Efficacy of Gene Modification in Placenta-Derived Mesenchymal Stem Cells Based on Nonviral Electroporation

Mesenchymal stem cell (MSC)-based therapy using gene delivery systems has been suggested for degenerative diseases. Although MSC-based clinical applications are effective and safe, the mode of action remains unclear. Researchers have commonly applied viral-based gene modification because this system has efficient vehicles. While viral transfection carries many risks, such as oncogenes and chromosomal integration, nonviral gene delivery techniques are less expensive, easier to handle, and safe, although they are less efficient. The electroporation method, which uses Nucleofection technology, provides critical opportunities for hard-to-transfect primary cell lines, including MSCs. Therefore, to improve the therapeutic efficacy using genetically modified MSCs, researchers must determine the optimal conditions for the introduction of the Nucleofection technique in MSCs. Here, we suggest optimal methods for gene modification in PD-MSCs using an electroporation gene delivery system for clinical application.

Upregulation of C-Reactive Protein by Placenta-Derived Mesenchymal Stem Cells Promotes Angiogenesis in A Rat Model with Cirrhotic Liver

Background and Objectives@#Liver cirrhosis is accompanied by abnormal vascular shunts. The Wnt pathway is essential for endothelial cell survival and proliferation. C-reactive protein (CRP), which is produced by hepatocyte, activates angiogenesis in cardiovascular diseases. @*Methods@#and Results: The expression of CRP in CCl 4 -injured rat livers was detected using qRT-PCR and Western blotting after transplantation of placenta-derived mesenchymal stem cells (PD-MSCs) into rats. To determine whether CRP functions in hepatic regeneration by promoting angiogenesis through the Wnt pathway, we detected VEGF and β-catenin in liver tissues and BrdU and β-catenin in hepatocytes by immunofluorescence. The expression levels of CRP, Wnt pathway-related and angiogenic factors were increased in CCl 4 -injured and PD-MSCs transplanted rat livers. In vitro, the expression levels of Wnt signaling and angiogenic factors were decreased in siRNA-CRP-transfected rat hepatocytes. @*Conclusions@#CRP upregulation by PD-MSCs participates in vascular remodeling to promote liver regeneration via the Wnt signaling pathway during hepatic failure.

Identification of microRNAs and their target genes in the placenta as biomarkers of inflammation / 대한생식의학회지

Objective@#Recently, microRNA (miRNA) has been identified both as a powerful regulator involved in various biological processes through the regulation of numerous genes and as an effective biomarker for the prediction and diagnosis of various disease states. The objective of this study was to identify and validate miRNAs and their target genes involved in inflammation in placental tissue. @*Methods@#Microarrays were utilized to obtain miRNA and gene expression profiles from placentas with or without inflammation obtained from nine normal pregnant women and 10 preterm labor patients. Quantitative real-time polymerase chain reaction and Western blots were performed to validate the miRNAs and differentially-expressed genes in the placentas with inflammation. Correlations between miRNA and target gene expression were confirmed by luciferase assays in HTR-8/SVneo cells. @*Results@#We identified and validated miRNAs and their target genes that were differentially expressed in placentas with inflammation. We also demonstrated that several miRNAs (miR-371a-5p, miR-3065-3p, miR-519b-3p, and miR-373-3p) directly targeted their target genes (LEF1, LOX, ITGB4, and CD44). However, some miRNAs and their direct target genes showed no correlation in tissue samples. Interestingly, miR-373-3p and miR-3065-3p were markedly regulated by lipopolysaccharide (LPS) treatment, although the expression of their direct targets CD44 and LOX was not altered by LPS treatment. @*Conclusion@#These results provide candidate miRNAs and their target genes that could be used as placental biomarkers of inflammation. These candidates may be useful for further miRNA-based biomarker development.

