1.Cilostazol and Probucol for Cognitive Decline after Stroke: A Cognitive Outcome Substudy of the PICASSO Trial
Jae-Sung LIM ; Sun U. KWON ; Kyung-Ho YU ; Sungwook YU ; Jong-Ho PARK ; Byung-Chul LEE ; Mi Sun OH ; Yong-Jae KIM ; Joung-Ho RHA ; Yang-Ha HWANG ; Ji Sung LEE ; Sung Hyuk HEO ; Seong Hwan AHN ; Woo-Keun SEO ; Jong-Moo PARK ; Ju-Hun LEE ; Jee-Hyun KWON ; Sung-Il SOHN ; Jin-Man JUNG ; Hahn Young KIM ; Eung-Gyu KIM ; Jae-Kwan CHA ; Man-Seok PARK ; Hyo Suk NAM ; Hee-Joon BAE ; Dong-Eog KIM ; Jaeseol PARK ; Yeonwook KANG ; Jimi CHOI ; Juneyoung LEE
Journal of Stroke 2021;23(1):128-131
2.STAT3 as a Potential Target for Tumor Suppressive Effects of 15-Deoxy-Δ12,14-prostaglandin J2 in Triple Negative Breast Cancer
Su-Jung KIM ; Nam-Chul CHO ; Young-Il HAHN ; Seong Hoon KIM ; Xizhu FANG ; Young-Joon SURH
Journal of Cancer Prevention 2021;26(3):207-217
STAT3 plays a prominent role in proliferation and survival of tumor cells. Thus, STAT3 has been considered to be a prime target for development of anti-cancer therapeutics. The electrophilic cyclopentenone prostaglandin,15-deoxy-Δ12,14-prostaglandin J2(15d-PGJ2 ) has been well recognized for its capability to modulate intracellular signaling pathways involved in cancer cell growth and progression. We previously reported that 15d-PGJ2 had potent cytotoxicity against harvey-ras transformed human mammary epithelial cells through direct interaction with STAT3. In this study, we have attempted to verify the inhibitory effects of 15d-PGJ2 on STAT3 signaling in human breast tumor cells. The triple negative breast cancer cell lines, MDA-MB-231 and MDA-MB-468 displaying constitutive phosphorylation of STAT3 on the tyrosine 705 (Tyr705) residue, underwent apoptosis upon inhibition of STAT3 by 15d-PGJ2 . In contrast, estrogen receptor positive MCF-7 breast cancer cells that do not exhibit elevated STAT3 phosphorylation were much less susceptible to 15d-PGJ2 -induced apoptosis as assessed by PARP cleavage. Furthermore, 15d-PGJ2 inhibited interleukin-6-induced tyrosine phosphorylation of STAT3 in LNCaP cells. According to molecular docking studies, 15d-PGJ2 may preferentially bind to the cysteine 259 residue (Cys259) present in the coiled-coil domain of STAT3. Site-directed mutagenesis of STAT3 identified Cys259 to be the critical amino acid for the 15d-PGJ2 -induced apoptosis as well as epithelial-to-mesenchymal transition. Taken together, these findings suggest STAT3 inactivation through direct chemical modification of its Cys259 as a potential therapeutic approach for treatment of triple negative breast cancer treatment.
3.STAT3 as a Potential Target for Tumor Suppressive Effects of 15-Deoxy-Δ12,14-prostaglandin J2 in Triple Negative Breast Cancer
Su-Jung KIM ; Nam-Chul CHO ; Young-Il HAHN ; Seong Hoon KIM ; Xizhu FANG ; Young-Joon SURH
Journal of Cancer Prevention 2021;26(3):207-217
STAT3 plays a prominent role in proliferation and survival of tumor cells. Thus, STAT3 has been considered to be a prime target for development of anti-cancer therapeutics. The electrophilic cyclopentenone prostaglandin,15-deoxy-Δ12,14-prostaglandin J2(15d-PGJ2 ) has been well recognized for its capability to modulate intracellular signaling pathways involved in cancer cell growth and progression. We previously reported that 15d-PGJ2 had potent cytotoxicity against harvey-ras transformed human mammary epithelial cells through direct interaction with STAT3. In this study, we have attempted to verify the inhibitory effects of 15d-PGJ2 on STAT3 signaling in human breast tumor cells. The triple negative breast cancer cell lines, MDA-MB-231 and MDA-MB-468 displaying constitutive phosphorylation of STAT3 on the tyrosine 705 (Tyr705) residue, underwent apoptosis upon inhibition of STAT3 by 15d-PGJ2 . In contrast, estrogen receptor positive MCF-7 breast cancer cells that do not exhibit elevated STAT3 phosphorylation were much less susceptible to 15d-PGJ2 -induced apoptosis as assessed by PARP cleavage. Furthermore, 15d-PGJ2 inhibited interleukin-6-induced tyrosine phosphorylation of STAT3 in LNCaP cells. According to molecular docking studies, 15d-PGJ2 may preferentially bind to the cysteine 259 residue (Cys259) present in the coiled-coil domain of STAT3. Site-directed mutagenesis of STAT3 identified Cys259 to be the critical amino acid for the 15d-PGJ2 -induced apoptosis as well as epithelial-to-mesenchymal transition. Taken together, these findings suggest STAT3 inactivation through direct chemical modification of its Cys259 as a potential therapeutic approach for treatment of triple negative breast cancer treatment.
