Combined metabolic and transcriptional profiling identifies pentose phosphate pathway activation by HSP27 phosphorylation during cerebral ischemia

The metabolic pathophysiology underlying ischemic stroke remains poorly understood. To gain insight into these mechanisms, we performed a comparative metabolic and transcriptional analysis of the effects of cerebral ischemia on the metabolism of the cerebral cortex using middle cerebral artery occlusion (MCAO) rat model. Metabolic profiling by gas-chromatography/mass-spectrometry analysis showed clear separation between the ischemia and control group. The decreases of fructose 6-phosphate and ribulose 5-phosphate suggested enhancement of the pentose phosphate pathway (PPP) during cerebral ischemia (120-min MCAO) without reperfusion. Transcriptional profiling by microarray hybridization indicated that the Toll-like receptor and mitogen-activated protein kinase (MAPK) signaling pathways were upregulated during cerebral ischemia without reperfusion. In relation to the PPP, upregulation of heat shock protein 27 (HSP27) was observed in the MAPK signaling pathway and was confirmed through real-time polymerase chain reaction. Immunoblotting showed a slight increase in HSP27 protein expression and a marked increase in HSP27 phosphorylation at serine 85 after 60-min and 120-min MCAO without reperfusion. Corresponding upregulation of glucose 6-phosphate dehydrogenase (G6PD) activity and an increase in the NADPH/NAD⁺ ratio were also observed after 120-min MCAO. Furthermore, intracerebroventricular injection of ataxia telangiectasia mutated (ATM) kinase inhibitor (KU-55933) significantly reduced HSP27 phosphorylation and G6PD upregulation after MCAO, but that of protein kinase D inhibitor (CID755673) did not affect HSP27 phosphorylation. Consequently, G6PD activation via ischemia-induced HSP27 phosphorylation by ATM kinase may be part of an endogenous antioxidant defense neuroprotection mechanism during the earliest stages of ischemia. These findings have important therapeutic implications for the treatment of stroke.

Studies of Pig Complement: Measurement of Pig CH50, ACH50, and Components

BACKGROUND

On the basis of a comparison of the hemolytic complement titer in pigs with that in humans, the complement system of pigs was investigated. The response of innate immunity, such as the natural antibodies, against humans was also examined.

METHODS

Hemolytic complement activity of pig serum was measured with the use of a microtitration technique. CH50 was determined according to the method of Mayer. ACH50 was assayed according to the methods of Platts-Milles and Ishizaka. Hemolytic activities of C1, C4, C2, C3, C5, C8, and C9 were estimated through the use of intermediate cells and reagents, as described previously. In addition, the pig natural anti-human antibody was studied with the use of human peripheral blood mononuclear cells (PBMCs). Human PBMCs were stained with 5% pig serum, followed by staining with fluorescein isothiocyanate-labeled goat anti-pig IgG and IgM. The resulting stained cells were quantified by use of a FACScalibur system. The alternative pathway of pig complement was also measured with the use of human erythrocytes and normal pooled pig serum with or without Mg(++)EGTA.

RESULTS

Both the CH50 and ACH50 titers were lower than those of humans. Concerning the components, except for C3, each component, that is, C1, C4, C2, C5, C8, and C9, was also lower than that of humans, based on measured values for human complement components. Pig serum clearly contains natural antibodies, IgG and IgM, to human PBMCs. The alternative pathway of pig complement reacted with human erythrocytes.

CONCLUSIONS

As a whole, pig innate immunity, the complement system and natural antibody, recognizes the surfaces of human cells.

An Effective New Cryopreservation Procedure for Pancreatic Islets Using Hollow Fiber Vitrification

The present study aimed at establishing a new cryopreservation method for mouse pancreatic islets by vitrification using hollow fibers as a container. A unique feature of the hollow fiber vitrification (HFV) method is that this method achieves stable vitrification using a minimum volume of cryoprotectant (CPA) solution, thereby ensuring high viability of the islets. The cytotoxicity, optimum composition, and concentration of the CPAs for vitrifying islets were examined. The viability, functional-integrity of vitrified islets were evaluated in comparison with those vitrified by conventional methods. Insulin secretion was measured in vitro by a static incubation assay and the metabolic functions was tested after transplantation into Streptozotocin-induced diabetic mice. The combination of 15% dimethyl sulfoxide+15% ethylene glycol resulted in the best CPA solution for the HFV of islets. HFV showed the highest viability in comparison to 2 vitrification methods, open pulled straws and vitrification with EDT324 solution. The vitrified islets stably expressed β-cells markers NeuroD, Pancreatic and duodenal homeobox-1, and MafA. Transplantation of the vitrified islets achieved euglycemia of the host diabetic mice and response to an intraperitoneal glucose tolerance test to a similar extent as non-vitrified transplanted islets. The HFV method allows for efficient long-term cryopreservation of islets.

Maternal Separation Induces Orofacial Mechanical Allodynia in Adulthood

It is well known that exposure to maternal separation (MS) in early life causes plastic changes in the nervous system in adulthood, occasionally resulting in ubiquitous chronic pain. However, the pathogenic mechanisms of pain hypersensitivity remain unclear. Here, the authors examined the involvement of corticosterone in orofacial mechanical hypersensitivity induced by MS. To establish a rat model of MS, pups were placed in isolated cages 180 min/d and kept in a temperature-controlled environment at 22 ± 2 °C for 14 d. Mechanical allodynia in the whisker pad skin in adulthood was induced by MS and was significantly suppressed by successive postnatal subcutaneous administration of the glucocorticoid receptor antagonist mifepristone. Corticosterone levels were increased in the serum of MS rats, and successive postnatal administration of subcutaneous corticosterone to naive rats induced mechanical allodynia in the whisker pad skin. The number of P2X3 receptor-immunoreactive (P2X3R-IR) trigeminal ganglion (TG) neurons innervating the whisker pad skin was significantly increased in MS rats and decreased following subcutaneous administration of mifepristone. The number of P2X3R-IR TG neurons innervating the whisker pad skin was also significantly increased following successive postnatal administration of subcutaneous corticosterone in naive rats. Moreover, the mechanical allodynia was suppressed 30 min after administration of the P2X3R antagonist A317491 to the whisker pad skin in MS rats. These findings suggest that the increase in P2X3R-IR TG neurons innervating the whisker pad skin via enhanced neonatal corticosterone signaling by MS plays an important role in orofacial mechanical allodynia in adulthood.

Diagnostic value of glutamate with 2-hydroxyglutarate in magnetic resonance spectroscopy for IDH1 mutant glioma

BACKGROUND

Mutations in the isocitrate dehydrogenase 1 (IDH1) gene that are frequently observed in low-grade glioma are strongly associated with the accumulation of 2-hydroxyglutarate (2HG), which is a valuable diagnostic and prognostic biomarker of IDH1 mutant glioma. However, conventional MR spectroscopy (MRS)-based noninvasive detection of 2HG is challenging. In this study, we aimed to determine the additional value of other metabolites in predicting IDH1 mutations with conventional MRS.

METHODS

Forty-seven patients with glioma underwent conventional single voxel short echo time MRS prior to surgery. A stereotactic navigation-guided operation was performed to resect tumor tissues in the center of the MRS voxel. MRS-based measurements of metabolites were validated with gas chromatography-mass spectrometry. We also conducted integrated analyses of glioma cell lines and clinical samples to examine the other metabolite levels and molecular findings in IDH1 mutant gliomas.

RESULTS

A metabolomic analysis demonstrated higher levels of 2HG in IDH1 mutant glioma cells and surgical tissues. Interestingly, glutamate levels were significantly decreased in IDH1 mutant gliomas. Through an analysis of metabolic enzyme genes in glutamine pathways, it was shown that the expressions of branched-chain amino acid transaminase 1 were reduced and glutamate dehydrogenase levels were elevated in IDH1 mutant gliomas. Conventional MRS detection of glutamate and 2HG resulted in a high diagnostic accuracy (sensitivity 72%, specificity 96%) for IDH1 mutant glioma.

