Cellular prion protein (PrP(C)) expression can be regulated by heat-shock stress, and we designed the present study to determine whether hypoglycemia could affect PrP(C) expression. RT-PCR and Western blotting were used to measure the expression of PrP(C) and heat-shock protein (Hsp70) in mouse neuroblastoma (N18) cells cultured 3 hr to 3 days in media deprived of 97.5% (L) or 75% (M) of its glucose. Hypoglycemia caused a concomitant time-dependent and glucose dose-dependent increase in PrP(C) and Hsp70. In addition, hypoglycemia also increased phosphorylated c-Jun N-terminal kinase (JNK) protein levels in a time-dependent manner. The upregulation of PrP(C) and Hsp70 under hypoglycemic conditions was disrupted by the specific JNK inhibitor SP600125. It was also found from in vitro studies that hypoglycemic conditions induced higher levels of PrP(C) promoter activity in PrP(C) promoters containing a heat-shock element (HSE) than in PrP(C) promoters lacking HSE. We propose that hypoglycemia-increased PrP(C) expression might be due to JNK phosphorylation of a heat-shock transcriptional factor, which then interacts with HSE in the promoter of PrP(C).
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http://dx.doi.org/10.1002/jnr.20509 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Department Biochemistry of Neurodegenerative Diseases, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum 44801, Germany.
Protein misfolding and aggregation are a hallmark of various neurodegenerative disorders. However, the underlying mechanisms driving protein misfolding in the cellular context are incompletely understood. Here, we show that the two-dimensional confinement imposed by a membrane anchor stabilizes the native protein conformation and suppresses liquid-liquid phase separation (LLPS) and protein aggregation.
View Article and Find Full Text PDFSci Rep
December 2024
Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
PrPc is expressed in various tumors and is associated with cancer progression, but previous studies have shown conflicting results regarding its relationship with patient prognosis-potentially due to differences in the antibodies used. This study aimed to clarify the relationship between PrPc expression and primary esophageal squamous cell carcinoma (ESCC) and primary hepatocellular carcinoma (HCC) using a novel anti-PrPc antibody, 4AA-m, noted for its high specificity and sensitivity. We used flow cytometry to detect PrPc expression in ESCC and HCC cell lines.
View Article and Find Full Text PDFJ Environ Manage
December 2024
School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310018, PR China; International Science and Technology Cooperation Platform for Low-Carbon Recycling of Waste and Green Development, Zhejiang Gongshang University, Hangzhou, 310012, PR China. Electronic address:
Volatile fatty acids (VFAs) are suitable substrates for synthesizing poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), wherein propionate is a precursor of PHBV biosynthesis; however, high concentrations are toxic to bacteria. Therefore, VFAs with suitable ratio are needed. Here, with the ratio of acetate: propionate: butyrate being 1:4:2, the maximum PHBV content and the 3HV content were 46.
View Article and Find Full Text PDFCancer Cell Int
December 2024
Sezione di Farmacologia, Dipartimento di Medicina Interna, Università di Genova, Genova, Italy.
Background: Cellular prion protein (PrP) is a widely expressed membrane-anchored glycoprotein, which has been associated with the development and progression of several types of human malignancies, controlling cancer stem cell activity. However, the different molecular mechanisms regulated by PrP in normal and tumor cells have not been characterized yet.
Methods: To assess the role of PrP in patient-derived glioblastoma stem cell (GSC)-enriched cultures, we generated cell lines in which PrP was either overexpressed or down-regulated and investigated, in 2D and 3D cultures, its role in cell proliferation, migration, and invasion.
BMC Cancer
December 2024
Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil.
Background: Glioblastoma (GBM) is an aggressive brain tumor driven by glioblastoma stem cells (GSCs), which represent an appealing target for therapeutic interventions. The cellular prion protein (PrP), a scaffold protein involved in diverse cellular processes, interacts with various membrane and extracellular matrix molecules, influencing tumor biology. Herein, we investigate the impact of PrP expression on GBM.
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