• The Korean Journal of Physiology and Pharmacology
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• v.19 no.4
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• pp.327-334
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• 2015

The cytoprotective enzyme heme oxygenase-1 (HO-1) influences endothelial cell survival, proliferation, inflammatory response, and angiogenesis in response to various angiogenic stimuli. In this study, we investigate the involvement of HO-1 in the angiogenic activity of orexin-A. We showed that orexin-A stimulates expression and activity of HO-1 in human umbilical vein endothelial cells (HUVECs). Furthermore, we showed that inhibition of HO-1 by tin (Sn) protoporphryin-IX (SnPP) reduced orexin- A-induced angiogenesis in vivo and ex vivo. Orexin-A-stimulated endothelial tube formation and chemotactic activity were also blocked in SnPP-treated vascular endothelial cells. Orexin-A treatment increased the expression of nuclear factor erythroid-derived 2 related factor 2 (Nrf2), and antioxidant response element (ARE) luciferase activity, leading to induction of HO-1. Collectively, these findings indicate that HO-1 plays a role as an important mediator of orexin-A-induced angiogenesis, and provide new possibilities for therapeutic approaches in pathophysiological conditions associated with angiogenesis.

• Journal of Cancer Prevention
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• v.21 no.3
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• pp.135-143
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• 2016

Background: Fraxetin (7,8-dihydroxy-6-methoxy coumarin), a coumarin derivative, has been reported to possess antioxidative, anti-inflammatory and neuroprotective effects. A number of recent observations suggest that the induction of heme oxygenase-1 (HO-1) inhibits inflammation and tumorigenesis. In the present study, we determined the effect of fraxetin on HO-1 expression in HaCaT human keratinocytes and investigated its underlying molecular mechanisms. Methods: Reverse transcriptase-PCR and Western blot analysis were performed to detect HO-1 mRNA and protein expression, respectively. Cell viability was measured by the MTS test. The induction of intracellular reactive oxygen species (ROS) by fraxetin was evaluated by 2′,7′-dichlorofluorescin diacetate staining. Results: Fraxetin upregulated mRNA and protein expression of HO-1. Incubation with fraxetin induced the localization of nuclear factor-erythroid-2-related factor-2 (Nrf2) in the nucleus and increased the antioxidant response element-reporter gene activity. Fraxetin also induced the phosphorylation of Akt and AMP-activated protein kinase $(AMPK){\alpha}$ and diminished the expression of phosphatase and tensin homolog, a negative regulator of Akt. Pharmacological inhibition of Akt and $AMPK{\alpha}$ abrogated fraxetin-induced expression of HO-1 and nuclear localization of Nrf2. Furthermore, fraxetin generated ROS in a concentration-dependent manner. Conclusions: Fraxetin induces HO-1 expression through activation of Akt/Nrf2 or $AMPK{\alpha}/Nrf2$ pathway in HaCaT cells.

• Journal of Microbiology and Biotechnology
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• v.28 no.8
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• pp.1310-1317
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• 2018

The stems of Dendrobium moniliforme have been used in traditional herbal medicine for the treatment of fever and lack of body fluid in Korea. In this study, we investigated anti-inflammatory effects of the aqueous extract of D. moniliforme stems (DM) in response to lipoteichoic acid (LTA), a major constituent of the cell wall of Gram-positive bacteria. DM inhibited LTA-induced expression of a pro-inflammatory mediator inducible nitric oxide synthase (iNOS) in the murine macrophages. And DM induced expression of heme oxygenase-1 (HO-1) at the transcriptional level. Conversely, the knockdown of HO-1 expression by siRNA markedly reversed the inhibitory effects of DM on LTA-induced iNOS expression. We also demonstrated that nuclear translocation of Nrf2 was increased following treatment with DM. In addition, DM-mediated Nrf2 activation and HO-1 expression were suppressed by PI3K/Akt and p38 inhibitors; treatment with DM also resulted in phosphorylation of Akt and p38. These results suggest that DM inhibits the expression of iNOS in LTA-stimulated macrophages, and that these effects are mediated by the upregulation of HO-1 expression via PI3K/Akt/p38-Nrf2 signaling.

