RESUMO
Aberrant aggregation of misfolded alpha-synuclein (α-syn), a major pathological hallmark of related neurodegenerative diseases such as Parkinson's disease (PD), can translocate between cells. Ubiquitin-like 3 (UBL3) is a membrane-anchored ubiquitin-fold protein and post-translational modifier. UBL3 promotes protein sorting into small extracellular vesicles (sEVs) and thereby mediates intercellular communication. Our recent studies have shown that α-syn interacts with UBL3 and that this interaction is downregulated after silencing microsomal glutathione S-transferase 3 (MGST3). However, how MGST3 regulates the interaction of α-syn and UBL3 remains unclear. In the present study, we further explored this by overexpressing MGST3. In the split Gaussia luciferase complementation assay, we found that the interaction between α-syn and UBL3 was upregulated by MGST3. While Western blot and RT-qPCR analyses showed that silencing or overexpression of MGST3 did not significantly alter the expression of α-syn and UBL3, the immunocytochemical staining analysis indicated that MGST3 increased the co-localization of α-syn and UBL3. We suggested roles for the anti-oxidative stress function of MGST3 and found that the effect of MGST3 overexpression on the interaction between α-syn with UBL3 was significantly rescued under excess oxidative stress and promoted intracellular α-syn to extracellular transport. In conclusion, our results demonstrate that MGST3 upregulates the interaction between α-syn with UBL3 and promotes the interaction to translocate intracellular α-syn to the extracellular. Overall, our findings provide new insights and ideas for promoting the modulation of UBL3 as a therapeutic agent for the treatment of synucleinopathy-associated neurodegenerative diseases.
Assuntos
Glutationa Transferase , Estresse Oxidativo , Ubiquitinas , alfa-Sinucleína , alfa-Sinucleína/metabolismo , alfa-Sinucleína/genética , Humanos , Glutationa Transferase/metabolismo , Glutationa Transferase/genética , Ubiquitinas/metabolismo , Ubiquitinas/genética , Regulação para Cima , Transporte Proteico , Doença de Parkinson/metabolismo , Doença de Parkinson/genética , Doença de Parkinson/patologia , Ligação ProteicaRESUMO
Ubiquitin-like proteins (Ubls) are involved in a variety of biological processes through the modification of proteins. Dysregulation of Ubl modifications is associated with various diseases, especially cancer. Ubiquitin-like protein 3 (UBL3), a type of Ubl, was revealed to be a key factor in the process of small extracellular vesicle (sEV) protein sorting and major histocompatibility complex class II ubiquitination. A variety of sEV proteins that affects cancer properties has been found to interact with UBL3. An increasing number of studies has implied that UBL3 expression affects cancer cell growth and cancer prognosis. In this review, we provide an overview of the relationship between various Ubls and cancers. We mainly introduce UBL3 and its functions and summarize the current findings of UBL3 and examine its potential as a therapeutic target in cancers.
Assuntos
Vesículas Extracelulares , Neoplasias , Humanos , Ubiquitinas/genética , Ubiquitinas/metabolismo , Ubiquitinação , Proteínas/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Vesículas Extracelulares/metabolismo , Processamento de Proteína Pós-TraducionalRESUMO
Ubiquitin-like 3 (UBL3) is a well-conserved ubiquitin-like protein (UBL) in eukaryotes and regulates the ubiquitin cascade, but the significant roles of UBL3 in cellular processes remained unknown. Recently, UBL3 was elucidated to be a post-translational modification factor that promotes protein sorting to small extracellular vesicles (sEVs). Proteins sorted into sEVs have been studied as etiologies of sEV-related diseases. Also, there have been attempts to construct drug delivery systems (DDSs) by loading proteins into sEVs. In this review, we introduce the new concept that UBL3 has a critical role in the protein-sorting system and compare structure conservation between UBL3 and other UBLs from an evolutionary perspective. We conclude with future perspectives for the utility of UBL3 in sEV-related diseases and DDS.Key words: UBL3, small extracellular vesicles, protein sorting, ubiquitin-like protein, post-translational modification.
Assuntos
Vesículas Extracelulares , Ubiquitinas/metabolismo , Animais , Vesículas Extracelulares/metabolismo , Humanos , Processamento de Proteína Pós-Traducional , Transporte Proteico , Ubiquitina/metabolismo , Ubiquitinas/genéticaRESUMO
Traumatic optic neuropathy (TON) is a serious complication of craniofacial trauma that directly or indirectly damages the optic nerve and can cause severe vision loss. The incidence of TON has been gradually increasing in recent years. Research on the protection and regeneration of the optic nerve after the onset of TON is still at the level of laboratory studies and which is insufficient to support clinical treatment of TON. And, due to without clear guidelines, there is much ambiguity regarding its diagnosis and management. Clinical interventions for TON include observation only, treatment with corticosteroids alone, or optic canal (OC) decompression (with or without steroids). There is controversy in clinical practice concerning which treatment is the best. A review of available studies shows that the visual acuity of patients with TON can be significantly improved after OC decompression surgery (especially endoscopic transnasal/transseptal optic canal decompression (ETOCD)) with or without the use of corticosteroids. And new findings of laboratory studies such as mitochondrial therapy, lipid change studies, and other studies in favor of TON therapy have also been identified. In this review, we discuss the evolving perspective of surgical treatment and experimental study.
