Characterization of Enlarged Tongues in Cloned Piglets

Although the efficiency of cloning remains very low, this technique has become the most reliable way to produce transgenic pigs. However, the high rate of abnormal offspring such as an enlarged tongue lowers the cloning efficiency by reducing the early survivability of piglets. Thus, the present study was conducted to identify the characteristics of the enlarged tongue from cloned piglets by histologic and transcriptomic analysis. As a result, it was observed that the tissues from enlarged tongues (n = 3) showed isolated and broken muscle bundles with wide spaces while the tissues from normal tongues (n = 3) showed the tight connection of muscle bundles without space by histological analysis. Additionally, transmission electron microscopy results also showed the formation of isolated and broken muscle bundles in enlarged tongues. The transcriptome analysis showed a total of 197 upregulated and 139 downregulated genes with more than 2-fold changes in enlarged tongues. Moreover, there was clear evidence for the difference between groups in the muscle system process with high relation in the biological process by gene ontology analysis. The analysis of the Kyoto Encyclopedia of Gene and Genomes pathway of differentially expressed genes indicated that the pentose phosphate pathway, glycolysis/gluconeogenesis, and glucagon signaling pathway were also involved. Conclusively, our results could suggest that the abnormal glycolytic regulation may result in the formation of an enlarged tongue. These findings might have the potential to understand the underlying mechanisms, abnormal development, and disease diagnosis in cloned pigs.

Adipose Tissue-Derived Mesenchymal Stem Cells Extend the Lifespan and Enhance Liver Function in Hepatocyte Organoids

In this study, we generated hepatocyte organoids (HOs) using frozen-thawed primary hepatocytes (PHs) within a three-dimensional (3D) Matrigel dome culture in a porcine model. Previously studied hepatocyte organoid analogs, spheroids, or hepatocyte aggregates created using PHs in 3D culture systems have limitations in their in vitro lifespans. By co-culturing adipose tissue-derived mesenchymal stem cells (A-MSCs) with HOs within a 3D Matrigel dome culture, we achieved a 3.5-fold increase in the in vitro lifespan and enhanced liver function compared to a conventional two-dimensional (2D) monolayer culture, i.e., more than twice that of the HO group cultured alone, reaching up to 126 d. Although PHs were used to generate HOs, we identified markers associated with cholangiocyte organoids such as cytokeratin 19 and epithelial cellular adhesion molecule (EPCAM). Co-culturing A-MSCs with HOs increased the secretion of albumin and urea and glucose consumption compared to HOs cultured alone. After more than 100 d, we observed the upregulation of tumor protein P53 (TP53)-P21 and downregulation of EPCAM, albumin (ALB), and cytochrome P450 family 3 subfamily A member 29 (CYP3A29). Therefore, HOs with function and longevity improved through co-culturing with A-MSCs can be used to create large-scale human hepatotoxicity testing models and precise livestock nutrition assessment tools.

Comparative transcriptome analysis between long- and short-term survival after pig-to-monkey cardiac xenotransplantation reveals differential heart failure development

Cardiac xenotransplantation is the potential treatment for end-stage heart failure, but the allogenic organ supply needs to catch up to clinical demand. Therefore, genetically-modified porcine heart xenotransplantation could be a potential alternative. So far, pig-to-monkey heart xenografts have been studied using multi-transgenic pigs, indicating various survival periods. However, functional mechanisms based on survival period-related gene expression are unclear. This study aimed to identify the differential mechanisms between pig-to-monkey post-xenotransplantation long- and short-term survivals. Heterotopic abdominal transplantation was performed using a donor CD46-expressing GTKO pig and a recipient cynomolgus monkey. RNA-seq was performed using samples from POD60 XH from monkey and NH from age-matched pigs, D35 and D95. Gene-annotated DEGs for POD60 XH were compared with those for POD9 XH (Park et al. 2021). DEGs were identified by comparing gene expression levels in POD60 XH versus either D35 or D95 NH. 1,804 and 1,655 DEGs were identified in POD60 XH versus D35 NH and POD60 XH versus D95 NH, respectively. Overlapped 1,148 DEGs were annotated and compared with 1,348 DEGs for POD9 XH. Transcriptomic features for heart failure and inhibition of T cell activation were observed in both long (POD60)- and short (POD9)-term survived monkeys. Only short-term survived monkey showed heart remodeling and regeneration features, while long-term survived monkey indicated multi-organ failure by neural and hormonal signaling as well as suppression of B cell activation. Our results reveal differential heart failure development and survival at the transcriptome level and suggest candidate genes for specific signals to control adverse cardiac xenotransplantation effects.

Mortality, growth, and egg production do not differ between nontransgenic and transgenic female chickens with ubiquitous expression of the 3D8 single chain variable fragment gene

To date, many transgenic (TG) chicken lines have been developed, but few studies have performed a comparative analysis of their mortality, growth, and egg productivity. Previously, we reported the production of 3D8 scFv TG chickens showing antiviral activity. Here, we performed a biometric characterization of TG offspring female chickens. We selected 40 TG and 40 non-TG offspring female chicks among newly hatched chicks produced via artificial insemination of semen from heterotypic 3D8 scFv males into wild-type female chickens. Serum was collected at 14 wk of age, and serum concentrations of biochemical parameters, cytokines, and sex hormones were analyzed. Mortality and growth were monitored daily from 1 to 34 wk, egg productivity was monitored daily from 20 to 34 wk, and the weekly average values were used for analyses. Some serum parameters and cytokines were significantly different between non-TG and TG offspring female chickens. The levels of phosphorus (PHOS), total protein (TP), albumin (ALB), globulin (GLOB), and alanine aminotransferase (ALT) were significantly higher in non-TG chickens (P < 0.05). The levels of alkaline phosphatase (ALP) and gamma-glutamyltransferase (GGT) were significantly higher in TG chickens (P < 0.05). The levels of insulin growth factor-1 (IGF-1), interferon-gamma (INF-γ), interleukin-4 (IL-4), and IL-8 were significantly lower in TG chickens (P < 0.05). Despite these differences, the mortality rates, body weight, egg production rates, and egg weight were not significantly different in the experimental groups of non-TG and TG offspring female chickens (P > 0.05). In conclusion, ubiquitous expression of the 3D8 scFv gene in TG offspring female chickens does not affect some biometric characteristics, including mortality, growth, and egg productivity.

