Bone marrow stem/progenitor cell mobilization in C57BL/6J and BALB/c mice

Hakmo Lee,Jeong-Hwan Che,Ju Eun Oh,Sung Soo Chung,Hye Seung Jung,Kyong Soo Park 한국실험동물학회 2014 Laboratory Animal Research Vol.30 No.1

Bone marrow (BM) has been considered as a reservoir of stem/progenitor cells which are able to differentiate into ectodermal, endodermal, and mesodermal origins in vitro as well as in vivo. Following adequate stimulation, such as granulocyte stimulating factor (G-CSF) or AMD3100, BM resident stem/ progenitor cells (BMSPCs) can be mobilized to peripheral blood. Several host-related factors are known to participate in this mobilization process. In fact, a significant number of donors are resistant to G-CSF induced mobilization protocols. AMD3100 is currently used in combination with G-CSF. However, information regarding host-related factors which may influence the AMD3100 directed mobilization is extremely limited. In this study, we were to get some more knowledge on the host-related factors that affect the efficiency of AMD3100 induced mobilization by employing in vivo mobilization experiments. As a result, we found that C57BL/6J mice are more sensitive to AMD3100 but less sensitive to G-CSF which promotes the proliferation of BMSPCs. We excluded S1P as one of the host related factor which influences AMD3100 directed mobilization because pre-treatment of S1P receptor antagonist FTY720 did not inhibit BMSPC mobilization. Further in vitro experiments revealed that BALB/c mice, compared to C57BL/6J mice, have less BMSPCs which migrate in response to host related factors such as sphingosine- 1-phosphate (S1P) and to CXCL12. We conclude that AMD3100-directed mobilization depends on the number of BMSPCs rather than on the host-related factors. These results suggest that the combination of AMD3100 and G-CSF is co-operative and is optimal for the mobilization of BMSPCs.

4-deoxypyridoxine improves the viability of isolated pancreatic islets ex vivo

Lee, Hakmo,Seon Park, Ho,Hee Hong, Shin,Kyung Choi, Ok,Cho, Sung-Dae,Park, Jongwoo,Eun Oh, Ju,Soo Chung, Sung,Jung, Hye Seung,Park, Kyong Soo Taylor Francis 2013 Islets Vol.5 No.3

Microvesicles Directing Insulin Producing Cell Differentiation

Hakmo Lee,Ju Eun Oh,Hye Seung Jung,Kyong Soo Park 한국실험동물학회 2015 한국실험동물학회 학술발표대회 논문집 Vol.2015 No.8

Granulocyte-Derived Cationic Peptide Enhances Homing and Engraftment of Bone Marrow Stem Cells after Transplantation

Hakmo Lee,Jeong-Hwan Che,Jae-Chul Lee,Sung Soo Chung,Hye Seung Jung,Kyong Soo Park 한국실험동물학회 2011 Laboratory Animal Research Vol.27 No.2

Current strategies to accelerate hematopoietic reconstitution after transplantation include transplantation of greater numbers of hematopoietic stem/progenitor cells (HSPCs) or ex vivo expansion of harvested HSPCs before transplant. However, the number of cells available for transplantation is usually low, and strategies to expand HSPCs and maintain equivalent engraftment capability ex vivo are limited. We noted that activated granulocyte-derived cationic peptides positively primed responsiveness of HSPCs to a CXCL12 gradient. Accordingly, we noted that accelerated homing/engraftment of β-defensin-2, a wellknown antimicrobial cationic peptide, primed bone marrow nucleated cells (BMNCs) compared to normal BMNCs after transplantation into lethally irradiated recipients. We envision that small cationic peptides, which primarily possess antimicrobial functions and are harmless to mammalian cells, could be applied to prime HSPCs before transplantation. This novel approach would be particularly important in cord blood transplantation, where the number of HSPCs available for transplantation is usually limited.

