DJ-1 Expression Research Articles

Effect of DJ-1 on the neuroprotection of astrocytes subjected to cerebral ischemia/reperfusion injury

Astrocytes are involved in neuroprotection, and DJ-1 is an important antioxidant protein that is abundantly expressed in reactive astrocytes. However, the role of DJ-1 in astrocytes’ neuroprotection in cerebral ischemia/reperfusion injury and its potential mechanism is unclear. Thus, to explore effects and mechanisms of DJ-1 on the neuroprotection of astrocytes, we used primary co-cultures of neurons and astrocytes under oxygen and glucose deprivation/reoxygenation in vitro and transient middle cerebral artery occlusion/reperfusion in vivo to mimic ischemic reperfusion insult. Lentiviral was used to inhibit and upregulate DJ-1 expression in astrocytes, and DJ-1 siRNA blocked DJ-1 expression in rats. Inhibiting DJ-1 expression led to decreases in neuronal viability. DJ-1 knockdown also attenuated total and nuclear Nrf2 and glutathione (GSH) levels in vitro and vivo. Similarly, loss of DJ-1 decreased Nrf2/ARE-binding activity and expression of Nrf2/ARE pathway-driven genes. Overexpression of DJ-1 yielded opposite results. This suggests that the mechanism of action of DJ-1 in astrocyte-mediated neuroprotection may involve regulation of the Nrf2/ARE pathway to increase GSH after cerebral ischemia/reperfusion injury. Thus, DJ-1 may be a new therapeutic target for treating ischemia/reperfusion injury.Key MessagesAstrocytes protect neurons in co-culture after OGD/RDJ-1 is upregulated in astrocytes and plays an important physiological roles in neuronal protection under ischemic conditionsDJ-1 protects neuron by the Nrf2/ARE pathway which upregulates GSH

Increased miR-142 and decreased DJ-1 enhance the sensitivity of pancreatic cancer cell to adriamycin.

Phosphatidylinositol-3 kinase (PI3K)/protein kinase B (AKT) signaling pathway is related to tumorigenesis by up-regulating survivin. Phosphatase and tensin homologue deleted on chromosome ten (PTEN) can suppress PI3K/AKT signaling pathway, while DJ-1 is the negative regulator of PTEN. DJ-1 up-regulation is closely correlated with the occurrence, progression, and drug resistance of pancreatic cancer. MicroRNA-142 (MiR-142) is significantly declined in pancreatic cancer tissue. Bioinformatics analysis demonstrated that complementary binding site exists between miR-142 and DJ-1. This investigation, therefore, aimed to study the role of miR-142 in the regulation of DJ-1-PTEN/PI3K/AKT/Survivin signaling pathway as well as in pancreatic cancer cell proliferation, apoptosis, and adriamycin (ADM) resistance. Dual luciferase assay was performed to assess the targeted relationship between miR-142 and DJ-1. MiR-142, DJ-1, and PTEN expressions in SW1990 cells and drug-resistant SW1990/ADM cells were compared. SW1990/ADM cells were divided into five groups, including mimic-NC, miR-142 mimic, small interfere normal control (si-NC), si-DJ-1, and miR-142 mimic + si-DJ-1 groups. DJ-1, PTEN, phosphorylated-AKT (p-AKT), and Survivin expressions were tested. Cell apoptosis was determined by flow cytometry. Cell proliferation was evaluated by EdU staining. MiR-142 targeted inhibited DJ-1 expression. MiR-142, PTEN, and cell apoptosis significantly down-regulated, while DJ-1, p-AKT, Survivin, and cell proliferation significantly elevated in SW1990/ADM cells compared with SW1990 cells. MiR-142 mimics and/or si-DJ-1 transfection markedly reduced DJ-1, p-AKT, and Survivin expressions enhanced PTEN level, attenuated cell proliferation, enhanced cell apoptosis, and weakened ADM resistance. MiR-142 over-expression weakened ADM resistance in pancreatic cancer cells by targeting DJ-1 to enhance PTEN expression and attenuate PI3K/AKT signaling pathway activity.

Da-Bu-Yin-Wan Improves the Ameliorative Effect of DJ-1 on Mitochondrial Dysfunction Through Augmenting the Akt Phosphorylation in a Cellular Model of Parkinson's Disease.

