scholarly journals Cellular prion protein mediates early apoptotic proteome alternation and phospho-modification in human neuroblastoma cells

2017 ◽  
Vol 8 (1) ◽  
pp. e2557-e2557 ◽  
Author(s):  
Saima Zafar ◽  
Christina Behrens ◽  
Hassan Dihazi ◽  
Matthias Schmitz ◽  
Inga Zerr ◽  
...  
2007 ◽  
Vol 18 (9) ◽  
pp. 3302-3312 ◽  
Author(s):  
Subhabrata Basu ◽  
Maradumane L. Mohan ◽  
Xiu Luo ◽  
Bishwajit Kundu ◽  
Qingzhong Kong ◽  
...  

The principal infectious and pathogenic agent in all prion disorders is a β-sheet–rich isoform of the cellular prion protein (PrPC) termed PrP-scrapie (PrPSc). Once initiated, PrPSc is self-replicating and toxic to neuronal cells, but the underlying mechanisms remain unclear. In this report, we demonstrate that PrPC binds iron and transforms to a PrPSc-like form (*PrPSc) when human neuroblastoma cells are exposed to an inorganic source of redox iron. The *PrPSc thus generated is itself redox active, and it induces the transformation of additional PrPC, simulating *PrPSc propagation in the absence of brain-derived PrPSc. Moreover, limited depletion of iron from prion disease-affected human and mouse brain homogenates and scrapie-infected mouse neuroblastoma cells results in 4- to 10-fold reduction in proteinase K (PK)-resistant PrPSc, implicating redox iron in the generation, propagation, and stability of PK-resistant PrPSc. Furthermore, we demonstrate increased redox-active ferrous iron levels in prion disease-affected brains, suggesting that accumulation of PrPSc is modulated by the combined effect of imbalance in brain iron homeostasis and the redox-active nature of PrPSc. These data provide information on the mechanism of replication and toxicity by PrPSc, and they evoke predictable and therapeutically amenable ways of modulating PrPSc load.


1999 ◽  
Vol 270 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Vito Vetrugno ◽  
Michaela Malchow ◽  
Quan-guo Liu ◽  
Giovanna Marziali ◽  
Angela Battistini ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Amnah M. Alshangiti ◽  
Eszter Tuboly ◽  
Shane V. Hegarty ◽  
Cathal M. McCarthy ◽  
Aideen M. Sullivan ◽  
...  

Neuroblastoma is an embryonal malignancy that arises from cells of sympathoadrenal lineage during the development of the nervous system. It is the most common pediatric extracranial solid tumor and is responsible for 15% of childhood deaths from cancer. Fifty percent of cases are diagnosed as high-risk metastatic disease with a low overall 5-year survival rate. More than half of patients experience disease recurrence that can be refractory to treatment. Amplification of the MYCN gene is an important prognostic indicator that is associated with rapid disease progression and a poor prognosis, highlighting the need for new therapeutic approaches. In recent years, there has been an increasing focus on identifying anticancer properties of naturally occurring chalcones, which are secondary metabolites with variable phenolic structures. Here, we report that 4-hydroxychalcone is a potent cytotoxin for MYCN-amplified IMR-32 and SK-N-BE (2) neuroblastoma cells, when compared to non-MYCN-amplified SH-SY5Y neuroblastoma cells and to the non-neuroblastoma human embryonic kidney cell line, HEK293t. Moreover, 4-hydroxychalcone treatment significantly decreased cellular levels of the antioxidant glutathione and increased cellular reactive oxygen species. In addition, 4-hydroxychalcone treatment led to impairments in mitochondrial respiratory function, compared to controls. In support of this, the cytotoxic effect of 4-hydroxychalcone was prevented by co-treatment with either the antioxidant N-acetyl-L-cysteine, a pharmacological inhibitor of oxidative stress-induced cell death (IM-54) or the mitochondrial reactive oxygen species scavenger, Mito-TEMPO. When combined with the anticancer drugs cisplatin or doxorubicin, 4-hydroxychalcone led to greater reductions in cell viability than was induced by either anti-cancer agent alone. In summary, this study identifies a cytotoxic effect of 4-hydroxychalcone in MYCN-amplified human neuroblastoma cells, which rationalizes its further study in the development of new therapies for pediatric neuroblastoma.


Author(s):  
Vega García-Escudero ◽  
Daniel Ruiz-Gabarre ◽  
Ricardo Gargini ◽  
Mar Pérez ◽  
Esther García ◽  
...  

AbstractTauopathies, including Alzheimer’s disease (AD) and frontotemporal lobar degeneration with Tau pathology (FTLD-tau), are a group of neurodegenerative disorders characterized by Tau hyperphosphorylation. Post-translational modifications of Tau such as phosphorylation and truncation have been demonstrated to be an essential step in the molecular pathogenesis of these tauopathies. In this work, we demonstrate the existence of a new, human-specific truncated form of Tau generated by intron 12 retention in human neuroblastoma cells and, to a higher extent, in human RNA brain samples, using qPCR and further confirming the results on a larger database of human RNA-seq samples. Diminished protein levels of this new Tau isoform are found by Westernblotting in Alzheimer’s patients’ brains (Braak I n = 3; Braak II n = 6, Braak III n = 3, Braak IV n = 1, and Braak V n = 10, Braak VI n = 8) with respect to non-demented control subjects (n = 9), suggesting that the lack of this truncated isoform may play an important role in the pathology. This new Tau isoform exhibits similar post-transcriptional modifications by phosphorylation and affinity for microtubule binding, but more interestingly, is less prone to aggregate than other Tau isoforms. Finally, we present evidence suggesting this new Tau isoform could be linked to the inhibition of GSK3β, which would mediate intron 12 retention by modulating the serine/arginine rich splicing factor 2 (SRSF2). Our results show the existence of an important new isoform of Tau and suggest that further research on this less aggregation-prone Tau may help to develop future therapies for Alzheimer’s disease and other tauopathies.


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