMBALISTA FLORENCE , DAUZONNE DANIEL , KOLB JEAN‐PIERRE
Published: March 2004

Abstract: Downregulation of iNOS and NO is a pathway common for flavones and polyphenols, two distinct families of phytoalexins. Our data suggest that inhibition of the NO pathway could be one of the mechanisms involved in the proapoptotic properties of these phytoalexins in leukemia B‐cells.
Sulforaphane Modulates Cell Cycle and Apoptosis in Transformed and Non‐transformed Human T Lymphocytes
Authors: FIMOGNARI CARMELA , NÜSSE MICHAEL , BERTI FAUSTO , IORI RENATO , CANTELLI‐FORTI GIORGIO , HRELIA PATRIZIA
Published: March 2004

Abstract: Isothiocyanates exert chemopreventive effects against chemically induced tumors in animals, modulating enzymes required for carcinogens' activation/detoxification and/or the induction of cell‐cycle arrest and apoptosis in tumor cell lines. To investigate the chemopreventive potential of isothiocyanates, we studied proliferation, apoptosis induction and p53, bcl‐2 and bax protein expression in Jurkat T‐leukemia cells by the isothiocyanate sulforaphane. Sulforaphane caused G2/M‐phase delay and increase of apoptotic cell fraction in a time‐ and dose‐dependent manner. Necrosis was observed after prolonged exposure to elevated sulforaphane doses. Moreover, it markedly increased p53 and bax protein expression, and slightly affected bcl‐2 expression. Since selective targeting and low toxicity for normal host tissues are fundamental requisites for proposed chemopreventive agents such as sulforaphane, we tested sulforaphane on non‐transformed phytohemagglutinin‐stimulated human T‐lymphocytes. We demonstrated that sulforaphane arrested cell‐cycle progression in G1 phase by a significant down‐modulation of cyclin D3. Moreover, sulforaphane induced apoptosis (and also necrosis), mediated by an increase in the expression of p53, whereas it exerted little effect on bcl‐2 and bax levels. These findings indicate that sulforaphane can exert protective effects inhibiting leukemic cell growth. Moreover, sulforaphane is active not only in transformed lymphocytes but also in their normal counterpart. Although in vitro studies do not necessarily predict in vivo outcomes, our findings raise important questions regarding the suitability of sulforaphane for cancer chemoprevention.
Peptides from Anchovy Sauce Induce Apoptosis in a Human Lymphoma Cell (U937) through the Increase of Caspase‐3 and ‐8 Activities
Authors: LEE YOUNG GON , KIM JI YEON , LEE KI WON , KIM KYOUNG HEON , LEE HYONG JOO
Published: March 2004

Abstract: Various biological activities of peptides have been found. In this study, the induction of apoptosis in a human lymphoma cell line (U937) by peptide fraction separated from anchovy sauce was studied using biochemical and flow cytometric methods. After U937 was treated with a hydrophobic peptide fraction of the anchovy sauce, a sub‐G1 peak, which represents apoptosis, was found in the cell cycle analysis. The apoptosis in the peptide‐treated U937 cell was also confirmed by apoptotic DNA fragmentation. Furthermore, an increase of caspase‐3 and ‐8 activities was observed. Our results suggest that the peptide fraction separated from the anchovy sauce may have cancer chemopreventive effects through the induction of apoptosis in cancer cells.
Hypoxic Regulation of Neutrophil Apoptosis Role: of Reactive Oxygen Intermediates in Constitutive and Tumor Necrosis Factor α‐Induced Cell Death
Authors: MURRAY J , WALMSLEY S R. , MECKLENBURGH K I. , COWBURN A S. , WHITE J F. , ROSSI A G. , CHILVERS E R.
Published: March 2004

Abstract: Activation of the NADPH oxidase system to generate reactive oxygen species (ROS) plays a key role in bacterial killing by human neutrophils. However, the involvement of such radicals in spontaneous and TNFα‐driven neutrophil apoptosis remains uncertain. While incubation of cells under anoxic conditions attenuated the pro‐apoptotic effect of TNFα, full activation of the respiratory burst using PAF followed by fMLP, or the addition of physiologically relevant concentrations of H2O2, had no effect on the rate of apoptosis. Furthermore, the phosphoinositide 3‐kinase inhibitor, LY294002, which abolishes receptor‐mediated activation of the NADPH oxidase, and five discrete anti‐oxidants all failed to affect apoptotic thresholds. Thus ROS do not appear to modulate constitutive apoptosis in neutrophils or appear sufficient to mediate the pro‐apoptotic effect of TNFα.
Hypoxic Stress Stably Alters Apoptotic Parameters on U937 Cells
Authors: DE NICOLA M , LIUZZI F , CERELLA C , D'ALESSIO M , BERGAMASCHI A , MAGRINI A , GHIBELLI L
Published: March 2004

Abstract: Tumor promonocytic U937 cells cultured under a low O2/high CO2 atmosphere display altered characteristics after restoration of normal atmosphere: increased resistance to apoptosis induced by different treatments; apoptotic morphology; lack of glutathione (GSH) extrusion in apoptosis; lack of protection by antioxidants; and lack of Ca2+ mobilization with thapsigargin. These alterations were stably maintained for many months of culture in normal conditions, originating the stable U937‐HX variant. Since the hypoxic treatment did not produce a great selective pressure, the alterations are conceivably the result of stable adaptative response.
A Novel Gene,Jpk, Induces Apoptosis in F9 Murine Teratocarcinoma Cell through ROS Generation
Authors: KONG KYOUNG‐AH , PARK SUNGDO , PARK HYOUNGWOO , KIM MYOUNG HEE
Published: March 2004

