Animal cloning technology with somatic cells provides an alternative tool to conventional methods for producing transgenic animals. Gene targeting in animals is made feasible using somatic cells with homologous recombination procedure that is a major technique in embryonic stem cells for knocking-out genes. Homologous recombination events in somatic cells are relatively inefficient as compared to those in ES cells, suggesting the need for establishment of efficient gene targeting system in somatic cells. To investigate the efficiency of positive and negative selection for gene targeting in pig fetal fibroblast cells, pig alpha-1,3-galactosyl transferase (13-GT) gene was used for gene targeting. The neomycin phosphotransferase (Neo(r)) and herpes simplex virus-thymidine kinase (HSV-tk) genes were used as positive and negative selection markers in this experiment. Following transfection with targeting DNA construct, the pig fetal fibroblast cells were selected against resistance of G418 and gancyclovir. In DMEM medium containing 5 to 10% serum, Pig fetal fibroblast cells failed to proliferate during drug selection. Increasing serum concentration to 15% of medium yielded less senescent colonies of pig fetal fibroblast cells following drug selection that allowed enough cell colonies to screen genomic DNA. The frequency of gene targeting in pig fetal fibroblast cells with double drug selection was more than 10-fold efficient compared to that with G418 single selection. Double selection method with Neo' and HSV-tk genes could be useful for gene targeting in somatic cells for production of cloned animals carrying targeted endogenous genes.
Animals ; Fibroblasts ; Galactosyltransferases/*genetics/*metabolism ; *Gene Targeting ; Genetic Vectors/genetics ; Polymerase Chain Reaction ; Swine/*embryology/genetics

This study sought to clone Chinese Banna minipig inbred-line (BMI) alpha1,3-galactosyltransferase (alpha1,3-GT) gene and construct its recombinant eukaryotic expression vector. Total RNA was isolated from BMI liver. Full length cDNA of alpha1,3-GT gene was amplified by RT-PCR and cloned into pMD18-T vector to sequence. Subsequently, alpha1,3-GT gene was inserted into pEGFP-N1 to construct eukaryotic expression vector pEGFP-N1-GT. Then the reconstructed plasmid pEGFP-N1-GT was transiently transfected into human lung cancer cell line A549. The expression of alpha1,3-GT mRNA in transfected cells was detected by RT-PCR. FITC-BS-IB4 lectin was used in the direct immunofluorescence method, which was performed to observe the alpha-Gal synthesis function of BMI alpha1,3-GT in transfected cells. The results showed that full length of BMI alpha1,3-GT cDNA was 1116 bp. BMI alpha1,3-GT cDNA sequence was highly homogenous with those of mouse and bovine, and was exactly the same as the complete sequence of those of swine, pEGFP-N1-GT was confirmed by enzyme digestion and PCR. The expression of alpha1,3-GT mRNA was detected in A549 cells transfected by pEGFP-N1-GT. The expression of alpha-Gal was observed on the membrane of A549 cells transfected by pEGFP-N1-GT. Successful cloning of BMI alpha1,3-GT cDNA and construction of its eukaryotic expression vector have established a foundation for further research and application of BMI alpha1,3-GT in the fields of xenotransplantation and immunological therapy of cancer.
Animals ; Animals, Inbred Strains ; Base Sequence ; China ; Cloning, Molecular ; Galactosyltransferases ; genetics ; metabolism ; Genetic Vectors ; genetics ; Molecular Sequence Data ; Recombinant Proteins ; genetics ; metabolism ; Sequence Analysis, DNA ; Swine ; Swine, Miniature ; genetics ; Transfection

OBJECTIVETo study whether the porcine alpha1, 3 galactosyltransferase gene siRNA targeted heterozygous hepatocyte negatively expresses GT mRNA and resists to the cytotoxicity of nature antibody in human serum.

METHODSThe porcine alpha1, 3 galactosyltransferase gene siRNA targeted vector (pPNTloxPGTsiRNA) were construct with pPNTloxPGT and pMXSV/U6 vector. Positive-negative selection was used to produce a heterozygous pPNTloxPGTsiRNA knockout (+/-) clone. The GT mRNA expressions were detected with northern blot. Complement-mediated NAb cytotoxicity after incubation of hepatocytes with NAbs and complement was determined using 3- (4, 5-dimethylthiazol-2-yl)-5-(3-carboxymethyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium(MTS, tetrazolium salt) colorimetric assay.

