Female naïve human pluripotent stem cells carry X chromosomes with Xa-like and Xi-like folding conformations

Three-dimensional (3D) genomics shows immense promise for studying X chromosome inactivation (XCI) by interrogating changes to the X chromosomes' 3D states. Here, we sought to characterize the 3D state of the X chromosome in naïve and primed human pluripotent stem cells (hPSCs). Using chromatin tracing, we analyzed X chromosome folding conformations in these cells with megabase genomic resolution. X chromosomes in female naïve hPSCs exhibit folding conformations similar to the active X chromosome (Xa) and the inactive X chromosome (Xi) in somatic cells. However, naïve X chromosomes do not exhibit the chromatin compaction typically associated with these somatic X chromosome states. In H7 naïve human embryonic stem cells, XIST accumulation observed on damaged X chromosomes demonstrates the potential for naïve hPSCs to activate XCI-related mechanisms. Overall, our findings provide insight into the X chromosome status of naïve hPSCs with a single-chromosome resolution and are critical in understanding the unique epigenetic regulation in early embryonic cells.

Improving the bioavailability of manganese and meat quality of broilers by using hot-melt extrusion nano method

1. Mineral excretion is an issue in the poultry industry. The use of micro minerals in nano form can increase bioavailability and decrease excretion rate. However, information concerning the bioavailability of nano manganese (Mn) in broiler chicks is limited.2. This experiment studied the influences of hot-melt extrusion (HME)-processed manganese sulphate on body weight gain, Mn bioavailability, nutrient digestibility and meat quality in broiler chicks fed a corn-soybean meal-based diet as a starter and grower phase. A total of 700 birds (Ross 308, 1-day-old) were randomly placed in 35 cages (20 birds per cage). The broiler chicks were fed one of seven experimental diets, which consisted of a control (without supplemental Mn), different levels of MnSO₄ (IN-Mn60; 60, 120, and 200 mg/kg), or HME MnSO₄ (HME-Mn; 60, 120, and 200 mg/kg).3. There was an increased serum Mn content in broilers fed diet supplemented with HME-Mn. In the grower phase, increased dietary Mn levels elevated the concentrations in the serum, liver, and tibia. There were increases in the excreta Mn content of broilers fed increasing levels. The supplementation of HME-Mn showed a lower percentage of abdominal fat compared with the IN-Mn treatment diets. Supplementation with HME-Mn decreased intramuscular fat compared with the diets supplemented with IN-Mn. The supplementation of HME-Mn decreased the thiobarbituric acid reactive substances (TBARS) at d 6 of age. The HME-Mn source showed a greater decrease in TBARS compared with the IN-Mn treatment.4. In conclusion, HME processing increased bioavailability and could be used as an environmentally friendly method to facilitate lower levels of Mn in the diet of broiler chickens.

A deep neural network for estimating the bladder boundary using electrical impedance tomography

OBJECTIVE

Accurate bladder size estimation is an important clinical parameter that assists physicians, enabling them to provide better treatment for patients who are suffering from urinary incontinence. Electrical impedance tomography (EIT) is a non-invasive medical imaging method that estimates organ boundaries assuming that the electrical conductivity values of the background, bladder, and adjacent tissues inside the pelvic domain are known a priori. However, the performance of a traditional EIT inverse algorithm such as the modified Newton-Raphson (mNR) for shape estimation exhibits severe convergence problems as it heavily depends on the initial guess and often fails to estimate complex boundaries that require greater numbers of Fourier coefficients to approximate the boundary shape. Therefore, in this study a deep neural network (DNN) is introduced to estimate the urinary bladder boundary inside the pelvic domain.

APPROACH

We designed a five-layer DNN which was trained with a dataset of 15 subjects that had different pelvic boundaries, bladder shapes, and conductivity. The boundary voltage measurements of the pelvic domain are defined as input and the corresponding Fourier coefficients that describe the bladder boundary as output data. To evaluate the DNN, we tested with three different sizes of urinary bladder.

MAIN RESULTS

Numerical simulations and phantom experiments were performed to validate the performance of the proposed DNN model. The proposed DNN algorithm is compared with the radial basis function (RBF) and mNR method for bladder shape estimation. The results show that the DNN has a low root mean square error for estimated boundary coefficients and better estimation of bladder size when compared to the mNR and RBF.

SIGNIFICANCE

We apply the first DNN algorithm to estimate the complex boundaries such as the urinary bladder using EIT. Our work provides a novel efficient EIT inverse solver to estimate the bladder boundary and size accurately. The proposed DNN algorithm has advantages in that it is simple to implement, and has better accuracy and fast estimation.

Dysregulation of BRD4 Function Underlies the Functional Abnormalities of MeCP2 Mutant Neurons

Rett syndrome (RTT), mainly caused by mutations in methyl-CpG binding protein 2 (MeCP2), is one of the most prevalent intellectual disorders without effective therapies. Here, we used 2D and 3D human brain cultures to investigate MeCP2 function. We found that MeCP2 mutations cause severe abnormalities in human interneurons (INs). Surprisingly, treatment with a BET inhibitor, JQ1, rescued the molecular and functional phenotypes of MeCP2 mutant INs. We uncovered that abnormal increases in chromatin binding of BRD4 and enhancer-promoter interactions underlie the abnormal transcription in MeCP2 mutant INs, which were recovered to normal levels by JQ1. We revealed cell-type-specific transcriptome impairment in MeCP2 mutant region-specific human brain organoids that were rescued by JQ1. Finally, JQ1 ameliorated RTT-like phenotypes in mice. These data demonstrate that BRD4 dysregulation is a critical driver for RTT etiology and suggest that targeting BRD4 could be a potential therapeutic opportunity for RTT.

Engineering of human brain organoids with a functional vascular-like system

Human cortical organoids (hCOs), derived from human embryonic stem cells (hESCs), provide a platform to study human brain development and diseases in complex three-dimensional tissue. However, current hCOs lack microvasculature, resulting in limited oxygen and nutrient delivery to the inner-most parts of hCOs. We engineered hESCs to ectopically express human ETS variant 2 (ETV2). ETV2-expressing cells in hCOs contributed to forming a complex vascular-like network in hCOs. Importantly, the presence of vasculature-like structures resulted in enhanced functional maturation of organoids. We found that vascularized hCOs (vhCOs) acquired several blood-brain barrier characteristics, including an increase in the expression of tight junctions, nutrient transporters and trans-endothelial electrical resistance. Finally, ETV2-induced endothelium supported the formation of perfused blood vessels in vivo. These vhCOs form vasculature-like structures that resemble the vasculature in early prenatal brain, and they present a robust model to study brain disease in vitro.

The RNA exosome nuclease complex regulates human embryonic stem cell differentiation

This work shows that the exosome modulates the levels of LINE-1 retrotransposons and specific miRNAs, lncRNAs, and mRNAs that encode developmental regulators or affect their expression. The exosome restrains stem cell differentiation in part by degrading transcripts encoding FOXH1, a transcription factor crucial for mesendoderm formation.

