Starvation insult induces the translocation of high mobility group box 1 to cytosolic compartments in glioma
- Xiaohang Cui
- Anhui Yao
- Liyun Jia
Affiliations: Department of Medical Genetics and Cell Biology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China, Department of Neurosurgery, 988th Hospital of Joint Logistic Support Force of PLA, Zhengzhou, Henan 450053, P.R. China
- Published online on: October 24, 2023 https://doi.org/10.3892/or.2023.8653
Copyright: © Cui
et al. This is an open access article distributed under the
terms of Creative
Commons Attribution License.
Views: 0 (Spandidos Publications: | PMC Statistics: )
Total PDF Downloads: 0 (Spandidos Publications: | PMC Statistics: )
This article is mentioned in:
High mobility group box 1 (HMGB1) is a highly conserved and ubiquitous nuclear protein in eukaryotic cells. In response to stress, it transfers from the nucleus to the cytoplasm and finally, to the extracellular matrix, participating in inflammation and carcinogenesis. Increased HMGB1 protein levels are frequently associated with the reduced survival of patients with glioma. HMGB1 plays contextual roles depending on its subcellular localization. However, the mechanisms underlying its subcellular localization and secretion remain unclear. In the present study, the subcellular localization and secretion of HMGB1 in starved glioma cells were investigated using immunofluorescence microscopy, enzyme‑linked immunosorbent assay, subcellular fractionation, western blotting and immunoelectron microscopy. The results demonstrated that starvation induced HMGB1 translocation from the nucleus to the cytoplasm and finally, to the extracellular milieu in glioma cells. HMGB1 was localized in the mitochondria, endoplasmic reticulum (ER), peroxisomes, autophagosomes, lysosomes, endosomes and the cytoskeleton. Immunoelectron microscopy confirmed that HMGB1 was present within or around cytosolic compartments. Subcellular fractionation further demonstrated that HMGB1 transferred to membrane‑bound compartments. In addition, HMGB1 was localized to specific contact areas between the ER and mitochondria, known as mitochondria‑associated membranes. On the whole, the results of the present study suggest that starvation induces HMGB1 secretion, which can be inhibited through the suppression of autophagy. Starvation insult induces HMGB1 translocation to the cytosolic compartments of glioma cells, and autophagy may be involved in the extracellular secretion of HMGB1 in starved glioma cells.