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Objective To explore the antitumor small molecules targeting the ubiquitin–proteasome system (UPS) on the basis of active molecules from traditional Chinese medicine. Methods UbG76V-GFP stably expressing cell line was constructed to screen novel small molecule inhibitors targeting UPS. The fluorogenic substrates of Suc-LLVY-AMC, Z-LLE-AMC, and Boc-LRR-AMC were used to assess the effect of dioscin on the 20S proteasome hydrolase activity. The Ub-AMC substrate was used to evaluate the effect of dioscin on the intracellular deubiquitinating enzyme activity. Western blot was used to detect the effect of dioscin on intracellular ubiquitination levels. CCK-8 and colony formation assays were used to detect the inhibitory effect of dioscin on the tumor cell proliferation. Results Dioscin is a UPS inhibitor discovered through the UbG76V-GFP reporter system. It enhances intracellular ubiquitination and inhibits tumor cell proliferation and colony formation by targeting deubiquitinating enzymes. Conclusion Dioscin could significantly inhibit tumor cell proliferation by targeting ubiquitin–proteasome.
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Immunoproteasome is a variant of proteasome with structural differences in 20S subunits optimizing them for the production of antigenic peptides with higher binding affinity to major histocompatibility complex (MHC)-I molecules. Apart from this primary function in antigen presentation, immunoproteasome is also responsible for the degradation of proteins, both unfolded proteins for the maintenance of protein homeostasis and tumor suppressor proteins contributing to tumor progression. The altered expression of immunoproteasome is frequently observed in cancers; however, its expression levels and effects vary among different cancer types exhibiting antagonistic roles in tumor development. This review focuses on the dichotomous role of immunoproteasome in different cancer types, as well as summarizes the current progression in immunoproteasome activators and inhibitors. Specifically targeting immunoproteasome may be a beneficial therapeutic intervention in cancer treatment and understanding the role of immunoproteasome in cancers will provide a significant therapeutic insight for the prevention and treatment of cancers.
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Targeted protein degradation (TPD) techniques eliminate pathogenic proteins by hijacking the intracellular proteolysis machinery which includes the ubiquitin-proteasome system (UPS) and the lysosomal degradation pathway, holding promise to overcome the limitations of traditional inhibitors and further broaden the target space including many “undruggable” targets, and provide new targeted treatments for drug discovery. In this review, recent advances in a variety of promising TPD strategies were summarized, such as proteolysis targeting chimera (PROTAC), molecular glue, lysosome-targeting chimaera (LYTAC), autophagosome-tethering compound (ATTEC), autophagy-targeting chimera AUTAC and AUTOTAC, particularly. The representative case studies, potential applications and challenges were analyzed.
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Chronic hepatitis B virus (HBV) infection is one of the leading causes of hepatocellular carcinoma (HCC). Ubiquitin-proteasome system (UPS) mediates the post-translational modification and degradation of protein in eukaryotic cells. Recent studies have revealed that UPS plays an important role in HBV infection and hepatocarcinogenesis. Targeting HBx to intervene in the progression of HBV infection or HBV-related HCC has become a research hotspot both domestically and internationally in recent years. This article reviewed the progress in HBx promoting HBV infection and hepatocarcinogenesis through UPS.