A defining feature of embryonic stem cells (ESCs) is the ability to differentiate into all three germ layers. Pluripotency is maintained in part by a unique transcription network that maintains expression of pluripotency-specific transcription factors and represses developmental genes. While the mechanisms that establish this transcription network are well studied, little is known of the posttranscriptional surveillance pathways that degrade differentiation-related RNAs. We report that the surveillance pathway mediated by the RNA exosome nuclease complex represses ESC differentiation. Depletion of the exosome expedites differentiation of human ESCs into all three germ layers. LINE-1 retrotransposons and specific miRNAs, lncRNAs, and mRNAs that encode developmental regulators or affect their expression are all bound by the exosome and increase in level upon exosome depletion. The exosome restrains differentiation in part by degrading transcripts encoding FOXH1, a transcription factor crucial for mesendoderm formation. Our studies establish the exosome as a regulator of human ESC differentiation and reveal the importance of RNA decay in maintaining pluripotency.

Are patients with mild to moderate renal impairment on metformin or other oral anti-hyperglycaemic agents at increased risk of contrast-induced nephropathy and metabolic acidosis after radiocontrast exposure?

AIM

To investigate whether the use of metformin during computed tomography (CT) with radiocontrast agents increases the risk of contrast-induced nephropathy (CIN) and metabolic acidosis after CT in type 2 diabetes patients with mild to moderate renal failure.

MATERIALS AND METHODS

Patient records from January 2015 to December 2017 were reviewed retrospectively. A total of 374 patients were included in the final analysis. Of them, 157 patients received metformin, and 217 patients were taking other oral hypoglycaemic agents (OHAs) during radiocontrast administration.

RESULTS

No significant difference in CIN incidence was observed between the metformin use group and the other OHAs group (p=0.085). Metabolic acidosis after CT was seen in 91 (58%) patients who used metformin and 141 (65%) patients who were taking other OHAs. There was no relationship between metabolic acidosis after CT and the use of metformin (p=0.195). Metabolic acidosis after radiocontrast agent exposure was associated with malignant disease, low serum albumin level, and low serum total CO₂ level at baseline.

CONCLUSION

These data show that other factors, but not metformin use, are associated with metabolic acidosis after radiocontrast agent exposure in patients with reduced renal function. These data support current recommendations that there is no need to discontinue metformin before CT using radiocontrast agents in patients with mild to moderate renal failure.

hESC-Derived Thalamic Organoids Form Reciprocal Projections When Fused with Cortical Organoids

Human brain organoid techniques have rapidly advanced to facilitate investigating human brain development and diseases. These efforts have largely focused on generating telencephalon due to its direct relevance in a variety of forebrain disorders. Despite its importance as a relay hub between cortex and peripheral tissues, the investigation of three-dimensional (3D) organoid models for the human thalamus has not been explored. Here, we describe a method to differentiate human embryonic stem cells (hESCs) to thalamic organoids (hThOs) that specifically recapitulate the development of thalamus. Single-cell RNA sequencing revealed a formation of distinct thalamic lineages, which diverge from telencephalic fate. Importantly, we developed a 3D system to create the reciprocal projections between thalamus and cortex by fusing the two distinct region-specific organoids representing the developing thalamus or cortex. Our study provides a platform for understanding human thalamic development and modeling circuit organizations and related disorders in the brain.

Abstract P4-01-11: Genomic alterations of cell-free DNA in early breast cancer patients with recurrence

Cell-free DNA (cfDNA), as a non-invasive strategy, provides substantial benefit to overcome tumor heterogeneity. Surveillance of recurrence after standard treatment in early breast cancer (BC) using cfDNA, enables to detect minimal residual disease (MRD), also to identify genomic alterations driving recurrences. We aimed to assess the role of cfDNA in detecting MRD by investigating genomic alterations of 1)primary, recurred tumor and 2)cfDNA at time of recurrence using deep targeted sequencing. Fifty-four early BC patients were enrolled prospectively between 2014 and 2017 at time of recurrence. Median disease free interval was 28.5 months (rage 6.2-49.8). 62.7% (32/51) were hormone receptor (HR) positive (28 HRpos/HER2neg, 4 HRpos/HER2pos), 11.8% (6/51) were HRneg/HER2pos and 25.5% (13/51) were triple negative BCs. 59.3% (32/54) patients developed loco-regional recurrence (15 local recurrence only, 13 regional only, 4 with both) and distant metastasis was observed among 40.7% (22/54) patients. Cell-free DNA was extracted from 5cc blood at time of recurrence. Deep targeted sequencing was performed using customized NGS panel –encompassing 426 cancer-related target coding region, 242 fusion and amplification-related region- of cfDNA and FFPE(formalin fixed paraffin embedded) tumor samples archived from surgical resection or biopsy. Deep targeted sequencing data was successfully performed in 72.1% (31/43) plasma samples and sequencing yield was significantly lower when stored for more than 2yrs (46.2% vs 83.3%).

Mutations of cfDNA and tumor (primary, recurred) were analyzed. Mean sequencing depth of cfDNA and FFPE were x425.7 and x777.6 respectively. Median number of pathogenic mutations found in primary tumor, cfDNA and recurred tumor were 27(range 12-99), 25(range 8-85) and 9(range 0-23). Among mutations found in primary tumor, 27.4% were shared mutations (range 8.1%-72.7%) with recurred tumor and 26.1% were shared mutations (range 4.7%-69.2%) observed in cfDNA sample. Among mutations found in recurred tumor, 40.9% were observed in cfDNA (range 17.7-87.5%). In primary tumor, median number of mutations with allelic fraction (MAF)>10% were 12 (range 4-21) and at least one mutation was found in cfDNA at time of recurrence. Among mutations with MAF>10%, 59.4% and 69.1% were found in cfDNA and recurred tumor. Known oncogenic mutations of PIK3CA, TP53, GATA3, AKT1, ESR1, RELN, ERBB2, ERBB3, BRCA1 mutation were found. PIK3CA gene (p.H1047R) was found in two cases both in primary tumor and cfDNA at recurrence (MAF 11.4% vs 5.3% and 12.3% vs 15.4%) suggesting de novo driver mutation. One patient developed regional recurrence during adjuvant aromatase inhibitor with ESR1 V392I mutation in both cfDNA and recurred tumor (MAF 48.1 and 54.5%), while another patient's recurred tumor during aromatase inhibitor harbored ESR1 D538G mutation exclusively in recurred tumor with MAF <1%. Both patients had no ESR1 hotpot mutation in primary tumor.

Our data showed sequencing yield of 83.3% in plasma samples within 2yr. Pathogenic mutations in primary tumor, especially when MAF>10%, half of them was observed in cfDNA at time of recurrence. ESR1 mutation should be included in cfDNA surveillance for patients undergoing endocrine therapy even absent in primary tumor.

Citation Format: Kim J, Jo WK, Kim KY, Kim BJ, Lee SB, Lee HJ, Yu JH, Kim HJ, Chung IY, Ko BS, Kim S-B, Jung KH, Ahn JH, Chang S, Lee JW, Son BH, Ahn SH. Genomic alterations of cell-free DNA in early breast cancer patients with recurrence [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-01-11.

Generation and Fusion of Human Cortical and Medial Ganglionic Eminence Brain Organoids

Three-dimensional (3D) brain organoid culture has become an essential tool for investigating human brain development and modeling neurological disorders during the past few years. Given the specific regionalization during brain development, it is important to produce distinct brain organoids that reproduce different brain regions and their interaction. The authors' laboratory recently established the platform to generate brain organoids resembling the medial ganglionic eminence (MGE), a specific brain region responsible for interneurogenesis, and found when fusing with organoid resembling the cortex, the fused organoids enabled modeling of interneuron migration in the brain. This unit describes four basic protocols that have been successfully applied in the authors' laboratory, covering the generation of embryonic body (EB) with neuroectodermal fate, the production of MGE organoids (hMGEOs) and cortical organoids (hCOs), and the fusion of the two organoids.

