Synthetic triterpenoids are potent anticancer agents, but their therapeutic efficacy or mechanism of action for prostate cancer has not been investigated. The goal of this study was to determine the antitumor activity and the mechanism of action of methyl-2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oate (CDDO-Me), a oleanane-derived synthetic triterpenoid for human prostate cancer cells.
The antitumor activity of CDDO-Me for hormone-refractory PC-3 (AR−) and C4-2 (AR+) prostate cancer cell lines was determined by effects on cell growth and induction of apoptosis, identification of molecular targets, and therapeutic efficacy in vivo in PC-3 xenograft model.
CDDO-Me inhibited the growth and induced apoptosis in PC-3 and C4-2 cells at extremely low concentrations. The antitumor activity of CDDO-Me was associated with the inhibition of p-Akt, mammalian target of rapamycin (mTOR), and nuclear factor kappa B (NF-κB) signaling proteins and their downstream targets such as p-Bad and p-Foxo3a (Akt); p-S6K1, p-eIF-4E and p-4E-BP1 (mTOR); and COX-2, VEGF and cyclin D1(NF-κB). Silencing of Akt sensitized the PC-3 cells to CDDO-Me, whereas overexpression of Akt induced resistance to CDDO-Me. Targeted silencing of Akt showed that Akt does not regulate mTOR activation in PC-3 cells, but targeted silencing of mTOR sensitized PC-3 cells to CDDO-Me mediated growth inhibition. Further, treatment with CDDO-Me inhibited the growth of PC-3 xenografts in nude mice.
This study demonstrated potent antitumor activity of CDDO-Me against prostate cancer cells both in vitro and in vivo. Data also identified Akt and mTOR as molecular targets of CDDO-Me in prostate cancer cells.
CDDO-Me; prostate cancer; apoptosis; Akt; mTOR; xenograft
Contemporary combined therapies that include the use of all-trans retinoic acid (ATRA) and arsenic compounds have reduced relapse rates from ~50 to <10% in acute promyelocytic leukemia (APL) patients, however relapse treatment remains controversial. Treatment outcomes in relapsed patients with APL previously treated with combined ATRA + arsenic compound therapy were investigated. A retrospective, observational study was conducted of 25 patients with APL (male to female ratio, 17:8; mean age, 36.4±10.3 years) exhibiting first-time relapse following combined ATRA + arsenic compound therapy. These patients were subsequently treated with secondary ATRA + arsenic compound therapy, salvage chemotherapy, monoclonal antibody therapy or intrathecal chemotherapy, between January 1994 and December 2010. The overall remission rate, duration of remission and toxic effects were assessed. Patient outcomes included mortality during secondary induction therapy (6/25, 24.0%); complete recovery from central nervous system (CNS) relapse following intrathecal chemotherapy (1/25, 4.0%); complete remission following ATRA + arsenic compound therapy (10/25, 40.0%), chemotherapy (3/25, 12.0%) and targeted therapy (1/25, 4.0%); and non-remission (NR) following ATRA + arsenic compound therapy (4/25, 16%). Four (16.0%) patients were subsequently treated with allogeneic hematopoietic stem cell transplantation (allo-HSCT), two of which remained disease-free at the end of the study period and two of which succumbed to the disease. Secondary bone marrow and CNS relapse occurred in 14 (56.0%) patients and one (4.0%) patient, respectively. ATRA + arsenic compound-based combination therapy was effective in re-inducing morphological remission in relapsed patients with APL with previous exposure to ATRA + arsenic compounds, producing low molecular remission rates and high risk of secondary relapse. Furthermore, investigation of early allo-HSCT is required to determine its potential as a therapeutic option for re-inducing morphological remission in relapsed patients with APL with previous exposure to ATRA + arsenic compounds.
