scholarly journals Differential activation of Fas (CD95) mediated apoptosis by apple procyanidins in human colon cancer cells SW480 and their derived metastatic cells SW620

2011 ◽  
pp. 166-176
Author(s):  
María Elena Maldonado-Celis ◽  
Souad Bousserouel ◽  
Francine Gossé ◽  
Annelise Lobstein ◽  
Francis Raul
Keyword(s):  
Membrane Potential ◽  
Dna Fragmentation ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Human Colon ◽  
Apoptotic Pathway ◽  
Fas Receptor ◽  
Metastatic Cells ◽  
Sw480 Cells ◽  
Sw620 Cells

Introduction: We investigated the effects of apple procyanidins (Pcy), oligomers of catechins and epicatechins on Fas receptor expression and function in human colon adenocarcinoma cells (SW480) and in their derived metastatic cells (SW620). Methods: Pcy were characterized by reverse-phase HPLC. Cell death, Fas proteins, DNA fragmentation, and mitochondrial membrane potential were analyzed by flow cytometry. Fas mRNA was analyzed by RT-PCR in real time. Results: Pcy up-regulated the expression of the Fas receptor at the cell surface of both cell lines but activated Fas gene transcription only in SW620 cells. In SW480 cells, Pcy combined with Fas agonist CH-11 enhanced Fas-mediated apoptosis involving the loss of mitochondrial membrane potential and DNA fragmentation, which were abrogated by the antagonist antibody of Fas receptor, the anti-Fas ZB4. On the contrary, in SW620 cells, CH-11 was not able to enhance Pcy-triggered apoptosis indicating that Fas receptor-mediated apoptosis was not activated in these cells despite an up-regulation of Fas receptor gene expression. However, it was observed in SW620 cells that Pcy activated the Fas receptor-mediated apoptotic pathway after a specific blockage of TRAIL-death DR4/DR5 receptors. Conclusions: The present data showed that Pcy were able to activate the Fas receptor apoptotic pathway in SW480 cells and favored a cross-talk between TRAIL and Fas receptors in SW620 cells because specific blocking of TRAIL death receptors favored activation of the Fas receptor-mediated apoptosis. These important data may allow the emergence of new therapeutic protocols targeting death receptors against resistant metastatic cells.

scholarly journals p38-mediated Regulation of an Fas-associated Death Domain Protein-independent Pathway Leading to Caspase-8 Activation during TGFβ-induced Apoptosis in Human Burkitt Lymphoma B Cells BL41

2001 ◽  
Vol 12 (10) ◽  
pp. 3139-3151 ◽  
Author(s):  
Nicolas Schrantz ◽  
Marie-Françoise Bourgeade ◽  
Shahul Mouhamad ◽  
Gérald Leca ◽  
Surendra Sharma ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Transforming Growth Factor ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Caspase 8 ◽  
Death Domain ◽  
Apoptotic Pathway ◽  
Domain Protein

On binding to its receptor, transforming growth factor β (TGFβ) induces apoptosis in a variety of cells, including human B lymphocytes. We have previously reported that TGFβ-mediated apoptosis is caspase-dependent and associated with activation of caspase-3. We show here that caspase-8 inhibitors strongly decrease TGFβ-mediated apoptosis in BL41 Burkitt's lymphoma cells. These inhibitors act upstream of the mitochondria because they inhibited the loss of mitochondrial membrane potential observed in TGFβ-treated cells. TGFβ induced caspase-8 activation in these cells as shown by the cleavage of specific substrates, including Bid, and the appearance of cleaved fragments of caspase-8. Our data show that TGFβ induces an apoptotic pathway involving sequential caspase-8 activation, loss of mitochondrial membrane potential, and caspase-9 and -3 activation. Caspase-8 activation was Fas-associated death domain protein (FADD)-independent because cells expressing a dominant negative mutant of FADD were still sensitive to TGFβ-induced caspase-8 activation and apoptosis. This FADD-independent pathway of caspase-8 activation is regulated by p38. Indeed, TGFβ-induced activation of p38 and two different inhibitors specific for this mitogen-activated protein kinase pathway (SB203580 and PD169316) prevented TGFβ-mediated caspase-8 activation as well as the loss of mitochondrial membrane potential and apoptosis. Overall, our data show that p38 activation by TGFβ induced an apoptotic pathway via FADD-independent activation of caspase-8.

