• Biomolecules & Therapeutics
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• v.27 no.4
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• pp.363-372
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• 2019

Daidzein isolated from soybean (Glycine max) has been widely studied for its antioxidant and anti-inflammatory activities. However, the protective effects of 7,8,4'-trihydroxyisoflavone (THIF), a major metabolite of daidzein, on 6-hydroxydopamine (OHDA)-induced neurotoxicity are not well understood. In the current study, 7,8,4'-THIF significantly inhibited neuronal cell death and lactate dehydrogenase (LDH) release induced by 6-OHDA in SH-SY5Y cells, which were used as an in vitro model of Parkinson's disease (PD). Moreover, pretreatment with 7,8,4'-THIF significantly increased the levels of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) and decreased malondialdehyde (MDA) activity in 6-OHDA-induced SH-SY5Y cells. In addition, 7,8,4'-THIF significantly recovered 6-OHDA-induced cleaved caspase-3, cleaved caspase-9, cleaved poly-ADP-ribose polymerase (PARP), increased Bax, and decreased Bcl-2 levels. Additionally, 7,8,4'-THIF significantly restored the expression levels of phosphorylated c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase 1/2 (ERK 1/2), phosphatidylinositol 3-kinases (PI3K)/Akt, and glycogen synthase kinase-3 beta ($GSK-3{\beta}$) in 6-OHDA-induced SH-SY5Y cells. Further, 7,8,4'-THIF significantly increased the reduced tyrosine hydroxylase (TH) level induced by 6-OHDA in SH-SY5Y cells. Collectively, these results suggest that 7,8,4'-THIF protects against 6-OHDA-induced neuronal cell death in cellular PD models. Also, these effects are mediated partly by inhibiting activation of the MAPK and PI3K/Akt/$GSK-3{\beta}$ pathways.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.2
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• pp.147-157
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• 2021

Coronary microembolization (CME) is associated with cardiomyocyte apoptosis and cardiac dysfunction. Puerarin confers protection against multiple cardiovascular diseases, but its effects and specific mechanisms on CME are not fully known. Hence, our study investigated whether puerarin pretreatment could alleviate cardiomyocyte apoptosis and improve cardiac function following CME. The molecular mechanism associated was also explored. A total of 48 Sprague-Dawley rats were randomly divided into CME, CME + Puerarin (CME + Pue), sham, and sham + Puerarin (sham + Pue) groups (with 12 rats per group). A CME model was established in CME and CME + Pue groups by injecting 42 ㎛ microspheres into the left ventricle of rats. Rats in the CME + Pue and sham + Pue groups were intraperitoneally injected with puerarin at 120 mg/kg daily for 7 days before operation. Cardiac function, myocardial histopathology, and cardiomyocyte apoptosis index were determined via cardiac ultrasound, hematoxylin-eosin (H&E) and hematoxylin-basic fuchsin-picric acid (HBFP) stainings, and TdT-mediated dUTP nick-end labeling (TUNEL) staining, respectively. Western blotting was used to measure protein expression related to the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/glycogen synthase kinase-3β (GSK-3β) pathway. We found that, puerarin significantly ameliorated cardiac dysfunction after CME, attenuated myocardial infarct size, and reduced myocardial apoptotic index. Besides, puerarin inhibited cardiomyocyte apoptosis, as revealed by decreased Bax and cleaved caspase-3, and up-regulated Bcl-2 and PI3K/Akt/GSK-3β pathway related proteins. Collectively, puerarin can inhibit cardiomyocyte apoptosis and thus attenuate myocardial injury caused by CME. Mechanistically, these effects may be achieved through activation of the PI3K/Akt/GSK-3β pathway.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.2
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• pp.155-161
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• 2014

Overexpression of amyloid precursor protein with the Swedish mutation causes abnormal hyperphosphorylation of the microtubule-associated protein tau. Hyperphosphorylated isoforms of tau are major components of neurofibrillary tangles, which are histopathological hallmarks of Alzheimer's disease. Protein phosphatase 2A (PP2A), a major tau protein phosphatase, consists of a structural A subunit, catalytic C subunit, and a variety of regulatory B subunits. The B subunits have been reported to modulate function of the PP2A holoenzyme by regulating substrate binding, enzyme activity, and subcellular localization. In the current study, we characterized regulatory B subunit-specific regulation of tau protein phosphorylation. We showed that the PP2A B subunit PPP2R2A mediated dephosphorylation of tau protein at Ser-199, Ser-202/Thr-205, Thr-231, Ser-262, and Ser-422. Down-regulation of PPP2R5D expression decreased tau phosphorylation at Ser-202/Thr-205, Thr-231, and Ser-422, which indicates activation of the tau kinase glycogen synthase kinase 3 beta ($GSK3{\beta}$) by PP2A with PPP2R5D subunit. The level of activating phosphorylation of the $GSK3{\beta}$ kinase Akt at Thr-308 and Ser-473 were both increased by PPP2R5D knockdown. We also characterized B subunit-specific phosphorylation sites in tau using mass spectrometric analysis. Liquid chromatography-mass spectrometry revealed that the phosphorylation status of the tau protein may be affected by PP2A, depending on the specific B subunits. These studies further our understanding of the function of various B subunits in mediating site-specific regulation of tau protein phosphorylation.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.48-49
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• 2001