acute promyelocytic leukemia; relapse; re-induction therapy; remission; all-trans retinoic acid; arsenic compound
Objectives. To explore sensitization and possible mechanisms of adjuvant magnetic fields (MFs) in radiotherapy (RT) of non-small-cell lung cancer. Methods. Human A549 lung adenocarcinoma cells were treated with MF, RT, and combined MF-RT. Colony-forming efficiency was calculated, cell cycle and apoptosis were measured, and changes in cell cycle- and apoptosis-related gene expression were measured by microarray. Results. A 0.5 T, 8 Hz stationary MF showed a duration-dependent inhibitory effect lasting for 1–4 hours. The MF-treated groups had significantly greater cell inhibition than did controls (P < 0.05). Surviving fractions and growth curves derived from colony-forming assay showed that the MF-only, RT-only, and MF-RT groups had inhibited cell growth; the MF-RT group showed a synergetic effect. Microarray of A549 cells exposed for 1 hour to MF showed that 19 cell cycle- and apoptosis-related genes had 2-fold upregulation and 40 genes had 2-fold downregulation. MF significantly arrested cells in G2 and M phases, apparently sensitizing the cells to RT. Conclusions. MF may inhibit A549 cells and can increase their sensitivity to RT, possibly by affecting cell cycle- and apoptosis-related signaling pathways.
Primary sarcoma of the aorta is extremely rare and accounts for <1% of all sarcomas. The present study describes the case of a 45-year-old male who presented with lower limb and abdominal pain. Abdominal computed tomography (CT) and magnetic resonance (MR) arteriography revealed a tumor that extended from the infrarenal aorta to the aortic bifurcation. The external and internal iliac arteries were occluded by the tumor incursion. Palliative surgery was performed for the sarcoma since the patient refused a radical resection. To improve the blood supply to the lower limbs, an axillary bifemoral bypass was established. Following the surgery, the pain was significantly reduced. However, the patient succumbed due to extensive metastasis 6 months after this surgery. Aortic sarcoma is an extremely rare disease with a poor prognosis. A diagnosis at a relatively early stage is necessary for a longer survival time. Radical surgery is the most significant treatment. Patients at advanced stages should consider palliative surgery in order to improve their quality of life.
abdominal aortic aneurysm; palliative surgery
Because of the periodically varying aerodynamic and inertial forces of the flapping wings, a hovering or constant-speed flying insect is a cyclically forcing system, and, generally, the flight is not in a fixed-point equilibrium, but in a cyclic-motion equilibrium. Current stability theory of insect flight is based on the averaged model and treats the flight as a fixed-point equilibrium. In the present study, we treated the flight as a cyclic-motion equilibrium and used the Floquet theory to analyse the longitudinal stability of insect flight. Two hovering model insects were considered—a dronefly and a hawkmoth. The former had relatively high wingbeat frequency and small wing-mass to body-mass ratio, and hence very small amplitude of body oscillation; while the latter had relatively low wingbeat frequency and large wing-mass to body-mass ratio, and hence relatively large amplitude of body oscillation. For comparison, analysis using the averaged-model theory (fixed-point stability analysis) was also made. Results of both the cyclic-motion stability analysis and the fixed-point stability analysis were tested by numerical simulation using complete equations of motion coupled with the Navier–Stokes equations. The Floquet theory (cyclic-motion stability analysis) agreed well with the simulation for both the model dronefly and the model hawkmoth; but the averaged-model theory gave good results only for the dronefly. Thus, for an insect with relatively large body oscillation at wingbeat frequency, cyclic-motion stability analysis is required, and for their control analysis, the existing well-developed control theories for systems of fixed-point equilibrium are no longer applicable and new methods that take the cyclic variation of the flight dynamics into account are needed.
insect; hovering; cyclic-motion stability; Floquet theory
The imaging performance of active matrix flat-panel imagers designed for megavoltage imaging (MV AMFPIs) is severely constrained by relatively low x-ray detection efficiency, which leads to a detective quantum efficiency (DQE) of only ~1%. Previous theoretical and empirical studies by our group have demonstrated the potential for addressing this constraint through utilization of thick, two-dimensional, segmented scintillators with optically isolated crystals. However, this strategy is constrained by degradation of high-frequency DQE resulting from spatial resolution loss at locations away from the central beam axis due to oblique incidence of radiation.