Effect of filling pressure in jetting dispenser on the performance of blood glucose test strips using immersion gold-plated printed circuit board

To ensure accurate glucose readings when dispensing glucose oxidase enzyme solution from a jetting dispenser onto glucose test strips fabricated from an immersion gold-plated printed circuit board, every drop of the enzyme solution needs to have nearly the same weight and to be dispensed on the reaction zone of the test strips. Experimental results in this study show that the filling pressure in the fluid reservoir containing the glucose enzyme solution to dispense onto the test strips significantly affect the glucose test results. A filling pressure of 12 psi produces test strips with lower coefficient of variation and standard deviation than 10 and 14 psi. Proper filling pressure for dispensing glucose enzyme onto glucose test strips needs to be determined for any enzyme compound formulation.

Ischemic Preconditioning Produces Comparable Protection Against Hepatic Ischemia/Reperfusion Injury Under Isoflurane and Sevoflurane Anesthesia in Rats

BACKGROUND

Various volatile anesthetics and ischemic preconditioning (IP) have been demonstrated to exert protective effect against ischemia/reperfusion (I/R) injury in liver. We aimed to determine whether application of IP under isoflurane and sevoflurane anesthesia would confer protection against hepatic I/R injury in rats.

METHODS

Thirty-eight rats weighing 270 to 300 grams were randomly divided into 2 groups: isoflurane (1.5%) and sevoflurane (2.5%) anesthesia groups. Each group was subdivided into sham (n = 3), non-IP (n = 8; 45 minutes of hepatic ischemia), and IP (n = 8, IP consisting of 10-minute ischemia plus 15-minute reperfusion before prolonged ischemia) groups. The degree of hepatic injury and expressions of B-cell lymphoma 2 (Bcl-2) and caspase 3 were compared at 2 hours after reperfusion.

RESULTS

Hepatic ischemia induced significant degree of I/R injuries in both isoflurane and sevoflurane non-IP groups. In both anesthetic groups, introduction of IP dramatically attenuated I/R injuries as marked by significantly lower aspartate aminotransferase and aminotransferase levels and better histologic grades compared with corresponding non-IP groups. There were 2.3- and 1.7-fold increases in Bcl-2 mRNA levels in isoflurane and sevoflurane IP groups, respectively, compared with corresponding non-IP groups (both P < .05). Caspase 3 level was significantly high in the isoflurane non-IP group compared with the sham group; however, there were no differences among the sevoflurane groups.

CONCLUSIONS

The degree of hepatic I/R injury was significantly high in both isoflurane and sevoflurane groups in rats. However, application of IP significantly protected against I/R injury in both volatile anesthetic groups to similar degrees, and upregulation of Bcl-2 might be an important mechanism.

MeV electron acceleration at 1 kHz with <10 mJ laser pulses: erratum

In this erratum the funding section of Opt. Lett.42, 215 (2017)OPLEDP0146-959210.1364/OL.42.000215 has been updated.

Effect of Changes in Body Mass Index on Cardiovascular Outcomes in Kidney Transplant Recipients

BACKGROUND

A higher body mass index (BMI) before kidney transplantation (KT) is associated with increased mortality and allograft loss in kidney transplant recipients (KTRs). However, the effect of changes in BMI after KT on these outcomes remains uncertain. The aim of this study was to investigate the effect of baseline BMI and changes in BMI on clinical outcomes in KTRs.

METHODS

A total of 869 KTRs were enrolled from a multicenter observational cohort study from 2012 to 2015. Patients were divided into low and high BMI groups before KT based on a BMI cutoff point of 23 kg/m². Differences in acute rejection and cardiovascular disease (CVD) between the 2 groups were analyzed. In addition, clinical outcomes across the 4 BMI groups divided by BMI change 1 year after KT were compared. Associations between BMI change and laboratory findings were also evaluated.

RESULTS

Patients with a higher BMI before KT showed significantly increased CVD after KT (P = .027) compared with patients with a lower BMI. However, among the KTRs with a higher baseline BMI, only persistently higher BMI was associated with increased CVD during the follow-up period (P = .003). Patients with persistently higher BMI had significantly decreased high-density lipoprotein cholesterol and increased hemoglobin, triglyceride, and hemoglobin A1c levels. Baseline BMI and post-transplantation change in BMI were not related to acute rejection in KTRs.

CONCLUSIONS

BMI in the 1st year after KT as well as baseline BMI were associated with CVD in KTRs. More careful monitoring of obese KTRs who do not undergo a reduction in BMI after KT is required.

Cystatin C-Based Equation for Predicting the Glomerular Filtration Rate in Kidney Transplant Recipients

BACKGROUND

Precise monitoring of the glomerular filtration rate (GFR) is needed to estimate the allograft function in kidney transplant recipients (KTRs). The GFR is widely estimated with the use of formulas based on serum cystatin C (SCys) and serum creatinine (SCr) levels. We compared the efficacy of SCys-based equations with that of SCr-based equations to predict the allograft function.

METHODS

We calculated the Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI Cr), CKD-EPI creatinine-cystatin C (CKD-EPI Cr/Cys), and CKD-EPI cystatin C (CKD-EP ICys) equations in 70 KTRs. The measured GFR (mGFR) was defined as the GFR estimated by technetium-99m-diethylene triamine pentaacetic acid (^99mTc-DTPA) clearance. The accuracy and precision of the equations were compared with the mGFR. The performance characteristics of SCr and SCys were analyzed with the use of receiver operating characteristic (ROC) curves to ascertain the sensitivity and specificity at the cutoff value of <45 mL/min/1.73 m² DTPA.

RESULTS

Overall, MDRD and CKD-EPICys did not show significant differences from mGFR (P = .05 and P = .077, respectively), whereas CKD-EPI Cr and CKD-EPI Cr/Cys significantly underestimated mGFR (P < .001 and P = .005, respectively). In the subgroup of patients with mGFR <45 mL/min/1.73 m², CKD-EPI Cys showed little bias (P = .122), whereas MDRD significantly underestimated mGFR (P = .037). The area under the ROC curve for predicting mGFR <45 mL/min/1.73 m² was 0.80 for SCys, which was better than that for SCr at 0.763.

CONCLUSIONS

Cystatin C-based equations showed better predictive performance of the allograft function than creatinine-based equations for the KTRs, including patients with lower GFR. Cystatin C level might be a good alternate measurement to monitor the allograft function.

Use of metal/metal oxide spherical cluster and hydroxyl metal coordination complex for descriptor calculation in development of nanoparticle cytotoxicity classification model

Computational approaches have been suggested as an informative tool for risk assessment of nanomaterials. Nano (quantitative) structure-activity relationship, nano-(Q)SAR, models have been developed to predict toxicity of metal oxide (MOx) nanoparticles (NPs); however, the packing structure and cluster of nanoparticle have been included for the descriptor calculation in only two studies. This study proposed spherical cluster and hydroxyl metal coordination complex to calculate descriptors for development of nanoparticle cytotoxicity classification model. The model cluster was generated from metal (M) or MOx crystal structure to calculate physicochemical properties of M/MOx NPs and the hydroxyl metal coordination complex was used to calculate the properties of the metal cation in an aqueous environment. Data were collected for 2 M and 19 MOx NPs in human bronchial epithelial cell lines and murine myeloid cell lines at 100 μg/ml after 24 hours exposure. The model was developed with scaled HOMO energy of the model cluster and polarizability of the hydroxyl metal coordination complex, as reactivity of the particles and the cations explained cause of cytotoxic action by M/MOx NPs. As the developed model achieved 90.31% accuracy, the classification model in this work can be used for virtual screening of toxic action of M/MOx NPs.