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Objective:To investigate the relationship between serum fibroblast growth factor 21 (FGF21) and sarcopenia in hemodialysis (HD) patients, and to explore the relationship between FGF21 and signal pathways related to skeletal muscle metabolism in uremic state at the cellular level.Methods:The data of the HD patients from the blood purification center of the Third Affiliated Hospital of Soochow University were collected in this prospective observational study between January 2018 and December 2019. Serum FGF21 concentration was detected by enzyme-linked immunosorbent assay (ELISA). Meanwhile, the skeletal muscle indexes (SMI) at the fourth thoracic vertebra (T4) and the first lumbar vertebra (L1) were assessed by chest CT. According to the T4 SMI and L1 SMI, the patients were divided into sarcopenia group and non-sarcopenia group. The relationship between serum FGF21 and sarcopenia was analyzed. The C2C12 mouse myoblasts were cultured in vitro, which were intervened with healthy human serum, healthy human serum+different concentrations of FGF21, uremic serum, uremic serum+different concentrations of FGF21. The expressions of muscle ring finger protein-1 (MURF1), muscle atrophy F-box (Atrogin-1), myogenic differentiation (MyoD) and myogenin (MyoG) were detected by Western blotting. Results:A total of 118 HD patients with age of (52.64±15.29) years were enrolled in the study, including 64 males (54.2%) and 54 females (45.8%). The images at T4 and L1 level assessed by chest CT could be acquired from 118 patients and 82 patients, respectively. According to the lowest sex-specific quartile ( P25) of T4 SMI (male < 59.92 cm 2/m 2, female < 46.75 cm 2/m 2) and the lowest sex-specific quartile ( P25) of L1 SMI (male < 29.02 cm 2/m 2, female < 24.50 cm 2/m 2), patients were divided into sarcopenia group and non-sarcopenia group, and there were 29(24.58%) and 20(24.39%) patients in the sarcopenia group, respectively. When the patients were divided into two groups according to the sex-specific lowest quartile of T4 SMI, although the serum FGF21 level in the sarcopenia group was higher than that in the non-sarcopenia group, there was no statistical significance between the two groups [448.52(183.96, 1 684.08) ng/L vs. 273.65 (152.83, 535.54) ng/L, Z=-1.741, P=0.082]. When the patients were divided into two groups according to the sex-specific lowest quartile of L1 SMI, the serum FGF21 level in the sarcopenia group was significantly higher than that in the non-sarcopenia group [460.95(188.91, 1 276.38) ng/L vs. 239.10(133.25, 466.36) ng/L, Z=-2.170, P=0.030]. Binary logistic regression analysis showed that higher serum FGF21 was an independent influencing factor for sarcopenia in HD patients regardless of whether the patients were divided into two groups according to the sex-specific lowest quartile of T4 SMI or the sex-specific lowest quartile of L1 SMI (T4 SMI grouping: OR=4.085, 95% CI 1.778-9.388, P=0.001; L1 SMI grouping: OR=7.327, 95% CI 1.841-29.160, P=0.005). At T4 and L1 levels, the area under the receiver operating characteristic curve of FGF21 in predicting sarcopenia in HD patients was 0.636(95% CI 0.494-0.779, P=0.036) and 0.684(95% CI 0.535-0.833, P=0.018), respectively. Cell experiment showed that compared with the uremic serum group, the expressions of MURF1 and Atrogin-1 in myotube cells were increased, while the expressions of MyoD and MyoG were significantly decreased in uremic serum+FGF21 group (both P < 0.05). Conclusions:Higher serum FGF21 is associated with an increased risk of sarcopenia in HD patients. FGF21 may increase the expression of ubiquitin proteasome system, reduce the synthesis and differentiation of skeletal muscle protein, and promote the occurrence of muscle atrophy in uremic patients
