Dysregulation of BCL-2 family proteins by leukemia fusion genes.

The genomic lesions that characterize acute lymphoblastic leukemia in childhood include recurrent translocations that result in the expression of fusion proteins that typically involve genes encoding tyrosine kinases, cytokine receptors, and transcription factors. These genetic rearrangements confer phenotypic hallmarks of malignant transformation, including unrestricted proliferation and a relative resistance to apoptosis. In this Minireview, we discuss the molecular mechanisms that link these fusions to the control of cell death. We examine how these fusion genes dysregulate the BCL-2 family of proteins, preventing activation of the apoptotic effectors, BAX and BAK, and promoting cell survival.

Ligustrazine suppresses neuron apoptosis via the Bax/Bcl-2 and caspase-3 pathway in PC12 cells and in rats with vascular dementia.

The aim of this study was to examine the comprehensive neuroprotective mechanism of ligustrazine, which is extracted from Ligusticum Chuanxiong Hort., against vascular dementia (VD) in rats and apoptosis in oxygen and glucose deprivation (OGD) PC12 cells. Rats were subjected to bilateral common carotid artery occlusion (BCCAO) surgery and administered ligustrazine intragastrically for 6 weeks. At the end of the experiments, the hippocampal biomarkers brain-derived neurotrophic factor (BDNF), monocyte chemotactic protein 1 (MCP-1), and homocysteine (Hcy) were examined. In experiments in vitro, OGD PC12 cells were treated with ligustrazine for 0.5, 1, 3, 6, 12, or 24 h. The cell-released biomarkers BDNF, MCP-1, and Hcy were examined. Microscopy, acridine orange-ethidium bromide (AO/EB) staining, and flow cytometry assays were performed to investigate apoptosis. Cleaved caspase-3, Bcl-2 associated X protein (Bax), and B cell lymphoma 2 (Bcl-2) expression was examined using Western blot assays. The results showed that biomarkers, including MCP-1 and Hcy, were significantly increased in both the in vivo and in vitro models, while the BDNF level was significantly decreased compared with the sham or vehicle models. Microscopy, AO/EB staining, and flow cytometry analysis showed that severe cell damage occurred in OGD PC12 cells, and apoptosis played a major role in this environment. Further Western blot studies showed that the apoptosis-related Bax/Bcl-2 protein ratio and cleaved caspase-3 were significantly increased in the experiment. However, ligustrazine profoundly suppressed the imbalance of these biomarkers, reduced cell damage, decreased the Bax/Bcl-2, and downregulated cleaved caspase-3. Pro- and anti-apoptotic biomarkers of multiple pathways including BDNF, MCP-1, and Hcy played a joint role in triggering the activation of the mitochondria-related Bax/Bcl-2 and caspase-3 apoptosis pathway in VD. Ligustrazine attenuated VD by comprehensively regulating BDNF, MCP-1, and Hcy and inactivating the Bax/Bcl-2 and caspase-3 apoptosis pathway. Our data provide novel insight into ligustrazine, which is a promising neuroprotective agent for VD disease treatment strategies. © IUBMB Life, 70(1):60-70, 2018.

Ghrelin protects adult rat hippocampal neural stem cells from excessive autophagy during oxygen-glucose deprivation.

Ghrelin functions as a neuroprotective agent and saves neurons from various insults include ischemic injury. However, it remains to be elucidated whether ghrelin protects neuronal cells against ischemic injury-induced excessive autophagy. Autophagy is required for the maintenance of neural stem cell homeostasis. However, regarding autophagic cell death, it is commonly assumed that excessive autophagy leads to self-elimination of mammalian cells. The purpose of this study was to investigate the potential neuroprotection effects of ghrelin from excessive autophagy in adult rat hippocampal neural stem cells (NSCs). Oxygen-Glucose Deprivation (OGD) strongly induces autophagy in adult rat hippocampal NSCs. Ghrelin treatment inhibited OGD-induced cell death of adult rat hippocampal NSCs assessed by cell-counting-kit-8 assay. Ghrelin also suppressed OGD-induced excessive autophagy activity. The protective effect of ghrelin was accompanied by an increased expression levels of Bcl-2, p-62 and decreased expression level of LC3-II, Beclin-1 by Western blot. Furthermore, ghrelin reduced autophagosome formation and number of GFP-LC3 transfected puncta. In conclusion, our data suggest that ghrelin protects adult rat hippocampal NSCs from excessive autophagy in experimental stroke (oxygen-glucose deprivation) model. Regulating autophagic activity may be a potential optimizing target for promoting adult rat hippocampal NSCs based therapy for stroke.

