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Enzyme
Compound
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Query: UNIPROT:P10415 (
Bcl-2
)
33,771
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We propose that 12E7 (CD99) expression, along with
TdT
, bcl-2, and CD34 reactivity in lymphoblastic lymphoma (LyL)/acute lymphoblastic leukemia (ALL), distinguishes this group of neoplasms from small noncleaved cell lymphomas (SNCLs) in both pediatric and adult patients, thereby narrowing the differential diagnosis of high-grade non-Hodgkin's lymphomas and acute lymphoblastic leukemias in paraffin sections. 12E7 (CD99) is one of a group of available antibodies that recognizes the product of the mic-2 gene, which was originally identified in ALL. Despite this, most clinicopathological research has focused on the reactivity of 12E7 in a subset of the small round cell tumors of childhood. Although
TdT
is widely used in the subtyping of blastic leukemias, its use in the distinction of high-grade lymphomas in paraffin sections has been limited. We collected 24 cases of LyL/ALL (13 B-cell and 11 T-cell) and 15 cases of SNCL from 1984 through 1993. We confirmed the diagnoses using morphology and analysis of immunologic data. We performed immunohistochemistry with the 12E7 antibody,
TdT
, bcl-2, and CD34 on formalin-fixed, paraffin-embedded material. The patients' ages ranged from 4 to 81 years; nine of the study patients were children. Sixteen of the 24 LyL/ALLs stained with 12E7. In contrast, none of the 15 cases of SNCL reacted with this antibody (chi-square P < .0001). A larger percentage of T-cell LyL/ALLs reacted with 12E7 than did B-cell LyL/ALLs (82% v 54%). Sixteen of 20 LyL/ALLs reacted with the anti-
TdT
antibody, as compared with none of 11 SNCLs (chi-square P < .0001). Six LyL/ALLs were CD34 positive (of 23), and none of the SNCLs were CD34 positive (0 of 12) (chi-square P = .0519).
Bcl-2
-positive cases were found among both LyL/ ALLs and SNCLs, although they were more prevalent among LyL/ ALLs (92% v 25%; chi-square P < .0001). When one considers the differential diagnosis of a high-grade lymphoma/acute lymphoblastic leukemia, positive reactions with 12E7,
TdT
, bcl-2, and CD34 support the diagnosis of LyL/ALL over SNCL. Moreover, we present data that suggests that evaluating for
TdT
in formalin-fixed paraffin-embedded tissue is a more sensitive test than using either 12E7, bcl-2 or CD34 alone.
...
PMID:MIC2, TdT, bcl-2, and CD34 expression in paraffin-embedded high-grade lymphoma/acute lymphoblastic leukemia distinguishes between distinct clinicopathologic entities. 934 23
Since apoptosis is observed in tuberculous granulomata, we investigated the molecular mechanisms underlying the apoptotic pathway in an in vitro model of mycobacterial infection of mononuclear phagocytes. We postulated that Mycobacterium tuberculosis could trigger the apoptotic pathway in macrophages, resulting in death of the microorganism by modulating the expression of bcl-2, bax, bcl-xL, and bcl-xS. We found that the mRNA of bcl-2, an inhibitor of apoptosis, was downregulated in peripheral blood monocytes (PBM) between 2 and 6 h following infection with M. bovis BCG or induction with heat-killed M. tuberculosis H37Ra. Western analysis showed a downregulation of the
Bcl-2
protein, with a half-life of 24 h. At the same time points, there was no change in the expression of Bax or Bcl-xS, inducers of apoptosis, but Bcl-xL, another inhibitor of apoptosis, was minimally upregulated by BCG. To determine if apoptosis could be a mechanism for growth inhibition in vivo, we obtained alveolar macrophages by bronchoalveolar lavage from involved sites in patients with active pulmonary tuberculosis. Using the TUNEL (
terminal deoxynucleotidyltransferase
mediated nick end labeling) technique, we observed significantly more apoptosis in involved segments of five tuberculosis patients (14.8 +/- 1.9%) than in those of normal controls (<1%, P = 0.02) or in uninvolved segments (4.3 +/- 0.9%, P < 0.05). We conclude that apoptosis of mononuclear phagocytes induced by M. tuberculosis occurs in vivo and that in an in vitro model of mycobacterial infection, apoptosis may be mediated by downregulation of
Bcl-2
.
...
