Hyperpolarized δ-[1- 13C]gluconolactone imaging visualizes response to TERT or GABPB1 targeting therapy for glioblastoma

TERT promoter mutations are a hallmark of glioblastoma (GBM). Accordingly, TERT and GABPB1, a subunit of the upstream mutant TERT promoter transcription factor GABP, are being considered as promising therapeutic targets in GBM. We recently reported that the expression of TERT or GABP1 modulates flux via the pentose phosphate pathway (PPP). Here, we investigated whether 13C magnetic resonance spectroscopy (MRS) of hyperpolarized (HP) δ- [1-13C]gluconolactone can serve to image the reduction in PPP flux following TERT or GABPB1 silencing. We investigated two different human GBM cell lines stably expressing shRNAs targeting TERT or GABPB1, as well as doxycycline-inducible shTERT or shGABPB1cells. MRS studies were performed on live cells and in vivo tumors, and dynamic sets of 13C MR spectra were acquired following injection of HP δ-[1-13C]gluconolactone. HP 6-phosphogluconolactone (6PG), the product of δ-[1-13C]gluconolactone via the PPP, was significantly reduced in TERT or GABPB1-silenced cells or tumors compared to controls in all our models. Furthermore, a positive correlation between TERT expression and 6PG levels was observed. Our data indicate that HP δ-[1-13C]gluconolactone, an imaging tool with translational potential, could serve to monitor TERT expression and its silencing with therapies that target either TERT or GABPB1 in mutant TERT promoter GBM patients.

Monitoring response to a clinically relevant IDH inhibitor in glioma-Hyperpolarized 13C magnetic resonance spectroscopy approaches

Background

Mutant isocitrate dehydrogenase (IDHmut) catalyzes 2-hydroxyglutarate (2HG) production and is considered a therapeutic target for IDHmut tumors. However, response is mostly associated with inhibition of tumor growth. Response assessment via anatomic imaging is therefore challenging. Our goal was to directly detect IDHmut inhibition using a new hyperpolarized (HP) 13C magnetic resonance spectroscopy-based approach to noninvasively assess α-ketoglutarate (αKG) metabolism to 2HG and glutamate.

Methods

We studied IDHmut-expressing normal human astrocyte (NHAIDH1mut) cells and rats with BT257 tumors, and assessed response to the IDHmut inhibitor BAY-1436032 (n ≥ 4). We developed a new 13C Echo Planar Spectroscopic Imaging sequence with an optimized RF pulse to monitor the fate of HP [1-13C]αKG and [5-12C,1-13C]αKG with a 2.5 × 2.5 × 8 mm3 spatial resolution.

Results

Cell studies confirmed that BAY-1436032-treatment leads to a drop in HP 2HG and an increase in HP glutamate detectable with both HP substrates. Data using HP [5-12C,1-13C]αKG also demonstrated that its conversion to 2HG is detectable without the proximal 1.1% natural abundance [5-13C]αKG signal. In vivo studies showed that glutamate is produced in normal brains but no 2HG is detectable. In tumor-bearing rats, we detected the production of both 2HG and glutamate, and BAY-1436032-treatment led to a drop in 2HG and an increase in glutamate. Using HP [5-12C,1-13C]αKG we detected metabolism with an signal-to-noise ratio of 23 for 2HG and 17 for glutamate.

Conclusions

Our findings point to the clinical potential of HP αKG, which recently received FDA investigational new drug approval for research, for noninvasive localized imaging of IDHmut status.

TMET-12. HYPERPOLARIZED Δ- [1-13C] GLUCONOLACTONE IMAGING VISUALIZES TERT-ASSOCIATED CHANGES IN DYNAMIC PENTOSE PHOSPHATE PATHWAY METABOLISM IN GLIOBLASTOMA

BACKGROUND

TERT promoter mutations are a hallmark of glioblastoma (GBM). We recently reported that the expression of TERT and its upstream transcriptional factor, GABPB1, are strongly correlated with redox in GBM with TERT promoter mutations. However, further imaging biomarkers which visualize redox-associated metabolism and TERT expression are needed. Here we demonstrate that 13C magnetic resonance spectroscopy (MRS) of hyperpolarized δ-[1-13C] gluconolactone metabolism is a useful imaging tool to visualize changes in dynamic pentose phosphate pathway (PPP) metabolism that reflect TERT-associated changes in redox in GBM.

METHODS

U251 human GBM cells stably expressing shRNA targeting TERT or GABPB1 were compared to controls. Doxycyclin-inducible shTERT or shGABPB1 U251 cells were also examined. For in vivo studies, cells were injected into immunodeficient rat brains and tumors confirmed by T2-weighted MRI. δ-[1-13C] gluconolactone was polarized using a Hypersense DNP polarizer and injected into live cells or tumor-bearing rats. For cells 13C-MRS was acquired using a 500MHz Agilent spectrometer and analyzed using Mnova and Matlab software. For in vivo13C-MRS studies, spectra were acquired using a 3T Bruker scanner and a spectral spatial echo-planar spectroscopic imaging sequence. Spectral signal to noise was improved using Tensor denoising. Spectra were processed using a custom-written Matlab script.

RESULTS

Hyperpolarized 6-phosphogluconolactone (6PG), the metabolic product from δ-[1-13C] gluconolactone via the PPP, was significantly reduced in TERT or GABPB1 silenced cells compared to control cells in both U251 models. The positive correlation between TERT expression and 6PG level was confirmed by linear regression analysis. Hyperpolarized 6PG production in both tumor models was also significantly reduced in TERT or GABPB1-silenced tumors compared to controls.

CONCLUSION

We successfully visualized TERT-associated changes in dynamic PPP metabolism in a GBM model in cells and in vivo. Hyperpolarized δ-[1-13C] gluconolactone is a potential tool for monitoring TERT expression in GBM with TERT promoter mutations.

TMET-16. DIRECT DETECTION OF 2HG AND GLUTAMATE PRODUCTION USING HYPERPOLARIZED [1-13C-5-12C]-Α-KETOGLUTARATE IN CELL AND IN VIVO GLIOMA MODELS

Mutant IDH leads to 2HG production, which drives glioma development. 13C MRS monitoring of hyperpolarized [1-13C]α-ketoglutarate (αKG) metabolism to 2HG and glutamate provides a non-invasive assessment of the IDH mutation and normal metabolism, respectively. However, monitoring 2HG production in vivo has been challenging because its resonance is within 0.1 ppm of the natural abundance [5-13C]αKG signal of the [1-13C]αKG substrate. Here, we utilized [1-13C -5-12C]αKG, which eliminated the [5-13C]αKG peak. This new approach, combined with an optimized sequence, made it possible to readily monitor the production of both 2HG and glutamate in cells and in vivo in healthy rats or rats with orthotopic patient-derived glioma. Hyperpolarized [1-13C -5-12C]αKG was injected into genetically engineered NHAIDHmut cell lysates, healthy rats, and rats implanted orthotopically with BT257 cells intravenously. 1-D dynamic 13C MRS spectra from cells and in vivo slab spectroscopy data were then acquired using an 11.7 T NMR system and a 3 T pre-clinical scanner, respectively. Injection of the hyperpolarized [1-13C -5-12C]αKG into cell lysates showed clearly detectable dynamic conversion of hyperpolarized [1-13C-5-12C]αKG to 2HG and glutamate. The normal brain showed clear production of glutamate but no 2HG was detected. In tumor-bearing rats, we were able to clearly detect the dynamic production of both 2HG and glutamate. This study demonstrated the utility of hyperpolarized [1-13C-5-12C]αKG as a substrate to clearly assess 2HG production without the confounding presence of the natural abundance peak which cannot be distinguished from 2HG in vivo. Importantly, the detection of 2HG provides a clear indicator of the IDH mutation within the tumor.

