• Journal of Nutrition and Health
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• v.53 no.4
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• pp.347-355
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• 2020

Purpose: Zinc is known to be associated with osteoblast proliferation and differentiation. Osterix as zinc-finger transcription factor is also related to osteoblast differentiation and bone formation. In the present study, we aimed to investigate whether zinc modulates osterix gene and protein expression in osteoblastic MC3T3-E1 cells. Methods: MC3T3-E1 cells were cultured in zinc-dependent concentrations (0, 0.5, 1, 5, or 15 µM Zn), along with osteogenic control (normal osteogenic medium) for 1 and 3 days. The gene and protein expression levels of osterix were analyzed by real-time reverse transcription polymerase chain reaction and Western blotting, respectively. Results: Zinc increased osteoblast proliferation in a concentration-dependent manner at day 1 and 3. Similarly, zinc increased the activity of osteoblast marker enzyme alkaline phosphatase in cells and media in a zinc concentration-dependent manner. Moreover, our results showed that the pattern of osterix gene expression by zinc was down-regulated within the low levels of zinc treatments (0.5-1 µM) at day 1, but it was up-regulated after extended culture period at day 3. Osterix protein expression by zinc showed the similar pattern of gene expression, which down-regulated by low zinc levels at day 1 and up-regulated back at day 3 as the early stage of osteoblast differentiation. Conclusion: Our results suggest that zinc modulates osterix gene and protein expression in osteoblasts, particularly in low level of zinc at early stage of osteoblast differentiation period.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.17 no.4
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• pp.365-378
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• 1995

Allogeneic bone grafting has recently been used in oral and maxillofacial regions to restore the cosmetic and functional problem. There are several types of allogeneic bone grafts ; bone powder, bone chips, bone blocks. Empirically, it is thought to be better to combine the allogeneic bone chips to any type of tissue adhesive not to displace during packing and condensing. But, there are no reports about using tissue adhesive in allogeneic bone grafting. This experimental study is designed to investigate the effect of the fibrin adhesive on bone healing process after demineralized allogeneic bone grafting in 60 rats. In control groups (30 rats), routine demineralized allogeneic bone grafting were done in 7 ${\times}$ 7mm calvarial bone defects which were drilled intentioally. And we used the fibrin adhesive for holding the bone particle in experimental groups (30 rats). Each experimental specimen was sacrified at 1, 2, 4, 6, 8 weeks postoperatively The results were as follows : 1. The degree of inflammatory cell infiltrations were more prominent in experimental than in control groups till 2 weeks. 2. Early fibroblast proliferation and new capillary proliferation were uncorporated around graft sites in the experimental groups later than in control groups at early stages. 3. Osteoblastic activity in control group was more prominent at 2 weeks. 4. Osteoblastic activity in experimental groups was more prominent than in control group till 4 weeks. 5. New bone formation was more in control group than experimental group till 3 weeks, but similar appearance after that time. As above results, initial bone healing within 2 weeks were more processed in without adhesive group than with adhesive group. But above 4 weeks; similar bone healing were observed.

• Tissue Engineering and Regenerative Medicine
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• v.15 no.6
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• pp.721-733
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• 2018

BACKGROUND: Because three-dimensional (3D) models more closely mimic native tissues, one of the goals of 3D in vitro tissue models is to aid in the development and toxicity screening of new drug therapies. In this study, a 3D skin wound healing model comprising of a collagen type I construct with fibrin-filled defects was developed. METHODS: Optical imaging was used to measure keratinocyte migration in the presence of fibroblasts over 7 days onto the fibrin-filled defects. Additionally, cell viability and growth of fibroblasts and keratinocytes was measured using the $alamarBlue^{(R)}$ assay and changes in the mechanical stiffness of the 3D construct was monitored using compressive indentation testing. RESULTS: Keratinocyte migration rate was significantly increased in the presence of fibroblasts with the cells reaching the center of the defect as early as day 3 in the co-culture constructs compared to day 7 for the control keratinocyte monoculture constructs. Additionally, constructs with the greatest rate of keratinocyte migration had reduced cell growth. When fibroblasts were cultured alone in the wound healing construct, there was a 1.3 to 3.4-fold increase in cell growth and a 1.2 to 1.4-fold increase in cell growth for keratinocyte monocultures. However, co-culture constructs exhibited no significant growth over 7 days. Finally, mechanical testing showed that fibroblasts and keratinocytes had varying effects on matrix stiffness with fibroblasts degrading the constructs while keratinocytes increased the construct's stiffness. CONCLUSION: This 3D in vitro wound healing model is a step towards developing a mimetic construct that recapitulates the complex microenvironment of healing wounds and could aid in the early studies of novel therapeutics that promote migration and proliferation of epithelial cells.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.4
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• pp.511-515
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• 2000