Bisulfite-independent analysis of CpG island methylation enables genome-scale stratification of single cells

Conventional DNA bisulfite sequencing has been extended to single cell level, but the coverage consistency is insufficient for parallel comparison. Here we report a novel method for genome-wide CpG island (CGI) methylation sequencing for single cells (scCGI-seq), combining methylation-sensitive restriction enzyme digestion and multiple displacement amplification for selective detection of methylated CGIs. We applied this method to analyzing single cells from two types of hematopoietic cells, K562 and GM12878 and small populations of fibroblasts and induced pluripotent stem cells. The method detected 21 798 CGIs (76% of all CGIs) per cell, and the number of CGIs consistently detected from all 16 profiled single cells was 20 864 (72.7%), with 12 961 promoters covered. This coverage represents a substantial improvement over results obtained using single cell reduced representation bisulfite sequencing, with a 66-fold increase in the fraction of consistently profiled CGIs across individual cells. Single cells of the same type were more similar to each other than to other types, but also displayed epigenetic heterogeneity. The method was further validated by comparing the CpG methylation pattern, methylation profile of CGIs/promoters and repeat regions and 41 classes of known regulatory markers to the ENCODE data. Although not every minor methylation differences between cells are detectable, scCGI-seq provides a solid tool for unsupervised stratification of a heterogeneous cell population.

Fusion of Regionally Specified hPSC-Derived Organoids Models Human Brain Development and Interneuron Migration

Organoid techniques provide unique platforms to model brain development and neurological disorders. Whereas several methods for recapitulating corticogenesis have been described, a system modeling human medial ganglionic eminence (MGE) development, a critical ventral brain domain producing cortical interneurons and related lineages, has been lacking until recently. Here, we describe the generation of MGE and cortex-specific organoids from human pluripotent stem cells that recapitulate the development of MGE and cortex domains, respectively. Population and single-cell RNA sequencing (RNA-seq) profiling combined with bulk assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) analyses revealed transcriptional and chromatin accessibility dynamics and lineage relationships during MGE and cortical organoid development. Furthermore, MGE and cortical organoids generated physiologically functional neurons and neuronal networks. Finally, fusing region-specific organoids followed by live imaging enabled analysis of human interneuron migration and integration. Together, our study provides a platform for generating domain-specific brain organoids and modeling human interneuron migration and offers deeper insight into molecular dynamics during human brain development.

Macelignan inhibits bee pathogenic fungi Ascophaera apis growth through HOG1 pathway

Ascosphaera apis is a bee pathogen that causes bee larvae infection disease, to which treatment is not yet well investigated. The aim of this study was to investigate antifungal susceptibility in vitro against A. apis and to identify a new antifungal agent for this pathogen through minimal inhibitory concentration (MIC) assay and western blot analysis. Macelignan had 1.56 and 3.125 μg/mL MIC against A. apis after 24 and 48 h, respectively, exhibiting the strongest growth inhibition against A. apis among the tested compounds (corosolic acid, dehydrocostus lactone, loganic acid, tracheloside, fangchinoline and emodin-8-O-β-D-glucopyranoside). Furthermore, macelignan showed a narrow-ranged spectrum against various fungal strains without any mammalian cell cytotoxicity. In spite of miconazole having powerful broad-ranged anti-fungal activity including A. apis, it demonstrated strong cytotoxicity. Therefore, even if macelignan alone was effective as an antifungal agent to treat A. apis, combined treatment with miconazole was more useful to overcome toxicity, drug resistance occurrence and cost effectiveness. Finally, HOG1 was revealed as a target molecule of macelignan in the anti-A. apis activity by inhibiting phosphorylation using S. cerevisiae as a model system. Based on our results, macelignan, a food-grade antimicrobial compound, would be an effective antifungal agent against A. apis infection in bees.

Population genetic characterization of the Japanese oak silkmoth, Antheraea yamamai (Lepidoptera: Saturniidae), using novel microsatellite markers and mitochondrial DNA gene sequences

The Japanese oak silkmoth, Antheraea yamamai Guérin-Méneville, 1861 (Lepidoptera: Saturniidae), is an important natural resource of industrial value for silk fiber production. Owing to a lack of geographic and population genetic information, systematic domestication of An. yamamai has not been possible yet. In this study, 10 microsatellite markers developed using next-generation sequencing and two mitochondrial DNA (mtDNA) gene sequences (COI and ND4) were used to investigate the genetic variation and geographic structure of An. yamamai populations in South Korea. The two mtDNA gene sequences revealed very low total genetic variation and, consequently, low geographic variation, validating the use of more variable molecular markers. Genotyping of 76 An. yamamai individuals from nine localities in South Korea showed that the observed number of alleles at each locus ranged from 3 to 26, the polymorphism information content was 0.2990-0.9014, the observed and expected heterozygosities were 0.3252-0.9076 and 0.2500-0.9054, respectively, and F_IS was -0.654-0.520. The population-based F_IS, F_ST, R_ST, and global Mantel tests all suggested that the An. yamamai populations were overall well-interconnected, suggesting that any population can be used as a genetic source for domestication. Nevertheless, STRUCTURE analyses using microsatellite data and mtDNA sequences indicated the presence of two genetic pools in many populations, although a plausible explanation for this observation requires further studies.

MeV electron acceleration at 1 kHz with <10 mJ laser pulses

We demonstrate laser-driven acceleration of electrons to MeV-scale energies at 1 kHz repetition rate using <10  mJ pulses focused on near-critical density He and H₂ gas jets. Using the H₂ gas jet, electron acceleration to ∼0.5  MeV in ∼10  fC bunches was observed with laser pulse energy as low as 1.3 mJ. Increasing the pulse energy to 10 mJ, we measure ∼1  pC charge bunches with >1  MeV energy for both He and H₂ gas jets.

Polymorphic microsatellite markers for the endangered fish, the slender shiner Pseudopungtungia tenuicorpa and cross-species amplification across five related species

The slender shiner Pseudopungtungia tenuicorpa (Cypriniformes; Cyprinidae; Gobioninae) is an endangered freshwater fish species endemic to Korea. The current strategies for its conservation involve the study of population genetic characters and identification of management units. These strategies require suitable molecular markers to study genetic diversity and genetic structure. Here, we developed nine polymorphic microsatellite markers for P. tenuicorpa for the first time by applying an enrichment method from a size-selected genomic library. The developed microsatellite markers produced a total of 101 alleles (average 11.2). The observed and expected heterozygosities averaged 0.805 and 0.835, respectively. Among the nine identified markers, five markers showed successful amplification across five related Korean Gobioninae species. Thus, the microsatellite markers developed in this study will be useful to establish conservation strategies for both P. tenuicorpa and other related species.

Regulation of the DNA Methylation Landscape in Human Somatic Cell Reprogramming by the miR-29 Family

Reprogramming to pluripotency after overexpression of OCT4, SOX2, KLF4, and MYC is accompanied by global genomic and epigenomic changes. Histone modification and DNA methylation states in induced pluripotent stem cells (iPSCs) have been shown to be highly similar to embryonic stem cells (ESCs). However, epigenetic differences still exist between iPSCs and ESCs. In particular, aberrant DNA methylation states found in iPSCs are a major concern when using iPSCs in a clinical setting. Thus, it is critical to find factors that regulate DNA methylation states in reprogramming. Here, we found that the miR-29 family is an important epigenetic regulator during human somatic cell reprogramming. Our global DNA methylation and hydroxymethylation analysis shows that DNA demethylation is a major event mediated by miR-29a depletion during early reprogramming, and that iPSCs derived from miR-29a depletion are epigenetically closer to ESCs. Our findings uncover an important miRNA-based approach to generate clinically robust iPSCs.