Effect of Serum and Oxygen on the In Vitro Culture of Hanwoo Korean Native Cattle-Derived Skeletal Myogenic Cells Used in Cellular Agriculture

Skeletal muscle-derived myogenic cells (SKMCs) are novel protein sources capable of replacing animal meat. However, SKMCs have not been commercialized owing to poor productivity and the high cost of in vitro cell culture. Therefore, we cultured SKMCs in varying serum (5–20%) and oxygen concentrations (5–20%) to investigate the parameters that most impact cell productivity (serum, hypoxia, and culture medium) and examined cell proliferation ability and genes involved in myogenesis/proliferation/apoptosis/reactive oxygen species (ROS). In fetal bovine serum (FBS) groups, hypoxia induction doubled cell number, and the 20% FBS/normoxia group exhibited similar cell numbers as 5% FBS/5% hypoxia, confirming that 5% hypoxia reduced serum requirement by four-fold. The use of 20% FBS downregulated MTF5/MYOD1/MYOG/MYH1, whereas hypoxia induction with ≤10% FBS upregulated them. Although 20% FBS lowered TERT expression through rapid cell proliferation, NOX1, a major factor of ROS, was suppressed. DMEM/F12 demonstrated better differentiation potential than F10 by upregulating MYF3/MYOD1/MYOG/MYH1 and downregulating MSTN, particularly DMEM/F12 with 2% FBS/5% hypoxia. The myogenic fusion index was higher in DMEM/F12 without FBS than in DMEM/F12 with FBS (0.5–5%); however, the total nuclei number was reduced owing to apoptosis. Therefore, high serum levels are essential in influencing SKMC growth, followed by hypoxia as a synergistic component.

Epigallocatechin-3-gallate protects porcine oocytes against post-ovulatory aging through inhibition of oxidative stress

Increased levels of oxidative stress are major factors that drive the process of post-ovulatory oocyte aging. Epigallocatechin-3-gallate (EGCG), which accounts for up to 50% of the catechins, possesses versatile biological functions, including preventing or treating diabetes, cancer, and heart diseases. The aim of this study was to explore whether EGCG can delay porcine oocyte aging by preventing oxidative stress. Metaphase II (MII) oocytes were cultured for 48 h with different concentrations of EGCG (0-100 μM) in vitro as a post-ovulatory aging model. An optimal concentration of 5 μM EGCG maintained oocyte morphology and developmental competence during aging. The oocytes were randomly divided into five groups: fresh, 24 h control, 24 h EGCG, 48 h control, and 48 h EGCG. The results suggest that EGCG significantly prevents aging-induced oxidative stress, glutathione (GSH) reduction, apoptosis, and autophagy. Moreover, mitochondria DNA copy number was decreased, and the number of active mitochondria and adenosine triphosphate (ATP) levels significantly increased by supplementation with EGCG. Thus, EGCG has a preventive role against aging in porcine post-ovulatory oocytes due to its ability to inhibit oxidative stress and promote mitochondrial biogenesis.

Establishment of intestinal organoids from small intestine of growing cattle (12 months old)

Recently, we reported the robust in vitro three-dimensional (3D) expansion of intestinal organoids derived from adult bovine (> 24 months) samples. The present study aimed to establish an in vitro 3D system for the cultivation of intestinal organoids derived from growing cattle (12 months old) for practical use as a potential alternative to in vivo systems for various purposes. However, very few studies on the functional characterization and 3D expansion of adult stem cells from livestock species compared to those from other species are available. In this study, intestinal crypts, including intestinal stem cells, from the small intestines (ileum and jejunum) of growing cattle were isolated and long-term 3D cultures were successfully established using a scaffold-based method. Furthermore, we generated an apical-out intestinal organoid derived from growing cattle. Interestingly, intestinal organoids derived from the ileum, but not the jejunum, could be expanded without losing the ability to recapitulate crypts, and these organoids specifically expressed several specific markers of intestinal stem cells and the intestinal epithelium. Furthermore, these organoids exhibited key functionality with regard to high permeability for compounds up to 4 kDa in size (e.g., fluorescein isothiocyanate [FITC]-dextran), indicating that apical-out intestinal organoids are better than other models. Collectively, these results indicate the establishment of growing cattle-derived intestinal organoids and subsequent generation of apical-out intestinal organoids. These organoids may be valuable tools and potential alternatives to in vivo systems for examining host-pathogen interactions involving epithelial cells, such as enteric virus infection and nutrient absorption, and may be used for various purposes.

Immunosuppression-enhancing effect of the administration of allogeneic canine adipose-derived mesenchymal stem cells (cA-MSCs) compared with autologous cA-MSCs in vitro

Background

Recently, mesenchymal stem cells therapy has been performed in dogs, although the outcome is not always favorable.

Objectives

To investigate the therapeutic efficacy of mesenchymal stem cells (MSCs) using dog leukocyte antigen (DLA) matching between the donor and recipient in vitro.