Early weaning is a means of breaking the disease cycle from sow to piglet as well as capitalising on the enormous growth potential of the pig. However, the transition from milk to dry diets results in a growth check. Feeding of supplemental milk, fermented to reduce pH and enterotoxigenic bactetial proliferation, may be a means of gradually weaning pigs on to solid feed. This study involved 216 pigs weaned from the sow at 12 days of age, allocated to groups of 6 males and 6 females per weaner pen and allowed ad libitum access to a pelleted diet. In addition, half the pigs were given supplemental fermented skim milk for the first 8 days after weaning. Feeding supplemental fermented milk increased feed intake (104 vs. 157 g DM/d, p=0.011), average daily gain (-3 vs. 112 g/d, p<0.001) and feed conversion efficiency (0.01 vs. 0.81, p=0.003) over the first 8 days after weaning. The improvements observed in the supplemented pigs continued to be augmented such that, by 42 days of age, the pigs that had received supplemental fermented milk were heavier (9.6 vs. 11.5 kg, p=0.003) than their unsupplemented counterparts. Feeding fermented supplemental milk to early-weaned pigs can improve growth performance in the immediate and subsequent post-weaning period.

• BMB Reports
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• v.54 no.7
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• pp.374-379
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• 2021

Tetranectin (TN), an adipogenic serum protein, enhances adipocyte differentiation, however, its functional mechanism has yet to be elucidated. In the present study, we investigated the adipogenic function of TN by using medium containing TN-depleted fetal bovine serum (TN-del-FBS) and recombinant mouse TN (mTN). The adipocyte differentiation of 3T3-L1 cells was significantly enhanced by mTN supplementation essentially at differentiation induction, which indicated a potential role of the protein in the early differentiation phase. The adipogenic effect of mTN was more significant with insulin in the differentiation induction cocktail, implicating their close functional relationship. mTN enhanced not only the proliferation of growing cells, but also mitotic clonal expansion (MCE) that is a prerequisite for adipocyte differentiation in the early phase. Consistently, mTN increased the phosphorylation of ERK in the early phase of adipocyte differentiation. Results of this study demonstrate that the adipogenic function of mTN is mediated by enhancing MCE via ERK signaling.

• Journal of Plant Biotechnology
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• v.29 no.2
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• pp.123-127
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• 2002

Effect of cytokinins (BA, TDZ, zeatin, 2iP, and kinetin) applied either singly or in combination on in vitro growth of two grape cultivars ('Cabernet Sauvignon' and 'Campbell Early') was investigated as a serial work for mass production of grapevine nursery stocks. In single treatment, shoot growth of two cultivars was most favorable in control. Shoot proliferation was satisfactory with 10 $\mu$M BA regardless of cultivars and cytokinin combinations, followed by TDZ. Other treatments resulted in very poor or no branching. Total explants ready for subculture produced by 10 $\mu$M BA outnumbered those by other treatments. TDZ was also effective. TDZ significantly increased the fresh weight and callus formation while shoot growth was unsatisfactory. Shoot growth response of two cultivars in combined treatments was also most favorable in control as was in single treatments. When TDZ was combined with zeatin, 2iP, and kinetin which failed to induce branching, proliferous branching was induced though the shoot number was behind that of single treatments of BA and TDZ. TDZ was very effective for total number of explants and fresh weight, showing 10-fold increase.

