Eriodictyol Protects Endothelial Cells against Oxidative Stress-Induced Cell Death through Modulating ERK/Nrf2/ARE-Dependent Heme Oxygenase-1 Expression

Lee, Seung Eun,Yang, Hana,Son, Gun Woo,Park, Hye Rim,Park, Cheung-Seog,Jin, Young-Ho,Park, Yong Seek MDPI 2015 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.16 No.7

<P>The pathophysiology of cardiovascular diseases is complex and may involve oxidative stress-related pathways. Eriodictyol is a flavonoid present in citrus fruits that demonstrates anti-inflammatory, anti-cancer, neurotrophic, and antioxidant effects in a range of pathophysiological conditions including vascular diseases. Because oxidative stress plays a key role in the pathogenesis of cardiovascular disease, the present study was designed to verify whether eriodictyol has therapeutic potential. Upregulation of heme oxygenase-1 (HO-1), a phase II detoxifying enzyme, in endothelial cells is considered to be helpful in cardiovascular disease. In this study, human umbilical vein endothelial cells (HUVECs) treated with eriodictyol showed the upregulation of HO-1 through extracellular-regulated kinase (ERK)/nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathways. Further, eriodictyol treatment provided protection against hydrogen peroxide-provoked cell death. This protective effect was eliminated by treatment with a specific inhibitor of HO-1 and RNA interference-mediated knockdown of HO-1 expression. These data demonstrate that eriodictyol induces ERK/Nrf2/ARE-mediated HO-1 upregulation in human endothelial cells, which is directly associated with its vascular protection against oxidative stress-related endothelial injury, and propose that targeting the upregulation of HO-1 is a promising approach for therapeutic intervention in cardiovascular disease.</P>

Up-regulation of Heme Oxygenase-1 by Korean Red Ginseng Water Extract as a Cytoprotective Effect in Human Endothelial Cells

Hana Yang,Seung Eun Lee,Seong Il Jeong,Cheung-Seog Park,Young-Ho Jin,Yong Seek Park 고려인삼학회 2011 Journal of Ginseng Research Vol.35 No.3

Korean red ginseng (KRG) is used worldwide as a popular traditional herbal medicine. KRG has shown beneficial effects on cardiovascular diseases, such as atherosclerosis, diabetes, and hypertension. Up-regulation of a cytoprotective protein, heme oxygenase (HO)-1, is considered to augment the cellular defense against various agents that may induce cytotoxic injury. In the present study, we demonstrate that KRG water extract induces HO-1 expression in human umbilical vein endothelial cells (HUVECs) and possible involvement of the anti-oxidant transcription factor nuclear factor-eythroid 2-related factor 2 (Nrf2). KRG-induced HO-1 expression was examined by western blots, reverse transcriptase polymerase chain reaction and immunofluorescence staining. Specific silencing of Nrf2 genes with Nrf2-siRNA in HUVECs abolished HO-1 expression. In addition, the HO inhibitor zinc protoporphyrin blunted the preventive effect of KRG on H₂O₂-induced cell death, as demonstrated by terminal transferase dUTP nick end labeling assay. Taken together, these results suggest that KRG may exert a vasculoprotective effect through Nrf2-mediated HO-1 induction in human endothelial cell by inhibition of cell death.

Study of decreased melanin production through p53 by heme oxygenase-1 inhibitor in normal human melanocytes

( Hee Sun Lim ),( Sun A Jin ),( Jee Bum Lee ),( Seong Jin Kim ),( Seung Chul Lee ),( Young Ho Won ),( Sook Jung Yoon ) 대한피부과학회 2015 대한피부과학회 학술발표대회집 Vol.67 No.2

