Bax, Bcl-2, and cyclin expression and apoptosis in rat substantia nigra during development

Hederagenin Suppresses Inflammation and Cartilage Degradation to Ameliorate the Progression of Osteoarthritis: An In vivo and In vitro Study

Osteoarthritis (OA), a common degenerative joint disease, is characterized by the progressive degradation of articular cartilage and inflammation. Hederagenin (HE) is a pentacyclic triterpenoid saponin extracted from many herb plants. It has anti-inflammatory, anti-lipid peroxidative, anti-cancer, and neuroprotective activities. However, its effect on OA has not been investigated. Our study found that HE may be a potential anti-OA drug. In vitro, HE could suppress extracellular matrix (ECM) degradation via up-regulating aggrecan and Collagen II levels as well as downregulating MMPs and ADAMTS5 levels. It could also reduce proinflammatory and inflammatory cytokines or enzymes production, including TNF-α, IL-6, iNOS, COX-2, NO, and PGE₂. Besides, HE markedly reduced IL-1β-induced C28/I2 cell apoptosis and ROS accumulation. Mechanistically, HE exerted chondroprotective and anti-inflammatory effects by partly inhibiting JAK2/STAT3/MAPK signalling pathway and the crosstalk of the two pathways. Also, HE exhibited anti-apoptotic and anti-oxidative effect via targeting Keap1-Nrf2/HO-1/ROS/Bax/Bcl-2 axis. In vivo, HE significantly reduced monosodium iodoacetate (MIA) induced cartilage destruction of rats with a lower OARSI score and inflammatory cytokine levels, further demonstrating its protective effects in OA progression. These results suggest that HE is a potential compound for the development of drugs to treat OA.

Thymax, a gross thymic extract, exerts cell cycle arrest and apoptosis in Ehrlich ascites carcinoma in vivo

Thymax is a gross thymic extract that has been shown to induce apoptosis in vitro for human breast cancer cells. Here we examine Thymax's ability to induce apoptosis in animals bearing Ehrlich ascites carcinoma (EAC). Thymax was administered six days/week orally to mice (5.45 mg/kg body weight) beginning either 14 days prior to EAC inoculation or 9 days post inoculation; treatment continued for 30 days post inoculation. Pretreatment of mice with Thymax markedly delayed tumor growth and reduced tumor incidence by 38.9%, and tumor volumes relative to untreated controls were suppressed by 90.5% and 55.0% for pre- and post-inoculation groups, respectively. Treatment with Thymax inhibited cellular proliferation by decreasing the expression of tumor markers Ki-67, PCNA, and Cyclin D1 in cancer cells and increasing the expression of p21 and p27. This was associated with the ability of Thymax to arrest the cell cycle of EAC cells in the G0/G1 phase and to induce apoptosis, as indicated by a significant increase in the sub-G1 phase's percentage of hypodiploid cells and further affirmed by DNA fragmentation and Annexin V/propidium iodide staining. In addition, Thymax exerted its apoptotic effect in EAC cancer cells through a mitochondrial-dependent pathway, as evidenced by an increased Bax/Bcl-2 ratio, up-regulation of p53 expression, and activation of caspase-3. We conclude that Thymax supplementation enhances tumor cell demise by arresting the cell cycle and inducing apoptosis. These data suggest that Thymax could be a new adjuvant for breast cancer treatment.

MytiLec-1 Shows Glycan-Dependent Toxicity against Brine Shrimp Artemia and Induces Apoptotic Death of Ehrlich Ascites Carcinoma Cells In Vivo

MytiLec-1, a 17 kDa lectin with β-trefoil folding that was isolated from the Mediterranean mussel (Mytilus galloprovincialis) bound to the disaccharide melibiose, Galα(1,6) Glc, and the trisaccharide globotriose, Galα(1,4) Galβ(1,4) Glc. Toxicity of the lectin was found to be low with an LC₅₀ value of 384.53 μg/mL, determined using the Artemia nauplii lethality assay. A fluorescence assay was carried out to evaluate the glycan-dependent binding of MytiLec-1 to Artemia nauplii. The lectin strongly agglutinated Ehrlich ascites carcinoma (EAC) cells cultured in vivo in Swiss albino mice. When injected intraperitoneally to the mice at doses of 1.0 mg/kg/day and 2.0 mg/kg/day for five consecutive days, MytiLec-1 inhibited 27.62% and 48.57% of cancer cell growth, respectively. Antiproliferative activity of the lectin against U937 and HeLa cells was studied by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in vitro in RPMI-1640 medium. MytiLec-1 internalized into U937 cells and 50 μg/mL of the lectin inhibited their growth of to 62.70% whereas 53.59% cell growth inhibition was observed against EAC cells when incubated for 24 h. Cell morphological study and expression of apoptosis-related genes (p53, Bax, Bcl-X, and NF-κB) showed that the lectin possibly triggered apoptosis in these cells.

