• Archives of Pharmacal Research
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• v.22 no.2
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• pp.108-112
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• 1999

Recombinant murine stem cell factor (rmSCF) or recombinant murine nerve growth factor (rmNGF) induced the morphological change of large numbers of rat peritoneal mast cells (RPMC). We investigated the role of phosphatidylinositol $3^{l}-kinase$ (PI3-kinase) in receptors-mediated morphological change in RPMC. Exposure of RPMC to PI3-kinase inhibitor, wortmannin, before the addition of rmSCF and rmNGF antagonized those factors-induced morphological change. These results suggest that the PI3-kinase is involved in the signal transduction pathway responsible for morphological change following stimulation of rmSCF and rmNGF and that wortmannin blocks these responses.

• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.1
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• pp.51-56
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• 2002

A recombinant transfer vector pBacSCF was constructed by inserting huamn stem cell factor (hSCF) cDNA into plasmid pBacPAK8. BmN cells were co-transfected with modified Bombyx mori, nuclear polyhedrosis virus (BmBacPAK) DNA and the recmbinant transfer vector to construct a recombinant baculovirus containing hSCE gene. DNA dot blotting and RNA dot blotting demonstrated that the hSCE gene was contained in the recombinant virus and transcribed. The recombinant baculovirus was infectious to BmN cells and to silkworm. SDS-PAGE analysis showed a specific band of expressed product in the extract of infected cells and in the heamolymph of infected larvae. Bioactivity of the recombinant hSCE was determined with W-1 cell line and MTT colorimetric method in synergy with interlukin-3 (IL-3). These results revealed that the hSCF gene was over-expressed in cultured cells and lavae of silkworm.

• BMB Reports
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• v.35 no.1
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• pp.87-93
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• 2002

Neural cell survival is an essential concern in the aging brain and many diseases of the central nervous system. Neural transplantation of the stem cells are already applied to clinical trials for many degenerative neurological diseases, including Huntington's disease, Parkinson's disease, and strokes. A critical problem of the neural transplantation is how to reduce their apoptosis and improve cell survival. Neurotrophic factors generally contribute as extrinsic cues to promote cell survival of specific neurons in the developing mammalian brains, but the survival factor for neural stem cell is poorly defined. To understand the mechanism controlling stem cell death and improve cell survival of the transplanted stem cells, we investigated the effect of plausible neurotrophic factors on stem cell survival. The neural stem cell, HiB5, when treated with PDGF prior to transplantation, survived better than cells without PDGF. The resulting survival rate was two fold for four weeks and up to three fold for twelve weeks. When transplanted into dorsal hippocampus, they migrated along hippocampal alveus and integrated into pyramidal cell layers and dentate granule cell layers in an inside out sequence, which is perhaps the endogenous pathway that is similar to that in embryonic neurogenesis. Promotion of the long term-survival and differentiation of the transplanted neural precursors by PDGF may facilitate regeneration in the aging adult brain and probably in the injury sites of the brain.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.5
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• pp.459-466
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• 2016

Adipogenic differentiation of mesenchymal stem cells (MSCs) is critical for metabolic homeostasis and nutrient signaling during development. However, limited information is available on the pivotal modulators of adipogenic differentiation of MSCs. Adaptor protein Lnk (Src homology 2B3 [SH2B3]), which belongs to a family of SH2-containing proteins, modulates the bioactivities of different stem cells, including hematopoietic stem cells and endothelial progenitor cells. In this study, we investigated whether an interaction between insulin-like growth factor-1 receptor (IGF-1R) and Lnk regulated IGF-1-induced adipogenic differentiation of MSCs. We found that wild-type MSCs showed greater adipogenic differentiation potential than $Lnk^{-/-}$ MSCs. An ex vivo adipogenic differentiation assay showed that $Lnk^{-/-}$ MSCs had decreased adipogenic differentiation potential compared with wild-type MSCs. Interestingly, we found that Lnk formed a complex with IGF-1R and that IGF-1 induced the dissociation of this complex. In addition, we observed that IGF-1-induced increase in the phosphorylation of Akt and mammalian target of rapamycin was triggered by the dissociation of the IGF-1R-Lnk complex. Expression levels of a pivotal transcription factor peroxisome proliferator-activated receptor gamma ($PPAR-{\gamma}$) and its adipogenic target genes (LPL and FABP4) significantly decreased in $Lnk^{-/-}$ MSCs. These results suggested that Lnk adaptor protein regulated the adipogenesis of MSCs through the $IGF-1/Akt/PPAR-{\gamma}$ pathway.