Abstract:A novel geneJpk(Jopock) has been originally isolated through yeast 1 hybridization technique as atrans‐acting factor interacting with the position‐specific regulatory element of a murineHoxa‐7. Northern analysis revealed that theJpkwas expressed at day 7.0 post coitum (p.c.) during early gastrulation. Previously it has been shown that a trace amount of JPK protein led bacterial cells to death. In eukaryotic F9 cells,Jpkalso led the cell to death‐generating DNA ladder: fewer than 50% of the cells survived after 72‐h transfection. Flow cytometric analysis with cells stained with each Annexin V/7‐amino‐actinomycin D (7‐AAD), MitoTracker, and hydroethidine (HE) revealed thatJpkinduced apoptotic cell death in a time‐dependent manner, reduced mitochondrial membrane potential, and increased ROS (reactive oxygen species) production, respectively. Additionally,Jpkseemed to regulate the Bcl family at the transcriptional level when RT‐PCR was performed. Although the precise mechanism is not clear, these results altogether suggest thatJpkis a potent inducer of apoptosis through generation of ROS as well as concomitant reduction of mitochondrial membrane potential.
Vitamin D Enhances Caspase‐Dependent and Independent TNF‐Induced Breast Cancer Cell Death
Authors: WEITSMAN GE , RAVID A , LIBERMAN UA , KOREN R
Published: March 2004

Abstract: Calcitriol, the hormonal form of vitamin D, enhanced TNF‐induced cytotoxicity in MCF‐7 breast cancer cells. It increased the induction of caspase‐3‐like activity and TNF‐induced caspase‐independent cytotoxicity in the presence of a pan‐caspase inhibitor. The antioxidants N‐acetylcysteine, glutathione, lipoic acid, and ascorbic acid markedly reduced the effect of the hormone on TNF‐induced caspase activation, attesting to the involvement of reactive oxygen species (ROS) in the cross‐talk between the hormone and the cytokine. Calcitriol augmented the drop in mitochondrial membrane potential induced by TNF as assessed by the fluorescent probe JC‐1. We postulate that the interaction of TNF and calcitriol on the level of the mitochondria underlies the enhancement of TNF‐induced, ROS‐mediated caspase‐dependent and ‐independent cell death.
Rescue of Cells from Apoptosis by Antioxidants Occurs Downstream from GSH Extrusion
Authors: LIUZZI FRANCESCA , FANELLI CLAUDIA , CIRIOLO MARIA ROSA , CERELLA CLAUDIA , D'ALESSIO MARIA , DENICOLA MILENA , MAGRINI ANDREA , BERGAMASCHI ANTONIO , GHIBELLI LINA
Published: March 2004

Abstract: Antioxidants‐that is, scavengers of free radicals and anaerobic conditions (5%CO2, 95% N2)‐protect monocytic U937 cells from damage‐induced apoptosis. Antioxidants rescue the cells acting on the apoptotic pathway at a step downstream from gluthatione extrusion. Reducing agents, such as DTT, also reduce stress‐induced apoptosis. Thus, apoptotic GSH extrusion triggers the downstream events of apoptosis by leaving cells unprotected against thiols oxidation and radical production.
Apoptotic GSH Extrusion Is Associated with Free Radical Generation
Authors: D'ALESSIO M , CERELLA C , DE NICOLA M , BERGAMASCHI A , MAGRINI A , GUALANDI G , ALFONSI AM , GHIBELLI L
Published: March 2004

Abstract: Reactive oxygen species (ROS) are involved in many forms of apoptosis and mediate apoptosis in a number of cell types. In this paper, we use a variant of U937 monocytic cells (U937 HX) that show different biochemical features with respect to standard U937. Apoptotic standard U937 extrude reduced glutathione (GSH) and generate free radicals concomitantly with loss of mitochondria transmembrane potential (mt Δψ). These events are correlated with the extrusion of intracellular GSH. Conversely, apoptotic U937 HX cells retain GSH, and the loss of mt Δψ is not accompanied by generation of free radicals. The perfect inverse correlation between (a) ROS generation and (b) the presence of intracellular GSH during apoptosis suggests novel mechanisms to finely tune ROS generation in apoptosis.
Innate Immune Collectins Bind Nucleic Acids and Enhance DNA Clearance in Vitro
Authors: PALANIYAR NADES , NADESALINGAM JEYA , REID KENNETH B.M.
Published: March 2004

Abstract: Collectins are a class of innate immune proteins that opsonize microbes and other ligands via their carbohydrate‐recognition domains and enhance their clearance by phagocytes. We hypothesized that collectins, such as pulmonary surfactant protein (SP‐) A and D and mannose‐binding lectin (MBL), could bind nucleic acid, which is a pentameric sugar‐based anionic polymer. We have shown that SP‐D and MBL bind to both DNA and RNA effectively and also that SP‐D enhances the uptake of DNA by human monocytic cells. Therefore, our results suggest that nucleic acids may be a novel class of ligands for collectins. This class of innate immune proteins could enhance the clearance of DNA that is released by necrotic cells or microbial cells. Our findings may have important biological implications, such as the alleviation of DNA‐mediated tissue inflammation.
Coinduction of GTP Cyclohydrolase I and Inducible NO Synthase in Rat Osteoblasts during Space Flight
Authors: KUMEI YASUHIRO , MORITA SADAO , NAKAMURA HIROSHI , AKIYAMA HIDEO , HIRANO MASAHIKO , SHIMOKAWA HITOYATA , OHYA KEI'ICHI
Published: March 2004

