scholarly journals Oxidative Stress and Protein Quality Control Systems in the Aged Canine Brain as a Model for Human Neurodegenerative Disorders

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Mariarita Romanucci ◽  
Leonardo Della Salda

Aged dogs are considered the most suitable spontaneous animal model for studying normal aging and neurodegenerative diseases. Elderly canines naturally develop cognitive dysfunction and neuropathological hallmarks similar to those seen in humans, especially Alzheimer’s disease-like pathology. Pet dogs also share similar living conditions and diets to humans. Oxidative damage accumulates in the canine brain during aging, making dogs a valid model for translational antioxidant treatment/prevention studies. Evidence suggests the presence of detective protein quality control systems, involving ubiquitin-proteasome system (UPS) and Heat Shock Proteins (HSPs), in the aged canine brain. Further studies on the canine model are needed to clarify the role of age-related changes in UPS activity and HSP expression in neurodegeneration in order to design novel treatment strategies, such as HSP-based therapies, aimed at improving chaperone defences against proteotoxic stress affecting brain during aging.

2021 ◽  
Vol 8 ◽  
Author(s):  
Diego Ruano

Aging is a biological and multifactorial process characterized by a progressive and irreversible deterioration of the physiological functions leading to a progressive increase in morbidity. In the next decades, the world population is expected to reach ten billion, and globally, elderly people over 80 are projected to triple in 2050. Consequently, it is also expected an increase in the incidence of age-related pathologies such as cancer, diabetes, or neurodegenerative disorders. Disturbance of cellular protein homeostasis (proteostasis) is a hallmark of normal aging that increases cell vulnerability and might be involved in the etiology of several age-related diseases. This review will focus on the molecular alterations occurring during normal aging in the most relevant protein quality control systems such as molecular chaperones, the UPS, and the ALS. Also, alterations in their functional cooperation will be analyzed. Finally, the role of inflammation, as a synergistic negative factor of the protein quality control systems during normal aging, will also be addressed. A better comprehension of the age-dependent modifications affecting the cellular proteostasis, as well as the knowledge of the mechanisms underlying these alterations, might be very helpful to identify relevant risk factors that could be responsible for or contribute to cell deterioration, a fundamental question still pending in biomedicine.


Author(s):  
Xu Zhou ◽  
Xiongjin Chen ◽  
Tingting Hong ◽  
Miaoping Zhang ◽  
Yujie Cai ◽  
...  

AbstractThe tetrapeptide repeat domain 3 (TTC3) gene falls within Down's syndrome (DS) critical region. Cognitive impairment is a common phenotype of DS and Alzheimer’s disease (AD), and overexpression of TTC3 can accelerate cognitive decline, but the specific mechanism is unknown. The TTC3-mediated protein quality control (PQC) mechanism, similar to the PQC system, is divided into three parts: it acts as a cochaperone to assist proteins in folding correctly; it acts as an E3 ubiquitin ligase (E3s) involved in protein degradation processes through the ubiquitin–proteasome system (UPS); and it may also eventually cause autophagy by affecting mitochondrial function. Thus, this article reviews the research progress on the structure, function, and metabolism of TTC3, including the recent research progress on TTC3 in DS and AD; the role of TTC3 in cognitive impairment through PQC in combination with the abovementioned attributes of TTC3; and the potential targets of TTC3 in the treatment of such diseases.


2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Matthew J Brody ◽  
Michelle A Sargent ◽  
Jeffery D Molkentin

p97 is a AAA-ATPase that plays critical roles in a myriad of cellular protein quality control processes, including the endoplasmic reticulum (ER)-associated degradation (ERAD) pathway that targets misfolded proteins in the ER for degradation in the cytosol by the ubiquitin proteasome system. Mutations in p97 cause a multisystem degenerative proteinopathy disorder called inclusion body myopathy with Paget disease of bone and frontotemporal dementia (IBMPFD) that includes pathologies of the nervous system, skeletal muscle, bone, and heart. Previous studies in the laboratory into the mechanisms whereby thrombospondin 4 has its cardioprotective effects and enhanced ERAD activity identified p97 as a direct interacting partner. This observation suggested that p97 itself could be an important cardioprotective effector by benefiting protein quality control in the heart. To address this hypothesis here we generated cardiac-specific transgenic mice overexpressing wildtype p97 or a p97 K524A mutant with deficient ATPase activity, the latter of which functioned as a dominant negative. Mice overexpressing wildtype p97 exhibit normal cardiac structure and function while mutant p97 overexpressing mice develop cardiomyopathy, upregulate several ERAD complex components, and have elevated levels of ubiquitinated proteins. Proteomics and immunoprecipitation assays identified overwhelming interactions between endogenous p97 and a number of interesting protein complexes that suggest unique functions for this protein in regulating protein quality control in the heart. The results and novel regulatory relationships will be presented, which suggests entirely unique pathways whereby p97 functions in the heart.


