[An effect of ethylmethylhydroxypyridine succinate and ethylmethylhydroxypyridine malate on changes in mitochondrial function under conditions of focal cerebral ischemia]. / Vliyanie etilmetilgidroksipiridina suktsinata i etilmetilgidroksipiridina malata na izmenenie mitokhondrial'noi funktsii v usloviyakh fokal'noi ishemii golovnogo mozga.

OBJECTIVE: To evaluate an effect of ethylmethylhydroxypyridine succinate and ethylmethylhydroxypyridine malate on changes in mitochondrial function under experimental focal cerebral ischemia. MATERIAL AND METHODS: Focal cerebral ischemia was modeled in Wistar rats by thermocoagulation of the middle cerebral artery. Ethylmethylhydroxypyridine succinate («Mexidol¼) and ethylmethylhydroxypyridine malate («Ethoxidol¼) were injected into the tail vein 30 minutes after ischemia simulation and then for 3 days at doses of 50 mg/kg, 100 mg/kg and 150 mg/kg. After 72 hours, changes in neurological deficits, aerobic and anaerobic respiration activity, the concentration of mitochondrial hydrogen peroxide and apoptosis-inducing factor, as well as the activity of succinate dehydrogenase and cytochrome c oxidase in brain tissue supernatants were assessed. RESULTS: The course administration of ethylmethylhydroxypyridine succinate and ethylmethylhydroxypyridine malate dose-dependently contributed to a decrease in the concentration of mitochondrial hydrogen peroxide and apoptosis-inducing factor in the brain tissue. The restoration of mitochondrial energy function was also shown with the use of ethylmethylhydroxypyridine succinate in all studied doses, while the administration of ethylmethylhydroxypyridine malate led to the restoration of mitochondrial-dependent energy production only at higher doses (100 mg/kg and 150 mg/kg). CONCLUSION: The effect of malic acid and succinic acid salts of ethylmethylhydroxypyridine on the change in the redox and apoptosis-regulating function of mitochondria does not depend on the type of anion, whereas the change in the energy function of mitochondria is associated with the salt residue included in the drug structure and its dosage.

Apoptosis-inducing factor-like protein-mediated stress and metronidazole-responsive programmed cell death pathway in Entamoeba histolytica.

Apoptosis-inducing factor (AIF) is the major component of the caspase-independent cell death pathway that is considered to be evolutionarily ancient. Apoptosis is generally evolved with multicellularity as a prerequisite for the elimination of aged, stressed, or infected cells promoting the survival of the organism. Our study reports the presence of a putative AIF-like protein in Entamoeba histolytica, a caspase-deficient primitive protozoan, strengthening the concept of occurrence of apoptosis in unicellular organisms as well. The putative cytoplasmic EhAIF migrates to the nucleus on receiving stresses that precede its binding with DNA, following chromatin degradation and chromatin condensation as evident from both in vitro and in vivo experiments. Down-regulating the EhAIF expression attenuates the apoptotic features of insulted cells and increases the survival potency in terms of cell viability and vitality of the trophozoites, whereas over-expression of the EhAIF effectively enhances the phenomena. Interestingly, metronidazole, the most widely used drug for amoebiasis treatment, is also potent to elicit similar AIF-mediated cell death responses like other stresses indicating the AIF-mediated cell death could be the probable mechanism of trophozoite-death by metronidazole treatment. The occurrence of apoptosis in a unicellular organism is an interesting phenomenon that might signify the altruistic death that overall improves the population health.

p20BAP31 induces cell apoptosis via both AIF caspase-independent and the ROS/JNK mitochondrial pathway in colorectal cancer.

