Programmed cell death

Quercetin mitigates memory deficits in scopolamine mice model via protection against neuroinflammation and neurodegeneration

AIMS

Neurodegenerative disorders like Alzheimer's disease (AD) are outcomes of neuroinflammatory processes that result in memory impairment. Quercetin (QT), a plant based flavonoid, has demonstrated notable effects against neurodegeneration and inflammation in models of dementia. However, the underlying mechanisms have not been well elucidated. This study evaluated the possible effects of QT against neuroinflammation and neurodegeneration in scopolamine (SC) induced memory impairment.

MAIN METHODS

SC was used to induce memory loss in mice after which novel object recognition test (NORT) was used to assess memory function. Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in the brain tissues of the animals. Brain histology was carried out on the hippocampus (cornus ammonis 1, cornus ammonis 3 and dentate gyrus), and the prefrontal cortex. The population of healthy neuronal cells was counted, using ImageJ software. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) was employed for the identification of cells undergoing apoptosis.

KEY FINDINGS

QT reversed memory impairment in the NORT. Increases in TNF-α and IL-6 were attenuated by QT, and histology revealed that QT attenuated SC-induced cell degeneration and death in the hippocampal sub-regions and prefrontal cortex. QT diminished the population of dead cells in SC-treated mice, and also reversed the process of apoptosis induced by SC.

SIGNIFICANCE

Findings from the study suggest that QT mitigates pro-inflammatory mediators and reverses neurodegeneration to restore memory function.

Treadmill exercise and wheel exercise improve motor function by suppressing apoptotic neuronal cell death in brain inflammation rats

Brain inflammation is involved in many brain disorders, such as brain ischemic injury, Alzheimer diseases, and Parkinson disease. Physical exercise has been recommended for the prevention and treatment of many brain inflammatory diseases. In the present study, the effects of exercise on motor function in relation with apoptotic neuronal cell death following neuroinflammation were investigated. Moreover, we compared the effect of forced exercise with voluntary exercise on neuroinflammation-induced motor malfunction. For this study, rota-rod test, vertical pole test, foot fault test, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay, immunohistochemistry for caspase-3, and western blot for Bcl-2 and Bax were performed. Lipopolysaccharide was intraventricular infused for induction of brain inflammation. Treadmill exercise and wheel exercise were conducted during 6 weeks. In the present results, Treadmill exercise and wheel exercise alleviated brain inflammation-induced motor impairments by suppressing apoptotic neuronal cell death in the motor cortex. These effects of treadmill exercise and wheel exercise were similarly appeared.

Peiminine inhibits colorectal cancer cell proliferation by inducing apoptosis and autophagy and modulating key metabolic pathways

Peiminine, a compound extracted from the bulbs of Fritillaria thunbergii and traditionally used as a medication in China and other Asian countries, was reported to inhibit colorectal cancer cell proliferation and tumor growth by inducing autophagic cell death. However, its mechanism of anticancer action is not well understood, especially at the metabolic level, which was thought to primarily account for peiminine's efficacy against cancer. Using an established metabolomic profiling platform combining ultra-performance liquid chromatography/tandem mass spectrometry with gas chromatography/mass spectrometry, we identified metabolic alterations in colorectal cancer cell line HCT-116 after peiminine treatment. Among the identified 236 metabolites, the levels of 57 of them were significantly (p < 0.05) different between peiminine-treated and -untreated cells in which 45 metabolites were increased and the other 12 metabolites were decreased. Several of the affected metabolites, including glucose, glutamine, oleate (18:1n9), and lignocerate (24:0), may be involved in regulation of the phosphoinositide 3-kinase/Akt/mammalian target of rapamycin (mTOR) pathway and in the oxidative stress response upon peiminine exposure. Peiminine predominantly modulated the pathways responsible for metabolism of amino acids, carbohydrates, and lipids. Collectively, these results provide new insights into the mechanisms by which peiminine modulates metabolic pathways to inhibit colorectal cancer cell growth, supporting further exploration of peiminine as a potential new strategy for treating colorectal cancer.

Salidroside induces apoptosis and autophagy in human colorectal cancer cells through inhibition of PI3K/Akt/mTOR pathway

The role of salidroside in colon cancer remains unknown. Here we show that salidroside, a phenylpropanoid glycoside extracted from Rhodiola rosea, exhibited potent anti-proliferative properties in human colorectal cancer cells via inducing apoptosis and autophagy. We ascertained that salidroside exerts an inhibitory effect on the proliferation of human colorectal cancer cells in a dose-dependent manner. In addition, salidroside induced cell apoptosis, accompanied by an increase of chromatin condensation and nuclear fragmentation, and a decrease of Bcl-2/Bax protein expression ratio. We also found that salidroside induced autophagy, evidenced by increased LC3+ autophagic vacuoles, positive acridine orange-stained cells, enhanced conversion of LC3-I to LC3-II, and elevation of Beclin-1. Treatment with autophagy-specific inhibitors [3-methyladenine (3-MA) and bafilomycin A1 (BA)] enhanced salidroside-induced apoptosis, indicating that salidroside-mediated autophagy may protect HT29 cells from undergoing apoptotic cell death. Additionally, salidroside decreased the phosphorylation of PI3K, Akt and mTOR. Treatment with PI3K inhibitor LY294002 augmented the effects of salidroside on the expression of Akt and mTOR. These findings indicate that salidroside could suppress the PI3K/Akt/mTOR signaling pathways. This study may provide a rationale for future clinical application using salidroside as a chemotherapeutic agent for human colorectal cancer.

