scholarly journals HEXA-018, a Novel Inducer of Autophagy, Rescues TDP-43 Toxicity in Neuronal Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Shinrye Lee ◽  
Myungjin Jo ◽  
Hye Eun Lee ◽  
Yu-Mi Jeon ◽  
Seyeon Kim ◽  
...  

The autophagy-lysosomal pathway is an essential cellular mechanism that degrades aggregated proteins and damaged cellular components to maintain cellular homeostasis. Here, we identified HEXA-018, a novel compound containing a catechol derivative structure, as a novel inducer of autophagy. HEXA-018 increased the LC3-I/II ratio, which indicates activation of autophagy. Consistent with this result, HEXA-018 effectively increased the numbers of autophagosomes and autolysosomes in neuronal cells. We also found that the activation of autophagy by HEXA-018 is mediated by the AMPK-ULK1 pathway in an mTOR-independent manner. We further showed that ubiquitin proteasome system impairment- or oxidative stress-induced neurotoxicity was significantly reduced by HEXA-018 treatment. Moreover, oxidative stress-induced mitochondrial dysfunction was strongly ameliorated by HEXA-018 treatment. In addition, we investigated the efficacy of HEXA-018 in models of TDP-43 proteinopathy. HEXA-018 treatment mitigated TDP-43 toxicity in cultured neuronal cell lines and Drosophila. Our data indicate that HEXA-018 could be a new drug candidate for TDP-43-associated neurodegenerative diseases.

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Antonella Tramutola ◽  
Fabio Di Domenico ◽  
Eugenio Barone ◽  
Marzia Perluigi ◽  
D. Allan Butterfield

Free radical-mediated damage to macromolecules and the resulting oxidative modification of different cellular components are a common feature of aging, and this process becomes much more pronounced in age-associated pathologies, including Alzheimer disease (AD). In particular, proteins are particularly sensitive to oxidative stress-induced damage and these irreversible modifications lead to the alteration of protein structure and function. In order to maintain cell homeostasis, these oxidized/damaged proteins have to be removed in order to prevent their toxic accumulation. It is generally accepted that the age-related accumulation of “aberrant” proteins results from both the increased occurrence of damage and the decreased efficiency of degradative systems. One of the most important cellular proteolytic systems responsible for the removal of oxidized proteins in the cytosol and in the nucleus is the proteasomal system. Several studies have demonstrated the impairment of the proteasome in AD thus suggesting a direct link between accumulation of oxidized/misfolded proteins and reduction of this clearance system. In this review we discuss the impairment of the proteasome system as a consequence of oxidative stress and how this contributes to AD neuropathology. Further, we focus the attention on the oxidative modifications of a key component of the ubiquitin-proteasome pathway, UCHL1, which lead to the impairment of its activity.


Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2219 ◽  
Author(s):  
Tong Su ◽  
Mingyue Yang ◽  
Pingping Wang ◽  
Yanxiu Zhao ◽  
Changle Ma

All eukaryotes rely on the ubiquitin-proteasome system (UPS) and autophagy to control the abundance of key regulatory proteins and maintain a healthy intracellular environment. In the UPS, damaged or superfluous proteins are ubiquitinated and degraded in the proteasome, mediated by three types of ubiquitin enzymes: E1s (ubiquitin activating enzymes), E2s (ubiquitin conjugating enzymes), and E3s (ubiquitin protein ligases). Conversely, in autophagy, a vesicular autophagosome is formed that transfers damaged proteins and organelles to the vacuole, mediated by a series of ATGs (autophagy related genes). Despite the use of two completely different componential systems, the UPS and autophagy are closely interconnected and mutually regulated. During autophagy, ATG8 proteins, which are autophagosome markers, decorate the autophagosome membrane similarly to ubiquitination of damaged proteins. Ubiquitin is also involved in many selective autophagy processes and is thus a common factor of the UPS and autophagy. Additionally, the components of the UPS, such as the 26S proteasome, can be degraded via autophagy, and conversely, ATGs can be degraded by the UPS, indicating cross regulation between the two pathways. The UPS and autophagy cooperate and jointly regulate homeostasis of cellular components during plant development and stress response.


2012 ◽  
Vol 443 (3) ◽  
pp. 681-689 ◽  
Author(s):  
Wan Ning Vanessa Chow ◽  
Hon Wing Luk ◽  
Ho Yin Edwin Chan ◽  
Kwok-Fai Lau

An unstable expansion of the polyglutamine repeat within exon 1 of the protein Htt (huntingtin) causes HD (Huntington's disease). Mounting evidence shows that accumulation of N-terminal mutant Htt fragments is the source of disruption of normal cellular processes which ultimately leads to neuronal cell death. Understanding the degradation mechanism of mutant Htt and improving its clearance has emerged as a new direction in developing therapeutic approaches to treat HD. In the present study we show that the brain-enriched adaptor protein FE65 is a novel interacting partner of Htt. The binding is mediated through WW–polyproline interaction and is dependent on the length of the polyglutamine tract. Interestingly, a reduction in mutant Htt protein level was observed in FE65-knockdown cells, and the process requires the UPS (ubiquitin/proteasome system). Moreover, the ubiquitination level of mutant Htt was found to be enhanced when FE65 is knocked down. Immunofluroescence staining revealed that FE65 associates with mutant Htt aggregates. Additionally, we demonstrated that overexpression of FE65 increases mutant Htt-induced cell death both in vitro and in vivo. These results suggest that FE65 facilitates the accumulation of mutant Htt in cells by preventing its degradation via the UPS, and thereby enhances the toxicity of mutant Htt.