Imaging biomarkers of TERT or GABPB1 silencing in TERT-positive glioblastoma

BACKGROUND

TERT promoter mutations are observed in 80% of wild-type IDH glioblastoma (GBM). Moreover, the upstream TERT transcription factor GABPB1 was recently identified as a cancer-specific therapeutic target for tumors harboring a TERT promoter mutation. In that context, noninvasive imaging biomarkers are needed for the detection of TERT modulation.

METHODS

Multiple GBM models were investigated as cells and in vivo tumors and the impact of TERT silencing, either directly or by targeting GABPB1, was determined using 1H and hyperpolarized 13C magnetic resonance spectroscopy (MRS). Changes in associated metabolic enzymes were also investigated.

RESULTS

1H-MRS revealed that lactate and glutathione (GSH) were the most significantly altered metabolites when either TERT or GABPB1 was silenced, and lactate and GSH levels were correlated with cellular TERT expression. Consistent with the drop in lactate, 13C-MRS showed that hyperpolarized [1-13C]lactate production from [1-13C]pyruvate was also reduced when TERT was silenced. Mechanistically, the reduction in GSH was associated with a reduction in pentose phosphate pathway flux, reduced activity of glucose-6-phosphate dehydrogenase, and reduced NADPH. The drop in lactate and hyperpolarized lactate were associated with reductions in glycolytic flux, NADH, and expression/activity of GLUT1, monocarboxylate transporters, and lactate dehydrogenase A.

CONCLUSIONS

Our study indicates that MRS-detectable GSH, lactate, and lactate production could serve as metabolic biomarkers of response to emerging TERT-targeted therapies for GBM with activating TERT promoter mutations. Importantly these biomarkers are readily translatable to the clinic, and thus could ultimately improve GBM patient management.

BIOM-14. METABOLIC BIOMARKERS OF TERT-TARGETED THERAPY FOR HUMAN GLIOBLASTOMA DETECTED BY MAGNETIC RESONANCE SPECTROSCOPY

BACKGROUND

TERT promoter mutations that result in TERT expression are observed in over 80% of GBM. Moreover, the upstream transcription factor GABPB1 was recently identified as an ideal therapeutic target for tumors with TERT promoter mutations. In that context, non-invasive reliable biomarkers that can help detect TERT expression are needed. The aim of this research was to assess the value of MRS-detectable metabolic changes as biomarkers of TERT expression and TERT-targeted therapy in GBM.

METHODS

Genetically engineered GBM cells (NHARas/TERT) treated with TERT siRNA were compared to siCtrl-treated cells, and stable TERT and GABPB1 knock down GBM cells (U251, GBM1) were compared to shCtrl. 1H-MRS and 13C-MRS metabolic data was acquired from cell extracts using a Bruker 500MHz scanner. Hyperpolarized MRS studies of live cells used a HyperSense DNP polarizer and data was acquired using a Varian 500MHz scanner. Spectra were analyzed using Mnova and Matlab software. Multivariate data analysis was performed using SIMCA software.

RESULTS

Unbiased PCA analysis of 1H-MRS metabolic data showed separation of TERT or GABPB1 knock down and control cells. VIP predictive scores revealed that lactate and GSH were the top altered metabolites with a significant drop observed in both metabolites in every model following TERT silencing. Consistent with the reduction in GSH, spectrophotometric assays showed a significant drop in NADPH and NADH. 2-13C glucose flux analysis revealed that both glycolysis and PPP-related metabolites were reduced in TERT knock down cells. Hyperpolarized [1-13C]-pyruvate flux to lactate was also reduced, confirming that the glycolytic pathway was altered following TERT knock down.

CONCLUSION

1H MRS-detectable lactate and GSH, combined with hyperpolarized 13C MRS-detectable metabolic fluxes, could serve as metabolic biomarkers of TERT-targeted therapy for human GBM with TERT promoter mutations. These biomarkers could be translated to the clinical, improve the monitoring of GBM patients and advance precision medicine.

EXTH-46. MRS BASED BIOMARKERS OF IDH1 MUTANT GLIOMA RESPONSE TO THE IDH INHIBITOR BAY-1436032

Gliomas are the most prevalent type of brain tumor in the central nervous system. Mutations in the cytosolic enzyme isocitrate dehydrogenase 1 (IDH1) are a common feature of primary low-grade gliomas, catalyzing the conversion of α-ketoglutarate (αKG) to the oncometabolite 2-hydroxyglutarate (2HG), and mutant IDH1 is a therapeutic target for these tumors. Several mutant IDH inhibitors are currently in clinical trials, nonetheless, complementary non-invasive early biomarkers to assess drug delivery and potential therapeutic response are still needed. The goal of this study was therefore to determine the potential of 1H and hyperpolarized 13C magnetic resonance spectroscopy (MRS)-based biomarkers as indicators of mutant IDH1 low-grade glioma response to treatment with the clinically-relevant IDH1 inhibitor BAY-1436032 in cells and animal models. Immortalized human astrocytes engineered to express mutant IDH1 were treated with 500nM (IC50 value) of BAY-1436032 and BT257 tumors implanted in rats were treated with 150mg/kg of BAY-1436032. To assess steady-state metabolite levels, 1H MRS spectra were acquired on a 500 MHz MRS cancer for cells and a 3 T scanner for animal studies. To assess metabolic fluxes, we used hyperpolarized 13C MRS and probed the fate of hyperpolarized [1-13C]αKG. 1H MRS showed a significant decrease in 2HG as well as a significant increase in glutamate (Glu) and phosphocholine (PCh) following BAY-1436032 treatment in both cell and animal models compared to controls. Furthermore, hyperpolarized 13C MRS showed that hyperpolarized 2HG production from hyperpolarized [1-13C]αKG was decreased and hyperpolarized glutamate production from hyperpolarized [1-13C]αKG was increased in the BAY-1436032 treated groups compared to controls. These findings are consistent with our previous study, which investigated the MRS-detectable consequences of two other mutant IDH inhibitors: AG120 and AG881. Collectively, our work identifies translatable MRS-based metabolic biomarkers of mutant IDH1 inhibition.

Lactate Reprograms Energy and Lipid Metabolism in Glucose-Deprived Oxidative Glioma Stem Cells

Fast-growing tumors satisfy their bioenergetic needs by supplementing glucose with alternative carbon sources. Cancer stem cells are the most versatile and robust cells within malignant tumors. They avoid potentially lethal metabolic and other types of stress through flexible reprogramming of relevant pathways, but it has remained unclear whether alternative carbon sources are important for the maintenance of their tumor-propagating ability. Here we assessed the ability of glycolytic and oxidative murine glioma stem cells (GSCs) to grow in an ultralow glucose medium. Sphere formation assays revealed that exogenous lactate and acetate reversed the growth impairment of oxidative GSCs in such medium. Extracellular flux analysis showed that lactate supported oxygen consumption in these cells, whereas metabolomics analysis revealed that it increased the intracellular levels of tricarboxylic acid cycle intermediates, ATP, and GTP as well as increased adenylate and guanylate charge. Lactate also reversed the depletion of choline apparent in the glucose-deprived cells as well as reprogrammed phospholipid and fatty acid biosynthesis. This metabolic reprogramming was associated with a more aggressive phenotype of intracranial tumors formed by lactate-treated GSCs. Our results thus suggest that lactate is an important alternative energetic and biosynthetic substrate for oxidative GSCs, and that it sustains their growth under conditions of glucose deprivation.

BIOM-19. METABOLIC ALTERATION INDUCED BY SELECTIVE KNOCK DOWN OF GABPB1L IN U251 CELLS

BACKGROUND

TERT promoter mutations that result in TERT expression are observed in over 80% of GBM and upstream inhibition of TERT expression by targeting GABPB1L is currently under investigation. In that context, non-invasive reliable biomarkers that can help detect TERT expression are needed. The aim of this research was to assess the value of magnetic resonance spectroscopy (MRS)-detectable metabolic changes as biomarkers of TERT expression in GBM.