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Objective:To investigate the effect of interfering S-phase kinase associated protein 1 (SKP1) gene on apoptosis in Parkinson's disease(PD) cell model induced by 1-methyl-4-phenyl-pyridine ion (MPP+ ) and the mechanism of ubiquitin proteasome system degradation of α-synuclein (α-syn) influence.Methods:SH-SY5Y cells were divided into control group, MPP+ group, SKP1 interference group, and SKP1 interference+ MG132(UPS inhibitor) group.The cells in the control group were cultured normally. The cells in the latter three groups were incubated with MPP+ (0.5 mmol/L) for 24 h as PD model cells.The cells in SKP1 interference group were transfected with lentivirus SKP1-siRNA, and the cells in SKP1 interference+ MG132 group were transfected with lentivirus SKP1 siRNA and added with MG132 (0.5 μmol/L) for 24 h. The protein levels and mRNA levels of SKP1, microtubule-associated protein light chain 3 (LC3), lysosome-associated membrane protein (LAMP), α-syn, ubiquitin activating enzyme E1 (UBE1), parkin, and p27 in cells were detected by Western blot and RT-PCR.Flow cytometry was used to detect cell apoptosis and cycle level, and CCK-8 method was used to detect cell proliferation level.Co-immunoprecipitation method was used to explore the interaction between SKP1 and p27. SPSS 23.0 software was used for statistical analysis. One-way ANOVA was used for comparison among groups, and LSD test was used for further pairwise comparison.Results:RT-PCR and Western blot results showed that the mRNA levels and protein levels of autophagy related proteins and ubiquitin related proteins LC3, LAMP2, α-syn, UBE1, parkin and p27 in the four groups were statistically significant(mRNA: F=99.155, 43.028, 138.464, 28.200, 22.009, 28.147, all P<0.05; F=245.517, 157.634, 315.920, 2 336.472, 477.429, 2 350.201, all P<0.05). The mRNA and protein levels of LC3, Lamp2, α-syn and p27 in SKP1 interference group were lower than those in MPP+ group (all P<0.05), while the mRNA and protein levels of UBE1 and parkin were higher than those in MPP+ group (all P<0.05). The mRNA and protein levels of LC3, α-syn and p27 in SKP1 interference+ MG132 group were higher than those in SKP1 interference group (all P<0.05), and the mRNA and protein levels of UBE1 and parkin were lower than those in SKP1 interference group (all P<0.05). The results of flow cytometry and CCK-8 method showed that the apoptosis rate and cell inhibition rate among the four groups were significantly different( F=2 749.420, 171.508, both P<0.05). The apoptosis rate of SKP1 interference group was lower than that of MPP+ group ((8.22±0.25)%, (15.30±0.21)%, P<0.05), while the cell inhibition rate of SKP1 interference group was lower than that of MPP+ group((26.31±3.73)%, (55.05±3.84)%, P<0.05). The apoptosis rate of SKP1 interference+ MG132 group ((9.49±0.07)%) was higher than that of SKP1 interference group, and the cell inhibition rate ((36.06±2.85)%) was higher than that of SKP1 interference group (both P<0.05). The results of immunoprecipitation method showed that P27 decreased after SKP1 immunoprecipitation. Conclusion:After SKP1 gene was interfered, the autophagy function of PD cells decreased, which may be related to parkin promoting α-syn ubiquitination, activating UBE1/ Parkin-mediated UPS pathway to degrade α-syn, and mediating P27 to inhibit apoptosis.
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ObjectiveTo explore the mechanism of Liu Junzitang in preventing and treating muscle atrophy in mice with lung cancer cachexia based on the signal transducer and activator of transcription 3（STAT3）/ubiquitin proteasome pathway in vivo. MethodForty C57BL/6 mice aged six weeks were randomly divided into a blank group， a model group， a Liu Junzitang group， an inhibitor group （stattic group），and a Liu Junzitang + inhibitor group （combination group）， with eight mice in each group. The cachectic muscle atrophy model was induced by subcutaneous inoculation of Lewis lung cancer cell line under the right anterior armpit in mice except those in the blank group. On the 8th day after subcutaneous inoculation， the mice in the corresponding groups received Liu Junzitang （9.56 g·kg-1·d-1） by gavage and intraperitoneal injection of stattic ［25 mg·kg-1·（2 d）-1］. After three weeks of drug intervention， the body weight and gastrocnemius muscle weight were recorded. Hematoxylin-eosin （HE） staining was used to observe the pathological changes and cross-sectional area of gastrocnemius muscle fibers in mice. Western blot was used to detect the expression of phosphorylated-STAT3 （p-STAT3）， STAT3， muscle atrophy F-box （MAFbx）， and muscle RING finger protein 1 （MuRF1） in the gastrocnemius muscle. