24 results on '"Huang, Chun-Fa"'
Search Results
2. Roles of oxidative stress/JNK/ERK signals in paraquat-triggered hepatic apoptosis
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Lee, Kuan-I, Fang, Kai-Min, Kuo, Chun-Ying, Huang, Chun-Fa, Liu, Shing-Hwa, Liu, Jui-Ming, Lai, Wei-Cheng, Chang, Kai-Chih, Su, Chin-Chuan, and Chen, Ya-Wen
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- 2024
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3. Roles of ERK/Akt signals in mitochondria-dependent and endoplasmic reticulum stress-triggered neuronal cell apoptosis induced by 4-methyl-2,4-bis(4-hydroxyphenyl)pent-1-ene, a major active metabolite of bisphenol A
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Huang, Chun-Fa, Liu, Shing-Hwa, Su, Chin-Chuan, Fang, Kai-Min, Yen, Cheng-Chieh, Yang, Ching-Yao, Tang, Feng-Cheng, Liu, Jui-Ming, Wu, Chin-Ching, Lee, Kuan-I, and Chen, Ya-Wen
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- 2021
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4. Cadmium exposure induces pancreatic β-cell death via a Ca2+-triggered JNK/CHOP-related apoptotic signaling pathway
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Huang, Cheng-Chin, Kuo, Chun-Ying, Yang, Ching-Yao, Liu, Jui-Ming, Hsu, Ren-Jun, Lee, Kuan-I, Su, Chin-Chuan, Wu, Chin-Ching, Lin, Ching-Ting, Liu, Shing-Hwa, and Huang, Chun-Fa
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- 2019
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5. Increased risk of bipolar disorder in patients with scabies: A nationwide population-based matched-cohort study
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Lin, Chien-Yu, Chang, Fung-Wei, Yang, Jing-Jung, Chang, Chun-Hung, Yeh, Chia-Lun, Lei, Wei-Te, Huang, Chun-Fa, Liu, Jui-Ming, and Hsu, Ren-Jun
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- 2017
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6. Arsenic and diabetes: Current perspectives
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Huang, Chun Fa, Chen, Ya Wen, Yang, Ching Yao, Tsai, Keh Sung, Yang, Rong Sen, and Liu, Shing Hwa
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- 2011
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7. Ototoxicity induced by cinnabar (a naturally occurring HgS) in mice through oxidative stress and down-regulated Na +/K +-ATPase activities
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Huang, Chun-Fa, Hsu, Chuan-Jen, Liu, Shing-Hwa, and Lin-Shiau, Shoei-Yn
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- 2008
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8. The association between scabies and myasthenia gravis: A nationwide population-based cohort study.
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Hsu, Ren-Jun, Lin, Chien-Yu, Chang, Fung-Wei, Huang, Chun-Fa, Chuang, Heng-Chang, and Liu, Jui-Ming
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Scabies is an infectious inflammatory pruritic skin disease. Cytokine-mediated inflammatory processes contribute to the pathologic mechanism in scabies. Myasthenia gravis (MG) is also an autoimmune disease that is mediated by cytokines. The study aimed to investigate the association between scabies and myasthenia gravis. We conducted a nationwide population-based cohort study utilized data from the National Health Insurance Research Database (NHIRD) of Taiwan. Patients with scabies (n = 5429) and control subjects without scabies (n = 20,176) were enrolled. We tracked the subjects in both groups for a 7-year period to identify new onset MG. Cox regression analysis was performed to calculate the hazard ratio (HR) for MG. A total of 25,605 patients were enrolled in the study, including 5429 patients in the scabies group and 20,176 in the control group. There were 40 (0.7%) patients from the scabies group and 84 (0.4%) subjects from the control group who were newly diagnosed with MG during the 7-year follow-up period. The scabies patients had a significantly increased risk of MG, with an adjusted HR of 1.27 (95% confidence interval [CI] 1.01–1.89). As such, prompt diagnosis and treatment of scabies may decrease the risk of subsequent MG. [ABSTRACT FROM AUTHOR]
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- 2017
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9. Pyrrolidine dithiocarbamate augments Hg2+-mediated induction of macrophage cell death via oxidative stress-induced apoptosis and necrosis signaling pathways
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Huang, Chun-Fa, Liu, Shing-Hwa, and Lin-Shiau, Shoei-Yn
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PYRROLIDINE derivatives , *MACROPHAGES , *OXIDATIVE stress , *APOPTOSIS , *NECROSIS , *IMMUNOLOGIC diseases , *ANTINEOPLASTIC agents , *HEAVY metals , *MERCURY , *CELL death - Abstract
