Cell suicide and caspases

Quinacrine, a PLA2 inhibitor, alleviates LPS-induced acute kidney injury in rats: Involvement of TLR4/NF-κB/TNF α-mediated signaling

Acute Kidney Injury (AKI) is a major factor in sepsis-related mortality and may occur due to lipopolysaccharide (LPS), an endotoxin produced by gram-negative bacteria that triggers a systemic acute inflammatory response. Quinacrine's (QC) renoprotective properties in sepsis and the underlying mechanism, however, are still not fully understood. This study was done to investigate the anti-inflammatory, antioxidative, and anti-apoptotic effects of QC, a phospholipase A2 (PLA2) inhibitor, against LPS-induced AKI. Rats were randomly divided into five groups: control group, QC30 group, LPS group, LPS+QC 10 group, and LPS+QC 30 group. The rats were administered intraperitoneally QC (10 and 30 mg/kg) for 3 days (once a day) prior to injection of LPS (3 mg/kg). Six hours after the LPS injection, the histopathological changes, oxidative stress, inflammation, and apoptosis in the collected kidney tissues were detected by hematoxylin and eosin staining, enzyme-linked immunosorbent assay (ELISA), real-time PCR (RT-PCR), and immunohistochemistry staining, respectively. QC pretreatment could successfully attenuate LPS-induced AKI, as evidenced by a decrease in tissue histopathological injury. Meanwhile, QC alleviated LPS-induced kidney oxidative stress; it reduced MDA levels and increased levels of SOD, CAT, GPX, and GSH. LPS-induced elevations in kidney TLR4, NF-κB, TNF-α, IL-1β, IL-6, PLA2, caspase 3, and Bax contents were significantly attenuated in QC-treated groups. Our findings revealed a significant effect of QC: protecting against LPS-induced AKI through inhibition of PLA2 and decreasing inflammation, oxidative stress, and apoptosis. To treat LPS-induced AKI, QC may be an effective substance with an excellent protection profile.

Blood mRNA Expression Profiles of Autophagy, Apoptosis, and Hypoxia Markers on Blood Cardioplegia and Custodiol Cardioplegia Groups

Introduction:

Blood cardioplegia (BC) and Custodiol cardioplegia (CC) have been used for a long time in open heart surgery and are highly effective solutions. The most controversial issue among these two is whether there is any difference between them regarding myocardial damage after ischemia surgery. In this study, autophagy, apoptosis, and hypoxia markers were investigated and that way we evaluated the differences between BC and CC patients.

Methods:

A total of 30 patients were included in this study, using two different cardioplegic solutions. Three different whole blood samples of the patients were taken from a central vein (preoperatively, immediately postoperatively, and one day after surgery). Total ribonucleic acid was extracted from these samples. Quantitative real-time polymerase chain reaction was performed, and changes in gene expression were determined by the 2-∆∆Ct method of relative quantification.

Results:

In the CC group, Beclin gene expression level was found to be higher and this difference was statistically significant (P=0.0024). Similarly, cysteine-aspartic acid protease (caspase) 9 and hypoxia-inducible factor 1α messenger ribonucleic acid (mRNA) gene expression level increased and were significantly different in the CC group. In the BC group, Beclin and microtubule-associated protein light chain 3 expressions were higher in the samples taken one day after surgery. Caspases 3 and 8 gene expressions were significantly different in the BC group.

Conclusion:

As a result of the analysis performed between the two cardioplegia groups, it has been shown that CC harms the myocardium more than BC at the level of mRNA expression of related markers.

Modulation of Heat-Shock Proteins Mediates Chicken Cell Survival against Thermal Stress

Heat stress is one of the most challenging environmental stresses affecting domestic animal production, particularly commercial poultry, subsequently causing severe yearly economic losses. Heat stress, a major source of oxidative stress, stimulates mitochondrial oxidative stress and cell dysfunction, leading to cell damage and apoptosis. Cell survival under stress conditions needs urgent response mechanisms and the consequent effective reinitiation of cell functions following stress mitigation. Exposure of cells to heat-stress conditions induces molecules that are ready for mediating cell death and survival signals, and for supporting the cell's tolerance and/or recovery from damage. Heat-shock proteins (HSPs) confer cell protection against heat stress via different mechanisms, including developing thermotolerance, modulating apoptotic and antiapoptotic signaling pathways, and regulating cellular redox conditions. These functions mainly depend on the capacity of HSPs to work as molecular chaperones and to inhibit the aggregation of non-native and misfolded proteins. This review sheds light on the key factors in heat-shock responses for protection against cell damage induced by heat stress in chicken.

The Effects of Lactobacillus plantarum-12 Crude Exopolysaccharides on the Cell Proliferation and Apoptosis of Human Colon Cancer (HT-29) Cells

The exopolysaccharide (EPS) of some Lactobacillus strains has been reported to exert anti-cancer activities. In this study, the effects of crude EPSs produced by four Lactobacillus plantarum strains (Lactobacillus plantarum-12, L. plantarum-14, L. plantarum-32, and L. plantarum-37) on HT-29 cell proliferation and apoptosis were studied. The results showed that the inhibition rate of the crude EPS produced by L. plantarum-12 on HT-29 cell proliferation was significantly higher than that of the EPS produced by the other three strains. L. plantarum-12 crude EPS (50, 100, 250, 500 μg/ml) exerted inhibitory effects on the expression of proliferating cell nuclear antigen (PCNA) in HT-29 cells in a positive dose-dependent manner. The reactive oxygen species (ROS) level and apoptosis rate were also increased in HT-29 cells treated with different concentrations of L. plantarum-12 crude EPS compared with control cells. Further studies found that the expression of the pro-apoptotic proteins Bax, Cyt C, caspase-3, caspase-8 and caspase-9 was upregulated and that the expression of the anti-apoptosis protein Bcl-2 was decreased in HT-29 cells treated with L. plantarum-12 crude EPS compared with control cells. The results suggested that the EPS produced by L. plantarum-12 could inhibit the proliferation of the human colon cancer cell line HT-29 through the mitochondrial pathway.

Notoginsenoside R1 attenuates sevoflurane-induced neurotoxicity

Background

Sevoflurane, a volatile anesthetic, is known to induce widespread neuronal degeneration and apoptosis. Recently, the stress-inducible protein sestrin 2 and adenosine monophosphate-activated protein kinase (AMPK) have been found to regulate the levels of intracellular reactive oxygen species (ROS) and suppress oxidative stress. Notoginsenoside R1 (NGR1), a saponin isolated from Panax notoginseng, has been shown to exert neuroprotective effects. The effects of NGR1 against neurotoxicity induced by sevoflurane were assessed.

Methods

Sprague-Dawley rat pups on postnatal day 7 (PD7) were exposed to sevoflurane (3%) anesthesia for 6 h. NGR1 at doses of 12.5, 25, or 50 mg/kg body weight was orally administered to pups from PD2 to PD7.

Results

Pretreatment with NGR1 attenuated sevoflurane-induced generation of ROS and reduced apoptotic cell counts. Western blotting revealed decreased cleaved caspase 3 and Bad and Bax pro-apoptotic protein expression. NGR1 substantially upregulated nuclear factor erythroid 2-related factor 2 (Nrf2) expression along with increased heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase-1 levels, suggesting Nrf2 signaling activation. Enhanced sestrin-2 and phosphorylated AMPK expression were noticed following NGR1 pretreatment.

Conclusion

This study revealed the neuroprotective effects of NGR1 through effective suppression of apoptosis and ROS via regulation of apoptotic proteins and activation of Nrf2/HO-1 and sestrin 2/AMPK signaling cascades.

