• Molecules and Cells
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• v.45 no.4
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• pp.257-272
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• 2022

In addition to inducing apoptosis, caspase inhibition contributes to necroptosis and/or autophagy depending on the cell type and cellular context. In macrophages, necroptosis can be induced by co-treatment with Toll-like receptor (TLR) ligands (lipopolysaccharide [LPS] for TLR4 and polyinosinic-polycytidylic acid [poly I:C] for TLR3) and a cell-permeable pan-caspase inhibitor zVAD. Here, we elucidated the signaling pathways and molecular mechanisms of cell death. We showed that LPS/zVAD- and poly I:C/zVAD-induced cell death in bone marrow-derived macrophages (BMDMs) was inhibited by receptor-interacting protein kinase 1 (RIP1) inhibitor necrostatin-1 and autophagy inhibitor 3-methyladenine. Electron microscopic images displayed autophagosome/autolysosomes, and immunoblotting data revealed increased LC3II expression. Although zVAD did not affect LPS- or poly I:C-induced activation of IKK, JNK, and p38, it enhanced IRF3 and STAT1 activation as well as type I interferon (IFN) expression. In addition, zVAD inhibited ERK and Akt phosphorylation induced by LPS and poly I:C. Of note, zVAD-induced enhancement of the IRF3/IFN/STAT1 axis was abolished by necrostatin-1, while zVAD-induced inhibition of ERK and Akt was not. Our data further support the involvement of autocrine IFNs action in reactive oxygen species (ROS)-dependent necroptosis, LPS/zVAD-elicited ROS production was inhibited by necrostatin-1, neutralizing antibody of IFN receptor (IFNR) and JAK inhibitor AZD1480. Accordingly, both cell death and ROS production induced by TLR ligands plus zVAD were abrogated in STAT1 knockout macrophages. We conclude that enhanced TRIF-RIP1-dependent autocrine action of IFNβ, rather than inhibition of ERK or Akt, is involved in TLRs/zVAD-induced autophagic and necroptotic cell death via the JAK/STAT1/ROS pathway.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.167-174
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• 2014

Tumor angiogenesis, growth and metastasis are three closely related processes. We therefore investigated the effects of barbigerone on all three in the B16F10 tumor model established in both zebrafish and mouse models, and explored underlying molecular mechanisms. In vitro, barbigerone inhibited B16F10 cell proliferation, survival, migration and invasion and suppressed human umbilical vascular endothelial cell migration, invasion and tube formation in concentration-dependent manners. In the transgenic zebrafish model, treatment with $10{\mu}M$ barbigerone remarkably inhibited angiogenesis and tumor-associated angiogenesis by reducing blood vessel development more than 90%. In vivo, barbigerone significantly suppressed angiogenesis as measured by H and E staining of matrigel plugs and CD31 staining of B16F10 melanoma tumors in C57BL/6 mice. Furthermore, it exhibited highly potent activity at inhibiting tumor growth and metastasis to the lung of B16F10 melanoma cells injected into C57BL/6 mice. Western blotting revealed that barbigerone inhibited phosphorylation of AKT, FAK and MAPK family members, including ERK, JNK, and p38 MAPKs, in B16F10 cells mainly through the MEK3/6/p38 MAPK signaling pathway. These findings suggested for the first time that barbigerone could inhibit tumor-angiogenesis, tumor growth and lung metastasis via downregulation of the MEK3/6/p38 MAPK signaling pathway. The findings support further investigation of barbigerone as a potential anti-cancer drug.

• Journal of Ginseng Research
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• v.45 no.1
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• pp.86-97
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• 2021

Background: Panax ginseng Meyer has been used as a nourishing edible herb in East Asia for thousands of years. 25-OH-PPT was first discovered as a natural rare triterpenoid saponin in ginseng stems and leaves by our group. Research found that it showed strong inhibitory effects on α-glucosidase and protein tyrosine phosphatase 1B, and protected cardiocytes (H9c2) through PI3K/Akt pathway. Methods: In the research, in order to optimize the 25-OH-PPT enrichment process, optimal macroporous resins and optimal purification conditions were studied. Meanwhile, the hypoglycemic effect and mechanism of 25-OH-PPT were evaluated by using STZ to establish insulin-dependent diabetic mice and the spontaneous type 2 diabetes DB/DB mice. Results and Conclusion: Research found that 25-OH-PPT can reduce blood glucose and enhance glucose tolerance in STZ model mice. It increases insulin sensitivity by upregulating GLUT4 and AMPK in skeletal muscle, and activating insulin signaling pathways. In DB/DB mice, 25-OH-PPT achieves hypoglycemic effects mainly by activating the insulin signaling pathway. Meanwhile, through the influence of liver inflammatory factors and lipids in serum, it can be seen that 25-OH-PPT has obvious anti-inflammatory and lipid-lowering effects. These results provide new insights into the study of ginseng as a functional food.