Abstract: The mechanism underlying space flight‐induced osteopenia is unknown. In osteoblasts, the inducible nitric oxide (NO) synthase (iNOS) is involved in the early response to mechanical strain and induction of apoptosis. GTP cyclohydrolase I (GTPCH) is a key enzyme that is essential for iNOS activity. The coordinate expression of GTPCH prevents apoptosis that is induced by iNOS/NO. The purpose of this study was to investigate the effects of space flight on the expression of apoptotic/anti‐apoptotic molecules iNOS and GTPCH in rat osteoblasts. Rat osteoblasts were cultured aboard a space shuttle and solubilized on the 4th and 5th days of the mission. The mRNA levels for iNOS and GTPCH in the flight cultures were increased to at least 120‐fold and threefold higher than the ground (1 × g) controls, respectively. The amount of cellular DNA per flight culture vessel was 53% and 58% of the ground controls on the 4th and 5th days, respectively. However, the increasing rate of the DNA amount from the 4th to the 5th day was not different between the flight cultures and the ground controls. Morphologically, the cells grew in space as well as on the ground. Co‐expression of GTPCH and iNOS may indicate a self‐protective mode of action in osteoblasts against the harmful stress under microgravity.
Opposite Phenotypes of Cancer and Aging Arise from Alternative Regulation of Common Signaling Pathways
Authors: UKRAINTSEVA SVETLANA V. , YASHIN ANATOLY I.
Published: March 2004

Abstract:Phenotypic features of malignant and senescent cells are in many instances opposite. Cancer cells do not “age”; their metabolic, proliferative, and growth characteristics are opposite to those observed with cellular aging (both replicative and functional). In many such characteristics cancer cells resemble embryonic cells. One can say that cancer manifests itself as a local, uncontrolled “rejuvenation” in an organism. Available evidence from human and animal studies suggests that the opposite phenotypic features of aging and cancer arise from the opposite regulation of genes participating in apoptosis/growth arrest or growth signal transduction pathways in cells. This fact may be applicable in the development of new anti‐aging treatments. Genes that are contrarily regulated in cancer and aging cells (e.g., proto‐oncogenes or tumor suppressors) could be candidate targets for anti‐aging interventions. Their “cancer‐like” regulation, if strictly controlled, might help to rejuvenate the human organism.
Ethanol‐Induced Decrease of the Expression of Glucose Transport Protein (Glut3) in the Central Nervous System as a Predisposing Condition to Apoptosis
Authors: FATTORETTI P , BERTONI‐FREDDARI C , CASOLI T , DI STEFANO G , GIORGETTI G , SOLAZZI M
Published: March 2004

Abstract: We measured the effect of chronic ethanol administration on the expression of Glut3 in the cerebellum and hippocampus of adult and old rats. Glut3 expression significantly decreased in aging, in ethanol‐treated rats vs. age‐matched controls, and in adult‐ vs. old ethanol‐treated rats. These findings lend consistent support to the hypothesis that disturbances of glucose metabolism due to ethanol may constitute an unfavorable condition predisposing to neuronal death.
Nuclear Translocation of a Clusterin Isoform Is Associated with Induction of Anoikis in SV40‐Immortalized Human Prostate Epithelial Cells
Authors: CACCAMO A E. , SCALTRITI M , CAPORALI A , D'ARCA D , SCORCIONI F , CANDIANO G , MANGIOLA M , BETTUZZI S
Published: March 2004

Abstract: Clusterin gene expression is potently induced in experimental models in which apoptosis is activated, such as rat prostate involution following castration. Nevertheless, its precise physiological role has not yet been established, and both anti‐apoptotic and pro‐apoptotic functions have been suggested for this gene. Clusterin expression level depends on cell proliferation state, and we recently showed that its over‐expression inhibited cell cycle progression of SV40‐immortalized human prostate epithelial cells PNT2 and PNT1a. Here we studied clusterin expression in PNT1a cells subjected to serum‐starvation with the aim of defining clusterin early molecular changes following apoptosis induction. Under serum‐starvation conditions, decreased growth rate, slow rounding‐up of cells, cell detachment, and formation of apoptotic bodies indicative of anoikis (detachment‐induced apoptosis) were preceded by significant downregulation of 70 kDa clusterin precursor and upregulation of 45–40 kDa isoforms. On the 8th day of serum‐free culturing, only the higher molecularweight protein‐band of about 45 kDa was clearly induced and accumulated in detached cells and apoptotic bodies in which PARP was activated. Anoikis was preceded by induction and transloction of a 45‐kDa clusterin isoform to the nucleus. Thus, nuclear targeting of a specific 45‐kDa isoform of clusterin appeared to be an early and specific molecular signal triggering anoikis‐death. Considering also that clusterin is downregulated during prostate cancer onset and progression, and that its upregulation has inhibited DNA synthesis and cell cycle progression of immortalized human prostate epithelial cells, we suggest that clusterin might be a new anti‐oncogene in the prostate.
The Role of Apoptosis in Pituitary Adenomas in the Field of Conventionally Used Therapeutic Approaches
Authors: CERMAN JAROSLAV , CAP JAN , MAREKOVA MARTINA , NEMECEK STANISLAV , MAREK JOSEF , RUDOLF EMIL , CERVINKA MIROSLAV
Published: March 2004

Abstract: The aim of the study was to investigate the mechanism of action of somatostatin analogues (SSA), ionizing radiation, and their combination on pituitary adenoma cells with special emphasis on proliferative and apoptotic activity. In the 14 GH‐secreting adenomas pretreated with SSA before surgery, more prominent regressive changes were found accompanied by compensatory increase in perivascular fibrosis than in the reference group of 17 unpretreated adenomas. The proliferative Ki‐67 labeling index was significantly lower in the treated group (median 1.6 per 1000) than in the untreated patients (median 5.0 per 1000). Apoptosis was detected in only 2 of the 14 pretreated adenomas, and it was more frequent (9/17) and more prominent in the untreated group. In cell lines, the SSA had minimal antiproliferative effect, and they were unable to induce apoptosis. Ionizing radiation at doses of 5–20 Gy induced apoptosis in the corticotroph cell line AtT20 with no cell‐cycle block. In the somatotroph GH3 cell line, the early (premitotic) apoptosis was detectable using only a high dose of 200 Gy; after irradiation with doses of 20–50 Gy, apoptosis appeared with the latency of 48–72 hours, and was preceded by cell‐cycle arrest in the G2/M phase. The treatment with somatostatin‐14 during irradiation increased the percentage of apoptotic cells in culture 10 days after irradiation (11% versus 3% using 20 Gy).
In Vivo Imaging of Chemotherapy‐Induced Apoptosis in Human Cancers
Authors: BELHOCINE TARIK , STEINMETZ NEIL , GREEN ALLAN , RIGO PIERRE
Published: March 2004

Abstract: Rationale. Induction of apoptosis in sensitive tumor cells is the main mechanism of action of chemotherapy agents in human cancers. Also, the assessment of drug‐induced apoptosis soon after chemotherapy may be an early predictor of treatment efficacy.