Da-Bu-Yin-Wan (DBYW) is recorded originally in China over six centuries ago, and it is used to treat Parkinson’s disease (PD) clinically in recent decades. DJ-1 is a homodimeric protein linked to early-onset PD, and found in the mitochondria. In addition, DJ-1 could protect the cells by regulating gene transcription and modulating the Akt signal pathways. Therefore, in this research, we aimed to investigate the ameliorative effect of DBYW on mitochondria in the view of the DJ-1 and Akt signaling. Rat adrenal pheochromocytoma cell line PC-12 was transfected with the plasmid pcDNA3-Flag-DJ-1 (pDJ-1). Subsequently, PC-12 cells were exposed to the PD-related mitochondrial toxin (1-methyl-4-phenylpyridinium) without/with the DBYW. After transfected with the plasmid pDJ-1, the 1-methyl-4-phenylpyridinium-induced toxicity was decreased, and the DJ-1 expression in protein level was increased. DJ-1 overexpression not only increased the mitochondrial mass, but also improved the total ATP content. Moreover, Akt phosphorylation was augmented by DJ-1 overexpression. Additionally, DBYW enhanced the above effects. Conclusively, these findings indicate that DBYW promotes the ameliorative effects of DJ-1 on mitochondrial dysfunction at least through augmenting the Akt phosphorylation in 1-methyl-4-phenylpyridinium-treated PC-12 cells.

Protocatechuic acid-mediated DJ-1/PARK7 activation followed by PI3K/mTOR signaling pathway activation as a novel mechanism for protection against ketoprofen-induced oxidative damage in the gastrointestinal mucosa

Oxidative stress contributes to the progression of non-steroidal anti-inflammatory drug (NSAID)-induced gastrointestinal (GI) cell apoptosis. In our previous study, we reported that nuclear factor erythroid 2-related factor 2 (Nrf2) plays a protective role against ketoprofen-induced GI mucosal oxidative injury. Recent reports suggest that Nrf2 could exhibit antioxidative and antiapoptosis responses through up-regulation of DJ-1 (PARK7). In the current study, we proposed that induction of DJ-1 expression by protocatechuic acid (PCA) might provide a potential therapeutic approach for treating oxidative stress-associated GI ulcer diseases. The results indicated that PCA increased mRNA expression of glutathione peroxidase and heme oxygenase-1 through up-regulation of DJ-1 followed by Nrf2 translocation. Furthermore, PCA protected Int-407 cells against ketoprofen-induced oxidative stress by regulating the DJ-1, PI3K, and mTOR pathways. Pretreatment with PCA inhibited mitochondrial ROS generation, up-regulated the mitochondrial membrane potential, and down-regulated pro-apoptotic Bax as well as downstream caspase-8, caspase-9, and caspase-3 activity, and reversed impaired DJ-1 and anti-apoptotic Bcl-2 protein expression in Int-407 cells induced by ketoprofen. Similar to the in vitro results, SD rats treated with PCA before administration of ketoprofen exhibited decreased caspase-3 protein expression as well as oxidative damage, and impairment of the antioxidant system and DJ-1 protein expression in the GI mucosa were reversed. The administration of lansoprazole, a type of proton pump inhibitor (PPI), strongly inhibited ketoprofen-induced GI mucosal injuries via up-regulation of DJ-1, indicating that DJ-1 is essential for the dietary antioxidant- and PPI drug-mediated mechanism of ulcer therapy. These results suggest that DJ-1 could be a novel target for protection against ketoprofen-induced GI ulcers due to its antioxidant and anti-apoptosis characteristics.

MiR-128-3p overexpression sensitizes hepatocellular carcinoma cells to sorafenib induced apoptosis through regulating DJ-1.

