Publications by authors named "Yu-Chin Su"

30 Publications

  • Page 1 of 1

Modulation of parietal cytokine and chemokine gene profiles by mesenchymal stem cell as a basis for neurotrauma recovery.

J Formos Med Assoc 2019 Dec 30;118(12):1661-1673. Epub 2019 Jan 30.

Department of Neurology, Chi Mei Medical Center, Tainan 710, Taiwan. Electronic address:

Background & Purpose: Following traumatic brain injury (TBI), primary mechanical injury to the brain may cause blood-brain-barrier damage followed by secondary injury, ultimately culminating in cell death. We aimed to test whether one injection of mesenchymal stem cells (MSC) derived from the human umbilical cord can modulate brain cytokine and chemokine gene profiles and attenuate neurological injury in rats with TBI.

Methods: One-day post-TBI, the injured rats were treated with one injection of MSC (4 × 10/rat, i.v.). Three days later, immediately after assessment of neurobehavioral function, animals were sacrificed for analysis of neurological injury (evidenced by both brain contusion volume and neurological deficits) and parietal genes encoding 84 cytokines and chemokines in the injured brain by qPCR methods.

Results: Three days post-TBI, rats displayed both neurological injury and upgrade of 11 parietal genes in the ipsilateral brain. One set of 8 parietal genes (e.g., chemokine [C-X-C motif] ligand 12, platelet factor 4, interleukin-7, chemokine [C-C motif] ligand (CCL)19, CCL 22, secreted phosphoprotein 1, pro-platelet basic protein 1, and CCL 2) differentially upgraded by TBI was related to pro-inflammatory and/or neurodegenerative processes. Another set of 3 parietal genes up-graded by TBI (e.g., glucose-6-phosphate isomerase, bone morphogenetic protein (BMP) 2, and BMP 4) was related to anti-inflammatory/neuroregenerative events. Administration of MSC attenuated neurological injury, down-regulated these 8 parietal pro-inflammatory genes, and up-regulated these 3 parietal anti-inflammatory genes in the rats with TBI.

Conclusion: Our data suggest that modulation of parietal cytokines and chemokines gene profiles by MSC as a basis for neurotrauma recovery.
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http://dx.doi.org/10.1016/j.jfma.2019.01.008DOI Listing
December 2019

Vascular, Cognitive, and Psychomental Survey on Elderly Recycling Volunteers in Northern Taiwan.

Front Neurol 2018 10;9:1176. Epub 2019 Jan 10.

Stroke Center and Department of Neurology, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City, Taiwan.

Stroke and dementia represent frequent causes of psychophysical and socioeconomic burdens. We conducted a vascular, cognitive, and psychomental survey involving elderly volunteers at community-based recycling stations in Northern Taiwan. Recycling volunteers aged ≥60 years were surveyed. We recorded seven parameters, namely (1) body mass index (BMI), (2) fasting glucose, (3) fasting cholesterol, (4) ankle-brachial index (ABI), (5) carotid duplex sonography, (6) five-item Brief Symptom Rating Scale (BSRS-5) score, and (7) eight-item Interview to Differentiate Aging and Dementia (AD8). During the carotid duplex study, we measured the carotid intima-media thickness (CIMT) and the carotid total plaque score (CTPS) of the common and internal carotid arteries. In total, 985 subjects (mean age: 70.8 years) participated in this study. Among these, 81% were women, and 52% were vegetarians. The average ABI, CIMT, and CTPS were higher in men, whereas women had higher cholesterol levels and BSRS-5 scores. Obesity, hypertension, hyperglycemia, and hyperlipidemia were present in 21, 38, 9, and 27% of all subjects, respectively. Carotid plaques with mild (CTPS 1-5), moderate (CTPS 5.1-10), and severe (CTPS > 10) atherosclerosis were detected in 45, 16, and 7% of the subjects, respectively. Mild cognitive impairment (AD8 > 2) was observed in 13% of the subjects, whereas moderate mood disorder (BSRS-5≧10) was observed in only 1% of subjects. Vegetarians had a lower BMI, systolic blood pressure (SBP), cholesterol, CIMT, and CTPS than did non-vegetarians. Substantial predictors of severe atherosclerosis were advanced age (>70 years), male sex, history of heart disease, hyperlipidemia, and currently elevated SBP and cholesterol levels. Predictors of mild cognitive impairment were illiteracy, history of hypertension, hyperlipidemia, and moderate mood disorder. Subclinical carotid atherosclerosis was common in elderly recycling volunteers, with 23% having moderate to severe stenosis. Vegetarians had a reduced risk of atherosclerosis. The low incidence of moderate mood disorder might indicate that recycling work enhances psychomental health. In addition, a healthier lifestyle, better mood condition, and vegetarian diet might contribute to lower incidence of mild cognitive impairment.
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http://dx.doi.org/10.3389/fneur.2018.01176DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6338017PMC
January 2019

EphA2-positive human umbilical cord-derived mesenchymal stem cells exert anti-fibrosis and immunomodulatory activities via secretion of prostaglandin E2.

Taiwan J Obstet Gynecol 2018 Oct;57(5):722-725

Meridigen Biotech Co. Ltd., Taipei, Taiwan. Electronic address:

Objective: Previous study has demonstrated that EphA2 is a biomarker of mesenchymal stem cells (MSCs) from human placenta or umbilical cord and is able to distinguish MSCs from fibroblasts. In this study, we further examine the potential efficacy of EphA2 human umbilical cord-derived MSCs (hUC-MSCs).

Materials And Methods: MSCs specific markers, EphA2 and CD146 expression on the surface of hUC-MSCs were determined by flow cytometry analysis. Quantitative real time polymerase chain reaction was used to examine pro-fibrotic gene expression of TGF-β1-stimulated lung fibroblast (MRC-5 cells). On the other hand, ELISA was used to analyze the content of pro-inflammatory cytokines (TNF-ɑ; and IP-10) in the LPS-activated macrophages culture supernatant.

Results: The pro-fibrotic gene (TGF-β1, CTGF, fibronectin, collagen I and TIMP-1) expression in TGF-β1-activated MRC-5 cells and the pro-inflammatory cytokines (TNF-ɑ and IP-10) in the LPS-activated macrophages culture supernatant were both attenuated when in present of EphA2 hUC-MSCs. Moreover, once EphA2 hUC-MSCs treated with prostaglandin E2 specific inhibitor NS-398, both anti-fibrotic and anti-inflammatory effects of EphA2 hUC-MSCs were abolished.

Conclusion: EphA2 hUC-MSCs possess immunomodulatory and anti-fibrotic properties, and PGE2 plays an important role in these activities. This implies that EphA2 hUC-MSCs have potentially effectiveness for treatment of acute inflammatory and chronic fibrotic lung diseases.
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http://dx.doi.org/10.1016/j.tjog.2018.08.020DOI Listing
October 2018

MRI tracking of polyethylene glycol-coated superparamagnetic iron oxide-labelled placenta-derived mesenchymal stem cells toward glioblastoma stem-like cells in a mouse model.