Kinetics of IFN-γ and IL-17 Production by CD4 and CD8 T Cells during Acute Graft-versus-Host Disease

Choi, Eun Young,Lee, Dong-Sup,Oh, Keunhee,Lee, Hakmo,Ju, Ji-Min 대한면역학회 2014 Immune Network Vol.14 No.2

Graft-versus-host disease (GVHD) is a fatal complication that occurs after allogeneic hematopoietic stem cell transplantation. To understand the dynamics of CD4 and CD8 T cell production of IFN-γ and IL-17 during GVHD progression, we established a GVHD model by transplanting T cell-depleted bone marrow (TCD-BM) and purified T cells from B6 mice into irradiated BALB.B, creating an MHC-matched but minor histocompatibility (H) antigen-mismatched transplantation (B6 → BALB.B GVHD). Transplantation-induced GVHD was confirmed by the presence of the appropriate compositional changes in the T cell compartments and innate immune cells in the blood and the systemic secretion of inflammatory cytokines. Using this B6 → BALB.B GVHD model, we showed that the production of IFN-γ and IL-17 by CD4 T cells preceded that by CD8 T cells in the spleen, mesenteric lymph node, liver, and lung in the BALB.B GVHD host, and Th1 differentiation predated Th17 differentiation in all organs during GVHD progression. Such changes in cytokine production were based on changes in cytokine gene expression by the T cells at different time points during GVHD development. These results demonstrate that both IFN-γ and IL-17 are produced by CD4 and CD8 T cells but with different kinetics during GVHD progression.

Kinetics of IFN-${\gamma}$ and IL-17 Production by CD4 and CD8 T Cells during Acute Graft-versus-Host Disease

Ju, Ji-Min,Lee, Hakmo,Oh, Keunhee,Lee, Dong-Sup,Choi, Eun Young The Korean Association of Immunobiologists 2014 Immune Network Vol.14 No.2

Graft-versus-host disease (GVHD) is a fatal complication that occurs after allogeneic hematopoietic stem cell transplantation. To understand the dynamics of CD4 and CD8 T cell production of IFN-${\gamma}$ and IL-17 during GVHD progression, we established a GVHD model by transplanting T cell-depleted bone marrow (TCD-BM) and purified T cells from B6 mice into irradiated BALB.B, creating an MHC-matched but minor histocompatibility (H) antigen-mismatched transplantation (B6 ${\rightarrow}$ BALB.B GVHD). Transplantation-induced GVHD was confirmed by the presence of the appropriate compositional changes in the T cell compartments and innate immune cells in the blood and the systemic secretion of inflammatory cytokines. Using this B6 ${\rightarrow}$ BALB.B GVHD model, we showed that the production of IFN-${\gamma}$ and IL-17 by CD4 T cells preceded that by CD8 T cells in the spleen, mesenteric lymph node, liver, and lung in the BALB.B GVHD host, and Th1 differentiation predated Th17 differentiation in all organs during GVHD progression. Such changes in cytokine production were based on changes in cytokine gene expression by the T cells at different time points during GVHD development. These results demonstrate that both IFN-${\gamma}$ and IL-17 are produced by CD4 and CD8 T cells but with different kinetics during GVHD progression.

Mithramycin A induces apoptosis by regulating the mTOR/Mcl-1/tBid pathway in androgen-independent prostate cancer cells

Choi, Eun-Sun,Chung, Taeho,Kim, Jun-Sung,Lee, Hakmo,Kwon, Ki Han,Cho, Nam-Pyo,Cho, Sung-Dae the Society for Free Radical Research Japan 2013 Journal of clinical biochemistry and nutrition Vol.53 No.2

<P>Mithramycin A (Mith) is an aureolic acid-type polyketide produced by various soil bacteria of the genus <I>Streptomyces</I>. Mith inhibits myeloid cell leukemia-1 (Mcl-1) to induce apoptosis in prostate cancer, but the molecular mechanism underlying this process has not been fully elucidated. The aim of this study was therefore to investigate the detailed molecular mechanism related to Mith-induced apoptosis in prostate cancer cells. Mith decreased the phosphorylation of mammalian target of rapamycin (mTOR) in both cell lines overexpressing phospho-mTOR compared to RWPE-1 human normal prostate epithelial cells. Mith significantly induced truncated Bid (tBid) and siRNA-mediated knock-down of Mcl-1 increased tBid protein levels. Moreover, Mith also inhibited the phosphorylation of mTOR on serine 2448 and Mcl-1, and increased tBid protein in prostate tumors in athymic nude mice bearing DU145 cells as xenografts. Thus, Mith acts as an effective tumor growth inhibitor in prostate cancer cells through the mTOR/Mcl-1/tBid signaling pathway.</P>