Phloretin induces apoptosis of non-small cell lung carcinoma A549 cells via JNK1/2 and p38 MAPK pathways

Phloretin (Ph) existing in apples, pears and various vegetables is known to have antitumor activities in several cancer cell lines. However, little is known about its effect on human lung cancer cells. The aim of the present study was to see whether Ph could induce apoptosis of non-small cell lung cancer (NSCLC) cells, and explore the possible underlying mechanism of action. We found that Ph markedly induced cell apoptosis of NSCLC cell line A549, and inhibited the migration of A549 cells in a dose-dependent manner. The expression level of BAX, cleaved caspase-3 and -9, and degraded form of PARP was increased and Bcl-2 was decreased after Ph treatment. In addition, the phosphorylation of P38 MAPK, ERK1/2 and JNK1/2 was increased in a dose-dependent manner in parallel with Ph treatment. Inhibition of P38 MAPK and JNK1/2 by specific inhibitors significantly abolished the Ph-induced activation of the caspase-3 and -9. In vivo tumor-suppression assay further indicated that Ph (20 mg/kg) displayed a more significant inhibitory effect on A549 xenografts in tumor growth. All these findings indicate that Ph is able to inhibit NSCLC A549 cell growth by inducing apoptosis through P38 MAPK and JNK1/2 pathways, and therefore may prove to be an adjuvant to the treatment of NSCLC.

Profile of expression of certain markers of apoptosis in chronic hepatitis C and hepatitis B patients in an Egyptian population

Increased peripheral blood mononuclear cell (PBMC) apoptosis during viral hepatitis has been suggested to cause impaired regulation of the immune response and maintenance of the infection. The purpose of this work was to study the expression of some apoptotic markers in chronic hepatitis B (CHB) and C (CHC) infections in order to understand the underlying mechanisms of immune failure and viral persistence. This study aims to evaluate the level of PBMC apoptosis and the expression of the apoptosis-related proteins Fas and Bcl-2 in CHB and CHC patients. This case control study was carried out on 38 cases (group I: 20 chronic HCV patients; group II: 18 chronic HBV patients) attending the Tropical Medicine Clinic, Mansoura University Hospital, in addition to 10 healthy controls. Morphological assessment of apoptosis of cultured PBMCs was done. The level of Fas and Bcl-2 expression by PBMCs was detected using flow cytometry. An increased level of apoptosis correlated with increased Fas expression, but no increase in Bcl-2 expression was found on the surface of PBMCs in CHC and CHB patients compared to controls. No significant difference in the level of apoptosis, Fas, or Bcl2 expression between CHC and CHB patients was detected. Modulation of apoptosis, particularly by manipulation of Fas receptor activation, may be of therapeutic benefit in chronic CHB and CHC.

The effects of acupuncture and traditional Chinese medicines on apoptosis of brain tissue in a rat intracerebral hemorrhage model

OBJECTIVE

This study aimed to evaluate the effects of Chinese herbs and acupuncture on the neuronal apoptosis and the expression of apoptosis-related genes in the brain tissue of rats following intracerebral hemorrhage (ICH).

METHODS

Collagenase VII was injected into the caudate nucleus of Sprague-Dawley rats to induce ICH. Chinese herbs (musk, borneol and tetrandrine) were intragastrically administered, and acupuncture was performed using Dazhui, Fengfu and Shuigou acupoints. Each group was further subdivided into 4 subgroups based on treatment duration (6-hour, 24-hour, 72-hour, and 1-week). Neurological impairment score, TUNEL assay and apoptotic markers, BCL-2, BAX, and caspase-3 were used to evaluate the apoptosis status after ICH and subsequent treatment.

RESULTS

Chinese herbal therapy and acupuncture improved neurological impairment compared with no therapy and sham-operated animals. Significant differences in TUNEL positive cells were found between treatment groups (p < 0.001) and over time (p < 0.001). Differential expression of BCL-2, BAX, and caspase-3 was observed between treatment groups (p = 0.014 for BAX and < 0.05 for BCL-2 and caspase-3) and treatment duration groups (p = 0.006 for BAX and < 0.05 BCL-2 and caspase-3).

CONCLUSIONS

Results indicate that Chinese herbs and acupuncture may improve neural impairment and reduce apoptosis, although there was no difference between therapies in a rat model of ICH. Additional experiments are needed to further clarify the role of these therapies following ICH.

Neuroprotective effect of 2-(4-methoxyphenyl)ethyl-2-acetamido-2-deoxy-β-D-pyranoside against sodium nitroprusside-induced neurotoxicity in HT22 cells

2-(4-Methoxyphenyl) ethyl-2-acetamido-2-deoxy-β-D-pyranoside (GlcNAc-Sal), the salidroside analog was synthesized and shown to inhibit hypoglycemia and serum limitation induced apoptosis in PC12 cells. This study investigated the protective effects of GlcNAc-Sal on sodium nitroprusside (SNP)-induced cytotoxicity in HT22 cells. Cell viability tests and Hoechst 33342 staining comfirmed that GlcNAc-Sal pretreatment attenuated SNP-stimulated apoptotic cell death in HT22 cells in a concentration-dependent manner. The measurements of reactive oxygen species (ROS), nitric oxide (NO) production and apoptosis-related gene and protein expression suggest that the protection of GlcNAc-Sal, shown in this study, might be mediated by inhibiting intracellular ROS and NO production, and regulating apoptosis-related gene and protein expression during SNP stimulation. Perhaps, this study might contribute to the development of GlcNAc-Sal as an agent for preventing and/or treating a variety of NO-induced brain diseases.

Effects of acupuncture on the intrastriatal hemorrhage-induced caspase3 expression and newly cell birth in rats

BACKGROUND

Intracerebral hemorrhage is one of the most devastating types of stroke. Caspases are essential players in apoptotic cell death both as initiators and executioners. The v-Fos FBJ murine osteosarcoma viral oncogene homolog (Fos, c-Fos) is an immediate early gene, and Fos expression is sometimes used as a marker for stimuli-induced changes in the metabolic activity of neurons. The expressions of caspase3 and Fos are enhanced with neuroregeneration and with neuronal cell death, respectively. Cells proliferation the dentate gyrus of adult rodents is enhanced by certain pathologic events as seizures and ischemic insult, and such up-regulation of cell proliferation occurring during pathologic situations is thought to be a compensatory response to lesion-induced cell death in the brain. In the present study, we investigated the effects of acupuncture on the intrastriatal hemorrhage-induced caspase3 expression in the striatum and on the Fos expression and cell proliferation in the dentate gyrus of rats.