Artif Cells Nanomed Biotechnol 2018 8;46(sup3):S448-S459. Epub 2018 Sep 8.

g The PhD Program for Translational Medicine , College of Medical Science and Technology, Taipei Medical University , Taipei , Taiwan.

Mesenchymal stem cells (MSCs) that display homing and infiltration properties towards tumor cells are a promising cellular targeting vector for brain tumor therapy but are limited to local-regional delivery in current preclinical models. Here, we investigated whether placenta-derived MSCs (P-MSCs) are a superior cellular vector for systemic targeting of glioblastoma stem-like cells (GSCs), with an imaging modality to real-time monitor the trafficking P-MSCs to glioblastoma sites. Results demonstrated that P-MSCs had greater migratory activity towards GSCs and across blood-brain barrier compared with bone marrow-derived MSCs, and this activity was enhanced by hypoxia precondition. Chemokine ligand 5 was identified as a chemoattractant responsible for the glioblastoma tropism of P-MSCs. Polyethylene glycol-coated superparamagnetic iron oxide (PEG-SPIO) was synthesized for cellular labelling and imaging P-MSCs, displaying high cellular uptake and no cytotoxic effect on P-MSCs cell proliferation or stemness property. The homing effects of intravenously administered PEG-SPIO-labelled P-MSCs towards intracerebral GSCs were able to be detected in mice models through T2-weighted magnetic resonance imaging (MRI). This study suggests the possibility of innovative systemic P-MSC-based cell therapy for aggressive GSCs, developing a state-of-the-art theranostic technique for real-time tracking of therapeutic P-MSCs tumor infiltration through cellular MRI.
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http://dx.doi.org/10.1080/21691401.2018.1499661DOI Listing
June 2019

Impact of code stroke on thrombolytic therapy in patients with acute ischemic stroke at a secondary referral hospital in Taiwan.

J Chin Med Assoc 2018 Nov 7;81(11):942-948. Epub 2018 Sep 7.

Stroke Center and Department of Neurology, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City, Taiwan, ROC; School of Medicine, Tzu Chi University, Hualien, Taiwan, ROC. Electronic address:

Background: Efficacy of thrombolytic therapy decreases with time elapsed from symptom onset. We sought to identify the impact of code stroke on the thrombolytic therapy.

Methods: Code stroke is activated by the emergency physician when a patient is eligible for thrombolytic therapy. We retrospectively reviewed patients with acute ischemic stroke between January 2011 and December 2014.

Results: In total, 1809 patients were enrolled. Code stroke was activated in 233 of 351 patients arriving at the emergency room (ER) within 3 h of symptom onset, and in 21 patients arriving >3 h. The sensitivity, specificity, and positive and negative predictive values of code stroke were 76%, 46%, 72%, and 51%, respectively. Thrombolytic therapy was provided to 58 patients, accounting for 3.4% of all cerebral infarcts. Code stroke was activated in 40 of these patients. The most common reasons for excluding thrombolytic therapy were: National Institute of Health Stroke Scale (NIHSS) < 6, intracranial hemorrhage (ICH), and age >80 years. Mean liaison-to-neurological evaluation time was only 6 min. Code stroke activation significantly reduced all the intervals, except for the onset-to-ER and door-to-order times. During the 4-year study period, there were significant reductions of the door-to-neurology liaison time by 28 min and door-to-laboratory time by 22 min. The proportion of door-to-needle time within 60 min improved from 33% in 2011 to 67% in 2014. Improved NIHSS scores during hospitalization were most prominent in tPA-treated patients. Symptomatic ICH occurred in 3.6% patients arriving within 3 h. Death occurred in 50% of patients received tPA treatment on family's request, and only 13% of those patients had favorable outcome.

Conclusion: Code stroke is effective in reducing in-hospital delays. The accuracy of code stroke activation has acceptable sensitivity but low specificity. Rapid patient assessment by neurologists increases the number of patients eligible for thrombolytic therapy.
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http://dx.doi.org/10.1016/j.jcma.2018.06.007DOI Listing
November 2018

Nuclear targeting of the betanodavirus B1 protein via two arginine-rich domains induces G1/S cell cycle arrest mediated by upregulation of p53/p21.

Sci Rep 2018 02 15;8(1):3079. Epub 2018 Feb 15.

Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan, 701, Taiwan.

The molecular functions of betanodavirus non-structural protein B and its role in host cell survival remain unclear. In the present study, we examined the roles of specific nuclear targeting domains in B1 localization as well as the effect of B1 nuclear localization on the cell cycle and host cell survival. The B1 protein of the Red spotted grouper nervous necrosis virus (RGNNV) was detected in GF-1 grouper cells as early as 24 hours post-infection (hpi). Using an EYFP-B1 fusion construct, we observed nuclear localization of the B1 protein (up to 99%) in GF-1 cells at 48 hpi. The nuclear localization of B1 was mediated by two arginine-rich nuclear targeting domains (B domain: RRSRR; C domain: RDKRPRR) and domain C was more important than domain B in this process. B1 nuclear localization correlated with upregulation of p53 and p21; downregulation of Cyclin D1, CDK4 and Mdm2; and G1/S cell cycle arrest in GF-1 cells. In conclusion, nuclear targeting of the RGNNV B1 protein via two targeting domains causes cell cycle arrest by up-regulating p53/p21 and down-regulating Mdm2, thereby regulating host cell survival.
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http://dx.doi.org/10.1038/s41598-018-21340-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5814437PMC
February 2018

CD34 human placenta-derived mesenchymal stem cells protect against heat stroke mortality in rats.

Oncotarget 2018 Jan 15;9(2):1992-2001. Epub 2017 Dec 15.

Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan.

CD34 is a transmembrane phosphoglycoprotein used to selectively enrich bone marrow in hematopoietic stem cells for transplantation. Treating rats with CD34 cells derived from human umbilical cord blood before or after heat stroke has been shown to promote survival. We investigated whether CD34 human placenta-derived stem cells (PDMSCs) could improve survival following heat stroke in rats. Rats were subjected to heat stress (42°C for 98 min) to induce heat stroke. Intravenous administration of PDMSCs 1 day before or immediately after the onset of heat stroke improved survival by 60% and 20%, respectively. Pre-treatment with CD34 PDMSCs protected against heat stroke injury more effectively than that treatment after injury. PDMSCs treatment attenuated cerebrovascular dysfunction, the inflammatory response, and lipid peroxidation. These data suggest human PDMSCs protect against heat stroke injury in rats. Moreover, these effects do not require the presence of CD34 cells.
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http://dx.doi.org/10.18632/oncotarget.23324DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5788615PMC
January 2018

Human Umbilical Cord Mesenchymal Stem Cells Preserve Adult Newborn Neurons and Reduce Neurological Injury after Cerebral Ischemia by Reducing the Number of Hypertrophic Microglia/Macrophages.

