Sung-Whan Kim

Stromal vascular fraction shows robust wound healing through high chemotactic and epithelialization property

BACKGROUND Although human stromal vascular fraction (SVF) has been regarded as an attractive stem cell source, its therapeutic mechanism in wound healing has not been fully elucidated. AIMS In this study, we investigated the molecular characteristics and therapeutic property of SVF for wound healing. METHODS Microarray data showed that SVF cells are enriched with a higher level of wound healing or epithelium development-related genes and micro RNA. RESULTS Quantitative polymerase chain reaction (PCR) and reverse transcriptase PCR results revealed that the epithelialization growth factor, epidermal growth factor (EGF), chemokines, stromal cell-derived factor (SDF-1 or CXCL12), neutrophil-activating protein-2 (NAP-2 or CXCL7), chemokine receptors (CXCR1, CCR2 and CCR3) and wound healing genes were up-regulated in SVF compared with those in adipose-derived mesenchymal stem cells (ASCs). An in vitro scratch wound closure experiment demonstrated that co-culture with SVF substantially accelerated the wound closure of fibroblasts. Wounds in nude mice were created by skin excisions followed by injections of SVF with Pluronic hydrogel. SVF implantation highly accelerated wound closure and increased cellularity and re-epithelialization. In addition, the transplanted SVF exhibited high engraftment rates in the wound area, suggesting direct benefits for cutaneous closure. CONCLUSIONS Taken together, these data suggest that SVF possesses high therapeutic capability for wound healing via the secretion of epithelialization and chemotactic growth factors and enhanced engraftment properties.

Ramipril inhibits high glucose-stimulated up-regulation of adhesion molecules via the ERK1/2 MAPK signaling pathway in human umbilical vein endothelial cells.

Abstract Ramipril has recently been shown to have anti-atherogenic properties. However, the specific mechanisms underlying these effects remain unclear. The purpose of this study was to determine the effects of ramipril on induction of adhesion molecules in human umbilical vein endothelial cells (HUVECs) using high-glucose (HG) conditions and to investigate possible underlying molecular mechanisms. The effects of ramipril on expression of intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1 production, and ERK phosphorylation were examined in HG-induced HUVECs with inhibitors targeting the mitogen-activated protein kinase (MAPK) signaling pathway. HG induced the expression of the adhesion molecules ICAM-1 and VCAM-1. Pretreatment with ramipril drastically inhibited ICAM-1 and VCAM-1 production in a time- and dose-dependent manner. Moreover, upon investigating the effects of ramipril on the MAPK/extracellular signal-regulated kinase (ERK) signaling pathway, we found that ramipril completely inhibited HG-induced phosphorylation of ERK1/2. ERK inhibitors completely prevented the inhibitory effect of HG. This study demonstrated that ramipril reduces HG-stimulated induction of ICAM-1 and VCAM-1 expression via MAPK signaling, which may be useful for inhibition of atherosclerosis.

Flt3 Ligand Induces Monocyte Proliferation and Enhances the Function of Monocyte-Derived Dendritic Cells In Vitro

Flt3 ligand (FL), a potent hematopoietic cytokine, plays an important role in development and activation of dendritic cells (DCs) and natural killer cells (NK). Although some post‐receptor signaling events of FL have been characterized, the role of FL on Flt3 expressing human peripheral blood monocyte is unclear. In the current study, we examined the role of FL on cell survival and growth of peripheral blood monocytes and function of monocyte‐derived DCs. FL promoted monocyte proliferation in a dose‐dependent manner and prevented spontaneous apoptosis. FL induced ERK phosphorylation and a specific ERK inhibitor completely abrogated FL‐mediated cellular growth, while p38 MAPK, JNK, and AKT were relatively unaffected. Addition of FL to GM‐CSF and IL‐4 during DCs generation from monocytes increased the yield of DCs through induction of cell proliferation. DCs generated in the presence of FL expressed more costimulatory molecules on their surfaces and stimulated allogeneic T cell proliferation in MLR to a higher magnitude. Furthermore, FL partially antagonized IL‐10‐mediated inhibition on DCs function. Further characterization of FL actions may provide new and important information for immunotherapeutic approaches utilizing DCs. J. Cell. Physiol. 230: 1740–1749, 2015.

Angiogenic characteristics of human stromal vascular fraction in ischemic hindlimb

INTRODUCTION In this study, we sought to characterize the angio-vasculogenic property of human adipose tissue-derived stromal vascular fraction (SVF) and to determine the therapeutic potential of SVF in the context of experimental ischemia. Although human SVF is used for cell therapy, its angiogenic and vasculogenic characteristics have not been fully elucidated. METHODS AND RESULTS We conducted flow cytometry, microarray, quantitative (q)-PCR, Matrigel tube formation assays and in vivo therapeutic assays using an ischemic hind limb mouse model. Gene/micro RNA microarray, quantitative (q)-PCR results revealed that the representative pro-angiogenic factors were highly upregulated in SVF compared with human adipose-derived mesenchymal stem cells (ASCs). In addition, SVF exhibited high expression of endothelium-specific genes and showed robust in vitro micro-vascular formation. SVF was transplanted into ischemic mouse hind limbs and compared with ASC transplantation. SVF transplantation prevented limb loss and augmented blood perfusion, indicating that SVF promotes neovascularization in hind limb ischemia. Transplanted SVF showed high vasculogenic potential in vivo compared with transplanted ASCs. CONCLUSIONS Our data indicate that SVF has remarkable therapeutic effects on hind limb ischemia via robust angiogenic and vasculogenic activity.