Expression of Bcl-2 Family Proteins in the Ovarian Follicular Apparatus in the Acute Period after Experimental Hyperthermia.

The expression of apoptosis regulators (proapoptotic protein Bad and anti-apoptotic protein Bcl-2) was analyzed and Bcl-2/Bad ratio in the follicular apparatus of the rat ovary was determined on day 3 after hyperthermia (rectal temperature 43.5°C). Hyperthermia in the catabolic phase leads to different degrees of activation of the molecular "switches" of apoptosis in cells of ovarian follicular epithelium. This was seen from increased intensity of immunohistochemical staining for Bad protein against the background of more pronounced expression of Bcl-2 protein. On day 3 after exposure to hyperthermia, Bcl-2/Bad ratio increased, which reflects antiapoptotic protection of cells and conditions for blockade of mitochondrial pathway of apoptosis in the follicular apparatus of the ovaries during the acute period after hyperthermia.

Cardiac ankyrin repeat protein attenuates cardiomyocyte apoptosis by upregulation of Bcl-2 expression.

Cardiac ankyrin repeat protein (CARP) is a nuclear transcriptional co-factor that has additional functions in the myoplasm as a component of the muscle sarcomere. Previous studies have demonstrated increased expression of CARP in cardiovascular diseases, however, its role in cardiomyocyte apoptosis is unclear and controversial. In the present study, we investigated possible roles of CARP in hypoxia/reoxygenation (H/R) -induced cardiomyocyte apoptosis and the underlying mechanisms. Neonatal mouse ventricular cardiomyocytes were isolated and infected with adenovirus encoding Flag-tagged CARP (Ad-CARP) and lentivirus encoding CARP targeted shRNA (sh-CARP), respectively. Cardiomyocyte apoptosis induced by exposure to H/R conditions was evaluated by TUNEL staining and western blot analysis of cleaved caspase-3. The results showed that H/R-induced apoptosis was significantly decreased in Ad-CARP cardiomyocytes and increased in sh-CARP cardiomyocytes, suggesting a protective anti-apoptosis role for CARP. Interestingly, over-expressed CARP was mainly distributed in the nucleus, consistent with its role in regulating transcriptional activity. qPCR analysis showed that Bcl-2 transcripts were significantly increased in Ad-CARP cardiomyocytes. ChIP and co-IP assays confirmed the binding of CARP to the Bcl-2 promoter through interaction with transcription factor GATA4. Collectively, our results suggest that CARP can protect against H/R induced cardiomyocyte apoptosis, possibly through increasing anti-apoptosis Bcl-2 gene expression.

Calcium-sensing receptor antagonist NPS2390 attenuates neuronal apoptosis though intrinsic pathway following traumatic brain injury in rats.

