• Molecules and Cells
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• 제37권8호
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• pp.598-604
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• 2014

Fatty acids, important components of a normal diet, have been reported to play a role in bone metabolism. Osteoclasts are bone-resorbing cells that are responsible for many bone-destructive diseases such as osteoporosis. In this study, we investigated the impact of a medium-chain fatty acid, capric acid, on the osteoclast differentiation, function, and survival induced by receptor activator of NF-${\kappa}B$ ligand (RANKL) and macrophage colony-stimulating factor (M-CSF). Capric acid inhibited RANKL-mediated osteoclastogenesis in bone marrow-derived macrophages and suppressed RANKL-induced $I{\kappa}B{\alpha}$ phosphorylation, p65 nuclear translocation, and NF-${\kappa}B$ transcriptional activity. Capric acid further blocked the RANKL-stimulated activation of ERK without affecting JNK or p38. The induction of NFATc1 in response to RANKL was also attenuated by capric acid. In addition, capric acid abrogated M-CSF and RANKL-mediated cytoskeleton reorganization, which is crucial for the efficient bone resorption of osteoclasts. Capric acid also increased apoptosis in mature osteoclasts through the induction of Bim expression and the suppression of ERK activation by M-CSF. Together, our results reveal that capric acid has inhibitory effects on osteoclast development. We therefore suggest that capric acid may have potential therapeutic implications for the treatment of bone resorption-associated disorders.

• Biomolecules & Therapeutics
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• 제20권1호
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• pp.57-61
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• 2012

The matrix metalloproteinase (MMP) family is involved in the breakdown of the extracellular matrix during normal physiological processes such as embryonic development, reproduction, and tissue remodeling, as well as in disease processes such as pathological aging, arthritis, and metastasis. Oxidative conditions generate reactive oxygen species (ROS) (e.g., hydrogen peroxide [$H_2O_2$]) in cells, which subsequently induce the synthesis of matrix metalloproteinase-1 (MMP-1). MMP-1, an interstitial collagenase, in turn stimulates an aging phenomenon. In this study, baicalein (5,6,7-trihydroxyfl avone) was investigated for its in vitro activity against $H_2O_2$-induced damage using a human skin keratinocyte model. Baicalein pretreatment signifi cantly inhibited $H_2O_2$-induced up-regulation of MMP-1 mRNA, MMP-1 protein expression and MMP-1 activity in cultured HaCaT keratinocytes. In addition, baicalein decreased the transcriptional activity of activator protein-1 (AP-1) and the expression of c-Fos and c-Jun, both components of the heterodimeric AP-1 transcription factor. Furthermore, baicalein reduced phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun-N-terminal kinase (JNK), which are upstream of the AP-1 transcription factor. The results of this study suggest that baicalein is involved in the inhibition of oxidative stress-induced expression of MMP-1 via inactivation of the ERK/JNK/AP-1 signaling pathway.

• 한국축산식품학회지
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• 제32권3호
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• pp.364-368
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• 2012

유청단백질의 일종인 lactoferrin은 이미 많은 보고에 의해서 여러 가지 생리활성기능이 있는 것으로 밝혀지고 있는데, U937, NK92, 수지상세포의 분화된 상태인 mutz-3와 muDC를 이용하여 과민반응과 천식, 면역 관련 유전자의 발현에 미치는 영향을 조사 한 결과 의미 있는 결과를 도출하였다. Lactoferrin 단독 또는 면역증강물질인 PMA와 혼합하여 처리 한 경우 상승효과 작용으로 과민반응과 천식, 면역 관련 유전자의 발현을 강하게 유도하였다. 이는 유청단백질의 주요 성분 중 하나인 lactoferrin이 면역기전에 중요한 역할을 하고 있다는 결과로 사료된다.

• 한국해양바이오학회지
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• 제6권2호
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• pp.102-109
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• 2014

Cetaceans (whales, dolphins, and porpoises) are aquatic mammals that experienced drastic changes during the transition from terrestrial to aquatic environment. Morphological changes include streamlined body, alterations in the face, transformation of the forelimbs into flippers, disappearance of the hindlimbs and the acquisition of flukes on the tail. For a prolonged diving, cetaceans acquired hypoxia-resistance by developing various anatomical and physiological changes. However, molecular mechanisms underlying these adaptations are still limited. CREB-binding protein (CREBBP) is a transcriptional co-activator critical for embryonic development, growth control, metabolic homeostasis and responses to hypoxia. Natural selection analysis of five cetacean CREBBPs compared with those from 15 terrestrial relatives revealed strong purifying selection, supporting the importance of its role in mammals. However, prediction for amino acid changes that elicit functional difference of CREBBP identified three cetacean specific changes localized within a region required for interaction with SRCAP and in proximal regions to KIX domain of CREBBP. Mutations in CREBBP or SRCAP are known to cause craniofacial and skeletal defects in human, and KIX domain of CREBBP serves as a docking site for transcription factors including c-Myb, an essential regulator of haematopoiesis. In these respects, our study provides interesting insights into the functional adaptation of cetacean CREBBP for aquatic lifestyle.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2007년도 Proceedings of The Convention
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• pp.153-158
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• 2007