BACKGROUND: During cell apoptosis, the C-terminus of BAP31 is cleaved by caspase-8 and generates p20BAP31, which has been shown to induce an apoptotic pathway between the endoplasmic reticulum (ER) and mitochondria. However, the underlying mechanisms of p20BAP31 in cell apoptosis remains unclear. METHODS: We compared the effects of p20BAP31 on cell apoptosis in six cell lines and selected the most sensitive cells. Functional experiments were conducted, including Cell Counting Kit 8 (CCK-8), reactive oxygen species (ROS), and mitochondrial membrane potential (MMP) assay. Then, cell cycle and apoptosis were investigated by flow cytometry and verified by immunoblotting. Next, NOX inhibitors (ML171 and apocynin), ROS scavenger (NAC), JNK inhibitor (SP600125), and caspase inhibitor (Z-VAD-FMK) were used to further investigate the underlying mechanisms of p20BAP31 on cell apoptosis. Finally, apoptosis-inducing factor (AIF) translocation from the mitochondria to the nuclei was verified by immunoblotting and immunofluorescence assay. RESULTS: We found that overexpression of p20BAP31 indeed induced apoptosis and had a much greater sensitivity in HCT116 cells. Furthermore, the overexpression of p20BAP31 inhibited cell proliferation by causing S phase arrest. Further study revealed that p20BAP31 reduced MMP, with a significant increase in ROS levels, accompanied by the activation of the MAPK signaling pathway. Importantly, the mechanistic investigation indicated that p20BAP31 induces mitochondrial-dependent apoptosis by activating the ROS/JNK signaling pathway and induces caspase-independent apoptosis by promoting the nuclear translocation of AIF. CONCLUSIONS: p20BAP31 induced cell apoptosis via both the ROS/JNK mitochondrial pathway and AIF caspase-independent pathway. Compared with antitumor drugs that are susceptible to drug resistance, p20BAP31 has unique advantages for tumor therapy.

Investigating the adverse outcome pathways (AOP) of neurotoxicity induced by DBDPE with a combination of in vitro and in silico approaches.

Current studies have shown an association between DBDPE and neurotoxicity. In this study, the adverse outcome pathway (AOP) and mechanistic analysis of DBDPE-induced neurotoxicity were explored by a combination of in vitro and in silico approaches in SK-N-SH cells. DBDPE-induced oxidative stress caused DNA strand breaks, resulting in the activation of poly (ADP-ribose) (PAR) polymerase-1 (PARP-1). Activation of PARP1 could cause toxic damage in various organ systems, especially in the nervous system. DBDPE-induced apoptosis via the caspase-dependent intrinsic mitochondrial pathway and the PARP1-dependent pathway. Activation of PARP1 by DBDPE was deemed the initiating event, thereby affecting the key downstream biochemical events (e.g., ROS production, DNA damage, membrane potential changes, and ATP reduction), which induced apoptosis. Furthermore, excessive activation of PARP1 was accompanied by the translocation of the apoptosis-inducing factor (AIF), which was associated with PARP1-dependent cell death. The inhibition of PARP1 by PJ34 reduced DBDPE-induced apoptosis and maintained cellular ATP levels. PJ34 also prevented the translocation of AIF from the mitochondria to the nucleus. These findings improve the understanding of the mechanism of DBDPE-induced neurotoxic effects and provide a theoretical basis for the ecological risk of DBDPE.

Effects of moxibustion at bilateral Feishu (BL13) and Xinshu (BL15) combined with benazepril on myocardial cells apoptosis index and apoptosis-related proteins cytochrome c and apoptosis-inducing factor in rats with chronic heart failure.

