Targeting glioblastoma stem cells: cell surface markers

Glioblastoma multiforme (GBM) is the most common primary brain tumor and among the most lethal cancers. There is increasing evidence that cancer stem cells within GBMs, which are often referred to as glioblastoma stem cells (GSCs), play a critical role in tumor initiation and maintenance. Identification of novel markers for GSCs will lead to better targeting of GSCs which could have tremendous impact on treatment of GBMs. Cell surface markers are particularly suitable as therapeutic targets. Although several promising cell surface markers have successfully been used for enrichment of GSCs, their functional roles in maintenance of GSC properties as well as in GBM formation and development remain to be characterized. In this review, we primarily summarize recent advances in identification of GSC markers, with a particular focus on cell surface markers.

21 EFFECT OF SECOND TIME XENOPUS EGG EXTRACT TREATMENT ON COLONY FORMATION AND CLONED BLASTOCYST FORMATION IN PIG

Extract from Xenopus eggs can induce reprogramming in somatic cells. In our previous study, cell colony formation was induced during culture of porcine fetal fibroblasts after a single treatment with Xenopus egg extract and culture for several passages and using these long-term cultured cells for cloning increased the resulting blastocyst rate (Liu et al. 2011 Reprod. Fertil. Dev. 23, 130). However, both colony number and cloned blastocyst rate decreased after Passage 15 and no colonies formed after Passage 18. Therefore, in this study we investigated the effect of a second extract treatment on colony formation and cloned blastocyst formation. Extract-treated (ExT) porcine fetal fibroblasts at Passage 13 (P13) grown on poly-L-lysine-coated coverslips were permeabilized by digitonin (7 μg mL–1, 2 min, 4°C) and incubated in extract at 37°C for 30 min. After resealing the membrane in DMEM supplemented with 2 mM CaCl2, the remaining cells were cultured in ES medium (Vejlsted et al. 2005 Mol. Reprod. Dev. 70, 445). The treated cells were split onto 2 coverslips on Day 7 after the second extract treatment (2ExT), defined as Passage 1 (2ExT P1, comparable with ExT P14). New subcultures were made every 7 to 8 days when 70 to 80% clusters became colonies (i.e. 2ExT P8). Colony cells from both ExT (P14 and P16) and 2ExT (P1, P3 and P6) were used for handmade cloning and nontreated cells were used as control (Day 0). Blastocyst rates were analysed by chi-square test and colony numbers were analysed by 1-way ANOVA (SAS version 9.2). Colony numbers and cloned blastocyst rates on Day 6 are summarised in Table 1. Colonies continued to form in treated cells from 2ExT P1 to P8. The colony number maintained at a high level (60 to 80) from 2ExT P4 to P8 and it was significantly higher than that of ExT cells at the comparable passage numbers. No colonies formed in control cells. When using 2ExT colony cells at P3 and P6 for cloning, the blastocyst rates increased compared with controls and they were also higher than in the ExT group. Cloned blastocyst rates were not different between 2ExT P1 and ExT P14 groups. In conclusion, a second extract treatment can induce colony formation and increase cloned blastocyst rates, indicating that this repeated extract treatment again could activate the extract-treated cells to an activity level similar to that achieved after the first treatment. Table 1.Summary of colony number and cloned blastocyst rate with ExT and 2ExT colony cells