A dynamic oppositional biogeography-based optimization approach for time-varying electrical impedance tomography

Dynamic electrical impedance tomography-based image reconstruction using conventional algorithms such as the extended Kalman filter often exhibits inferior performance due to the presence of measurement noise, the inherent ill-posed nature of the problem and its critical dependence on the selection of the initial guess as well as the state evolution model. Moreover, many of these conventional algorithms require the calculation of a Jacobian matrix. This paper proposes a dynamic oppositional biogeography-based optimization (OBBO) technique to estimate the shape, size and location of the non-stationary region boundaries, expressed as coefficients of truncated Fourier series, inside an object domain using electrical impedance tomography. The conductivity of the object domain is assumed to be known a priori. Dynamic OBBO is a novel addition to the family of dynamic evolutionary algorithms. Moreover, it is the first such study on the application of dynamic evolutionary algorithms for dynamic electrical impedance tomography-based image reconstruction. The performance of the algorithm is tested through numerical simulations and experimental study and is compared with state-of-the-art gradient-based extended Kalman filter. The dynamic OBBO is shown to be far superior compared to the extended Kalman filter. It is found to be robust to measurement noise as well as the initial guess, and does not rely on a priori knowledge of the state evolution model.

Tgif1 Counterbalances the Activity of Core Pluripotency Factors in Mouse Embryonic Stem Cells

Core pluripotency factors, such as Oct4, Sox2, and Nanog, play important roles in maintaining embryonic stem cell (ESC) identity by autoregulatory feedforward loops. Nevertheless, the mechanism that provides precise control of the levels of the ESC core factors without indefinite amplification has remained elusive. Here, we report the direct repression of core pluripotency factors by Tgif1, a previously known terminal repressor of TGFβ/activin/nodal signaling. Overexpression of Tgif1 reduces the levels of ESC core factors, whereas its depletion leads to the induction of the pluripotency factors. We confirm the existence of physical associations between Tgif1 and Oct4, Nanog, and HDAC1/2 and further show the level of Tgif1 is not significantly altered by treatment with an activator/inhibitor of the TGFβ/activin/nodal signaling. Collectively, our findings establish Tgif1 as an integral member of the core regulatory circuitry of mouse ESCs that counterbalances the levels of the core pluripotency factors in a TGFβ/activin/nodal-independent manner.

Ethanol upregulates NMDA receptor subunit gene expression in human embryonic stem cell-derived cortical neurons

Chronic alcohol consumption may result in sustained gene expression alterations in the brain, leading to alcohol abuse or dependence. Because of ethical concerns of using live human brain cells in research, this hypothesis cannot be tested directly in live human brains. In the present study, we used human embryonic stem cell (hESC)-derived cortical neurons as in vitro cellular models to investigate alcohol-induced expression changes of genes involved in alcohol metabolism (ALDH2), anti-apoptosis (BCL2 and CCND2), neurotransmission (NMDA receptor subunit genes: GRIN1, GRIN2A, GRIN2B, and GRIN2D), calcium channel activity (ITPR2), or transcriptional repression (JARID2). hESCs were differentiated into cortical neurons, which were characterized by immunostaining using antibodies against cortical neuron-specific biomarkers. Ethanol-induced gene expression changes were determined by reverse-transcription quantitative polymerase chain reaction (RT-qPCR). After a 7-day ethanol (50 mM) exposure followed by a 24-hour ethanol withdrawal treatment, five of the above nine genes (including all four NMDA receptor subunit genes) were highly upregulated (GRIN1: 1.93-fold, P = 0.003; GRIN2A: 1.40-fold, P = 0.003; GRIN2B: 1.75-fold, P = 0.002; GRIN2D: 1.86-fold, P = 0.048; BCL2: 1.34-fold, P = 0.031), and the results of GRIN1, GRIN2A, and GRIN2B survived multiple comparison correction. Our findings suggest that alcohol responsive genes, particularly NMDA receptor genes, play an important role in regulating neuronal function and mediating chronic alcohol consumption-induced neuroadaptations.

Transcriptome Signature and Regulation in Human Somatic Cell Reprogramming

Reprogramming of somatic cells produces induced pluripotent stem cells (iPSCs) that are invaluable resources for biomedical research. Here, we extended the previous transcriptome studies by performing RNA-seq on cells defined by a combination of multiple cellular surface markers. We found that transcriptome changes during early reprogramming occur independently from the opening of closed chromatin by OCT4, SOX2, KLF4, and MYC (OSKM). Furthermore, our data identify multiple spliced forms of genes uniquely expressed at each progressive stage of reprogramming. In particular, we found a pluripotency-specific spliced form of CCNE1 that is specific to human and significantly enhances reprogramming. In addition, single nucleotide polymorphism (SNP) expression analysis reveals that monoallelic gene expression is induced in the intermediate stages of reprogramming, while biallelic expression is recovered upon completion of reprogramming. Our transcriptome data provide unique opportunities in understanding human iPSC reprogramming.

•

Initial transcriptional change relies on histone modifications in fibroblast

•

Allele-specific gene expression is manifested during reprogramming

•

A large number of spliced forms of genes are identified during reprogramming

•

Pluripotent-specific splicing of CCNE1 (pCCNE1) enhances reprogramming

Dose-related effect of urinary cotinine levels on pulmonary function among Korean women

SETTING

Country-wide general population in South Korea.

BACKGROUND

The dose-response relationship between smoking and pulmonary function in women may have been significantly over-estimated by studies that employed a self-reporting questionnaire.

OBJECTIVE

To evaluate whether this relationship was still observed among Korean women when smoking levels were determined by urinary cotinine measurements.

DESIGN

A total of 4584 Korean women from the spirometry data set of the Korean National Health and Nutrition Examination Surveys IV and V (2008-2010) were included. Analysis of covariance was performed to estimate the dose-related effect of urinary cotinine levels on pulmonary function after adjusting for covariates in this country-wide cross-sectional study.

RESULTS

Compared to urinary cotinine levels (cut-off 50 ng/ml), the false-positive rate of self-reported smoking was 53.2%. After the smokers were divided into deciles, the regression coefficients for percentage forced expiratory volume in 1 second (FEV₁%) and percentage forced expiratory volume/forced volume capacity (FEV₁/FVC) ratio (FEV1/FVC%) were -0.2903 and -0.2680 (%/decile), respectively (both P < 0.001).

CONCLUSION

It is necessary to use objective methods when determining the smoking status of Korean women. Even after reducing information bias, smoking affected pulmonary function in a dose-dependent manner.