Cell Transplant 2017 11;26(11):1798-1810

3 Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan City, Taiwan.

Microglia are the first source of a neuroinflammatory cascade, which seems to be involved in every phase of stroke-related neuronal damage. Two weeks after transient middle cerebral artery occlusion (MCAO), vehicle-treated rats displayed higher numbers of total ionized calcium-binding adaptor molecule 1 (Iba-1)-positive cells, greater cell body areas of Iba-1-positive cells, and higher numbers of hypertrophic Iba-1-positive cells (with a cell body area over 80 μm) in the ipsilateral ischemic brain regions including the frontal cortex, striatum, and parietal cortex. In addition, MCAO decreased the number of migrating neuroblasts (or DCX- and 5-ethynyl-2'-deoxyuridine-positive cells) in the cortex, subventricular zone, and hippocampus of the ischemic brain, followed by neurological injury (including brain infarct and neurological deficits). Intravenous administration of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs; 1 × 10 or 4 × 10) at 24 h after MCAO reduced neurological injury, decreased the number of hypertrophic microglia/macrophages, and increased the number of newborn neurons in rat brains. Thus, the accumulation of hypertrophic microglia/macrophages seems to be detrimental to neurogenesis after stroke. Treatment with hUC-MSCs preserved adult newborn neurons and reduced functional impairment after transient cerebral ischemia by reducing the number of hypertrophic microglia/macrophages.
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http://dx.doi.org/10.1177/0963689717728936DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5784525PMC
November 2017

Betanodavirus B2 protein triggers apoptosis and necroptosis in lung cancer cells that suppresses autophagy.

Oncotarget 2017 Nov 6;8(55):94129-94141. Epub 2017 Oct 6.

Department of Biotechnology and Bioindustry, Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan.

The betanodavirus B2 protein targets the mitochondria and acts as a "death factor", but its effect on lung cancer cells is unknown. We examined the effect of the B2 protein on triggering apoptosis or necroptosis P53-dependent and P53-independent pathways and increased in suppression of autophagy. The B2 protein targets the mitochondria of A549 (P53) and H1299 (P53) lung cancer cells due to a specific signal sequence (RTFVISAHAA). This triggers generation of reactive oxygen species within the mitochondria, and a minor stress response in A549 cells, but a strong stress response in H1299 cells. We examined the molecular mechanism of this cell death pathway, and found that B2 protein induces the P53/Bax-mediated apoptotic pathway in A549 cells, and that a P53 specific inhibitor (pifithrin-α) switches this response to RIP3-mediated necroptosis. On the other hand, B2 induces RIP3-mediated necroptosis pathway in H1299 cells, and a necroptosis inhibitor (necrostatin-1) switches this response to the apoptotic pathway. Both types of cell death signals inhibited autophagy a tightly increased balance of beclin-1 and Bcl-2. Thus, B2 protein triggers P53-dependent apoptosis in A549 cells and ROS/RIP3-mediated necroptosis in H1299 cells, and crosstalk of these pathways limits initiation of autophagy. These findings provide new insights into the possible control and treatment of lung cancer.
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http://dx.doi.org/10.18632/oncotarget.21588DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5706861PMC
November 2017

Anti-apoptotic genes Bcl-2 and Bcl-xL overexpression can block iridovirus serine/threonine kinase-induced Bax/mitochondria-mediated cell death in GF-1 cells.

Fish Shellfish Immunol 2017 Feb 23;61:120-129. Epub 2016 Dec 23.

Lab of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, No. 1 University Road, Tainan City 701, Taiwan, ROC; Department of Biotechnology and Bioindustry, National Cheng Kung University, No. 1 University Road, Tainan City 701, Taiwan, ROC. Electronic address:

Although serine/threonine (ST) kinase is known to induce host cell death in GF-1 cells, it remains unclear how ST kinase induces mitochondrial function loss. In the present study, we addressed the issue of mitochondrial function loss by determining whether the Bcl-2 family members Bcl-2 and Bcl-xL can prevent ST kinase-induced cell death activity via interacting with the pro-apoptotic gene Bax. Grouper fin cells (GF-1) carrying EGFP-Bal-xL and EGFP-Bcl-2 fused genes were selected, established in cell culture, and used to examine the involvement of Bcl-2 and Bcl-xL overexpression in protection of GF-1 cells from the effects of the giant sea perch iridovirus (GSIV) ST kinase gene. Using the TUNEL assay, we found that EGFP-Bcl-2 and EGFP-Bcl-xL reduced GSIV ST kinase-induced apoptosis to 20% all at 24 h and 48 h post-transfection (pt). Also, Bcl-2 and Bcl-xL substantially reduced the percentage of cells with GSIV ST kinase-induced loss of mitochondrial membrane potential (Δψps) at 24 and 48 hpt, respectively, and this reduction correlated with a 30% and 50% enhancement of host cell viability at 24 and 48 hpt as compared with vector control. Moreover, analysis of the effect of Bcl-2 and Bcl-xL interaction with Bax targeted to mitochondria during ST kinase expression at 48 hpt found that Bcl-2 and Bcl-xL also interacted with Bax to block cytochrome c release. Finally, Bcl-2 and Bcl-xL overexpression caused blockage of ST kinase function at 48 hpt, which was correlated with preventing caspase-9 and -3 cleavage and activation, thereby blocking downstream death signaling events. Taken together, our results suggest that the ST kinase-induced Bax/mitochondria-mediated cell death pathway can be blocked by the interaction of Bcl-2 and Bcl-xL with Bax to inhibit cytochrome c release during MMP loss. This rescue activity also correlated with inhibition of caspase-9 and -3 activation, thereby enhancing cell viability.
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http://dx.doi.org/10.1016/j.fsi.2016.12.026DOI Listing
February 2017

Evaluation of cerebral blood flow in acute ischemic stroke patients with atrial fibrillation: A sonographic study.

J Formos Med Assoc 2017 Apr 8;116(4):287-294. Epub 2016 Jul 8.

Stroke Center and Department of Neurology, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taiwan; School of Medicine, Tzu Chi University, Hualien, Taiwan. Electronic address:

Background/purpose: Although cerebral emboli are a frequent cause of cardiogenic stroke, the possibility of a reduction in cerebral perfusion consequent to arrhythmia or impaired cardiac function should be considered in patients with atrial fibrillation (AF).

Methods: We reviewed sonographic studies and clinical features of patients with acute ischemic stroke. A total of 144 patients with AF and 144 age- and sex-matched patients with small vessel occlusion but without AF were included.

