The effects of bisphosphonates on differentiation of human amniotic fluid-derived mesenchymal stem cells into osteoblast / 대한산부인과학회지

OBJECTIVE: It has been known that amniotic fluid (AF) is rich source of mesenchymal stem cells (MSCs). Bisphosphonates are widely used in clinical treatment of various metabolic bone diseases and their primary action is the inhibition of osteoclastic bone resorption. However, litter is known about whether bisphosphonates affect the differentiation into osteoblast, especially from AF-derived MSCs (AFMSCs). Therefore, the purpose of this study is to investigate whether these bisphosphonates influence in the process of AFMSCs differentiation into osteoblast. METHODS: AF samples were obtained by second trimester amniocentesis for fetal karyotyping from 6 pregnant women. Cells were treated with various concentration (0, 10(-10), 10(-8), 10(-6) M) of zoledronate and alendronate and analyzed over 21 days of culture. Differentiation into osteoblast was determined by cell staining and RT-PCR for alkaline phosphatase (ALP). RESULTS: It was observed that AFMSCs could differentiate into osteoblast. Alendronate had more potent effect than zoledronate in osteoblastic differentiation. ALP expression was increased with increasing concentration of zoledronate and it was highest in 10(-8) M alendronate. However, no effect of bisphosphonates was found in 14 days of culture. CONCLUSION: This study shows that AFMSCs can be differentiated into osteoblast. The induction of these differentiation following bisphosphonate treatment was appear to be drug type-, dose-, and culture time-dependent. However, further studies are needed to conclude a consistent outcome for the effects of bisphosphonate on differentiation potential of AFMSCs.

Effects of Leptin on Proliferation, Anabolic and Catabolic Metabolism in Chondrocytes / 대한정형외과연구학회지

PURPOSE: Leptin may play an important role in the pathophysiology of osteoarthritis. However, the effect of letpin on the anabolic and catabolic metabolisms in chondrocytes remains unclearly elucidated. Therefore, the purpose of this study was to investigate the effect of leptin on proliferation, anabolic and catabolic metabolism of chondrocyte using ATDC5 chondrogenic cell line. MATERIALS AND METHODS: The effects of leptin on chodnrocyte proliferation, anabolic and catabolic meatabolism were examined in ATDC5 cells treated with leptin at varying concentrations(10, 100, 300, 600 ng/ml) for 24, 48, and 72 hours. The cell proliferation was evaluated by MTT assay. The anabolic and catabolic activities were assayed by RT-PCR for transforming growth factor-beta(TNF-alpha), proteoglycan-4 (PRG4), type- I collagen (type- I Col) and tumor necrosis factor-beta(TNF-alpha), matrix metalloproteinase -2 (MMP-2), respectively. RESULTS: Leptin treatment did not influence cell proliferation of chondrocyte regardless of concentration. TGF-beta expression was increased until 48 hours of leptin treatment compared to controls. Especially, it was significantly increased in leptin of 10 ng/ml and 100 ng/ml (P<0.05). PRG4 expression was not different between letpin treatment and controls. Type-I Col expression was decreased in dose- and time-dependent manner. Leptin of 10ng/ml significantly inhibited MMP-2 and TNF-alpha expressions compared to controls (P<0.05). CONCLUSION: This study shows that leptin at low concentration increases TGF-beta expression, but inhibits the expression of TNF-alpha and MMP-2. Also this study shows that leptin do not affect the cell proliferation of chondrocytes. These results suggest that leptin at low or physiological level contributes to the prevention of cartilage damage by stimulating anabolic activity and inhibiting catabolic activity of chondrocyte rather than chondrocyte regeneration by increasing cell proliferation.

Relationship between Osteoarthritis and Leptin Concentrations in Synovial Fluid / 대한정형외과연구학회지

PURPOSE: Leptin may play an important role in the pathophysiology of osteoarthritis. This study investigated whether leptin concentration in synovial fluid is related to the radiographic severity of osteoarthritis. MATERIALS AND METHODS: Synovial fluids were obtained from 29 osteoarthritis patients who underwent knee surgery and 10 who had no abnormality on articular cartilage during arthoscopic examination. The progression of osteoarthritis was classified by Kellgren Lawrence grading scale. The concentrations of leptin was measured with commercial enzyme-linked immnosorbent assay kits. RESULTS: A significant increase in synovial fluid concentrations was observed in osteoarthritis patients (6.7+/-4.1 ng/ml) compared to the control (2.4+/-1.3 ng/ml). Leptin levels were increased with advancing osteoarthritis stage, resulting in the highest level in stage IV patients(10.7+/-4.9 ng/ml; range 4.7-15.8) compared to that of stage I patients (4.0+/-2.0 ng/ml; range 1.2-7.3). In osteoarthritis patients, age showed a significant correlation with leptin concentrations. CONCLUSION: This study shows that synovial fluid leptin concentrations were closely related to the radiographic severity of osteoarthritis, and suggests that the age of patient may influence synovial fluid leptin concentrations during osteoarthritis progression.

The Effect of Zoledronate on the Differentiation of Human Amniotic Fluid-Derived Mesencymal Stem Cells into Adipocytes / 대한수혈학회지

BACKGROUND: Amniotic fluid is a rich source of fetal mesenchymal stem cells (MSCs). However, little is known about whether bisphosphonates affect the differentiation into adipocytes. Therefore, this study was aimed to investigate whether zoledronate influences the differentiation of AFMSCs into adipocytes. METHODS: Amniotic fluid cells samples were obtained from 6 pregnant women by second trimester amniocentesis for performing fetal karyotyping. The cells were treated with various concentration (10(-10), 10(-8), 10(-6) M) of zoledronate and the cells were analyzed over 21 days of culture. Differentiation into adipocytes was determined by oil-red O staining and for fatty acid synthase (FAS), acetyl CoA carboxylase 1 (ACC1) and sterol regulatory elementary binding protein-1 (SREBP-1). RESULTS: Differentiation of AFMSCs into adipocytes was found by oil-red O staining. Zoledronate influenced the differentiation of AFMSCs into adipocytes in a dose- and time-dependent manner. At 7 days of culture, the expressions of FAS and SREBP-1 showed no significant differences compared to that of the control regardless of the dose of zoledronate. Very little ACC1 expression was found. However, the expressions of these three markers were remarkably increased at 14 days of culture. Of them, the ACC1 expression was significantly increased by 10(-8) M and 10(-6) M of zoledronate. At 21 days of culture, there were no effects of zoledronate on the expressions of FAS and SREBP-1. However, the ACC1 expression was decreased with an increasing dose of zoledronate (P<.05). CONCLUSION: This study shows that AFMSCs can be differentiated into adipocytes. The induction of this differentiation following zoledronate treatment appears to be dose dependent and time-of-culture dependent.