OBJECTIVE: To observe the effects of moxibustion at bilateral Feishu (BL13) and Xinshu (BL15) combined with benazepril on myocardial cells apoptosis index, the expression levels of apoptosis-related proteins cytochrome c (Cyt-C) and apoptosis-inducing factor (AIF) in chronic heart failure (CHF) rats. METHODS: Sixty-five rats were randomly divided into normal group () and model-I group (). After modeling, CHF rats in model-I group were divided into model group, moxibustion group, benazepril group, moxibustion plus benazepril group (abbreviated as aibei group, the same below), 10 rats in each group. Echocardiogram index was examined by echocardiography. Hemodynamic indices were measured by rat cardiac function meter. Serum B-type brain natriuretic peptide (BNP) was detected by enzyme-linked immunosorbent assay. Myocardial cells apoptosis index was detected by terminal-deoxynucleoitidyl transferase mediated nick end labeling staining. Pathological changes of myocardial tissues were observed by hematoxylin and eosin staining. The expression levels of Cyt-C and AIF in myocardial tissues were detected by Western blot. RESULTS: Compared with normal group, ejection fraction and left ventricular diameter shortening rate in model-Ⅰ group were significantly reduced, myocardial cells of rats in model group exhibited unclear transverse striations, cells swellings and vacuoles, cardiac functions were deteriorated, serum BNP level, myocardial cells apoptosis index, and the expression levels of Cyt-C and AIF were significantly increased. Compared with model group, myocardial cells of rats in moxibustion group, benazepril group, and aibei group were dyed more evenly, muscle fibers were arranged relatively neatly, cardiac functions were improved, serum BNP level, myocardial cells apoptosis index, and the expression levels of Cyt-C and AIF were significantly decreased. Compared with aibei group, cardiac functions were worsened, myocardial cells apoptosis index, and the expression levels of Cyt-C and AIF were increased. CONCLUSION: Moxibustion at bilateral Feishu (BL13) and Xinshu (BL15) combined with benazepril could improve CHF better than moxibustion at bilateral Feishu (BL13) and Xinshu (BL15) or benazepril alone. The mechanisms might be that they can inhibit the expressions of Cyt-C and AIF, and inhibit the apoptosis of cardiomyocytes.

Methylmercury induced apoptosis of human neuroblastoma cells through the reactive oxygen species mediated caspase and poly ADP-ribose polymerase/apoptosis-inducing factor dependent pathways.

Methylmercury (MeHg) is an environmental neurotoxic substance, which can easily cross the blood-brain barrier, causing irreversible damage to the human central nervous system. Reactive oxygen species (ROS) are involved in various ways of intracellular physiological or pathological processes including neuronal apoptosis. This study attempted to explore the role of ROS-mediated poly ADP-ribose polymerase (PARP)/apoptosis-inducing factor (AIF) apoptosis signaling pathway in the process of MeHg-induced cell death of human neuroblastoma cells (SH-SY5Y). Here, we found that SH-SY5Y cells underwent apoptosis in response to MeHg, which was accompanied by the increased levels of ROS and calcium ion, and the activation of caspase cascades and PARP. Inhibiting the production of ROS can reduce the apoptosis rate to a certain extent. PARP/AIF apoptotic pathway is independent of caspase dependent signaling pathway and regulates it. In conclusion, these results suggest that ROS mediated activation of caspase pathway and PARP/AIF signaling pathway are involved in MeHg induced apoptosis, and these two pathways interact with each other.

Design, Optimization, and Structural Characterization of an Apoptosis-Inducing Factor Peptide Targeting Human Cyclophilin A to Inhibit Apoptosis Inducing Factor-Mediated Cell Death.

Blocking the interaction between the apoptosis-inducing factor (AIF) and cyclophilin A (CypA) by the AIF fragment AIF(370-394) is protective against glutamate-induced neuronal cell death and brain injury in mice. Starting from AIF(370-394), we report the generation of the disulfide-bridged and shorter variant AIF(381-389) and its structural characterization by nuclear magnetic resonance (NMR) in the free and CypA-bound state. AIF(381-389) in both the free and bound states assumes a ß-hairpin conformation similar to that of the fragment in the AIF protein and shows a highly reduced conformational flexibility. This peptide displays a similar in vitro affinity for CypA, an improved antiapoptotic activity in cells and an enhanced proteolytic stability compared to the parent peptide. The NMR-based 3D model of the AIF(381-389)/CypA complex provides a better understanding of the binding hot spots on both the peptide and the protein and can be exploited to design AIF/CypA inhibitors with improved pharmacokinetic and pharmacodynamics features.

Goose parvovirus and the protein NS1 induce apoptosis through the AIF-mitochondrial pathway in goose embryo fibroblasts.

