• Reproductive and Developmental Biology
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• v.36 no.1
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• pp.33-37
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• 2012

Differential capacity of the parthenogenetic embryonic stem cells (PESCs) is still under controversy and the mechanisms of its neural induction are yet poorly understood. Here we demonstrated neural lineage induction of PESCs by addition of insulin-like growth factor-2 (Igf2), which is an important factor for embryo organ development and a paternally expressed imprinting gene. Murine PESCs were aggregated to embryoid bodies (EBs) by suspension culture under the leukemia inhibitory factor-free condition for 4 days. To test the effect of exogenous Igf2, 30 ng/ml of Igf2 was supplemented to EBs induction medium. Then neural induction was carried out with serum-free medium containing insulin, transferrin, selenium, and fibronectin complex (ITSFn) for 12 days. Normal murine embryonic stem cells derived from fertilized embryos (ESCs) were used as the control group. Neural potential of differentiated PESCs and ESCs were analyzed by immunofluorescent labeling and real-time PCR assay (Nestin, neural progenitor marker; Tuj1, neuronal cell marker; GFAP, glial cell marker). The differentiated cells from both ESC and PESC showed heterogeneous population of Nestin, Tuj1, and GFAP positive cells. In terms of the level of gene expression, PESC showed 4 times higher level of GFAP expression than ESCs. After exposure to Igf2, the expression level of GFAP decreased both in derivatives of PESCs and ESCs. Interestingly, the expression level of $Tuj1$ increased only in ESCs, not in PESCs. The results show that IGF2 is a positive effector for suppressing over-expressed glial differentiation during neural induction of PESCs and for promoting neuronal differentiation of ESCs, while exogenous Igf2 could not accelerate the neuronal differentiation of PESCs. Although exogenous Igf2 promotes neuronal differentiation of normal ESCs, expression of endogenous $Igf2$ may be critical for initiating neuronal differentiation of pluripotent stem cells. The findings may contribute to understanding of the relationship between imprinting mechanism and neural differentiation and its application to neural tissue repair in the future.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.5
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• pp.648-656
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• 2019

Objective: An experiment was conducted to determine the effect of reduced energy density of close-up diets on metabolites, lipolysis and gluconeogenesis in cows during the transition period. Methods: Thirty-nine Holstein dry cows were blocked and assigned randomly to three groups, fed a high energy density diet (HD, 1.62 Mcal of net energy for lactation $[NE_L]/kg$ dry matter [DM]), a medium energy density diet (MD, $1.47Mcal\;NE_L/kg\;DM$), or a low energy density diet (LD, $1.30Mcal\;NE_L/kg\;DM$) prepartum; they were fed the same lactation diet to 28 days in milk (DIM). All the cows were housed in a free-stall barn and fed ad libitum. Results: The reduced energy density diets decreased the blood insulin concentration and increased nonesterified fatty acids (NEFA) concentration in the prepartum period (p<0.05). They also increased the concentrations of glucose, insulin and glucagon, and decreased the concentrations of NEFA and ${\beta}-hydroxybutyrate$ during the first 2 weeks of lactation (p<0.05). The plasma urea nitrogen concentration of both prepartum and postpartum was not affected by dietary energy density (p>0.05). The dietary energy density had no effect on mRNA abundance of insulin receptors, leptin and peroxisome proliferator-activated $receptor-{\gamma}$ in adipose tissue, and phosphoenolpyruvate carboxykinase, carnitine palmitoyltransferase-1 and peroxisome proliferator-activated $receptor-{\alpha}$ in liver during the transition period (p>0.05). The HD cows had higher mRNA abundance of hormone-sensitive lipase at 3 DIM compared with the MD cows and LD cows (p = 0.001). The mRNA abundance of hepatic pyruvate carboxy-kinase at 3 DIM tended to be increased by the reduced energy density of the close-up diets (p = 0.08). Conclusion: The reduced energy density diet prepartum was effective in controlling adipose tissue mobilization and improving the capacity of hepatic gluconeogenesis postpartum.