DJ-1 expression is elevated in a variety of tumors and is related to the survival of tumor cells under adverse stimuli. DJ-1 3'-untranslated region (3'-UTR) contains the target of miR-128-3p, and the expression of miR-128-3p is decreased in hepatoma cells. Therefore, we speculate and address in this study, that miR-128-3p can regulate DJ-1 expression in hepatocellular carcinoma (HCC) and play an important role in HCC cells survival. MiR-128-3p and DJ-1 expression in HCC cell lines were measured using quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) and Western blot analysis. Dual luciferase reporter assay was adopted to confirm the miR-128-3p binding sequences in the 3'-UTR of DJ-1. Sorafenib-induced apoptosis was evaluated by flow cytometry, and the apoptosis-associated proteins were detected by Western blot analysis. Overexpression of miR-128-3p and DJ-1 were achieved via transfection with miR-128-3p mimic and DJ-1 plasmid, respectively. We revealed that miR-128-3p expression was downregulated, while DJ-1 expression was upregulated in HCC cell lines, and DJ-1 expression can be regulated by miR-128-3p via directly binding to it. Moreover, functional assays showed that overexpression of miR-128-3p sensitized HCC cells to sorafenib-induced apoptosis, and this phenomenon was partly abolished by DJ-1. Mechanistically, PTEN/PI3K/Akt signaling pathway was found to participate in the miR-128-3p induced sensitivity to sorafenib via DJ-1. We conclude that miR-128-3p overexpression sensitized HCC to sorafenib-induced apoptosis via PTEN/PI3K/Akt signaling pathway by regulating DJ-1 expression.

DJ-1 promotes survival of human colon cancer cells under hypoxia by modulating HIF-1α expression through the PI3K-AKT pathway.

BackgroundProtein/nucleic acid deglycase (DJ-1) and hypoxia-inducible factor-1α (HIF-1α) play significant roles in the progression of various types of cancer and are associated with the phosphatidylinositol 3-kinase (PI3K) pathway. However, their functions in colorectal cancer (CRC) have not been identified. The aim of this study was to analyze the putative signaling pathway encompassing DJ-1, PI3K, and HIF-1α in a series of CRC tissues and cell lines.PurposeThis study aimed at exploring the expression status of DJ-1 in colon cancer and its role in survival of cancer cell lines.MethodsThe expression and localization of DJ-1, PI3K-p110α, phosphorylated Akt (p-AKT), and HIF-1α were determined by immunohistochemistry in 73 resected CRC tissues. The effect of DJ-1 on cell activity was explored by in vitro knockdown and overexpression experiments in SW480 and HT-29 cells. The cells were treated with a PI3K inhibitor (LY294002 or wortmannin), and p-AKT and HIF-1α protein expression were then analyzed. Apoptosis was analyzed by flow cytometry. The expression levels of several HIF-1 target genes were assessed under hypoxic conditions by reverse transcription-PCR and Western blot. Xenograft tumor growth studies were conducted in DJ-1 knockdown or overexpression cells.ResultsHigh DJ-1 expression was found in 68.49% (50/73) of CRC tissues and associated with larger tumor size and advanced clinical stages. DJ-1 expression was positively associated with PI3K-p110α, p-AKT, and HIF-1α expression in CRC. HIF-1α and p-AKT protein levels were lower in SW480 and HT-29 cells with stable DJ-1 knockdown than in those with DJ-1 overexpression. PI3K inhibitors almost completely blocked DJ-1-induced AKT phosphorylation. However, the expression of HIF-1α was partially preserved after treatment with PI3K inhibitors. We also show that DJ-1 is necessary for the transcriptional ability of HIF-1α and CRC cell survival after hypoxic stress. Moreover, DJ-1 promoted the growth of established tumor xenografts in nude mice.ConclusionOur findings are the first to show that DJ-1 is overexpressed in CRC. We suggest a model in which DJ-1 mediates CRC cell survival by regulating the PI3K-AKT-HIF-1α pathway.

Understanding multifactorial architecture of Parkinson's disease: pathophysiology to management.

