The role of caspase-3, apoptosis-inducing factor, and B-cell lymphoma-2 expressions in term premature rupture of membrane

Abstract Objective To determine the role of caspase-3, apoptosis-inducing factor (AIF), and Bcell lymphoma-2 (Bcl-2) expressions in term premature rupture of membrane (PROM). Methods An analytic observational study with case-control design was conducted, involving 52 subjects (37-42 weeks of gestation) who were divided into 2 groups: 26 cases of term delivery with PROM, and 26 controls of term delivery without PROM. The expressions of caspase-3, AIF, and Bcl-2 in the amniotic membrane were determined by immunohistochemistry. Data were analyzed using the chi-squared test. The risk of PROM was expressed by odds ratio (OR). Results There were no significant differences in age, parity and body mass index between the two groups (p > 0.05). High caspase-3 and AIF expressions increased the risk of PROM 17.64 times (OR = 17.64; 95% CI = 4.44-70.07; p = 0.001) and 9.45 times (OR = 9.45; 95% CI= 2.62-34.07; p = 0.001), respectively, while low Bcl-2 expression increased 10.39 times (OR = 10.39; 95% CI = 2.73-39.56; p = 0.001)the risk of PROM . Conclusion High caspase-3 and AIF expressions and low Bcl-2 expression were risk factors for term PROM. Caspase-dependent and independent pathways of apoptosis were involved in the mechanism of PROM in term pregnancy.

Incremento de la expresión de Bax (proapoptótico) y disminución de la expresión de Bcl-2 (antiapoptótico) en recién nacidos con enterocolitis necrosante / Increase in pro-apoptotic Bax expression and decrease in anti-apoptotic Bcl-2 expression in newborns with necrotizing enterocolitis

Antecedentes/Objetivo: El objetivo de este estudio fue determinar si se producía un incremento de la expresión de Bax (proapoptótico) y una disminución de la expresión de Blc-2A1 (antiapoptótico) en el intestino de los recién nacidos con enterocolitis necrosante. Materiales y métodos: Comparamos a ocho pacientes recién nacidos de manera consecutiva sometidos a resección intestinal debido a enterocolitis necrosante con ocho recién nacidos sometidos a resección intestinal debido a atresia ileal. La evaluación histopatológica de la lesión tisular y la apoptosis se realizó mediante microscopía óptica y el método TUNEL. El nivel de ARNm en los genes apoptóticos (CASP3, CASP6, CASP7, Bax, BIRC2) y antiapoptóticos se evaluó con el método de matriz de RCP (PCR array). La expresión de proteínas se evaluó mediante inmunohistoquímica. Resultados: Los puntajes de las lesiones tisulares y los puntajes medios de apoptosis fueron significativamente más altos en el grupo con enterocolitis necrosante en comparación con el grupo de referencia (p < 0,01). La expresión de los genes proapoptóticos aumentó significativamente en el grupo con enterocolitis necrosante frente al grupo de referencia (p < 0,01). La expresión del gen Bcl-2A1 (antiapoptótico) disminuyó significativamente en el grupo con enterocolitis necrosante (p < 0,01). La expresión de las proteínas Bax y CASP3 aumentó significativamente en el grupo con enterocolitis necrosante (p < 0,01). Conclusión: Según nuestros datos, la alteración del equilibrio entre la expresión de Bax (proapoptótico) y la expresión de Bcl-2A1 (antiapoptótico) en el lugar de la lesión es un posible mecanismo de la patogenia en recién nacidos que presentan enterocolitis necrosante.

Background/Aim. The aim of the present study was to find out if there is an increase in the expression of pro-apoptotic Bax and reduction in expression of anti-apoptotic Blc-2A1 in newborn intestines with necrotizing enterocolitis (NEC). Material and Methods. We compared 8 consecutive newborn patients undergoing bowel resection for NEC with 8 neonates undergoing intestinal resection for ileal atresia. Histopathological evaluation of tissue injury and apoptosis was performed by using light microscopic examination and TUNEL method. The mRNA level of apoptotic (CASP3, CASP6, CASP7, Bax, BIRC2) and anti-apoptotic genes were evaluated by PCR array method. Protein expression was assessed by immunohistochemistry. Results. Tissue injury scores and mean apoptosis scores were significantly higher in NEC group when compared with control group (p <0.01). Expression of pro-apoptotic genes were significantly increased in NEC group when compared with control group (p <0.01). Expression of anti-apoptotic Bcl-2A1 gene was significantly decreased in NEC group, (p <0.01). Protein expression of Bax and CASP3 was significantly increased in NEC group, (p <0.01). Conclusion. Our data in humannewborns suggest that alteration of the balance between pro-apoptotic Bax expression and anti-apoptotic Bcl-2A1 expression in the site of injury is a possible mechanism in the pathogenesis of NEC.

