HERC3-Mediated SMAD7 Ubiquitination Degradation Promotes Autophagy-Induced EMT and Chemoresistance in Glioblastoma.

PURPOSE: Glioblastoma, a common malignant intracranial tumor, has the most dismal prognosis. Autophagy was reported to act as a survival-promoting mechanism in gliomas by inducing epithelial-to-mesenchymal transition (EMT). Here, we determined the critical molecules involved in autophagy-induced EMT and elucidated the possible mechanism of chemoradiotherapy resistance and tumor recurrence. EXPERIMENTAL DESIGN: We used isobaric tags for relative and absolute quantitation to identify the critical proteins and pathway mediating EMT via autophagy inducer treatment, and tested the expression of these proteins using tissue microarray of gliomas and clinical glioblastoma samples as well as tissues and cells separated from the core lesion and tumor-peripheral region. Analysis of the Cancer Genome Atlas database and 110 glioblastoma cases revealed the prognostic value of these molecules. The functional role of these critical molecules was further confirmed by in vitro experiments and intracranial xenograft in nude mice. RESULTS: Autophagy inducers significantly upregulated the expression of HERC3, which promotes ubiquitination-mediated degradation of SMAD7 in an autolysosome-dependent manner. The corresponding increase in p-SMAD2/3 level and TGFß pathway activation finally induced EMT in cell lines and primary glioblastoma cells. Moreover, HERC3 overexpression was observed in pseudo-palisade cells surrounding tumor necrosis and in tumor-adjacent tissue; high HERC3 and low SMAD7 levels predicted poor clinical outcome in glioblastoma; xenograft of nude mice and in vitro experiments confirmed these findings. CONCLUSIONS: Together, our findings reveal the indispensable role of HERC3 in regulating canonical SMAD2/3-dependent TGFß pathway involvement in autophagy-induced EMT, providing insights toward a better understanding of the mechanism of resistance to temozolomide and peripheral recurrence of glioblastoma.

[Role of allograft inflammatory factor-1 in regulating the proliferation, migration and apoptosis of colorectal cancer cells].

OBJECTIVE: To investigate the role of allograft inflammatory factor-1 (AIF-1) in colorectal cancer (CRC) progression and explore the possible mechanism. METHODS: The expression levels of AIF-1 in 70 CRC tissues and paired adjacent tissues were detected using immunohistochemistry and Western blotting, and the correlation of AIF-1 expression with the clinicopathological features of the patients was analyzed. In the CRC cell line SW480, the functional role of AIF-1 in regulating tumor progression was investigated by transfecting the cells with an AIF-1-overexpressing plasmid (AIF-1) and a negative control plasmid (NC). EdU proliferation assay and flow cytometry were used to assess the cell proliferation and cell cycle changes; Transwell migration assay and Annexin V-APC/7-AAD apoptosis assay kit were used to analyze the cell migration and apoptosis. The changes in the biological behaviors of the cells were observed after application of SB203580 to block the p38 MAPK pathway. The expression levels of CDK4, cyclin D1, P21, P27, MMP2, MMP9, Bax, Bcl2, Bcl-xl, p38 and p-p38 were detected using Western blotting. RESULTS: AIF-1 was down-regulated in CRC tissues compared with the adjacent normal tissues, and its expression level was positively correlated with lymph node metastasis (P=0.008), TNM stage (P=0.003) and tumor size (P=0.023). Overexpression of AIF-1 in SW480 cells significantly reduced EdU-positive cells and caused obvious cell cycle arrest in G1 phase (P<0.05). AIF-1 overexpression resulted in significantly lowered protein expressions of CDK4 and cyclin D1, enhanced expressions of P21 and P27, attenuated cell migration ability (P<0.001), and decreased protein levels of MMP2 and MMP9. AIF-1 overexpression also induced obvious apoptosis of SW480 cells (P<0.01), significantly increased the protein levels of Bax and p-p38, and decreased the protein levels of Bcl-2 and Bcl-xl; SB203580 significantly attenuated the apoptosis-inducing effect of AIF-1 overexpression. CONCLUSION: AIF-1 plays the role of a tumor suppressor in CRC by inhibiting cell proliferation, suppressing cell migration and inducing cell apoptosis. AIF-1 overexpression promotes the apoptosis of CRC cells by activating the p38 MAPK pathway.