CONCLUSIONS

IDH1 mutations alter glutamate metabolism. Combining glutamate levels optimizes the 2HG-based monitoring of IDH1 mutations via MRS and represents a reliable clinical application for diagnosing IDH1 mutant gliomas.

Involvement of Microglial P2Y12 Signaling in Tongue Cancer Pain

To elucidate if microglial P2Y12 receptor (P2Y12R) mechanisms are involved in the trigeminal spinal subnucleus caudalis (Vc; also known as the medullary dorsal horn) in intraoral cancer pain, we developed a rat model of tongue cancer pain. Squamous cell carcinoma (SCC) cells were inoculated into the tongue of rats; sham control rats received the vehicle instead. Nociceptive behavior was measured as the head-withdrawal reflex threshold (HWRT) to mechanical or heat stimulation applied to the tongue under light anesthesia. On day 14 after the SCC inoculation, activated microglia and P2Y12R expression were examined immunohistochemically in the Vc. The HWRT was also studied in SCC-inoculated rats with successive intra-cisterna magna (i.c.m.) administration of specific P2Y12R antagonist (MRS2395) or intraperitoneal administration of minocycline, a microglial activation inhibitor. Tongue cancer was histologically verified in SCC-inoculated rats, within which the HWRT to mechanical stimulation of the tongue was significantly decreased, as compared with that of vehicle-inoculated rats, although the HWRT to heat stimulation was not. Microglia was strongly activated on day 14, and the administration of MRS2395 or minocycline reversed associated nocifensive behavior and microglial activation in SCC-inoculated rats for 14 d. The activity of Vc wide dynamic range nociceptive neurons was also recorded electrophysiologically in SCC-inoculated and sham rats. Background activity and noxious mechanically evoked responses of wide dynamic range neurons were significantly increased in SCC-inoculated rats versus sham rats, and background activity and mechanically evoked responses were significantly suppressed following i.c.m. administration of MRS2395 in SCC-inoculated rats as compared with sham. The present findings suggest that SCC inoculation that produces tongue cancer results in strong activation of microglia via P2Y12 signaling in the Vc, in association with increased excitability of Vc nociceptive neurons, reflecting central sensitization and resulting in tongue mechanical allodynia.

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.

Tumor-Associated Macrophages Associate with Cerebrospinal Fluid Interleukin-10 and Survival in Primary Central Nervous System Lymphoma (PCNSL)

Increased tumor-associated macrophages (TAMs) have been reported to be associated with poor prognosis in various tumors; however, the importance of TAMs in primary central nervous system lymphoma (PCNSL) has not been clarified. In 47 patients with PCNSL who were treated with high-dose methotrexate (MTX) and radiotherapy, the relationships between the infiltration levels of TAMs and the clinicopathological parameters were analyzed. Univariate analysis of the Cox proportional hazards model using continuous scales revealed that increased CD68 positive (+) TAMs was significantly associated with inferior progression-free survival (PFS) (P = 0.04), and trends were observed for the increased CD163(+)  TAMs and having shorter PFS (P = 0.05). However, increased TAMs were not associated with overall survival. Because TAMs are known to produce various cytokines, we examined the relationships between cerebrospinal fluid (CSF) cytokines and TAMs. CSF interleukin-6 (IL-6) and soluble IL-2 receptor were not correlated with the infiltration rate of TAMs; however, CSF IL-10 level was correlated with infiltration levels of CD68 and CD163(+)  TAMs. We also confirmed the expression of IL-10 in CD68(+)  and CD163(+)  TAMs by double immunostaining analysis. Our results indicate that a high level of IL-10 in CSF may be positively associated with the infiltration level of TAMs in PCNSLs.

Epidemiology of fragility fractures in Sakaiminato, Japan: incidence, secular trends, and prognosis

We investigated the incidence of fragility fractures from 2010 to 2012 in Sakaiminato, Japan. The incidence rates of limb fractures in Sakaiminato were lower than in Caucasian populations but had increased relative to data obtained in Japan in the 1990s. Clinical vertebral fractures occurred at higher rates in Sakaiminato than in Caucasian populations.

INTRODUCTION

To elucidate the incidence and prognosis of fragility fractures in Sakaiminato, Japan.

METHODS

A survey of all hip, distal radius, proximal humerus, and clinical vertebral fractures was performed from 2010 to 2012 in patients aged 50 or older in Sakaiminato city, Tottori prefecture, Japan. The age- and gender-specific incidence rates (per 100,000 person-years) were calculated based on the population of Sakaiminato city each year. The incidence rates of hip, distal radius, and proximal humerus fractures were compared with previous reports. We conducted a follow-up study assessing patients within 1 year following their initial treatment at two Sakaiminato hospitals.

RESULTS

The age-adjusted incidence rates in population aged 50 years or older (per 100,000 person-years) of hip, distal radius, proximal humerus, and clinical vertebral fractures were, respectively, 217, 82, 26, and 412 in males and 567, 432, 96, and 1229 in females. Age-specific incidence rates of hip, distal radius, and proximal humerus fractures all increased since the 1990s. Our study also revealed that anti-osteoporotic pharmacotherapy was prescribed 1 year post-fracture at rates of 29, 20, 30, and 50 % for patients with hip, distal radius, proximal humerus, and clinical vertebral fractures, respectively.

CONCLUSIONS

The incidence rates of limb fractures in Sakaiminato were substantially lower than Caucasian populations in northern Europe but had increased relative to data obtained in Japan in the 1990s. Unlike upper and lower limb fractures, clinical vertebral fractures occurred at higher rates in our study population than in other Asian and North European countries.

[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.

Compensatory glutamine metabolism promotes glioblastoma resistance to mTOR inhibitor treatment

The mechanistic target of rapamycin (mTOR) is hyperactivated in many types of cancer, rendering it a compelling drug target; however, the impact of mTOR inhibition on metabolic reprogramming in cancer is incompletely understood. Here, by integrating metabolic and functional studies in glioblastoma multiforme (GBM) cell lines, preclinical models, and clinical samples, we demonstrate that the compensatory upregulation of glutamine metabolism promotes resistance to mTOR kinase inhibitors. Metabolomic studies in GBM cells revealed that glutaminase (GLS) and glutamate levels are elevated following mTOR kinase inhibitor treatment. Moreover, these mTOR inhibitor-dependent metabolic alterations were confirmed in a GBM xenograft model. Expression of GLS following mTOR inhibitor treatment promoted GBM survival in an α-ketoglutarate-dependent (αKG-dependent) manner. Combined genetic and/or pharmacological inhibition of mTOR kinase and GLS resulted in massive synergistic tumor cell death and growth inhibition in tumor-bearing mice. These results highlight a critical role for compensatory glutamine metabolism in promoting mTOR inhibitor resistance and suggest that rational combination therapy has the potential to suppress resistance.

