Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.22.56 (caspase-3)
 35,750 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Naturally occurring apoptotic cells have been demonstrated in the postnatal cerebellum of rodents (Wood et al. [1993] Neuron 11:621-632; Krueger et al. [1995] J. Neurosci. 15:3366-3374). The nature of these cells differs among species: they are considered to be granule cells in mouse and astrocytes in rat. We labeled proliferating and apoptotic cells in the postnatal human cerebellar cortex by using antibodies against the Ki-67/proliferating cell nuclear antigen and the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling method for fragmented DNA. We also immunocytochemically detected some proteins encoded by genes modulating apoptosis and specific markers of neuronal/glial differentiation. Proliferating cells were observed from birth to 4 months, representing 31-35% of cells within the external granular layer (EGL). Apoptotic cells were detected during the first 3 months and corresponded to 5-7% of EGL cells. Much lower percentages were calculated in other cortical layers and white matter. The balance between proliferation and apoptosis was quantitatively favorable to the latter during the first postnatal week. Expression of BCL-2, CPP32, and interleukin-1beta-converting enzyme (ICE) proteins was spatially and developmentally regulated in parallel with apoptosis. Apoptotic cells were often CPP32/ICE immunoreactive but negative for BCL-2. Some apoptotic cells were positive for vimentin and, less frequently, for alpha-internexin or type-III beta tubulin, but never expressed the glial fibrillary acidic protein. This study demonstrates that apoptosis is a significant phenomenon in early postnatal development of human cerebellar cortex and shares some of the regulatory mechanisms described in other vertebrates.
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PMID:Apoptosis of undifferentiated progenitors and granule cell precursors in the postnatal human cerebellar cortex correlates with expression of BCL-2, ICE, and CPP32 proteins. 973 83

Apoptosis is a physiological, programmed process for the elimination of cells from living organisms. Currently, one of the most frequently used methods to detect apoptosis is TUNEL assay. It has provided valuable information about apoptosis in various tissues. However, the sensitivity and the specificity of TUNEL technique have also been criticized. We detected an intense false-positive apoptotic signal in nude and Balb/c mice kidney and liver. In kidney the signal was confined to the proximal, distal and collecting tubular cells, and in liver to hepatocytes. Both tissues appeared normal in light microscopy, and no DNA ladder formation or increase in caspase-3 enzyme activity was detected. BrdU labelling and Ki-67 immunostaining did not reveal increased cell proliferation in these tissues. On the other hand, false-positive signal was not detected in testis, spleen, pancreas or renal cell carcinoma from the same animals. Also, no false-positive signal was seen in human liver or kidney samples. Although factors known to produce false-positive staining related to sample harvesting, preparation and staining protocols were eliminated, the cause of the false- positive apoptotic signal remains unknown. We conclude that caution must be exercised when examining apoptosis in mouse tissues with TUNEL assay.
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PMID:False-positive apoptosis signal in mouse kidney and liver detected with TUNEL assay. 1122 14

Giant proerythroblasts are hallmarks of human parvovirus B19 infection. We attempted to characterize these cells in 5 patients with parvovirus B19-induced pure red cell aplasia using immunostaining of paraffin-embedded bone marrow sections with antibodies against erythroid-lineage-specific proteins, viral capsid antigen VP-1, and apoptosis- and cell-cycle-related proteins. Giant proerythroblasts are immunohistochemically consistent with early erythroid precursors of cells in the differentiation stage of CD34-, cytoplasmic spectrin+, glycophorin A-, and band-3-. VP-1 was expressed in the nucleus and cytoplasm of small- to medium-sized spectrin+ erythroid cells but not in giant proerythroblasts. The giant proerythroblasts displayed nuclear staining for p53 (41%+/-16%) and Ki-67 antigen (100%+/-0%) and cytoplasmic staining for Bax (65%+/-11%) and procaspase-3 (78%+/-10%), whereas they were not stained for p21Wafl/Cip1, active form of caspase-3, or terminal deoxynucleotidyltransferase-mediated deoxyuridine nick-end labeling (TUNEL). Antiapoptotic proteins, Bcl-2 and Mcl-1, were not expressed in the giant cells, and Bcl-x was infrequently expressed in these cells (11%+/-4%). These immunohistochemical findings suggest that giant proerythroblasts are proliferating erythroid precursors with accumulation of nonfunctional p53.
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PMID:Expression of p53 and Ki-67 antigen in bone marrow giant proerythroblasts associated with human parvovirus B19 infection. 1159 14

