Publications by authors named "Cheng-Yi Chang"

64 Publications

TNF-α Receptor Inhibitor Alleviates Metabolic and Inflammatory Changes in a Rat Model of Ischemic Stroke.

Antioxidants (Basel) 2021 May 26;10(6). Epub 2021 May 26.

Department of Medical Research, Taichung Veterans General Hospital, Taichung City 407, Taiwan.

Hyperglycemia and inflammation, with their augmented interplay, are involved in cases of stroke with poor outcomes. Interrupting this vicious cycle thus has the potential to prevent stroke disease progression. Tumor necrosis factor-α (TNF-α) is an emerging molecule, which has inflammatory and metabolic roles. Studies have shown that TNF-α receptor inhibitor R-7050 possesses neuroprotective, antihyperglycemic, and anti-inflammatory effects. Using a rat model of permanent cerebral ischemia, pretreatment with R-7050 offered protection against poststroke neurological deficits, brain infarction, edema, oxidative stress, and caspase 3 activation. In the injured cortical tissues, R-7050 reversed the activation of TNF receptor-I (TNFRI), NF-κB, and interleukin-6 (IL-6), as well as the reduction of zonula occludens-1 (ZO-1). In the in vitro study on bEnd.3 endothelial cells, R-7050 reduced the decline of ZO-1 levels after TNF-α-exposure. R-7050 also reduced the metabolic alterations occurring after ischemic stroke, such as hyperglycemia and increased plasma corticosterone, free fatty acids, C reactive protein, and fibroblast growth factor-15 concentrations. In the gastrocnemius muscles of rats with stroke, R-7050 improved activated TNFRI/NF-κB, oxidative stress, and IL-6 pathways, as well as impaired insulin signaling. Overall, our findings highlight a feasible way to combat stroke disease based on an anti-TNF therapy that involves anti-inflammatory and metabolic mechanisms.
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http://dx.doi.org/10.3390/antiox10060851DOI Listing
May 2021

Glycerol Improves Intracerebral Hemorrhagic Brain Injury and Associated Kidney Dysfunction in Rats.

Antioxidants (Basel) 2021 Apr 19;10(4). Epub 2021 Apr 19.

Department of Medical Research, Taichung Veterans General Hospital, Taichung City 407, Taiwan.

In stroke patients, the development of acute kidney injury (AKI) is closely linked with worse outcomes and increased mortality. In this study, the interplay between post-stroke and AKI and treatment options was investigated in a rodent model of hemorrhagic stroke. Intrastriatal collagenase injection for 24 h caused neurological deficits, hematoma formation, brain edema, apoptosis, blood-brain barrier disruption, oxidative stress, and neuroinflammation in Sprague Dawley rats. Elevation of serum blood urea nitrogen, serum creatinine, urine cytokine-induced neutrophil chemoattractant-1, and urine Malondialdehyde, as well as moderate histological abnormality in the kidney near the glomerulus, indicated evidence of kidney dysfunction. The accumulation of podocalyxin DNA in urine further suggested a detachment of podocytes and structural deterioration of the glomerulus. Circulating levels of stress hormones, such as epinephrine, norepinephrine, corticosterone, and angiotensin II were elevated in rats with intracerebral hemorrhage. Osmotic agent glycerol held promising effects in alleviating post-stroke brain injury and kidney dysfunction. Although the detailed protective mechanisms of glycerol have yet to be determined, the intrastriatal collagenase injection hemorrhagic stroke model in rats allowed us to demonstrate the functional and structural integrity of glomerulus are targets that are vulnerable to post-stroke injury and stress hormones could be surrogates of remote communications.
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http://dx.doi.org/10.3390/antiox10040623DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8073011PMC
April 2021

Endoplasmic Reticulum Stress Contributes to Gefitinib-Induced Apoptosis in Glioma.

Int J Mol Sci 2021 Apr 11;22(8). Epub 2021 Apr 11.

Department of Medical Research, Taichung Veterans General Hospital, Taichung 407, Taiwan.

Adequate stress on the Endoplasmic Reticulum (ER) with the Unfolded Protein Response (UPR) could maintain glioma malignancy. Uncontrolled ER stress, on the other hand, predisposes an apoptosis-dominant UPR program. We studied here the proapoptotic actions of the Epidermal Growth Factor Receptor (EGFR) inhibitor gefitinib, with the focus on ER stress. The study models were human H4 and U87 glioma cell lines. We found that the glioma cell-killing effects of gefitinib involved caspase 3 apoptotic cascades. Three branches of ER stress, namely Activating Transcription Factor-6 (ATF6), Protein Kinase R (PKR)-Like ER Kinase (PERK), and Inositol-Requiring Enzyme 1 (IRE1), were activated by gefitinib, along with the elevation of intracellular free Ca, Reactive Oxygen Species (ROS), and NADPH Oxidase2/4 (NOX2/4). Specifically, elevated IRE1 phosphorylation, Tumor Necrosis Factor (TNF) Receptor-Associated Factor-2 (TRAF2) expression, Apoptosis Signal-Regulating Kinase-1 (Ask1) phosphorylation, c-Jun N-Terminal Kinase (JNK) phosphorylation, and Noxa expression appeared in gefitinib-treated glioma cells. Genetic, pharmacological, and biochemical studies further indicated an active ROS/ER stress/Ask1/JNK/Noxa axis causing the glioma apoptosis induced by gefitinib. The findings suggest that ER-stress-based therapeutic targeting could be a promising option in EGFR inhibitor glioma therapy, and may ultimately achieve a better patient response.
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http://dx.doi.org/10.3390/ijms22083934DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8069544PMC
April 2021

Exosomal HMGB1 Promoted Cancer Malignancy.

Cancers (Basel) 2021 Feb 19;13(4). Epub 2021 Feb 19.

Department of Medical Research, Taichung Veterans General Hospital, Taichung City 407, Taiwan.

Reciprocal crosstalk between platelets and malignancies underscores the potential of antiplatelet therapy in cancer treatment. In this study, we found that human chronic myeloid leukemia K562 cell-differentiated megakaryocytes and murine platelets produced bioactive substances and these are released into the extracellular space, partly in their exosomal form. High-mobility group box 1 (HMGB1) is a type of exosomal cargo, and the antiplatelet drugs aspirin and dipyridamole interfered with its incorporation into the exosomes. Those released substances and exosomes, along with exogenous HMGB1, promoted cancer cell survival and protected cells from doxorubicin cytotoxicity. In a tumor-bearing model established using murine Lewis lung carcinoma (LLC) cells and C57BL/6 mice, the tumor suppressive effect of dipyridamole correlated well with decreased circulating white blood cells, soluble P-selectin, TGF-β1 (Transforming Growth Factor-β1), exosomes, and exosomal HMGB1, as well as tumor platelet infiltration. Exosome release inhibitor GW4869 exhibited suppressive effects as well. The suppressive effect of dipyridamole on cancer cell survival was paralleled by a reduction of HMGB1/receptor for advanced glycation end-products axis, and proliferation- and migration-related β-catenin, Yes-associated protein 1, Runt-related transcription factor 2, and TGF- β1/Smad signals. Therefore, exosomes and exosomal HMGB1 appear to have roles in platelet-driven cancer malignancy and represent targets of antiplatelet drugs in anticancer treatment.
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http://dx.doi.org/10.3390/cancers13040877DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7921955PMC
February 2021

DHA attenuated Japanese Encephalitis virus infection-induced neuroinflammation and neuronal cell death in cultured rat Neuron/glia.

