• Title/Summary/Keyword: mediated inhibition

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Ginsenoside Rg1 attenuates cerebral ischemia-reperfusion injury due to inhibition of NOX2-mediated calcium homeostasis dysregulation in mice

  • Han, Yuli;Li, Xuewang;Yang, Liu;Zhang, Duoduo;Li, Lan;Dong, Xianan;Li, Yan;Qun, Sen;Li, Weizu
    • Journal of Ginseng Research
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    • v.46 no.4
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    • pp.515-525
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    • 2022
  • Background: The incidence of ischemic cerebrovascular disease is increasing in recent years and has been one of the leading causes of neurological dysfunction and death. Ginsenoside Rg1 has been found to protect against neuronal damage in many neurodegenerative diseases. However, the effect and mechanism by which Rg1 protects against cerebral ischemia-reperfusion injury (CIRI) are not fully understood. Here, we report the neuroprotective effects of Rg1 treatment on CIRI and its possible mechanisms in mice. Methods: A bilateral common carotid artery ligation was used to establish a chronic CIRI model in mice. HT22 cells were treated with Rg1 after OGD/R to study its effect on [Ca2+]i. The open-field test and poleclimbing experiment were used to detect behavioral injury. The laser speckle blood flowmeter was used to measure brain blood flow. The Nissl and H&E staining were used to examine the neuronal damage. The Western blotting was used to examine MAP2, PSD95, Tau, p-Tau, NOX2, PLC, p-PLC, CN, NFAT1, and NLRP1 expression. Calcium imaging was used to test the level of [Ca2+]i. Results: Rg1 treatment significantly improved cerebral blood flow, locomotion, and limb coordination, reduced ROS production, increased MAP2 and PSD95 expression, and decreased p-Tau, NOX2, p-PLC, CN, NFAT1, and NLRP1 expression. Calcium imaging results showed that Rg1 could inhibit calcium overload and resist the imbalance of calcium homeostasis after OGD/R in HT22 cells. Conclusion: Rg1 plays a neuroprotective role in attenuating CIRI by inhibiting oxidative stress, calcium overload, and neuroinflammation.

EID3 Promotes Glioma Cell Proliferation and Survival by Inactivating AMPKα1

  • Xiang, Yaoxian;Zhu, Lei;He, Zijian;Xu, Lei;Mao, Yuhang;Jiang, Junjian;Xu, Jianguang
    • Journal of Korean Neurosurgical Society
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    • v.65 no.6
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    • pp.790-800
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    • 2022
  • Objective : EID3 (EP300-interacting inhibitor of differentiation) was identified as a novel member of EID family and plays a pivotal role in colorectal cancer development. However, its role in glioma remained elusive. In current study, we identified EID3 as a novel oncogenic molecule in human glioma and is critical for glioma cell survival, proliferation and invasion. Methods : A total of five patients with glioma were recruited in present study and fresh glioma samples were removed from patients. Four weeks old male non-obese diabetic severe combined immune deficiency (NOD/SCID) mice were used as transplant recipient models. The subcutaneous tumor size was calculated and recorded every week with vernier caliper. EID3 and AMP-activated protein kinase α1 (AMPKα1) expression levels were confirmed by real-time polymerase chain reaction and Western blot assays. Colony formation assays were performed to evaluate cell proliferation. Methyl thiazolyl tetrazolium (MTT) assays were performed for cell viability assessment. Trypan blue staining approach was applied for cell death assessment. Cell Apoptosis DNA ELISA Detection Kit was used for apoptosis assessment. Results : EID3 was preferentially expressed in glioma tissues/cells, while undetectable in astrocytes, neuronal cells, or normal brain tissues. EID3 knocking down significantly hindered glioma cell proliferation and invasion, as well as induced reduction of cell viability, apoptosis and cell death. EID3 knocking down also greatly inhibited tumor growth in SCID mice. Knocking down of AMPKα1 could effectively rescue glioma cells from apoptosis and cell death caused by EID3 absence, indicating that AMPKα1 acted as a key downstream regulator of EID3 and mediated suppression effects caused by EID3 knocking down inhibition. These findings were confirmed in glioma cells generated patient-derived xenograft models. AMPKα1 protein levels were affected by MG132 treatment in glioma, which suggested EID3 might down regulate AMPKα1 through protein degradation. Conclusion : Collectively, our study demonstrated that EID3 promoted glioma cell proliferation and survival by inhibiting AMPKα1 expression. Targeting EID3 might represent a promising strategy for treating glioma.