4.Changes in High-Density Lipoprotein Cholesterol and Risks of Cardiovascular Events: A Post Hoc Analysis from the PICASSO Trial
Eun-Jae LEE ; Sun U. KWON ; Jong-Ho PARK ; Yong-Jae KIM ; Keun-Sik HONG ; Sungwook YU ; Yang-Ha HWANG ; Ji Sung LEE ; Juneyoung LEE ; Joung-Ho RHA ; Sung Hyuk HEO ; Sung Hwan AHN ; Woo-Keun SEO ; Jong-Moo PARK ; Ju-Hun LEE ; Jee-Hyun KWON ; Sung-Il SOHN ; Jin-Man JUNG ; Hahn Young KIM ; Eung-Gyu KIM ; Sung Hun KIM ; Jae-Kwan CHA ; Man-Seok PARK ; Hyo Suk NAM ; Dong-Wha KANG ;
Journal of Stroke 2020;22(1):108-118
Background:
and purpose Whether pharmacologically altered high-density lipoprotein cholesterol (HDL-C) affects the risk of cardiovascular events is unknown. Recently, we have reported the Prevention of Cardiovascular Events in Asian Patients with Ischaemic Stroke at High Risk of Cerebral Haemorrhage (PICASSO) trial that demonstrated the non-inferiority of cilostazol to aspirin and superiority of probucol to non-probucol for cardiovascular prevention in ischemic stroke patients (clinicaltrials.gov: NCT01013532). We aimed to determine whether on-treatment HDL-C changes by cilostazol and probucol influence the treatment effect of each study medication during the PICASSO study.
Methods:
Of the 1,534 randomized patients, 1,373 (89.5%) with baseline cholesterol parameters were analyzed. Efficacy endpoint was the composite of stroke, myocardial infarction, and cardiovascular death. Cox proportional hazards regression analysis examined an interaction between the treatment effect and changes in HDL-C levels from randomization to 1 month for each study arm.
Results:
One-month post-randomization mean HDL-C level was significantly higher in the cilostazol group than in the aspirin group (1.08 mmol/L vs. 1.00 mmol/L, P<0.001). The mean HDL-C level was significantly lower in the probucol group than in the non-probucol group (0.86 mmol/L vs. 1.22 mmol/L, P<0.001). These trends persisted throughout the study. In both study arms, no significant interaction was observed between HDL-C changes and the assigned treatment regarding the risk of the efficacy endpoint.
Conclusions
Despite significant HDL-C changes, the effects of cilostazol and probucol treatment on the risk of cardiovascular events were insignificant. Pharmacologically altered HDL-C levels may not be reliable prognostic markers for cardiovascular risk.
5.In Vitro Analysis of Histology, Mechanics, and Safety of Radiationfree Pre-hydrated Human Acellular Dermal Matrix
Ji Young KIM ; Kyung Min YANG ; Ji Hyun YOUN ; Heejun PARK ; Hyung Min HAHN ; Il Jae LEE
Journal of Breast Cancer 2020;23(6):635-646
Purpose:
Acellular dermal matrix (ADM) supports tissue expanders or implants in implant-based breast reconstruction. The characteristics of ADM tissue are defined by the manufacturing procedure, such as decellularization, preservation, and sterilization, and are directly related to clinical outcomes. This study aimed to compare the properties of a new pre-hydrated-ADM (H-ADM-low) obtained using a decellularization reagent reduction process with a low concentration of detergent with those of radiation-sterilized H-ADM and freeze-dried ADM (FD-ADM).