PMID:Effects of mycobacteria on regulation of apoptosis in mononuclear phagocytes. 939 26
Seizure-induced neuronal damage may involve both excitotoxic and apoptotic (programmed cell death) mechanisms. In the present study, we used an amygdala kindled seizure model to study whether apoptotic cell death occurs. To evaluate apoptosis, we counted the numbers of cells that had DNA fragments labeled at the 3' end with digoxigenin using
terminal transferase
(ApopTag, Oncor). Additionally, the expression of Bax and
Bcl-2
, two genes associated with apoptotic cell death, was also measured following kindled seizures. We found that the number of ApopTag-positive cells in the hippocampus increased 30.4% after one kindled seizure and 82.5% after 20 seizures compared to sham controls. The ApopTag-labeled cells could be mainly interneurons of the hippocampal formation, although additional studies are required. Preferential vulnerability of inhibitory interneurons is consistent with previous studies on seizure-induced cell loss. These results, coupled with our findings that the ratio of Bax/
Bcl-2
expression is increased in the hippocampus by seizures, suggest that apoptosis of hippocampal interneurons may lead to dysinhibition in the hippocampus and increased seizure susceptibility.
...
PMID:Apoptosis of hippocampal neurons after amygdala kindled seizures. 958 22
In the central nervous system, interleukin (IL)-3 has been shown to exert a trophic action only on septal cholinergic neurons in vitro and in vivo, but a widespread distribution of IL-3 receptor (IL-3R) in the brain does not conform to such a selective central action of the ligand. Moreover, the mechanism(s) underlying the neurotrophic action of IL-3 has not been elucidated, although an erythroleukemic cell line is known to enter apoptosis after IL-3 starvation possibly due to a rapid decrease in
Bcl-2
expression. This in vivo study focused on whether IL-3 rescued noncholinergic hippocampal neurons from lethal ischemic damage by modulating the expression of Bcl-xL, a
Bcl-2
family protein produced in the mature brain. 7-d IL-3 infusion into the lateral ventricle of gerbils with transient forebrain ischemia prevented significantly hippocampal CA1 neuron death and ischemia-induced learning disability. TUNEL (
terminal deoxynucleotidyltransferase
-mediated 2'-deoxyuridine 5'-triphosphate-biotin nick end labeling) staining revealed that IL-3 infusion caused a significant reduction in the number of CA1 neurons exhibiting DNA fragmentation 7 d after ischemia. The neuroprotective action of IL-3 appeared to be mediated by a postischemic transient upregulation of the IL-3R alpha subunit in the hippocampal CA1 field where IL-3Ralpha was barely detectable under normal conditions. In situ hybridization histochemistry and immunoblot analysis demonstrated that Bcl-xL mRNA expression, even though upregulated transiently in CA1 pyramidal neurons after ischemia, did not lead to the production of Bcl-xL protein in ischemic gerbils infused with vehicle. However, IL-3 infusion prevented the decrease in Bcl-xL protein expression in the CA1 field of ischemic gerbils. Subsequent in vitro experiments showed that IL-3 induced the expression of Bcl-xL mRNA and protein in cultured neurons with IL-3Ralpha and attenuated neuronal damage caused by a free radical-producing agent FeSO4. These findings suggest that IL-3 prevents delayed neuronal death in the hippocampal CA1 field through a receptor-mediated expression of Bcl-xL protein, which is known to facilitate neuron survival. Since IL-3Ralpha in the hippocampal CA1 region, even though upregulated in response to ischemic insult, is much less intensely expressed than that in the CA3 region tolerant to ischemia, the paucity of IL-3R interacting with the ligand may account for the vulnerability of CA1 neurons to ischemia.
...
PMID:Interleukin 3 prevents delayed neuronal death in the hippocampal CA1 field. 970 46
Many B cell precursors die while differentiating in mouse bone marrow. To ascertain the mechanisms involved in this process, populations of B lineage cells and their tissue localization were analyzed in bone marrow of transgenic mice overexpressing the apoptosis inhibitor,
Bcl-2
. Immunofluorescence labeling and mitotic arrest were used to quantitate the number and proliferative activity of mu- pro-B cells (terminal deoxynucleotidyl transferase [
TdT
]+B220-, TdT+B220+, and
TdT
-B220+); pre-B cells (cmu+); and B cells (smu+). Mature B cells (IgM+IgD+) were increased 16- to 20-fold. In addition, immature B lymphocytes (IgM+IgD-/low), representing newly formed cells, were increased three- to sixfold, whereas pre-B cells and late pro-B cells were increased 30 to 60% in production rate. Earlier pro-B cells expressing
TdT
were unaffected. In spleen, both mature and immature B cells were greatly increased, but cells of precursor phenotype were few and TdT+ cells were absent. The in vivo location of B cells was examined by autoradiography using light and electron microscopy after intravenous injection of 125I-labeled antibodies. B lineage cells (B220+) were increased throughout bone marrow, often within dilated venous sinusoids, particularly in subosteal regions. Many intravascular and perisinusoidal cells were IgDhigh mature B lymphocytes. In contrast, many other IgM+ and IgDlow immature B lymphocytes clustered extravascularly around the central venous sinus. Plasma cells with distended endoplasmic reticulum were numerous. These findings provide evidence that, in addition to expanding the recirculating pool of B cells entering bone marrow from the blood stream, high levels of
Bcl-2
can inhibit some of the apoptosis occurring during B cell differentiation, thereby expanding populations of B lymphopoietic precursor cells within the bone marrow parenchyma.
