• Biomolecules & Therapeutics
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• v.26 no.5
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• pp.464-473
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• 2018

Cripto is a small glycosylphosphatidylinositol-anchored signaling protein that can detach from the anchored membrane and stimulate proliferation, migration, differentiation, vascularization, and angiogenesis. In the present study, we demonstrated that Cripto positively affected proliferation and survival of mesenchymal stem cells (MSCs) without affecting multipotency. Cripto also increased expression of phosphorylated janus kinase 2 (p-JAK2), phosphorylated signal transducer and activator of transcription 3 (p-STAT3), 78 kDa glucose-regulated protein (GRP78), c-Myc, and cyclin D1. Notably, treatment with an anti-GRP78 antibody blocked these effects. In addition, pretreatment with STAT3 short interfering RNA (siRNA) inhibited the increase in p-JAK2, c-Myc, cyclin D1, and BCL3 levels caused by Cripto and attenuated the pro-survival action of Cripto on MSCs. We also found that incubation with Cripto protected MSCs from apoptosis caused by hypoxia or $H_2O_2$ exposure, and the level of caspase-3 decreased by the Cripto-induced expression of B-cell lymphoma 3-encoded protein (BCL3). These effects were sensitive to down-regulation of BCL3 expression by BCL3 siRNA. Finally, we showed that Cripto enhanced expression levels of vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), and hepatocyte growth factor (HGF). In summary, our results demonstrated that Cripto activated a novel biochemical cascade that potentiated MSC proliferation and survival. This cascade relied on phosphorylation of JAK2 and STAT3 and was regulated by GRP78. Our findings may facilitate clinical applications of MSCs, as these cells may benefit from positive effects of Cripto on their survival and biological properties.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.5
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• pp.251-258
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• 2011

Here we have investigated how lactosylceramide (LacCer) modulates gene expression of adhesion molecules in TNF-${\alpha}$ and IFN ${\gamma}$ (CM)-stimulated astrocytes. We have observed that stimulation of astrocytes with CM increased the gene expression of ICAM-1 and VCAM-1. D-Threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) and N-butyldeoxynojirimycin (NBDNJ), inhibitors of glucosylceramide synthase (GLS) and LacCer synthase (galactosyltransferase, GalT-2), inhibited the gene expression of ICAM-1 and VCAM-1 and activation of their gene promoter induced by CM, which were reversed by exogenously supplied LacCer. Silencing of GalT-2 gene using its antisense oligonucleotides also attenuated CM-induced ICAM-1 and VCAM-1 expression, which were reversed by LacCer. PDMP treatment and silencing of GalT-2 gene significantly reduced CM-induced luciferase activities in NF-${\kappa}B$, AP-1, GAS, and STAT-3 luciferase vectors-transfected cells. In addition, LacCer reversed the inhibition of NF-${\kappa}B$ and STAT-1 luciferase activities by PDMP. Taken together, our results suggest that LacCer may play a crucial role in the expression of ICAM-1 and VCAM-1 via modulating transcription factors, such as NF-${\kappa}B$, AP-1, STAT-1, and STAT-3 in CM-stimulated astrocytes.

• 대한생식의학회:학술대회논문집
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• 2007.06a
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• pp.128-128
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• 2007

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.350-356
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• 2017

We previously reported that the CopA3 peptide (LLCIALRKK, ${\small{D}}-form$) originally isolated from the Korean dung beetle has antimicrobial and immunosuppressive effects. However, the high cost of producing the synthetic peptide, especially the ${\small{D}}-form$, has limited the development of CopA3 for therapeutic purposes. Here, we investigated whether the CopA3 deletion derivative, CopA5, which is composed of only five amino acids (LLCIA) and has the ${\small{L}}-form$ structure, could inhibit the lipopolysaccharide (LPS)-induced activation of macrophages. Peritoneal exudate macrophages (PEM) were isolated from mice and exposed to LPS in the presence or absence of CopA5, and biomarkers of macrophage activation were measured. Our results revealed that LPS-induced nitric oxide (NO) production, tumor necrosis factor $(TNF)-{\alpha}$ secretion, and phagocytic activity of PEM were significantly inhibited by CopA5 treatment. Similar to CopA3, the structurally modified CopA5 peptide had no cell toxicity (as assessed by measurement of cell viability loss and apoptosis) in PEM. Moreover, the LPS-induced upregulation of the activating phosphorylation of signal transducer and activator of transcription 1 (STAT1) was markedly inhibited by CopA5 treatment. These results suggest that, similar to CopA3, CopA5 inhibits macrophage activation by inhibiting STAT1 phosphorylation and blocking the release of NO and $TNF-{\alpha}$. CopA5 may therefore prove therapeutically useful in the realm of immune suppression.