A constant remodeling of islet cell mass mediated by proliferative and apoptotic stimuli ensures a dynamic response to a changing demand for insulin. In this study, we investigated the effect of glucagon-like peptide-1 (GLP-1) in Zucker diabetic rats, an animal model in which the onset of diabetes occurs when the proliferative potential and the rate of beta-cell apoptosis no longer compensate for the increased demand for insulin. We subjected diabetic rats to a 2-d infusion of GLP-1 and tested their response to an ip glucose tolerance test. GLP-1 produced a significant increase of insulin secretion, which was paralleled by a decrease in plasma glucose levels (P < 0.001 and P < 0.01, respectively). Four days after the removal of the infusion pumps, rats were killed and the pancreas harvested to study the mechanism by which GLP-1 ameliorated glucose tolerance. Ex vivo immunostaining with the marker of cell proliferation, Ki-67, showed that the metabolic changes observed in rats treated with GLP-1 were associated with an increase in cell proliferation of the endocrine and exocrine component of the pancreas. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling staining, a marker of cellular apoptosis, indicated a reduction of apoptotic cells within the islet as well in the exocrine pancreas in GLP-1-treated rats. Double immunostaining for the apoptotic marker caspase-3 and for insulin showed a significant reduction of caspase-3 expression and an increase in insulin content in GLP-1-treated animals. Finally, staining of pancreatic sections with the nuclear dye 4,6-Diaminidino-2-phenyl-dihydrochloride demonstrated a marked reduction of fragmented nuclei in the islet cells of rats treated with GLP-1. Our findings provide evidence that the beneficial effects of GLP-1 in Zucker diabetic rats is mediated by an increase in islet cell proliferation and a decrease of cellular apoptosis.
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PMID:Glucagon-like peptide-1 promotes islet cell growth and inhibits apoptosis in Zucker diabetic rats. 1239 37

Programmed cell death and proliferation are evolutionary conserved processes that play a major role during normal development and homeostasis. In the testis, during the fetal and newborn periods, they might determine final adult size and fertility potential. In the present study, we have measured the relative number of testicular cells in apoptosis and in active proliferation in the seminiferous cords and in the interstitium, at different age periods of prepubertal testicular development in humans. Testes from 44 prepubertal subjects without endocrine and metabolic abnormalities were collected at necropsy. They were divided in three age groups (Gr): Gr 1, newborn (1- to 21-d-old neonates), n = 18, mean (+/-SD) age 0.3 +/- 0.23 months; Gr 2, post natal activation (1- to 6-month-old infants), n = 13, mean age 3.93 +/- 1.90 months; and Gr 3, early childhood period (1- to <6-yr-old boys), n = 13, mean age 31.5 +/- 18.9 months. Apoptosis was detected in 5- microm tissue sections using a modified terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay and cell proliferation was assessed by Ki-67 immunohistochemistry. Evaluation of apoptosis was confirmed by estimation of active caspase-3. Mean (+/-SD) testicular weight was 0.38 +/- 0.20, 0.54 +/- 0.35, and 0.51 +/- 0.11 g in Gr 1, Gr 2, and Gr 3, respectively. In Gr 1, there was a significant positive correlation between age and testis weight (P = 0.02). Mean (+/-SD) germ cell apoptotic index, AI, (% of apoptotic cells out of total cell number) was 15.0 +/- 6.60, 27.0 +/- 8.80 and 33.4 +/- 11.4 in Gr 1, Gr 2, and Gr 3, respectively. In Sertoli cells, it was 6.60 +/- 4.07, 22.0 +/- 14.0 and 27.5 +/- 19.8, respectively. In interstitial cells, it was 10.2 +/- 6.38, 18.0 +/- 6.70 and 25.7 +/- 15.5, respectively. In the three types of cells, AI in Gr 1 was significantly lower than in Gr 2 or Gr 3 (P < 0.05). Mean (+/-SD) germ cell proliferation index, PI, was 18.6 +/- 13.0, 10.0 +/- 6.50 and 10.9 +/- 6.24% in Gr 1, Gr 2, and Gr 3, respectively. In Sertoli cells and in interstitial cells PI was similar in the three age groups. The PI/AI ratio was used to compare relative differences among age groups. The PI/AI ratio of germ cells, Sertoli cells and interstitial cells in Gr 1 was significantly higher than in Gr 2 or Gr 3 (P < 0.05). It is concluded that, in normal subjects, there is a vigorous growth of the testis during the newborn period with subsequent stabilization during the first years of prepuberty. This cell growth seems to be mainly mediated by decreased apoptosis. The factors that modulate apoptosis of testicular cells are not known, but it is remarkable that this change takes place before the testosterone peak of the post natal gonadal activation of the first trimester of life. These changes taking place during the newborn period might be important to define testicular function in adults.
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PMID:Apoptosis and proliferation of human testicular somatic and germ cells during prepuberty: high rate of testicular growth in newborns mediated by decreased apoptosis. 1241 80