Immunomodulatory Effects of Placenta-derived Mesenchymal Stem Cells on T Cells by Regulation of FoxP3 Expression

The immunomodulatory effects of mesenchymal stem cells (MSCs) are an important mediator of their therapeutic effects in stem cell therapy and regenerative medicine. The regulation mechanism of MSCs is orchestrated by several factors in both intrinsic and extrinsic events. Recent studies have shown that the dynamic expression of cytokines secreted from MSCs control T cell function and maturation by regulating the expression of FoxP3, which figures prominently in T cell differentiation. However, there is no evidence that placenta-derived mesenchymal stem cells (PD-MSCs) have strong immunomodulatory effects on T cell function and maturation via FoxP3 expression. Therefore, we compared the expression of FoxP3 in activated T cells isolated from peripheral blood and co-cultured with PD-MSCs or bone marrow-derived mesenchymal stem cells (BM-MSCs) and analyzed their effect on T cell proliferation and cytokine profiles. Additionally, we verified the immunomodulatory function of PD-MSCs by siRNA-mediated silencing of FoxP3. MSCs, including PD-MSCs and BM-MSCs, promoted differentiation of naive peripheral blood T cells into CD4+CD25+FoxP3+ regulatory T (Treg) cells. Intriguingly, the population of CD4+CD25+FoxP3+ Treg cells co-cultured with PD-MSCs was significantly expanded in comparison to those co-cultured with BM-MSCs or WI38 cells (p < 0.05, p < 0.001). Dynamic expression patterns of several cytokines, including anti- and pro-inflammatory cytokines and members of the transforming growth factor-beta (TGF-β) family secreted from PD-MSCs according to FoxP3 expression were observed. The results suggest that PD-MSCs have an immunomodulatory effect on T cells by regulating FoxP3 expression.

Effects of selenium on the survival and invasion of trophoblasts / 대한생식의학회지

OBJECTIVE: Placental oxidative stress is known to be a factor that contributes to pregnancy failure. The aim of this study was to determine whether selenium could induce antioxidant gene expression and regulate invasive activity and mitochondrial activity in trophoblasts, which are a major cell type of the placenta. METHODS: To understand the effects of selenium on trophoblast cells exposed to hypoxia, the viability and invasive activity of trophoblasts were analyzed. The expression of antioxidant enzymes was assessed by reverse-transcription polymerase chain reaction. In addition, the effects of selenium treatment on mitochondrial activity were evaluated in terms of adenosine triphosphate production, mitochondrial membrane potential, and reactive oxygen species levels. RESULTS: Selenium showed positive effects on the viability and migration activity of trophoblast cells when exposed to hypoxia. Interestingly, the increased heme oxygenase 1 expression under hypoxic conditions was decreased by selenium treatment, whereas superoxide dismutase expression was increased in trophoblast cells by selenium treatment for 72 hours, regardless of hypoxia. Selenium-treated trophoblast cells showed increased mitochondrial membrane potential and decreased reactive oxygen species levels under hypoxic conditions for 72 hours. CONCLUSION: These results will be used as basic data for understanding the mechanism of how trophoblast cells respond to oxidative stress and how selenium promotes the upregulation of related genes and improves the survival rate and invasive ability of trophoblasts through regulating mitochondrial activity. These results suggest that selenium may be used in reproductive medicine for purposes including infertility treatment.

Decreased C-reactive protein induces abnormal vascular structure in a rat model of liver dysfunction induced by bile duct ligation

BACKGROUND/AIMS: Chronic liver disease leads to liver fibrosis, and although the liver does have a certain regenerative capacity, this disease is associated with dysfunction of the liver vessels. C-reactive protein (CRP) is produced in the liver and circulated from there for metabolism. CRP was recently shown to inhibit angiogenesis by inducing endothelial cell dysfunction. The objective of this study was to determine the effect of CRP levels on angiogenesis in a rat model of liver dysfunction induced by bile duct ligation (BDL). METHODS: The diameter of the hepatic vein was analyzed in rat liver tissues using hematoxylin and eosin (H&E) staining. The expression levels of angiogenic factors, albumin, and CRP were analyzed by real-time PCR and Western blotting. A tube formation assay was performed to confirm the effect of CRP on angiogenesis in human umbilical vein endothelial cells (HUVECs) treated with lithocholic acid (LCA) and siRNA-CRP. RESULTS: The diameter of the hepatic portal vein increased significantly with the progression of cirrhosis. The expression levels of angiogenic factors were increased in the cirrhotic liver. In contrast, the expression levels of albumin and CRP were significantly lower in the liver tissue obtained from the BDL rat model than in the normal liver. The CRP level was correlated with the expression of albumin in hepatocytes treated with LCA and siRNA-CRP. Tube formation was significantly decreased in HUVECs when they were treated with LCA or a combination of LCA and siRNA-CRP. CONCLUSION: CRP seems to be involved in the abnormal formation of vessels in hepatic disease, and so it could be a useful diagnostic marker for hepatic disease.