CD31(+) cell transplantation promotes recovery from peripheral neuropathy.

Recently, we reported that human peripheral blood (PB)-derived CD31(+) cells are highly angiogenic. In this study, we investigated the beneficial effects of CD31(+) cells on peripheral neuropathy in mice. CD31(+) cells were collected from the peripheral blood using magnetic activated cell sorting. CD31(+) cells exhibited higher levels of expression of angiogenic genes on real-time reverse transcriptase polymerase chain reaction. Peripheral neuropathy was induced by crushing the sciatic nerve with a hemostat, and CD31(+) cells were then injected intramuscularly along the sciatic nerve. CD31(+) cell transplantation restored motor nerve conduction velocity and voltage amplitude and improved motor coordination. In addition, CD31(+) cell transplantation significantly improved blood perfusion and increased intraneural vascularity in the sciatic nerve. Whole-mount fluorescent imaging and dot blot analysis showed that CD31(+) cells in the nerve possessed high engraftment and anti-apoptotic properties. Additionally, injected CD31(+) cells displayed neurovascular tropism and are highly incorporated with vasculature. Angiogenic cytokines were augmented in CD31(+)-injected nerve tissue, suggesting increased neovascularization. Taken together, these results indicate that CD31(+) cells might be a novel therapeutic strategy in the treatment of peripheral neuropathy.

Cesarean section and tissue adhesions

We are responding to the article by Herzberger et al., ‘‘Adhesions at repeat cesarean delivery: is there a personal impact?’’ [1]. Herzberger et al. enrolled patients in a single teaching hospital who had had more than two deliveries by cesarean section (CS) [1]. The study consisted of a retrospective review in which the data were retrieved from computerized medical records. Adhesions were categorized as significant or non-significant, as shown in Table 1 of their article [1]. We have questions regarding the adhesion categories in Table 1. We consider that Herzberger et al. should have described in detail how adhesion was categorized based on other articles and adhesion classifications. In our opinion, adhesions should be classified according to relevant evidence, which would allow a standard that could easily be applied by clinicians. Herzberger et al. did not point out that fetal delivery time and vesicouterine fold adhesion are important factors in CS adhesion. The distinction between bladder and uterine adhesions may affect the delivery time in births by CS. Moreover, in CS, the myometrial suture thread may influence the postoperative development of intraabdominal adhesions. Therefore, it would have been of interest to be informed of the materials used at their hospital. Another potential determinant is whether the patients had placenta previa or placenta accreta during previous pregnancies. The amount of bleeding or uterine preservation methods may also influence adhesions formation. The authors did not provide this information. An assessment of adhesions should also document whether the patient underwent adhesiolysis for significant adhesions during the first cesarean delivery. This might demonstrate a relationship between adhesiolysis and adhesions formation during subsequent CS deliveries. Information on the mean operating time and the intra-operative blood loss in patients with significant adhesions after primary and secondary CS would also be valuable. Among the 160 patients enrolled in the study, 43 % developed significant adhesions following their first CS. The authors did not state whether this rate was lower or higher than reported elsewhere. Korean pharmaceutical companies currently offer three adhesion barriers and there is great interest in their use among Korean abdominal and pelvic surgeons, including in the obstetrics and gynecologic settings. To date, however, there are insufficient clinical data to evaluate the efficacy of these products and their use has not been approved by the US Food and Drug Administration [2]. Consequently, the authors’ experience with adhesion barriers, if any, and their opinion about their use in CS patients would have been of interest. Future studies should address these questions and comments to determine whether CS adhesions are patient or procedure related. This comment refers to the article available at doi:10.1007/s00404-015-3718-x and an author’s reply to this comment is available at doi:10.1007/s00404-015-3806-y.

