ROR2 expression predicts human induced pluripotent stem cell differentiation into neural stem/progenitor cells and GABAergic neurons.

Despite the development of various in vitro differentiation protocols for the efficient derivation of specific cell types, human induced pluripotent stem cell (hiPSC) lines have varing ability to differentiate into specific lineages. Therefore, surrogate markers for accurately predicting the differentiation propensity of hiPSC lines may facilitate cell-based therapeutic product development and manufacture. We attempted to identify marker genes that could predict the differentiation propensity of hiPSCs into neural stem/progenitor cells (NS/PCs). Using Spearman's rank correlation coefficients, we investigated genes in the undifferentiated state, the expression levels of which were significantly correlated with the neuronal differentiation propensity of several hiPSC lines. Among genes significantly correlated with NS/PC differentiation (P < 0.01), we identified ROR2 as a novel predictive marker. ROR2 expression in hiPSCs was negatively correlated with NS/PC differentiation tendency, regardless of the differentiation method, whereas its knockdown enhanced differentiation. ROR2 regulates NS/PC differentiation, suggesting that ROR2 is functionally essential for NS/PC differentiation. Selecting cell lines with relatively low ROR2 expression facilitated identification of hiPSCs that can differentiate into NS/PCs. Cells with ROR2 knockdown showed increased efficiency of differentiation into forebrain GABAergic neurons compared to controls. These findings suggest that ROR2 is a surrogate marker for selecting hiPSC lines appropriate for NS/PC and GABAergic neuronal differentiations.

Single-Cell RNA-Seq Reveals LRRC75A-Expressing Cell Population Involved in VEGF Secretion of Multipotent Mesenchymal Stromal/Stem Cells Under Ischemia.

Human multipotent mesenchymal stromal/stem cells (MSCs) have been utilized in cell therapy for various diseases and their clinical applications are expected to increase in the future. However, the variation in MSC-based product quality due to the MSC heterogeneity has resulted in significant constraints in the clinical utility of MSCs. Therefore, we hypothesized that it might be important to identify and ensure/enrich suitable cell subpopulations for therapies using MSC-based products. In this study, we aimed to identify functional cell subpopulations to predict the efficacy of angiogenic therapy using bone marrow-derived MSCs (BM-MSCs). To assess its angiogenic potency, we observed various levels of vascular endothelial growth factor (VEGF) secretion among 11 donor-derived BM-MSC lines under in vitro ischemic culture conditions. Next, by clarifying the heterogeneity of BM-MSCs using single-cell RNA-sequencing analysis, we identified a functional cell subpopulation that contributed to the overall VEGF production in BM-MSC lines under ischemic conditions. We also found that leucine-rich repeat-containing 75A (LRRC75A) was more highly expressed in this cell subpopulation than in the others. Importantly, knockdown of LRRC75A using small interfering RNA resulted in significant inhibition of VEGF secretion in ischemic BM-MSCs, indicating that LRRC75A regulates VEGF secretion under ischemic conditions. Therefore, LRRC75A may be a useful biomarker to identify cell subpopulations that contribute to the angiogenic effects of BM-MSCs. Our work provides evidence that a strategy based on single-cell transcriptome profiles is effective for identifying functional cell subpopulations in heterogeneous MSC-based products.

Different Mechanisms for Visual Attention at the Hand-movement Goal and Endogenous Visual Attention.