Results: Patients with AF had significantly lower peak systolic velocity (PSV), mean velocity, flow volume (p < 0.001), and end-diastolic velocity (p = 0.035) of the internal carotid artery (ICA); significantly lower cerebral blood flow (p < 0.001); and lower flow velocities of the middle cerebral artery (p < 0.01) than patients with small vessel occlusion but without AF. In patients with AF, there was an inverse linear correlation between ICA end-diastolic velocity, mean velocity (p < 0.001), flow volume (p = 0.025), middle cerebral artery flow velocities (p < 0.05), and age. Cardiac ejection fraction had a positive linear correlation with ICA PSV (p = 0.016) but an inverse correlation with the heart rate (p = 0.009). There was a significant decline in PSV (p = 0.002), resistance index (p < 0.001), and flow volume (p = 0.0121) of the ICA as well as cerebral blood flow (p = 0.009) as the heart rate increased.

Conclusion: Cerebral blood flow is markedly reduced in ischemic stroke patients with AF as compared with that in patients with small vessel disease but without AF.
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http://dx.doi.org/10.1016/j.jfma.2016.05.009DOI Listing
April 2017

MOAP-1 Mediates Fas-Induced Apoptosis in Liver by Facilitating tBid Recruitment to Mitochondria.

Cell Rep 2016 06 16;16(1):174-185. Epub 2016 Jun 16.

Department of Pharmacy, National University of Singapore, Singapore 117543, Singapore. Electronic address:

Fas apoptotic signaling regulates diverse physiological processes. Acute activation of Fas signaling triggers massive apoptosis in liver. Upon Fas receptor stimulation, the BH3-only protein Bid is cleaved into the active form, tBid. Subsequent tBid recruitment to mitochondria, which is facilitated by its receptor MTCH2 at the outer mitochondrial membrane (OMM), is a critical step for commitment to apoptosis via the effector proteins Bax or Bak. MOAP-1 is a Bax-binding protein enriched at the OMM. Here, we show that MOAP-1-deficient mice are resistant to Fas-induced hepatocellular apoptosis and lethality. In the absence of MOAP-1, mitochondrial accumulation of tBid is markedly impaired. MOAP-1 binds to MTCH2, and this interaction appears necessary for MTCH2 to engage tBid. These findings reveal a role for MOAP-1 in Fas signaling in the liver by promoting MTCH2-mediated tBid recruitment to mitochondria.
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http://dx.doi.org/10.1016/j.celrep.2016.05.068DOI Listing
June 2016

A New Visual Stimulation Program for Improving Visual Acuity in Children with Visual Impairment: A Pilot Study.

Front Hum Neurosci 2016 18;10:157. Epub 2016 Apr 18.

Stroke Center and Department of Neurology, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation New Taipei City, Taiwan.

The purpose of this study was to investigate the effectiveness of visual rehabilitation of a computer-based visual stimulation (VS) program combining checkerboard pattern reversal (passive stimulation) with oddball stimuli (attentional modulation) for improving the visual acuity (VA) of visually impaired (VI) children and children with amblyopia and additional developmental problems. Six children (three females, three males; mean age = 3.9 ± 2.3 years) with impaired VA caused by deficits along the anterior and/or posterior visual pathways were recruited. Participants received eight rounds of VS training (two rounds per week) of at least eight sessions per round. Each session consisted of stimulation with 200 or 300 pattern reversals. Assessments of VA (assessed with the Lea symbol VA test or Teller VA cards), visual evoked potential (VEP), and functional vision (assessed with the Chinese-version Functional Vision Questionnaire, FVQ) were carried out before and after the VS program. Significant gains in VA were found after the VS training [VA = 1.05 logMAR ± 0.80 to 0.61 logMAR ± 0.53, Z = -2.20, asymptotic significance (2-tailed) = 0.028]. No significant changes were observed in the FVQ assessment [92.8 ± 12.6 to 100.8 ±SD = 15.4, Z = -1.46, asymptotic significance (2-tailed) = 0.144]. VEP measurement showed improvement in P100 latency and amplitude or integration of the waveform in two participants. Our results indicate that a computer-based VS program with passive checkerboard stimulation, oddball stimulus design, and interesting auditory feedback could be considered as a potential intervention option to improve the VA of a wide age range of VI children and children with impaired VA combined with other neurological disorders.
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http://dx.doi.org/10.3389/fnhum.2016.00157DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4834310PMC
May 2016

Elevation of troponin I in acute ischemic stroke.

PeerJ 2016 11;4:e1866. Epub 2016 Apr 11.

Stroke Center and Department of Neurology, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City, Taiwan; School of Medicine, Tzu Chi University, Hualien, Taiwan.

Background. Cardiac morbidities account for 20% of deaths after ischemic stroke and is the second commonest cause of death in acute stroke population. Elevation of cardiac troponin has been regarded as a prognostic biomarker of poor outcome in patients with acute stroke. Methods. This retrospective study enrolled 871 patients with acute ischemic stroke from August 2010 to March 2015. Data included vital signs, laboratory parameters collected in the emergency department, and clinical features during hospitalization. National Institutes of Health Stroke Scale (NIHSS), Barthel index, and modified Rankin Scale (mRS) were used to assess stroke severity and outcome. Results. Elevated troponin I (TnI) > 0.01 µg/L was observed in 146 (16.8%) patients. Comparing to patients with normal TnI, patients with elevated TnI were older (median age 77.6 years vs. 73.8 years), had higher median heart rates (80 bpm vs. 78 bpm), higher median white blood cells (8.40 vs. 7.50 1,000/m(3)) and creatinine levels (1.40 mg/dL vs. 1.10 mg/dL), lower median hemoglobin (13.0 g/dL vs. 13.7 g/dL) and hematocrit (39% vs. 40%) levels, higher median NIHSS scores on admission (11 vs. 4) and at discharge (8 vs. 3), higher median mRS scores (4 vs3) but lower Barthel index scores (20 vs. 75) at discharge (p < 0.001). Multivariate analysis revealed that age ≥ 76 years (OR 2.25, CI [1.59-3.18]), heart rate ≥ 82 bpm (OR 1.47, CI [1.05-2.05]), evidence of clinical deterioration (OR 9.45, CI [4.27-20.94]), NIHSS score ≥ 12 on admission (OR 19.52, CI [9.59-39.73]), and abnormal TnI (OR 1.98, CI [1.18-3.33]) were associated with poor outcome. Significant factors for in-hospital mortality included male gender (OR 3.69, CI [1.45-9.44]), evidence of clinical deterioration (OR 10.78, CI [4.59-25.33]), NIHSS score ≥ 12 on admission (OR 8.08, CI [3.04-21.48]), and elevated TnI level (OR 5.59, CI [2.36-13.27]). C-statistics revealed that abnormal TnI improved the predictive power of both poor outcome and in-hospital mortality. Addition of TnI > 0.01 ug/L or TnI > 0.1 ug/L to the model-fitting significantly improved c-statistics for in-hospital mortality from 0.887 to 0.926 (p = 0.019) and 0.927 (p = 0.028), respectively. Discussion. Elevation of TnI during acute stroke is a strong independent predictor for both poor outcome and in-hospital mortality. Careful investigation of possible concomitant cardiac disorders is warranted for patients with abnormal troponin levels.
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http://dx.doi.org/10.7717/peerj.1866DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4830242PMC
April 2016

Common Neurological Disorders Involving Inpatient Liaisons at a Secondary Referral Hospital in Taiwan: A Retrospective Cross-Sectional Study.

