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Park Y.S.,Ewha Womans University | Lee J.-Y.,Nano Intelligent Biomedical Engineering Corporation NIBEC | Suh J.S.,Seoul National University | Jin Y.M.,Ewha Womans University | And 5 more authors.
Biomaterials | Year: 2014

Mineralization in mammalian cells is accomplished by concerted regulation of protein-based extracellular matrix (ECM) components, such as non-collagenous proteins and collagen fibrils. In this study, we investigated the ability of a collagen-binding motif (CBM) peptide derived from osteopontin to selectively affect osteogenic or adipogenic differentiation in vitro and in vivo. In particular, increased osteogenic differentiation and decreased adipogenic differentiation were observed in human mesenchymal stem cells (hMSCs). Osteocalcin (OCN) protein expression in MC3T3-E1 cells without osteogenic inducers was then investigated following treatment with the CBM peptide. In ovariectomized (OVX) mice, estrogen deficiency induced osteoporosis and increased fat tissue deposition. However, after the CBM peptide or estradiol was injected into the OVX mice for 2 months, the increased serum OCN concentration and alkaline phosphate (ALP) activity were decreased in the estradiol-treated group (OVX-E) and the high-concentration CBM peptide-treated group (OVX-HP). Significant bone loss was also observed in the ovariectomized mice (OVX-PBS). In particular, the bone volume per total volume (BV/TV) and bone mineral density (BMD) were significantly decreased in the OVX mice; however, both of these markers were restored in the OVX-HP group, which also had significantly well-developed bone structure and bone formation. In contrast to the bone structural change, adipose tissue was increased in the OVX-PBS. However, a significant decrease in total fat and subcutaneous fat was observed in the low-concentration CBM peptide-treated group (OVX-LP) and the estradiol-treated group (OVX-E). Taken together, these results suggest that the CBM peptide could be an effective therapeutic agent for osteoporosis due to its selective stimulation of osteogenic differentiation, rather than adipogenesis. © 2014 Elsevier Ltd. All rights reserved. Source


Choi Y.J.,Seoul National University | Lee J.Y.,Nano Intelligent Biomedical Engineering Corporation NIBEC | Chung C.-P.,Nano Intelligent Biomedical Engineering Corporation NIBEC | Park Y.J.,Seoul National University | Park Y.J.,Nano Intelligent Biomedical Engineering Corporation NIBEC
Journal of Biomedical Materials Research - Part A | Year: 2013

Bone sialoprotein (BSP) is a mineralized, tissuespecific, and noncollagenous protein. The binding of BSP to collagen is thought to be important for the initiation of bone mineralization and formation. In this study, we elucidated the osteogenic efficiency of the collagen-binding (CB) peptide derived from BSP in vitro and in vivo. The CB peptide increased osteoblastic differentiation marker gene and protein expression without affecting cell proliferation. The osteoblastic differentiation by the CB peptide is performed by the activation of extracellular signal-regulated kinase (ERK1/2) and protein kinase B (Akt). Notably, the activation of CB peptide-induced osteogenic differentiation was completely blocked to the basal level by the specific inhibitors for ERK1/2 (U0126) and Akt (LY294002). In vivo results further demonstrated that the CB peptide-coated hydroxyapatite scaffold was able to induce bone formation in the bone defect. Taken together, the CB peptide can be developed as an osteoblastic differentiation agent as well as a fusion biomaterial for bone regeneration therapy. © 2012 WILEY PERIODICALS, INC. Source


Lee J.-Y.,Nano Intelligent Biomedical Engineering Corporation NIBEC | Seo Y.-N.,Nano Intelligent Biomedical Engineering Corporation NIBEC | Park H.-J.,Nano Intelligent Biomedical Engineering Corporation NIBEC | Park Y.-J.,Nano Intelligent Biomedical Engineering Corporation NIBEC | And 3 more authors.
Biochemical and Biophysical Research Communications | Year: 2012