31 PRODUCTION EFFICIENCY OF GENE KNOCKOUT PIGS USING GENOME EDITING AND SOMATIC CELL CLONING

Genome editing technologies have been used as a powerful strategy for the generation of genetically modified pigs. We previously developed genetically modified clone pigs with organogenesis-disabled phenotypes, as well as pigs exhibiting diseases with similar features to those of humans. Here, we report the production efficiency of various gene knockout cloned pigs from somatic cells that were genetically modified using zinc finger nucleases (ZFN) or transcription activator-like effector nucleases (TALEN). The ZFN- or TALEN-encoding mRNAs, which targeted 7 autosomal or X-linked genes, were introduced into porcine fetal fibroblast cells using electroporation. Clonal cell populations carrying induced mutations were selected after limiting dilution. The targeted portion of the genes was amplified using PCR, followed by sequencing and mutation analysis. Among the collected knockout cell colonies, cells showing good proliferation and morphology were selected and used for somatic cell nuclear transfer (SCNT). In vitro-matured oocytes were obtained from porcine cumulus-oocyte complexes cultured in NCSU23-based medium and were used to obtain recipient oocytes for SCNT after enucleation. SCNT was performed as reported previously (Matsunari et al. 2008). The cloned embryos were cultured for 7 days in porcine zygote medium (PZM)-5 to assess their developmental ability. Cloned embryos were transplanted into the oviduct or uterus of oestrus-synchronized recipient gilts to evaluate their competence to develop to fetuses or piglets. Cloned embryos reconstructed with 7 types of knockout cells showed equal development to blastocysts compared with those derived from the wild-type cells (54.5–83.3% v. 60.7%). Our data (Table 1) demonstrated that the reconstructed embryos derived from knockout cells could efficiently give rise to cloned offspring regardless of the type of genome editing methodology (i.e. ZFN or TALEN). Table 1.Production efficiency of gene knockout cloned pigs using genome editing This study was supported by JST, ERATO, the Nakauchi Stem Cell and Organ Regeneration Project, JST, CREST, Meiji University International Institute for Bio-Resource Research (MUIIBR), and JSPS KAKENHI Grant Number 26870630.

73 APPLICATION OF THE HOLLOW FIBER VITRIFICATION METHOD TO THE CRYOPRESERVATION OF HIGHLY CRYOSENSITIVE EMBRYOS

We recently demonstrated that the hollow fibre vitrification (HFV) method (Matsunari et al. 2012) could effectively be applied to the cryopreservation of embryos from diverse species. In this study, we applied the HFV method to the cryopreservation of highly cryosensitive specimens, such as in vitro matured (IVM)/IVF-derived porcine zona-free morulae and blastomeres isolated from those morulae, as well as IVM/IVF-derived cattle embryos at early cleavage stages. Porcine parthenogenetic morulae (d-4) derived from IVM oocytes were treated with 0.25% pronase to remove zona pellucidae. The resulting blastomeres were isolated from the zona-free morulae by a decompaction treatment followed by gentle pipetting. Bovine IVM-IVF embryos at the 2 to 4 cell (d-1), 8 to 16 cell (d-3), and morula stages (d-5) were then subjected to vitrification. The HFV procedure was performed as described previously using 15% dimethyl sulfoxide, 15% ethylene glycol, and 0.5 M trehalose as cryoprotectants. Four to twenty embryos, or all of the blastomeres isolated from a single morula, were individually loaded into a cellulose acetate hollow fibre (25 mm long, 185 μm φ, 15 μm membrane thickness) and vitrified. Survival of the vitrified embryos was assessed by in vitro development to blastocysts. Blastomeres recovered after vitrification were aggregated in micro-wells to examine their ability to form blastocysts. The HFV method was demonstrated to be effective for cryopreserving zona-free in vitro-produced porcine morulae and the blastomeres isolated from them (Table 1), as well as bovine IVM-IVF embryos at early cleavage stages. These data demonstrate that the HFV method is effective for highly cryosensitive specimens, such as IVM/IVF-derived porcine zona-free morulae and blastomeres isolated from those morulae, and IVM/IVF-derived cattle embryos at early cleavage stages. These achievements may expand the technological options in the production of cloned and genetically modified pigs that are useful for biomedical research. Table 1.Survival of zona-free porcine morulae and isolated blastomeres after vitrification (top) and blastocyst formation rates in bovine early-stage in vitro matured-IVF embryos after vitrification (bottom) This study was supported by JST, ERATO, the Nakauchi Stem Cell and Organ Regeneration Project, and MUIIBR.

Molecular Stability of Chicken and Rabbit Immunoglobulin G

Molecular stability of chicken egg yolk immunoglobulin G (IgY) and that of rabbit IgG were compared by measuring antibody activities and conformational changes. Stability of rabbit IgG to acid denaturation was much higher than that of IgY. Conformation of the IgY molecule was readily changed in acidic conditions, resulting in a rapid loss of antibody activity. Much less stable natures of IgY to heat-treatment and guanidine-HCl denaturation than rabbit IgG were also observed. Differences in the structure between the two immunoglobulins that might participate in their different stability were inferred from their amino acid sequence data. Importance of the intramolecular disulfide linkage in the rabbit light chain and some other structural differences were suggested.

26 IN VIVO EXOGENIC ORGAN GENERATION WITH ORGANOGENESIS-DISABLED CLONED PIGS AS A PLATFORM

The generation of organs from pluripotent stem cells (PSC) is one of the ultimate goals of regenerative medicine. We have demonstrated that functional organs can be generated in vivo from xenogenic PSC in the body of organogenesis-disabled mice using blastocyst complementation. To apply this principle in generating human organs, a technical platform using large non-rodent mammals is essential. The aim of the present study was to establish a blastocyst complementation system using cloned pig embryos. We generated transgenic-cloned pigs with an apancreatic phenotype via the overexpression of Hes1 (hairy and enhancer of split-1) under the Pdx1 promoter (pancreatic and duodenal homeobox-1). Cloned embryos of apancreatic pigs (host embryos, male) were complemented (i.e. chimerized) by blastomeres of cloned embryos (donor cells, female) with normal developmental competence. Chimeric embryos were cultured for 1 or 2 days before being transferred into the uteri of oestrus-synchronized gilts. The complementation of 292 Pdx1-Hes1 cloned embryos gave rise to 260 (89.0%) blastocysts. The transfer of these blastocysts resulted in 5 male chimeric pigs. Chimerism was confirmed by the detection of host embryo-derived Pdx1-Hes1 and marker transgenes of the donor cells, such as humanized Kusabira-Orange (huKO) or Pdx1-Venus. Chimeric pigs possessed normally formed pancreata entirely derived from the exogenous donor cells. We thus established a blastocyst complementation system in the pig using cloned embryos that would otherwise give rise to apancreatic animals. Chimeric pigs obtained developed normally, maintaining normal serum glucose concentrations up to maturity, and became fertile boars. Mating the chimeric boars with 7 wild-type sows gave rise to 72 fetuses/piglets of which 37 (51.4%) exhibited the apancreatic phenotype. These results indicate that a missing organ can be generated from exogenous cells when functionally normal pluripotent cells chimerize with a cloned dysorganogenetic embryo. Blastocyst complementation using cloned porcine embryos may permit the use of a large animal for the generation of functional organs from xenogenic PSC, including human iPSC. The chimeric boar produced by blastocyst complementation sired fetuses/offspring with the apancreatic phenotype in a Mendelian fashion. Porcine fetuses with an organogenesis-disabled phenotype may provide a useful platform for organ regeneration research. Table 1.Production of chimeric pigs by complementation and of Pdx1-Hes1 cloned embryos

