scholarly journals Deoxynivalenol induces caspase-8-mediated apoptosis through the mitochondrial pathway in hippocampal nerve cells of piglet

2019 ◽  
Author(s):  
Jinjie Wu ◽  
Xichun Wang ◽  
Yunjing Jiang ◽  
Lei Zhu ◽  
Li Cao ◽  
...  

Abstract Background: Deoxynivalenol (DON) is a common trichothecene mycotoxin found throughout the world. DON has broad toxicity in animals and humans. Its neurotoxicity in vitro, however, is still unclear. This study was designed to investigate the hypothesis that DON toxicity in neurons occurs via the mitochondrial apoptotic pathway. Results: Using piglet hippocampal nerve cells (PHNCs), we evaluated the effects of varying concentrations of DON on typical indicators of apoptosis. The results obtained demonstrated that DON treatment inhibited PHNC proliferation and led to morphological, biochemical, and transcriptional changes consistent with apoptosis, including decreased mitochondrial membrane potential, mitochondrial release of CYCS and AIF, and increased abundance of active cleaved-caspase-9 and cleaved-caspase-3. Increasing concentrations of DON led to decreased Bcl-2 expression and increased expression of Bax and Bid, which in turn increased transcriptional activity of the transcription factors AIF and P53. Addition of a caspase-8 inhibitor abrogated these effects. Conclusion: These data reveal that DON induces apoptosis in PHNCs via the mitochondrial apoptosis pathway, and that caspase-8 plays an important role during apoptosis regulation.

Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 73
Author(s):  
Li Cao ◽  
Yunjing Jiang ◽  
Lei Zhu ◽  
Wei Xu ◽  
Xiaoyan Chu ◽  
...  

Deoxynivalenol (DON) is a common trichothecene mycotoxin found worldwide. DON has broad toxicity towards animals and humans. However, the mechanism of DON-induced neurotoxicity in vitro has not been fully understood. This study investigated the hypothesis that DON toxicity in neurons occurs via the mitochondrial apoptotic pathway. Using piglet hippocampal nerve cells (PHNCs), we evaluated the effects of different concentrations of DON on typical indicators of apoptosis. The obtained results demonstrated that DON treatment inhibited PHNC proliferation and led to morphological, biochemical, and transcriptional changes consistent with apoptosis, including decreased mitochondrial membrane potential, mitochondrial release of cytochrome C (CYCS) and apoptosis inducing factor (AIF), and increased abundance of active cleaved-caspase-9 and cleaved-caspase-3. Increasing concentrations of DON led to decreased B-cell lymphoma-2 (Bcl-2) expression and increased expression of BCL2-associated X (Bax) and B-cell lymphoma-2 homology 3 interacting domain death agonist (Bid), which in turn increased transcriptional activity of the transcription factors AIF and P53 (a tumor suppressor gene, promotes apoptosis). The addition of a caspase-8 inhibitor abrogated these effects. These results reveal that DON induces apoptosis in PHNCs via the mitochondrial apoptosis pathway, and caspase-8 is shown to play an important role during apoptosis regulation.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Jianqiu Gu ◽  
Qian Wei ◽  
Hongzhi Zheng ◽  
Xin Meng ◽  
Jin Zhang ◽  
...  

Type 2 diabetes is a heterogeneous disorder that develops as a result of relatively inappropriate insulin secretion and insulin resistance. Increased levels of free fatty acids (FFAs) are one of the important factors for the pathogenesis of type 2 diabetes and contribute to defectiveβ-cell proliferation and increasedβ-cell apoptosis. Recently, glucagon-like peptide-1 (GLP-1) receptor agonists have been shown to possess an antiapoptotic effect, by increasingβ-cell mass and improvingβ-cell function. However, their effects onβ-cells in vitro against lipotoxicity have not been elucidated completely. In this study, we investigated whether the GLP-1 receptor agonist exendin-4 displays prosurvival effects in pancreaticβ-cells exposed to chronic elevated FFAs. Results showed that exendin-4 inhibited apoptosis induced by palmitate in MIN6 cells. After 24 h of incubation, exendin-4 caused rapid activation of extracellular signal-related kinase 1/2 (ERK1/2) under lipotoxic conditions. The ERK1/2 inhibitor PD98059 blocked the antilipotoxic effect of exendin-4 on MIN6 cells. Exendin-4 also inhibited the mitochondrial pathway of apoptosis. This inhibition is associated with upregulation of BCL-2. Our findings suggested that exendin-4 may exert cytoprotective effects through activation of ERK1/2 and inhibition of the mitochondrial apoptosis pathway.