Visual perception is closely related to body movements and action, and it is known that processing visual stimuli is facilitated at the hand or at the hand-movement goal. Such facilitation suggests that there may be an attentional process associated with the hands or hand movements. To investigate the underlying mechanisms of visual attention at a hand-movement goal, we conducted two experiments to examine whether attention at the hand-movement goal is a process independent from endogenous attention. Endogenous attention is attention that is intentionally focused on a location, feature, or object. We controlled the hand-movement goal and endogenous attention separately to investigate the spatial profiles of the two types of attention. A visual target was presented either at the goal of hand movement (same condition) or at its opposite side (opposite condition) while steady-state visual-evoked potential (SSVEP) was used to estimate the spatial distributions of the facilitation effect from the 2 types of attention around the hand-movement goal and around the visual target through EEG. We estimated the spatial profile of attentional modulation for the hand-movement goal by taking the difference in SSVEP amplitude between conditions with and without hand movement, thereby obtaining the effect of visual endogenous attention alone. The results showed a peak at the hand-movement goal, independent of the location of the visual target where participants intentionally focused their attention (endogenous attention). We also found differences in the spatial extent of attentional modulation. Spatial tuning was narrow around the hand-movement goal (i.e., attentional facilitation only at the goal location) but was broadly tuned around the focus of endogenous attention (i.e., attentional facilitation spreading over adjacent stimulus locations), which was obtained from the condition without hand movement. These results suggest the existence of two separate mechanisms, one underlying the attention at the hand-movement goal and another underlying endogenous attention.

Tumor-Specificity, Neurotoxicity, and Possible Involvement of the Nuclear Receptor Response Pathway of 4,6,8-Trimethyl Azulene Amide Derivatives.

BACKGROUND: Very few papers covering the anticancer activity of azulenes have been reported, as compared with those of antibacterial and anti-inflammatory activity. This led us to investigate the antitumor potential of fifteen 4,6,8-trimethyl azulene amide derivatives against oral malignant cells. METHODS: 4,6,8-Trimethyl azulene amide derivatives were newly synthesized. Anticancer activity was evaluated by tumor-specificity against four human oral squamous cell carcinoma (OSCC) cell lines over three normal oral cells. Neurotoxicity was evaluated by cytotoxicity against three neuronal cell lines over normal oral cells. Apoptosis induction was evaluated by Western blot and cell cycle analyses. RESULTS: Among fifteen derivatives, compounds 7, 9, and 15 showed the highest anticancer activity, and relatively lower neurotoxicity than doxorubicin, 5-fluorouracil (5-FU), and melphalan. They induced the accumulation of a comparable amount of a subG1 population, but slightly lower extent of caspase activation, as compared with actinomycin D, used as an apoptosis inducer. The quantitative structure-activity relationship analysis suggests the significant correlation of tumor-specificity with a 3D shape of molecules, and possible involvement of inflammation and hormone receptor response pathways. CONCLUSIONS: Compounds 7 and 15 can be potential candidates of a lead compound for developing novel anticancer drugs.

A simple method to estimate the in-house limit of detection for genetic mutations with low allele frequencies in whole-exome sequencing analysis by next-generation sequencing.

BACKGROUND: Next-generation sequencing (NGS) has profoundly changed the approach to genetic/genomic research. Particularly, the clinical utility of NGS in detecting mutations associated with disease risk has contributed to the development of effective therapeutic strategies. Recently, comprehensive analysis of somatic genetic mutations by NGS has also been used as a new approach for controlling the quality of cell substrates for manufacturing biopharmaceuticals. However, the quality evaluation of cell substrates by NGS largely depends on the limit of detection (LOD) for rare somatic mutations. The purpose of this study was to develop a simple method for evaluating the ability of whole-exome sequencing (WES) by NGS to detect mutations with low allele frequency. To estimate the LOD of WES for low-frequency somatic mutations, we repeatedly and independently performed WES of a reference genomic DNA using the same NGS platform and assay design. LOD was defined as the allele frequency with a relative standard deviation (RSD) value of 30% and was estimated by a moving average curve of the relation between RSD and allele frequency. RESULTS: Allele frequencies of 20 mutations in the reference material that had been pre-validated by droplet digital PCR (ddPCR) were obtained from 5, 15, 30, or 40 G base pair (Gbp) sequencing data per run. There was a significant association between the allele frequencies measured by WES and those pre-validated by ddPCR, whose p-value decreased as the sequencing data size increased. By this method, the LOD of allele frequency in WES with the sequencing data of 15 Gbp or more was estimated to be between 5 and 10%. CONCLUSIONS: For properly interpreting the WES data of somatic genetic mutations, it is necessary to have a cutoff threshold of low allele frequencies. The in-house LOD estimated by the simple method shown in this study provides a rationale for setting the cutoff.

The hsa-miR-302 cluster controls ectodermal differentiation of human pluripotent stem cell via repression of DAZAP2.

