Chih-Jen Chou

Intramuscular transplantation of pig amniotic fluid derived progenitor cells has therapeutic potential in a mouse model of myocardial infarction

Acute myocardial infarction (MI) is a fatal event that causes a large number of deaths worldwide. MI results in pathological remodeling and decreased cardiac function, which could lead to heart failure and fatal arrhythmia. Cell therapy is a potential strategy to repair the damage through enhanced angiogenesis or by modulation of the inflammatory process via paracrine signaling. Amniotic fluid-derived progenitor cells (AFPCs) have been reported to differentiate into several lineages and can be used without ethical concerns or risk of teratoma formation. Since pigs are anatomically, physiologically, and genetically similar to humans, and pregnant pigs can be an abundant source of AFPCs, we used porcine AFPCs (pAFPCs) as our target cells. Intramyocardial injection of AFPCs has been shown to cure MI in animal models. However, intramuscular transplantation of cells has not been extensively investigated. In this study, we investigated the therapeutic potential of intramuscular injection of pAFPCs on acute MI. MI mice were divided into 1) PBS control, 2) medium cell dose (1 × 106 cells per leg; cell-M), and 3) high cell dose (4 × 106 cells per leg; cell-H) groups. Cells or PBS were directly injected into the hamstring muscle 20 min after MI surgery. Four weeks after MI surgery, the cell-M and cell-H groups exhibited significantly better ejection fraction, significantly greater wall thickness, smaller infarct scar sizes, and lower LV expansion index compared to the PBS group. Using in vivo imaging, we showed that the hamstring muscles from animals in the cell-M and cell-H groups had RFP-positive signals. In summary, intramuscular injection of porcine AFPCs reduced scar size, reduced pathological remodeling, and preserved heart function after MI.

Cell fusion phenomena detected after in utero transplantation of Ds-red-harboring porcine amniotic fluid stem cells into EGFP transgenic mice.

Amniotic fluid stem cells (AFSCs) are derived from the amniotic fluid of the developing fetus and can give rise to diverse differentiated cells of ectoderm, mesoderm, and endoderm lineages. Intrauterine transplantation is an approach used to cure inherited genetic fetal defects during the gestation period of pregnant dams. Certain disease such as osteogenesis imperfecta was successfully treated in affected fetal mice using this method. However, the donor cell destiny remains uncertain.

Generation and characterization of a transgenic pig carrying a DsRed-monomer reporter gene.

Background Pigs are an optimal animal for conducting biomedical research because of their anatomical and physiological resemblance to humans. In contrast to the abundant resources available in the study of mice, few fluorescent protein-harboring porcine models are available for preclinical studies. In this paper, we report the successful generation and characterization of a transgenic DsRed-Monomer porcine model. Methods The transgene comprised a CMV enhancer/chicken-beta actin promoter and DsRed monomeric cDNA. Transgenic pigs were produced by using pronuclear microinjection. PCR and Southern blot analyses were applied for identification of the transgene. Histology, blood examinations and computed tomography were performed to study the health conditions. The pig amniotic fluid progenitor/stem cells were also isolated to examine the existence of red fluorescence and differentiation ability. Results Transgenic pigs were successfully generated and transmitted to offspring at a germ-line transmission rate of 43.59% (17/39). Ubiquitous expression of red fluorescence was detected in the brain, eye, tongue, heart, lung, liver, pancreas, spleen, stomach, small intestine, large intestine, kidney, testis, and muscle; this was confirmed by histology and western blot analyses. In addition, we confirmed the differentiation potential of amniotic fluid progenitor stem cells isolated from the transgenic pig. Conclusions This red fluorescent pig can serve as a host for other fluorescent-labeled cells in order to study cell-microenvironment interactions, and can provide optimal red-fluorescent-labeled cells and tissues for research in developmental biology, regenerative medicine, and xenotransplantation.