In this study, the effects of Goose parvovirus (GPV) infection as well as the possible role of NS1 protein on apoptosis induction in goose embryo fibroblast (GEF) cells were examined. Flow cytometry analysis and TUNEL assays revealed that GPV infection and NS1 transfection induced significant apoptosis in GEF cells compared to what was observed in mock-infected cells. Interestingly, the increase in the rate of apoptosis detected in GPV-infected GEFs was accompanied by an increased viral load in the cells. In addition, the apoptotic pathway was mediated by apoptosis-inducing factors (AIFs) and internal factors that influence the release of AIFs. The results indicated that the mitochondrial membrane potential was decreased, and AIF expression was increased in the nucleus (P < 0.01). Reactive oxygen species (ROS) increased gradually within 48 h (P < 0.001). Cathepsin D activities were also increased (P < 0.05). The results demonstrated that the AIF-mediated pathway is a new mitochondrial apoptotic pathway and that mitochondrial depolarization, ROS content, and cathepsin D activities are the key factors influencing apoptosis in GEF cells.

Hexavalent chromium-induced apoptosis in Hep3B cells is accompanied by calcium overload, mitochondrial damage, and AIF translocation.

Hexavalent chromium [Cr(VI)] is a pervasive environmental pollutant that can enter the body through a variety of routes and cause organ toxicity, genetic damage, and cancer. Cr(VI)-induced apoptosis is a toxicant mechanism of Cr(VI). Studies have shown that Cr(VI) can induce p53-independent apoptosis, but the mechanisms are not fully understood. The intracellular calcium concentration affects cellular life. Apoptosis-inducing factor (AIF), a caspase-independent apoptotic effector, can induce DNA degradation. Using p53-null Hep3B cells, we investigated the effects of cytoplasmic calcium homeostasis and AIF on Cr(VI)-induced apoptosis. We found that 20 µM of Cr(VI) induced DNA damage and mitochondrial permeability transition pore (MPTP) openings, causing calcium overload that was accompanied by decreased Ca2+-Mg2+-ATPase and Na+-K+-ATP activities, downregulation of calmodulin (CaM) and Ca2+/CaM-dependent protein kinase II (CAMKII) mRNA, and increased expression of p-CaMKII/CaMKII protein. After treatment with calcium chelating agent BAPTA-AM, Cr(VI)-induced DNA damage, calcium overload, and apoptosis were reduced. AIF was released from the mitochondria and translocated into the nuclei. As the Cr(VI) treatment time progressed, the mRNA and protein expression of B cell lymphoma 2 (Bcl-2) and heat-shock protein 70 (HSP70) decreased, whereas the mRNA and protein expression of Bcl-2-associated X (Bax), cyclophilin A (CypA), and endonuclease G (EndoG) were upregulated. These results indicated that Cr(VI)-induced apoptosis of Hep3B cells (p53-null) was closely associated with calcium overload, and was accompanied by the activation of Ca2+/CaM/CaMKII signaling pathway. Besides, Cr(VI) triggered AIF nuclear translocation in Hep3B cells, accompanied by the changes in the levels of apoptosis-associated factors. These results provide additional experimental evidence of the molecular mechanisms involved in Cr(VI)-induced p53-independent apoptosis.

Inhibiting the interaction between apoptosis-inducing factor and cyclophilin A prevents brain injury in neonatal mice after hypoxia-ischemia.

The interaction between apoptosis-inducing factor (AIF) and cyclophilin A (CypA) has been shown to contribute to caspase-independent apoptosis. Blocking the AIF/CypA interaction protects against glutamate-induced neuronal cell death in vitro, and the purpose of this study was to determine the in vivo effect of an AIF/CypA interaction blocking peptide (AIF(370-394)-TAT) on neonatal mouse brain injury after hypoxia-ischemia (HI). The pups were treated with AIF (370-394)-TAT peptide intranasally prior to HI. Brain injury was significantly reduced at 72 h after HI in the AIF(370-394)-TAT peptide treatment group compared to vehicle-only treatment for both the gray matter and the subcortical white matter, and the neuroprotection was more pronounced in males than in females. Neuronal cell death was evaluated in males at 8 h and 24 h post-HI, and it was decreased significantly in the CA1 region of the hippocampus and the nucleus habenularis region after AIF(370-394)-TAT treatment. Caspase-independent apoptosis was decreased in the cortex, striatum, and nucleus habenularis after AIF(370-394)-TAT treatment, but no significant change was found on caspase-dependent apoptosis as indicated by the number of active caspase-3-labeled cells. Further analysis showed that both AIF and CypA nuclear accumulation were decreased after treatment with the AIF(370-394)-TAT peptide. These results suggest that AIF(370-394)-TAT inhibited AIF/CypA translocation to the nucleus and reduced HI-induced caspase-independent apoptosis and brain injury in young male mice, suggesting that blocking AIF/CypA might be a potential therapeutic target for neonatal brain injury.

