Proteasomal activity oxidative

Thomas, S., Kotamraju, S., Zielonka, J., Harder, D. R., and Kalyanaraman, B. (2007). Hydrogen peroxide induces nitric oxide and proteasome activity in endothelial cells A bellshaped signaling response. Free Radic. Biol. Med. 42, 1049-1061. 

Oxidative damage to cells is a common phenomenon, and quality control of modified proteins is important to maintain normal cellular functions. In the cytoplasm, nucleus, and endoplasmic reticulum, the proteasome is involved in the removal of various types of proteins such as ubiquinated, misfolded, or unfolded proteins, and oxidized proteins. Abnormal inhibition of proteasome may contribute to neuro-degenerative diseases such as Alzheimer disease, Parkinson disease, Lewy body dementia, and Huntington disease [31-40]. Neuromuscular diseases, such as sporadic inclusion-body myositis (s-IBM) share several phenotypes described in the brain tissues of Alzheimer and Parkinson disease patients [41]. One such similarity to Alzheimer disease is the accumulation of amyloid-P (AP), phosphory-lated tau (p-tau), and ubiquitin, which are often found within these aggregates [42, 43]. In s-IBM patients, significant proteasome abnormalities were identified including, increased 26 S proteasome expression and abnormal accumulation of 26S proteasome, but reduced proteasome activities [44]. The inverse relationship between increased expression... 

Oxidized LDL alter cellular functions role in cell death Oxidized LDL seem to be poorly degraded by lysosomal enzymes and accumulate in lysosomes altering in turn their functionality (Dean et al., 1997). It has been proposed that inhibition of oxidized LDL degradation and subsequent lipid accumulation may induce a destabilization of the acidic compartment, and lysosomal rupture with a relocation of lysosomal enzymes in the cytosol (li W et al, 1998). This process, also called endopepsis , occurs early and could precede mitochondrial dysfunction and cell death (Lossel et al., 1994). Moreover, oxidized LDL trigger a dysfunction of the intracellular proteolytic ubiquitin/proteasome pathway (early activation followed by inhibition)... 

Vieira, O., EscargueU-Blanc, I., Jurgens, G Bomer, C, Almeida, L, Salvayre, R., and Negre-Salvayre, A., 2000, Oxidized LDLs alter the activity of the ubiquitin-proteasome pathway potential role in oxidized LDL-induced apoptosis, FASEB J. 14 532-542. 

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