20 GENERATION AND CHARACTERIZATION OF TRANSGENIC-CLONED PIGS EXPRESSING THE FAR-RED FLUORESCENT PROTEIN MONOMERIC PLUM

Transgenic (Tg) pigs expressing a fluorescent protein are extremely useful for research into transplantation and regenerative medicine. This study aimed to create Tg pigs expressing monomeric Plum (mPlum), a far-red fluorescent protein with a longer wavelength than enhanced green fluorescent protein (EGFP) and humanized Kusabira Orange (huKO), the two fluorescent proteins that have been used previously for Tg pig production. A linearized CAG-mPlum transgene construct was transferred into porcine fetal fibroblasts (PFF) by electroporation. mPlum fluorescence-positive cells were collected using a cell sorter and used as nuclear donors (mPlum-PFF) for somatic cell nuclear transfer (SCNT). In vitro-matured oocytes were obtained from porcine cumulus–oocyte complexes cultured in NCSU23-based medium and were used to obtain recipient oocytes for SCNT after enucleation. Then, SCNT was performed as reported previously (Matsunari et al., 2008). The reconstructed embryos were cultured for 7 days in porcine zygote medium-5 (PZM-5). mPlum fluorescence expression was screened during the early development of the embryos. After 5 or 6 days of culture, the SCNT embryos were surgically transferred to the uterus of a recipient gilt. We first obtained fetuses on Day 36 or 37 of gestation by Caesarean section and the PFF were retrieved from their skin. Fluorescence expression was analysed using fluorescence microscope, and the number of transgene copies in each fetus was determined by Southern blot analysis. We also analysed whether unique spectral properties of mPlum are suitable for multicolor imaging using confocal microscope and flow cytometer. The identification of mPlum-expressing PFF under the mixed culture of PFF expressing EGFP and huKO was examined. The 2 cell lines of PFF expressing EGFP and huKO were previously generated in our laboratory. Rates of normal cleavage and blastocyst formation occurred in the SCNT embryos generated with mPlum-PFF (mPlum embryos) were equivalent to those of SCNT embryos derived from nontransgenic PFF (34/42, 81.0%; 33/42, 78.6% v. 37/40, 92.5%; 30/40, 75.0%). Total cell numbers in mPlum and control blastocysts did not differ significantly (88.3 ± 6.0 v. 99.9 ± 8.8). Fluorescence expression in the mPlum embryos began at the 8-cell stage and became brighter from the morula stage. The gilt into which 103 mPlum embryos were transferred produced 3 fetuses. These fetuses expressed mPlum fluorescence systemically and had 1 to 5 copies of the transgene. Multicolor fluorescence imaging and flow cytometric analyses of a mixed culture of mPlum PFF and PFF expressing EGFP and huKO showed that clear identification and isolation of cells displaying each of the 3 fluorescence signals was possible. These observations demonstrate that the transfer of CAG-mPlum did not interfere with the development of porcine SCNT embryos and resulted in the successful generation of Tg cloned pigs that systemically expressed mPlum. This work was supported by JSPS KAKENHI Grant Number 25293279.

49 PRACTICAL APPLICATION OF THE HOLLOW FIBER VITRIFICATION METHOD FOR CRYOPRESERVATION OF MAMMALIAN EMBRYOS

We recently developed the hollow fibro vitrification (HFV) method, which is a novel, high-performance embryo cryopreservation method (Matsunari et al., 2012). In this study, we aimed to verify the applicability of the HFV method for cryopreserving various types of embryos; BDF1 mouse embryos at the 2-cell stage, porcine parthenogenetic morulae derived from in vitro-matured oocytes, bovine morulae produced by in vitro maturation/fertilization (LIAJ Animal Biotechnology Center, Tokyo, Japan), and in vivo-derived blastocysts of common marmosets were vitrified, and their survival was assessed by culture or transfer. The embryos were vitrified using 20 mM HEPES-buffered TCM-199 containing 20% calf serum as a base medium. Cellulose acetate hollow fibres (25 mm) containing 1 to 20 embryos were placed in an equilibration solution containing 7.5% ethylene glycol (EG) and 7.5% dimethyl sulfoxide (DMSO) for 5 to 7 min, followed by incubation for 1 min in vitrification solution containing 15% EG, 15% DMSO, and 0.5 M sucrose. The embryos were then vitrified by immersion in LN. The embryos were devitrified by immersing the hollow fibre in a 1 M sucrose solution at 38.5°C, which was followed by stepwise dilution of the cryoprotectants and washing. For a subset of the vitrified mouse embryos, rewarming in a non-ultra-rapid manner by melting a hollow fibre in air at room temperature for 5 s was tested. Embryo transfer was performed to assess the viability of the vitrified mouse embryos. For porcine embryos, vitrification in LN vapor (–150°C) was tested. Development of the vitrified mouse embryos to blastocysts was equal to that of the non-vitrified embryos [105/110 (95.5%) v. 109/110 (99.1%)]. Post-transfer development to fetuses was also equal between the vitrified and non-vitrified embryos [pregnancy rates: 4/4 v. 2/2; developmental rates: 55/80 (68.8%) v. 35/40 (87.5%)]. Non-ultra-rapid rewarming did not decrease the survival of the vitrified mouse embryos [blastocysts: 94/100 (94.0%); pregnancy: 4/4; fetuses: 55/80 (68.8%)]. Blastocyst formation was equivalent for vitrification of porcine embryos in LN vapor [27/34 (79.4%)], direct immersion into LN [28/35 (80.0%)], and the non-vitrified control [31/32 (96.9%)]. Vitrification of 191 bovine morulae resulted in 153 (80.1%) blastocysts. In preliminary experiments, survival of marmoset blastocysts was 100% (n = 6). These data demonstrate that the HFV method is (1) effective for embryos of various species and production methods; (2) effective even for porcine in vitro-derived morulae, which are highly cryosensitive; and (3) amenable to modifications such as non-ultra-rapid warming and cooling in LN vapor, increasing the potential applicability of the HFV method. For instance, vitrification in LN vapor may allow embryo cryopreservation with high hygienic standards. This study was supported by JST, ERATO, Nakauchi Stem Cell and Organ Regeneration Project.

Transgenic pig expressing the red fluorescent protein kusabira-orange as a novel tool for preclinical studies on hepatocyte transplantation

INTRODUCTION

Research on hepatocyte transplantation as an alternative or supplementary treatment for liver transplantation is progressing. However, to advance to clinical trials, confidence in the technique must be established and its safety must be validated by conducting experiments using animals of comparable sizes to humans, such as pigs. We used transgenic pigs expressing red fluorescence protein for investigating the distribution and survival of transplanted cells.

MATERIALS AND METHODS

Donor hepatocytes were isolated from transgenic Kusabira-Orange (KO)-expressing pigs (age, 41 days; weight, 10 kg) created by in vitro fertilization using sperm from a transgenic-cloned KO pig by Matsunari et al. and ova from a domestic pig. The hepatocyte transplant recipients were the nontransgenic, KO-negative littermates. In these recipient pigs, double lumen cannulae were inserted into the supramesenteric veins to access the hepatic portal region. KO-positive donor hepatocytes from the transgenic male pig were isolated using collagenase perfusion. Hepatocytes (1 × 10(9) cells) were transplanted through the cannula. For estimating allogeneic immunogenicity, full-thickness skin (3 × 3 cm) from the same donor was grafted orthotopically on the neck region of the recipients. Immunosuppressive treatment was not implemented. The recipient pigs were humanely killed at 7 and 39 days after transplantation, and the organs were harvested, including the lungs, heart, liver, pancreas, and kidneys.

RESULTS

Strong red fluorescence was detected in both the parenchymal and nonparenchymal hepatocytes of the transgenic male donor pig by fluorescent microscopy. Transplanted cells were detected in the liver and lung of the recipient pigs at 7 days after perfusion. Hepatocytes remained in the liver and lung of recipients on day 39, with lower numbers than that on day 7.

CONCLUSION

Transgenic pigs expressing the fluorescent protein KO serve as a useful model of cell transplantation in preclinical studies.

Detection of masked mycotoxins derived from type A trichothecenes in corn by high-resolution LC-Orbitrap mass spectrometer

Masked mycotoxins (mycotoxin glucosides) derived from type A trichothecenes were detected in commercially available corn powder reference material. These new glucosides were identified as neosolaniol-glucoside (NESGlc) and diacetoxyscirpenol-glucoside (DASGlc) on the basis of accurate mass measurements of characteristic ions and fragmentation patterns using high-resolution liquid chromatography-Orbitrap mass spectrometric (LC-Orbitrap MS) analysis. Although the absolute structure was not clarified, 3-OH glucosylation appeared to be the most probable when considering the structures of neosolaniol and diacetoxyscirpenol and the fragmentation profiles of these masked mycotoxins. Concomitant detection of deoxynivalenol-3-glucoside, the most well-known masked mycotoxin derived from the type B trichothecene, deoxynivalenol, in the identical material further supports this probability.