Sanggenol L promotes apoptotic cell death in melanoma skin cancer cells through activation of caspase cascades and apoptosis-inducing factor.

Sanggenol L is one component of root bark of Morus alba. The molecular and cellular mechanisms of sanggenol L effects on melanoma cells are not well known. Recently, melanoma is the most common skin cancer with a high mortality rate not only in United States, but also in East Asia. Therefore, safe and effective treatments for melanoma treatment are required. In this study, we investigated whether or not sanggenol L possesses anti-cancer activity in human and mouse melanoma skin cancer cells. Sanggenol L treatment exerted significant cell growth inhibitory effects and inhibited colony formation capacity against B16, SK-MEL-2, and SK-MEL-28 melanoma skin cancer cells, whereas HaCaT human epithelial keratinocyte cells was unaffected by sanggenol L treatment. Sanggenol L treatment resulted in apoptotic cell death in melanoma skin cancer cells, which was characterized by accumulation of apoptotic cells, nuclear condensation, and apoptotic bodies. We also showed that sanggenol L treatment induced caspase-dependent apoptosis (up-regulation of Bax and cleaved-PARP or down-regulation of Bid, Bcl-2, procaspse-3, -8, and -9), induction of caspase-independent apoptosis (up-regulation of AIF and Endo G on cytosol) in melanoma skin cancer cells. These results suggest that sanggenol L induces caspase-dependent and -independent apoptosis in melanoma skin cancer cells.

Endonuclease G takes part in AIF-mediated caspase-independent apoptosis in Mycobacterium bovis-infected bovine macrophages.

Mycobacterium bovis, the causative agent of bovine tuberculosis encodes different virulence mechanisms to survive inside of host cells. One of the possible outcomes in this host-pathogen interaction is cell death. Previous results from our group showed that M. bovis induces a caspase-independent apoptosis in bovine macrophages with the possible participation of apoptosis inducing factor mitochondria associated 1 (AIFM1/AIF), a flavoprotein that functions as a cell-death regulator. However, contribution of other caspase-independent cell death mediators in M. bovis-infected macrophages is not known. In this study, we aimed to further characterize M. bovis-induced apoptosis, addressing Endonuclease G (Endo G) and Poly (ADP-ribose) polymerase 1 (PARP-1). In order to accomplish our objective, we infected bovine macrophages with M. bovis AN5 (MOI 10:1). Analysis of M. bovis-infected nuclear protein extracts by immunoblot, identified a 15- and 43-fold increase in concentration of mitochondrial proteins AIF and Endo G respectively. Interestingly, pretreatment of M. bovis-infected macrophages with cyclosporine A, a mitochondrial permeability transition pore inhibitor, abolished AIF and Endo G nuclear translocation. In addition, it also decreased macrophage DNA fragmentation to baseline and caused a 26.2% increase in bacterial viability. We also demonstrated that PARP-1 protein expression in macrophages did not change during M. bovis infection. Furthermore, pretreatment of M. bovis-infected bovine macrophages with 3-aminobenzamide, a PARP-1 inhibitor, did not change the proportion of macrophage DNA fragmentation. Our results suggest participation of Endo G, but not PARP-1, in M. bovis-induced macrophage apoptosis. To the best of our knowledge this is the first report associating Endo G with caspase-independent apoptosis induced by a member of the Mycobacterium tuberculosis complex.

Effects of sulfur mustard on mesenchymal stem cells.