Traumatic brain injury (TBI) initiates a complex cascade of neurochemical and signaling changes that leads to neuronal apoptosis, which contributes to poor outcomes for patients with TBI. Previous study indicates that calcium-sensing receptor (CaSR) activation contributes to neuron death in focal cerebral ischemia-reperfusion mice, however, its role in neuronal apoptosis after TBI is not well-established. Using a controlled cortical impact model in rats, the present study was designed to determine the effect of CaSR inhibitor NPS2390 upon neuronal apoptosis after TBI. Rats were randomly distributed into three groups undergoing the sham surgery or TBI procedure, and NPS2390 (1.5 mg/kg) was infused subcutaneously at 30 min and 120 min after TBI. All rats were sacrificed at 24 h after TBI. Our data indicated that NPS2390 significantly reduced the brain edema and improved the neurological function after TBI. In addition, NPS2390 decreased caspase-3 levels and the number of apoptotic neurons. Furthermore, NPS2390 up-regulated anti-apoptotic protein Bcl-2 expression and down-regulated pro-apoptotic protein Bax, and reduced subsequent release of cytochrome c into the cytosol. In summary, this study indicated that inhibition of CaSR by NPS2390 attenuates neuronal apoptosis after TBI, in part, through modulating intrinsic apoptotic pathway.

Carnitine-mediated antioxidant enzyme activity and Bcl2 expression involves peroxisome proliferator-activated receptor-γ coactivator-1α in mouse testis.

The protective effects of carnitine have been attributed to inhibition of apoptosis, alleviating oxidative stress and DNA repair mechanism by decreasing oxidative radicles. Carnitine also increases mitochondrial biogenesis via peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α). The role of carnitine in testicular PGC1α expression has not been documented. We hypothesised that the effects of carnitine as an antioxidant, inhibitor of apoptosis and controller of steroidogenesis in mouse testis may involve PGC1α as a regulator. The present study was designed to evaluate the localisation of PGC1α and the effects of carnitine treatment on the expression of PGC1α, Bcl2 and antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)) in mouse testis and serum testosterone concentrations. PGC1α was primarily immunolocalised to the Leydig cells and primary spermatocytes. Western blot analysis showed that carnitine (50mgkg-1 and 100mgkg-1 for 7 days) significantly increased PGC1α and Bcl2 expression in the testis in a dose-dependent manner. In addition, carnitine treatment significantly increased antioxidant enzyme (CAT, SOD and GPx) levels. The carnitine-induced changes in PGC1α in the testis were significantly correlated with changes in serum testosterone concentrations, as well as with changes in Bcl2 expression and antioxidant enzyme activity in the testis, as evaluated by electrophoresis. Therefore, the results of the present study suggest that carnitine treatment of mice increases PGC1α levels in the testis, which may, in turn, regulate steroidogenesis by increasing expression of Bcl2 and antioxidant enzymes.

Microwave-Assisted Synthesis of Imidazo[4,5-f][1,10]phenanthroline Derivatives as Apoptosis Inducers in Chemotherapy by Stabilizing Bcl-2 G-quadruplex DNA.

Herein, a series of imidazo[4,5-f][1,10] phenanthroline derivatives RPIP (PIP = imidazo [4,5-f][1,10] phenanthroline, R = NO2, 1; CF3, 2; Cl, 3; OH, 4) have been synthesized in yields of 82.3-94.7% at 100 °C under the irradiation of microwave. MTT assay has been utilized to evaluate the inhibitory activity (IC50) of these compounds against the growth of various tumor cells, and the results revealed that these compounds, especially 1, exhibited excellent inhibitory activity against the growth of A549 cells with IC50 of 15.03 µM. Moreover, it's also confirmed that 1 can penetrate into the membrane of tumor cells and distribute in mitochondria when observed under microscopy, resulting apoptosis of tumor cells. The further studies showed that 1 can bind to bcl-2 G-quadruplex DNA, which demonstrated by the increase of melting point of bcl-2 G4 DNA in the presence of 1, as well as electronic titration and emission spectra. In a word, this kind of compound may develop as a potential apoptosis inducer in cancer chemotherapy via binding and stabilizing to the bcl-2 G-quadruplex DNA.

Hair Regenerative Mechanisms of Red Ginseng Oil and Its Major Components in the Testosterone-Induced Delay of Anagen Entry in C57BL/6 Mice.