Neuroprotección por ácido valproico y cambios en la expresión de Bcl-2 y caspasa-3 activada en ratas sometidas a isquemia/reperfusión / Neuroprotective action of valproic acid accompanied of the modification on the expression of Bcl-2 and activated caspase-3 in the brain of rats submitted to ischemia/reperfusion

El ácido valproico, que además de ser un conocido antiepiléptico, una serie de trabajos en los últimos años lo proponen como un agente neuroprotector. En éste trabajo se investigó primeramente, si el ácido valproico protege a las neuronas del daño producido por el estrés oxidativo inducido por la isquemia-reperfusión en el cerebro de ratas sanas sometidas a la oclusión transitoria de la arteria cerebral media derecha; en segundo lugar, se indagó si este fármaco induce cambios en la expresión de Bcl-2 y caspasa 3-activada como un posible mecanismo de acción sobre la muerte celular del tipo apoptótico. La evaluación neurológica de los animales que fueron sometidos a isquemia/reperfusión y recibieron ácido valproico fue mejor que los que no lo recibieron. Por otro lado, los niveles de malondialdehído en el hemisferio cerebral derecho en las ratas tratadas con ácido valproico fueron inferiores a los del mismo hemisferio del grupo control, mientras la cantidad de proteínas carboniladas se redujeron un 67% en comparación al grupo control. Además, se encontró por western blot, que en homogeneizados de tejido cerebral de los animales sometidos a isquemia/reperfusión y que recibieron ácido valproico, hubo un aumento significativo de la densidad de las bandas correspondientes a Bcl-2 y una disminución de caspasa 3-activada en comparación a los que no fueron tratados con este fármaco. Se concluye que el tratamiento con ácido valproico previno el déficit neurológico en ratas sanas sometidas a isquemia-reperfusión, bloqueando el efecto de los radicales libres sobre lípidos y proteínas de la corteza cerebral afectada y se sugiere que posiblemente este fármaco interviene en la muerte por apoptosis inducida durante este tipo de lesión, pudiendo ser una alternativa terapéutica en el tratamiento de la isquemia cerebral.

Valproic acid, apart from being known as an anti-epileptic drug, has been proposed in the past few years, as a neuroprotective agent. The purpose of this study was to investigate firstly, if valproic acid protects the neurons from the damage produced by oxidative stress induced by ischemia-reperfusion in the brain of healthy rats, under the transitory occlusion of the right middle cerebral artery. Secondly it was studied if this antiepileptic drug induces changes on the expression of Bcl-2 and activated caspase-3 as a possible mechanism of action on apoptosis. The neurological evaluation of the animals that were subject to ischemia-reperfusion and received valproic acid was better than the ones who didn’t receive it. On another subject, the levels of malondialdehyde on the right cerebral hemisphere in the rats treated with valproic acid were below the levels of the control group in the same hemisphere, whereas the amount of carbonylated proteins was reduced by 67% compared to the control group. Besides, it was found by western blot, that in homogenized brain tissue of the animals under ischemia-reperfusion which received valproic acid, there was a rise on the density of the bands corresponding to Bcl-2, and a reduction of activated 3-capase in comparison to the ones who were not treated with the antiepileptic drug. It’s concluded that the treatment with valproic acid prevented the neurological deficit in healthy rats under Ischemia-reperfusion, blocking the effect of free radicals on lipids and proteins of the affected brain cortex, and it is suggested that the same drug intervenes on apoptosis induced during this type of damage, being able to be a therapeutic alternative in the treatment of cerebral ischemia.

Genetic alterations in benign, preneoplastic and malignant breast lesions.