Brain Behav Immun 2021 03 21;93:194-205. Epub 2021 Jan 21.

Department of Medical Research, Taichung Veterans General Hospital, Taichung City, Taiwan; Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung City, Taiwan; Ph.D. Program in Translational Medicine, College of Life Sciences, National Chung-Hsing University, Taichung City, Taiwan. Electronic address:

Japanese Encephalitis Virus (JEV) is a neurotropic virus and its Central Nervous System (CNS) infection causes fatal encephalitis with high mortality and morbidity. Microglial activation and consequences of bystander damage appear to be the dominant mechanisms for Japanese Encephalitis and complications. Docosahexaenoic acid (DHA), an essential fatty acid and a major component of brain cell membranes, possesses additional biological activities, including anti-apoptosis, anti-inflammation, and neuroprotection. Through this study, we have provided experimental evidence showing the anti-inflammatory, neuroprotective, and anti-viral effects of DHA against JEV infection in rat Neuron/glia cultures. By Neuron/glia and Neuron cultures, DHA protected against neuronal cell death upon JEV infection and reduced JEV amplification. In Neuron/glia and Microglia cultures, the effects of DHA were accompanied by the downregulation of pro-inflammatory M1 microglia, upregulation of anti-inflammatory M2 microglia, and reduction of neurotoxic cytokine expression, which could be attributed to its interference in the Toll-Like Receptor (TLR), Mitogen-Activated Protein Kinase (MAPK), and Interferon/Janus Kinase/Signal Transducers and Activators of Transcription (Stat), along with the NF-κB, AP-1, and c-AMP Response Element Binding Protein (CREB) controlled transcriptional programs. Parallel anti-inflammatory effects against JEV infection were duplicated by G Protein-Coupled Receptor (GPR120) and GPR40 agonists and a reversal of DHA-mediated anti-inflammation was seen in the presence of GPR120 antagonist, while the GPR40 was less effectiveness. Since increasing evidence indicates its neuroprotection against neurodegenerative diseases, DHA is a proposed anti-inflammatory and neuroprotective candidate for the treatment of neuroinflammation-accompanied viral pathogenesis such as Japanese Encephalitis.
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http://dx.doi.org/10.1016/j.bbi.2021.01.012DOI Listing
March 2021

Quercetin protects against cerebral ischemia/reperfusion and oxygen glucose deprivation/reoxygenation neurotoxicity.

J Nutr Biochem 2020 09 30;83:108436. Epub 2020 May 30.

Department of Medical Research, Taichung Veterans General Hospital, Taichung City, Taiwan; Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung City, Taiwan. Electronic address:

Beyond nutrition effect, quercetin is applied as a complement or an alternative for promoting human health and treating diseases. However, its complicated neuroprotective mechanisms have not yet been fully elucidated. This study provides evidence of an alternative target for quercetin, and sheds light on the mechanisms of its neuroprotection against cerebral ischemia/reperfusion (I/R) injury in Sprague-Dawley rats. Oral pretreatment using quercetin has alleviated cerebral I/R-induced neurological deficits, brain infarction, blood-brain barrier disruption, oxidative stress, TNF-α and IL-1β mRNA expression, along with apoptotic caspase 3 activity. The neuroprotective, anti-oxidative, anti-inflammatory, and anti-apoptotic effects of quercetin were replicated in rat hippocampal slice cultures and neuron/glia cultures which suffered from oxygen-glucose deprivation and reoxygenation (OGDR). Biochemical studies revealed a reduction of extracellular signal-regulated kinase (ERK) and Akt phosphorylation, along with an increase in protein tyrosine and serine/threonine phosphatase activity in cerebral I/R rat cortical tissues and OGDR hippocampal slice and neuron/glia cultures. Quercetin alleviated the changes in ERK/Akt phosphorylation and protein phosphatase activities. Inhibition of ERK or Akt alone was enough to cause apoptotic cell death and cytotoxicity in hippocampal slice cultures and neuron/glia cultures, while activators of ERK or Akt alleviated OGDR-induced cytotoxicity. Taken together, our results demonstrate that quercetin alleviated the increment of protein tyrosine and serine/threonine phosphatase activity, along with the reduction of ERK and Akt phosphorylation, which may play pivotal roles in the expansion of brain injury after cerebral I/R.
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http://dx.doi.org/10.1016/j.jnutbio.2020.108436DOI Listing
September 2020

Aspirin Induced Glioma Apoptosis through Noxa Upregulation.

Int J Mol Sci 2020 Jun 13;21(12). Epub 2020 Jun 13.

Department of Medical Research, Taichung Veterans General Hospital, Taichung City 407, Taiwan.

Clinically, high cyclooxygenase-2 expression in malignant glioma correlates well with poor prognosis and the use of aspirin is associated with a reduced risk of glioma. To extend the current understanding of the apoptotic potential of aspirin in most cell types, this study provides evidence showing that aspirin induced glioma cell apoptosis and inhibited tumor growth, in vitro and in vivo. We found that the human H4 glioma cell-killing effects of aspirin involved mitochondria-mediated apoptosis accompanied by endoplasmic reticulum (ER) stress, Noxa upregulation, Mcl-1 downregulation, Bax mitochondrial distribution and oligomerization, and caspase 3/caspase 8/caspase 9 activation. Genetic silencing of Noxa or Bax attenuated aspirin-induced viability loss and apoptosis, while silencing Mcl-1 augmented the effects of aspirin. Data from genetic and pharmacological studies revealed that the axis of ER stress comprised an apoptotic cascade leading to Noxa upregulation and apoptosis. The apoptotic programs and mediators triggered by aspirin in H4 cells were duplicated in human U87 glioma cell line as well as in tumor-bearing BALB/c nude mice. The involvement of ER stress in indomethacin-induced Mcl-1 downregulation was reported in our previous study on glioma cells. Therefore, the aforementioned phenomena indicate that ER stress may be a valuable target for intervention in glioma apoptosis.
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http://dx.doi.org/10.3390/ijms21124219DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7352791PMC
June 2020

Effects of β-Adrenergic Blockade on Metabolic and Inflammatory Responses in a Rat Model of Ischemic Stroke.

Cells 2020 06 1;9(6). Epub 2020 Jun 1.

Department of Medical Research, Taichung Veterans General Hospital, Taichung City 407, Taiwan.