Glia maturation factor beta is required for reactive gliosis after traumatic brain injury in zebrafish.

Gliosis is a hallmark of neural pathology that occurs after most forms of central nervous system (CNS) injuries including traumatic brain injury (TBI). Identification of genes that control gliosis may provide novel treatment targets for patients with diverse CNS injuries. Glia maturation factor beta (GMFB) is crucial in brain development and stress response. In the present study, GMFB was found to be widely expressed in adult zebrafish telencephalon. A gmfb mutant zebrafish was created using CRISPR/cas9. In the uninjured zebrafish telencephalon, glial fibrillary acidic protein (GFAP) fibers in gmfb mutants were disorganized and shorter than wild type zebrafish. After TBI, transformation of quiescent type I radial glial cells (RGC) to proliferative type II RGCs was significantly suppressed in the gmfb mutant. RGC proliferation and hypertrophy post-TBI was reduced in gmfb mutants, indicating that reactive gliosis was attenuated. TBI-induced acute inflammation was also found to be alleviated in the gmfb mutant. Morphological changes also suggest attenuation of microglial reactive gliosis. In a mouse model of TBI, GMFB expression was increased around the injury site. These GMFB+ cells were identified as astrocytes and microglia. Taken together, the data suggests that GMFB is not only required for normal development of GFAP fibers in the zebrafish telencephalon, but also promotes reactive gliosis after TBI. Our findings provide novel information to help better understand the reactive gliosis process following TBI.

A protocol for the culture and isolation of murine synovial fibroblasts.

The culture of synovial fibroblasts (SFs) is one of the most effective tools for investigating the pathology and physiology of synovial tissues and should prove useful for identifying the importance of SFs in disease as well as for the development of novel therapeutic approaches for several chronic joint diseases, such as rheumatoid arthritis. However, thus far, a detailed protocol for the primary culture and isolation of murine SFs has not been established. Therefore, the present study describes an easy and convenient method for isolating and culturing SFs from C57BL/6 mice. This protocol can be divided into 4 stages: Isolation of synovial tissues, isolation of SFs, seeding of SFs for growth in culture and purity analysis of SFs using the four cell markers, vimentin, cluster of differentiation 90.2 (CD90.2; Thy-1.2), intracellular adhesion molecule 1 (CD54) and vascular cell adhesion molecule 1 (CD106). This method is efficient and a purified population of SFs can be obtained 10 days after the initiation of culture.

Quercetin inhibits the migration and proliferation of astrocytes in wound healing.

A previous study showed that quercetin inhibits astrogliosis in a scratch-wound model, but did not identify the underlying mechanisms. Here, we show that quercetin exerts no effect on apoptosis or the viability of astrocytes, but significantly inhibits their proliferation, arresting them in the G1 phase and decreasing the percentage of cells in the S and G2 phase. In addition, we found that quercetin significantly decreased the phosphorylation of ERK1/2 and FAK, a downstream ERK signaling protein. Inhibition of this pathway with U0126, an inhibitor of MAP kinase, retarded wound closure, whereas sustained p-ERK1/2 activation, induced by vanadate, restored astrocyte migration. Our findings thus indicate that quercetin inhibits healing in the scratch-wound model of primary astrocytes in two ways: blockade of the G1 to S phase cell cycle transition and inhibition of the ERK/FAK signaling pathway, which may contribute toward decreasing astroglial scar formation in vivo.

Quercetin inhibits proliferation and drug resistance in KB/VCR oral cancer cells and enhances its sensitivity to vincristine.

