• BMB Reports
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• 제55권6호
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• pp.299-304
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• 2022

Chloride channel-5 (ClC-5), an important branch of the ClC family, is involved in the regulation of the proliferation and cell-fate of a variety of cells, including tumor cells. However, its function in cholangiocarcinoma (CCA) cells remains enigmatic. Here, we discovered that ClC-5 was up-regulated in CCA tissues and CCA cell lines, while ClC-5 silencing inhibited CCA cell proliferation and induced apoptosis. Further mechanism studies revealed that ClC-5 inhibition could inhibit Wnt/β-catenin signaling activity and further activate the mitochondria apoptotic pathway in CCA cells. Furthermore, rescuing Wnt/β-catenin signaling activation eliminated the anti-tumor function of ClC-5 knockdown. Together, our research findings illustrated that ClC-5 inhibition plays an anti-tumor role in CCA cells via inhibiting the activity of the Wnt/β-catenin pathway, which in turn activates the mitochondrial apoptotic pathway.

• The Korean Journal of Physiology and Pharmacology
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• 제17권5호
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• pp.447-453
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• 2013

Osteoblastic activity of nectandrin A was examined in C2C12 cells. Nectandrin A enhances the BMP-induced osteoblastic differentiation and mineralization, manifested by the up-regulation of differentiation markers (alkaline phosphatase and osteogenic genes) and increased calcium contents. In C2C12 cells co-transfected with expression vector encoding Smad4 and Id1-Luc reporter, nectandrin A increased Id1 luciferase activity in a concentration-dependent manner, when compared to that in BMP-2 treated cells, indicating that Smad signaling pathway is associated with nectandrin A-enhanced osteoblastic differentiation in C2C12 cells. In addition, nectandrin A activated p38 mitogen-activated protein kinase (MAPK) in time- and concentration-dependent manners, and phosphorylated form of pSmad1/5/8 and alkaline phosphatase activity were both decreased when the cells were pretreated with SB203580, a p38 MAPK inhibitor, suggesting that p38 MAPK might be an upstream kinase for Smad signaling pathway. Taken together, nectandrin A enhances the BMP-induced osteoblastic differentiation and mineralization of C2C12 cells via activation of p38 MAPK-Smad signaling pathway, and it has a therapeutic potential for osteoporosis by promoting bone formation.

• BMB Reports
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• 제52권5호
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• pp.336-341
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• 2019

The cGAS-STING pathway plays an important role in pathogen-induced activation of the innate immune response. The 29-kDa amino-terminal fibronectin fragment (29-kDa FN-f) found predominantly in the synovial fluid of osteoarthritis (OA) patients increases the expression of catabolic factors via the toll-like receptor-2 (TLR-2) signaling pathway. In this study, we investigated whether 29-kDa FN-f induces inflammatory responses via the cyclic GMP-AMP synthase (cGAS)/stimulator of interferon gene (STING) pathway in human primary chondrocytes. The levels of cGAS and STING were elevated in OA cartilage compared with normal cartilage. Long-term treatment of chondrocytes with 29-kDa FN-f activated the cGAS/STING pathway together with the increased level of gamma-H2AX, a marker of DNA breaks. In addition, the expression of pro-inflammatory cytokines, including granulocyte-macrophage colony-stimulating factor (GM-CSF/CSF-2), granulocyte colony-stimulating factor (G-CSF/CSF-3), and type I interferon ($IFN-{\alpha}$), was increased more than 100-fold in 29-kDa FN-f-treated chondrocytes. However, knockdown of cGAS and STING suppressed 29-kDa FN-f-induced expression of GM-CSF, G-CSF, and $IFN-{\alpha}$ together with the decreased activation of TANK-binding kinase 1 (TBK1), interferon regulatory factor 3 (IRF3), and inhibitor protein ${\kappa}B{\alpha}$ ($I{\kappa}B{\alpha}$). Furthermore, NOD2 or TLR-2 knockdown suppressed the expression of GM-CSF, G-CSF, and $IFN-{\alpha}$ as well as decreased the activation of the cGAS/STING pathway in 29-kDa FN-f-treated chondrocytes. These data demonstrate that the cGAS/STING/TBK1/IRF3 pathway plays a critical role in 29-kDa FN-f-induced expression of pro-inflammatory cytokines.