Methods:
ADMs were evaluated in terms of structure, mechanical quality, and cytotoxicity using histochemical staining, tensile strength testing, and in vitro cell viability analysis.
Results:
The tissue structure of H-ADM-low (CGDERM ONE-STEP) was similar to that of native skin despite complete decellularization. By contrast, in FD-ADM, the tissue structure was damaged by the freeze-drying process, and radiation-sterilized H-ADM showed a compact fibrillar arrangement. Furthermore, matrix components such as collagen and elastin were preserved in H-ADM-low, whereas a loss of elastin fibers with fragmented distribution was observed in radiation-sterilized H-ADMs. H-ADM-low's tensile strength (58.84 MPa) was significantly greater than that of FD-ADM (38.60 MPa) and comparable with that of radiationsterilized H-ADMs. The residual detergent content in H-ADM-low (47.45 mg/L) was 2.67-fold lower than that of H-ADM decellularized with a conventional detergent concentration (126.99 mg/mL), and this finding was consistent with the cell viability results (90.7% and 70.7%, respectively), indicating that H-ADM-low has very low cytotoxicity.
Conclusions
H-ADM-low produced through aseptic processes retains the original tissue structure, demonstrates excellent mechanical properties, and does not affect cell viability.Therefore, this newer H-ADM is suitable for use in implant-based breast reconstruction.
6.Differences in Therapeutic Responses and Factors Affecting Post-Stroke Depression at a Later Stage According to Baseline Depression.
Eun Jae LEE ; Jong S KIM ; Dae Il CHANG ; Jong Ho PARK ; Seong Hwan AHN ; Jae Kwan CHA ; Ji Hoe HEO ; Sung Il SOHN ; Byung Chul LEE ; Dong Eog KIM ; Hahn Young KIM ; Seongheon KIM ; Do Young KWON ; Jei KIM ; Woo Keun SEO ; Jun LEE ; Sang Won PARK ; Seong Ho KOH ; Jin Young KIM ; Smi CHOI-KWON ; Min Sun KIM ; Ji Sung LEE
Journal of Stroke 2018;20(2):258-267
BACKGROUND AND PURPOSE: The pathophysiology of post-stroke depression (PSD) is complex and may differ according to an individual’s mood immediately after stroke. Here, we compared the therapeutic response and clinical characteristics of PSD at a later stage between patients with and without depression immediately after stroke. METHODS: This study involved a post hoc analysis of data from EMOTION (ClinicalTrials.gov NCT01278498), a placebo-controlled, double-blind trial that examined the efficacy of escitalopram (10 mg/day) on PSD and other emotional disturbances among 478 patients with acute stroke. Participants were classified into the Baseline-Blue (patients with baseline depression at the time of randomization, defined per the Montgomery-Asberg Depression Rating Scale [MADRS] ≥8) or the Baseline-Pink groups (patients without baseline depression). We compared the efficacy of escitalopram and predictors of 3-month PSD (MADRS ≥8) between these groups. RESULTS: There were 203 Baseline-Pink and 275 Baseline-Blue patients. The efficacy of escitalopram in reducing PSD risk was more pronounced in the Baseline-Pink than in the Baseline-Blue group (p for interaction=0.058). Several risk factors differentially affected PSD development based on the presence of baseline depression (p for interaction < 0.10). Cognitive dysfunction was an independent predictor of PSD in the Baseline-Blue, but not in the Baseline-Pink group, whereas the non-use of escitalopram and being female were more strongly associated with PSD in the Baseline-Pink group. CONCLUSIONS: Responses to escitalopram and predictors of PSD 3 months following stroke differed based on the presence of baseline depression. Our data suggest that PSD pathophysiology is heterogeneous; therefore, different therapeutic strategies may be needed to prevent PSD emergence following stroke.
Affective Symptoms
;
Anger
;
Citalopram
;
Depression*
;
Female
;
Humans
;
Random Allocation
;
Risk Factors
;
Stroke
7.Cardiac Resynchronization Therapy and QRS Duration: Systematic Review, Meta-analysis, and Meta-regression.
