IFN-α induces barrier destabilization and apoptosis in renal proximal tubular epithelium

2008 ◽  
Vol 294 (1) ◽  
pp. C153-C160 ◽  
Author(s):  
Judith Lechner ◽  
Nadia Malloth ◽  
Thomas Seppi ◽  
Bea Beer ◽  
Paul Jennings ◽  
...  

Type I IFNs, like IFN-α, are major immune response regulators produced and released by activated macrophages, dendritic cells, and virus-infected cells. Due to their immunomodulatory functions and their ability to induce cell death in tumors and virus-infected cells, they are used therapeutically against cancers, viral infections, and autoimmune diseases. However, little is known about the adverse effects of type I IFNs on nondiseased tissue. This study examined the effects of IFN-α on cell death pathways in renal proximal tubular cells. IFN-α induced apoptosis in LLC-PK1 cells, characterized by the activation of caspase-3, -8, and -9, DNA fragmentation, and nuclear condensation. IFN-α also caused mitochondrial depolarization. Effector caspase activation was dependent on caspase-8 and -9. In addition to apoptosis, IFN-α exposure also decreased renal epithelial barrier function, which preceded apoptotic cell death. Caspase inhibition did not influence permeability regulation while significantly attenuating and delaying cell death. These results indicate that IFN-α causes programmed cell death in nondiseased renal epithelial cells. IFN-α-induced apoptosis is directed by an extrinsic death receptor signaling pathway, amplified by an intrinsic mitochondrial pathway. Caspase-dependent and -independent apoptotic mechanisms are involved. These findings reveal a novel aspect of IFN-α actions with implications for normal renal function in immune reactions and during IFN-α therapy.

2013 ◽  
Vol 33 (16) ◽  
pp. 3137-3149 ◽  
Author(s):  
Kai Guan ◽  
Zirui Zheng ◽  
Ting Song ◽  
Xiang He ◽  
Changzhi Xu ◽  
...  

The mitochondrial antiviral signaling protein MAVS (IPS-1, VISA, or Cardif) plays an important role in the host defense against viral infection by inducing type I interferon. Recent reports have shown that MAVS is also critical for virus-induced apoptosis. However, the mechanism of MAVS-mediated apoptosis induction remains unclear. Here, we show that MAVS binds to voltage-dependent anion channel 1 (VDAC1) and induces apoptosis by caspase-3 activation, which is independent of its role in innate immunity. MAVS modulates VDAC1 protein stability by decreasing its degradative K48-linked ubiquitination. In addition, MAVS knockout mouse embryonic fibroblasts (MEFs) display reduced VDAC1 expression with a consequent reduction of the vesicular stomatitis virus (VSV)-induced apoptosis response. Notably, the upregulation of VDAC1 triggered by VSV infection is completely abolished in MAVS knockout MEFs. We thus identify VDAC1 as a target of MAVS and describe a novel mechanism of MAVS control of virus-induced apoptotic cell death.


1996 ◽  
Vol 270 (4) ◽  
pp. F593-F603 ◽  
Author(s):  
B. Van de Water ◽  
M. Kruidering ◽  
J. F. Nagelkerke

The mechanism of nephrotoxin-induced apoptosis was studied in rat renal proximal tubular cells (PTC) exposed to the nephrotoxin S-(1,2-dichlorovinyl)-L-cysteine (DCVC). After a 6-h incubation, DCVC caused a condensation of heterochromatin and a fragmentation of the nucleus in 84 and 16% of the cells, respectively, which is indicative of apoptosis. This was confirmed biochemically by agarose gel electrophoresis demonstrating the formation of DNA fragments with multiples of 200 bp. The antioxidant N,N'-diphenyl-p-phenylenediamine prevented neither the fragmentation of the nucleus nor the formation of DNA fragments, but it did prevent lactate dehydrogenase release and bleb formation by DCVC. Apoptosis induced by DCVC was closely associated with F-actin disorganization: every cell with a fragmented nucleus displayed completely disorganized F-actin, while cells with a normal nucleus still possessed at least some intact F-actin also induced apoptosis in PTC. Similarly, dithiothreitol, which damages F-actin in PTC, caused apoptosis of PTC. These data suggest a causal relationship between F-actin disorganization and apoptosis of PTC.