The incidence of cancer increases with advancing age, but the biological behavior of cancer is known to be less aggressive in elderly people. Thus, the proliferative activity and extent of apoptosis of cancer cells were assessed in samples from 163 cases of colorectal cancer focusing on the age of patients, using Ki-67 labeling index (LI) and apoptotic index (AI) by terminal deoxynucleotidyl transferase (TdT)-mediated d-UTP nick end labeling method and staining for activated caspase-3. The Ki-67 LI of colorectal cancer ranged from 2.33 to 80.4% (mean 32.2%), while the AI ranged from 0.00 to 14.8% (mean 3.57%). Concerning the aging effect, linear and positive correlations were found for the Ki-67 LI of cancer with age (p<0.05) and the AI of cancer with age (p<0.05). However, in normal colorectal mucosa, aging of patients revealed a significant correlation only with the AI but not with the Ki-67 LI. The AI in earlier stages of cancers (stages 0 and 1) revealed a significant difference between younger cases (age<65) and more elderly cases (age>/=65) (p<0.05), however, the Ki-67 LI did not exhibit a significant difference. Therefore, an increased frequency of apoptosis in colorectal cancer tissues, especially in the earlier stages, may possibly explain the slower growth of colorectal cancers in the elderly. Next, the expressions of several regulatory molecules for the proliferation/apoptosis of tumor cells were determined. The results demonstrated a tendency for stronger and more frequent expressions of c-myc, Bak and Bax despite a rather weaker expression of Bcl-2 in cancer tissues from the elderly compared with those from the younger patients. The potential roles of these regulatory molecules on age-change in the proliferation/apoptosis of colorectal cancers are discussed.
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PMID:Incidence of apoptosis increases with age in colorectal cancer. 1255 16

Smac (or DIABLO) is a recently identified, novel proapoptotic molecule, which is released from mitochondria into the cytosol during apoptosis. Smac functions by eliminating the caspase-inhibitory properties of the inhibitors of apoptosis proteins (IAP), particularly XIAP. In this study, we stably transfected both full-length (FL) and mature (MT) Smac genes into the K562 and CEM leukaemic cell lines. Both FL and MT Smac transfectants increased the sensitivity of leukaemic cells to UV light-induced apoptosis and the activation of caspase-9 and caspase-3. Purified cytosol from the mature Smac transfectants, or the addition of human recombinant Smac protein or N-7 peptide into nontransfected cytosol, showed an increased sensitivity to cytochrome c-induced activation of caspase-3. The mature Smac enhanced the susceptibility of both K562 and CEM cells to TRAIL-induced apoptosis. Overexpression of the mature Smac protein also inhibited proliferation, as detected by reduced colony formation and Ki-67 expression in leukaemic cells. Cell cycle analysis revealed that Smac transfectants displayed significant G0/G1 arrest and reduction in 5-bromo-2'-deoxyuridine (BrdU) incorporation. Smac sensitized human acute myeloid leukaemia blasts to cytochrome c-induced activation of caspase-3. However, Smac failed to overcome Apaf-1-deficiency-mediated resistance to cytochrome c in primary leukaemic blasts. In summary, this study reveals that Smac/DIABLO exhibits a potential role in increasing apoptosis and suppressing proliferation in human leukaemic cells. Importantly, it also indicates that it is crucial to evaluate the levels of Apaf-1 and XIAP proteins in patient samples before using Smac peptide therapy in the treatment of human leukaemia.
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PMID:Role of Smac in human leukaemic cell apoptosis and proliferation. 1264 62

With the aim to investigate histopathological changes and proliferative and apoptotic activity in GH-secreting adenomas we compared 14 cases pre-treated with somatostatin analogues before surgery with a reference group of 17 un-pretreated ones. Besides routine histology, immunocytochemical detection of all pituitary hormones, caspase-3, cytokeratin-18, and "M30 antigen", its apoptosis-specific fragment was performed. Proliferation activity of the tumour was determined by the Ki-67 antigen expression. In treated adenomas more prominent regressive changes were found accompanied by compensatory increase in perivascular fibrosis. The Ki-67 labelling index was lower in treated group (mean 2.5, median 1.6 per mille) than in untreated patients (mean 9.4, median 5.0 per mille). The difference was statistically significant (p=0.049 using Mann-Whitney Rank Sum Test). Apoptosis was detected in only 2 of the 14 pre-treated adenomas, and it was more frequent (9/17) and more prominent in the untreated group.
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PMID:The influence of treatment with somatostatin analogues on morphology, proliferative and apoptotic activity in GH-secreting pituitary adenomas. 1285 83