METHODS

For this study, immunohistochemistry for caspase3, Fos and 5-bromo-2'-deoxyuridine (BrdU) was performed.

RESULTS

Caspase3 expression in the striatum was increased by intrastriatal hemorrhage. Fos expression and cell proliferation in the dentate gyrus of rats with intracerebral hemorrhage were also increased. Acupunctural treatment, especially at the ST36 acupoint, suppressed the intracerebral hemorrhage-induced caspase3 expression in the stratum, and it also inhibited expression of Fos and cell proliferation in the dentate gyrus.

CONCLUSION

In the present study, we have shown that acupuncture treatment has a neuroprotective effect on intrastrstriatal hemorrhage-induced neuronal cell death, and this suggests that acupuncture can aid in the recovery of the central nervous system following stroke.

Brazilin inhibits growth and induces apoptosis in human glioblastoma cells

Brazilin, isolated from the methanol extract of the heart wood of Caesalpinia sappan, sensitizes cancer cells to apoptosis. Glioblastoma multiforme (GBM), which accounts for most cases of central nervous system malignancy, has a very poor prognosis and lacks effective therapeutic interventions. We, therefore, investigated the effects of different concentrations of and different periods of exposure to brazilin on cell proliferation and apoptosis in the glioma U87 cell line. Cell proliferation was investigated by MTT assays and growth curve analysis, apoptosis was assessed by FACS analysis and western blot studies. Brazilin showed dose-dependent inhibition of cell proliferation and induction of apoptosis in glioma cells. It also increased the ratio of cleaved poly-(ADP)-ribose polymerase and decreased the expression of caspase-3 and caspase-7.

Biophytum sensitivum: Ancient medicine, modern targets

Research on medicinal plants began to focus on discovery of natural products as potential active principles against various diseases. Medicinal plants are very interesting, have the ability to produce remarkable chemical structures with diverse biological activities. Biophytum sensitivum is used as traditional medicine to cure variety of diseases. During the last few decades, extensive research has been carried out to elucidate the chemistry, biological activities, and medicinal applications of B. sensitivum. Phytochemical analysis have shown that the plant parts are rich in various beneficial compounds which include amentoflavone, cupressuflavone, and isoorientin. Extracts and its bioactive compounds have been known to possess antibacterial, anti-inflammatory, antioxidant, antitumor, radioprotective, chemoprotective, antimetastatic, antiangiogenesis, wound-healing, immunomodulation, anti-diabetic, and cardioprotective activity. The present review has been carried out to shed light on the diverse role of this plant in the management of various ailments facing us.

Neuroprotective effects of bovine colostrum on intracerebral hemorrhage-induced apoptotic neuronal cell death in rats

Brain cell death after intracerebral hemorrhage may be mediated in part by an apoptotic mechanism. Colostrum is the first milk produced by mammals for their young. It plays an important role in protection and development by providing various antibodies, growth factors and nutrients, and has been used for various diseases in many countries. In the present study, we investigated the anti-apoptotic effects of bovine colostrum using organotypic hippocampal slice cultures and an intracerebral hemorrhage animal model. We performed densitometric measurements of propidium iodide uptake, a step-down avoidance task, Nissl staining, and caspase-3 immunohistochemistry. The present results revealed that colostrum treatment significantly suppressed N-methyl-D-aspartic acid-induced neuronal cell death in the rat hippocampus. Moreover, colostrum treatment improved short-term memory by suppressing hemorrhage-induced apoptotic neuronal cell death and decreasing the volume of the lesion induced by intracerebral hemorrhage in the rat hippocampus. These results suggest that colostrum may have a beneficial role in recovering brain function following hemorrhagic stroke by suppressing apoptotic cell death.

Haeamtang Induces Apoptosis of Colon Cancer HT-29 Cells through Activation of Caspase-3

The effect of Haeamtang (HAT) on the colon cancer HT-29 cells was investigated in this study. A water extract of HAT significantly decreased the number of HT-29 cells in a dose-and time-dependent manner as determined by a MTT assay. Flow cytometry results revealed a dose- and time-dependent increase of dead cells in HT-29 cells treated with HAT extract. The anticancer activity of the H AT extract is attributed to apoptosis induced in HT-29 cells, which was demonstrated by increased caspase-3 activity and poly-ADP-ribose polymerase fragmentation. A selective caspase inhibitor, z-VAD-fmk, inhibited the HAT-induced cell death. Taken together, these results demonstrate that HAT extract induces apoptosis in HT-29 cells.

Remifentanil alleviates transient cerebral ischemia-induced memory impairment through suppression of apoptotic neuronal cell death in gerbils

BACKGROUND

During neurosurgical procedures, patients are often exposed to hypoxic and ischemic brain damage. Cerebral ischemia leads to neuronal cell death and eventually causes neurological impairments. Remifentanil is a new ultra-short acting phenylpiperidine opioid analgesic. In this study, we evaluated remifentanil to determine if it exerts an anti-apoptotic effect in the hippocampal dentate gyrus following transient global ischemia in gerbils.

METHODS

Step-down avoidance task, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay, and immunohistochemical staining for caspase-3 were performed.