Parkinson's disease (PD) is the second most common multifactorial neurodegenerative disorder affecting 3% of population during elder age. The loss of substantia nigra, pars compacta (SNpc) neurons and deficiency of striatal dopaminergic neurons produces stables motor deficient. Further, increase alpha-synuclein accumulation, mitochondrial dysfunction, oxidative stress, excitotoxicity, and neuroinflammation plays a crucial role in the pathogenesis of PD. Alpha-synuclein protein encodes for SNCA gene and disturbs the normal physiological neuronal signaling via altering mitochondrial homeostasis. The level of α-synuclein is increased in both normal aging and PD brain to a greater extent and secondly reduced clearance results in accumulation of Lewy bodies (LB). Emerging evidences indicate that mitochondrial dysfunction might be a common cause but pathological insult through protein misfolding, aggregation, and accumulation leads to neuronal apoptosis. The observation supporting that expression of DJ-1, LLRK2, PARKIN, PINK1, and excessive excitotoxicity mediated by dysbalance between GABA and glutamate reduced mitochondrial functioning and increased neurotoxicity. Therefore, the present review summarizes the various pathological mechanisms and also explores the therapeutic strategies which could be useful to ameliorate movement disorder like Parkinsonism.

P38 Inhibitor Protects Mitochondrial Dysfunction by Induction of DJ-1 Mitochondrial Translocation After Subarachnoid Hemorrhage

p38 mitogen-activated protein kinase (MAPK) is a major player in mitochondrial dysfunction after subarachnoid hemorrhage (SAH). Moreover, DJ-1, which responds to oxidative stress and translocates to mitochondria, maintains mitochondrial homeostasis. Although a few studies have demonstrated that DJ-1 indirectly regulates p38 activation, the relationship between DJ-1 and p38 in mitochondrial dysfunction after SAH has not been delineated. Using an in vitro SAH model, alterations in p38, p-p38, DJ-1, and autophagic-related protein expression were detected. As expected, p38 inhibitor significantly blocked excessive expression of p38 and p-p38 after SAH, whereas total DJ-1 expression and mitochondrial DJ-1 were up-regulated. Further analysis showed that p38 inhibitor significantly blocked oxyhemoglobin (OxyHb) induced mitochondrial dysfunction, including mitochondrial membrane potential depolarization and reactive oxygen species (ROS) release. In addition, p38 inhibitor restored OxyHb-induced abnormal autophagic flux at the initiation and formation stage by regulating Atg5, beclin-1, the ratio of LC3-II/LC3-I, and p62 expression. This study suggested that overexpression of p38 induced the accumulation of mitochondrial dysfunction partly due to abnormal activation of autophagy, which largely relied on DJ-1 mitochondrial translocation.

Down-regulation of miR-192 protects against rat ischemia-reperfusion injury after myocardial infarction.

DJ-1-phosphate and tension homology deleted on chromosome ten/phosphatidylinositol-3-kinase/protein kinase B (PTEN/PI3K/AKT) signaling pathway plays a role in the regulation of ischemic reperfusion (I-R) injury. Bioinformatics analysis demonstrated that there is a complementary binding site between microRNA-192 (miR-192) and the 3'-UTR of DJ-1 mRNA. This study investigated the role of miR-192 in regulating DJ-1-PTEN/PI3K/AKT signaling pathway and myocardial I-R injury. miR-122 and DJ-1 mRNA expressions in myocardial tissue were detected by Real-time PCR (RT-PCR). DJ-1, PTEN, and phosphorylated AKT (p-AKT) protein expressions were tested by Western blot. Reactive oxygen species (ROS) content was measured by flow cytometry. Malondialdehyde (MDA) content and superoxide dismutase (SOD) enzyme activity were detected by the kits. I-R treatment was performed at 72 h after transfection. Cell apoptosis was evaluated with flow cytometry. Compared with sham group, miR-192, PTEN expressions and MDA content were significantly increased (p<0.05), while DJ-1, p-AKT levels and SOD activities were significantly reduced (p<0.05) in myocardial tissue of I-R group. Compared with control, I-R treatment significantly up-regulated miR-192 level, significantly decreased DJ-1 and p-AKT proteins, significantly elevated PTEN expression, and significantly induced apoptosis and ROS production in H9C2 cells (p<0.05). Transfection of miR-192 inhibitor significantly enhanced DJ-1 level, declined PTEN expression, elevated p-AKT level, and restrained apoptosis, ROS production and MDA content, and promoted SOD activity in H9C2 cells under I-R condition. The expression of miR-192 increased significantly, while the expression of DJ-1 reduced obviously during I-R injury after myocardial infarction. Down-regulation of miR-192 markedly enhanced DJ-1 expression and PTEN/PI3K/AKT pathway activity, inhibited cell apoptosis and ROS generation, and reduced I-R injury in cardiomyocytes.