Methods

Canine adipose-derived MSCs (cA-MSCs) isolated from the subcutaneous tissue of Dog 1 underwent characterization. For major DLA genotyping (DQA1, DQB1, and DRB1), peripheral blood mononuclear cells (PBMCs) from two dogs (Dogs 1 and 2) were analyzed by direct sequencing of polymerase chain reaction (PCR) products. The cA-MSCs were co-cultured at a 1:10 ratio with activated PBMCs (DLA matching or mismatching) for 3 days and analyzed for immunosuppressive (IDO, PTGS2, and PTGES), inflammatory (IL6 and IL10), and apoptotic genes (CASP8, BAX, TP53, and BCL2) by quantitative real-time reverse transcriptase-PCR.

Results

cA-MSCs were expressed cell surface markers such as CD90⁺/44⁺/29⁺/45^- and differentiated into osteocytes, chondrocytes, and adipocytes in vitro. According to the Immuno Polymorphism Database, DLA genotyping comparisons of Dogs 1 and 2 revealed complete differences in genes DQA1, DQB1, and DRB1. In the co-culturing of cA-MSCs and PBMCs, DLA mismatch between the two cell types induced a significant increase in the expression of immunosuppressive (IDO/PTGS2) and apoptotic (CASP8/BAX) genes.

Conclusions

The administration of cA-MSCs matching the recipient DLA type can alleviate the need to regulate excessive immunosuppressive responses associated with genes, such as IDO and PTGES. Furthermore, easy and reliable DLA genotyping technology is required because of the high degree of genetic polymorphisms of DQA1, DQB1, and DRB1 and the low readability of DLA 88.

Effect of sex-specific differences on function of induced hepatocyte-like cells generated from male and female mouse embryonic fibroblasts

BACKGROUND

The liver is one of the vital organs involved in detoxification and metabolism. The sex-based differences between the functionality of male and female liver have been previously reported, i.e., male's liver are good in alcohol clearance and lipid metabolism, while female's liver are better in cholesterol metabolism. To date, studies on novel drug toxicity have not considered the sex-specific dimorphic nature of the liver. However, the use of hepatocyte-like cells to treat liver diseases has increased recently.

METHODS

Mouse embryos were isolated from a pregnant female C57BL/6J mouse where mouse embryonic fibroblasts (MEFs) were isolated from back skin tissue of each embryo. MEFs were transduced with human transcription factors hHnf1α, hHnf4α, and hFoxa3 using the lentiviral system. The transduced MEFs were further treated with hepatocyte-conditioned media followed by its analysis through RT-qPCR, immunofluorescence, functional assays, and finally whole-transcriptome RNA sequencing analysis. For in vivo investigation, the mouse hepatocyte-like cells (miHep) were transplanted into CCl4-induced acute liver mouse model.

RESULTS

In this study, we evaluated the sex-specific effect of miHep induced from male- and female-specific mouse embryonic fibroblasts (MEFs). We observed miHeps with a polygonal cytoplasm and bipolar nucleus and found that male miHeps showed higher mHnf4a, albumin secretion, and polyploidization than female miHeps. Transcriptomes from miHeps were similar to those from the liver, especially for Hnf4a of male miHeps. Male Cyps were normalized to those from females, which revealed Cyp expression differences between liver and miHeps. In both liver and miHeps, Cyp 4a12a and Cyp 4b13a/2b9 predominated in males and females, respectively. After grafting of miHeps, AST/ALT decreased, regardless of mouse sex.

CONCLUSION

In conclusion, activation of endogenic Hnf4a is important for generation of successful sex-specific miHeps; furthermore, the male-derived miHep exhibits comparatively enhanced hepatic features than those of female miHep.

Comprehensive Analysis of Cardiac Xeno-Graft Unveils Rejection Mechanisms

Porcine heart xenotransplantation is a potential treatment for patients with end-stage heart failure. To understand molecular mechanisms of graft rejection after heart transplantation, we transplanted a 31-day-old alpha-1,3-galactosyltransferase knockout (GTKO) porcine heart to a five-year-old cynomolgus monkey. Histological and transcriptome analyses were conducted on xenografted cardiac tissue at rejection (nine days after transplantation). The recipient monkey's blood parameters were analyzed on days -7, -3, 1, 4, and 7. Validation was conducted by quantitative real-time PCR (qPCR) with selected genes. A non-transplanted GTKO porcine heart from an age-matched litter was used as a control. The recipient monkey showed systemic inflammatory responses, and the rejected cardiac graft indicated myocardial infarction and cardiac fibrosis. The transplanted heart exhibited a total of 3748 differentially expressed genes compared to the non-transplanted heart transcriptome, with 2443 upregulated and 1305 downregulated genes. Key biological pathways involved at the terminal stage of graft rejection were cardiomyopathies, extracellular interactions, and ion channel activities. The results of qPCR evaluation were in agreement with the transcriptome data. Transcriptome analysis of porcine cardiac tissue at graft rejection reveals dysregulation of the key molecules and signaling pathways, which play relevant roles on structural and functional integrities of the heart.

Induction of the differentiation of porcine bone marrow mesenchymal stem cells into premature hepatocyte-like cells in an indirect coculture system with primary hepatocytes

Liver transplantation is currently the only option for patients with end-stage liver disease. Thus, other alternate therapeutic strategies are needed. Bone marrow mesenchymal stem cells (BM-MSCs) are nonhematopoietic cells present in the bone marrow stroma that serve as precursors cells for various other cells. In this study, we evaluated the differentiation of porcine BM-MSCs into hepatocyte-like cells using three types of culture systems: hepatic induction medium (HIM), HIM/primary hepatocyte culture supernatant (HCS; 1:1 ratio), and a hepatocyte coculture system (HCCS; primary hepatocytes in the upper chamber, and BM-MSCs in the lower chamber). Primary hepatocytes were isolated from anesthetized healthy 1-month-old pigs by enzymatic digestion. Hepatic-specific marker expression (albumin [ALB], transferrin [TF], α-fetoprotein [AFP]), glycogen storage, low-density lipoprotein, and indocyanine green uptake were evaluated. Upregulation of hepatic-specific markers (ALB, TF, and AFP) was observed by real-time polymerase chain reaction in the HCCS group. Periodic acid-Schiff staining revealed enhanced glycogen storage in hepatocyte-like cells from the HCCS group compared with that from the HIM/HCS group. Furthermore, hepatocyte like-cells in the HCCS group showed improved LDL and ICG uptake than those in the other groups. Overall, our current study revealed that indirect coculture of primary hepatocytes and BM-MSCs enhanced the differentiation efficacy of BM-MSCs into hepatocyte-like cells by unknown useful soluble factors, including paracrine factors.