• Journal of Embryo Transfer
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• v.27 no.2
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• pp.121-126
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• 2012

The objective of this study was to examine the effect of in vitro culture media on embryonic development of in vitro-matured (IVM) oocytes after parthenogenetic activation (PA) in pigs. Immature pig oocytes were matured in TCM-199 supplemented with porcine follicular fluid, cysteine, pyruvate, EGF, insulin, and hormones for the first 22 h and then further cultured in hormone-free medium for an additional 22~26 h. IVM oocytes were activated by electric pulses and cultured in porcine zygote medium-3 (PZM-3) and North Carolina State University-23 supplemented with essential and non-essential amino acids (NCSU-23aa). These media were further modified by supplementing 2.77 mM myo-inositol, 0.34 mM trisodium citrate, and $10{\mu}M$ ${\beta}$-mercaptoethanol (designated as mPZM-3 and mNCSU-23aa, respectively). Culture of PA embryos in mPZM-3 significantly increased development to the blastocyst stage than culture in NCSU-23aa (36.2% vs. 24.8%, p<0.05). Modified PZM-3 showed a significantly higher blastocyst formation than NCSU-23aa in both groups of embryos that were activated at 44 h and 48 h of IVM (51.0% vs. 35.5% and 49.0% vs. 34.2% in oocytes activated at 44 h and 48 h of IVM, respectively). Irrespective of the follicle diameter where oocytes were collected, embryonic development to the blastocyst stage was increased (p<0.05) by the culture in mPZM-3 compared to culture in NCSU-23aa (25.9% vs. 34.2% and 32.9% vs. 44.8% in embryos derived from small and medium size follicles, respectively). Our results demonstrated that culture media had significant effect on preimplantation development PA embryos and that mPZM-3 was superior to mNCSU-23 in supporting development to the blastocyst stage in pigs. This beneficial effect of mPZM-3 on embryonic development was not impaired by other factors such as time of oocyte activation and origin of immature oocytes (small and medium size follicles).

• Journal of Embryo Transfer
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• v.28 no.2
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• pp.127-132
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• 2013

The objective of this study was to examine the effect of in vitro maturation (IVM) medium, cytochalasin B (CB) treatment during intracytoplasmic sperm injection (ICSI), and electric activation on in vitro development ICSI-derived embryos in pigs. Immature pig oocytes were matured in vitro in medium 199 (M199) or porcine zygote medium (PZM)-3 that were supplemented with porcine follicular fluid, cysteine, pyruvate, EGF, insulin, and hormones for the first 22 h and then further cultured in hormone-free medium for an additional 21~22 h. ICSI embryos were produced by injecting single sperm directly into the cytoplasm of IVM oocytes. The oocytes matured in PZM-3 with 61.6 mM NaCl (low-NaCl PZM-3) tended to decrease (0.05

• Journal of Life Science
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• v.17 no.5 s.85
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• pp.687-693
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• 2007

Insulin-like growth factor-I(IGF-I) has significant insulin-like anabolic effects which include the stimulation of glucose and amino acid uptake, as well as protein and glycogen synthesis. IGFs exist in serum and other biological fluids as complexes bound to a family of structurally related insulin-like growth factor binding proteins(IGFBPs). Six human IGFBPs can modulate the effects of IGFs on target tissues by several mechanisms, including altering the serum's half-life and the transcapillary transport of IGFs, as well as changing the availability of IGFs to specific cell surface receptors. Human fibroblasts secrete IGFBPs that can modify IGF-I action. Previous to our study using either Northern blotting, and Western blotting have shown that fibroblasts express mRNA IGFBP-3, -4, and -5, and synthesize these proteins. In addition, fibroblast cell lysates revealed that the IGFBP-3 was most abundant. For these reasons, we undertook to gain further insight into the effects of high and low glucose incubation condition on metabolism and IGFBP-3 expression. In results of metabolites and IGFBP-3 expression in GM10 cells cultivated with various glucose concentration, the consumption of glucose and accumulation of triglyceride were increased in condition of high glucose, and total protein level was decreased. in the course of time. After 5 days incubation, levels of free amino acid in medium containing glucose of high concentration glucose were higher than in conditions of low glucose. Although the levels of IGFBP-3 protein and mRNA levels were increased in low glucose, and IGFBP-3 was not affected by any pretense. Taken together, we suggest that the study of growth factors, like IGFs, might be a possible model of diabetes militus in cell, although the results in cell models were not in accord with in vivo.