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to detect the mRNA expression of STAT3， MAFbx， and MuRF1 in the gastrocnemius muscle. ResultCompared with the blank group， the model group showed lightened body and the gastrocnemius muscle， reduced cross-sectional area of gastrocnemius muscle fibers， and increased protein expression of p-STAT3， STAT3， MAFbx， and MuRF1 and mRNA expression of STAT3， MuRF1， and MAFbx in the gastrocnemius muscle （P<0.05）. Compared with the model group， the Liu Junzitang group showed increased body weight， gastrocnemius muscle weight， and cross-sectional area of gastrocnemius muscle fibers （P<0.05）， and decreased protein expression of p-STAT3， STAT3， MuRF1， MAFbx， and mRNA expression of STAT3 and MAFbx in gastrocnemius muscle （P<0.05）. Compared with the model group， the inhibitor group showed increased body weight and cross-sectional area of gastrocnemius muscle fibers （P<0.05）， and reduced protein expression of p-STAT3， STAT3， MuRF1， MAFbx， and mRNA expression of STAT3 and MAFbx in gastrocnemius muscle （P<0.05）. Compared with the model group， the combination group showed increased body weight and gastrocnemius muscle weight （P<0.05），and decreased protein expression of p-STAT3， STAT3， MuRF1， and mRNA expression of STAT3 and MAFbx in the gastrocnemius muscle （P<0.05）. Compared with the Liu Junzitang group， the stattic group and the combination group showed reduced expression of p-STAT3 protein in the gastrocnemius muscle （P<0.05）. ConclusionLiu Junzitang can prevent and treat muscle atrophy in mice with lung cancer cachexia， and its mechanism may be associated with the protein and mRNA expression related to the STAT3-mediated ubiquitin proteasome pathway.
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The abnormality of ubiquitin proteasome pathway is an important factor leading to the imbalance of protein homeostasis. In this process, the deubiquitinase responsible for removing the ubiquitin chain of protein substrate is very important. Its abnormal activity or expression can cause the functional changes of key oncogenic/tumor suppressor proteins, which directly or indirectly lead to the occurrence, development and malignant evolution of tumors. Based on this, the discovery and research of small molecule inhibitors targeting deubiquitinases have become a hot field of anti-tumor candidate drugs. This review will focus on the regulatory effect and mechanism of ubiquitin proteasome pathway, especially deubiquitinase on tumor, introduce the application of deubiquitinase small molecule inhibitors in tumor treatment, and discuss the research status and latest progress of small molecule inhibitors, so as to provide ideas for the research of new anti-tumor strategies based on deubiquitinase.
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Ubiquitin-proteasome system (UPS) plays an important role in neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). The discovery of UPS activators for anti-neurodegenerative diseases is becoming increasingly important. In this study, we aimed to identify potential UPS activators using the high-throughput screening method with the high-content fluorescence imaging system and validate the neuroprotective effect in the cell models of AD. At first, stable YFP-CL1 HT22 cells were successfully constructed by transfecting the YFP-CL1 plasmid into HT22 cells, together with G418 screening. The degradation activity of the test compounds via UPS was monitored by detecting the YFP fluorescence intensity reflected by the ubiquitin-proteasome degradation signal CL1. By employing the high-content fluorescence imaging system, together with stable YFP-CL1 HT22 cells, the UPS activators were successfully screened from our established TCM library. The representative images were captured and analyzed, and quantification of the YFP fluorescence intensity was performed by flow cytometry. Then, the neuroprotective effect of the UPS activators was investigated in pEGFP-N1-APP (APP), pRK5-EGFP-Tau P301L (Tau P301L), or pRK5-EGFP-Tau (Tau) transiently transfected HT22 cells using fluorescence imaging, flow cytometry, and Western blot. In conclusion, our study established a high-content fluorescence imaging system coupled with stable YFP-CL1 HT22 cells for the high-throughput screening of the UPS activators. Three compounds, namely salvianolic acid A (SAA), salvianolic acid B (SAB), and ellagic acid (EA), were identified to significantly decrease YFP fluorescence intensity, which suggested that these three compounds are UPS activators. The identified UPS activators were demonstrated to clear AD-related proteins, including APP, Tau, and Tau P301L. Therefore, these findings provide a novel insight into the discovery and development of anti-AD drugs.