...
PMID:Effect of a bcl-2 transgene on production and localization of precursor B cells in mouse bone marrow. 972 34
Apoptosis and the apoptosis-regulatory gene bcl-2 have been suggested from animal studies to be important during the development of the central nervous system (CNS), but information on apoptotic activities of the developing human CNS has been scarce. To establish spatial and temporal distributions of apoptotic cells and
Bcl-2
oncoprotein expression, we examined sections taken from cerebral cortex, hippocampus and brainstem at weeks 14, 18, 27, and 32 of gestation.
Terminal transferase
-mediated nick end labelling (TUNEL), histological analyses, and immunocytochemical staining using monoclonal antibodies were employed. Except for layer I of the motor cortex and the molecular layer of the hippocampus, both at week 14 of gestation, TUNEL-positive cells with typical apoptotic appearance and apoptotic indices, ranging from 0.08 to 2.85, were found in all other brain regions examined including visual, sensory, frontal and motor cortices, hippocampus, dorsal raphe, locus coeruleus, and periaqueductal grey of the brainstem. No specific spatial or temporal distribution patterns of apoptotic cells were found in the cortices. However, the apoptotic index of the molecular layer of the hippocampus increased with the gestation age. The periaqueductal grey of the brainstem showed high apoptotic indices (ranging from 0.37 to 2.85) at all the gestation ages studied. An inverse correlation between apoptosis and
Bcl-2
oncoprotein expression was found in visual, sensory, and motor cortices but not in the frontal cortex and hippocampus. Apoptosis and
Bcl-2
oncoproteins are important for CNS development and, apart from being an apoptosis regulator,
Bcl-2
oncoproteins may also have other roles to play during neural development.
...
PMID:Apoptosis and Bcl-2 oncoprotein expression in the human fetal central nervous system. 977 71
Apoptosis is a key phenomenon in the regulation of the life span of terminally differentiated leukocytes. Human gingiva represents an established model to study immune responses to bacterial infection. In this investigation, we used the TUNEL (
terminal deoxynucleotidyltransferase
-mediated dUTP-biotin nick end labeling) technique to evaluate presence and topographic location of apoptosis-associated DNA damage in human gingival biopsies along with the expression of the p53 and
Bcl-2
apoptosis-regulating proteins. Qualitative data analysis showed high densities of cells expressing DNA damage and p53 both within the epithelial attachment to the tooth and in the perivascular infiltrate (infiltrated connective tissue [ICT]) immediately underlying the site of chronic bacterial aggression. Topographic consistency between DNA damage- and p53-positive cells was consistently observed. Quantitative analysis of the ICT showed mean densities of DNA damage- and p53-positive cells of 345 +/- 278 and 403 +/- 182 cells/mm2, respectively. Numerical consistency was confirmed by multivariate regression analysis: densities of DNA damage-positive cells were significantly predicted by densities of p53-positive cells (P = 0. 001, r2 = 0.84). In the ICT, cells displaying biotinylated DNA nicks were 3.8% +/- 2.7% of total cellularity, while p53- and
Bcl-2
-positive cells represented 4.4% +/- 1.7% and 15.4% +/- 6.7% of total cells, respectively. It is suggested that p53 expression associated with DNA damage is a prevalent phenomenon in chronically inflamed human gingiva, and that apoptosis may be a relevant process for the maintenance of local immune homeostasis at sites of chronic bacterial challenge in vivo.
...