J Clin Neurol 2016 Jan;12(1):93-100

Stroke Center and Department of Neurology, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taipei, Taiwan.

Background And Purpose: The requirement for neurology liaison is increasing in accordance with the growing health care demands associated with aging populations. The aim of this study was to characterize the nature of neurological inpatient liaisons (NILs) to help plan for the appropriate use of neurology resources.

Methods: This was a retrospective cross-sectional study of NILs in a secondary referral hospital over a 12-month period.

Results: There were 853 neurological consultations with a liaison rate of 3% per admission case. Chest medicine, gastroenterology, and infectious disease were the three most frequent specialties requesting liaison, and altered consciousness, seizure, and stroke were the three most frequent disorders for which a NIL was requested. Infection was the most common cause of altered consciousness. Epilepsy, infection, and previous stroke were common causes of seizure disorders. Acute stroke accounted for 44% of all stroke disorders. Electroencephalography was the most recommended study, and was also the most frequently performed. Ninety-five percent of emergency consultations were completed within 2 hours, and 85% of regular consultations were completed within 24 hours. The consult-to-visit times for emergency and regular consultations were 44±47 minutes (mean±standard deviation) and 730±768 minutes, respectively, and were shorter for regular consultations at intensive care units (p=0.0151) and for seizure and stroke disorders (p=0.0032).

Conclusions: Altered consciousness, seizure, and stroke were the most common reasons for NILs. Half of the patients had acute neurological diseases warranting immediate diagnosis and treatment by the consulting neurologists. Balancing increasing neurologist workloads and appropriate health-care resources remains a challenge.
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http://dx.doi.org/10.3988/jcn.2016.12.1.93DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4712292PMC
January 2016

Giant seaperch iridovirus (GSIV) induces mitochondria-mediated cell death that is suppressed by bongkrekic acid and cycloheximide in a fish cell line.

Virus Res 2016 Feb 10;213:37-45. Epub 2015 Nov 10.

Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng-Kung University, Tainan 701, Taiwan. Electronic address:

Giant seaperch iridovirus (GSIV) induces cell death by an unknown mechanism. We postulated that this mechanism involves mitochondria-mediated cell death. Cell viability assays revealed a steady increase in dead grouper fin cells (GF-1) after GSIV infection, from 11% at 2 days post-infection (dpi) to 67% at 5 dpi. Annexin V/PI staining revealed GSIV infection induced apoptosis in a steadily increasing fraction of cells, from 4% at 1 dpi to 29% at 5 dpi. Furthermore, post-apoptotic necrosis was apparent at 4 and 5 dpi in the late replication stage. In the early replication stage, JC-1 dye revealed mitochondrial membrane potential (ΔΨm) loss in 42% of infected cells at 1 dpi, increasing to 98% at 3 dpi. Phosphatidylserine (PS) exposure and loss of ΔΨm from apoptosis/necrosis was attenuated by treatment with the adenine nucleotide translocase inhibitor bongkrekic acid (BKA) and the protein synthesis inhibitor cyclohexamide (CHX). These data suggest GSIV induces GF-1 apoptotic/necrotic cell death through pathways that require newly synthesized protein and involve the mitochondrial function.
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http://dx.doi.org/10.1016/j.virusres.2015.11.003DOI Listing
February 2016

Modulator of apoptosis 1 (MOAP-1) is a tumor suppressor protein linked to the RASSF1A protein.

J Biol Chem 2015 Oct 12;290(40):24100-18. Epub 2015 Aug 12.

From the Departments of Biochemistry and Pediatrics, the Department of Experimental Oncology, Cross Cancer Institute, University of Alberta, Edmonton, Alberta T6G 1Z2, Canada, and the Cancer Research Institute of Northern Alberta, Edmonton, Alberta T6G 1Z2, Canada, the Alberta IBD Consortium, Edmonton, Alberta T6G 2X8, Canada, and the Women and Children's Health Research Institute, Edmonton, Alberta T6G 1C9, Canada

Modulator of apoptosis 1 (MOAP-1) is a BH3-like protein that plays key roles in cell death or apoptosis. It is an integral partner to the tumor suppressor protein, Ras association domain family 1A (RASSF1A), and functions to activate the Bcl-2 family pro-apoptotic protein Bax. Although RASSF1A is now considered a bona fide tumor suppressor protein, the role of MOAP-1 as a tumor suppressor protein has yet to be determined. In this study, we present several lines of evidence from cancer databases, immunoblotting of cancer cells, proliferation, and xenograft assays as well as DNA microarray analysis to demonstrate the role of MOAP-1 as a tumor suppressor protein. Frequent loss of MOAP-1 expression, in at least some cancers, appears to be attributed to mRNA down-regulation and the rapid proteasomal degradation of MOAP-1 that could be reversed utilizing the proteasome inhibitor MG132. Overexpression of MOAP-1 in several cancer cell lines resulted in reduced tumorigenesis and up-regulation of genes involved in cancer regulatory pathways that include apoptosis (p53, Fas, and MST1), DNA damage control (poly(ADP)-ribose polymerase and ataxia telangiectasia mutated), those within the cell metabolism (IR-α, IR-β, and AMP-activated protein kinase), and a stabilizing effect on microtubules. The loss of RASSF1A (an upstream regulator of MOAP-1) is one of the earliest detectable epigenetically silenced tumor suppressor proteins in cancer, and we speculate that the additional loss of function of MOAP-1 may be a second hit to functionally compromise the RASSF1A/MOAP-1 death receptor-dependent pathway and drive tumorigenesis.
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http://dx.doi.org/10.1074/jbc.M115.648345DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4591801PMC
October 2015

Threonine 56 phosphorylation of Bcl-2 is required for LRRK2 G2019S-induced mitochondrial depolarization and autophagy.

Biochim Biophys Acta 2015 Jan 15;1852(1):12-21. Epub 2014 Nov 15.

Department of Physiology and Biophysics Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.

The G2019S leucine-rich repeat kinase 2 (LRRK2) mutation is the most common cause of genetic Parkinson's disease (PD). However, the molecular mechanism underlying LRRK2 G2019S-induced cellular pathology is poorly understood. Here, we demonstrated that LRRK2 G2019S bound to and phosphorylated Bcl-2, a mitochondrial anti-apoptotic protein, at Threonine 56. Either stable expression of Bcl-2 or transient expression of a Bcl-2 phosphor mutant (Bcl-2(T56A)) abolished LRRK2 G2019S-induced mitochondrial depolarization and autophagy. Together, our findings reveal a previously unidentified target of LRRK2 G2019S, showing that Bcl-2 serves as a point of crosstalk between LRRK2 G2019S-mediated mitochondrial disorder and dysregulation of autophagy.
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http://dx.doi.org/10.1016/j.bbadis.2014.11.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4268371PMC
January 2015

Inhibition of excessive mitochondrial fission reduced aberrant autophagy and neuronal damage caused by LRRK2 G2019S mutation.

