The effects of difficulty and gain versus loss on vocal physiology and acoustics

To examine the basis of emotional changes to the voice, physiological and electroglottal measures were combined with acoustic speech analysis of 30 men performing a computer task in which they lost or gained points under two levels of difficulty. Predictions of the main effects of difficulty and reward on the voice were not borne out by the data. Instead, vocal changes depended largely on interactions between gain versus loss and difficulty. The rate at which the vocal folds open and close (fundamental frequency; f0) was higher for loss than for gain when difficulty was high, but not when difficulty was low. Electroglottal measures revealed that f0 changes corresponded to shorter glottal open times for the loss conditions. Longer closed and shorter open phases were consistent with raised laryngeal tension in difficult loss conditions. Similarly, skin conductance indicated higher sympathetic arousal in loss than gain conditions, particularly when difficulty was high. The results provide evidence of the physiological basis of affective vocal responses, confirming the utility of measuring physiology and voice in the study of emotion.

Fas ligand-induced apoptosis is regulated by nitric oxide through the inhibition of fas receptor clustering and the nitrosylation of protein kinase Cepsilon

Apoptosis induced by the death-inducing ligand FasL (CD95L) is a major mechanism of cell death. Trophoblast cells express the Fas receptor yet survive in an environment that is rich in the ligand. We report that basal nitric oxide (NO) production is responsible for the resistance of trophoblasts to FasL-induced apoptosis. In this study we demonstrate that basal NO production resulted in the inhibition of receptor clustering following ligand binding. In addition NO also protected cells through the selective nitrosylation, and inhibition, of protein kinase Cepsilon (PKCepsilon) but not PKCalpha. In the absence of NO production PKCepsilon interacted with, and phosphorylated, the anti-apoptotic protein cFLIP. The interaction is predominantly with the short form of cFLIP and its phosphorylation reduces its recruitment to the death-inducing signaling complex (DISC) that is formed following binding of a death-inducing ligand to its receptor. Inhibition of cFLIP recruitment to the DISC leads to increased activation of caspase 8 and subsequently to apoptosis. Inhibition of PKCepsilon using siRNA significantly reversed the sensitivity to apoptosis induced by inhibition of NO synthesis suggesting that NO-mediated inhibition of PKCepsilon plays an important role in the regulation of Fas-induced apoptosis.

Increased apoptosis in first trimester extravillous trophoblasts from pregnancies at higher risk of developing preeclampsia

Preeclampsia complicates 5 to 10% of pregnancies and is a leading cause of maternal and fetal mortality and morbidity. Although the cause is unknown, inadequate invasion and remodeling of maternal uterine arteries by extravillous trophoblasts (EVTs) in the first trimester is a common feature. Uterine spiral artery resistance as detected by Doppler ultrasound is commonly used in the second trimester to identify pregnancies destined to develop preeclampsia. Correlation between high uterine resistance and the failure of trophoblast invasion has been reported as early as 12 weeks. However, the reason for this failure has not been established. Understanding the processes involved would significantly improve our diagnostic potential. In this study, we correlated increased first trimester uterine artery resistance with a biological abnormality in trophoblast function. EVTs derived from high-resistance pregnancies were more sensitive to apoptotic stimuli than those from normal-resistance pregnancies. Survival of EVTs from high-resistance pregnancies could be increased by nitric oxide, whereas inhibition of nitric oxide in cells from normal-resistance pregnancies increased apoptotic sensitivity. This predates the onset of symptoms by several weeks and provides evidence for a mechanism responsible for the incomplete uterine vessel remodeling and the differences in artery resistance between preeclamptic and normal pregnancies.

Ascorbate does not protect macrophages against apoptosis induced by oxidised low density lipoprotein

Apoptosis of macrophages and smooth muscle cells is observed in atherosclerotic lesions and may play an important role in the disease progression. Oxidised low density lipoprotein (LDL) is cytotoxic and induces apoptosis in a variety of cell types. We reported previously that ascorbate protects arterial smooth muscle cells from apoptosis induced by oxidised LDL containing the peak levels of lipid hydroperoxides. We now demonstrate that macrophages undergo apoptosis when treated with this species of oxidised LDL, as detected by increased annexin V binding and DNA fragmentation. Ascorbate treatment of macrophages did not protect against the cytotoxicity of oxidised LDL, and modestly increased the levels of annexin V binding and DNA fragmentation. Oxidised LDL treatment also increased the expression of the antioxidant stress protein heme oxygenase-1 in macrophages; however, this increase was markedly attenuated by ascorbate pretreatment. Although apoptosis induced by oxidised LDL was modestly promoted by ascorbate, ascorbate apparently decreased the levels of oxidative stress in macrophages, suggesting that this pro-apoptotic effect was not mediated by a pro-oxidant mechanism, but may instead have been due to intracellular protection of the apoptotic machinery by ascorbate. (c) 2006 Elsevier Inc. All rights reserved.