The carcinogens 2-amino-3-methylimidazo［4, 5-f］quinoline (IQ) and 1, 2-dimethylhydrazine (DMH) induce colon tumors in the Fisher 344 rat that contain mutations in Ctnnbl, the gene for b-catenin, but the pattern of mutation differs from that found in human colon cancers. In both species, mutations affect the glycogen synthase kinase 3$\beta$ (GSK-3$\beta$) consensus region of $\beta$-catenin, but whereas they directly substitute critical Ser/Thr phosphorylation sites in human colon cancers, the majority of mutations cluster around Ser$_{33}$ in the rat tumors.(omitted)d)

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10b
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• pp.5-6
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• 2001

The carcinogens 2-arnioo-3-methylimidazo［4,5-f］quinoline (IQ) and 1,2-dimethylhydrazine (DMH) induce colon tumors in the Fisher 344 rat that contain mutations in Ctnnb1, the gene for b-catenin, but the pattern of mutation differs from that found in human colon cancers. in both species, mutations affect the glycogen synthase kinase 3$\beta$ (GSK-3$\beta$) consensus region of $\beta$-catenin, but whereas they directly substitute critical Ser/Thr phosphorylation sites in human colon cancers, the majority of mutations cluster around Ser$^{33}$ in the rat tumors.(omitted)

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.769-773
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• 2014

Fangchinoline (Fan) inhibits cell proliferation and induces apoptosis in several cancer cell lines. The effects of Fan on cell growth and proliferation in breast cancer cells remain to be elucidated. Here, we show that Fan inhibited cell proliferation in the MDA-MB-231 breast cancer cell line through suppression of the AKT/Gsk-3beta/cyclin D1 signaling pathway. Furthermore, Fan induced apoptosis by increasing the expression of Bax (relative to Bcl-2), active caspase 3 and cytochrome-c. Fan significantly inhibited cell proliferation of MDA-MB-231 cells in a concentration and time dependent manner as determined by MTT assay. Flow cytometry analysis demonstrated that Fan treatment of MDA-MB-231 cells resulted in cell cycle arrest at the G1 phase, which correlated with apparent downregulation of both mRNA and protein levels of both PCNA and cyclin D1. Further analysis demonstrated that Fan decreased the phosphorylation of AKT and GSK-3beta. In addition, Fan up-regulated active caspase3, cytochrome-c protein levels and the ratio of Bax/Bcl-2, accompanied by apoptosis. Taken together, these results suggest that Fan is a potential natural product for the treatment of breast cancer.

• The Journal of Korean Obstetrics and Gynecology
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• v.19 no.4
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• pp.61-76
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• 2006

Purpose : This study examined the non-toxic and the anti-oxidative effect of Dioscoreae Rhizoma on PC12 cells. Sanyak(Dioscoreae Rhizoma; chinese yam, shan yao) is well-known for its curing power for kidney, lung, spleen. Tonifies and augments the spleen and stomach. Tonifies the lung gi and augments the kidney yin. Tonifies the kidneys and also stabilizes and binds. it also binds the essence and treats spermatorrhea, frequent urination, and vaginal discharge. We are therefore interested in whether Dioscoreae Rhizoma is capable of causing abnormal apoptosis processes, and whether this condition can be rectified through Dioscoreae Rhizoma herb treatment. Methods : We used aqueous extract to treat PC12 cells with different concentrations treated with a water or a MeOH extract of Dioscoreae Rhizoma (0, x10, x20, x40, x80). The MTT (3, (4, 5-dimethyl-thiazol) 2, 5-diphenyl-tetraxolium bromide) reduction assay was employed to quantify the differences in cell activity and viability. The Bax expression level was monitored using western-blotting techniques. The patterns of the changes in expression were scanned and analyzed. Results : Bax and GSK-3${\beta}$ promotes cell death and down-regulated during the development of the PC12 cells. This is indicated that Dioscoreae Rhizoma is capable of inducing apoptosis in PC12 cells. The induced cell death and significantly inhibited by Dioscoreae Rhizoma, which can be explained by the increase in the inhibition of Bax and GSK-3${\beta}$ expression. It was also shown that Dioscoreae Rhizoma inhibits the release of $H_2O_2$ and prevents lipid peroxidation. Furthermore, the accumulation of wild type Bax protein significantly downregulated in a dose-dependent manner upon treatment with Dioscoreae Rhizoma. Conclusion : In conclusion, Dioscoreae Rhizoma can induce apoptosis via a Bax-dependent pathway or GSK-3${\beta}$ dependent pathway in PC12 cells into anti-oxidant and protective effect.