Advancing pig cloning technologies towards application in regenerative medicine

Regenerative medicine is expected to make a significant contribution by development of novel therapeutic treatments for intractable diseases and for improving the quality of life of patients. Many advances in regenerative medicine, including basic and translational research, have been developed and tested in experimental animals; pigs have played an important role in various aspects of this work. The value of pigs as a model species is being enhanced by the generation of specially designed animals through cloning and genetic modifications, enabling more sophisticated research to be performed and thus accelerating the clinical application of regenerative medicine. This article reviews the significant aspects of the creation and application of cloned and genetically modified pigs in regenerative medicine research and considers the possible future directions of the technology. We also discuss the importance of reproductive biology as an interface between basic science and clinical medicine.

297 PRODUCTION OF CHIMERIC PORCINE FETUSES BY AGGREGATION METHOD USING PARTHENOGENETIC EMBRYOS

Porcine induced pluripotent stem (iPS) cells are considered to be an invaluable research tool in translational research with pigs as a large animal model. Pluripotency of the iPS cells needs to be verified by their competence to contribute to chimera formation. The aim of the present study is to establish feasible system to create chimeric pig fetuses using parthenogenetic embryos. In Experiment 1, inner cell mass (ICM) was isolated by immunosurgery from Day 6 blastocysts obtained by parthenogenetic activation of in vitro matured (IVM) oocytes. Isolated ICM were used as the donor cells after staining with fluorescent carbocyanine dye (DiI). Using parthenogenetic morulae or 4- to 8-cell embryos as the host embryos, chimeric embryos were prepared by injection or aggregation method. Injection of ICM was performed by micromanipulation: a single ICM was directly injected into the centre portion of the host morulae. In the aggregation method, a single ICM was aggregated with blastomeres isolated from 2 host embryos at the morula or 4- to 8-cell stage in a micro-well (400 µm diameter, 300 µm deep). The chimeric embryos were cultured in PZM-5 (Yoshioka et al. 2008) for 2 to 3 days to examine development to blastocysts and incorporation of donor ICM cells into the resultant blastocysts ICM (ICM chimerism). In Experiment 2, donor blastomeres isolated from a parthenogenetic morula or 4- to 8-cell embryo were stained by DiI and aggregated with a parthenogenetic host embryo at the morula or 4- to 8-cell stage, and the in vitro development to the blastocyst stage and the ICM chimerism were examined. In Experiment 3, ICM isolated from IVF blastocysts harboring humanized Kusabira-Orange (huKO) gene were used as donor cells. Donor ICM were aggregated with the host embryos at the morula or 4- to 8-cell stage, and the resultant blastocysts were transferred to 4 recipient gilts to collect fetuses on Day 18. Results of Experiments 1 and 2 are summarised in Table 1. Combination of the donor ICM and host morulae yielded high rates of blastocyst formation (~95%) and ICM chimerism (~85%), regardless of the method used (injection or aggregation). Transfer of 73 blastocysts developed from host morulae to 2 recipients (Experiment 3) gave rise to 25 (34.2%) fetuses, of which 6 (24.0%) were confirmed to be chimeric by their clear orange fluorescence and immunostaining by anti-huKO antibody. Of 22 (40.7%) fetuses obtained after transfer of 54 blastocysts derived from 4- to 8-cell host embryos to 2 recipients, 3 (13.6%) were chimeric. Contribution of the donor cells in the tissues of the chimeric fetuses measured by image analysis software (ImageJ, NIH, Bethesda, MD, USA) ranged between 16.1 and 65.2%. These results demonstrate that the aggregation method using parthenogenetic host embryos is an efficient means to produce chimeric pig fetuses, and thereby feasible for verification of pluripotent cells such as iPS cells. Table 1.In vitro development of injected or aggregated porcine embryos

322 POTENTIAL OF PRIMARY PORCINE KIDNEY CELLS FOR THE GENERATION OF TRANSGENIC PIGS VIA SOMATIC CELL NUCLEAR TRANSFER

The generation of genetically tailored pig models for biomedical research using somatic cell nuclear transfer (SCNT) is an efficient and precise approach, whereas the outcome is crucially dependent on the source of nuclear donor cells. Especially for site-directed mutagenesis by homologous recombination, including the generation of single cell clones, the demands on the target cells are high. Different primary cells used for SCNT have been tested for their efficiency in SCNT experiments, but further characterisation of the specific cell types, their morphology, proliferation, lifespan, and stability of karyotype is mostly lacking. We have evaluated the potential of 2 primary porcine kidney cell lines (PKC) isolated from juvenile pigs by a simple collagenase digestion and culture in collagen-coated dishes as cell source for SCNT, including their morphology, proliferation capacity, transfection efficiency, and capacity to support full-term development of SCNT embryos after additive gene transfer or homologous recombination. Single cell clones generated by subcloning of PKC at passage 3 showed different morphologies, proliferation rates, and lifespan, indicating that PKC culture is a mixed population of different types of fibroblasts and/or other cells types. The PKC could be maintained in culture for up to 71 passages without signs of senescence and decreased proliferation, exhibiting a stable karyotype containing 74% normal chromosome numbers (2N = 38) determined from metaphase spreads. In contrast, porcine fetal fibroblasts (PFF) and porcine ear fibroblasts (PEF) could be not be passaged more than 20 times. The calculation of growth curves at passage 4 to 5 showed that PKC exhibited a higher proliferation rate with a population doubling time of 16.6 to 18.4 h compared with PFF (23.2. h) and PEF (32.9 h). Furthermore the determination of the developmental competence after SCNT using PKC at passage 4 in 3 independent experiments and in vitro cultivation for 7 days resulted in a higher blastocyst rate (21%) compared with that in PFF (9.1%) and PEF (4.3%). The comparison of different transfection methods (lipofection, nanofection, conventional electroporation, nucleofection), using an expression vector for green fluorescent protein (GFP), showed that the NucleofectorTM technology gave the best results with transfection efficiencies of 70 to 89%, high fluorescence intensity, low cytotoxicity, good cell proliferation, and almost no morphological signs of stress. So far, around 150 cloned piglets using 18 different gene constructs have been produced using stable transfected PKC after additive gene transfer and targeting of 3 different loci. These findings demonstrate that among the 3 tested types of donor cells, PKC, PFF, PEF, primary PKC have outstanding potential for the production of genetically modified pigs by SCNT. This work is supported by the DFG (FOR535, FOR793), the Bayerische Forschungsstiftung, and Mukoviszidose e.V.