• Journal of Ginseng Research
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• v.47 no.5
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• pp.615-621
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• 2023

Korean Red Ginseng (KRG) plays a key role in heme oxygenase (HO)-1 induction under physical and moderate oxidative stress conditions. The transient and mild induction of HO-1 is beneficial for cell protection, mitochondrial function, regeneration, and intercellular communication. However, chronic HO-1 overexpression is detrimental in severely injured regions. Thus, in a chronic pathological state, diminishing HO-1-mediated ferroptosis is beneficial for a therapeutic approach. The molecular mechanisms by which KRG protects various cell types in the central nervous system have not yet been established, especially in terms of HO-1-mediated mitochondrial functions. Therefore, in this review, we discuss the multiple roles of KRG in the regulation of astrocytic HO-1 under pathophysiological conditions. More specifically, we discuss the role of the KRG-mediated astrocytic HO-1 pathway in regulating mitochondrial functions in acute and chronic neurodegenerative diseases as well as physiological conditions.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.4
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• pp.309-313
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• 2009

Spontaneous hypertensive rats (SHR) are an established model of genetic hypertension. Vascular smooth muscle cells (VSMC) from SHR proliferate faster than those of control rats (Wistar-Kyoto rats; WKY). We tested the hypothesis that induction of heme oxygenase (HO)-1 induced by aprotinin inhibits VSMC proliferation through cell cycle arrest in hypertensive rats. Aprotinin treatment inhibited VSMC proliferation in SHR more than in normotensive rats. These inhibitory effects were associated with cell cycle arrest in the G1 phase. Tin protoporphyrin IX (SnPPIX) reversed the anti-proliferative effect of aprotinin in VSMC from SHR. The level of cyclin D was higher in VSMC of SHR than those of WKY. Aprotinin treatment downregulated the cell cycle regulator, cyclin D, but upregulated the cyclin-dependent kinase inhibitor, p21, in VSMC of SHR. Aprotinin induced HO-1 in VSMC of SHR, but not in those of control rats. Furthermore, aprotinin-induced HO-1 inhibited VSMC proliferation of SHR. Consistently, VSMC proliferation in SHR was significantly inhibited by transfection with the HO-1 gene. These results indicate that induction of HO-1 by aprotinin inhibits VSMC proliferation through cell cycle arrest in hypertensive rats.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.5
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• pp.1334-1336
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• 2006

Effects of twenty-three aqueous herbal extracts used in oriental medicines on heme oxygenase (HO)-1 expression were estimated in a mouse hippocampal cell line, HT22. HO-1 is one of the cytoprotective enzymes activated various stimuli, and Western blot analysis was used for evaluated HO-1 expression. Six aqueous extracts such as Rhei Rhizoma, Paeoniae Radix, Uncariae Ramulus et Uncus, Theae Folium, Prunellae Spica, and Coptidis Rhizoma significantly increased HO-1 expression in HT22 cells at the concentration of 300 ${\mu}$g/ml. In Addition, four aqueous extracts including Eucommiae Cortex, Moutan Cortex Radicis, Ginseng Radix Rubra, and Scutellariae Radix moderately increased HO-1 expression. These results would be usefulfor the isolation and identification of their neuroprotective principles.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.1
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• pp.63-68
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• 2014

The fruit of Tribulus terrestris L. (Zygophyllaceae) is an important source of traditional Korean and Chinese medicines. In this study, NNMBS223, consisting of the ethanol extract of T. terrestris, showed potent anti-inflammatory activities in RAW264.7 macrophages. We investigated the effect of NNMBS223 in suppressing the protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 and production of iNOS-derived nitric oxide (NO), COX-2-derived prostaglandin E2 (PGE2) in lipopolysaccharide (LPS)-stimulated macrophages. In addition, NNMBS223 induced expression of heme oxygenase (HO)-1 through nuclear translocation of nuclear factor E2-related factor 2 (Nrf2) in macrophages. The effects of NNMBS223 on LPS-induced production of NO and PGE2 were partially reversed by the HO activity inhibitor tin protoporphyrin (SnPP). These findings suggest that Nrf2-dependent increases in expression of HO-1 induced by NNMBS223 conferred anti-inflammatory activities in LPS stimulated RAW264.7 macrophages.

