J M Ryu

Publications (3)13.48 Total impact

• Article: Effects of peripheral benzodiazepine receptor ligands on proliferation and differentiation of human mesenchymal stem cells.

  D H Lee, S K Kang, R H Lee, J M Ryu, H Y Park, H S Choi, Y C Bae, K T Suh, Y K Kim, Jin Sup Jung
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  ABSTRACT: The peripheral benzodiazepine receptor (PBR) has been known to have many functions such as a role in cell proliferation, cell differentiation, steroidogenesis, calcium flow, cellular respiration, cellular immunity, malignancy, and apoptosis. However, the presence of PBR has not been examined in mesenchymal stem cells. In this study, we demonstrated the expression of PBR in human bone marrow stromal cells (hBMSCs) and human adipose stromal cells (hATSCs) by RT-PCR and immunocytochemistry. To determine the roles of PBR in cellular functions of human mesenchymal stem cells (hMSCs), effects of diazepam, PK11195, and Ro5-4864 were examined. Adipose differentiation of hMSCs was decreased by high concentration of PBR ligands (50 microM), whereas it was increased by low concentrations of PBR ligands (<10 microM). PBR ligands showed a biphasic effect on glycerol-3-phosphate dehydrogenase (GPDH) activity. High concentration of PBR ligands (from 25 to 75 microM) inhibited proliferation of hMSCs. However, clonazepam, which does not have an affinity to PBR, did not affect adipose differentiation and proliferation of hMSCs. The PBR ligands did not induce cell death in hMSCs. PK11195 (50 microM) and Ro5-5864 (50 microM) induced cell cycle arrest in the G(2)/M phase. These results indicate that PBR ligands play roles in adipose differentiation and proliferation of hMSCs.
  Journal of Cellular Physiology 01/2004; 198(1):91-9. · 3.87 Impact Factor
• Article: Effects of peripheral benzodiazepine receptor ligands on proliferation and differentiation of human mesenchymal stem cells

  D.H. Lee, S.K. Kang, R.H. Lee, J.M. Ryu, H.Y. Park, H.S. Choi, Y.C. Bae, K.T. Suh, Y.K. Kim, Jin Sup Jung
  [show abstract] [hide abstract]
  ABSTRACT: The peripheral benzodiazepine receptor (PBR) has been known to have many functions such as a role in cell proliferation, cell differentiation, steroidogenesis, calcium flow, cellular respiration, cellular immunity, malignancy, and apoptosis. However, the presence of PBR has not been examined in mesenchymal stem cells. In this study, we demonstrated the expression of PBR in human bone marrow stromal cells (hBMSCs) and human adipose stromal cells (hATSCs) by RT-PCR and immunocytochemistry. To determine the roles of PBR in cellular functions of human mesenchymal stem cells (hMSCs), effects of diazepam, PK11195, and Ro5-4864 were examined. Adipose differentiation of hMSCs was decreased by high concentration of PBR ligands (50 μM), whereas it was increased by low concentrations of PBR ligands (<10 μM). PBR ligands showed a biphasic effect on glycerol-3-phosphate dehydrogenase (GPDH) activity. High concentration of PBR ligands (from 25 to 75 μM) inhibited proliferation of hMSCs. However, clonazepam, which does not have an affinity to PBR, did not affect adipose differentiation and proliferation of hMSCs. The PBR ligands did not induce cell death in hMSCs. PK11195 (50 μM) and Ro5-5864 (50 μM) induced cell cycle arrest in the G2/M phase. These results indicate that PBR ligands play roles in adipose differentiation and proliferation of hMSCs. J. Cell. Physiol. 198: 91–99, 2004. © 2003 Wiley-Liss, Inc.
  Journal of Cellular Physiology 08/2003; 198(1):91 - 99. · 3.87 Impact Factor
• Article: Increased bioavailability of propranolol in rats by retaining thermally gelling liquid suppositories in the rectum.

  J M Ryu, S J Chung, M H Lee, C K Kim, ShimCK
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  ABSTRACT: Mucoadhesive liquid suppositories were prepared by adding mucoadhesive polymers (0.6%) to a formulation of thermally gelling suppositories that contained poloxamer 407 (15%), poloxamer 188 (15%) and propranolol HCl (2%). Hydroxypropylcellulose (HPC), polyvinylpyrrolidone (PVP), carbopol, polycarbophil and sodium alginate were examined as mucoadhesive polymers. The characteristics of the suppositories differed depending on the choice of mucoadhesive polymer. For example, the gelation temperature was between 30 and 36 degrees C, the mucoadhesive force was between 430 and 5800 dyne/cm2, the apparent first-order release rate constant in phosphate buffer, pH 6.8, was between 0.399 and 0.271 h-1, the migration distance of the suppository in the rectum 4 h after administration was between 1 and 5 cm, and the bioavailability of propranolol was between 60.9 and 84.7%. Rectal bioavailability increased as the mucoadhesive force increased (r=0.984, p<0.0005), and the migration distance decreased (r=-0.951, p<0.005). No relationship was found between the bioavailability and the gelation temperature, drug release or irritation of the rectal mucosal membrane by the suppository. Therefore, retaining propranolol at the dosed site in the rectum by the addition of appropriate mucoadhesives to the formulation of liquid suppositories appears to be a very important factor in avoiding first-pass hepatic elimination and thereby increasing the bioavailability of the drug. Among the mucoadhesive polymers examined, sodium alginate and polycarbophil exhibited the largest mucoadhesive force and the smallest intrarectal migration resulting in the largest bioavailability of propranolol (84.7 and 82.3%, respectively). In contrast to other polymers, sodium alginate alone caused no irritation of the rectal mucosal membrane. Thus, poloxamer liquid suppositories containing sodium alginate appears to be a preferred formulation for drugs that are sensitive to extensive first-pass metabolism.
  Journal of Controlled Release 05/1999; 59(2):163-72. · 5.73 Impact Factor