To address this challenge, segmented scintillators constructed so that the crystals are individually focused toward the radiation source are proposed and theoretically investigated. The study was performed using Monte Carlo simulations of radiation transport to examine the modulation transfer function and DQE of focused segmented scintillators with thicknesses ranging from 5 to 60 mm. The results demonstrate that, independent of scintillator thickness, the introduction of focusing largely restores spatial resolution and DQE performance otherwise lost in thick, unfocused segmented scintillators. For the case of a 60 mm thick BGO scintillator and at a location 20 cm off the central beam axis, use of focusing improves DQE by up to a factor of ~130 at non-zero spatial frequencies. The results also indicate relatively robust tolerance of such scintillators to positional displacements, of up to 10 cm in the source-to-detector direction and 2 cm in the lateral direction, from their optimal focusing position, which could potentially enhance practical clinical use of focused segmented scintillators in MV AMFPIs.
AMFPI; DQE; segmented crystalline scintillator; focused geometry; EPID
In this study, we seek to investigate the effects of simvastatin on proliferation, migration and apoptosis in human U251 and U87 glioma cells and the underlying molecular mechanism.
We used colony formation assay to test the cell proliferation, in vitro scratch assay to examine the cell migration, and caspase-3 activity assay, annexin V staining and cytochrome C release to evaluate the cell apoptosis. Lipid raft fractions were isolated from glioma cells. Total cholesterol content assay was used to test the change of cholesterol level in lipid raft fractions. Immunocytochemistry staining was performed to detect the changes of lipid rafts in cell membrane. Western blotting analysis was performed to examine the signal transduction both in cells and in lipid raft fractions.
Simvastatin inhibited proliferation and migration of U251 and U87 cells dose-dependently. Simvastatin induced an increase of caspase-3 activity, annexin V staining, and downregulated the PI3K/Akt pathway. Simvastatin also decreased cholesterol content in lipid raft fractions, suppressed caveolin-1 expression in the lipid rafts and induced Fas translocation into lipid rafts, suggesting that simvastatin may inhibit pro-survival PI3K/Akt pathway and trigger caspase-3-dependent apoptotic cell death through the modulation of lipid rafts.
These results suggest that modulation of lipid rafts, Fas translocation and PI3K/Akt/caspase-3 pathway are involved in the antitumor effect of simvastatin and it may have a potential role in cancer prevention and treatment.
apoptosis; glioma; lipid rafts; PI3K/Akt pathway; simvastatin
Our previous studies found that simvastatin treatment of traumatic brain injury (TBI) in rats had beneficial effects on spatial learning functions. In the current study we wanted to determine whether simvastatin suppressed neuronal cell apoptosis after TBI, and if so, the underlying mechanisms of this process.
Saline or simvastatin (1 mg/kg) was administered orally to rats starting at Day 1 after TBI and then daily for 14 days. Modified neurological severity scores (NSS) were employed to evaluate the sensory motor functional recovery. Rats were sacrificed at 1, 3, 7, 14 and 35 days after treatment and brain tissue was harvested for TUNEL staining, caspase-3 activity assay and Western blot analysis. Simvastatin significantly decreased NSS from Days 7 to 35 after TBI, significantly reduced the number of TUNEL-positive cells at Day 3, suppressed the caspase-3 activity at Days 1 and 3 after TBI, and increased phosphorylation of Akt as well as FOXO1, IκB and eNOS, which are the downstream targets of the pro-survival Akt signaling protein.
These data suggested that simvastatin reduces the apoptosis in neuronal cells and improves the sensory motor function recovery after TBI. These beneficial effects of simvastatin may be mediated through activation of Akt, FOXO1 and NF-κB signaling pathways, which suppress the activation of caspase-3 and apoptotic cell death, and thereby lead to neuronal function recovery after TBI.