Hydrogen-rich Water Exerting a Protective Effect on Ovarian Reserve Function in a Mouse Model of Immune Premature Ovarian Failure Induced by Zona Pellucida 3

Background:

Premature ovarian failure (POF) is a disease that affects female fertility but has few effective treatments. Ovarian reserve function plays an important role in female fertility. Recent studies have reported that hydrogen can protect male fertility. Therefore, we explored the potential protective effect of hydrogen-rich water on ovarian reserve function through a mouse immune POF model.

Methods:

To set up immune POF model, fifty female BALB/c mice were randomly divided into four groups: Control (mice consumed normal water, n = 10), hydrogen (mice consumed hydrogen-rich water, n = 10), model (mice were immunized with zona pellucida glycoprotein 3 [ZP3] and consumed normal water, n = 15), and model-hydrogen (mice were immunized with ZP3 and consumed hydrogen-rich water, n = 15) groups. After 5 weeks, mice were sacrificed. Serum anti-Müllerian hormone (AMH) levels, granulosa cell (GC) apoptotic index (AI), B-cell leukemia/lymphoma 2 (Bcl-2), and BCL2-associated X protein (Bax) expression were examined. Analyses were performed using SPSS 17.0 (SPSS Inc., Chicago, IL, USA) software.

Results:

Immune POF model, model group exhibited markedly reduced serum AMH levels compared with those of the control group (5.41 ± 0.91 ng/ml vs. 16.23 ± 1.97 ng/ml, P = 0.033) and the hydrogen group (19.65 ± 7.82 ng/ml, P = 0.006). The model-hydrogen group displayed significantly higher AMH concentrations compared with that of the model group (15.03 ± 2.75 ng/ml vs. 5.41 ± 0.91 ng/ml, P = 0.021). The GC AI was significantly higher in the model group (21.30 ± 1.74%) than those in the control (7.06 ± 0.27%), hydrogen (5.17 ± 0.41%), and model-hydrogen groups (11.24 ± 0.58%) (all P < 0.001). The GC AI was significantly higher in the model-hydrogen group compared with that of the hydrogen group (11.24 ± 0.58% vs. 5.17 ± 0.41%, P = 0.021). Compared with those of the model group, ovarian tissue Bcl-2 levels increased (2.18 ± 0.30 vs. 3.01 ± 0.33, P = 0.045) and the Bax/Bcl-2 ratio decreased in the model-hydrogen group.

Conclusions:

Hydrogen-rich water may improve serum AMH levels and reduce ovarian GC apoptosis in a mouse immune POF model induced by ZP3.

The effect of mono-(2-ethylhexyl) phthalate on apoptosis of rat ovarian granulosa cells in vitro

Mono-(2-ethylhexyl) phthalate (MEHP), the active metabolite of di-(2-ethylhexyl) phthalate (DEHP), is considered to be a reproductive toxicant. This study was performed to evaluate the effect of MEHP on apoptosis of rat ovarian granulosa cells and explore potential mechanism. Granulosa cells were treated with MEHP (0, 25, 50, and 100 μmol/l). Inhibited cell viability and increased apoptosis rate were observed in 50 and 100 μmol/l groups. CASPASE3 activity and BAX expression were significantly raised in all MEHP-treated groups; BCL2 expression was elevated in 25 μmol/l group, while inhibited in 50 and 100 μmol/l groups; BAX/BCL2 ratio was increased in a typical dose-effect relationship. In conclusion, this study showed that MEHP exposure induced cell viability decrease and apoptosis, associated with increase of CASPASE3 activity and BAX/BCL2 ratio. Moreover, CASPASE3 activity showed a reversed dose-dependent effect in MEHP-treated groups, indicating there might exist other CASPASE-independent pathway involved in MEHP-induced apoptosis.