Authors:
Yu-Chin Su Xin Qi

Hum Mol Genet 2013 Nov 27;22(22):4545-61. Epub 2013 Jun 27.

Department of Physiology and Biophysics and.

LRRK2 G2019S mutation is the most common genetic cause of Parkinson's disease (PD). Cellular pathology caused by this mutant is associated with mitochondrial dysfunction and augmented autophagy. However, the underlying mechanism is not known. In this study, we determined whether blocking excessive mitochondrial fission could reduce cellular damage and neurodegeneration induced by the G2019S mutation. In both LRRK2 G2019S-expressing cells and PD patient fibroblasts carrying this specific mutant, treatment with P110, a selective peptide inhibitor of fission dynamin-related protein 1 (Drp1) recently developed in our lab, reduced mitochondrial fragmentation and damage, and corrected excessive autophagy. LRRK2 G2019S directly bound to and phosphorylated Drp1 at Threonine595, whereas P110 treatment abolished this phosphorylation. A site-directed mutant, Drp1(T595A), corrected mitochondrial fragmentation, improved mitochondrial mass and suppressed excessive autophagy in both cells expressing LRRK2 G2019S and PD patient fibroblasts carrying the mutant. Further, in dopaminergic neurons derived from LRRK2 G2019S PD patient-induced pluripotent stem cells, we demonstrated that either P110 treatment or expression of Drp1(T595A) reduced mitochondrial impairment, lysosomal hyperactivity and neurite shortening. Together, we propose that inhibition of Drp1-mediated excessive mitochondrial fission might be a strategy for treatment of PD relevant to LRRK2 G2019S mutation.
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http://dx.doi.org/10.1093/hmg/ddt301DOI Listing
November 2013

Effects of visual rehabilitation on a child with severe visual impairment.

Am J Occup Ther 2013 Jul-Aug;67(4):437-47

School of Occupational Therapy, College of Medicine, National Taiwan University, Taipei.

We examined the effects of visual rehabilitation, including a chromatic luminance discrimination program and a fixation training program, on a 6-yr-old boy with severe visual impairment. Single-subject ABA and AB designs were used. The programs were conducted 2×/wk and included 6 to 7 sessions for the baseline phase and 10 to 11 sessions for the intervention phase. Play was integrated into the visual training programs. Goggle visual evoked potential (VEP) testing was used to evaluate neural activity in the primary visual cortex. Correct responses increased and response times were shortened after training in luminance discrimination. The total and maximum fixation time also improved, as did P100 latency and amplitude of VEPs. While walking, the boy was able to detect obstacles he had not noticed before training. The results indicate the value of visual training and the possibility of brain plasticity in a child with severe visual impairment.
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http://dx.doi.org/10.5014/ajot.2013.007054DOI Listing
October 2013

A novel Drp1 inhibitor diminishes aberrant mitochondrial fission and neurotoxicity.

J Cell Sci 2013 Feb 13;126(Pt 3):789-802. Epub 2012 Dec 13.

Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Case Western Reserve University School of Medicine Cleveland, OH 44106 Cleveland, OH 44106 USA.

Excessive mitochondrial fission is associated with the pathology of a number of neurodegenerative diseases. Therefore, inhibitors of aberrant mitochondrial fission could provide important research tools in addition to potential leads for drug development. Using a rational approach, we designed a novel and selective peptide inhibitor, P110, of excessive mitochondrial fission. P110 inhibits Drp1 enzyme activity and blocks Drp1/Fis1 interaction in vitro and in cultured neurons, whereas it has no effect on the interaction between Drp1 and other mitochondrial adaptors, as demonstrated by co-immunoprecipitation. Furthermore, using a model of Parkinson's disease (PD) in culture, we demonstrated that P110 is neuroprotective by inhibiting mitochondrial fragmentation and reactive oxygen species (ROS) production and subsequently improving mitochondrial membrane potential and mitochondrial integrity. P110 increased neuronal cell viability by reducing apoptosis and autophagic cell death, and reduced neurite loss of primary dopaminergic neurons in this PD cell culture model. We also found that P110 treatment appears to have minimal effects on mitochondrial fission and cell viability under basal conditions. Finally, P110 required the presence of Drp1 to inhibit mitochondrial fission under oxidative stress conditions. Taken together, our findings suggest that P110, as a selective peptide inhibitor of Drp1, might be useful for the treatment of diseases in which excessive mitochondrial fission and mitochondrial dysfunction occur.
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http://dx.doi.org/10.1242/jcs.114439DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3619809PMC
February 2013

Betanodavirus induces oxidative stress-mediated cell death that prevented by anti-oxidants and zfcatalase in fish cells.

PLoS One 2011 3;6(10):e25853. Epub 2011 Oct 3.

Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan, Taiwan, Republic of China.

The role of oxidative stress in the pathogenesis of RNA nervous necrosis virus infection is still unknown. Red-spotted grouper nervous necrosis virus (RGNNV) induced free radical species (ROS) production at 12-24 h post-infection (pi; early replication stage) in fish GF-1 cells, and then at middle replication stage (24-48 h pi), this ROS signal may upregulate some expressions of the anti-oxidant enzymes Cu/Zn SOD and catalase, and eventually expression of the transcription factor Nrf2. Furthermore, both antioxidants diphenyliodonium and N-acetylcysteine or overexpression of zebrafish catalase in GF-1 cells also reduced ROS production and protected cells for enhancing host survival rate due to RGNNV infection. Furthermore, localization of ROS production using esterase activity and Mitotracker staining assays found that the ROS generated can affect mitochondrial morphology changes and causes ΔΨ loss, both of which can be reversed by antioxidant treatment. Taken together, our data suggest that RGNNV induced oxidative stress response for playing dual role that can initiate the host oxidative stress defense system to upregulate expression of antioxidant enzymes and induces cell death via disrupting the mitochondrial morphology and inducing ΔΨ loss, which can be reversed by anti-oxidants and zfcatalase, which provide new insight into betanodavirus-induced ROS-mediated pathogenesis.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0025853PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3185053PMC
February 2012

Betanodavirus up-regulates chaperone GRP78 via ER stress: roles of GRP78 in viral replication and host mitochondria-mediated cell death.

Apoptosis 2011 Mar;16(3):272-87

Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan, ROC.