Hair loss (alopecia) is a universal problem for numerous people in the world. The present study was conducted to investigate the effects of red ginseng oil (RGO) and its major components on hair re-growth using testosterone (TES)-induced delay of anagen entry in C57BL/6 mice and their mechanisms of action. Seven-week-old C57BL/6 mice were daily treated with TES for 1 h prior to topical application of 10% RGO, 1% linoleic acid (LA), 1% ß-sitosterol (SITOS), or 1% bicyclo(10.1.0)tridec-1-ene (BICYCLO) once a day for 28 days. Hair regenerative capacity was significantly restored by treatment of RGO and its major compounds in the TES-treated mice. Histological analysis showed that RGO along with LA and SITOS but not BICYCLO promoted hair growth through early inducing anagen phase that was delayed by TES in mice. Treatment of mice with RGO, LA, or SITOS up-regulated Wnt/ß-catenin and Shh/Gli pathways-mediated expression of genes such as ß-catenin, Lef-1, Sonic hedgehog, Smoothened, Gli-1, Cyclin D1, and Cyclin E in the TES-treated mice. In addition, RGO and its major components reduced the protein level of TGF-ß but enhanced the expression of anti-apoptotic protein Bcl-2. These results suggest that RGO is a potent novel therapeutic natural product for treatment of androgenic alopecia possibly through hair re-growth activity of its major components such as LA and SITOS.

Senna singueana: Antioxidant, Hepatoprotective, Antiapoptotic Properties and Phytochemical Profiling of a Methanol Bark Extract.

Natural products are considered as an important source for the discovery of new drugs to treat aging-related degenerative diseases and liver injury. The present study profiled the chemical constituents of a methanol extract from Senna singueana bark using HPLC-PDA-ESI-MS/MS and 36 secondary metabolites were identified. Proanthocyanidins dominated the extract. Monomers, dimers, trimers of (epi)catechin, (epi)gallocatechin, (epi)guibourtinidol, (ent)cassiaflavan, and (epi)afzelechin represented the major constituents. The extract demonstrated notable antioxidant activities in vitro: In DPPH (EC50 of 20.8 µg/mL), FRAP (18.16 mM FeSO4/mg extract) assays, and total phenolic content amounted 474 mg gallic acid equivalent (GAE)/g extract determined with the Folin-Ciocalteu method. Also, in an in vivo model, the extract increased the survival rate of Caenorhabditis elegans worms pretreated with the pro-oxidant juglone from 43 to 64%, decreased intracellular ROS inside the wild-type nematodes by 47.90%, and induced nuclear translocation of the transcription factor DAF-16 in the transgenic strain TJ356. Additionally, the extract showed a remarkable hepatoprotective activity against d-galactosamine (d-GalN) induced hepatic injury in rats. It significantly reduced elevated AST (aspartate aminotransferase), and total bilirubin. Moreover, the extract induced a strong cytoplasmic Bcl-2 expression indicating suppression of apoptosis. In conclusion, the bark extract of S. sengueana represents an interesting candidate for further research in antioxidants and liver protection.

Inhibition of Apoptosis Stages of Human Blood Lymphocytes after Exposure to Carbon Monoxide in the Presence of Recombinant Interleukin-2.

We studied the effect of carbon monoxide (60-, 75-, and 90-min exposure) on the expression of antiapoptotic proteins (survivin and Bcl-2) in human blood lymphocytes in the presence of recombinant IL-2 in an apoptosis-inducing dose (0.1 ng/ml). Incubation of cells in atmosphere with carbon monoxide in the presence of recombinant IL-2 was accompanied by accumulation of Bcl-2 protein with simultaneous decrease of survivin content. It was concluded that carbon monoxide plays a role in the dysregulation of apoptosis of human blood lymphocytes Bcl-2 (i.e. CO inhibits the proapoptotic effect of recombinant IL-2).

Melatonin-Aluminum Oxide-Polymethylsiloxane Complex on Apoptosis of Liver Cells in a Model of Obesity and Type 2 Diabetes Mellitus.