Patients and Methods. A phase I/II study was prospectively conducted in 15 patients presenting with proven lung cancers (n= 10), breast cancers (n= 2), and lymphomas (n= 3) to assess the value of the 99mTc‐radiolabeled recombinant human (rh) Annexin V for imaging apoptosis immediately after completion of the first course of chemotherapy. Early Annexin V findings post‐chemotherapy (day+1, day+2) were also compared to the tumor status at 6 to 12 weeks post‐treatment.

Results. All lung and lymphoma patients with an increased tracer uptake post‐treatment (n= 8) had either partial or complete tumor response. Five patients with no tracer uptake had progressive disease. However, two breast cancers had a response to treatment, although no significant tracer uptake was observed. Tumor response and survival time were significantly correlated with the 99mTc‐labeled Annexin V uptake. No serious events related to tracer administration were noted.

Conclusion. Preliminary results of this pilot study demonstrate the feasibility of the 99mTc‐labeled Annexin V uptake for the in vivo imaging of apoptosis after one course of chemotherapy. If confirmed on larger series, these promising results may open new perspectives in the management of oncology patients.
Effects of Membrane Attack Complex of Complement on Apoptosis in Experimental Autoimmune Encephalomyelitis
Authors: NICULESCU TEODORA , WEERTH SUSANNA , SOANE LUCIAN , NICULESCU FLORIN , RUS VIOLETA , RAINE CEDRIC S. , SHIN MOON L. , RUS HOREA
Published: March 2004

Abstract: Complement activation is involved in the initiation of inflammation and antibody‐mediated demyelination in experimental autoimmune encephalomyelitis (EAE). We investigated the role of MAC in apoptosis in myelin‐induced EAE in complement C5‐deficient (C5‐d) and C5‐sufficient (C5‐s) mice. The number of apoptotic cells assessed by TUNEL assay was significantly increased in C5‐d mice during clinical recovery as compared with C5‐s mice. Most of the apoptotic cells were lymphocytes, monocytes, and oligodendrocytes. DNA microarray was performed using total RNA extracted from spinal cords. Genes expressed higher in C5‐s included members of the caspase (caspase 6, 7), TNF and TNFR families (CD27, FasL, lymphotoxin‐beta R) and survivin. These results indicate that C5 and possibly MAC may be required for the limitation of inflammatory response within the central nervous system.
Blood Cell Apoptosis/Necrosis: Some Clinical and Laboratory Aspects
Authors: SEGHATCHIANA JERARD , DE SOUSA GRACINDA
Published: March 2004

Abstract: Exposure of phosphatidyl‐serine on blood cell membrane surface and microvesiculation as the hallmarks of apoptosis/necrosis were investigated. The effect of leukofiltration on the retention/generation of microvesicules, leukocyte subsets and major biological response modifiers were evaluated in a like study. It is concluded that apoptotic cells potentially contribute to transfusion reactions in donor/recipient‐specific ways.
Early Activation of Antioxidant Mechanisms in Muscle of Mutant Cu/Zn‐Superoxide Dismutase‐Linked Amyotrophic Lateral Sclerosis Mice
Authors: JOKIC NATASA , DI SCALA FRANCK , DUPUIS LUC , RENE FREDERIQUE , MULLER ANDRE , DE AGUILAR JOSE‐LUIS GONZALEZ , LOEFFLER JEAN‐PHILIPPE
Published: March 2004

Abstract: A subset of familial ALS cases is associated with missense mutations in the gene encoding Cu/Zn‐superoxide dismutase (SOD1), a free radical scavenging enzyme that protects cells against oxidative stress. Overexpression of these ALS‐linked mutations confers an unidentified gain of function to the enzyme that triggers a series of neurological disorders characteristic of human ALS. To understand how skeletal muscle may counteract the progression of the disease, we explored the expression of different molecular effectors involved in antioxidant pathways. Our results are strongly indicative of the early and long‐lasting activation of a series of molecular effectors thought to act coordinately in preventing the increased oxidative stress characteristic of ALS.
CD4+ Lymphocyte Increases in HIV Patients during Potent Antiretroviral Therapy Are Dependent on Inhibition of CD8+ Cell Apoptosis
Authors: GRELLI SANDRO , D'ETTORE GABRIELLA , LAURIA FILIPPO , MONTELLA FRANCESCO , DI TRAGLIA LOIDE , D'AGOSTINI CARTESIO , LICHTNER MIRIAM , VULLO VINCENZO , FAVALLI CARTESIO , VELLA STEFANO , MACCHI BEATRICE , MASTINO ANTONIO
Published: March 2004

Abstract: Although suppression of apoptosis contributes to immune‐reconstitution during potent antiretroviral therapy, its relationship with the majors indicators of response to therapy, that is, changes in CD4+ cell counts and in viral loads (VL), is still debated. We extended our previous study by collecting data on the relationships among apoptosis and immunological and virological parameters during a long‐term follow‐up of HIV patients with an overall positive response to potent antiretroviral therapy. We report results from 15 patients who completed two years of therapy. In a smaller group of patients, we focused our attention on investigating the specific contribution of the CD8+ subset in the overall changes in lymphocyte apoptosis, which occur concomitantly with the response to the therapy. Our data, while again confirming that inhibition of PBMC apoptosis is a phenomenon strictly related to a positive response to potent antiretroviral therapy, suggest that CD4+ cell rescue is not directly dependent on inhibition of CD4+ cell apoptosis but rather on that of the CD8+ subset.
NF‐κB and Bcl‐2 in Helicobacter pylori‐Induced Apoptosis in Gastric Epithelial Cells
Authors: CHU SANG HUI , LIM JOO WEON , KIM KYUNG HWAN , KIM HYEYOUNG
Published: March 2004