Real time expression of ACC oxidase and PR-protein genes mediated by Methylobacterium spp. in tomato plants challenged with Xanthomonas campestris pv. vesicatoria

Biotic stress like pathogenic infection increases ethylene biosynthesis in plants and ethylene inhibitors are known to alleviate the severity of plant disease incidence. This study aimed to reduce the bacterial spot disease incidence in tomato plants caused by Xanthomonas campestris pv. vesicatoria (XCV) by modulating stress ethylene with 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity of Methylobacterium strains. Under greenhouse condition, Methylobacterium strains inoculated and pathogen challenged tomato plants had low ethylene emission compared to pathogen infected ones. ACC accumulation and ACC oxidase (ACO) activity with ACO related gene expression increased in XCV infected tomato plants over Methylobacterium strains inoculated plants. Among the Methylobacterium spp., CBMB12 resulted lowest ACO related gene expression (1.46 Normalized Fold Expression), whereas CBMB20 had high gene expression (3.42 Normalized Fold Expression) in pathogen challenged tomato. But a significant increase in ACO gene expression (7.09 Normalized Fold Expression) was observed in the bacterial pathogen infected plants. In contrast, Methylobacterium strains enhanced β-1,3-glucanase and phenylalanine ammonia-lyase (PAL) enzyme activities in pathogen challenged tomato plants. The respective increase in β-1,3-glucanase related gene expressions due to CBMB12, CBMB15, and CBMB20 strains were 66.3, 25.5 and 10.4% higher over pathogen infected plants. Similarly, PAL gene expression was high with 0.67 and 0.30 Normalized Fold Expression, in pathogen challenged tomato plants inoculated with CBMB12 and CBMB15 strains. The results suggest that ethylene is a crucial factor in bacterial spot disease incidence and that methylobacteria with ACC deaminase activity can reduce the disease severity with ultimate pathogenesis-related protein increase in tomato.

X Chromosome of female cells shows dynamic changes in status during human somatic cell reprogramming

Induced pluripotent stem cells (iPSCs) acquire embryonic stem cell (ESC)-like epigenetic states, including the X chromosome. Previous studies reported that human iPSCs retain the inactive X chromosome of parental cells, or acquire two active X chromosomes through reprogramming. Most studies investigated the X chromosome states in established human iPSC clones after completion of reprogramming. Thus, it is still not fully understood when and how the X chromosome reactivation occurs during reprogramming. Here, we report a dynamic change in the X chromosome state throughout reprogramming, with an initial robust reactivation of the inactive X chromosome followed by an inactivation upon generation of nascent iPSC clones. iPSCs with two active X chromosomes or an eroded X chromosome arise in passaging iPSCs. These data provide important insights into the plasticity of the X chromosome of human female iPSCs and will be crucial for the future application of such cells in cell therapy and X-linked disease modeling.

•

The X chromosome state changes dynamically during human somatic cell reprogramming

•

Ectopic reprogramming factors transiently activate the inactive X chromosome

•

Nascent iPSC colonies carry an inactive X chromosome

•

Class I and class III iPSCs arise from nascent iPSCs

Localization and expression of CaBP1/caldendrin in the mouse brain

Ca(2+) binding protein 1 (CaBP1) and caldendrin are alternatively spliced variants of a subfamily of CaBPs with high homology to calmodulin. Although CaBP1 and caldendrin regulate effectors including plasma membrane and intracellular Ca(2+) channels in heterologous expression systems, little is known about their functions in vivo. Therefore, we generated mice deficient in CaBP1/caldendrin expression (C-KO) and analyzed the expression and cellular localization of CaBP1 and caldendrin in the mouse brain. Immunoperoxidase labeling with antibodies recognizing both CaBP1 and caldendrin was absent in the brain of C-KO mice, but was intense in multiple brain regions of wild-type mice. By Western blot, the antibodies detected two proteins that were absent in the C-KO mouse and consistent in size with caldendrin variants originating from alternative translation initiation sites. By quantitative PCR, caldendrin transcript levels were far greater than those for CaBP1, particularly in the cerebral cortex and hippocampus. In the frontal cortex but not in the hippocampus, caldendrin expression increased steadily from birth. By double-label immunofluorescence, CaBP1/caldendrin was localized in principal neurons and parvalbumin-positive interneurons. In the cerebellum, CaBP1/caldendrin antibodies labeled interneurons in the molecular layer and in basket cell terminals surrounding the soma and axon initial segment of Purkinje neurons, but immunolabeling was absent in Purkinje neurons. We conclude that CaBP1/caldendrin is localized both pre- and postsynaptically where it may regulate Ca(2+) signaling and excitability in select groups of excitatory and inhibitory neurons.

Transcriptional regulation in pluripotent stem cells by methyl CpG-binding protein 2 (MeCP2)

Rett syndrome (RTT) is one of the most prevalent female mental disorders. De novo mutations in methyl CpG-binding protein 2 (MeCP2) are a major cause of RTT. MeCP2 regulates gene expression as a transcription regulator as well as through long-range chromatin interaction. Because MeCP2 is present on the X chromosome, RTT is manifested in an X-linked dominant manner. Investigation using murine MeCP2 null models and post-mortem human brain tissues has contributed to understanding the molecular and physiological function of MeCP2. In addition, RTT models using human induced pluripotent stem cells derived from RTT patients (RTT-iPSCs) provide novel resources to elucidate the regulatory mechanism of MeCP2. Previously, we obtained clones of female RTT-iPSCs that express either wild-type or mutant MECP2 due to the inactivation of one X chromosome. Reactivation of the X chromosome also allowed us to have RTT-iPSCs that express both wild-type and mutant MECP2. Using these unique pluripotent stem cells, we investigated the regulation of gene expression by MeCP2 in pluripotent stem cells by transcriptome analysis. We found that MeCP2 regulates genes encoding mitochondrial membrane proteins. In addition, loss of function in MeCP2 results in de-repression of genes on the inactive X chromosome. Furthermore, we showed that each mutation in MECP2 affects a partly different set of genes. These studies suggest that fundamental cellular physiology is affected by mutations in MECP2 from early development, and that a therapeutic approach targeting to unique forms of mutant MeCP2 is needed.

[Recovery from parkinsonism with N-acetylcysteine-differentiated neurons]

The upregulation of dopaminergic neuronal differentiation is necessary for stem cell therapy in Parkinson's disease (PD). In this study, neuronal differentiation efficiency increased by more than 2 times in P19 embryonic stem cells (ESCs) induced by N-acetylcysteine (NAC) and retinoic acid (RA) as compared to RA alone, with suppressed glial differentiation. The majority of NAC-treated stem cells grafted into brains of PD mice differentiated into dopaminergic neurons and persisted well for 6 weeks. Parkinsonism was also greatly improved after grafting NAC-treated cells in comparison to cells treated with only RA. Our results strongly suggest that NAC treatment may be an effective strategy for generating stem cells fated to become dopaminergic neurons for PD clinical therapy.

MeCP2 regulates the synaptic expression of a Dysbindin-BLOC-1 network component in mouse brain and human induced pluripotent stem cell-derived neurons

Clinical, epidemiological, and genetic evidence suggest overlapping pathogenic mechanisms between autism spectrum disorder (ASD) and schizophrenia. We tested this hypothesis by asking if mutations in the ASD gene MECP2 which cause Rett syndrome affect the expression of genes encoding the schizophrenia risk factor dysbindin, a subunit of the biogenesis of lysosome-related organelles complex-1 (BLOC-1), and associated interacting proteins. We measured mRNA and protein levels of key components of a dysbindin interaction network by, quantitative real time PCR and quantitative immunohistochemistry in hippocampal samples of wild-type and Mecp2 mutant mice. In addition, we confirmed results by performing immunohistochemistry of normal human hippocampus and quantitative qRT-PCR of human inducible pluripotent stem cells (iPSCs)-derived human neurons from Rett syndrome patients. We defined the distribution of the BLOC-1 subunit pallidin in human and mouse hippocampus and contrasted this distribution with that of symptomatic Mecp2 mutant mice. Neurons from mutant mice and Rett syndrome patients displayed selectively reduced levels of pallidin transcript. Pallidin immunoreactivity decreased in the hippocampus of symptomatic Mecp2 mutant mice, a feature most prominent at asymmetric synapses as determined by immunoelectron microcopy. Pallidin immunoreactivity decreased concomitantly with reduced BDNF content in the hippocampus of Mecp2 mice. Similarly, BDNF content was reduced in the hippocampus of BLOC-1 deficient mice suggesting that genetic defects in BLOC-1 are upstream of the BDNF phenotype in Mecp2 deficient mice. Our results demonstrate that the ASD-related gene Mecp2 regulates the expression of components belonging to the dysbindin interactome and these molecular differences may contribute to synaptic phenotypes that characterize Mecp2 deficiencies and ASD.