• International Journal of Oral Biology
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• v.37 no.4
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• pp.175-180
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• 2012

Skin-derived precursor cells (SKPs) are multipotent, sphere-forming and embryonic neural crest-related precursor cells that can be isolated from dermis. It is known that the properties of porcine SKPs can be enhanced by leukemia inhibitory factor (LIF) which is an essential factor for the generation of embryonic stem cells in mice. In our present study, to enhance or maintain the properties of murine SKPs, LIF was added to the culture medium. SKPs were treated with 1,000 IU LIF for 72 hours after passage 3. Quantitative real time RT-PCR was then performed to quantify the expression of the pluripotent stem cell specific genes Oct4, Nanog, Klf4 and c-Myc, and the neural crest specific genes Snai2 and Ngfr. The results show that the expression of Oct4 is increased in murine SKPs by LIF treatment whereas the level of Ngfr is decreased under these conditions. Interestingly, LIF treatment reduced Nanog expression which is also important for cell proliferation in adult stem cells and for osteogenic induction in mesenchymal stem cells. These findings implicate LIF in the maintenance of stemness in SKPs through the suppression of lineage differentiation and in part through the control of cell proliferation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.2
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• pp.97-108
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• 2011

Cancer stem cells have stem cell-like features, such as the ability for self-renewal and differentiation but show unlimited growth because they have the lost normal regulation of cell growth. Cancer stem cells and normal stem cells have similar features. They show high motility, diversity of progeny, robust proliferative potential, association with blood vessels, immature expression profiles, nestin expression, epidermal growth factor (EGF)-receptor expression, phosphatase and tensin homolog (PTEN) expression, hedgehog pathway activity, telomerase activity, and Wnt pathway activity. On the other hand, with cancer cells, some of these signaling pathways are abnormally modified. In 1875, Cohnheim suggested the concept of cancer stem cells. Recently, evidence for the existence of cancer stem cells was identified. In 1994, the cancer stem cells' specific cell surface marker for leukemia was identified. Since then, other specific cell surface markers for cancer stem cells in solid tumors (e.g. breast and colon cancer) have been identified. In oral cancer, studies on cancer stem cells have been performed mainly with squamous cell carcinomas. Oral cancer specific cell surface markers, which are genes strongly expressed in oral cancer and cancer stem cell specific side populations, have been identified. Cancer stem cells are resistant to radiotherapy and chemotherapy. Therefore, to eliminate malignant tumors efficiently and reduce the recurrence rate, therapy targeting cancer stem cells needs to be performed. Currently, studies targeting the cancer stem cells' specific signaling pathways, telomerase and tumor vasculatures are being done.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.437-442
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• 2015

Aim: To establish a pancreatic cancer stem cell model using human pancreatic cancer cells in nude mice to provide a platform for pancreatic cancer stem cell research. Materials and Methods: To establish pancreatic cancer xenografts using human pancreatic cancer cell line SW1990, nude mice were randomly divided into control and gemcitabine groups. When the tumor grew to a volume of $125mm^3$, they treated with gemcitabine at a dose of 50mg/kg by intraperitoneal injection of 0.2ml in the gemcitabine group, while the mice in control group were treated with the same volume of normal saline. Gemcitabine was given 2 times a week for 3 times. When the model was established, the proliferation of pancreatic cancer stem cells was observed by clone formation assay, and the protein and/or mRNA expression of pancreatic stem cell surface markers including CD24, CD44, CD133, ALDH, transcription factors containing Oct-4, Sox-2, Nanog and Gli, the key nuclear transcription factor in Sonic Hedgehog signaling pathway was detected by Western blot and/or RT-PCR to verify the reliability of this model. Results: This model is feasible and safe. During the establishment, no mice died and the weight of nude mice maintained above 16.5g. The clone forming ability in gemcitabine group was stronger than that of the control group (p<0.01). In gemcitabine group, the protein expression of pancreatic cancer stem cell surface markers including CD44, and ALDH was up-regulated, the protein and mRNA expression of nuclear transcription factor including Oct-4, Sox-2 and Nanog was also significantly increased (P<0.01). In addition, the protein expression of key nuclear transcription factor in Sonic Hedgehog signaling pathway, Gli-1, was significantly enhanced (p<0.01). Conclusions: The pancreatic cancer stem cell model was successfully established using human pancreatic cancer cell line SW1990 in nude mice. Gemcitabine could enrich pancreatic cancer stem cells, simultaneously accompanied by the activation of Sonic Hedgehog signaling pathway.