Abstract: Helicobacter pylori (H. pylori) has been considered as an important pathogen of gastroduodenal inflammation and gastric carcinogenesis. However, the pathogenic mechanisms including H. pylori‐induced apoptosis and subsequent molecular mechanisms have not been clarified yet. The present study examined the role of Bcl‐2 and its relation to NF‐κB in H. pylori‐induced apoptosis in human gastric epithelial AGS cells. AGS cells were cultured in the presence of H. pylori, at a bacterium/cell ratio of 300:1, for the determination of apoptosis, NF‐κB activation with IkBa degradation, and Bcl‐2 level. AGS cells were transfected with a control vector (pCMV cells) or a full‐length human Bcl‐2 expression vector (Bcl‐2 cells). H. pylori‐induced apoptosis and NF‐κB activation were compared in the wild‐type cells and the transfected cells. As a result, H. pylori increased apoptotic cells with chromatin condensation and reduced Bcl‐2 levels, which were accompanied with NF‐κB activation. H. pylori induced sixfold increase in the number of apoptotic cells in wild‐type cells and pCMV cells. H. pylori‐induced increment of apoptotic cells were relatively lower in Bcl‐2 cells than pCMV cells. H. pylori‐induced NF‐κB activation and IkBa degradation were not different in the wild‐type cells, pCMV cells, and Bcl‐2 cells. In conclusion, the reduced gastric Bcl‐2 level may be the main pathogenic mechanism of H. pylori‐induced apoptosis in gastric epithelial cells.
Glycoprotein of Nonpathogenic Rabies Viruses Is a Major Inducer of Apoptosis in Human Jurkat T Cells
Authors: LAY STÉPHANIE , PRÉHAUD CHRISTOPHE , DIETZSCHOLD BERNHARD , LAFON MONIQUE
Published: March 2004

Abstract: This study sought to identify the RV protein that causes apoptosis. For this purpose, we first compared the ability of G and N proteins of a pathogenic and a nonpathogenic strain to trigger apoptosis of Jurkat rtTA by using an inducible Tet‐on expression system. Then we analyzed apoptosis induced by a reverse genetic‐engineered recombinant rabies virus in which the G gene from a nonpathogenic strain was replaced by its pathogenic strain counterpart. No other virus proteins than G of nonpathogenic RV strains induce apoptosis, and the G polypeptide of RV is a critical determinant for apoptosis in human cells.
Prion Protein Fragment 106–126 Induces a p38 MAP Kinase—Dependent Apoptosis in SH‐SY5Y Neuroblastoma Cells Independently from the Amyloid Fibril Formation
Authors: CORSARO A , THELLUNG S , VILLA V , PRINCIPE D ROSSI , PALUDI D , ARENA S , MILLO E , SCHETTINI D , DAMONTE G , ACETO A , SCHETTINI G , FLORIO T
Published: March 2004

Abstract: Prion diseases are neurodegenerative disorders of the central nervous system of humans and animals, characterized by spongiform degeneration of the central nervous system, astrogliosis, and deposition of amyloid into the brain. The conversion of a cellular glycoprotein (prion protein, PrPC) into an altered isoform (PrPSc) has been proposed to represent the causative event responsible for these diseases. The peptide corresponding to the residues 106–126 of PrP sequence (PrP106‐126) is largely used to explore the neurotoxic mechanisms underlying the prion diseases. We investigated the intracellular signaling responsible for PrP106‐126‐dependent cell death in the SH‐SY5Y human neuroblastoma cell line. In these cells, PrP106‐126 treatment induced apoptotic cell death and the activation of caspase‐3. The p38 MAP‐kinase blockers (SB203580 and PD169316) prevented the apoptotic cell death evoked by PrP106‐126 and Western blot analysis revealed that the exposure of the cells to the peptide induced p38 activation. However, whether the neuronal toxicity of PrP106‐126 is caused by a soluble or fibrillar form of this peptide is still unknown. In this study, we correlated the structural state of this peptide with its neurotoxicity. We show that the two conserved glycines in position 114 and 119 prevent the peptide to assume a structured conformation, favoring its aggregation in amyloid fibrils. The substitution of both glycines with alanine residues (PrP106‐126AA) generates a soluble nonamyloidogenic peptide, that retained its toxic properties when incubated with neuroblastoma cells. These data show that the amyloid aggregation is not necessary for the induction of the toxic effects of PrP106‐126.
Neuronal Death versus Synaptic Pathology in Alzheimer's Disease
Authors: BERTONI‐FREDDARI CARLO , FATTORETTI PATRIZIA , SOLAZZI MORENO , GIORGETTI BELINDA , DI STEFANO GIUSEPPINA , CASOLI TIZIANA , MEIER‐RUGE WILLIAM
Published: March 2004

Abstract: Neuron and synapse numeric densities as well as the average size and surface density of the synaptic junctional areas were measured in the hippocampus and cerebellum of adult, old, and demented (Alzheimer's disease) patients. Our findings support the notion that synaptic loss represents per se a prominent and early damage affecting zones of the central nervous system reported to show a different vulnerability to age‐ and pathology‐related changes.
Induction of Cyclooxygenase‐2 and Peroxisome Proliferator‐Activated Receptor‐γ during Nitric Oxide‐Induced Apoptotic PC12 Cell Death
Authors: LIM SO‐YOUNG , JANG JUNG‐HEE , SURH YOUNG‐JOON
Published: March 2004