Abstract: Exposure to mercury can lead to several injuries in mammals, including immune system dysfunction, and pyrrolidine dithiocarbamate (PDTC), as a metal chelator and antioxidant, has been indicated to increase the cytotoxic effects of toxic metals. However, the toxicological effects and possible mechanisms of mercury in combination with PDTC are mostly unclear. In this study, we showed that PDTC dramatically increase the cytotoxic effect of HgCl2 on cultured murine macrophages (RAW 264.7 cells). PDTC augmented HgCl2-induced cytotoxic effects by facilitating the entry of mercury into the cells. The Hg2+/PDTC complex significantly and rapidly increased the formation of reactive oxygen species (ROS) and decreased intracellular glutathione (GSH) levels in these cells. Flow cytometry analysis showed that the numbers of sub-G1 hypodiploid cells and annexin V-FITC binding cells increased after Hg2+/PDTC complex exposure, and several features of mitochondria-dependent apoptosis were also induced, including mitochondrial membrane depolarization, cytosolic cytochrome c release, poly(ADP-ribose) polymerase (PARP) and caspase 3/7 activation, and DNA fragmentation. Moreover, both apoptotic and necrotic cells were detected using acridine orange/ethidium bromide dual staining. Meanwhile, depleted intracellular ATP levels and increased lactate dehydrogenase (LDH) release were observed, suggesting the induction of necrotic cell death processes. These Hg2+/PDTC complex-induced cytotoxicity-related signals could be reversed by pretreatment with the antioxidant N-acetylcysteine. In conclusion, these results suggest that Hg2+/PDTC complex-induced oxidative stress causes macrophage cell death via both apoptosis and necrosis. These findings imply for the first time that PDTC dramatically increases the uptake and toxicological effects of Hg2+ instead of detoxification. [Copyright &y& Elsevier]
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- 2012
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10. Neurotoxicological effects of low-dose methylmercury and mercuric chloride in developing offspring mice
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Huang, Chun-Fa, Liu, Shing-Hwa, Hsu, Chuan-Jen, and Lin-Shiau, Shoei-Yn
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NEUROTOXICOLOGY , *METHYLMERCURY , *MERCURIC chloride , *ANIMAL offspring sex ratio , *LABORATORY mice , *HEAVY metals , *PROBABILITY theory , *EXPERIMENTAL design , *PEROXIDATION , *MALONDIALDEHYDE - Abstract
Abstract: Mercury is a well-known toxic metal and potently induces severe neurotoxicological effects, especially in infants and children. The purpose of this study was to explore the underlying mechanisms of neurotoxic effects of mercurial compounds on the different stages of developing mice. Low-doses (the probability of human exposure in mercury-contaminated areas) of methylmercury (MeHg) (M, 0.02mg/kg/day) and mercury chloride (HgCl2) (H, 0.5mg/kg/day) were administered to mice of the following groups: (1) treatment with distilled water for 7 consecutive weeks after weaning (control-vehicle (CV)); exposure to mercurial compounds at different stages; (2) for 7 consecutive weeks after weaning (control-MeHg (CM) and control-HgCl2 (CH)); (3) only during perinatal and weaning stages (MeHg-vehicle (MV) and HgCl-vehicle (HV)); and (4) in all experimental stages (MeHg–MeHg (MM) and HgCl2–HgCl2 (HH)). Results revealed the neurobehavioral defects (increased locomotor activities, motor equilibrium impairment, and auditory dysfunction) that correlated with increasing Hg accumulation in CM and CH groups. However, it revealed a decrease and an increase in locomotor activities in MV and HV groups, respectively; these became more severe in MM and HH groups than in MV and HV groups. Motor equilibrium performance in MV and HV groups remained normal, while that in MM and HH groups was decreased. The most severe auditory defects (altered auditory brainstem response, ABR test) found in MM and HH groups than those in the respective CM and CH, MV and HV, including absolute wave III delays and interwave I–III latencies, which suggested that the irreversible auditory dysfunction caused by mercurial compounds. Furthermore, the alteration of lipid peroxidation (LPO), Na+/K+-ATPase activities, and nitric oxide (NO x ) in the brain tissues contributed to the observed neurobehavioral dysfunction and hearing impairment. These findings provide evidence that fetuses were much more susceptible to the effects of mercurial compounds with regard to inducing severely neurotoxicological injuries as that found in human beings. The signaling of ROS/Na+-K+-ATPase/NO x plays a crucial role in the underlying mechanism for mercurial compound-induced toxic effects in offspring. [Copyright &y& Elsevier]
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- 2011
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11. Titanium implants alter endothelial function and vasoconstriction via a protein kinase C-regulated pathway.