Background: Heme oxygenase (HO)-1 is induced by oxidative stress and plays important roles in anti-apoptosis and the rapid growth of several solid tumors. p53 has a central role in skin pigmentation and may impact onmelanoma at all stages. However, there has been little study of HO-1 in relation with p53 on melanin production Objectives: To know the effect of HO-1 on melanogenesis through p53 in normal human melanocytes Methods: Human melanocytes (hM) were primarily cultured from foreskin. After incubation, cells were rinsed twice with PBS then transfection with p53 siRNA Results: Melanin content was detected with ELISA and Western blot analysis and RT-PCR of tyrosinase, MITF were performed after ZnPP treatment and p53 transfection. After ZnPP treatment, melanin content was decreased, and tyrosinase and MITF protein levels were decreased. Tyrosinase and MITF mRNA levels were also decreased. However, melanin content and tyrosinase and MITF protein levels were increased after CoPP treatment. After p53 transfection, HO-1 expression was decreased when HO-1 stimulator was treated. In addition, melanin content was decreased, and tyrosinase expression was decreased in Western blot analysis Conclusion: These results suggest that melanogenesis is inhibited by ZnPP by decreased melanin production, tyrosinase and MITF protein and mRNA levels. Furthermore, those inhibitory effects of ZnPP may be dependent on p53 in normal human melanocytes. Therefore, HO-1 may play an important role in melanogensis

사과 추출물과 phloretin에 의한 항염증 활성

김근호(Geun-Ho Kim),이은주(Eun-Joo Lee),류승민(Seung-Min Ryu),손호용(Ho-Yong Sohn),김종식(Jong-Sik Kim) 한국생명과학회 2021 생명과학회지 Vol.31 No.2

본 연구에서는 풋사과의 열수추출물(GAHW)과 에탄올추출물(GAE), 그리고 애사과 열수추출물(UAHW)을 제조하고 LPS로 활성화된 RAW264.7세포주를 이용하여 이들의 항염증 활성을 연구하였다. 모든 추출물이 세포생존율에는 영향을 미치지 않고 nitric oxide (NO) 생산을 저해하였으며, iNOS의 발현도 감소시켰다. 반면, UAHW만이 COX-2의 발현을 저해하였다. 또한 모든 추출물이 모든 MAPKs의 인산화를 감소시켰다. 모든 추출물이 ROS의 생산을 농도의존적으로 감소시켰으며, GAHW와 GAE에 의해 HO-1의 발현이 증가됨을 확인하였다. 또한, 사과 flavonoid인 phloretin과 phloridzin의 항염증 활성을 연구하였다. Phloretin은 농도의존적으로 NO의 생산을 저해하였으나, phloridzin은 NO 생산에 아무 영향이 없었다. 또한, phloretin은 iNOS와 COX-2 단백질의 발현을 감소시킨 반면, phloridzin은 두 단백질 발현에 영향을 주지 못하였다. 따라서, 이러한 연구결과는 사과 추출물은 MAPK 경로와 HO-1 경로를 조절함으로써 항염증 활성을 가지며, phloretin이 사과의 항염증 활성을 담당하는 파이토케미칼의 하나가 될 수 있음을 제시한다. In the present study, we prepared hot water extracts of green apple (GAHW) and unripe apple (UAHW), and ethanol extract of green apple (GAE), and investigated their anti-inflammatory activities in LPS-activated RAW264.7 cells. All extracts dramatically suppressed nitric oxide (NO) production in a dose-dependent manner in LPS-stimulated RAW264.7 cells without affecting cell viability. In addition, all extracts decreased the expression of iNOS, whereas UAHW only reduced the expression of COX-2. All extracts suppressed the phosphorylation of MAPKs (p38, ERK, and JNK) indicating all extracts show their anti-inflammatory activities via regulating MAPK pathway. Furthermore, all extracts reduced the production of reactive oxygen species in a dose-dependent manner and they increased the expression of heme oxygenase-I (HO-I) whereas UAHW could not. We also investigated whether apple flavonoids phloretin and phloridzin can have their anti-inflammatory activities in same in vitro model. Phloretin dramatically decreased NO production in a dose dependent manner without affecting cell viability, whereas phloridzin have no effects. Phloretin also reduced the expression of iNOS as well as COX-2, whereas phloridzin could not. Overall, these results suggest that apple extracts have their anti-inflammatory activities via regulating MAPKs and HO-1 pathways, and apple flavonoid phloretin can be one of phytochemicals responsible for anti-inflammatory effect of apple.