Ischemic stroke provokes an inflammatory response concurrent with both sympathetic nervous system activation and hyperglycemia. Currently, their crosstalk and consequences in stroke outcomes are of clinical attraction. We have provided experimental evidence showing the suppressive effects of the nonselective β-adrenoreceptor antagonist propranolol on hyperglycemia, inflammation, and brain injury in a rat model experiencing cerebral ischemia. Pretreatment with propranolol protected against postischemic brain infarction, edema, and apoptosis. The neuroprotection caused by propranolol was accompanied by a reduction in fasting glucose, fasting insulin, glucose tolerance impairment, plasma C-reactive protein, plasma free fatty acids, plasma corticosterone, brain oxidative stress, and brain inflammation. Pretreatment with insulin alleviated-while glucose augmented-postischemic brain injury and inflammation. Additionally, the impairment of insulin signaling in the gastrocnemius muscles was noted in rats with cerebral ischemia, with propranolol improving the impairment by reducing oxidative stress and tumor necrosis factor-α signaling. The anti-inflammatory effects of propranolol were further demonstrated in isoproterenol-stimulated BV2 and RAW264.7 cells through its ability to decrease cytokine production. Despite their potential benefits, stroke-associated hyperglycemia and inflammation are commonly linked with harmful consequences. Our findings provide new insight into the anti-inflammatory, neuroprotective, and hypoglycemic mechanisms of propranolol in combating neurodegenerative diseases, such as stroke.
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http://dx.doi.org/10.3390/cells9061373DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7349353PMC
June 2020

β-Funaltrexamine Displayed Anti-inflammatory and Neuroprotective Effects in Cells and Rat Model of Stroke.

Int J Mol Sci 2020 May 29;21(11). Epub 2020 May 29.

Department of Medical Research, Taichung Veterans General Hospital, Taichung City 407, Taiwan.

Chronic treatment involving opioids exacerbates both the risk and severity of ischemic stroke. We have provided experimental evidence showing the anti-inflammatory and neuroprotective effects of the μ opioid receptor antagonist β-funaltrexamine for neurodegenerative diseases in rat neuron/glia cultures and a rat model of cerebral Ischemia/Reperfusion (I/R) injury. Independent of in vitro Lipopolysaccharide (LPS)/interferon (IFN-γ)-stimulated neuron/glia cultures and in vivo cerebral I/R injury in Sprague-Dawley rats, β-funaltrexamine downregulated neuroinflammation and ameliorated neuronal degeneration. Alterations in microglia polarization favoring the classical activation state occurred in LPS/IFN-γ-stimulated neuron/glia cultures and cerebral I/R-injured cortical brains. β-funaltrexamine shifted the polarization of microglia towards the anti-inflammatory phenotype, as evidenced by decreased nitric oxide, tumor necrosis factor-α, interleukin-1β, and prostaglandin E2, along with increased CD163 and arginase 1. Mechanistic studies showed that the suppression of microglia pro-inflammatory polarization by β-funaltrexamine was accompanied by the reduction of NF-κB, AP-1, cyclic AMP response element-binding protein, along with signal transducers and activators of transcription transcriptional activities and associated upstream activators. The effects of β-funaltrexamine are closely linked with its action on neuroinflammation by switching microglia polarization from pro-inflammatory towards anti-inflammatory phenotypes. These findings provide new insights into the anti-inflammatory and neuroprotective mechanisms of β-funaltrexamine in combating neurodegenerative diseases, such as stroke.
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http://dx.doi.org/10.3390/ijms21113866DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7313048PMC
May 2020

Endoplasmic Reticulum Stress Contributes to Indomethacin-Induced Glioma Apoptosis.

Int J Mol Sci 2020 Jan 15;21(2). Epub 2020 Jan 15.

Department of Medical Research, Taichung Veterans General Hospital, Taichung City 407, Taiwan.

The dormancy of cellular apoptotic machinery has been highlighted as a crucial factor in therapeutic resistance, recurrence, and poor prognosis in patients with malignancy, such as malignant glioma. Increasing evidence indicates that nonsteroidal anti-inflammatory drugs (NSAIDs) confer chemopreventive effects, and indomethacin has been shown to have a novel chemotherapeutic application targeting glioma cells. To extend these findings, herein, we studied the underlying mechanisms of apoptosis activation caused by indomethacin in human H4 and U87 glioma cells. We found that the glioma cell-killing effects of indomethacin involved both death receptor- and mitochondria-mediated apoptotic cascades. Indomethacin-induced glioma cell apoptosis was accompanied by a series of biochemical changes, including reactive oxygen species generation, endoplasmic reticulum (ER) stress, apoptosis signal-regulating kinase-1 (Ask1) activation, p38 hyperphosphorylation, protein phosphatase 2A (PP2A) activation, Akt dephosphorylation, Mcl-1 and FLICE-inhibiting protein (FLIP) downregulation, Bax mitochondrial distribution, and caspases 3/caspase 8/caspase 9 activation. Data on pharmacological inhibition related to oxidative stress, ER stress, free Ca, and p38 revealed that the axis of oxidative stress/ER stress/Ask1/p38/PP2A/Akt comprised an apoptotic cascade leading to Mcl-1/FLIP downregulation and glioma apoptosis. Since indomethacin is an emerging choice in chemotherapy and its antineoplastic effects have been demonstrated in glioma tumor-bearing models, the findings further strengthen the argument for turning on the aforementioned axis in order to activate the apoptotic machinery of glioma cells.
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http://dx.doi.org/10.3390/ijms21020557DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7013513PMC
January 2020

Corrigendum to "Magnolol ameliorates pneumonectomy and monocrotaline-induced pulmonary arterial hypertension in rats through inhibition of angiotensin II and endothelin-1 expression" [Phytomedicine 51 (2018) 205-213].

Phytomedicine 2019 Sep 11;62:152988. Epub 2019 Jul 11.

Department of Biotechnology, Asia University, Taichung, Taiwan; China Medical University Hospital, Taichung, Taiwan. Electronic address:

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http://dx.doi.org/10.1016/j.phymed.2019.152988DOI Listing
September 2019

Fibronectin Promotes Cell Growth and Migration in Human Renal Cell Carcinoma Cells.

Int J Mol Sci 2019 Jun 7;20(11). Epub 2019 Jun 7.

Department of Medical Research, Taichung Veterans General Hospital, Taichung 407, Taiwan.