simvastatin; apoptosis; Akt; FOXO1; IκB; traumatic brain injury
It is often difficult to track the spatio-temporal variability of vegetation distribution in lakes because of the technological limitations associated with mapping using traditional field surveys as well as the lack of a unified field survey protocol. Using a series of Landsat remote sensing images (i.e. MSS, TM and ETM+), we mapped the composition and distribution area of emergent, floating-leaf and submerged macrophytes in Taihu Lake, China, at approximate five-year intervals over the past 30 years in order to quantify the spatio-temporal dynamics of the aquatic vegetation. Our results indicated that the total area of aquatic vegetation increased from 187.5 km2 in 1981 to 485.0 km2 in 2005 and then suddenly decreased to 341.3 km2 in 2010. Similarly, submerged vegetation increased from 127.0 km2 in 1981 to 366.5 km2 in 2005, and then decreased to 163.3 km2. Floating-leaf vegetation increased continuously through the study period in both area occupied (12.9 km2 in 1981 to 146.2 km2 in 2010) and percentage of the total vegetation (6.88% in 1981 to 42.8% in 2010). In terms of spatial distribution, the aquatic vegetation in Taihu Lake has spread gradually from the East Bay to the surrounding areas. The proportion of vegetation in the East Bay relative to that in the entire lake has decreased continuously from 62.3% in 1981, to 31.1% in 2005 and then to 21.8% in 2010. Our findings have suggested that drastic changes have taken place over the past 30 years in the spatial pattern of aquatic vegetation as well as both its relative composition and the amount of area it occupies.
Though postoperative radiation for esophageal squamous cell carcinoma is offered in selected cases, there is conflicting evidence as to whether it improves overall survival (OS). A retrospective investigation was performed to analyze the prognostic impact of postoperative radiation therapy (PORT) in a large cohort of patients.
From 2001 to 2009, 725 patients underwent radical esophagectomy (R0) with or without PORT were eligible for retrospective analysis. Patients were grouped into surgery alone (n = 467) and surgery plus PORT (n = 258). Median irradiation doses were 50 Gy (range: 40-56 Gy). Radiation fields encompassed the bilateral supraclavicular fossa, mediastinum, subcarinal area, and the tumor bed for the upper/middle-third disease; the bilateral supraclavicular fossa, mediastinum, the tumor bed, subcarinal area, and lower thoracic paraesophageal area for the lower-third disease. Kaplan-Meier and Cox regression analysis were used to compare OS.
After median follow-up of 53 months, the median OS was 29 months in the PORT group and 23 months in the surgery alone group. The addition of PORT improved OS at 3 years from 36.6 to 43.6% compared with surgery alone. The use of PORT was associated with significantly improved OS (p = 0.018). For American Joint Committee on Cancer (AJCC) stage III esophageal cancer (T1-2N2M0, T3N1-2M0, T4N1-3M0), there was significant improvement in OS (p = 0.002) in the PORT group, not only for lymph-node metastatic ratio (LNMR) ≥0.25 (p = 0.001), but also for LNMR <0.25 (p = 0.043). However, for stage IIB disease (T1-2N1M0) there was no significant differences. The addition of POCT didn’t prolong the OS significantly (Surgery alone group, p = 0.079; PORT group, p = 0.111).
This large retrospective analysis supports the use of PORT for pathologic lymph node positive stage III esophageal squamous cell carcinoma. Given the retrospective nature of this study, the results should be confirmed by appropriately powered randomized trials. Further development of adjuvant therapy in EC is warranted.
Esophageal cancer; Postoperative radiation; Esophagectomy; Survival
ES cell pluripotency requires bivalent epigenetic modifications of key developmental genes regulated by various transcription factors and chromatin modifying enzymes. How these factors coordinate with one another to maintain the bivalent chromatin state so that ES cells can undergo rapid self-renewal while retaining pluripotency is poorly understood. We report that Utf1, a target of Oct4 and Sox2, is a bivalent chromatin component that buffers poised states of bivalent genes. By limiting PRC2 loading and Histone 3 lysine-27 trimethylation, Utf1 sets proper activation thresholds for bivalent genes. It also promotes nuclear tagging of mRNAs transcribed from insufficiently silenced bivalent genes for cytoplasmic degradation through mRNA de-capping. These opposing functions of Utf1 promote coordinated differentiation. The mRNA degradation function also ensures rapid cell proliferation by blocking the Myc-Arf feedback control. Thus, Utf1 couples the core pluripotency factors with Myc and PRC2 networks to promote the pluripotency and proliferation of ESCs.