A heparin-binding peptide (HBP) sequence from human heparin-binding epidermal growth factor-like growth factor (HB-EGF) was identified and was shown to exhibit cell penetration activity. This cell penetration induced an anti-inflammatory reaction in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. HBP penetrated the cell membrane during the 10. min treatment and reduced the LPS-induced production of nitric oxide (NO), inducible nitric oxide synthase (iNOS), and cytokines (TNF-α and IL-6) in a concentration-dependent manner. Additionally, HBP inhibited the LPS-induced upregulation of cytokines, including TNF-α and IL-6, and decreased the interstitial infiltration of polymorphonuclear leukocytes in a lung inflammation model. HBP inhibited NF-κB-dependent inflammatory responses by directly blocking the phosphorylation and degradation of IκBα and by subsequently inhibiting the nuclear translocation of the p65 subunit of NF-κB. Taken together, this novel HBP may be potentially useful candidate for anti-inflammatory treatments and can be combined with other drugs of interest to transport attached molecules into cells. © 2012 Elsevier Inc. Source


Choi Y.J.,Seoul National University | Lee J.Y.,Seoul National University | Lee J.Y.,Nano Intelligent Biomedical Engineering Corporation NIBEC | Lee S.J.,Ewha Womans University | And 5 more authors.
Biochemical and Biophysical Research Communications | Year: 2011

Recent researches have indicated a role for antihypertensive drugs including alpha- or beta-blockers in the prevention of bone loss. Some epidemiological studies reported the protective effects of those agents on fracture risk. However, there is limited information on the association with those agents especially at the mechanism of action. In the present study, we investigated the effects of doxazosin, an alpha-blocker that is clinically used for the treatment of benign prostatic hyperplasia (BPH) along with antihypertensive medication, on the osteogenic stem cell differentiation. We found that doxazosin increased osteogenic differentiation of human mesenchymal stem cells, detected by Alizarin red S staining and calcein. Doxazosin not only induced expression of alkaline phosphatase, type I collagen, osteopontin, and osteocalcin, it also resulted in increased phosphorylation of extracellular signal-regulated kinase (ERK1/2), a MAP kinase involved in osteoblastic differentiation. Treatment with U0126, a MAP kinase inhibitor, significantly blocked doxazosin-induced osteoblastic differentiation. Unrelated to activation of osteogenic differentiation by doxazosin, we found that there were no significant changes in adipogenic differentiation or in the expression of adipose-specific genes, including peroxisome proliferator-activated receptor γ, aP2, or LPL. In this report, we suggest that doxazosin has the ability to increase osteogenic cell differentiation via ERK1/2 activation in osteogenic differentiation of adult stem cells, which supports the protective effects of antihypertensive drug on fracture risk and according to our data doxazosin might be useful for application in the field of bone metabolism. © 2011 Elsevier Inc.. Source


Choi Y.J.,Seoul National University | Lee J.Y.,Seoul National University | Lee J.Y.,Nano Intelligent Biomedical Engineering Corporation NIBEC | Park J.H.,Seoul National University | And 8 more authors.
Biomaterials | Year: 2010

The presence of heparin binding has been become crucial in exerting growth factor related tissue formation. Receptor-mediated osteoblastic differentiation by bone morphogenetic protein (BMP)-4 and supportive function of its heparin binding has been proposed, direct role of the heparin binding site of BMP-4 on osteogenesis has not yet been fully investigated. If the binding site itself plays role on osteogenesis, the site domain can be useful in bone formation in combination with biomaterial. Herein, we synthesized a peptide sequence corresponding to residues 15-24 of BMP-4 (HBD, RKKNPNCRRH), as potential heparin binding sequence. The HBD peptide-induced ostoegenic differentiation by activating extracellular signal-regulated kinase (ERK1/2), one of the key regulators in hMSC. Also, treatment of cultured hMSCs with heparinase blocked both HBD peptide-induced osteogenic differentiation and GAG chain detection while abolishing the increased phospho-ERK level. These results suggest that the identified heparin binding domain peptide (HBD) stimulated osteoblastic differentiation via interaction with heparin and the ERK signaling. In vivo results further demonstrated that HBD, as a form of complex with alginate gel, was able to induce bone formation in the bone defect. © 2010 Elsevier Ltd. Source

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