2009 ◽  
Vol 21 (9) ◽  
pp. 28
Author(s):  
K. J. Askelund ◽  
P. Stone ◽  
L. W. Chamley

Background: Trophoblast deportation is the process whereby multinucleated fragments of the syncytiotrophoblast are shed from the placenta into the maternal blood. It is estimated that 150,000 are shed from the placenta and deported daily in normal pregnancy and that more are shed during preeclampsia1. In normal pregnancy deported trophoblasts are thought to die by apoptosis, which is also increased in villous trophoblast in preeclampsia2. However, experimental confirmation that apoptosis leads to trophoblast shedding is required and it is not clear which components of the apoptotic pathway are involved in trophoblast shedding. Objectives: To determine the effect of inhibiting caspase 3 (executioner), caspases 8 and 9 (initiators), and Rho-associated kinase (ROCK; bleb formation) on the number of trophoblasts shed from first trimester human placentae. Methods : Using an in vitro placental explant model of trophoblast deportation, first trimester placentae were cultured for 72 hours in media containing specific inhibitors of ROCK, caspases 3, 8 or 9. Trophoblasts shed from quintuple explants/inhibitor from five placentae were depleted of contaminating leucocytes and erythrocytes, labelled with trypan blue and the sizes and numbers of shed trophoblasts quantified using a Nexcelom automated counter. Results: The number of trophoblasts that were shed from the explants was significantly increased (p=0.04) when caspase 3 (2.4 fold) and caspase 8 (2.7 fold) were inhibited. There was no significant change following caspase 9 inhibition. The number of shed trophoblasts was significantly decreased when ROCK was inhibited. None of the inhibitors significantly altered the size of the shed trophoblasts. Conclusion: Our data suggest that the apoptosis pathway is involved in trophoblast shedding in vitro from first trimester placentae. That caspase 8 but not caspase 9 affected shedding suggests trophoblasts from normal placentae are induced to die via the extrinsic apoptosis pathway. Aberrant regulation of the apoptosis pathway may contribute to pregnancy pathology.


2006 ◽  
Vol 80 (1) ◽  
pp. 395-403 ◽  
Author(s):  
Yin Liu ◽  
Yinghui Pu ◽  
Xuming Zhang

ABSTRACT A previous study demonstrated that infection of rat oligodendrocytes by mouse hepatitis virus (MHV) resulted in apoptosis, which is caspase dependent (Y. Liu, Y. Cai, and X. Zhang, J. Virol. 77:11952-11963, 2003). Here we determined the involvement of the mitochondrial pathway in MHV-induced oligodendrocyte apoptosis. We found that caspase-9 activity was 12-fold higher in virus-infected cells than in mock-infected cells at 24 h postinfection (p.i.). Pretreatment of cells with a caspase-9 inhibitor completely blocked caspase-9 activation and partially inhibited the apoptosis mediated by MHV infection. Analyses of cytochrome c release further revealed an activation of the mitochondrial apoptotic pathway. Stable overexpression of the two antiapoptotic proteins Bcl-2 and Bcl-xL significantly, though only partially, blocked apoptosis, suggesting that activation of the mitochondrial pathway is partially responsible for the apoptosis. To identify upstream signals, we determined caspase-8 activity, cleavage of Bid, and expression of Bax and Bad by Western blotting. We found a drastic increase in caspase-8 activity and cleavage of Bid at 24 h p.i. in virus-infected cells, suggesting that Bid may serve as a messenger to relay the signals from caspase-8 to mitochondria. However, treatment with a caspase-8 inhibitor only slightly blocked cytochrome c release from the mitochondria. Furthermore, we found that Bax but not Bad was significantly increased at 12 h p.i. in cells infected with both live and UV-inactivated viruses and that Bax activation was partially blocked by treatment with the caspase-8 inhibitor. These results thus establish the involvement of the mitochondrial pathway in MHV-induced oligodendrocyte apoptosis.


2021 ◽  
Vol 22 (18) ◽  
pp. 9956
Author(s):  
Piotr Wójcik ◽  
Agnieszka Gęgotek ◽  
Neven Žarković ◽  
Elżbieta Skrzydlewska

Although apoptosis of keratinocytes has been relatively well studied, there is a lack of information comparing potentially proapoptotic treatments for healthy and diseased skin cells. Psoriasis is a chronic autoimmune-mediated skin disease manifested by patches of hyperproliferative keratinocytes that do not undergo apoptosis. UVB phototherapy is commonly used to treat psoriasis, although this has undesirable side effects, and is often combined with anti-inflammatory compounds. The aim of this study was to analyze if cannabidiol (CBD), a phytocannabinoid that has anti-inflammatory and antioxidant properties, may modify the proapoptotic effects of UVB irradiation in vitro by influencing apoptotic signaling pathways in donor psoriatic and healthy human keratinocytes obtained from the skin of five volunteers in each group. While CBD alone did not have any major effects on keratinocytes, the UVB treatment activated the extrinsic apoptotic pathway, with enhanced caspase 8 expression in both healthy and psoriatic keratinocytes. However, endoplasmic reticulum (ER) stress, characterized by increased expression of caspase 2, was observed in psoriatic cells after UVB irradiation. Furthermore, decreased p-AKT expression combined with increased 15-d-PGJ2 level and p-p38 expression was observed in psoriatic keratinocytes, which may promote both apoptosis and necrosis. Application of CBD partially attenuated these effects of UVB irradiation both in healthy and psoriatic keratinocytes, reducing the levels of 15-d-PGJ2, p-p38 and caspase 8 while increasing Bcl2 expression. However, CBD increased p-AKT only in UVB-treated healthy cells. Therefore, the reduction of apoptotic signaling pathways by CBD, observed mainly in healthy keratinocytes, suggests the need for further research into the possible beneficial effects of CBD.