Utf1; PRC2; Myc; bivalency; pluripotency; self-renewal; ES cells; epigenetics; mRNA degradation; differentiation
Histone H3K4 methylation is associated with active genes and, along with H3K27 methylation, is part of a bivalent chromatin mark that typifies poised developmental genes in embryonic stem cells (ESCs). However, its functional roles in ESC maintenance and differentiation are not established. Here we show that mammalian Dpy-30, a core subunit of the SET1/MLL histone methyltransferase complexes, modulates H3K4 methylation in vitro, and directly regulates chromosomal H3K4 trimethylation (H3K4me3) throughout the mammalian genome. Depletion of Dpy-30 does not affect ESC self-renewal, but significantly alters the differentiation potential of ESCs, particularly along the neural lineage. The differentiation defect is accompanied by defects in gene induction and in H3K4 methylation at key developmental loci. Our results strongly indicate an essential functional role for Dpy-30 and SET1/MLL complex-mediated H3K4 methylation, as a component of the bivalent mark, at developmental genes during the ESC fate transitions.
The copper(I)-catalyzed azide-alkyne cycloaddition, the most widely recognized reaction of click chemistry, is accelerated by tris(triazolylmethyl)amine-based ligands. Here, we compared two new ligands in this family, BTTP and the corresponding sulfated ligand BTTPS, for three bioconjugation applications: (1) labeling of alkyne-tagged glycoproteins in crude cell lysates, (2) labeling of alkyne/azide-tagged glycoproteins on the surface of live mammalian cells, and (3) labeling of azides in surface proteins of live Escherichia coli. Though BTTPS exhibits faster kinetics than BTTP in accelerating the CuAAC in in vitro kinetic measurements, its labeling efficiency is slightly lower than BTTP in conjugating biomolecules bearing a significant amount of negative charges due to electrostatic repulsion. Nevertheless, the negative charge conferred by the sulfate at physiological conditions significantly reduced the cellular internalization of the coordinated Cu(I), thus making BTTPS-Cu(I) a better choice for live cell labeling.
click chemistry; copper; bioconjugation; glycoconjugates
Non-destructive estimation using digital cameras is a common approach for estimating leaf area index (LAI) of terrestrial vegetation. However, no attempt has been made so far to develop non-destructive approaches to LAI estimation for aquatic vegetation. Using the submerged plant species Potamogeton malainus, the objective of this study was to determine whether the gap fraction derived from vertical photographs could be used to estimate LAI of aquatic vegetation. Our results suggested that upward-oriented photographs taken from beneath the water surface were more suitable for distinguishing vegetation from other objects than were downward-oriented photographs taken from above the water surface. Exposure settings had a substantial influence on the identification of vegetation in upward-oriented photographs. Automatic exposure performed nearly as well as the optimal trial exposure, making it a good choice for operational convenience. Similar to terrestrial vegetation, our results suggested that photographs taken for the purpose of distinguishing gap fraction in aquatic vegetation should be taken under diffuse light conditions. Significant logarithmic relationships were observed between the vertical gap fraction derived from upward-oriented photographs and plant area index (PAI) and LAI derived from destructive harvesting. The model we developed to depict the relationship between PAI and gap fraction was similar to the modified theoretical Poisson model, with coefficients of 1.82 and 1.90 for our model and the theoretical model, respectively. This suggests that vertical upward-oriented photographs taken from below the water surface are a feasible alternative to destructive harvesting for estimating PAI and LAI for the submerged aquatic plant Potamogeton malainus.