Author(s):  
Yasmeena Akhter ◽  
Jahangir Nabi ◽  
Hinna Hamid ◽  
Nahida Tabassum ◽  
Faheem Hyder Pottoo ◽  
...  

Proteostasis is essential for regulating the integrity of the proteome. Disruption of proteostasis under some rigorous conditions leads to the aggregation and accumulation of misfolded toxic proteins, which plays a central role in the pathogenesis of protein conformational disorders. The protein quality control (PQC) system serves as a multi-level security system to shield cells from abnormal proteins. The intrinsic PQC systems maintaining proteostasis include the ubiquitin-proteasome system (UPS), chaperon-mediated autophagy (CMA), and autophagy-lysosome pathway (ALP) that serve to target misfolded proteins for unfolding, refolding, or degradation. Alterations of PQC systems in neurons have been implicated in the pathogenesis of various neurodegenerative disorders. This chapter provides an overview of PQC pathways to set a framework for discussion of the role of PQC in neurodegenerative disorders. Additionally, various pharmacological approaches targeting PQC are summarized.


2018 ◽  
Vol 87 (1) ◽  
pp. 725-749 ◽  
Author(s):  
Charisma Enam ◽  
Yifat Geffen ◽  
Tommer Ravid ◽  
Richard G. Gardner

Nuclear proteins participate in diverse cellular processes, many of which are essential for cell survival and viability. To maintain optimal nuclear physiology, the cell employs the ubiquitin-proteasome system to eliminate damaged and misfolded proteins in the nucleus that could otherwise harm the cell. In this review, we highlight the current knowledge about the major ubiquitin-protein ligases involved in protein quality control degradation (PQCD) in the nucleus and how they orchestrate their functions to eliminate misfolded proteins in different nuclear subcompartments. Many human disorders are causally linked to protein misfolding in the nucleus, hence we discuss major concepts that still need to be clarified to better understand the basis of the nuclear misfolded proteins’ toxic effects. Additionally, we touch upon potential strategies for manipulating nuclear PQCD pathways to ameliorate diseases associated with protein misfolding and aggregation in the nucleus.


Author(s):  
Thomas Nyström

Propagation of a species requires periodic cell renewal to avoid clonal extinction. Sexual reproduction and the separation of germ cells from the soma provide a mechanism for such renewal, but are accompanied by an apparently mandatory ageing of the soma. Data obtained during the last decade suggest that a division of labour exists also between cells of vegetatively reproducing unicellular organisms, leading to the establishment of a soma-like and germ-like lineage with distinct fitness and longevity characteristics. This division of labour in both bacteria and yeast entails segregation of damaged and aggregated proteins such that the germ-like lineage is kept free of damage to the detriment of the soma-like lineage. In yeast, this spatial protein quality control (SQC) encompasses a CCT-chaperonin-dependent translocation and merging of cytotoxic protein aggregates. This process is regulated by Sir2, a protein deacetylase that modulates the rate of ageing in organisms ranging from yeast to worms and flies. Recent data also demonstrate that SQC is intimately integrated with the machinery establishing proper cell polarity and that this machinery is required for generating a soma-like and germ-like lineage in yeast. Deciphering the details of the SQC network may increase our understanding of the development of age-related protein folding disorders and shed light on the selective forces that paved the way for polarity and lineage-specific ageing to evolve.


2013 ◽  
Vol 41 (6) ◽  
pp. 1483-1488 ◽  
Author(s):  
Jaime L. Schneider ◽  
Ana Maria Cuervo

The importance of cellular quality-control systems in the maintenance of neuronal homoeostasis and in the defence against neurodegeneration is well recognized. Chaperones and proteolytic systems, the main components of these cellular surveillance mechanisms, are key in the fight against the proteotoxicity that is often associated with severe neurodegenerative diseases. However, in recent years, a new theme has emerged which suggests that components of protein quality-control pathways are often targets of the toxic effects of pathogenic proteins and that their failure to function properly contributes to pathogenesis and disease progression. In the present mini-review, we describe this dual role as ‘saviour’ and ‘victim’ in the context of neurodegeneration for chaperone-mediated autophagy, a cellular pathway involved in the selective degradation of cytosolic proteins in lysosomes.


2014 ◽  
Vol 204 (6) ◽  
pp. 869-879 ◽  
Author(s):  
Annamaria Ruggiano ◽  
Ombretta Foresti ◽  
Pedro Carvalho

Even with the assistance of many cellular factors, a significant fraction of newly synthesized proteins ends up misfolded. Cells evolved protein quality control systems to ensure that these potentially toxic species are detected and eliminated. The best characterized of these pathways, the ER-associated protein degradation (ERAD), monitors the folding of membrane and secretory proteins whose biogenesis takes place in the endoplasmic reticulum (ER). There is also increasing evidence that ERAD controls other ER-related functions through regulated degradation of certain folded ER proteins, further highlighting the role of ERAD in cellular homeostasis.


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