Whether viral pathogens that induce ER stress responses benefit the host or the virus remains controversial. In this study we show that betanodavirus induced ER stress responses up-regulate GRP78, which regulates the viral replication and host cellular mitochondrial-mediated cell death. Betanodavirus (redspotted grouper nervous necrosis virus, RGNNV) infection resulted in the following increased ER stress responses in fish GF-1 grouper fin cells: (1) IRE-1 and ATF-6 sensors at 48 h post-infection (p.i.) that up-regulated chaperone protein GRP78; (2) activation of caspase-12; and (3) PERK phosphorylation and down-regulation of Bcl-2. Analyses of GRP78 functions during viral replication using either loss-of-function or gain-of-function approaches showed that GRP78 over-expression also enhanced viral replication and induced cell death. Then, we found that zfGRP78 localization gradually increased in mitochondria after RGNNV infection by EGFP tagging approach. Furthermore, zfGRP78 can interact with viral RNA-dependent RNA polymerase (RdRp) by using immunofluorescent and immunoprecipitation assays. Finally, we found that blocking GRP78-mediated ER signals can reduce the viral death factors protein α and protein B2 expression and decrease the Bcl-2 down-regulation mediated mitochondria-dependent cell death, which also enhances host cellular viability. Taken together, our results suggest that RGNNV infection and expression can trigger ER stress responses, which up-regulate the chaperone GRP78 at early replication stage. Then, GRP78 can interact with RdRp that may enhance the viral replication for increasing viral death factors' expressions at middle-late replication stage, which can enhance mitochondrial-mediated cell death pathway and viral spreading. These results may provide new insights into the mechanism of ER stress-mediated cell death in RNA viruses.
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http://dx.doi.org/10.1007/s10495-010-0565-xDOI Listing
March 2011

Betanodavirus B2 causes ATP depletion-induced cell death via mitochondrial targeting and complex II inhibition in vitro and in vivo.

J Biol Chem 2010 Dec 24;285(51):39801-10. Epub 2010 Sep 24.

Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan.

The betanodavirus non-structural protein B2 is a newly discovered necrotic death factor with a still unknown role in regulation of mitochondrial function. In the present study, we examined protein B2-mediated inhibition of mitochondrial complex II activity, which results in ATP depletion and thereby in a bioenergetic crisis in vitro and in vivo. Expression of protein B2 was detected early at 24 h postinfection with red-spotted grouper nervous necrosis virus in the cytoplasm. Later B2 was found in mitochondria using enhanced yellow fluorescent protein (EYFP) and immuno-EM analysis. Furthermore, the B2 mitochondrial targeting signal peptide was analyzed by serial deletion and specific point mutation. The sequence of the B2 targeting signal peptide ((41)RTFVISAHAA(50)) was identified and its presence correlated with loss of mitochondrial membrane potential in fish cells. Protein B2 also was found to dramatically inhibit complex II (succinate dehydrogenase) activity, which impairs ATP synthesis in fish GF-1 cells as well as human embryonic kidney 293T cells. Furthermore, when B2 was injected into zebrafish embryos at the one-cell stage to determine its cytotoxicity and ability to inhibit ATP synthesis, we found that B2 caused massive embryonic cell death and depleted ATP resulting in further embryonic death at 10 and 24 h post-fertilization. Taken together, our results indicate that betanodavirus protein B2-induced cell death is due to direct targeting of the mitochondrial matrix by a specific signal peptide that targets mitochondria and inhibits mitochondrial complex II activity thereby reducing ATP synthesis.
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http://dx.doi.org/10.1074/jbc.M110.164988DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3000961PMC
December 2010

RGNNV induces mitochondria-mediated cell death via newly synthesized protein dependent pathway in fish cells.

Fish Shellfish Immunol 2010 Sep;29(3):451-63

Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan, ROC.

The RNA nervous necrosis virus induces necrotic cell death in fish; however, the molecular mechanism remains unknown. In this study, we demonstrated that beta-nodavirus-induced mitochondria-mediated dependent cell death is through newly synthesized protein dependent pathway in replication cycle. We determined that newly synthesized protein dependent pathway is required for red-spotted grouper nervous necrosis virus (RGNNV)-induced cell death. UV irradiation of the virus effectively blocked viral replication and cell death. Next, RGNNV RNA-dependent RNA polymerase (RdRp or protein A) was cloned and its involvement in RNA genome replication and viral protein synthesis was analyzed. Protein A was initially expressed 48 h post-infection and localized to the cytoplasm. Knockdown of protein A expression completely blocked viral genomic replication and expression of viral protein expression RNA1 small hairpin RNA (shRNA) producing cell lines, which coincided with inhibition of phosphatidylserine exposure, mitochondria-mediated death signaling, and increased cell viability 72 h post-infection. Furthermore, RGNNV-induced mitochondria-mediated caspase-3-independent necrotic cell death is dependent on viral synthesized protein dependent pathway at the middle-late replication stage. Taken together, for instance these results suggested that RGNNV induces cell death may require newly synthesized protein for triggering host mitochondria-mediated cell death. These findings may provide new insights into RNA viral pathogenesis.
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http://dx.doi.org/10.1016/j.fsi.2010.05.003DOI Listing
September 2010

Betanodavirus non-structural protein B1: A novel anti-necrotic death factor that modulates cell death in early replication cycle in fish cells.

Virology 2009 Mar 10;385(2):444-54. Epub 2009 Jan 10.

Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology; National Cheng Kung University, Tainan 701, Taiwan.

The functions of the Betanodavirus non-structural protein B1 is still unknown. We examined B1 expression patterns and investigated novel cell death regulatory functions for this viral protein following RGNNV infection in fish cells. The B1 gene (336 nt) was cloned from the redspotted grouper nervous necrosis virus (RGNNV) genome. B1 mRNA was rapidly expressed in the fish cells from viral RNA3 at 12 h post-infection (p.i.). At the protein level, expression was low at 12 h p.i., and then increased rapidly between 24 h and 72 h p.i. In RGNNV-infected, B1-containing fish cells, over expression of RGNNV B1 reduced Annexin-V positive cells by 50% and 65% at 48 h and 72 h p.i., respectively, and decreased loss of mitochondrial membrane potential (MMP) by 20% and 70% at 48 h and 72 h p.i., respectively. Finally, B1 knockdown during RGNNV infection using anti-sense RNA increased necrotic cell death and reduced cell viability during the early replication cycle (24 h p.i.). Our results suggest that B1 is an early expression protein that has an anti-necrotic cell death function which reduces the MMP loss and enhances viral host cell viability. This finding provides new insights into RNA viral pathogenesis and disease control.
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http://dx.doi.org/10.1016/j.virol.2008.11.048DOI Listing
March 2009

Betanodavirus non-structural protein B2: A novel necrotic death factor that induces mitochondria-mediated cell death in fish cells.

Virology 2009 Mar 29;385(1):143-54. Epub 2008 Dec 29.

Institute of Biotechnology, National Cheng Kung University, Taiwan, ROC.