Heat shock protein 27 is the major differentially phosphorylated protein involved in renal epithelial cellular stress response and controls focal adhesion organization and apoptosis

We used two-dimensional difference gel electrophoresis to determine early changes in the stress-response pathways that precede focal adhesion disorganization linked to the onset of apoptosis of renal epithelial cells. Treatment of LLC-PK1 cells with the model nephrotoxicant 1,2-(dichlorovinyl)-L-cysteine (DCVC) resulted in a >1.5-fold up- and down-regulation of 14 and 9 proteins, respectively, preceding the onset of apoptosis. Proteins included those involved in metabolism, i.e. aconitase and pyruvate dehydrogenase, and those related to stress responses and cytoskeletal reorganization, i.e. cofilin, Hsp27, and alpha-b-crystallin. The most prominent changes were found for Hsp27, which was related to a pI shift in association with an altered phosphorylation status of serine residue 82. Although both p38 and JNK were activated by DCVC, only inhibition of p38 with SB203580 reduced Hsp27 phosphorylation, which was associated with accelerated reorganization of focal adhesions, cell detachment, and apoptosis. In contrast, inhibition of JNK with SP600125 maintained cell adhesion as well as protection against apoptosis. Active JNK co-localized at focal adhesions after DCVC treatment in a FAK-dependent manner. Inhibition of active JNK localization at focal adhesions did not prevent DCVC-induced phosphorylation of Hsp27. Overexpression of a phosphorylation-defective mutant Hsp27 acted as a dominant negative and accelerated the DCVC-induced changes in the focal adhesions as well as the onset of apoptosis. Our data fit a model whereby early p38 activation results in a rapid phosphorylation of Hsp27, a requirement for proper maintenance of cell adhesion, thus suppressing renal epithelial cell apoptosis.

Heat shock protein 27 is the major differentially phosphorylated protein involved in renal epithelial cellular stress response and controls focal adhesion organization and apoptosis

We used two-dimensional difference gel electrophoresis to determine early changes in the stress-response pathways that precede focal adhesion disorganization linked to the onset of apoptosis of renal epithelial cells. Treatment of LLC-PK1 cells with the model nephrotoxicant 1,2-(dichlorovinyl)-L-cysteine ( DCVC) resulted in a > 1.5-fold up- and down-regulation of 14 and 9 proteins, respectively, preceding the onset of apoptosis. Proteins included those involved in metabolism, i.e. aconitase and pyruvate dehydrogenase, and those related to stress responses and cytoskeletal reorganization, i.e. cofilin, Hsp27, and alpha-b-crystallin. The most prominent changes were found for Hsp27, which was related to a pI shift in association with an altered phosphorylation status of serine residue 82. Although both p38 and JNK were activated by DCVC, only inhibition of p38 with SB203580 reduced Hsp27 phosphorylation, which was associated with accelerated reorganization of focal adhesions, cell detachment, and apoptosis. In contrast, inhibition of JNK with SP600125 maintained cell adhesion as well as protection against apoptosis. Active JNK co-localized at focal adhesions after DCVC treatment in a FAK-dependent manner. Inhibition of active JNK localization at focal adhesions did not prevent DCVC-induced phosphorylation of Hsp27. Overexpression of a phosphorylation-defective mutant Hsp27 acted as a dominant negative and accelerated the DCVC-induced changes in the focal adhesions as well as the onset of apoptosis. Our data fit a model whereby early p38 activation results in a rapid phosphorylation of Hsp27, a requirement for proper maintenance of cell adhesion, thus suppressing renal epithelial cell apoptosis.

Pectin and pectic-oligosaccharides induce apoptosis in in vitro human colonic adenocarcinoma cells

Background: Dietary fibres have been associated with decreased risk of various cancers, although the mechanisms are unclear. Induction of apoptosis in tumour cells is thought to be an important protective mechanism against colorectal cancer. This work investigates the effects of pectins and pecticoligosaccharides (POS) on the human colonic adenocarcinoma cell line HT29. Materials and Methods: The anti-proliferative effects of pectin and POS were studied by testing the HT29 cells for cytotoxicity, differentiation and/or apoptosis by lactate dehydrogenase, alkaline phosphatase and caspase-3 activity assays. DNA agarose gel electrophoresis was also carried out. Results: A significant reduction in attached cell numbers was observed after three days incubation. This decrease was neither due to cells undergoing necrosis nor differentiation. Increased apoptosis frequency, after incubation with 1% (w/v) pectin andlor POS, was demonstrated by caspase-3 activity and DNA laddering on agarose gel electrophoresis. Conclusion: Dietary pectins and their degradation products may contribute to the reported protective effects of fruits against colon cancer.