Neuroprotective benefits of grape seed and skin extract in a mouse model of Parkinson's disease

Parkinson's disease is a neurodegenerative disorder characterized by the progressive loss of midbrain dopaminergic (mDA) neurons in the substantia nigra pars compacta, and it involves oxidative stress. Our goal was to evaluate the neuroprotective effect of Vitis vinifera red grape seed and skin extract (GSSE) in a model of Parkinson's disease. GSSE is very rich in phenolic compounds, such as flavonoids, anthocyanins, catechins and stilbenes, which are present in the pulp, seeds, and leaves of the fruit. GSSE is known for its antioxidant properties and has shown beneficial effects against oxidative injury in different organs, such as the kidneys, liver, heart and brain. In this study, we revealed the neuroprotective effect of GSSE on midbrain dopaminergic neurons both in vitro and in vivo. We used the neurotoxin 6-hydroxydopamine (6-OHDA), which induces oxidative damage and mimics the degeneration of dopaminergic neurons observed in Parkinson's disease. We found that GSSE was effective in protecting dopamine neurons from 6-OHDA toxicity by reducing apoptosis, the level of reactive oxygen species (ROS) and inflammation. Furthermore, we found that GSSE treatment efficiently protected against neuronal loss and improved motor function in an in vivo 6-OHDA model of Parkinson's disease (PD). Altogether, our results show that GSSE acts at multiple levels to protect dopamine neurons from degeneration in a model of PD.

Clinical implications of a novel prognostic factor AIFM3 in breast cancer patients

Background

In a time of increasing concerns over personalized and precision treatment in breast cancer (BC), filtering prognostic factors attracts more attention. Apoptosis-Inducing Factor Mitochondrion-associated 3 (AIFM3) is widely expressed in various tissues and aberrantly expressed in several cancers. However, clinical implication of AIFM3 has not been reported in BC. The aim of the study is to investigate the crystal structure, clinical and prognostic implications of AIFM3 in BC.

Methods

AIFM3 expression in 151 BC samples were assessed by immunohistochemistry (IHC). The Cancer Genome Atlas (TCGA) and Kaplan-Meier survival analysis were used to demonstrate expression and survival of AIFM3 signature. Gene Set Enrichment Analysis (GSEA) was performed to investigate the mechanisms related to AIFM3 expression in BC.

Results

AIFM3 was significantly more expressed in breast cancer tissues than in normal tissues. AIFM3 expression had a significant association with tumor size, lymph node metastasis, TNM stage and molecular typing. Higher AIFM3 expression was related to a shorter overall survival (OS) and disease-free survival (DFS). Lymph node metastasis and TNM stage were independent factors of AIFM3 expression. The study presented the crystal structure of AIFM3 successfully and predicted several binding sites when AIFM3 bonded to PTPN12 by Molecular Operating Environment software (MOE).

Conclusions

AIFM3 might be a potential biomarker for predicting prognosis in BC, adding to growing evidence that AIFM3 might interact with PTPN12.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5659-4) contains supplementary material, which is available to authorized users.

Citicoline protects against lead-induced oxidative injury in neuronal PC12 cells

Lead is a major environmental pollutant that causes serious adverse effects on biological systems and cells. In this study, we examined the effect of citicoline on lead-induced apoptosis in PC12 cells. The PC12 cells were pre-treated with citicoline and then exposed to lead for 48 h. The effect of citicoline on cell survival was examined by MTT assay. In addition, levels of lipid peroxidation (LPO), total thiol groups, total antioxidant power (TAP), catalase (CAT), superoxide dismutase (SOD), and reduced glutathione (GSH) were evaluated. The levels of Bax, Bcl-2, and caspase-3 were also measured, by Western blot analysis. Citicoline significantly increased the cell viability of PC12 cells exposed to lead. Treatment of PC12 cells with lead increased LPO levels, and citicoline effectively decreased LPO. Levels of total thiol groups and TAP, CAT, SOD, and GSH were significantly increased in citicoline-treated PC12 cells compared with the lead-treated group. Citicoline pretreatment significantly reduced Bax expression, and increased the level of Bcl-2 expression. Citicoline also reduced caspase-3 activation in PC12 cells compared with the lead-treated group. Our findings indicate that citicoline exerts a neuroprotective effect against lead-induced injury in PC12 cells through mitigation of oxidative stress and, at least in part, through suppression of the mitochondria-mediated apoptotic pathway.

Inhibitory effect of INT-777 on lipopolysaccharide-induced cognitive impairment, neuroinflammation, apoptosis, and synaptic dysfunction in mice

Neuroinflammation plays an important role in the pathophysiology of Alzheimer's disease (AD) and memory impairment. Herein, we evaluated the neuroprotective effects of 6-ethyl-23(S)-methyl-cholic acid (INT-777), a specific G-protein coupled bile acid receptor 1 (TGR5) agonist, in the LPS-treated mouse model of acute neurotoxicity. Single intracerebroventricular (i.c.v.) injection of LPS remarkably induced mouse behavioral impairments in Morris water maze, novel object recognition, and Y-maze avoidance tests, which were ameliorated by INT-777 (1.5 or 3.0 μg/mouse, i.c.v.) treatment. Importantly, INT-777 treatment reversed LPS-induced TGR5 down-regulation, suppressed the increase of nuclear NF-κB p65, and mitigated neuroinflammation, evidenced by lower proinflammatory cytokines, less activation of microglia, and increased the ratio of p-CREB/CREB or mBDNF/proBDNF in the hippocampus and frontal cortex. In addition, INT-777 treatment also suppressed neuronal apoptosis, as indicated by the reduction of TUNEL-positive cells, decreased activation of caspase-3, increased the ratio of Bcl-2/Bax, and ameliorated synaptic dysfunction as evidenced by the upregulation of PSD95 and synaptophysin in the hippocampus and frontal cortex. Taken together, this study showed the potential neuroprotective effects of INT-777 against LPS-induced cognitive impairment, neuroinflammation, apoptosis, and synaptic dysfunction in mice.

Elucidating sex differences in response to cerebral ischemia: immunoregulatory mechanisms and the role of microRNAs

Cerebral ischemia remains a major cause of death and disability worldwide, yet therapeutic options remain limited. Differences in sex and age play an important role in the final outcome in response to cerebral ischemia in both experimental and clinical studies: males have a higher risk and worse outcome than females at younger ages and this trend reverses in older ages. Although the molecular mechanisms underlying sex dimorphism are complex and are still not well understood, studies suggest steroid hormones, sex chromosomes, differential cell death and immune pathways, and sex-specific microRNAs may contribute to the outcome following cerebral ischemia. This review focuses on differential effects between males and females on cell death and immunological pathways in response to cerebral ischemia, the central role of innate sex differences in steroid hormone signaling, and upstreamregulation of sexually dimorphic gene expression by microRNAs.

Deoxyelephantopin ameliorates lipopolysaccharides (LPS)-induced memory impairments in rats: Evidence for its anti-neuroinflammatory properties

AIM

Neuroinflammation is a critical pathogenic mechanism of most neurodegenerative disorders especially, Alzheimer's disease (AD). Lipopolysaccharides (LPS) are known to induce neuroinflammation which is evident from significant upsurge of pro-inflammatory mediators in in vitro BV-2 microglial cells and in vivo animal models. In present study, we investigated anti-neuroinflammatory properties of deoxyelephantopin (DET) isolated from Elephantopus scaber in LPS-induced neuroinflammatory rat model.

MATERIALS AND METHODS

In this study, DET (0.625. 1.25 and 2.5 mg/kg, i.p.) was administered in rats for 21 days and those animals were challenged with single injection of LPS (250 μg/kg, i.p.) for 7 days. Cognitive and behavioral assessment was carried out for 7 days followed by molecular assessment on brain hippocampus. Statistical significance was analyzed with one-way analysis of variance followed by Dunnett's test to compare the treatment groups with the control group.