• Journal of Embryo Transfer
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• v.25 no.1
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• pp.1-7
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• 2010

The objective of this study was to examine the effect of vitamin B (pantothenic acid, folic acid, and myo-inositol) that was supplemented to embryo culture medium on in vitro development of parthenogenetically activated (PA) pig embryos. Cumulus-oocyte complexes derived from slaughtered ovaries were matured in TCM-199 supplemented with porcine follicular fluid, cysteine, pyruvate, EGF, insulin, and hormones (hCG and eCG) for the first 22 h and then further cultured in hormone-free medium for an additional 22 h. After maturation culture, metaphase II oocytes that extruded 1st polar body were electrically activated and treated with $5.0\;{\mu}g/ml$ cytochalasin B for 4 h. Then, PA embryos were cultured for 7 days in a modified NCSU-23 that was supplemented with pantothenic acid, myo-inositol, or folic acid at different concentrations ($3{\sim}300\;{\mu}M$) according to the experimental design. Myo-inositol added to culture medium did not show any beneficial or inhibitory effects on embryo cleavage and blastocyst formation. However, $300\;{\mu}M$ pantothenic acid significantly inhibited blastocyst formation compared to control (no addition) (24% vs. 36%, p<0.05). Folic acid ($300\;{\mu}M$) significantly (p<0.05) increased blastocyst formation (56%) compared to control (41%). Our results demonstrated that in vitro development of PA embryos was significantly influenced by vitamin B and addition of $300\;{\mu}M$ folic acid to culture medium improved in vitro development of pig PA embryos.

• Journal of Nutrition and Health
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• v.35 no.2
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• pp.192-200
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• 2002

Conjugated linoleic acid (CLA) is a collective term for positional and geometric isomers of octadecadienoic acid in which the double bonds are conjugated. CLA has anticancer activity in a variety of animal cancer models, and cis-9, trans-11 (c9t11) and trans-10, cis-12(t10c12) CLA are the most predominant isomers present in the synthetic preparations utilized in these animal studies. To compare the ability of c9t11, t10c12 and an isomeric mixture of CLA to inhibit TSU-Prl cell growth, cells were incubated in a serum-free medium with various concentrations of these fatty acids. The isomeric mixture inhibited cell growth in a dose-dependent manner (1-3 $\mu$M) with a 41 $\pm$ 1% inhibition observed at 3 $\mu$M concentration after 48 hours. T10c12 also inhibited cell proliferation in a dote-dependent manner, However, the efficacy and potency of this isomer was much greater than that of the isomeric mixture with a 49 $\pm$ 2% inhibition observed at 0.3 $\mu$M concentration after 48 hours. By contrast, c9t11 slightly increased cell proliferation. To determine whether the growth-inhibiting effect of CLA is related to the changes in production of insulin-like growth factors (IGF) and IGF-binding proteins (IGFBP) by these cells, serum-free conditioned media were collected. Immunoblot analysis of conditioned media using a monoclonal anti-IGF-II antibody showed that both the isomeric mixture and t10c12 inhibited secretion of both mature 7,500 Mr and higher Mr forms of pro IGF-II, whereas c9t11 had no effect. Ligand blot analysis with 125I-IGF-II revealed the presence of two types of IGFBPs : 24,000 Mr IGFBP-4 and 30,000 Mr IGFBP-6. The production of IGFBP-4 slightly decreased at the highest concentrations of the isomeric mixture and t10c12. These results indicate that CLA inhibits human prostate cancer cell growth, an effect largely due to the action of t10c12. The growth inhibition may result, at least in part, from decreased production of IGF-II and IGFBP-4 by these cells.

• Tuberculosis and Respiratory Diseases
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• v.50 no.5
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• pp.549-556
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• 2001

Background : IGF-I is an important mitogen in many types of malignancies. Tumors also express many IGF binding proteins, which modulate IGF action. The propose of this study was to evaluate the effect of IGF-I and IGFBP on cell proliferation in mouse lung cancer cells (3LL). Methods : The cellular proliferation of 3LL with the treatment of growth factors was evaluated using MTT assay. Western ligand blot was performed in order to determine whether 3LL cells secrete IGFBPs and we evaluated the effect of IGFBP on cellular proliferation. Results : The treatment of 3LL cells with IGF-I increased cellular proliferation in a serum free media. Western ligand blot of conditioned medium of 3LL with $^{125}I$-IGF-I demonstrated one single major band with an estimated molecular mass of 24 kDa. This band was identified as IGFBP-4 with immunoblot analysis using antisera. The addition of anti-IGFBP-4 antibody to abrogate the effect of IGFBP-4 resulted in increased cellular proliferation suggesting that IGFBP-4 inhibits cell growth. Conclusion : IGF-I increases cellular proliferation, however the secreted IGFBP-4 has an inhibitory function on cell growth in 3LL. These findings suggest that IGF-I and IGFBP are involved in the cell proliferation.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.10
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• pp.1508-1513
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• 2006