• Korean Journal of Pharmacognosy
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• v.41 no.3
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• pp.190-195
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• 2010

Glutamate-induced oxidative injury contributes to neuronal degeneration in many central nervous system (CNS) diseases, such as Parkinson's disease, Alzheimer's disease, epilepsy and ischemia. Inducible heme oxygenase (HO)-1 acts against oxidants that are thought to play a role in the pathogenesis of these diseases. NNMBS098, a composition comprising the water insoluble of the 70% EtOH extract of Zingiberis Rhizoma, showed the potent neuroprotective effects on glutamateinduced neurotoxicity by induced the expression of heme oxygenase (HO)-1 and increased HO activity in the mouse hippocampal HT22 cells. Furthermore, NNMBS098 caused the nuclear accumulation of nuclear factor E2-related factor 2 (Nrf2) in mouse hippocampal HT22 cells. In addition, we found that treatment with c-Jun N-terminal kinase (JNK) inhibitor (SP600125) reduced NNMBS098-induced HO-1 expression and NNMBS098 also increased JNK phosphorylation. Therefore, these results suggest that NNMBS098 increases cellular resistance to glutamate-induced oxidative injury in mouse hippocampal HT22 cells, presumably through JNK pathway-Nrf2-dependent HO-1 expression.

• Journal of Microbiology and Biotechnology
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• v.29 no.1
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• pp.11-20
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• 2019

Ecklonia cava, an edible marine brown alga (Laminariaceae), is a rich source of bioactive compounds such as fucoidan and phlorotannins. Ecklonia cava extract (ECE) was prepared using 70% ethanol extraction and ECE contained 67% and 10.6% of total phlorotannins and dieckol, respectively. ECE treatment significantly inhibited receptor activator of nuclear $factor-{\kappa}B$ ligand (RANKL)-induced osteoclast differentiation of RAW 264.7 cells and pit formation in bone resorption assay (p <0.05). Moreover, it suppressed RANKL-induced $NF-{\kappa}B$ and mitogen-activated protein kinase signaling in a dose dependent manner. Downregulated osteoclast-specific gene (tartrate-resistant acid phosphatase, cathepsin K, and matrix metalloproteinase-9) expression and osteoclast proliferative transcriptional factors (nuclear factor of activated T cells-1 and c-fos) confirmed ECE-mediated suppression of osteoclastogenesis. ECE treatment ($100{\mu}g/ml$) increased heme oxygenase-1 expression by 2.5-fold and decreased intercellular reactive oxygen species production during osteoclastogenesis. The effective inhibition of RANKL-stimulated osteoclast differentiation and oxidative stress by ECE suggest that ECE has therapeutic potential in alleviating osteoclast-associated disorders.

• Journal of Photoscience
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• v.9 no.3
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• pp.33-36
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• 2002

This study describes RT-PCR and in situ hybridisation protocols, and the immunohistochemical detection method that we have developed to detect and localise cells that express HO-1 in the skin. We found that HO-1 mRNA was absent in normal mouse skin, but after UVA irradiation HO-1 mRNA was expressed in the dermal fibroblasts, and strongly in basal epidermal cells. HO-1 protein was also induced strongly in dermal fibroblasts, and also in epidermal cells. In addition, the HO substrate heme was reduced in skin microsome at 72 hrs post UVA (when HO activity is high). At the same time, the HO products bilirubin and iron levels were elevated in the cutaneous tissue. Thus in addition to a dermal response, there appears to be an epidermal HO response to UVA in vivo that may be relevant for immune modulation by UVA radiation.