Morphometric analysis of alpha-1, 3-galactosyltransferase knockout pig kidney and heart

We report a morphometric evaluation of α1,3-galactosyltransferase knockout (GTKO) pig heart and kidney (n = 9) at the end of one, three and seven months. Organs parameters gradually increased with the age (p < 0.05) and body weight (p < 0.05) of the pigs. Organs morphometries were significantly correlated to the age and body weight of the animal. We were able to conclude the average size of GTKO pig heart and kidney based on age and body weight, which could be helpful in estimating the size of these organs non-invasively for transplantation.

Connexin 43 Knockdown Induces Mitochondrial Dysfunction and Affects Early Developmental Competence in Porcine Embryos

Connexin 43 (CX43) is a component of gap junctions. The lack of functional CX43 induces oxidative stress, autophagy, and apoptosis in somatic cells. However, the role of CX43 in the early development of porcine embryos is still unknown. Thus, the aim of this study was to investigate the role of CX43, and its underlying molecular mechanisms, on the developmental competence of early porcine embryos. We performed CX43 knockdown by microinjecting dsRNA into parthenogenetically activated porcine parthenotes. The blastocyst development rate and the total number of cells in the blastocysts were significantly reduced by CX43 knockdown. Results from FITC-dextran assays showed that CX43 knockdown significantly increased membrane permeability. ZO-1 protein was obliterated in CX43 knockdown blastocysts. Mitochondrial membrane potential and ATP production were significantly reduced following CX43 knockdown. Reactive oxygen species (ROS) levels were significantly increased in the CX43 knockdown group compared to those in control embryos. Moreover, CX43 knockdown induced autophagy and apoptosis. Our findings indicate that CX43 is essential for the development and preimplantation of porcine embryos and maintains mitochondrial function, cell junction structure, and cell homeostasis by regulating membrane permeability, ROS generation, autophagy, and apoptosis in early embryos.

Codon optimized membrane cofactor protein expression in α 1, 3 galactosyltransferase knockout pig cells improve protection against cytotoxicity of monkey serum

In this study, we attempted to upgrade GT ^-MCP/-MCP pig genetically to express MCP at a higher level and additionally thrombomodulin (TBM), which have respective roles as a complement regulatory protein and a coagulation inhibitor. We constructed a dicistronic cassette consisting of codon-optimized MCP (mMCP) and TBM (m-pI2), designed for ubiquitous expression of MCP and endothelium specific expression of TBM. The cassette was confirmed to allow extremely increased MCP expression compared with non-modified MCP, and an endothelial-specific TBM expression. We thus transfected m-pI2 into ear-skin fibroblasts isolated from a GT ^-MCP/-MCP pig. By twice selection using magnetically activated cell sorting (MACS), and single-cell culture, we were able to obtain clones over 90% expressing MCP. The cells of a clone were provided as a donor for nuclear transfer resulting in the generation of a GT ^-MCP/-MCP /mMCP/TBM pig, which was confirmed to be carrying cells expressing MCP and functioning as an inhibitor against the cytotoxic effect of normal monkey serum, comparable with donor cells. Collectively, these results demonstrated an effective approach for upgrading transgenic pig, and we assumed that upgraded pig would increase graft survival.

Transdifferentiation of α-1,3-galactosyltransferase knockout pig bone marrow derived mesenchymal stem cells into pancreatic β-like cells by microenvironment modulation

OBJECTIVE

To evaluate the pancreatic differentiation potential of α-1,3-galactosyltransferase knockout (GalTKO) pig-derived bone marrow-derived mesenchymal stem cells (BM-MSCs) using epigenetic modifiers with different pancreatic induction media.

METHODS

The BM-MSCs have been differentiated into pancreatic β-like cells by inducing the overexpression of key transcription regulatory factors or by exposure to specific soluble inducers/small molecules. In this study, we evaluated the pancreatic differentiation of GalTKO pig-derived BM-MSCs using epigenetic modifiers, 5-azacytidine (5-Aza) and valproic acid (VPA), and two types of pancreatic induction media - advanced Dulbecco's modified Eagle's medium (ADMEM)-based and N2B27-based media. GalTKO BM-MSCs were treated with pancreatic induction media and the expression of pancreas-islets-specific markers was evaluated by real-time quantitative polymerase chain reaction, Western blotting, and immunofluorescence. Morphological changes and changes in the 5'-C-phosphate-G-3' (CpG) island methylation patterns were also evaluated.

RESULTS

The expression of the pluripotent marker (POU class 5 homeobox 1 [OCT4]) was upregulated upon exposure to 5-Aza and/or VPA. GalTKO BM-MSCs showed increased expression of neurogenic differentiation 1 in the ADMEM-based (5-Aza) media, while the expression of NK6 homeobox 1 was elevated in cells induced with the N2B27-based (5-Aza) media. Moreover, the morphological transition and formation of islets-like cellular clusters were also prominent in the cells induced with the N2B27-based media with 5-Aza. The higher insulin expression revealed the augmented trans-differentiation ability of GalTKO BM-MSCs into pancreatic β-like cells in the N2B27-based media than in the ADMEM-based media.