Induction of heme oxygenase-1 protects against podocyte apoptosis under diabetic conditions

Lee, Sang Choel,Han, Seung Hyeok,Li, Jin Ji,Lee, Sun Ha,Jung, Dong-Sub,Kwak, Seung-Jae,Kim, Seung Hye,Kim, Dong Ki,Yoo, Tae-Hyun,Kim, Jin Hyun,Chang, Se-Ho,Han, Dae Suk,Kang, Shin-Wook International Society of Nephrology 2009 Kidney international Vol.76 No.8

Heme oxygenase-1 (HO-1) is an anti-oxidant enzyme normally upregulated in response to oxidant injury. Here we determined the role of HO-1 in podocyte apoptosis in glomeruli of streptozotocin-treated rats and in immortalized mouse podocytes cultured in media containing normal or high glucose. HO-1 expression, its activity, the ratio of Bax/Bcl-2 protein, and active caspase-3 fragments were all significantly higher in isolated glomeruli of diabetic rats and in high glucose–treated podocytes. These increases were inhibited by zinc protoporphyrin treatment of the rats or by HO-1 siRNA treatment of the podocytes in culture. The number of apoptotic cells was also significantly increased in the glomeruli of diabetic rats and in high glucose–treated podocytes. Inhibition of HO-1 accentuated the increase in apoptotic cells both in vivo and in vitro. Our findings suggest that HO-1 expression protects against podocyte apoptosis under diabetic conditions.

Up-regulation of Heme Oxygenase-1 by Korean Red Ginseng Water Extract as a Cytoprotective Effect in Human Endothelial Cells

Yang, Ha-Na,Lee, Seung-Eun,Jeong, Seong-Il,Park, Cheung-Seog,Jin, Young-Ho,Park, Yong-Seek The Korean Society of Ginseng 2011 Journal of Ginseng Research Vol.35 No.3

Korean red ginseng (KRG) is used worldwide as a popular traditional herbal medicine. KRG has shown beneficial effects on cardiovascular diseases, such as atherosclerosis, diabetes, and hypertension. Up-regulation of a cytoprotective protein, heme oxygenase (HO)-1, is considered to augment the cellular defense against various agents that may induce cytotoxic injury. In the present study, we demonstrate that KRG water extract induces HO-1 expression in human umbilical vein endothelial cells (HUVECs) and possible involvement of the anti-oxidant transcription factor nuclear factor-eythroid 2-related factor 2 (Nrf2). KRG-induced HO-1 expression was examined by western blots, reverse transcriptase polymerase chain reaction and immunofluorescence staining. Specific silencing of Nrf2 genes with Nrf2-siRNA in HUVECs abolished HO-1 expression. In addition, the HO inhibitor zinc protoporphyrin blunted the preventive effect of KRG on $H_2O_2$-induced cell death, as demonstrated by terminal transferase dUTP nick end labeling assay. Taken together, these results suggest that KRG may exert a vasculoprotective effect through Nrf2-mediated HO-1 induction in human endothelial cell by inhibition of cell death.

N-acetyl cysteine inhibits H2O2-mediated reduction in the mineralization of MC3T3-E1 cells by down-regulating Nrf2/HO-1 pathway

( Daewoo Lee ),( Sung Ho Kook ),( Hyeok Ji ),( Seung Ah Lee ),( Ki Choon Choi ),( Kyung Yeol Lee ),( Jeong Chae Lee ) 생화학분자생물학회(구 한국생화학분자생물학회) 2015 BMB Reports Vol.48 No.11

There are controversial findings regarding the roles of nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway on bone metabolism under oxidative stress. We investigated how Nrf2/HO-1 pathway affects osteoblast differentiation of MC3T3-E1 cells in response to hydrogen peroxide (H2O2), N-acetyl cysteine (NAC), or both. Exposing the cells to H2O2 decreased the alkaline phosphatase activity, calcium accumulation, and expression of osteoblast markers, such as osteocalcin and runt-related transcription factor-2. In contrast, H2O2 treatment increased the expression of Nrf2 and HO-1 in the cells. Treatment with hemin, a chemical HO-1 inducer, mimicked the inhibitory effect of H2O2 on osteoblast differentiation by increasing the HO-1 expression and decreasing the osteogenic marker genes. Pretreatment with NAC restored all changes induced by H2O2 to near normal levels in the cells. Collectively, our findings suggest that H2O2-mediated activation of Nrf2/HO-1 pathway negatively regulates the osteoblast differentiation, which is inhibited by NAC. [BMB Reports 2015; 48(11): 636-641]

Protective Effect of Heme Oxygenase-1 on High Glucose-Induced Pancreatic β-Cell Injury