We studied the effects of a melatonin-aluminum oxide-polymethylsiloxane complex (complex M) on the expression of apoptosis regulators Bcl-2 and Bad in the liver of homozygous db/db BKS.Cg-Dock7m+/+Leprdb/J mice with obesity and type 2 diabetes. Complex M or placebo was administered daily through the gastric tube during weeks 8-16 of life. In mice with type 2 diabetes mellitus receiving placebo, enhanced immunohistochemical reactions for proapoptotic Bad protein and weak response for anti-apoptotic Bcl-2 protein were observed. Administration of complex M shifted the ratio of apoptosis regulators: the area of Bcl-2 expression significantly increased and against the background of reduced Bad expression area. These findings attest to antiapoptotic effect of complex M in the liver on the model of type 2 diabetes mellitus.

Calotropin from Asclepias curasavica induces cell cycle arrest and apoptosis in cisplatin-resistant lung cancer cells.

Calotropin (M11), an active compound isolated from Asclepias curasavica L., was found to exert strong inhibitory and pro-apoptotic activity specifically against cisplatin-induced resistant non-small cell lung cancer (NSCLC) cells (A549/CDDP). Molecular mechanism study revealed that M11 induced cell cycle arrest at the G2/M phase through down-regulating cyclins, CDK1, CDK2 and up-regulating p53 and p21. Furthermore, M11 accelerated apoptosis through the mitochondrial apoptotic pathway which was accompanied by increase Bax/Bcl-2 ratio, decrease in mitochondrial membrane potential, increase in reactive oxygen species production, activations of caspases 3 and 9 as well as cleavage of poly ADP-ribose polymerase (PARP). The activation and phosphorylation of JNK was also found to be involved in M11-induced apoptosis, and SP610025 (specific JNK inhibitor) partially prevented apoptosis induced by M11. In contrast, all of the effects that M11 induce cell cycle arrest and apoptosis in A549/CDDP cells were not significant in A549 cells. Drugs with higher sensitivity against resistant tumor cells than the parent cells are rather rare. Results of this study supported the potential application of M11 on the non-small lung cancer (NSCLC) with cisplatin resistance.

Involvement of Bcl-2 Signal Pathway in the Protective Effects of Apigenin on Anoxia/Reoxygenation-induced Myocardium Injury.

Apigenin is a type of flavonoids, which has been demonstrated to protect myocardium against ischemia/reperfusion (I/R) injury. However, the mechanism is still unclear. We hypothesized that the mechanism of cardioprotective action of apigenin on the I/R-induced injury might be caused via B-cell lymphoma (Bcl) signaling pathway. In this study, an in vitro I/R model was replicated on Langendorff-perfused heart and H9c2 cardiomyocytes by anoxia/reoxygenation (A/R) treatment. The recovery of cardiac contractile function, infarct size, lactate dehydrogenase (LDH) and creatine kinase (CK) in the perfusate, the expression and activity of Bcl-2 and caspase-3, and cardiomyocyte apoptosis were measured in the Langendorff heart undergoing A/R injury. In addition, the cell viability, LDH release, intracellular reactive oxygen species (ROS), mitochondrial membrane potential (Δψm), expression of cytochrome c in the cytosol, and cell apoptosis were examined in the culture of H9c2 cardiomyocytes after the A/R. The results showed that apigenin significantly improved rat heart contractile function, reduced LDH release, infarct size and apoptotic rate, upregulated the expression of Bcl-2 and caspase-3, and downregulated the expression of cleaved caspase-3 after the A/R. Moreover, apigenin increased the cell viability and decreased the release of LDH, production of reactive oxygen species, release of mitochondrial cytochrome c into the cytosol, and cell apoptosis in the culture of H9c2 cardiomyocytes after the A/R. In addition, inhibition of Bcl-2 activity by ABT-737 markedly attenuated the protective effect of apigenin on the A/R-induced myocardium injury. Taken together, we firstly demonstrated that the effect of apigenin against A/R injury in cardiomyocytes involves Bcl-2 signal pathway and at least partly depends on its effect of upregulating the expression of Bcl-2.

Melatonin controlled apoptosis and protected the testes and sperm quality against bisphenol A-induced oxidative toxicity.