CONCLUSION

5-Aza treated GalTKO BM-MSCs showed an enhanced demethylation pattern in the second CpG island of the OCT4 promoter region compared to that in the GalTKO BM-MSCs. The exposure of GalTKO pig-derived BM-MSCs to the N2B27-based microenvironment can significantly enhance their trans-differentiation ability into pancreatic β-like cells.

Ubiquinol-10 delays postovulatory oocyte aging by improving mitochondrial renewal in pigs

Ubiquinol-10, the reduced form of coenzyme Q10, protects mammalian cells from oxidative damage and enhances mitochondrial activity. However, the protective effect of ubiquinol-10 on mammalian oocytes is not well understood. In this study, we investigated the effect of ubiquinol-10 on porcine oocytes during postovulatory aging. Metaphase II oocytes were selected as fresh oocytes and further cultured for 48 h with different concentrations of ubiquinol-10 (0–400 μM) in vitro as a postovulatory aging model. After choosing the optimal concentration of ubiquinol-10 (100 μM) that maintained oocyte morphology and developmental competence during the progression of aging, the oocytes were randomly divided into five groups: fresh, control-24 h, ubiquinol-24 h, control-48 h, and ubiquinol-48 h. The results revealed that ubiquinol-10 significantly prevented aging-induced oxidative stress, GSH reduction, cytoskeleton impairment, apoptosis, and autophagy. Mitochondrial biogenesis (SIRT1 and PGC-1α) and mitophagy (PINK1 and PARKIN)-related proteins were decreased during aging. Addition of ubiquinol-10 prevented the aging-induced reduction of these proteins. Consequently, although mitochondrial content was decreased, the number of active mitochondria and ATP level were significantly increased upon treatment with ubiquinol-10. Thus, ubiquinol-10 has beneficial effects on porcine postovulatory aging oocytes owing to its antioxidant properties and ability to promote mitochondrial renewal.

Stable Regulation of Senescence-Related Genes in Galactose-alpha1,3-galactose Epitope Knockout and Human Membrane Cofactor Protein hCD46 Pig

BACKGROUND

Pigs are considered suitable animal donor models for xenotransplantation. For successful organ transplantation, immune rejection must be overcome. Xenotransplantation has recently been successfully performed using galactose-alpha1,3-galactose epitopes knockout (GalTKO) and a human membrane cofactor protein (hCD46) in a pig model. However, the growth and lifespan of the grafted organ have not been evaluated. Therefore, in the present study we evaluated aging and 84 senescence-related genes using the RT² Profiler PCR array and whole blood samples from GalTKO/hCD46 Massachusetts General Hospital (MGH) pigs.

METHODS

Experimental groups were double GalTKO/hCD46 (5-month-old), single GalTKO/hCD46 (2-year-old), and non-genetically modified (>3.5-year-old; control group within the same strain). Age-matched white hairless Yucatan (WHY) miniature pig groups were used as controls.

RESULTS

Among the 19 senescence-related genes selected from the 84 genes for further evaluation, 13 were upregulated in the double GalTKO/hCD46 MGH pigs compared to control MGH pigs; however, in WHY pigs, only 4 genes were up- or down-regulated among the 19 genes. Moreover, in double GalTKO/hCD46 MGH and WHY pigs, the expression of the 19 genes changed only 1- to 2-fold, suggesting that there were no significant differences in senescence signals between the 2 pig lines.

CONCLUSIONS

The present results indicate that the double GalTKO/hCD46 MGH pig might be a suitable model for human xenotransplantation studies. However, we used a limited number of experimental individuals, so further studies using larger experimental groups should be conducted to verify the present results.

Immune molecular profiling of whole blood drawn from a non-human primate cardiac xenograft model treated with anti-CD154 monoclonal antibodies

Most studies of xenografts have been carried out with complex immunosuppressive regimens to prevent immune rejection; however, such treatments may be fatal owing to unknown causes. Here, we performed immune molecular profiling following anti-CD154 monoclonal antibody (mAb) treatment in heterotopic abdominal cardiac xenografts from α-1,3-galactosyltransferase-knockout pigs into cynomolgus monkeys to elucidate the mechanisms mediating the undesirable fatal side effects of immunosuppressive agents. Blood samples were collected from healthy monkeys as control and then at 2 days after xenograft transplantation and just before humane euthanasia; 94 genes related to the immune system were analyzed. The basic immunosuppressive regimen included cobra venom factor, anti-thymocyte globulin, and rituximab, with and without anti-CD154 mAbs. The maintenance therapy was followed with tacrolimus, MMF, and methylprednisolone. The number of upregulated genes was initially decreased on Day 2 (-/+ anti-CD154 mAb, 22/13) and then increased before euthanasia in recipients treated with anti-CD154 mAbs (-/+ anti-CD154 mAb, 30/37). The number of downregulated genes was not affected by anti-CD154 mAb treatment. Additionally, the number of upregulated genes increased over time for both groups. Interestingly, treatment with anti-CD154 mAbs upregulated coagulation inducers (CCL2/IL6) before euthanasia. In conclusion, immunosuppressive regimens used for cardiac xenografting affected upregulation of 6 inflammation genes (CXCL10, MPO, MYD88, NLRP3, TNFα, and TLR1) and downregulation of 8 genes (CCR4, CCR6, CD40, CXCR3, FOXP3, GATA3, STAT4, and TBX21).