324 PRODUCTION OF GENETICALLY MODIFIED PIGS BY ARTIFICIAL REPRODUCTIVE TECHNOLOGIES USING FROZEN EPIDIDYMAL SPERM

Genetically modified (GM) pigs are useful tools for many types of biomedical research. The objective of this study was to develop a reliable protocol for the reproduction of GM pigs using frozen epididymal sperm. Epididymal sperm were collected from 3 GM boars: (1) humanized Kusabira-Orange (huKO) transgenic, (2) mutant human hepatocyte nuclear factor 1α (HNF-1α) transgenic, and (3) α1,3-galactosyltransferase gene knockout (GalT-KO). Additionally, a wild type (WT) boar was also used for sperm collection. After collection, the sperm were frozen in Niwa and Sasaki freezing medium (Niwa et al. 1989 Manual for Cryopreservation of Pig Spermatozoa 19–23; 1.0 × 109 sperm mL–1) using 0.5-mL straws. The sperm were cooled utilising the 2-step method, from 25 to 15°C at a rate of 0.17°C min–1, and then from 15 to 5°C at 0.08°C min–1. After cooling to 5°C, the straws were frozen in liquid nitrogen with 3% glycerol for storage. After storage for 0.5 to 21 months, the straws were thawed by immersion into a 37°C water bath. The recovered sperm were washed by centrifugation in PBS + 1 mg mL–1 BSA and were resuspended in either Beltsville thawing solution (Pursel and Johnson. 1975 J. Anim. Sci. 40, 99–102) for intra-fallopian AI or in porcine fertilization medium (PFM, Research Institute for the Functional Peptides, Yamagata, Japan) for IVF. Prepubertal gilts (6.5 months), in which oestrus was induced by 1000 IU eCG and 1500 IU hCG given 66 or 72 h apart, were surgically inseminated with 0.9–7.9 × 106 progressive motile sperm 41 to 51 h after receiving an hCG injection. Oocytes, which matured in vitro either in modified porcine oocyte medium (IFP) or modified NCSU23 medium, were inseminated in PFM for 8 h with either 0.5 (huKO, GalT-KO) or 1.6 (HNF-1α) × 106 progressive motile sperm mL–1. The in vitro fertilized oocytes were cultured in porcine zygote medium-5 (Research Institute for the Functional Peptides) for 5 to 6 days until they were transferred. Some of these oocytes were examined for their fertilization rates. Blastocysts were transferred into the uterus of the recipient 150 h after hCG treatment. The fertilization rates for huKO, HNF-1α and GalT-KO sperm were 63.5% (61/96), 62.5% (70/112) and 92.4% (61/66), respectively; 50.8% (31/61), 82.9% (58/70) and 60.7% (37/61) of these were monospermic. The rate at which the IVF embryos developed into blastocysts was 47.8–52.4%. This study demonstrates that IVF using frozen epididymal sperm is more efficient method for reproducing genetically modified pigs than AI (87.5 v. 33.3%). Table 1.Pig production efficiencies of frozen epididymal sperm from genetically modified pigs utilising AI and IVF This study was supported by JST, ERATO, NAKAUCHI Stem Cell and Organ Regeneration Project, Tokyo.

326 GENERATION OF A DOUBLE-TRANSGENIC PIG WITH PANCREAS-SPECIFIC GREEN AND LIVER-SPECIFIC RED FLUORESCENCE

Transgenic (Tg) pigs with organ/tissue-specific fluorescence expression provide invaluable research tools for many types of studies, such as organogenesis analysis, in vitro tissue generation from pluripotent cells, and progenitor/stem cell transplantation therapy. We aimed to develop a Tg pig characterised by pancreas- and liver-specific fluorescence expression. A 8.4 kb transgene construct expressing Venus (green fluorescence) under the control of the mouse Pdx1 (pancreatic duodenal homeobox-1) promoter and a BAC-derived construct (170 kb) consisting of the whole-length porcine albumin (Alb) promoter and humanized Kusabira-Orange (huKO, red fluorescence) was introduced into porcine in vitro-matured oocytes using the intracytoplasmic sperm injection (ICSI)-mediated gene transfer method. Injected embryos were transferred to the oviducts of oestrus-synchronized recipients after culture for 1 to 3 days. The transfer of 370 Pdx1-Venus embryos into 4 recipients produce 22 (5.9%) fetuses/piglets, and 9 (40.9%) Tg pigs exhibited pancreas-specific Venus expression. Two (1 male and 1 female) founder Pdx1-Venus-Tg pigs were mated with wild-type (WT) pigs and produced 32 offspring in 3 litters, of which 16 (50.0%) were transgenic. Pancreas-specific Venus expression was inherited in these Tg offspring. The transfer of 523 Alb-huKO embryos into 4 recipients resulted in 19 (3.6%) piglets including a Tg female, which showed liver-specific huKO fluorescent expression. Expression of huKO was detected by RT-PCR exclusively in liver, but not in 7 other organs/tissues examined, including heart, lung, stomach, small intestine, spleen, kidney and skin. This founder Tg female produced a total of 12 non-Tg and 5 Tg offspring (in 2 litters) after mating with a WT boar. Liver-specific huKO expression was inherited in these Tg offspring. Furthermore, the mating of a female Pdx1-Venus pig with an Alb-huKO boar yielded 7 non-Tg and 10 Tg pigs. Four of these Tg pigs carrying both of the transgenes exhibited both pancreas-specific Venus and liver-specific huKO expression in single individuals. Double-Tg pigs with pancreas-specific green fluorescence and liver-specific red fluorescence grew normally, and tests of their reproduction ability are currently underway. These data demonstrate that transgene introduction by ICSI-mediated gene transfer into in vitro-matured oocytes is a feasible option for generating pigs expressing fluorescent proteins in a tissue-specific manner.

67 A HOLLOW FIBER VITRIFICATION METHOD ENABLES CRYOBANKING OF IN VITRO-MATURATION/IN VITRO-FERTILIZATION-DERIVED TRANSGENIC PIG EMBRYOS

We have recently developed a novel high-performance embryo cryopreservation method: the hollow fiber vitrification (HFV) method (Matsunari et al. 2012 J. Reprod. Dev., in press). In this study, we aimed to demonstrate the utility of the HFV method for the cryopreservation of transgenic pig embryos produced by in vitro oocyte maturation/fertilization (IVM/IVF). In vitro-matured oocytes were inseminated with cryopreserved epididymal sperm (Kikuchi et al. 1998 Theriogenology 50, 615–623) from a transgenic pig carrying the humanized Kusabira-Orange gene (Matsunari et al. 2008 Cloning Stem Cell 10, 313–323) and then cultured for 96 h. Morulae with normal morphology were divided into the vitrification and nonvitrification groups. The vitrification of embryos was performed by the HFV method using 20-mM HEPES-buffered TCM199 containing 20% calf serum as a base medium. Cellulose acetate hollow fibers (25 mm), each containing 10 to 20 embryos, were placed in an equilibration solution containing 7.5% ethylene glycol and 7.5% dimethyl sulfoxide for 5 to 7 min and were then placed for 1 min in the vitrification solution containing 15% ethylene glycol, 15% dimethyl sulfoxide, and 0.5 M sucrose. The embryos were then vitrified by immersion in liquid nitrogen and held there for 5 to 10 min. The embryos were warmed by immersing the hollow fiber in a 1-M sucrose solution at 38.5°C, followed by a stepwise dilution of the cryoprotectants using 0.5-M sucrose solution (3 min) and the base medium (10 min). Vitrified and nonvitrified embryos were cultured for 40 h, and their development into blastocysts was evaluated. The in vitro development of vitrified embryos to the blastocyst stage was compared with that of the nonvitrified controls on Day 6. In the embryo-transfer experiments, blastocysts at either Day 5 or Day 6 from both the vitrification and nonvitrification groups were transferred to 3 recipient gilts per group (25–32 blastocysts/gilt), and their development through farrowing was compared. To test long-term preservation, some of the vitrified morulae were kept in liquid nitrogen for 43 days, and their development to Day 30 fetuses was evaluated after transfer to an additional recipient. The differences in proportional data between the 2 groups were analyzed with the χ2-test. Of the 393 putative zygotes obtained by IVM/IVF, 169 (43.0%) developed into morulae. In vitro development of the vitrified morulae to blastocysts (66/85, 77.6%) was comparable with that of the nonvitrified morulae (67/84, 79.8%, not significant: NS). The embryo-transfer experiments resulted in pregnancy in all 6 of the recipients. The production efficiency of piglets (piglets/embryos transferred) was 17/88 (19.3%) for the vitrification group and 27/88 (27.7%, NS) for the nonvitrification group. Approximately 50% of the offspring in both groups were transgenic. Long-term cryopreservation using the HFV method resulted in similar piglet production efficiency (7 piglets produced out of 32 embryos transferred). This study demonstrated for the first time that the HFV method effectively cryopreserves IVM/IVF-derived transgenic pig embryos. Supported by the JST CREST program.