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Yang, Rong Sen, Tzeng, Huei Ping, Ho, Feng Ming, Chuang, Chia Chi, Chen, Bo Lin, Huang, Chun-Fa, Chen, Ya-Wen, Chen, Ruei Ming, and Liu, Shing Hwa
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ARTIFICIAL implants ,TITANIUM ,CELL physiology ,VASOCONSTRICTORS ,PROTEIN kinase C ,CELLULAR signal transduction ,CELLULAR control mechanisms ,ENDOTHELIUM - Abstract
Abstract: The application of titanium (Ti) alloy in joint prostheses is a good choice in orthopedic reconstruction. An elevated serum concentration of Ti has been shown in the patients with loosened knee prostheses. The precise actions of elevated Ti on the circulation remain unclear. In this study the maximal contractile responses elicited by phenylephrine in the aortas of rats 4weeks after Ti alloy implantation and in cultured rat aortas treated with a soluble form of Ti for a period of 18h were significantly decreased as compared with controls. Aortas isolated from rats with Ti alloy implants or aortas treated with a soluble form of Ti had enhanced protein expression of endothelial nitric oxide synthase (eNOS) and protein kinase C (PKC)-α and enhanced phosphorylation of extracellular signal-regulated kinase (ERK) 1/2. Treatment of human umbilical vein endothelial cells (HUVECs) with a soluble form of Ti for 24h dose-dependently increased eNOS protein expression. Short-term treatment of HUVECs with Ti for 1h effectively enhanced the phosphorylation of eNOS, PKC (pan) and ERK1/2. PKC inhibitors RO320432 and chelerythrine effectively inhibited Ti-enhanced phosphorylation of eNOS and PKC (pan). These results indicate that Ti in the circulation may alter endothelial function and reduce vasoconstriction. [Copyright &y& Elsevier]
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- 2009
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12. Ototoxicity induced by cinnabar (a naturally occurring HgS) in mice through oxidative stress and down-regulated Na+/K+-ATPase activities
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Huang, Chun-Fa, Hsu, Chuan-Jen, Liu, Shing-Hwa, and Lin-Shiau, Shoei-Yn
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OTOTOXICITY , *CINNABAR , *MERCURY , *SULFUR , *OXIDATIVE stress , *MICE - Abstract
Abstract: Cinnabar, a naturally occurring mercuric sulfide (HgS), has long been used in Chinese mineral medicine for more than 2000 years; currently it is still used as a sedative for infants in Asian countries. Since methylmercury is potently ototoxic, whether cinnabar also induces hearing impairment is awaited for delineation. In this study, we attempted to explore the toxic effects of cinnabar on the auditory brainstem response (ABR) system during 2–10 weeks administration at a clinical oral dosage of 10mg/kg/day in mice. The results showed that Hg contents of the brainstem were significantly increased accompanied with gradually progressive abnormality of ABR during 4–10 weeks of cinnabar administration. The progressive increase in hearing thresholds, prolonged absolute and interwave latencies of ABR apparently exhibited a gender difference. Male mice were more sensitive to cinnabar in producing hearing impairment correlated with the biochemical alterations in plasma and brainstem, e.g. an increase of lipid peroxidation (LPO), altered Na+/K+-ATPase activities and decrease of nitric oxide (NO x ) levels. Moreover, accumulation of Hg contents in brainstem with a greater extent was found in male mice. These findings provide important information that the clinical dosage of cinnabar (10mg/kg/day) still exhibited ototoxicity after continuously long-term exposure. The signaling pathway of oxidative stress/Na+–K+-ATPase activities/NO of brainstem (a central auditory regulatory system) probably plays an important role in the toxic mechanisms of cinnabar-induced ototoxicity. The gender difference in cinnabar-induced neurotoxic effects merits further investigation. [Copyright &y& Elsevier]
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- 2008
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13. Neurotoxicological mechanism of methylmercury induced by low-dose and long-term exposure in mice: Oxidative stress and down-regulated Na+/K+-ATPase involved
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Huang, Chun-Fa, Hsu, Chuan-Jen, Liu, Shing-Hwa, and Lin-Shiau, Shoei-Yn
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METHYLMERCURY , *LABORATORY mice , *OXIDATIVE stress , *ADENOSINE triphosphatase - Abstract
Abstract: Methylmercury (MeHg), a potent neurotoxicant, easily passes through the blood-brain barrier (BBB), accumulates in the brain regions and causes severe irreversible damage. However, the neurotoxic effects and action mechanisms of MeHg are still unclear, especially in low-dose and long-term exposure. In this study, we attempted to explore the toxic effects of low-dose MeHg (0.05mg/kg/day), which was the possible exposed dose by ingestion in MeHg-contaminated areas, on the time course of changes in locomotor activities and auditory brainstem response (ABR) system after administration for 7 consecutive weeks in mice. The results showed that the retention time on the rotating rod (60rpm) was preferentially decreased after 1-week oral administration with MeHg. The locomotor activities parameters of ambulatory distances and stereotype-1 episodes were significantly increased and vertical-plane entries were progressively decreased after MeHg exposure in 3 consecutive weeks. Gradually progressive abnormality of ABR (increase in hearing thresholds, prolonged absolute and interwave latencies) was found during 4–6 weeks administration of MeHg. These impairments correlated with significant Hg accumulation and biochemical alterations in brain regions and/or other tissues, including the increase of lipid peroxidation (LPO) production, influence of Na+/K+-ATPase activities and nitric oxide (NO) levels were found. These findings provide evidence that the signaling of oxidative stress/Na+/K+-ATPase/NO plays a role in the underlying mechanisms of the neurotoxic effects induced by low-dose and long-term exposure of MeHg. [Copyright &y& Elsevier]
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- 2008
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14. Oxidative storm in a patient with acute rotenone-containing plant poisoning.