Recent Studies on Natural Products that Improve Browning (Browning 촉진에 관여하는 최근 천연물의 동향)

  • Lee, Eunbi;Nam, Ju-Ock
    • Journal of Life Science
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    • v.31 no.11
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    • pp.1037-1045
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    • 2021
  • The prevalence of obesity is increasing worldwide, and since obesity is associated with dietary factors and sedentary lifestyles, it is a disease that is readily developing in the modern population. Because obesity is accompanied by serious complications such as diabetes and cardiovascular disease, prevention and treatment are important. Currently, drugs such as liraglutide and phentermine are used to treat obesity by suppressing appetite and inducing gastrointestinal motility delay. However, various side effects may occur, including thyroid cancer, cardiovascular problems, and central nervous system disorders. Therefore, to explore an obesity treatment method with relatively few side effects, a method known as "fat browning" was introduced to change white adipose tissue into brown adipose tissue to increase energy consumption. Ongoing studies are attempting to find effective natural substances to safely induce browning. Many natural substances have been identified. The induction of browning by treatment with natural substances generally involves three mechanisms: positive control of browning-inducing factors, inhibition of differentiation into white adipose tissue, and the activation of mechanisms related to browning. In this study, we describe plant extracts with known browning-inducing effects, such as strawberry, black raspberry, cinnamomum cassia, and Ecklonia stolonifera extracts. We also summarize the underlying mechanisms of action identified thus far, including the signaling pathway mediated by these extracts to induce browning. Furthermore, the effects of brown adipose tissue generated through browning on heart disease as an endocrine organ disruptor are discussed.

Effects of β-Asarone on Pro-Inflammatory Cytokines and Learning and Memory Impairment in Lipopolysaccharide-Treated Mice (β-Asarone이 Lipopolysaccharide에 의한 생쥐 해마의 염증성 사이토카인 발현과 학습 및 기억 장애에 미치는 영향)

  • Choi, Moon-Sook;Kwak, Hee-Jun;Kweon, Ki-Jung;Hwang, Ji-Mo;Shin, Jung-Won;Sohn, Nak-Won
    • The Korea Journal of Herbology
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    • v.28 no.6
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    • pp.119-127
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    • 2013
  • Objectives : ${\beta}$-Asarone (BAS) is an active ingredient in Acori Rhizoma. This study investigated anti-neuroinflammatory and memory ameliorating effects of BAS in systemic lipopolysaccharide (LPS)-treated C57BL/6 mice. Methods : BAS was administered orally at doses of 7.5, 15, and 30 mg/kg for 3 days prior to LPS (3 mg/kg, intraperitoneal) injection. Pro-inflammatory cytokine mRNA, including tumor necrosis factor-${\alpha}$ (TNF-ㅍ), interleukin (IL)-$1{\beta}$ and IL-6, was measured in hippocampus tissue using real-time polymerase chain reaction at 4 h after the LPS injection. An ameliorating effect of 30 mg/kg BAS on learning and memory impairment in the LPS-treated mice was verified using the Morris water maze test. Results : BAS significantly attenuated up-regulation of TNF-${\alpha}$, IL-$1{\beta}$, and IL-6 mRNA in hippocampus tissue of the LPS-treated mice. In acquisition training test, BAS improved learning performance of the LPS-treated mice with a significant decrease of escape latency to the platform. In memory retention test, BAS also ameliorated memory impairment of the LPS-treated mice with a significant increase of swimming time in zones neighboring to the platform, number of target heading, and memory score. Conclusion : The results suggest that inhibition of pro-inflammatory cytokines and neuroinflammation in the hippocampus by BAS could be one of the mechanisms for BAS-mediated ameliorating effect on learning and memory impairment in LPS-treated mice.