The prognostic and therapeutic values of fibronectin have been reported in patients with renal cell carcinoma (RCC). However, the underlying mechanisms of malignancy in RCC are not completely understood. We found that silencing of fibronectin expression attenuated human RCC 786-O and Caki-1 cell growth and migration. Silencing of potential fibronectin receptor integrin α5 and integrin β1 decreased 786-O cell ability in movement and chemotactic migration. Biochemical examination revealed a reduction of cyclin D1 and vimentin expression, transforming growth factor-β1 (TGF-β1) production, as well as Src and Smad phosphorylation in fibronectin-silenced 786-O and Caki-1 cells. Pharmacological inhibition of Src decreased 786-O cell growth and migration accompanied by a reduction of cyclin D1, fibronectin, vimentin, and TGF-β1 expression, as well as Src and Smad phosphorylation. In 786-O cells, higher activities in cell growth and migration than in Caki-1 cells were noted, along with elevated fibronectin and TGF-β1 expression. The additions of exogenous fibronectin and TGF-β1 promoted Caki-1 cell growth and migration, and increased cyclin D1, fibronectin, vimentin, and TGF-β1 expression, as well as Src and Smad phosphorylation. These findings highlight the role of fibronectin in RCC cell growth and migration involving Src and TGF-β1 signaling.
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http://dx.doi.org/10.3390/ijms20112792DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6600362PMC
June 2019

Anti-inflammatory and Neuroprotective Effects of Fungal Immunomodulatory Protein Involving Microglial Inhibition.

Int J Mol Sci 2018 Nov 21;19(11). Epub 2018 Nov 21.

Department of Medical Research, Taichung Veterans General Hospital, Taichung 407, Taiwan.

Microglia polarization of classical activation state is crucial to the induction of neuroinflammation, and has been implicated in the pathogenesis of numerous neurodegenerative diseases. Fungal immunomodulatory proteins are emerging health-promoting natural substances with multiple pharmacological activities, including immunomodulation. Herein, we investigated the anti-inflammatory and neuroprotective potential of fungal immunomodulatory protein extracted from (GMI) in an in vitro rodent model of primary cultures. Using primary neuron/glia cultures consisting of neurons, astrocytes, and microglia, a GMI showed an alleviating effect on lipopolysaccharide (LPS)/interferon-γ (IFN-γ)-induced inflammatory mediator production and neuronal cell death. The events of neuroprotection caused by GMI were accompanied by the suppression of Nitric Oxide (NO), Tumor Necrosis Factor-α (TNF-α), Interleukin-1β (IL-1β), and Prostaglandin E2 (PGE2) production, along with the inhibition of microglia activation. Mechanistic studies showed that the suppression of microglia pro-inflammatory polarization by GMI was accompanied by the resolution of oxidative stress, the preservation of protein tyrosine phosphatase and serine/threonine phosphatase activity, and the reduction of NF-κB, AP-1, cyclic AMP response element-binding protein (CREB), along with signal transducers and activators of transcription (Stat1) transcriptional activities and associated upstream activators. These findings suggest that GMI may have considerable potential towards the treatment of neuroinflammation-mediated neurodegenerative diseases.
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http://dx.doi.org/10.3390/ijms19113678DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6274830PMC
November 2018

Magnolol ameliorates pneumonectomy and monocrotaline-induced pulmonary arterial hypertension in rats through inhibition of angiotensin II and endothelin-1 expression.

Phytomedicine 2018 Dec 4;51:205-213. Epub 2018 Oct 4.

Department of Medical Research, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City, Taiwan; Department of Biotechnology, Asia University, Taichung, Taiwan; China Medical University Hospital, Taichung, Taiwan. Electronic address:

Background: Magnolol, a major bioactive component extracted from Magnolia officinalis, exerts several beneficial effects, such as anti-inflammatory and anti-hypertensive activities.

Purpose: In this study, we investigated whether magnolol has a protective effect on pneumonectomy and monocrotaline-induced pulmonary arterial hypertension (PAH) in rats.

Design/methods: The alterations of right ventricular (RV) hypertrophy, pulmonary vascular remodeling, histopathological parameters, and related gene expression and signaling pathways in lungs by magnolol treatment were studied in the PAH rats.

Results: Administration of magnolol greatly ameliorated the characteristic features of PAH, including increased pulmonary arterial pressure, RV hypertrophy, and pulmonary vascular remodeling. Moreover, magnolol inhibited angiotensin-converting enzyme (ACE)/angiotensin II (Ang II)/Ang II type 1 receptor (AT-1R) cascade, whereas upregulates ACE2 in the lungs of PAH rats. The overexpression of endothelin-1 (ET-1) and ET receptor occurred in the PAH rats was significantly attenuated by magnolol through inhibition of Akt/ERK1/2/GSK3β/β-catenin pathway. Compared with that of untreated PAH rats, higher expression of endothelial nitric oxide synthase, and lower expression of inducible nitric oxide synthase and O production in lungs were observed in magnolol-treated PAH rats.

Conclusion: We demonstrated that treatment with magnolol reduces the development of PAH induced by pneumonectomy and monocrotaline in rats, and suppressing Ang II and ET-1-mediated processes may contribute to its protective effects. These findings suggest that magnolol may be a potential agent for PAH therapy.
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http://dx.doi.org/10.1016/j.phymed.2018.10.001DOI Listing
December 2018

Platycodin D Reverses Pathological Cardiac Hypertrophy and Fibrosis in Spontaneously Hypertensive Rats.

Am J Chin Med 2018 29;46(3):537-549. Epub 2018 Mar 29.

* Graduate Institute of Basic Medical Science, China Medical University, Taichung 40402, Taiwan.

Platycodin D (PD) is the main active saponin isolated from Platycodon grandiflorum (PG) and is reported to exhibit anticancer, anti-angiogenic, anti-inflammation and anti-obesity biological effects. The current study aims to evaluate the therapeutic efficacy of PD in cardiac fibrosis and for hypertrophy in spontaneous hypertension rats (SHRs) and to verify inhibition of the signaling pathway. Significant increases in the cardiac functional indices of left ventricular internal diameter end diastole (LVIDd) and left ventricular internal diameter end systole (LVIDs); the eccentric hypertrophy marker p-MEK5; concentric hypertrophy markers, such as CaMKII[Formula: see text] and calcineurin; and expression levels of NFATc3, p-GATA4 and BNP were observed in spontaneously hypertensive groups. PD treatment reversed these increases in SHRs. In addition, an increase in the fibrosis markers FGF2, uPA, MMP2, MMP9, TGF[Formula: see text]-1 and CTGF during cardiac hypertrophy was detected by western blotting analyses. These results demonstrated that PD treatment considerably attenuates cardiac fibrosis. Histopathological examination revealed that PD treatment remarkably reduced collagen accumulation in contrast to spontaneously hypertensive groups. This study clearly suggests that PD provides myocardial protection by alleviating two damaging responses to hypertension, fibrosis and hypertrophy, in the heart.
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http://dx.doi.org/10.1142/S0192415X18500271DOI Listing
July 2018

Indomethacin induced glioma apoptosis involving ceramide signals.

Exp Cell Res 2018 04 19;365(1):66-77. Epub 2018 Feb 19.