METHODS

GABPB1L knock down clones (GABPB1LKD) were established by introducing Crispr Cas9 plasmid vector targeting GABPB1L into U251 cells. Two representative clones with different knock down efficiency were chosen and compared to control cells. Tumor forming capacity was evaluated by colony formation assay and magnetic resonance imaging of orthotopically implanted tumors in mice. Cells were extracted using the dual phase extraction method and 1H-MRS data of cell extracts acquired using a Bruker 500 scanner. The data was analyzed using Mnova software. Multivariate analysis was performed using the SIMCA software.

RESULTS

TERT expression was significantly reduced in GABPB1LKD compared to control cells depending on the GABPB1L knock down efficiency. Colony forming capacity was impaired in GABPB1LKD compared to control cells. In vivo MRI data showed significantly smaller tumor volumes in GABPB1LKD compared to control. Unbiased PCA analysis of 1H-MRS data showed separation of GABPB1LKD and control extracts and VIP scores derived from the OPLS-DA analysis, demonstrated that the common metabolites leading to separation of GABPB1LKD and control cells were aspartate, glutathione, glycerophosphocholine, glutamine, NAD(P)+, AXP. This data was confirmed by univariate analysis that revealed that aspartate, glutathione, glutamine, NAD(P)+, AXP level was significantly reduced in GABPB1LKD.

CONCLUSIONS

GABPB1L knock down cells that show reduced TERT expression demonstrate MRS-detectable metabolic changes. These could be translated into clinical applications, improve the monitoring of GBM patients and advance precision medicine.

IMP dehydrogenase-2 drives aberrant nucleolar activity and promotes tumorigenesis in glioblastoma

In many cancers, high proliferation rates correlate with elevation of rRNA and tRNA levels, and nucleolar hypertrophy. However, the underlying mechanisms linking increased nucleolar transcription and tumorigenesis are only minimally understood. Here we show that IMP dehydrogenase-2 (IMPDH2), the rate-limiting enzyme for de novo guanine nucleotide biosynthesis, is overexpressed in the highly lethal brain cancer glioblastoma. This leads to increased rRNA and tRNA synthesis, stabilization of the nucleolar GTP-binding protein nucleostemin, and enlarged, malformed nucleoli. Pharmacological or genetic inactivation of IMPDH2 in glioblastoma reverses these effects and inhibits cell proliferation, whereas untransformed glia cells are unaffected by similar IMPDH2 perturbations. Impairment of IMPDH2 activity triggers nucleolar stress and growth arrest of glioblastoma cells even in the absence of functional p53. Our results reveal that upregulation of IMPDH2 is a prerequisite for the occurance of aberrant nucleolar function and increased anabolic processes in glioblastoma, which constitutes a primary event in gliomagenesis.

Metabolic heterogeneity and plasticity of glioma stem cells in a mouse glioblastoma model

Background

Glioblastomas have been shown to rely on glycolysis as an energy source. However, recent evidence suggests that at least a subset of glioma cells with stem cell-like properties can thrive on oxidative phosphorylation. It remains unclear whether both metabolic phenotypes support tumor propagation, if they are independent, and how stable they are. The present study investigated these questions with the use of isogenic murine glioma stem cells (GSCs).

Methods

GSCs were established from tumors formed by Ink4a/Arf-null, H-RasV12-expressing glioma-initiating cells that differed in extracellular acidification potential. Metabolic characteristics of GSCs were determined by measurement of glucose, oxygen, and glutamine uptake, ATP content, and lactate production. Effects of metabolic inhibitors and changes in oxygen or nutrient availability on lactate production and tumorsphere growth were also determined.

Results

GSCs were found either to consume more glucose and produce more lactate or to consume more oxygen and maintain a higher ATP content depending on the metabolic characteristics of the tumor cells of origin. The latter, mitochondrial-type GSCs increased lactate production after treatment with the oxidative phosphorylation inhibitor oligomycin or phenformin. Exposure to hypoxia also increased lactate production and expression of glycolysis-related enzymes and metabolites in mitochondrial-type GSCs in a reversible manner.

Conclusions

Both glycolytic and mitochondrial-type energy production can sustain tumor propagation by isogenic GSCs. Whereas both phenotypes can be independent and stable, cells that rely on oxidative phosphorylation can also switch to a more glycolytic phenotype in response to metabolic stress, suggesting that plasticity is a further characteristic of GSC metabolism.

Abstract 5031: Organotypic brain explant culture as a drug evaluation system for malignant brain tumors

Background: Inhibition of major metabolic pathways is being assessed for several intractable tumors, including glioblastoma. Following screening in 2D-systems, evaluating metabolic inhibitors in assays that include both tumor and normal brain tissue is indispensable for selecting compounds that can affect gliomas within their microenvironment. Here we asked whether organotypic brain slices from adult mice can be used to evaluate the effects of metabolic inhibitors on malignant glioma cells. Methods: Retroviral expression of H-RasV12 and dsRed in Ink4a/Arf-/- neural stem / progenitor cells was adopted to establish glioma initiating cells (GICs). GICs with different extracellular acidification potential were derived by single cell cloning and used after one in vivo passage. GICs or their clones were implanted into the forebrain of 6-weeks-old wild-type mice. Tumor-bearing brain explants were established as 200 µm coronal brain slices, treated with cisplatin, dichloroacetate or phenformin. The effects of the drugs were assessed by fluorescence microscopy of the live explants, as well as immunohistochemical staining at the end of the treatment. Results: The feasibility of assessing drug effects in brain tumor explants from adult mice was confirmed with the use of the DNA-damaging agent cisplatin. Treatment of brain slices carrying tumors formed by GICs with 50 μM cisplatin for 4 days effectively decreased the tumor burden, as shown by a significant reduction of the tumor area on fluorescence imaging and a marked increase in tumor cells positive for cleaved caspase 3 on immunohistochemical analysis. The action of metabolic inhibitors was assessed in explants with tumors formed by GIC-derived populations that predominantly use either glycolysis or mitochondrial respiration. Treatment of the brain slices with dichloroacetate, an inhibitor of pyruvate dehydrogenase kinase, resulted in a marked increase in cleaved caspase 3-positive cells in glycolytic tumors. In contrast, phenformin, which inhibits respiratory complex I, had a pronounced pro-apoptotic effect in tumors formed by cells with a high mitochondrial activity. Conclusion: Inhibitors of both glycolysis and oxidative phosphorylation effectively and selectively induced apoptosis of the targeted tumor cells in cultured brain slices. Our results suggest that brain explants from adult mice can be used to assess the effects of anti-metabolic drugs on the survival of glioma initiating cells within a syngeneic microenvironment. Explants could thus be useful in the evaluation of new metabolic inhibitors.

Citation Format: Noriaki Minami. Organotypic brain explant culture as a drug evaluation system for malignant brain tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5031.

Tranilast inhibits the expression of genes related to epithelial-mesenchymal transition and angiogenesis in neurofibromin-deficient cells

Neurofibromatosis type 1 (NF1) is caused by germline mutations in the NF1 gene and is characterized by café au lait spots and benign tumours known as neurofibromas. NF1 encodes the tumour suppressor protein neurofibromin, which negatively regulates the small GTPase Ras, with the constitutive activation of Ras signalling resulting from NF1 mutations being thought to underlie neurofibroma development. We previously showed that knockdown of neurofibromin triggers epithelial-mesenchymal transition (EMT) signalling and that such signalling is activated in NF1-associated neurofibromas. With the use of a cell-based drug screening assay, we have now identified the antiallergy drug tranilast (N-(3,4-dimethoxycinnamoyl) anthranilic acid) as an inhibitor of EMT and found that it attenuated the expression of mesenchymal markers and angiogenesis-related genes in NF1-mutated sNF96.2 cells and in neurofibroma cells from NF1 patients. Tranilast also suppressed the proliferation of neurofibromin-deficient cells in vitro more effectively than it did that of intact cells. In addition, tranilast inhibited sNF96.2 cell migration and proliferation in vivo. Knockdown of type III collagen (COL3A1) also suppressed the proliferation of neurofibroma cells, whereas expression of COL3A1 and SOX2 was increased in tranilast-resistant cells, suggesting that COL3A1 and the transcription factor SOX2 might contribute to the development of tranilast resistance.