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.593-598
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• 2007

The current study was undertaken to determine the effects of sex steroid hormones(estrogen, testosterone and 19-nortestosterone) on differentiation and proliferation of pig preadipocytes. The preadipocytes were isolated from the backfat of new-born female pigs by collagenase digestion. 10－8M and 10－7M sex steroid hormones were treated to the cultured preadipocytes. Sex steroid hormones treated during the early stage of cell growth did not affect differentiation and proliferation of preadipocytes. However, testosterone and 19- nortestosterone treated during the late stage of cell growth stimulated differentiation of pig preadipocytes.

• Childhood Kidney Diseases
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• v.21 no.1
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• pp.1-7
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• 2017

Mitogen-activated protein kinases (MAPKs) play important roles in various cellular functions including proliferation, differentiation, and apoptosis. We showed that MAPKs are developmentally regulated in the rat kidney. p38 MAPK (p38) and extracellular signal-regulated kinase (ERK) were strongly expressed in the fetal kidney, whereas c-Jun N-terminal kinase (JNK) was detected predominantly in the adult kidney. The inhibition of p38 or ERK in organ culture resulted in reduced nephron formation with or without reduced kidney size. On the other hand, persistent fetal expression pattern of MAPKs, i.e., upregulation of p38 and ERK and downregulation of JNK, was observed in the cyst epithelium of human renal dysplasia, ovine fetal obstructive uropathy, and pcy mice, a model of polycystic kidney disease. Furthermore, activated p38 and ERK induced by cyclic stretch mediated proliferation and $TGF-{\beta}1$ expression in ureteric bud cells, probably leading to cyst formation and dysplastic changes. Inhibition of ERK slowed the disease progression in pcy mice. Finally, ERK and p38 were inactivated in the early embryonic kidney subjected to maternal nutrient restriction, characterized by reduced ureteric branching and nephron number. Thus, MAPKs mediate the development of normal and diseased kidney. Their modulation may result in novel therapeutic strategies against developmental abnormalities of the kidney.

• Development and Reproduction
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• v.20 no.3
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• pp.179-185
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• 2016

The insulin-like growth factor (IGF) pathway is a key signal transduction pathway involved in cell proliferation, migration, and apoptosis. In dairy cows, IGF family proteins and binding receptors, including their intracellular binding partners, regulate mammary gland development. IGFs and IGF receptor interactions in mammary glands influence the early stages of mammogenesis, i.e., mammary ductal genesis until puberty. The IGF pathway includes three major components, IGFs (such as IGF-I, IGF-II, and insulin), their specific receptors, and their high-affinity binding partners (IGF binding proteins [IGFBPs]; i.e., IGFBP1-6), including specific proteases for each IGFBP. Additionally, IGFs and IGFBP interactions are critical for the bioactivities of various intracellular mechanisms, including cell proliferation, migration, and apoptosis. Notably, the interactions between IGFs and IGFBPs in the IGF pathway have been difficult to characterize during specific stages of bovine mammary gland development. In this review, we aim to describe the role of the interaction between IGFs and IGFBPs in overall mammary gland development in dairy cows.

• Journal of Life Science
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• v.11 no.4
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• pp.362-370
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• 2001

Regulation of cell proliferation is a complex process involving the regulated expression and /or modification of discrete gene products. which control transition between different stages of the cycle. The purpose of this short review is to provide an overview of somatic cell cycle events and their controls. Cycline have appeared as major positive regulators in this network, because their association to the cyclin-dependent kinases(Cdks) allows the subsequent activation on the Cdk/cyclin complexes and their catalatic activity. In mammalian cells, early to mid G1 progression and late G1 progression leading to S phase entry are directed by D-type cyclins-Cdk4, 6 and cyclin E-Cdk 2 both of which can phosphorylate the retinoblastoma protein (pRB). pRB is a transcriptional repressor which, in its unphosphorylated state, binds to members of the E2F transcription factor family and blocks E2F-dependent transcription of genes controlling the G1 to S phase transition an subsequent DNA synthesis. Cyclin A is produced in late G1 and expressed during S and G2 phae, and expression of B-type cyclins is typically maximal during the G2 to M phase transition and it controls the passage through M phase. They primarily associate with the activate Cdk2, and Cdc2, respectively. On the other hand, the Cdk inhibitors negatively control the activity of C아/cyclin complex by coordinating internal and/or external signals and impending proliferation at several key checkpoints. These current and further findings will provide novel approaches to understanding and treating major diseases.