Department of Medical Research, Taichung Veterans General Hospital, No. 1650, Section 4, Taiwan Boulevard, Taichung City 407, Taiwan; Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung City 404, Taiwan. Electronic address:

Nonsteroidal anti-inflammatory drugs (NSAIDs) are increasingly implicated in the prevention and treatment of cancers apart from their known inhibitory effects on eicosanoid production. One of the NSAIDs, indomethacin, in particular shows promising antineoplastic outcome against glioma. To extend such finding, we here studied in human H4 and U87 glioma cells the possible involvement of the ceramide/protein phosphatase 2 A (PP2A)/Akt axis in the indomethacin-induced apoptosis. We found that the induced apoptosis was accompanied by a series of biochemical events, including intracellular ceramide generation, PP2A activation, Akt dephosphorylation, Mcl-1 and FLICE inhibiting protein (FLIP) transcriptional downregulation, Bax mitochondrial distribution, and caspase 3 activation. Such events were also duplicated with a cell-permeable C2-ceramide and Akt inhibitor LY294002. Pharmacological inhibition of ceramide synthase by fumonisin B1 and PP2A by okadaic acid moderately attenuated indomethacin-induced Akt dephosphorylation along with the apoptosis. Results suggested that the ceramide/PP2A/Akt axis is involved in the apoptosis and a possible cyclooxygenase-independent target for indomethacin. Furthermore, apoptosis regulatory proteins such as Mcl-1 and FLIP are potential downstream effectors of this axis and their downregulation could turn on the apoptotic program.
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http://dx.doi.org/10.1016/j.yexcr.2018.02.019DOI Listing
April 2018

Treadmill exercise alleviated prenatal buprenorphine exposure-induced depression in rats.

Neurochem Int 2017 Nov 27;110:91-100. Epub 2017 Sep 27.

Department of Medical Research, Taichung Veterans General Hospital, Taichung City 407, Taiwan; Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung City 404, Taiwan. Electronic address:

Mounting evidence suggests that physical exercise shows health benefits in a range of diseases, including psychiatric disorders. Perinatal opioid exposure produces neurobehavioral abnormality, which includes depression symptoms, in patients and their offspring following chronic use of buprenorphine, a mixed agonist/antagonist with a high affinity to opioid receptors, for pain control. Previously, we demonstrated that prenatal buprenorphine exposure in pregnant Sprague-Dawley rats starting from gestation day 7 and lasting for 14 days caused the development of depression-like phenotypes in pups at postnatal day 21. Using the same prenatal buprenorphine exposure model, we further demonstrated that a 4-week course of moderate treadmill exercise conducted on pups starting from postnatal day 22 improved depression-like neurobehaviors. Prenatal buprenorphine exposure-induced neurobehavioral changes were accompanied by reductions of neuronal survival, neural stem cell-associated genes, plasma level of brain-derived neurotrophic factor (BDNF) and serotonin, phosphorylated tropomyosin-related kinase receptor type B (TrkB), phosphorylated extracellular signal-regulated kinase (ERK), PKA activity, phosphorylated cAMP response element-binding protein (CREB), and CREB DNA binding activity, as well as elevation of repressor element-1 silencing transcription factor (REST), oxidative stress, and inflammatory responses. Those changes in parameters of plasma and brain were improved by treadmill exercise. In conclusion, the findings of the current study suggest that a non-pharmacological option, i.e., moderate treadmill exercise, alleviated the development of depression-like neurobehaviors by resolving the oxidative and inflammatory burden as well as by enhancing neurochemical and neuroendocrine signaling.
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http://dx.doi.org/10.1016/j.neuint.2017.09.012DOI Listing
November 2017

Interplay of inflammatory gene expression in pericytes following Japanese encephalitis virus infection.

Brain Behav Immun 2017 Nov 6;66:230-243. Epub 2017 Jul 6.

Department of Medical Research, Taichung Veterans General Hospital, Taichung City 407, Taiwan; Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung City 404, Taiwan. Electronic address:

Neuroinflammation is a pathological hallmark and has been implicated in the pathogenesis of Japanese encephalitis. Although brain pericytes show regulatory effects on neuroinflammation, their involvement in Japanese encephalitis-associated neuroinflammation is not understood. Here, we demonstrated that brain microvascular pericytes could be an alternative cellular source for the induction and/or amplification of neuroinflammation caused by Japanese encephalitis virus (JEV) infection. Infection of cultured pericytes with JEV caused profound production of IL-6, RANTES, and prostaglandin E2 (PGE2). Mechanistic studies revealed that JEV infection elicited an elevation of the toll-like receptor 7 (TLR7)/MyD88 signaling axis, leading to the activation of NF-κB through IKK signaling and p65 phosphorylation as well as cAMP response element-binding protein (CREB) via phosphorylation. We further demonstrated that extracellular signal-regulated kinase (ERK) could be an alternative regulator in transducing signals to NF-κB, CREB, and cytosolic phospholipase A2 (cPLA2) through the phosphorylation mechanism. Released IL-6 and RANTES played an active role in the disruption of endothelial barrier integrity and leukocyte chemotaxis, respectively. cPLA2/PGE2 had a role in activating NF-κB and CREB DNA-binding activities and inflammatory cytokine transcription via the EP2/cAMP/PKA mechanism in an autocrine loop. These inflammatory responses and biochemical events were also detected in the brain of JEV-infected mice. The current findings suggest that pericytes might have pathological relevance in Japanese encephalitis-associated neuroinflammation through a TLR7-related mechanism. The consequences of pericyte activation are their ability to initiate and/or amplify inflammatory cytokine expression by which cellular function of endothelial cells and leukocytes are regulated in favor of CNS infiltration by leukocytes.
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http://dx.doi.org/10.1016/j.bbi.2017.07.003DOI Listing
November 2017

Susceptibility of naïve and differentiated PC12 cells to Japanese encephalitis virus infection.

IUBMB Life 2017 02 23;69(2):79-87. Epub 2017 Jan 23.

Department of Medical Research, Taichung Veterans General Hospital, Taichung City, Taiwan.

Japanese encephalitis is a mosquito-borne disease caused by Japanese encephalitis virus (JEV) infection. Although JEV infects and replicates in cells with multiple tissue origins, neurons are the preferential cells for JEV infection. Currently, the identities of JEV cell tropism are largely unclear. To gain better insight into the underlying identities of JEV cell tropism, this study was designed to compare the JEV cell tropism with naïve or differentiated PC12 cells. Through nerve growth factor-differentiated PC12 cells, we discovered that JEV efficiently replicated in differentiated PC12 cells rather than naïve cells. Mechanistic studies revealed that viral adsorption/attachment seemed not to be a crucial factor. Supporting data showed that antagonizing postreceptor intracellular signaling of interferons, along with the activation of suppressor of cytokine signaling-3 (SOCS3) expression and protein tyrosine phosphatase activity, were apparent in differentiated PC12 cells after JEV infection. Independent of differentiating inducing agents, the upregulation of SOCS3 expression and protein tyrosine phosphatase activity, as well as preferential JEV tropism, were common in JEV-infected differentiated PC12 cells. Using cultured primary neurons, JEV efficiently replicated in embryonic neurons rather than adult neurons, and the preference was accompanied by higher SOCS3 expression and protein tyrosine phosphatase activity. Given that both SOCS3 and protein tyrosine phosphatases have been implicated in the process of neuronal differentiation, JEV infection seems to not only create an antagonizing strategy to escape host's interferon antiviral response but also takes advantage of cellular machinery to favor its replication. Taken together, current findings imply that dynamic changes within cellular regulators of antiviral machinery could be accompanied by events of neuronal differentiation, thus concurrently playing roles in the control of JEV cell tropism and replication. © 2017 IUBMB Life, 69(2):79-87, 2017.
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http://dx.doi.org/10.1002/iub.1595DOI Listing
February 2017

Valproic acid sensitizes human glioma cells to gefitinib-induced autophagy.

