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In the present work, by using tobacco cell suspension and wheat seedlings, we studied that eATP (extracellular ATP) released by copper (Cu) stress could act as diffusible signal in alleviating the Cu stress-induced cell death. A semipermeable membrane was fixed in the middle of a plastic box to divide the box into two equal compartments (A and B, respectively). This semipermeable membrane can prevent direct cell-to-cell (or seedling-to-seedling) contact and the diffusion of the macromolecules [such as ATPase (adenosine 5'-triphosphatase)] between these two compartments. The cell suspension directly stressed with CuCl 2 was placed in compartment A and was incubated with the untreated cell suspension in compartment B. Such treatment significantly increased the levels of cell death and eATP content of the cell suspension in these two compartments. In contrast, addition of ATPase into the cell suspension directly stressed with CuCl 2 decreased the eATP level in these two compartments but further increased the level of cell death in compartment B, compared to no addition of ATPase. Similar results were obtained when tobacco cell suspension was replaced by wheat seedlings. These observations indicate that when Cu stress from compartment A induced the plant cell death in compartment B, ATP transferred from compartment A could play a role in alleviating this cell death. Thus, it is suggested that eATP released by copper stress could act as diffusible signal in alleviating the Cu stress-induced cell death.

Status epilepticus (SE) is a severe clinical manifestation of epilepsy which causes brain damage. The pathological process and underlying mechanisms involved in the programmed cell death (PCD) are still not fully clear. In the current study, rats were induced SE by lithium-pilocarpine administration. Our data showed hippocampal neurons death appeared at 6h after SE and sustained for 7 days. By blotting the activation of mu-calpain and its specific cleavage of nonerythroid alpha-spectrin (alphaSpII) (145 kDa) was evident at 1 and 3 days after SE, which coincided with Bid activation, apoptosis inducing factor (AIF) translocation and cytochrome c release from mitochondria, whereas, activated caspase-3 and caspase-3-specific fragments of alphaSpII (120 kDa) predominantly appeared at 5 and 7 days after SE. Moreover, MDL-28170, a calpain inhibitor, partially rescued the neuron death and attenuated the expression of activated mu-calpain, cleavage of Bid (15 kDa), AIF translocation and cytochrome c release. Taken together, our study indicated that mu-calpain mediated hippocampal neuron PCD is prior to caspase-3 activation. It functioned via translocation of Bid, AIF and cytochrome c release.

Recent reports have suggested that abnormal miR-29c expression in hippocampus have been implicated in the pathophysiology of some neurodegenerative and neuropsychiatric diseases. However, the underlying effect of miR-29c in regulating hippocampal neuronal function is not clear. In this study, HT22 cells were infected with lentivirus containing miR-29c or miR-29c sponge. Cell counting kit-8 (CCK8) and lactate dehydrogenase (LDH) assay kit were applied to evaluate cell viability and toxicity before and after TNF-α administration. Reactive oxygen species (ROS) generation and mitochondrial membrane potential (MMP) were measured with fluorescent probes. Hoechst 33258 staining and TUNEL assay were used to evaluate cell apoptosis. The expression of key mRNA/proteins (TNFR1, Bcl-2, Bax, TRADD, FADD, caspase-3, -8 and -9) in the apoptosis pathway was detected by PCR or WB. In addition, the protein expression of microtubule-associated protein-2 (MAP-2), nerve growth-associated protein 43 (GAP-43) and synapsin-1 (SYN-1) was detected by WB. As a result, we found that miR-29c overexpression could improve cell viability, attenuate LDH release, reduce ROS production and inhibit MMP depolarization in TNF-α-treated HT22 cells. Furthermore, miR-29c overexpression was found to decrease apoptotic rate, along with decreased expression of Bax, cleaved caspase-3, cleaved caspase-9, and increased expression of Bcl-2 in TNF-α-treated HT22 cells. However, miR-29c sponge exhibited an opposite effects. In addition, in TNF-α-treated HT22 cells, miR-29c overexpression could decrease the expressions of TNFR1, TRADD, FADD and cleaved caspase-8. However, in HT22 cells transfected with miR-29c sponge, TNF-α-induced the expressions of TNFR1, TRADD, FADD and cleaved caspase-8 was significantly exacerbated. At last, TNF-α-induced the decreased expression of MAP-2, GAP-43 and SYN-1 was reversed by miR-29c but exacerbated by miR-29c sponge. Overall, our study demonstrated that miR-29c protects against TNF-α-induced HT22 cells injury through alleviating ROS production and reduce neuronal apoptosis. Therefore, miR-29c might be a potential therapeutic agent for TNF-α accumulation and toxicity-related brain diseases. [ABSTRACT FROM AUTHOR]

