Ethanol-induced augmentation of annexin IV in cultured cells and the enhancement of cytotoxicity by overexpression of annexin IV by ethanol

Abstract

The annexins are a family of highly homologous Ca(2+) and phospholipid binding proteins. The expressive amounts of several annexins have been shown to alter in certain pathological states such as brain ischemia and Alzheimer's disease. It has been demonstrated that ethanol induces cytotoxicity, which results in brain damage. In this study, we examined the relationship between ethanol-induced cytotoxicity and the intrinsic amount of annexins using cell lines (rat glioma C6 cells and human adenocarcinoma A549 cells). A decrease in the mitochondrial enzyme (dehydrogenase) activity, which is widely used to measure cytotoxicity, was observed with a high concentration of ethanol (200 mM or more) after a 24-h exposure in both C6 and A549 cells. Western blot analysis revealed that the amount of annexin IV was augmented in both cells by ethanol, whereas levels of annexins I and V were unchanged. The amount of annexin IV was augmented with increasing concentration of ethanol. The overexpression of annexin IV in C6 cells by transfection with annexin IV-DNA enhanced ethanol-induced cell lesion and was accompanied by NFkappaB activation. Thus, it might be indicated that the amount of annexin IV is selectively augmented and this augmentation facilitates the development of cell lesion by ethanol.

Targeting annexin A4 to counteract chemoresistance in clear cell carcinoma of the ovary

“…By western blotting analysis, Sohma et al showed significantly increased expression of annexin A4 in the hippocampi of postmortem brains of alcoholic patients compared with controls [69]. In addition to this finding, the augmentation of annexin A4 expression following ethanol exposure was also demonstrated in cultured cells (rat glioma C6 cells and human adenocarcinoma A549 cells), suggesting that the expression of annexin A4 is induced by specific cellular stress [70].…”

Annexin A4 interacts with the NF-κB p50 subunit and modulates NF-κB transcriptional activity in a Ca2+-dependent manner

“…The p50-p65 heterodimers are sequestered in the cytoplasm through interactions with Ij-B in the resting state. Following application of various stimuli, these dimers are released from Ij-B and translocate to the nucleus, where they activate the transcription of various downstream target genes [12][13][14][15][16][17][18][19]. To determine the effects of ANXA4 on the composition of the NF-jB complex, we performed immunoprecipitation experiments using extracts from control or ANXA4-overexpressing Bosc 23 cells.…”

“…NF-jB, one of the most extensively characterized transcription factors in mammalian cells, regulates numerous genes involved in the immune response, cell proliferation, differentiation, survival, and apoptosis [12][13][14][15][16]. The NF-jB family is composed of five members, specifically, p65 (RelA), p105/p50 (NF-jB1), p100/p52 (NF-jB2), c-Rel, and RelB [15,16].…”

Consensus paper of the WFSBP task force on biological markers: Biological markers for alcoholism

“…Short-term exposure attenuates the channel activity; however, long-term exposure up regulates the number of channels, which in turn increases the intracellular Ca 2 ϩ -concentration. Using neuronal and glial cell cultures, increased expression of annexin IV, a calcium and phospholipid binding protein, has been found in relation to heavy ethanol exposure (Ohkawa et al 2002) and annexin IV may be a specifi c marker for the effects of ethanol. The augmented expression of annexin IV in specimens from alcoholics suggests that it may be involved in the recovery from the damage caused by alcohol.…”