Pea lectin inhibits growth of Ehrlich ascites carcinoma cells by inducing apoptosis and G2/M cell cycle arrest in vivo in mice

Pea (Pisum sativum L.) lectin is known to have interesting pharmacological activities and of great interest on biomedical research. In the current research pea lectin was purified followed by ion exchange chromatography on DEAE column and affinity chromatography on glucose-sepharose column. The lectin shown 11.7-84% inhibitory effect against Ehrlich ascites carcinoma (EAC) cells at the concentration range of 8-120 μg/ml in RPMI 1640 medium as determined by MTT assay. Pea lectin was also shown 63% and 44% growth inhibition against EAC cells in vivo in mice when administered 2.8 mg/kg/day and 1.4 mg/kg/day (i.p.) respectively for five consequent days. When Pea lectin injected into the EAC bearing mice for 10 days its significantly increased the hemoglobin and RBC with the decreased of WBC levels toward the normal. Apoptotic cell morphological change of the treated EAC cells of mice was determined by fluorescence and optical microscope. Interestingly, cell growth inhibition of the lectin was significantly reduced in the presence of caspase inhibitors. Treatment with the lectin caused the cell cycle arrest at G2/M phase of EAC cells which was determined by flow cytometry. The expression of apoptosis-related genes, Bcl-2, Bcl-X and Bax was evaluated by reverse transcriptase polymerase chain reaction (RT-PCR). Intensive increase of Bax gene expression and totally despaired of Bcl-2 and Bcl-X gene expression were observed in the cells treated with Pea lectin for five consecutive days.

Depletion of BIRC6 leads to retarded bovine early embryonic development and blastocyst formation in vitro

Baculoviral inhibitors of apoptosis repeat-containing 6 (BIRC6) is believed to inhibit apoptosis by targeting key cell-death proteins. To understand its involvement during bovine preimplantation embryo development, two consecutive experiments were conducted by targeted knockdown of its mRNA and protein using RNA interference. In Experiment 1, the effect of BIRC6 knockdown during the early stages of preimplantation embryo development was assessed by injecting zygotes with long double-stranded RNA (ldsRNA) and short hairpin RNA (shRNA) against BIRC6 mRNA followed by in vitro culturing until 96 h post insemination (hpi). The results showed that in RNA-injected zygote groups, reduced levels of BIRC6 mRNA and protein were accompanied by an increase (P < 0.05) in the proportion of 2- and 4-cell and uncleaved embryos and a corresponding decrease (P < 0.05) in the number of 8-cell embryos. In Experiment 2, the effect of BIRC6 knockdown on blastocyst formation, blastocyst total cell number and the extent of apoptosis was investigated. Consequently, zygotes injected with ldsRNA and shRNA resulted in lower (P < 0.05) blastocyst formation and total blastocyst cell number. Moreover, the apoptotic cell ratio, CASPASE 3 and 7 activity, BAX to BCL-2 ratio and levels of SMAC and CASPASE 9 were higher in blastocysts derived from the ldsRNA and shRNA groups, suggesting increased apoptosis in those blastocysts. The results of this study reveal the importance of BIRC6 expression for embryo survival during bovine preimplantation embryo development. However, whether BIRC6 is essential for implantation and fetal development during bovine pregnancy needs further research.

Pathological apoptosis in the developing brain

More than half of the initially-formed neurons are deleted in certain brain regions during normal development. This process, whereby cells are discretely removed without interfering with the further development of remaining cells, is called programmed cell death (PCD). The term apoptosis is used to describe certain morphological manifestations of PCD. Many of the effectors of this developmental cell death program are highly expressed in the developing brain, making it more susceptible to accidental activation of the death machinery, e.g. following hypoxia-ischemia or irradiation. Recent evidence suggests, however, that activation and regulation of cell death mechanisms under pathological conditions do not exactly mirror physiological, developmentally regulated PCD. It may be argued that the conditions after e.g. ischemia are not even compatible with the execution of PCD as we know it. Under pathological conditions cells are exposed to various stressors, including energy failure, oxidative stress and unbalanced ion fluxes. This results in parallel triggering and potential overshooting of several different cell death pathways, which then interact with one another and result in complex patterns of biochemical manifestations and cellular morphological features. These types of cell death are here called "pathological apoptosis," where classical hallmarks of PCD, like pyknosis, nuclear condensation and caspase-3 activation, are combined with non-PCD features of cell death. Here we review our current knowledge of the mechanisms involved, with special focus on the potential for therapeutic intervention tailored to the needs of the developing brain.

Saccade induced cortical activation in patients with post-stroke visual field defects

Substantial disability in patients with hemianopia results from reduced visual perception. Several studies have shown that these patients have impaired saccades but may improve search strategies with appropriate training of saccades. We used fMRI to study the representation of saccades in patients with post-stroke hemianopia to the left. Brain activation during visually guided saccades was measured in 10 patients with a pure occipital cortical lesion causing homonymous hemianopia and in 10 healthy control subjects. Differences in activation between rest and saccades and between controls and patients were assessed with statistical parametric mapping (SPM'99). In normal subjects, significant activation was found in the frontal and parietal eye fields bilaterally and in the supplementary eye field. These areas were also activated in patients, however, to a lesser degree. In contrast, an area of increased activation in patients was found in the posterior parietal cortex of the (non-affected) left hemisphere. Visual field defects after striate lesions are associated with changes in the frontoparietal network underlying the cortical control of saccades.