114 Omega-3-enriched diet improves fertilization competence of cryopreserved sperm

2020 ◽  
Vol 32 (2) ◽  
pp. 184
Author(s):  
D. Kalo ◽  
D. Reches ◽  
A. Komsky-Elbaz ◽  
U. Moallem ◽  
Y. Zeron ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Dna Fragmentation ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Semen Quality ◽  
Sperm Quality ◽  
Fatty Acid Content ◽  
Moderate Increase ◽  
Omega 3 ◽  
Feeding Trial

Intensive reproductive management in dairy herds is mostly based on AI using high-merit bulls. Therefore, semen quality of bulls is of high importance. An association between semen quality and fatty acid content in feed has been suggested. Accordingly, the aim of this study was to examine the effect of omega-3 supplementation on sperm traits and fertilization competence. Fifteen Israeli Holstein bulls were assigned to three experimental groups. Bulls were fed over 13 weeks with a standard ration top-dressed with encapsulated-fat supplementation-fish oil (FO) or flaxseed oil (FLX; i.e. omega-3 sources), or saturated fatty acids (SFA, control). Ejaculates were collected before initiation of the study, during the feeding trial, and 1 month after feeding trial. Ejaculates were treated according to the routine procedure of the Israeli AI centre (Sion Ltd.), frozen, and stored in straws. Frozen-thawed samples were subjected to “swim-up” procedure, and spermatozoon viability, mitochondrial membrane potential, reactive oxygen species (ROS) level, acrosome membrane integrity, and DNA fragmentation were evaluated via flow cytometry, using sperm-specific kits (EasyCyte, IMV Technologies). Feeding with FO, FLX, or SFA did not affect the viability or mitochondrial membrane potential of sperm collected before, during, or after the feeding trial. On the other hand, a reduced proportion of sperm with ROS expression was recorded in the FLX samples compared to the SFA sample at the end of the feeding trial (42.2±1.2 vs. 47.3±4.3%, respectively; P<0.05) and one month later (36.3±2.2 vs. 41.6±4.6%, respectively; P<0.05). A low proportion of sperm with damaged acrosomal membrane was observed in both FLX and FO samples compared with SFA at the end of the feeding trial (48.8±3.4 and 41.7±2.7 vs. 59.8±3.4%, respectively; P<0.05). The proportion of sperm with fragmented DNA was lower in the FLX group than in the SFA group, collected one month after the end of the feeding trial (2.3±0.6 vs. 5.4±1.2%, respectively; P<0.05). To examine fertilization competence, oocytes were aspirated from ovaries collected from a local abattoir, then matured (n=216; 3 replicates) and fertilized invitro with a pool of samples from each group, collected one month after the end of the feeding trial (n=5 samples per group). The proportions of 2- to 4-cell-stage embryos and of blastocysts were determined 42h and 8 days after fertilization, respectively. Although the proportion of cleaved embryos did not differ between groups, a higher blastocyst formation rate was recorded in the FLX group (P<0.05), and a moderate increase was noted in the FO group, relative to the SFA group (28.1±4.4, 19.1±2.6, and 11.9±3.4%, respectively). Results imply that feeding bulls with omega-3 originating from FLX improves sperm quality, most likely due to improved redox status and decreased DNA fragmentation. This nutritional approach seems to be an effective tool for improving bull fertility competence. Nevertheless, invivo examination is required.

scholarly journals Platelet-activating factor-induced apoptosis is blocked by Bcl-2 in rat intestinal epithelial cells

2004 ◽  
Vol 286 (2) ◽  
pp. G340-G350 ◽  
Author(s):  
Jing Lu ◽  
Michael S. Caplan ◽  
Anita P. Saraf ◽  
Dan Li ◽  
Luba Adler ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Epithelial Cells ◽  
Dna Fragmentation ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Caspase 3 ◽  
Intestinal Epithelial Cells ◽  
Regulatory Gene ◽  
Mucosal Injury ◽  
Intestinal Epithelial