2016 ◽  
Vol 33 ◽  
pp. 73-81 ◽  
Author(s):  
Karnam Shruthi ◽  
S. Sreenivasa Reddy ◽  
P. Yadagiri Reddy ◽  
Potula Shivalingam ◽  
Nemani Harishankar ◽  
...  

2006 ◽  
Vol 2006 (Spring) ◽  
Author(s):  
Silke Meiners ◽  
Andrea Weller ◽  
Antje Ludwig ◽  
Karl Stangl ◽  
Verena Stangl

2015 ◽  
Vol 402 (1-2) ◽  
pp. 193-202 ◽  
Author(s):  
Luiz Henrique Soares de Andrade ◽  
Wilson Max Almeida Monteiro de Moraes ◽  
Eduardo Hiroshi Matsuo Junior ◽  
Elizabeth de Orleans Carvalho de Moura ◽  
Hanna Karen Moreira Antunes ◽  
...  

2021 ◽  
Author(s):  
Saba Ubaid ◽  
Shivani Pandey ◽  
Mohd. Sohail Akhtar ◽  
Mohammad Rumman ◽  
Babita Singh ◽  
...  

Abstract Camel milk is rich in nutritional factors, such as α- Lactalbumin, and important for brain development. It is known to act as a potential therapeutic candidate for brain disorder via regulation of inflammatory and apoptotic pathways. Mechanisms that are critically involved with Parkinson’s disease (PD) are apoptosis, inflammation, and oxidative stress, and the aberrated ubiquitin-proteasome system. Adverse effects of current therapies are imposing the need for the development of natural neuroprotective agents that are very effective and have fewer or no side effects. The present study aimed to evaluate the potential activity of camel α-Lactalbumin (α-LA) in rotenone induced in-vitro PD model. In this study, we hypothesized the use of camel α-lactalbumin as an effective curative agent for PD. The mechanism of action of camel α-lactalbumin was investigated by assessing the effect of α-LA on the level of nitric oxide, NADH, MMP9, inflammatory markers, and on the expression level of SIRT1 and FOXO3a in SH-SY5Y cell line. Overall, the results revealed the potent neuroprotective efficacy of α-Lactalbumin in rotenone-induced PD model via effectively modulating apoptotic pathways, oxidative stress, and neuroinflammatory cascades. Conclusively, these findings confirmed that α-LA could be a biologically effective protective agent against rotenone induced neurotoxic impacts and neurobehavioral aberrations.


2011 ◽  
Vol 19 (5) ◽  
pp. 847-858 ◽  
Author(s):  
J Lewerenz ◽  
H Sato ◽  
P Albrecht ◽  
N Henke ◽  
R Noack ◽  
...  

2012 ◽  
Vol 443 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Ayano Fukuhara ◽  
Mao Yamada ◽  
Ko Fujimori ◽  
Yuya Miyamoto ◽  
Toshihide Kusumoto ◽  
...  

L-PGDS [lipocalin-type PGD (prostaglandin D) synthase] is a dual-functional protein, acting as a PGD2-producing enzyme and a lipid transporter. L-PGDS is a member of the lipocalin superfamily and can bind a wide variety of lipophilic molecules. In the present study we demonstrate the protective effect of L-PGDS on H2O2-induced apoptosis in neuroblastoma cell line SH-SY5Y. L-PGDS expression was increased in H2O2-treated neuronal cells, and the L-PGDS level was highly associated with H2O2-induced apoptosis, indicating that L-PGDS protected the neuronal cells against H2O2-mediated cell death. A cell viability assay revealed that L-PGDS protected against H2O2-induced cell death in a concentration-dependent manner. Furthermore, the titration of free thiols in H2O2-treated L-PGDS revealed that H2O2 reacted with the thiol of Cys65 of L-PGDS. The MALDI–TOF (matrix-assisted laser-desorption ionization–time-of-flight)-MS spectrum of H2O2-treated L-PGDS showed a 32 Da increase in the mass relative to that of the untreated protein, showing that the thiol was oxidized to sulfinic acid. The binding affinities of oxidized L-PGDS for lipophilic molecules were comparable with those of untreated L-PGDS. Taken together, these results demonstrate that L-PGDS protected against neuronal cell death by scavenging reactive oxygen species without losing its ligand-binding function. The novel function of L-PGDS could be useful for the suppression of oxidative stress-mediated neurodegenerative diseases.


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