Involvement of Multiple Signaling Molecules in Peptidoglycan-induced Expression of Interleukin-1α in THP-1 Monocytes/Macrophages (THP-1 단핵구의 펩티도글리칸 유래 인터루킨-1 알파 발현에서 TLR2, PI3K/Akt/mTOR, MAPKs의 역할)

  • Heo, Weon;Son, Yonghae;Cho, Hyok-rae;Kim, Koanhoi
    • Journal of Life Science
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    • v.32 no.6
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    • pp.421-429
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    • 2022
  • The expression of interleukin-1α (IL-1α) is elevated in monocytic cells, such as monocytes and macro-phages, within atherosclerotic arteries, yet the cellular molecules involved in cytokine upregulation remain unclear. Because peptidoglycan (PG), a major component of gram-positive bacterial cell walls, is detected within the inflammatory cell-rich regions of atheromatous plaques, it was investigated if PG contributes to IL-1α expression in monocytes/macrophages. Exposure of THP-1 monocytic cells to PG resulted in elevated levels of IL-1α gene transcripts and increased secretion of IL-1α protein. The transcription and secretion of IL-1α were abrogated by OxPAPC, an inhibitor of TLR2/4, but not by polymyxin B that inhibits lipopolysaccharide-induced TLR4 activation. To understand the molecular mechanisms of the inflammatory responses due to bacterial pathogen-associated molecular patterns (PAMPs) in diseased arteries, we attempted to determine the cellular factors involved in the PG-induced upregulation of IL-1α expression. Pharmacological inhibition of cell signaling pathways with LY294002 (a PI3K inhibitor), Akti IV (an inhibitor of Akt activation), rapamycin (an mTOR inhibitor), U0126 (a MEK inhibitor), SB202190 (a p38 MAPK inhibitor), SP6001250 (a JNK inhibitor), and DPI (a NOX inhibitor) also significantly attenuated the PG-mediated expression of IL-1α. These results suggest that PG induces the monocytic or macrophagic expression of IL-1α, thereby contributing to vascular inflammation, via multiple signaling molecules, including TLR2, PI3K/Akt/mTOR, and MAPKs.

Regulation of Blastocyst Differentiation by the Serial Exposure of Conconavalin A and $PGE_2$ (Concanavalin A와 $PGE_2$의 순차적 노출에 의한 포배의 분화 조절)

  • Cheon, Yong Pil
    • Development and Reproduction
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    • v.12 no.3
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    • pp.267-274
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    • 2008
  • Differentiation of blastocyst is critical step for implantation and is under the control of regulation factors originated from embryo or reproductive tracts. The sequential communication with those factors is suspected as critical events for differentiation. It has been suggested that intracellular signaling pathways activated by calcium is essential in differentiation of blastocyst. Previously, it was known that concanavalin A (Con A) increase the levels of free calcium in blastocyst stage. However, Con A can not accelerate the hatching, although heparin-binding epidermal growth factor-like growth factor (HB-EGF), a modulator of calcium level, accelerate the hatching of blastocyst. In this study, it was investigated whether Con A or prostaglandin $E_2$ ($PGE_2$) can modulate the differentiation of blastocyst. Con A accelerated the expansion of blastocyst in both 1 hr pulse treatment group and continuous treatment group. However, Con A significantly suppressed the hatching in both groups. The inhibition was significantly strong in continuous treatment group compared with 1 hr pulse treatment group. On the other hand, $PGE_2$ induced the increase the free calcium level, but did not accelerate the expansion. In addition $10{\mu}m\;PGE_2$ inhibited hatching. However, $PGE_2$ could accelerate hatching in Con A pretreated blastocyst. $PGE_2$ also caused the increase of free calcium level in Con A pretreated blastocyst. From these results, it is suggested that changes of the free calcium level induce a different calcium-mediated signaling pathways. In addition, sequential stimulation by signal molecules may triggers the cellular mechanisms for the differentiation of blastocyst.