• Journal of Veterinary Science
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• v.23 no.1
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• pp.3.1-3.12
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• 2022

Background: Domestic yaks are the most important livestock species on the Qinghai-Tibetan Plateau. Adult female yaks normally breed in the warm season (July to September) and enter anestrous in the cold season (November to April). Nevertheless, it is unclear how ovarian activity is regulated at the molecular level. Objectives: The peculiarities of yak reproduction were assessed to explore the molecular mechanism of postpartum anestrus ovaries in yaks after pregnancy and parturition. Methods: Sixty female yaks with calves were observed under natural grazing in Haiyan County, Qinghai Province. Three yak ovaries in pregnancy and postpartum anestrus were collected. RNA sequencing and quantitative proteomics were employed to analyze the pregnancy and postpartum ovaries after hypothermia to identify the genes and proteins related to the postpartum ovarian cycle. Results: The results revealed 841 differentially expressed genes during the postpartum hypoestrus cycle; 347 were up-regulated and 494 genes were down-regulated. Fifty-seven differential proteins were screened: 38 were up-regulated and 19 were down-regulated. The differential genes and proteins were related to the yak reproduction process, rhythm process, progesterone-mediated oocyte maturation, PI3K/AKT signaling pathway, and MAPK signaling pathway categories. Conclusions: Transcriptome and proteomic sequencing approaches were used to investigate postpartum anestrus and pregnancy ovaries in yaks. The results confirmed that BHLHE40, SF1IX1, FBPX1, HSPCA, LHCGR, BMP15, and ET-1R could affect postpartum hypoestrus and control the state of estrus.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.1
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• pp.21-30
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• 2024

The challenging clinical outcomes associated with advanced cervical cancer underscore the need for a novel therapeutic approach. Monensin, a polyether antibiotic, has recently emerged as a promising candidate with anti-cancer properties. In line with these ongoing efforts, our study presents compelling evidence of monensin's potent efficacy in cervical cancer. Monensin exerts a pronounced inhibitory impact on proliferation and anchorage-independent growth. Additionally, monensin significantly inhibited cervical cancer growth in vivo without causing any discernible toxicity in mice. Mechanism studies show that monensin's anti-cervical cancer activity can be attributed to its capacity to inhibit the Wnt/β-catenin pathway, rather than inducing oxidative stress. Monensin effectively reduces both the levels and activity of β-catenin, and we identify Akt, rather than CK1, as the key player involved in monensin-mediated Wnt/β-catenin inhibition. Rescue studies using Wnt activator and β-catenin-overexpressing cells confirmed that β-catenin inhibition is the mechanism of monensin's action. As expected, cervical cancer cells exhibiting heightened Wnt/β-catenin activity display increased sensitivity to monensin treatment. In conclusion, our findings provide pre-clinical evidence that supports further exploration of monensin's potential for repurposing in cervical cancer therapy, particularly for patients exhibiting aberrant Wnt/β-catenin activation.

• 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.

• Journal of Life Science
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• v.21 no.8
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• pp.1134-1141
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• 2011

Transmembrane protein 21 (TMP21) is a member of the p24 cargo protein family and has been shown to modulate ${\alpha}$-secretase-mediated A${\beta}$ production which was specifically observed in the brains of subjects with Alzheimer's disease (AD). In order to investigate whether TMP21 could affect nerve growth factor (NGF) receptor signaling pathway, the alteration of NGF receptors and their downstream proteins were detected in TMP21 over-expressed cells. CMV/hTMP21 vector used in this study was successfully expressed into TMP21 proteins in B35 cells after lipofectamin transfection. Expressed TMP21 proteins induced the down-regulation of ${\gamma}$-secretase complex components including Presenlin-1 (PS-1), PS-2, Nicastrin (NST), Pen-2 and APH-1. Also, the expression level of NGF receptor $p75^{NTR}$ and RhoA were significantly higher in CMV/hTMP21 transfectants than vehicle transfectants, while their levels returned to vehicle levels after NGF treatment. However, the phosphorylation of NGF receptor TrkA was dramtically decreased in NGF No-treated CMV/hTMP21 transfectants compared with vehicle transfectants, and increased in NGF treated CMV/hTMP21 transfectants. In TrkA downstream signaling pathway, the phosphorylation level of ERK was also decreased in CMV/hTMP21 transfectants, while the phosphorylation of Akt was increased in the same transfectants. Furthermore, NGF treatment induced the increase of phosphorylation level of Akt and ERK in CMV/hTMP21 transfectants. Therefore, these results suggested that over-expression of TMP21may simultaneously induce the up-regulation of $p75^{NTR}$/RhoA expression and the down-regulation of TrkA/ERK phosphorylation through the inhibition of ${\gamma}$-secretase activity.