Si Hyuck KANG ; Il Young OH ; Do Yoon KANG ; Myung Jin CHA ; Youngjin CHO ; Eue Keun CHOI ; Seokyung HAHN ; Seil OH
Journal of Korean Medical Science 2015;30(1):24-33
Cardiac resynchronization therapy (CRT) has been shown to reduce the risk of death and hospitalization in patients with advanced heart failure with left ventricular dysfunction. However, controversy remains regarding who would most benefit from CRT. We performed a meta-analysis, and meta-regression in an attempt to identify factors that determine the outcome after CRT. A total of 23 trials comprising 10,103 patients were selected for this meta-analysis. Our analysis revealed that CRT significantly reduced the risk of all-cause mortality and hospitalization for heart failure compared to control treatment. The odds ratio (OR) of all-cause death had a linear relationship with mean QRS duration (P=0.009). The benefit in survival was confined to patients with a QRS duration > or =145 ms (OR, 0.86; 95% CI, 0.74-0.99), while no benefit was shown among patients with a QRS duration of 130 ms (OR, 1.00; 95% CI, 0.80-1.25) or less. Hospitalization for heart failure was shown to be significantly reduced in patients with a QRS duration > or =127 ms (OR, 0.77; 95% CI, 0.60-0.98). This meta-regression analysis implies that patients with a QRS duration > or =150 ms would most benefit from CRT, and in those with a QRS duration <130 ms CRT implantation may be potentially harmful.
Bundle-Branch Block/physiopathology
;
Cardiac Resynchronization Therapy/*methods
;
Cardiac Resynchronization Therapy Devices
;
Defibrillators, Implantable
;
Electrocardiography
;
Heart Failure/mortality/physiopathology/*therapy
;
Humans
;
Myocardial Contraction/*physiology
;
Treatment Outcome
;
Ventricular Dysfunction, Left/mortality/physiopathology/*therapy
8.Clinical Characteristics of Cerebral Venous Thrombosis in a Single Center in Korea.
Dong Sun PARK ; Chang Taek MOON ; Young Il CHUN ; Young Cho KOH ; Hahn Young KIM ; Hong Gee ROH
Journal of Korean Neurosurgical Society 2014;56(4):289-294
OBJECTIVE: The purpose of this study is to investigate the clinical characteristics of cerebral venous thrombosis (CVT) in a single center in Korea. METHODS: A total of 36 patients were diagnosed with CVT from August 2005 to May 2013. The patient data regarding age, sex, disease stage, pathogenesis, location, laboratory findings, radiological findings, and treatment modalities were retrospectively collected. The results were compared with those of previous studies in other countries. RESULTS: The patient group comprised 21 men and 15 women with a mean age of 46.9 years (ranging from three months to 77 years). The most common cause was a prothrombotic condition (8 patients, 22.2%). Within the patient group, 13 patients (36.1%) had a hemorrhagic infarction, whereas 23 (63.9%) had a venous infarction without hemorrhage. By location, the incidence of hemorrhagic infarction was the highest in the group with a transverse and/or sigmoid sinus thrombosis (n=9); however, the proportion of hemorrhagic infarction was higher in the cortical venous thrombosis group (75%) and the deep venous thrombosis group (100%). By pathogenesis, the incidence of hemorrhagic infarction was the highest in the prothrombotic group (n=6), which was statistically significant (p=0.016). CONCLUSION: According to this study, CVT was more prevalent in men, and the peak age group comprised patients in the sixth decade. The most common cause was a prothrombotic condition. This finding was comparable with reports from Europe or America, in which CVT was more common in younger women. Hemorrhagic infarction was more common in the prothrombotic group (p=0.016) than in the non-prothrombotic group in this study.
Americas
;
Colon, Sigmoid
;
Europe
;
Female
;
Hemorrhage
;
Humans
;
Incidence
;
Infarction
;
Korea
;
Male
;
Retrospective Studies
;
Sinus Thrombosis, Intracranial
;
Venous Thrombosis*
9.Constitutive stabilization of hypoxia-inducible factor alpha selectively promotes the self-renewal of mesenchymal progenitors and maintains mesenchymal stromal cells in an undifferentiated state.