Dual chemotactic factors-secreting human amniotic mesenchymal stem cells via TALEN-mediated gene editing enhanced angiogenesis

BACKGROUND Even though mesenchymal stem cells (MSCs) have angiogenic property, their cytokine secretory capacity is limited to treat ischemic vascular disorders. In present study, we produced genome-edited MSCs that secreted dual chemokine granulocyte chemotactic protein-2 (GCP-2) and stromal-derived factor-1α (SDF-1α) and determined their therapeutic potential in the context of experimental ischemia. METHODS GCP-2 and SDF-1α genes were integrated into safe harbor site at the safe harbor genomic locus of amniotic mesenchymal stem cells (AMM) via transcription activator-like effector nucleases (TALEN). GCP-2 and SDF-1α gene-edited AMM (AMM/GS) were used for quantitative (q)-PCR, Matrigel tube formation, cell migration, Matrigel plug assays and in vivo therapeutic assays using hindlimb ischemia mouse model. RESULTS AMM/GS-derived culture media (CM) induced significantly higher tube lengths and branching points as compared to AMM/S CM and AMM CM. Interestingly, Matrigel plug assays revealed that significantly higher levels of red blood cells were found in AMM/GS than AMM/S and AMM Matigel plugs and exhibited micro-vascular like formation. Cells was transplanted into ischemic mouse hindlimbs and compared with control groups. AMM/GS injection prevented limb loss and augmented blood perfusion, suggesting that enhances neovascularization in hindlimb ischemia. In addition, transplanted AMM/GS revealed high vasculogenic potential in vivo compared with transplanted AMM/S. CONCLUSION Taken together, genome-edited MSCs that express dual chemokine GCP-2 and SDF-1α might be alternative therapeutic options for the treatment of ischemic vascular disease.

Human adipose mesenchymal stem cells overexpressing dual chemotactic gene showed enhanced angiogenic capacity in ischaemic hindlimb model

Aims In present study, we sought to characterize the angio-vasculogenic property of human adipose mesenchymal stem cells (ASCs) overexpressing dual chemokine GCP-2 and SDF-1α (ASC-G/S) and to determine the therapeutic potential of ASC-G/S in the context of experimental ischaemia. Methods and results We generated ASC-G/S line and performed flow cytometry, quantitative (q)-PCR, Matrigel tube formation, Matrigel plug assays, and in vivo therapeutic assays using hind limb ischaemia mouse model. Q-PCR results showed that the representative pro-angiogenic factors were highly upregulated in ASC-G/S compared with ASCs single chemokine overexpressing GCP-2 (ASC-G). In addition, ASC-G/S exhibited high expression of endothelium-specific genes shch as vWF and Flk-1 and showed robust in vitro micro-vascular formation. ASC-G/S was transplanted into ischaemic mouse hind limbs and compared with control groups. ASC-G/S injection prevented limb loss and augmented blood perfusion, suggesting that ASC-G/S enhances neovascularization in hind limb ischaemia. In addition, transplanted ASC-G/S revealed high vasculogenic potential in vivo compared with transplanted ASC-G. Conclusion Our data suggest that ASC-G/S has high therapeutic effects on hind limb ischaemia via robust angiogenic and vasculogenic action.

Rosuvastatin inhibits high glucose-stimulated upregulation of VCAM-1 via the MAPK-signalling pathway in endothelial cells

Abstract Objective: The aim of this study is to investigate the molecular mechanisms and effect of rosuvastatin on adhesion molecule induction in human endothelial cells under high-glucose conditions (HG). Methods and results: The effects of rosuvastatin on vascular cell adhesion molecule (VCAM)-1 production and pERK phosphorylation were measured in HG-induced human umbilical vein endothelial cells (HUVECs) with inhibitors targeting the mitogen-activated protein kinase (MAPK) signal pathway. HG increased levels of VCAM-1. Treatment with rosuvastatin inhibited VCAM-1 expression in a concentration- and time-dependent manner. In addition, we investigated the effects of rosuvastatin on the extracellular signal-regulated kinase (ERK) 1/2 signal pathway. Rosuvastatin completely inhibited HG-induced phosphorylation of ERK. ERK/MAPK inhibitors completely prevented the VCAM-1 inhibition effect of rosuvastatin under HG condition. Conclusions: This study demonstrated that rosuvastatin suppresses HG-induced VCAM-1 production via the MAPK signalling pathway, playing a role in the suppression of atherosclerosis.

Cordyceps bassiana inhibits smooth muscle cell proliferation via the ERK1/2 MAPK signaling pathway

Cordyceps belongs to a genus of acormycete fungi and is known to exhibit various pharmacological effects. The aim of this study was to investigate the effect of Cordyceps species on the proliferation of vascular smooth muscle cells (VSMC) and their underlying molecular mechanism. A cell proliferation assay showed that Cordyceps bassiana ethanol extract (CBEE) significantly inhibited VSMC proliferation. In addition, neointimal formation was significantly reduced by treatment with CBEE in the carotid artery of balloon-injured rats. We also investigated the effects of CBEE on the extracellular signal-regulated kinase (ERK) signal pathway. Western blot analysis revealed increased ERK 1/2 phosphorylation in VSMCs treated with CBEE. Pretreatment with U0126 completely abrogated CBEE-induced ERK 1/2 phosphorylation. In conclusion, CBEE exhibited anti-proliferative properties that affected VSMCs through the ERK1/2 MAPK signaling pathway. Our data may elucidate the inhibitory mechanism of this natural product.