• Nutrition Research and Practice
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• v.4 no.5
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• pp.351-355
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• 2010

Our previous proteomic study demonstrated that oxidative stress and antioxidant delphinidin regulated the cellular level of $p27^{kip1}$ (referred to as p27) as well as some heat shock proteins in human colon cancer HT 29 cells. Current study was conducted to validate and confirm the regulation of these proteins using both in vitro and in vivo systems. The level of p27 was decreased by hydrogen peroxide in a dose-dependent manner in human colon carcinoma HCT 116 (p53-positive) cells while it was increased upon exposure to hydrogen peroxide in HT 29 (p53-negative) cells. However, high concentration of hydrogen peroxide (100 ${\mu}M)$ downregulated p27 in both cell lines, but delphindin, one of antioxidative anthocyanins, enhanced the level of p27 suppressed by 100 ${\mu}M$ hydrogen peroxide. ICR mice were injected with varying concentrations of hydrogen peroxide, delphinidin and both. Western blot analysis for the mouse large intestinal tissue showed that the expression of p27 was upregulated by 25 mg/kg BW hydrogen peroxide. To investigate the association of p27 regulation with hypoxia-inducible factor 1-beta (HIF-$1{\beta}$), the level of p27 was analyzed in wild-type mouse hepatoma hepa1c1c7 and Aryl Hydrocarbon Nuclear Translocator (arnt, HIF-$1{\beta}$)-defective mutant BPRc1 cells in the absence and presence of hydrogen peroxide and delphinidin. While the level of p27 was responsive to hydrogen peroxide and delphinidin, it remained unchanged in BPRc1, suggesting that the regulation of p27 requires functional HIF-$1{\beta}$. We also found that hydrogen peroxide and delphinidin affected PI3K/Akt/mTOR signaling pathway which is one of upstream regulators of HIFs. In conclusion, hydrogen peroxide and antioxidant delphinidin seem to regulate intracellular level of p27 through regulating HIF-1 level which is, in turn, governed by its upstream regulators comprising of PI3K/Akt/mTOR signaling pathway. The results should also encourage further study for the potential of p27 as a biomarker for intracellular oxidative or antioxidant status.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.4983-4988
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• 2013

Objectives: To establish a taxol-resistant cell line of human ovarian carcinoma (A2780/Taxol) and investigate its biological features. Methods: The drug-resistant cell line (A2780/Taxol) was established by continuous stepwise selection with increasing concentrations of Taxol. Cell morphology was assessed by microscopy and growth curves were generated with in vitro and in vivo tumor xenograft models. With rhodamine123 (Rh123) assays, cell cycle distribution and the apoptotic rate were analyzed by flow cytometry (FCM). Drug resistance-related and signal associated proteins, including P-gp, MRPs, caveolin-1, PKC-${\alpha}$, Akt, ERK1/2, were detected by Western blotting. Results: A2780/Taxol cells were established with stable resistance to taxol. The drug resistance index (RI) was 430.7. Cross-resistance to other drugs was also shown, but there was no significant change to radioresistance. Compared with parental cells, A2780/Taxol cells were significantly heteromorphous, with a significant delay in population doubling time and reduced uptake of Rh123 (p<0.01). In vivo, tumor take by A2780 cells was 80%, and tumor volume increased gradually. In contrast, with A2780/Taxol cells in xenograft models there was no tumor development. FCM analysis revealed that A2780/Taxol cells had a higher percentage of G0/G1 and lower S phase, but no changes of G2 phase and the apoptosis rate. Expression of P-gp, MRP1, MRP2, BCRP, LRP, caveolin-1, PKC-${\alpha}$, Phospho-ERK1/2 and Phospho-JNK protein was significantly up-regulated, while Akt and p38 MARK protein expression was not changed in A2780/Taxol cells. Conclusion: The A2780/Taxol cell line is an ideal model to investigate the mechanism of muti-drug resistance related to overexpression of drug-resistance associated proteins and activation of the PKC-${\alpha}/ERK$ (JNK) signaling pathway.

• Journal of Life Science
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• v.32 no.5
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• pp.355-361
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• 2022

Melanin pigments are the main cause of skin color. They are produced in melanocytes and then transferred to keratinocytes, which eventually gives the skin surface a variety of colors. Although many skin-lightening or depigmenting agents have been developed, the demand for materials to reduce pig- mentation is still increasing. Here, we tried to find materials for skin-lightening or depigmentation using natural compounds and found that mistletoe (Viscum album var. coloratum) extracts (ME) had an inhibitory effect on tyrosinase activity. As a result, ME significantly reduced pigmentation in human primary melanocytes. In addition, a promoter reporter assay revealed that ME inhibited the transcription of microphthalmia-associated transcription factor (MITF), melanophilin (MLPH), tyrosinase-related protein-2 (TRP-2), and tyrosinase (TYR) genes in HM3KO melanoma cells. In addition, ME decreased the protein level for pigmentation-related molecules, such as TYR and TRP-1. Furthermore, it markedly inhibited the melanogenesis of zebrafish embryos, an in vivo evaluation model for pigmentation. To elucidate the action mechanism of ME, we investigated its effects on intracellular signaling. Eventually, the ME dramatically decreased the phosphorylation of the cAMP responsive element binding protein (CREB), AKT, and ERK. The data suggest that ME may inhibit the melanogenesis pathway by regulating the signaling pathway related to pigmentation. Taken together, these data propose that ME can be developed as a depigmenting or skin-lightening agent.