Overexpression of MicroRNA-29b Decreases Expression of DNA Methyltransferases and Improves Quality of the Blastocysts Derived from Somatic Cell Nuclear Transfer in Cattle

MicroRNA (miR)-29b plays a crucial role during somatic cell reprogramming. The aim of the current study was to explore the effects of miR-29b on the developmental competence of bovine somatic cell nuclear transfer (SCNT) embryos, as well as the underlying mechanisms of action. The expression level of miR-29b was lower in bovine SCNT embryos at the pronuclear, 8-cell, and blastocyst stages compared with in vitro fertilized embryos. In addition, miR-29b regulates the expression of DNA methyltransferases (Dnmt3a/3b and Dnmt1) in bovine SCNT embryos. We further investigated SCNT embryo developmental competence and found that miR-29b overexpression during bovine SCNT embryonic development does not improve developmental potency and downregulation inhibits developmental potency. Nevertheless, the quality of bovine SCNT embryos at the blastocyst stage improved significantly. The expression of pluripotency factors and cellular proliferation were significantly higher in blastocysts from the miR-29b overexpression group than the control and downregulation groups. In addition, outgrowth potential in blastocysts after miR-29b overexpression was also significantly greater in the miR-29b overexpression group than in the control and downregulation groups. Taken together, these results demonstrated that miR-29b plays an important role in bovine SCNT embryo development.

Dog cloning with in vivo matured oocytes obtaining using serum estradiol levels for predicting time of ovulation

Dog cloning using in vivo-matured oocytes has been carried out for a decade. To obtain mature oocytes, serum progesterone (P₄) levels are used to evaluate ovulation. However, the accuracy of these methods is not sufficient. Thus, the aim of the present study was to verify the feasibility of serum estradiol (E₂) on canine ovulation determination as assessed by the percentage of dogs yielding mature oocytes. In vivo-matured oocytes were utilized for canine somatic cell nuclear transfer (SCNT), and serum P₄ and E₂ levels were assessed to determine ovulation and oocyte maturation. Canine serum P₄ and E₂ concentrations during both pro-estrus and estrus were analyzed by electrochemiluminescence immunoassay. The percentage of dogs yielding mature oocytes using each of the two ovulation prediction methods were compared, and correlations between the percentage of each method and temperature were analyzed. Following evaluation, oocytes were collected surgically, and a significantly higher percentage (P < 0.05) of dogs yielding mature oocytes was observed using E₂ (56.43%) for ovulation detection as compared with that using P₄ (39.60%). The percentage of dogs yielding mature oocytes using P₄ significantly lower (P < 0.05) than E₂ in autumn (P₄, 37.50% vs. E₂, 52.00%) and winter (P₄, 29.17% vs. E₂, 59.09%). Using E₂, the percentage was maintained at about 52.00-66.67% regardless of the season and temperature. Correlation analysis showed that the dynamic of percentage of dogs yielding mature oocyte using P₄ was highly correlated with environmental temperature (R_P4 = 0.862), whereas E₂ was not affected by temperature (R_E2 = 0.199). To determine whether serum E₂ could be used for ovulation prediction for canine cloning, ovulation of 25 and 19 dogs (P < 0.05) were predicted using P₄ or E₂ methods, respectively and two puppies, one from each ovulation prediction method, were obtained after SCNT and embryo transfer. Thus, compared with the P₄ method, E₂ was an accurate and reliable method for canine cloning.

Enhanced in vitro maturation of canine oocytes by oviduct epithelial cell co-culture

Canine-assisted reproductive techniques have been successful for several years; however, the lack of an oocyte in vitro maturation system has limited their application. The aim of this study was to evaluate the effect of canine oviduct epithelial cells (cOECs) on canine oocyte maturation in vitro. Specifically, the method used for isolation of cOECs did not affect the expression of epithelial markers, E-cadherin and cytokeratin, on fresh, cultured and cryopreserved cells. Moreover, BrdU analysis showed that cOECs cultured in Medium 171 supplemented with mammary epithelial growth supplement were more proliferative than counterparts in advanced Dulbecco's modified Eagle medium or Medium 199. Maturation rate of canine oocytes collected from bitches at diestrus was significantly increased when oocytes were co-cultured with either fresh, cultured or frozen/thawed cOECs (13.23 ± 1.15%, 10.38 ± 4.89%, or 10.54 ± 2.96%, respectively) than that of control oocytes cultured without cOECs (2.48 ± 2.16%, p < 0.05). Additionally, the number of oocytes collected from bitches at estrus the reached metaphase II was increased ∼4 fold in co-culture with fresh, cultured, or frozen/thawed cOECs (47.2 ± 3.82%, 45.4 ± 7.34%, and 46.9 ± 1.51%, respectively) as compared with oocytes cultured without cOECs (11.9 ± 3.18%, p < 0.05). Nuclear maturation was further confirmed by assessing the formation of normal metaphase-II spindles, whereas cytoplasmic maturation was confirmed by inducing parthenogenetic oocyte activation. Embryonic development to the 8-cell stage was similar between in vivo and in vitro matured oocytes. These results suggested that co-culturing immature canine oocytes with cOECs facilitated canine oocyte maturation and early stages of embryonic development.

Fluoride impairs oocyte maturation and subsequent embryonic development in mice

The damage caused by fluorosis is permanent, and has been recognized as a public health problem in a number of regions of the world. Although multiple studies provided evidence that sodium fluoride (NaF) elicits adverse effects on reproductive function, the effect of fluoride on female germ cell development is not well understood. Therefore, the present study aimed at evaluating the effect of fluoride treatments on in vivo maturation and developmental potential of mouse oocytes, in which female ICR mice were treated with a range of doses (0, 30, 60, and 150 mg/L) of NaF. After treatment, mice were superovulated to collect ovulated oocytes. The effects of NaF on oocyte quality, fertilization potential and early embryonic development were evaluated, as well as the underlying mechanisms were primarily investigated. The findings of this study showed that NaF treatment resulted in abnormal spindle configuration, actin cap formation, and cortical granule-free domain formation. Additionally, overexposure of mice to NaF notably reduced ATP production and mitochondrial membrane potential, further influencing in vitro fertilization and subsequent embryonic development. These results indicated that NaF treatment impairs the subsequent embryonic developmental potential of the oocytes. In conclusion, overexposure to fluoride in vivo was associated with a significant disruption of cytoskeletal dynamics and decreased oocyte quality, affecting the oocyte's subsequent fertilization and embryonic development. Results of this study provide a rationale for treating reproductive diseases such as infertility or miscarriage caused by environmental contaminants. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1486-1495, 2016.