RESULTS

The numbers of TUNEL-positive cells and caspase-3-positive cells in the dentate gyrus were increased by ransient global ischemia. Latency in the step-down avoidance task was increased by transient global ischemia. Results revealed that apoptotic cell death in the dentate gyrus was increased significantly following transient global ischemia, resulting in memory impairment. However, treatment with remifentanil suppressed ischemia-induced apoptosis in the dentate gyrus, thereby alleviating the memory impairment that was induced by ischemic cerebral injury.

CONCLUSIONS

These results indicate that remifentanil may exert a neuroprotective effect on ischemic brain damage during surgery.

Protective Effect of Coriolus versicolor Cultivated in Citrus Extract Against Nitric Oxide-Induced Apoptosis in Human Neuroblastoma SK-N-MC Cells

Nitric oxide (NO) is a reactive free radical and a messenger molecule in many physiological functions. However, excessive NO is believed to be a mediator of neurotoxicity. The medicinal plant Coriolus versicolor is known to possess anti-tumor and immune-potentiating activities. In this study, we investigated whether Coriolus versicolor possesses a protective effect against NO donor sodium nitroprusside (SNP)-induced apoptosis in the human neuroblastoma cell line SK-N-MC. We utilized 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, 4,6-diamidino-2-phenylindole (DAPI) staining, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, DNA fragmentation assay, reverse transcription-polymerase chain reaction (RT-PCR), Western blot analysis, and caspase-3 enzyme activity assay in SK-N-MC cells. MTT assay showed that SNP treatment significantly reduces the viability of cells, and the viabilities of cells pre-treated with the aqueous extract of Coriolus versicolor cultivated in citrus extract (CVE_citrus) was increased. However, aqueous extract of Coriolus versicolor cultivated in synthetic medium (CVE_synthetic) showed no protective effect and aqueous citrus extract (CE) had a little protective effect. The cell treated with SNP exhibited several apoptotic features, while those pre-treated for 1 h with CVE_citrus prior to SNP expose showed reduced apoptotic features. The cells pre-treated for 1 h with CVE_citrus prior to SNP expose inhibited p53 and Bax expressions and caspase-3 enzyme activity up-regulated by SNP. We showed that CVE_citrus exerts a protective effect against SNP-induced apoptosis in SK-N-MC cells. Our study suggests that CVE_citrus has therapeutic value in the treatment of a variety of NO-induced brain diseases.

Protective effect of catechin on apoptosis of the lens epithelium in rats with N-methyl-N-nitrosourea-induced cataracts

Purpose

To investigate the effect of catechin on apoptotic cell death in the lens epithelium of rats with cataract.

Methods

Cataract was induced by intraperitoneal injection of 100 mg/kg N-methyl-N-nitrosourea (MNU) to ten day-old Sprague-Dawley rats. The neonatal rats were randomly divided into five groups (n=15 in each group): a control group, and four cataract-induction groups, treated with either 0, 50, 100, 200 mg/kg catechin. We performed slit-lamp biomicroscopic analysis, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay, Western-blot for Bcl-2 and Bax, and immunohistochemistry for caspase-3.

Results

Apoptotic cell death in lens epithelial cells that increased following cataract formation in rats was suppressed by cathechin.

Conclusions

Catechin inhibited cataract-induced apoptotic cell death in the lens epithelium and may prove useful for the prevention of cataract progression.

Effects of ethanol on mouse embryonic stem cells

BACKGROUND

Fetal alcohol syndrome (FAS) reflects a constellation of congenital abnormalities caused by excess maternal consumption of alcohol. It is likely that interference with embryonic development plays a role in the pathogenesis of the disorder. Ethanol-induced apoptosis has been suggested as a causal factor in the genesis of FAS. Mouse embryonic stem (mES) cells are pluripotent cells that differentiate in vitro to cell aggregates termed embryoid bodies (EBs), wherein differentiation capacity and gene expression profile are similar to those of the early embryo.

METHODS

To investigate the effects of ethanol during differentiation, mES cells were cultured on a gelatin surface in the presence of leukemia inhibitory factor which maintains adherent undifferentiated cells or in suspension to promote formation of EBs. All cells were treated (1-6 days) with 80 mM ethanol. The pluripotency and differentiation of mES cells were evaluated by western blotting of stage-specific embryonic antigen (SSEA-1), transcription factors Oct-3/4, Sox-2, and Nanog, using alkaline phosphatase staining. Apoptosis (early to late stages) was assessed by fluorescence-activated cell sorting using TdT-mediated biotin-dUTP nick-end labelling assay and fluorescein isothiocyanate-Annexin V/propidium iodide staining.

RESULTS

Ethanol increased apoptosis during in vitro differentiation of mES cells to EBs, whereas undifferentiated cells were not affected. Ethanol exposure also interfered with pluripotency marker patterns causing an upregulation of SSEA-1 under self-renewal conditions. In EBs, ethanol delayed the downregulation of SSEA-1 and affected the regulation of transcription factors during differentiation.

CONCLUSION

Our findings suggest that ethanol may contribute to the pathogenesis of FAS by triggering apoptotic pathways during differentiation of embryonic stem cells and deregulating early stages of embryogenesis.

Tadalafil improves short-term memory by suppressing ischemia-induced apoptosis of hippocampal neuronal cells in gerbils

Cerebral ischemia resulting from transient or permanent cerebral artery occlusion leads to neuronal cell death, and eventually causes neurological impairments. Tadalafil (Cialis)is a long-acting phosphodiesterase type-5 (PDE-5) inhibitor used to treat erectile dysfunction. The therapeutic effects of PDE-5 inhibitors on chronic obstructive pulmonary disease, prostate hyperplasia, hypertension, and coronary heart disease have been reported. The present study investigated the effects of tadalafil on short-term memory, cyclic guanosine monophosphate (cGMP) level, apoptotic neuronal cell death, and cell proliferation in the hippocampus following transient global ischemia in gerbils. For this study, a step-down avoidance task, cGMP assay, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, and immunohistochemistry for caspase-3 and 5-bromo-2'-deoxyuridine were performed. The results revealed that ischemic injury increased apoptotic neuronal cell death in the hippocampal CA1 region, impaired short-term memory, and decreased cGMP level. Ischemic injury enhanced cell proliferation in the hippocampal dentate gyrus. Tadalafil treatment improved short-term memory by suppressing ischemia-induced apoptotic neuronal cell death in the hippocampal CA1 region, and decreased cGMP level. Also, tadalafil suppressed the ischemia-induced increase in cell proliferation in the hippocampal dentate gyrus. We showed that tadalafil can overcome ischemia-induced apoptotic neuronal cell death, thus facilitates recovery following ischemic cerebral injury.

