• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.2
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• pp.99-105
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• 2000

Cell-Cell interaction and the extracellular matrix (ECM) are belisved to play essential roles during in vitro culturing of primary hepatocytes in the control of differentiation and in the maintenance of tissue spcific functions. The objective of this study was to examine the effects of degree of cell-cell contact (DCC) on liver sperific function of rat promary hepatocytes. Hepatocyte aggregates with various with various degrees of cell-cell contantact, I. e., dispersed cell, longish aggregate, rugged aggregate, and smooth spheroid were obtained at 1, 5-6, 15-20, and 36-48 hrs, respectively in suspension cultures grown in spinner flasks embedded in Caalginate bead and collagen gel in order. The may result from mass transfer limitation and shear damage caused by agitation during aggregation. The rugged aggregate showed a higer viability and albumin secretion rate than the dispersed cells or the other aggregates. This result indicates the possible enhancement of a bioartificial liver's (BAL) performance using primary hepatocytes and the reduction in time to prepare a BAL through optimization of the immobilization time.

• Molecules and Cells
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• v.39 no.3
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• pp.186-194
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• 2016

Epidemiological evidence suggests that bone is especially sensitive to oxidative stress, causing bone loss in the elderly. Previous studies indicated that human amnion-derived mesenchymal stem cells (HAMSCs), obtained from human amniotic membranes, exerted osteoprotective effects in vivo. However, the potential of HAMSCs as seed cells against oxidative stress-mediated dysfunction is unknown. In this study, we systemically investigated their antioxidative and osteogenic effects in vitro. Here, we demonstrated that HAMSCs significantly promoted the proliferation and osteoblastic differentiation of $H_2O_2$-induced human bone marrow mesenchymal stem cells (HBMSCs), and down-regulated the reactive oxygen species (ROS) level. Further, our results suggest that activation of the ERK1/2 MAPK signal transduction pathway is essential for both HAMSCs-mediated osteogenic and protective effects against oxidative stress-induced dysfunction in HBMSCs. U0126, a highly selective inhibitor of extracellular ERK1/2 MAPK signaling, significantly suppressed the antioxidative and osteogenic effects in HAMSCs. In conclusion, by modulating HBMSCs, HAMSCs show a strong potential in treating oxidative stress- mediated bone deficiency.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.23 no.3
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• pp.9-23
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• 1997

Retinoids are essential regulators of spithelial cell growth and celluar differentiation. They are also known to be effective in photoaging. It was reported that topical application of retinoic acid improves facial wrinkle carsed by collagen synthesis reduction in photodamaged skin. Collagen synthesis by retinoic acid may contribute to the wrinkle effacement. Since celluar retinoic acid binding protein II is slsctively induced in human skin and dermal fibroblasts in vitro by retinoic acid, this response can be used to mesure retinoids potency and activity. In order to know the activity of retinoids and their relations with collagen synthesis, we treated dermal fibroblasts with retinoids for 48 hours at 10-6-10-7M and measured CRABPII mRNA level by quantitative Nortern blotting. We also measured the rate of collagen systhesis by retinoids using 3-dimensional dermal equivalent. CRABPII mRNA level was increased 3-fold by retinoic acid, 2.1-fold by retinol and 1.4-fold by retinaldehyde. Collagen systhesis was increased 34% by all-trans retinioc acid, 26% by retinol, 17% by retinaldehyde and 7% by retinyl palmitate. From the above results, retinoids were found to be a potent indecers of CRABPII mRNA and collagen synthesis. Though retinoic acid was the most effective, its use has been restricted because of the side effects. Instead, retinol can be a best candidate in cosmetics for the treatment of photodamaged skin in terms of efficacy and safety.

• Reproductive and Developmental Biology
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• v.36 no.4
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• pp.283-290
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• 2012

Skin serves as an easily accessible source of multipotent stem cells with potential for cellular therapies. In pigs, stem cells from skin tissues of fetal and adult origins have been demonstrated as either floating spheres (cell aggregates) or adherent spindle-shaped mesenchymal stem cell (MSC)-like cells depending on culture conditions. The cells isolated from the epidermis and dermis of porcine skin showed plastic adherent growth in the presence of serum and positively expressed a range of surface and intracellular markers that are considered to be specific for MSCs. The properties of primitive stem cells have been observed with the expression of alkaline phosphatase and markers related to pluripotency. Further, studies have shown the ability of skin-derived MSCs to differentiate in vitro along mesodermal, neuronal and germ-line lineages. Moreover, preclinical studies have also been performed to assess their in vivo potential, and the findings appear to be effective in tissue regeneration at the defected site after transplantation. The present review describes the recent progress on the biological features of porcine skin-derived MSCs as adherent cells, and summarizes their potential in advancing stem cell based therapies.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.6
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• pp.409-416
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• 2009

Acute pancreatitis is a multifactorial disease associated with the premature activation of digestive enzymes. The genes expressed in pancreatic acinar cells determine the severity of the disease. The present study determined the differentially expressed genes in pancreatic acinar cells treated with cerulein as an in vitro model of acute pancreatitis. Pancreatic acinar AR42J cells were stimulated with $10^{-8}$ M cerulein for 4 h, and genes with altered expression were identified using a cDNA microarray for 4,000 rat genes and validated by real-time PCR. These genes showed a 2.5-fold or higher increase with cerulein: lithostatin, guanylate cyclase, myosin light chain kinase 2, cathepsin C, progestin-induced protein, and pancreatic trypsin 2. Stathin 1 and ribosomal protein S13 showed a 2.5-fold or higher decreases in expression. Real-time PCR analysis showed time-dependent alterations of these genes. Using commercially available antibodies specific for guanylate cyclase, myosin light chain kinase 2, and cathepsin C, a time-dependent increase in these proteins were observed by Western blotting. Thus, disturbances in proliferation, differentiation, cytoskeleton arrangement, enzyme activity, and secretion may be underlying mechanisms of acute pancreatitis.