• Biomolecules & Therapeutics
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• v.23 no.2
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• pp.134-140
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• 2015

Conjugated linoleic acids (CLA) are a family of isomers of linoleic acid. CLA increases growth arrest and apoptosis of human colorectal cancer cells through an isomer-specific manner. ATF3 belongs to the ATF/CREB family of transcription factors and is associated with apoptosis in colorectal cancer. The present study was performed to investigate the molecular mechanism by which t10, c12-CLA stimulates ATF3 expression and apoptosis in human colorectal cancer cells. t10, c12-CLA increased an apoptosis in human colorectal cancer cells in dose dependent manner. t10, c12-CLA induced ATF3 mRNA and luciferase activity of ATF3 promoter in a dose-dependent manner. The responsible region for ATF3 transcriptional activation by t10, c12-CLA is located between -147 and -1850 of ATF3 promoter. mRNA stability of ATF3 was not affected by t10, c12-CLA treatment. t10, c12-CLA increases $GSK3{\beta}$ expression and suppresses IGF-1-stimulated phosphorylation of Akt. The knockdown of ATF3 suppressed expression of $GSK3{\beta}$ and NAG-1 and PARP cleavage. The results suggest that t10, c12-CLA induces apoptosis through ATF3-mediated pathway in human colorectal cancer cells.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.16
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• pp.6829-6835
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• 2014

Chemotherapy is the primary therapy for malignant lymphoma (ML). However, the clinical outcome is still far from satisfactory. Consequently, an understanding of the mechanism of modulating cancer cell invasion, migration and metastasis is important for the development of more effective chemotherapeutic agents. FNC, 2'-deoxy-2'-${\beta}$-fluoro-4'-azidocytidine, a novel cytidine analogue, has demonstrated significantly inhibitory effects on proliferation of several non-Hodgkin lymphoma (NHL) cell lines. A previous study indicated that FNC effectively inhibited the growth of Raji and JeKo-1 cells in dose-time dependent effects with $IC_{50}$ values of $0.2{\mu}M$ and $0.097{\mu}M$, respectively. This study was focused on investigating the anti-invasive properties of FNC on NHL cells and its potential mechanisms of action. Cell adhesion and transwell chamber assays were utilized to investigate the anti-invasive effects of FNC on Raji and JeKo-1 cells. Real-time PCR and Western blotting were employed to qualify the expression of ${\beta}$-catenin, the glycogen synthase kinase-3 beta (GSK-$3{\beta}$), E-cadherin vascular endothelial growth factor (VEGF), matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). The results revealed that FNC remarkably inhibited the adhesion, migration and invasion of two human aggressive non-Hodgkin lymphoma cell lines in a dose dependent manner. Furthermore, ${\beta}$-catenin, MMP-2, MMP-9, VEGF mRNA and protein levels were decreased after FNC treatment, while GSK-$3{\beta}$ and E-cadherin increased. Our studies thus provide evidence and a rationale that FNC may offer an effective chemotherapeutic agent by regulating the invasion and metastasis of aggressive non-Hodgkin lymphoma via inhibition of the Wnt/${\beta}$-catenin signaling pathway.

• Korean Journal of Medicinal Crop Science
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• v.25 no.5
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• pp.328-334
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• 2017

Background: In this study, we evaluated the anti-cancer activity and potential molecular mechanism of 70% ethanol extracts of the root of Aralia cordata var. continentalis (Kitagawa) Y. C. Chu (RAc-E70) against human colorectal cancer cells. Methods and Results: RAc-E70 suppressed the proliferation of the human colorectal cancer cell lines, HCT116 and SW480. Although RAc-E70 reduction cyclin D1 expression at the protein and mRNA levels, RAc-E70-induced reduction in cyclin D1 protein level occurred more dramatically than that of cyclin D1 mRNA. The RAc-E70-induced downregulation of cyclin D1 expression was attenuated in the presence of MG132. Additionally, RAc-E70 reduced HA-cyclin D1 levels in HCT116 cells transfected with HA-tagged wild type-cyclin D1 expression vector. RAc-E70-mediated cyclin D1 degradation was blocked in the presence of LiCl, a $GSK3{\beta}$ inhibitorbut, but not PD98059, an ERK1/2 inhibitor and SB203580, a p38 inhibitor. Furthermore, RAc-E70 phosphorylated cyclin D1 at threonine-286 (T286), and LiCl-induced $GSK3{\beta}$ inhibition reduced the RAc-E70-mediated phosphorylation of cyclin D1 at T286. Conclusions: Our results suggested that RAc-E70 may downregulate cyclin D1 expression as a potential anti-cancer target through $GSK3{\beta}$-dependent cyclin D1 degradation. Based on these findings, RAc-E70 maybe a potential candidate for the development of chemopreventive or therapeutic agents for human colorectal cancer.