Advanced Research on Stem Cell Therapy for Hepatic Diseases: Potential Implications of a Placenta-derived Mesenchymal Stem Cell-based Strategy / 한양의대학술지

The category of chronic liver diseases comprise one of the most common medical diagnoses worldwide. Currently, orthotopic liver transplantation is the only effective treatment for end-stage hepatic disease, but this procedure is associated with many problems, including donor scarcity, operative damage, high cost, risk of immune rejection and lifelong immunosuppressive treatments. Thus, the development of new therapies is highly desirable. Cell therapy with stem cells is increasingly being used to repair damaged tissue or to promote organ regeneration. Stem cells, which possess self-renewal activity as well as differentiation potential, can be categorized as embryonic stem cells (ESCs) or adult stem cells (ASCs), which include hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs). Recently, placenta-derived mesenchymal stem cells (PD-MSCs) have been reported, and they are attracting much interest in stem cell research for their multiple advantages: 1) no ethical concerns, 2) the ability to obtain abundant cell numbers, 3) multi-lineage differentiation potential, and 4) strong immunosuppressive properties. PD-MSCs differentiate into hepatocyte-like cells when exposed to hepatogenic differentiation-inducing conditions and PD-MSCs transplantation has been shown to enhance hepatic regeneration and/or survival in a rat hepatic failure model by suppressing the progression of fibrosis and apoptosis and activating autophagy. In this review, we will explain the characteristics of several kinds of PD-MSCs and discuss recent studies of the therapeutic potential of PD-MSCs in the repair of liver injury and their utility in regenerative medicine. Although many problems remain to be solved, many studies support the potential for human stem cell therapies, including PD-MSCs, as a promising new technology for the therapeutic regeneration of human liver intractably damaged due to chronic disease and/or toxic and environmental insult.

Epigenetic Alterations of IL-6/STAT3 Signaling by Placental Stem Cells Promote Hepatic Regeneration in a Rat Model with CCl4-induced Liver Injury

BACKGROUND: Human chorionic plate-derived mesenchymal stem cells (CP-MSCs) isolated from the placenta have been reported to demonstrate therapeutic effects in animal models of liver injury; however, the underlying epigenetic mechanism of this effect has not been elucidated. Thus, we investigated whether CP-MSCs influence epigenetic processes during regeneration of the injured liver. METHODS: CP-MSCs were engrafted into a carbon tetrachloride (CCl4)-injured rat model through direct transplantation into the liver (DTX), intrasplenic transplantation (STX), and intravenous transplantation via the tail vein (TTX). Non-transplanted (NTX) rats were maintained as sham controls. Liver tissues were analyzed after transplantation using immunohistochemistry, western blot analysis, and quantitative methylation-specific polymerase chain reaction. Proliferation and human interleukin-6 (hIL-6) enzyme-linked immunosorbent assays were performed using CCl4-treated hepatic cells that were co-cultured with CP-MSCs. RESULTS: The Ki67 labeling index, cell cyclins, albumin, IL-6, and gp130 levels were elevated in the CP-MSC transplantation groups. The concentration of hIL-6 in supernatants and the proliferation of CCl4-treated rat hepatic cells were enhanced by co-culturing with CP-MSCs (p<0.05), while the methylation of IL-6/IL-6R and STAT3 by CP-MSC transplantation decreased. CONCLUSION: These results suggest that administration of CP-MSCs promotes IL-6/STAT3 signaling by decreasing the methylation of the IL-6/SATA3 promoters and thus inducing the proliferation of hepatic cells in a CCl4-injured liver rat model. These data advance our understanding of the therapeutic mechanisms in injured livers, and can facilitate the development of cell-based therapies using placenta-derived stem cells.

Significance of Serum Antibody Test for Toxocariasis in Healthy Healthcare Examinees with Eosinophilia in Seoul and Gyeongsangnam-do, Korea

There have been numerous reports on the relationship between eosinophilia and toxocariasis. The present study investigated seropositive rates of toxocariasis among healthy people with or without eosinophilia in urban and rural areas, and assessed risk factors for positive antibody test. A total of 610 healthy people, who visited health check-up (Medicheck(R), Korea Association of Health Promotion), 310 from Seoul and 300 from Gyeongsangnam-do, were subjected for this study. Their serum samples were tested by ELISA with the crude antigen of Toxocara canis larvae. Cross-reactions with other tissue invading helminth antigens were also investigated. Total antibody positive rate of toxocariasis was 8.7% of the 610 subjects. When the subjects were grouped into 3 by their eosinophil counts, the antibody positive rates significantly differed by the groups; 5.9% (18/306) in the group500/microL (P=0.028). A total of 22 serum samples cross-reacted with other tissue-invading helminth antigens. A questionnaire analysis recognized drinking alcohol and smoking as significant risk factors of toxocariasis. In conclusion, toxocariasis antibody positive rate is correlated with eosinophil counts. It is recommended that healthy subjects with eosinophilia by routine health examination and risk factors undergo Toxocara serology by multiantigen ELISA to investigate etiology.