DJ-1 promotes colorectal cancer progression through activating PLAGL2/Wnt/BMP4 axis

Metastasis remains a big barrier for the clinical treatment of colorectal cancer (CRC). Our previous proteomics analysis identified DJ-1 as a potential metastasis biomarker of CRC. In this study, we found that DJ-1 was upregulated in CRC. The levels of DJ-1 were closely correlated with the depths of invasion and predicted patient outcome. Enforced expression of DJ-1 could enhance CRC proliferation and metastasis in vitro and in vivo by stimulating Wnt-β-catenin signaling. Specifically, DJ-1-induced β-catenin nuclear translocation stimulated TCF transcription activity, which promoted BMP4 expression for CRC cell migration and invasion, and elevated CCND1 expression for CRC cell proliferation, respectively. Furthermore, DJ-1-induced Wnt signaling activation was dependent on PLAGL2 expression. In conclusion, our study demonstrates that DJ-1 can promote CRC metastasis by activating PLAGL2–Wnt–BMP4 axis, suggesting novel therapeutic opportunities for postoperative adjuvant therapy in CRC patients.

Clinicopathologic Significance of SATB1 and DJ-1 Proteins Expression in Cervical Carcinoma

Background: Special AT-rich sequence binding protein 1 (SATB1) and DJ-1 proteins play a crucial role in tumorigenesis and tumor progression in many human malignancies. Limited data is available in literature about their role in cervical carcinomas. Aims: The present study was designed to investigate the immunohistochemical expression of SATB1 and DJ-1 proteins in cervical carci­noma and their relationships to clinicopathologic variables. Material and Methods: Tissue sections from 100 cervical lesions distributed as 60 cases of cervical carcinoma, 30 cases of squamous intraepithelial lesion (SIL) and 10 cases with normal cervical tissue were evaluated for SATB1 and DJ-1 proteins expression by immunohistochemistry. Results: SATB1 expression was detected in 41.7% of cervical carcinomas versus 20% and 6.7% of HSIL and LSIL, respectively (p = 0.019). A significant positive correlation between SATB1 expression to lymph node metastasis (p = 0.004) and pTNM (p = 0.028) was noted. DJ-1 expression was detected in 68.3% versus 33.3% and 13.3% of HSIL and LSIL, respectively (p = 0.001). A significant positive association between DJ-1 expression and lymph node metastasis (p = 0.037) was noted. Normal cervical tissue was negative for SATB1 and DJ-1 expression. A significant positive association between SATB1 and DJ-1 immunoreactivity was detected in investigated cervical carcinomas (p = 0.027). Conclusions: SATB1 and DJ-1 are shown to be promising potential prognostic biomarkers in cervical carcinoma since their overexpression is correlated with advanced clinicopathologic variables including lymph node metastasis. SATB1 and DJ-1 can be promising therapeutic targets for cervical cancer.

Effect of tert-butylhydroquinone on DJ-1/Nrf2 pathway during renal ischemia-reperfusion in diabetic rats

Objective To evaluate the effect of tert-butylhydroquinone (t-BHQ) on DJ-1/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway during renal ischemia-reperfusion (I/R) in diabetic rats. Methods Forty SPF healthy adult male Sprague-Dawley rats, weighing 200-220 g, were divided into 4 groups (n=10 each) using a random number table method: control group (group C), diabetes mellitus group (group D), diabetes mellitus plus renal I/R group (I/R group) and t-BHQ group (group T). Diabetes mellitus was induced by intraperitoneal streptozotocin 60 mg/kg and confirmed by fasting blood glucose level>16.7 mmol/L 72 h later.t-BHQ 50 mg/kg was intraperitoneally injected in 3 times at an interval of 8 h starting from 24 h before surgery in group T, while the equal volume of normal saline was given instead in D and I/R groups.Blood samples were collected from the apex of the heart at 24 h of reperfusion for determination of serum creatinine (Cr), cystatin C (Cys C) and β2-microglobulin (β2-MG) concentrations.The rats were then sacrificed, and kidneys were removed for determination of pathological changes of kidneys (with a light microscope) and for detection of the expression of DJ-1, Nrf2 and heme oxygenase-1 (HO-1) in renal tissues (by Western blot). Results Compared with group C, the concentrations of serum Cr, Cys C and β2-MG and pathological scores were significantly increased, and the expression of DJ-1, Nrf2 and HO-1 was up-regulated in D, I/R and T groups (P<0.05). Compared with group D and group I/R, the concentrations of serum Cr, Cys C and β2-MG and pathological scores were significantly decreased, and the expression of DJ-1, Nrf2 and HO-1 was up-regulated in group T (P<0.05). Conclusion t-BHQ can attenuate renal I/R injury by activating DJ-1/Nrf2 pathway in diabetic rats. Key words: Diabetes mellitus; Kidney; Reperfusion injury; Transcription factors; t-BHQ; DJ-1