INTRODUCTION: Recent studies have revealed that microRNAs (miRNAs, miRs) are important for self-renewal, differentiation, and cellular reprogramming of somatic cells into induced pluripotent stem cells (iPSC); however, their functional roles and target genes that are regulated by human PSC-specific miRs including hsa-miR-302 clusters remain largely unknown. Analysis of their target gene will give us the opportunity to understand the functional roles of such miRs. METHODS: We analyzed the expression profiles of miRs in 4 somatic cell lines, 8 human iPSC lines derived from 4 different cell types, 3 human ESC lines, and embryoid bodies differentiated from the human ESCs to identify human PSC-specific miRs. We also analyzed the simultaneous expression profiles of miRs and mRNAs to identify candidate targets of human PSC-specific miRs. Then, we constructed a vector for overexpressing one of the target gene to dissect the functions of human PSC-specific miR in maintenance of self-renew and differentiation. RESULTS: We focused on hsa-miR-302 cluster as a human PSC-specific miR and identified 22 candidate targets of hsa-miR-302 cluster that were moderately expressed in undifferentiated human PSCs and up-regulated in differentiated cells. Deleted in azoospermia-associated protein 2 (DAZAP2), one such target, was directly repressed by hsa-miR-302a, -302b, -302c and -302d, but not by hsa-miR-367. Overexpression of DAZAP2 caused a decrease in cell proliferation of undifferentiated human iPSCs, although morphology and undifferentiated marker gene expression was not affected. In addition, neural differentiation was suppressed in DAZAP2-overexpressing human iPSCs. CONCLUSION: Our study revealed that hsa-miR-302 cluster controls the cell proliferation of human PSCs and the neural differentiation of human PSCs by repression of DAZAP2, thereby highlighting an additional function of human PSC-specific miRs in maintaining pluripotency.

SALL3 expression balance underlies lineage biases in human induced pluripotent stem cell differentiation.

Clinical applications of human induced pluripotent stem cells (hiPSCs) are expected, but hiPSC lines vary in their differentiation propensity. For efficient selection of hiPSC lines suitable for differentiation into desired cell lineages, here we identify SALL3 as a marker to predict differentiation propensity. SALL3 expression in hiPSCs correlates positively with ectoderm differentiation capacity and negatively with mesoderm/endoderm differentiation capacity. Without affecting self-renewal of hiPSCs, SALL3 knockdown inhibits ectoderm differentiation and conversely enhances mesodermal/endodermal differentiation. Similarly, loss- and gain-of-function studies reveal that SALL3 inversely regulates the differentiation of hiPSCs into cardiomyocytes and neural cells. Mechanistically, SALL3 modulates DNMT3B function and DNA methyltransferase activity, and influences gene body methylation of Wnt signaling-related genes in hiPSCs. These findings suggest that SALL3 switches the differentiation propensity of hiPSCs toward distinct cell lineages by changing the epigenetic profile and serves as a marker for evaluating the hiPSC differentiation propensity.

CXCL4/PF4 is a predictive biomarker of cardiac differentiation potential of human induced pluripotent stem cells.

Selection of human induced pluripotent stem cell (hiPSC) lines with high cardiac differentiation potential is important for regenerative therapy and drug screening. We aimed to identify biomarkers for predicting cardiac differentiation potential of hiPSC lines by comparing the gene expression profiles of six undifferentiated hiPSC lines with different cardiac differentiation capabilities. We used three platforms of gene expression analysis, namely, cap analysis of gene expression (CAGE), mRNA array, and microRNA array to efficiently screen biomarkers related to cardiac differentiation of hiPSCs. Statistical analysis revealed candidate biomarker genes with significant correlation between the gene expression levels in the undifferentiated hiPSCs and their cardiac differentiation potential. Of the candidate genes, PF4 was validated as a biomarker expressed in undifferentiated hiPSCs with high potential for cardiac differentiation in 13 additional hiPSC lines. Our observations suggest that PF4 may be a useful biomarker for selecting hiPSC lines appropriate for the generation of cardiomyocytes.