Quercetin has been confirmed to possess antihistamine, anti-inflammatory, antiviral, immunomodulatory, and antioxidant properties. Herein, we evaluated their antitumor activity in vitro by using KB/VCR oral cancer cells. We found that quercetin at 25 to 100 µmol/L effectively inhibited the migration and invasion of KB/VCR cells. Quercetin at dose ranging from 25 to 100 µmol/L significantly inhibited the growth of the KB/VCR cells and at 50 µmol/L arrested cells at the G1 phase and decreased the amount of cells in the S and G2 phase. Apoptosis analysis showed that quercetin at 50 or 100 µmol/L induced apoptosis of KB/VCR cells by suppressing expression of Bax and inducing the expression of Caspase-3 and Bcl-2. Furthermore, we also confirmed that quercetin from 25 to 100 µmol/L reversed gene-encoded Pglycoprotein (P-gp)-mediated MDR in KB/VCR cells by inhibiting the expression of P-gp. For combination treatment with vincristin (0.375 µmol/L) and quercetin (50 µmol/L), the proliferation rate significantly decreased and apoptosis rate significantly increased. This study provided evidence that quercetin induced apoptosis and reversed drug resistance in oral tumor cells and may be a potential candidate for other tumors treatment.

Simultaneous detection and identification of bacteria and fungi in cerebrospinal fluid by TaqMan probe-based real-time PCR.

BACKGROUND: To develop a real-time PCR assay for simultaneous detection and identification of clinically common bacteria and fungi causing meningitis from cerebrospinal fluid (CSF) samples. METHODS AND RESULTS: A total of 11 Gram-positive bacteria, 9 Gram-negative bacteria, and 7 fungi were identified correctly with a universal primer and probe designed based on ribosomal RNA conserved sequences. The detection limit was defined as 10(2) copies of plasmid DNA as C(T) value < 35 for boundaries. Among 137 CSF samples from patients with suspicion of meningitis, 23 samples were positive with a rate of 16.8%, and significantly higher than that of conventional methods, such as microbial culture and India ink stain (chi2 = 5.82, p < 0.05). CONCLUSIONS: TaqMan probe-based real-time PCR was proven to be a more rapid, sensitive, and specific method for the simultaneous detection of common bacteria and fungi. The method we established was not only applied to detect pathogens of CSF specimens, but also can also be applied to diagnose other biological fluids; it may be a supplementary assay and screening method to diagnose microorganisms.

[Effect of quercetin on glioma cell U87 apoptosis and feedback regulation of MDM2-p53].

OBJECTIVE: To investigate the effect of quercetin on apoptosis and feedback regulation of MDM2-p53 in multiform glioblastoma U87 cells in vitro. METHODS: U87 cells exposed to different concentrations of quercetin (50, 100, and 150 µmol/L) were examined with flow cytometry, RT-PCR and Western blotting for detecting the cell apoptosis, MDM2 mRNA expression, and p53 and caspase-3 expressions. RESULTS: Quercetin induced obvious apoptosis in U87 cells in a concentration-dependent manner, with apoptosis rates of (12.40∓0.70)% at Q0, (22.53∓0.72)% at Q50, (29.06∓0.81)% at Q100, and (31.5∓0.45)% at Q150. Quercetin significantly increased the expressions of MDM2 mRNA and active caspase-3 protein but decreased the expression of p53 in the cells. CONCLUSION: Quercetin promotes the apoptosis of multiform glioblastoma U87 cells mediated by caspase-3 and influences the feedback balance of MDM2-p53.

[Application of pyrosequencing in detection of common pathogens in sepsis].

OBJECTIVE: To apply pyrosequencing technique in the detection of the common pathogens in sepsis. METHODS: The primers for amplification and sequencing in pyrosequencing were designed according to alignment of the bacterial 16S rRNA sequence. Bacterial genomic DNA was extracted for pyrosequencing, and the pathogen species were determined according to the sequencing data obtained. RESULTS: Pyrosequencing effectively yielded the sequencing data of the 28 bp sequences of the pathogens and clearly distinguished the pathogen species of Streptococcus pyogenes, Streptococcus pneumonia, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Neisseria meningitides, and Salmonella, but failed to distinguish Staphylococcus epidermidis from Staphylococcus aureus. CONCLUSION: Pyrosequencing technique can effectively distinguish the common pathogens in sepsis at the species level.

[Effect of quercetin on invasion, migration, proliferation and cell cycle of glioma U87 cells].

