scholarly journals Xenopus LAP2β protein knockdown affects location of lamin B and nucleoporins and has effect on assembly of cell nucleus and cell viability

PROTOPLASMA ◽  
2015 ◽  
Vol 253 (3) ◽  
pp. 943-956 ◽  
Author(s):  
Magda Dubińska-Magiera ◽  
Magdalena Chmielewska ◽  
Katarzyna Kozioł ◽  
Magdalena Machowska ◽  
Christopher J. Hutchison ◽  
...  
Keyword(s):  
Cell Death ◽  
Protein Expression ◽  
Nuclear Envelope ◽  
Cell Viability ◽  
Cell Nucleus ◽  
Chromatin Structure ◽  
Integral Membrane Proteins ◽  
Nuclear Abnormalities ◽  
Lamin B ◽  
A Cell

Abstract Xenopus LAP2β protein is the single isoform expressed in XTC cells. The protein localizes on heterochromatin clusters both at the nuclear envelope and inside a cell nucleus. The majority of XLAP2β fraction neither colocalizes with TPX2 protein during interphase nor can be immunoprecipitated with XLAP2β antibody. Knockdown of the XLAP2β protein expression in XTC cells by synthetic siRNA and plasmid encoded siRNA resulted in nuclear abnormalities including changes in shape of nuclei, abnormal chromatin structure, loss of nuclear envelope, mislocalization of integral membrane proteins of INM such as lamin B2, mislocalization of nucleoporins, and cell death. Based on timing of cell death, we suggest mechanism associated with nucleus reassembly or with entry into mitosis. This confirms that Xenopus LAP2 protein is essential for the maintenance of cell nucleus integrity and the process of its reassembly after mitosis.

scholarly journals Pituitary Adenylate Cyclase Activating Polypeptide Elicits Neuroprotection Against Acute Ischemic Neuronal Cell Death Associated with NMDA Receptors

2018 ◽  
Vol 51 (4) ◽  
pp. 1982-1995 ◽  
Author(s):  
Yuji Kaneko ◽  
Julian P. Tuazon ◽  
Xunming Ji ◽  
Cesario V. Borlongan
Keyword(s):  
Cell Death ◽  
Adenylate Cyclase ◽  
Protein Expression ◽  
Cell Viability ◽  
Caspase 3 ◽  
High Mobility ◽  
High Mobility Group ◽  
Expression Levels ◽  
Pituitary Adenylate Cyclase ◽  
Nmdar Subunits

Background/Aims: The endogenous neurotrophic peptides pituitary adenylate cyclase-activating polypeptides (PACAP-27/38) protect against stroke, but the molecular mechanism remains unknown. Methods: Primary rat neural cells were exposed to PACAP-27 or PACAP-38 before induction of experimental acute ischemic stroke via oxygen-glucose deprivation-reperfusion (OGD/R) injury. To reveal PACAP’s role in neuroprotection, we employed fluorescent live/dead cell viability and caspase 3 assays, optical densitometry of mitochondrial dehydrogenase and cell growth, glutathione disulfide luciferase activity, ELISA for high mobility group box1 extracellular concentration, ATP bioluminescence, Western blot analysis of PACAP, NMDA subunits, apoptosis regulator Bcl-2, social interaction hormone oxytocin, and trophic factor BDNF, and immunocytochemical analysis of PACAP. Results: Both PACAP-27 and PACAP-38 (PACAP-27/38) increased cell viability, decreased oxidative stress-induced cell damage, maintained mitochondrial activity, prevented the release of high mobility group box1, and reduced cytochrome c/caspase 3-induced apoptosis. PACAP-27/38 increased the protein expression levels of BDNF, Bcl-2, oxytocin, and precursor PACAP. N-methyl-D-aspartate receptor (NMDAR)-induced excitotoxicity contributes to the cell death associated with stroke. PACAP-27/38 modulated the protein expression levels of NMDAR subunits. PACAP-27/38 increased the protein expression levels of the GluN1 subunit, and decreased that of the GluN2B and GluN2D subunits. PACAP-27, but not PACAP-38, increased the expression level of the GluN2C subunit. Conclusion: This study provides evidence that PACAP regulated NMDAR subunits, affording neuroprotection after OGD/R injury.

scholarly journals SIRT3-SOD2-ROS pathway is involved in Linalool-induced glioma cell apoptotic death

2017 ◽  
Vol 64 (2) ◽  
Author(s):  
Yanhao Cheng ◽  
Chao Dai ◽  
Jian Zhang
Keyword(s):  
Cell Death ◽  
Protein Expression ◽  
Cell Viability ◽  
Glioma Cell ◽  
Apoptotic Cell ◽  
Immunoblot Analysis ◽  
Apoptotic Cell Death ◽  
Dependent Manner ◽  
Sod Activity ◽  
Mrna And Protein Expression