98 EFFECT OF ZONA PELLUCIDA ON PORCINE PARTHENOGENETICALLY ACTIVATED EMBRYOS

The need for zona pellucida (ZP) during pre-implantation embryo development is still debated. In porcine parthenogenetically activated (PA) embryos, we have previously shown a different distribution in cell numbers on Day 6 blastocysts cultured with or without ZP (Li et al. 2010 Reprod. Fertil. Dev. 22, 234). In the present study, we expanded this study to include also the timing of early development and the resulting quality and robustness (for vitrification) of porcine PA embryos. Parthenogenetic activation was made first by an electric pulse (1.26 kV cm–1, 80 μs) and then by incubation with 5 μg mL–1 cytochalasin B and 10 μg mL–1 cycloheximide in PZM-3 medium for 4 h. ZP was removed by 3.3 mg mL–1 pronase. Both zona-intact (PAZI) and zona-free (PAZF) embryos were cultured individually for 6 days either in time-lapse incubator (Embryoscope D, Unisense A/S, Aarhus, Denmark) for 15-min observations (Exp. 1; 60 oocytes, 2 replicates) or in standard a incubator for blastocyst quality studies on Day 6 (Exp. 2; 524 oocytes, 11 replicates) or for cryo-tolerance studies with vitrification using Cryotop on Day 4, followed by warming and 2 days further culture (Exp. 3; 449 oocytes, 4 replicates). The timing of morulae was recorded when they completed compaction. Good blastocysts were defined when they expanded to 1.5 times larger than oocytes and formed regular blastocoel cavity with uniform colour and distribution of cells. Timing data were analysed by Student's t-test, while development rates and survival rates were analysed by chi-squared test. Exp. 1: after activation, 42 blastocysts formed on Day 6, during which the timing of development was monitored (Table 1). PAZF embryos developed faster than PAZI, especially during the first 3 cell cycles. Exp. 2: after activation, 212 and 197 blastocysts formed on Day 6 with or without ZP, respectively. Both rates of total blastocysts and good blastocysts of PAZI embryos were significantly higher than those of PAZF embryos (80.1 ± 2.7% vs 69.9 ± 1.1%, 61.9 ± 3.3% vs 49.5 ± 2.5%, respectively), but no difference was found in all blastocyst's cell numbers between PAZI and PAZF (48.2 ± 2.3 and 47.9 ± 3.2, respectively). Exp. 3: after activation, 107 PAZI and 44 PAZF embryos were vitrified on Day 4. More PAZI than PAZF embryos survived (60.8 ± 8.3% vs 30.4 ± 11.9%; P < 0.05). In conclusion, removal of ZP can increase the speed of development of porcine PA embryos, especially at the timing of embryonic genome activation (5-cell stage). Furthermore, the zona pellucida can benefit the blastocyst formation and cryo-tolerance for PA embryos, perhaps by creating a more stable microenvironement. Table 1.Timing of developmental stages of porcine PA embryos with (PAZI) or without (PAZF) zona pellucida*

Antihyperglycemic effect of ginsenoside Rh2 by inducing islet β-cell regeneration in mice

The present study was designed to determine the antihyperglycemic function of ginsenoside Rh2 (GS-Rh2) by the regeneration of β-cells in mice that underwent 70% partial pancreatectomy (PPx), and to explore the mechanisms of GS-Rh2-induced β-cell proliferation. Adult C57BL/6J mice were subjected to PPx or a sham operation. Within 14 days post-PPx, mice that underwent PPx received GS-Rh2 (1 mg/kg body weight) or saline injection. GS-Rh2-treated mice exhibited an improved glycemia and glucose tolerance, an increased serum insulin levels, and β-cell hyperplasia. Meanwhile, increased β-cell proliferation percentages and decreased β-cell apoptosis percentages were also observed in GS-Rh2-treated mice. Further studies on the Akt/Foxo1/PDX-1 signaling pathway revealed that GS-Rh2 probably induced β-cell proliferation via activation of Akt and PDX-1 and inactivation of Foxo1. Studies on the abundance and activity of cell cycle proteins suggested that GS-Rh2-induced β-cell proliferation may ultimately be achieved through the regulation of cell cycle proteins. These findings demonstrate that GS-Rh2 administration could inhibit the tendency of apoptosis, and reverse the impaired β-cell growth potential by modulating Akt/Foxo1/PDX-1 signaling pathway and regulating cell cycle proteins. Induction of islet β-cell proliferation by GS-Rh2 suggests its therapeutic potential in the treatment of diabetes.