KEY FINDINGS

DET ameliorated LPS-induced neuroinflammation by suppressing major pro-inflammatory mediators such as iNOS and COX-2. Furthermore, DET enhanced the anti-inflammatory cytokines and concomitantly suppressed the pro-inflammatory cytokines and chemokine production. DET treatment also reversed LPS-induced behavioral and memory deficits and attenuated LPS-induced elevation of the expression of AD markers. DET improved synaptic-functionality via enhancing the activity of pre- and post-synaptic markers, like PSD-95 and SYP. DET also prevented LPS-induced apoptotic neurodegeneration via inhibition of PARP-1, caspase-3 and cleaved caspase-3.

SIGNIFICANCE

Overall, our studies suggest DET can prevent neuroinflammation-associated memory impairment and neurodegeneration and it could be developed as a therapeutic agent for the treatment of neuroinflammation-mediated and neurodegenerative disorders, such as AD.

ALDH7A1 is a protein that protects Atlantic salmon against Aeromonas salmonicida at the early stages of infection

Aldehyde dehydrogenases (ALDHs) belong to a super-family of detoxifying proteins and perform a significant role in developing epithelial homeostasis, protecting cells from toxic aldehydes and drug resistance. However, the activity and function of these detoxifying proteins remain unknown, especially in fish. In our research, we aimed to study functions of aldehyde dehydrogenase 7A1 (ALDH7A1) in Atlantic salmon infected by Aeromonas salmonicida. Recombinant ALDH7A1 (rALDH7A1) was verified by SDS-PAGE and western blot. The molecular mass of the deduced amino acid sequence of rALDH7A1 is 58.9 kDa with an estimated pI of 7.09. Only a low complexity region (¹⁴¹yvegvgevqeyvdv¹⁵³) without a signal peptide existed in rALDH7A1. Results of ELISA indicated that rALDH7A1 exhibited apparent binding activities with A. salmonicida and its expression was highest in fish kidney. A Real-Time PCR (qRT-PCR) assay in kidneys confirmed that fish in this experiment were authentically infected and bacterial loads in rALDH7A1-adminsitered fish were significantly reduced at an early stage of infection. Meanwhile, we found the mRNA expression of NF-kβ, P-38 MAPK, caspase-3 and TNF-α were mainly up-regulated at 72 h in the kidneys and livers of highly infected fish injected with rALDH7A1, and the same variation trend existed in fish spleens at 12 h. Consistent with these observations, neutralization experiments in vivo indicated that rALDH7A1 could obviously reduce the death rate compared to the BSA and control group. Taken together, we concluded that rALDH7A1 could act in host immune defense against bacterial infection and decrease the mortality rate of Atlantic salmon at early stages of infection with A. salmonicida.

Genistein exerts potent antitumour effects alongside anaesthetic, propofol, by suppressing cell proliferation and nuclear factor-κB-mediated signalling and through upregulating microRNA-218 expression in an intracranial rat brain tumour model

Objective

This study was implemented to evaluate the effect of genistein and propofol on intracranial tumour model.

Methods

Male Fischer 344 rats were subjected to intracranial implantation of 9L gliosarcoma cells. Genistein (100 or 200 mg/kg b.wt) was administered orally regularly from 3rd day after implantation to 25th day. Propofol (20 mg/kg; i.p.) was administered once every 5 days till 25th day and was administered 2 h after genistein.

Key findings

Human gliosarcoma cells (U251) exposed to genistein (12.5–200 μg) for 24 h exhibited reduced cell viability as assessed by MTT assay and Hoechst staining. In intracranial tumour model, genistein treatment either with or without administration of propofol significantly reduced tumour volume and extended survival time of tumour-bearing rats. Genistein, either alone or with propofol upregulated pro-apoptotic proteins (Bad and Bax) and miRNA-218 expression and also had induced activation of cleaved caspase-3. Activated NF-κB signalling and overproduction of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) were reduced.

Conclusions

Genistein and propofol effectively inhibited growth of gliosarcoma cells and induced apoptosis. Genistein administration with propofol was found to be more effective than propofol or genistein alone suggesting the positive effects of genistein on propofol-mediated antitumour effects and vice versa.

Protective effects of a green tea polyphenol, epigallocatechin-3-gallate, against sevoflurane-induced neuronal apoptosis involve regulation of CREB/BDNF/TrkB and PI3K/Akt/mTOR signalling pathways in neonatal mice

Epigallocatechin-3-gallate (EGCG), a polyphenol in green tea, is an effective antioxidant and possesses neuroprotective effects. Brain-derived neurotrophic factor (BDNF) and cyclic AMP response element-binding protein (CREB) are crucial for neurogenesis and synaptic plasticity. In this study, we aimed to assess the protective effects of EGCG against sevoflurane-induced neurotoxicity in neonatal mice. Distinct groups of C57BL/6 mice were given EGCG (25, 50, or 75 mg/kg body weight) from postnatal day 3 (P3) to P21 and were subjected to sevoflurane (3%; 6 h) exposure on P7. EGCG significantly inhibited sevoflurane-induced neuroapoptosis as determined by Fluoro-Jade B staining and terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL). Increased levels of cleaved caspase-3, downregulated Bad and Bax, and significantly enhanced Bcl-2, Bcl-xL, xIAP, c-IAP-1, and survivin expression were observed. EGCG induced activation of the PI3K/Akt pathway as evidenced by increased Akt, phospho-Akt, GSK-3β, phospho-GSK-3β, and mTORc1 levels. Sevoflurane-mediated downregulation of cAMP/CREB and BDNF/TrkB signalling was inhibited by EGCG. Reverse transcription PCR analysis revealed enhanced BDNF and TrkB mRNA levels upon EGCG administration. Improved performance of mice in Morris water maze tests suggested enhanced learning and memory. The study indicates that EGCG was able to effectively inhibit sevoflurane-induced neurodegeneration and improve learning and memory retention of mice via activation of CREB/BDNF/TrkB-PI3K/Akt signalling.

Protective effect of a polysaccharide from Anoectochilus roxburghii against carbon tetrachloride-induced acute liver injury in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Anoectochilus roxburghii (Wall.) Lindl. is traditionally used for the treatment of various types of chronic and acute hepatitis in China. Considering that Anoectochilus roxburghii polysaccharide (ARPT) is the main constituent of Anoectochilus roxburghii, the present study was designed to investigate the hepatoprotective effect of ARPT and its possible mechanism in carbon tetrachloride (CCl₄)-induced mice.

MATERIAL AND METHODS

The hepatoprotective activity of ARPT (150, 300 and 500mg/kg) were investigated on CCl₄-induced acute liver damage in mice. The activities of alanine transaminase (ALT), aspartate transaminase (AST) were determined in serum. The hepatic levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) were measured in liver homogenates. The levels of cytochrome P450 sub family 2E1 (CYP2E1), tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-2 (MIP-2), KC (Murine IL-8 ortholog), transforming growth factor-beta1 (TGF-β1), Bcl-2 and Bax were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The expressions of CYP2E1, nuclear factor-kappa B (NF-κB) p65 and caspase-3 were evaluated by western blot assays. The hepatic levels of TNF-α, IL-6, MIP-2 and TGF-β1 were measured by enzyme-linked immunosorbent assay (ELISA). Furthermore, histopathological observation and terminal-deoxynucleoitidyl transferase mediated nick end labeling assay (TUNEL) were carried out on the separated livers of mice.