OBJECTIVE: To explore the effect of quercetin on the invasion, migration, proliferation and cell cycle of glioma U87 cells. METHODS: Glioma U87 cells were treated with 50, 100, or 150 µmol/L quercetin (Q(50), Q(100) and Q(150) groups, respectively) or with DMSO (Q(0) group). Transwell in vitro invasion and migration assays, Click-iT Edu test and flow cytometry were performed to evaluate the effect of quercetin on the invasion, migration, proliferation and cell cycle of U87 cells. RESULTS: After 36 h of quercetin treatment, the cells in Q(50), Q(100) and Q(150) groups showed invasive cell percentages (relative to Q(0) group) of 52.08%, 24.63%, and 13.13%, respectively (P<0.05). After quercetin treatment for 12 h, the migrating cell percentages (relative to Q(0) group) in Q(50), Q(100) and Q(150) groups were 49.46%, 26.78%, and 14.56%, respectively (P<0.05). After 24 h of quercetin treatment, the cell proliferation ratios in Q(0), Q(50), Q(100) and Q(150) groups were 25.21%, 18.38%, 16.74% and 15.24%; the cell percentages in phase G0/Gl were 71.14%, 72.71%, 69.29%, and 66.47%, phase S were 25.32%, 22.48%, 21.96%, and 23.32%, and phase G(2)/M were 3.53%, 4.80%, 8.75%, and 10.25% in the 4 groups, respectively, showing a significant difference between groups Q(100), Q(150) and group Q(0) in phase G(2)/M cell percentages (P<0.05). CONCLUSIONS: Quercetin can significantly inhibit the invasion, migration and proliferation of glioma U87 cells by blocking the cell cycle progression.

[Establishment of real-time PCR and loop-mediated isothermal amplification for detecting Cryptococcus neoformans CAP10 gene].

OBJECTIVE: To establish real-time PCR and loop-mediated isothermal amplification (LAMP) systems for detecting Cryptococcus neoformans CAP10 gene. METHODS: Specific primers were designed targeting CAP10 gene of Cryptococcus neoformans, and the plasmid was constructed. After optimization of the reaction condition, the plasmid was quantitatively detected using real-time PCR and LAMP, and the detection sensitivity and specificity were evaluated. Clinical samples were also detected using the two methods. RESULTS: The detection sensitivity of real-time PCR and LAMP was 6.8×10(1) and 6.8×10(3) copies, respectively. Real-time PCR yielded a higher positivity rate than LAMP. Both of the two methods showed a high detection specificity and produced negative results in the detection of Neisseria meningitidis, Candida albicans, Candida tropicalis, Aspergillus flavus, Aspergillus niger and Escherichia coli. CONCLUSION: Real-time PCR is highly sensitive and specific for detecting Cryptococcus neoformans CAP10 gene but requires sophisticated equipment. LAMP, though with a relatively lower sensitivity, is simple to operate without the need of special equipment, and the result can be conveniently observed. Both of the two methods are suitable for detecting Cryptococcus neoformans and evaluating the treatment outcomes.

[Sensitivity and specificity of nested PCR pyrosequencing in hepatitis B virus drug resistance gene testing].

OBJECTIVE: To evaluate the sensitivity and specificity of nested PCR combined with pyrosequencing in the detection of HBV drug-resistance gene. METHODS: RtM204I (ATT) mutant and rtM204 (ATG) nonmutant plasmids mixed at different ratios were detected for mutations using nested-PCR combined with pyrosequencing, and the results were compared with those by conventional PCR pyrosequencing to analyze the linearity and consistency of the two methods. Clinical specimens with different viral loads were examined for drug-resistant mutations using nested PCR pyrosequencing and nested PCR combined with dideoxy sequencing (Sanger) for comparison of the detection sensitivity and specificity. RESULTS: The fitting curves demonstrated good linearity of both conventional PCR pyrosequencing and nested PCR pyrosequencing (R(2)>0.99, P<0.05). Nested PCR showed a better consistency with the predicted value than conventional PCR, and was superior to conventional PCR for detection of samples containing 90% mutant plasmid. In the detection of clinical specimens, Sanger sequencing had a significantly lower sensitivity than nested PCR pyrosequencing (92% vs 100%, P<0.01). The detection sensitivity of Sanger sequencing varied with the viral loads, especially in samples with low viral copies (HBV DNA ≤3log10 copies/ml), where the sensitivity was 78%, significantly lower than that of pyrosequencing (100%, P<0.01). Neither of the two methods yielded positive results for the negative control samples, suggesting their good specificity. CONCLUSION: Compared with nested PCR and Sanger sequencing method, nested PCR pyrosequencing has a higher sensitivity especially in clinical specimens with low viral copies, which can be important for early detection of HBV mutant strains and hence more effective clinical management.