Overexpression of the receptor tyrosine kinase HER-2/neu is associated with poor prognosis in patients with breast and ovarian cancer. Recent excitement has surrounded the therapeutic effects of HER-2-blocking therapy strategies and has rekindled interest on the molecular mechanisms of HER-2/neu in tumor biology. To study the role of HER-2/neu overexpression in vivo, we used a murine fibroblast cell line (NIH3T3-her2) conditionally expressing human HER-2/neu under control of a tetracycline-responsive promoter. Expression of HER-2 could be down-regulated below detection limit (>625-fold dilution) by exposure of NIH3T3-her2 cells to anhydrotetracycline (ATc). Subcutaneous injection of NIH3T3-her2 cells into nude mice resulted in rapid tumor growth. Mice with mean tumor volumes of 0.2, 0.8, 1.9, and 14.9 cm(3) were treated daily with 10 mg/kg ATc to switch off HER-2/neu expression, producing reductions in tumor size of 100, 98.1, 81.4, and 74.2%, respectively, by 7 days after onset of ATc administration (P = 0.005, Kruskal-Wallis test). Different long-term effects of HER-2 down-regulation were observed when mice with small (0.2 cm(3); n = 7), intermediate (0.8-1.2 cm(3); n = 10) and large (> or =1.9 cm(3); n = 11) tumors received ATc for up to 40 days. Complete remission was observed for 100, 40, and 18% of the small-, intermediate-, and large-sized tumors, respectively (P = 0.003). However, after 20-45 days of ATc administration, recurrent tumor growth was observed for all mice, even in those with previous complete remissions. The time periods for which mean tumor volume could be suppressed to volumes <0.1 cm(3) under ATc administration were 34, 22, 8, and 0 days for tumors with initial volumes of 0.2, 0.8, 1.9 and 14.9 cm(3), respectively (P = 0.005, Kruskal-Wallis test). Interestingly, HER-2 remained below the detection limit in recurrent tumor tissue, suggesting that initially HER-2-dependent tumors switched to HER-2 independence. The "second hits" leading to HER-2-independent tumor growth have not yet been identified. The rapid regression of tumors after down-regulation of HER-2 was explained by two independent mechanisms: (a) a block in cell cycle progression, as evidenced by a decrease in Ki-67 antigen expression from 40% before ATc treatment to 8.3% after 7 days of ATc treatment; and (b) induction of apoptosis as demonstrated by caspase-3 activation and by the terminal deoxynucleotidyltransferase (Tdt)-mediated nick end labeling assay (TUNEL). In conclusion, we have shown that switching off HER-2 may disturb the sensitive balance between cell proliferation and cell death, leading to apoptosis and tumor remission. Tumor remission was dependent on the volume of the tumors before down-regulation of HER-2/neu.
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PMID:Switching off HER-2/neu in a tetracycline-controlled mouse tumor model leads to apoptosis and tumor-size-dependent remission. 1461 17

We have investigated the expression of P2X5, P2X7, P2Y1, and P2Y2 receptor subtypes in 8- to 11-wk-old human fetal epidermis in relation to markers of proliferation (proliferating cell nuclear antigen (PCNA) and Ki-67), keratinocyte differentiation (cytokeratin K10 and involucrin), and markers of apoptosis (TdT-mediated dUTP nick end labeling (TUNEL) and anti-caspase-3). Immunohistochemistry showed that each of the four receptors was expressed in spatially distinct zones of the developing epidermis: P2Y1 receptors were found in the basal layer, P2X5 receptors were predominantly in the basal and intermediate layers, and both P2Y2 and P2X7 receptors were in the periderm. Colocalization experiments suggested different functional roles for these receptors. P2Y1 receptors were found in fetal keratinocytes positive for PCNA and Ki-67, suggesting a role in proliferation. P2X5 receptors double labeled with differentiated fetal keratinocytes that were positive for cytokeratin K10, suggesting a role in differentiation. P2X7 receptors colocalized with anti-caspase-3 antibody and were also expressed in periderm cells positive for TUNEL, suggesting a role in periderm cell apoptosis. P2Y2 receptors were found only in periderm cells and may have a role in chloride and fluid secretion into the amniotic fluid.
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PMID:Purinergic receptors are part of a signaling system for keratinocyte proliferation, differentiation, and apoptosis in human fetal epidermis. 1470 18


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