Abstract: Inappropriate expression of inducible nitric oxide synthase (iNOS) and unregulated production of nitric oxide (NO) may contribute to neuronal cell death implicated in neurological disorders such as Alzheimer's disease. In this study, we have investigated the molecular mechanisms underlying nitrosative cell death induced by NO in cultured rat pheochromocytoma (PC12) cells. Incubation of PC12 cells with the NO donor sodium nitroprusside (SNP) resulted in apoptotic death as revealed by the decrease of mitochondrial transmembrane potential (δψm), cleavage of poly(ADP‐ribose) polymerase (PARP), and induction of p21Waf1/Cip1. It has been reported that the expression of cyclooxygenase‐2 (COX‐2) and peroxisome proliferator‐activated receptor‐γ (PPARγ) is elevated in Alzheimer's disease, and certain nonsteroidal anti‐inflammatory drugs (NSAIDs) can reduce the risk and delay the onset of Alzheimer's disease. Treatment of PC12 cells with a proapoptotic dose of SNP induced expression of both COX‐2 and PPARγ. Addition of the PPARγ antagonist GW9662 to the media augmented the NO‐induced cytotoxicity. Although cotreatment of PGE2 (50 μM) and SNP (0.4 mM) aggravated the NO‐induced cytotoxicity, preincubation of the same concentration of PGE2 was cytoprotective. Taken together, the above findings suggest that the proinflammatory mediators such as PGE2 and PPARγ may regulate the nitrosative stress‐induced apoptotic cell death.
Drugs of Abuse Induce Apoptotic Features in PC12 Cells
Authors: OLIVEIRA M T. , REGO A C. , MACEDO TR A. , OLIVEIRA C R.
Published: March 2004

Abstract: Drugs of abuse induce the release of dopamine in the central nervous system, particularly in the mesolimbic‐mesocortical pathway. As dopamine may act as a neurotoxin, in this study, we analyzed the effects of the drugs of abuse, cocaine, heroin, and amphetamine, on the neurodegeneration of PC12 cells, a dopaminergic cell line, by evaluating the activity of caspase‐3 and mitochondrial cytochrome c release. All the drugs were shown to induce caspase‐3 activation, similarly to staurosporine, a classical inducer of apoptotic cell death. Furthermore, like staurosporine, the drugs of abuse induced a decrease in mitochondrial cytochrome c content, suggesting the involvement of the mitochondrial apoptotic pathway.
Dopaminergic Modulation of Apoptosis in Human Peripheral Blood Mononuclear Cells
Authors: COLOMBO CRISTINA , COSENTINO MARCO , MARINO FRANCA , RASINI EMANUELA , OSSOLA MARIA , BLANDINI FABIO , MANGIAGALLI ANNA , SAMUELE ALBERTA , FERRARI MARCO , BOMBELLI RAFFAELLA , LECCHINI SERGIO , NAPPI GIUSEPPE , FRIGO GIANMARIO
Published: March 2004

Abstract: Dopamine (DA) modulates apoptosis in neuronal and non‐neuronal cells, and dopaminergic pathways contribute to neurodegenerative disease. Human lymphocytes express dopaminergic receptors and DA transporters, and synthesize endogenous catecholamines, which may modulate apoptosis in these cells. In the present study, dopaminergic modulation of apoptosis was investigated in human peripheral blood mononuclear cells (PBMCs) obtained from healthy donors. Twenty‐four‐hour DA reduced at 0.1–5 × 3 10−6 M and enhanced at 1–5 × 310−4 M spontaneous apoptosis. DA 1 × 310−6 M was inhibited by the D1‐like receptor antagonist SCH 23390 1 × 310−6 M, but not by the D2‐like receptor antagonists domperidone 1 × 3 10−6 M or haloperidol 1 × 3 10−6 M, while the effect of DA 5 × 3 10−4 M was prevented by the antioxidants glutathione 5–10 mM or N‐acetyl‐l‐cysteine 1–10 mM. Intracellular reactive oxygen species were respectively reduced and increased by 1–3 h incubation with DA 0.1–10 × 3 10−6 M and 1–5×310−4 M. Twenty‐four‐hour DA 1 × 3 10−6 M or 5 × 3 10−4 M had no effect on PBMC expression of Cu/Zn superoxide dismutase or Bcl‐2; however, DA 5 × 3 10−4 M decreased caspase‐3 activity. In human PBMCs, DA seems to promote apoptosis through oxidative mechanisms but may also result in cell rescue from apoptotic death possibly through activation of D1‐like receptors. The dual effect of DA on human PBMCs closely resembles that on striatal neurons. Lymphocytes of patients with Parkinson's disease may show reduced DA content and impaired DA transporter immunoreactivity. Human PBMCs may thus represent a simple and readily accessible model to study DA‐related mechanisms relevant for neurodegenerative disease.
TNFα Stimulated ATP‐Sensitive Potassium Channels and Attenuated Deoxyglucose and Ca Uptake of H9c2 Cardiomyocytes
Authors: El‐Ani D , Zimlichman R
Published: March 2004

Abstract: Tumor necrosis factor (TNFα) is an inflammatory cytokine that induces programmed cell death in a variety of tissue types, including the heart. Recent experimental data suggest that the TNF expressed within the myocardium in response to environmental injury plays an important role in initiating homeostatic response. The effect of TNFα (10–50 ng/mL) was studied on 86Rb efflux, 3H‐deoxyglucose uptake, or 45Ca uptake in H9c2 cardiomyocytes. TNFα stimulated 86Rb efflux from cultures, while 2 μM glibenclamide blocker of ATP‐sensitive potassium channels or 20 μM zvad‐fmk caspase inhibitor attenuated this effect. TNFα also depressed the stimulatory effect of 80 mM KCl on 45Ca uptake in the cardiomyocytes. TNFα inhibited the stimulatory effect of 100 nM insulin on 3H‐deoxyglucose uptake. Our findings further suggest that TNFα mediated adaptive and protective effects in the heart during a brief environmental injury.
Evaluation of Apoptosis Markers in Conjunctival and Eyelid Benign and Malignant Tumors
Authors: RESZEC JOANNA , SULKOWSKA MARIOLA , KANCZUGA‐KODA LUIZA , JANICA JERZY , SKAWRONSKA MALGORZATA , PEPINSKI WITOLD , SULKOWSKI STANISLAW
Published: March 2004

