• Molecules and Cells
• /
• v.40 no.6
• /
• pp.393-400
• /
• 2017

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease characterized by lack of insulin and high glucose levels. T2DM can cause bone loss and fracture, thus leading to diabetic osteoporosis. Promoting osteogenic differentiation of osteoblasts may effectively treat diabetic osteoporosis. We previously reported that Sirtuin 1 (Sirt1), a $NAD^+$-dependent deacetylase, promotes osteogenic differentiation through downregulation of peroxisome proliferator-activated receptor (PPAR) ${\gamma}$. We also found that miR-132 regulates osteogenic differentiation by downregulating Sirt1 in a $PPAR{\beta}/{\delta}$-dependent manner. The ligand-activated transcription factor, $PPAR{\alpha}$, is another isotype of the peroxisome proliferator-activated receptor family that helps maintain bone homeostasis and promot bone formation. Whether the regulatory role of $PPAR{\alpha}$ in osteogenic differentiation is mediated via Sirt1 remains unclear. In the present study, we aimed to determine this role and the underlying mechanism by using high glucose (HG) and free fatty acids (FFA) to mimic T2DM in MC3T3-E1 cells. The results showed that HG-FFA significantly inhibited expression of $PPAR{\alpha}$, Sirt1 and osteogenic differentiation, but these effects were markedly reversed by $PPAR{\alpha}$ overexpression. Moreover, siSirt1 attenuated the positive effects of $PPAR{\alpha}$ on osteogenic differentiation, suggesting that $PPAR{\alpha}$ promotes osteogenic differentiation in a Sirt1-dependent manner. Luciferase activity assay confirmed interactions between $PPAR{\alpha}$ and Sirt1. These findings indicate that $PPAR{\alpha}$ promotes osteogenic differentiation via the Sirt1-dependent signaling pathway.

• Journal of Korean Foot and Ankle Society
• /
• v.6 no.2
• /
• pp.233-237
• /
• 2002

Osteogenic sarcoma is the most common primary malignant tumor of bone in which tumor cells form neoplastic osteoid or bone or both. Classic osteogenic sarcoma usually involves the metaphysis of the more rapidly growing long bones (distal femur, proximal tibia). Osteogenic sarcoma of the foot is rarely noted and only a few well documented cases have been reported. Osteogenic sarcoma of foot can clinically, radiographically, and histologically mimic several benign lesions and tumor-like lesions, so it sometimes leads to late diagnosis and delayed treatment. We experienced a case of primary osteogenic sarcoma on left calcaneus in 66-years-old female and report it with a review of references.

• Archives of Plastic Surgery
• /
• v.34 no.5
• /
• pp.537-542
• /
• 2007

Purpose: Adipose tissue contains a population of pluripotent stem cells capable of differentiating along multiple mesenchymal cell lineages. It is well known that fat depots from different part of our body shows different nature not only in morphological aspect but also physiologic aspect. The authors compared the adipogenic potentials and osteogenic potentials of adipose stem cells from different anatomical sites of human. Methods: After laparotomy by surgery team, the authors isolated these adipose stem cells successfully from 7 men with an average age of 58, and induced differentiation along adipogenic and osteogenic lineages in vitro. On the 14th day, cells cultured in adipogenic media differentiated into adipocytes in vitro, as evidenced by positive Oil Red O staining of lipid vacuoles. On the 21st day, cells cultured in osteogenic media differentiated into osteoblasts in vitro as demonstrated by Alizarin red staining of a calcified extracellular matrix. Results: After exposure to adipogenic and osteogenic differentiation medium, subcutaneous adipose stem cells were found to possess greater adipogenic and osteogenic potentials than cells isolated from visceral adipose tissues. Conclusion: This study indicates that adipogenic and osteogenic potentials of adipose stem cells vary by their anatomical sites, with subcutaneous adipose stem cells exhibiting higher adipogenic and osteogenic potential than those isolated from visceral fat.