39 FACTORS INFLUENCING THE EFFICIENCY OF GENERATING GENETICALLY ENGINEERED PIGS BY NUCLEAR TRANSFER: MULTI-FACTORIAL ANALYSIS OF A LARGE DATA SET

Somatic cell nuclear transfer (SCNT) using genetically engineered donor cells is currently the most widely used strategy to generate genetically tailored pig models for biomedical research. Although this approach facilitates a similar spectrum of genetic modifications as in rodent models, including inducible transgene expression and gene targeting, the outcome in terms of live cloned piglets is quite variable. We used a large data set from 274 SCNT experiments (in total, 18 649 reconstructed embryos transferred into 193 recipients), performed over a period of 3 years, and evaluated it by multivariate analysis for combined assessment of multiple factors and their relative contribution to the efficiency of generation of genetically modified cloned pigs. Specifically, we addressed the effects of season, type of genetic modification (additive gene transfer v. gene targeting), donor cell source (mesenchymal stem cells, postnatal fibroblasts, fetal fibroblasts, and kidney cells), serial NT, and pre-selection of SCNT embryos for early development. Target parameters were pregnancy and delivery rates, as well as the numbers of born, live, and healthy offspring. Cloning efficiency was calculated as the number of cloned piglets relative to the number of transferred SCNT embryos. We used robust linear models adjusted to the underlying empirical distribution of the cloning outcome, as a straightforward approach to determine the statistically significant part of the network of factors affecting pig cloning. The SCNT experiments performed during the winter using fetal fibroblasts or kidney cells after additive gene transfer resulted in the highest number of live and healthy offspring, whereas sequential NT and NT experiments performed during the summer decreased it. Although the effects of individual factors may be different between various laboratories, the statistical approach described in this study may help to identify and optimize the most critical specific factors to cloning success in programs aimed at the generation of genetically engineered pig models. Supported by the DFG (FOR535, FOR793), the Bayerische Forschungsstiftung, and Mukoviszidose e.V.

A cloning of cytidine monophospho-N-acetylneuraminic acid hydroxylase from porcine endothelial cells

INTRODUCTION

The Hanganutziu-Deicher (H-D) antigen with terminal N-glycolyl neuraminic acid-(NeuGc) is widely distributed in mammalian species including monkeys and apes, but is not found in humans and birds. After the knock out of α1, 3galactosyltransfease, the H-D antigen became a major antigen of the "non-Gal antigen." The expression of NeuGc is controlled by the activity of cytidine monophospho-N-acetylneuraminic acid hydroxylase (CMAH). In this study, molecular cloning of pig CMAH was performed, as the first step in producing H-D knockout pigs.

METHODS

A pig endothelial cell line, MYP30, was used. The DNA sequence of pig CMAH was queried in dbEST (NCBI) using the BLAST program to search for cDNA fragments of pig CMAH, based on an alignment analysis of the mouse CMAH sequence. A polymerase chain reaction experiment was performed and candidate cDNA clones were isolated. To obtain the 5'-end and 3'-end of the open reading frame sequence, a 5'-full RACE Core Set and 3'-full RACE Core Set were used.

RESULTS

We cloned and characterized the pig CMAH gene. The ATG is located in exon 4, which corresponds to the mouse gene, and the stop codon is in exon 17. In the case of the 5' site of the gene, exon 3 was identified but exons 1 and 2 are still being investigated. On the other hand, exon 18 was newly identified in the 3' site of the gene.

CONCLUSION

The results represent useful information for future clinical xenotransplantation studies.

Emerging applications of sperm, embryo and somatic cell cryopreservation in maintenance, relocation and rederivation of swine genetics

Advances in porcine assisted reproductive technology (ART) make it possible to use cryopreserved sperm, embryos and somatic cells in the maintenance, relocation and regeneration of swine genetics. In this review, development of key application-limiting technology is discussed in each cell type, focusing on the efficiencies, ease of storage and transportation, and minimization of pathogen transmission. Methods to regenerate swine genetics and/or models using frozen sperm, embryos and somatic cells in combination with other porcine ARTs, such as in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), and somatic cell nuclear transplantation (SCNT), are also discussed. The applications of these ARTs utilizing cryopreserved cells will greatly increase the efficiency as well as biosecurity for maintenance, relocation and rederivation of swine genetics/models.

The use of LC-Orbitrap MS for the detection of Fusarium masked mycotoxins: the case of type A trichothecenes

‘Masked mycotoxins’ (mycotoxin glucosides) derived from type A trichothecenes (T-2 toxin and HT-2 toxin) were detected in commercially available maize powder reference material. These novel glucosides were identified as T-2 toxin-glucoside (T2-Glc) and HT-2 toxin-glucoside (HT2-Glc) on the basis of accurate mass measurements of characteristic ions and fragmentation patterns using high-resolution liquid chromatography Orbitrap mass spectrometric analysis. Although their absolute structures were not clarified, 3-OH glucosylation appeared to be the most probable when considering the structure of T-2 toxin and the fragment profiles of each masked mycotoxin. Concomitant detection of deoxynivalenol-3-glucoside (DON-3G) in the same material further supports this probability. According to an extrapolation based on the molar ratio DON-3G/DON (0.059), amounts of T2-Glc and HT2-Glc were estimated to be approximately 24 μg/kg and 41 μg/kg, respectively.

Pediatric orbital schwannoma originating from the oculomotor nerve

Intraorbital schwannoma is a rare tumor that constitutes approximately 1%-8% of all orbital tumors. The authors report a case of orbital schwannoma in a 5-year-old boy who was admitted to their institute with exophthalmos and ptosis of the right eye. Computed tomography scanning and MR imaging revealed a retroocular mass in the right orbit. The tumor was successfully removed via a transcranial approach. The pathological diagnosis was schwannoma that appeared to originate from the superior branch of the oculomotor nerve. Despite the rarity of these intraorbital extraocular tumors in children, schwannomas should be differentiated from other intraorbital tumors.

Posterior occipitocervical fixation under skull-femoral traction for the treatment of basilar impression in a child with Klippel-Feil syndrome

We present the case of a 15-year-old boy with symptoms due to Klippel-Feil syndrome. Radiographs and CT scans demonstrated basilar impression, occipitalisation of C1 and fusion of C2/C3. MRI showed ventral compression of the medullocervical junction. Skull traction was undertaken pre-operatively to determine whether the basilar impression could be safely reduced. During traction, the C3/C4 junction migrated 12 mm caudally and spasticity resolved. Peri-operative skull-femoral traction enabled posterior occipitocervical fixation without decompression. Following surgery, cervical alignment was restored and spasticity remained absent. One year after surgery he was not limited in his activities. The surgical strategy for patients with basilar impression and congenital anomalies remains controversial. The anterior approach with decompression is often recommended for patients with ventral compression of the medullocervical region, but such procedures are technically demanding and carry a significant risk of complications. Our surgical strategy was an alternative solution. Prior to a posterior cervical fixation, without decompression, skull traction was used to confirm that the deformity was reducible and effective in resolving associated myelopathy.

23 DEVELOPMENTAL POTENTIAL OF CLONED TRANSGENIC PORCINE EMBRYOS PRODUCED BY SERIAL NUCLEAR TRANSFER CAN BE IMPROVED BY TREATMENT WITH HISTONE DEACETYLASE INHIBITORS

