scholarly journals The Short Isoform of DNAJB6 Protects against 1-Methyl-4-phenylpridinium Ion-Induced Apoptosis in LN18 Cells via Inhibiting Both ROS Formation and Mitochondrial Membrane Potential Loss

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Yeon-Mi Hong ◽  
Yohan Hong ◽  
Yeong-Gon Choi ◽  
Sujung Yeo ◽  
Soo Hee Jin ◽  
...  

In a previous study, we found that the short isoform of DNAJB6 (DNAJB6(S)) had been decreased in the striatum of a mouse model of Parkinson’s disease (PD) induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). DNAJB6, one of the heat shock proteins, has been implicated in the pathogenesis of PD. In this study, we explored the cytoprotective effect of DNAJB6(S) against 1-methyl-4-phenylpyridinium ion- (MPP+-) induced apoptosis and the underlying molecular mechanisms in cultured LN18 cells from astrocytic tumors. We observed that MPP+ significantly reduced the cell viability and induced apoptosis in LN18 glioblastoma cells. DNAJB6(S) protected LN18 cells against MPP+-induced apoptosis not only by suppressing Bax cleavage but also by inhibiting a series of apoptotic events including loss of mitochondrial membrane potential, increase in intracellular reactive oxygen species, and activation of caspase-9. These observations suggest that the cytoprotective effects of DNAJB6(S) may be mediated, at least in part, by the mitochondrial pathway of apoptosis.

2008 ◽  
Vol 30 (5) ◽  
pp. 435-450
Author(s):  
Wilfried Kugler ◽  
Leo Veenman ◽  
Yulia Shandalov ◽  
Svetlana Leschiner ◽  
Ilana Spanier ◽  
...  

Background: We have previously shown that the anti-neoplastic agent erucylphosphohomocholine (ErPC3) requires the mitochondrial 18 kDa Translocator protein (TSPO), formerly known as the peripheral-type benzodiazepine receptor (PBR), to induce cell death via the mitochondrial apoptosis pathway.Methods: With the aid of the dye JC-1 and cyclosporin A, applied to glioblastoma cells, we now investigated the significance of opening of the mitochondrial permeability transition pore (MPTP) for ErPC3-induced apoptosis in interaction with the TSPO ligands, PK 11195 and Ro5 4864. Furthermore, we measured cytochrome c release, and caspase-9 and -3 activation in this paradigm.Results: The human glioblastoma cell lines, U87MG, A172 and U118MG express the MPTP-associated TSPO, voltage-dependent anion channel and adenine nucleotide transporter. Indeed, ErPC3-induced apoptosis was inhibited by the MPTP blocker cyclosporin A and by PK 11195 and Ro5 4864 in a concentration-dependent manner. Furthermore, PK 11195 and Ro5 4864 inhibited collapse of the mitochondrial membrane potential, cytochrome c release, and caspase-9 and -3 activation caused by ErPC3 treatment.Conclusions: This study shows that PK 11195 and Ro5 4864 inhibit the pro-apoptotic function of ErPC3 by blocking its capacity to cause a collapse of the mitochondrial membrane potential. Thus, the TSPO may serve to open the MPTP in response to anti-cancer drugs such as ErPC3.


2018 ◽  
Author(s):  
Xu Chao ◽  
Guoquan Wang ◽  
Yuping Tang ◽  
Changhu Dong ◽  
Hong Li ◽  
...  

AbstractPeiminine is a compound that is isolated fromBolbostemma paniculatum(Maxim) Franquet (Cucurbitaceae family), which has demonstrated antitumor activities. Its precise molecular mechanisms underlying antitumor activity remain elusive. In this study, peiminine-induced apoptosis towards human hepatocellular carcinoma and its molecular mechanisms were investigated. MTT assay was employed to assess anticancer effects of peiminine at concentrations of 2, 4, 6, 8, 10, 12, and 14 μg/ml after 24, 48, or 72 h. Nuclear staining and flow cytometry were carried out to further assess apoptosis. Mitochondrial membrane potential evaluation and Western blot analysis were performed to investigate the mechanism of peiminine-induced apoptosis. Peiminine reduced the viability of HepG2 cells in a time- and dose-dependent manner and had an IC50of 4.58 μg/mL at 24h. Flow cytometry assessment indicated that peiminine markedly increased the cell number of apoptotic cells and the mitochondrial membrane potential dose-dependently in HepG2 cells. The results of Western blotting showed the expression of Bcl-2, procaspase-3, procaspase-8, procaspase-9, and PARP1decreased in HepG2 cells treated with peiminine, while the expression of Bax, caspase-3, caspase-8, caspase-9, and cleaved PARP1increased. The result suggest taht peiminine can induce apoptosis in human hepatocellular carcinoma HepG2 cells through both extrinsic and intrinsic apoptotic pathways.