Chronic wound healing disorders that occur as a result of a sulfur mustard (SM) exposure present a particular challenge. These chronic wounds are similar to other chronic wounds. In the past, it has been shown that mesenchymal stem cells (MSC) play an important role in the healing of chronic wounds. An important property to support wound healing is their ability to migrate. However, we were able to show that SM leads to a reduction in MSC migration even at low concentrations. Currently, exposed MSCs are still able to differentiate. Further alterations are not known. The current investigation therefore focused onto the question how SM affects MSC. MATERIAL & METHODS: The effect of SM on MSC was investigated. Here, the alkylation of DNA was considered, and DNA adducts were quantified over a period of 48h. The modification of the nuclei under the influence of SM was analyzed as well as proliferation of the cells by immunohistochemical staining with Ki-67 and quantification. For the quantification of the apoptosis rate, antibodies against cleaved Caspase-3, 8, and apoptosis inducing factor (AIF) were used. The senescence analysis was performed after histological staining against ß-galactosidase. Quantifications were carried out by using the TissueQuest System and the software TissueFAX. RESULTS: SM exposure of MSC results in a dose dependent formation of nuclear DNA adducts. 4h after exposure the cells display a decreasing concentration of DNA adducts. This process is accompanied by a change of nuclei shape but without an increase of apoptosis induction. In parallel the number of cells undergoing senescence increases as a function of the SM concentration. DISCUSSION: SM exposure of MSC leads to adduct formation on chromosomal DNA. These DNA adducts can be reduced without MSC are undergoing apoptosis. This indicates an active DNA damage response (DDR) pathway in combination with the formation of persistent nuclear DNA damage foci. This process is accompanied by a reduced capability of proliferation and a transition into the senescent state.

Understanding the Dr. Jekyll and Mr. Hyde nature of apoptosis-inducing factor: future perspectives.

Apoptosis-inducing factor (AIF) is emerging as a key protein in regulation of basic physiological processes including phagocytosis, mitophagy and regulation of the redox state. Recent evidences suggest that the enzymatic activity of AIF may play an active role in tumor progression controlling energy metabolism and redox balance. The present manuscript briefly describes the story of this protein from its initial discovery as caspase-independent apoptotic protein, throughout its role in oxidative phosphorylation and lately involvement in tumor progression. Understanding the dualistic nature of AIF is a critical starting point to clarify its contribution in tumor metabolic balance and to develop new AIF-specific therapeutic strategies.

Apoptosis-inducing Effect of a Palladium(II) Complex-[PdCl(terpy)](sac).2H2O] on Ehrlich Ascites Carcinoma (EAC) in Mice.

BACKGROUND/AIM: New compounds for cancer treatment are needed due to persistenly unsatisfactory management of cancer. [PdCl(terpy)](sac)·2H2O] (sac=saccharinate, and terpy=2,2':6',2"-terpyridine) is a compound synthesized for this purpose. We investigated its anti-proliferative and pro-apoptotic effects on Ehrlich Ascites Carcinoma (EAC) in vivo. MATERIALS AND METHODS: 42 Balb-c female mice were subcutaneously (s.c.) injected with EAC cells (1st day) and then randomly divided into 5 groups: control (0.9% NaCl), complex (2 mg/kg), complex (3 mg/kg) cisplatin (4 mg/kg) and paclitaxel (12.5 mg/kg). On the 5th and 12th day animals were drug administrated. At 14th day, animals were sacrificed. Expression of cell death and/or cell cycle-related markers (Bcl-2, Bax, active caspase-3, p53, PCNA) and apoptosis were investigated immunohisto-chemically. Survival-related markers (Akt, GSK-3ß, IGF-1R, IR, IRS-1, p70S6K, PRAS40) were evaluated by luminex analysis. RESULTS: Expression of p53, PCNA, Bcl-2 was found decreased (p<0.001) and that of active caspase-3, Bax, and apoptotic cells was found increased (p<0.001) in all groups. The survival-related markers did not show any statistical difference in complex groups. CONCLUSION: The Pd(II)-complex seems to have a strong anticancer activity on EAC by inducing apoptosis via both suppression of proliferation and activation of apoptosis in vivo, similar to the effects of cisplatin and paclitaxel.