Epidemiological reports have indicated a correlation between the increasing bisphenol A (BPA) levels in the environment and the incidence of male infertility. In this study, the protective effects of melatonin on BPA-induced oxidative stress and apoptosis were investigated in the rat testes and epididymal sperm. Melatonin (10 mg/kg body weight (bw)) was injected concurrently with BPA (50 mg/kg bw) for 3 and 6 weeks. The administration of BPA significantly increased oxidative stress in the testes and epididymal sperm. This was associated with a decrease in the serum testosterone level as well as sperm quality, chromatin condensation/de-condensation level, and the percentage of haploid germ cells in the semen. BPA administration caused a significant increase in apoptosis accompanied by a decrease in the expression of the antiapoptotic proteins Bcl-2 in the testes and epididymal sperm. The concurrent administration of melatonin decreased oxidative stress by modulating the levels of glutathione, superoxide dismutase, and catalase as well as the malondialdehyde and hydrogen peroxide concentrations in the testes and sperm. Melatonin sustained Bcl-2 expression and controlled apoptosis. Furthermore, melatonin maintained the testosterone levels, ameliorated histopathological changes, increased the percentages of seminal haploid germ cells, and protected sperm chromatin condensation process, indicating appropriate spermatogenesis with production of functional sperm. In conclusion, melatonin protected against BPA-induced apoptosis by controlling Bcl-2 expression and ameliorating oxidative stress in the testes and sperm. Thus, melatonin is a promising pharmacological agent for preventing the potential reproductive toxicity of BPA following occupational or environmental exposures.

The effect of Metformin on endometrial tumor-regulatory genes and systemic metabolic parameters in polycystic ovarian syndrome--a proof-of-concept study.

The aim of this proof-of-concept study was to determine the effects of three-month Metformin therapy on the expression of tumor-regulatory genes (p53, cyclin D2 and BCL-2) in the endometrium of women with polycystic ovary syndrome (PCOS). A total of 40 women, aged between 21 and 45 years with PCOS (Rotterdam criteria) were recruited. The participants were assessed at pre- and 3-month-post-Metformin therapy for the menstrual regularities, weight reduction, Ferriman Galway scores, fasting blood glucose (FBG), total cholesterol, LDL, HDL and p53, BCL-2 and cyclin D2 gene expression. Five participants conceived spontaneously after the initial recruitment. Majority (68%) resumed regular menstrual cycles after Metformin. There were significant reduction in BMI (p = 0.001), weight (p = 0.001) and Ferriman Galway scores (p = 0.001). A significant improvement was seen in mean FBG (p = 0.002), total cholesterol (p = 0.001), LDL (p = 0.003) and HDL cholesterol levels (p = 0.015). Tumor suppressor gene (p53) was significantly up-regulated after Metformin (10 out of 14 women), with p value 0.016. BCL-2 and cyclin D2 (oncogenes) were slightly up-regulated without significant difference (p = 0.119 and 0.155, respectively). In conclusion, Metformin therapy improved clinical and metabolic parameters in women with PCOS and up-regulated p53 tumor suppressor gene significantly. Further studies are however required to independently validate our findings.

Effects of intermittent hypobaric hypoxia preconditioning on the expression of neuroglobin and Bcl-2 in the rat hippocampal CA1 area following ischemia-reperfusion.

This study was aimed at understanding the effect of intermittent hypobaric hypoxia preconditioning (IHHP) on neuroglobin (NGB) and Bcl-2 expression in the hippocampal CA1 region of rats following global cerebral ischemia-reperfusion. Wistar rats were randomly divided into sham, IHHP control, global cerebral ischemia-reperfusion (IR group), and IHHP+IR groups. The four-vessel occlusion rat model of Pulsinelli was used for the IR groups, in which the common carotid artery was occluded for 8 min before reperfusion. Thionin and immunohistochemical staining were used to observe NGB and Bcl-2 expression in the hippocampal CA1 region. Data was analyzed using the SPSS software. There was a significant increase in the number of surviving cells in the hippocampal CA1 region of the IHHP+IR group (119.5 ± 14) compared to the IR group (41.7 ± 3.8) (P < 0.05). There was a significant increase in the expression of NGB and Bcl-2 in the hippocampal CA1 region of the IHHP+IR group compared to the IR group. By upregulating hippocampal NGB and Bcl-2 expression, IHHP may play a role in neural protection by reducing hippocampal neuronal apoptosis following IR.