192 Culture Conditions Supporting Long-Term Expansion of Bovine Spermatogonial Stem Cells Isolated from Adult and Immature Testes

Spermatogonial stem cells (SSC) self-renew and differentiate into spermatocytes to produce haploid sperm. Because SSC are a small population of adult stem cells in the testis, numerous studies have been reported to derive cell lines from cultured SSC. It has been reported that neonatal and adult mouse SSC can be cultured in vitro over the long term. Male germline stem (GS) cells, embryonic stem (ES)-like cells, and multipotent male germline stem (MGS) cells were derivated from mouse SSC. However, in domestic species including cattle, information about in vitro culture of SSC is mainly available in the neonatal and immature animal. To our knowledge, there are no reports about long-term culture of SSC isolated from adult bovine testis. In this report, we established culture conditions to maintain SSC isolated from adult and immature testes. The SSC were isolated by 3-step enzymatic digestion and enriched by Percoll gradient centrifugation. For adult testicular cell suspensions, SSC were further enriched by differential plating on precoated gelatin dish. After Percoll gradient centrifugation, we found differential expression of SSC markers (GFRα-1 and UCHL-1) in the isolated cells from immature and adult testis. The RT-PCR results also confirmed the expression of differentiated spermatogonia markers (SYCP3 and STRA-8) in adult testicular cell suspensions. It suggests that isolated testicular germ cell population from adult testis are more heterogeneous than those of immature testis. The SSC isolated from adult testes were cultured in low-serum media containing 6-bromoindirubin-3′-oxime (BIO), an inhibitor of glycogen synthase kinase-3α (GSK3), and subsequently the cultures were maintained in the medium containing glial cell line-derived neurotropic factor (GDNF). The cell lines have characteristics resembling mouse GS cell lines as confirmed by their grape-like shape morphology, the expression of SSC markers (UCHL-1, DBA, and GFRa-1), and pluripotent stem cell markers (POU5F1, SOX2, KLF4). The SSC from immature testes were proliferated for more than 3 months in serum-free culture conditions in the presence of GDNF and bovine leukemia inhibitory factor (LIF). The cell lines had ES-like cell morphology, expressed pluripotent stem cell markers and SSC-specific markers. They differentiated in vitro into 3 germ layers confirmed by the expression of ectoderm (NESTIN), mesoderm (BMP4), and endoderm (GATA-6) markers by RT-PCR and neuron like-cells confirmed by the expression of glial fibrillary acidic protein (GFAP) by immunofluorescence analysis. In conclusion, these findings indicate an efficient method to enrich SSC without cell sorting method and different long-term culture systems subsequently established to maintain SSC from adult and immature testes. Furthermore, our data would be useful for further studies that aim to preserve endangered species and improve livestock production through genome editing technology.

Organotypic brain explant culture as a drug evaluation system for malignant brain tumors

Therapeutic options for malignant brain tumors are limited, with new drugs being continuously evaluated. Organotypic brain slice culture has been adopted for neuroscience studies as a system that preserves brain architecture, cellular function, and the vascular network. However, the suitability of brain explants for anticancer drug evaluation has been unclear. We here adopted a mouse model of malignant glioma based on expression of H‐Ras^V12 in Ink4a/Arf^−/− neural stem/progenitor cells to establish tumor‐bearing brain explants from adult mice. We treated the slices with cisplatin, temozolomide, paclitaxel, or tranilast and investigated the minimal assays required to assess drug effects. Serial fluorescence‐based tumor imaging was sufficient for evaluation of cisplatin, a drug with a pronounced cytotoxic action, whereas immunostaining of cleaved caspase 3 (a marker of apoptosis) and of Ki67 (a marker of cell proliferation) was necessary for the assessment of temozolomide action and immunostaining for phosphorylated histone H3 (a marker of mitosis) allowed visualization of paclitaxel‐specific effects. Staining for cleaved caspase 3 was also informative in the assessment of drug toxicity for normal brain tissue. Incubation of explants with fluorescently labeled antibodies to CD31 allowed real‐time imaging of the microvascular network and complemented time‐lapse imaging of tumor cell invasion into surrounding tissue. Our results suggest that a combination of fluorescence imaging and immunohistological staining allows a unified assessment of the effects of various classes of drug on the survival, proliferation, and invasion of glioma cells, and that organotypic brain slice culture is therefore a useful tool for evaluation of antiglioma drugs.

Fatal pulmonary arterial hypertension in an infant girl with incontinentia pigmenti

We report the case of an infant girl with incontinentia pigmenti (IP) complicated by fatal pulmonary arterial hypertension (PAH). She was diagnosed with IP, based on the presence of specific skin lesions, neonatal seizures, hypereosinophilia and a maternal family history of IP. At the age of 2 months, she was diagnosed with PAH on systolic heart murmur due to tricuspid valve regurgitation. Despite several treatments for PAH but not including epoprostenol, severe PAH persisted and she died of pulmonary hypertensive crisis at the age of 5 months. On postmortem histopathology the pulmonary artery had severe intimal thickening, with occlusion or stenosis of the vascular lumen of the small pulmonary arteries as well as partial plexiform lesions, all of which were compatible with PAH. Modulation of nuclear factor-κB signaling may be involved in the development of PAH in IP.

Radiographic occult cerebellar germinoma presenting with progressive ataxia and cranial nerve palsy

Background

Although the usefulness of susceptibility-weighted imaging (SWI) for detecting basal ganglia germinoma has been reported, the technique is not widely used. We recently encountered an unusual case of primary cerebellar germinoma, presenting with progressive ataxia and cranial nerve palsy, characterized by gradually enlarging low-intensity lesions visible with both T2*-weighted imaging (T2*WI), which were the key to the diagnosis.

Case presentation

A 30-year-old man was referred to our hospital because of slowly progressive dizziness and mild ataxia. Magnetic resonance imaging (MRI) revealed a small, low-intensity spot in the left cerebellar peduncle on the T2*WI and SWI without enhancement. Cerebral angiography revealed no vascular abnormality. The serum α-fetoprotein value was normal. A steroid-pulse was administered as a therapeutic and diagnostic trial, but the symptoms improved little. The patient was discharged from the hospital but soon developed brainstem dysfunction, characterized by dyspnea or hiccups, and he was readmitted. T2*WI imaging revealed expanded and extended spotty lesions in the cerebellum and brainstem, which had not enhanced with contrast agent previously. Targeted stereotactic biopsy of the newly enhanced cerebellar lesion was performed; histopathological examination of the tissue revealed pure germinoma. Serum and cerebral spinal fluid values of beta-human chorionic gonadotropin were not significantly elevated. Chemotherapy with carboplatin and etoposide was initiated. The enhanced lesion disappeared promptly, but the patient continued to require assisted automatic ventilation because of paralysis of respiratory muscles.

Conclusions

We conclude that enlarging low-intensity lesions on T2*WI and SWI may be a reliable clue to the diagnosis of germinomas, irrespective of their location, even without enhancement. Biopsy of the tumor at an early stage is the only way to make the diagnosis conclusively and enable prompt start of treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-015-0516-9) contains supplementary material, which is available to authorized users.

Acute Myositis Associated with Concurrent Infection of Rotavirus and Norovirus in a 2-Year-Old Girl

Rotavirus and norovirus are common pathogens associated with gastroenteritis in children. Although rotavirus occasionally induces central nervous system disease, only 3 cases with rotavirus-induced acute myositis have been reported in the English literature. We recently treated a female patient with acute myositis associated with gastroenteritis induced by concurrent infection with rotavirus and norovirus. Having suffered from gastroenteritis for 3 days, she suddenly developed myositis affecting her lower extremities with concomitant creatine kinase elevation. Herein, we present our patient and review the previous cases including those reported in the Japanese literature.