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Yu, Jiun-Hao, Huang, Chun-Fa, Wang, Te-Hao, Hung, Dong-Zong, Mu, Han-Wei, and Pan, Chi-Syuan
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A 64-year-old woman presented with coma, seizure, and lactic acidosis after ingesting 80 yam bean seeds. This rotenone-containing seeds cause cellular asphyxia via blockage of the mitochondrial electron transport. Subsequent oxidative stress results in the formation of lipid peroxidation (LPO). Rotenone analysis via liquid chromatography mass spectrometry revealed the following: 31,590 ng/mL in cooked yam bean seed and 100 ng/mL in the blood. We attempted to use N-acetylcysteine to alleviate oxidative stress and documented the continuous decline in the plasma concentration of LPO. [ABSTRACT FROM AUTHOR]
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- 2020
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15. The diabetogenic effects of the combination of humic acid and arsenic: In vitro and in vivo studies
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Yen, Cheng-Chieh, Lu, Fung-Jou, Huang, Chun-Fa, Chen, Wen-Kang, Liu, Shing-Hwa, and Lin-Shiau, Shoei-Yn
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FOOT blood-vessel diseases , *PANCREATIC secretions , *BLOOD plasma , *INSULIN - Abstract
Abstract: Black foot disease (BFD) is a peripheral arterial occlusive disease found among the inhabitants of the southwest coast of Taiwan. Moreover, within the BFD-endemic areas, diabetes mellitus occur at significantly higher rates than in other areas of Taiwan. A high concentration of humic acid (HA), and arsenic (As) are present in the artesian well water from BFD-endemic area. The aim of this paper is to study the diabetogenic effect of the combination of HA and AS. Treatment of HIT-T15 cells with HA, As, or both of them resulted loss of cell viability, apoptosis, depletion of ATP, increment of oxidative stress, activation of caspase 3, and dysfunction of insulin secretion. In addition, the plasma insulin of ICR mice, which were exposed to HA and As in drinking water for 12 weeks, was decreased in the 5, 7, and 12 weeks, and increased at early stage of exposure (3 weeks). The results reported herein reveal that HA and As exert HIT-T15 cell dysfunction and inhibited insulin secretive effects. In addition, the sub-acute peri-pancreatitis and islet damage caused by the infiltration of inflammatory cells after exposure of HA and As in drinking water for 5 weeks. Our study has important implications in the diabetogenic effect of the HA and AS which may be mediated by ROS and further information of the toxicity mechanisms will provide under our progressive studies. [Copyright &y& Elsevier]
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- 2007
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16. Chlorpyrifos induces neuronal cell death via both oxidative stress and Akt activation downstream-regulated CHOP-triggered apoptotic pathways.
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Lin, Jhe-Wei, Fu, Shih-Chang, Liu, Jui-Ming, Liu, Shing-Hwa, Lee, Kuan-I, Fang, Kai-Min, Hsu, Ren-Jun, Huang, Chun-Fa, Liu, Kun-Min, Chang, Kai-Chih, Su, Chin-Chuan, and Chen, Ya-Wen
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CELL death , *OXIDATIVE stress , *DISEASE risk factors , *CHLORPYRIFOS , *CELL populations - Abstract
Chlorpyrifos (CPF) is one of the most abundant and widely used organophosphate pesticides for agricultural, industrial, and household purposes in the world. Epidemiological studies have reported that CPF can induce neurotoxic impairments in mammalian, which is linked to an important risk factor for development of neurodegenerative diseases (NDs). However, limited information is available on CPF-induced neurotoxicity, with the underlying exact mechanism remains unclear. In this study, CPF exposure (10–400 μM) significantly reduced Neuro-2a cell viability and induced apoptotic events, including the increase in caspase-3 activity, apoptotic cell population, and cleavage of caspase-3/−7 and PARP. Exposure of Neuro-2a cells to CPF also triggered CHOP activation. Transfection with CHOP-specific siRNA markedly suppressed the expression of CHOP, and attenuated cytotoxicity and apoptotic events in CPF-exposed Neuro-2a cells. Furthermore, CPF exposure obviously evoked the phosphorylation of Akt as well as ROS generation in a time-dependent manner. Pretreatment with LY294002 (an Akt inhibitor) effectively attenuated the CPF-induced Akt phosphorylation, CHOP activation, and apoptotic events, but not that ROS production. Of note, buffering the ROS generation with antioxidant N -acetylcysteine effectively prevented the CPF-induced ROS generation, CHOP activation, and apoptotic events, but not that the Akt phosphorylation. Collectively, these findings indicate that CPF exposure exerts neuronal cytotoxicity via the independent pathways of ROS generation and Akt activation downstream-regulated CHOP-triggered apoptosis, ultimately leading to neuronal cell death. • Chlorpyrifos (CPF) induced neuronal cell cytotoxicity and death underwent apoptosis. • Akt-activated CHOP signaling was involved in CPF-induced neuronal apoptosis. • Oxidative stress was also involved in CPF-induced neuronal cell apoptosis. • Oxidative stress and Akt signals were independent in CPF-induced neuronal apoptosis. [ABSTRACT FROM AUTHOR]
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- 2023
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17. Etoposide induces pancreatic β-cells cytotoxicity via the JNK/ERK/GSK-3 signaling-mediated mitochondria-dependent apoptosis pathway.