2002 ◽  
Vol 83 (6) ◽  
pp. 1367-1376 ◽  
Author(s):  
Rei-Lin Kuo ◽  
Szu-Hao Kung ◽  
Yueh-Ying Hsu ◽  
Wu-Tse Liu

Enterovirus 71 (EV71) is the causative agent of human diseases with distinct severity, from mild hand-foot-and-mouth disease to severe neurological syndromes, such as encephalitis and meningitis. Infection of several different cell lines with EV71 causes extensive cytopathic effect, leading to destruction of the entire monolayer and the death of infected cells. In this study, cell death processes during EV71 infection and the underlying mechanisms of them were investigated. The hallmarks of apoptosis, nuclear condensation and fragmentation, were observed 24 h after infection. Apoptosis in infected cells was also confirmed by detectable cleavage of cellular DNA and degradation of poly(ADP-ribose) polymerase. Transient expression of EV71 2A protease (2Apro) alone resulted in the induction of apoptotic change. Infection of EV71 or expression of EV71 2Apro leads to cleavage of the eukaryotic initiation factor 4GI, a key factor for host protein synthesis. This study added one more example to the growing list of human viruses that induce apoptosis by a virus-encoded protein.


2019 ◽  
Vol 20 (24) ◽  
pp. 6149 ◽  
Author(s):  
Yiqun Li ◽  
Nan Jiang ◽  
Yuding Fan ◽  
Yong Zhou ◽  
Wenzhi Liu ◽  
...  

Chinese giant salamander iridovirus (GSIV) is the causative pathogen of Chinese giant salamander (Andrias davidianus) iridovirosis, leading to severe infectious disease and huge economic losses. However, the infection mechanism by GSIV is far from clear. In this study, a Chinese giant salamander muscle (GSM) cell line is used to investigate the mechanism of cell death during GSIV infection. Microscopy observation and DNA ladder analysis revealed that DNA fragmentation happens during GSIV infection. Flow cytometry analysis showed that apoptotic cells in GSIV-infected cells were significantly higher than that in control cells. Caspase 8, 9, and 3 were activated in GSIV-infected cells compared with the uninfected cells. Consistently, mitochondria membrane potential (MMP) was significantly reduced, and cytochrome c was released into cytosol during GSIV infection. p53 expression increased at an early stage of GSIV infection and then slightly decreased late in infection. Furthermore, mRNA expression levels of pro-apoptotic genes participating in the extrinsic and intrinsic pathway were significantly up-regulated during GSIV infection, while those of anti-apoptotic genes were restrained in early infection and then rose in late infection. These results collectively indicate that GSIV induces GSM apoptotic cell death involving mitochondrial damage, caspases activation, p53 expression, and pro-apoptotic molecules up-regulation.


2021 ◽  
pp. 1-7
Author(s):  
Zhen Li ◽  
Gang Hou

<b><i>Introduction:</i></b> LincRNA-p21 is predicted to interact with miR-449a, which plays a protective role in cisplatin-induced acute kidney injury (CIA). <b><i>Objective:</i></b> This study aimed to analyze the involvement of lincRNA-p21 in breast cancer patients with CIA. <b><i>Methods:</i></b> Levels of lincRNA-p21 in plasma from CIA, triple negative breast cancer, and control groups were measured by performing RT-qPCR. The potential interaction between lincRNA-p21 and miR-449a was first predicted by RT-qPCR. The relationship between lincRNA-p21 and miR-449a was analyzed by overexpression experiment. <b><i>Results:</i></b> We found that lincRNA-p21 is downregulated in CIA. Dual luciferase activity assay showed that lincRNA-p21 and miR-449a can interact with each other, while overexpression of lincRNA-p21 and miR-449a failed to affect the expression of each other. In human renal proximal tubular epithelial cells (HRPTEpCs), cisplatin led to the upregulated miR-449a but downregulated lincRNA-p21. Interestingly, lincRNA-p21 overexpression led to reduced enhancing effects of miR-449a on the cisplatin-induced apoptosis of HRPTEpCs. <b><i>Conclusion:</i></b> Therefore, lincRNA-p21 is downregulated in CIA and may sponge miR-449a to inhibit cisplatin-induced apoptosis of HRPTEpCs.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Sung Min Ju ◽  
Jun Gue Kang ◽  
Jun Sang Bae ◽  
Hyun Ock Pae ◽  
Yeoung Su Lyu ◽  
...  