Glioma is the most prevalent type of adult primary brain tumor and chemotherapy of glioma was limited by drug-resistance. Linalool is an acyclic monoterpene alcohol possessing various pharmacological activities. The present study was conducted to evaluate the effect of Linalool on glioma cell growth. The effect of Linalool on U87-MG cells was investigated and the results showed that Linalool significantly reduced cell viability in U87-MG cells in a concentration and time-dependent manner. In addition, exposure of cells to Linalool resulted in concentration-dependent increase of TUNEL-stained cells, indicating the occurrence of apoptotic cell death. Linalool decreased mitochondrial oxygen consumption rate, increased the expression of Bax and Bcl-2, reduced the expression of Bcl-2 and Bcl-xl, and increased the activities of caspase 3 and caspase 9, leading to increase of apoptosis. Linalool resulted in a concentration-dependent decrease of SOD activity but had no significant effect on the mRNA and protein expression of SOD2. Moreover, Linalool resulted in a significant increase of acetylated SOD2. The mRNA and protein expression of SIRT3 was significantly inhibited by Linalool. Immunoblot analysis showed that there were protein/protein interaction of SOD2 and SIRT3 in control U87-MG cells. Linalool treatment significantly decreased the interaction of SOD2 and SIRT3. Overexpression of SIRT3 significantly inhibited Linalool-induced increase of mitochondrial ROS level, apoptotic cell death and decrease of cell viability. In summary, we found that Linalool exhibited inhibitory effect on glioma cells through regulation of SIRT3-SOD2-ROS signaling.

scholarly journals Regulatory elements can be essential for maintaining broad chromatin organization and cell viability

2020 ◽  
Author(s):  
Ying Liu ◽  
Bo Ding ◽  
Lina Zheng ◽  
Ping Xu ◽  
Zhiheng Liu ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Viability ◽  
Cell Survival ◽  
Chromatin Structure ◽  
Synergistic Effects ◽  
Regulatory Elements ◽  
Essential Genes ◽  
Chromatin Organization ◽  
Cellular Functions ◽  
3D Chromatin Structure

Increasing evidence shows that promoters and enhancers could be related to 3D chromatin structure, thus affecting cellular functions. Except for functioning through the canonical chromatin loops formed by promoters and enhancers, their roles in maintaining broad chromatin organization have not been well studied. Here, we focused on the active promoters/enhancers (referred to as hotspots) predicted to form many 3D contacts with other active promoters/enhancers, and identified dozens of loci critical for cell survival. While the essentiality of hotspots is not resulted from their association with essential genes, deletion of an essential hotspot could lead to change of broad chromatin organization and expressions of distal genes. We demonstrated that multiple affected genes that are individually non-essential could have synergistic effects to cause cell death.

scholarly journals UXT Is a Novel Centrosomal Protein Essential for Cell Viability

2005 ◽  
Vol 16 (12) ◽  
pp. 5857-5865 ◽  
Author(s):  
Huiwu Zhao ◽  
Qiang Wang ◽  
Hongtao Zhang ◽  
Qingdu Liu ◽  
Xiulian Du ◽  
...  
Keyword(s):  
Cell Death ◽  
Protein Expression ◽  
Cell Viability ◽  
Small Interfering Rna ◽  
Human Tumor ◽  
Centrosomal Protein ◽  
Normal Tissues ◽  
Tumor Tissues ◽  
Rna Knockdown ◽  
Interfering Rna

Ubiquitously expressed transcript (UXT) is a prefoldinlike protein that has been suggested to be involved in human tumorigenesis. Here, we have found that UXT is overexpressed in a number of human tumor tissues but not in the matching normal tissues. We demonstrate that UXT is located in human centrosomes and is associated with γ-tubulin. In addition, overexpression of UXT disrupts centrosome structure. Furthermore, abrogation of UXT protein expression by small interfering RNA knockdown leads to cell death. Together, our findings suggest that UXT is a component of centrosome and is essential for cell viability. We propose that UXT may facilitate transformation by corrupting regulated centrosome functions.

scholarly journals DNA replication in cell-free extracts from Xenopus eggs is prevented by disrupting nuclear envelope function

1992 ◽  
Vol 101 (1) ◽  
pp. 43-53 ◽  
Author(s):  
L.S. Cox
Keyword(s):  
Dna Replication ◽  
Nuclear Envelope ◽  
Cell Nucleus ◽  
Wheat Germ ◽  
Nuclear Dna ◽  
Nuclear Transport ◽  
Sperm Chromatin ◽  
Cell Free Extract ◽  
Nuclear Assembly ◽  
A Cell