Electrokinetic measurements of dielectric properties of membrane for apoptotic HL-60 cells on chip-based device

The specific membrane capacitance and conductance of mammalian cells reflect the surface morphological complexities and barrier functions of cell membrane, respectively, and could potentially respond to cell physiological and pathological changes in a measurable manner. In this study, an electrokinetic system was developed by using negative dielectrophoretic force (nDEP force) assisted positioning and electroroation (ROT) measurement. Numerical simulations regarding the geometric model of the electrode were performed primarily for the electric field analysis. The dielectric responses of membrane for apoptotic HL-60 cells induced by bufalin were detected. The membrane capacitance of the cells was found to fall from an initial value of 15.6 +/- 0.9 mF/cm(2) to 6.4 +/- 0.6 mF/cm(2) after a 48 h treatment with 10 nM bufalin. However, the membrane conductance remained almost constant at (2.25 +/- 1.1) x 10(3) S/m(2) during the first 12 h of bufalin treatment and then increased distinctly to (4.2 +/- 1.3) x 10(3) S/m(2) thereafter. Scan electron microscopy (SEM) studies of the cells revealed a decreased complexity in cell membrane morphology following bufalin treatments, suggesting that the observed changes in the membrane capacitance was dominated by the alterations of cell surface structures. The results demonstrate that the ROT technique gives a quantitative analysis of the toxic damage by chemicals to cells and can be exploited in the testing and development of new pharmaceuticals and active cell agents.

The expression of pro- and anti-apoptotic Bcl-2 family proteins in peribronchiolar lymphocytes from patients with diffuse panbronchiolitis

Diffuse panbronchiolitis (DPB) is a distinctive form of small airway disease, which is characterized by chronic inflammation with lymphocyte infiltration around bronchioles. The aim of this study was to evaluate the importance of factors related to apoptosis in peribronchiolar lymphocytes of DPB. We employed immunohistochemical methods for the localization of Bax (a promoter of apoptosis), Bcl-2 (an inhibitor of apoptosis), and caspase-3 (a key executioner molecule of apoptosis) in lung tissues of five patients with DPB. In all patients, immunostaining for Bax was almost completely absent in accumulated lymphocytes around the bronchioles and in lymphocytes of the parafollicular area that correspond to a zone populated by T cells. In contrast to the reaction for Bax, Bcl-2 immunoreactivity was uniformly strong in all of the patients. The pattern of staining for caspase-3 was similar to that for Bax in all of the patients. In normal lung tissue, a few lymphocytes showed negative immunostaining for Bcl-2 and a positive reaction for caspase-3. Our results suggest that Bcl-2 protein may provide T-lymphocyte survival and hypercellularity in the bronchioles, thereby contributing to the progression of DPB.

Effect of polypeptides in bee venom on growth inhibition and apoptosis induction of the human hepatoma cell line SMMC-7721 in-vitro and Balb/c nude mice in-vivo

Polypeptides in bee venom (PBV) produced a significant growth inhibition against SMMC-7721 human hepatoma cell line. Analysis of the mechanisms of cell death indicated that PBV induced an apoptotic cell death. SMMC-7721 cells exposed to PBV (10.0 microg mL(-1)) produced an insignificant morphological change. Analysis of the cytotoxicity with the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium) assay confirmed that the cytotoxic effects of PBV were dose- and timedependent. The result of Ki67 immunohistochemistry demonstrated that the proliferation of SMMC-7721 cells treated with PBV (10.0 mug mL(-1)) was inhibited. The apoptotic cell death was then confirmed by annexin V, propidium iodide staining and DNA fragmentation analysis. In in-vivo experiments, treatment with PBV (1.5 or 3 mg kg(-1)) resulted in a significant retardation of SMMC-7721 cell growth in Balb/c nude mice. These findings suggested that PBV could be used as a chemotherapeutic agent against tumours.

Transfection of CD40Ig into liver prevents acute rejection in rat liver transplantation

OBJECTIVE

To investigate the effect of CD40Ig upon acute rejection of rat liver transplants.

METHODS

Thirty-two orthotopic liver transplants were performed using Lewis to BN rats with "the two-cuff technique". The rats were randomly divided into three groups. Group A served as controls (n = 10); group B (n = 11) and group C (n = 11); Lipofectamine2000-pcDNA3.1 or Lipofectamine2000-pcDNA3.1. CD40Ig complex was injected into Lewis portal vein ex vivo before cold storage of the liver. On the fifth day after transplantation, three rats in each group were killed to study the pathological changes and TUNEL immune histochemistry performed to examine CD40Ig expression. Lymphocytes were obtained from the spleen. The mixed lymphocyte reaction (MLR) was performed to determine tolerance and sheep anti-human immunoglobulin G (IgG)-FITC-labeled T cells counted by flow cytometry. Postoperative survival times of rats in each group were recorded. The pathological changes of dead rats were observed.