Purpose: Ferroptosis is a form of regulated cell death that has the potential to be targeted as a cancer therapeutic strategy. But cancer cells have a wide range of sensitivities to ferroptosis, which limits its therapeutic potential. Accumulation of lipid peroxides determines the occurrence of ferroptosis. However, the type of lipid involved in peroxidation and the mechanism of lipid peroxide accumulation are less studied. Methods: The effects of fatty acids (10 μM) with different carbon chain length and unsaturation on ferroptosis were evaluated by MTT and LDH release assay in cell lines derived from prostate cancer (PC3, 22RV1, DU145 and LNCaP), colorectal cancer (HT-29), cervical cancer (HeLa) and liver cancer (HepG2). Inhibitors of apoptosis, necroptosis, autophagy and ferroptosis were used to determine the type of cell death. Then the regulation of reactive oxygen species (ROS) and lipid peroxidation by docosahexaenoic acid (DHA) was measured by HPLC–MS and flow cytometry. The avtive form of DHA was determined by siRNA mediated gene silencing. The role of lipoxygenases was checked by inhibitors and gene silencing. Finally, the effect of DHA on ferroptosis-mediated tumor killing was verified in xenografts. Results: The sensitivity of ferroptosis was positively correlated with the unsaturation of exogenously added fatty acid. DHA (22:6 n-3) sensitized cancer cells to ferroptosis-inducing reagents (FINs) at the highest level in vitro and in vivo. In this process, DHA increased ROS accumulation, lipid peroxidation and protein oxidation independent of its membrane receptor, GPR120. Inhibition of long chain fatty acid-CoA ligases and lysophosphatidylcholine acyltransferases didn't affect the role of DHA. DHA-involved ferroptosis can be induced in both arachidonate lipoxygenase 5 (ALOX5) negative and positive cells. Down regulation of ALOX5 inhibited ferroptosis, while overexpression of ALOX5 promoted ferroptosis. Conclusion: DHA can effectively promote ferroptosis-mediated tumor killing by increasing intracellular lipid peroxidation. Both ALOX5 dependent and independent pathways are involved in DHA-FIN induced ferroptosis. And during this process, free DHA plays an important role. [ABSTRACT FROM AUTHOR]

Glioma is a highly malignant type of intracranial tumor with a poor prognosis resulting from traditional chemo-resistance with temozolomide (TMZ). Luteolin has been detected to exert limited anti-tumor effects on gliomas, while valproic acid (VPA) is a common chemotherapy sensitizer in the treatment of tumors. In this study, three glioma cell lines including U251, LN229 and SNB19 were selected for evaluation of combined anti-tumor effects of VPA and luteolin via Cell Counting Kit-8 (CCK-8) assay, colony formation assay, wound-healing assay, flow cytometry and western blot assay. The results disclosed that VPA sensitized glioma cells to luteolin by repressing cell viability, colony formation and migration. Mechanically, VPA boosted cellular apoptosis and cell-cycle arrest by increased level of cleaved caspase-3/caspase-3, cleaved PARP/PARP and Bax/Bcl-2. In addition, VPA also facilitated cellular autophagy via the decline of p62, p-Akt/Akt and the accumulation of LC3-II. These findings suggested that VPA enhanced the anticancer effects of luteolin by strengthening apoptosis and autophagy via Akt signaling, which could be adopted as a novel therapy for glioma. [ABSTRACT FROM AUTHOR]

Background: Alzheimer’s disease (AD) is one of the most common and devastating aging related neurodegenerative diseases. Aging is a natural physiological process, a progressive deterioration of the overall homeostatic brain mechanisms, accompanied by cognitive decline. CXCL12/CXCR4 chemokine signaling plays a critical role in modulating various nervous system developmental processes and in regulating synaptic plasticity.Results: In this article, we have firstly shown that CXCR4 is critical for cell proliferation and cytotoxicity in the SH-SY5Y cell model. Moreover, it has been firstly demonstrated that CXCR4 colocalized with AKT on the membrane and regulated the AKT activation to prevent aging and AD.Discussion: In a word, we supply a novel pathway that CXCR4 pathway stimulated by CXCL12 regulated AKT activation, CREB phosphorylation and P53 level to affect the process of aging and AD. Therefore, CXCR4 may be a novel target and biomarker for the diagnosis and treatment of AD and aging. [ABSTRACT FROM AUTHOR]

Apoptosis proteins play an important role in the mechanism of programmed cell death. Predicting subcellular localization of apoptosis proteins is an essential step to understand their functions and identify drugs target. Many computational prediction methods have been developed for apoptosis protein subcellular localization. However, these existing works only focus on the proteins that have one location; proteins with multiple locations are either not considered or assumed as not existing when constructing prediction models, so that they cannot completely predict all the locations of the apoptosis proteins with multiple locations. To address this problem, this paper proposes a novel multilabel predictor named MultiP-Apo, which can predict not only apoptosis proteins with single subcellular location but also those with multiple subcellular locations. Specifically, given a query protein, GO-based feature extraction method is used to extract its feature vector. Subsequently, the GO feature vector is classified by a new multilabel classifier based on the label-specific features. It is the first multilabel predictor ever established for identifying subcellular locations of multilocation apoptosis proteins. As an initial study, MultiP-Apo achieves an overall accuracy of 58.49% by jackknife test, which indicates that our proposed predictor may become a very useful high-throughput tool in this area. [ABSTRACT FROM AUTHOR]