The lectin, wheat germ agglutinin (WGA), has previously been shown to prevent transport into the cell nucleus. This paper shows that WGA also inhibits nuclear DNA replication, under the same conditions that prevent transport. Although WGA eliminates sperm nuclear DNA replication in a cell-free extract of Xenopus eggs, DNA synthesis on a single-stranded template proceeds normally. Inhibition of nuclear DNA replication is partially reversed by addition of N-acetylglucosamine, and completely reversed by triacetylchitotriose. Sensitivity to inhibition by WGA is greatest during the nuclear assembly phase, and nuclear formation on sperm chromatin is blocked. DNA replication in preformed nuclear templates is also sensitive to WGA inhibition. I propose that WGA blocks DNA replication by preventing nuclear transport. The data presented here also indicate that, under certain circumstances, the elongation stage of DNA replication does not proceed in the absence of an intact nuclear envelope. The roles of the nuclear envelope and active nuclear transport in DNA replication are discussed.

scholarly journals Correction to: Xenopus LAP2β protein knockdown affects location of Lamin B and nucleoporins and has effect on assembly of cell nucleus and cell viability

PROTOPLASMA ◽  
2020 ◽  
Vol 257 (1) ◽  
pp. 331-332
Author(s):  
Magda Dubińska-Magiera ◽  
Magdalena Chmielewska ◽  
Katarzyna Kozioł ◽  
Magdalena Machowska ◽  
Christopher J. Hutchison ◽  
...  
Keyword(s):  
Cell Viability ◽  
Cell Nucleus ◽  
Lamin B

scholarly journals AB0068 NOVEL CHONDROPROTECTIVE AND ANTI-INFLAMMATORY EFFECTS OF THE SELECTIVE HUMAN MELANOCORTIN MC3 RECEPTOR AGONIST PG-990 ON SNAP ACTIVATED CHONDROCYTES

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1334.2-1335
Author(s):  
V. Can ◽  
I. Locke ◽  
P. Grieco ◽  
S. Getting
Keyword(s):  
Cell Death ◽  
Protein Expression ◽  
Cell Viability ◽  
Cell Line ◽  
Receptor Agonist ◽  
Caspase 3 ◽  
Degenerative Joint Disease ◽  
Joint Disease ◽  
Blue Staining ◽  
Anti Inflammatory

Background:Osteoarthritis (OA) is a degenerative joint disease that affects over 250 million people worldwide [1] with treatments focussing on the symptoms rather than the cause of the pathology [2, 3]. Thus, this degenerative joint disease requires novel treatment options [3, 4].Therefore, the melanocortin system [4] could provide a novel avenue to explore given its ability to exert anti-inflammatory effects and chondroprotection [5], although the receptor subtype involved is unclear.Objectives:This study aims to assess the chondroprotective and anti-inflammatory effects of the selective human melanocortin MC1 receptor agonist BMS-470539 dihydrochloride and the selective human MC3 receptor agonist PG-990 on S-Nitroso-N-acetyl-DL-penicillamine (SNAP) activated chondrocytes.Methods:The human chondrocytic cell-line C-20/A4 was seeded at 25.0 x 106viable cells/ml (5 μl droplet was transferred into individual wells of a 96-well plate). Micromass cultures [6] were stimulated with SNAP (1.0 mM) and after 2h treated with Dexamethasone (1.0 μM), selective human melanocortin MC1 receptor agonist BMS-470539 dihydrochloride (10.0 μg/ml) or selective human melanocortin MC3 receptor agonist PG-990 (10.0 μg/ml) for 6h. Cell viability was determined by MTT assay, Caspase -3 and -7 activity determined by Caspase-Glo 3/7 apoptosis assay. Glycosaminoglycan (GAG) content determined by alcian blue staining and anti-inflammatory heme-oxygenase-1 (HO-1) protein expression was determined by western blot. Data are expressed as Mean ±S.E.M ofn=4 samples repeated in triplicate. #p≤0.05vscontrol or *p≤0.05vsstimulus.Results:Cell viability analysis showed SNAP stimulation caused a maximal cell death of 23% (#p≤0.05), Dexamethasone, BMS-470539 dihydrochloride and PG-990 inhibited cell death by 2%, 98% and 129% respectively (*p≤0.05). SNAP stimulation caused a significant increase in Caspase -3 and -7 activity, which was inhibited by Dexamethasone, BMS-470539 dihydrochloride and PG-990 by 8%, 5% and 19% respectively (*p≤0.05). GAG content was significantly reduced by SNAP by 29% (#p≤0.05), which was inhibited by Dexamethasone, BMS-470539 dihydrochloride and PG-990 by 1%, 3% and 14% respectively (*p≤0.05). SNAP also caused a significant decrease in HO-1 protein expression, which was increased by Dexamethasone, BMS-470539 dihydrochloride and PG-990 by a 1.0-fold, 1.1-fold and 2.1-fold increase respectively (*p≤0.05).Conclusion:The selective human melanocortin MC3 receptor agonist PG-990 exhibited enhanced chondroprotection and modulation of inflammatory and tissue destructive mediators following SNAP activation compared to Dexamethasone and the selective human melanocortin MC1 receptor agonist BMS-470539 dihydrochloride. This suggests that melanocortin peptides display enhanced chondroprotective and anti-inflammatory effects at the MC3 receptor sub-type in this cell line.References:[1]Hunter DJ and Bierma-Zeinstra S. (2019).Lancet.393: 1745–59.[2]Can VCet al.(2020).Euro J Pharmacol. doi:https://doi.org/10.1016/j.ejphar.2020.172971.[3]Intekhab-Alam NYet al. (2013).Cell death & disease.4: 1-6.[4]Getting SJet al.(2006).Mol Pharmacol70: 1850-1855.[5]Kaneva MKet al.(2014).Biochem Pharmacol92: 336-47.[6]Greco KVet al.(2011).Biochem Pharmacol82: 1919-29.Disclosure of Interests:None declared