RESULTS

The mean survival times of group A and B were 11.00 +/- 4.28 and 12.75 +/- 5.57 days, respectively. There were serious acute rejections in allograft liver in groups A and B. Apoptosis index was 33.67 +/- 5.69 versus 39.00 +/- 5.29. Group C mean survival time was 41.25 +/- 13.70 days (P < .01). Immune histochemistry showed CD40Ig-positive elements in the allograft liver, which revealed light acute rejection and apoptosis index was 0.27 +/- 0.21 (P < .01). The part of the allografted liver in a dead rat showed light acute rejection while the others displayed chronic rejection. Recipients were specifically tolerant to donors in the MLR assay. The IgG-FITC-labeled T cells accounted for 11.57% of all T cells in group C.

CONCLUSIONS

CD40Ig transfection inhibited T-cell costimulatory pathway, prevented acute rejection, and prolonged graft survival.

The effects of regular aerobic exercise in adolescent period on hippocampal neuron density, apoptosis and spatial memory

It is known that positive effects of regular aerobic exercise on cognitive functions in humans and also animals; but how to the effects of aerobic exercise in adolescent period is unknown. The present study examined the effects of regular aerobic exercise on spatial memory using the Morris water maze, cell density and apoptosis of hippocampus in adolescent rats. Twenty-two days of age male rats were run on a treadmill for 30 min/session at a speed of 8m/min and 0 degrees slope, five times a week for 8 weeks. The present study showed that exercise induced significant cognitive improvement throughout brain maturation in rats. The number of hippocampal CA1 and CA3 neurons, and gyrus dentatus neurons were significantly increased in the exercised rats. There was no significant difference of CA2 neuron density between exercise and control groups. There was no significantly differences in any groups according to the results of apoptosis that account of TUNEL positive cells. The present results suggest that regular moderate aerobic treadmill exercise benefit in cognitive functions. This result may derive from treadmill exercise-induced increase cell density without altering of apoptosis in the hippocampus and dentate gyrus of adolescent rats.

Nicotine induces apoptosis in TM3 mouse Leydig cells

OBJECTIVE

To investigate whether nicotine-induced testicular toxicity involves the induction of apoptosis in Leydig cells.

DESIGN

Cell study using cells of the TM3 cell line derived from mouse Leydig cells.

SETTING

Academic research laboratory.

INTERVENTION(S)

Morphological and biochemical analyses for the detection of apoptosis.

MAIN OUTCOME MEASURE(S)

The effect of nicotine on the occurrence of apoptosis was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, 4,6-diamidino-2-phenylindole staining, terminal deoxynuclotidyl transferase-mediated dUTP nick end labeling assay, DNA fragmentation assay, reverse transcription-polymerase chain reaction, caspase-3 enzyme assay, and Western blot analysis. Nicotine treatment exhibits several features of apoptosis in mouse Leydig cells.

RESULT(S)

TM3 cells treated with nicotine exhibit several features of apoptosis. It was also shown that nicotine increases the mRNA level of bax and decreases that of bcl-2. In addition, nicotine enhanced the expression of the activated form of caspase-3 and caspase-3 enzyme activity.

CONCLUSION(S)

Nicotine appears to activate specific intracellular death-related pathways, probably by bax-dependent activation of caspase-3, inducing apoptosis in Leydig cells. Thus, nicotine-induced apoptosis of Leydig cells might be one of the important mechanisms behind nicotine-related urogenital disorders in men.

Nitric Oxide Induces Apoptosis in Mouse C2C12 Myoblast Cells

To investigate whether nitric oxide (NO) induces apoptosis in myoblast cells, the effect of the sodium nitroprusside (SNP), NO donor, on the apoptosis of mouse C2C12 myoblast cells was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, 4,6-diamidino-2-phenylindole (DAPI) staining, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, DNA fragmentation assay, reverse transcription-polymerase chain reaction (RT-PCR), Western blot analysis, and caspase-3 enzyme assay. Mouse C2C12 myoblast cells treated with SNP exhibited several apoptotic features. SNP increased p53 expression and bax expression. SNP also enhanced caspase-3 enzyme activity. The data show that NO may induce apoptotic cell death in myoblast cells through the activation of p53-, bax-, and caspase-dependent intracellular death-related pathways.

Acupuncture suppresses intrastriatal hemorrhage-induced apoptotic neuronal cell death in rats

Intracerebral hemorrhage is one of the most devastating types of stroke. In the present study, the effect of acupuncture on intrastriatal hemorrhage-induced neuronal cell death in rats was investigated via Nissl staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, and immunohistochemistry for caspase-3. The present results showed that lesion size and apoptotic neuronal cell death in the striatum were significantly increased following intrastriatal hemorrhage in rats and that acupunctural treatment at the Zusanli acupoint suppressed the hemorrhage-induced increase in lesion size and apoptotic neuronal cell death in the striatum. In the present study, it can be suggested that acupunctural treatment, especially at the Zusanli acupoint, may aid in the recovery following central nervous system sequellae following intracerebral hemorrhage.

Treadmill exercise suppresses ischemia-induced increment in apoptosis and cell proliferation in hippocampal dentate gyrus of gerbils

Cerebral ischemia resulting from transient or permanent occlusion of cerebral arteries leads to neuronal cell death and eventually causes neurological impairments. In the present study, the effects of treadmill exercise on apoptosis and cell proliferation in the hippocampal dentate gyrus following transient global ischemia in gerbils were investigated using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay and immunohistochemistry for caspase-3 and 5-bromo-2'-deoxyuridine (BrdU). It was shown that apoptotic cell death and cell proliferation in the hippocampal dentate gyrus were significantly increased following transient global ischemia in gerbils and that treadmill exercise suppressed the ischemia-induced increase in apoptosis and cell proliferation in the dentate gyrus. The present results suggest that treadmill exercise may protect cells from apoptotic death and aid in recovery from the central nervous system sequelae following stroke.