22 MALFORMATIONS FOUND BY AUTOPSY OF CLONED AND TRANSGENIC PIGLETS OF DIFFERENT BREEDS

Viability of cloned and transgenic piglets is seriously compromised and one obvious reason could be malformations. The aim of the present study was therefore to describe gross pathological conditions in dead pre-weaned piglets born after transfer to Large White (LW) recipients of cloned (LW donor cells) or transgenic (Yucatan or Göttingen donor cells) embryos. Donor cells were fibroblasts and the Göttingen and Yucatan cells were made transgenic with 1 of 5 genes known to dispose for different human diseases. Handmade cloning was used to produce embryos that after 5 to 6 days of in vitro culture were transferred surgically to 108 LW sows 4 days after their natural heat. Of these, 21 sows delivered cloned LW piglets, whereas 17 and 16 sows, respectively, delivered transgenic Göttingen and Yucatan piglets. Stillborn and dead pre-weaned piglets were necropsied and malformations registered. Data were analysed by Fisher's exact test with a significance level of P < 0.05. In the 54 litters, total litter size ranged from 1 to 22 piglets (mean 5.4 ± 0.5) and the overall mortality rate until weaning on day 28 was 59%. Malformations were found in piglets from 38 litters where an average of 35% of the piglets showed malformations (between 8 and 100%). In those litters, 1 to 7 piglets had 1, 2, or several malformations (Table 1). The malformation rate in the autopsied transgenic Göttingen was 58% and in Yucatan 46%; these were significantly higher than in the autopsied cloned LW piglets with 18%. Some of the malformations seemed to be related to breed and/or transgene; for instance, heart malformations were most frequent in Yucatan litters (70%) independent of the transgene, whereas gallbladder and gonad malformations were more frequent in various litters with the same transgene. These results show that the use of cloning in pigs results in a considerable loss of piglets due to malformations and transgenic transformation of the cells used for cloning superimpose on this problem. In combination, these elements could seriously compromise the use of pigs as a model for human diseases and the choice of breeds and also transgenes for this kind of work should be considered carefully. However, further improvements in production of cloned/transgenic embryos may ultimately reduce the incidence of malformations. Table 1.Number of malformations in 54 litters of cloned or transgenic piglets

Weight-loss-associated changes in bone mineral density and bone turnover after partial weight regain with or without aerobic exercise in obese women

Background/Objectives

Moderate, long-term weight loss results in loss of bone mass in overweight or obese premenopausal women. However, whether these changes persist during weight maintenance or regain remains to be determined.

Subjects/Methods

Overweight or obese (BMI: 25.8–42.5 kg/m²) women (n=40) with at least two risk factors for the metabolic syndrome participated in this 12-mo study that examined the effects of prescribed weight loss and regain, with or without exercise, on bone turnover and on bone mineral density (BMD) in a subset of participants (n=24). During the first 6 mo, participants lost ~10% of their initial body weight via energy restriction and supervised aerobic exercise. Following weight loss, participants were randomly assigned to either an exercise or a no-exercise treatment for the regain (+50% of weight lost) phase. A one-way (time) repeated measures ANOVA tested the effects of weight loss on BMD and bone turnover, and a two-way RM ANOVA (time, exercise) was used to examine the effects of exercise during weight regain.

Results

Hip (p=0.007) and lumbar spine (p=0.05) BMD decreased with weight loss, and remained reduced after weight regain with or without exercise. Likewise, the weight-loss-associated increases in osteocalcin (p<0.001) and C-terminal peptide of type I collagen (p<0.001) persisted following weight regain, independent of exercise.

Conclusions

the results of the present study, which is the first to examine changes in bone mass and turnover during carefully controlled weight regain, suggest that weight-loss-induced perturbations in bone mass and turnover persist after partial weight regain, regardless of whether regular, weight-bearing aerobic exercise was continued.

A randomized trial of high-dose vitamin D2 in relapsing-remitting multiple sclerosis

OBJECTIVE

Higher latitude, lower ultraviolet exposure, and lower serum 25-hydroxyvitamin D (25OHD) correlate with higher multiple sclerosis (MS) prevalence, relapse rate, and mortality. We therefore evaluated the effects of high-dose vitamin D2 (D2) in MS.

METHODS

Adults with clinically active relapsing-remitting MS (RRMS) were randomized to 6 months' double-blind placebo-controlled high-dose vitamin D2, 6,000 IU capsules, dose adjusted empirically aiming for a serum 25OHD 130-175 nM. All received daily low-dose (1,000 IU) D2 to prevent deficiency. Brain MRIs were performed at baseline, 4, 5, and 6 months. Primary endpoints were the cumulative number of new gadolinium-enhancing lesions and change in the total volume of T2 lesions. Secondary endpoints were Expanded Disability Status Scale (EDSS) score and relapses.

RESULTS

Twenty-three people were randomized, of whom 19 were on established interferon or glatiramer acetate (Copaxone) treatment. Median 25OHD rose from 54 to 69 nM (low-dose D2) vs 59 to 120 nM (high-dose D2) (p = 0.002). No significant treatment differences were detected in the primary MRI endpoints. Exit EDSS, after adjustment for entry EDSS, was higher following high-dose D2 than following low-dose D2 (p = 0.05). There were 4 relapses with high-dose D2 vs none with low-dose D2 (p = 0.04).