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Desmarestia tabacoides Ameliorates Lipopolysaccharide-induced Inflammatory Responses via Attenuated TLR4/MAPKs/NF-κB Signaling Cascade in RAW264.7 Cells (RAW 264.7 세포에서 담배잎산말의 TLR4/MAPKs/NF-κB 신호전달체계 조절을 통한 항염증 효과)

  • Hyun-Seo Yoon;Hyun An;Chung Mu Park
    • Journal of Life Science
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    • v.33 no.6
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    • pp.463-470
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    • 2023
  • Desmarestia tabacoides Okamura is a brown macroalgae that is found worldwide. Although several genera of Desmarestia have been reported as having anti-tumorigenic, anti-melanogenic, and photoprotective properties, the anti-inflammatory activity of D. tabacoides Okamura has not yet been evaluated. In this study, we analyzed the anti-inflammatory mechanisms of D. tabacoides Okamura ethanol extract (DTEE) via the inhibition of nitric oxide (NO) and prostaglandin (PG) E2 production and the expression of their corresponding enzymes, inducible NO synthase (iNOS), and cyclooxygenase (COX)-2. In addition, their upstream signaling molecules were evaluated by Western blot analysis, such as nuclear factor (NF)-κB, mitogen-activated protein kinase (MAPK), and phosphoinositide-3-kinase (PI3K)/Akt, in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. The DTEE treatment significantly inhibited LPS-induced NO and PGE2 production as well as the expression of their corresponding enzymes, iNOS, and COX-2 without cytotoxicity. The stimulated transcription factor NF-κB and upstream signaling molecules extracellular signal-regulated kinase (ERK), c-Jun NH2-terminal kinase (JNK), and p38 were attenuated by the DTEE treatment, which was statistically significant, while Akt did not provide any inhibitory effect. Moreover, the DTEE treatment significantly mitigated the LPS-activated adaptor molecules, toll-like receptor 4 (TLR4), and myeloid differentiation primary response 88 (MyD88) in the RAW 264.7 cells. These results suggest that DTEE attenuates TLR4-mediated inflammatory responses by inhibiting NF-κB activation and suppressing MAPK phosphorylation in LPS-stimulated RAW 264.7 cells.

Antioxidant and anti-inflammatory activities of Lespedeza cuneata in Coal fly ash-induced murine alveolar macrophage cells

  • Abdul Wahab;Hwayong Sim;Kyubin Choi;Yejin Kim;Yookyeong Lee;Byungwook Kang;Yu Seong No;Dongyeop Lee;Inseo Lee;Jaehyeon Lee;Hwajun Cha;Sung Dae Kim;Evelyn Saba;Man Hee Rhee
    • Korean Journal of Veterinary Research
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    • v.63 no.3
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    • pp.27.1-27.9
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    • 2023
  • Lespedeza cuneata (LC) is a perennial plant used in herbal medicine to treat numerous diseases, including prostatic hyperplasia, diabetes, early atherosclerosis, and hematuria. Reference collections of bioactive compounds of LC are crucial for the determination of their pharmacological properties. However, little is known regarding its anti-oxidative and anti-inflammatory effects in alveolar macrophage (MH-S) cells. This study examined whether LC can inhibit reactive oxygen species and Coal fly ash (CFA) induced inflammation in MH-S cells. The anti-oxidative effects of LC were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays, anti-inflammatory effects were examined using nitric oxide (NO) assay, and cytotoxicity was analyzed using methyl thiazolyl tetrazolium assay. The expression of inflammatory cytokine genes was assessed through a reverse-transcription polymerase chain reaction. Our results revealed that LC exhibited high radical scavenging activity and a dose-dependent (7.8-1,000 ㎍/mL) inhibition of oxidation as compared to ascorbic acid and Trolox. It also inhibited CFA-induced NO production in MH-S cells. Moreover, it suppressed the CFA exposure-mediated expression of pro-inflammatory mediators and cytokines, including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin (IL)-1β, IL-6, and tumor necrosis factor-α. These results suggest that LC is a potent antioxidant and anti-inflammatory agent that can be useful as a nutraceutical product.