PMID:In situ detection of apoptosis at sites of chronic bacterially induced inflammation in human gingiva. 978 21
The products of a growing number of genes have been shown to display seemingly contradictory functions; namely, the induction of tumorigenesis and the induction of apoptosis. Heregulin's involvement in oncogenesis occurs through its interactions with members of the EGF receptor tyrosine kinase family. Recently one isoform of heregulin, beta2b, was isolated in an in vitro screen for dominant, apoptosis-inducing genes in kidney epithelial cells. Here we show that heregulin is also capable of mediating apoptosis in human and murine mammary tumor cell lines and murine tumors. Furthermore, through transfection of the human breast cancer cell line MCF-7 with the truncated transmembrane/cytoplasmic segment of the heregulin gene, we show that the intracellular region of the heregulin precursor is sufficient for induction of apoptosis. Through the use of DNA fragmentation assays we also show that apoptosis occurs in cell lines established from heregulin-induced mammary gland tumors.
TdT
addition of digoxigenin labeled nucleotides to 3' OH ends of DNA breaks recapitulated these results in the actual tumors. Finally, over-expression of heregulin is shown to lead to the down-regulation of
Bcl-2
, an inhibitor of apoptosis. Conversely, the transfection of
Bcl-2
into MCF-7 cells inhibits heregulin-mediated programmed cell death.
...
PMID:The oncogene heregulin induces apoptosis in breast epithelial cells and tumors. 979 82
The in situ apoptosis and the expression of molecules involved in this process, such as
Bcl-2
, Fas, and its ligand, Fas ligand (FasL), were examined in bronchial biopsies from healthy control subjects and from steroid-untreated or -treated asthmatics, using
terminal transferase
-mediated deoxyuridyltriphosphate nick-end labeling and immunohistochemical techniques, respectively. Bronchial submucosa from steroid- untreated asthmatics showed an increase in the number of eosinophils and a decrease in that of apoptotic cells compared with that of control subjects, but no significant changes in the number of T lymphocytes or in that of cells expressing
Bcl-2
, Fas, or FasL. Treatment with steroids reduced airway eosinophilia and augmented the proportion of apoptotic eosinophils. Compared with control subjects or untreated patients, steroid-treated asthmatics exhibited increased expression of
Bcl-2
, Fas, FasL, and of proliferating cell nuclear antigen (PCNA) in their bronchial epithelium, without changes in the number of apoptotic cells. Moreover, the intensity of the expression of
Bcl-2
, Fas, and FasL correlates well with that of PCNA. We conclude that steroids may reduce the inflammatory cell infiltrate in the bronchial submucosa in part by promoting eosinophil apoptosis and by inducing the expression of FasL on bronchial epithelial cells. Treatment with steroids may also augment survival and proliferation of epithelial cells, possibly via the expression of
Bcl-2
and PCNA.
...
PMID:Apoptosis, proliferation, and expression of Bcl-2, Fas, and Fas ligand in bronchial biopsies from asthmatics. 980 39
Lymphomas in 10 cynomolgus monkeys infected with a simian immunodeficiency virus (SIVsm) were studied with regard to proliferative activity and apoptosis-related gene expression. All were diffuse large-cell lymphomas, showed mono or oligoclonality and a 9/10 diploid cellular DNA content. Expression of a simian homologue to Epstein-Barr virus (HVMF-1) was shown in nine cases. The lymphomas showed moderate to high proliferative activity by Ki67 immunostaining and DNA flow cytometry, and a low number of apoptotic cells detected by
TdT
-mediated dUTP nick-end labeling (TUNEL). Immunohistochemistry showed abundant tumor infiltrating TIA-1(+) cytotoxic lymphocytes (CTL) and macrophages.
Bcl-2
, Mcl-1, and also Bax and Bak, but not p53 were demonstrable in the tumor cells by immunostaining. Our findings suggest a causal relationship between HVMF-1 infection and a low apoptotic index of the lymphomas due to the expression of
Bcl-2
. The apparent inefficient function of tumor-infiltrating CTL could be due to inactivation of CTL and/or resistance of the lymphoma cells to CTL effects. The tumors showed immunoreactivity for CD18, CD29, and CD49d, but not for CD11a, mimicking the phenotype of human Epstein-Barr virus (EBV)-related lymphomas. In summary, our observations indicate a high similarity between this simian model of acquired immunodeficiency syndrome (AIDS)-related lymphomas (ARL) and human ARL and other immunosuppression-related lymphomas.
...
PMID:Proliferation and apoptosis-related gene expression in experimental acquired immunodeficiency syndrome-related simian lymphoma. 994 80
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