Zygote ◽  
2019 ◽  
Vol 27 (4) ◽  
pp. 203-213 ◽  
Author(s):  
Anima Tripathi ◽  
Vivek Pandey ◽  
A.N. Sahu ◽  
Alok K. Singh ◽  
Pawan K. Dubey

SummaryThe present study investigated if the presence of encircling granulosa cells protected against di(2-ethylhexyl)phthalate (DEHP)-induced oxidative stress in rat oocytes cultured in vitro. Denuded oocytes and cumulus–oocyte complexes (COCs) were treated with or without various doses of DEHP (0.0, 25.0, 50.0, 100, 200, 400 and 800 μM) in vitro. Morphological apoptotic changes, levels of oxidative stress and reactive oxygen species (ROS), mitochondrial membrane potential, and expression levels of apoptotic markers (Bcl2, Bax, cytochrome c) were analyzed. Our results showed that DEHP induced morphological apoptotic changes in a dose-dependent manner in denuded oocytes cultured in vitro. The effective dose of DEHP (400 µg) significantly (P>0.05) increased oxidative stress by elevating ROS levels and the mitochondrial membrane potential with higher mRNA expression and protein levels of apoptotic markers (Bax, cytochrome c). Encircling granulosa cells protected oocytes from DEHP-induced morphological changes, increased oxidative stress and ROS levels, as well as increased expression of apoptotic markers. Taken together our data suggested that encircling granulosa cells protected oocytes against DEHP-induced apoptosis and that the presence of granulosa cells could act positively towards the survival of oocytes under in vitro culture conditions and may be helpful during assisted reproductive technique programmes.


2005 ◽  
Vol 102 (6) ◽  
pp. 1147-1157 ◽  
Author(s):  
Torsten Loop ◽  
David Dovi-Akue ◽  
Michael Frick ◽  
Martin Roesslein ◽  
Lotti Egger ◽  
...  

Background Volatile anesthetics modulate lymphocyte function during surgery, and this compromises postoperative immune competence. The current work was undertaken to examine whether volatile anesthetics induce apoptosis in human T lymphocytes and what apoptotic signaling pathway might be used. Methods Effects of sevoflurane, isoflurane, and desflurane were studied in primary human CD3 T lymphocytes and Jurkat T cells in vitro. Apoptosis and mitochondrial membrane potential were assessed using flow cytometry after green fluorescent protein-annexin V and DiOC6-fluorochrome staining. Activity and proteolytic processing of caspase 3 was measured by cleaving of the fluorogenic effector caspase substrate Ac-DEVD-AMC and by anti-caspase-3 Western blotting. Release of mitochondrial cytochrome c was studied after cell fractionation using anti-cytochrome c Western blotting and enzyme-linked immunosorbent assays. Results Sevoflurane and isoflurane induced apoptosis in human T lymphocytes in a dose-dependent manner. By contrast, desflurane did not exert any proapoptotic effects. The apoptotic signaling pathway used by sevoflurane involved disruption of the mitochondrial membrane potential and release of cytochrome c from mitochondria to the cytosol. In addition, the authors observed a proteolytic cleavage of the inactive p32 procaspase 3 to the active p17 fragment, increased caspase-3-like activity, and cleavage of the caspase-3 substrate poly-ADP-ribose-polymerase. Sevoflurane-induced apoptosis was blocked by the general caspase inhibitor Z-VAD.fmk. Death signaling was not mediated via the Fas/CD95 receptor pathway because neither anti-Fas/CD95 receptor antagonism nor FADD deficiency or caspase-8 deficiency were able to attenuate sevoflurane-mediated apoptosis. Conclusion Sevoflurane and isoflurane induce apoptosis in T lymphocytes via increased mitochondrial membrane permeability and caspase-3 activation, but independently of death receptor signaling.


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