Abnormal discharges from the temporal neocortex after selective amygdalohippocampectomy and seizure outcomes

The present study examined the relationship between residual discharges from the temporal neocortex postoperatively and seizure outcomes, in mesial temporal lobe epilepsy (MTLE) patients with hippocampal sclerosis (HS) who were treated with selective amygdalohippocampectomy (SelAH). Abnormal discharges from the temporal neocortex are often observed and remain postoperatively. However, no recommendations have been made regarding whether additional procedures to eliminate these discharges should be performed for seizure relief. We retrospectively analyzed 28 patients with unilateral MTLE and HS, who underwent transsylvian SelAH. The mean follow-up period was 29 months (range: 16-49). In the pre- and postresection states, electrocorticography (ECoG) was recorded for the temporal base and lateral temporal cortex. The extent of resection was not influenced by the results of the preresection ECoG. Even if residual abnormal discharges were identified on the temporal neocortex, no additional procedures were undertaken to eliminate these abnormalities. The postresection spike counts were examined to determine the postresective alterations in spike count, and the frequency of residual spike count. The seizure outcomes were evaluated in all patients using the Engel classification. The postoperative seizure-free rate was 92.9%. No significant correlations were seen between a decreasing spike count and seizure outcomes (p=0.9259), or between the absence of residual spikes and seizure outcomes (p=1.000). Residual spikes at the temporal neocortex do not appear to influence seizure outcomes. Only mesial temporal structures should be removed, and additional procedures to eliminate residual spikes are not required.

Surgery for amygdala enlargement with mesial temporal lobe epilepsy: pathological findings and seizure outcome

OBJECTIVE

Amygdala enlargement (AE) has been suggested to be a subtype of mesial temporal lobe epilepsy (MTLE). However, most reports related to AE have referred to imaging studies, and there have been few reports regarding surgical and pathological findings. The present study was performed to clarify the surgical outcomes and pathology of AE.

METHODS

Eighty patients with drug-resistant MTLE were treated surgically at the Tokyo Metropolitan Neurological Hospital between April 2010 and July 2013. Of these patients, 11 were diagnosed as AE based on presurgical MRI. Nine patients with AE underwent selective amygdalohippocampectomy, while the remaining two patients underwent selective amygdalotomy with hippocampal transection. Intraoperative EEG was routinely performed. The histopathology of the resected amygdala tissue was evaluated and compared with the amygdala tissue of patients with hippocampal sclerosis.

RESULTS

Pathological findings indicated that 10 of 11 specimens had closely clustering hypertrophic neurons with vacuolisation of the background matrix. Slight gliosis was seen in nine specimens, while the remaining two showed no gliotic changes. Intraoperative EEG showed abnormal sharp waves that seemed to originate not from the amygdala but from the hippocampus in all cases. Ten patients became seizure-free during the postoperative follow-up period.

CONCLUSIONS

Histopathologically, clustering hypertrophic neurons and vacuolation with slight gliosis or without gliosis were considered to be pathological characteristics of AE. Amygdalohippocampectomy or hippocampal transection with amygdalotomy is effective for seizure control in patients with AE.

[Two cases of cerebral infarction due to focal irradiation for glioma in adults]

Radiation-induced vasculopathy is a complication of radiation therapy. Most reports regarding post-irradiation ischemic stroke with intracranial tumors are restricted to pediatric cases. Here we report two adult cases of delayed brain infarction due to anterior and middle cerebral artery stenosis or occlusion seemingly caused by focal radiation therapy for malignant glioma. Although radiation-induced ischemic stroke in adults is relatively uncommon, it is possible that the morbidity rate of radiation-induced stroke in malignant glioma patients will increase with prolonged survival due to advances in therapy. Therefore, regular evaluation of intracranial vasculature following radiation therapy is necessary.

Effectiveness of zigzag Incision and 1.5-Layer method for frontotemporal craniotomy

Background:

In this era of minimally invasive treatment, it is important to make operative scars as inconspicuous as possible, and there is a great deal of room for improvement in daily practice. Zigzag incision with coronal incision has been described mainly in the field of plastic surgery, and its applicability for skin incision in general neurosurgery has not been reported.

Methods:

Zigzag incision with 1.5-layer method was applied to 14 patients with unruptured cerebral aneurysm between April 2011 and August 2012. A questionnaire survey was administered among patients with unruptured aneurysm using SF-36v2 since April 2010. The results were compared between patients with zigzag incision and a previous cohort with traditional incision.

Results:

There were no cases of complications associated with the operative wound. In the questionnaire survey, all parameters tended to be better in the patients with zigzag incision, and role social component score (RCS) was significantly higher in the zigzag group than in the traditional incision group (P =0.0436).

Conclusion:

Zigzag incision using the 1.5-layer method with frontotemporal craniotomy seems to represent an improvement over the conventional curvilinear incision with regard to cosmetic outcome and RCS.

A surgical case of frontal lobe epilepsy due to focal cortical dysplasia accompanied by olfactory nerve enlargement: case report

A 45-year-old man came to our clinic due to refractory general tonic seizure and an attack of unintended yelling. Magnetic resonance imaging (MRI) demonstrated mild cortical hyperintensity on fluid attenuated inversion recovery (FLAIR) image in the left basal frontal area. Enlargement of the left olfactory nerve was also detected below the affected gyrus. Subtotal resection of the MRI-visible epileptogenic lesion was performed without any neurological deficit. The final pathological diagnosis was focal cortical dysplasia (FCD) type IIa. Seizures and yelling attacks subsided after surgery. Extracerebral abnormalities, including cranial nerve enlargement, are common in patients with hemimegalencephaly. However, such abnormalities are rare with FCD.

Emerging sylvian subpial hematoma after the repair of the ruptured anterior cerebral artery aneurysm with interhemispheric approach: case report

A 60-year-old woman was admitted to the hospital due to a sudden loss of consciousness. Computed tomography (CT) revealed a thick subarachnoid hemorrhage in almost all of the parachiasmatic cisterns, including the sylvian cisterns, with mild hydrocephalus. Three dimensional (3D)-CT angiography showed an irregularly shaped aneurysm at the bifurcation of the left A2 and the frontopolar artery. The aneurysm was successfully obliterated by clipping through the interhemispheric approach. CT performed immediately after the operation showed a newly formed left temporal subpial hematoma. The patient's neurological status improved gradually after surgery, but deteriorated again 2 days after the operation. CT revealed an enlarging right sylviansubpial hematoma. The subpial hematoma was rapidly removed surgically. Slight hemiparesis and impaired higher cognitive function remained after a shunt procedure for subsequent hydrocephalus. Emerging sylvian hematoma associated with a distant site of a ruptured aneurysm is extremely rare. However, adequate attention is required in cases with a thick subarachnoid hemorrhage in distant fissures.

Transsylvian hippocampal transection for mesial temporal lobe epilepsy: surgical indications, procedure, and postoperative seizure and memory outcomes

Object

Amygdalohippocampectomy is a well-established, standard surgery for medically intractable mesial temporal lobe epilepsy (MTLE). However, in the case of MTLE without hippocampal atrophy or sclerosis, amygdalohippocampectomy is associated with decreased postoperative memory function. Hippocampal transection (HT) has been developed to overcome this problem. In HT the hippocampus is not removed; rather, the longitudinal hippocampal circuits of epileptic activities are disrupted by transection of the pyramidal layer of the hippocampus. The present study describes a less invasive modification of HT (transsylvian HT) and presents the seizure and memory outcomes for this procedure.