Alkaloid fraction of Uncaria rhynchophylla protects against N-methyl-D-aspartate-induced apoptosis in rat hippocampal slices

Uncaria rhynchophylla is a medicinal herb which has sedative and anticonvulsive effects and has been applied in the treatment of epilepsy in Oriental medicine. In this study, the effect of alkaloid fraction of U. rhynchophylla against N-methyl-D-aspartate (NMDA)-induced neuronal cell death was investigated. Pretreatment with an alkaloid fraction of U. rhynchophylla for 1 h decreased the degree of neuronal damage induced by NMDA exposure in cultured hippocampal slices and also inhibited NMDA-induced enhanced expressions of apoptosis-related genes such as c-jun, p53, and bax. In the present study, the alkaloid fraction of U. rhynchophylla was shown to have a protective property against NMDA-induced cytotoxicity by suppressing the NMDA-induced apoptosis in rat hippocampal slices.

In vitro effects of ciprofloxacin and roxithromycin on apoptosis of jurkat T lymphocytes

Ciprofloxacin (CPFX) and roxithromycin (RXM) induced apoptosis of activated Jurkat T cells in vitro. CPFX showed concentration-dependent acceleration of apoptosis of activated Jurkat T cells by enhancing the expression of FasL and activities of caspase-3 and -8. RXM accelerated cell death, enhanced expression of FasL and caspase-3 but not caspase-8, and did not show the concentration dependency.

Bee venom induces apoptosis and inhibits expression of cyclooxygenase-2 mRNA in human lung cancer cell line NCI-H1299

To investigate whether bee venom (BV) induces apoptosis, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, terminal deoxynucleotidyl transferase- mediated dUTP nick end-labeling assay, 4,6-diamidino-2-phenylindole staining, flow cytometric analysis, and DNA fragmentation assay were performed on NCI-H1299 lung cancer cells treated with BV. Through morphological and biochemical analyses, it was demonstrated that NCI-H1299 cells treated with BV exhibit several features of apoptosis. In addition, reverse transcription-polymerase chain reaction and prostaglandin E(2) (PGE(2)) immunoassay were performed to verify whether BV possesses an inhibitory effect on the expression of cyclooxygenase (COX) and PGE(2 )synthesis. Expression of COX-2 mRNA and synthesis of PGE(2) were inhibited by BV. These results suggest the possibility that BV may exert an anti-tumor effect on human lung cancer.

Membrane dielectric changes indicate induced apoptosis in HL-60 cells more sensitively than surface phosphatidylserine expression or DNA fragmentation

The specific membrane capacitance and conductivity of mammalian cells, which reflect their surface morphological complexities and membrane barrier functions, respectively, have been shown to respond to cell physiologic and pathologic changes. Here, the effects of induced apoptosis on these membrane properties of cultured human promyelocytic HL-60 cells are reported. Changes in membrane capacitance and conductivity were deduced from measurements of cellular dielectrophoretic crossover frequencies following treatment with genistein (GEN). The apparent specific cell membrane capacitance of HL-60 cells fell from an initial value of 17.6+/-0.9 to 9.1+/-0.5 mF/m(2) 4 h after treatment. Changes began within minutes of treatment and preceded both the externalization of phosphatidylserine (PS), as gauged by the Annexin V assay, and the appearance of a sub-G1 cell subpopulation, as determined through ethidium bromide staining of DNA. Treatment by the broad spectrum caspase inhibitor N-benzyloxycarbony-Val-Ala-Asp(O-methyl)-fluoromethyketone (zVAD-fmk) did not prevent these early cell membrane dielectric responses, suggesting that the caspase system was not involved. Although membrane conductivity did not alter during the first 4 h of GEN treatment, it rose significantly and progressively thereafter. Finally, as the barrier function failed and the cells became necrotic, it increased by many orders of magnitude. The effective membrane capacitance and conductivity findings serve to focus attention on the membrane as a site for early participation in apoptosis. In conjunction with our prior reports of the use of dielectric methods for cell manipulation and separation, these results demonstrate that dielectrophoretic technologies should be applicable to the rapid detection, separation, and quantification of normal, apoptotic, and necrotic cells from cell mixtures.

Alcohol induces apoptosis in TM3 mouse Leydig cells via bax-dependent caspase-3 activation

To investigate whether ethanol induces apoptosis in Leydig cells, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, terminal deoxynuclotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay, 4,6-diamidino-2-phenylindole (DAPI) staining, DNA fragmentation assay, caspase-3 enzyme assay, reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis were performed on TM3 mouse Leydig cells. Through morphological and biochemical analyses, it was demonstrated that TM3 cells treated with ethanol at concentrations of 50 and 100 mM exhibit classical apoptotic features. In addition, it was shown that ethanol induces increases in levels of bax and caspase-3 and a decrease in bcl-2 expression. Based on the results, alcohol appears to activate specific intracellular death-related pathways leading to bax-dependant caspase-3 activation and the induction of apoptosis in Leydig cells.

Amiodarone induces apoptosis in L-132 human lung epithelial cell line

To investigate whether amiodarone induces apoptosis in cells of the L-132 human lung epithelial cell line, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, 4,6-diamidino-2-phenylindole staining, DNA fragmentation assay, reverse transcription-polymerase chain reaction, and casapse-3 enzyme assay were performed. Through morphological and biochemical analyses, it was demonstrated that L-132 cells treated with amiodarone exhibit several features of apoptosis. In addition, it was shown that amiodarone increases the mRNA levels of bax and caspase-3. Based on the results, amiodarone appears to activate specific intracellular death-related pathways, including possibly the bax-dependent caspase-3 activation pathway, and thus induce apoptosis in human lung epithelial cells.