Immunosenescence-like state is accelerated by constant light exposure and counteracted by melatonin or turmeric administration through DJ-1/Nrf2 and P53/Bax pathways

The awareness of the interrelationship between immunosenescence and constant light exposure can provide new insights into the consequences of excessive exposure to light at night due to light pollution or shift work. Here, we investigated whether constant light exposure (LL) acts as an inducer of immunosenescence. We also determined the role of melatonin or turmeric in reversing the putative effects of constant light and explored for the first time the underlying molecular mechanisms. Young (3–4-month-old) rats were exposed daily to LL alone or in combination with each of melatonin and turmeric for 12 weeks. A group of aged rats (18-months old; n = 6) was used as a reference for natural immunosenescence. Constant light exposure resulted in remarkable pathophysiological alterations resembling those noticed in normal aged rats, manifested as apparent decreases in antioxidant activities as well as Nrf2 and DJ-1 expressions, striking augmentation in oxidative stress, proinflammatory cytokines and expression of TNFα, Bax, and p53 genes, and deleterious changes of lymphoid organs, Co-administration of melatonin or turmeric was able to reverse all alterations induced by LL through upregulation of Nrf2/DJ-1 and downregulation of p53/Bax pathways. These data suggest that LL accelerates immunosenescence via oxidative stress and apoptotic pathways. They also demonstrate for the first time that turmeric is comparable to melatonin in boosting the immune function and counteracting the LL-associated immunosenescence. These effects suggest that turmeric supplementation can be used as an inexpensive intervention to prevent circadian disruption-related immunosenescence. However, to validate the effects of turmeric on humans further studies are warranted.

Attenuating Ischemia/Reperfusion-Induced Cardiomyocyte Apoptosis by Increasing the Expression of DJ-1 in Diabetic Rats

Attenuating Ischemia/Reperfusion-Induced Cardiomyocyte Apoptosis by Increasing the Expression of DJ-1 in Diabetic Rats

Overexpression of DJ-1 correlates with aggressive clinicopathological characteristics and poor prognosis in malignant tumors: a meta-analysis.

PurposeA number of studies have investigated the role of DJ-1 in the development and progression of malignant tumors. This meta-analysis aims to systematically estimate the rela-tionship between the expression level of DJ-1 and the malignant biological behaviors of tumors and to assess the clinical significances of DJ-1 in the prognosis and diagnosis of cancer.Materials and methodsWe searched PubMed, Web of Science, China National Knowledge Infrastructure and Wanfang databases from inception to December 1, 2017. Pooled odds ratio (OR) and hazard ratio (HR) with their 95% confidence interval and the diagnostic value of DJ-1 were calculated.ResultsFourteen eligible studies with a total of 1,947 subjects were enrolled in our meta-analysis. The results showed that DJ-1 was overexpressed in cancer patients compared with noncancer patients (OR = 30.72), and elevated expression of DJ-1 was demonstrated to be closely associated with high tumor-node-metastasis stage (OR = 5.52), poor differentiated degree (OR = 2.46), positive lymph node metastasis (OR = 4.12) and worse overall survival (HR = 2.23). In addition, the combined sensitivity and specificity for DJ-1 to discern malignant tumors were 0.73 and 0.93, respectively. The diagnostic OR was 34.87, and the area under the summary receiver operating characteristic curve was 0.88.ConclusionThis meta-analysis demonstrated that DJ-1 was an important biomarker in tumor assessment and prognosis prediction.