Apigenin is a member of the flavone subclass of flavonoids present in fruits and vegetables. Apigenin has long been considered to have various biological activities, such as antioxidant, anti-inflammatory, and antitumorigenic properties, in various cell types. Cisplatin was known to exhibit cytotoxic effect to renal cells by inducing apoptosis through activation of p53. The present study investigated the antiapoptotic effects of apigenin on the cisplatin-treated human renal proximal tubular epithelial (HK-2) cells. HK-2 cells were pretreated with apigenin (5, 10, 20 μM) for 1 h and then treated with 40 μM cisplatin for various times. Apigenin inhibited the cisplatin-induced apoptosis of HK-2 cells. Interestingly, apigenin itself exerted cytostatic activity because of its ability to induce cell cycle arrest. Apigenin inhibited caspase-3 activity and PARP cleavage in cisplatin-treated cells. Apigenin reduced cisplatin-induced phosphorylation and expression of p53, with no significant influence on production of ROS that is known to induce p53 activation. Furthermore, apigenin promoted cisplatin-induced Akt phosphorylation, suggesting that enhanced Akt activation may be involved in cytoprotection. Taken together, these results suggest that apigenin ameliorates cisplatin-induced apoptosis through reduction of p53 activation and promotion of PI3K/Akt pathway in HK-2 cells.


2004 ◽  
Vol 32 (03) ◽  
pp. 377-387 ◽  
Author(s):  
Hyung-Jin Kim ◽  
Seon Il Jang ◽  
Young-Jun Kim ◽  
Hyun-Ock Pae ◽  
Hae-Young Won ◽  
...  

We studied the effect of 4-acetyl-12,13-epoxyl-9-trichothecene-3,15-diol (AETD) isolated from Isaria japonica, one of the most popular Chinese fungal medicines, on the induction of apoptosis in rat bladder carcinoma NBT-II cells. AETD was cytotoxic to NBT-II cells, and this cytotoxic effect appears to be attributed to its induction of apoptotic cell death, as AETD induced nuclear morphological changes and internucleosomal DNA fragmentation, and increased the proportion of hypodiploid cells and activity of caspase-3. AETD treatment also decreased the expression of the anti-apoptotic protein Bcl-2 and increased the expression of the pro-apoptotic protein Bax. These results provide important information in understanding the mechanism(s) of AETD-induced apoptosis.


Acta Naturae ◽  
2012 ◽  
Vol 4 (3) ◽  
pp. 88-94 ◽  
Author(s):  
M. A. Savitskaya ◽  
M. S. Vildanova ◽  
O. P. Kisurina-Evgenieva ◽  
E. A. Smirnova ◽  
G. E. Onischenko

Vitamin E derivatives are known to act as agents exhibiting cytotoxity against tumor cells. The effect of vitamin E succinate on human epidermoid carcinoma cell line A431 was investigated in this study using live imaging, immunocytochemistry, and transmission electron microscopy. -Tocopheryl succinate-induced apoptotic cell death in A431 cells was shown to be both dose- and time-dependent. The hyperproduction of reactive oxygen species, changes in size, shape and ultrastructural characteristics of mitochondria followed by the release of cytochrome c from mitochondria to cytosol were observed. These results suggest that -tocopheryl succinate induces apoptosis that occurs via the mitochondrial pathway. Mitochondria are shown to be crucial targets in -tocopheryl succinate-induced caspase-dependent cell death in human carcinoma A431 cells.


2015 ◽  
Vol 236 (3) ◽  
pp. 145-153 ◽  
Author(s):  
Somsak Fongsupa ◽  
Sirima Soodvilai ◽  
Chatchai Muanprasat ◽  
Varanuj Chatsudthipong ◽  
Sunhapas Soodvilai

1996 ◽  
Vol 270 (4) ◽  
pp. F700-F708 ◽  
Author(s):  
W. Lieberthal ◽  
V. Triaca ◽  
J. Levine

We have examined the mechanisms of cell death induced by cisplatin in primary cultures of mouse proximal tubular cells. High concentrations of cisplatin (800 microM) led to necrotic cell death over a few hours. Much lower concentrations of cisplatin (8 microM) led to apoptosis, which caused loss of the cell monolayer over several days. Necrosis was characterized by a cytosolic swelling and early loss of plasma membrane integrity. In contrast, early features of cells undergoing apoptosis included cell shrinkage and loss of attachment to the monolayers. Nuclear chromatin became condensed and fragmented in apoptosing cells. These features were absent in necrotic cells. DNA electrophoresis of cells exposed to 800 microM cisplatin yielded a "smear" pattern, due to random DNA degradation. In contrast, the DNA of apoptosing cells demonstrated a "ladder" pattern resulting from internucleosomal DNA cleavage. Antioxidants delayed cisplatin-induced apoptosis but not necrosis. Thus the mechanism of cell death induced by cisplatin is concentration dependent. Reactive oxygen species play a role in mediating apoptosis but not necrosis induced by cisplatin.


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