Nonspecific cytotoxic cells and innate immunity: regulation by programmed cell death

Although programmed cell death (PCD) and the cellular pathology of apoptosis have been extensively studied in mammals and invertebrates, little is known regarding these important regulatory processes in cold blooded vertebrates, especially teleost fish. In the present review, select immunoregulatory properties of PCD/apoptosis in nonspecific cytotoxic cells (NCC) from catfish and tilapia were identified. The techniques used to define the characteristics of PCD in NCC were DNA ploidy, Annexin-V binding and cellular morphology. Using these procedures, we determined that the biochemical/genetic changes that NCC undergo during PCD are similar to those described in mammalian cells. We hypothesize that one immediate response of NCC to acute stress in teleost fish is the release of apoptosis regulatory factors (ARF) or stress activated serum factors (SASF) into the peripheral blood. These cytokine-like factors activate NCC by protecting them from initiation of: "activation induced cell death" (AICD); from "receptor induced apoptosis"; and from initiation of dexamethasone induced DNA hypoploidy. We predict that the mechanism of these actions is enhanced NCC recycling capacity and initiation of migration of NCC into sites of inflammation. In this review, studies were also summarized regarding the expression and release of "death and survival proteins" by NCC. Although the survey was not exhaustive, we showed that tilapia NCC that were activated in vitro with SASF contained increased levels of two adaptor proteins (i.e. CAS, FADD) and soluble FasL. At present the relevance of expression of the adaptor proteins by NCC is not known, however, additional evidence for the role of FasL in NCC innate immune responses was presented. Interestingly, NCC contained constitutive cytosolic FasL, and activation with tumor cells caused a significant decrease in the cytoplasmic levels of this "death protein". This indicated that FasL in NCC may function as a secretory cytokine-like molecule. Unlike mammalian NK cells and T-cells, activated NCC do not express membrane FasL. A level of phosphatase regulation of NCC apoptosis was indicated by demonstrating a reduced camptothecin induce DNA hypoploidy by pretreatment of NCC with the tyrosine phosphatase inhibitor sodium orthovanadate. This review emphasized the important regulatory functions of PCD/apoptosis for NCC in innate immune responses.

Persistence of stable intragraft cell chimerism in rat liver allografts after drug-induced tolerance

BACKGROUND

Drug-induced tolerance of rat liver allografts is well documented. We analyzed cellular events during immunosuppressive therapy on day (d) 10 and in the late phase (d 100) after transplantation to assess for characteristics in the intrahepatic leukocyte (IHL) population in the phase of tolerance.

METHODS

Lewis rats served as recipients of Dark Agouti rat livers. Temporary immunosuppression with either cyclosporine (CsA) monotherapy (3 mg/kg/d) or triple therapy that consisted of a subtherapeutic CsA dosage (0.25 mg/kg/d) and monoclonal antibodies directed against the interleukin-2 receptor (IL-2R, CD25) and the intercellular adhesion molecule-1 (ICAM-1, CD54) was administered from postoperative d 0 to d 13. Cell migration and cell activation within liver grafts was assessed by standard histology and flow cytometry. IHL apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling (TUNEL).

RESULTS

Both CsA monotherapy and triple therapy prolonged liver allograft survival to more than 100 d and led to the induction of donor-specific tolerance. Untreated recipients rejected their allografts within 14 d. In both groups, donor-specific IHLs initially dropped to 18% to 25% on d 10, but they rebounded to as much as 40% on d 100 as a common characteristic of both groups. Within this population, donor-specific T cells were dominant. In both groups, increased numbers of activated (IL-2R+) CD8+ T lymphocytes were present on d 100. No accumulation of apoptotic IHL was observed on d 100. Their proportion was unchanged in the triple therapy group and slightly decreased in the CsA group compared to the syngeneic controls.

CONCLUSIONS

The present study reveals that tolerant liver allografts are repopulated by donor-specific T lymphocytes. This phenomenon is independent of the type of applied immunosuppression. The persistence of activated CD8+ T cells in the phase of proven donor-specific tolerance on d 100 indicates that liver tolerance is associated with the state of a permanent intragraft immune activation. It seems that the coexistence of donor cells with infiltrating recipient cells within liver grafts, termed intrahepatic cell chimerism, is characteristic for tolerated liver allografts.

Programmed cell death signaling via cell-surface expression of a single-chain antibody transgene

BACKGROUND

The monoclonal antibody, 5H7, is specific for a monomorphic determinant on the a3 domain of human class I MHC (A, B, C). Immobilized 5H7 delivers programmed cell death (PCD) signals to human lymphoid tumor cells as well as peripheral blood mononuclear cells.

METHODS

The potential clinical utility of 5H7 was addressed by design of a single-chain variable antibody (scFv), termed 5H7scFv, which was coupled to glycophosphotidylinostitol (GPI), thereby providing membrane expression of the 5H7 idiotype (5H7scFv-GPI). Membrane expression of 5H7scFv-GPI conferred PCD-inducing properties to cells that do not normally have the capability to process and express whole antibody molecules. The initial construction was undertaken in a bacterial expression system, and appropriate protein folding was determined by binding to class I MHC-expressing cells.

RESULTS

5H7scFv-GPI-transfected Chinese hamster ovary cells demonstrated reconstitution of the 5H7 idiotype and binding to soluble HLA-A2. Cross-linking of class I MHC, via membrane expression of the scFv, provided effective PCD signaling in B and T lymphocyte tumor cells. Peripheral blood mononuclear cells were susceptible to 5H7scFv-GPI-induced PCD, and augmentation of PCD signals was noted with anti-CD3 and anti-CD28 preactivation. Responder cells demonstrated typical histologic features of PCD and Annexin V-fluorescein isothiocyanate binding.

CONCLUSIONS

Cell surface anchorage of scFv thus provides effective delivery of immune modulatory signals, which may be manipulated for various therapeutic strategies.

The significance of apoptosis in the liver

Apoptosis is a form of cell death which occurs in normal as well as in pathological tissues. We provide a description of the morphological changes during apoptosis and an overview of the role of apoptosis dysregulation in the pathogenesis of non-neoplastic liver diseases.