• The Korean Journal of Physiology and Pharmacology
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• 제16권3호
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• pp.211-217
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• 2012

Recent studies have demonstrated that nitric oxide (NO) activates transient receptor potential vanilloid subtype 1 (TRPV1) via S-nitrosylation of the channel protein. NO also modulates various cellular functions via activation of the soluble guanylyl cyclase (sGC)/protein kinase G (PKG) pathway and the direct modification of proteins. Thus, in the present study, we investigated whether NO could indirectly modulate the activity of TRPV1 via a cGMP/PKG-dependent pathway in cultured rat dorsal root ganglion (DRG) neurons. NO donors, sodium nitroprusside (SNP) and S-nitro-N-acetylpenicillamine (SNAP), decreased capsaicin-evoked currents ($I_{cap}$). NO scavengers, hemoglobin and 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (CPTIO), prevented the inhibitory effect of SNP on $I_{cap}$. Membrane-permeable cGMP analogs, 8-bromoguanosine 3', 5'-cyclic monophosphate (8bromo-cGMP) and 8-(4chlorophenylthio)-guanosine 3',5'-cyclic monophosphate (8-pCPT-cGMP), and the guanylyl cyclase stimulator YC-1 mimicked the effect of SNP on $I_{cap}$. The PKG inhibitor KT5823 prevented the inhibition of $I_{cap}$ by SNP. These results suggest that NO can downregulate the function of TRPV1 through activation of the cGMP/PKG pathway in peripheral sensory neurons.

• Biomolecules & Therapeutics
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• 제24권6호
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• pp.623-629
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• 2016

(1S,2S,3E,7E,11E)-3,7,11,15-cembratetraen-17,2-olide (LS-1), a marine cembrenolide diterpene, has anticancer activity against colon cancer cells such as HT-29, SNU-C5/5-FU (fluorouracil-resistant SNU-C5) and SNU-C5. However, the action mechanism of LS-1 on SNU-C5 human colon cancer cells has not been fully elucidated. In this study, we investigated whether the anticancer effect of LS-1could result from apoptosis via the modulation of $Wnt/{\beta}$-catenin and the TGF-${\beta}$ pathways. When treated with the LS-1, we could observe the apoptotic characteristics such as apoptotic bodies and the increase of sub-G1 hypodiploid cell population, increase of Bax level, decrease of Bcl-2 expression, cleavage of procaspase-3 and cleavage of poly (ADP-ribose) polymerase in SNU-C5 cells. Furthermore, the apoptosis induction of SNU-C5 cells upon LS-1 treatment was also accompanied by the down-regulation of $Wnt/{\beta}$-catenin signaling pathway via the decrease of GSK-$3{\beta}$ phosphorylation followed by the decrease of ${\beta}$-catenin level. In addition, the LS-1 induced the activation of TGF-${\beta}$ signaling pathway with the decrease of carcinoembryonic antigen which leads to decrease of c-Myc, an oncoprotein. These data suggest that the LS-1 could induce the apoptosis via the down-regulation of $Wnt/{\beta}$-catenin pathway and the activation of TGF-${\beta}$ pathway in SNU-C5 human colon cancer cells. The results support that the LS-1 might have potential for the treatment of human colon cancer.

• 유기물자원화
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• 제5권1호
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• pp.63-69
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• 1997

5-Aminolevulinic acid (ALA) 생합성의 $C_5$ 경로의 전구물질인 L-glutamic acid가 Rhodospirillum rubrum N-1 새포내에서 ALA 생산의 역할을 검토하였다. Lascelles의 기본배지에 L-glutamic acid와 levulinic acid (LA)를 각각 30, 20 mM 첨가배양으로써 균체외 ALA 생산성이 40배 증가(76 mg/l)하였다. 한편 $C_4$ 경로의 기질인 glycine과 succinic acid를 대수기 중기에 각각 60 mM 첨가함으로써, 균의 증식은 억제되었으나 균체외의 ALA는 52 mg/l에 달하였다.

• 한국미생물·생명공학회지
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• 제21권6호
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• pp.527-533
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• 1993

Aminolevulinic acid(ALA) was shown to be synthesized via active pathways of either C4 or C5 ALA biosynthesis in cells of a photosynthetic bacterium, Rhodocyclus gelatinosus KUP-74, where the C5 pathway was appeared to be preferntially expressed in the cells. It was strongly suggested that L-glutamine might be utilized more effectively than L-glutamate to synthesize ALA via C5 pathway in this bacterium from the fact of relationship between the cellular uptake rates of glutamate and its Gamma-derivaties and corresponded ALA productivities in vitro and in vivo.