Abstract: The balance between cell proliferation and programmed cell death plays a crucial role in malignant development. Bcl‐2 family proteins, including proapoptosis protein Bak and antiapoptosis protein Bcl‐2, regulate the apoptotic process. Mutation of the p53 gene, which results in P53 protein accumulation, was observed in many types of human cancer. The aim of our study was to evaluate immunohistochemical Bcl‐2, Bak, and P53 protein expression and the relation between these proteins in conjunctival and eyelid benign and malignant tumors. We examined a series of 42 papillomas (CEP), 12 squamous cell cancers (SCC), and 19 cases of basal cell cancer (BCC). The age in the CEP group ranged from 18–94 years, and in the SCC and BCC groups from 42–87 years. Staining patterns were correlated with sex, age, and tumor localization. P53 protein‐positive immunostaining was observed in 71% of cases, Bcl‐2 in 83.9%, and Bak in 74.2 cases in the SCC and BCC groups. In the CEP group, P53 overexpression was observed in 90.5% of cases, Bcl‐2 in 71.4%, and Bak in 76.2%. No statistically significant correlation was found between examined protein expression and sex, age, and tumor localization. An inverse correlation was observed between P53 and Bak protein expression in the CEP group. No statistically significance correlation was noted between Bcl‐2 and P53 and Bcl‐2 and Bak protein expression in both examined groups. The obtained data suggests that P53 and Bcl‐2 protein expression coupled with decreasing Bak expression are associated with apoptosis and proliferation as well as malignant progression in conjunctival and eyelid tumors.
Immunohistochemical Status of p53, MDM2, bcl2, bax, and ER in Invasive Ductal Breast Carcinoma in Tunisian Patients
Authors: BACCOUCHE SAMI , DAOUD JAMEL , FRIKHA MOUNIR , MOKDAD‐GARGOURI RAJA , GARGOURI ALI , JLIDI RACHID
Published: March 2004

Abstract: TP53 gene alterations have been associated with sporadic breast cancer. To assess the role of p53 in invasive ductal carcinoma (IDC) of the breast among Tunisian patients, p53 protein status was studied by immuno‐histochemical analysis. The p53 protein was expressed in 41 of 70 (58%) tumors. Study of the status of its target gene expression showed that MDM2 was overexpressed in 43 tumors (61%), bcl2 in 29 (41%), and bax in only 9 (12%). Estrogen receptor (ER) was detected in 38 tumor tissues (54%). The accumulated p53 was significantly associated with MDM2‐positive, bcl2‐negative, and ER‐negative tumors (P= 0.024, P= 0.000027, and P= 0.000008, respectively), whereas with bax the correlaton was not significant. Bcl2 immunostaining displayed a positive correlation with ER (P= 0.001). A significantly higher fraction of p53‐positive cells was observed in ER‐negative SBRII‐SBRIII tumors than in ER‐positive SBRI‐SBRII tumors (P= 0.000066). bcl2‐positive tumors were significantly correlated with ER‐positive/SBRI‐SBRII tumors (P= 0.007), but negatively correlated with p53/bax (P= 0000004). MDM2 immunostaining displayed the same phenotype as p53 in the correlation with bcl2 and ER (P= 0.003), strengthened by significant associations between MDM2‐positive/p53‐positive and bcl2‐negative or ER‐negative, respectively (P= 0.00005 and P= 0.000001, respectively). MDM2‐positive cells were significantly correlated with the p53‐positive/bax‐negative phenotype (P= 0.04). These results suggest that p53 accumulated in these tumor tissues is associated with bad prognostic markers (ER‐negative, SBRIII) of IDC. MDM2 overexpression might be responsible for the accumulated p53 value in IDC. Regulation of the apoptotic process is involved in IDC; bcl2 is associated with a good prognostic marker (ER‐positive and SBRI‐II), whereas the regulation of bax is complex and does not necessarily correlate with the overexpression of p53.
Changes in Apoptotic and Mitotic Index, bcl2, and p53 Expression in Rectum Carcinomas after Short‐Term Cytostatic Treatment
Authors: FARCZÁDI E , KASZÁS I , BAKI M , SZENDE B
Published: March 2004

Abstract: Twenty patients with rectal adenocarcinoma were endoscopically biopsied and given short‐term cytostatic therapy [5‐fluorouracil (5‐FU) (600 mg/m2) and Ca‐folinate (60 mg/m2) for 2 days]. Seven days later, the tumor was resected or a second biopsy was performed. Apoptotic and mitotic indices as well as (mutant) p53 and bcl2 expression were determined in the tumor tissue before and after the short‐term chemotherapy. The patients were treated thereafter with long‐term, intermittent 5‐FU administration and followed up clinically for 7–26 months. Six patients showed progression of the disease and died, whereas 14 improved or showed no tumor progression. Significant increase of the apoptotic index and nonsignificant decrease of the mitotic index after the short‐term cytostatic treatment were seen in the tumor tissue of responder cases. Nonresponders showed no change in both mitotic activity and apoptotic activity. Both survivors and deceased showed high mutant p53 expression, and the changes after short‐term 5‐FU treatment were not significant. Expression of bcl2 was present in only 5 cases, with the postchemotherapy changes being not significant. These findings suggest that apoptotic response to short‐term cytostatic therapy may be an additional predictive factor in rectal adenocarcinoma.
Apoptosis in Prostate Carcinoma before and after Neoadjuvant Therapy with LH‐RH Analog
Authors: BENCINI STEFANIA , MIGALDI MARIO , CASTAGNETTI GIOVANNI , PINCELLI CARLO , FERRARI PAOLO , DE GAETANI CARMELA , TRENTINI GIAN PAOLO
Published: March 2004