Context: The c-erbB-2 proto-oncogene is a member of the epidermal growth factor receptor family and has been associated with a more aggressive breast tumor biology and resistance to some types of treatments. Aims: The aim is to investigate the correlation among bcl-2 and c-erbB-2 and the micronucleus (MN) formation in patients with early breast cancer (BC). Materials and Methods: This study was conducted between May 2010 and December 2011. We analyzed the MN frequencies in 15 patients with invasive breast carcinoma (IBC), 13 patients with intraductal proliferative lesion (IDPL) and 12 benign breast lesion (BBL). The sample consisted of 40 formalin-fixed, paraffin-embedded blocks of benign and malignant breast tissue. The specimens were evaluated for bcl-2 or c-erbB-2 immunoreactivity was semi-quantitatively evaluated in at least 1000 cells examined under the microscope at 40Χ magnification and recorded as the percentage of c-erbB-2 and bcl-2 positive tumor cells over the total number of cells examined in the same area. The percentage scores were subsequently categorized using the 5% cut-off point for positive staining. Results: The MN was significantly increased in IBC and in IDPL patients compared to BBL patients (3.82 ± 0.17 and 2.37 ± 0.52, respectively, vs. 1.61 ± 0.40, P < 0.001). On other hand, the MN frequencies in IBC patients were higher than those in IDPL patients (3.82 ± 0.17 vs. 2.37 ± 0.52, P < 0.01). c-erbB-2, had the highest record in IBC (60%), and the score was not observed in both IDPL and BBL: bcl-2 immunostaining was also assessed, the lowest recorded score was in IBC (46.66%) and the highest in both BBL and IDPL (100%). Furthermore, there was a significantly difference in the mean MN frequency between c-erbB-2 positive IBC patients (4.06 ± 0.48) and c-erbB-2 negative IBC patients (3.44 ± 0.39) (P < 0.05). Conclusions: Our results suggest that increased chromosome / DNA instabilities may be associated with the pathogenesis of early BC.

A priming role of local estrogen on exogenous estrogen-mediated synaptic plasticity and neuroprotection

The localization of estrogen (E2) has been clearly shown in hippocampus, called local hippocampal E2. It enhanced neuronal synaptic plasticity and protected neuron form cerebral ischemia, similar to those effects of exogenous E2. However, the interactive function of hippocampal and exogenous E2 on synaptic plasticity activation and neuroprotection is still elusive. By using hippocampal H19-7 cells, we demonstrated the local hippocampal E2 that totally suppressed by aromatase inhibitor anastrozole. Anastrozole also suppressed estrogen receptor (ER)beta, but not ERalpha, expression. Specific agonist of ERalpha (PPT) and ERbeta (DPN) restored ERbeta expression in anastrozole-treated cells. In combinatorial treatment with anastrozole and phosphoinositide kinase-3 (PI-3K) signaling inhibitor wortmannin, PPT could not improve hippocampal ERbeta expression. On the other hand, DPN induced basal ERbeta translocalization into nucleus of anastrozole-treated cells. Exogenous E2 increased synaptic plasticity markers expression in H19-7 cells. However, exogenous E2 could not enhance synaptic plasticity in anastrozole-treated group. Exogenous E2 also increased cell viability and B-cell lymphoma 2 (Bcl2) expression in H2O2-treated cells. In combined treatment of anastrozole and H2O2, exogenous E2 failed to enhance cell viability and Bcl2 expression in hippocampal H19-7 cells. Our results provided the evidence of the priming role of local hippocampal E2 on exogenous E2-enhanced synaptic plasticity and viability of hippocampal neurons.

Strong BCL2 expression in Burkitt lymphoma is not uncommon in adults.

