Topics (18) View all

Research experience

  • Jan 2012
    Research: Emory University
    Emory University
    USA · Atlanta
  • Dec 2009–
    present
    Research: Georgia Institute of Technology
    Georgia Institute of Technology · Department of Biomedical Engineering
    USA · Atlanta
  • Jan 2008
    Research: Postdoctoral Scholar
    University of Iowa · Department of Pathology
    USA · Iowa City
  • Jan 2004
    Research: Soonchunhyang University
    Soonchunhyang University
    South Korea · Asan
  • Jan 2004–
    Nov 2008
    Research: Chungbuk National University
    Chungbuk National University · College of Pharmacy
    South Korea · Tyundyu

Other

  • Languages
    Korean
    English
  • Scientific Memberships
    American Heart Association (AHA), member.
    North American Vascular Biology Organization (NAVBO), member.
    Biomedical Engineering Society, member.
  • Journal Referees
    Dataset Papers in Pharmacology, Bulletin of the Polish Academy of Sciences Mathematics, 2012-current.

Questions and Answers (1) View all

Publications (44) View all

  • Source
    Article: Anti-Inflammatory and Antiatherogenic Role of BMP Receptor II in Endothelial Cells.
    [show abstract] [hide abstract]
    ABSTRACT: OBJECTIVE: Atherosclerosis is an inflammatory disease with multiple underlying metabolic and physical risk factors. Bone morphogenic protein 4 (BMP4) expression is increased in endothelium in atherosclerosis-prone regions and is known to induce endothelial inflammation, endothelial dysfunction, and hypertension. BMP actions are mediated by 2 different types of BMP receptors (BMPRI and BMPRII). Here, we show a surprising finding that loss of BMPRII expression causes endothelial inflammation and atherosclerosis.Approach and Results-Using BMPRII siRNA and BMPRII(+/-) mice, we found that specific knockdown of BMPRII, but not other BMP receptors (Alk1, Alk2, Alk3, Alk6, ActRIIa, and ActRIIb), induced endothelial inflammation in a ligand-independent manner by mechanisms mediated by reactive oxygen species, NFκB, and NADPH oxidases. Further, BMPRII(+/-)ApoE(-/-) mice developed accelerated atherosclerosis compared with BMPRII(+/+)ApoE(-/-) mice. Interestingly, we found that multiple proatherogenic stimuli, such as hypercholesterolemia, disturbed flow, prohypertensive angiotensin II, and the proinflammatory cytokine (tumor necrosis factor-α), downregulated BMPRII expression in endothelium, whereas antiatherogenic stimuli, such as stable flow and statin treatment, upregulated its expression in vivo and in vitro. Moreover, BMPRII expression was significantly diminished in human coronary advanced atherosclerotic lesions. Also, we were able to rescue the endothelial inflammation induced by BMPRII knockdown by overexpressing the BMPRII wild type, but not by the BMPRII short form lacking the carboxyl-terminal tail region. CONCLUSIONS: These results suggest that BMPRII is a critical, anti-inflammatory, and antiatherogenic protein that is commonly targeted by multiple pro- and antiatherogenic factors. BMPRII may be used as a novel diagnostic and therapeutic target in atherosclerosis.
    Arteriosclerosis Thrombosis and Vascular Biology 04/2013; · 6.37 Impact Factor
  • Article: Piperlongumine inhibits proliferation and survival of Burkitt lymphoma in vitro.
    [show abstract] [hide abstract]
    ABSTRACT: Piperlongumine (PL), a pepper plant alkaloid from Piper longum, kills solid tumor cells in a highly selective, potent fashion. To evaluate whether PL may have similar effects on malignant blood cells, we determined the efficacy with which PL inhibits the B-lymphocyte derived neoplasm, Burkitt lymphoma (BL). Low micromolar concentrations of PL (IC(50)=2.8μM×8.5μM) curbed growth and survival of two EBV(+) BL cell lines (Daudi, Raji) and two EBV BL cell lines (Ramos, DG-75), but left normal peripheral blood B-lymphocytes unharmed. PL-dependent cytotoxicity was effected in part by reduced NF-κB and MYC activity, with the former being caused by inhibition of IκBα degradation, nuclear translocation of p65, and binding of NF-κB dimers to cognate DNA sequences in gene promoters. In 4 of 4 BL cell lines, the NF-κB/MYC-regulated cellular target genes, E2F1 and MYB, were down regulated, while the stress sensor gene, GADD45B, was up regulated. The EBV-encoded oncogene, LMP-1, was suppressed in Daudi and Raji cells. Considering that NF-κB, MYC and LMP-1 play a crucial role in the biology of many blood cancers including BL, our results provide a strong preclinical rationale for considering PL in new intervention approaches for patients with hematologic malignancies.
    Leukemia research 12/2012; · 2.36 Impact Factor
  • Article: Piperlongumine inhibits atherosclerotic plaque formation and vascular smooth muscle cell proliferation by suppressing PDGF receptor signaling.