Methods

Thirty-seven patients with MTLE (18 men and 19 women; age range 9–63 years; 19 with surgery on the right side and 18 with surgery on the left side; seizure onset from 3 to 34 years) who were treated with transsylvian HT were retrospectively analyzed. All patients had left-side language dominance, and follow-up periods ranged from 12 to 94 months (median 49 months). Seizure outcomes were evaluated for all patients by using the Engel classification. Memory function was evaluated for 22 patients based on 3 indices (verbal memory, nonverbal memory, and delayed recall), with those scores obtained using the Wechsler Memory Scale–Revised. Patients underwent evaluation of the memory function before and after surgery (6 months–1 year).

Results

Engel Class I (completely seizure free) was achieved in 25 patients (67.6%). Class II and Class III designation was achieved in 10 (27%) and 2 patients (5.4%), respectively. There were differences in memory outcome between the sides of operation. On the right side, verbal memory significantly increased postoperatively (p = 0.003) but nonverbal memory and delayed recall showed no significant change after the operation (p = 0.718 and p = 0.210, respectively). On the left side, all 3 indices (verbal memory, nonverbal memory, and delayed recall) showed no significant change (p = 0.331, p = 0.458, and p = 0.366, respectively).

Conclusions

Favorable seizure outcome and preservation of verbal memory were achieved with transsylvian HT for the treatment of MTLE without hippocampal atrophy or sclerosis.

Nonspecies-specific effects of mouse oviducts on the development of bovine IVM/IVF embryos by a serum free co-culture

In Experiment 1, development of bovine embryos derived from in vitro-matured (IVM) and in vitro-fertilized (IVF) oocytes was examined under 4 culture conditions: 1) co-culture with mouse ampullae continuously for 8 d, 2) co-culture with mouse ampullae that were replaced with fresh ampullae at 48-h intervals, 3) co-culture with bovine granulosa cell monolayers, and 4) culture in medium alone. Culture medium consisted of tissue culture medium 199 (TCM-199) supplemented with 1% fetal calf serum (FCS). Inseminated oocytes were transferred to each of the culture treatment 24 h after insemination and were cultured for 8 d. The number of blastocysts per number of cleaved ova obtained after co-culture with mouse ampullae (42.9%) was significantly (P<0.05) higher than that obtained after co-culture with granulosa cell monolayers (28.3%) or culture without cells (4.2%). In Experiment 2, the developmental ability of bovine IVM/IVF embryos co-cultured with mouse ampullae supplemented with or without serum was examined. When serum was excluded from the culture medium, 26.4% (33 125 ) of the total number of embryos cultured were able to develop to the blastocysts stage using this co-culture system. This value was comparable to that obtained in a serum-supplemented co-culture system (30.7%; 39 125 ). In addition, the developmental ability of embryos that reached to the 4-cell stage or beyond at 46 to 48 h after insemination was not significantly different when the embryos were co-cultured with mouse ampullae with (38.5 vs 44.6%) or without (37.0 vs 33.8%) serum.

Impact of screening with thyroid ultrasonography in myasthenia gravis patients

OBJECTIVES

This study was conducted to screen thyroid abnormality evaluated with ultrasonography (US) in patients with myasthenia gravis (MG) and investigate further when malignancy is suspected.

METHODS

Thyroid screening using US was conducted in 162 patients with MG. In cases where malignancy was suspected, further investigations were performed.

RESULTS

Abnormal US findings were detected in 125 of 162 patients with MG (72 patients with nodules, 74 patients with cysts, 27 patients with diffuse findings such as enlargement, atrophy, a hypoechoic pattern or a heterogenous echoic pattern, and 28 patients with calcification). From among these 125 subjects, 30 patients underwent further examinations such as needle aspiration cytology. As a result, six patients (3.7% of 162 cases) were positive for papillary carcinoma. The size of the carcinoma in three patients was <10 mm, yet the stage of thyroid carcinomas was high (stage III or IVa) in all six cases.

CONCLUSIONS

Our data suggest that the prevalence of thyroid carcinoma in cases of MG may be higher than that of the general population. Furthermore, in patients with MG, there is a possibility that the stage of the carcinoma is higher even when the carcinoma is of a very small size. Patients with MG, when diagnosed, should be advised to undergo US screening of the thyroid because most cases of thyroid carcinoma are highly curable.

10 TRACEABILITY SYSTEM FOR AN INDIVIDUAL FROZEN SEMEN STRAW BY A TINY RADIO FREQUENCY IDENTIFICATION CHIP

A traceability of frozen semen straws that certify the bloodline of a sire will improve the efficiency of cattle breeding. Semen of the sire can be generally identified by the colour of a straw and printing on a straw. However, it is difficult to identify individual frozen semen straws by the conventional method. To identify straws individually, each straw must be tagged with a unique ID that is able to be read quickly in the frozen state. We have established the identification method for individual frozen semen straws using radio frequency identification (RFID) and developed a traceability system that is able to record the distribution history of an individual semen straw from the production of frozen semen to artificial insemination (AI). We used a 2.5-mm diameter straw combined with an RFID tag, which consisted of a tiny RFID chip (μ-Chip: Hitachi Co. Ltd, 0.4 × 0.4 × 0.2 mm) and a thin aluminum antenna on the polyester sheet (54 × 1.5 × 0.05 mm). The μ-chip contains a unique ID (128 bit). It responds to the 2.45 GHz microwave frequency that is emitted from the RFID reader and transmits its ID to the RFID reader. The μ-Chip retains its function on a straw, which has been stored in the liquid nitrogen (–196°C). Artificial insemination of the frozen semen straw with the RFID tag could be performed using a conventional AI gun. The semen traceability system consisted of the database server and the client software. Information about semen straws is connected with their ID and stored on the database server. Producers and distributors of frozen semen can count the number of semen straws correctly by reading their ID one by one and can send information to the database server through the web by easy operation using the client software. Artificial insemination information can be instantly recorded by the handy terminal that is able to read both a bar-code on the ear tag of the cow and the RFID tag of the straw. The system has been used on fields at Gifu Prefecture in Japan for ∼3 months. Eight hundred thirty-one frozen semen straws with the RFID tag were produced from 3 bulls. After freezing of the straws, 17 straws were not identified with their ID. It was speculated that their μ-Chips were disconnected from the antenna during freezing. Six hundred ninety-four straws were distributed to the 7 AI centers. Five hundred thirty straws were used for AI by 15 inseminators to a total of 424 cows at the 101 farms. Although only one straw could not read its ID after AI, information of the remaining 529 straws were recorded on the database accurately. A strict traceability of frozen semen straws can be established using the individual identification of straws by RFID. Information stored in the database would be useful for the evaluation of sire and the reproductive management of cows. This work was supported by a grant from the Ministry of Agriculture, Forestry and Fisheries of Japan (MAFF).

Rational Construction of Polymeric Nonlinear Optical Materials. Properties of Chromophore-Functionalized Polystyrenes

Processable polymeric nonlinear optical materials can be synthesized by functionalizing a glassy macromolecule with chromophores having large quadratic hyperpolarizabilities, followed by poling in an electric field. In the present case, the functionalization of polystyrene with 4- (4-nitrophenylaza)(N-ethyl)(2-hydroxyethyl))aniline, 4-(4-N,N-dimethylaminostyryl) pyridine, and N-(4-nitrophenyl)-L-prolinol is described. Particularly noteworthy is the high level of chromophore units that can be incorporated into transparent films of these materials, the high second harmonic coefficients that can be achieved (as high as d33 – 11 × 10-9 esu at 1064 nm), and the long-term temporal stability of the second harmonic generation capacity.

Statistical properties of spectral fluctuations for a quantum system with infinitely many components

Extending the idea formulated in Makino [Phys. Rev. E 67, 066205 (2003)], that is based on the Berry-Robnik approach [M. V. Berry and M. Robnik, J. Phys. A 17, 2413 (1984)], we investigate the statistical properties of a two-point spectral correlation for a classically integrable quantum system. The eigenenergy sequence of this system is regarded as a superposition of infinitely many independent components in the semiclassical limit. We derive the level number variance (LNV) in the limit of infinitely many components and discuss its deviations from Poisson statistics. The slope of the limiting LNV is found to be larger than that of Poisson statistics when the individual components have a certain accumulation. This property agrees with the result from the semiclassical periodic-orbit theory that is applied to a system with degenerate torus actions [D. Biswas, M. Azam, and S. V. Lawande, Phys. Rev. A 43, 5694 (1991)].