Background: Naturally occurring antioxidants were used to regulate the skin damage caused by ultraviolet (UV) radiation because several antioxidants have demonstrated that they can inhibit wrinkle formation through prevention of matrix metalloproteinases (MMPs) and/or increase of collagen synthesis. We examined the effect of oral administration of the antioxidant mixture ("L-Skin Care") on UVB-induced wrinkle formation. In addition, we investigated the possible molecular mechanisms of photoprotection against UVB through inhibition of collagen-degrading MMP activity or through enhancing of pro collagen synthesis in mouse dorsal skin. Methods: Female SKH-l hairless mice were orally administrated "L-Skin Care" (test group) or vehicle (control group) for 10 weeks with UVB irradiation by three times a week. The intensity of irradiation was gradually increased from 30 to $180mJ/cm^2$. Microtopographic and histological assessments of the dorsal skins were carried out at the end of 10 weeks to evaluate wrinkle formation. Western blot analysis and EMSA were also carried out to investigate the changes in the balance of collagen synthesis and collagen degradation. Results: Our "L-Skin Care" significantly reduced UVB-induced wrinkle formation, accompanied by significant reduction of epidermal thickness, and UVB-induced hyperplasia, acanthosis and hyperkeratosis. Oral administration of "L-Skin Care" significantly prevented UVB-induced expressions of MMPs, mitogen-activated protein (MAP) kinases and activation of activator protein (AP)-1 transcriptional factor in addition to enhanced type I procollagen and transforming growth factor-$\beta$ (TGF-$\beta$) expression. Conclusion: Oral administration of "L-Skin Care" significantly inhibited wrinkle formation caused by chronic UVB irradiation through significant inhibition of UVB-induced MMP activity accompanied with enhancement of collagen synthesis.

• Molecules and Cells
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• 제43권1호
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• pp.34-47
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• 2020

The circadian clock regulates various physiological processes, including bone metabolism. The nuclear receptors Reverbs, comprising Rev-erbα and Rev-erbβ, play a key role as transcriptional regulators of the circadian clock. In this study, we demonstrate that Rev-erbs negatively regulate differentiation of osteoclasts and osteoblasts. The knockdown of Rev-erbα in osteoclast precursor cells enhanced receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast formation, as well as expression of nuclear factor of activated T cells 1 (NFATc1), osteoclast-associated receptor (OSCAR), and tartrate-resistant acid phosphatase (TRAP). The overexpression of Rev-erbα leads to attenuation of the NFATc1 expression via inhibition of recruitment of c-Fos to the NFATc1 promoter. The overexpression of Rev-erbα in osteoblast precursors attenuated the expression of osteoblast marker genes including Runx2, alkaline phosphatase (ALP), bone sialoprotein (BSP), and osteocalcin (OC). Rev-erbα interfered with the recruitment of Runx2 to the promoter region of the target genes. Conversely, knockdown of Rev-erbα in the osteoblast precursors enhanced the osteoblast differentiation and function. In addition, Rev-erbα negatively regulated osteoclast and osteoblast differentiation by suppressing the p38 MAPK pathway. Furthermore, intraperitoneal administration of GSK4112, a Rev-erb agonist, protects RANKL-induced bone loss via inhibition of osteoclast differentiation in vivo. Taken together, our results demonstrate a molecular mechanism of Rev-erbs in the bone remodeling, and provide a molecular basis for a potential therapeutic target for treatment of bone disease characterized by excessive bone resorption.

• 동의생리병리학회지
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• 제33권4호
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• pp.191-197
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• 2019

This study aims to evaluate the effects of the root bark of Morus alba (RMA) on the regulation of the Hippo-YAP pathway. Hippo-YAP signaling is a critical regulator in controlling organ size and tissue homeostasis. Hippo, the serine/threonine kinase phosphorylate the LATS. Phosphorylated LATS then phosphorylates and inactivates the YAP and TAZ, which are two closely related transcriptional co-activator. Here we report RMA activates the Hippo signaling, thereby inhibits the YAP/TAZ activity. First, we examine the cytotoxic effects of RMA by MTT assay. RMA was cytotoxic at concentrations higher than $50{\mu}g/ml$ in HEK293A cells. The reporter gene assay was performed to measure the activity of TEAD, a key transcription factor that controls cell growth and proliferation. RMA significantly suppressed the luciferase activity. By phos-taq gel shift assay, and western blotting, we showed that RMA enhanced the phosphorylation of YAP in wild type cells, but not in LATS1/2 knock out cells, which means RMA activates classical Hippo pathway. RMA induced the cytoplasmic sequestration of YAP. RMA also suppressed the mRNA expression of CTGF and CYR61; the two major YAP dependent genes. Taken together, RMA is considered to be a good candidate for proliferative disease such as cancer, by facilitating cell death through activating the Hippo signaling pathway.