RESULTS

ARPT significantly decreased serum ALT and AST activities, hepatic MDA level, and markedly enhanced antioxidant enzyme (SOD, CAT and GSH-Px) activities and GSH level in hepatic tissue, in a dose-dependent manner, when compared to the model group. Histopathological observation revealed the hepatoprotective effect of ARPT against the damage. Furthermore, ARPT remarkably inhibited CYP2E1 mRNA expression, decreased NF-κB p65 expression and therefore to prevent the secretion of pro-inflammatory cytokines (TNF-α and IL-6) and chemokines (MCP-1, MIP-2 and KC), suppressed TGF-β1 expression and hepatocytes apoptosis. Moreover, ARPT could prevent DNA fragmentation based on TUNEL assay results.

CONCLUSION

These findings suggested that ARPT possessed hepatoprotective effect against CCl₄-induced hepatotoxicity in mice and the action might in part be through reducing oxidative stress, inflammation and apoptosis.

Gold Rods Irradiated with Ultrasound for Combination of Hyperthermia and Cancer Chemotherapy

PURPOSE

The aim of this study was to analyze feasibility (in vitro and in vivo) the use of hyperthermia produced by gold rods irradiated with ultrasound and their combination with chemotherapy with doxorubicin.

MATERIALS AND METHODS

initially was determined the cell viability and Hsp70 levels after treatment by gold rods irradiated with ultrasound (GR+U) in cell culture. The pretreatment with GR+U combined with doxorubicin (DOX) was evaluated from IC₅₀, caspase-3 expression and mechanisms of cell death by electron microscopy. For evaluate the in vivo effects was used solid Ehrlich carcinoma (SEC) Tumor. The animals received three treatments with the combination of GR+U+DOX over 16 days.

RESULTS

The cell viability was completely inhibited after 40 min of treatment with GR+U and significant increases the expression of HSP70 was only observed after 10 min of treatment. GR+U+DOX presented significant reduction of IC₅₀ representing 50.7%, 76.5% 45.2% and 46.6% for cell lines K562, NCI-H292, Hep-2 and MCF-7 respectively. GR+U+DOX presented significant reduction of IC₅₀ representing 50.7%, 76.5% 45.2% and 46.6% for cell lines K562, NCI-H292, Hep-2 and MCF-7 respectively. The caspase-3 level and ultraestructural analysis showed that treatment with GR+U+DOX enhances induction of apoptosis. Pretreatment with GR+U combined with doxorubicin (1 mg) showed 87% inhibition against SEC. and no showed cardiotoxic effect.

CONCLUSIONS

The combined treatment of GR+U and DOX exhibit synergistic characteristics observed by increasing the efficiency of doxorubicin.

Multi-level structure-based pharmacophore modelling of caspase-3-non-peptide complexes: Extracting essential pharmacophore features and its application to virtual screening

Enormous caspase-3-non-peptide crystal structures have been developed to study the structural basis of caspase-3 enzyme inhibition using active site directed small molecular design. These complexes have not been explored thoroughly to decipher the essential non-covalent interactions made by crystal ligands. We present here a multi-level analysis of these caspase-3 complexes using structure-based pharmacophore approach wherein numerous candidate pharmacophore hypotheses were assessed for its ability to cover available caspase-3 small molecular inhibitor dataset. The reliability of the resultant pharmacophores was evaluated using three different validation sets comprising focussed caspase-3 inhibitors, focussed + random decoys, and focussed + structurally similar random decoys and its performance was measured by the Güner-Henry (GH) scoring and enrichment statistics. Furthermore, the effect on excluded volumes toward caspase-3 inhibitors mapping was investigated by an iterative deletion in the structure-based models and created optimal structure-based pharmacophore models to enable effective design of caspase-3 small molecular inhibitor design.

Osmotin attenuates LPS-induced neuroinflammation and memory impairments via the TLR4/NFκB signaling pathway

Toll-like receptor 4 (TLR4) signaling in the brain mediates autoimmune responses and induces neuroinflammation that results in neurodegenerative diseases, such as Alzheimer’s disease (AD). The plant hormone osmotin inhibited lipopolysaccharide (LPS)-induced TLR4 downstream signaling, including activation of TLR4, CD14, IKKα/β, and NFκB, and the release of inflammatory mediators, such as COX-2, TNF-α, iNOS, and IL-1β. Immunoprecipitation demonstrated colocalization of TLR4 and AdipoR1 receptors in BV2 microglial cells, which suggests that osmotin binds to AdipoR1 and inhibits downstream TLR4 signaling. Furthermore, osmotin treatment reversed LPS-induced behavioral and memory disturbances and attenuated LPS-induced increases in the expression of AD markers, such as Aβ, APP, BACE-1, and p-Tau. Osmotin improved synaptic functionality via enhancing the activity of pre- and post-synaptic markers, like PSD-95, SNAP-25, and syntaxin-1. Osmotin also prevented LPS-induced apoptotic neurodegeneration via inhibition of PARP-1 and caspase-3. Overall, our studies demonstrated that osmotin prevented neuroinflammation-associated memory impairment and neurodegeneration and suggest AdipoR1 as a therapeutic target for the treatment of neuroinflammation and neurological disorders, such as AD.

Remote Limb Preconditioning Generates a Neuroprotective Effect by Modulating the Extrinsic Apoptotic Pathway and TRAIL-Receptors Expression

As remote limb preconditioning (RPC) ameliorates brain damage after ischemic cerebral stroke (ICS), the purpose of the present study was to explore the molecular mechanisms in the course of RPC. Results of TUNEL staining and cleaved caspase-3 expression showed that ischemia-induced neuronal apoptosis was inhibited by RPC. The expression changes in cleaved caspase-8, cFLIP, Bid itself, and its truncated form represented that RPC suppressed the activation of extrinsic apoptotic pathway during ICS. Then, the level of cytoplasmic cytochrome c was also decreased by RPC. In addition, RPC might partially suppress TNF-related apoptosis-inducing ligand (TRAIL)-induced extrinsic apoptosis through downregulation of TRAIL death receptors and upregulation of TRAIL decoy receptors. As a counterproof, immunoneutralization of TRAIL in dMCAO rats resulted in significant restraint of tissue damage and in a marked functional recovery. Our data complemented the knowledge of RPC neuroprotective mechanism and provided new evidence for its clinical application.

Inhibition of A2780 Human Ovarian Carcinoma Cell Proliferation by a Rubus Component, Sanguiin H-6

The effects of a red raspberry component, sanguiin H-6 (SH-6), on the induction of apoptosis and the related signaling pathways in A2780 human ovarian carcinoma cells were investigated. SH-6 caused an antiproliferative effect and a severe morphological change resembling that of apoptotic cell death but no effect on the cancer cell cycle arrest. In addition, SH-6 induced an early apoptotic effect and activation of caspases as well as the cleavage of PARP, which is a hallmark of apoptosis. The early apoptotic percentages of A2780 cells exposed to 20 and 40 μM SH-6 were 35.39 and 41.76, respectively. Also, SH-6 caused the activation of mitogen-activated protein kinases (MAPKs), especially p38, and the increase of truncated p15/BID. These results in the present study suggest that the apoptosis of A2780 human ovarian carcinoma cells by SH-6 is mediated by the MAPK p38 and a caspase-8-dependent BID cleavage pathway.

