Endoplasmic reticulum stress and apoptosis markers (ER stress and apoptosis markers)

Endoplasmic reticulum (ER) stress and apoptosis markers represent a collective group of proteins and signaling events used to evaluate cellular health and the Unfolded Protein Response (UPR). When misfolded proteins accumulate in the ER, the cell activates sensors such as PERK, IRE1α, and ATF6 to restore homeostasis, often measured by the upregulation of the chaperone GRP78 (BiP) [1]. If the stress is prolonged or severe, the UPR shifts from a pro-survival to a pro-apoptotic phase, primarily mediated by the transcription factor CHOP (DDIT3), which downregulates anti-apoptotic BCL-2 and promotes the activation of the caspase cascade [2][3]. Common markers for this transition include the splicing of XBP1 mRNA, phosphorylation of eIF2α, and the presence of cleaved Caspase-3 [4]. These markers are pivotal in drug discovery for neurodegenerative diseases, where reducing ER stress is therapeutic, and in oncology, where inducing ER stress can overcome drug resistance [5]. Therapeutic agents like 4-phenylbutyric acid (4-PBA) act as chemical chaperones to alleviate stress, while proteasome inhibitors like bortezomib deliberately trigger these markers to induce tumor cell death [6]. Sources: [1] Lee, A. S. (2005). Methods, 35(4), 373-381. [2] Zinszner, H., et al. (1998). Genes & Development, 12(7), 982-995. [3] Tabas, I., & Ron, D. (2011). Nature Cell Biology, 13(3), 184-190. [4] Walter, P., & Ron, D. (2011). Science, 334(6059), 1081-1086. [5] Wang, M., & Kaufman, R. J. (2016). Nature, 529(7586), 326-335. [6] Obeng, E. A., et al. (2006). Blood, 107(12), 4907-4916.

Other names

Unfolded protein response markersUPR markersER stress-induced apoptosis indicatorsER proteostasis markers

Modulation of the unfolded protein response (UPR) through chemical chaperones to enhance folding capacity or through inhibitors of UPR sensors to sensitize cancer cells to apoptosis.