2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Shaobo Du ◽  
Biao Han ◽  
Kang Li ◽  
Xuan Zhang ◽  
Xueli Sha ◽  
...  

Lycium barbarumpolysaccharides (LBPs) have been shown to play a key role in protecting the eyes by reducing the apoptosis induced by certain types of damage. However, it is not known whether LBPs can protect damaged corneal cells from apoptosis. Moreover, no reports have focused on the role of LBPs in guarding against ultraviolet B- (UVB-) induced apoptosis. The present study aimed to investigate the protective effect and underlying mechanism of LBPs against UVB-induced apoptosis in rat corneal epithelial (RCE) cells. The results showed that LBPs significantly prevented the loss of cell viability and inhibited cell apoptosis induced by UVB in RCE cells. LBPs also inhibited UVB-induced loss of mitochondrial membrane potential, downregulation ofBcl-2, and upregulation ofBaxand caspase-3. Finally, LBPs attenuated the phosphorylation of c-Jun NH2-terminal kinase (JNK) triggered by UVB. In summary, LBPs protect RCE cells against UVB-induced damage and apoptosis, and the underlying mechanism involves the attenuation of the mitochondrial apoptosis pathway and the inhibition of JNK phosphorylation.


2021 ◽  
Author(s):  
Dianrong Li ◽  
Jie Chen ◽  
Jia Guo ◽  
Lin Li ◽  
Gaihong Cai ◽  
...  

AbstractReceptor-interacting serine/threonine-protein kinase 3 (RIPK3) normally signals to necroptosis by phosphorylating MLKL. We report here that when the cellular RIPK3 chaperone Hsp90/CDC37 level is low, RIPK3 also signals to apoptosis. The apoptotic function of RIPK3 requires phosphorylation of the serine 165/threonine 166 sites on its kinase activation loop, resulting in inactivation of RIPK3 kinase activity while gaining the ability to recruit RIPK1, FADD, and caspase-8 to form a cytosolic caspase-activating complex, thereby triggering apoptosis. We found that PGF2α induces RIPK3 expression in luteal granulosa cells in the ovary to cause luteal regression through this RIPK3-mediated apoptosis pathway. Mice carrying homozygous phosphorylation-resistant RIPK3 S165A/T166A knockin mutations failed to respond to PGF2α but retained pro-necroptotic function, whereas mice with phospho-mimicking S165D/T166E homozygous knockin mutation underwent spontaneous apoptosis in multiple RIPK3-expressing tissues and died shortly after birth. Thus, RIPK3 signals to either necroptosis or apoptosis depending on its serine 165/threonine 166 phosphorylation status.


2006 ◽  
Vol 16 (3) ◽  
pp. 1321-1329 ◽  
Author(s):  
E. K. Yim ◽  
S. B. Lee ◽  
K. H. Lee ◽  
C. J. Kim ◽  
J. S. Park

5-Fluorouracil (5-FU) is currently being used as an anticancer drug to reduce tumor bulk in order to increase the operability rate and postoperative survival in patients with cervical cancer, which has been combined with cisplatin (CP) because of its superior activities observed in human carcinoma cells. However, the combined anticancer effect of 5-FU and CP in cervical carcinoma cells is poorly understood. Therefore, we conducted a study to investigate whether anticancer drugs 5-FU and CP may exhibit the combined antiproliferative effect in cervical carcinoma cells. Using proteomics analysis, including two-dimensional gel electrophoresis and matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS), we investigated the antiproliferative effect–related proteins after treatment with 5-FU and/or CP. Our experiments showed that the combination of 5-FU and CP engaged both the apoptotic pathways: the membrane death receptor–mediated apoptosis pathway and the mitochondrial apoptotic pathway. Moreover, the combination of 5-FU and CP resulted in remarkable increasing susceptibility to apoptosis. We suggest that the combination of 5-FU and CP suppresses the growth of cervical carcinoma cells by synergistic effect with the induction of apoptosis. In vitro synergistic effect of 5-FU and CP supports the basis of the clinical application of the combination chemotherapy to the patients with cervical cancer.


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