• Animal Bioscience
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• v.36 no.5
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• pp.710-719
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• 2023

Objective: The present study investigated whether protodioscin (PD), a steroidal saponin mainly found in rhizome of Dioscorea species, alleviates oxidative stress-induced damage of porcine oocytes during in vitro maturation. Methods: Oocytes were treated with different concentrations of PD (0, 1, 10, 100, and 200 µM) in the presence of 200 µM H₂O₂ during in vitro maturation. Following maturation, spindle morphology and mitogen-activated protein kinase activity was assessed along with reactive oxygen species level, GSH activity, and mRNA expression of endogenous antioxidant genes at the MII stage. On the day 7 after parthenogenetic activation, blastocyst formation rate was calculated and the quality of embryo and mRNA expression of development-related genes was evaluated. Results: Developmental competence was significantly poorer in the 0 µM PD-treated (control) group than in the non-treated (normal) and 10 µM PD-treated (10PD) groups. Although the reactive oxygen species level did not significantly differ between these three groups, the glutathione level and mRNA expression of antioxidant genes (superoxide dismutase 1 [SOD1], SOD2, nuclear factor erythroid 2-related factor 2 [Nrf2], and hemo oxygenase-1 [HO-1]) were significantly higher in the normal and 10PD groups than in the control group. In addition, the percentage of oocytes with defective spindle and abnormal chromosomal alignment was significantly lower and the ratio of phosphorylated p44/42 to total p44/42 was significantly higher in the normal and 10PD groups than in the control group. The total cell number per blastocyst was significantly higher in the 10PD group than in the control group. The percentage of apoptotic cells in blastocysts was highest in the control group; however, the difference was not significant. mRNA expression of development-related genes (POU domain, class 5, transcription factor 1 [POU5F1], caudal type homeobox 2 [CDX2], Nanog homeobox [NANOG]) was consistently increased by addition of PD. Conclusion: The PD effectively improves the developmental competence and quality of blastocysts by protecting porcine oocytes against oxidative stress.

• Molecules and Cells
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• v.38 no.9
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• pp.806-813
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• 2015

Gaucher disease (GD) is an autosomal recessive lysosomal storage disorder caused by mutations in the glucocerebrosidase gene (GBA), which encodes the lysosomal enzyme glucosylceramidase (GCase). Deficiency in GCase leads to characteristic visceral pathology and lethal neurological manifestations in some patients. Investigations into neurogenesis have suggested that neurodegenerative disorders, such as GD, could be overcome or at least ameliorated by the generation of new neurons. Bone marrowderived mesenchymal stem cells (BM-MSCs) are potential candidates for use in the treatment of neurodegenerative disorders because of their ability to promote neurogenesis. Our objective was to examine the mechanism of neurogenesis by BM-MSCs in GD. We found that neural stem cells (NSCs) derived from a neuronopathic GD model exhibited decreased ability for self-renewal and neuronal differentiation. Co-culture of GBA-deficient NSCs with BM-MSCs resulted in an enhanced capacity for self-renewal, and an increased ability for differentiation into neurons or oligodendrocytes. Enhanced proliferation and neuronal differentiation of GBA-deficient NSCs was associated with elevated release of macrophage colony-stimulating factor (M-CSF) from BM-MSCs. Our findings suggest that soluble M-CSF derived from BM-MSCs can modulate GBA-deficient NSCs, resulting in their improved proliferation and neuronal differentiation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.95-103
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• 2019

Periodontal inflammation, a major kind of periodontal diseases, is characterized to bleed, pain, and teeth loss, and it is resulted from oxidative stress. Membrane-free stem cell extract could avoid the immunogencity rejection by removal of cell membrane. In the present study, we investigated the protective effect of membrane-free stem cell extract from oxidative stress-induced periodontal inflammation in human periodontal ligament fibroblasts (HPLF). In the cell viability measurement, membrane-free stem cell extract showed significant increase of cell viability, compared with the $H_2O_2$-treated control group. To further investigation of molecular mechanisms, we measured inflammation and apoptosis related protein expressions. Membrane-free stem cell extract attenuated inflammation-related protein expressions such as nuclear factor kappa light chain enhancer of activated B cells, inducible nitric oxide synthase, and interleukin-6. In addition, the treatment of membrane-free stem cell extract decreased apoptotic protein expressions such as cleaved caspase-9, -3, poly (ADP-ribose) polymerase, and B-cell lymphoma 2 (Bcl-2)-associated X protein/Bcl-2 ratio in the $H_2O_2$-treated HPLF cells. In conclusion, membrane-free stem cell extract exhibited anti-oxidative stress effects by regulation of inflammation and apoptosis in HPLF, suggesting that it could be used as the treatment agents for periodontal inflammatory disease.