    [show abstract] [hide abstract]
    ABSTRACT: Piperlongumine (piplartine, PL) is an alkaloid found in the long pepper (Piper longum L.) and has well-documented anti-platelet aggregation, anti-inflammatory, and anti-cancer properties; however, the role of PL in prevention of atherosclerosis is unknown. We evaluated the anti-atherosclerotic potential of PL in an in vivo murine model of accelerated atherosclerosis and defined its mechanism of action in aortic vascular smooth muscle cells (VSMCs) in vitro. Local treatment with PL significantly reduced atherosclerotic plaque formation as well as proliferation and nuclear factor-kappa B (NF-κB) activation in an in vivo setting. PL treatment in VSMCs in vitro showed inhibition of migration and platelet-derived growth factor BB (PDGF-BB)-induced proliferation to the in vivo findings. We further identified that PL inhibited PDGF-BB-induced PDGF receptor beta activation and suppressed downstream signaling molecules such as phospholipase Cγ1, extracellular signal-regulated kinases 1 and 2 and Akt. Lastly, PL significantly attenuated activation of NF-κB-a downstream transcriptional regulator in PDGF receptor signaling, in response to PDGF-BB stimulation. In conclusion, our findings demonstrate a novel, therapeutic mechanism by which PL suppresses atherosclerosis plaque formation in vivo.
    Biochemical and Biophysical Research Communications 09/2012; 427(2):349-54. · 2.48 Impact Factor
  • Article: Dynamic immune cell accumulation during flow-induced atherogenesis in mouse carotid artery: an expanded flow cytometry method.
    [show abstract] [hide abstract]
    ABSTRACT: Inflammation plays a central role in atherosclerosis. However, the detailed changes in the composition and quantity of leukocytes in the arterial wall during atherogenesis are not fully understood in part because of the lack of suitable methods and animal models. We developed a 10-fluorochrome, 13-parameter flow cytometry method to quantitate 7 major leukocyte subsets in a single digested arterial wall sample. Apolipoprotein E-deficient mice underwent left carotid artery (LCA) partial ligation and were fed a high-fat diet for 4 to 28 days. Monocyte/macrophages, dendritic cells, granulocytes, natural killer cells, and CD4 T cells significantly infiltrated the LCA as early as 4 days. Monocyte/macrophages and dendritic cells decreased between 7 and 14 days, whereas T-cell numbers remained steady. Leukocyte numbers peaked at 7 days, preceding atheroma formation at 14 days. B cells entered LCA by 14 days. Control right carotid and sham-ligated LCAs showed no significant infiltrates. Polymerase chain reaction and ELISA arrays showed that expression of proinflammatory cytokines and chemokines peaked at 7 and 14 days postligation, respectively. This is the first quantitative description of leukocyte number and composition over the life span of murine atherosclerosis. These results show that disturbed flow induces rapid and dynamic leukocyte accumulation in the arterial wall during the initiation and progression of atherosclerosis.
    Arteriosclerosis Thrombosis and Vascular Biology 03/2012; 32(3):623-32. · 6.37 Impact Factor
  • Source
    Article: Piperlongumine inhibits proliferation and survival of Burkitt lymphoma in vitro
    Seong-Su Han | Dong-Ju Son | Hwakyung Yun | Natalie L. Kamberos | Siegfried Janz
    [show abstract] [hide abstract]
    ABSTRACT: Piperlongumine (PL), a pepper plant alkaloid from Piper longum, kills solid tumor cells in a highly selective, potent fashion. To evaluate whether PL may have similar effects on malignant blood cells, we determined the efficacy with which PL inhibits the B-lymphocyte derived neoplasm, Burkitt lymphoma (BL). Low micromolar concentrations of PL (IC50=2.8μM×8.5μM) curbed growth and survival of two EBV+ BL cell lines (Daudi, Raji) and two EBV BL cell lines (Ramos, DG-75), but left normal peripheral blood B-lymphocytes unharmed. PL-dependent cytotoxicity was effected in part by reduced NF-κB and MYC activity, with the former being caused by inhibition of IκBα degradation, nuclear translocation of p65, and binding of NF-κB dimers to cognate DNA sequences in gene promoters. In 4 of 4 BL cell lines, the NF-κB/MYC-regulated cellular target genes, E2F1 and MYB, were down regulated, while the stress sensor gene, GADD45B, was up regulated. The EBV-encoded oncogene, LMP-1, was suppressed in Daudi and Raji cells. Considering that NF-κB, MYC and LMP-1 play a crucial role in the biology of many blood cancers including BL, our results provide a strong preclinical rationale for considering PL in new intervention approaches for patients with hematologic malignancies.
    Leukemia research 12/2012; · 2.36 Impact Factor

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