Permanent changes in growth and physiology of Bacillus subtilis ToC46 after loss of a recombinant plasmid

The physiology and growth of plasmid-bearing Bacillus subtilis carrying plasmid pPFF1, the non-transformed host, and cells after loss of the plasmid (so-called plasmid-cured cells) were investigated. It was found that, following plasmid loss, cells exhibited phenotypic characteristics different from those of the non-transformed host strains. Compared to plasmid-bearing cells and non-transformed host cells, an approximate 25% increase in the maximum specific growth rate and a more rapid increase in total RNA per unit cell mass were observed in plasmid-cured cells. The total enthalpy associated with irreversible denaturation events was determined in whole cells by differential scanning calorimetry. This showed higher enthalpies for plasmid-cured cells compared with the non-transformed host, which suggests increased ribosome numbers. The result from cellular DNA hybridisation suggests that there was no direct evidence of plasmid integration into the host chromosome. (C) 2004 Elsevier Inc. All rights reserved.

Differential induction of apoptosis in human colonic carcinoma cells (Caco-2) by Atopobium, and commensal, probiotic and enteropathogenic bacteria: mediation by the mitochondrial pathway

The induction of apoptosis in mammalian cells by bacteria is well reported. This process may assist infection by pathogens whereas for non-pathogens apoptosis induction within carcinoma cells protects against colon cancer. Here, apoptosis induction by a major new gut bacterium, Atopobium minutum, was compared with induction by commensal (Escherichia coli K-12 strains), probiotic (Lactobacillus rhamnosus, Bifidobacterium latis) and pathogenic (E. coli: EPEC and VTEC) gut bacteria within the colon cancer cell line, Caco-2. The results show a major apoptotic effect for the pathogens, mild effects for the probiotic strains and A. minutum, but no effect for commensal E. coli. The mild apoptotic effects observed are consistent with the beneficial roles of probotics in protection against colon cancer and suggest, for the first time, that A. minutum possesses similar advantageous, anti-cancerous activity. Although bacterial infection increased Caco-2 membrane FAS levels, caspase-8 was not activated indicating that apoptosis is FAS independent. Instead, in all cases, apoptosis was induced through the mitochondrial pathway as indicated by BAX translocation, cytorchrome c release, and caspase-9 and -3 cleavage. This suggests that an intracellular stimulus initiates the observed apoptosis responses.

Novel titanocene anti-cancer drugs and their effect on apoptosis and the apoptotic pathway in prostate cancer cells

Advanced prostate cancer is not curable by current treatment strategies indicating a significant need for new chemotherapeutic options. Highly substituted ansatitanocene compounds have shown promising cytotoxic activity in a range of cancers. The objectives of this study are to examine the effects of these titanocene compounds on prostate cancer cells. Prostate cell lines were treated with three novel titanocene compounds and compared to titanocene dichloride and cisplatin. Percent apoptosis, viability and cell cycle were assessed using propidium iodide DNA incorporation with flow cytometry. Cytochrome C was assessed by western blotting of mitochondrial and cytoplasmic fractions. Apoptosis Inducing Factor was assessed by confocal microscopy. These novel compounds induced more apoptosis compared to cisplatin in a dose dependent manner. Compound Y had the most significant effect on cell cycle and apoptosis. Despite the release of cytochrome C from the mitochondrial fraction there was no inhibition of apoptosis with the pan caspase inhibitor, ZVAD-FMK. AIF was shown to translocate from the cytosol to the nucleus mediating a caspase independent cell death. Bcl-2 over expressing PC-3 cells, which were resistant to cisplatin induced apoptosis, underwent apoptosis following treatment with all the titanocene compounds. This study demonstrates possible mechanisms by which these novel titanocene compounds can mediate their apoptotic effect in vitro. The fact that they can induce more apoptosis than cisplatin in advanced cancer cell lines would confer an advantage over cisplatin. They represent exciting new agents with future potential for the treatment of advanced prostate cancer.

Nox2 regulates endothelial cell cycle arrest and apoptosis via p21 (cip1) and p53

Endothelial cells (EC) express constitutively two major isofonns (Nox2 and Nox4) of the catalytic subunit of NADPH oxidase, which is a major source of endothelial reactive oxygen species. However, the individual roles of these Noxes in endothelial function remain unclear. We have investigated the role of Nox2 in nutrient deprivation-induced cell cycle arrest and apoptosis. In proliferating human dermal microvascular EC, Nox2 mRNA expression was low relative to Nox4 (Nox2:Nox4 similar to 1:13), but was upregulated 24 It after starvation and increased to 8 +/- 3.5-fold at 36 h of starvation. Accompanying the upregulation of Nox2, there was a 2.28 +/- 0.18-fold increase in O-2(-); production, a dramatic induction of p21(cip1) and p53, cell cycle arrest, and the onset of apoptosis (all p < 0.05). All these changes were inhibited significantly by in vitro deletion of Nox2 expression and in coronary microvascular EC isolated from Nox2 knockout mice. In Nox2 knockout cells, although there was a 3.8 +/- 0.5fold increase in Nox4 mRNA expression after 36 h of starvation (p < 0.01), neither production nor the p21(cip1) or p53 expression was increased significantly and only 0.46% of cells were apoptotic. In conclusion, Nox2-derived O-2(-), through the modulation of p21(cip1) and p53 expression, participates in endothelial cell cycle regulation and apoptosis. (c) 2007 Elsevier Inc. All rights reserved.