Subject(s)
Humans , Alzheimer Disease/drug therapy , Neuroprotective Agents , Optical Imaging , Proteasome Endopeptidase Complex , UbiquitinABSTRACT
Targeted protein degradation (TPD) technology facilitates specific and efficient degradation of disease-related proteins through hijacking the two major protein degradation systems in mammalian cells: ubiquitin-proteasome system and lysosome pathway. Compared with traditional small molecule-inhibitors, TPD-based drugs exhibit the characteristics of a broader target spectrum. Compared with techniques interfere with protein expression on the gene and mRNA level, TPD-based drugs are target-specific, efficaciously rapid, and not constrained by post-translational modification of proteins. In the past 20 years, various TPD-based technologies have been developed. Most excitingly, two TPD-based therapeutic drugs have been approved by FDA for phase Ⅰ clinical trials in 2019. Despite of the early stage characteristics and various obstructions of the TPD technology, it could serve as a powerful tool for the development of novel drugs. This review summarizes the advances of different degradation systems based on TPD technologies and their applications in disease therapy. Moreover, the advantages and challenges of various technologies were discussed systematically, with the aim to provide theoretical guidance for further application of TPD technologies in scientific research and drug development.
Subject(s)
Animals , Proteasome Endopeptidase Complex/metabolism , Protein Processing, Post-Translational , Proteins/metabolism , Proteolysis , TechnologyABSTRACT
Pluripotent stem cells (PSCs) can immortally self-renew in culture with a high proliferation rate, and they possess unique metabolic characteristics that facilitate pluripotency regulation. Here, we review recent progress in understanding the mechanisms that link cellular metabolism and homeostasis to pluripotency regulation, with particular emphasis on pathways involving amino acid metabolism, lipid metabolism, the ubiquitin-proteasome system and autophagy. Metabolism of amino acids and lipids is tightly coupled to epigenetic modification, organelle remodeling and cell signaling pathways for pluripotency regulation. PSCs harness enhanced proteasome and autophagy activity to meet the material and energy requirements for cellular homeostasis. These regulatory events reflect a fine balance between the intrinsic cellular requirements and the extrinsic environment. A more complete understanding of this balance will pave new ways to manipulate PSC fate.
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Methylmercury is an environmental pollutant that causes neurotoxicity. Recent studies have reported that the ubiquitin-proteasome system is involved in defense against methylmercury toxicity through the degradation of proteins synthesizing the pyruvate. Mitochondrial accumulation of pyruvate can enhance methylmercury toxicity. In addition, methylmercury exposure induces several immune-related chemokines, specifically in the brain, and may cause neurotoxicity. This summary highlights several molecular mechanisms of methylmercury-induced neurotoxicity.
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Animals , Humans , Mice , Rats , Chemokines , Metabolism , Methylmercury Compounds , Toxicity , Neurotoxins , Toxicity , Proteolysis , Saccharomyces cerevisiaeABSTRACT
Blocking the biological functions of scaffold proteins and aggregated proteins is a challenging goal. PROTAC proteolysis-targeting chimaera (PROTAC) technology may be the solution, considering its ability to selectively degrade target proteins. Recent progress in the PROTAC strategy include identification of the structure of the first ternary eutectic complex, extra-terminal domain-4-PROTAC-Von-Hippel-Lindau (BRD4-PROTAC-VHL), and PROTAC ARV-110 has entered clinical trials for the treatment of prostate cancer in 2019. These discoveries strongly proved the value of the PROTAC strategy. In this perspective, we summarized recent meaningful research of PROTAC, including the types of degradation proteins, preliminary biological data in vitro and in vivo, and new E3 ubiquitin ligases. Importantly, the molecular design, optimization strategy and clinical application of candidate molecules are highlighted in detail. Future perspectives for development of advanced PROTAC in medical fields have also been discussed systematically.