Molecular immunology profiles of monkeys following xenografting with the islets and heart of α-1,3-galactosyltransferase knockout pigs

Effective immunosuppression strategies and genetically modified animals have been used to prevent hyperacute and acute xenograft rejection; however, the underlying mechanisms remain unknown. In this study, we evaluated the expression of a comprehensive set of immune system-related genes (89 genes, including five housekeeping genes) in the blood of cynomolgus monkeys (~5 yr old) used as graft recipients, before and after the xenografting of the islets and heart from single and double α-1,3-galactosyltransferase (GalT) knockout (KO) pigs (<6 weeks old). The immunosuppressive regimen included administration of cobra venom factor, anti-thymocyte globulin, rituximab, and anti-CD154 monoclonal antibodies to recipients before and after grafting. Islets were xenografted into the portal vein in type 1 diabetic monkeys, and the heart was xenografted by heterotopic abdominal heart transplantation. Genes from recipient blood were analyzed using RT(2) profiler PCR arrays and the web-based RT(2) profiler PCR array software v.3.5. Recipients treated with immunosuppressive agents without grafting showed significant downregulation of CCL5, CCR4, CCR6, CD4, CD40LG, CXCR3, FASLG, CXCR3, FOXP3, GATA3, IGNG, L10, IL23A, TRAF6, MAPK8, MIF, STAT4, TBX21, TLR3, TLR7, and TYK2 and upregulation of IFNGR1; thus, genes involved in protection against viral and bacterial infection were downregulated, confirming the risk of infection. Notably, C3-level control resulted in xenograft failure within 2 days because of a 7- to 11-fold increase in all xenotransplanted models. Islet grafting using single GalT-KO pigs resulted in upregulation of CXCL10 and MX1, early inflammation, and acute rejection-associated signals at 2 days after xenografting. We observed at least 5-fold upregulation in recipients transplanted with islets grafts from single (MX1) or double (C3, CCR8, IL6, IL13, IRF6, CXCL10, and MX1) GalT-KO pigs after 77 days; single GalT-KO incurred early losses owing to immune attacks. Our results suggest that this novel, simple, non-invasive, and time-efficient procedure (requiring only 1.5 ml blood) for evaluating graft success, minimizing immune rejection, and blocking infection.

Nucleofection-mediated α1,3-galactosyltransferase gene inactivation and membrane cofactor protein expression for pig-to-primate xenotransplantation

Xenotransplantation of pig organs into primates leads to hyperacute rejection (HAR). Functional ablation of the pig α 1,3-galactosyltransferase (GalT) gene, which abrogates expression of the Gal α 1-3Gal β 1-4GlcNAc-R (Gal) antigen, which inhibits HAR. However, antigens other than Gal may induce immunological rejection by their cognate antibody responses. Ultimately, overexpression of complement regulatory proteins reduces acute humoral rejection by non-Gal antibodies when GalT is ablated. In this study, we developed a vector-based strategy for ablation of GalT function and concurrent expression of membrane cofactor protein (MCP, CD46). We constructed an MCP expression cassette (designated as MCP-IRESneo) and inserted between the left and the right homologous arms to target exon 9 of the GalT gene. Nucleofection of porcine ear skin fibroblasts using the U-023 and V-013 programs resulted in high transfection efficiency and cell survival. We identified 28 clones in which the MCP-IRESneo vector had been successfully targeted to exon 9 of the GalT gene. Two of those clones, with apparent morphologically mitotic fibroblast features were selected through long-term culture. GalT gene expression was downregulated in these 2 clones. Importantly, MCP was shown to be efficiently expressed at the cell surface and to efficiently protect cell lysis against normal human complement serum attack in vitro.

Influence of epidermal growth factor supplementation during in vitro maturation on nuclear status and gene expression of canine oocytes

This study evaluated the effect of epidermal growth factor (EGF) supplementation during in vitro maturation on the meiotic status and the expression of EGF receptor (EGFr), luteinizing hormone receptor (LHr) and gap junction protein α 5 (GJA5) in canine cumulus-oocyte-complexes (COCs). COCs of ≥110 μm diameter, exhibiting dark pigmentation and completely surrounded by three or more layers of cumulus cells collected from anestrus stage ovaries in natural cycle were matured in TCM-199 supplemented with 10% fetal bovine serum, 0.57 mM cysteine, 10 μg/ml LH and FSH, and different concentrations of EGF (0, 10 and 30 ng/ml). Oocytes cultured for 72 h were fixed to assess the nuclear maturation. Expression of EGFr, LHr and GAJ5 was assessed by immunocytochemistry and real-time PCR. Proportion of metaphase II status of oocytes cultured in in vitro maturation (IVM) medium supplemented with 10 ng/ml EGF for 72 h was significantly (P<0.05) higher than 0 and 30 ng/ml EGF supplemented IVM medium (9.8% vs. 6.5% and 5.2%). In both cumulus cells and oocytes, EGFr protein was undetectable, LHr protein level of expression was low and a strong expression of GJA5 protein was observed. The relative abundance (RA) of EGFr transcript revealed low levels and the LHr expression decreased steadily with addition of EGF. However it did not vary among different concentrations of EGF supplementation. The RA of GJA5 transcript exhibited lower level at 10 ng/ml EGF supplementation. In conclusion, the supplementation of 10 ng/ml EGF in IVM media exerted a positive influence on the progression of maturation to MII phase and the expression level of GJA5 at 72 h, but did not demonstrate any stimulatory role on the expression of EGFr and LHr during the maturation of the canine IVM oocytes.