Off-axis phase-matched terahertz emission from two-color laser-induced plasma filaments

We observe off-axis phase-matched terahertz generation in long air-plasma filaments produced by femtosecond two-color laser focusing. Here, phase matching naturally occurs due to off-axis constructive interference between locally generated terahertz waves, and this determines the far-field terahertz radiation profiles and yields. For a filament longer than the characteristic two-color dephasing length, it emits conical terahertz radiation in the off-axis direction, peaked at 4-7° depending on the radiation frequencies. The total terahertz yield continuously increases with the filament length, well beyond the dephasing length. The phase-matching condition observed here provides a simple method for scalable terahertz generation in elongated plasmas.

N-acetylcysteine enhances neuronal differentiation of P19 embryonic stem cells via Akt and N-cadherin activation

We examined whether N-acetylcysteine (NAC) enhanced embryonic body (EB) formation and neuronal differentiation in terms of EB formation, neuronal marker (microtubule-associated protein 2; MAP-2) expression, and neuron maturation using P19 embryonic stem cells. The size and numbers of EBs were greatly increased, together with the up-regulated N-cadherin expression. Also, MAP-2 expression and neurite outgrowth were much increased with activation of serine/threonine protein kinase (Akt) and blocked by addition of an Akt inhibitor (LY294002). Our results suggested that NAC increased EB formation by up-regulating the N-cadherin expression. Furthermore, NAC-enhanced neuronal differentiation was mediated by activation of Akt.

Two-dimensional plasma current and optimized terahertz generation in two-color photoionization

Two-dimensional (2-D) transverse photocurrent generation is studied and applied to control and optimize terahertz energy and polarization in two-color, laser-produced air filaments. A full control of terahertz output is demonstrated and explained in the context of 2-D photocurrent model.

Modeling supravalvular aortic stenosis syndrome with human induced pluripotent stem cells

BACKGROUND

Supravalvular aortic stenosis (SVAS) is caused by mutations in the elastin (ELN) gene and is characterized by abnormal proliferation of vascular smooth muscle cells (SMCs) that can lead to narrowing or blockage of the ascending aorta and other arterial vessels. Having patient-specific SMCs available may facilitate the study of disease mechanisms and development of novel therapeutic interventions.

METHODS AND RESULTS

Here, we report the development of a human induced pluripotent stem cell (iPSC) line from a patient with SVAS caused by the premature termination in exon 10 of the ELN gene resulting from an exon 9 four-nucleotide insertion. We showed that SVAS iPSC-derived SMCs (iPSC-SMCs) had significantly fewer organized networks of smooth muscle α-actin filament bundles, a hallmark of mature contractile SMCs, compared with control iPSC-SMCs. The addition of elastin recombinant protein or enhancement of small GTPase RhoA signaling was able to rescue the formation of smooth muscle α-actin filament bundles in SVAS iPSC-SMCs. Cell counts and BrdU analysis revealed a significantly higher proliferation rate in SVAS iPSC-SMCs than control iPSC-SMCs. Furthermore, SVAS iPSC-SMCs migrated at a markedly higher rate to the chemotactic agent platelet-derived growth factor compared with the control iPSC-SMCs. We also provided evidence that elevated activity of extracellular signal-regulated kinase 1/2 is required for hyperproliferation of SVAS iPSC-SMCs. The phenotype was confirmed in iPSC-SMCs generated from a patient with deletion of elastin owing to Williams-Beuren syndrome.

CONCLUSIONS

SVAS iPSC-SMCs recapitulate key pathological features of patients with SVAS and may provide a promising strategy to study disease mechanisms and to develop novel therapies.

Effects of Polycan, a β-glucan, on experimental periodontitis and alveolar bone loss in Sprague-Dawley rats

BACKGROUND AND OBJECTIVE

Polycan is a promising candidate for the treatment of periodontal disease. This study was undertaken to examine whether Polycan, a type of β-glucan, has a protective effect on ligature-induced experimental periodontitis and related alveolar bone loss in Sprague-Dawley rats.

MATERIAL AND METHODS

 Polycan was orally administered, daily, for 10 d, at 21.25, 42.5 or 85 mg/kg, beginning 1 d after ligation. Changes in body weight and alveolar bone loss were monitored, and the anti-inflammatory effects of Polycan were determined by measuring the levels of myeloperoxidase (MPO), interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) in gingival tissue. We also evaluated inducible nitric oxide synthase (iNOS) activity and malondialdehyde (MDA) concentrations as a measure of the antioxidant effect.

RESULTS

Ligature placement led to a marked decrease in body weight, increased alveolar bone loss and increased concentrations of MPO, IL-1β, TNF-α and MDA, as well as increased iNOS activity and inflammatory cell infiltration and decreased collagen-fiber content. Histological examination revealed increases in the number and activity of osteoclast cells, decreases in alveolar bone volume and elevated percentages of osteclasts on the alveolar bone surface. Daily oral treatment with 42.5 or 85 mg/kg of Polycan for 10 d led to significant, dose-dependent inhibition of the effect of ligature placement.

CONCLUSION

Taken together, these results suggest that 10 d of oral treatment with Polycan effectively inhibits ligature placement-induced periodontitis and related alveolar bone loss via an antioxidant effect.

Cellular reprogramming: a novel tool for investigating autism spectrum disorders

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairment in reciprocal social interaction and communication, as well as the manifestation of stereotyped behaviors. Despite much effort, ASDs are not yet fully understood. Advanced genetics and genomics technologies have recently identified novel ASD genes, and approaches using genetically engineered murine models or postmortem human brain have facilitated understanding ASD. Reprogramming somatic cells into induced pluripotent stem cells (iPSCs) provides unprecedented opportunities in generating human disease models. Here, we present an overview of applying iPSCs in developing cellular models for understanding ASD. We also discuss future perspectives in the use of iPSCs as a source of cell therapy and as a screening platform for identifying small molecules with efficacy for alleviating ASD.

Reprogramming human somatic cells into induced pluripotent stem cells (iPSCs) using retroviral vector with GFP

Human embryonic stem cells (hESCs) are pluripotent and an invaluable cellular sources for in vitro disease modeling and regenerative medicine(1). It has been previously shown that human somatic cells can be reprogrammed to pluripotency by ectopic expression of four transcription factors (Oct4, Sox2, Klf4 and Myc) and become induced pluripotent stem cells (iPSCs)(2-4) . Like hESCs, human iPSCs are pluripotent and a potential source for autologous cells. Here we describe the protocol to reprogram human fibroblast cells with the four reprogramming factors cloned into GFP-containing retroviral backbone(4). Using the following protocol, we generate human iPSCs in 3-4 weeks under human ESC culture condition. Human iPSC colonies closely resemble hESCs in morphology and display the loss of GFP fluorescence as a result of retroviral transgene silencing. iPSC colonies isolated mechanically under a fluorescence microscope behave in a similar fashion as hESCs. In these cells, we detect the expression of multiple pluripotency genes and surface markers.