CONCLUSION

We did not find a therapeutic advantage in RRMS for high-dose D2 over low-dose D2 supplementation.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that high-dose vitamin D2 (targeting 25OHD 130-175 nM), compared to low-dose supplementation (1,000 IU/d), was not effective in reducing MRI lesions in patients with RRMS.

A validation study of multicenter diffusion tensor imaging: reliability of fractional anisotropy and diffusivity values

BACKGROUND AND PURPOSE

DTI is increasingly being used as a measure to study tissue damage in several neurologic diseases. Our aim was to investigate the comparability of DTI measures between different MR imaging magnets and platforms.

MATERIALS AND METHODS

Two healthy volunteers underwent DTI on five 3T MR imaging scanners (3 Trios and 2 Signas) by using a matched 33 noncollinear diffusion-direction pulse sequence. Within each subject, a total of 16 white matter (corpus callosum, periventricular, and deep white matter) and gray matter (cortical and deep gray) ROIs were drawn on a single image set and then were coregistered to the other images. Mean FA, ADC, and longitudinal and transverse diffusivities were calculated within each ROI. Concordance correlations were derived by comparing ROI DTI values among each of the 5 magnets.

RESULTS

Mean concordance for FA was 0.96; for both longitudinal and transverse diffusivities, it was 0.93; and for ADC, it was 0.88. Mean scan-rescan concordance was 0.96-0.97 for all DTI measures. Concordance correlations within platforms were, in general, better than those between platforms for all DTI measures (mean concordance of 0.96).

CONCLUSIONS

We found that a 3T magnet and high-angular-resolution pulse sequence yielded comparable DTI measurements across different MR imaging magnets and platforms. Our results indicate that FA is the most comparable measure across magnets, followed by individual diffusivities. The comparability of DTI measures between different magnets supports the feasibility of multicentered clinical trials by using DTI as an outcome measure.

Serial evaluation of high-resolution CT findings in patients with pneumonia in novel swine-origin influenza A (H1N1) virus infection

OBJECTIVES

The purpose of our study was to review the changes in the serial high-resolution CT (HRCT) findings from patients with novel swine-origin influenza A (H1N1) virus (S-OIV) infection.

METHODS

HRCT findings of 70 patients with presumed or laboratory-confirmed novel S-OIV infection were reviewed. The pattern (consolidation, ground glass, fibrosis and air trapping), distribution and extent of abnormality of the lesions on the HRCT were evaluated at different time points. To assess changes that occurred over time, the CT scans in 56 patients were examined in sequence.

RESULTS

The most common CT findings in patients with S-OIV infection are ground-glass opacities with or without consolidation at the first week. The abnormalities peaked at the second week and resolved after that time, which resulted in substantial reduced residual disease at 4 weeks or later. The development of fibrosis was noted in the first week and peaked at the third week of illness (34.7%), then decreased slowly after that time. The mean time of air trapping being noted after the onset of symptoms was 55.5 ± 20.6 days. Comparing the findings of initial CT, most results (96.4%) of follow-up chest CT findings showed improvement (p<0.01).

CONCLUSION

The abnormalities of ground-glass opacities and/or consolidation on initial CT scans tended to resolve to fibrosis, which then resolved completely or displayed substantially reduced residual disease. HRCT may show more changes in disease progression and play an important role in the evaluation of severe S-OIV.

The increased expression of metabotropic glutamate receptor 5 in subventricular zone neural progenitor cells and enhanced neurogenesis in a rat model of intracerebral hemorrhage