Background: The distinction between Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL) is not always easy, so much so that the WHO 2008 Blue Book has incorporated a provisional category of "B-cell lymphoma, unclassifiable with features intermediate between DLBCL and BL." One of the immunohistochemical (IHC) markers used at times to differentiate between the two is IHC expression of BCL2, which was initially believed to be consistently negative in BL. Later it was recognized that weak BCL2 expression is still compatible with the diagnosis of BL. To verify or otherwise this current view this study was undertaken. Materials and Methods: We retrieved 39 confirmed cases of BL, in both children and adults. All these cases had typical morphology, IHC profile, and Mib-1 index that are typical of BL. All these cases were then stained with a monoclonal antibody against BCL2 oncoprotein, using 2-step Envision system. Results: Out of 39 cases, 31 cases (79.4%) were completely negative for BCL2, whereas 5 (12.8%) were weak focal positive. However, another 4 (10.2%) cases did show strong diffuse cytoplasmic staining for BCL2. Fluorescent in-Situ hybridization (FISH) for t(14:18) was optimally done on 6 out of 9 cases. All these 4 cases were from adults with 3 out of 4 arising in the parotid region. Two out of 4 cases also showed t(8:14) on FISH. Conclusions: It was concluded that contrary to the common belief, strong BCL2 IHC expression is possible in typical BL in adults and cannot be absolutely relied upon to distinguish between BL and DLBCL.

IL-1beta Acts in Synergy with Endogenous IL-1beta in A375-S2 Human Melanoma Cell Apoptosis Through Mitochondrial Pathway

Interleukin-1beta (IL-1beta) is a pivotal proinflammatory cytokine. To investigate the mechanism of IL-1beta-induced cell death in human malignant melanoma A375-S2 cells, MTT assay, photomicroscopical observation, DNA agarose gel electrophoresis, radioimmunoassay and Western blot analysis were carried out. IL-1beta did not only induce nuclear condensation and DNA fragmentation, but also increased degradation of two substrates of caspase-3, poly ADP-ribose polymerase (PARP) and inhibitor of caspase-activated DNase (ICAD). Simultaneously, release of precursor of IL-1beta (pro-IL-1beta) and endogenous IL-1beta production were involved in the apoptotic process. IL-1beta enhanced the ratio of Bax/Bcl-2 and Bax/Bcl-xL expression and up-regulated apoptosis inducing factor (AIF) expression, which required the activation of downstream caspases. These results suggest that IL-1beta induces endogenous IL-1beta production, enhances cleavage of caspase downstream substrates and promotes mitochondria mediated apoptosis in A375-S2 cells.

Experimental study on the preventive mechanism of salviae miltiorrhizae against atherosclerosis in rabbits models / 华中科技大学学报（医学）（英德文版）

The preventive mechanism of salviae miltiorrhizae (SM) against experimental atherosclerosis (AS) in rabbits models was investigated. The experimental AS rabbit models were reproduced by feeding the high cholesterol diet. The changes of atherosclerotic plaques in normal group, model group and SM treated group were observed. The levels of serum TG, TC, HDL-C and LDL-C were determined. The immunohistochemistry was used to detect the expression of Bcl-2, Bax and IL-6 proteins in atherosclerotic plaques. The results showed that the level of serum TG in SM treated group was significantly lower than in model group (P<0.01). Immunohistochemistry revealed that the expression of Bcl-2, Bax and TL-6 in model group was significantly higher than in normal group. In the SM group, the expression of Bcl-2 protein was up-regulated and that of Bax was down-regulated. It was suggested that SM could inhibit formation of AS in experimental rabbits. To decrease the expression of Bax and increase the expression of Bcl-2 protein may be one of the mechanisms of SM against atherosclerosis.

Involvement of Sox-4 in the cytochrome c-dependent AIF-independent apoptotic pathway in HeLa cells induced by delta12-prostaglandin J2

delta12-Prostaglandin (PG) J2 is known to elicit an anti-neoplastic effects via apoptosis induction. Previous study showed delta12-PGJ2-induced apoptosis utilized caspase cascade through cytochrome c-dependent pathways in HeLa cells. In this study, the cellular mechanism of delta12-PGJ2- induced apoptosis in HeLa cells, specifically, the role of two mitochondrial factors; bcl-2 and apoptosis-inducing factor (AIF) was investigated. Bcl-2 attenuated delta12-PGJ2-induced caspase activation, loss of mitochondrial transmembrane potential (delta psi m), nuclear fragmentation, DNA laddering, and growth curve inhibition for approximately 24 h, but not for longer time. AIF was not released from mitochondria, even if the delta psi m was dissipated. One of the earliest events observed in delta12-PGJ2-induced apoptotic events was dissipation of delta psi m, the process known to be inhibited by bcl-2. Pre-treatment of z-VAD- fmk, the pan-caspase inhibitor, resulted in the attenuation of delta psi m depolarization in delta12-PGJ2- induced apoptosis. Up-regulation of Sox-4 protein by delta12-PGJ2 was observed in HeLa and bcl-2 overexpressing HeLa B4 cell lines. Bcl-2 overexpression did not attenuate the expression of Sox-4 and its expression coincided with other apoptotic events. These results suggest that delta12-PGJ2 induced Sox-4 expression may activate another upstream caspases excluding the caspase 9-caspase 3 cascade of mitochondrial pathway. These and previous findings together suggest that delta12-PGJ2-induced apoptosis in HeLa cells is caspase-dependent, AIF-independent events which may be affected by Sox-4 protein expression up-regulated by delta12-PGJ2.

