Apoptosis Signal-regulating Kinase 1 promotes Ochratoxin A-induced renal cytotoxicity

Abstract

Oxidative stress and apoptosis are involved in Ochratoxin A (OTA)-induced renal cytotoxicity. Apoptosis signal-regulating kinase 1 (ASK1) is a Mitogen-Activated Protein Kinase Kinase Kinase (MAPKKK, MAP3K) family member that plays an important role in oxidative stress-induced cell apoptosis. In this study, we performed RNA interference of ASK1 in HEK293 cells and employed an iTRAQ-based quantitative proteomics approach to globally investigate the regulatory mechanism of ASK1 in OTA-induced renal cytotoxicity. Our results showed that ASK1 knockdown alleviated OTA-induced ROS generation and Δψm loss and thus desensitized the cells to OTA-induced apoptosis. We identified 33 and 24 differentially expressed proteins upon OTA treatment in scrambled and ASK1 knockdown cells, respectively. Pathway classification and analysis revealed that ASK1 participated in OTA-induced inhibition of mRNA splicing, nucleotide metabolism, the cell cycle, DNA repair, and the activation of lipid metabolism. We concluded that ASK1 plays an essential role in promoting OTA-induced renal cytotoxicity.

Ochratoxin A mediates MAPK activation, modulates <i>IL-2</i> and <i>TNF-α</i> mRNA expression and induces apoptosis by mitochondria-dependent and mitochondria-independent pathways in human H9 T cells

“…Oxidative stress is often cited as a key mechanism in OTA-induced apoptosis in different cell types (Marin-Kuan et al, 2011): it has been reported that OTA accelerates reactive oxygen species (ROS) formation by lipid peroxidation and the inhibition of antioxidant enzymes such as superoxide dismutase. Increased ROS induce Ca 2+ release from intracellular organelles, affecting MAPK phosphorylation and the intracellular signaling cascade (Liang et al, 2015). In vitro OTA stimulated the phosphorylation of three major MAPKs identified in mammalian cells: ERK1/2, JNK and p38.…”

Toxicity study of ochratoxin A using HEK293 and HepG2 cell lines based on microRNA profiling

“…15 In brief, the cells were treated as above and then washed once with PBS and incubated with JC-1 (Beyotime, China) staining solution (5 mg/ml) for 20 min at 37 C. After the cells were washed twice with the JC-1 staining buffer, the fluorescence densities of the JC-1 monomers ( ex ¼ 488 nm, em ¼ 529 nm) and JC-1 aggregates ( ex ¼ 524 nm, em ¼ 594 nm) were detected using a microplate reader. The Á m of the HEK293 and HepG2 cells was expressed as the fluorescence intensity ratio of the JC-1 aggregates over the JC-1 monomers.…”

Lipid Rafts Disruption Increases Ochratoxin A Cytotoxicity to Hepatocytes

“…After 1μM OTA treatment for 5 h, the biological processes that the changed proteins were involved in included metabolic process, cellular process, cellular component organization, developmental process, cell communication, immune system process, generation of precursor metabolites and energy, transport, system process, response to stimulus, cell cycle and cell adhesion. In Liang et al’ s study, 20 μM OTA exposure for 24 h to apoptosis signal‐regulating kinase 1 knockdown HEK 293 cells exerted influences on mRNA splicing, nucleotide metabolism, the cell cycle, DNA repair, and lipid and lipoprotein metabolism . Different exposure time and OTA concentration may contribute to the different enriched pathways.…”