• IMMUNE NETWORK
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• 제21권5호
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• pp.36.1-36.16
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• 2021

Peroxiredoxins (Prxs) are ubiquitously expressed peroxidases that reduce hydrogen peroxide or alkyl peroxide production in cells. Prxs are released from cells in response to various stress conditions, and they function as damage-associated molecular pattern molecules. However, the secretory mechanism of Prxs and their roles have not been elucidated. Thus, we aimed to determine whether inflammasome activation is a secretory mechanism of Prxs and subsequently identify the effect of the secreted Prxs on activation of the classical complement pathway. Using J774A.1, a murine macrophage cell line, we demonstrated that NLRP3 inflammasome activation induces Prx1, Prx2, Prx5, and Prx6 secretion in a caspase-1 dependent manner. Using HEK293T cells with a transfection system, we revealed that the release of Prx1 and Prx2 relies on gasdermin-D (GSDMD)-mediated secretion. Next, we confirmed the binding of both Prx1 and Prx2 to C1q; however, only Prx2 could induce the C1q-mediated classical complement pathway activation. Collectively, our results suggest that inflammasome activation is a secretory mechanism of Prxs and that GSDMD is a mediator of their secretion. Moreover, secreted Prx1 and Prx2 bind with C1q, but only Prx2 mediates the classical complement pathway activation.

• Journal of Microbiology and Biotechnology
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• 제8권1호
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• pp.96-100
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• 1998

Pseudomonas sp. S-47 degraded 4-chlorobenzoate (4CBA) to 4-chlorocatechol (4CC) that was subsequently ring-cleaved to form 5-chloro-2-hydroxymuconic semialdehyde. These intermediate compounds were identified by GC-mass spectrometry and UV-visible spectrophotometry. 5-chloro-2-hydroxymuconic acid converted from 5-chloro-2- hydroxymuconic semialdehyde (5C-2HMS) was dechlorinated to produce 2-hydroxypenta-2,4-dienoic acid (2HP-2,4DA) by the strain. These results indicate that Pseudomonas sp. S-47 degrades 4CBA to 2HP-2,4DA via a novel pathway including the meta-cleavage of 4CC and dechlorination of 5C-2HMS.

• Nutrition Research and Practice
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• 제18권5호
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• pp.587-601
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• 2024

BACKGROUND/OBJECTIVES: UV radiation is a major factor contributing to DNA damage in skin cells, including stem cells and mesenchymal stem cells, leading to the depletion of these crucial cells. This study examined whether a mixture of Indian gooseberry and barley sprout (IB) could inhibit UVB irradiation and 3-isobutyl-1-methylxanthine (IBMX)-induced photoaging and oxidative stress in the skin using HaCaT, Hs27, and B16F10 cells. MATERIALS/METHODS: The moisturizing-related factors, the collagen synthesis-related c-Jun N-terminal kinase (JNK)/c-Fos/c-Jun/matrix metalloproteinases (MMPs) pathway, and the melanogenesis-related cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)/cAMP-responsive binding protein (CREB)/melanocyte inducing transcription factor (MITF)/tyrosinase-related protein (TRP)/tyrosinase activation pathways were analyzed in vitro by an enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and Western blot analysis. RESULTS: The IB complex increased the hyaluronic acid and sphingomyelin levels and the collagenase inhibitory activity, enhanced hydration-related factors, including collagen, hyaluronic acid synthase (HAS), elastin, long chain base subunit 1 (LCB1) (serine palmitoyltransferase; SPT), and delta 4-desaturase sphingolipid 1 (DEGS1), modulated the inflammatory cytokines levels, antioxidant enzyme activities and the NF-κB/MMPs/cyclooxygenase-2 (COX-2) pathway in UVB-irradiated HaCaT cells, and inhibited wrinkle formation by down-regulation of the JNK/c-Fos/c-Jun/MMP pathway and up-regulation of the transforming growth factor-𝛽 receptor I (TGF𝛽R1)/small mothers against decapentaplegic homolog (Smad3)/procollagen type I pathway in UVB-irradiated Hs27 cells. Moreover, the IB complex prevented melanin production by down-regulating the PKA/CREB/MITF/TRP-1/TRP-2 pathway in IBMX-induced B16F10 cells. CONCLUSION: These findings suggest that the IB complex has the potential to serve as a safeguard, shielding the skin from UVB radiation-induced photo-damage.