Engraftment of mouse amniotic fluid-derived progenitor cells after in utero transplantation in mice

BACKGROUND/PURPOSE Amniotic fluid-derived progenitor cells (AFPCs) are oligopotent and shed from the fetus into the amniotic fluid. It was reported that AFPCs express stem cell-like markers and are capable of differentiating into specific cell type in in vitro experiments. However, no study has fully investigated the potentiality and destiny of these cells in in vivo experiments. METHODS Ds-red transgenic mice (on Day 13.5 of pregnancy) were transplanted in utero with enhanced green fluorescent protein-labeled mouse AFPC (EGFP-mAFPCs). After birth, baby mice were euthanized at 3-week intervals beginning 3 weeks postnatally, and the specimens were examined by polymerase chain reaction, histology, and flow cytometry. RESULTS Our results demonstrate the transplantability of mAFPCs into all three germ layers and the potential of mAFPCs in the study of progenitor cell homing, differentiation, and function. Engraftment of EGFP-mAFPCs was detected in the intestine, kidney, muscle, skin, bladder, heart, stomach, etc., at 3 weeks after delivery. CONCLUSION This model using EGFP-mAFPCs injected in utero may provide an ideal method for determining the fate of transplanted cells in recipients and these findings may justify a clinical trial of in utero transplantation during gestation for patients who have inherited genetic disorders.

Differentiation of Enhanced Green Fluorescent Protein-Labeled Mouse Amniotic Fluid-Derived Stem Cells into Cardiomyocyte-Like Beating Cells

BACKGROUND Amniotic fluid-derived stem cells (AFSCs) possess optimal differentiation potential and are a promising resource for cell therapy and tissue engineering. Mouse is a good model to be studied for pre-clinical research. METHODS In this study, we successfully established enhanced green fluorescent protein mouse-derived amniotic fluid stem cells (EGFP-mAFSCs) and investigated whether EGFP-mAFSCs possess the ability to differentiate into cardiomyocytes by in vitro culture. We evaluated stem-cell differentiation using immunofluorescence. RESULTS This study showed that EGFP-mAFSCs can give rise to spontaneously beating cardiomyocyte-like cells expressing the specific markers c-kit, myosin heavy chain, and cardiac troponin I. CONCLUSIONS We demonstrated that mAFSCs have the in vitro propensity to acquire a cardiomyogenic phenotype and to a certain extent cardiomyocytes; however the process efficiency which gives rise to cardiomyocyte-like cells remains quite low (2 out of 10 were found). KEY WORDS Amniotic fluid; Cardiomyocytes; In vitro differentiation; Stem cells.

Infusion of Porcine-Derived Amniotic Fluid Stem Cells for Treatment of Experimental Colitis in Mice

Recently, stem cells have offered an alternative treatment for inflammatory bowel disease (IBD) or colitis to overcome the poor outcomes associated with current therapies. Amniotic fluid-derived stem cells (AFSCs) have the potential for the regeneration of impaired organs and the recovery of normal physiologic functions of damaged tissues without ethical concerns or risk of tumor formation. In this work, we aimed to examine the therapeutic effects of infusion of porcine AFSCs (pAFSCs) in dextran sulfate sodium (DSS)-induced colitis in mice. Treatment with pAFSCs was shown to inhibit the shortening of the colon after induction of colitis and dramatically ameliorated the body weightloss induced by the DSS treatment. In addition, pAFSCs could also reduce the extent of the inflamed area represented by epithelial mesenchymal transformation in the colitis mice. The levels of the inflammatory cytokines interleukin 6 (IL-6) and interferon gamma (IFN-γ) were also reduced in colitis mice transplanted with pAFSCs. In conclusion, pAFSCs can ameliorate experimental colitis in mice, suggesting that they may be a potential treatment for IBD or colitis.

Establishment of a DsRed-Monomer-Harboring ICR Transgenic Mouse Model and Effects of the Transgene on Tissue Development

DsRed-monomer is an enhanced red fluorescent protein that may serve as a marker for studies in biotechnology and cell biology. Since the ICR mouse strain is a widely utilized outbred strain for oncology, toxicology, vaccine development and for aging studies, the objective of this study was to produce a DsRed-monomer transgenic mouse by means of pronuclear micro-injection of a vector driven by the cytomegalovirus (CMV) enhancer/chicken beta-actin promoter. Four transgenic mice were successfully produced, one of which expressed the DsRed-monomer protein in every tissue, although at varying levels. High expression levels were observed in the heart, pancreas and muscle. Moreover, amniotic fluid-derived progenitor cells, which also expressed the DsRed-monomer protein, could be collected from the DsRed-monomer- harboring ICR mice. As compared to wild-type mice, a few biochemical and histological dissimilarities were found in the DsRed-monomer transgenic mice, including the presence of intra-cytoplasmic eosinophilic threadlike materials in the acinar cells. Taken together, transgenic mice stably expressing DsRed-monomer can be produced using pronuclear micro-injection; however, expression of the DsRed-monomer gene or its insertion position may lead to minor influences.