Tumorigenicity-associated characteristics of human iPS cell lines.

Human induced pluripotent stem cells (hiPSCs) represent promising raw materials of human cell-based therapeutic products (hCTPs). As undifferentiated hiPSCs exhibit intrinsic tumorigenicity properties that enable them to form teratomas, hCTPs containing residual undifferentiated hiPSCs may cause tumor formation following transplantation. We first established quantitative and sensitive tumorigenicity testing of hiPSCs dissociated into single cells using NOD/Shi-scid IL2Rγnull (NOG) mice by inhibiting apoptosis of hiPSCs with a Rho kinase inhibitor. To examine different features in tumorigenicity of various hiPSCs, 10 commonly available hiPSC lines were subjected to in vivo tumorigenicity testing. Transplanted hiPSC lines showed remarkable variation in tumor incidence, formation latency, and volumes. Most of the tumors formed were classified as immature teratomas. However, no signs of malignancies, such as carcinoma and sarcoma, were recognized in the tumors. Characteristics associated tumorigenicity of hiPSCs were investigated with microarray analysis, karyotype analysis, and whole exome sequencing. Gene expression profiling and pathway analysis supported different features of hiPSC lines in tumorigenicity. hiPSC lines showed chromosomal abnormalities in some lines and 61-77 variants of cancer-related genes carrying effective nonsynonymous mutations, which were confirmed in the COSMIC databases. In this study, the chromosomal abnormalities and cancer-related gene mutations observed in hiPSC lines did not lead to the malignancy of tumors derived from hiPSCs. Our results suggest that the potential tumorigenicity risk of hCTPs containing residual undifferentiated hiPSCs is dependent on not only amounts of undifferentiated hiPSCs but also features of the cell lines used as raw materials, a finding that should be considered from the perspective of quality of hCTPs used.

A case of intussusceptions at two parts of the ileum caused by an ileus tube.

An 87-year-old woman was admitted to our hospital for paralytic ileus, and she was treated using an ileus tube. Although her symptoms improved, abdominal fullness developed again on day 3 after ileus tube insertion. Abdominal computed tomography indicated intussusceptions at the ileum and the terminal part of the ileum;therefore, an emergency surgery was performed. During the surgery, antegrade intussusceptions were found in the ileum 60cm from the ileocecal valve and the terminal part of the ileum into the ascending colon. The intussusception of the anal side was resolved by manual reduction, but the oral side needed a partial resection of small bowel because of the presence of necrosis. There were no lesions, such as tumors, at the intussusceptions sites. Therefore, the two intussusceptions were thought to be caused by the ileus tube. We diagnosed a rare case of intussusceptions in the two parts of the ileum as a complication of the placement of an ileus tube.

Randomized controlled trial of perioperative antimicrobial therapy based on the results of preoperative bile cultures in patients undergoing biliary reconstruction.

BACKGROUND: The high frequency of surgical site infections (SSIs) after hepato-pancreato-biliary (HPB) surgery is a problem that needs to be addressed. This prospective, randomized, controlled study examined whether perioperative prophylactic use of antibiotics based on preoperative bile culture results in HPB surgery could decrease SSI. METHODS: Participants comprised 126 patients who underwent HPB (bile duct, gallbladder, ampullary, or pancreatic) cancer surgery with biliary reconstruction at Hokkaido University Hospital between August 2008 and March 2013 (UMIN Clinical Trial Registry #00001278). Before surgery, subjects were randomly allocated to a targeted group administered antibiotics based on bile culture results or a standard group administered cefmetazole. The primary endpoint was SSI rates within 30 days after surgery. Secondary endpoint was SSI rates for each operative procedure. RESULTS: Of the 126 patients, 124 were randomly allocated (targeted group, n = 62; standard group, n = 62). Frequency of SSI after surgery was significantly lower in the targeted group (27 patients, 43.5%) than in the standard group (44 patients, 71.0%; P = 0.002). Among patients who underwent pancreaticoduodenectomy and hepatectomy, SSI occurred significantly less frequently in the targeted group (P = 0.001 and P = 0.025, respectively). CONCLUSIONS: This study demonstrated that preoperative bile culture-targeted administration of prophylactic antibiotics decreased SSIs following HBP surgery with biliary reconstruction.