• Journal of Applied Biological Chemistry
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• v.60 no.4
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• pp.373-381
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• 2017

Hippocampus abdominalis, the big belly sea horse, is widely known for its medicinal value in Chinese folk medicine. In this study, extract obtained by proteolytic degradation of this species was investigated for its effects on skeletal muscle development, both in vitro and in vivo. Muscle cell lines ($C_2C_{12}$ and $L_6$) treated with the bioactive peptide did not have any detrimental effects on the cell viability, which was above 80%. Optical microscopy analysis on the morphology of the sea horse extract (SHE)-treated cells showed enhanced differentiating ability with myotube formation. Moreover, cells incubated with the hydrolysate displayed decreased proliferation rate, as recorded by the electric cell substrate impedance sensing system, thereby supporting enhanced differentiation. For a period of 12 weeks, mice models were fed with SHE and simultaneously subjected to treadmill exercise, which increased the expression of Myogenin, a key myogenic regulatory factor. In addition, there was an increase in the expression of AMPK- and Cytochrome C, both of which are important in mitochondrial biogenesis. Thus, the SHE from Hippocampus abdominalis can be a promising candidate as protein supplement aiding muscle development.

• Journal of Periodontal and Implant Science
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• v.32 no.4
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• pp.801-809
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• 2002

The ultimate goal of periodontal therapy is to promote the regeneration of lost periodontal tissue, there have been many attempts to develop a method to achieve this goal, hut none of them was completely successful. The purpose of this study is to evaluate the effects of Bio-Oss(R) on alkaline Phosphatase (ALP) activity in human fetal osteoblasts (hFOB1). The results of this study were as follows, in ALP Activity, 100 ${\mu}g/ml$ Bio-Oss(R) treated group showed significantly increased value than negative control group, but positive group($10^{-7}$ M dexamethasone treated group) showed the highest ALP activity at 3 day. In mineralization assay, numerous mineralized nodules were identified as darkly stained spots in 100${\mu}g/ml$ Bio-Oss(R) treated group than two control groups, whereas a small number of mineralized nodules were showed in the positive control. ALP may relate to the initial phase of bone nodule formation. On the basis of these results, this study showed Bio-Oss(R) is capable of accelerating new bone formation through hFOBl differentiation in vitro.

• Molecules and Cells
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• v.39 no.6
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• pp.484-494
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• 2016

Plant cells have a remarkable ability to induce pluripotent cell masses and regenerate whole plant organs under the appropriate culture conditions. Although the in vitro regeneration system is widely applied to manipulate agronomic traits, an understanding of the molecular mechanisms underlying callus formation is starting to emerge. Here, we performed genome-wide transcriptome profiling of wild-type leaves and leaf explant-derived calli for comparison and identified 10,405 differentially expressed genes (> two-fold change). In addition to the well-defined signaling pathways involved in callus formation, we uncovered additional biological processes that may contribute to robust cellular dedifferentiation. Particular emphasis is placed on molecular components involved in leaf development, circadian clock, stress and hormone signaling, carbohydrate metabolism, and chromatin organization. Genetic and pharmacological analyses further supported that homeostasis of clock activity and stress signaling is crucial for proper callus induction. In addition, gibberellic acid (GA) and brassinosteroid (BR) signaling also participates in intricate cellular reprogramming. Collectively, our findings indicate that multiple signaling pathways are intertwined to allow reversible transition of cellular differentiation and dedifferentiation.

• Biomolecules & Therapeutics
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• v.29 no.5
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• pp.519-526
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• 2021

In a search for effective PPAR-γ agonists, 110 clinical drugs were screened via molecular docking, and 9 drugs, including parecoxib, were selected for subsequent biological evaluation. Molecular docking of parecoxib to the ligand-binding domain of PPAR-γ showed high binding affinity and relevant binding conformation compared with the PPAR-γ ligand/antidiabetic drug rosiglitazone. Per the docking result, parecoxib showed the best PPAR-γ transactivation in Ac2F rat liver cells. Further docking simulation and a luciferase assay suggested parecoxib would be a selective (and partial) PPAR-γ agonist. PPAR-γ activation by parecoxib induced adipocyte differentiation in 3T3-L1 murine preadipocytes. Parecoxib promoted adipogenesis in a dose-dependent manner and enhanced the expression of adipogenesis transcription factors PPAR-γ, C/EBPα, and C/EBPβ. These data indicated that parecoxib might be utilized as a partial PPAR-γ agonist for drug repositioning study.

• Journal of Microbiology and Biotechnology
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• v.8 no.1
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• pp.74-80
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• 1998

CS-2l lymphoma cells that preferentially metastasize to lymph nodes after s.c. inoculation into BALB/c mice were grown in vitro in the presence of CA- 12 stromal cells isolated from lymph nodes. In order to obtain fundamental data on the identification and characterization of the soluble factors produced by CA-12 stromal cells, the conditioned medium of CA-12 stromal cells that inhibited apoptosis of CS-21 cells was examined. Various analytical treatments revealed that the soluble factors in CA-12 conditioned medium are very sensitive to heat treatment and trypsinization. Moreover CA-12 conditioned medium has an affinity with heparin but not with Con-A. In addition to these, the activity of CA-12 conditioned medium was blocked by H-7, a PKC inhibitor, but the conditioned medium could not induce the differentiation of thymocytes. We concluded that CA-12 conditioned medium contains stromal cell-derived apoptosis-inhibitory molecules that play an important role in proliferation of CS-2l cells by suppressing cell apoptosis.