Abstract: This study investigated apoptosis in prostate cancer before and after neoadjuvant treatment with LH‐RH analog, demonstrating that this therapy induced high AI and bax and survivin overexpression, thus acting as a proapoptotic agent in prostate cancer. A statistically significant correlation was found between high AI and overexpression of bax protein after therapy. It is probable that this kind of therapy is deeply implicated in promoting the apoptotic intrinsic pathway.
Induction of Apoptosis in Human Pancreatic Cancer Cells by Docosahexaenoic Acid
Authors: MERENDINO N , MOLINARI R , LOPPI B , PESSINA G , D'AQUINO M , TOMASSI G , VELOTTI F
Published: March 2004

Abstract: Polyunsaturated fatty acids have been indicated to induce anti‐proliferative and/or apoptotic effects in various tumor cells. We showed that, at a 200‐μM concentration, both alpha‐linoleic (18:2 n‐6; LA) or docosahexaenoic (22:6 n‐3; DHA) acid inhibited cell growth, while only DHA induced apoptosis in the human Paca‐44 pancreatic cancer cell line. Investigating the mechanism underlying DHA‐induced apoptosis, we showed that DHA induced a rapid and dramatic (>60%) intracellular depletion of reduced glutathione (GSH), without affecting oxidized glutathione (GSSG). Moreover, using two specific inhibitors of carrier‐mediated GSH extrusion, cystathionine or methionine, we observed that GSH depletion occurred via an active GSH extrusion, and that inhibition of GSH efflux completely reversed apoptosis. These results provide the first evidence for a possible causative role of GSH depletion in DHA‐induced apoptosis.
On the scaling of mammalian long bones
Authors: Garcia Guilherme J. M. , da Silva Jafferson K. L.
Published: March 2004

Although there is much data available on mammalian long-bone allometry, a theory explaining these data is still lacking. We show that bending and axial compression are the relevant loading modes and elucidate why the elastic similarity model failed to explain the experimental data. Our analysis provides scaling relations connecting bone diameter and length to the axial and transverse components of the force, in good agreement with experimental data. The model also accounts for other important features of long-bone allometry.
The crayfish Procambarus clarkii CRY shows daily and circadian variation
Authors: Fanjul-Moles María Luisa , Escamilla-Chimal Elsa G. , Gloria-Soria Andrea , Hernández-Herrera Gabriela
Published: March 2004

The circadian rhythms of crayfish are entrained by blue light, through putative extra retinal photoreceptors. We investigated the presence and daily variation of CRY, a protein photosensitive to blue light spectra and ubiquitous in animals and plants, in the putative pacemakers of Procambarus clarkii, namely the eyestalk and brain, at different times of the 24 h light:dark cycles. Using different experimental light protocols and by means of qualitative/quantitative immunofluorescence anatomical and biochemical methods, we identified CRY immunoreactivity in cells located in the medulla-terminalis-hemiellipsoidal complex (MT-HB) and the anterior margin of the median protocerebrum (PR). The immunoreaction varied with the time of day and the two neural structures showed a semi-mirror image. The results of the biochemical analysis matched these variations. Western blotting demonstrated statistically significant circadian rhythms in brain CRY abundance, but no daily circadian CRY abundance oscillations in the eyestalk. These immunocytochemical and biochemical results link a specific photoreceptor molecule to circadian rhythmicity. We propose that CRY may be linked to the photoreception of the clock and to the generation of circadian rhythmicity.
Ventricular diastolic filling characteristics in stage-24 chick embryos after extra-embryonic venous obstruction
Authors: Ursem Nicolette T. C. , Stekelenburg-de Vos Sandra , Wladimiroff Juriy W. , Poelmann Robert E. , Gittenberger-de Groot Adriana C. , Hu Norman , Clark Edward B.
Published: March 2004

Alteration of extra-embryonic venous blood flow in stage-17 chick embryos results in well-defined cardiovascular malformations. We hypothesize that the decreased dorsal aortic blood volume flow observed after venous obstruction results in altered ventricular diastolic function in stage-24 chick embryos. A microclip was placed at the right lateral vitelline vein in a stage-17(52–64 h of incubation) chick embryo. At stage 24 (4.5 days of incubation), we measured simultaneously dorsal aortic and atrioventricular blood flow velocities with a 20-MHz pulsed-Doppler velocity meter. The fraction of passive and active filling was integrated and multiplied by dorsal aortic blood flow to obtain the relative passive and active ventricular filling volumes. Data were summarized as means ± s.e.m. and analyzed by t-test. At similar cycle lengths ranging from 557 ms to 635 ms (P>0.60),dorsal aortic blood flow and stroke volume measured in the dorsal aorta were similar in stage-24 clipped and normal embryos. Passive filling volume(0.07±0.01 mm3) was decreased, and active filling volume(0.40±0.02 mm3) was increased in the clipped embryo when compared with the normal embryo (0.15±0.01 mm3,0.30±0.01 mm3, respectively) (P<0.003). In the clipped embryos, the passive/active ratio was decreased compared with that in normal embryos (P<0.001). Ventricular filling components changed after partially obstructing the extra-embryonic venous circulation. These results suggest that material properties of the embryonic ventricle are modified after temporarily reduced hemodynamic load.
The mechanism of sodium chloride uptake in hyperregulating aquatic animals
Authors: Kirschner Leonard B.
Published: March 2004

The emphasis in this review will be on Na+ absorption across the skin and gills of vertebrates and the gills of crustaceans. However, some recent studies of Cl– uptake, especially in crustaceans, will also be described.