Expression of Bcl2 proto-oncogene in primary tumors of the central nervous system.

The present study was addressed to find out the expression of Bcl2 proto-oncogene in tumor tissues derived from 25 patients with primary central nervous system tumors. Brain parenchyma in 8 cases, with deeply located tumor, was also examined for Bcl2 expression which served as control. Both benign and malignant tumors (confirmed by histopathological examination) expressed Bcl2 gene product. Tumors exhibited 2-6 fold increase in Bcl2 expression as compared to the normal parenchyma adjacent to some of these tumors studied. However, no correlation was found between the histopathological types of tumor, glial fibrillary acidic protein positivity and degree of Bcl2 expression. Based on this study, we propose that the overexpression of Bcl2 gene product found in primary CNS tumors may be an important molecular event which is known to make the various types of tumor resistant to chemotherapy or radiotherapy.

Topographic expression of p21WAF1/SDI1/CIP1, bcl2, and p53 is altered at the early stage of colorectal carcinogenesis

We analyzed the expression of p21, bcl2, and p53 in normal and different pathologic mucosa of the human colorectum using immunohistochemistry and cold polymerase chain reaction-single strand conformation polymorphism. The topography of normal mucosa showed; bcl2 and p53 expression restricted to basal epithelial cells and p21 expressed only in superficial epithelial cells. This topographic expression was altered in hyperplastic polyps and adenomas. Hyperplastic polyps revealed absence of or weak bcl2 expression and strong p21 expression without topography. In adenomas, whereas bcl2 expression increased and extended to parabasal and superficial dysplastic epithelium, the increase of p21 expression was limited to surface dysplastic epithelium. p53 was weakly expressed throughout the full thickness of dysplastic epithelium. Bcl2 expression in adenomas was stronger than in carcinomas; p53 expression was converse and p21 expression was variable. In carcinomas, this topographic expression was largely abrogated but p53 mutation (36%) was more frequent than in adenomas (2%). In carcinomas, p21 and p53 expression correlated inversely, but there was no relationship with bcl2. These results suggest that there is precisely ordered topographic pattern of p21, bcl2, and wild p53 expression in normal colorectal cells, but this becomes disordered during the early stage of colorectal carcinogenesis.

Effects of allyl sulfur compounds and garlic extract on the expression of Bcl-2, Bax, and p53 in non small cell lung cancer cell lines

Allyl sulfur compounds play a major role in the chemoprevention against carcinogenesis. The present study compared the antiproliferative effects of diallyl sulfide (DAS), diallyl disulfide (DADS) and garlic extract on p53-wild type H460 and p53-null type H1299 non small cell lung cancer cells (NSCLC). The DAS and DADS treatment of both H460 and H1299 cells resulted in the highest numbers of cells in apoptotic state as measured by acridine orange staining, however, garlic extract treatment did not induce any significant apoptotic cells by MTT assay. DADS was found to be more effective in inducing apoptosis on NSCLC. The level of p53 protein in H460 cell was increased following DADS treatment. DAS and garlic extract treatment of H460 cells induced a rise in the level of Bax and a fall of Bcl-2 level. These results demonstrate that DAS, DADS and garlic extract are effective in reduction of anti-proliferative gene in NSCLC and suggest that modulation of apoptosis-associated cellular proteins by DAS, DADS and garlic extract may be the mechanism for apoptosis which merit further investigation as potential chemoprevention agents.