RESULTSThe pPNTloxPGTsiRNA targeted porcine hepatocyte (+/-) negative express GT mRNA. Only 14% to 18% cytotoxicity can be detected at the highest serum concentration. The pPNTloxPGT targeted porcine hepatocyte (+/-) express GT mRNA just as the wild type porcine cells and the cytotoxicity are 77% to 83%.

CONCLUSIONThe porcine a1, 3 galactosyltransferase gene siRNA targeted heterozygous hepatocyte (+/-) negative express GT and resisted to nature antibody in human serum.

Animals ; Cells, Cultured ; Cloning, Molecular ; Cytotoxicity, Immunologic ; genetics ; Galactosyltransferases ; biosynthesis ; genetics ; Gene Silencing ; Gene Targeting ; methods ; Hepatocytes ; cytology ; metabolism ; Heterozygote ; Immune Tolerance ; genetics ; Killer Cells, Natural ; immunology ; Mutation ; RNA, Small Interfering ; biosynthesis ; genetics ; Swine ; Transfection

Recent developments in genome editing technology using meganucleases demonstrate an efficient method of producing gene edited pigs. In this study, we examined the effectiveness of the transcription activator-like effector nuclease (TALEN) system in generating specific mutations on the pig genome. Specific TALEN was designed to induce a double-strand break on exon 9 of the porcine α1,3-galactosyltransferase (GGTA1) gene as it is the main cause of hyperacute rejection after xenotransplantation. Human decay-accelerating factor (hDAF) gene, which can produce a complement inhibitor to protect cells from complement attack after xenotransplantation, was also integrated into the genome simultaneously. Plasmids coding for the TALEN pair and hDAF gene were transfected into porcine cells by electroporation to disrupt the porcine GGTA1 gene and express hDAF. The transfected cells were then sorted using a biotin-labeled IB4 lectin attached to magnetic beads to obtain GGTA1 deficient cells. As a result, we established GGTA1 knockout (KO) cell lines with biallelic modification (35.0%) and GGTA1 KO cell lines expressing hDAF (13.0%). When these cells were used for somatic cell nuclear transfer, we successfully obtained live GGTA1 KO pigs expressing hDAF. Our results demonstrate that TALEN-mediated genome editing is efficient and can be successfully used to generate gene edited pigs.
Animals ; Antigens, CD55/genetics ; Cell Line ; DNA Breaks, Double-Stranded ; Exons/genetics ; Galactosyltransferases/*genetics ; Gene Editing/*veterinary ; Gene Knockout Techniques ; Humans ; Nuclear Transfer Techniques ; Swine ; Transcription Activator-Like Effector Nucleases/*genetics/*metabolism

BACKGROUNDThere are few reports of a biological role for glycosyltransferases in the infiltration of osteoarthritic synovitis. The aim of this research was to investigate the expression and cellular location of β-1,4-galactosyltransferase I (β-1,4-GalT-I) in a surgically-induced rat model of knee osteoarthritis (OA), and explore the role of β-1,4-GalT-I in the pathogenesis of OA.

METHODSMale Sprague-Dawley rats were randomly divided into three groups: OA group, sham group and normal group. The model of OA was established in the right knees of rats by anterior cruciate ligament transaction (ACLT) with partial medial meniscectomy. Fibroblast-like synoviocytes (FLSs) obtained from normal rat synovial tissue were cultured. The expression of β-1,4-GalT-I mRNA in the synovial tissue, articular cartilage and FLSs treated with tumor necrosis factor-α (TNF-α) were assayed by real-time PCR. Western-blotting and immunohistochemisty were used to observe the expression of β-1,4-GalT-I at the protein level. Double immunofluorescent staining was used to define the location of the β-1,4-GalT-I with macrophage-like synoviocytes, FLSs, neutrophils, and TNF-α in the OA synovium. The alteration of TNF-α in FLSs which were treated with lipopolysaccharide (LPS) and β-1,4-GalT-I-Ab were detected by enzyme-linked immunosorbent assay (ELISA).