In Ho PARK ; Kwang Ho KIM ; Hyun Kyung CHOI ; Jae Seung SHIM ; Soo Young WHANG ; Sang JUNE HAHN ; Oh Joo KWON ; Il Hoan OH
Experimental & Molecular Medicine 2013;45(9):e44-
With the increasing use of culture-expanded mesenchymal stromal cells (MSCs) for cell therapies, factors that regulate the cellular characteristics of MSCs have been of major interest. Oxygen concentration has been shown to influence the functions of MSCs, as well as other normal and malignant stem cells. However, the underlying mechanisms of hypoxic responses and the precise role of hypoxia-inducible factor-1alpha (Hif-1alpha), the master regulatory protein of hypoxia, in MSCs remain unclear, due to the limited span of Hif-1alpha stabilization and the complex network of hypoxic responses. In this study, to further define the significance of Hif-1alpha in MSC function during their self-renewal and terminal differentiation, we established adult bone marrow (BM)-derived MSCs that are able to sustain high level expression of ubiquitin-resistant Hif-1alpha during such long-term biological processes. Using this model, we show that the stabilization of Hif-1alpha proteins exerts a selective influence on colony-forming mesenchymal progenitors promoting their self-renewal and proliferation, without affecting the proliferation of the MSC mass population. Moreover, Hif-1alpha stabilization in MSCs led to the induction of pluripotent genes (oct-4 and klf-4) and the inhibition of their terminal differentiation into osteogenic and adipogenic lineages. These results provide insights into the previously unrecognized roles of Hif-1alpha proteins in maintaining the primitive state of primary MSCs and on the cellular heterogeneities in hypoxic responses among MSC populations.
*Cell Differentiation
;
Cell Proliferation
;
Humans
;
Hypoxia-Inducible Factor 1, alpha Subunit/genetics/*metabolism
;
Kruppel-Like Transcription Factors/genetics/metabolism
;
Mesenchymal Stromal Cells/cytology/*metabolism/physiology
;
Octamer Transcription Factor-3/genetics/metabolism
;
Protein Stability
10.Transcriptional Upregulation of Plasminogen Activator Inhibitor-1 in Rat Primary Astrocytes by a Proteasomal Inhibitor MG132.
Kyu Suk CHO ; Kyoung Ja KWON ; Se Jin JEON ; So Hyun JOO ; Ki Chan KIM ; Jae Hoon CHEONG ; Geon Ho BAHN ; Hahn Young KIM ; Seol Heui HAN ; Chan Young SHIN ; Sung Il YANG
Biomolecules & Therapeutics 2013;21(2):107-113
Plasminogen activator inhibitor-1 (PAI-1) is a member of serine protease inhibitor family, which regulates the activity of tissue plasminogen activator (tPA). In CNS, tPA/PAI-1 activity is involved in the regulation of a variety of cellular processes such as neuronal development, synaptic plasticity and cell survival. To gain a more insights into the regulatory mechanism modulating tPA/PAI-1 activity in brain, we investigated the effects of proteasome inhibitors on tPA/PAI-1 expression and activity in rat primary astrocytes, the major cell type expressing both tPA and PAI-1. We found that submicromolar concentration of MG132, a cell permeable peptide-aldehyde inhibitor of ubiquitin proteasome pathway selectively upregulates PAI-1 expression. Upregulation of PAI-1 mRNA as well as increased PAI-1 promoter reporter activity suggested that MG132 transcriptionally increased PAI-1 expression. The induction of PAI-1 downregulated tPA activity in rat primary astrocytes. Another proteasome inhibitor lactacystin similarly increased the expression of PAI-1 in rat primary astrocytes. MG132 activated MAPK pathways as well as PI3K/Akt pathways. Inhibitors of these signaling pathways reduced MG132-mediated upregulation of PAI-1 in varying degrees and most prominent effects were observed with SB203580, a p38 MAPK pathway inhibitor. The regulation of tPA/PAI-1 activity by proteasome inhibitor in rat primary astrocytes may underlie the observed CNS effects of MG132 such as neuroprotection.
Animals
;
Astrocytes*
;
Brain
;
Cell Survival
;
Humans
;
Neurons
;
p38 Mitogen-Activated Protein Kinases
;
Plasminogen Activator Inhibitor 1
;
Plasminogen Activators*
;
Plasminogen*
;
Plastics
;
Proteasome Endopeptidase Complex
;
Proteasome Inhibitors
;
Rats*
;
RNA, Messenger
;
Serine Proteases
;
Tissue Plasminogen Activator
;
Ubiquitin
;
Up-Regulation*

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