• International Journal of Oral Biology
• /
• v.38 no.3
• /
• pp.111-119
• /
• 2013

Objective. To investigate the effects of the hypoxia inducible factor-1 (HIF-1) activation-mimicking agent cobalt chloride ($CoCl_2$) on the osteogenic differentiation of human mesenchymal stem cells (hMSCs) and elucidate the underlying molecular mechanisms. Study design. The dose and exposure periods for $CoCl_2$ in hMSCs were optimized by cell viability assays. After confirmation of $CoCl_2$-induced HIF-$1{\alpha}$ and vascular endothelial growth factor expression in these cells by RT-PCR, the effects of temporary preconditioning with $CoCl_2$ on hMSC osteogenic differentiation were evaluated by RT-PCR analysis of osteogenic gene expression, an alkaline phosphatase (ALP) activity assay and by alizarin red S staining. Results. Variable $CoCl_2$ dosages (up to $500{\mu}M$) and exposure times (up to 7 days) on hMSC had little effect on hMSC survival. After $CoCl_2$ treatment of hMSCs at $100{\mu}M$ for 24 or 48 hours, followed by culture in osteogenic differentiating media, several osteogenic markers such as Runx-2, osteocalcin and osteopontin, bone sialoprotein mRNA expression level were found to be up-regulated. Moreover, ALP activity was increased in these treated cells in which an accelerated osteogenic capacity was also verified by alizarin red S staining. Conclusions. The osteogenic differentiation potential of hMSCs could be preserved and even enhanced by $CoCl_2$ treatment.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.33 no.7
• /
• pp.629-636
• /
• 2009

Mechanical stimulation is known to play a vital role on the differentiation of mesenchymal stem cells (MSCs) to pre-osteoblasts. In this research, we developed a tensile cell stimulator, composed of a DC motor-driven actuator and LVDT sensor for measuring linear displacement, to study the effects of tensile stress on osteogenic differentiation of MSCs. First, we demonstrated the reliability of this device by showing the uniform strain field in the silicon substrate. Secondly, we investigated the effects of tensile stretching on osteogenic differentiation. We imposed a pre-set cyclic strain at a fixed frequency on cell monolayer cultured on a flexible silicon substrate while varying its amplitude and duration. 60 min of resting period was allowed between 30 min of cyclic stretching and this cycle is repeated up to 7 days. Under the combined stimulation with osteogenic media and mechanical stretching, the osteogenic markers such as alkaline phosphatase (ALP), osterix, and osteopontin began to get expressed as early as 4 days of stimulation, which is much shorter than what is typically required for osteogenic media induced differentiation. Moreover, different markers were induced at different magnitudes of the applied strains. Lastly, for the case of ALP, we observed the antagonistic effects of osteogenic media when combined with mechanical stretching.

• International Journal of Oral Biology
• /
• v.33 no.3
• /
• pp.91-95
• /
• 2008

Embryonic stem cells have a pluripotency and a potential to differentiate to all type of cells. In our previous study, we have shown that embryonic stem cells (ESCs) lines can be generated from murine parthenogenetic embryos. This parthenogenetic ESCs line can be a useful stem cell source for tissue repair and regeneration. The defect in full-term development of parthenogenetic ESCs line enables researchers to avoid the ethical concerns related with ESCs research. In this study, we presented the results demonstrating that parthenogenetic ESCs can be induced into osteogenic cells by supplementing culture media with ascorbic acid and $\beta$-glycerophosphate. These cells showed morphologies of osteogenic cells and it was proven by Von Kossa staining and Alizarin Red staining. Expression of marker genes for osteogenic cells (osteopontin, osteonectin, alkaline phosphatase, osteocalcin, bone-sialoprotein, collagen type1, and Cbfa1) also confirmed osteogenic potential of these cells. These results demonstrate that osteogenic cells can be generated from parthenogenetic ESCs in vitro.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.30 no.2
• /
• pp.133-141
• /
• 2008

Stem cells have self-renewal capacity, long-term viability, and multiline age potential. Adult bone marrow contains mesenchymal stem cells. Bone marrow-derived mesenchymal stem cells (BMSCs) are progenitors of skeletal tissue components and can differentiate into adipocytes, chondrocytes, osteoblasts, and myoblasts in vitro and undergo differentiation in vivo. However, the clinical use of BMSCs has presented problems, including pain, morbidity, and low cell number upon harvest. Recent studies have identified a putative stem cell population within the adipose tissue. Human adipose tissue contains pluripotent stem cells simillar to bone marrow-derived stem cells that can differentiate toward the osteogenic, adipogenic, myogenic, and chondrogenic lineages. Human adipose tissue-derived stem cells (ATSCs) could be proposed as an alternative source of adult bone marrow stem cells, and could be obtained in large quantities, under local anesthesia, with minimal discomfort. Human adipose tissue obtained by liposuction was processed to obtain ATSCs. In this study, we compared the osteogenic differentiation of ATSCs in a specific osteogenic induction medium with that in a non-osteogenic medium. ATSCs were incubated in an osteogenic medium for 28 days to induce osteogenesis respectively. Osteogenic differentiation was assessed by von Kossa and alkaline phosphatase staining. Expression of osteocyte specific bone sialoprotein, osteocalcin, collagen type I and alkaline phosphatase, bone morphogenic protein 2, bone morphogenic protein 6 was confirmed by RT-PCR. ATSCs incubated in the osteogenic medium were stained positively for von Kossa and alkaline phosphatase staining. Expression of osteocyte specific genes was also detected. Since this cell population can be easily identified through fluorescence microscopy, it may be an ideal source of ATSCs for further experiments on stem cell biology and tissue engineering. The present results show that ADSCs have an ability to differentiate into osteoblasts. In the present study, we extend this approach to characterize adipose tissue-derived stem cells.