• Clinical and Experimental Pediatrics
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• v.53 no.4
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• pp.592-597
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• 2010

Hyperimmunoglobulin E syndrome (HIES) is a rare immunodeficiency disease which is characterized by high serum IgE levels, eczema, and recurrent infections. Herein we present the case of a patient with HIES associated with STAT3 gene ($stat3$) mutation. A 16 year-old girl was admitted to our hospital due to hemoptysis caused by pneumonia with bronchiectasis. She had a history of recurrent skin and respiratory tract infections, such as pneumonia caused by MRSA (methicillin-resistant $Staphylococcus$ $aureus$) and $Pseudomonas$ $aeruginosa$. On physical examination, a broad round shaped nose, oral thrush, and chronic eczematous skin rash over her whole body were found. Laboratory data showed an elevated eosinophil count ($750/{\mu}L$) and total IgE level (5,001 U/mL). The patient's National Institutes of Health (NIH) score for HIES was 44. Direct sequencing of the STAT3 gene revealed that the patient was heterozygous for a missense mutation in the DNA binding domain of the STAT3 protein (c.1144C>T, p. Arg382Trp). HIES should be suspected in patients with recurrent infections and can be confirmed by clinical scoring and genetic analysis.

• Nutrition Research and Practice
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• v.5 no.3
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• pp.219-223
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• 2011

Obesity has been reported to be associated with low grade inflammatory status. In this study, we investigated the inflammatory response as well as associated signaling molecules in immune cells from diet-induced obese mice. Four-week-old C57BL mice were fed diets containing 5% fat (control) or 20% fat and 1% cholesterol (HFD) for 24 weeks. Splenocytes ($1{\times}10^7$ cells) were stimulated with $10\;{\mu}g/mL$ of lipopolysaccharide (LPS) for 6 or 24 hrs. Production of interleukin (IL)-$1{\beta}$, IL-6, and TNF-${\alpha}$ as well as protein expression levels of nucleotide-binding oligomerization domain (NOD)2, signal transducer and activator of transcription (STAT)3, and pSTAT3 were determined. Mice fed HFD gained significantly more body weight compared to mice fed control diet ($28.2{\pm}0.6$ g in HFD and $15.4{\pm}0.8$ g in control). After stimulation with LPS for 6 hrs, production of IL-$1{\beta}$ was significantly higher (P=0.001) and production of tumor necrosis factor (TNF)-${\alpha}$ tended to be higher (P < 0.064) in the HFD group. After 24 hrs of LPS stimulation, splenocytes from the HFD group produced significantly higher levels of IL-6 ($10.02{\pm}0.66$ ng/mL in HFD and $7.33{\pm}0.56$ ng/mL in control, P=0.005) and IL-$1{\beta}$ ($121.34{\pm}12.72$ pg/mL in HFD and $49.74{\pm}6.58$ pg/mL in control, P < 0.001). There were no significant differences in the expression levels of STAT3 and pSTAT3 between the HFD and the control groups. However, the expression level of NOD2 protein as determined by Western blot analysis was 60% higher in the HFD group compared with the control group. NOD2 contributes to the induction of inflammation by activation of nuclear factor ${\kappa}B$. These findings suggest that diet-induced obesity is associated with increased inflammatory response of immune cells, and higher expression of NOD2 may contribute to these changes.