A xenogeneic-free system generating functional human gut organoids from pluripotent stem cells.

Functional intestines are composed of cell types from all 3 primary germ layers and are generated through a highly orchestrated and serial developmental process. Directed differentiation of human pluripotent stem cells (hPSCs) has been shown to yield gut-specific cell types; however, these structures do not reproduce critical functional interactions between cell types of different germ layers. Here, we developed a simple protocol for the generation of mature functional intestinal organoids from hPSCs under xenogeneic-free conditions. The stem cell-derived gut organoids produced here were found to contain distinct types of intestinal cells, including enterocytes, goblet cells, Paneth cells, and enteroendocrine cells, that were derived from all 3 germ layers; moreover, they demonstrated intestinal functions, including peptide absorption, and showed innervated bowel movements in response to stimulation with histamine and anticholinergic drugs. Importantly, the gut organoids obtained using this xenogeneic-free system could be stably maintained in culture for prolonged periods and were successfully engrafted in vivo. Our xenogeneic-free approach for generating gut organoids from hPSCs provides a platform for studying human intestinal diseases and for pharmacological testing.

Generation of primitive neural stem cells from human fibroblasts using a defined set of factors.

In mice, leukemia inhibitory factor (LIF)-dependent primitive neural stem cells (NSCs) have a higher neurogenic potential than bFGF-dependent definitive NSCs. Therefore, expandable primitive NSCs are required for research and for the development of therapeutic strategies for neurological diseases. There is a dearth of suitable techniques for the generation of human long-term expandable primitive NSCs. Here, we have described a method for the conversion of human fibroblasts to LIF-dependent primitive NSCs using a strategy based on techniques for the generation of induced pluripotent stem cells (iPSCs). These LIF-dependent induced NSCs (LD-iNSCs) can be expanded for >100 passages. Long-term cultured LD-iNSCs demonstrated multipotent neural differentiation potential and could generate motor neurons and dopaminergic neurons, as well as astrocytes and oligodendrocytes, indicating a high level of plasticity. Furthermore, LD-iNSCs easily reverted to human iPSCs, indicating that LD-iNSCs are in an intermediate iPSC state. This method may facilitate the generation of patient-specific human neurons for studies and treatment of neurodegenerative diseases.

Long-lived and oxygen-responsive photoluminescence in the solid state of copper(I) complexes bearing fluorinated diphosphine and bipyridine ligands.

Luminescence properties of a family of newly synthesized copper(i) complexes bearing 2,2'-bipyridine derivatives and 1,2-bis[bis(pentafluorophenyl)phosphino]ethane (dfppe), [Cu(diimine)(dfppe)]PF6, were investigated. The quantum yield and the lifetime of the emission of [Cu(6dmbpy)(dfppe)]PF6 (6dmbpy = 6,6'-dimethyl-2,2'-bipyridine) in the solid state under argon (Φ = 9%, τ = 16, 180 µs), which is one of the longest lifetimes among all copper(i) complexes bearing diimine and diphosphine, are much larger than those under air (Φ < 0.5%, τ = 1.5, 8.0 µs). Crystal packing, structural rearrangement in the excited state, and nature of the transitions are important for the photophysics of dfppe complexes. The voids in the crystals as well as the very long lifetimes of the excited states play a key role for oxygen responsive photoluminescence in the solid state.

Xenogeneic-free defined conditions for derivation and expansion of human embryonic stem cells with mesenchymal stem cells.