Pre-treatment with a Xingnaojing preparation ameliorates sevoflurane-induced neuroapoptosis in the infant rat striatum

Xingnaojing (XNJ), is a standardized Chinese herbal medicine product derived from An Gong Niu Huang Pill. It may be involved in neuroprotection in a number of neurological disorders. Exposure to anesthetic agents during the brain growth spurt may trigger widespread neuroapoptosis in the developing brain. Thus the present study aimed to identify whether there was a neuroprotective effect of XNJ on anesthesia-induced neuroapoptosis. Seven-day-old rats received treatment with 2.1% sevoflurane for 6 h. Rat pups were injected intraperitoneally with 1 or 10 ml/kg XNJ at 0.2, 24 and 48 h prior to sevoflurane exposure. The striata of neonatal rats were collected following administration of anesthesia. Western blotting and immunohistochemistry were used to analyze the expression of activated caspase 3, Bax and phosphorylated protein kinase B (p-AKT) in the striatum. It was found that activated caspase 3 and Bax expression were upregulated in the striatum following sevoflurane treatment. Preconditioning with XNJ attenuated the neuronal apoptosis induced by sevoflurane in a dose-dependent manner. Anesthesia reduced the expression of p-AKT (phosphorylated at sites Thr308 and Ser473) and phosphorylated extracellular-regulated protein kinase (p-ERK) in the striatum. Pre-treatment with XNJ reversed the reduction in p-AKT, but not p-ERK expression. These data suggest that XNJ has an antiapoptotic effect against sevoflurane-induced cell loss in the striatum. It thus holds promise as a safe and effective neuroprotective agent. The action of XNJ on p-AKT may make a significant contribution to its neuroprotective effect.

Anthraquinone G503 induces apoptosis in gastric cancer cells through the mitochondrial pathway

G503 is an anthraquinone compound isolated from the secondary metabolites of a mangrove endophytic fungus from the South China Sea. The present study elucidates the anti-tumor activity and the underlying mechanism of G503. Cell viability assay performed in nine cancer cell lines and two normal cell lines demonstrated that the gastric cancer cell line SGC7901 is the most G503-sensitive cancer cells. G503 induced SGC7901 cell death via apoptosis. G503 exposure activated caspases-3, -8 and -9. Pretreatment with the pan-caspase inhibitor Z-VAD-FMK and caspase-9 inhibitor Z-LEHD-FMK, but not caspase-8 inbibitor Z-IETD-FMK, attenuated the effect of G503. These results suggested that the intrinsic mitochondrial apoptosis pathway, rather than the extrinsic pathway, was involved in G503-induced apoptosis. Furthermore, G503 increased the ratio of Bax to Bcl-2 in the mitochondria and decreased the ratio in the cytosol. G503 treatment resulted in mitochondrial depolarization, cytochrome c release and the subsequent cleavage of caspase -9 and -3. Moreover, it is reported that the endoplasmic reticulum apoptosis pathway may also be activated by G503 by inducing capase-4 cleavage. In consideration of the lower 50% inhibitory concentration for gastric cancer cells, G503 may serve as a promising candidate for gastric cancer chemotherapy.

Effects of grape seed proanthocyanidin extract on pentylenetetrazole-induced kindling and associated cognitive impairment in rats

Numerous studies have demonstrated the antioxidant effects of grape seed proanthocyanidin extract (GSPE). The generation of free radicals and the ensuing apoptosis may contribute to the pathogenesis of epilepsy; therefore, in the present study, we examined the effects of GSPE on cognitive impairment and neuronal damage induced by chronic seizures in rats. Seizures were induced by a daily intraperitoneal (i.p.) injection of pentylenetetrazole (PTZ; 35 mg/kg/day, 36 days). Two other groups were treated with GSPE (100 or 200 mg/kg/day, orally) for 24 days and then for 36 days prior to each PTZ injection. After the final PTZ injection, hippocampus-dependent spatial learning was assessed using the Morris water maze (MWM). The rats were then sacrificed for the measurement of hippocampal malondialdehyde (MDA, a measure of lipid peroxidation) and glutathione (GSH, a measure of endogenous antioxidant capacity) levels, and for the expression of pro-apoptotic factors [cytochrome c (Cyt c), caspase‑9 and caspase‑3]. The mitochondrial generation of reactive oxygen species (ROS), degree of mitochondrial swelling, neuronal damage and mitochondrial ultrastructure were also examined. Performance in the MWM was markedly impaired by PTZ-induced seizures, as evidenced by longer escape latencies during training and fewer platform crossings during the probe trial. This cognitive decline was accompanied by oxidative stress (MDA accumulation, ROS generation, reduced GSH activity), an increased expression of pro-apoptotic proteins, as well as damage to CA1 pyramidal neurons and the mitochondria. Pre-treatment with GSPE dose‑dependently reversed PTZ-induced impaired performance in the MWM, oxidative stress, mitochondrial ROS generation, the expression of pro-apoptotic proteins and neuronal and mitochondrial damage. Thus, GSPE may reverse the hippocampal dysfunction induced by chronic seizures, by reducing oxidative stress and preserving mitochondrial function.

Apomorphine attenuates ethanol-induced neurodegeneration in the adult rat cortex

Apomorphine, therapeutically used for Parkinson's disease, is a dopamine D1/D2 receptor agonist that has been determined to be a potent antioxidant and to prevent the reaction of free radicals in the brain. Alcohol is a neurotoxic agent that induces neurodegeneration possibly through the generation of free radicals. In this study, we investigated the antioxidant potential of apomorphine upon ethanol-induced neurodegeneration in the cortex of adult rats. Ethanol-induced apoptotic neurodegeneration was measured via the suppression of Bcl-2, the induction of Bax, the release of cytochrome C and the activation of caspase-9 and caspase-3. Moreover, ethanol-induced elevated levels of cleaved PARP-1 indicated exaggerated neuronal DNA damage. Our results demonstrated the neuroprotective effect of apomorphine by reversing the ethanol-induced apoptotic trend as observed by the increased expression of Bcl-2, down regulation of Bax, inhibition of mitochondrial cytochrome C release and inhibition of activated caspase-9 and caspase-3. Moreover, apomorphine treatment further decreased the expression of cleaved PARP-1 to reveal a reduction in ethanol-induced neuronal damage. Immunohistochemical analysis and Nissl staining also revealed neuroprotective effect of apomorphine after ethanol-induced neuronal cell death. In this study, our results indicated that apomorphine at doses of 1 and 5mg/kg has neuroprotective effects for ethanol-induced neuronal damage. Finally, we can conclude that apomorphine has effective therapeutic potential to protect the brain against ethanol-induced neurotoxicity.

Gene expression of pro- and anti-apoptotic proteins in rock bream (Oplegnathus fasciatus) infected with megalocytivirus (family Iridoviridae)

Viruses belonging to the genus Megalocytivirus cause diseases in marine fishes primarily in East and Southeast Asian countries. Rock bream iridovirus (RBIV), which is a member of the Megalocytivirus genus, causes severe mass mortalities in rock beam (Oplegnathus fasciatus) in Korea. In this study, we assessed apoptosis-related gene expression patterns in Megalocytivirus-infected rock bream in high mortality and low mortality conditions to determine important apoptosis-related factors, which may affect fish survival/or death. In the high mortality group (100% mortality at 15 dpi), significantly high levels of perforin, granzyme, Fas ligand and caspase 9 expression (5.6-, 10.2-, 13.4- and 4.2-fold, respectively) were observed in the kidney at 8 dpi. Basal expression levels of Fas and caspase 3 were observed at 8 d (1.5-/0.7-fold) and 10 dpi (1.3-/0.6-fold), accompanied by heavy viral loads (8.12 × 10(6)-2.21 × 10(7)/μl). Inhibitor of apoptosis 1 (IAP1) was highly expressed (3.5- to 4.8-fold) at 1 d and 4 dpi; however, IAP1 was reduced when fish died at 8 d and 10 dpi (1.7- to 2.0-fold), which was not significantly different from that of the control group. A similar expression pattern was observed in the low mortality group (18% expected mortality at 30 dpi), which was characterised by a delayed lower magnitude of expression with lower viral loads than the high mortality group. Perforin, granzyme and Fas ligand expression was significantly higher in the low mortality group than in the control group at several sampling points until 30 dpi. Fas and caspases 8, 9 and 3 expression levels showed no statistical significance until 30 dpi. In the low mortality group, significantly higher IAP1 expression compared with the control was observed at 10 d (2.2-fold), 20 d (3.6-fold) and 22 dpi (2.0-fold). In summary, perforin- and granzyme-related apoptosis initiation signals were activated; however, the Fas-induced apoptosis pathway did not efficiently respond. Upregulated IAP1 in RBIV-infected rock bream, which was reported for the first time in this study, exhibited inhibited apoptotic responses in RBIV-infected fish. Although it remains unclear whether apoptosis inhibition aids or impedes fish survival, our data clearly show that the apoptotic response is inhibited in RBIV-infected rock bream.