• Journal of Acupuncture Research
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• v.29 no.1
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• pp.25-35
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• 2012

목적 : 이 연구는 $Vipera$ $lebetina$ $turanica$ 사독(蛇毒)이 인간 대장암 세포주인 HCT116 세포에서 세포주기진행, death receptor 의존적 세포자멸사 경로 관련단백질 발현 및 NK-${\kappa}B$와 STAT3 활성에 미치는 영향을 규명함으로써 대장암 세포 성장에 대한 억제와 그 기전에 대하여 살펴보고자 하였다. 방법 : 사독을 처리한 후 HCT116의 세포주기를 분석하기 위해서 FACS analysis를 시행하였고, apoptosis 평가에는 TUNEL assay를 시행하였으며 death receptor 의존적 세포자멸사 경로 관련단백질 및 NF-${\kappa}B$와 STAT3 활성 변동 관찰에는 RT-PCR 및 western blot analysis를 시행하였다. 결과 : 1. 0.1, 0.5 및 $1{\mu}g/m{\ell}$ 등의 사독을 처리한 결과 농도 의존적으로 HCT116 대장암 세포활성의 억제가 나타났다. 2. 0.1, 0.5 및 $1{\mu}g/m{\ell}$ 등의 사독을 처리한 결과 농도의존적으로 세포자멸사 활성세포의 증가가 나타났고, SVT $1{\mu}g/m{\ell}$에서는 60-70%의 대장암세포 억제 효과가 나타났다. 3. 0.1, 0.5 및 $1{\mu}g/m{\ell}$ 등의 사독을 처리한 결과 약한 G1 arrest와 강한 G2/M arrest가 나타났고, G0/G1 또는 G2/M 관련 cyclin D, E 및 B1의 증가가 나타났다. 4. 0.1, 0.5 및 $1{\mu}g/m{\ell}$ 등의 사독을 처리한 결과 death receptor4, 5의 발현증가와 그에 따른 세포자멸사 촉진 Bax, PARP, caspase-3, -8, -9 발현 증가 및 세포자멸사 억제의 Bcl-2의 발현 감소 등이 나타났다. 6. 0.1, 0.5 및 $1{\mu}g/m{\ell}$ 등의 사독을 처리한 결과 NF-${\kappa}B$와 STAT3의 활성변동은 관찰되지 않았다. 결론 : 이상의 연구에서 사독은 death receptor 의존적인 세포자멸사를 촉진하여 대장암의 화학치료 내성을 극복할 수 있는 하나의 대안이 될 것으로 생각되지만 보다 심화된 연구가 필요할 것으로 사료된다.

• Journal of Korean Medicine for Obesity Research
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• v.20 no.1
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• pp.1-9
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• 2020

Objectives: Artemisinin and its derivatives extracted from Artemisia annua, a Chinese herbal medicine, have variable biological effects due to structural differences. Up to date, the anti-obesity effect of dihydroartemisinin (DHA), a derivative of artemisinin, is unknown. The purpose of this study was to investigate the anti-adipogenic and lipolytic effects of DHA on 3T3-L1 preadipocytes. Methods: Oil Red O staining and AdipoRed assay were used to measure lipid accumulation and triglyceride (TG) content in 3T3-L1 cells, respectively. Cell count analysis was used to determine the cytotoxicity of 3T3-L1 cells. Western blot and real-time reverse transcription polymerase chain reaction analyses were used to analyze the expression of protein and mRNA in 3T3-L1 cells, respectively. Results: DHA at 5 μM markedly inhibited lipid accumulation and reduced TG content in differentiating 3T3-L1 cells with no cytotoxicity. Furthermore, DHA at 5 μM inhibited the expression of CCAAT/enhancer-binding protein-α (C/EBP-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), fatty acid synthase (FAS), and perilipin A as well as the phosphorylation of signal transducer and activator of transcription-3 (STAT-3) in differentiating 3T3-L1 cells. Moreover, while DHA at 5 μM had no effect on the mRNA expression of adiponectin, it strongly suppressed that of leptin in differentiating 3T3-L1 cells. However, DHA at 5 μM had no lipolytic effect on differentiated 3T3-L1 cells, as assessed by no enhancement of glycerol release. Conclusions: These results demonstrate that DHA at 5 μM has a strong anti-adipogenic effect on differentiating 3T3-L1 cells through the reduced expression and phosphorylation of C/EBP-α, PPAR-γ, FAS, perilipin A, and STAT-3.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.9
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• pp.1226-1234
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• 2012