The potential applications of human embryonic stem cells (hESCs) in regenerative medicine and developmental research have made stem cell biology one of the most fascinating and rapidly expanding fields of biomedicine. The first clinical trial of hESCs in humans has begun, and the field of stem cell therapy has just entered a new era. Here, we report seven hESC lines (SEES-1, -2, -3, -4, -5, -6, and -7). Four of them were derived and maintained on irradiated human mesenchymal stem cells (hMSCs) grown in xenogeneic-free defined media and substrate. Xenogeneic-free hMSCs isolated from the subcutaneous tissue of extra fingers from individuals with polydactyly showed appropriate potentials as feeder layers in the pluripotency and growth of hESCs. In this report, we describe a comprehensive characterization of these newly derived SEES cell lines. In addition, we developed a scalable culture system for hESCs having high biological safety by using gamma-irradiated serum replacement and pharmaceutical-grade recombinant basic fibroblast growth factor (bFGF, also known as trafermin). This is first report describing the maintenance of hESC pluripotency using pharmaceutical-grade human recombinant bFGF (trafermin) and gamma-irradiated serum replacement. Our defined medium system provides a path to scalability in Good Manufacturing Practice (GMP) settings for the generation of clinically relevant cell types from pluripotent cells for therapeutic applications.

The role of maternal-specific H3K9me3 modification in establishing imprinted X-chromosome inactivation and embryogenesis in mice.

Maintaining a single active X-chromosome by repressing Xist is crucial for embryonic development in mice. Although the Xist activator RNF12/RLIM is present as a maternal factor, maternal Xist (Xm-Xist) is repressed during preimplantation phases to establish imprinted X-chromosome inactivation (XCI). Here we show, using a highly reproducible chromatin immunoprecipitation method that facilitates chromatin analysis of preimplantation embryos, that H3K9me3 is enriched at the Xist promoter region, preventing Xm-Xist activation by RNF12. The high levels of H3K9me3 at the Xist promoter region are lost in embryonic stem (ES) cells, and ES-cloned embryos show RNF12-dependent Xist expression. Moreover, lack of Xm-XCI in the trophectoderm, rather than loss of paternally expressed imprinted genes, is the primary cause of embryonic lethality in 70-80% of parthenogenotes immediately after implantation. This study reveals that H3K9me3 is involved in the imprinting that silences Xm-Xist. Our findings highlight the role of maternal-specific H3K9me3 modification in embryo development.

A new preoperative prognostic scoring system to predict prognosis in patients with locally advanced pancreatic body cancer who undergo distal pancreatectomy with en bloc celiac axis resection: a retrospective cohort study.

BACKGROUND: Distal pancreatectomy with en bloc celiac axis resection (DP-CAR) provides good local control for locally advanced pancreatic body cancer, but early recurrence still occurs. In this study, we aimed to establish a new scoring system to predict prognosis using preoperative factors in patients with locally advanced pancreatic body cancer who undergo DP-CAR. METHODS: Prognostic factors were analyzed using various data collected retrospectively from 50 consecutive patients who underwent DP-CAR. Using these preoperative factors, a scoring system to predict prognosis was established. RESULTS: Multivariate analysis identified intraoperative blood loss (≥940 mL; hazard ratio [HR], 25.179; P = .0003), preoperative platelet counts (<150 × 10(9)/L; HR, 7.433; P = .0043), preoperative C-reactive protein (CRP) levels (≥0.4 mg/dL; HR, 7.064; P = .0018), and preoperative carbohydrate antigen 19-9 (CA19-9) levels (≥300 U/mL; HR, 8.197; P = .0053) as independent adverse prognostic factors. For the 3 preoperative factors, preoperative platelet counts <150 × 10(9)/L, preoperative CRP levels ≥0.4 mg/dL, and preoperative CA19-9 levels ≥300 U/mL were allocated 1 point each. The total score was defined as the Preoperative Prognostic Score (PPS). The estimated disease-specific 1- and 5-year survival rates for the 26 patients with PPS0 were 95.7%, and 49.1%, respectively, and for the 15 patients with PPS1, they were 86.7% and not available, respectively. The median survival times for PPS0 and PPS1 were 50.6 and 22.3 months, respectively. In contrast, in the 9 patients with PPS2/3, 1- and 5-year survival rates were 33.3% and 0%, respectively, and median survival time was only 7.7 months. CONCLUSION: A new prognostic scoring system using the preoperative platelet count, CRP, and CA19-9 enables preoperative prediction of prognosis and facilitates selection of appropriate treatment for borderline resectable cases of locally advanced pancreatic body cancer.

Age-associated telomere shortening in mouse oocytes.