Plateletactivating factor (PAF) is a key mediator in pathogenesis of inflammatory bowel diseases (IBDs) but mechanisms of PAF-induced mucosal injury are poorly understood. To determine whether apoptosis and the Bcl-2-family of apoptosis regulatory gene products play a role in PAF-induced mucosal injury, we stably and conditionally overexpressed bcl-2 in rat small intestinal epithelial cells-6 under the control of a lactose-inducible promoter. Western blot analysis and immuno-histochemistry were used to verify inducible Bcl-2 and to analyze Bcl-2 and a proapoptotic member of the Bcl-2 family, Bax, subcellular distribution. DNA fragmentation was quantified by ELISA, caspase activity was measured by using fluorogenic peptide substrates, and mitochondrial membrane potential was assayed by 5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazolylcarbocyanine iodide (JC-1) and fluorescence digital imaging. Bcl-2 expression was highly inducible by lactose analog isopropyl-β-d-thiogalactoside (IPTG) and was localized predominantly to mitochondria. In the absence of bcl-2 overexpression and after treatment with PAF, Bax translocated to mitochondria, and mitochondrial membrane potential collapsed within 1 h, followed by caspase-3 activation, which peaked at 6 h with an ensuing DNA fragmentation maximizing at 18 h. After IPTG-induction of bcl-2 expression, PAF failed to induce DNA fragmentation, caspase-3 activation, Bax translocation, or a collapse of mitochondrial membrane potential. These data are the first to show that PAF can activate apoptotic machinery in enterocytes via a mechanism involving Bax translocation and collapse of mitochondrial membrane potential and that both of these events are under control by bcl-2 expression levels. A better understanding of the role of PAF and Bcl-2 family of apoptosis regulators in epithelial cell death might aid design of better therapeutic or preventive strategies for IBDs.

scholarly journals Ovarian fragment sizes affect viability and morphology of preantral follicles during storage at 4°C

Reproduction ◽  
2017 ◽  
Vol 153 (5) ◽  
pp. 577-587 ◽  
Author(s):  
G D A Gastal ◽  
B G Alves ◽  
K A Alves ◽  
M E M Souza ◽  
A D Vieira ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Dna Fragmentation ◽  
Cell Density ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Stromal Cell ◽  
Ovarian Tissue ◽  
Ovarian Tissue Cryopreservation ◽  
Preantral Follicles ◽  
Whole Ovary

The method of transportation and the conditions imposed on the ovarian tissue are pivotal aspects for the success of ovarian tissue cryopreservation (OTC). The aim of this study was to evaluate the effect of the size of the ovarian tissue (e.g. whole ovary, biopsy size and transplant size) during different times of storage (0, 6, 12 and 24 h) on the structural integrity of equine ovarian tissue transported at 4°C. Eighteen pairs of ovaries from young mares (<10 years old) were harvested in a slaughterhouse and processed to simulate the fragment sizes (biopsy and transplant size groups) or kept intact (whole ovary group) and stored at 4°C for up to 24 h in α-MEM-enriched solution. The effect of the size of the ovarian tissue was observed on the morphology of preantral follicles, stromal cell density, DNA fragmentation and mitochondrial membrane potential. The results showed that (i) biopsy size fragments had more morphologically normal preantral follicles after 24 h of storage at 4°C; (ii) mitochondrial membrane potential was the lowest during each storage time when the whole ovary was used; (iii) DNA fragmentation rate in the ovarian cells of all sizes of fragments increased as storage was prolonged and (iv) transplant size fragments had increased stromal cell density during storage at cool temperature. In conclusion, the biopsy size fragment was the best to preserve follicle morphology for long storage (24 h); however, transportation/storage should be prior determined according to the distance (time of transportation) between patient and reproduction centers/clinics.

scholarly journals Selective Targeting of Non-nuclear Estrogen Receptors with PaPE-1 as a New Treatment Strategy for Alzheimer’s Disease

2020 ◽  
Vol 38 (4) ◽  
pp. 957-966
Author(s):  
Agnieszka Wnuk ◽  
Karolina Przepiórska ◽  
Joanna Rzemieniec ◽  
Bernadeta Pietrzak ◽  
Małgorzata Kajta
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Membrane Potential ◽  
Estrogen Receptors ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Neurodegenerative Disorder ◽  
Apoptotic Pathway ◽  
Selective Targeting ◽  
Nuclear Estrogen Receptors

Abstract Alzheimer’s disease (AD) is a multifactorial and severe neurodegenerative disorder characterized by progressive memory decline, the presence of Aβ plaques and tau tangles, brain atrophy, and neuronal loss. Available therapies provide moderate symptomatic relief but do not alter disease progression. This study demonstrated that PaPE-1, which has been designed to selectively activate non-nuclear estrogen receptors (ERs), has anti-AD capacity, as evidenced in a cellular model of the disease. In this model, the treatment of mouse neocortical neurons with Aβ (5 and 10 μM) induced apoptosis (loss of mitochondrial membrane potential, activation of caspase-3, induction of apoptosis-related genes and proteins) accompanied by increases in levels of reactive oxygen species (ROS) and lactate dehydrogenase (LDH) as well as reduced cell viability. Following 24 h of exposure, PaPE-1 inhibited Aβ-evoked effects, as shown by reduced parameters of neurotoxicity, oxidative stress, and apoptosis. Because PaPE-1 downregulated Aβ-induced Fas/FAS expression but upregulated that of Aβ-induced FasL, the role of PaPE-1 in controlling the external apoptotic pathway is controversial. However, PaPE-1 normalized Aβ-induced loss of mitochondrial membrane potential and restored the BAX/BCL2 ratio, suggesting that the anti-AD capacity of PaPE-1 particularly relies on inhibition of the mitochondrial apoptotic pathway. These data provide new evidence for an anti-AD strategy that utilizes the selective targeting of non-nuclear ERs with PaPE-1.