Low doses of Paclitaxel repress breast cancer invasion through DJ-1/KLF17 signalling pathway.

Paclitaxel (taxol) is an important agent against many tumours, including breast cancer. Ample data documents that paclitaxel inhibits breast cancer metastasis while others prove that paclitaxel enhances breast cancer metastasis. The mechanisms by which paclitaxel exerts its action are not well established. This study focuses on the effect of paclitaxel, particularly the low doses on breast cancer metastasis and the mechanisms that regulate it. Current results show that, paclitaxel exerts significant cytotoxicity even at low doses in both MCF-7 and MDA-MB-231 cells. Interestingly, paclitaxel significantly inhibits cell invasion and migration, decreases Snail and increases E-cadherin mRNA expression levels at the indicated low doses. Furthermore, paclitaxel-inhibiting breast cancer metastasis is associated with down-regulation of DJ-1 and ID-1 mRNA expression level with a concurrent increase in KLF17 expression. Under the same experimental conditions, paclitaxel induces KLF17 and concurrently represses ID-1 protein levels. Our results show for the first time that paclitaxel inhibits breast cancer metastasis through regulating DJ-1/KLF17/ID-1 signalling pathway; repressed DJ-1 and ID-1 and enhanced KLF17 expression.

Elevated expression of DJ-1 (encoded by the human PARK7 gene) protects neuronal cells from sevoflurane-induced neurotoxicity.

Sevoflurane, an inhaled ether general anesthetic agent, exerts a variety of neurotoxic effects, including oxidative stress, mitochondrial dysfunction, and neuronal apoptosis. However, the underlying molecular mechanisms remain to be elucidated. DJ-1 is a protein that exerts neuroprotective effects against different kinds of stress through multiple pathways. This study aimed to investigate the neuroprotective effects of DJ-1 against sevoflurane-induced neurotoxicity. Here, we found that sevoflurane treatment significantly increased DJ-1 expression in human neuroblastoma M17 cells in a dose-dependent manner at both the mRNA and protein levels. Interestingly, we found that overexpression of wild-type (WT) DJ-1 prevented sevoflurane-induced generation of reactive oxygen species (ROS) and nitric oxide (NO), deletion of reduced GSH, reduction of adenosine triphosphate (ATP), and mitochondrial membrane potential. Interestingly, we found that WT DJ-1 could inhibit sevoflurane-induced apoptosis by modulating the mitochondrial pathway. However, its "loss of function" mutation DJ-1(L166P) exacerbated sevoflurane-induced neurotoxicity in M17 cells. Our findings suggest that WT DJ-1 protects neuronal cells against sevoflurane-induced neurotoxicity.

Sophora flavescens Aiton Decreases MPP+-Induced Mitochondrial Dysfunction in SH-SY5Y Cells.

Sophora flavescens Aiton (SF) has been used to treat various diseases including fever and inflammation in China, South Korea and Japan. Several recent reports have shown that SF has anti-inflammatory and anti-apoptotic effects, indicating that it is a promising candidate for treatment of Parkinson’s disease (PD). We evaluated the protective effect of SF against neurotoxin 1-methyl-4-phenylpyridinium ion (MPP+)-induced mitochondrial dysfunction in SH-SY5Y human neuroblastoma cells, an in vitro PD model. SH-SY5Y cells were incubated with SF for 24 h, after which they were treated with MPP+. MPP+-induced cytotoxicity and apoptosis were confirmed by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling assay. MitoSOX red mitochondrial superoxide indicator, tetramethylrhodamine methyl ester perchlorate and Parkin, PTEN-induced putative kinase 1 (PINK1), and DJ-1 immunofluorescent staining were conducted to confirm the mitochondrial function. In addition, western blot was performed to evaluate apoptosis factors (Bcl-2, Bax, caspase-3 and cytochrome c) and mitochondrial function-related factors (Parkin, PINK1 and DJ-1). SF suppressed MPP+-induced cytotoxicity, apoptosis and collapse of mitochondrial membrane potential by inhibiting the increase of reactive oxidative species (ROS) and DNA fragmentation, and controlling Bcl-2, Bax, caspase-3 and cytochrome c expression. Moreover, it attenuated Parkin, PINK1 and DJ-1 expression from MPP+-induced decrease. SF effectively suppressed MPP+-induced cytotoxicity, apoptosis and mitochondrial dysfunction by regulating generation of ROS, disruption of mitochondrial membrane potential, mitochondria-dependent apoptosis and loss or mutation of mitochondria-related PD markers including Parkin, PINK1 and DJ-1.