Fas-mediated apoptosis and expression of related genes in human malignant hematopoietic cells

Fas transduces apoptotic signals upon cross-linking with the Fas ligand (FasL), which is experimentally replaced by agonistic anti-Fas monoclonal antibodies (mAb). Of eight human malignant hematopoietic cell lines (HL-60, KG-1, THP-1, K562, U937, Jurkat, IM-9, RPMI-8226) examined by flow cytometric analysis, all, except K562, were found to be positive for surface Fas antigen. However, despite surface Fas expression, the agonistic anti-Fas mAb (7C11) induced apoptosis in only three of seven Fas-expressing cell lines (KG-1, Jurkat and IM-9). This Fas-resistance did not correlated with high levels of mRNA either for DcR3, a decoy receptor for FasL, or for FAP-1, a Fas-associated phosphatase that can block the apoptotic function of Fas. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis did not show consistent differences in the expression of Bcl-2 and Bax between Fas-sensitive and Fas-resistant cell lines examined. These findings indicated that the presence or absence of mRNA expression of DcR3, FAP-1, Bcl-2 and Bax did not always correlate with relative sensitivity to Fas-mediated apoptosis. Treatment of cells with cycloheximide converted the phenotype of resistant cell lines from Fas-resistant to Fas-sensitive, and enhanced the sensitivity of Fas-sensitive cell lines. These results suggest that the Fas-resistance is dependent on the presence of labile proteins that determine resistance to Fas-mediated apoptosis and the apoptotic machinery is already in place in Fas-resistant cell lines.

TGF-beta1 inhibition of apoptosis through the transcriptional up-regulation of Bcl-X(L) in human monocytic leukemia U937 cells

To characterize the TGF-beta1 response of monocytic leukemia cells, we analyzed the effects of TGF-beta1 on cell proliferation, differentiation, and apoptosis of human monoblastic U937 cells. Treatment of cells with TGF-beta1 in the absence of growth factors significantly enhanced cell viability. Flow cytometric analysis of DNA content and CD14 expression revealed that TGF-beta1 does not affect cell proliferation and differentiation. Consistent with these results was the finding that no transcriptional induction of Cdk inhibitors such as p21Waf1, p15Ink4b, and p27Kip1 was detected following TGF-beta1 treatment. Interestingly, however, pretreatment of TGF-beta1 significantly inhibited Fas-, DNA damage-, and growth factor deprivation-induced apoptosis. This antiapoptotic effect was totally abrogated by anti-TGF-beta1 antibody. Quantitative RT-PCR analysis demonstrated a dose- and time-dependent transcriptional up-regulation of Bcl-X(L), suggesting its implication in the TGF-1-mediated antiapoptotic pathway. We also observed elevated expression of c-Fos and PTEN/MMAC1. But, no detectable change was recognized in expression of c-Jun, Fas, Fadd, Fap-1, Bcl-2, and Bax. Taken together, our study shows that TGF-beta1 enhancement of cellular viability is associated with its antiapoptotic effect, which may result from the transcriptional up-regulation of Bcl-X(L).

Increased rate of apoptosis and decreased expression of bcl-2 protein in peripheral blood lymphocytes from patients with active systemic lupus erythematosus.

Defective regulation of apoptosis may play a role in the development of autoimmune diseases, and the proto-oncogene bcl-2 is known to inhibit cells from undergoing apoptosis. We studied the rate of apoptosis with the expression of bcl-2 in peripheral blood lymphocytes of patients with systemic lupus erythematosus (SLE). A lower proportion of lymphocytes were bcl-2+ in SLE patients with active disease (median 84.9%) than in patients with inactive disease or normal (medians 95.3% and 97.1% respectively, p < 0.05). The rate of apoptosis of freshly isolated PBL was significantly higher in SLE patients than in normal (medians 1.2% vs 0.5%, p < 0.05). After 48-hour culture the apoptotic rate was further increased in SLE patients, particularly those with active disease (SLE overall 34.2%, active 62% inactive 27.5%, normal 11.25%). These findings support the theory that in SLE patients increased apoptosis may provide a source of extracellular nuclear antigens which stimulate the autoimmune response and form immune complexes with autoantibodies.