The glycoprotein clusterin (CLU) is involved in cell proliferation and DNA damage repair and is highly expressed in tumor cells. Here, we aimed to investigate the effects of CLU dysregulation on two human astrocytic cell lines: CCF-STTG1 astrocytoma cells and SV-40 immortalized normal human astrocytes. We observed that suppression of CLU expression by RNA interference inhibited cell proliferation, triggered the DNA damage response, and resulted in cellular senescence in both cell types tested. To further investigate the underlying mechanism behind these changes, we measured reactive oxygen species, assessed mitochondrial function, and determined selected markers of the senescence-associated secretory phenotype. Our results suggest that CLU deficiency triggers oxidative stress-mediated cellular senescence associated with pronounced alterations in mitochondrial membrane potential, mitochondrial mass, and expression levels of OXPHOS complex I, II, III and IV, indicating mitochondrial dysfunction. This report shows the important role of CLU in cell cycle maintenance in astrocytes. Based on these data, targeting CLU may serve as a potential therapeutic approach valuable for treating gliomas.

• Klíčová slova
• Astrocytes, Cellular senescence, Clusterin, Mitochondria, Oxidative stress,
• MeSH
• astrocyty * metabolismus   patologie   MeSH
• klusterin * nedostatek   metabolismus   MeSH
• lidé MeSH
• membránový potenciál mitochondrií MeSH
• mitochondrie metabolismus   MeSH
• nádorové buněčné linie MeSH
• oxidační stres MeSH
• oxidativní fosforylace MeSH
• poškození DNA MeSH
• proliferace buněk MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• stárnutí buněk * fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• CLU protein, human MeSH Prohlížeč
• klusterin * MeSH
• reaktivní formy kyslíku MeSH

Amyloid β42 (Aβ42) plays a decisive role in the pathology of Alzheimer's disease. The Aβ42 peptide can aggregate into various supramolecular structures, with oligomers being the most toxic form. However, different Aβ species that cause different effects have been described. Many cell death pathways can be activated in connection with Aβ action, including apoptosis, necroptosis, pyroptosis, oxidative stress, ferroptosis, alterations in mitophagy, autophagy, and endo/lysosomal functions. In this study, we used a model of differentiated SH-SY5Y cells and applied two different Aβ42 preparations for 2 and 4 days. Although we found no difference in the shape and size of Aβ species prepared by two different methods (NaOH or NH4OH for Aβ solubilization), we observed strong differences in their effects. Treatment of cells with NaOH-Aβ42 mainly resulted in damage of mitochondrial function and increased production of reactive oxygen species, whereas application of NH4OH-Aβ42 induced necroptosis and first steps of apoptosis, but also caused an increase in protective Hsp27. Moreover, the two Aβ42 preparations differed in the mechanism of interaction with the cells, with the effect of NaOH-Aβ42 being dependent on monosialotetrahexosylganglioside (GM1) content, whereas the effect of NH4OH-Aβ42 was independent of GM1. This suggests that, although both preparations were similar in size, minor differences in secondary/tertiary structure are likely to strongly influence the resulting processes. Our work reveals, at least in part, one of the possible causes of the inconsistency in the data observed in different studies on Aβ-toxicity pathways.

• Klíčová slova
• Alzheimer´s disease, Amyloid β42, Apoptosis, Cell death, GM1, Necroptosis, Reactive oxygen species,
• MeSH
• Alzheimerova nemoc metabolismus   patologie   MeSH
• amyloidní beta-protein * metabolismus   farmakologie   MeSH
• apoptóza * účinky léků   MeSH
• buněčná smrt účinky léků   MeSH
• lidé MeSH
• mitochondrie metabolismus   účinky léků   MeSH
• nádorové buněčné linie MeSH
• nekroptóza účinky léků   MeSH
• neuroblastom * patologie   metabolismus   MeSH
• oxidační stres účinky léků   MeSH
• peptidové fragmenty * farmakologie   MeSH
• reaktivní formy kyslíku * metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• amyloid beta-protein (1-42) MeSH Prohlížeč
• amyloidní beta-protein * MeSH
• peptidové fragmenty * MeSH
• reaktivní formy kyslíku * MeSH