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Lee, Kuan-I, Su, Chin-Chuan, Yang, Ching-Yao, Hung, Dong-Zong, Lin, Ching-Ting, Lu, Tien-Hui, Liu, Shing-Hwa, and Huang, Chun-Fa
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PANCREATIC beta cells , *ETOPOSIDE , *CELL-mediated cytotoxicity , *C-Jun N-terminal kinases , *CELLULAR signal transduction , *APOPTOSIS - Abstract
Etoposide is widely used in the treatment of the different types of tumors such as pancreatic cancer. However, etoposide also causes several unwanted side-effects in normal viable cells, including pancreatic β-cells, which are vulnerable to chemical-induced injuries, and the molecular mechanisms underlying etoposide-induced apoptosis are still unclear. Here, the results showed that in RIN-m5F cells (a β-cell-derived cell line), the number of viable cells was significantly decreased after 24 h of etoposide treatment and underwent mitochondria-dependent apoptotic signals accompanied by mitochondrial dysfunction, and increases in the population of sub-G1 hypodiploid cells and apoptotic cells, caspase-3 activity, and the activation of caspase cascades. Etoposide also increased the phosphorylation levels of glycogen synthase kinase (GSK)-3α/β in treated RIN-m5F cells. Pretreatment with LiCl, a GSK-3 inhibitor, prevented etoposide-induced mitochondria-dependent apoptosis and GSK-3 protein phosphorylation in RIN-m5F cells. Furthermore, exposure of the cells to etoposide induced the phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular signal-related kinase (ERK)1/2 but not p38-MAPK, which was suppressed by the specific JNK inhibitor (SP600125) and ERK1/2 inhibitor (PD98059), respectively. Additionally, pretreatment with both SP600125 and PD98059 effectively suppressed etoposide-induced β-cell cytotoxicity, apoptosis, and GSK-3 protein phosphorylation; however, LiCl did not reverse JNK and ERK1/2 phosphorylation. Taken together, these results suggest that etoposide is capable of causing cytotoxicity on pancreatic β-cells by inducing apoptosis through the JNK/ERK-mediated GSK-3 downstream-triggered mitochondria-dependent signaling pathway. [ABSTRACT FROM AUTHOR]
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- 2016
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18. The in vivo antioxidant and antifibrotic properties of green tea (Camellia sinensis, Theaceae)
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Tsai, Chia-Fang, Hsu, Yu-Wen, Ting, Hung-Chih, Huang, Chun-Fa, and Yen, Cheng-Chieh
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ANTIOXIDANTS , *GREEN tea , *CARBON tetrachloride , *OXIDATIVE stress , *HEPATIC fibrosis , *GLUTATHIONE reductase , *CATALASE - Abstract
Abstract: The in vivo antioxidant and antifibrotic properties of green tea (Camellia sinensis, Theaceae) were investigated with a study of carbon tetrachloride (CCl4)-induced oxidative stress and hepatic fibrosis in male ICR mice. Oral administration of green tea extract at doses of 125, 625 and 1250mg/kg for 8weeks significantly reduced (p <0.05) the levels of thiobarbituric acid-reactive substances (TBARS) and protein carbonyls in the liver by at least 28% compared with that was induced by CCl4 (1mL/kg) in mice. Moreover, green tea extract administration significantly increased (p <0.05) the activities of catalase, glutathione peroxidase (GSH-Px) and glutathione reductase (GSH-Rd) in the liver. Our study found that oral administration of green tea extract prevented CCl4-induced hepatic fibrosis, as evidenced by a decreased hydroxyproline level in the liver and a reduced incidence of hepatic fibrosis by histological observations. These results indicate that green tea exhibits potent protective effects against CCl4-induced oxidative stress and hepatic fibrosis in mice by inhibiting oxidative damage and increasing antioxidant enzyme activities. [Copyright &y& Elsevier]
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- 2013
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19. Chloroacetic acid induced neuronal cells death through oxidative stress-mediated p38-MAPK activation pathway regulated mitochondria-dependent apoptotic signals
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Chen, Chun-Hung, Chen, Sz-Jie, Su, Chin-Chuan, Yen, Cheng-Chieh, Tseng, To-Jung, Jinn, Tzyy-Rong, Tang, Feng-Cheng, Chen, Kuo-Liang, Su, Yi-Chang, Lee, kuan-I, Hung, Dong-Zong, and Huang, Chun-Fa
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CHLOROACETIC acids , *NEURONS , *CELL death , *OXIDATIVE stress , *MITOGEN-activated protein kinases , *CELLULAR signal transduction , *APOPTOSIS , *NEUROTOXICOLOGY , *CHEMICAL industry - Abstract