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Pluripotent stem cells (PSCs) can immortally self-renew in culture with a high proliferation rate, and they possess unique metabolic characteristics that facilitate pluripotency regulation. Here, we review recent progress in understanding the mechanisms that link cellular metabolism and homeostasis to pluripotency regulation, with particular emphasis on pathways involving amino acid metabolism, lipid metabolism, the ubiquitin-proteasome system and autophagy. Metabolism of amino acids and lipids is tightly coupled to epigenetic modification, organelle remodeling and cell signaling pathways for pluripotency regulation. PSCs harness enhanced proteasome and autophagy activity to meet the material and energy requirements for cellular homeostasis. These regulatory events reflect a fine balance between the intrinsic cellular requirements and the extrinsic environment. A more complete understanding of this balance will pave new ways to manipulate PSC fate.
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Pluripotent stem cells (PSCs) can immortally self-renew in culture with a high proliferation rate, and they possess unique metabolic characteristics that facilitate pluripotency regulation. Here, we review recent progress in understanding the mechanisms that link cellular metabolism and homeostasis to pluripotency regulation, with particular emphasis on pathways involving amino acid metabolism, lipid metabolism, the ubiquitin-proteasome system and autophagy. Metabolism of amino acids and lipids is tightly coupled to epigenetic modification, organelle remodeling and cell signaling pathways for pluripotency regulation. PSCs harness enhanced proteasome and autophagy activity to meet the material and energy requirements for cellular homeostasis. These regulatory events reflect a fine balance between the intrinsic cellular requirements and the extrinsic environment. A more complete understanding of this balance will pave new ways to manipulate PSC fate.
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OBJECTIVE: To explore the effects of human A30P mutant α-synuclein (α-syn) on autophagy lysosome pathway and ubiquitin proteasome system. METHODS: Constructing stable cell lines expressing human A30P mutant α-syn in PC12 cells, and detecting the levels of autophagy related proteins LC3-II and p62 as well as ubiquitinated proteins. Furthermore, the influence of A30P mutant α-syn on cell viability upon normal and stress conditions was conducted by MTT assay. RESULTS: Expressing A30P mutant α-syn could significantly reduce autophagy related protein LC3-II level and increase level of autophagy substrate p62, as well as promote aggregation of ubiquitinated proteins. Otherwise, expressing A30P mutant α-syn did not reduce cell viability under normal conditions. However, cell viability was significantly reduced under treatment with neurotoxin rotenone or serum free condition in A30P mutant α-syn groups compared with empty vector group. CONCLUSION: Over expression of human A30P mutant α-syn could impair the protein degradation system and increase the sensitivity of cells to toxic insults.
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Ubiquitin-proteasome system (UPS) is the important protein degradation system in eukaryotic cells, participates in cell cycle, gene transcription, antigen-presenting, cell proliferation and differentiation, signal transduction and many other physiological processes.UPS dysfunction relates to pathogenic mechanisms in a variety of diseases such as cancer, neurodegenerative diseases and cardiovascular disease.In recent years, more and more researches confirmed that UPS exists in the retina, some retinal damage appeared in patients with neurodegenerative conditions.UPS is involved in the pathogenesis of diabetic retinopathy, age-related macular degeneration, macular pigment degeneration and other retinal diseases by regulating retinal oxidative stress, inflammation, angiogenesis, nerve damage, signal transduction and so on.Some signaling pathways, such as nuclear factor κB (NF-κB), transforming growth factor-β (TGF-β) and reactive oxygen species (ROS) play an important role.Their proteins degradation and synthesis of imbalances have a significant impact on the pathophysiological process of retinal diseases.Proteasome inhibitors can reduce inflammation pathological changes in retinal lesions.This review focused on the research progress of UPS in the development of retinopathy.
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Ubiquitin-proteasome system ( UPS ) is the important protein degradation system in eukaryotic cells,participates in cell cycle, gene transcription, antigen-presenting, cell proliferation and differentiation, signal transduction and many other physiological processes. UPS dysfunction relates to pathogenic mechanisms in a variety of diseases such as cancer, neurodegenerative diseases and cardiovascular disease. In recent years, more and more researches confirmed that UPS exists in the retina,some retinal damage appeared in patients with neurodegenerative conditions. UPS is involved in the pathogenesis of diabetic retinopathy, age-related macular degeneration, macular pigment degeneration and other retinal diseases by regulating retinal oxidative stress,inflammation,angiogenesis,nerve damage,signal transduction and so on. Some signaling pathways,such as nuclear factor κB (NF-κB),transforming growth factor-β ( TGF-β) and reactive oxygen species ( ROS) play an important role. Their proteins degradation and synthesis of imbalances have a significant impact on the pathophysiological process of retinal diseases. Proteasome inhibitors can reduce inflammation pathological changes in retinal lesions. This review focused on the research progress of UPS in the development of retinopathy.