Lee, Eun-Mi,Lee, Young-Eun,Lee, Esder,Ryu, Gyeong Ryul,Ko, Seung-Hyun,Moon, Sung-Dae,Song, Ki-Ho,Ahn, Yu-Bae Korean Diabetes Association 2011 Diabetes and Metabolism Journal Vol.35 No.5

<P><B>Background</B></P><P>Glucose toxicity that is caused by chronic exposure to a high glucose concentration leads to islet dysfunction and induces apoptosis in pancreatic β-cells. Heme oxygenase-1 (HO-1) has been identified as an anti-apoptotic and cytoprotective gene. The purpose of this study is to investigate whether HO-1 up-regulation when using metalloprotophyrin (cobalt protoporphyrin, CoPP) could protect pancreatic β-cells from high glucose-induced apoptosis.</P><P><B>Methods</B></P><P>Reverse transcription-polymerase chain reaction was performed to analyze the CoPP-induced mRNA expression of HO-1. Cell viability of INS-1 cells cultured in the presence of CoPP was examined by acridine orange/propidium iodide staining. The generation of intracellular reactive oxygen species (ROS) was measured using flow cytometry. Glucose stimulated insulin secretion (GSIS) was determined following incubation with CoPP in different glucose concentrations.</P><P><B>Results</B></P><P>CoPP increased HO-1 mRNA expression in both a dose- and time-dependent manner. Overexpression of HO-1 inhibited caspase-3, and the number of dead cells in the presence of CoPP was significantly decreased when exposed to high glucose conditions (HG). CoPP also decreased the generation of intracellular ROS by 50% during 72 hours of culture with HG. However, decreased GSIS was not recovered even in the presence of CoPP.</P><P><B>Conclusion</B></P><P>Our data suggest that CoPP-induced HO-1 up-regulation results in protection from high glucose-induced apoptosis in INS-1 cells; however, glucose stimulated insulin secretion is not restored.</P>

Crotonaldehyde-exposed macrophages induce heme oxygenase-1 expression as an adaptive mechanism

Seung Eun Lee,Hana Yang,Gun Woo Son,Hye Rim Park,Young-Ho Jin,Cheung-Seog Park,Yong Seek Park 대한독성 유전단백체 학회 2015 Molecular & cellular toxicology Vol.11 No.2

Cigarette smoke represents one of the most significant risk factors for the progression of vascular disease. Exposure to cigarette smoke induces oxidative stress in the vascular system and results in vascular dysfunction. Crotonaldehyde, a highly reactive α,β-unsaturated aldehyde, is a foremost compound of cigarette smoke and a product of endogenous lipid peroxidation. Heme oxygenase-1 (HO-1) expression plays an essential role in cellular defense against environmental insults and represents an adaptive response. Here, we showed the effects of crotonaldehyde on the induction of HO-1 expression in RAW 264.7 macrophages. Crotonaldehyde treatment resulted in significantly increased phosphorylation of p38 mitogenactivated protein kinase (MAPK) and nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2). Furthermore, treatment with zinc protoporphyrin (ZnPP; the specific HO-1 inhibitor) markedly augmented the death of crotonaldehyde-treated macrophages. In summary, these results highlight the role of the HO-1 upregulation through p38 MAPK-Nrf2 activation in the adaptive response to crotonaldehyde in macrophages.

Simplified Effective Compressive Strengths of Columns with Intervening Floor Slabs

Seung?Ho Choi,Jin?Ha Hwang,Sun?Jin Han,Hae?Chang Cho,Jae Hyun Kim,Kang Su Kim 한국콘크리트학회 2020 International Journal of Concrete Structures and M Vol.14 No.5

The current design codes discuss the effective compressive strengths of columns, which reflect a decrease in load transfer performance that can occur when columns and slabs have different concrete compressive strengths. The effective compressive strength of a column increases as it is confined by the slab, and the design codes mandate three different effective compressive strengths for interior columns (confinement on four sides), exterior columns (confinement on three sides), and corner columns (confinement on two sides). For both corner and exterior columns, the confinement effect of the slab is significantly smaller than that for the interior column, and there is a more marked decrease in load transfer performance. However, there is still a lack of theoretical studies investigating the effective compressive strengths of the corner and exterior columns. Therefore, based on the analysis model established in previous research, this study has proposed an equation for calculating the effective compressive strengths of the corner, exterior and isolated columns without any confinement effects of the slab. In addition, axial loading tests of isolated columns were conducted and the proposed equation was verified.