Diallyl disulfide effect on the invasion and migration ability of HL-60 cells with a high expression of DJ-1 in the nucleus through the suppression of the Src signaling pathway.

The present study examined the effect of diallyl disulfide (DADS) on the invasion and migration ability of HL-60 cells with a high expression of parkinsonism associated deglycase (DJ-1) in the nucleus (HHDN), and its molecular mechanism. A western blot assay was used to measure the effects of DADS and an Src inhibitor on the expression of DJ-1 and the Src signal pathway in HHDN. The effects of DADS and Src inhibitors on the invasion and migration ability of HHDN was detected using Transwell migration and invasion chamber experiments. The experiments were divided into three groups: A control group (HL-60 cells), an empty vector group and a high expression group (HHDN cells). Western blot assays revealed that the expression of DJ-1 in HHDN was inhibited in a time-dependent manner following treatment with DADS for 24, 48 and 72 h. Following DADS treatment, the expression of phosphorylated Src (p-Src) and phosphorylated Fak (p-Fak) were significantly decreased in all groups compared with the untreated groups, however the expression level of Src, Fak and integrin did not change significantly. Western blot analysis results revealed that following treatment with DADS and Src inhibitor, the expression levels of p-Src and p-Fak significantly decreased in all three groups compared with untreated groups, whereas the expression levels of Src, Fak and integrin did not change significantly. The expression of DJ-1 in HHND was inhibited in time-dependent manner following treatment with DADS and Src inhibitor for 24, 48 and 72 h. Transwell migration and invasion assay results revealed that DADS and Src inhibitors may suppress migration and invasion in leukemic cells, and a combination of the two treatments may result in more efficient suppression. DADS may downregulate DJ-1-mediated invasion and migration in leukemic cells through suppressing the Src-Fak-Integrin signaling pathway, and the Src inhibitor may enhance the antitumor effect of DADS.

Cistanche deserticola polysaccharides protects PC12 cells against OGD/RP-induced injury

Ischemia stroke is a disease with high morbidity and mortality. Cistanche deserticola polysaccharides (CDP) possess a wide range of beneficial effects, including hepatoprotection and immune homeostasis. As far as we know, the protective effect of CDP on neurons injured by oxygen-glucose deprivation/reperfusion (OGD/RP) has not been investigated. In this study, OGD/RP injured a PC12 cell model. Briefly, CDP (0.05, 0.5 and 5 μg/ml) was administered before reperfusion. The protective effect of CDP was then evaluated on the basis of cell viability, lactate dehydrogenase (LDH) leakage, [Ca2+]i, mitochondrial membrane potential (MMP)and cell apoptosis, and redox status after reperfusion was evaluated by assaying reactive oxygen species (ROS), catalase (CAT), glutathione peroxidase (GSH-Px) and total antioxidant capacity. Basing on the fact that Parkinson’s disease-associated protein DJ-1 participates in endogenous antioxidation and performs neuroprotective effects after ischemia stroke, we investigated the interaction between CDP and DJ-1. DJ-1 expression was detected through ELISA and Western blot analysis, and the translocation of DJ-1 was evaluated through immunofluorescence. Result showed that CDP (0.05, 0.5 and 5 μg/ml) attenuated PC12 cell death, preserved MMP and calcium homeostasis; inhibited oxidative stress and decreased cell apoptosis. Moreover, CDP (5 μg/ml) markedly stimulated DJ-1 secretion and expression. Overall, the results suggested that CDP exerts neuroprotective effect against OGD/RP-induced injury by inhibiting oxidative stress and regulating the DJ-1 pathway.