Hyperacute rejection of porcine organs by old world primate recipients is mediated through preformed antibodies against galactosyl-␣-1,3-galactose (Gal␣-1,3-Gal) epitopes expressed on the pig cell surface. Previously, we generated inbred miniature swine with a null allele of the ␣-1,3-galactosyltransferase locus (GGTA1) by nuclear transfer (NT) with gene-targeted fibroblasts. To expedite the generation of GGTA1 null pigs, we selected spontaneous null mutant cells from fibroblast cultures of heterozygous animals for use in another round of NT. An unexpectedly high rate of spontaneous loss of GGTA1 function was observed, with the vast majority of null cells resulting from loss of the WT allele. Healthy piglets, hemizygous and homozygous for the genetargeted allele, were produced by NT by using fibroblasts that had undergone deletional and crossover͞gene conversion events, respectively. Aside from loss of Gal␣-1,3-Gal epitopes, there were no obvious phenotypic differences between these null piglets and WT piglets from the same inbred lines. In fact, congenital abnormalities observed in the heterozygous NT animals did not reappear in the serially produced null animals.A ntibodies against galactosyl-␣-1,3-galactose (Gal␣-1,3-Gal) residues on cell surface glycoproteins of pig cells mediate hyperacute rejection of porcine organs in primate model recipients and are the most immediate barrier to successful clinical xenotransplantation (1, 2). High levels of preformed ''natural'' antibodies against the Gal␣-1,3-Gal epitope are found in humans and old world primates, following evolutionary loss of the corresponding galactosyltransferase activity (encoded by GGTA1) (3). The presence of these antibodies, along with the high density of Gal␣-1,3-Gal residues on most pig cells (4), suggests that elimination of GGTA1 function would provide a practical means of overcoming both hyperacute rejection and subsequent acute or chronic tissue damage associated with antibody binding to this epitope.The lack of GGTA1 function in humans and old world primates, along with the viability of GGTA1 knockout mice produced with embryonic stem cell technology (5, 6), suggested that a knockout strategy might be biologically feasible in pigs. The cloning of sheep (7) and subsequently pigs (8-10) by nuclear transfer with somatic cells has made attempts to knockout the GGTA1 locus in pigs technically feasible.We have previously reported the generation of GGTA1 heterozygous inbred miniature swine using nuclear transfer with gene-targeted fibroblasts (11). Starting with heterozygous fibroblasts from such animals, we now report the isolation of GGTA1 null cells with spontaneous loss of the WT allele. The rate of loss of heterozygosity (LOH) was several orders of magnitude greater than typically expected, an observation that may be related to the inbred background of the heterozygous animals. LOH resulted in some cases from deletion of the WT allele and in others from either somatic crossing over or gene conversion. Similarly high rates of somatic recombi...
To identify susceptibility loci for schizophrenia, we performed a two-stage genome-wide association study (GWAS) of schizophrenia in the Han Chinese population (GWAS: 746 individuals with schizophrenia and 1,599 healthy controls; validation: 4,027 individuals with schizophrenia and 5,603 healthy controls). We identified two susceptibility loci for schizophrenia at 6p21-p22.1 (rs1233710 in an intron of ZKSCAN4, P(combined) = 4.76 × 10(-11), odds ratio (OR) = 0.79; rs1635 in an exon of NKAPL, P(combined) = 6.91 × 10(-12), OR = 0.78; rs2142731 in an intron of PGBD1, P(combined) = 5.14 × 10(-10), OR = 0.79) and 11p11.2 (rs11038167 near the 5' UTR of TSPAN18, P(combined) = 1.09 × 10(-11), OR = 1.29; rs11038172, P(combined) = 7.21 × 10(-10), OR = 1.25; rs835784, P(combined) = 2.73 × 10(-11), OR = 1.27). These results add to previous evidence of susceptibility loci for schizophrenia at 6p21-p22.1 in the Han Chinese population. We found that NKAPL and ZKSCAN4 were expressed in postnatal day 0 (P0) mouse brain. These findings may lead to new insights into the pathogenesis of schizophrenia.
BackgroundBecause few studies exist to describe the unique molecular network regulation behind pig pre-implantation embryonic development (PED), genetic engineering in the pig embryo is limited. Also, this lack of research has hindered derivation and application of porcine embryonic stem cells and porcine induced pluripotent stem cells (iPSCs).ResultsWe identified and analyzed the genome wide transcriptomes of pig in vivo-derived and somatic cell nuclear transferred (SCNT) as well as mouse in vivo-derived pre-implantation embryos at different stages using mRNA deep sequencing. Comparison of the pig embryonic transcriptomes with those of mouse and human pre-implantation embryos revealed unique gene expression patterns during pig PED. Pig zygotic genome activation was confirmed to occur at the 4-cell stage via genome-wide gene expression analysis. This activation was delayed to the 8-cell stage in SCNT embryos. Specific gene expression analysis of the putative inner cell mass (ICM) and the trophectoderm (TE) revealed that pig and mouse pre-implantation embryos share regulatory networks during the first lineage segregation and primitive endoderm differentiation, but not during ectoderm commitment. Also, fatty acid metabolism appears to be a unique characteristic of pig pre-implantation embryonic development. In addition, the global gene expression patterns in the pig SCNT embryos were different from those in in vivo-derived pig embryos.ConclusionsOur results provide a resource for pluripotent stem cell engineering and for understanding pig development.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-15-4) contains supplementary material, which is available to authorized users.