Attenuation of PERK enhances glucose-stimulated insulin secretion in islets

Kim, Min Joo,Min, Se Hee,Shin, Seon Young,Kim, Mi Na,Lee, Hakmo,Jang, Jin Young,Kim, Sun-Whe,Park, Kyong Soo,Jung, Hye Seung Journal of Endocrinology, Ltd. [etc.] 2018 The Journal of endocrinology Vol. No.

<P>PERK is a pancreatic endoplasmic reticulum (ER) kinase. Its complete deletion in pancreatic beta cells induces insulin deficiency; however, the effects of partial Perk suppression are unclear. We investigated the effect of partial PERK suppression using the specific PERK inhibitors GSK2606414 and GSK2656157. Low-dose GSK2606414 treatment for 24 h enhanced glucose-stimulated insulin secretion (GSIS), islet insulin content and calcium transit in mouse (at 40 nM) and human (at 50-100 nM) pancreatic islets. GSK2606414 also induced the expression of the ER chaperone BiP and the release of calcium from the ER. When Bip expression was inhibited using a Bip siRNA, the GSK2606414-induced augmentation of the ER calcium level, islet insulin contents, glucose-stimulated cytosolic calcium transit and GSIS were abrogated. In both wild-type and insulin-deficient Atg7-knockout mice, 8 weeks of GSK2656157 treatment enhanced GSIS and improved hyperglycemia without affecting body weight. In conclusion, partial PERK inhibition induced BiP expression in islets, increased glucose-stimulated calcium transit and islet insulin contents and enhanced GSIS, suggesting that low-dose PERK inhibitors could potentially be used to treat insulin deficiency.</P>

<i>Senp2</i> expression was induced by chronic glucose stimulation in INS1 cells, and it was required for the associated induction of <i>Ccnd1</i> and <i>Mafa</i>

Jung, Hye Seung,Kang, Yu Mi,Park, Ho Seon,Ahn, Byung Yong,Lee, Hakmo,Kim, Min Joo,Jang, Jin Young,Kim, Sun-Whe Taylor & Francis 2016 Islets Vol.8 No.6

<P><B>ABSTRACT</B></P><P>Post-translational modification by bonding of small ubiquitin-like modifier (SUMO) peptides influences various cellular functions, and is regulated by SUMO-specific proteases (SENPs). Several proteins have been suggested to have diverse impact on insulin synthesis and secretion through SUMO modification in β cells. However, the role of SUMO modification in β cell mass has not been established. Here, we examined the changes in expression of <I>Senp</I> in INS1 cells and pancreatic islets under diabetes-relevant stress conditions and associated changes in β cell mass. Treatment with 25 mM glucose for 72 h induced <I>Senp2</I> mRNA expression but not that of <I>Senp1</I> in INS1 cells. Immunohistochemical staining with anti-SENP2 antibody on human pancreas sections revealed that SENP2 was localized in the nucleus. Moreover, in a patient with type 2 diabetes, SENP2 levels were enhanced, especially in the cytoplasm. Senp2 cytoplasmic levels were also increased in islet cells in obese diabetic mice. Cell number peaked earlier in INS1 cells cultured in high-glucose conditions compared to those cultured in control media. This finding was associated with increased <I>Ccnd1</I> mRNA expression in high-glucose conditions, and siRNA-mediated <I>Senp2</I> suppression abrogated it. <I>Mafa</I> expression, unlike <I>Pdx1</I>, was also dependent on <I>Senp2</I> expression during high-glucose conditions. In conclusion, Senp2 may play a role in β cell mass in response to chronic high-glucose through Cyclin D1 and Mafa.</P>

Bone Marrow Stem/Progenitor Cell Mobilization in C57BL/6 and Balb/c Mice

Jaehyung Thomas Joung,Ju Eun Oh,Hye Seung Jung,Hakmo Lee 한국실험동물학회 2014 한국실험동물학회 학술발표대회 논문집 Vol.2014 No.2