Induction of apoptosis in SGC-7901 cells by polysaccharide-peptide GFPS1b from the cultured mycelia of Grifola frondosa GF9801

The biological function of GFPPS1b, a novel polysaccharide-peptide isolated from cultured mycelia of Grifola frondosa GF9801, was well investigated. GFPS1b has anti-tumor activity and can significantly inhibit the proliferation of SGC-7901 cells, whereas slightly influences the growth of human normal liver cell line L-02. When treated with GFPS1b, SGC-7901 cells showed typical apoptotic morphological features such as the loss of villus and appearance of apoptotic bodies on the cell surface, volume reduction, and chromatin condensation, by scanning electron microscopy (SEM) and fluorescent microscopy (Hoechst 33342). The results of flow cytometry analysis and annexin V-PI assay showed that the SGC-7901 cell cycle was arrested in the G(2)/M phase, the subdiploid peak of DNA characteristic of apoptotic was also observed, and the apoptosis ratio was about 15.08%. DNA isolated from SGC-7901 cells cultured with GFPS1b showed a typical DNA 'ladders' of apoptosis in agarose gel electrophoresis. Further investigation results showed that the apoptotic machinery of SGC-7901 induced by GFPS1b was associated with drop in mitochondrial trans-membrane potential, upregulation of Bax, downregulation of Bcl-2, and activation of caspase-3. Our finding suggests that GFPS1b could suppress SGC-7901 cell growth and reduce cell survival via arresting cell cycle and inducing apoptosis of tumor cells.

Ultrastructural characterization of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-induced cell death in embryonic dopaminergic neurons

Developing neuronal populations undergo significant attrition by natural cell death. Dopaminergic neurons in the substantia nigra pars compacta undergo apoptosis during synaptogenesis. Following this time window, destruction of the anatomic target of dopaminergic neurons results in dopaminergic cell death but the morphology is no longer apoptotic. We describe ultrastructural changes that appear unique to dying embryonic dopaminergic neurons. In primary cultures of mesencephalon, death of dopaminergic neurons is triggered by activation of glutamate receptors sensitive to alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), and differs ultrastructurally from both neuronal apoptosis or typical excitotoxicity. AMPA causes morphological changes selectively in dopaminergic neurons, without affecting other neurons in the same culture dishes. Two hours after the onset of treatment swelling of Golgi complexes is apparent. At 3 h, dopaminergic neurons display loss of membrane asymmetry (coinciding with commitment to die), as well as nuclear membrane invagination, irregular aggregation of chromatin, and mitochondrial swelling. Nuclear changes continue to worsen until loss of cytoplasmic structures and cell death begins to occur after 12 h. These changes are different from those described in neurons undergoing either apoptosis or excitotoxic death, but are similar to ultrastructural changes observed in spontaneous death of dopaminergic neurons in the natural mutant weaver mouse.

Effects of lycorine on HL-60 cells via arresting cell cycle and inducing apoptosis

As a natural anti-cancer alkaloid extracted from Amaryllidaceae, lycorine shows various biological effects on tumor cells. The survival rate of HL-60 cells exposed to lycorine was decreased in a dose-dependent manner with 1 microM as the 50% inhibitory concentration (IC50), cell growth was slowed down by arresting cell cycle at G2/M phase, and cell regeneration potential was inhibited. HL-60 cells exhibited typical apoptotic morphological changes, apoptotic DNA "ladder" pattern, and sub-G1 peak in cell phase distribution, showing apoptosis of HL-60 cells. To further understand the apoptotic molecular mechanism of lycorine on HL-60 cells, caspase activity was tested by colorimetric assay, and the expression of Bcl-2 and Bax proteins was examined by Western blotting. The increase of caspase-8, -9, -3 activities demonstrated that caspase was a key mediator of apoptotic pathways induced by lycorine. Under-expression of Bcl-2 and increase of Bax:Bcl-2 ratio showed that Bcl-2 family proteins were involved in apoptosis. Our finding suggests that lycorine can suppress leukemia growth and reduce cell survival via arresting cell cycle and inducing apoptosis of tumor cells.