We report regional rates of cerebral protein synthesis (rCPS) measured with the fully quantitative L-[1-(11)C]leucine positron emission tomography (PET) method. The method accounts for the fraction (lambda) of unlabeled amino acids in the precursor pool for protein synthesis derived from arterial plasma; the remainder (1-lambda) comes from tissue proteolysis. We determined rCPS and lambda in 18 regions and whole brain in 10 healthy men (21 to 24 years). Subjects underwent two 90-min dynamic PET studies with arterial blood sampling at least 2 weeks apart. Rates of cerebral protein synthesis varied regionally and ranged from 0.97+/-0.70 to 2.25+/-0.20 nmol/g per min. Values of rCPS were in good agreement between the two PET studies. Mean differences in rCPS between studies ranged from 9% in cortical regions to 15% in white matter. The lambda value was comparatively more uniform across regions, ranging from 0.63+/-0.03 to 0.79+/-0.02. Mean differences in lambda between studies were 2% to 8%. Intersubject variability in rCPS was on average 6% in cortical areas, 9% in subcortical regions, and 12% in white matter; intersubject variability in lambda was 2% to 8%. Our data indicate that in human subjects low variance and highly reproducible measures of rCPS can be made with the L-[1-(11)C]leucine PET method.
The aim of the study was to evaluate risk factors for long-term mortality and progressive chronic kidney disease (CKD) after cardiac surgery in patients with normal preoperative renal function and postoperative acute kidney injury (AKI). From April 2009 to December 2012, we prospectively enrolled 3245 cardiac surgery patients of our hospital. The primary endpoints included survival rates and the secondary endpoint was the incidence of progressive chronic kidney disease (CKD) in a follow-up period of 2 years. Acute kidney injury was staged by KDIGO classification. Progressive CKD was defined as GFR ≤ 30 mL/min/1.73 m2 or end-stage renal disease (ESRD) (starting renal replacement therapy or renal transplantation).The AKI incidence was 39.9% (n = 1295). The 1 and 2 year overall survival (OS) rates of AKI patients were significantly lower than that for non-AKI patients (85.9% and 82.3% vs 98.1% and 93.7%, P < 0.001), even after complete recovery of renal function during 2 years after intervention (P < 0.001). The 2-year overall survival (OS) rates of patients with AKI stage 1, 2, and 3 were 89.9%, 78.6%, and 61.4% (P < 0.001), respectively. Multivariate Cox regression analysis of factors for 2-year survival rates revealed that besides age (P < 0.001), chronic cardiac failure (P < 0.001), diabetes (P < 0.001), cardiopulmonary bypass time (P < 0.01), and length of intensive care unit (ICU) stay (P = 0.004), AKI was a significant risk factor for reducing 2-year survival rates even after complete recovery of renal function (P < 0.001). The accumulated progressive CKD prevalence was significantly higher in AKI than in non-AKI patients (6.8% vs 0.2%, P < 0.001) in the 2 years after surgery. Even with complete recovery of renal function at discharge, AKI was still a risk factor for accumulated progressive CKD (RR 1.92, 95% CI 1.37–2.69).The 2-year mortality and progressive CKD incidence even after complete recovery of renal function were significantly increased in cardiac surgery patients with postoperative AKI.
Sun (2013) Maternal factors required for oocyte developmental competence in mice: Transcriptome analysis of non-surrounded nucleolus (NSN) and surrounded nucleolus (SN) oocytes, Cell Cycle, 12:12, 1928Cycle, 12:12, -1938
Background: Mammalian first lineage segregation generates trophectoderm (TE) and pluripotent inner cell mass (ICM), which provides an ideal model for studying the mechanisms of maintenance and loss of pluripotency. In mouse, the transcription factor OCT4 restricts to ICM and plays a key role in TE/ICM specification and pluripotent regulatory networks. However, in pig, OCT4 does not restrict to ICM cells, suggesting a different molecular basis in TE/ICM specification and pluripotent regulatory networks. Results: To explore molecular basis of porcine TE/ICM specification and pluripotent regulatory networks, we examined expression pattern of pluripotency factors, including SOX2, REX1, SALL4, ESG1, NANOG, TBX3, LIN28, KLF2, and KLF5, in porcine blastocysts. We found that SOX2 is a faithful pluripotent marker that anchored to the pluripotent cells including embryonic part cells, ICM cells and newly EPI cells along with developmental progress, whereas OCT4 expressed in almost all the cells at the same time. Consistently, analysis of spatiotemporal distribution of SOX2 and the TE marker CDX2 revealed an exclusive expression pattern in D6 blastocysts, whereas no correlation was observed between OCT4 and CDX2 at the same stage. Conclusions: Our results provide a molecular basis in porcine embryonic patterning and a clue for further studying porcine pluripotent regulatory networks. Developmental Dynamics 244:619-627, 2015. V C 2015 Wiley Periodicals, Inc.
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