3,4,3',5'-Tetrahydroxy-trans-stilbene (piceatannol) is a derivative of resveratrol with a variety of biological activities, including anti-inflammatory, anti-proliferative, and anti-cancer activities. We assessed the mechanisms by which piceatannol inhibits inflammatory responses using lipopolysaccharide (LPS)-treated Raw264.7 murine macrophages. Piceatannol (0~10 ${\mu}mol/L$) decreased LPS-induced release of nitric oxide, tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-6, IL-$1{\beta}$, and inhibited LPS-induced protein expression of inducible nitric oxide synthase (iNOS). Activation of nuclear factor-kappaB (NF-${\kappa}B$), activator protein (AP)-1, and signal transducer and activator of transcription 3 (STAT3) are crucial steps during an inflammatory response. Piceatannol prevented LPS-induced degradation of inhibitor of ${\kappa}B$ ($I{\kappa}B$), translocation of p65 to the nucleus, and phosphorylation of stress-activated protein kinase/c-Jun NH2-terminal kinase (SAPK/JNK). Additionally, piceatannol inhibited LPS-induced phosphorylation of STAT3 and IL-6-induced translocation of STAT3 to the nucleus. Furthermore, piceatannol increased the protein and mRNA levels of hemeoxygenase (HO)-1, the rate-limiting enzyme of heme catabolism that plays a critical role in mediating antioxidant and anti-inflammatory effects. Piceatannol further induced antioxidant response elements (ARE)-driven luciferase activity in Raw264.7 cells transfected with an ARE-luciferase reporter construct containing the enhancer 2 and minimal promoter region of HO-1. These results suggest that piceatannol exerts anti-inflammatory effects via the down-regulation of iNOS expression and up-regulation of HO-1 expression.

• The Korea Journal of Herbology
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• v.35 no.4
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• pp.9-16
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• 2020

Objective : To identify the effects of the water extract of Liriope platyphylla tuber (Liriopis tuber, LT) on the activation of astocytes, we investigated the regulatory effects of LT extract on H₂O₂-induced oxidative damage in C6 rat astrocytes. Methods : LT extract was extracted with boiling water. C6 cell line were treated with LT extract at 1, 2, and 3 mg/㎖ or without for 30 min and then stimulated with H₂O₂ at 5 ㎛ for 24 hr. The cell viability was measured by MTT assay. The expression of glial fibrillary acidic protein (GFAP), signal transducer and activator of transcription 3 (STAT3), phospho-STAT3 (pSTAT3), cyclooxygenase (COX-2), Nuclear factor-κB (NF-κB), superoxide dismutase 2 (SOD2), heme oxygenase-1 (HO-1), catalase, Akt, phospho-Akt (p-Akt) phosphoinositide 3-kinases (PI3K), and protein kinase C alpha (PKCα) proteins were determined by Western blot, respectively. GFAP expression was also observed with immunocytochemistry under a fluorescence microscope. Results : LT extract induced cell proliferation in H₂O₂-stimulated C6 cells. LT extract significantly inhibited the expression of GFAP, NF-κB and COX-2 and increased the expression of HO-1 and the phosphorylation of STAT3 in H₂O₂-stimulated C6 cells. LT extract also significantly increased the phosphorylation of Akt and decreased the expression of PKCα in a dose-dependent manner in H₂O₂-stimulated C6 cells. Conclusions : LT extract can regulate H₂O₂-induced activation of astrocytes through inhibiting the expression of NF-κB, COX-2 and regulating Akt / HO-1, STAT3 or PKCα signaling pathway.