IUBMB Life 2015 Nov 21;67(11):869-79. Epub 2015 Oct 21.

Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan.

Autophagy and apoptosis represent important cellular processes involved in cancer cell killing mechanisms. Epidermal growth factor receptor inhibitor gefitinib and valproic acid have been implicated in the treatment of malignancies including glioma involving autophagic and apoptotic mechanisms. Therefore, it is interesting to investigate whether a combination of gefitinib and valproic acid shows better cancer cell killing effect on human glioma cells. We found that a nontoxic concentration of valproic acid sensitized U87 and T98G glioma cells to gefitinib cytotoxicity by inhibiting cell growth and long-term clonogenic survival. The augmented consequences were accompanied by the formation of autophagic vacuoles, conversion of microtubule-associated protein-1 light chain 3-II (LC3-II), and degradation of p62. Autophagy inhibitor 3-methyladenosine and chloroquine and genetic silencing of LC3 but not broad-spectrum caspase inhibitor attenuated gefitinib/valproic acid-induced growth inhibition. Gefitinib/valproic acid-induced autophagy was accompanied by the activation of liver kinase-B1 (LKB1)/AMP-activated protein kinase (AMPK)/ULK1. Silencing of AMPK and ULK1 suppressed gefitinib/valproic acid-induced autophagy and growth inhibition. Mechanistic studies showed that gefitinib/valproic acid increased intracellular reactive oxygen species generation and N-acetyl cysteine attenuated gefitinib/valproic acid-caused autophagy and growth inhibition. In addition to demonstrating the autophagic mechanisms of gefitinib/valproic acid, the results of this study further suggest that intracellular oxidative stress and the LKB1/AMPK signaling might be a potential target for the development of therapeutic strategy against glioma.
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http://dx.doi.org/10.1002/iub.1445DOI Listing
November 2015

Enterovirus 71 infection caused neuronal cell death and cytokine expression in cultured rat neural cells.

IUBMB Life 2015 Oct 24;67(10):789-800. Epub 2015 Sep 24.

Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan.

Fatal enterovirus type-71 (EV71) cases are associated with central nervous system infection characterized by inflammatory cell infiltration and activation, cytokine overproduction, and neuronal cell death. Although EV71 antigen has been detected in neurons and glia, the molecular mechanisms underlying EV71-associated neuroinflammation and neuronal cell death are not fully understood. Using cultured rodent neural cell models, we found that EV71 infection preferentially caused cell death in neurons but not brain-resident immune cells astrocytes and microglia. Neurons, astrocytes, and microglia responded to EV71 infection by releasing distinct profiles of cytokines, including nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, regulated on activation normal T cell expressed and secreted (RANTES), and glutamate. EV71 infection-induced neuronal cell death correlated well with the elevated production of NO, TNF-α, IL-1β, and glutamate as well as activation of microglia. Exogenous addition studies further demonstrated the neurotoxic potential of NO, TNF-α, IL-1β, and glutamate. EV71 infection-induced cytokine expression was accompanied by activation of protein tyrosine phosphorylation, mitogen-activated protein kinases (MAPKs), and NF-κB. Intriguingly, EV71 susceptibility was accompanied by infection-elevated neuronal human scavenger receptor class B member 2 expression in cultured neural cells with age-dependent manner. Biochemical and pharmacological studies revealed that after EV71 infection, microglia and accompanied cytokines play an active role in triggering bystander damage to neurons involving the tyrosine kinase/MAPKs/NF-κB signaling cascade. These data suggest that bystander damage caused by activated glia particularly the microglia could be an alternative mechanism of EV71-associated neuronal cell death. However, its clinical importance and implication require further investigation.
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http://dx.doi.org/10.1002/iub.1434DOI Listing
October 2015

Tetramethylpyrazine inhibits neutrophil activation following permanent cerebral ischemia in rats.

Biochem Biophys Res Commun 2015 Jul 1;463(3):421-7. Epub 2015 Jun 1.

Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan; Institute of Biomedical Sciences, National Chung-Hsing University, Taichung, Taiwan. Electronic address:

Experimental studies have demonstrated the beneficial effects of tetramethylpyrazine (TMP) against ischemic stroke and highlighted its crucial role in anti-inflammatory activity. This study provides evidence of an alternative target for TMP and sheds light on the mechanism of its anti-inflammatory action against ischemic brain injury. We report a global inhibitory effect of TMP on inflammatory cell intracerebral activation and infiltration in a rat model of permanent cerebral ischemia. The results of immunohistochemistry, enzymatic assay, flow cytometric analysis, and cytological analysis revealed that intraperitoneal TMP administration reduced neuronal loss, macrophage/microglia activation, brain parenchyma infiltrative neutrophils, and circulating neutrophils after cerebral ischemia. Biochemical studies of cultured neutrophils further demonstrated that TMP attenuated neutrophil migration, endothelium adhesion, spontaneous nitric oxide (NO) production, and stimuli-activated NO production after cerebral ischemia. In parallel with these anti-neutrophil phenomena, TMP also attenuated the activities of ischemia-induced inflammation-associated signaling molecules, including plasma high-mobility group box-1 protein (HMGB1) and neutrophil toll-like receptor-4 (TLR4), Akt, extracellular signal-regulated kinase (ERK), and inducible nitric oxide synthase. Another finding in this study was that the anti-neutrophil effect of TMP was accompanied by a further elevated expression of NF-E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in neutrophils after cerebral ischemia. Taken together, our results suggest that both the promotion of endogenous anti-inflammatory defense capacity and the attenuation of pro-inflammatory responses via targeting of circulating neutrophils by elevating Nrf2/HO-1 expression and inhibiting HMGB1/TLR4, Akt, and ERK signaling might actively contribute to TMP-mediated neuroprotection against cerebral ischemia.
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http://dx.doi.org/10.1016/j.bbrc.2015.05.088DOI Listing
July 2015

Disruption of in vitro endothelial barrier integrity by Japanese encephalitis virus-Infected astrocytes.

Glia 2015 Nov 8;63(11):1915-1932. Epub 2015 May 8.

Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan.

Blood-brain barrier (BBB) characteristics are induced and maintained by crosstalk between brain microvascular endothelial cells and neighboring cells. Using in vitro cell models, we previously found that a bystander effect was a cause for Japanese encephalitis-associated endothelial barrier disruption. Brain astrocytes, which neighbor BBB endothelial cells, play roles in the maintenance of BBB integrity. By extending the scope of relevant studies, a potential mechanism has been shown that the activation of neighboring astrocytes could be a cause of disruption of endothelial barrier integrity during the course of Japanese encephalitis viral (JEV) infection. JEV-infected astrocytes were found to release biologically active molecules that activated ubiquitin proteasome, degraded zonula occludens-1 (ZO-1) and claudin-5, and disrupted endothelial barrier integrity in cultured brain microvascular endothelial cells. JEV infection caused astrocytes to release vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), and matrix metalloproteinases (MMP-2/MMP-9). Our data demonstrated that VEGF and IL-6 released by JEV-infected astrocytes were critical for the proteasomal degradation of ZO-1 and the accompanying disruption of endothelial barrier integrity through the activation of Janus kinase-2 (Jak2)/signal transducer and activator of transcription-3 (STAT3) signaling as well as the induction of ubiquitin-protein ligase E3 component, n-recognin-1 (Ubr 1) in endothelial cells. MMP-induced endothelial barrier disruption was accompanied by MMP-mediated proteolytic degradation of claudin-5 and ubiquitin proteasome-mediated degradation of ZO-1 via extracellular VEGF release. Collectively, these data suggest that JEV infection could activate astrocytes and cause release of VEGF, IL-6, and MMP-2/MMP-9, thereby contributing, in a concerted action, to the induction of Japanese encephalitis-associated BBB breakdown. GLIA 2015;63:1915-1932.
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http://dx.doi.org/10.1002/glia.22857DOI Listing
November 2015

Effects of garlic oil on interleukin-6 mediated cardiac hypertrophy in hypercholesterol-fed hamsters.

Chin J Physiol 2014 Dec;57(6):320-8

Department of Health and Nutrition Biotechnology, Asia University, Taichung 41354, Taiwan, Republic of China.

Hypercholesterol diets are the major causes of cardiac hypertrophy and various cardiac disorders. The purpose of this study is to evaluate the effects of garlic oil on cardiac hypertrophy induced by hypercholesterol diets. Golden Syrian hamsters were fed with 2% cholesterol or 2% cholesterol plus 1% garlic oil for 2 months. Heart architecture changes were measured by hematoxylin-eosin staining and the molecular mechanism was determined by western blotting. Garlic oil reduced whole-heart weight to bone weight ratio, and left ventricle weight to bone weight ratio in the cholesterol-fed group. Moreover, the garlic oil group showed significantly reduced interleukin-6, phosphorylated (p)-extracellular signal-regulated kinase-5, p-mitogen-activated protein kinase-5, calcineurin, nuclear transcription factor of nuclear factor of activated T-cells-3 and p-GATA binding protein 4 when compared with the cholesterol group. However, no changes were observed in gp-130, signal transducer and activator of transcription-3, p-P38 and p-Jun N-terminal kinases protein levels in all groups. The results show that garlic oil may be useful in the treatment of hypertrophy-associated cardiovascular diseases.
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http://dx.doi.org/10.4077/CJP.2014.BAC261DOI Listing
December 2014

Primary axillary anaplastic large cell lymphoma mimicking pyogenic granuloma clinically.

Kaohsiung J Med Sci 2014 Jul 14;30(7):380-1. Epub 2014 May 14.

Division of Plastic Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan. Electronic address:

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http://dx.doi.org/10.1016/j.kjms.2014.03.012DOI Listing
July 2014

Autophagy contributes to gefitinib-induced glioma cell growth inhibition.

Exp Cell Res 2014 Sep 27;327(1):102-12. Epub 2014 May 27.

Department of Medical Research, Taichung Veterans General Hospital, Taichung 407, Taiwan; Institute of Biomedical Sciences, National Chung Hsing University, Taichung 402, Taiwan; Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung 402, Taiwan; Center for General Education, Tunghai University, Taichung 407, Taiwan; Department of Nursing, HungKuang University, Taichung 433, Taiwan. Electronic address:

Epidermal growth factor receptor tyrosine kinase inhibitors, including gefitinib, have been evaluated in patients with malignant gliomas. However, the molecular mechanisms involved in gefitinib-mediated anticancer effects against glioma are incompletely understood. In the present study, the cytostatic potential of gefitinib was demonstrated by the inhibition of glioma cell growth, long-term clonogenic survival, and xenograft tumor growth. The cytostatic consequences were accompanied by autophagy, as evidenced by monodansylcadaverine staining of acidic vesicle formation, conversion of microtubule-associated protein-1 light chain 3-II (LC3-II), degradation of p62, punctate pattern of GFP-LC3, and conversion of GFP-LC3 to cleaved-GFP. Autophagy inhibitor 3-methyladenosine and chloroquine and genetic silencing of LC3 or Beclin 1 attenuated gefitinib-induced growth inhibition. Gefitinib-induced autophagy was not accompanied by the disruption of the Akt/mammalian target of rapamycin signaling. Instead, the activation of liver kinase-B1/AMP-activated protein kinase (AMPK) signaling correlated well with the induction of autophagy and growth inhibition caused by gefitinib. Silencing of AMPK suppressed gefitinib-induced autophagy and growth inhibition. The crucial role of AMPK activation in inducing glioma autophagy and growth inhibition was further supported by the actions of AMP mimetic AICAR. Gefitinib was shown to be capable of reducing the proliferation of glioma cells, presumably by autophagic mechanisms involving AMPK activation.
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http://dx.doi.org/10.1016/j.yexcr.2014.05.011DOI Listing
September 2014

Depression-like effect of prenatal buprenorphine exposure in rats.

PLoS One 2013 18;8(12):e82262. Epub 2013 Dec 18.

Graduate School of Nursing, HungKuang University, Taichung, Taiwan, ROC ; Department of Education and Research, Taichung Veterans General Hospital, Taichung, Taiwan, ROC ; Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan, ROC ; Center for General Education, Tunghai University, Taichung, Taiwan, ROC.