Total alkaloids of Tripterygium hypoglaucum (levl.) Hutch inhibits tumor growth both in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Tripterygium hypoglaucum (levl.) Hutch (Celastraceae) (THH) root is a traditional Chinese medicinal herb commonly used for treating autoimmune diseases and cancer. Alkaloid is one of the most bioactive components of THH extract. To evaluate the in vitro and in vivo antitumor properties of the total alkaloids of THH (THHta).

MATERIALS AND METHODS

THHta was extracted in pilot-scale. HCT116 cells were chose to establish human colon cancer xenograft model. The in vitro anti-tumor activity of THHta was tested by Cell malignant transformation test, Soft agar colony formation assay and MTT assay. The in vivo anti-tumor effect of THHta was confirmed by xenograft mouse model. THHta-induced apoptosis was examined by flow cytometry. The levels of apoptosis-related proteins were investigated by Western blot.

RESULTS

TPA-induced cell transformation was significantly inhibited by THHta in JB6 Cl41 cells. THHta inhibits the growth of colon cancer cells in vitro in a significant dose-dependent manner. Compared to the control set, i.p. administration of THHta to xenograft mice significantly reduced both tumor weight and volume. Apoptosis induction of THHta was mediated by activation of caspase-3, PARP and inhibiting of Bcl-2, Bcl-xL and XIAP.

CONCLUSION

THHta was effective in inhibiting tumor growth both in vitro and in vivo at less toxic concentrations by inducing apoptosis which suggested it could be developed as a potential anticancer agent.

Inhibitory effects of caspase inhibitors on the activity of matrix metalloproteinase-2

Matrix metalloproteinase (MMP)-2, a zinc-dependent endopeptidase, plays a detrimental role in several diseases including ischemia and reperfusion (I/R) injury of the heart. Caspases are a group of cysteine-dependent, aspartate-directed proteases which regulate cellular apoptosis. Interestingly, protective effects of caspase inhibitors independent of apoptosis have been shown in I/R injury of the heart. The cardioprotective actions of both these classes of protease inhibitors led us to hypothesize that caspase inhibitors may also reduce MMP-2 activity. Five known caspase inhibitors (Z-IE(OMe)TD(OMe)-fmk, Ac-DEVD-CHO, Ac-LEHD-cmk, Z-VAD-fmk and Ac-YVAD-cmk) were tested for their possible inhibitory effects on MMP-2 activity in comparison to the MMP inhibitors ONO-4817 and ARP-100 (which themselves were unable to inhibit caspase-3 activity). MMP-2 activity was assessed by an in vitro troponin I (TnI) proteolysis assay and a quantitative kinetic fluorescence assay using a fluorogenic peptide substrate (OmniMMP). TnI proteolysis was also measured by western blot in neonatal cardiomyocytes subjected to hypoxia-reoxygenation injury. Using human recombinant MMP-2 and TnI as its substrate, the caspase inhibitors, in comparison with ONO-4817, significantly inhibited MMP-2-mediated TnI degradation in a concentration-dependent manner. The kinetic assay using OmniMMP revealed that these caspase inhibitors blocked MMP-2 activity in a concentration-dependent manner with similar IC50 values. TnI degradation in neonatal cardiomyocytes was enhanced following hypoxia-reoxygenation and this was blocked by ARP-100 and Ac-LEHD-cmk. Inhibition of MMP-2 activity is an additional pharmacological action which contributes to the protective effects of some caspase inhibitors.

Protein tyrosine phosphatases in cancer: friends and foes!

Tyrosine phosphorylation of proteins serves as an exquisite switch in controlling several key oncogenic signaling pathways involved in cell proliferation, apoptosis, migration, and invasion. Since protein tyrosine phosphatases (PTPs) counteract protein kinases by removing phosphate moieties on target proteins, one may intuitively think that PTPs would act as tumor suppressors. Indeed, one of the most described PTPs, namely, the phosphatase and tensin homolog (PTEN), is a tumor suppressor. However, a growing body of evidence suggests that PTPs can also function as potent oncoproteins. In this chapter, we provide a broad historical overview of the PTPs, their mechanism of action, and posttranslational modifications. Then, we focus on the dual properties of classical PTPs (receptor and nonreceptor) and dual-specificity phosphatases in cancer and summarize the current knowledge of the signaling pathways regulated by key PTPs in human cancer. In conclusion, we present our perspective on the potential of these PTPs to serve as therapeutic targets in cancer.

The HIV-1 transactivator factor (Tat) induces enterocyte apoptosis through a redox-mediated mechanism

The intestinal mucosa is an important target of human immunodeficiency virus (HIV) infection. HIV virus induces CD4+ T cell loss and epithelial damage which results in increased intestinal permeability. The mechanisms involved in nutrient malabsorption and alterations of intestinal mucosal architecture are unknown. We previously demonstrated that HIV-1 transactivator factor (Tat) induces an enterotoxic effect on intestinal epithelial cells that could be responsible for HIV-associated diarrhea. Since oxidative stress is implicated in the pathogenesis and morbidity of HIV infection, we evaluated whether Tat induces apoptosis of human enterocytes through oxidative stress, and whether the antioxidant N-acetylcysteine (NAC) could prevent it. Caco-2 and HT29 cells or human intestinal mucosa specimens were exposed to Tat alone or combined with NAC. In an in-vitro cell model, Tat increased the generation of reactive oxygen species and decreased antioxidant defenses as judged by a reduction in catalase activity and a reduced (GSH)/oxidized (GSSG) glutathione ratio. Tat also induced cytochrome c release from mitochondria to cytosol, and caspase-3 activation. Rectal dialysis samples from HIV-infected patients were positive for the oxidative stress marker 8-hydroxy-2'-deoxyguanosine. GSH/GSSG imbalance and apoptosis occurred in jejunal specimens from HIV-positive patients at baseline and from HIV-negative specimens exposed to Tat. Experiments with neutralizing anti-Tat antibodies showed that these effects were direct and specific. Pre-treatment with NAC prevented Tat-induced apoptosis and restored the glutathione balance in both the in-vitro and the ex-vivo model. These findings indicate that oxidative stress is one of the mechanism involved in HIV-intestinal disease.

Generation of a reference transcriptome for evaluating rainbow trout responses to various stressors

Background

Fish under intensive culture conditions are exposed to a variety of acute and chronic stressors, including high rearing densities, sub-optimal water quality, and severe thermal fluctuations. Such stressors are inherent in aquaculture production and can induce physiological responses with adverse effects on traits important to producers and consumers, including those associated with growth, nutrition, reproduction, immune response, and fillet quality. Understanding and monitoring the biological mechanisms underlying stress responses will facilitate alleviating their negative effects through selective breeding and changes in management practices, resulting in improved animal welfare and production efficiency.