72 PRESERVATION OF PORCINE GONOCYTES AT 4°C AND IN LIQUID NITROGEN - A PRESERVATION MODEL OF GENETIC RESOURCES IN DOMESTIC ANIMALS AND IN ENDANGERED SPECIES

Gonocytes are primitive germ cells that reside in neonatal testis and are believed to be progenitor-type stem cells that differentiate into spermatogonial stem cells. Because of their self-renewal ability, gonocytes may be one of the targets for cryopreservation of genetic resources in domestic animals and in endangered species. However, there are only a few reports regarding the preservation of gonocytes and spermatogonial stem cells isolated from the testis. In this experiment, porcine gonocytes were used as a model for preservation of genetic resources. Porcine testes were collected at 2–6 days after birth. They were divided into the 5 experimental groups for storage: (1) DMEM/F12 medium, (2) DMEM/F12 + 15 mm HEPES, (3) PBS, (4) PBS + 15 mm HEPES, and (5) Liquid-Free, and stored at 4�C for 24 h. The testes were minced by scissors and digested with 2-step enzyme treatments. The gonocytes were isolated by Percoll density gradients and recovered from the fraction between 50 and 60%. The viability of cells was assessed using trypan blue dye exclusion. To determine optimum cryopreservation conditions for gonocytes, 10% DMSO, 10% glycerol, and 0.07 mm sucrose were used as cryoprotectants. The isolated gonocytes were suspended in DMEM/F12 + 10% FBS containing cryoprotectant at 4�C, kept at –80�C overnight, and finally immersed in liquid nitrogen. After freezing and thawing of gonocytes, cells were examined for viability and then cultured in DMEM/F12 + 10% FBS in 5% CO2, 95% air at 37�C in humidified atmosphere. Identification of gonocytes was performed using a specific marker of gonocytes, a lectin Dolichos biflorus agglutinin (DBA; Goel et al. 2007 Biol. Reprod. 77, 127–137). The gonocytes were recovered from testes at the purity level of around 70%. Cell viability in average after storage of testes at 4�C was significantly higher in DMEM/F12 + HEPES (95.3%) and PBS + HEPES (89.8%) than in DMEM/F12 (73.9%), PBS (79.7%), and Liquid-Free (72.2%) (P < 0.05; ANOVA). The addition of HEPES in storage medium seemed to be effective for improving cell viability. The use of 10% DMSO and 0.07 mm sucrose as cryoprotectants supported high cell viability (74.4%) of gonocytes after freezing and thawing. The addition of glycerol had an adverse effect on cell viability after freezing (18.3%). When cells were cultured, gonocytes started to form colonies after 3 days and continued to proliferate for at least 7 days in culture. These colonies showed DBA affinity and maintained their nature as gonocytes. The viability of gonocytes can be maintained in the testis at 4�C for at least 24 h and after freezing and thawing. The stored gonocytes successfully proliferated in culture for at least 7 days. In conclusion, these results may provide useful information for short-term storage of primitive germ cells and preservation of genetic resources in domestic animals and in endangered species. It may also have implications for assisted reproductive technology in humans.

A unique case of limb-girdle muscular dystrophy type 2A carrying novel compound heterozygous mutations in the human CAPN3 gene

A unique sib pair afflicted by limb girdle muscular dystrophy type 2A (LGMD2A) is described showing a slowly progressive autosomal recessive type of muscular dystrophy with onset in the third and fourth decades. The patients had early asymmetric muscle involvement characterized by prominent biceps brachii atrophy with sparing of the knee extensors. Additional findings included elevation of serum creatine kinase level, myopathic EMG changes and dystrophic type of pathology on muscle biopsy. Asymmetrical wasting of muscles in the extremities exhibited uniform and highly selective CT imaging patterns. RNA and DNA analyses confirmed novel compound heterozygous mutations (R147X/L212F) in the human CAPN3 gene.

Evaluation of acrosomal status of bovine spermatozoa using concanavalin a lectin

We report here that fluorescein isothiocyanate-conjugated concanavalin A (FITC-ConA) specifically labels the acrosomal region of acrosome-reacted bovine spermatozoa. This labeling is found to be useful in evaluating the acrosome status of bovine spermatozoa. When fresh bovine spermatozoa that had been fixed with 4% formaldehyde, smeared on glass slides and then air-dried were stained by FITC-ConA, weak fluorescence was observed on the acrosomal region, although almost all the spermatozoa appeared to be acrosome-intact. However, when fresh sperm suspensions were incubated with FITC-ConA and then mounted on glass slides, no fluorescence was observed on the acrosomal region. Therefore, in the ensuing experiments, both the fixation and the FITC-ConA staining of spermatozoa were done in suspension. When ethanol-treated spermatozoa, whose outer membrane may be permeabilized, were stained with FITC-ConA, the fluorescence was extensively observed on the inner acrosomal region. This fluorescence was inhibited in the presence of 0.2 M D-mannose, a competitive sugar, suggesting that FITC-ConA binds specifically to glycocomponents on the inner acrosomal membrane. We next tried to stain fresh or frozen-thawed spermatozoa from 3 different bulls that had been treated with the calcium ionophore A23187, which is known to induce acrosome reaction of bovine spermatozoa, with FITC-ConA. A significant correlation between the percentage of ConA-labeled spermatozoa and that of rose bengal stained negative ones at various time points during A23187 incubation was achieved. Furthermore, suitability of dual staining to distinguish between physiological acrosome reaction (acrosome-lost and live) and degenerative acrosomal loss (acrosome-lost and dead) using FITC-ConA and Hoechst bis-benzimide 33258 (H258) supravital stain was also confirmed. From these results, it was concluded that the FITC-ConA labeling procedure is a feasible and reliable method for the assessment of physiological acrosome reaction of bovine spermatozoa.

13 MANAGEMENT SYSTEM FOR FROZEN BULL SEMEN USING A RADIO FREQUENCY IDENTIFICATION TAG

An appropriate traceability system is essential for safety during production and distribution of food products. In Japan, the ear-tag system has been applied for this purpose. In this system, newborn calves are tagged individually with a bar code, and are registered to the database, so that everyone can know the information regarding individual cattle and meat. However, the management of frozen semen and the validation of frozen straws are out of the scope of the system. A traceability system for beef production totally covering the progression from semen to meat is necessary for food safety and validation. We applied radio frequency identification (RFID) for the identification of individual frozen semen straws. RFID is the management technology that uses a small tag with a radio transmitter (RFID tag) that has recently been used in the field of distribution management. We consider this technology as a tool to trace artificial insemination (AI) data before the birth of a calf and to establish a management system for production of the Japanese Black cattle breed. The microchip (�-chip) we used as an RFID tag was manufactured by Hitachi, Ltd., Tokyo, Japan. The �-chip is the smallest RFID chip in the world (0.4 mm square) and has a unique identification number (capable of corresponding to 128 bits, 1038 in decimal notation) readable by the RFID tag reader. The �-chip was attached to the frozen semen straw by ultrasonic sealing. We demonstrated that the �-chip retained its function after being stored in liquid nitrogen for at least several months. The information for bull semen, which was dispensed into frozen semen straws with the attached �-chips, was stored in the system database, and the straws were stored in liquid nitrogen. These straws with the �-chips were distributed to local farmers and inseminated into recipient cattle; the AI conditions, results of pregnancy diagnosis, and birth conditions were recorded in the system database. This system using the �-chips may be useful for confirmation and acquisition of trust for a commercially valuable bull and for the study of the improvement of AI for reproduction.