Background Limb remote ischemic postconditioning ( RIPost C) has been recognized as an applicable strategy in protecting against cerebral ischemic injury. However, the time window for application of limb RIPost C and the mechanisms behind RIPost C are still unclear. Aims In this study, we investigated the protective efficacy and the role of autophagy in limb RIPost C using a transient middle cerebral artery occlusion rat model. Results Limb RIPost C applied in the early phase of reperfusion reduced infarct size and improved neurological function. Autophagy levels in penumbral tissues were elevated in neurons of limb RIPost C rats, with an increase in the phosphorylation of AKT and glycogen synthase kinase 3β ( GSK3β). Blocking the AKT/ GSK3β pathway via the AKT inhibitor LY294002 prior to limb RIPost C suppressed the RIPost C-induced autophagy and resulted in the activation of caspase-3 in RIPost C rats, suggesting a critical role for AKT/ GSK3β-dependent autophagy in reducing cell death after cerebral ischemia. Conclusions These results aid optimization of the time window for RIPost C use and offer novel insight into, and a better understanding of, the protective mechanism of autophagy in limb RIPost C. [ABSTRACT FROM AUTHOR]

Brain arteriovenous malformations (BAVMs) can cause devastating stroke in young people and contribute to half of all hemorrhagic stroke in children. Unfortunately, the pathogenesis of BAVMs is unknown. In this article we show that activation of Notch signaling in the endothelium during brain development causes BAVM in mice. We turned on constitutively active Notch4 (int3) expression in endothelial cells from birth by using the tetracycline-regulatable system. All mutants developed hallmarks of BAVMs, including cerebral arteriovenous shunting and vessel enlargement, by 3 weeks of age and died by 5 weeks of age. Twenty-five percent of the mutants showed signs of neurological dysfunction, including ataxia. and seizure. Affected mice exhibited hemorrhage and neuronal cell death within the cerebral cortex and cerebellum. Strikingly, int3 repression resolved ataxia and reversed the disease progression, demonstrating that int3 is not only sufficient to induce, but also required to sustain the disease. We show that int3 expression results in widespread enlargement of the microvasculature, which coincided with a reduction in capillary density, linking vessel enlargement to Notch's known function of inhibiting vessel sprouting. Our data suggest that the Notch pathway is a molecular regulator of BAVM pathogenesis in mice, and offer hope that their regression might be possible by targeting the causal molecular lesion. [ABSTRACT FROM AUTHOR]

The c-Myc protein has been implicated in playing a pivotal role in regulating the expression of a large number of genes involved in many aspects of cellular function. Consistent with this view, embryos lacking the c-myc gene exhibit severe developmental defects and die before midgestation. Here, we show that Sox2Cre-mediated deletion of the conditional c-mycflox allele specifically in the epiblast (hence trophoectoderm and primitive endoderm structures are wild type) rescues the majority of developmental abnormalities previously characterized in c-myc knockout embryos, indicating that they are secondary defects and arise as a result of placental insufficiency. Epiblast-restricted c-Myc-null embryos appear morphologically normal and do not exhibit any obvious proliferation defects. Nonetheless, these embryos are severely anemic and die before E12. c-Myc-deficient embryos exhibit fetal liver hypoplasia, apoptosis of erythrocyte precursors and functionally defective definitive hematopoietic stem/progenitor cells. Specific deletion of c-mycflox in hemogenic or hepatocytic lineages validate the hematopoietic-specific requirement of c-Myc in the embryo proper and provide in vivo evidence to support a synergism between hematopoietic and liver development. Our results reveal for the first time that physiological levels of c-Myc are essential for cell survival and demonstrate that, in contrast to most other embryonic lineages, erythroblasts and hematopoietic stem/progenitor cells are particularly dependent on c-Myc function. [ABSTRACT FROM AUTHOR]