RESULTSThe mRNA and protein expression of β-1,4-GalT-I increased in synovial tissue of the OA group compared with the normal and sham groups at two and four weeks after the surgery, however, no significant difference appeared in the articular cartilage. Immunohistochemistry also indicated that the β-1,4-GalT-I expression in OA synovium at four weeks after surgery increased sharply compared with the control group. β-1,4-GalT-I co-localized with macrophage-like synoviocytes, FLSs, neutrophils and TNF-α in rat OA synovitis. Moreover, in vitro β-1,4-GalT-I mRNA in FLSs was affected in a dose- and time-dependent manner in response to TNF-α stimulation. ELISA revealed that the expression of TNF-α was attenuated in FLSs in vitro when treated with anti β-1,4-GalT-I antibody.

CONCLUSIONβ-1,4-GalT-I may play an important role in the inflammation process of rat OA synovial tissue which would provide the foundation for further researching into the concrete mechanism of β-1,4-GalT-I in OA synovitis.

Animals ; Blotting, Western ; Cells, Cultured ; Enzyme-Linked Immunosorbent Assay ; Galactosyltransferases ; genetics ; metabolism ; Immunohistochemistry ; Knee Joint ; enzymology ; pathology ; surgery ; Male ; Osteoarthritis, Knee ; enzymology ; genetics ; pathology ; Polymerase Chain Reaction ; Rats ; Rats, Sprague-Dawley ; Synovial Membrane ; enzymology ; Synovitis ; enzymology ; etiology

Azacitidine ; pharmacology ; Base Sequence ; Chromosomes, Human, X ; genetics ; DNA Methylation ; drug effects ; DNA Mutational Analysis ; Galactosyltransferases ; metabolism ; Gene Expression Regulation ; drug effects ; Glomerulonephritis, IGA ; etiology ; genetics ; metabolism ; Glycosylation ; Humans ; Immunoglobulin A ; metabolism ; Lipopolysaccharides ; pharmacology ; Lymphocytes ; metabolism ; Molecular Chaperones ; genetics ; metabolism ; Mutation ; Polymorphism, Single Nucleotide

Intestinal epithelial cells (IECs) have been known to produce galactose-alpha1,4-galactose-beta1,4-glucose ceramide (Gb3) that play an important role in the mucosal immune response. The regulation of Gb3 is important to prevent tissue damage causing shiga like toxin. Epigallocatechin-3-gallate (EGCG) has been studied as anti-carcinogenic, anti-oxidant, anti-angiogenic, and anti-viral activities, and anti-diabetic. However, little is known between the expressions of Gb3 on IECs. The aim of this study was to examine the inhibitory effect of EGCG, a major ingredient of green tea, on Gb3 production via mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-kappa B) in the TNF-alpha stimulated human colon epithelial cells, HT29. To investigate how Gb3 is regulated, ceramide glucosyltransferase (CGT), lactosylceramide synthase (GalT2), and Gb3 synthase (GalT6) were analyzed by RT-PCR in HT 29 cells exposed to TNF-alpha in the presence or absence of EGCG. EGCG dose-dependently manner, inhibits TNF-alpha induced Gb3 expression by blocking in both the MAPKs and NF-kappaB pathways in HT29 cells. TNF-alpha enhanced CGT, GalT2 and GalT6 mRNA levels and EGCG suppressed the level of these enzymes enhanced by TNF-alpha treatment.
Apoptosis/drug effects ; Blotting, Western ; Catechin/*analogs & derivatives/pharmacology ; Cell Nucleus/drug effects/metabolism ; Cell Proliferation/drug effects ; Dose-Response Relationship, Drug ; Epithelial Cells/drug effects/metabolism/pathology ; Flow Cytometry ; Galactosyltransferases/genetics ; Gene Expression Regulation, Enzymologic/drug effects ; Glucosyltransferases/genetics ; HT29 Cells ; Humans ; Intestinal Mucosa/drug effects/metabolism/pathology ; Mitogen-Activated Protein Kinases/antagonists & inhibitors/*metabolism ; NF-kappa B/antagonists & inhibitors/*metabolism ; Phosphorylation/drug effects ; Protein Transport/drug effects ; RNA, Messenger/genetics/metabolism ; Research Support, Non-U.S. Gov't ; Reverse Transcriptase Polymerase Chain Reaction ; Trihexosylceramides/*biosynthesis ; Tumor Necrosis Factor-alpha/*pharmacology