Management of water levels for flood control, water quality, and water safety purposes has become a priority for many lakes worldwide. However, the effects of water level management on the distribution and composition of aquatic vegetation has received little attention. Relevant studies have used either limited short-term or discrete long-term data and thus are either narrowly applicable or easily confounded by the effects of other environmental factors. We developed classification tree models using ground surveys combined with 52 remotely sensed images (15–30 m resolution) to map the distributions of two groups of aquatic vegetation in Taihu Lake, China from 1989–2010. Type 1 vegetation included emergent, floating, and floating-leaf plants, whereas Type 2 consisted of submerged vegetation. We sought to identify both inter- and intra-annual dynamics of water level and corresponding dynamics in the aquatic vegetation. Water levels in the ten-year period from 2000–2010 were 0.06–0.21 m lower from July to September (wet season) and 0.22–0.27 m higher from December to March (dry season) than in the 1989–1999 period. Average intra-annual variation (CVa) decreased from 10.21% in 1989–1999 to 5.41% in 2000–2010. The areas of both Type 1 and Type 2 vegetation increased substantially in 2000–2010 relative to 1989–1999. Neither annual average water level nor CVa influenced aquatic vegetation area, but water level from January to March had significant positive and negative correlations, respectively, with areas of Type 1 and Type 2 vegetation. Our findings revealed problems with the current management of water levels in Taihu Lake. To restore Taihu Lake to its original state of submerged vegetation dominance, water levels in the dry season should be lowered to better approximate natural conditions and reinstate the high variability (i.e., greater extremes) that was present historically.
Members of the Bacteroidales order are among the most abundant gram-negative bacteria of the human colonic microbiota. These species decorate their cell surface glycoproteins with fucosylated glycans, which are believed to play important roles in host intestinal colonization. Currently, there is no method for the enrichment of these glycoproteins for their identification. Here, we describe a chemical approach directed toward labeling and detecting fucosylated glycoproteins from cultured Bacteroidales species, namely Bacteroides fragilis and Parabacteroides distasonis. We treated these bacteria with an alkyne-bearing fucose analog, which is metabolically integrated into the bacterial surface fucosylated glycoproteins. The alkyne-tagged glycoproteins can then react with azide-bearing biophysical probes via bioorthogonal click chemistry for detection or glycoproteomic analysis.
High dimensional bioinformatics data sets provide an excellent and challenging research problem in machine learning area. In particular, DNA microarrays generated gene expression data are of high dimension with significant level of noise. Supervised kernel learning with an SVM classifier was successfully applied in biomedical diagnosis such as discriminating different kinds of tumor tissues. Correlation Kernel has been recently applied to classification problems with Support Vector Machines (SVMs). In this paper, we develop a novel and parsimonious positive semidefinite kernel. The proposed kernel is shown experimentally to have better performance when compared to the usual correlation kernel. In addition, we propose a new kernel based on the correlation matrix incorporating techniques dealing with indefinite kernel. The resulting kernel is shown to be positive semidefinite and it exhibits superior performance to the two kernels mentioned above. We then apply the proposed method to some cancer data in discriminating different tumor tissues, providing information for diagnosis of diseases. Numerical experiments indicate that our method outperforms the existing methods such as the decision tree method and KNN method.
EPCs were isolated primarily in 1997 by Asahara et al. and recent studies indicated that bone-marrow-derived EPCs contributed little to the endothelium of tumor vessels. Tumors of the CNS system demonstrate various features of angiogenesis.
EPCs derived from rat bone marrow were isolated and cultured in M199 medium without any induced factors. EPCs were studied using immunohistochemical staining, Flow cytometry and culture under three-dimensional condition to determine EPCs’ characteristics in vitro. We also established an animal model by injecting EPCs marked with Hoechst 33342 into the back of BALB/c nude mice and performed hematoxylin-eosin (HE) and immunofluorescent staining to study EPCs’ features in vivo. To research effect of EPCs on glioma, animals bearing tumors model with C6 glioma were established. About 27 day after injection, we performed immunohistochemical staining and Immunofluorescence staining.
Our results showed that EPCs derived from rat bone marrow appeared typical morphological characteristics and were positive of CD34, CD133, KDR and CD31 antigens at different time in vitro under the special M199 medium without any induced factors. The percentage of cells that expressed CD133 decreased gradually. In brief, the present study showed that EPCs derived from rat bone marrow differentiated into ECs in medium the without any induced factors and formed tubular structures in three-dimensional circumstances. Animal experiments suggested that EPCs differentiated into ECs and other else non-endothelial cells, and that EPCs contributed M199 of glioma.