Ontogenic cell death in the nigrostriatal system

Like most neural systems, dopamine neurons of the substantia nigra undergo apoptotic natural cell death during development. In rodents, this occurs largely postnatally and is biphasic with an initial major peak just after birth and a second minor peak on postnatal day 14. As envisioned by classic neurotrophic theory, this event is regulated by interactions with the target of these neurons, the striatum, because a developmental target lesion results in an augmented natural cell death event with fewer nigral dopamine neurons surviving into adulthood. Until recently, the striatal target-derived neurotrophic factors providing developmental support of dopamine neurons were unknown, but there is now growing evidence that glial-cell-line-derived neurotrophic factor (GDNF) serves as a physiologic limiting neurotrophic factor for these neurons during the first phase of natural cell death. During this phase, intrastriatal injection of GDNF diminishes the natural cell death event and neutralizing antibodies augment it. Sustained overexpression of GDNF in the striatum throughout development in a unique double transgenic mouse model results in an increased number of dopamine neurons surviving the first phase of natural cell death. However, this increase does not persist into adulthood. Therefore, other factors or mechanisms must play important roles in the determination of the mature number of nigral dopamine neurons. Further elucidation of these mechanisms will be important in the development of neuroprotective and cell replacement therapies for Parkinson's disease.

Regulation of the development of mesencephalic dopaminergic systems by the selective expression of glial cell line-derived neurotrophic factor in their targets

Glial cell line-derived neurotrophic factor (GDNF) has been shown to protect and restore dopamine (DA) neurons in injury models and is being evaluated for the treatment of Parkinson's disease. Nevertheless, little is known of its physiological role. We have shown that GDNF suppresses apoptosis in DA neurons of the substantia nigra (SN) postnatally both in vitro and during their first phase of natural cell death in vivo. Furthermore, intrastriatal injection of neutralizing antibodies augments cell death, suggesting that endogenous GDNF plays a role as a target-derived factor. Such a role would predict that overexpression of GDNF in striatum would increase the surviving number of SN DA neurons. To test this hypothesis, we used the tetracycline-dependent transcription activator (tTA)/tTA-responsive promoter system to create mice that overexpress GDNF selectively in the striatum, cortex, and hippocampus. These mice demonstrate an increased number of SN DA neurons after the first phase of natural cell death. However, this increase does not persist into adulthood. As adults, these mice also do not have increased dopaminergic innervation of the striatum. They do, however, demonstrate increased numbers of ventral tegmental area (VTA) neurons and increased innervation of the cortex. This morphologic phenotype is associated with an increased locomotor response to amphetamine. We conclude that striatal GDNF is necessary and sufficient to regulate the number of SN DA neurons surviving the first phase of natural cell death, but it is not sufficient to increase their final adult number. GDNF in VTA targets, however, is sufficient to regulate the adult number of DA neurons.

Nitric oxide synthase inhibition during development: effect on apoptotic death of dopamine neurons

Naturally occurring cell death via apoptosis occurs in the substantia nigra pars compacta (SNc) during rat development, culminating during the perinatal period. We previously showed that lipid peroxidation-mediated oxidative stress is not involved in this cell death process. Nitric oxide (NO) has been proposed to be critical for many developmental processes in brain and has been shown to mediate cell death in neurotoxin models of neurodegenerative disorders. Here, we reported that in vivo pre- and postnatal treatment with the non-specific NO synthase (NOS) inhibitor, L-NAME (60 mg/kg), or with the neuronal NOS inhibitor, 7-NI (30 mg/kg), dramatically decreased the NOS activity as well as the NADPH-diaphorase staining in brain. However, those treatments did not rescue dopamine neurons from developmental death, suggesting that NO is not involved in vivo in developmental death of these neurons or in the overall development of the SNc.

Human Meissner corpuscles express Bcl-2 but not Bax protein

Bcl-2 and Bax proteins play major roles in the control of apoptosis. The Bcl-2/Bax ratio is considered a marker of a cell's susceptibility to apoptotic stimuli. Immunohistochemical expression of Bcl-2 and Bax in Meissner corpuscles was investigated in 30 human skin samples. All of the Meissner corpuscles showed immunoreactivity for Bcl-2 and Bax was negative. These data support a role for Bcl-2 as a resistance mechanism of these mechanoreceptors to apoptosis.

A role for calcium in Bcl-2 action?

Changes in the cytosolic Ca(2+) concentration ([Ca(2+)](c)) translate a variety of extracellular signals into widely diverse intracellular effects, ranging from secretion to movement, proliferation and also cell death. As regards the last one, it has long been known that large [Ca(2+)](c) increases lead cells to death. More recently, experimental evidence has been obtained that the oncogene Bcl-2 reduces the state of filling of intracellular Ca(2+) stores and thus affects the Ca(2+) responses induced by physiological and pathological stimuli. In this contribution, we will discuss this effect and its significance for the mechanism of action of Bcl-2, an important checkpoint of the apoptotic process.