The role of autophagy in the placenta as a regulator of cell death / 대한생식의학회지

The placenta is a temporary fetomaternal organ capable of supporting fetal growth and development during pregnancy. In particular, abnormal development and dysfunction of the placenta due to cha nges in the proliferation, differentiation, cell death, and invasion of trophoblasts induce several gynecological diseases as well as abnormal fetal development. Autophagy is a catalytic process that maintains cellular structures by recycling building blocks derived from damaged microorganelles or proteins resulting from digestion in lysosomes. Additionally, autophagy is necessary to maintain homeostasis during cellular growth, development, and differentiation, and to protect cells from nutritional deficiencies or factors related to metabolism inhibition. Induced autophagy by various environmental factors has a dual role: it facilitates cellular survival in normal conditions, but the cascade of cellular death is accelerated by over-activated autophagy. Therefore, cellular death by autophagy has been known as programmed cell death type II. Autophagy causes or inhibits cellular death via the other mechanism, apoptosis, which is programmed cell death type I. Recently, it has been reported that autophagy increases in placenta-related obstetrical diseases such as preeclampsia and intrauterine growth retardation, although the mechanisms are still unclear. In particular, abnormal autophagic mechanisms prevent trophoblast invasion and inhibit trophoblast functions. Therefore, the objectives of this review are to examine the characteristics and functions of autophagy and to investigate the role of autophagy in the placenta and the trophoblast as a regulator of cell death.

Altered expression of norepinephrine transporter and norepinephrine in human placenta cause pre-eclampsia through regulated trophoblast invasion / 대한생식의학회지

OBJECTIVE: We investigated the norepinephrine transporter (NET) expression in normal and pre-eclamptic placentas and analyzed the invasion activity of trophoblastic cells based on norepinephrine (NE)-NET regulation. METHODS: NET and NE expression levels were examined by western blot and enzyme-linked immunosorbent assay, respectively. Trophoblast invasion activity, depending on NE-NET regulation, was determined by NET-small interfering RNA (siRNA) and NET transfection into the human extravillous trophoblast cells with or without NE treatment and invasion rates were analyzed by zymography and an invasion assay. RESULTS: NET mRNA was expressed at a low level in pre-eclamptic placentas compared with normal placentas and NE concentration in maternal plasma increased significantly in pre-eclamptic women compared to normal pregnant women (p<0.05). NET gene upregulation and NE treatment stimulated trophoblast cell invasion up to 2.5-fold (p<0.05) by stimulating matrix metalloproteinase-9 activity via the phosphoinositol-3-kinase/AKT signaling pathway, whereas NET-siRNA with NE treatment reduced invasion rates. CONCLUSION: NET expression is reduced by inadequate regulation of NE levels during placental development. This suggests that a complementary balance between NET and NE regulates trophoblast cell invasion activities during placental development.

Effects of hypoxia inducible factors-1alpha on autophagy and invasion of trophoblasts / 대한생식의학회지

OBJECTIVE: This study was undertaken to determine the effect of hypoxia inducible factor (HIF)-1alpha on the cell death, autophagy, and invasion of trophoblasts. METHODS: To understand the effect of HIF-1alpha, we inhibited HIF-1alpha using siRNA under normoxia and hypoxia conditions. Invasion assay and zymography were performed to determine changes in the invasion ability of HIF-1alpha. Western blotting and immunofluorescence were performed to determine some of the signal events involved in apoptosis and autophagy. RESULTS: There was no difference in cell death through the inhibition of HIF-1alpha expression by siRNA; however, the expression of LC3 and autophagosome formation increased. On the other hand, autophagy was increased, and the invasive ability of trophoblast cells decreased according to the inhibition of HIF-1alpha expression by siRNA. These experimental results mean that HIF-1alpha genes regulate the invasive ability of trophoblasts by increasing autophagy. CONCLUSION: This study contributes important data for understanding the mechanism of early pregnancy implantation and the invasive ability of trophoblasts by defining the relationship between the roles of HIF-1alpha and autophagy.