89 ZYGOTICALLY ACTIVATED GENES ARE SUPPRESSED IN MOUSE NUCLEAR-TRANSFERRED EMBRYOS

Mammalian oocytes have the ability to confer totipotency to terminally differentiated somatic cell nuclei. Viable cloned animals have been produced by somatic cell nuclear transfer (NT) into oocytes in many mammalian species including mouse. However, the success rates of the production were quite low in all species. Many studies have measured differences in gene expression between NT and fertilized embryos in relatively advanced stages of development such as pre- and post-natal stages or the blastocyst stage. In the mouse, major zygotic gene activation (ZGA) occurs at the 2-cell stage after fertilization and leads to the transition of gene regulation from maternal control to embryonic control. Suppression of the ZGA by a transcription inhibitor was shown to decrease the viability of embryos, and causes developmental arrest at the 2-cell stage. An abnormal ZGA may therefore affect the viability of NT embryos and cause further abnormalities in later embryonic development. In the present study, we compared gene expression patterns using differential display RT-PCR (DDRT-PCR) between the NT and IVF embryos at the 2-cell stage to detect some abnormalities affecting later development of NT embryos. The developmental rate of NT embryos to blastocysts (32.9%) was significantly lower than that of IVF (92.7%) or PA (92.8%). In addition, the cell numbers of NT embryos at the blastocyst stage (39.5 � 2.6; n = 19) were less than those of IVF (66.8 � 2.1; n = 30) or PA embryos (48.2 � 2.1; n = 30). Using these embryos, we first identified 4 genes that were differentially expressed between NT and IVF embryos at the 2-cell stage. Among the identified genes, Inpp5b and Chst12 were up-regulated, and MuERV-L and Dnaja2 were down-regulated in the NT embryos compared with IVF embryos. Further analysis showed that the expression of zygotically activated genes such as Interferon-γ, Dub-1, Spz1, DD2106, and DD2111 were not properly activated in NT embryos, suggesting that the cellular process involved in the control of the zygotic genome activation is not appropriately regulated. These results indicate that abnormal gene expression has already occurred at the early stage of pre-implantation development as a failure of nuclear reprogramming.

65 NUCLEAR REPROGRAMMING OF PORCINE CELLS AND THEIR USE AS DONOR CELL FOR NUCLEAR TRANSFER AFTER TREATMENT IN XENOPUS EGG EXTRACTS

Revealing an adequate cell state for nuclear reprogramming is essential to achieve efficient production of cloned embryos and animals. Previous reports suggest that nuclei from undifferentiated cells such as blastomeres or embryonic stem cells can support efficient development of cloned embryos to term. In recent years, differentiated somatic cells are frequently used for donor cells because of ease of preparation and application for genetic modification. The efficiency of the somatic cell nuclear transfer (SCNT) is still extremely low. We hypothesized that somatic cells that had been reprogrammed to dedifferentiated states before SCNT might support higher developmental ability of SCNT embryos. To test this hypothesis, porcine fibroblast cells were treated with Xenopus egg extracts, and the extract-treated cells (ETCs) were used as donor cell for SCNT to examine their ability to support early embryonic development. Xenopus egg extracts were prepared from activated S-phase eggs. Porcine fibroblast cells (106/mL) were permeabilized by 500 ng mL-1 of Streptolysin O and were incubated in the egg extracts with the energy-regenerating system for 2 hours at 23�C. After the extract treatment, permeabilized membranes were resealed in DMEM containing 2 mM CaCl2. The ETCs were fused with porcine enucleated oocytes and simultaneously activated. The reconstructed embryos were cultured in PZM-3 medium for 7 days. All statistical differences were analyzed by ANOVA. Reprogramming of ETCs was evaluated on changes of chromatin states and gene expression. Chromatin-binding proteins of ETCs were separated and analyzed on SDS-PAGE. Some proteins were incorporated onto and/or released from chromatins after the extract treatment. Especially, Xenopus egg-specific linker histone B4 was assembled on chromatins. Non-permeabilized control cells did not show these protein exchanges. Deacetylation of histone H3 lysine9 was detected in half number of ETCs in an ATP-dependent manner. In contrast, a high population of histone H3-acetylated cells was observed in buffer-treated cells as well as cells before the extract treatment. The pluripotent marker gene expression, such as OCT4 and SOX2, was also observed in ETCs after culture. The gene expression of these genes was not detected in non-treated cells. These results indicate that the extract treatment induces or triggers a part of dedifferentiation of somatic cells. These ETCs were used as donor cell for SCNT, and reconstructed cloned embryos were cultured. SCNT embryos showed no significant difference in cleavage rates and developmental rates to the blastocyst stage (25%) compared with non-treated control cells (26%). However, the total cell number of embryos at the blastocyst stage was significantly higher in SCNT embryos from ETCs compared with those of control cells (62 � 7 vs. 43 � 2, respectively; P &lt; 0.05). These results indicate that the extract treatment before nuclear transfer may stimulate cell proliferation of SCNT embryos but not improve early development. More studies, however, are needed to investigate their developmental ability to term.

146 LECTIN DOLICHOS BIFLOURUS AGGLUTININ (DBA) IS A SPECIFIC MARKER for PRIMITIVE GERM CELLS IN NEONATAL PORCINE TESTIS

Livestock transgenesis is primarily directed towards improving productive traits or for biomedical research. Transgenic pig is of immense interest because it could provide tissues and organs for xenotransplantation to humans. Conventional methods like pronuclear microinjection of zygote and, more recently, somatic cell nuclear transfer (SCNT) have been used for generating genetically modified pigs. These methods are, however, inefficient and have numerous shortcomings. Male germline stem cells have enormous potential, because they could serve as an alternative approach to generate genetically modified pigs, in which the homologous recombination technique could be applied. However, this could not be achieved due to lack of knowledge of culture conditions and markers that can distinguish germ cells from somatic cells, enabling their isolation and identification in culture. Lectin dolichos biflourus agglutinin (DBA), which has specific affinity for ?-d-N-acetyl-galactosamine, reacts with the large round primordial germ cells of the pig genital ridge (Takagi et al. 1997 Mol. Reprod. Dev. 46, 567–580). Immunohistochemical analysis of testicular samples from different age groups revealed that DBA binds to primitive germ cells in neonatal pig testis like gonocytes and pre-spermatogonia. Variable DBA affinity among germ cells and its progressive loss with age suggested that DBA bound strongly to gonocytes, weakly to undifferentiated spermatogonia, and not at all to spermatogonia. The presence of alkaline phosphatase activity in germ cells from neonatal pig testis further confirmed the existence of primitive germ cells. Gonocytes from neonatal pig testis were isolated using 2-step enzymatic digestion and discontinuous Percoll density gradient. Approximately 70% gonocytes were present in the fraction 5 (50–60% gradient) that were identified by their DBA affinity. Isolated cells were cultured in DMEM/F12 supplemented with 10 �g mL-1 of insulin, 10 �g mL-1 of apo-transferrin, 100 U mL-1 of penicillin, 50 �g mL-1 of streptomycin, 40 �g mL-1 of gentamycin sulphate, 1 mM pyruvate, 1� non-essential amino acid solution, and 10% fetal bovine serum at 37�C in 5% CO2 in air in a humidified atmosphere. Initially, gonocytes grew as adherent cells that formed foci of flat colonies. These colonies grew in size during the culture period, and DBA-positive cells were observed. Flat colonies transformed to ES-like colonies by 6–7 days of culture, which were still positive for DBA binding. Proliferation of germ cells was evaluated by double immunostaining with DBA and anti-bromodeoxyuridine (BrdU) antibody following BrdU incorporation, suggesting that 53–55% DBA-positive cells were in S phase after 7 days of culture. In conclusion, lectin DBA is a marker for porcine primitive germ cells in neonatal pig testis including gonocytes that could be used for their identification during isolation and in culture. Isolated gonocytes could proliferate in vitro without specific growth factor supplementation.