The clinical treatment of human acute myeloid leukemia (AML) is rapidly progressing from chemotherapy to targeted therapies led by the BCL-2 inhibitor venetoclax (VEN). Despite its unprecedented success, VEN still encounters clinical resistance. Thus, uncovering the biological vulnerability of VEN-resistant AML disease and identifying effective therapies to treat them are urgently needed. We have previously demonstrated that iron oxide nanozymes (IONE) are capable of overcoming chemoresistance in AML. The current study reports a new activity of IONE in overcoming VEN resistance. Specifically, we revealed an aberrant redox balance with excessive intracellular reactive oxygen species (ROS) in VEN-resistant monocytic AML. Treatment with IONE potently induced ROS-dependent cell death in monocytic AML in both cell lines and primary AML models. In primary AML with developmental heterogeneity containing primitive and monocytic subpopulations, IONE selectively eradicated the VEN-resistant ROS-high monocytic subpopulation, successfully resolving the challenge of developmental heterogeneity faced by VEN. Overall, our study revealed an aberrant redox balance as a therapeutic target for monocytic AML and identified a candidate IONE that could selectively and potently eradicate VEN-resistant monocytic disease. [Display omitted] • VEN-resistant monocytic AML exhibits aberrant redox balance with excessive intracellular ROS. • IONE induces ROS dependent cell death in monocytic AML cells. • In primary AML samples with mixed subpopulations, IONE selectively eradicated the VEN-resistant monocytic subpopulation. • IONE potently resolves the challenge of developmental heterogeneity faced by VEN. [ABSTRACT FROM AUTHOR]

Large tumor suppressor 2 (LATS2), an important mediator of the cell apoptotic response pathway, has been linked to the progression of several cancers. Here, we described the molecular feature of LATS2 as a novel antitumor factor in liver cancer cells in vitro. Western blotting was used to detect the expression of LATS2 and its downstream factors. ELISA, immunofluorescence, and flow cytometry were used to evaluate the alterations of mitochondrial function in response to LATS2 overexpression. Adenovirus-loaded LATS2 and siRNA against DRP1 were transfected into liver cancer cells to overexpress LATS2 and knockdown DRP1 expression, respectively. The results of the present study demonstrated that overexpression of LATS2 was closely associated with more liver cancer cell death. Mechanistically, LATS2 overexpression increased the expression of DRP1, and DRP1 elevated mitochondrial division, an effect that was accompanied by mitochondrial dysfunction, including mitochondrial membrane potential reduction, mitochondrial respiratory complex downregulation, mitochondrial cyt-c release into the nucleus and mitochondrial oxidative injury. Moreover, LATS2 overexpression also initiated mitochondrial apoptosis, and this process was highly dependent on DRP1-related mitochondrial division. Molecular investigations demonstrated that LATS2 modulated DRP1 expression via the Wnt/β-catenin pathway. Inhibition of the Wnt/β-catenin pathway pregented LATS2-mediated DRP1 upregulation, ultimately sustaining mitochondrial function and cell viability in the presence of LATS2 overexpression. Altogether, the above data identify LATS2-Wnt/β-catenin/DRP1/mitochondrial division as a novel anticancer signaling pathway promoting cancer cell death, which might be an attractive therapeutic target for the treatment of hepatocellular carcinoma. [ABSTRACT FROM AUTHOR]

Abstract: Ghrelin, a 28-amino-acid peptide, is mainly secreted by the stomach. Evidence has shown ghrelin to have neuroprotective effects. However, whether ghrelin protects hippocampal neurons against cell death in pilocarpine-induced seizures is unknown. We used Nissl staining to show that ghrelin attenuated the neuronal loss caused by pilocarpine-induced seizures in the hippocampus. Ghrelin exerted the protective action through regulating the phosphatidylinositol-3-kinase and Akt pathway. Moreover, ghrelin treatment reversed the decreased ratio of Bcl-2 to Bax induced by seizures while inhibiting the activated caspase-3. Ghrelin can inhibit hippocampal neuronal damage caused by pilocarpine-induced seizures, which might have therapeutic value in seizures. [Copyright &y& Elsevier]

Abstract: Status epilepticus (SE) is a severe clinical manifestation of epilepsy which causes brain damage. The pathological process and underlying mechanisms involved in the programmed cell death (PCD) are still not fully clear. In the current study, rats were induced SE by lithium–pilocarpine administration. Our data showed hippocampal neurons death appeared at 6h after SE and sustained for 7 days. By blotting the activation of μ-calpain and its specific cleavage of nonerythroid α-spectrin (αSpII) (145kDa) was evident at 1 and 3 days after SE, which coincided with Bid activation, apoptosis inducing factor (AIF) translocation and cytochrome c release from mitochondria, whereas, activated caspase-3 and caspase-3-specific fragments of αSpII (120kDa) predominantly appeared at 5 and 7 days after SE. Moreover, MDL-28170, a calpain inhibitor, partially rescued the neuron death and attenuated the expression of activated μ-calpain, cleavage of Bid (15kDa), AIF translocation and cytochrome c release. Taken together, our study indicated that μ-calpain mediated hippocampal neuron PCD is prior to caspase-3 activation. It functioned via translocation of Bid, AIF and cytochrome c release. [Copyright &y& Elsevier]