Assuntos
Traumatismos do Nervo Óptico , Descompressão Cirúrgica , Humanos , Nervo Óptico/cirurgia , Traumatismos do Nervo Óptico/diagnóstico , Traumatismos do Nervo Óptico/cirurgia , Osso Esfenoide/cirurgia , Resultado do Tratamento , Acuidade VisualRESUMO
Endocannabinoid 2-arachidonoylglycerol (2-AG) has been implicated in habituation to stress, and its augmentation reduces stress-induced anxiety-like behavior. Chronic restraint stress (CRS) changes the 2-AG levels in some gross brain areas, such as the forebrain. However, the detailed spatial distribution of 2-AG and its changes by CRS in stress processing-related anatomical structures such as the anterior cingulate cortex (ACC), caudate putamen (CP), nucleus accumbens (NAc), and piriform cortex (PIR) are still unclear. In this study, mice were restrained for 30 min in a 50 mL-centrifuge tube for eight consecutive days, followed by imaging of the coronal brain sections of control and stressed mice using desorption electrospray ionization mass spectrometry imaging (DESI-MSI). The results showed that from the forebrain to the cerebellum, 2-AG levels were highest in the hypothalamus and lowest in the hippocampal region. 2-AG levels were significantly (p < 0.05) upregulated and 2-AG precursors levels were significantly (p < 0.05) downregulated in the ACC, CP, NAc, and PIR of stressed mice compared with control mice. This study provided direct evidence of 2-AG expression and changes, suggesting that 2-AG levels are increased in the ACC CP, NAc, and PIR when individuals are under chronic stress.
Assuntos
Núcleo Accumbens , Córtex Piriforme , Camundongos , Animais , Núcleo Accumbens/metabolismo , Endocanabinoides/metabolismo , Giro do Cíngulo/metabolismo , PutamenRESUMO
Ubiquitin-like 3 (UBL3) is a membrane-anchored protein that plays a crucial role in sorting proteins into small extracellular vesicles. Aggregations of alpha-synuclein (α-syn) are associated with the pathology of neurodegenerative diseases such as Parkinson's disease. Recently, the interaction between UBL3 and α-syn was discovered, with potential implications in clearing excess α-syn from neurons and its role in disease spread. However, the regulator that can mediate the interaction between UBL3 and α-syn remains unclear. In this study, using the split gaussian luciferase complementation assay and RNA interference technology, we identified that QSOX2, HTATIP2, UBE3C, MGST3, NSF, HECTD1, SAE1, and ATG3 were involved in downregulating the interaction between UBL3 and α-syn. Notably, silencing MGST3 had the most significant impact. Immunocytochemistry staining confirmed the impact of MGST3 silencing on the co-localization of UBL3 and α-syn in cells. MGST3 is a part of the antioxidant system, and silencing MGST3 is believed to contribute to oxidative stress. We induced oxidative stress with hydrogen peroxide, observing its effect on the UBL3-α-syn interaction, and showing that 800 µM of H2O2 downregulated this interaction. In conclusion, silencing MGST3 downregulates the interaction between UBL3 and α-syn.
RESUMO
As an important neurotransmitter, glutamate acts in over 90% of excitatory synapses in the human brain. Its metabolic pathway is complicated, and the glutamate pool in neurons has not been fully elucidated. Tubulin polyglutamylation in the brain is mainly mediated by two tubulin tyrosine ligase-like (TTLL) proteins, TTLL1 and TTLL7, which have been indicated to be important for neuronal polarity. In this study, we constructed pure lines of Ttll1 and Ttll7 knockout mice. Ttll knockout mice showed several abnormal behaviors. Matrix-assisted laser desorption/ionization (MALDI) Imaging mass spectrometry (IMS) analyses of these brains showed increases in glutamate, suggesting that tubulin polyglutamylation by these TTLLs acts as a pool of glutamate in neurons and modulates some other amino acids related to glutamate.
Assuntos
Ácido Glutâmico , Tubulina (Proteína) , Animais , Humanos , Camundongos , Encéfalo/metabolismo , Ácido Glutâmico/metabolismo , Camundongos Knockout , Neurônios/metabolismo , Processamento de Proteína Pós-Traducional , Tubulina (Proteína)/metabolismoRESUMO
Ubiquitin-like 3 (UBL3) acts as a post-translational modification (PTM) factor and regulates protein sorting into small extracellular vesicles (sEVs). sEVs have been reported as vectors for the pathology propagation of neurodegenerative diseases, such as α-synucleinopathies. Alpha-synuclein (α-syn) has been widely studied for its involvement in α-synucleinopathies. However, it is still unknown whether UBL3 interacts with α-syn, and is influenced by drugs or compounds. In this study, we investigated the interaction between UBL3 and α-syn, and any ensuing possible functional and pathological implications. We found that UBL3 can interact with α-syn by the Gaussia princeps based split luciferase complementation assay in cells and immunoprecipitation, while cysteine residues at its C-terminal, which are considered important as PTM factors for UBL3, were not essential for the interaction. The interaction was upregulated by 1-methyl-4-phenylpyridinium exposure. In drug screen results, the interaction was significantly downregulated by the treatment of osimertinib. These results suggest that UBL3 interacts with α-syn in cells and is significantly downregulated by epidermal growth factor receptor (EGFR) pathway inhibitor osimertinib. Therefore, the UBL3 pathway may be a new therapeutic target for α-synucleinopathies in the future.