Abstract: Chloroacetic acid (CA), a toxic chlorinated analog of acetic acid, is widely used in chemical industries as an herbicide, detergent, and disinfectant, and chemical intermediates that are formed during the synthesis of various products. In addition, CA has been found as a by-product of chlorination disinfection of drinking water. However, there is little known about neurotoxic injuries of CA on the mammalian, the toxic effects and molecular mechanisms of CA-induced neuronal cell injury are mostly unknown. In this study, we examined the cytotoxicity of CA on cultured Neuro-2a cells and investigated the possible mechanisms of CA-induced neurotoxicity. Treatment of Neuro-2a cells with CA significantly reduced the number of viable cells (in a dose-dependent manner with a range from 0.1 to 3mM), increased the generation of ROS, and reduced the intracellular levels of glutathione depletion. CA also increased the number of sub-G1 hypodiploid cells; increased mitochondrial dysfunction (loss of MMP, cytochrome c release, and accompanied by Bcl-2 and Mcl-1 down-regulation and Bax up-regulation), and activated the caspase cascades activations, which displayed features of mitochondria-dependent apoptosis pathway. These CA-induced apoptosis-related signals were markedly prevented by the antioxidant N-acetylcysteine (NAC). Moreover, CA activated the JNK and p38-MAPK pathways, but did not that ERK1/2 pathway, in treated Neuro-2a cells. Pretreatment with NAC and specific p38-MAPK inhibitor (SB203580), but not JNK inhibitor (SP600125) effectively abrogated the phosphorylation of p38-MAPK and attenuated the apoptotic signals (including: decrease in cytotoxicity, caspase-3/-7 activation, the cytosolic cytochrome c release, and the reversed alteration of Bcl-2 and Bax mRNA) in CA-treated Neuro-2a cells. Taken together, these data suggest that oxidative stress-induced p38-MAPK activated pathway-regulated mitochondria-dependent apoptosis plays an important role in CA-caused neuronal cell death. [Copyright &y& Elsevier]
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- 2013
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20. Nickel(II) induced JNK activation-regulated mitochondria-dependent apoptotic pathway leading to cultured rat pancreatic β-cell death
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Wu, Hsi-Chin, Yang, Ching-Yao, Hung, Dong-Zong, Su, Chin-Chuan, Chen, Kuo-Liang, Yen, Cheng-Chieh, Ho, Tsung-Jung, Su, Yi-Chang, Huang, Chun-Fa, Chen, Chun-Hung, Tsai, Ling-Mei, and Chen, Ya-Wen
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METAL toxicology , *NICKEL , *LABORATORY rats , *CELL death , *HEAVY metals , *CELL-mediated cytotoxicity , *PANCREAS , *ELECTROPLATING , *NICKEL alloys , *MITOGEN-activated protein kinases , *DIABETES , *MITOCHONDRIAL pathology - Abstract
Abstract: Nickel (Ni), a well-known toxic metal, is widely used in electroplating and alloy production. It is also significantly implicated in industrial and environmental pollution caused by uncontrolled industrial and municipal discharges. In this study, we characterized and investigated the cytotoxic effects of Ni exposure and their probable toxicological mechanisms in the pancreatic β-cells. The results showed that it was significantly decreased cell viability after exposing pancreatic β-cell-derived RIN-m5F cells to NiCl2 for 24h in a dose-dependent manner. NiCl2 also increased sub-G1 hypodiploid cells and Annexin V-Cy3 binding population in RIN-m5F cells, indicating that it has apoptosis-inducing ability. Moreover, the exposure of RIN-m5F cells to NiCl2 induced distinct signals of mitochondria-dependent apoptosis, including mitochondrial dysfunction (the disruption of mitochondrial membrane potential (MMP) and increase in mitochondrial cytochrome c release into the cytosol), Bak and Bid mRNA up-regulation, and activation of caspase-3, caspase-7, and caspase-9, and poly(ADP-ribose) polymerase (PARP) degradation. In addition, NiCl2 also markedly induced the activation of c-Jun N-terminal kinases (JNK), but not of extracellular signal-regulated kinase (ERK)1/2 and p38. These NiCl2-induced apoptosis-related signaling responses could be effectively reversed by specific JNK inhibitor SP600125. To the best of our knowledge, this study is the first to show that Ni causes pancreatic β-cell death through a JNK activation-regulated mitochondria-dependent apoptosis-signaling pathway. [Copyright &y& Elsevier]
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- 2011
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21. A subacute toxicity evaluation of green tea (Camellia sinensis) extract in mice