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OBJECTIVE: Ubiquitin-specific peptidase 46 gene (USP46) polymorphisms is part of ubiquitin-proteasome system, which is responsible for dynamic cellular processes such as the regulation of cell cycle. USP46 has been reported to be associated with major depressive disorder. The objective of the present study was to investigate the association of USP46 polymorphisms with affective temperamental traits in healthy subjects. METHODS: A total of 557 Korean healthy volunteers were recruited, and 545 subjects (328 male, 217 female) were included in the final analysis. The DNA of the subjects was isolated from saliva samples. Two single-nucleotide polymorphisms (SNPs) rs346005, rs2244291 in USP46 were genotyped. Affective temperaments were assessed using the Korean version of Temperament Evaluation of the Memphis, Pisa, Paris, and San Diego Autoquestionnaire (TEMPS-A). RESULTS: A significant association was found between rs346005 genotypes and TEMPS-A only in male subjects. In particular, subjects with the CC genotype of rs346005 showed a more depressive temperament than subjects with AA or CA genotypes in males. For rs2244291, there were no associations between the rs2244291 genotypes and TEMPS-A scores. CONCLUSION: Some affective temperaments may serve as a genetic predisposing factors for affective disorders, such as depressive disorder, via vulnerability genes related to the ubiquitin-proteasome system.
Subject(s)
Humans , Male , Causality , Cell Cycle , Depressive Disorder , Depressive Disorder, Major , DNA , Genetic Association Studies , Genotype , Healthy Volunteers , Mood Disorders , Saliva , Temperament , VolunteersABSTRACT
OBJECTIVE: To explore the mechanism of ubiquitin-proteasome pathway(UPP) in the degradation of hyperphosphorylated tau protein in aluminum-induced mouse neuroblastoma N2 a cells. METHODS: N2 a cells in logarithmic growth period were randomly divided into control group and MG132 group. Cells in control group were exposed to concentrations of 0 or 1 mmol/L aluminum chloride for 24 hours. Cells in MG132 group were pretreated with MG132 at a concentration of 5 μmol/L for 6 hours, then exposed to concentrations of 0 or 1 mmol/L aluminum chloride for 24 hours. After exposure, the cells were collected. Western blotting was used to detect the relative expression of tau-5, P-tau181, P-tau231, P-tau262, P-tau396, heat shock protein 70(Hsp70) and carboxyl terminus of the Hsp70-interacting protein(CHIP). The ubiquitin relative expression was detected by enzyme-linked immunosorbent assay. RESULTS: The results of factorial analysis showed that the relative expression of tau-5, P-tau231, P-tau262, P-tau396, CHIP, Hsp70 and ubiquitin in N2 a cells were statistically significant in the main effect and interaction effect of aluminum chloride and MG132 treatment(P<0.05). Both in the control group and MG132 group, the relative expression of tau-5, P-tau231, P-tau262, P-tau396, CHIP, Hsp70 and ubiquitin in N2 a cells exposed to 1 mmol/L aluminum chloride increased(P<0.05) when compared with the N2 a cells without exposed to aluminum chloride. No matter aluminum chloride exposed or not, the relative expression of tau-5, P-tau231, P-tau262, P-tau396, CHIP, Hsp70 and ubiquitin in N2 a cells of MG132 group was higher than that of control group(P<0.05). CONCLUSION: UPP is involved in the regulation of hyperphosphorylated tau protein by proteasome degradation in aluminum-induced N2 a cells. UPP mainly regulates P-tau231, P-tau262, and P-tau396 sites. CHIP and Hsp70 played an important role in the UPP pathway.