Expression pattern of oxygen and stress-responsive gene transcripts at various developmental stages of in vitro and in vivo preimplantation bovine embryos

The present study examined the expression pattern of oxygen (O(2)) and stress-responsive gene transcripts at various preimplantation developmental stages of in vitro produced (IVP) and in vivo derived (IVD) bovine embryos. Embryos were produced in vitro from oocytes matured, fertilized and cultured in synthetic oviductal fluid (SOF) medium under low (5%) and high (20%) O(2) concentrations. In vivo embryos were derived from 18 superovulated and artificially inseminated cows. In IVP and IVD groups, embryos were collected at 2-, 4-, 8-, 16-cell morula and blastocyst stages at specific time points for gene expression analysis. The cleavage rates (69.8+/-4.8%) did not differ significantly, but blastocyst rates were significantly higher (28.5+/-3.7%) in low O(2) than those in high O(2) group (18.7+/-3.9%). Mean cell number in low O(2) (145+/-12) and high O(2) (121+/-73) IVP blastocyst were lower (P<0.05) than those of IVD blastocyst (223+/-25). The ICM ratio of IVD blastocyst (26+/-4) was lower (P<0.05) than that of IVP embryos under 5% O(2) (33+/-5) and 20% O(2) (34+/-4) concentrations, respectively. Using real time PCR, for the set of target transcripts (Glut1, Glut5, Sox, G6PD, MnSOD, PRDX5, NADH and Hsp 70.1) analyzed, there were differences in the mRNA expression pattern at 2-, 4-, 8-, 16-cell morula and Day 7 blastocyst stages between the two embryo sources. It can be concluded that, although in vitro bovine embryo culture in SOF medium under low (5%) O(2) concentration provided a more conducive environment in terms of blastocyst formation; differences in the total cell number and gene expression pattern between the IVP and IVD embryos reflected the effect of O(2) concentration.

Effects of Confluent, Roscovitine Treatment and Serum Starvation on the Cell-cycle Synchronization of Bovine Foetal Fibroblasts

The present study was designed to examine the effects of cell-cycle synchronization protocols, such as confluent, roscovitine treatment and serum starvation, in bovine foetal fibroblasts on synchronization accuracy at G0/G1, viability, apoptosis, necrosis and ploidy for use as a nuclei donor. The cells in 5-10 passages were randomly allocated into three treated groups. Cells were cultured either in Dulbecco's modified Eagle's medium (DMEM) + 10% foetal bovine serum (FBS) until 90% confluent (group 1, confluent), in DMEM + 10% FBS + 30 microM roscovitine for 12 h (group 2, roscovitine), or in DMEM + 0.5% FBS for 5 days (group 3, serum starvation). Most of the cells (>80%) in all groups were arrested at the G0/G1 stage. Although the rates did not differ, cells in group 1 showed an increased cell population arrested at the G0/G1 phase. Significantly (p < 0.05) higher rates of apoptosis occurred in group 3 than in group 1 and 2 (10% vs 6% and 6%, respectively). No differences in chromosomal abnormality were observed among groups. However, by increasing the number of cell culture passages up to 15, significantly (p < 0.05) higher chromosomal abnormality was observed than in 5 and 10 passages (39% vs 28% and 23%, respectively) in group 1. The results clearly indicated that bovine foetal fibroblasts could be effectively synchronized at G0/G1 stages by all the three different treatments, confluent, roscovitine and serum starvation. However, cells in confluent showed reduced apoptosis and necrosis when they underwent 5-10 passages, exhibiting increased percentage of cells with stable chromosome diversity. Hence, cells in confluent merit further studies before they could be used as nuclear donors.

Different activation treatments for successful development of bovine oocytes following intracytoplasmic sperm injection

In this study, the developmental capacity and cytogenetic composition of different oocyte activation protocols was evaluated following intracytoplasmic sperm injection (ICSI) of in vitro matured bovine oocytes. Motile spermatozoa selected by Percoll density gradient were treated with 5 mM dithiothreitol (DTT) and analysed for ultrastructural changes of the head using transmission electron microscopy (TEM). The alterations in sperm morphology after DTT treatment for different times (15, 30 and 60 min) were 10%, 45-55% and 70-85%, respectively. Further, a partial decondensation of sperm heads was observed after DTT treatment for 30 min. Oocytes were injected with sperm treated with DTT for 30 min. In group 1, sperm injection was performed without any activation stimulus to the oocytes. In group 2, sham injection without sperm was performed without activating the oocytes. Oocytes injected with sperm exposed to 5 microM ionomycin for 5 min (group 3), 5 microM ionomycin + 1.9 mM dimethylaminopurine (DMAP) for 3 h (group 4) and 5 microM ionomycin + 3 h culture in M199 + 1.9 mM DMAP (group 5) were also evaluated for cleavage, development and chromosomal abnormality. Cleavage and development rates in groups 1, 2 and 3 were significantly (p < 0.05) lower than those in groups 4 and 5. The incidence of chromosomal abnormality in the embryos treated directly with DMAP after ionomycin (group 4) was higher than in group 5. We conclude that immediate DMAP treatment after ionomycin exposure of oocytes results in arrest of release of the second polar body, and thus leads to changes in chromosomal pattern. Therefore, the time interval between ionomycin and DMAP plays a crucial role in bovine ICSI.