[Effect of quercetin on neural stem cell proliferation in the subventricular zone of rats after focal cerebral ischemia-reperfusion injury].

OBJECTIVE: To study the effect of quercetin on the proliferation of neural stem cells in the subventricular zone (SVZ) of rats after focal cerebral ischemia. METHODS: An adult rat model of middle cerebral artery occlusion (MCAO) model was established by placement of an intraluminal filament at the origin of the MCA. Quercetin was administered intraperitoneally in the rats at a dose of 50 mg/kg every 3 days starting at 6 h after MCAO, and BrdU (50 mg/kg daily) was also injected intraperitoneally starting at 4 h after MCAO. BrdU-positive cells in the SVZ were counted at 7, 14 and 21 days after MCAO. RESULTS: Compared with the sham-operated group, the rats in the ischemic model group showed significantly increased BrdU-positive cells in the ipsilateral SVZ 7 days after MCAO, reaching the peak level on day 14 and beginning to decrease on day 21 (P<0.05). The number of ipsilateral BrdU-positive cells in quercetin group was significantly greater than that in the model group on days 7, 14 and 21 (P<0.05), and maintained the high level on day 21. CONCLUSION: Quercetin can maintain a high level of neural stem cell proliferation in the SVZ after focal cerebral ischemia in adult rats.

Immunohistochemical localization of mu opioid receptor in the marginal division with comparison to patches in the neostriatum of the rat brain.

BACKGROUND: Mu opioid receptor (MOR), which plays key roles in analgesia and also has effects on learning and memory, was reported to distribute abundantly in the patches of the neostriatum. The marginal division (MrD) of the neostriatum, which located at the caudomedial border of the neostriatum, was found to stain for enkephalin and substance P immunoreactivities and this region was found to be involved in learning and memory in our previous study. However, whether MOR also exists in the MrD has not yet been determined. METHODS: In this study, we used western blot analysis and immunoperoxidase histochemical methods with glucose oxidase-DAB-nickel staining to investigate the expression of MOR in the MrD by comparison to the patches in the neostriatum. RESULTS: The results from western blot analyses revealed that the antibody to MOR detected a 53 kDa protein band, which corresponded directly to the molecular weight of MOR. Immunohistochemical results showed that punctate MOR-immunoreacted fibers were observed in the "patch" areas in the rostrodorsal part of the neostriatum but these previous studies showed neither labelled neuronal cell bodies, nor were they shown in the caudal part of the neostriatum. Dorsoventrally oriented dark MOR-immunoreactive nerve fibers with individual labelled fusiform cell bodies were firstly observed in the band at the caudomedial border, the MrD, of the neostriatum. The location of the MOR-immunoreactivity was in the caudomedial border of the neostriatum. The morphology of the labelled fusiform neuronal somatas and the dorsoventrally oriented MOR-immunoreacted fibers in the MrD was distinct from the punctate MOR-immunoreactive diffuse mosaic-patterned patches in the neostriatum. CONCLUSIONS: The results indicated that MOR was expressed in the MrD as well as in patches in the neostriatum of the rat brain, but with different morphological characteristics. The punctate MOR-immunoreactive and diffuse mosaic-patterned patches were located in the rostrodorsal part of the neostriatum. By contrast, in the MrD, the dorsoventrally parallel oriented MOR-immunoreactive fibers with individual labelled fusiform neuronal somatas were densely packed in the caudomedial border of the neostriatum. The morphological difference in MOR immunoreactivity between the MrD and the patches indicated potential functional differences between them. The MOR most likely plays a role in learning and memory associated functions of the MrD.

[Protective effect of mild hypothermia on astrocytes with traumatic or ischemic injury].