These findings provides some novel results about biological characteristics of EPCs in vivo and ex vivo, and an update on the effect of EPCs on glioma and which would be helpful for the overall understanding of EPCs and make EPCs to be implied on the clinical therapy.
Fragile X syndrome (FXS) is caused by the absence of the mRNA-binding protein Fragile X mental retardation protein (FMRP), encoded by the Fmr1 gene. Overactive signaling by group 1 metabotropic glutamate receptor (Grp1 mGluR) could contribute to slowed synaptic development and other symptoms of FXS. Our previous study has identified that facilitation of synaptic long-term potentiation (LTP) by D1 receptor is impaired in Fmr1 knockout (KO) mice. However, the contribution of Grp1 mGluR to the facilitation of synaptic plasticity by D1 receptor stimulation in the prefrontal cortex has been less extensively studied.
Here we demonstrated that DL-AP3, a Grp1 mGluR antagonist, rescued LTP facilitation by D1 receptor agonist SKF81297 in Fmr1KO mice. Grp1 mGluR inhibition restored the GluR1-subtype AMPA receptors surface insertion by D1 activation in the cultured Fmr1KO neurons. Simultaneous treatment of Grp1 mGluR antagonist with D1 agonist recovered the D1 receptor signaling by reversing the subcellular redistribution of G protein-coupled receptor kinase 2 (GRK2) in the Fmr1KO neurons. Treatment of SKF81297 alone failed to increase the phosphorylation of NR2B-containing N-methyl D-aspartate receptors (NMDARs) at Tyr-1472 (p-NR2B-Tyr1472) in the cultures from KO mice. However, simultaneous treatment of DL-AP3 could rescue the level of p-NR2B-Tyr1472 by SKF81297 in the cultures from KO mice. Furthermore, behavioral tests indicated that simultaneous treatment of Grp1 mGluR antagonist with D1 agonist inhibited hyperactivity and improved the learning ability in the Fmr1KO mice.
The findings demonstrate that mGluR1 inhibition is a useful strategy to recover D1 receptor signaling in the Fmr1KO mice, and combination of Grp1 mGluR antagonist and D1 agonist is a potential drug therapy for the FXS.
Group I mGluRs; Dopamine; Long-term potentiation prefrontal cortex
A strategy for analyzing flavone C-glucosides in the leaves of different species of bamboo was developed. Firstly, the flavone C-glycosides were extracted from the bamboo leaves (51 species in 17 genera) with methanol and chromatographed on silica gel 60 plates in automatic developing chamber (ADC2), and a qualitative survey using simple derivatization steps with the NP reagent was carried out. The flavone C-glycosides were found in 40 of 51 species of bamboo examined. Secondly, an HPLC method with photodiode array and multiple wavelength detector was optimized and validated for the simultaneous determination of flavone C-glycosides, including isoorientin, isovitexin, orientin, and vitexin in the leaves of three species of bamboo and the flavone C-glycosides were confirmed by LC/MS. The optimized HPLC method proved to be linear in the concentration range tested (0.2–100 μg/mL, r2 ≥ 0.9997), precise (RSD ≤ 1.56%), and accurate (88–106%). The concentration ranges of isoorientin, isovitexin, orientin, and vitexin in three bamboo leaves samples were 1.00–2.78, 0–0.31, 0–0.07, and 0.20–0.68 mg/g, respectively. The proposed method was validated to be simple and reliable and can be a tool for quality control of bamboo leaf extract or its commercial products.
Our previous studies demonstrated that simvastatin reduced neuronal death, increased neurogenesis, and promoted functional recovery after TBI. Objective: To investigate the effect of simvastatin on angiogenesis after TBI, and the related signaling pathways.
Saline or simvastatin (1 mg/kg) was administered orally to rats starting at day 1 after TBI or sham surgery and then daily for 14 days. Rats were sacrificed at 3 and 14 days after treatment. Brain sections and tissues were prepared for immunohistochemical staining, ELISA, and Western blot analysis, respectively. Cultured rat brain microvascular endothelial cells (RBMVECs) were subjected to oxygen-glucose deprivation (OGD) followed by immunocytochemical staining with phallotoxins and vascular endothelial growth factor receptor-2 (VEGFR-2). Western blot analysis was carried out to examine the simvastatin-induced activation of the v-akt murine thymoma viral oncogene homolog (Akt) signaling pathway. The expression of VEGFR-2 was detected by ELISA.