Results

Physiological responses to five treatments associated with stress were characterized by measuring plasma lysozyme activity, glucose, lactate, chloride, and cortisol concentrations, in addition to stress-associated transcripts by quantitative PCR. Results indicate that the fish had significant stressor-specific changes in their physiological conditions. Sequencing of a pooled normalized transcriptome library created from gill, brain, liver, spleen, kidney and muscle RNA of control and stressed fish produced 3,160,306 expressed sequence tags which were assembled and annotated. SNP discovery resulted in identification of ~58,000 putative single nucleotide polymorphisms including 24,479 which were predicted to fall within exons. Of these, 4907 were predicted to occupy the first position of a codon and 4110 the second, increasing the probability to impact amino acid sequence variation and potentially gene function.

Conclusion

We have generated and characterized a reference transcriptome for rainbow trout that represents multiple tissues responding to multiple stressors common to aquaculture production environments. This resource compliments existing public transcriptome data and will facilitate approaches aiming to evaluate gene expression associated with stress in this species.

Protective function of nicotinamide against ketamine-induced apoptotic neurodegeneration in the infant rat brain

During development, anesthetics activate neuroapoptosis and produce damage in the central nervous system that leads to several types of neurological disorders. A single dose of ketamine (40 mg/kg) during synaptogenesis in a 7-day-old rat brain activated the apoptotic cascade and caused extensive neuronal cell death in the forebrain. In this study, we investigated the protective effect of nicotinamide against ketamine-induced apoptotic neurodegeneration. After 4 h, neuronal cell death induced by ketamine was associated with the induction of Bax, release of cytochrome c into the cytosol, and activation of caspase-3. One single dose of 1 mg/g nicotinamide was administered to a developing rat and was found to inhibit ketamine-induced neuroapoptosis by downregulating Bax, inhibiting cytochrome c release from mitochondria into cytosol, and inhibiting the expression of activated caspase-3. TUNEL and immunohistochemical analyses showed that ketamine-induced cell death occurred through apoptosis and that it was inhibited by nicotinamide. Fluoro-Jade-B staining demonstrated an increased number of dead cells in the cortex and thalamus after ketamine treatment; treatment with nicotinamide reduced the number of dead cells in these brain regions. Our findings suggest that nicotinamide attenuated ketamine-induced neuronal cell loss in the developing rat brain and is a promising therapeutic and neuroprotective agent for the treatment of neurodevelopmental disorders.

Nicotinamide inhibits alkylating agent-induced apoptotic neurodegeneration in the developing rat brain

BACKGROUND

Exposure to the chemotherapeutic alkylating agent thiotepa during brain development leads to neurological complications arising from neurodegeneration and irreversible damage to the developing central nerve system (CNS). Administration of single dose of thiotepa in 7-d postnatal (P7) rat triggers activation of apoptotic cascade and widespread neuronal death. The present study was aimed to elucidate whether nicotinamide may prevent thiotepa-induced neurodegeneration in the developing rat brain.

METHODOLOGY/PRINCIPAL FINDINGS

Neuronal cell death induced by thiotepa was associated with the induction of Bax, release of cytochrome-c from mitochondria into the cytosol, activation of caspase-3 and cleavage of poly (ADP-ribose) polymerase (PARP-1). Post-treatment of developing rats with nicotinamide suppressed thiotepa-induced upregulation of Bax, reduced cytochrome-c release into the cytosol and reduced expression of activated caspase-3 and cleavage of PARP-1. Cresyl violet staining showed numerous dead cells in the cortex hippocampus and thalamus; post-treatment with nicotinamide reduced the number of dead cells in these brain regions. Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) and immunohistochemical analysis of caspase-3 show that thiotepa-induced cell death is apoptotic and that it is inhibited by nicotinamide treatment.

CONCLUSION

Nicotinamide (Nic) treatment with thiotepa significantly improved neuronal survival and alleviated neuronal cell death in the developing rat. These data demonstrate that nicotinamide shows promise as a therapeutic and neuroprotective agent for the treatment of neurodegenerative disorders in newborns and infants.

A role for caveolin-1 in desmoglein binding and desmosome dynamics

Desmoglein-2 (Dsg2) is a desmosomal cadherin that is aberrantly expressed in human skin carcinomas. In addition to its well-known role in mediating intercellular desmosomal adhesion, Dsg2 regulates mitogenic signaling that may promote cancer development and progression. However, the mechanisms by which Dsg2 activates these signaling pathways and the relative contribution of its signaling and adhesion functions in tumor progression are poorly understood. In this study we show that Dsg2 associates with caveolin-1 (Cav-1), the major protein of specialized membrane microdomains called caveolae, which functions in both membrane protein turnover and intracellular signaling. Sequence analysis revealed that Dsg2 contains a putative Cav-1-binding motif. A permeable competing peptide resembling the Cav-1 scaffolding domain bound to Dsg2, disrupted normal Dsg2 staining and interfered with the integrity of epithelial sheets in vitro. Additionally, we observed that Dsg2 is proteolytically processed; resulting in a 95-kDa ectodomain shed product and a 65-kDa membrane-spanning fragment, the latter of which localizes to lipid rafts along with full-length Dsg2. Disruption of lipid rafts shifted Dsg2 to the non-raft fractions, leading to the accumulation of these proteins. Interestingly, Dsg2 proteolytic products are elevated in vivo in skin tumors from transgenic mice overexpressing Dsg2. Collectively, these data are consistent with the possibility that accumulation of truncated Dsg2 protein interferes with desmosome assembly and/or maintenance to disrupt cell-cell adhesion. Furthermore, the association of Dsg2 with Cav-1 may provide a mechanism for regulating mitogenic signaling and modulating the cell-surface presentation of an important adhesion molecule, both of which could contribute to malignant transformation and tumor progression.

Mitochondria-mediated apoptosis in patients with adenocarcinoma of the breast: Correlation with histological grade and menopausal status

The present study was designed to investigate the abnormalities in the expression of apoptosis-associated proteins that lead to the progression of breast cancer. Sixty breast cancer patients histologically categorized as grade I, II and III, and as pre- and post-menopausal were chosen for the study. We analyzed the expression of the anti-apoptotic and pro-apoptotic Bcl-2 family proteins as well as cytochrome C, Apaf-1 and caspases in tumour and adjacent tissues by immunohistochemical and Western blot analyses. The breast tumours analyzed in the present study were characterized by increased expression of Bcl-2, Bcl-xL and Mcl-1, associated with downregulation in the expression of Bax, cytosolic cytochrome C, Apaf-1 and caspases. The magnitude of the changes was however more pronounced in premenopausal patients and in grade III tumours. The results of the present study confirm that differential expression patterns of Bcl-2 family proteins and caspases are involved in evasion of apoptosis and in the progression of breast cancer.

Hyperbaric oxygen preconditioning promotes survival of retinal ganglion cells in a rat model of optic nerve crush

In this study we tested the hypothesis that hyperbaric oxygen preconditioning (HBO-PC) reduces retinal neuronal death due to optic nerve crush (ONC). Adult male Sprague-Dawley rats were subjected to ONC accompanied by a contralateral sham operation. HBO-PC was conducted four times by giving 100% oxygen at 2.5 atmospheres absolute (ATA) for 1 h every 12 h for 2 days prior to ONC. The rats were euthanized at 1 or 2 weeks after ONC. Retinal ganglion cell (RGC) density was counted by hematoxylin and eosin (H&E) staining of the retina and retrograde labeling with FluoroGold application to the superior colliculus. Visual function was assessed by flash visual evoked potentials (FVEP). TUNEL straining and caspase-3 and caspase-9 activity in the retinas were assessed. The RGC density in the retinas of ONC HBO-PC-treated rats was significantly higher than that of the corresponding ONC-only rats (the survival rate was 67.2% versus 49.7% by H&E staining, and 60.3% versus 28.9% by retrograde labeling with FluoroGold, respectively; p < 0.01) at 2 weeks after ONC. FVEP measurements indicated a significantly better preserved latency and amplitude of the P1 wave in the ONC HBO-PC-treated rats than the ONC-only rats (92 +/- 7 msec, 21 +/- 3 microv in the sham-operated group, 117 +/- 12 msec, 14 +/- 2 microv in the HBO-PC-treated group, and 169 +/- 15 msec, 7 +/- 1 microv in the corresponding ONC group; p < 0.01). TUNEL assays showed fewer apoptotic cells in the HBO-PC-treated group, accompanied by the suppression of caspase-3 and caspase-9 activity. These results demonstrate that HBO-PC appears to be neuroprotective against ONC insult via inhibition of neuronal apoptosis pathways.