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Hsu, Yu-Wen, Tsai, Chia-Fang, Chen, Wen-Kang, Huang, Chun-Fa, and Yen, Cheng-Chieh
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GREEN tea , *PLANT extracts , *TOXICOLOGY , *ANTIOXIDANTS , *ANTIVIRAL agents , *ANTINEOPLASTIC agents , *ALKALINE phosphatase , *ALANINE aminotransferase , *ANALYSIS of variance , *ASPARTATE aminotransferase , *CATECHIN , *LABORATORY mice - Abstract
Abstract: Green tea is believed to be beneficial to health because it possesses antioxidant, antiviral and anticancer properties. The potential toxicity of green tea when administered at high doses via concentrated extracts, however, has not been completely investigated. The objective of the present study was to evaluate the safety of green tea extract in ICR mice using a subacute exposure paradigm. In this study, mice were orally administered (gavage) green tea extract at doses of 0 (as normal group), 625, 1250 and 2500mg/kgbody weight/day for 28days. The results showed that oral administration of green tea extract did not cause adverse effects on body weight, organ weights, hematology, serum biochemistry, urinalysis or histopathology. Additionally, administering green tea extract via gavage significantly reduced triglyceride and cholesterol levels. These observed effects could be attributed to the high levels of catechins present in green tea as these compounds have been reported to have beneficial health effects. The no-observed-adverse-effect level for green tea extract derived from the results of the present study was 2500mg/kgbody weight/day. [Copyright &y& Elsevier]
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- 2011
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22. Involvement of oxidative stress-mediated ERK1/2 and p38 activation regulated mitochondria-dependent apoptotic signals in methylmercury-induced neuronal cell injury
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Lu, Tien-Hui, Hsieh, Shan-Yu, Yen, Cheng-Chien, Wu, Hsi-Chin, Chen, Kuo-Liang, Hung, Dong-Zong, Chen, Chun-Hung, Wu, Chin-Ching, Su, Yi-Chang, Chen, Ya-Wen, Liu, Shing-Hwa, and Huang, Chun-Fa
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NEUROTOXICOLOGY , *OXIDATIVE stress , *MITOCHONDRIA , *APOPTOSIS , *CELLULAR signal transduction , *GENETIC regulation , *METHYLMERCURY , *CENTRAL nervous system injuries , *GENE expression , *NEURODEGENERATION , *EXTRACELLULAR enzymes , *ENZYME activation - Abstract
Abstract: Methylmercury (MeHg) is well-known for causing irreversible damage in the central nervous system as well as a risk factor for inducing neuronal degeneration. However, the molecular mechanisms of MeHg-induced neurotoxicity remain unclear. Here, we investigated the effects and possible mechanisms of MeHg in the mouse cerebrum (in vivo) and in cultured Neuro-2a cells (in vitro). In vivo study showed that the levels of LPO in the plasma and cerebral cortex significantly increased after administration of MeHg (50μg/kg/day) for 7 consecutive weeks. MeHg could also decrease glutathione level and increase the expressions of caspase-3, -7, and -9, accompanied by Bcl-2 down-regulation and up-regulation of Bax, Bak, and p53. Moreover, treatment of Neuro-2a cells with MeHg significantly reduced cell viability, increased oxidative stress damage, and induced several features of mitochondria-dependent apoptotic signals, including increased sub-G1 hypodiploids, mitochondrial dysfunctions, and the activation of PARP, and caspase cascades. These MeHg-induced apoptotic-related signals could be remarkably reversed by antioxidant NAC. MeHg also increased the phosphorylation of ERK1/2 and p38, but not JNK. Pharmacological inhibitors NAC, PD98059, and SB203580 attenuated MeHg-induced cytotoxicity, ERK1/2 and p38 activation, MMP loss, and caspase-3 activation in Neuro-2a cells. Taken together, these results suggest that the signals of ROS-mediated ERK1/2 and p38 activation regulated mitochondria-dependent apoptotic pathways that are involved in MeHg-induced neurotoxicity. [Copyright &y& Elsevier]
- Published
- 2011
- Full Text
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23. Arsenic induces pancreatic β-cell apoptosis via the oxidative stress-regulated mitochondria-dependent and endoplasmic reticulum stress-triggered signaling pathways
- Author
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Lu, Tien-Hui, Su, Chin-Chuan, Chen, Ya-Wen, Yang, Ching-Yao, Wu, Chin-Ching, Hung, Dong-Zong, Chen, Chun-Hung, Cheng, Po-Wen, Liu, Shing-Hwa, and Huang, Chun-Fa
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ARSENIC poisoning , *PANCREATIC beta cells , *APOPTOSIS , *OXIDATIVE stress , *ENDOPLASMIC reticulum , *MITOCHONDRIA , *PHYSIOLOGICAL stress , *CELLULAR signal transduction , *OXYGEN in the body , *MALONDIALDEHYDE , *MITOCHONDRIAL pathology , *PROTEIN kinases - Abstract