BACKGROUND: Oocytes may undergo two types of aging. The first is induced by exposure to an aged ovarian microenvironment before being ovulated, known as 'reproductive or maternal aging', and the second by either a prolonged stay in the oviduct before fertilization or in vitro aging prior to insemination, known as 'postovulatory aging'. However, the molecular mechanisms underlying these aging processes remain to be elucidated. As telomere shortening in cultured somatic cells triggers replicative senescence, telomere shortening in oocytes during reproductive and postovulatory aging may predict developmental competence. This study aimed to ascertain the mechanisms underlying altered telomere biology in mouse oocytes during reproductive and postovulatory aging. METHODS: We studied Tert expression patterns, telomerase activity, cytosolic reactive oxygen species (ROS) production, and telomere length in fresh oocytes from young versus reproductively-aged female mice retrieved from oviducts at 14 h post-human chorionic gonadotropin (hCG), in vivo or in vitro postovulatory-aged mouse oocytes at 23 h post-hCG. Oocytes were collected from super-ovulated C57BL/6 J mice of 6-8 weeks or 42-48 weeks of age. mRNA and protein expressions of the Tert gene were quantified using real-time quantitative reverse transcriptase polymerase chain reaction (Q-PCR) and immunochemistry. Telomerase activity was measured by a telomeric repeat amplification protocol assay, while telomere length was measured by Q-PCR and quantitative fluorescence in situ hybridization analyses. RESULTS: The abundance of Tert expression in oocytes significantly decreased during reproductive and postovulatory aging. Immunofluorescent staining clearly demonstrated an altered pattern and intensity of TERT protein expression in oocytes during reproductive aging. Furthermore, relative telomerase activity (RTA) in oocytes from reproductively-aged females was significantly lower than that in oocytes from young females. In contrast, RTA in postovulatory-aged oocytes was similar to that in fresh oocytes. Oocytes from reproductively-aged females and postovulatory-aged oocytes showed higher ROS levels than oocytes from young females. Relative telomere length (RTL) was remarkably shorter in oocytes from reproductively-aged females compared to oocytes from young females. However, postovulatory aging had no significant effect on RTL of oocytes. CONCLUSIONS: Long-term adverse effects of low telomerase activity and increased ROS exposure are likely associated with telomere shortening in oocytes from reproductively-aged female mice.

ß-catenin functions pleiotropically in differentiation and tumorigenesis in mouse embryo-derived stem cells.

The canonical Wnt/ß-catenin signaling pathway plays a crucial role in the maintenance of the balance between proliferation and differentiation throughout embryogenesis and tissue homeostasis. ß-Catenin, encoded by the Ctnnb1 gene, mediates an intracellular signaling cascade activated by Wnt. It also plays an important role in the maintenance of various types of stem cells including adult stem cells and cancer stem cells. However, it is unclear if ß-catenin is required for the derivation of mouse embryo-derived stem cells. Here, we established ß-catenin-deficient (ß-cat(Δ/Δ)) mouse embryo-derived stem cells and showed that ß-catenin is not essential for acquiring self-renewal potential in the derivation of mouse embryonic stem cells (ESCs). However, teratomas formed from embryo-derived ß-cat(Δ/Δ) ESCs were immature germ cell tumors without multilineage differentiated cell types. Re-expression of functional ß-catenin eliminated their neoplastic, transformed phenotype and restored pluripotency, thereby rescuing the mutant ESCs. Our findings demonstrate that ß-catenin has pleiotropic effects in ESCs; it is required for the differentiation of ESCs and prevents them from acquiring tumorigenic character. These results highlight ß-catenin as the gatekeeper in differentiation and tumorigenesis in ESCs.

Six new secoiridoids from the dried fruits of Ligustrum lucidum.

Six new secoiridoid constituents, named isoligustrosidic acid (1), 6'-O-trans-cinnamoyl 8-epikingisidic acid (2), 6'-O-cis-cinnamoyl 8-epikingisidic acid (3), oleopolynuzhenide A (4), nuzhenals A (5) and B (6) were isolated from the dried fruits of Ligustrum lucidum AIT. Their structures were established on the basis of spectral and chemical data.