Impact of a single intracoronary administration of adiponectin on myocardial ischemia/reperfusion injury in a pig model

BACKGROUND

Adiponectin plays a protective role in the development of obesity-linked disorders. We demonstrated that adiponectin exerts beneficial actions on acute ischemic injury in mice hearts. However, the effects of adiponectin treatment in large animals and its feasibility in clinical practice have not been investigated. This study investigated the effects of intracoronary administration of adiponectin on myocardial ischemia-reperfusion (I/R) injury in pigs.

METHODS AND RESULTS

The left anterior descending coronary artery was occluded in pigs for 45 minutes and then reperfused for 24 hours. Recombinant adiponectin protein was given as a bolus intracoronary injection during ischemia. Cardiac functional parameters were measured by a manometer-tipped catheter. Apoptosis was evaluated by terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling staining. Tumor necrosis factor-alpha and interleukin-10 transcripts were analyzed by real-time polymerase chain reaction. Serum levels of derivatives of reactive oxygen metabolites and biological antioxidant potential were measured. Adiponectin protein was determined by immunohistochemical and Western blot analyses. Intracoronary administration of adiponectin protein led to a reduction in myocardial infarct size and improvement of left ventricular function in pigs after I/R. Injected adiponectin protein accumulated in the I/R-injured heart. Adiponectin treatment resulted in decreased tumor necrosis factor-alpha and increased interleukin-10 mRNA levels in the myocardium after I/R. Adiponectin-treated pigs had reduced apoptotic activity in the I/R-injured heart and showed increased biological antioxidant potential levels and decreased derivatives of reactive oxygen metabolite levels in the blood stream after I/R.

CONCLUSIONS

These data suggest that adiponectin protects against I/R injury in a preclinical pig model through its ability to suppress inflammation, apoptosis, and oxidative stress. Administration of intracoronary adiponectin could be a useful adjunctive therapy for acute myocardial infarction.

Programmed cell death of tobacco BY-2 cells induced by still culture conditions is affected by the age of the culture under agitation

Evans Blue staining indicated that actively growing tobacco BY-2 cells in the exponential phase died more rapidly than quiescent cells in the stationary phase when the cells cultured under agitation were placed under still conditions. Fifty percent cell death was induced at about 18, 26, 80 and 140 h for early, mid, late exponential- and stationary-phase cells, respectively. Actively growing cells became TUNEL (transferase-mediated dUTP nick end labelling)-positive more rapidly than quiescent cells, suggesting that the cell death evaluated by Evans Blue is accompanied by DNA cleavages. Electrophoresis of genomic DNA showed a typical 'DNA laddering' pattern formed by multiples of about 200 bp internucleosomal units. Chromatin condensation was first detected at least within 24 h by light microscopy, and then cell shrinkage followed. These findings suggest that the death of BY-2 cells induced by still conditions is PCD (programmed cell death).

Expression of X-linked inhibitor of apoptosis protein in human prostate cancer specimens with and without neo-adjuvant hormonal therapy

PURPOSE

X-linked inhibitor of apoptosis (XIAP) has high affinity and strong inhibitory activity on apoptosis-related caspase-3. The relationships between expression of XIAP and cleaved caspase-3, and response to neo-adjuvant hormonal therapy (NHT) remain elusive. The aim was to investigate whether NHT influences with XIAP expression in prostate cancer patients. In addition, the relationship between XIAP expression and apoptosis in patients who did or did not receive NHT was also investigated.

METHODS

Eighty-three patients who had undergone radical prostatectomy were examined retrospectively and divided into NHT group (n = 40) and non-NHT group (n = 43). Immunohistochemistry was used to analyze the expressions of XIAP and cleaved caspase-3. The apoptotic cells reconfirmed the number of terminal deoxynucleotidyl transferase-mediated nick and labeling (TUNEL)-positive cells.

RESULTS

In the non-NHT group, the proportion of TUNEL-positive cells correlated with expression of cleaved caspase-3 (r = 0.592, P < 0.001), and the expression of XIAP correlated negatively with that of cleaved caspase-3 and TUNEL-positive cells (r = -0.464, P < 0.001 and r = 0.431, P = 0.002, respectively). The expression of cleaved caspase-3, but not that of XIAP, was higher in NHT group than non-NHT group (P = 0.017). In the NHT group, there was no significant correlation between XIAP expression and cleaved caspase-3 expression or the proportion of TUNEL-positive cells.

CONCLUSIONS

NHT did not influence XIAP expression. We speculate that the inhibition of XIAP expression may reinforce the apoptotic effect of NHT and improve the prognosis in patients with prostate cancer.

Studies of the molecular mechanism of caspase-8 activation by solution NMR

Caspases are the key players of apoptosis and inflammation. They are present in the cells as latent precursors, procaspases, and are activated upon an apoptotic or inflammatory stimulus. The activation mechanism of caspases has been studied extensively by biochemical and biophysical methods. Additional structural information on active caspases with a variety of different inhibitors bound at the active site is available. In this study, we investigated the cleavage mechanism of caspase-8 from its zymogen to active caspase-8 by solution NMR and by biochemical methods. The intermolecular cleavage reaction using the catalytically inactive C285A procaspase-8 mutant is triggered by adding caspase-8 and followed by (15)N,(1)H-NMR spectroscopy. The spectrum that initially resembles the one of procaspase-8 gradually over time changes to that of caspase-8, and disappearing peaks display exponential decaying intensities. Removal of either one of the cleavage recognition motifs in the linker, or phosphorylation at Tyr380, is shown to reduce the rate of the cleavage reaction. The data suggest that dimerization repositions the linker to become suitable for intermolecular processing by the associated protomer. Furthermore, analysis of inhibitor binding to the active caspase-8 reveals an induced-fit mechanism for substrate binding.

Characteristics of dengue virus-infected peripheral blood mononuclear cell death that correlates with the severity of illness

The pathogenic mechanism of the severe form of dengue is complicated. Recent reports indicate that apoptotic death of various tissues or organs may be associated with vascular leakage, and ultimately leads to the death of DENV-infected patients. In the present study, we provide additional evidence supporting the detrimental role of apoptosis in DENV infection. A comparison of the rate of apoptosis in PBMCs isolated from patients suffering DF, a mild form of the disease, and the rate in patients with DHF, a life-threatening disease, revealed that PBMCs from DHF patients underwent apoptosis at a significantly higher rate than those suffering from DF alone. This suggests that the severity of natural DENV infection correlates with PBMC apoptosis. In addition, this cell death was induced not only by DENV itself, but also by the apoptotic activities of pro-inflammatory cytokines, such as TNF-alpha, and IL-1beta, that were upregulated in DHF patients. The death of these mononuclear cells that function in an innate immune system may explain the higher viral load in DHF patients than in DF patients. Interestingly, a gene expression profile pattern elucidated that apoptosis occurring during natural DENV infection involved mainly the extrinsic apoptosis pathway, which is mediated via both caspase-dependent and caspase-independent mechanisms. In conclusion, our data highlight the adverse effect of apoptosis induced by DENV and by pro-inflammatory cytokines during natural DENV infection.