Recently, we generated cloned transgenic pigs by nuclear transfer (NT) using fetal fibroblasts transfected with a LEA29Y gene specifically expressed in pancreatic β-cells (INS-LEA). Transfer of 216 NT embryos into 3 recipients resulted in the birth of 9 piglets. Furthermore, we examined serial NT with donor cells of the INS-LEA cloned pigs as a means of propagating the genotype of these valuable animals. Surprisingly, no piglets were obtained after transfer of 512 NT embryos into 5 recipients, which might be due to epigenetic alterations that presumably occurred during post-implantation development of the first round cloned embryos or during nuclear reprogramming in the second round of NT. In this study we tested whether in vitro development of re-cloned embryos can be improved by their treatment with histone deacetylase inhibitors (HDACi), scriptaid and suberoylanilide hydroxamic acid (SAHA). As nuclear donors, ear fibroblast cells derived from the INS-LEA cloned pig were used. Nuclear transfer was performed using in vitro-matured oocytes as previously reported (Kurome et al. 2006, Transgenic Res. 15, 229–240). After activation, reconstructed embryos were treated immediately by scriptaid (500 nM) and SAHA (10 μM) for 16 and 10 h, respectively. Development of NT embryos was assessed by cleavage and blastocyst formation during culture for 7 days. The cell number of blastocysts was also counted after fixation and staining. There was no significant difference in the cleavage rate between treated and non-treated by both HDACi, whereas treatment of NT embryos with scriptaid or SAHA significantly enhanced their development to blastocyst compared with non-treated NT embryos (22.2%, 43/194 and 22.7%, 34/150 vs 7.7%, 15/195 and 12.3%, 18/146, respectively; P < 0.05). Notably, blastocyst rates obtained after treatment of re-cloned embryos with HDACi were similar to those in the first round of NT (21.2%, 33/156). Treatment of NT embryos with HDACi did not increase mean cell number of blastocysts compared with non-treated embryos. The results of our study show that in vitro developmental competence of embryos produced by serial NT can be improved by both HDACi used, scriptaid as well as SAHA, which has not been reported before in pig cloning. To determine the post-implantation developmental potential, re-cloned embryos treated with HDACi will be transferred to surrogate gilts. This work is supported by the DFG (FOR535, FOR793), the Bayerische Forschungsstiftung and Mukoviszidose e.V.

239 A NOVEL PIG MODEL OF CYSTIC FIBROSIS GENERATED BY SEQUENTIAL TARGETING OF CFTR BY BACTERIAL ARTIFICIAL CHROMSOME VECTORS

Cystic fibrosis (CF), the most common inherited disease in the Caucasian population, is caused by mutations of the CFTR gene, coding for an anion channel responsible for chloride movement, determining transepithelial salt transport, fluid flow and ion concentrations. Cystic fibrosis is determined by chronic lung disease, marked by airway surface dehydration, reduced mucus clearance and increased mucus obstruction, impaired bacterial killing and inflammation and continuous destruction of the lung tissue. The lack of suitable CF mouse models has so far impeded the understanding of disease mechanisms and the development of novel therapies. Recently, a pig model reflecting the main hallmarks of the human disease in the respiratory, gastrointestinal and genital tracts has been reported (Rogers et al. 2008 Science 321, 1837–1841). In the present study, we generated a new CF pig model by disrupting the CFTR gene using an approach that differs in 3 major aspects from the previously published model: (1) gene targeting was achieved using a modified bacterial artificial chromosome (BAC) vector; (2) transcription of the CFTR gene was completely prevented; and (3) homozygous CFTR mutant pigs were derived by nuclear transfer from cells in which both alleles were inactivated by sequential BAC targeting. We characterised 2 cloned litters with a total of 13 piglets (including 4 stillborns). All piglets showed a characteristic CF multi-organ disease with severe meconium ileus, microcolon, microgallbladder, hypoplasia of the exocrine pancreas, congenital aplasia of the vas deferens and malformations of the trachea. In contrast to the recently published CF pig, where the majority of the intestinal obstructions occurred proximal to the ileocecal junction, we found obstructions exclusively distal to this site. We thus present a novel pig model for CF that reflects the main hallmarks of the human disease. It confirms the suitability of the CFTR mutant pig for cystic fibrosis research and increases the availability of CF models for molecular and translational CF research. The help by Prof. K. Heinritzi and his team from the Pig Clinic, LMU Munich, is gratefully acknowledged. This study was supported by Mukoviszidose e.V.

238 TAILORED PIG MODEL OF DUCHENNE MUSCULAR DYSTROPHY

Duchenne muscular dystrophy (DMD) is one of the most common genetic diseases in humans, affecting 1 in 3500 boys. It is characterised by progressive muscle weakness and wasting due to mutations in the dystrophin (DMD) gene resulting in absence of dystrophin protein in skeletal muscle. Although curative treatments are currently not available, genetic and pharmacological approaches are under investigation including early-phase clinical trials. Existing animal models in different species (e.g. mdx mouse, GRMD dog) have been instrumental to understand the pathophysiology of DMD, but have several limitations. Importantly, the causative point mutations (mdx mouse: nonsense mutation; GRMD dog: splice mutation) are different from the most common human mutations (out-of-frame deletion of one or several exons of the DMD gene). We used gene targeting in somatic cells and nuclear transfer to generate a genetically tailored pig model of DMD. A bacterial artificial chromosome (BAC) from the porcine DMD gene was modified by recombineering to replace exon 52, resulting in a frame shift in the transcript. Modified BAC were transfected into male neonatal kidney cells, which were screened by quantitative polymerase chain reaction for replacement of exon 52 in the X-linked DMD gene. Eight of 436 cell clones were successfully targeted and 2 of them were used for nuclear transfer. For each of the cell clones, a pregnancy was established by transfer of cloned embryos into recipient gilts. Four piglets of the first litter were live born and killed within 48 h and tissue samples were processed for histological characterisation. Two piglets of the second litter died during birth due to obstetric complications, whereas the other 2 piglets were delivered by Caesarean section and raised in an artificial feeding system. Their serum creatine kinase (CK) levels were grossly elevated. Although both piglets showed reduced mobility compared with age-matched controls, they were able to move and feed on their own. Immunofluorescence staining of dystrophin was negative in muscle fibres of DMD mutant piglets and the complete absence of dystrophin protein was confirmed by immunoblot analysis. Histological examination of biceps femoris muscle from DMD mutant pigs showed a degenerative myopathy with fibre size variation, rounded fibres, central nuclei, fibrosis and fatty replacement of muscle tissue mimicking the hallmarks of the human disease. In conclusion, we generated the first pig model for a genetic muscle disease. The DMD mutant pig appears to be a bona fide model of the human dystrophy as ascertained by absence of the dystrophin protein, elevated serum CK levels and early degenerative changes on muscle histology. Because deletion of exon 52 is one of the most frequent mutations found in human DMD, the exon 52 mutated DMD pig represents an excellent model for testing targeted genetic treatments. This study was supported by the Bayerische Forschungsstiftung.

Preliminary assessment of the safety and efficacy of tanezumab in Japanese patients with moderate to severe osteoarthritis of the knee: a randomized, double-blind, dose-escalation, placebo-controlled study

OBJECTIVE

To investigate the use of tanezumab, a humanized monoclonal antibody that inhibits nerve growth factor, for the treatment of moderate to severe osteoarthritis in Japanese patients.

DESIGN

Patients received tanezumab 10, 25, 50, 100, 200 μg/kg, or placebo and were followed for 92 or 120 days. Endpoints included the incidence of adverse events (AEs) and the change from baseline to week 8 in pain intensity and the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) subscales.

RESULTS

Patients (n = 83) were 69% female, age 44-73 years, with a Kellgren-Lawrence X-ray grade of 2-4. At week 8, compared with placebo, tanezumab 25, 100, and 200 μg/kg improved index knee pain during walking (-18.5, -14.3, and -27.6, respectively), index knee pain in the past 24 h (-19.1, -14.6, and -24.2, respectively), current index knee pain (-16.5, -10.9, and -22.8, respectively), and the WOMAC pain (-11.5, -9.6, and -18.8, respectively), physical function (-8.7, -9.5, and -17.6, respectively), and stiffness (-20.4, -11.2, and -10.2, respectively) subscales. Overall, seven patients reported AEs of abnormal peripheral sensation: allodynia (two in the tanezumab 200 μg/kg group); paresthesia (two in the tanezumab 200 μg/kg group), dysesthesia (one in the tanezumab 200 μg/kg group); thermohypoesthesia (one in the tanezumab 100 μg/kg group), and decreased vibratory sense (one in the placebo group). All of these AEs were mild to moderate in severity and transient in nature.

CONCLUSIONS

Tanezumab was safe and generally well tolerated and may improve pain symptoms in Japanese patients with moderate to severe osteoarthritis of the knee. CLINICALTRIALS.GOV IDENTIFIER: NCT00669409.