OBJECTIVE: To investigate the protective effect of mild hypothermia on rat astrocytes with traumatic or ischemic injury. METHODS: Rat astrocytes in primary culture were subjected to scratching or hypoxic injury and exposed to normothermia (37 degrees celsius;) or hypothermia (34 or 32 degrees celsius;) for 24 h. The morphology of the astrocytes was evaluated by live/dead staining, and the cell injury was measured by lactate dehydrogenase (LDH) release assay. RESULTS: As the temperature reduced the LDH release rate from the cells in hypoxic group decreased significantly, to (11.48 - or + 1.53)% at 34 degrees celsius; and (3.79 - or + 0.45)% at 32 degrees celsius; as compared to that in normothermia [(33.02 - or + 3.58)%] in the absence of rat white blood cells (WBC) (P<0.001). LDH release rate of the hypoxic cells further decreased in the presence of rat WBC to (51.14 - or + 2.17 )% at 37 degrees celsius;, (19.53 - or + 4.37)% at 34 degrees celsius; and (16.68 - or + 1.47)% at 32 degrees celsius; (P<0.001). In the scratched cells, with or without WBC, LDH release rate showed no significant variation between the 3 temperatures (P>0.05). CONCLUSION: Mild hypothermia offers obvious protective effects on rat astrocytes against ischemic damage but not against mechanical injury.

[Construction of delta-pIRES2-EGFP plasmid and its expression in HEK293 cells].

OBJECTIVE: To construct the delta-pIRES2-EGFP plasmid and investigate its expression in HEK293 cells. METHODS: Full length cDNA of rat delta opioid receptor gene amplified from rat brain tissues using reverse transcription and nested PCR was cloned into pMD20 T vector. The delta cDNA was inserted into pIRES2-EGFP plasmid to construct the recombinant eukaryotic plasmid delta-pIRES2-EGFP, which was transfected into HEK293 cells via Lipofectamine2000. The expression of delta was examined under fluorescence microscope. RESULTS: The recombinant delta-pIRES2-EGFP plasmid was successfully constructed, and high expression of delta was detected in HEK293 cells transfected by the plasmid. CONCLUSION: delta-pIRES2-EGFP has been successfully cloned, which shows high expression of delta in HEK293 cells.

[Construction and identification of cDNA library of E.coli mRNA with poly(A) tracts].

OBJECTIVE: To construct and identify the cDNA library of E.coli mRNA with poly(A) tracts. METHODS: The cDNA library of E.coli was constructed by restriction display-PCR (RD-PCR) technique, followed by sequencing and bioinformatics analyses. RESULTS: cDNA library of E.coli mRNA with poly(A) tracts was successfully constructed, and 66 gene fragments were sequenced. CONCLUSION: The constructed cDNA library of E.coli mRNA with poly(A) tracts contains a low rate of repetition and is of high quality.

[Cloning E. coli mRNAs with poly (A) tails by restriction digest polymerase chain reaction].

OBJECTIVE: To investigate the polyadenylation at the 3' terminal of the mRNAs in E.coli. METHODS: mRNAs of E.coli was enriched from total RNA with oligo (dT)-cellulose, and reverse transcription was performed using oligo(dT)18 as primer prior to synthesis of double strands cDNA which was digested with Sau 3A I to produce multiple gene fragments that were then ligated with adapters. Restriction digest-polymerase chain reaction (RD-PCR) was employed to divide the fragments into 10 groups using 10 different combinations of the 4 primers, and the products were cloned into T-vectors. RESULTS: More than 100 gene fragments were cloned, 30 of which were sequenced. CONCLUSION: Polyadenylation of E.coli mRNA is not a biochemical curiosity, and very likely, it is a general attribute of the mRNAs of bacteria.

A method for evaluation of the quality of DNA microarray spots.

To establish a method to evaluate the quality of the printed microarray and DNA fragments' immobilization. The target gene fragments that were made with the restriction display PCR (RD-PCR) technique were printed on a superamine modified glass slide, then immobilized with UV cross-linking and heat. This chip was hybridized with universal primers that were labeled with cy3-dUTP, as well as cDNA that was labeled with cy3-dCTP, as the conventional protocol. Most of the target gene fragments on the chip showed positive signals, but the negative control showed no signal, and vice versa. We established a method that enables an effective evaluation of the quality of the microarrays.