The metabotropic glutamate receptor 5 (mGluR5) is closely relative to the proliferation, survival, and differentiation of neural progenitor cells (NPCs). This study primarily examined the mGluR5 expression of NPCs in subventricular zone (SVZ) and the effects of mGluR5 on neurogenesis to intracerebral hemorrhage (ICH) rat. The experiment was designated as the following: (1) The ICH model was established by collagenase infusion into the right striatum of the rats, and the brain tissue was collected to assess the expression of mGluR5 in SVZ NPCs. (2) The rat brains were sampled for immunostaining of doublecortin (DCX) and 5-bromo-2'-deoxyuridine (BrdU) to examine the effects of the (R,S)-2-chloro-5-hydroxyphenylglycine (CHPG) on neurogenesis. (3) Behavioral testing was carried out to evaluate the effects of CHPG on neurofunctional recovery. The results of Western blot analysis showed that mGluR5 levels in the ipsilateral SVZ increased as early as at 3 days after ICH, peaked at 14 days. The change of mGluR5 mRNA level in the ipsilateral SVZ was generally similar to the pattern of Western blot analysis. The immunostaining also demonstrated that some nestin-positive cells were co-expressed with mGluR5. The injection of CHPG into ipsilateral ventricle increased DCX levels both in the ipsilateral striatum (STR) and the peri-lesion area of the striatum (PLA). Meanwhile, a significant difference in behavioral score was presented at 28 days after ICH between the CHPG-treated rats and the vehicle-treated or the non-treated rats. Our results demonstrated for the first time that the increased expression of mGluR5 in SVZ NPCs occurred in ICH rat. The CHPG promoted the neurogenesis and improved neurofunctional symptom induced by ICH. These results suggested that the increased expression of mGluR5 on NPCs in SVZ may play an important role in neurogenesis in ICH rat.

Basic fibroblast growth factor inhibits osteogenic differentiation of stem cells from human exfoliated deciduous teeth through ERK signaling

OBJECTIVE

Stem cells from human exfoliated deciduous teeth (SHED) are a unique postnatal stem cell population capable of regenerating mineralized tissue and treating immune disorders. However, the mechanism that controls SHED differentiation is not fully understood. Here, we showed that basic fibroblast growth factor (bFGF) treatment attenuated SHED-mediated mineralized tissue regeneration through activation of the extracellular signal-regulated kinase (ERK) 1/2 pathway.

MATERIAL AND METHOD

The level of mineralized nodule formation was assessed by alizarin red staining. Expression levels of osteogenic genes, osteocalcin and runt-related transcription factor 2, were examined by RT-PCR. Subcutaneous implantation approach was used to assess in vivo bone formation. Downstream signaling pathways of bFGF were examined by Western blotting.

RESULT

Activation of ERK1/2 signaling by bFGF treatment inhibited WNT/β-catenin pathway, leading to osteogenic deficiency of SHED. ERK1/2 inhibitor treatment rescued bFGF-induced osteogenic differentiation deficiency.

CONCLUSION

These data suggest that bFGF inhibits osteogenic differentiation of SHED via ERK1/2 pathway. Blockade ERK1/2 signaling by small molecular inhibitor treatment improves bone formation of SHED after bFGF treatment.

Wγ production and limits on anomalous WWγ couplings in pp collisions at sqrt[s] = 1.96 TeV

We measure the cross section and the difference in rapidities between photons and charged leptons for inclusive W(→lν) + γ production in eγ and μγ final states. Using data corresponding to an integrated luminosity of 4.2  fb(-1) collected with the D0 detector at the Fermilab Tevatron Collider, the measured cross section times branching fraction for the process pp → Wγ + X → lνγ + X and the distribution of the charge-signed photon-lepton rapidity difference are found to be in agreement with the standard model. These results provide the most stringent limits on anomalous WWγ couplings for data from hadron colliders: -0.4<Δκ(γ)<0.4 and -0.08<λ(γ)<0.07 at the 95% C.L.

An overview of odorant-binding protein functions in insect peripheral olfactory reception

Insect olfactory perception involves many aspects of insect life, and can directly or indirectly evoke either individual or group behaviors. Insect olfactory receptors and odorant-binding proteins (OBPs) are considered to be crucial to insect-specific and -sensitive olfaction. Although the mechanisms of interaction between OBPs or OBP/ligand complex with olfactory receptors are still not well understood, it has been shown that many OBPs contribute to insect olfactory perception at various levels. Some of these are numerous and divergent members in OBP family; expression in the olfactory organ at high concentration; a variety of combinational patterns between different OBPs and ligands, but exclusive affinity for one OBP to specific binding ligands; complicated interactions between OBP/ligand complex and transmembrane proteins (olfactory receptors or sensory neuron membrane proteins). First, we review OBPs' ligand-binding property based on OBP structural research and ligand-binding test; then, we review current progress around the points cited above to show the role of such proteins in insect olfactory signal transmission; finally, we discuss applications based on insect OBP research.