Rg3-enriched red ginseng extracts enhance apoptosis in CoCl2-stimulated breast cancer cells by suppressing autophagy

  • Yun-Jeong Jeong;Mi-Hee Yu;Yuna Cho;Min-Young Jo;Kwon-Ho Song;Yung Hyun Choi;Taeg Kyu Kwon;Jong-Young Kwak;Young-Chae Chang
    • Journal of Ginseng Research
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    • v.48 no.1
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    • pp.31-39
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    • 2024
  • Background: Ginsenoside Rg3, a primary bioactive component of red ginseng, has anti-cancer effects. However, the effects of Rg3-enriched ginseng extract (Rg3RGE) on apoptosis and autophagy in breast cancer have not yet been investigated. In the present study, we explored the anti-tumor effects of Rg3RGE on breast cancer cells stimulated CoCl2, a mimetic of the chronic hypoxic response, and determined the operative mechanisms of action. Methods: The inhibitory mechanisms of Rg3RGE on breast cancer cells, such as apoptosis, autophagy and ROS levels, were detected both in vitro. To determine the anti-cancer effects of Rg3RGE in vivo, the cancer xenograft model was used. Results: Rg3RGE suppressed CoCl2-induced spheroid formation and cell viability in 3D culture of breast cancer cells. Rg3RGE promoted apoptosis by increasing cleaved caspase 3 and cleaved PARP and decreasing Bcl2 under the hypoxia mimetic conditions. Further, we identified that Rg3RGE promoted apoptosis by inhibiting lysosomal degradation of autophagosome contents in CoCl2-induced autophagy. We further identified that Rg3RGE-induced apoptotic cell death and autophagy inhibition was mediated by increased intracellular ROS levels. Similarly, in the in vivo xenograft model, Rg3RGE induced apoptosis and inhibited cell proliferation and autophagy. Conclusion: Rg3RGE-stimulated ROS production promotes apoptosis and inhibits protective autophagy under hypoxic conditions. Autophagosome accumulation is critical to the apoptotic effects of Rg3RGE. The in vivo findings also demonstrate that Rg3RGE inhibits breast cancer cell growth, suggesting that Rg3RGE has potential as potential as a putative breast cancer therapeutic.

C-reactive protein accelerates DRP1-mediated mitochondrial fission by modulating ERK1/2-YAP signaling in cardiomyocytes

  • Suyeon Jin;Chan Joo Lee;Gibbeum Lim;Sungha Park;Sang-Hak Lee;Ji Hyung Chung;Jaewon Oh;Seok-Min Kang
    • BMB Reports
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    • v.56 no.12
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    • pp.663-668
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    • 2023
  • C-reactive protein (CRP) is an inflammatory marker and risk factor for atherosclerosis and cardiovascular diseases. However, the mechanism through which CRP induces myocardial damage remains unclear. This study aimed to determine how CRP damages cardiomyocytes via the change of mitochondrial dynamics and whether survivin, an anti-apoptotic protein, exerts a cardioprotective effect in this process. We treated H9c2 cardiomyocytes with CRP and found increased intracellular ROS production and shortened mitochondrial length. CRP treatment phosphorylated ERK1/2 and promoted increased expression, phosphorylation, and translocation of DRP1, a mitochondrial fission-related protein, from the cytoplasm to the mitochondria. The expression of mitophagy proteins PINK1 and PARK2 was also increased by CRP. YAP, a transcriptional regulator of PINK1 and PARK2, was also increased by CRP. Knockdown of YAP prevented CRP-induced increases in DRP1, PINK1, and PARK2. Furthermore, CRP-induced changes in the expression of DRP1 and increases in YAP, PINK1, and PARK2 were inhibited by ERK1/2 inhibition, suggesting that ERK1/2 signaling is involved in CRP-induced mitochondrial fission. We treated H9c2 cardiomyocytes with a recombinant TAT-survivin protein before CRP treatment, which reduced CRP-induced ROS accumulation and reduced mitochondrial fission. CRP-induced activation of ERK1/2 and increases in the expression and activity of YAP and its downstream mitochondrial proteins were inhibited by TAT-survivin. This study shows that mitochondrial fission occurs during CRP-induced cardiomyocyte damage and that the ERK1/2-YAP axis is involved in this process, and identifies that survivin alters these mechanisms to prevent CRP-induced mitochondrial damage.