Combined inhibition of cell death induced by apoptosis inducing factor and caspases provides additive neuroprotection in experimental traumatic brain injury.

Neuronal programmed cell death (PCD) contributes to delayed tissue damage after traumatic brain injury (TBI). Both caspase-dependent and caspase-independent mechanisms have been implicated, with the latter including apoptosis inducing factor (AIF). The peptidyl-proplyl isomerase Cyclophilin A (CypA) transports AIF from the cytosol to the nucleus, a key step for AIF-dependent cell death. We compared the effects of single versus combined inhibition of caspase and AIF pathways in a mouse controlled cortical impact (CCI) model, by examining the effects of CypA gene knockout (CypA(-/-)), caspase inhibition with a pan-caspase inhibitor (boc-aspartyl(OMe)-fluoromethylketone, BAF), or combined modulation. TBI caused caspase activation as well as translocation of AIF to the nucleus. Markers of caspase activation including caspase-specific fodrin cleavage fragments and number of FLIVO-positive cells were reduced in BAF-treated CypA(+/+) mice, whereas markers of AIF activation including AIF/H2AX interaction and AIF translocation to the nucleus were attenuated in CypA(-/-) mice. Each single intervention, (CypA(-/-) or BAF-treated CypA(+/+)) reduced the number of apoptotic cells (TUNEL-positive) in the cortex and improved long-term sensorimotor function; CypA(-/-) also attenuated microglial activation after injury. Importantly, BAF-treated CypA(-/-) mice, showed greater effects than either intervention alone on multiple outcomes including: reduction in TUNEL-positive cells, decrease in neuroinflammation, improved motor and cognitive recovery, and attenuation of lesion volume and neuronal loss in the hippocampus. Using two in vitro neuronal cell death models known to induce AIF-mediated PCD, we also showed that neurons from CypA(-/-) animals were protected and that effects were unrelated to caspase activation. These data indicate that AIF-mediated and caspase-dependent pathways contribute independently and in parallel to secondary injury after TBI, and suggest that combined therapeutic strategies directed at multiple PCD pathways may provide superior neuroprotection than those directed at single mechanisms.

Dibenzylbutane- and butyrolactone-type lignans as apoptosis inducers in human hepatoma HuH-7 cells.

Seven lignans, previously isolated from Pycnanthus angolensis or obtained by derivatization, namely the dibenzylbutane-type lignans threo-4,4'-dihydroxy-3-methoxylignan (1), 4'-hydroxy-3,3',4-trimethoxylignan (2), (-)-dihydroguaiaretic acid (3), 3,3',4,4'-tetramethoxylignan (4), 4,4'-diacetyl-3,3'-dimethoxylignan (5), heliobuphthalmin (6) and the butyrolactone lignan hinokinin (7), were evaluted for their ability as apoptosis inducers in human hepatoma HuH-7 cells. Cell viability assays, morphological evaluation of apoptosis and enzymatic analyses of caspase activity in HuH-7 cells were carried out. Using the lactate dehydrogenase lactate dehydrogenase (LDH) assay, it was demonstrated that the lignans (1-7) tested significantly reduced viability of HuH-7 cells. Morphologic evaluation of HuH-7 cells using Hoechst staining and fluorescence microscopy revealed that lignans 1-7 were strong inducers of apoptosis. In fact, HuH-7 cells developed morphological changes of apoptosis, including chromatin condensation, nuclear fragmentation and formation of apoptotic bodies. However, lignans 2 and 7 were the most promising compounds in this study, inducing 2.4- and 2.5-fold increases in apoptotic cells as compared to controls. Caspase-3-like activity assays confirmed the morphologic data.

Alginate oligosaccharide protects against endoplasmic reticulum- and mitochondrial-mediated apoptotic cell death and oxidative stress.