Simvastatin significantly increased the length of vascular perimeter, promoted the proliferation of endothelial cells, and improved the sensorimotor function after TBI. Simvastatin stimulated endothelial cell tube formation after OGD in vitro. VEGFR-2 expression in both brain tissues and cultured RBMVECs was enhanced after simvastatin treatment, which may be modulated by activation of Akt. Akt-dependent endothelial nitric oxide synthase (eNOS) phosphorylation was also induced by simvastatin in vivo and in vitro.
Simvastatin augments TBI-induced angiogenesis in the lesion boundary zone and hippocampus and improves functional recovery. Simvastatin also promotes angiogenesis in vitro. These beneficial effects on angiogenesis may be related to simvastatin-induced activation of the VEGFR-2/Akt/eNOS signaling pathway.
Angiogenesis; Simvastatin; Traumatic brain injury; VEGFR-2
Megavoltage, cone-beam computed tomography (MV CBCT) employing an electronic portal imaging device (EPID) is a highly promising technique for providing soft-tissue visualization in image-guided radiotherapy. However, current EPIDs based on active matrix flat-panel imagers (AMFPIs), which are regarded as the gold standard for portal imaging and referred to as conventional MV AMFPIs, require high radiation doses to achieve this goal due to poor x-ray detection efficiency (~2% at 6 MV). To overcome this limitation, the incorporation of thick, segmented, crystalline scintillators, as a replacement for the phosphor screens used in these AMFPIs, has been shown to significantly improve the DQE performance, leading to improved image quality for projection imaging at low dose. Toward the realization of practical AMFPIs capable of low dose, soft-tissue visualization using MV CBCT imaging, two prototype AMFPIs incorporating segmented scintillators with ~11 mm thick CsI:Tl and BGO crystals were evaluated. Each scintillator consists of 120 × 60 crystalline elements separated by reflective septal walls, with an element-to-element pitch of 1.016 mm. The prototypes were evaluated using a bench-top CBCT system, allowing the acquisition of 180 projection, 360° tomographic scans with a 6 MV radiotherapy photon beam. Reconstructed images of a spatial resolution phantom, as well as of a water-equivalent phantom, embedded with tissue equivalent objects having electron densities (relative to water) varying from ~0.28 to ~1.70, were obtained down to one beam pulse per projection image, corresponding to a scan dose of ~4 cGy – a dose similar to that required for a single portal image obtained from a conventional MV AMFPI. By virtue of their significantly improved DQE, the prototypes provided low contrast visualization, allowing clear delineation of an object with an electron density difference of ~2.76%. Results of contrast, noise and contrast-to-noise ratio are presented as a function of dose and compared to those from a conventional MV AMFPI.
Megavoltage cone-beam CT; soft-tissue contrast; flat-panel imager; electronic portal imaging device; segmented crystalline scintillators; high x-ray detection efficiency
Physiological responses to abiotic stress in plants exhibit sexual differences. Females usually experience greater negative effects than males; however, little is known about the molecular mechanisms of sexual differences in abiotic stress responses. In the present study, transcriptional responses to salinity treatments were compared between male and female individuals of the poplar Populus yunnanensis. It was found that several functional groups of genes involved in important pathways were differentially expressed, including photosynthesis-related genes, which were mainly up-regulated in males but down-regulated in females. This gene expression pattern is consistent with physiological observations showing that salinity inhibited photosynthetic capacity more in females than in males. Furthermore, genes located in autosomes rather than in the female-specific region of the W chromosome are the major contributors to the sexual differences in the salinity tolerance of poplars. In conclusion, this study provided molecular evidence of sexual differences in the salinity tolerance of poplars. The identified sex-related genes in salinity tolerance and their functional groups will enhance our understanding of sexual differences in salinity stress at the transcription level.
Next-generation sequencing; physiological responses; Populus; salinity tolerance; sexual differences; transcriptional profiling