• Journal of Veterinary Science
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• 제23권4호
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• pp.47.1-47.11
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• 2022

Background: In lipopolysaccharide-induced RAW264.7 cells, Aster tataricus (AT) inhibits the nuclear factor kappa-light-chain-enhancer of activated B cells and MAPKs pathways and critical pathways of osteoclast development and bone resorption. Objectives: This study examined how aster saponin A2 (AS-A2) isolated from AT affects the processes and function of osteoclastogenesis induced by receptor activator of nuclear factor kappa-B ligand (RANKL) in RAW264.7 cells and bone marrow macrophages (BMMs). Methods: The cell viability, tartrate-resistant acid phosphatase staining, pit formation assay, polymerase chain reaction, and western blot were carried out to determine the effects of AS-A2 on osteoclastogenesis. Results: In RAW264.7 and BMMs, AS-A2 decreased RANKL-initiated osteoclast differentiation in a concentration-dependent manner. In AS-A2-treated cells, the phosphorylation of ERK1/2, JNK, and p38 protein expression were reduced considerably compared to the control cells. In RAW264.7 cells, AS-A2 suppressed the RANKL-induced activation of osteoclast-related genes. During osteoclast differentiation, AS-A2 suppressed the transcriptional and translational expression of NFATc1 and c-Fos. AS-A2 inhibited osteoclast development, reducing the size of the bone resorption pit area. Conclusion: AS-A2 isolated from AT appears to be a viable therapeutic therapy for osteolytic illnesses, such as osteoporosis, Paget's disease, and osteogenesis imperfecta.

• 한국축산식품학회지
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• 제42권6호
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• pp.1031-1045
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• 2022

Postbiotics are defined as probiotics inactivated by heat, ultraviolet radiation, sonication, and other physical or chemical stresses. Postbiotics are more stable than probiotics, and these properties are advantageous for food additives and pharmacological agents. This study investigated the immunostimulatory effects of heat-treated Lactiplantibacillus plantarum LM1004 (HT-LM1004). Cellular fatty acid composition of L. plantarum LM1004 isolated form kimchi was analyzed by gas chromatography-mass spectrometry detection system. The nitric oxide (NO) content was estimated using Griess reagent. Immunostimulatory cytokines were evaluated using enzyme-linked immunosorbent assay. Relative protein expressions were evaluated by western blotting. Phagocytosis was measured using enzyme-labelled Escherichia coli particles. L. plantarum LM1004 showed 7 kinds of cellular fatty acids including palmitic acid (C16:0). The HT-LM1004 induced release of NO and upregulated the inducible NO synthase in RAW 264.7 macrophage cells. Tumor necrosis factor-α and interleukin-6 levels were also increased compared to control (non-treated macrophages). Furthermore, HT-LM1004 modulated mitogen-activated protein kinase (MAPK) subfamilies including p38 MAPK, extracellular signal-regulated kinase 1/2, and c-Jun N-terminal kinase. Therefore, these immunostimulatory effects were attributed to the production of transcriptional factors, such as nuclear factor kappa B (NF-κB) and the activator protein 1 family (AP-1). However, HT-LM1004 did not showed significant phagocytosis of RAW 264.7 macrophage cells. Overall, HT-LM1004 stimulated MAPK/AP-1 and NF-κB expression, resulting in the release of NO and cytokines. These results will contribute to the development of diverse types of food and pharmacological products for immunostimulatory agents with postbiotics.

• Oncology Letters
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• 제17권4호
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• pp.3981-3989
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• 2019

Tamoxifen (TAM) is the most widely used treatment for estrogen receptor-positive breast cancer patients. Unfortunately, the majority of these patients exhibit TAM resistance following treatment. We previously reported that proliferation and migration were greater in TAM-resistant MCF-7 (TAMR-MCF-7) cells than in parental MCF-7 cells. Janus kinases (JAKs) are cytosolic tyrosine kinases that transduce signals from plasma membrane cytokines and growth factor receptors. JAK2 selectively phosphorylates signal transducer and activator of transcription (STAT)-3, and the JAK2-STAT3 signaling pathway is known as a crucial signaling pathway for the regulation of cancer progression and metastasis. In the present study, basal phosphorylation of STAT3 was revealed to be greater in TAMR-MCF-7 cells than in control MCF-7 cells. Ruxolitinib, a potent JAK2 inhibitor, was demonstrated to attenuate STAT3 phosphorylation and the proliferation of TAMR-MCF-7 cells. Ruxolitinib also suppressed the enhanced cell migration of TAMR-MCF-7 cells through the inhibition of epithelial mesenchymal transition. Vascular endothelial growth factor (VEGF), a representative target gene of the JAK2-STAT3 pathway, functions as a key regulator of invasion and angiogenesis. Ruxolitinib significantly inhibited VEGF mRNA expression and transcriptional activity. The present study also performed a chick embryo chorioallantoic membrane assay to assess tumor growth and angiogenesis in TAMR-MCF-7 cells. Ruxolitinib reduced tumor weight and the number of blood vessels produced by TAMR-MCF-7 cells in a concentration-dependent manner. These results indicated that JAK2 could be a new therapeutic target for TAM-resistant breast cancer.