The lesser known story of X chromosome reactivation: a closer look into the reprogramming of the inactive X chromosome

X-chromosome inactivation (XCI) is an important mechanism employed by mammalian XX female cells to level X-linked gene expression with that of male XY cells. XCI occurs early in development as the pluripotent cells of the inner cell mass (ICM) in blastocysts successively differentiate into cells of all three germ layers. X-chromosome reactivation (XCR), the reversal of XCI, is critical for germ cell formation as a mechanism to diversify the X-chromosome gene pool. Here we review the characterization of XCR, and further explore its natural occurrence during development and the in vitro models of cellular reprogramming. We also review the key regulators involved in XCI for their role in suppressing the active histone marks and the genes in the active chromosome for their inhibition of X inactivation signals.

Platelet mitochondrial dysfunction is evident in type 2 diabetes in association with modifications of mitochondrial anti-oxidant stress proteins

OBJECTIVE

Mitochondrial dysfunction and oxidative stress in insulin responsive tissues is implicated in the pathogenesis of type 2 diabetes. Whether these perturbations extend to other tissues and contribute to their pathophysiology is less well established. The objective of this study was to investigate platelet mitochondria to evaluate whether type 2 diabetes associated mitochondrial dysfunction is evident in circulating cells.

METHOD

A pilot study of mitochondrial respiratory function and proteomic changes comparing platelets extracted from insulin sensitive (n=8) and type 2 diabetic subjects (n=7).

RESULTS

In-situ platelet mitochondria show diminished oxygen consumption and lower oxygen-dependent ATP synthesis in diabetic vs. control subjects. Mass spectrometric identification and confirmatory immunoblot analysis identifies induction of the mitochondrial anti-oxidant enzymes superoxide dismutase 2 and thioredoxin-dependent peroxide reductase 3 in platelets of diabetic subjects. As oxidative stress upregulates anti-oxidant enzymes we assessed mitochondrial protein carbonylation as an index of oxidative-stress. Platelets of diabetic subjects exhibit significantly increased protein carbonylation compared to controls.

CONCLUSIONS

As platelets are anuclear fragments of megakaryocytes, our data suggest that the bone marrow compartment in type 2 diabetic subjects is exposed to increased mitochondrial oxidative stress with upregulation of nuclear-encoded antioxidant mitochondrial enzymes. This 'stress-signature' in platelets of diabetic subjects is associated with a diminution of their mitochondrial contribution to energy production and support that mitochondrial perturbations in type 2 diabetes extends beyond the classical insulin responsive tissues. Platelets, as "accessible human tissue", may be useful to measure the mitochondrial modulatory effects of emerging anti-diabetic therapeutics.

Synthesis and photoluminescence of nano-sized (Gd,Y)PO4:Eu3+ by solution combustion method

We synthesized (Gd(1-x)Yx)(0.94)PO4:Eu(0.06) (0 < or = x < or = 1.0) phosphor powders of an ultra-fine size (approximately 23 nm), smooth surface, and spherical and regular morphologies by the solution combustion method. The crystallite sizes of the annealed (Gd(1-x)Yx)(0.94)PO4:Eu(0.06) phosphors with x = 0, 0.25, 0.5, 0.75, and 1.0 were 63.3, 62.3, 49.9, 45.1, and 43.3 nm, respectively. The photoluminescent characteristics of the phosphors were studied under vacuum ultraviolet excitation, depending on the Y3+ concentration. The intensity of the peaks corresponding to the red emission increased with increases in the Y3+ concentration. The Y(0.94)PO4:Eu(0.06) phosphor emitted the strongest intensity and the purest red color.

External validation of nomogram for the prediction of recurrence after curative resection in early gastric cancer

BACKGROUND

Nomograms are statistics-based tools that provide the overall probability of a specific outcome. In our previous study, we developed a nomogram that predicts recurrence of early gastric cancer (EGC) after curative resection. We carried out this study to externally validate our EGC nomogram.

PATIENTS AND METHODS

The EGC nomogram was established from a retrospective EGC database that included 2923 consecutive patients. This nomogram was independently externally validated for a cohort of 1058 consecutive patients. For the EGC nomogram validation, we assessed both discrimination and calibration.

RESULTS

Within the follow-up period (median 37 months), a total of 11 patients (1.1%) experienced recurrence. The concordance index (c-index) was 0.7 (P = 0.02) and the result of the overall C index was 0.82 [P = 0.006, 95% confidence interval (CI) 0.59-1.00]. The goodness of fit test showed that the EGC nomogram had significantly good fit for 1- and 2-year survival intervals (P = 0.998 and 0.879, respectively). The actual and predicted survival outcomes showed good agreement, suggesting that the survival predictions from the nomogram are well calibrated externally.

CONCLUSIONS

A preexisting nomogram for predicting disease-free survival (DFS) of EGC after surgery was externally validated. The nomogram is useful for accurate and individual prediction of DFS, patient prognostication, counseling, and follow-up planning.

IFITM6 expression is increased in macrophages of tumor-bearing mice

The family of interferon-induced transmembrane protein (IFITM) genes consists of IFITM1, 2, 3, 5, and 6. They encode cell surface proteins that modulate cell-cell adhesion and cell differentiation. In a previous study, we showed that IFITM1 is involved in the immune escape and metastasis of gastric cancer cells. In this study, we determined the difference in expression of IFITM family genes in tumor-bearing mice. IFITM1 and 6 were found to be significantly increased. IFITM6 gene expression was increased only in the spleen of tumor-bearing mice but not in the bone marrow, lymph node, or thymus. IFITM6 expression was induced in various macrophages, including splenic, thioglycollate-elicited, and bone marrow-derived macrophages, but not in T cells. Lipopolysaccharides (LPS) also increased IFITM6 expression 24 h after administration, and Toll-like receptor 1, 2, 3, 4, and 9 agonists stimulated IFITM6 expression. These findings imply that the increase in IFITM6 expression may be involved in macrophage functions of tumor-bearing mice.

Laser modulation of heat and capsaicin receptor TRPV1 leads to thermal antinociception

Er,Cr:YSGG lasers are used clinically in dentistry. The advantages of laser therapy include minimal thermal damage and the alleviation of pain. This study examined whether the Er,Cr:YSGG laser has in vivo and in vitro antinociceptive effects in itself. In capsaicin-evoked acute licking/shaking tests and Hargreaves tests, laser irradiation with an aerated water spray suppressed nociceptive behavior in mice. Laser irradiation attenuated TRPV1 activation by capsaicin in Ca(2+) imaging experiments with TRPV1-overexpressing cells and cultured trigeminal neurons. Therefore, the laser-induced behavioral changes are probably due to the loss of TRPV1 activity. TRPV4 activity was also attenuated, but limited mechanical antinociception by the laser was observed. The laser failed to alter the other receptor functions, which indicates that the antinociceptive effect of the laser is dependent on TRPV1. These results suggest that the Er,Cr:YSGG laser has analgesic effects via TRPV1 inhibition. Such mechanistic approaches may help define the laser-sensitive pain modality and increase its beneficial uses.