Genomic Imbalances in Ependymoma by Degenerate Oligonucleotide Primed PCR-Comparative Genomic Hybridization

BACKGROUND: The most consistent chromosomal abnormality in ependymomas, is loss of 22q (17-75%) and gain of 1q (0-50%). However, significance of this abnormality is uncertain. METHODS: Genomic imbalances in 27 Korean ependymomas, including 21 low grade ependymomas, 4 anaplastic and 2 myxopapillary ependymomas, were analyzed by degenerate oligonucleotide primed-PCR-comparative genomic hybridization. RESULTS: Common gains were found in 17 (63%), 20q (59%), 9q34 (41%), 15q24-qter (33%), 11q13 (30%), 12q23 (26%), 7q23-qter (26%), 16q23-qter (30%), 19 (26%), and 1q32-qter (22%). DNA amplification was identified in 12 tumors (44%). Chromosomal loss was a less common occurrence in our study, but was found in 13q (26%), 6q (19%), and 3 (11%). CONCLUSION: The recurrent gains or losses of the chromosomal regions which were identified in this study provide candidate regions that may be involved in the development and progression of ependymomas.

Expression of Laminin Chains in the Neuronal Cells of Mouse Brain

Laminin-1 is biologically active and can effect cellular proliferation, differentiation, migration, and apoptosis. In the central nervous system, neuronal cells are rarely reported to give positive reaction by laminin antibody staining. However, the original cell type which can produce the laminin molecule has not been well established. Since the neuronal cells of brain are derived from neuroectoderm, we thought that the neuronal cells should be able to produce the laminin molecules as other epithelial cells. In this study we aimed to explore whether the neuronal cells express the laminin chain mRNAs, and further to identify which types of laminin isoform are expressed at the specific sites of the brain structure. We found that neuronal cell was the important cell type in mouse brain, which could produce laminin isoforms. Although immunostainings disclosed reactivity of laminins in the basement membrane of capillaries as well as neuronal cells, mRNA expressions of laminins were intense only in the neuronal cells. It was relatively weak in the endothelial cells. Among neuronal cells the cortical cells of cerebrum, pyramidal cells of hippocampus, and Purkinje cells of cerebellum showed pronounced expression of laminin chain mRNA. Glial cells, especially astrocytes, were negative for laminin subtypes both in immunohistochemistry and in situ hybridization. Taken together, our data indicate that the neuronal cells of mouse brain actively produce laminin isoforms, and the resultant polymerized laminins are accumulated mainly in the basement membrane of capillaries. In conclusion, the results indicate that neuronal cells produce and utilize the different laminin chains to maintain the neurovascular environment of brain.

An Effective Role Pulsed Unipolar Magnetic Field for Bony Decalcification

To achieve optimal decalcification in tissue and tissue preservation, we have tried magnetic field method and made some promising results. We used pulsed unipolar magnetic field obtained by rectification of 250 V-60 cycle, A.C. As a new method of bony decalcification, using 5% nitric acid, 10% formic acid and 10% formic acid+3% hydrochloric acid solutions, experimental groups were decalcified in the center of the magnetic field. The concentration of calcium ion in the decalcifying solution was measured by calcium-oxalate turbidity test by photometry method, and direct visualization of calcium radiopacity was obtained by soft X-ray view during the decalcification process. The pH change during decalcification was continuously checked and needle penetration method was also used. All the decalcification solution used in this study showed accelerated effect of bony decalcification in the strong magnetic field. Among them 5% nitric acid produced complete decalcification for the medium size bony specimen (less than 10x10x10 mm) within 24 hours, and the histologic feature was almost free of acid-chemical degeneration. The pH of all the decalcification solutions decreased in the strong magnetic field, maximum within 4~6 hours, and kept strong acidity throughout the decalcification procedure. After removal of the magnetic field the pH of all the decalcification solution returned to their original values after 24 hours. It was presumed that the cause of the accelerated decalcification in the magnetic field was due to combined effects of the rapid increase of acidity and the increased molecular resonance to stimulate the ionization of mineral elements.

An experimental study on the residual stress and bond strength of ceramo-metal system / 대한치과보철학회지

No abstract available.