Abstract: Arsenic (As), a ubiquitous toxic metal, is an important environmental and industrial pollutant throughout the world. Inorganic As (iAs) is usually more harmful than organic ones and with a high risk of diabetes incidence by exposure. However, the toxicological effects of iAs on growth and function of pancreatic β-cells still remain unclear. Here, we found that iAs significantly decreased insulin secretion and cell viability, and increased ROS and MDA formation in pancreatic β-cell-derived RIN-m5F cells. iAs also induced the increases in sub-G1 hypodiploids, annexin V-Cy3 binding, and caspase-3 activity in RIN-m5F cells, indicating that iAs could induce β-cell apoptosis. Moreover, iAs induced MAPKs activation, mitochondria dysfunction, p53 up-regulation, Bcl-2 and Mdm-2 down-regulation, PARP, and caspase cascades, which displayed features of mitochondria-dependent apoptotic signals. In addition, exposure of RIN-m5F cells to iAs, could trigger ER stress as indicated by the enhancement in ER stress-related molecules induction (such as GRP78, GRP94, CHOP, and XBP1), procaspase-12 cleavage, and calpain activation. The iAs-induced apoptosis and its-related signalings could be effectively reversed by antioxidant N-acetylcysteine. We next observed that exposure of mice to iAs in drinking water for 6 consecutive weeks significantly decreased decreased the plasma insulin, elevated glucose intolerance and plasma lipid peroxidation, and induced islet cells apoptosis, which accompanied with arsenic accumulation in the whole blood and pancreas. N-acetylcysteine effectively antagonized the iAs-induced responses in mice. Taken together, these results suggest that iAs-induced oxidative stress causes pancreatic β-cells apoptosis via the mitochondria-dependent and ER stress-triggered signaling pathways. [Copyright &y& Elsevier]
- Published
- 2011
- Full Text
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24. Extract isolated from Angelica hirsutiflora with insulin secretagogue activity
- Author
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Leu, Yann Lii, Chen, Ya Wen, Yang, Ching Yao, Huang, Chun Fa, Lin, Guan Hong, Tsai, Keh Sung, Yang, Rong Sen, and Liu, Shing Hwa
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ANGELICA (Plants) , *ETHNOPHARMACOLOGY , *TRADITIONAL medicine , *TREATMENT of diabetes , *CELL lines ,THERAPEUTIC use of plant extracts - Abstract
Abstract: Ethnopharmacological relevance: Angelica genus (Umbelliferae) has traditionally been used as the medicine and health food considered alleviating several disorders including diabetes mellitus. Angelica hirsutiflora Liu Chao & Chuang is an endemic species and a folk medicine in Taiwan. Aim of the study: The scientific evidence of anti-diabetic effect for Angelica hirsutiflora remains unknown. The methanolic extracts isolated from Angelica hirsutiflora were studied for its insulin secretagogue and hypoglycemic activities. Materials and methods: The in vitro effects and possible mechanisms of Angelica hirsutiflora extract on the insulin secretion in isolated mouse and human islets and pancreatic β-cell line HIT-T15 were determined; and tested the regulation of blood glucose in fasted mice and high-fat diet-induced diabetic mice. Results: Angelica hirsutiflora extract potently stimulated the release of insulin from cultured HIT-T15 cells and isolated mouse and human islets. The intracellular calcium levels were also increased in HIT-T15 cells and isolated human islets treated with Angelica hirsutiflora extract. Angelica hirsutiflora extract was capable of enhancing the phosphorylation of extracellular signal-regulated protein kinases (ERK)1/2 protein in HIT-T15 cells. Specific ERK inhibitor PD98059 inhibited the increase of insulin secretion by Angelica hirsutiflora extract in HIT-T15 cells and isolated mouse islets. When Angelica hirsutiflora extract was administered to the fasted mice, it decreased the rise in blood glucose level after starch loading. The plasma insulin level was also increased by Angelica hirsutiflora extract treatment. In high-fat diet-induced diabetic mice, Angelica hirsutiflora extract markedly improved the oral glucose intolerance as compared with the vehicle control. Conclusions: These findings support that Angelica hirsutiflora extract may be useful in the control of hyperglycemia in non-insulin-dependent diabetes mellitus by acting as an insulin secretagogue. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
- View/download PDF
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