Myostatin (MSTN) and insulin-like growth factors (IGFs) are a known inhibitor and stimulators of proliferation and differentiation of muscle cells, respectively. The present study was performed to investigate the relationship of MSTN-induced growth inhibition to expression of the IGF system components and myogenin, a muscle cell-specific transcription factor, in rat L6 myoblasts. The L6 cells transfected with a green fluorescent protein-MSTN plasmid expression construct had a 47% less cell number than mock-transfected cells after 3-d serum-free culture, accompanied by delayed differentiation which was suggested by inhibited aggregation of cells. Moreover, cells transfected with the expression construct had decreased expression of IGF-II and myogenin genes, but not IGF-I or its receptor genes, as examined by reverse transcription-polymerase chain reaction. The reduced mitosis of the L6 cells transfected with the MSTN-expression construct increased following an addition of either IGF-I or IGF-II to the culture medium, but not to the level of mock-transfected cells. By contrast, myogenin gene expression in these cells increased after the addition of either IGF to the level of mock-transfected cells. Collectively, these results suggest that the inhibitory effect of MSTN on L6 cell proliferation and differentiation is likely to be partly mediated by serially suppressed expression of IGF-II and myogenin genes, not IGF-I gene.

• Journal of Periodontal and Implant Science
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• v.24 no.2
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• pp.219-237
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• 1994

The ultimate goal of clinical periodontal therapy is to achieve regeneration of a healthy connective tissue reattachment. Conventional therapy including scaling, root planing, gingival curettage, gingivectomy and flap procedures of various types results primarily in repair rather than regeneration of the periodontium. In order for periodontal regeneration to occur, progenitor periodontal ligament cells must migrate to the denuded root surface, attach to it, proliferate and mature into an organized and functional fibrous attachment apparatus. Polypeptide growth factors belong to a class of potent biologic mediators which regulate cell differentiation, proliferation, migration and metabolism. Insulin-like growth factor-I (IGF- I ) of these factors appear to have an important role in periodontal wound healing and bone formation. The purpose of this study is to evaluate the effects of IGF- I on the periodontal ligament cells to use as a regeneration promoting agent of periodontal tissue. Human periodontal ligament cells were obtained from periodontal tissue explants culture of the first premolar tooth extracted for the orthodontic treatment. Cells were cultured in Dulbecco's modified Eagle medium(DMEM) with 10% fetal bovine serum. Fourth to seventh passage cells were plated in 24 well tissue culture plates and medium changed to serum-free medium prior to addition of growth factors. Cell proliferation was measured by the incorporation of $[^3H]-thymidine$ into DNA, Protein synthesis was determined by measurement of $[^3H]-proline$ incorporation into collagenase-digestible protein(CDP) and noncollagenous protein(NCP) according to the method of Peterkofsky and Diegelmann (1971), And alkaline phosphatase activity was measured as one parameter of osteoblastic differentiation. The results were as follows : The DNA synthetic activity was increased in a dose-dependent manner with IGF- I except for 0.1ng/ml concentration of IGF- I At the concentration of 10, 100ng/ml, IGF- I significantly increased the DNA synthetic activity(P<0.05) The total protein, collagen and noncollagen synthesis was increased in a dose-dependent manner with IGF- I except for 0.1ng/ml concentration of IGF- I. At the concentration of 1, 10, 100ng/ml, IGF- I significantly increased the total protein, collagen and noncollagen synthesis activity(P<0.95, P<0.001). The % of collagen was not effected according to the concentration of IGF- I. The alkaline phosphatase activity was increased in a dose-, time-dependent manner with IGF- I (10, 100ng/ml). In conclusions, the present study shows that IGF- I has a potentiality to enhance the DNA synthesis of periodontal ligament cells with including the increase of the total protein and collagen synthetic activity. The use of IGF- I to mediate biological stimulation of periodontal ligament cells shows promise for future therapeutic applications.