Activation of nuclear factor erythroid 2-related factor 2 and PPARγ plays a role in the genistein-mediated attenuation of oxidative stress-induced endothelial cell injury.

We investigate the cytoprotective effects and the molecular mechanism of genistein in oxidative stress-induced injury using an endothelial cell line (EA.hy926). An oxidative stress model was established by incubating endothelial cells with H2O2. According to the present results, genistein pretreatment protected endothelial cells against H2O2-induced decreases in cell viability and increases in apoptosis. Genistein also prevented the inhibition of B-cell lymphoma 2 and the activation of caspase-3 induced by H2O2. Genistein increased superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) levels and attenuated the decrease in these antioxidants during oxidative stress. We also found that genistein induced the promoter activity of both nuclear factor erythroid 2-related factor 2 (Nrf2) and PPARγ. Additionally, genistein induced the nuclear translocation of Nrf2 and PPARγ. While genistein caused the up-regulation of both Nrf2 and PPARγ, it also activated and up-regulated the protein expression and transcription of a downstream protein, haem oxygenase-1 (HO-1). Moreover, the use of Nrf2 small interfering RNA transfection and HO-1- or PPARγ-specific antagonists (Znpp and GW9662, respectively) blocked the protective effects of genistein on endothelial cell viability during oxidative stress. Therefore, we conclude that oxidative stress-induced endothelial cell injury can be attenuated by treatment with genistein, which functions via the regulation of the Nrf2 and PPARγ signalling pathway. Additionally, the endogenous antioxidants SOD, CAT and GSH appear to play a role in the antioxidant activity of genistein. The present findings suggest that the beneficial effects of genistein involving the activation of cytoprotective antioxidant genes may represent a novel strategy in the prevention and treatment of cardiovascular endothelial damage.

Demethoxycurcumin induces Bcl-2 mediated G2/M arrest and apoptosis in human glioma U87 cells.

Docking analysis of curcumin (C1), demethoxycurcumin (C2) and bisdemethoxycurcumin (C3) with Bcl-2 illustrated that among the three curcuminoids, C2 binds more efficiently into its putative active site. C1, C2 and C3 were purified from turmeric rhizomes to demonstrate the molecular mechanism of their anticancer activity on human glioma U87 cells. Human glioma U87 cells treated with curcuminoids resulted in activation of Bcl-2 mediated G2 checkpoint, which was associated with the induction of G2/M arrest and apoptosis. The binding of C1, C2 and C3 with Bcl-2 protein was confirmed with circular dichroism (CD) spectroscopy. Present work revealed that C2 induced Bcl-2 mediated G2/M arrest and apoptosis most effectively.

Bax, Bak and beyond - mitochondrial performance in apoptosis.

Bax and Bak are members of the Bcl-2 family and core regulators of the intrinsic pathway of apoptosis. Upon apoptotic stimuli, they are activated and oligomerize at the mitochondrial outer membrane (MOM) to mediate its permeabilization, which is considered a key step in apoptosis. However, the molecular mechanism underlying Bax and Bak function has remained a key question in the field. Here, we review recent structural and biophysical evidence that has changed our understanding of how Bax and Bak promote MOM permeabilization. We also discuss how the spatial regulation of Bcl-2 family preference for binding partners contributes to regulate Bax and Bak activation. Finally, we consider the contribution of mitochondrial composition, dynamics and interaction with other organelles to apoptosis commitment. A new perspective is emerging, in which the control of apoptosis by Bax and Bak goes beyond them and is highly influenced by additional mitochondrial components.