Studies indicate that perinatal opioid exposure produces a variety of short- and long-term neurobehavioral consequences. However, the precise modes of action are incompletely understood. Buprenorphine, a mixed agonist/antagonist at the opioid receptors, is currently being used in clinical trials for managing pregnant opioid addicts. This study provides evidence of depression-like consequence following prenatal exposure to supra-therapeutic dose of buprenorphine and sheds light on potential mechanisms of action in a rat model involving administration of intraperitoneal injection to pregnant Sprague-Dawley rats starting from gestation day 7 and lasting for 14 days. Results showed that pups at postnatal day 21 but not the dams had worse parameters of depression-like neurobehaviors using a forced swimming test and tail suspension test, independent of gender. Neurobehavioral changes were accompanied by elevation of oxidative stress, reduction of plasma levels of brain-derived neurotrophic factor (BDNF) and serotonin, and attenuation of tropomyosin-related kinase receptor type B (TrkB) phosphorylation, extracellular signal-regulated kinase (ERK) phosphorylation, protein kinase A activity, cAMP response element-binding protein (CREB) phosphorylation, and CREB DNA-binding activity. Since BDNF/serotonin and CREB signaling could orchestrate a positive feedback loop, our findings suggest that the induction of oxidative stress, reduction of BDNF and serotonin expression, and attenuation of CREB signaling induced by prenatal exposure to supra-therapeutic dose of buprenorphine provide evidence of potential mechanism for the development of depression-like neurobehavior.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0082262PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3867331PMC
October 2014

Prenatal buprenorphine exposure decreases neurogenesis in rats.

Toxicol Lett 2014 Feb 7;225(1):92-101. Epub 2013 Dec 7.

Graduate School of Nursing, HungKuang University, Taichung 433, Taiwan; Department of Education and Research, Taichung Veterans General Hospital, Taichung 407, Taiwan; Institute of Biomedical Sciences, National Chung Hsing University, Taichung 402, Taiwan; Center for General Education, Tunghai University, Taichung 407, Taiwan. Electronic address:

Perinatal opioid exposure has a negative effect on neurogenesis and produces neurological consequences. However, its mechanisms of action are incompletely understood. Buprenorphine, a mixed opioid agonist/antagonist, is an alternative medication for managing pregnant opioid addicts. This study provides evidence of decreased neurogenesis and depression-like consequences following prenatal exposure to buprenorphine and sheds light on mechanisms of action in a rat model involving administration of intraperitoneal injection to pregnant rats starting from gestation day 7 and lasting for 14 days and a cultured neurosphere model. Results of forced swimming test and tail suspension test showed that pups at postnatal day 21 had worse parameters of depression-like neurobehaviors, independent of gender. Neurobehavioral changes were accompanied by reduction of neuronal composition, biochemical parameters of neural stem/progenitor cells, brain-derived neurotrophic factor (BDNF) expression, tropomyosin-related kinase receptor type B phosphorylation, protein kinase A (PKA) activity, and cAMP response element-binding protein phosphorylation. Results of parallel cell studies further demonstrated a negative impact of buprenorphine on cultured neurospheres, including proliferation, differentiation, BDNF expression and signaling, and PKA activity. Taken together, our results suggest that prenatal exposure to buprenorphine might result in depression-like phenotypes associated with impaired BDNF action and decreased neurogenesis in the developing brain of weanlings.
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http://dx.doi.org/10.1016/j.toxlet.2013.12.001DOI Listing
February 2014

Infection of pericytes in vitro by Japanese encephalitis virus disrupts the integrity of the endothelial barrier.

J Virol 2014 Jan 6;88(2):1150-61. Epub 2013 Nov 6.

Department of Education and Research, Taichung Veterans General Hospital, Taichung, Taiwan.

Though the compromised blood-brain barrier (BBB) is a pathological hallmark of Japanese encephalitis-associated neurological sequelae, the underlying mechanisms and the specific cell types involved are not understood. BBB characteristics are induced and maintained by cross talk between brain microvascular endothelial cells and neighboring elements of the neurovascular unit. In this study, we show a potential mechanism of disruption of endothelial barrier integrity during the course of Japanese encephalitis virus (JEV) infection through the activation of neighboring pericytes. We found that cultured brain pericytes were susceptible to JEV infection but were without signs of remarkable cytotoxicity. JEV-infected pericytes were found to release biologically active molecules which activated ubiquitin proteasome, degraded zonula occludens-1 (ZO-1), and disrupted endothelial barrier integrity in cultured brain microvascular endothelial cells. Infection of pericytes with JEV was found to elicit elevated production of interleukin-6 (IL-6), which contributed to the aforementioned endothelial changes. We further demonstrated that ubiquitin-protein ligase E3 component n-recognin-1 (Ubr 1) was a key upstream regulator which caused proteasomal degradation of ZO-1 downstream of IL-6 signaling. During JEV central nervous system trafficking, endothelial cells rather than pericytes are directly exposed to cell-free viruses in the peripheral bloodstream. Therefore, the results of this study suggest that subsequent to primary infection of endothelial cells, JEV infection of pericytes might contribute to the initiation and/or augmentation of Japanese encephalitis-associated BBB breakdown in concerted action with other unidentified barrier disrupting factors.
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http://dx.doi.org/10.1128/JVI.02738-13DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3911661PMC
January 2014

Docosahexaenoic acid reduces cellular inflammatory response following permanent focal cerebral ischemia in rats.

J Nutr Biochem 2013 Dec 15;24(12):2127-37. Epub 2013 Oct 15.

Department of Surgery, Fong Yuan Hospital, Taichung 420, Taiwan.

Cellular inflammatory response plays an important role in ischemic brain injury and anti-inflammatory treatments in stroke are beneficial. Dietary supplementation with docosahexaenoic acid (DHA) shows anti-inflammatory and neuroprotective effects against ischemic stroke. However, its effectiveness and its precise modes of neuroprotective action remain incompletely understood. This study provides evidence of an alternative target for DHA and sheds light on the mechanism of its physiological benefits. We report a global inhibitory effect of 3 consecutive days of DHA preadministration on circulating and intracerebral cellular inflammatory responses in a rat model of permanent cerebral ischemia. DHA exhibited a neuroprotective effect against ischemic deficits by reduction of behavioral disturbance, brain infarction, edema and blood-brain barrier disruption. The results of enzymatic assay, Western blot, real-time reverse transcriptase polymerase chain reaction and flow cytometric analysis revealed that DHA reduced central macrophages/microglia activation, leukocyte infiltration and pro-inflammatory cytokine expression and peripheral leukocyte activation after cerebral ischemia. In parallel with these immunosuppressive phenomena, DHA attenuated post-stroke oxidative stress, c-Jun N-terminal kinase (JNK) phosphorylation, c-Jun phosphorylation and activating protein-1 (AP-1) activation but further elevated ischemia-induced NF-E2-related factor-2 (Nrf2) and heme oxygenase-1 (HO-1) expression. DHA treatment also had an immunosuppressive effect in lipopolysaccharide/interferon-γ-stimulated glial cultures by attenuating JNK phosphorylation, c-Jun phosphorylation and AP-1 activation and augmenting Nrf2 and HO-1 expression. In summary, we have shown that DHA exhibited neuroprotective and anti-inflammatory effects against ischemic brain injury and these effects were accompanied by decreased oxidative stress and JNK/AP-1 signaling as well as enhanced Nrf2/HO-1 expression.
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http://dx.doi.org/10.1016/j.jnutbio.2013.08.004DOI Listing
December 2013