The Betanodavirus non-structural protein B2 plays a role in silencing RNA interference (RNAi), which mediated regulation of animal and plant innate immune responses, but little is known regarding the role of B2 in cell death. The present study examined the effects of B2 on mitochondria-mediated necrotic cell death in grouper liver (GL-av) cells. B2 was expressed at 12 h post-infection (pi), with increased expression between 24 and 72 h pi by Western blot. B2 was transiently expressed to investigate possible novel protein functions. Transient expression of B2 in GL-av cells resulted in apoptotic cell features and positive TUNEL assays (28%) at 24 h post-transfection (pt). During mechanistic studies of cell death, B2 upregulated expression of the proapoptotic gene Bax (2.8 fold at 48 h pt) and induced loss of mitochondria membrane potential (MMP) but not mitochondrial cytochrome c release. Furthermore, over expression of Bcl-2 family member zfBcl-xL effectively prevented B2-induced, mitochondria-mediated necrotic cell death. Finally, using RNA interference to reduce B2 expression, both B2 and Bax expression were downregulated and RGNNV-infected cells were rescued from secondary necrosis. Taken together, our results suggest that B2 upregulates Bax and triggers mitochondria-mediated necrotic cell death independent of cytochrome c release.
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http://dx.doi.org/10.1016/j.virol.2008.11.036DOI Listing
March 2009

Long-term anterior thalamus stimulation for intractable epilepsy.

Chang Gung Med J 2008 May-Jun;31(3):287-96

Section of Epilepsy, Department of Neurology, Chang Gung Memorial Hospital, Taipei, Taiwan, ROC.

Background: Deep brain stimulation (DBS) has re-emerged as an alternative therapy for intractable epilepsy. In this study, we investigated the feasibility, efficacy and safety of long-term anterior thalamic nucleus (ATN) stimulation for intractable epilepsy.

Methods: In this open-label pilot study of electrical stimulation of the ATN, we investigated four cases of intractable epilepsy (one man with generalized seizure, and three woman with partial seizure and secondary generalization; age range, 18-45 years), with a follow up of 2 years. Under the indication of bilateral or nonlocalized epileptic foci, each patient underwent stereotactic implantation of a quadripolar stimulating electrode in the bilateral ATN, guided by single-unit microelectrode recording. The stimulator was turned on after a sham period of 2-4 weeks. Seizure frequency was monitored and compared with the pre-implantation baseline. Twenty-one similar cases reported in the literature during the past 20 years were reviewed.

Results: Insertion into and stimulation through electrodes implanted in the ATN decreased seizure frequency, with a mean reduction rate of 49.6% in the current series. Two patients had seizure reductions of > or = 60%, with complete remission achieved in one patient. These findings were consistent with those in four other investigations of intractable epilepsy, which showed an overall rate of 45-55% in seizure reduction. One of our patients suffered a small frontal hemorrhage, and a second patient had extension erosion over the scalp; however, no resultant major or permanent neurological deficits were observed.

Conclusions: Based on our study results and literature review, it appears reasonable to conclude that long-term ATN stimulation is a safe and effective treatment for seizure reduction in patients with intractable epilepsy.
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October 2008

Electrical stimulation of the anterior nucleus of the thalamus for intractable epilepsy: a long-term follow-up study.

Epilepsia 2007 Feb;48(2):342-7

Section of Epilepsy, Department of Neurology, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taipei, Taiwan.

Purpose: The anterior nucleus of the thalamus (ANT) modulates temporal lobe and hypothalamic activities, and relays information to the cingulate gyrus and entorhinal cortex. Deep brain stimulation (DBS) of the ANT has been reported to decrease seizure activity in a limited number of human subjects. However, long-term effect of chronic ANT stimulation on such patients remains unknown. We report long-term follow-up results in four patients receiving ANT stimulation for intractable epilepsy.

Methods: Four patients underwent stereotactic implantation of quadripolar stimulating electrodes in the bilateral ANT, guided by single-unit microelectrode recording. Electrode location was confirmed by postoperative magnetic resonance imaging (MRI). The stimulator was activated 2-4 weeks following electrode insertion; initial stimulation parameters were 4-5 V, 90-110 Hz, and 60-90 micros. Seizure frequency was monitored and compared with preimplantation baseline frequency. Intelligence quotient (IQ) test and auditory P300 response were performed before and after implantation of electrodes.

Results: Four patients (one man with generalized seizures, and three women with partial seizures and secondary generalization) aged 18-45 years old were studied with mean follow-up period of 43.8 months. The four patients demonstrated a sustained effect of 49% (range, 35-76%) seizure reduction to ANT stimulation. Simple insertion of DBS electrodes (Sham period, no stimulation) produced a mean reduction in seizures of 67% (range, 44-94%). One patient was seizure-free for 15 months with anticonvulsant medications. One patient had a small frontal hemorrhage and a second patient had extension erosion over scalp; no resultant major or permanent neurological deficit was observed. Preoperative IQ index and auditory P300 were not significantly different with those after electrodes implantation.

Conclusions: Implantation of electrodes in the ANT and subsequent stimulation is associated with a significant reduction in seizure frequency. However, our study could not differentiate whether the implantation itself, the subsequent stimulation or postimplantation drug manipulation had the greatest impact. These experimental results prompt further controlled study in a large patient population.
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http://dx.doi.org/10.1111/j.1528-1167.2006.00898.xDOI Listing
February 2007

Anti-Bcl-2 family members, zfBcl-x(L) and zfMcl-1a, prevent cytochrome c release from cells undergoing betanodavirus-induced secondary necrotic cell death.

Apoptosis 2007 Jun;12(6):1043-60

Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan.

Nervous necrosis virus (NNV)-induced, host cell apoptosis mediates secondary necrosis by an ill-understood process. In this study, redspotted grouper nervous necrosis virus (RGNNV) is shown to induce mitochondria-mediated necrotic cell death in GL-av cells (fish cells) via cytochrome c release, and anti-apoptotic proteins are shown to protect these cells from death. Western blots revealed that cytochrome c release coincided with disruption of mitochondrial ultrastructure and preceded necrosis, but did not correlate with caspases activation. To identify the mediator(s) of this necrotic process, a protein synthesis inhibitor (cycloheximide; CHX; 0.33 microg/ml) was used to block cytochrome c release as well as PS exposure and mitochondrial membrane permeability transition pore (MMP) loss. CHX (0.33 microg/ml) completely blocked viral protein B2 expression, and partly blocked protein A, protein alpha, and a pro-apoptotic death protein (Bad) expression. Overexpression of B2 gene increased necrotic-like cell death up to 30% at 48 h post-transfection, suggesting that newly synthesized protein (B2) may be involved in this necrotic process. Finally, necrotic death was prevented by overexpression of Bcl-2 family proteins, zfBcl-x(L) and xfMcl-1a. Thus, new protein synthesis and release of cytochrome c are required for RGNNV-induced necrotic cell death, which can be blocked by anti-apoptotic Bcl-2 members.
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http://dx.doi.org/10.1007/s10495-006-0032-xDOI Listing
June 2007