265 TESTICULAR DEGENERATION AFFECTED PLASMA, ACROSOMAL AND MITOCHONDRIAL MEMBRANE INTEGRITY, AND DNA FRAGMENTATION IN RAM SPERMATOZOA

2015 ◽  
Vol 27 (1) ◽  
pp. 222
Author(s):  
M. Bianchi Rodrigues Alves ◽  
A. Furugen Cesar de Andrade ◽  
R. Paes de Arruda ◽  
L. Batissaco ◽  
R. Lançoni ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Membrane Potential ◽  
Dna Fragmentation ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Membrane Integrity ◽  
Mitochondrial Potential ◽  
Plasma Membrane Integrity ◽  
Scrotal Insulation ◽  
Testicular Degeneration

Testicular degeneration, an important cause of male infertility, adversely affects sperm motility and morphology. However, few studies describe effects on integrity of plasma and acrosomal membranes, mitochondrial membrane potential, and DNA fragmentation; therefore, they were evaluated in the present study. Testicular degeneration was induced in 17 White Dorper rams (scrotal insulation for 72 h). Semen was collected (artificial vagina) twice before insulation and twice thereafter (15-day intervals between post-insulation collections). Sperm motility and morphology were analysed by SCA software (Sperm Class Analyser®, MICROPTIC®, Barcelona, Spain) and differential interference contrast microscopy (DIC, model 80i, Nikon, Tokyo, Japan), respectively. Membrane integrity and potential were assessed with fluorescent probes: Hoescht 33342, propidium iodide, FITC-PSA, and JC-1 (Celeghini et al. 2010 Arq. Bras. Med. Vet. Zootec. 62, 536–543) and imaged with fluorescence microscopy (Nikon Model 80i, Nikon, Tokyo, Japan). Fragmentation of DNA was evaluated with a Halomax® kit (Halotech® DNA, Madrid, Spain). Data were analysed with Statview software (Stat View 1998, SAS Institute Inc., Cary, NC, USA). Data obtained from the periods (before × after insulation) were evaluated by analysis of variance (ANOVA) and means were compared using Tukey's test. Total motility (before: 87.53 ± 1.21%; after: 46.53 ± 4.46%) and progressive motility (before: 58.64 ± 2.00%; after: 31.33 ± 3.82%) were reduced (P < 0.01) by scrotal insulation, as were sperm major defects (before: 10.64 ± 1.65%; after: 54.30 ± 3.67%) and total defects (before: 20.50 ± 2.40%; after: 63.85 ± 3.41%; P < 0.0001). Sperm with intact plasma and acrosomal membranes and high mitochondrial potential (PIAIH) decreased (P < 0.0001) after insulation. In that regard, 53.19 ± 2.20 and 28.48 ± 3.48% of sperm were classified as PIAIH before v. after insulation, respectively. Furthermore, plasma membrane integrity, acrosome membrane integrity, and high mitochondrial potential were assessed independently. The quantity of plasma membrane integrity cells (before: 62.01 ± 2.07%; after: 33.92 ± 3.94%), acrosome membrane integrity cells (before: 57.17 ± 2.30%; after: 31.47 ± 3.77%), and high mitochondrial potential cells (before: 85.72 ± 1.42%; after: 57.28 ± 3.12%) were also reduced (P < 0.0001) after insulation. Likewise, DNA integrity decreased (P = 0.002) from 98.87 ± 0.26% before insulation to 91.88 ± 2.6% afterward. In conclusion, sperm plasma and acrosomal membrane integrity, mitochondrial membrane potential, and DNA fragmentation were adversely affected by testicular degeneration in rams induced by scrotal insulation.Research was supported by FAPESP process 2012/00040-0 and 2011/16744-3.

Sign in / Sign up

Export Citation Format

Share Document