It is known that endoplasmic reticulum (ER) and nucleus communicate with each other to cope with ER stress. However, the mechanisms through which extracellular transmission of ER stress occurs remain unexplored. When the ER stress-induced unfolded protein response (UPR) is activated, the X-box binding protein 1 (XBP1) mRNA is spliced by inositol-requiring enzyme-1α (IRE1α) to produce the spliced form of XBP1 (sXBP1). In the present study, we found that sXBP1 mRNA in the cell may be incorporated into the exosomes and was released extracellularly. We found that the ratio of the mRNA levels of sXBP1 to unspliced XBP1 (uXBP1) in the exosome was higher than that of cells in MIN6 mouse pancreatic β cells. A similar effect was observed when XBP1 splicing was induced by overexpressing IRE1α in HEK293T cells. These results suggest that the incorporation of sXBP1 into the exosomes is a novel mechanism of UPR transmitted to extracellularly, which would be triggered when cells are exposed to stress.
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http://dx.doi.org/10.3389/fphys.2018.01357 | DOI Listing |
Cells
December 2024
Neuroscience Institute, Section of Padova, National Research Council (CNR), 35131 Padova, Italy.
Astrocytes from different brain regions respond with Ca elevations to the catecholamine norepinephrine (NE). However, whether this noradrenergic-mediated signaling is present in astrocytes from the ventral tegmental area (VTA), a dopaminergic circuit receiving noradrenergic inputs, has not yet been investigated. To fill in this gap, we applied a pharmacological approach along with two-photon microscopy and an AAV strategy to express a genetically encoded calcium indicator in VTA astrocytes.
View Article and Find Full Text PDFJ Am Heart Assoc
January 2025
Division of Cardiovascular Science, Faculty of Biology, Medicine and Health The University of Manchester Manchester UK.
Background: Heart failure with preserved ejection fraction (HFpEF) is linked to prolonged endoplasmic reticulum (ER) stress. P21-activated kinase 2 (Pak2) facilitates a protective ER stress response. This study explores the mechanism and role of Pak2 in HFpEF pathology.
View Article and Find Full Text PDFInt J Mol Med
March 2025
National Local Joint Engineering Research Center for Precision Surgery and Regenerative Medicine, Shaanxi Provincial Center for Regenerative Medicine and Surgical Engineering, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China.
Cold‑inducible RNA‑binding protein (CIRP) is a cold shock protein implicated in the regulation of multiple biological processes depending on its cellular localization. However, to the best of our knowledge, the role of CIRP in liver regeneration and injury after hepatectomy has not been investigated. The present study was therefore designed to explore whether CIRP is involved in liver regeneration after hepatectomy and its specific role and underlying molecular mechanism.
View Article and Find Full Text PDFHeliyon
January 2025
Department of Neonatology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China.
Background: Maternal hypertensive disorders of pregnancy (HDP) was associated with increased risk of congenital hypothyroidism in preterm infants, but its underlying mechanisms remain unclear.
Objective: To investigate the possible mechanisms by which intrauterine exposure to HDP affects thyroid hormone synthesis in preterm infant rats.
Methods: preterm infant rats were obtained by Caesarean section delivery from the L-NAME group and Control groups which was induced by L-NAME and saline, respectively.
J Cancer Prev
December 2024
Department of Nutrition and Food Science, College of Agriculture and Natural Resources, University of Maryland, College Park, MD, USA.
Identifying the roles of genes in cancer is critical in discovering potential genetic therapies for cancer care. Translocon-associated protein delta (TRAPδ), also known as signal sequence receptor 4 (SSR4), is a constituent unit in the TRAP/SSR complex that resides in the endoplasmic reticulum and plays a key role in transporting newly synthesized proteins into the endoplasmic reticulumn. However, its biological role in disease development remains unknown to date.
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