• Archives of Plastic Surgery
• /
• v.34 no.2
• /
• pp.141-148
• /
• 2007

Purpose: The object of this study was to evaluate the development of continuous osteogenic differentiation and bone formation after the subcutaneous implantation of the tissue-engineered bone, in vitro. Methods: Human adipose-derived stem cells were obtained by proteolytic digestion of liposuction aspirates. Adipose-derived stem cells were seeded in PLGA scaffolds after being labeled with PKH26 and cultured in osteogenic differentiation media for 1 month. The PLGA scaffolds with osteogenic stimulated adipose-derived stem cells were implanted in subcutaneous layer of four nude mice. Osteogenesis was assessed by RT-PCR for mRNA of osteopontin and bone sialoprotein(BSP), and immunohistochemistry for osteocalcin, and von Kossa staining for calcification of extracellular matrix at 1 and 2 months. Results: Implanted PLGA scaffold with adipose-derived stem cells were well vascularized, and PLGA scaffolds degraded and were substituted by host tissues. The mRNA of osteopontin and BSP was detected by RT-PCR in both osteogenic stimulation group and also osteocalcin was detected by immunohistochemistry at osteogenic stimulation 1 and 2 months, but no calcified extracellular deposit in von Kossa stain was found in all groups. Conclusion: In vivo, it could also maintain the characteristics of osteogenic differentiation that adipose-derived stem cells within PLGA scaffold after stimulation of osteogenic differentiation in vitro, but there were not normal bone formation in subcutaneous area. Another important factor to consider is in vivo, heterologous environment would have negative effect on bone formation as.[p1]

• Molecules and Cells
• /
• v.43 no.1
• /
• pp.58-65
• /
• 2020

Fat mass and obesity-associated (FTO) gene helps to regulate energy homeostasis in mammals by controlling energy expenditure. In addition, FTO functions in the regulation of obesity and adipogenic differentiation; however, a role in osteogenic differentiation is unknown. This study investigated the effects of FTO on osteogenic differentiation of C3H10T1/2 cells and the underlying mechanism. Expression of osteogenic and endoplasmic reticulum (ER) stress markers were characterized by reverse-transcriptase polymerase chain reaction and western blotting. Alkaline phosphatase (ALP) staining was performed to assess ALP activity. BMP2 treatment increased mRNA expression of osteogenic genes and FTO. Overexpression of FTO increased expression of the osteogenic genes distal-less homeobox5 (Dlx5) and runt-related transcription factor 2 (Runx2). Activation of adenosine monophosphate-activated protein kinase (AMPK) increased FTO expression, and there was a positive feedback loop between FTO and p-AMPK. p-AMPK and FTO induced mild ER stress; however, tunicamycin-induced severe ER stress suppressed FTO expression and AMPK activation. In summary, FTO induces osteogenic differentiation of C3H10T1/2 cells upon BMP2 treatment by inducing mild ER stress via a positive feedback loop with p-AMPK. FTO expression and AMPK activation induce mild ER stress. By contrast, severe ER stress inhibits osteogenic differentiation by suppressing FTO expression and AMPK activation.

• Journal of Chest Surgery
• /
• v.26 no.5
• /
• pp.413-416
• /
• 1993

Extraskeletal osteogenic sarcoma is a rare malignant tumor of soft tissue, and its predilection sites are the extremity, retroperitoneum, trunk, and the head and neck area. To our knowledge 5 cases of primary involvement of the mediastinum have been reported. Because of its rarity and difficulty in exact diagnosis preoperatively, we report an extraskeletal osteogenic sarcoma in the anterior mediastinum. The patient was a thirty eight old male. He complained of cough and sputum over 2 months. The chest roentgenogram and the chest MRI[magnetic resonance image] were done and showed anterior mediastinal mass with calcification. Excision of the mass was done under the preoperative impression of thymoma, and the pathologic report was extraskeletal osteogenic sarcoma of the mediastinum.