Oxidative stress is a major component of harmful cascades activated in neurodegenerative disorders. We sought to elucidate possible effects of alginate oligosaccharide (AOS) on H(2)O(2)-induced cell death and to determine the underlying molecular mechanisms in neuron-like PC12 cells. We found that AOS treatment protected PC12 cells against H(2)O(2)-induced endoplasmic reticulum (ER) and mitochondrial-dependent apoptotic cell death. AOS promoted Bcl-2 expression, while blocked Bax expression and inhibited H(2)O(2)-induced caspase-3 activation. It also blocked PARP cleavage. AOS acted on key molecules in apoptotic cell death pathway and reduced p53, p38, c-June NH2-terminal kinase phosphorylations, inhibited NFkB, and enhanced Nrf2 activation. These results suggest that treatment of PC12 cells with AOS can block H(2)O(2)-induced oxidative stress and caspase-dependent apoptotic cascades originating from both ER and mitochondria. Our in vivo experiments further confirm the neuroprotective potential of AOS against Aß-induced neural damage. According to our data, the involvement of caspase-independent pathway in AOS-induced protection appears to be unlikely.

Cytotoxic and apoptosis-inducing activities of triterpene acids from Poria cocos.

Six lanostane-type triterpene acids (1a-6a), isolated from Poria cocos , and their methyl ester (1b-6b) and hydroxy derivatives (1c-6c) were prepared. Upon evaluation of the cytotoxic activity of these compounds against leukemia (HL60), lung (A549), melanoma (CRL1579), ovary (NIH:OVCAR-3), breast (SK-BR-3), prostate (DU145), stomach (AZ521), and pancreas (PANC-1) cancer cell lines, 11 compounds (5a, 6a, 2b-5b, 1c, and 3c-6c) exhibited activity with single-digit micromolar IC(50) values against one or more cell lines. Poricotriol A (1c), a hydroxy derivative of poricoic acid A (1a), exhibited potent cytotoxicities against six cell lines with IC(50) values of 1.2-5.5 µM. Poricotriol A induced typical apoptotic cell death in HL60 and A549 cells on evaluation of the apoptosis-inducing activity by flow cytometric analysis. Western blot analysis in HL60 cells showed that poricotriol A activated caspases-3, -8, and -9, while increasing the ratio of Bax/Bcl-2. This suggested that poricotriol A induced apoptosis via both mitochondrial and death receptor pathways in HL60. On the other hand, poricotriol A did not activate caspases-3, -8, and -9, but induced translocation of apoptosis-inducing factor (AIF) from mitochondria and increased the ratio of Bax/Bcl-2 in A549. This suggested that poricotriol A induced apoptosis via the mitochondrial pathway mostly by translocation of AIF, independent from the caspase pathway in A549. Furthermore, poricotriol A was shown to possess high selective toxicity in lung cancer cells since it exhibited only weak cytotoxicity against a normal lung cell line (WI-38).

Antimycin A-induced mitochondrial apoptotic cascade is mitigated by phenolic constituents of Phyllanthus amarus aqueous extract in Hep3B cells.

Antimycin A (AMA) treatment of cells blocks mitochondrial electron transport chain, and leads to elevated ROS generation, thereby causing damage to mtDNA, proteins and lipids, along with mitochondrial membrane depolarization, release of pro-apoptotic proteins into the cytoplasm, and induction of apoptosis. Prevention of such oxidative cellular damage by the aqueous extract of Phyllanthus amarus has been investigated in this study. The extract demonstrated significant potential in mitigating H(2)O(2)-induced membrane damage along with considerable recession in AMA-governed mitochondrial protein and lipid degradation in Hep3B cells. 8-OHdG analysis of mtDNA damage revealed substantial protective potential of the extract against mtDNA damage. SQ-PCR of selected mtDNA sequences confirmed the potential of the extract to alleviate levels of mtDNA damage. FACS analysis with JC-1 fluorescent dye established significant escalation of mitochondrial membrane potential by the extract in AMA-treated cells. Extract treatment resulted in a distinct decline in the degrees of AMA-induced release of cytochrome c and AIF into the cytoplasm along with consequent pacification of apoptosis. All protective efficiencies of the extract reported in this study were found to hold strong and significant (P<0.05) positive correlation to its total phenolic contents, thereby proving that polyphenolic constituents of P. amarus aqueous extract mitigate oxidative stress-induced cellular degeneration and aging.