Nuclear Envelope Dynamics During Mitosis

1988 ◽  
Vol 46 ◽  
pp. 224-225
Author(s):  
Brian Burke
Keyword(s):  
Nuclear Envelope ◽  
Membrane Vesicles ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Animal Cells ◽  
Interphase Chromosome ◽  
Lamin B ◽  
Chromosome Architecture ◽  
Complex Membrane ◽  
Pore Complexes

The nuclear envelope is a complex membrane structure that forms the boundary of the nuclear compartment in eukaryotes. It regulates the passage of macromolecules between the two compartments and may be important for organizing interphase chromosome architecture. In interphase animal cells it forms a remarkably stable structure consisting of a double membrane ouerlying a protein meshwork or lamina and penetrated by nuclear pore complexes. The latter form the channels for nucleocytoplasmic exchange of macromolecules, At the onset of mitosis, however, it rapidly disassembles, the membranes fragment to yield small vesicles and the lamina, which is composed of predominantly three polypeptides, lamins R, B and C (MW approx. 74, 68 and 65 kDa respectiuely), breaks down. Lamins B and C are dispersed as monomers throughout the mitotic cytoplasm, while lamin B remains associated with the nuclear membrane vesicles.

Lamin B receptor: role on chromatin structure, cellular senescence and possibly aging

2020 ◽  
Vol 477 (14) ◽  
pp. 2715-2720
Author(s):  
Susana Castro-Obregón
Keyword(s):  
Cellular Senescence ◽  
Nuclear Membrane ◽  
Chromatin Structure ◽  
Cholesterol Synthesis ◽  
Reductase Activity ◽  
Chimeric Protein ◽  
Nuclear Lamina ◽  
Lamin B ◽  
Inner Nuclear Membrane ◽  
Lamin B Receptor

The nuclear envelope is composed by an outer nuclear membrane and an inner nuclear membrane, which is underlain by the nuclear lamina that provides the nucleus with mechanical strength for maintaining structure and regulates chromatin organization for modulating gene expression and silencing. A layer of heterochromatin is beneath the nuclear lamina, attached by inner nuclear membrane integral proteins such as Lamin B receptor (LBR). LBR is a chimeric protein, having also a sterol reductase activity with which it contributes to cholesterol synthesis. Lukasova et al. showed that when DNA is damaged by ɣ-radiation in cancer cells, LBR is lost causing chromatin structure changes and promoting cellular senescence. Cellular senescence is characterized by terminal cell cycle arrest and the expression and secretion of various growth factors, cytokines, metalloproteinases, etc., collectively known as senescence-associated secretory phenotype (SASP) that cause chronic inflammation and tumor progression when they persist in the tissue. Therefore, it is fundamental to understand the molecular basis for senescence establishment, maintenance and the regulation of SASP. The work of Lukasova et al. contributed to our understanding of cellular senescence establishment and provided the basis that lead to the further discovery that chromatin changes caused by LBR reduction induce an up-regulated expression of SASP factors. LBR dysfunction has relevance in several diseases and possibly in physiological aging. The potential bifunctional role of LBR on cellular senescence establishment, namely its role in chromatin structure together with its enzymatic activity contributing to cholesterol synthesis, provide a new target to develop potential anti-aging therapies.

A Cell Death Pathway Induced by Antibody-Mediated Cross-Linking of CD45 on Lymphocytes

2003 ◽  
Vol 23 (5-6) ◽  
pp. 421-440 ◽  
Author(s):  
Ann-Muriel Steff ◽  
Marylene Fortin ◽  
Fabianne Philippoussis ◽  
Sylvie Lesage ◽  
Chantal Arguin ◽  
...  
Keyword(s):  
Cell Death ◽  
Cross Linking ◽  
Cell Death Pathway ◽  
A Cell
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